pe The effects of monosodium glutamate on PSMA radiotracer uptake in men with recurrent prostate cancer: a prospective, randomized, double-blind, placebo-controlled intra-individual imaging study. By jnm.snmjournals.org Published On :: 2020-05-08T13:18:58-07:00 The prostate-specific membrane antigen (PSMA) is an excellent target for theranostic applications in prostate cancer (PCa). However, PSMA-targeted radioligand therapy can cause undesirable effects due to high accumulation of PSMA radiotracers in salivary glands and kidneys. This study assessed orally administered monosodium glutamate (MSG) as a potential means of reducing kidney and salivary gland radiation exposure using a PSMA targeting radiotracer. Methods: This prospective, double-blind, placebo-controlled study enrolled 10 biochemically recurrent PCa patients. Each subject served as his own control. [18F]DCFPyl PET/CT imaging sessions were performed 3 – 7 days apart, following oral administration of either 12.7 g of MSG or placebo. Data from the two sets of images were analyzed by placing regions of interest on lacrimal, parotid and submandibular glands, left ventricle, liver, spleen, kidneys, bowel, urinary bladder, gluteus muscle and malignant lesions. The results from MSG and placebo scans were compared by paired analysis of the ROI data. Results: A total of 142 pathological lesions along with normal tissues were analyzed. As hypothesized a priori, there was a significant decrease in maximal standardized uptake values corrected for lean body mass (SULmax) on images obtained following MSG administration in the parotids (24 ± 14%, P = 0.001), submandibular glands (35 ± 11%, P<0.001) and kidneys (23 ± 26%, P = 0.014). Significant decreases were also observed in lacrimal glands (49 ± 13%, P<0.001), liver (15 ± 6%, P<0.001), spleen (28 ± 13%, P = 0.001) and bowel (44 ± 13%, P<0.001). Mildly lower blood pool SULmean was observed after MSG administration (decrease of 11 ± 13%, P = 0.021). However, significantly lower radiotracer uptake in terms of SULmean, SULpeak, and SULmax was observed in malignant lesions on scans performed after MSG administration compared to the placebo studies (SULmax median decrease 33%, range -1 to 75%, P<0.001). No significant adverse events occurred and vital signs were stable following placebo or MSG administration. Conclusion: Orally administered MSG significantly decreased salivary gland, kidney and other normal organ PSMA radiotracer uptake in human subjects, using [18F]DCFPyL as an exemplar. However, MSG caused a corresponding reduction in tumor uptake, which may limit the benefits of this approach for diagnostic and therapeutic applications. Full Article
pe Mobilizing Multinational Military Operations in Africa: Quick Fixes or Sustainable Solutions? By feedproxy.google.com Published On :: Wed, 16 Oct 2019 09:55:01 +0000 Research Event 25 October 2019 - 9:30am to 11:15am Chatham House | 10 St James's Square | London | SW1Y 4LE Event participants Professor Tony Chafer, University of PortsmouthProfessor Gordon Cumming, Cardiff UniversityDr Roel van der Velde, Cardiff UniversityAhmed Soliman, Research Fellow, Horn of Africa, Chatham HouseDr Elisa Lopez Lucia, Université Libre de Bruxelles; University of PortsmouthChair: Janet Adama Mohammed, West Africa Programme Director, Conciliation Resources Peacekeeping missions which have sought to address evolving forms of conflict and instability on the African continent – led by the United Nations, African Union and European Union – have frequently been overstretched.Across regions including the Sahel, the Horn and West Africa, the issues of violent extremism and criminality – often set against a backdrop of collapsing or severely weakened central states – have led to the mobilisation of a diverse set of new collective responses.These include notable African-led efforts such as AMISOM in Somalia or more recently the G5 Sahel, where France have played a pivotal role in initiating new and more ad hoc approaches to coalition-building.As existing multinational missions in Africa continue to evolve on the ground and while new collective opportunities increasingly present themselves, it is critical for policymakers to understand how far such efforts reflect meaningful long-term solutions to the challenges of conflict and insecurity.At this roundtable event, participants will reflect on how such missions become mobilised and legitimised, the extent to which they can be defined as ‘new’, and whether they represent a truly sustainable means to tackle the issue of conflict in Africa.This roundtable is held in partnership with Cardiff University and the University of Portsmouth and is supported by the Leverhulme Trust. Department/project Africa Programme, West Africa, African Peace and Security, Horn of Africa Fergus Kell Projects Assistant, Africa Programme + 44 (0) 20 7314 3671 Email Full Article
pe Prospects for Peace and Stability in South Sudan By feedproxy.google.com Published On :: Tue, 29 Oct 2019 15:20:01 +0000 Research Event 11 November 2019 - 5:00pm to 6:15pm Chatham House | 10 St James's Square | London | SW1Y 4LE Event participants Alan Boswell, Senior Analyst for South Sudan, International Crisis GroupMiklos Gosztonyi, Conflict Analyst, South Sudan, Norwegian Refugee CouncilNaomi Pendle, Research Fellow, Firoz Lalji Centre for Africa, London School of EconomicsGolda Abbé, Founding Member, Ghidam (Via Skype)Chair: Teohna Williams, CEO, Business Plan for Peace South Sudan’s prolonged peace process is approaching a critical juncture. There is uncertainty about whether the country’s political leaders will meet the 12 November 2019 deadline to form a transitional government of national unity – a process already delayed after a revitalized power-sharing deal was signed in September 2018. A political impasse has been caused by a lack of progress on outstanding issues such as deciding on the number of states and reunifying the security forces. The latter issue is seen as critical to preventing the reoccurrence of large-scale violence which would exacerbate already considerable humanitarian needs. Continued mediation by regional and international partners remains important to finding a way forward and preventing a return to widespread conflict.At this event, a panel of speakers will examine the status of the peace deal, the issue of federalism and subdivision, measures needed to prevent the humanitarian crisis from worsening and opportunities to foster greater security and unity in the country.THIS EVENT IS NOW FULL AND REGISTRATION HAS CLOSED. Department/project Africa Programme, African Peace and Security, Horn of Africa Sahar Eljack Programme Administrator, Africa Programme + 44 (0) 20 7314 3660 Email Full Article
pe Central and Eastern Europe and Sub-Saharan Africa: The Potential of Investment Partnerships for Mutual Benefit By feedproxy.google.com Published On :: Thu, 31 Oct 2019 08:54:39 +0000 31 October 2019 Trade between Central and Eastern Europe and sub-Saharan Africa has increased significantly in the last decade and a half. There is a strong case to be made for greater economic re-engagement, especially in terms of investment, that has the potential to support inclusive growth in both regions. Read online Download PDF Damir Kurtagic Former Academy Robert Bosch Fellow, Africa Programme @kurtagic_damir LinkedIn recycled-containerboard-warehouse_mondi_poland.jpg Recycled containerboard warehouse, Mondi Group, Poland. Photo: Mondi Group. SummaryThere are growing economic links between the economies of Central and Eastern Europe and sub-Saharan Africa in terms of both trade and investment. However, while trade has picked up significantly from pre-EU accession levels, investment has not increased to the same extent.Contrary to common assumption, investment flows are not solely from Central and Eastern Europe to sub-Saharan Africa. In reality, the largest investment flow between the two blocs occurs in the opposite direction – from South Africa into Central and Eastern Europe.Sub-Saharan Africa can benefit from a greater commercial relationship focused on attracting sustainable investment from Central and Eastern Europe. For this to happen, commercial strategies towards Central and Eastern European countries need to be put in place before strategy can be reinforced by greater diplomatic and informational support.For many sub-Saharan African governments, there is no overall targeted approach to attracting Central and Eastern European investors. A notable exception is South Africa, where departments have been established at provincial government level to specifically target investment from Central and Eastern Europe.Sub-Saharan African governments expect Central and Eastern European private-sector investment to result not only in job creation, but also to bring spillover benefits such as the transfer of skills and knowledge to domestic industries.Each sub-Saharan African country, in accordance with its individual circumstances, will need to adopt a discrete mix of administrative reform (particularly aimed at cutting red tape), as well as infrastructural and other policies that improve the business environment and generate investor confidence.Much of the private sector in Central and Eastern Europe is somewhat hesitant to invest in sub-Saharan Africa on a greater scale. Many companies are most comfortable operating within their domestic environment; when they invest abroad, it tends to be in the ‘neighbourhood’ with which they are already familiar. Perceptions of risk are often compounded by popular misperceptions and generalizations about sub-Saharan Africa.Central and Eastern European countries stand to gain from a deeper investment relationship. While greater engagement with sub-Saharan Africa has already been pursued by some countries, most of them focus on trade. Institutional support to companies from Central and Eastern Europe (both public and private) has evolved to a degree, but is still not comprehensive. Information for companies interested in investing is either lacking or not shared in an efficient way. And the greatest challenge is ensuring top-level political engagement.EU membership offers clear opportunities for Central and Eastern European countries to invest sustainably and responsibly in sub-Saharan Africa. Not only is financial support forthcoming, through innovative EU financial instruments, but the availability of information relevant to business and the EU’s extensive diplomatic presence in Africa should help to alleviate some of the concerns of Central and Eastern European investors. Department/project Africa Programme, Foreign Relations and Africa’s Agency in the International System, Inclusive Economic Growth, Governance and Technology Full Article
pe Understanding South Africa's Political Landscape By feedproxy.google.com Published On :: Mon, 04 Nov 2019 15:55:01 +0000 Members Event 14 November 2019 - 6:00pm to 7:00pm Chatham House | 10 St James's Square | London | SW1Y 4LE Event participants Carien du Plessis, Journalist; Co-Author, Understanding South AfricaJames Hamill, Associate Fellow, International Institute for Strategic Studies; Author, Africa's Lost Leader: South Africa's Continental Role Since ApartheidMartin Plaut, Senior Researcher, Institute of Commonwealth Studies; Co-Author, Understanding South AfricaChair: Pumela Salela, UK Country Head, Brand South Africa President Cyril Ramaphosa led the African National Congress (ANC) to electoral victory in South Africa in May 2019. His promise of rooting out corruption and generating job-creating growth resonated with an electorate scarred by corruption scandals and structural economic and racial inequality.However, divisions within the ruling party have meant that the delivery of these promises has been slow. Complex and often divisive racial dynamics continue to dominate political discourse especially around land reform and economic transformation.The country’s main opposition party, the Democratic Alliance (DA), faces its own political crisis following the resignation of former leader Mmusi Maimane, bringing into question the role of opposition parties in the young democracy. At this event, South African journalists, Martin Plaut and Carien du Plessis, discuss their new book, Understanding South Africa, providing insights into the current and historical trends that define the political fault lines of modern South Africa. Is Ramaphosa shying away from the difficult political decisions necessary to encourage meaningful change in South Africa’s political environment? And how should the international community understand the trends and dynamics that dominate South African politics? Members Events Team Email Full Article
pe Can the New European Commission Deliver on Its Promises to Africa? By feedproxy.google.com Published On :: Tue, 03 Dec 2019 15:27:00 +0000 4 December 2019 Fergus Kell Projects Assistant, Africa Programme LinkedIn Damir Kurtagic Former Academy Robert Bosch Fellow, Africa Programme @kurtagic_damir LinkedIn Familiar promises of equal partnership must be backed by bolder action, including an expanded budget, internal reform and a rethink of its approach to trade negotiations. 2019-12-03-Urpilainen.jpg Jutta Urpilainen, new EU commissioner for international partnerships, at the European Parliament in Brussels in October. Photo: Getty Images. The new European Commission, headed by Ursula von der Leyen, assumed office on 1 December, and there are early signs that Africa will begin near the top of their foreign policy priorities. Policy towards Africa under the new EU administration is yet to be fully defined, but its contours are already visible in the selection of commissioners and assignment of portfolios. Although rumours of a dedicated commissioner for Africa were unfounded, the appointment of Jutta Urpilainen to the new role of commissioner for international partnerships – replacing the former post of development commissioner – is a strong signal of ongoing change in EU development thinking, away from bilateral aid towards trade and investment, including by the private sector. This may have significant consequences for the EU’s relationship with Africa. In her mission letter to Urpilainen in September, von der Leyen listed the first objective as a new ‘comprehensive strategy for Africa’. Urpilainen, Finland’s finance minister before being posted to Ethiopia as special representative on mediation, has also described her appointment as an opportunity to move on from traditional measures of aid delivery. Ambition or incoherence? However, this ambition may be at odds with other EU priorities and practices, notably managing migration and institutions and instruments for governing EU–Africa relations that remain rooted in a ‘traditional’ model of North–South development cooperation rather than equitable partnership.Another newly created post will see Margaritis Schinas assume the role of vice-president for promoting the European way of life – formerly ‘protecting our European way of life’ before a backlash saw it changed – a reminder that migration will remain high on the EU’s foreign policy agenda. The new high representative for foreign and security policy and chief EU diplomat, Josep Borrell, has highlighted the need for bilateral partnership with countries of origin and transit, mainly in Africa. Negotiations also continue to stall on a replacement to the Cotonou Agreement, the 20-year partnership framework between the EU and the African, Caribbean and Pacific (ACP) group of states, which now looks certain to be extended for at least 12 months beyond its expiry in February 2020.Ambiguities in the EU’s negotiating approach have certainly contributed to the delay: having pushed initially for a separate regional pillar for Africa that would be opened to the North African countries (who are not ACP members) and include a loosely defined role for the African Union, this would later be abandoned in favour of a dual-track process on separate new agreements with the AU and ACP respectively.The EU also continues to pursue controversial economic partnership agreements under the aegis of Cotonou, despite their increasing appearance of incompatibility with the pathbreaking African Continental Free Trade Area (AfCFTA) – one of the clearest expressions to date of African agency.The EU has so far attempted to gloss over this incoherence, claiming that EPAs can somehow act as the ‘building blocks’ for Africa-wide economic integration. But tensions are appearing between EU departments and within the commission, with the European External Action Service inclined to prioritize a more strategic continental relationship with the AU, while the Directorate-General for International Cooperation and Development remains committed to the ACP as the conduit for financial support and aid delivery.And it is unlikely to get away with such incoherence for much longer. Change is now urgent, as numerous countries in sub-Saharan Africa continue to attract the strategic and commercial interests of the EU’s competitors: from established players such as China and potentially in future the UK, which is intent on remodelling its Africa ties post-Brexit, to emerging actors such as Turkey or Russia, which held its first Africa summit in October. The need for deliveryIf the EU is serious about its rhetoric on equal partnership, it must therefore move beyond convoluted hybrid proposals. Delivering on the Juncker administration’s proposal to increase funding for external action by 30 per cent for 2021–27 would mark an important first step, particularly as this involves streamlining that would see the European Development Fund – the financial instrument for EU-ACP relations – incorporated into the main EU budget.The new commission should therefore continue to exert pressure on the European Council and European Parliament to adopt this proposal, as negotiations on this financial framework have been repeatedly subject to delay and may not be resolved before the end of the year. Beyond this, proactive support for the AfCFTA and for structural transformation more broadly must be prioritized ahead of vague promises for a continent-to-continent free trade agreement, as held out by Juncker in his final State of the Union address in 2018. The significance of internal EU reforms for Africa should also not be discounted. The EU’s Common Agricultural Policy, for instance, has placed the African sector at a particular disadvantage and has made it harder to compete even in domestic markets, let alone in the distant EU export markets. EU efforts to stimulate inflows of private investments into the African agricultural sector, abolish import tariffs and offer technical support for African producers to satisfy EU health and safety regulations will be of little use if they are undermined by heavy subsidies across Europe.Ultimately, changes to job titles alone will be insufficient. The new commission’s rhetoric, while ambitious, differs little from that of the previous decade – Africa has heard the promise of a ‘partnership of equals’ and of ‘shared ownership’ since before the advent of the Joint Africa–EU Strategy in 2007. Now is the time for truly bold steps to implement this vision. Full Article
pe Africa’s Long-standing Leaders Are Disappearing By feedproxy.google.com Published On :: Fri, 03 Jan 2020 16:07:49 +0000 3 January 2020 Dr Alex Vines OBE Managing Director, Ethics, Risk & Resilience; Director, Africa Programme Leaders who cling to power are being pushed out across the continent, and the trend looks set to continue in 2020. 2020-01-03-Zim.jpg A man holds a portrait of Robert Mugabe during his official funeral ceremony. Photo: Getty Images. Africa’s dinosaur leaders are members of an increasingly small and unstable club. Popular protests last year forced Algeria’s president, Abdelaziz Bouteflika, out of office after almost 20 years in power, as well as Sudan’s president, Omar al-Bashir, who ruled for 30 years. In 2017, Robert Mugabe was deposed in a military coup (although this was denied) after 40 years. And in 2011, mass protests led to the downfall of Tunisia’s president, Zine el-Abidine Ben Ali, after he had been in power for 23 years.Somewhat smoother are the political transitions in Angola and the Democratic Republic of the Congo (DRC). José Eduardo dos Santos, after almost 38 years in power, stepped down from office in 2017 as his term ended. So did his younger neighbour, Joseph Kabila, in January 2019, after 18 years in the presidency.What the six former leaders had in common was that they wanted to remain heads of state and considered succession planning or stepping down only as a last resort. This year will be crucial for the six countries in political transition particularly as the reform-window period is short.From A to Z Algeria: Tens of thousands of protesters have rallied in the capital Algiers and other cities against the December 2019 elections, rejecting what they see as sham transitional politics. A soft landing for Algeria in 2020 is unlikely, and what happens in the year has significant regional implications.Angola: A transition is under way, led by President João Lourenço. This shift is smoother than many others, but 2020 will be the watershed year. The country has been in economic recession for four years but is predicted to see gross domestic product growth in 2020. Investment and job creation will determine the pace of change. The honeymoon period has ended and there are signs of increasing frustration among the urban youth and the middle class.DRC: Despite his constitutionally mandated term expiring in December 2016, Joseph Kabila continued his presidency by continuously postponing elections until 30 December 2018. This election saw a three-way contest between the Union for Democracy and Social Progress (UDSP), the Engagement for Citizenship and Development party and the People’s Party for Reconstruction and Democracy (PPRD). Fèlix Tshisekedi of the UDSP was declared the winner by the Independent National Electoral Commission on January 10 last year with 38.6% votes. He was followed by Martin Fayulu of the Engagement for Citizenship and Development party, with 34.8%. He denounced the election results. In third place was Emmanuel Ramazani Shadary, of the PPRD, a key ally of Kabila.Although this was the first peaceful transition of power in DRC, there were widespread electoral inconsistencies and some observers believed that Fayulu was the legitimate winner. In 2020 it will become clearer whether a genuine transition from Kabila’s influence is taking place.Sudan: More promising than the DRC or Algeria, a 39-month transitional administration led by a technocratic prime minister, Abdalla Hamdok, has been established and enjoys domestic and international goodwill. This honeymoon is likely to be short, and the transitional administration needs to show results. The United States can help by removing Sudan from its terror list, thereby lifting the de facto ban on Sudan’s access to the dollar-based international financial system.Tunisia: A low-profile, conservative law professor beat a charismatic media magnate released from prison in the presidential election runoff in October 2019. Kais Saied won 70% of the vote and his victory and the putting together of a new governing coalition is another step forward in an open-ended democratic transition that started in 2011 after Ben Ali fell.Zimbabwe: This is a deeply troubled transition with an acute foreign exchange liquidity crisis, a deteriorating economy, hyperinflation and underperforming government. The state’s clinics and hospitals are closed or turn away patients as medical supplies run out and the doctors’ strike over decimated wages continues. There are power outages and almost half of the people face hunger and starvation as a result of drought and the economic crisis.Zimbabwe’s 2020 looks bleak, a far cry from the euphoria of two years ago when a “military assisted transition” removed Mugabe and replaced him with Emmerson Mnangagwa.More changes comingSo what do these political developments in 2019 tell us more broadly?Long-standing leaders have been persistent in Africa, despite the end of single-party rule in favour of a multiparty system. About a fifth of all African heads of state since independence can be classed as long-standing leaders — in power for more than a decade — and only five countries have never experienced one. But the trend is in decline.It remains most resilient in central Africa and in the Great Lakes regions. Cracks are appearing in their citadels in Malabo and Kampala, but in 2019 Equatorial Guinea’s President Teodoro Obiang Mbasogo celebrated 40 years in power and Uganda’s Yoweri Museveni 33 years.Will there be any more departures from the dinosaurs club in 2020?One of the shortest serving members of this club, President Pierre Nkurunziza (14 years in power) has said he will not stand for the 2020 elections in Burundi, although this is uncertain given that a 2018 constitutional referendum could allow him to stay in power until 2034. Togo’s Faure Gnassingbé (14 years in power) will stand for re-election to the presidency again after Parliament in 2019 approved a constitutional change permitting him to potentially stay in office until 2030.Amending constitutions to change term limits so that incumbent leaders can run for office is a favoured tactic. Rwanda’s Paul Kagame (19 years in office) and the Republic of Congo’s Denis Sassou Nguesso (25 years in power) have done this. But Eritrea’s Isaias Afwerki has never held an election during his 16 years in power.Attempts at dynasties have been less successful, such as with Grace Mugabe in Zimbabwe or Gamal Mubarak in Egypt, but Obiang is grooming his playboy son Teodorin to succeed him and Gabon’s Ali Bongo and Togo’s Gnassingbé both succeeded their fathers.The year is a reminder that more of these long-standing leaders will, in 2020 and beyond, step down or die. Most long-standing leaders in Africa are over the age of 70, with Paul Biya, aged 86, having served 37 years as Cameroon’s president.Some former leaders capitulated under internal pressure: in Algeria, Sudan, Tunisia and Zimbabwe. Only in Angola and the DRC was a transition process organized as part of an elite bargain.What the political transitions have in common is that honeymoons are short and that, whether they are led by interim administrations or elected leaders, they need to deliver political and socioeconomic improvements to succeed, but have inherited shambolic economies. Their success depends on accountable political leadership and domestic and international support.This article was originally published by the Mail & Guardian. Full Article
pe Central & Eastern Europe and Africa Engagement: Labour Mobility and Policy in East Africa By feedproxy.google.com Published On :: Wed, 08 Jan 2020 12:35:01 +0000 Research Event 15 January 2020 - 10:00am to 12:30pm Nairobi, Kenya Strengthened links between the states of sub-Saharan Africa (SSA) and Central and Eastern Europe (CEE) are emerging marked by growth in diplomatic representation, trade and economic ties and supporting networks.Against this backdrop, labour migration within and from the CEE and East Africa sub-regions are a key policy area with significant potential for shared learning and cooperation. For both regions, migration trends in recent years have evolved as a result of a diverse range of interactions among public, private and civil society actors and at local, national, regional and international levels. Unpacking such interactions and their political and geographical specificities is essential to effective engagement and cooperation within and between the regions on issues of labour migration and their management.This roundtable brainstorming workshop will provide a platform for stakeholders based in East Africa to discuss the way in which different actors and agencies in the region influence and shape labour migration processes and policy responses.This event is supported by the Robert Bosch Stiftung. Event attributes Chatham House Rule Department/project Africa Programme, Foreign Relations and Africa’s Agency in the International System, Inclusive Economic Growth, Governance and Technology Fergus Kell Projects Assistant, Africa Programme + 44 (0) 20 7314 3671 Email Full Article
pe Equatorial Guinea in 2020: Prospects for Economic and Governance Reforms By feedproxy.google.com Published On :: Fri, 24 Jan 2020 14:50:01 +0000 Research Event 31 January 2020 - 2:00pm to 3:00pm Chatham House | 10 St James's Square | London | SW1Y 4LE Event participants Tutu Alicante, Executive Director, EG JusticeChair: Dr Alex Vines OBE, Managing Director, Ethics, Risk & Resilience; Director, Africa Programme, Chatham House Despite boasting one of Africa’s highest GDP per capita rates, much of Equatorial Guinea’s population remain in poverty, with the world’s largest gap between its GDP per capita rates and human development index score. Equatorial Guinea’s economy is highly dependent on oil exports but production is in decline. In December 2019, the IMF Executive Board approved a US$282.8 million three-year Extended Fund Facility loan for Equatorial Guinea with provisions for promoting economic diversification, good governance, increasing transparency and fighting corruption. The country is also seeking to join the Extractive Industries Transparency Initiative.At this event, Tutu Alicante will discuss prospects for meaningful reforms in Equatorial Guinea to improve economic governance, human rights and achieve sustainable and inclusive economic growth.THIS EVENT IS NOW FULL AND REGISTRATION HAS CLOSED. Department/project Africa Programme, West Africa, Inclusive Economic Growth, Governance and Technology, Sustainable Resource Governance Sahar Eljack Programme Administrator, Africa Programme + 44 (0) 20 7314 3660 Email Full Article
pe Deepening Economic Ties? The Future of Africa-UK Trade and Investment By feedproxy.google.com Published On :: Fri, 07 Feb 2020 12:10:01 +0000 Corporate Members Event 25 February 2020 - 6:00pm to 7:00pm Chatham House | 10 St James's Square | London | SW1Y 4LE Event participants Raj Kulasingam, Senior Counsel, DentonsMegan McDonald, Head of Investment Banking (International), Standard Bank GroupChair: Dr Alex Vines OBE, Managing Director, Ethics, Risk & Resilience; Director, Africa Programme, Chatham House Theresa May’s announcement in 2018 on the UK’s ambition to become the G7’s largest investor in Africa by 2022 has been followed by similar stated ambitions at the recent UK-Africa Investment Summit, which saw the attendance of 16 African heads of states. Such ambitions mirror overtures from various international players including a call for a ‘comprehensive strategy for Africa’ by the EU in 2019. While the UK’s recent expansion of its diplomatic networks in Africa and the signing of the Economic Partnership Agreement with the Southern African Customs Union and Mozambique appear promising, there are significant challenges to deepening partnerships including visa restrictions and complex business environments. At this event, the panellists will assess the future of trade and investment relations between the UK and Africa. Amid a proliferation of new trading partners including Asia’s emerging economies, Russia and the Gulf states, what are the points of change and continuity in the long-standing relationship between Africa and the UK? And what are the challenges and opportunities facing governments and businesses in Africa and the UK in efforts to build long-lasting economic ties? This event will be followed by a drinks reception.This event is open to Chatham House Corporate Members and corporate contacts of Chatham House's Africa Programme only. Not a member? Find out more. For further information on the different types of Chatham House events, visit Our Events Explained. Members Events Team Email Full Article
pe Realizing South Sudan's Peace Deal By feedproxy.google.com Published On :: Wed, 19 Feb 2020 15:45:01 +0000 Invitation Only Research Event 24 February 2020 - 5:00pm to 6:15pm Chatham House | 10 St James's Square | London | SW1Y 4LE Event participants Miklos Gosztonyi, Conflict Analyst, South Sudan, Norwegian Refugee CouncilMatthew F. Pritchard, Research and Policy Specialist, McGill UniversityJoshua Craze, Writer and ResearcherTeohna Williams, CEO, Business Plan for Peace South Sudan’s new power sharing government must be formed by 22 February 2020, as specified in the Revitalized Agreement on the Resolution of the Conflict in the Republic of South Sudan (R-ARCSS). There have been two extensions to this process already, reflecting the continued distrust among leaders and the complexity of the conflict.The lack of progress in several contentious areas has delayed the formation of the Revitalized Transitional Government of National Unity (R-TGoNU) for nine months, but the recent decision taken by President Salva Kiir Mayardit to re-establish 10 states has been welcomed by opposition groups, regional mediators and international partners.It is seen as the breakthrough needed for an agreement to be reached, despite some outstanding concerns. Further meaningful compromises and difficult decisions will be needed to implement a lasting peace agreement.At this event, a panel of speakers will examine the status of the peace deal following the February deadline and the steps needed to progress the key issues underlying implementation. Event attributes Chatham House Rule Department/project Africa Programme, African Peace and Security, Horn of Africa Sahar Eljack Programme Administrator, Africa Programme + 44 (0) 20 7314 3660 Email Full Article
pe POSTPONED: UN Peacekeeping in Africa: Insights from Successes and Failures of the Past By feedproxy.google.com Published On :: Thu, 20 Feb 2020 14:30:01 +0000 Research Event 10 March 2020 - 3:00pm to 4:00pm Chatham House | 10 St James's Square | London | SW1Y 4LE Event participants Alan Doss, President, Kofi Annan Foundation With Africa hosting half of the UN peacekeeping missions currently in operation and more than 80 per cent of the UN’s peacekeepers, it is clear that crisis management and conflict resolution on the continent remain key priorities. However, traditional international supporters, notably Canada and the United States, have reduced their financial support for peacekeeping in recent years. Together with frequent reports on peacekeeping abuse, declining support is proving disruptive for the maintenance and predictability of UN missions.At this event, which will launch the book A Peacekeeper in Africa: Learning from UN Interventions in Other People’s Wars, Alan Doss will reflect on past UN peacekeeping missions in Africa and will consider how lessons learned might help to improve future UN peace operations.PLEASE NOTE THIS EVENT IS POSTPONED UNTIL FURTHER NOTICE. Department/project Africa Programme, African Peace and Security, Foreign Relations and Africa’s Agency in the International System Sahar Eljack Programme Administrator, Africa Programme + 44 (0) 20 7314 3660 Email Full Article
pe Deletion of fatty acid transport protein 2 (FATP2) in the mouse liver changes the metabolic landscape by increasing the expression of PPAR{alpha}-regulated genes [Lipids] By feedproxy.google.com Published On :: 2020-04-24T06:08:45-07:00 Fatty acid transport protein 2 (FATP2) is highly expressed in the liver, small intestine, and kidney, where it functions in both the transport of exogenous long-chain fatty acids and the activation of very-long-chain fatty acids. Here, using a murine model, we investigated the phenotypic impacts of deleting FATP2, followed by a transcriptomic analysis using unbiased RNA-Seq to identify concomitant changes in the liver transcriptome. WT and FATP2-null (Fatp2−/−) mice (5 weeks) were maintained on a standard chow diet for 6 weeks. The Fatp2−/− mice had reduced weight gain, lowered serum triglyceride, and increased serum cholesterol levels and attenuated dietary fatty acid absorption. Transcriptomic analysis of the liver revealed 258 differentially expressed genes in male Fatp2−/− mice and a total of 91 in female Fatp2−/− mice. These genes mapped to the following gene ontology categories: fatty acid degradation, peroxisome biogenesis, fatty acid synthesis, and retinol and arachidonic acid metabolism. Targeted RT-quantitative PCR verified the altered expression of selected genes. Of note, most of the genes with increased expression were known to be regulated by peroxisome proliferator–activated receptor α (PPARα), suggesting that FATP2 activity is linked to a PPARα-specific proximal ligand. Targeted metabolomic experiments in the Fatp2−/− liver revealed increases of total C16:0, C16:1, and C18:1 fatty acids; increases in lipoxin A4 and prostaglandin J2; and a decrease in 20-hydroxyeicosatetraenoic acid. We conclude that the expression of FATP2 in the liver broadly affects the metabolic landscape through PPARα, indicating that FATP2 provides an important role in liver lipid metabolism through its transport or activation activities. Full Article
pe Combining Precursor and Fragment Information for Improved Detection of Differential Abundance in Data Independent Acquisition [Technological Innovation and Resources] By feedproxy.google.com Published On :: 2020-02-01T00:05:30-08:00 In bottom-up, label-free discovery proteomics, biological samples are acquired in a data-dependent (DDA) or data-independent (DIA) manner, with peptide signals recorded in an intact (MS1) and fragmented (MS2) form. While DDA has only the MS1 space for quantification, DIA contains both MS1 and MS2 at high quantitative quality. DIA profiles of complex biological matrices such as tissues or cells can contain quantitative interferences, and the interferences at the MS1 and the MS2 signals are often independent. When comparing biological conditions, the interferences can compromise the detection of differential peptide or protein abundance and lead to false positive or false negative conclusions. We hypothesized that the combined use of MS1 and MS2 quantitative signals could improve our ability to detect differentially abundant proteins. Therefore, we developed a statistical procedure incorporating both MS1 and MS2 quantitative information of DIA. We benchmarked the performance of the MS1-MS2-combined method to the individual use of MS1 or MS2 in DIA using four previously published controlled mixtures, as well as in two previously unpublished controlled mixtures. In the majority of the comparisons, the combined method outperformed the individual use of MS1 or MS2. This was particularly true for comparisons with low fold changes, few replicates, and situations where MS1 and MS2 were of similar quality. When applied to a previously unpublished investigation of lung cancer, the MS1-MS2-combined method increased the coverage of known activated pathways. Since recent technological developments continue to increase the quality of MS1 signals (e.g. using the BoxCar scan mode for Orbitrap instruments), the combination of the MS1 and MS2 information has a high potential for future statistical analysis of DIA data. Full Article
pe Thorough Performance Evaluation of 213 nm Ultraviolet Photodissociation for Top-down Proteomics [Technological Innovation and Resources] By feedproxy.google.com Published On :: 2020-02-01T00:05:30-08:00 Top-down proteomics studies intact proteoform mixtures and offers important advantages over more common bottom-up proteomics technologies, as it avoids the protein inference problem. However, achieving complete molecular characterization of investigated proteoforms using existing technologies remains a fundamental challenge for top-down proteomics. Here, we benchmark the performance of ultraviolet photodissociation (UVPD) using 213 nm photons generated by a solid-state laser applied to the study of intact proteoforms from three organisms. Notably, the described UVPD setup applies multiple laser pulses to induce ion dissociation, and this feature can be used to optimize the fragmentation outcome based on the molecular weight of the analyzed biomolecule. When applied to complex proteoform mixtures in high-throughput top-down proteomics, 213 nm UVPD demonstrated a high degree of complementarity with the most employed fragmentation method in proteomics studies, higher-energy collisional dissociation (HCD). UVPD at 213 nm offered higher average proteoform sequence coverage and degree of proteoform characterization (including localization of post-translational modifications) than HCD. However, previous studies have shown limitations in applying database search strategies developed for HCD fragmentation to UVPD spectra which contains up to nine fragment ion types. We therefore performed an analysis of the different UVPD product ion type frequencies. From these data, we developed an ad hoc fragment matching strategy and determined the influence of each possible ion type on search outcomes. By paring down the number of ion types considered in high-throughput UVPD searches from all types down to the four most abundant, we were ultimately able to achieve deeper proteome characterization with UVPD. Lastly, our detailed product ion analysis also revealed UVPD cleavage propensities and determined the presence of a product ion produced specifically by 213 nm photons. All together, these observations could be used to better elucidate UVPD dissociation mechanisms and improve the utility of the technique for proteomic applications. Full Article
pe Mass Spectrometry Based Immunopeptidomics Leads to Robust Predictions of Phosphorylated HLA Class I Ligands [Technological Innovation and Resources] By feedproxy.google.com Published On :: 2020-02-01T00:05:30-08:00 The presentation of peptides on class I human leukocyte antigen (HLA-I) molecules plays a central role in immune recognition of infected or malignant cells. In cancer, non-self HLA-I ligands can arise from many different alterations, including non-synonymous mutations, gene fusion, cancer-specific alternative mRNA splicing or aberrant post-translational modifications. Identifying HLA-I ligands remains a challenging task that requires either heavy experimental work for in vivo identification or optimized bioinformatics tools for accurate predictions. To date, no HLA-I ligand predictor includes post-translational modifications. To fill this gap, we curated phosphorylated HLA-I ligands from several immunopeptidomics studies (including six newly measured samples) covering 72 HLA-I alleles and retrieved a total of 2,066 unique phosphorylated peptides. We then expanded our motif deconvolution tool to identify precise binding motifs of phosphorylated HLA-I ligands. Our results reveal a clear enrichment of phosphorylated peptides among HLA-C ligands and demonstrate a prevalent role of both HLA-I motifs and kinase motifs on the presentation of phosphorylated peptides. These data further enabled us to develop and validate the first predictor of interactions between HLA-I molecules and phosphorylated peptides. Full Article
pe Site-specific N-glycan Analysis of Antibody-binding Fc {gamma} Receptors from Primary Human Monocytes [Research] By feedproxy.google.com Published On :: 2020-02-01T00:05:30-08:00 FcRIIIa (CD16a) and FcRIIa (CD32a) on monocytes are essential for proper effector functions including antibody dependent cellular cytotoxicity (ADCC) and phagocytosis (ADCP). Indeed, therapeutic monoclonal antibodies (mAbs) that bind FcRs with greater affinity exhibit greater efficacy. Furthermore, post-translational modification impacts antibody binding affinity, most notably the composition of the asparagine(N)-linked glycan at N162 of CD16a. CD16a is widely recognized as the key receptor for the monocyte response, however the post-translational modifications of CD16a from endogenous monocytes are not described. Here we isolated monocytes from individual donors and characterized the composition of CD16a and CD32a N-glycans from all modified sites. The composition of CD16a N-glycans varied by glycosylation site and donor. CD16a displayed primarily complex-type biantennary N-glycans at N162, however some individuals expressed CD16a V158 with ~20% hybrid and oligomannose types which increased affinity for IgG1 Fc according to surface plasmon resonance binding analyses. The CD16a N45-glycans contain markedly less processing than other sites with >75% hybrid and oligomannose forms. N38 and N74 of CD16a both contain highly processed complex-type N-glycans with N-acetyllactosamine repeats and complex-type biantennary N-glycans dominate at N169. The composition of CD16a N-glycans isolated from monocytes included a higher proportion of oligomannose-type N-glycans at N45 and less sialylation plus greater branch fucosylation than we observed in a recent analysis of NK cell CD16a. The additional analysis of CD32a from monocytes revealed different features than observed for CD16a including the presence of a predominantly biantennary complex-type N-glycans with two sialic acids at both sites (N64 and N145). Full Article
pe Blistering1 Modulates Penicillium expansum Virulence Via Vesicle-mediated Protein Secretion [Research] By feedproxy.google.com Published On :: 2020-02-01T00:05:30-08:00 The blue mold fungus, Penicillium expansum, is a postharvest apple pathogen that contributes to food waste by rotting fruit and by producing harmful mycotoxins (e.g. patulin). To identify genes controlling pathogen virulence, a random T-DNA insertional library was created from wild-type P. expansum strain R19. One transformant, T625, had reduced virulence in apples, blistered mycelial hyphae, and a T-DNA insertion that abolished transcription of the single copy locus in which it was inserted. The gene, Blistering1, encodes a protein with a DnaJ domain, but otherwise has little homology outside the Aspergillaceae, a family of fungi known for producing antibiotics, mycotoxins, and cheese. Because protein secretion is critical for these processes and for host infection, mass spectrometry was used to monitor proteins secreted into liquid media during fungal growth. T625 failed to secrete a set of enzymes that degrade plant cell walls, along with ones that synthesize the three final biosynthetic steps of patulin. Consequently, the culture broth of T625 had significantly reduced capacity to degrade apple tissue and contained 30 times less patulin. Quantitative mass spectrometry of 3,282 mycelial proteins revealed that T625 had altered cellular networks controlling protein processing in the endoplasmic reticulum, protein export, vesicle-mediated transport, and endocytosis. T625 also had reduced proteins controlling mRNA surveillance and RNA processing. Transmission electron microscopy of hyphal cross sections confirmed that T625 formed abnormally enlarged endosomes or vacuoles. These data reveal that Blistering1 affects internal and external protein processing involving vesicle-mediated transport in a family of fungi with medical, commercial, and agricultural importance. Full Article
pe Profiling the Surfaceome Identifies Therapeutic Targets for Cells with Hyperactive mTORC1 Signaling [Research] By feedproxy.google.com Published On :: 2020-02-01T00:05:30-08:00 Aberrantly high mTORC1 signaling is a known driver of many cancers and human disorders, yet pharmacological inhibition of mTORC1 rarely confers durable clinical responses. To explore alternative therapeutic strategies, herein we conducted a proteomics survey to identify cell surface proteins upregulated by mTORC1. A comparison of the surfaceome from Tsc1–/– versus Tsc1+/+ mouse embryonic fibroblasts revealed 59 proteins predicted to be significantly overexpressed in Tsc1–/– cells. Further validation of the data in multiple mouse and human cell lines showed that mTORC1 signaling most dramatically induced the expression of the proteases neprilysin (NEP/CD10) and aminopeptidase N (APN/CD13). Functional studies showed that constitutive mTORC1 signaling sensitized cells to genetic ablation of NEP and APN, as well as the biochemical inhibition of APN. In summary, these data show that mTORC1 signaling plays a significant role in the constitution of the surfaceome, which in turn may present novel therapeutic strategies. Full Article
pe Deep Characterization of the Human Antibody Response to Natural Infection Using Longitudinal Immune Repertoire Sequencing [Research] By feedproxy.google.com Published On :: 2020-02-01T00:05:30-08:00 Human antibody response studies are largely restricted to periods of high immune activity (e.g. vaccination). To comprehensively understand the healthy B cell immune repertoire and how this changes over time and through natural infection, we conducted immune repertoire RNA sequencing on flow cytometry-sorted B cell subsets to profile a single individual's antibodies over 11 months through two periods of natural viral infection. We found that 1) a baseline of healthy variable (V) gene usage in antibodies exists and is stable over time, but antibodies in memory cells consistently have a different usage profile relative to earlier B cell stages; 2) a single complementarity-determining region 3 (CDR3) is potentially generated from more than one VJ gene combination; and 3) IgG and IgA antibody transcripts are found at low levels in early human B cell development, suggesting that class switching may occur earlier than previously realized. These findings provide insight into immune repertoire stability, response to natural infections, and human B cell development. Full Article
pe Advances in Tools to Determine the Glycan-Binding Specificities of Lectins and Antibodies [Reviews] By feedproxy.google.com Published On :: 2020-02-01T00:05:29-08:00 Proteins that bind carbohydrate structures can serve as tools to quantify or localize specific glycans in biological specimens. Such proteins, including lectins and glycan-binding antibodies, are particularly valuable if accurate information is available about the glycans that a protein binds. Glycan arrays have been transformational for uncovering rich information about the nuances and complexities of glycan-binding specificity. A challenge, however, has been the analysis of the data. Because protein-glycan interactions are so complex, simplistic modes of analyzing the data and describing glycan-binding specificities have proven inadequate in many cases. This review surveys the methods for handling high-content data on protein-glycan interactions. We contrast the approaches that have been demonstrated and provide an overview of the resources that are available. We also give an outlook on the promising experimental technologies for generating new insights into protein-glycan interactions, as well as a perspective on the limitations that currently face the field. Full Article
pe MaXLinker: Proteome-wide Cross-link Identifications with High Specificity and Sensitivity [Technological Innovation and Resources] By feedproxy.google.com Published On :: 2020-03-01T00:05:26-08:00 Protein-protein interactions play a vital role in nearly all cellular functions. Hence, understanding their interaction patterns and three-dimensional structural conformations can provide crucial insights about various biological processes and underlying molecular mechanisms for many disease phenotypes. Cross-linking mass spectrometry (XL-MS) has the unique capability to detect protein-protein interactions at a large scale along with spatial constraints between interaction partners. The inception of MS-cleavable cross-linkers enabled the MS2-MS3 XL-MS acquisition strategy that provides cross-link information from both MS2 and MS3 level. However, the current cross-link search algorithm available for MS2-MS3 strategy follows a "MS2-centric" approach and suffers from a high rate of mis-identified cross-links. We demonstrate the problem using two new quality assessment metrics ["fraction of mis-identifications" (FMI) and "fraction of interprotein cross-links from known interactions" (FKI)]. We then address this problem, by designing a novel "MS3-centric" approach for cross-link identification and implementing it as a search engine named MaXLinker. MaXLinker outperforms the currently popular search engine with a lower mis-identification rate, and higher sensitivity and specificity. Moreover, we performed human proteome-wide cross-linking mass spectrometry using K562 cells. Employing MaXLinker, we identified a comprehensive set of 9319 unique cross-links at 1% false discovery rate, comprising 8051 intraprotein and 1268 interprotein cross-links. Finally, we experimentally validated the quality of a large number of novel interactions identified in our study, providing a conclusive evidence for MaXLinker's robust performance. Full Article
pe N-glycosylation Site Analysis Reveals Sex-related Differences in Protein N-glycosylation in the Rice Brown Planthopper (Nilaparvata lugens) [Research] By feedproxy.google.com Published On :: 2020-03-01T00:05:26-08:00 Glycosylation is a common modification of proteins and critical for a wide range of biological processes. Differences in protein glycosylation between sexes have already been observed in humans, nematodes and trematodes, and have recently also been reported in the rice pest insect Nilaparvata lugens. Although protein N-glycosylation in insects is nowadays of high interest because of its potential for exploitation in pest control strategies, the functionality of differential N-glycosylation between sexes is yet unknown. In this study, therefore, the occurrence and role of sex-related protein N-glycosylation in insects were examined. A comprehensive investigation of the N-glycosylation sites from the adult stages of N. lugens was conducted, allowing a qualitative and quantitative comparison between sexes at the glycopeptide level. N-glycopeptide enrichment via lectin capturing using the high mannose/paucimannose-binding lectin Concanavalin A, or the Rhizoctonia solani agglutinin which interacts with complex N-glycans, resulted in the identification of over 1300 N-glycosylation sites derived from over 600 glycoproteins. Comparison of these N-glycopeptides revealed striking differences in protein N-glycosylation between sexes. Male- and female-specific N-glycosylation sites were identified, and some of these sex-specific N-glycosylation sites were shown to be derived from proteins with a putative role in insect reproduction. In addition, differential glycan composition between males and females was observed for proteins shared across sexes. Both lectin blotting experiments as well as transcript expression analyses with complete insects and insect tissues confirmed the observed differences in N-glycosylation of proteins between sexes. In conclusion, this study provides further evidence for protein N-glycosylation to be sex-related in insects. Furthermore, original data on N-glycosylation sites of N. lugens adults are presented, providing novel insights into planthopper's biology and information for future biological pest control strategies. Full Article
pe Discovery of Species-unique Peptide Biomarkers of Bacterial Pathogens by Tandem Mass Spectrometry-based Proteotyping [Research] By feedproxy.google.com Published On :: 2020-03-01T00:05:26-08:00 Mass spectrometry (MS) and proteomics offer comprehensive characterization and identification of microorganisms and discovery of protein biomarkers that are applicable for diagnostics of infectious diseases. The use of biomarkers for diagnostics is widely applied in the clinic and the use of peptide biomarkers is increasingly being investigated for applications in the clinical laboratory. Respiratory-tract infections are a predominant cause for medical treatment, although, clinical assessments and standard clinical laboratory protocols are time-consuming and often inadequate for reliable diagnoses. Novel methods, preferably applied directly to clinical samples, excluding cultivation steps, are needed to improve diagnostics of infectious diseases, provide adequate treatment and reduce the use of antibiotics and associated development of antibiotic resistance. This study applied nano-liquid chromatography (LC) coupled with tandem MS, with a bioinformatics pipeline and an in-house database of curated high-quality reference genome sequences to identify species-unique peptides as potential biomarkers for four bacterial pathogens commonly found in respiratory tract infections (RTIs): Staphylococcus aureus; Moraxella catarrhalis; Haemophilus influenzae and Streptococcus pneumoniae. The species-unique peptides were initially identified in pure cultures of bacterial reference strains, reflecting the genomic variation in the four species and, furthermore, in clinical respiratory tract samples, without prior cultivation, elucidating proteins expressed in clinical conditions of infection. For each of the four bacterial pathogens, the peptide biomarker candidates most predominantly found in clinical samples, are presented. Data are available via ProteomeXchange with identifier PXD014522. As proof-of-principle, the most promising species-unique peptides were applied in targeted tandem MS-analyses of clinical samples and their relevance for identifications of the pathogens, i.e. proteotyping, was validated, thus demonstrating their potential as peptide biomarker candidates for diagnostics of infectious diseases. Full Article
pe Peptidomic Analysis of Urine from Youths with Early Type 1 Diabetes Reveals Novel Bioactivity of Uromodulin Peptides In Vitro [Research] By feedproxy.google.com Published On :: 2020-03-01T00:05:26-08:00 Chronic hyperglycemia is known to disrupt the proteolytic milieu, initiating compensatory and maladaptive pathways in the diabetic kidney. Such changes in intrarenal proteolysis are captured by the urinary peptidome. To elucidate the early kidney response to chronic hyperglycemia, we conducted a peptidomic investigation into urines from otherwise healthy youths with type 1 diabetes and their non-diabetic peers using unbiased and targeted mass spectrometry-based techniques. This cross-sectional study included two separate cohorts for the discovery (n = 30) and internal validation (n = 30) of differential peptide excretion. Peptide bioactivity was predicted using PeptideRanker and subsequently verified in vitro. Proteasix and the Nephroseq database were used to identify putative proteases responsible for peptide generation and examine their expression in diabetic nephropathy. A total of 6550 urinary peptides were identified in the discovery analysis. We further examined the subset of 162 peptides, which were quantified across all thirty samples. Of the 15 differentially excreted peptides (p < 0.05), seven derived from a C-terminal region (589SGSVIDQSRVLNLGPITRK607) of uromodulin, a kidney-specific protein. Increased excretion of five uromodulin peptides was replicated in the validation cohort using parallel reaction monitoring (p < 0.05). One of the validated peptides (SGSVIDQSRVLNLGPI) activated NFB and AP-1 signaling, stimulated cytokine release, and enhanced neutrophil migration in vitro. In silico analyses highlighted several potential proteases such as hepsin, meprin A, and cathepsin B to be responsible for generating these peptides. In summary, we identified a urinary signature of uromodulin peptides associated with early type 1 diabetes before clinical manifestations of kidney disease and discovered novel bioactivity of uromodulin peptides in vitro. Our present findings lay the groundwork for future studies to validate peptide excretion in larger and broader populations, to investigate the role of bioactive uromodulin peptides in high glucose conditions, and to examine proteases that cleave uromodulin. Full Article
pe Integration of IgA and IgG Autoantigens Improves Performance of Biomarker Panels for Early Diagnosis of Lung Cancer [Research] By feedproxy.google.com Published On :: 2020-03-01T00:05:26-08:00 Lung cancer (LC) remains the leading cause of mortality from malignant tumors worldwide. In our previous study, we surveyed both IgG and IgM-bound serological biomarkers and validated a panel of IgG-bound autoantigens for early LC diagnosis with 50% sensitivity at 90% specificity. To further improve the performance of these serological biomarkers, we surveyed HuProt arrays, comprised of 20,240 human proteins, for IgA-bound autoantigens because IgAs are a major immunoglobulin isotype in the lung. Integrating with IgG-bound autoantigens, we discovered and validated a combined biomarker panel using ELISA-format tests. Specifically, in Phase I, we obtained IgA-based autoimmune profiles of 69 early stage LC patients, 30 healthy subjects and 25 patients with lung benign lesions (LBL) on HuProt arrays and identified 28 proteins as candidate autoantigens that were significantly associated with early stage LC. In Phase II, we re-purified the autoantigens and converted them into an ELISA-format testing to profile an additional large cohort, comprised of 136 early stage LC patients, 58 healthy individuals, and 29 LBL patients. Integration of IgG autoimmune profiles allowed us to identify and validate a biomarker panel of three IgA autoantigens (i.e. BCL7A, and TRIM33 and MTERF4) and three IgG autoantigens (i.e. CTAG1A, DDX4 and MAGEC2) for diagnosis of early stage LC with 73.5% sensitivity at >85% specificity. In Phase III, the performance of this biomarker panel was confirmed with an independent cohort, comprised of 88 early stage LC patients, 18 LBL patients, and 36 healthy subjects. Finally, a blind test on 178 serum samples was conducted to confirm the performance of the biomarker panel. In summary, this study demonstrates for the first time that an integrated panel of IgA/IgG autoantigens can serve as valuable biomarkers to further improve the performance of early diagnosis of LC. Full Article
pe The Challenge of Classifying Metastatic Cell Properties by Molecular Profiling Exemplified with Cutaneous Melanoma Cells and Their Cerebral Metastasis from Patient Derived Mouse Xenografts [Research] By feedproxy.google.com Published On :: 2020-03-01T00:05:26-08:00 The prediction of metastatic properties from molecular analyses still poses a major challenge. Here we aimed at the classification of metastasis-related cell properties by proteome profiling making use of cutaneous and brain-metastasizing variants from single melanomas sharing the same genetic ancestry. Previous experiments demonstrated that cultured cells derived from these xenografted variants maintain a stable phenotype associated with a differential metastatic behavior: The brain metastasizing variants produce more spontaneous micro-metastases than the corresponding cutaneous variants. Four corresponding pairs of cutaneous and metastatic cells were obtained from four individual patients, resulting in eight cell-lines presently investigated. Label free proteome profiling revealed significant differences between corresponding pairs of cutaneous and cerebellar metastases from the same patient. Indeed, each brain metastasizing variant expressed several apparently metastasis-associated proteomic alterations as compared with the corresponding cutaneous variant. Among the differentially expressed proteins we identified cell adhesion molecules, immune regulators, epithelial to mesenchymal transition markers, stem cell markers, redox regulators and cytokines. Similar results were observed regarding eicosanoids, considered relevant for metastasis, such as PGE2 and 12-HETE. Multiparametric morphological analysis of cells also revealed no characteristic alterations associated with the cutaneous and brain metastasis variants. However, no correct classification regarding metastatic potential was yet possible with the present data. We thus concluded that molecular profiling is able to classify cells according to known functional categories but is not yet able to predict relevant cell properties emerging from networks consisting of many interconnected molecules. The presently observed broad diversity of molecular patterns, irrespective of restricting to one tumor type and two main classes of metastasis, highlights the important need to develop meta-analysis strategies to predict cell properties from molecular profiling data. Such base knowledge will greatly support future individualized precision medicine approaches. Full Article
pe Proteomic Analysis Reveals that Topoisomerase 2A is Associated with Defective Sperm Head Morphology [Research] By feedproxy.google.com Published On :: 2020-03-01T00:05:26-08:00 Male infertility is widespread and estimated to affect 1 in 20 men. Although in some cases the etiology of the condition is well understood, for at least 50% of men, the underlying cause is yet to be classified. Male infertility, or subfertility, is often diagnosed by looking at total sperm produced, motility of the cells and overall morphology. Although counting spermatozoa and their associated motility is routine, morphology assessment is highly subjective, mainly because of the procedure being based on microscopic examination. A failure to diagnose male-infertility or sub-fertility has led to a situation where assisted conception is often used unnecessarily. As such, biomarkers of male infertility are needed to help establish a more consistent diagnosis. In the present study, we compared nuclear extracts from both high- and low-quality spermatozoa by LC-MS/MS based proteomic analysis. Our data shows that nuclear retention of specific proteins is a common facet among low-quality sperm cells. We demonstrate that the presence of Topoisomerase 2A in the sperm head is highly correlated to poor head morphology. Topoisomerase 2A is therefore a potential new biomarker for confirming male infertility in clinical practice. Full Article
pe Guidance Document: Validation of a High-Performance Liquid Chromatography-Tandem Mass Spectrometry Immunopeptidomics Assay for the Identification of HLA Class I Ligands Suitable for Pharmaceutical Therapies [Commentary] By feedproxy.google.com Published On :: 2020-03-01T00:05:26-08:00 For more than two decades naturally presented, human leukocyte antigen (HLA)-restricted peptides (immunopeptidome) have been eluted and sequenced using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Since, identified disease-associated HLA ligands have been characterized and evaluated as potential active substances. Treatments based on HLA-presented peptides have shown promising results in clinical application as personalized T cell-based immunotherapy. Peptide vaccination cocktails are produced as investigational medicinal products under GMP conditions. To support clinical trials based on HLA-presented tumor-associated antigens, in this study the sensitive LC-MS/MS HLA class I antigen identification pipeline was fully validated for our technical equipment according to the current US Food and Drug Administration (FDA) and European Medicines Agency (EMA) guidelines. The immunopeptidomes of JY cells with or without spiked-in, isotope labeled peptides, of peripheral blood mononuclear cells of healthy volunteers as well as a chronic lymphocytic leukemia and a bladder cancer sample were reliably identified using a data-dependent acquisition method. As the LC-MS/MS pipeline is used for identification purposes, the validation parameters include accuracy, precision, specificity, limit of detection and robustness. Full Article
pe Tandem Mass Tag Approach Utilizing Pervanadate BOOST Channels Delivers Deeper Quantitative Characterization of the Tyrosine Phosphoproteome [Technological Innovation and Resources] By feedproxy.google.com Published On :: 2020-04-01T00:05:32-07:00 Dynamic tyrosine phosphorylation is fundamental to a myriad of cellular processes. However, the inherently low abundance of tyrosine phosphorylation in the proteome and the inefficient enrichment of phosphotyrosine(pTyr)-containing peptides has led to poor pTyr peptide identification and quantitation, critically hindering researchers' ability to elucidate signaling pathways regulated by tyrosine phosphorylation in systems where cellular material is limited. The most popular approaches to wide-scale characterization of the tyrosine phosphoproteome use pTyr enrichment with pan-specific, anti-pTyr antibodies from a large amount of starting material. Methods that decrease the amount of starting material and increase the characterization depth of the tyrosine phosphoproteome while maintaining quantitative accuracy and precision would enable the discovery of tyrosine phosphorylation networks in rarer cell populations. To achieve these goals, the BOOST (Broad-spectrum Optimization Of Selective Triggering) method leveraging the multiplexing capability of tandem mass tags (TMT) and the use of pervanadate (PV) boost channels (cells treated with the broad-spectrum tyrosine phosphatase inhibitor PV) selectively increased the relative abundance of pTyr-containing peptides. After PV boost channels facilitated selective fragmentation of pTyr-containing peptides, TMT reporter ions delivered accurate quantitation of each peptide for the experimental samples while the quantitation from PV boost channels was ignored. This method yielded up to 6.3-fold boost in pTyr quantification depth of statistically significant data derived from contrived ratios, compared with TMT without PV boost channels or intensity-based label-free (LF) quantitation while maintaining quantitative accuracy and precision, allowing quantitation of over 2300 unique pTyr peptides from only 1 mg of T cell receptor-stimulated Jurkat T cells. The BOOST strategy can potentially be applied in analyses of other post-translational modifications where treatments that broadly elevate the levels of those modifications across the proteome are available. Full Article
pe A Compact Quadrupole-Orbitrap Mass Spectrometer with FAIMS Interface Improves Proteome Coverage in Short LC Gradients [Technological Innovation and Resources] By feedproxy.google.com Published On :: 2020-04-01T00:05:32-07:00 State-of-the-art proteomics-grade mass spectrometers can measure peptide precursors and their fragments with ppm mass accuracy at sequencing speeds of tens of peptides per second with attomolar sensitivity. Here we describe a compact and robust quadrupole-orbitrap mass spectrometer equipped with a front-end High Field Asymmetric Waveform Ion Mobility Spectrometry (FAIMS) Interface. The performance of the Orbitrap Exploris 480 mass spectrometer is evaluated in data-dependent acquisition (DDA) and data-independent acquisition (DIA) modes in combination with FAIMS. We demonstrate that different compensation voltages (CVs) for FAIMS are optimal for DDA and DIA, respectively. Combining DIA with FAIMS using single CVs, the instrument surpasses 2500 peptides identified per minute. This enables quantification of >5000 proteins with short online LC gradients delivered by the Evosep One LC system allowing acquisition of 60 samples per day. The raw sensitivity of the instrument is evaluated by analyzing 5 ng of a HeLa digest from which >1000 proteins were reproducibly identified with 5 min LC gradients using DIA-FAIMS. To demonstrate the versatility of the instrument, we recorded an organ-wide map of proteome expression across 12 rat tissues quantified by tandem mass tags and label-free quantification using DIA with FAIMS to a depth of >10,000 proteins. Full Article
pe Large-scale Identification of N-linked Intact Glycopeptides in Human Serum using HILIC Enrichment and Spectral Library Search [Research] By feedproxy.google.com Published On :: 2020-04-01T00:05:32-07:00 Large-scale identification of N-linked intact glycopeptides by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) in human serum is challenging because of the wide dynamic range of serum protein abundances, the lack of a complete serum N-glycan database and the existence of proteoforms. In this regard, a spectral library search method was presented for the identification of N-linked intact glycopeptides from N-linked glycoproteins in human serum with target-decoy and motif-specific false discovery rate (FDR) control. Serum proteins were firstly separated into low-abundance and high-abundance proteins by acetonitrile (ACN) precipitation. After digestion, the N-linked intact glycopeptides were enriched by hydrophilic interaction liquid chromatography (HILIC) and a portion of the enriched N-linked intact glycopeptides were processed by Peptide-N-Glycosidase F (PNGase F) to generate N-linked deglycopeptides. Both N-linked intact glycopeptides and deglycopeptides were analyzed by LC-MS/MS. From N-linked deglycopeptides data sets, 764 N-linked glycoproteins, 1699 N-linked glycosites and 3328 unique N-linked deglycopeptides were identified. Four types of N-linked glycosylation motifs (NXS/T/C/V, X=P) were used to recognize the N-linked deglycopeptides. The spectra of these N-linked deglycopeptides were utilized for N-linked deglycopeptides library construction and identification of N-linked intact glycopeptides. A database containing 739 N-glycan masses was constructed and utilized during spectral library search for the identification of N-linked intact glycopeptides. In total, 526 N-linked glycoproteins, 1036 N-linked glycosites, 22,677 N-linked intact glycopeptides and 738 N-glycan masses were identified under 1% FDR, representing the most in-depth serum N-glycoproteome identified by LC-MS/MS at N-linked intact glycopeptide level. Full Article
pe Arginine in C9ORF72 Dipolypeptides Mediates Promiscuous Proteome Binding and Multiple Modes of Toxicity [Research] By feedproxy.google.com Published On :: 2020-04-01T00:05:32-07:00 C9ORF72-associated Motor Neuron Disease patients feature abnormal expression of 5 dipeptide repeat (DPR) polymers. Here we used quantitative proteomics in a mouse neuronal-like cell line (Neuro2a) to demonstrate that the Arg residues in the most toxic DPRS, PR and GR, leads to a promiscuous binding to the proteome compared with a relative sparse binding of the more inert AP and GA. Notable targets included ribosomal proteins, translation initiation factors and translation elongation factors. PR and GR comprising more than 10 repeats appeared to robustly stall on ribosomes during translation suggesting Arg-rich peptide domains can electrostatically jam the ribosome exit tunnel during synthesis. Poly-GR also recruited arginine methylases, induced hypomethylation of endogenous proteins, and induced a profound destabilization of the actin cytoskeleton. Our findings point to arginine in GR and PR polymers as multivalent toxins to translation as well as arginine methylation that may explain the dysfunction of biological processes including ribosome biogenesis, mRNA splicing and cytoskeleton assembly. Full Article
pe Improving Identification of In-organello Protein-Protein Interactions Using an Affinity-enrichable, Isotopically Coded, and Mass Spectrometry-cleavable Chemical Crosslinker [Research] By feedproxy.google.com Published On :: 2020-04-01T00:05:32-07:00 An experimental and computational approach for identification of protein-protein interactions by ex vivo chemical crosslinking and mass spectrometry (CLMS) has been developed that takes advantage of the specific characteristics of cyanurbiotindipropionylsuccinimide (CBDPS), an affinity-tagged isotopically coded mass spectrometry (MS)-cleavable crosslinking reagent. Utilizing this reagent in combination with a crosslinker-specific data-dependent acquisition strategy based on MS2 scans, and a software pipeline designed for integrating crosslinker-specific mass spectral information led to demonstrated improvements in the application of the CLMS technique, in terms of the detection, acquisition, and identification of crosslinker-modified peptides. This approach was evaluated on intact yeast mitochondria, and the results showed that hundreds of unique protein-protein interactions could be identified on an organelle proteome-wide scale. Both known and previously unknown protein-protein interactions were identified. These interactions were assessed based on their known sub-compartmental localizations. Additionally, the identified crosslinking distance constraints are in good agreement with existing structural models of protein complexes involved in the mitochondrial electron transport chain. Full Article
pe Integrative Metabolic Pathway Analysis Reveals Novel Therapeutic Targets in Osteoarthritis [Research] By feedproxy.google.com Published On :: 2020-04-01T00:05:32-07:00 In osteoarthritis (OA), impairment of cartilage regeneration can be related to a defective chondrogenic differentiation of mesenchymal stromal cells (MSCs). Therefore, understanding the proteomic- and metabolomic-associated molecular events during the chondrogenesis of MSCs could provide alternative targets for therapeutic intervention. Here, a SILAC-based proteomic analysis identified 43 proteins related with metabolic pathways whose abundance was significantly altered during the chondrogenesis of OA human bone marrow MSCs (hBMSCs). Then, the level and distribution of metabolites was analyzed in these cells and healthy controls by matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), leading to the recognition of characteristic metabolomic profiles at the early stages of differentiation. Finally, integrative pathway analysis showed that UDP-glucuronic acid synthesis and amino sugar metabolism were downregulated in OA hBMSCs during chondrogenesis compared with healthy cells. Alterations in these metabolic pathways may disturb the production of hyaluronic acid (HA) and other relevant cartilage extracellular matrix (ECM) components. This work provides a novel integrative insight into the molecular alterations of osteoarthritic MSCs and potential therapeutic targets for OA drug development through the enhancement of chondrogenesis. Full Article
pe Identification of an Unconventional Subpeptidome Bound to the Behcet's Disease-associated HLA-B*51:01 that is Regulated by Endoplasmic Reticulum Aminopeptidase 1 (ERAP1) [Research] By feedproxy.google.com Published On :: 2020-05-01T00:05:26-07:00 Human leukocyte antigen (HLA) B*51:01 and endoplasmic reticulum aminopeptidase 1 (ERAP1) are strongly genetically associated with Behcet's disease (BD). Previous studies have defined two subgroups of HLA-B*51 peptidome containing proline (Pro) or alanine (Ala) at position 2 (P2). Little is known about the unconventional non-Pro/Ala2 HLA-B*51-bound peptides. We aimed to study the features of this novel subpeptidome, and investigate its regulation by ERAP1. CRISPR-Cas9 was used to generate an HLA-ABC-triple knockout HeLa cell line (HeLa.ABC-KO), which was subsequently transduced to express HLA-B*51:01 (HeLa.ABC-KO.B51). ERAP1 was silenced using lentiviral shRNA. Peptides bound to HLA-B*51:01 were eluted and analyzed by mass spectrometry. The characteristics of non-Pro/Ala2, Pro2, and Ala2 peptides and their alteration by ERAP1 silencing were investigated. Effects of ERAP1 silencing on cell surface expression of HLA-B*51:01 were studied using flow cytometry. More than 20% of peptides eluted from HLA-B*51:01 lacked Pro or Ala at P2. This unconventional group of HLA-B*51:01-bound peptides was relatively enriched for 8-mers (with relatively fewer 9-mers) compared with the Pro2 and Ala2 subpeptidomes and had similar N-terminal and C-terminal residue usages to Ala2 peptides (with the exception of the less abundant leucine at position ). Knockdown of ERAP1 increased the percentage of non-Pro/Ala2 from 20% to ~40%, increased the percentage of longer (10-mer and 11-mer) peptides eluted from HLA-B*51:01 complexes, and abrogated the predominance of leucine at P1. Interestingly knockdown of ERAP1 altered the length and N-terminal residue usage of non-Ala2&Pro2 and Ala2 but not the Pro2 peptides. Finally, ERAP1 silencing regulated the expression levels of cell surface HLA-B*51 in a cell-type-dependent manner. In conclusion, we have used a novel methodology to identify an unconventional but surprisingly abundant non-Pro/Ala2 HLA-B*51:01 subpeptidome. It is increased by knockdown of ERAP1, a gene affecting the risk of developing BD. This has implications for theories of disease pathogenesis. Full Article
pe Quantitative Profiling of the Human Substantia Nigra Proteome from Laser-capture Microdissected FFPE Tissue [Research] By feedproxy.google.com Published On :: 2020-05-01T00:05:26-07:00 Laser-capture microdissection (LCM) allows the visualization and isolation of morphologically distinct subpopulations of cells from heterogeneous tissue specimens. In combination with formalin-fixed and paraffin-embedded (FFPE) tissue it provides a powerful tool for retrospective and clinically relevant studies of tissue proteins in a healthy and diseased context. We first optimized the protocol for efficient LCM analysis of FFPE tissue specimens. The use of SDS containing extraction buffer in combination with the single-pot solid-phase-enhanced sample preparation (SP3) digest method gave the best results regarding protein yield and protein/peptide identifications. Microdissected FFPE human substantia nigra tissue samples (~3,000 cells) were then analyzed, using tandem mass tag (TMT) labeling and LC-MS/MS, resulting in the quantification of >5,600 protein groups. Nigral proteins were classified and analyzed by abundance, showing an enrichment of extracellular exosome and neuron-specific gene ontology (GO) terms among the higher abundance proteins. Comparison of microdissected samples with intact tissue sections, using a label-free shotgun approach, revealed an enrichment of neuronal cell type markers, such as tyrosine hydroxylase and alpha-synuclein, as well as proteins annotated with neuron-specific GO terms. Overall, this study provides a detailed protocol for laser-capture proteomics using FFPE tissue and demonstrates the efficiency of LCM analysis of distinct cell subpopulations for proteomic analysis using low sample amounts. Full Article
pe The Secretome Profiling of a Pediatric Airway Epithelium Infected with hRSV Identified Aberrant Apical/Basolateral Trafficking and Novel Immune Modulating (CXCL6, CXCL16, CSF3) and Antiviral (CEACAM1) Proteins [Research] By feedproxy.google.com Published On :: 2020-05-01T00:05:26-07:00 The respiratory epithelium comprises polarized cells at the interface between the environment and airway tissues. Polarized apical and basolateral protein secretions are a feature of airway epithelium homeostasis. Human respiratory syncytial virus (hRSV) is a major human pathogen that primarily targets the respiratory epithelium. However, the consequences of hRSV infection on epithelium secretome polarity and content remain poorly understood. To investigate the hRSV-associated apical and basolateral secretomes, a proteomics approach was combined with an ex vivo pediatric human airway epithelial (HAE) model of hRSV infection (data are available via ProteomeXchange and can be accessed at https://www.ebi.ac.uk/pride/ with identifier PXD013661). Following infection, a skewing of apical/basolateral abundance ratios was identified for several individual proteins. Novel modulators of neutrophil and lymphocyte activation (CXCL6, CSF3, SECTM1 or CXCL16), and antiviral proteins (BST2 or CEACAM1) were detected in infected, but not in uninfected cultures. Importantly, CXCL6, CXCL16, CSF3 were also detected in nasopharyngeal aspirates (NPA) from hRSV-infected infants but not healthy controls. Furthermore, the antiviral activity of CEACAM1 against RSV was confirmed in vitro using BEAS-2B cells. hRSV infection disrupted the polarity of the pediatric respiratory epithelial secretome and was associated with immune modulating proteins (CXCL6, CXCL16, CSF3) never linked with this virus before. In addition, the antiviral activity of CEACAM1 against hRSV had also never been previously characterized. This study, therefore, provides novel insights into RSV pathogenesis and endogenous antiviral responses in pediatric airway epithelium. Full Article
pe Decreased Immunoglobulin G Core Fucosylation, A Player in Antibody-dependent Cell-mediated Cytotoxicity, is Associated with Autoimmune Thyroid Diseases [Research] By feedproxy.google.com Published On :: 2020-05-01T00:05:26-07:00 Autoimmune thyroid diseases (AITD) are the most common group of autoimmune diseases, associated with lymphocyte infiltration and the production of thyroid autoantibodies, like thyroid peroxidase antibodies (TPOAb), in the thyroid gland. Immunoglobulins and cell-surface receptors are glycoproteins with distinctive glycosylation patterns that play a structural role in maintaining and modulating their functions. We investigated associations of total circulating IgG and peripheral blood mononuclear cells glycosylation with AITD and the influence of genetic background in a case-control study with several independent cohorts and over 3,000 individuals in total. The study revealed an inverse association of IgG core fucosylation with TPOAb and AITD, as well as decreased peripheral blood mononuclear cells antennary α1,2 fucosylation in AITD, but no shared genetic variance between AITD and glycosylation. These data suggest that the decreased level of IgG core fucosylation is a risk factor for AITD that promotes antibody-dependent cell-mediated cytotoxicity previously associated with TPOAb levels. Full Article
pe Proximity Dependent Biotinylation: Key Enzymes and Adaptation to Proteomics Approaches [Reviews] By feedproxy.google.com Published On :: 2020-05-01T00:05:26-07:00 The study of protein subcellular distribution, their assembly into complexes and the set of proteins with which they interact with is essential to our understanding of fundamental biological processes. Complementary to traditional assays, proximity-dependent biotinylation (PDB) approaches coupled with mass spectrometry (such as BioID or APEX) have emerged as powerful techniques to study proximal protein interactions and the subcellular proteome in the context of living cells and organisms. Since their introduction in 2012, PDB approaches have been used in an increasing number of studies and the enzymes themselves have been subjected to intensive optimization. How these enzymes have been optimized and considerations for their use in proteomics experiments are important questions. Here, we review the structural diversity and mechanisms of the two main classes of PDB enzymes: the biotin protein ligases (BioID) and the peroxidases (APEX). We describe the engineering of these enzymes for PDB and review emerging applications, including the development of PDB for coincidence detection (split-PDB). Lastly, we briefly review enzyme selection and experimental design guidelines and reflect on the labeling chemistries and their implication for data interpretation. Full Article
pe Biosynthesis of depsipeptides with a 3-hydroxybenzoate moiety and selective anticancer activities involves a chorismatase [Metabolism] By feedproxy.google.com Published On :: 2020-04-17T00:06:05-07:00 Neoantimycins are anticancer compounds of 15-membered ring antimycin-type depsipeptides. They are biosynthesized by a hybrid multimodular protein complex of nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS), typically from the starting precursor 3-formamidosalicylate. Examining fermentation extracts of Streptomyces conglobatus, here we discovered four new neoantimycin analogs, unantimycins B–E, in which 3-formamidosalicylates are replaced by an unusual 3-hydroxybenzoate (3-HBA) moiety. Unantimycins B–E exhibited levels of anticancer activities similar to those of the chemotherapeutic drug cisplatin in human lung cancer, colorectal cancer, and melanoma cells. Notably, they mostly displayed no significant toxicity toward noncancerous cells, unlike the serious toxicities generally reported for antimycin-type natural products. Using site-directed mutagenesis and heterologous expression, we found that unantimycin productions are correlated with the activity of a chorismatase homolog, the nat-hyg5 gene, from a type I PKS gene cluster. Biochemical analysis confirmed that the catalytic activity of Nat-hyg5 generates 3-HBA from chorismate. Finally, we achieved selective production of unantimycins B and C by engineering a chassis host. On the basis of these findings, we propose that unantimycin biosynthesis is directed by the neoantimycin-producing NRPS–PKS complex and initiated with the starter unit of 3-HBA. The elucidation of the biosynthetic unantimycin pathway reported here paves the way to improve the yield of these compounds for evaluation in oncotherapeutic applications. Full Article
pe A peroxisome deficiency-induced reductive cytosol state up-regulates the brain-derived neurotrophic factor pathway [Metabolism] By feedproxy.google.com Published On :: 2020-04-17T00:06:05-07:00 The peroxisome is a subcellular organelle that functions in essential metabolic pathways, including biosynthesis of plasmalogens, fatty acid β-oxidation of very-long-chain fatty acids, and degradation of hydrogen peroxide. Peroxisome biogenesis disorders (PBDs) manifest as severe dysfunction in multiple organs, including the central nervous system (CNS), but the pathogenic mechanisms in PBDs are largely unknown. Because CNS integrity is coordinately established and maintained by neural cell interactions, we here investigated whether cell-cell communication is impaired and responsible for the neurological defects associated with PBDs. Results from a noncontact co-culture system consisting of primary hippocampal neurons with glial cells revealed that a peroxisome-deficient astrocytic cell line secretes increased levels of brain-derived neurotrophic factor (BDNF), resulting in axonal branching of the neurons. Of note, the BDNF expression in astrocytes was not affected by defects in plasmalogen biosynthesis and peroxisomal fatty acid β-oxidation in the astrocytes. Instead, we found that cytosolic reductive states caused by a mislocalized catalase in the peroxisome-deficient cells induce the elevation in BDNF secretion. Our results suggest that peroxisome deficiency dysregulates neuronal axogenesis by causing a cytosolic reductive state in astrocytes. We conclude that astrocytic peroxisomes regulate BDNF expression and thereby support neuronal integrity and function. Full Article
pe COQ11 deletion mitigates respiratory deficiency caused by mutations in the gene encoding the coenzyme Q chaperone protein Coq10 [Lipids] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 Coenzyme Q (Qn) is a vital lipid component of the electron transport chain that functions in cellular energy metabolism and as a membrane antioxidant. In the yeast Saccharomyces cerevisiae, coq1–coq9 deletion mutants are respiratory-incompetent, sensitive to lipid peroxidation stress, and unable to synthesize Q6. The yeast coq10 deletion mutant is also respiratory-deficient and sensitive to lipid peroxidation, yet it continues to produce Q6 at an impaired rate. Thus, Coq10 is required for the function of Q6 in respiration and as an antioxidant and is believed to chaperone Q6 from its site of synthesis to the respiratory complexes. In several fungi, Coq10 is encoded as a fusion polypeptide with Coq11, a recently identified protein of unknown function required for efficient Q6 biosynthesis. Because “fused” proteins are often involved in similar biochemical pathways, here we examined the putative functional relationship between Coq10 and Coq11 in yeast. We used plate growth and Seahorse assays and LC-MS/MS analysis to show that COQ11 deletion rescues respiratory deficiency, sensitivity to lipid peroxidation, and decreased Q6 biosynthesis of the coq10Δ mutant. Additionally, immunoblotting indicated that yeast coq11Δ mutants accumulate increased amounts of certain Coq polypeptides and display a stabilized CoQ synthome. These effects suggest that Coq11 modulates Q6 biosynthesis and that its absence increases mitochondrial Q6 content in the coq10Δcoq11Δ double mutant. This augmented mitochondrial Q6 content counteracts the respiratory deficiency and lipid peroxidation sensitivity phenotypes of the coq10Δ mutant. This study further clarifies the intricate connection between Q6 biosynthesis, trafficking, and function in mitochondrial metabolism. Full Article
pe The mRNA levels of heat shock factor 1 are regulated by thermogenic signals via the cAMP-dependent transcription factor ATF3 [Metabolism] By feedproxy.google.com Published On :: 2020-05-01T00:06:09-07:00 Heat shock factor 1 (HSF1) regulates cellular adaptation to challenges such as heat shock and oxidative and proteotoxic stresses. We have recently reported a previously unappreciated role for HSF1 in the regulation of energy metabolism in fat tissues; however, whether HSF1 is differentially expressed in adipose depots and how its levels are regulated in fat tissues remain unclear. Here, we show that HSF1 levels are higher in brown and subcutaneous fat tissues than in those in the visceral depot and that HSF1 is more abundant in differentiated, thermogenic adipocytes. Gene expression experiments indicated that HSF1 is transcriptionally regulated in fat by agents that modulate cAMP levels, by cold exposure, and by pharmacological stimulation of β-adrenergic signaling. An in silico promoter analysis helped identify a putative response element for activating transcription factor 3 (ATF3) at −258 to −250 base pairs from the HSF1 transcriptional start site, and electrophoretic mobility shift and ChIP assays confirmed ATF3 binding to this sequence. Furthermore, functional assays disclosed that ATF3 is necessary and sufficient for HSF1 regulation. Detailed gene expression analysis revealed that ATF3 is one of the most highly induced ATFs in thermogenic tissues of mice exposed to cold temperatures or treated with the β-adrenergic receptor agonist CL316,243 and that its expression is induced by modulators of cAMP levels in isolated adipocytes. To the best of our knowledge, our results show for the first time that HSF1 is transcriptionally controlled by ATF3 in response to classic stimuli that promote heat generation in thermogenic tissues. Full Article
pe Perturbation of phosphoglycerate kinase 1 (PGK1) only marginally affects glycolysis in cancer cells [Metabolism] By feedproxy.google.com Published On :: 2020-05-08T03:41:14-07:00 Phosphoglycerate kinase 1 (PGK1) plays important roles in glycolysis, yet its forward reaction kinetics are unknown, and its role especially in regulating cancer cell glycolysis is unclear. Here, we developed an enzyme assay to measure the kinetic parameters of the PGK1-catalyzed forward reaction. The Km values for 1,3-bisphosphoglyceric acid (1,3-BPG, the forward reaction substrate) were 4.36 μm (yeast PGK1) and 6.86 μm (human PKG1). The Km values for 3-phosphoglycerate (3-PG, the reverse reaction substrate and a serine precursor) were 146 μm (yeast PGK1) and 186 μm (human PGK1). The Vmax of the forward reaction was about 3.5- and 5.8-fold higher than that of the reverse reaction for the human and yeast enzymes, respectively. Consistently, the intracellular steady-state concentrations of 3-PG were between 180 and 550 μm in cancer cells, providing a basis for glycolysis to shuttle 3-PG to the serine synthesis pathway. Using siRNA-mediated PGK1-specific knockdown in five cancer cell lines derived from different tissues, along with titration of PGK1 in a cell-free glycolysis system, we found that the perturbation of PGK1 had no effect or only marginal effects on the glucose consumption and lactate generation. The PGK1 knockdown increased the concentrations of fructose 1,6-bisphosphate, dihydroxyacetone phosphate, glyceraldehyde 3-phosphate, and 1,3-BPG in nearly equal proportions, controlled by the kinetic and thermodynamic states of glycolysis. We conclude that perturbation of PGK1 in cancer cells insignificantly affects the conversion of glucose to lactate in glycolysis. Full Article
pe DHS herding people on to an imperfect system in myGov By www.smh.com.au Published On :: Mon, 10 Aug 2015 14:17:52 GMT Over the past few weeks I have been answering calls for the myGov helpdesk. Full Article
pe Sydney start-up Suppertime acquired by food delivery giant By www.smh.com.au Published On :: Mon, 12 Oct 2015 06:29:04 GMT Australian premium restaurant delivery service Suppertime has been snapped by a major international company, as the local food delivery market continues to heat up. Full Article
pe From making scarves to building a $165 million tech start-up: Canva's Melanie Perkins By www.smh.com.au Published On :: Tue, 06 Oct 2015 10:42:33 GMT To say it has been a wild ride for Canva founder and CEO Melanie Perkins would be an understatement. Full Article
pe How Australian public service's digital reforms will happen, according to the Digital Transformation Office By www.smh.com.au Published On :: Thu, 15 Oct 2015 08:31:11 GMT The millions of customers, the short deadline: how the public service's digital revolution will start. Full Article
pe Cyber security expert issues dire warning over vulnerability of key infrastructure By www.smh.com.au Published On :: Thu, 22 Oct 2015 13:00:00 GMT Data theft and cybercrime is a major source of funding for Islamic State which is likely to have secretly planted insiders "around the world" in positions where critical data could be extracted and exploited, a leading cyber security expert has warned. Full Article