Interferon-regulated myxovirus resistance protein B (MxB) is an interferon-induced GTPase belonging to the dynamin superfamily. It inhibits infection with a wide range of different viruses, including HIV-1, by impairing viral DNA entry into the nucleus. Unlike the related antiviral GTPase MxA, MxB possesses an N-terminal region that contains a nuclear localization signal and is crucial for inhibiting HIV-1. Because MxB previously has been shown to reside in both the nuclear envelope and the cytoplasm, here we used bioinformatics and biochemical approaches to identify a nuclear export signal (NES) responsible for MxB's cytoplasmic location. Using the online computational tool LocNES (Locating Nuclear Export Signals or NESs), we identified five putative NES candidates in MxB and investigated whether their deletion caused nuclear localization of MxB. Our results revealed that none of the five deletion variants relocates to the nucleus, suggesting that these five predicted NES sequences do not confer NES activity. Interestingly, deletion of one sequence, encompassing amino acids 505–527, abrogated the anti-HIV-1 activity of MxB. Further mutation experiments disclosed that amino acids 515–519, and Pro-515 in particular, regulate MxB oligomerization and its binding to HIV-1 capsid, thereby playing an important role in MxB-mediated restriction of HIV-1 infection. In summary, our results indicate that none of the five predicted NES sequences in MxB appears to be required for its nuclear export. Our findings also reveal several residues in MxB, including Pro-515, critical for its oligomerization and anti-HIV-1 function.

Bacterial products such as lipopolysaccharides (or endotoxin) cause systemic inflammation, resulting in a substantial global health burden. The onset, progression, and resolution of the inflammatory response to endotoxin are usually tightly controlled to avoid chronic inflammation. Members of the NF-κB family of transcription factors are key drivers of inflammation that activate sets of genes in response to inflammatory signals. Such responses are typically short-lived and can be suppressed by proteins that act post-translationally, such as the SOCS (suppressor of cytokine signaling) family. Less is known about direct transcriptional regulation of these responses, however. Here, using a combination of in vitro approaches and in vivo animal models, we show that endotoxin treatment induced expression of the well-characterized transcriptional repressor Krüppel-like factor 3 (KLF3), which, in turn, directly repressed the expression of the NF-κB family member RELA/p65. We also observed that KLF3-deficient mice were hypersensitive to endotoxin and exhibited elevated levels of circulating Ly6C+ monocytes and macrophage-derived inflammatory cytokines. These findings reveal that KLF3 is a fundamental suppressor that operates as a feedback inhibitor of RELA/p65 and may be important in facilitating the resolution of inflammation.

Ivan Matic
Jan 1, 2008; 7:132-144
Research

2 March 2020

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The colored "strings" you see represent air flow around the soccer ball, with the dark blue streams behind the ball signifying a low-pressure wake. Computational fluid dynamics and wind tunnel experiments have shown that there is a transition point between smooth and turbulent flow at around 30 mph, which can dramatically change the path of a kick approaching the net as its speed decreases through the transition point. Players taking free-kicks need not be mathematicians to score, but knowing the results obtained from mathematical facts can help players devise better strategies. The behavior of a ball depends on its surface design as well as on how it.s kicked. Topology, algebra, and geometry are all important to determine suitable shapes, and modeling helps determine desirable ones. The researchers studying soccer ball trajectories incorporate into their mathematical models not only the pattern of a new ball, but also details right down to the seams. Recently there was a radical change from the long-used pentagon-hexagon pattern to the adidas +TeamgeistTM. Yet the overall framework for the design process remains the same: to approximate a sphere, within less than two percent, using two-dimensional panels.

The earth we abuse and the living things we kill will, in the end, take their revenge; for in exploiting their presence we are diminishing our future. ~ Marya Mannes Each species represents a thread in the closely woven fabric of Nature. For centuries, we humans have prided ourselves on being the most 'evolved' species. Superior intelligence and technological capability have bred this arrogance.

In the wake of the COVID-19 crisis, any economic stimulus measures must safeguard nature or governments risk exposing humanity to further pandemics.

From its brightly coloured card to the user experience of its app and the benefits it offers, the long-gestating Natwest fintech project looks like little more than a Monzo copycat

S. S. Lohvinenko and K. V. Ralchenko
Theor. Probability and Math. Statist. 99 (2020), 149-168.
Abstract, references and article information

Quanlei Fang and Jingbo Xia
Proc. Amer. Math. Soc. 148 (2020), 2497-2507.
Abstract, references and article information

Deborah Hinnen
Aug 1, 2017; 30:202-210
Feature Articles

(Georgia Institute of Technology) The science behind sticky gecko's feet lets gecko adhesion materials pick up about anything. But cost-effective mass production of the materials was out of reach until now. A new method of making them could usher the spread of gecko-inspired grabbers to assembly lines and homes.

Inter-α-inhibitor is a proteoglycan essential for mammalian reproduction and also plays a less well-characterized role in inflammation. It comprises two homologous “heavy chains” (HC1 and HC2) covalently attached to chondroitin sulfate on the bikunin core protein. Before ovulation, HCs are transferred onto the polysaccharide hyaluronan (HA) to form covalent HC·HA complexes, thereby stabilizing an extracellular matrix around the oocyte required for fertilization. Additionally, such complexes form during inflammatory processes and mediate leukocyte adhesion in the synovial fluids of arthritis patients and protect against sepsis. Here using X-ray crystallography, we show that human HC1 has a structure similar to integrin β-chains, with a von Willebrand factor A domain containing a functional metal ion-dependent adhesion site (MIDAS) and an associated hybrid domain. A comparison of the WT protein and a variant with an impaired MIDAS (but otherwise structurally identical) by small-angle X-ray scattering and analytical ultracentrifugation revealed that HC1 self-associates in a cation-dependent manner, providing a mechanism for HC·HA cross-linking and matrix stabilization. Surprisingly, unlike integrins, HC1 interacted with RGD-containing ligands, such as fibronectin, vitronectin, and the latency-associated peptides of transforming growth factor β, in a MIDAS/cation-independent manner. However, HC1 utilizes its MIDAS motif to bind to and inhibit the cleavage of complement C3, and small-angle X-ray scattering–based modeling indicates that this occurs through the inhibition of the alternative pathway C3 convertase. These findings provide detailed structural and functional insights into HC1 as a regulator of innate immunity and further elucidate the role of HC·HA complexes in inflammation and ovulation.

Bacterial products such as lipopolysaccharides (or endotoxin) cause systemic inflammation, resulting in a substantial global health burden. The onset, progression, and resolution of the inflammatory response to endotoxin are usually tightly controlled to avoid chronic inflammation. Members of the NF-κB family of transcription factors are key drivers of inflammation that activate sets of genes in response to inflammatory signals. Such responses are typically short-lived and can be suppressed by proteins that act post-translationally, such as the SOCS (suppressor of cytokine signaling) family. Less is known about direct transcriptional regulation of these responses, however. Here, using a combination of in vitro approaches and in vivo animal models, we show that endotoxin treatment induced expression of the well-characterized transcriptional repressor Krüppel-like factor 3 (KLF3), which, in turn, directly repressed the expression of the NF-κB family member RELA/p65. We also observed that KLF3-deficient mice were hypersensitive to endotoxin and exhibited elevated levels of circulating Ly6C+ monocytes and macrophage-derived inflammatory cytokines. These findings reveal that KLF3 is a fundamental suppressor that operates as a feedback inhibitor of RELA/p65 and may be important in facilitating the resolution of inflammation.

(Virginia Institute of Marine Science) New study indicates the increase in rainfall forecast by global climate models is likely to hasten the release of carbon dioxide from tropical soils, further intensifying global warming by adding to human emissions of this greenhouse gas into Earth's atmosphere.

"It felt like prison." Those are the exact words of Jermaine who returned to the island yesterday after he was stranded on a cruise ship for 56 days in South Hampton, United Kingdom. "Bwoy we are out of prison ... it was rough mentally. They...

Insulin-like growth factors (IGFs), specifically IGF1 and IGF2, promote glucose metabolism, with their availability regulated by IGF-binding proteins (IGFBPs). We hypothesized that IGF1 and IGF2 levels, or their bioavailability, are reduced during type 1 diabetes development. Total serum IGF1, IGF2, and IGFBP1–7 levels were measured in an age-matched, cross-sectional cohort at varying stages of progression to type 1 diabetes. IGF1 and IGF2 levels were significantly lower in autoantibody (AAb)⁺ compared with AAb^– relatives of subjects with type 1 diabetes. Most high-affinity IGFBPs were unchanged in individuals with pre–type 1 diabetes, suggesting that total IGF levels may reflect bioactivity. We also measured serum IGFs from a cohort of fasted subjects with type 1 diabetes. IGF1 levels significantly decreased with disease duration, in parallel with declining β-cell function. Additionally, plasma IGF levels were assessed in an AAb⁺ cohort monthly for a year. IGF1 and IGF2 showed longitudinal stability in single AAb⁺ subjects, but IGF1 levels decreased over time in subjects with multiple AAb and those who progressed to type 1 diabetes, particularly postdiagnosis. In sum, IGFs are dysregulated both before and after the clinical diagnosis of type 1 diabetes and may serve as novel biomarkers to improve disease prediction.

Rationale: The treatment of choice for insulinomas and focal lesions in congenital hyperinsulinism (CHI) is surgery. However, intra-operative detection can be challenging. This could be overcome with intra-operative fluorescence imaging, which provides real-time lesion detection with a high spatial resolution. Here, a novel method for targeted near-infrared (NIR) fluorescence imaging of glucagon-like peptide 1 receptor (GLP-1R) positive lesions, using the GLP-1 agonist exendin-4, labeled with IRDye800CW, was examined in vitro and in vivo. Methods: A competitive binding assay was performed using Chinese hamster lung (CHL) cells transfected with the GLP-1R. Tracer biodistribution was determined in BALB/c nude mice bearing subcutaneous CHL-GLP-1R xenografts. In vivo NIR fluorescence imaging of CHL-GLP-1R xenografts was performed. Localization of the tracer in the pancreatic islets of BALB/c nude mice was examined using fluorescence microscopy. Laparoscopic imaging was performed to detect the fluorescent signal of the tracer in the pancreas of mini pigs. Results: Exendin-4-IRDye800CW binds the GLP-1R with an IC50 value of 3.96 nM. The tracer accumulates in CHL-GLP-1R xenografts. Subcutaneous CHL-GLP-1R xenografts were visualized using in vivo NIR fluorescence imaging. The tracer accumulates specifically in the pancreatic islets of mice and a clear fluorescent signal was detected in the pancreas of mini pigs. Conclusion: These date provide the first in vivo evidence of the feasibility of targeted fluorescence imaging of GLP-1R positive lesions. Intra-operative lesion delineation using exendin-4-IRDye800CW could benefit open as well as laparoscopic surgical procedures for removal of insulinomas and focal lesions in CHI.

Treatment of hyperinsulinemic hypoglycemia is challenging. Surgical treatment of insulinomas and focal lesions in congenital hyperinsulinism (CHI) is invasive and carries major risks of morbidity. Medication to treat nesidioblastosis and diffuse CHI has varying efficacy and causes significant side effects. Here, we describe a novel method for therapy of hyperinsulinemic hyperglycemia, highly selectively killing beta cells by targeted photodynamic therapy (tPDT) with exendin-4-IRDye700DX, targeting the glucagon-like peptide 1 receptor (GLP-1R). A competitive binding assay was performed using Chinese hamster lung (CHL) cells transfected with the GLP-1R. The efficacy and specificity of tPDT with exendin-4-IRDye700DX was examined in vitro in cells with different levels of GLP-1R expression. Tracer biodistribution was determined in BALB/c nude mice bearing subcutaneous CHL-GLP-1R xenografts. Induction of cellular damage and the effect on tumor growth were analyzed to determine treatment efficacy. Exendin-4-IRDye700DX has a high affinity for the GLP-1R with an IC50 value of 6.3 nM. TPDT caused significant specific phototoxicity in GLP-1R positive cells (2.3 ± 0.8 % and 2.7 ± 0.3 % remaining cell viability in CHL-GLP-1R and INS-1 cells resp.). The tracer accumulates dose-dependently in GLP-1R positive tumors. In vivo tPDT induces cellular damage in tumors, shown by strong expression of cleaved-caspase-3 and leads to a prolonged median survival of the mice (36.5 vs. 22.5 days resp. p<0.05). These data show in vitro as well as in vivo evidence for the potency of tPDT using exendin-4-IRDye700DX. This could in the future provide a new, minimally invasive and highly specific treatment method for hyperinsulinemic hypoglycemia.

Slow internet is causing headaches during a busy time at the Tax Office.

2 March 2020

In this week's UK Tech Weekly Podcast host Matt Egan is joined by PC Advisor staff writer Chris Minasians chats about Facebook's new like buttons, the team has contracted smartphone fever from the Mobile World Conference in Barcelona and finally, acting editor of Macworld UK David Price, discusses Donald Trump boycotting Apple.  

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Henry Burrell is the master of ceremonies this week, dropping beats on the hottest tech topics. First up, producer Chris joins to chat about the latest Android OS: Nougat. Then staff writer at Techworld.com Scott Carey jumps in to chat about the Deliveroo strikes this week and what this means for sharing economy companies like Uber and Airbnb in general (15:30). Finally, staff writer at Tech Advisor Lewis Painter has some Playstation console rumours to discuss (27:00).  

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Invitation Only Research Event

Event participants

Kirsty Brimelow QC, Barrister, Doughty Street Chambers
Miles Jackson, Associate Professor of Law, University of Oxford
Anton Korynevych, Representative of the President of Ukraine for Crimea
Oleksandra Matviychuk, Head of the Board, Centre for Civil Liberties
Taras Tsymbrivksyy, Head, USAID Human Rights in Action Program; Ukrainian Helsinki Human Rights Union

Angiopoietin-like protein 3 (ANGPTL3) inhibits lipid clearance and is a promising target for managing cardiovascular disease. Here we investigated the effects of a high-sugar (high-fructose) diet on circulating ANGPTL3 concentrations in rhesus macaques. Plasma ANGPTL3 concentrations increased ~30% to 40% after 1 and 3 months of a high-fructose diet (both P < 0.001 vs. baseline). During fructose-induced metabolic dysregulation, plasma ANGPTL3 concentrations were positively correlated with circulating indices of insulin resistance [assessed with fasting insulin and the homeostatic model assessment of insulin resistance (HOMA-IR)], hypertriglyceridemia, adiposity (assessed as leptin), and systemic inflammation [C-reactive peptide (CRP)] and negatively correlated with plasma levels of the insulin-sensitizing hormone adropin. Multiple regression analyses identified a strong association between circulating APOC3 and ANGPTL3 concentrations. Higher baseline plasma levels of both ANGPTL3 and APOC3 were associated with an increased risk for fructose-induced insulin resistance. Fish oil previously shown to prevent insulin resistance and hypertriglyceridemia in this model prevented increases of ANGPTL3 without affecting systemic inflammation (increased plasma CRP and interleukin-6 concentrations). ANGPTL3 RNAi lowered plasma concentrations of ANGPTL3, triglycerides (TGs), VLDL-C, APOC3, and APOE. These decreases were consistent with a reduced risk of atherosclerosis. In summary, dietary sugar-induced increases of circulating ANGPTL3 concentrations after metabolic dysregulation correlated positively with leptin levels, HOMA-IR, and dyslipidemia. Targeting ANGPTL3 expression with RNAi inhibited dyslipidemia by lowering plasma TGs, VLDL-C, APOC3, and APOE levels in rhesus macaques.

Bile acids (BAs) facilitate intestinal absorption of lipid-soluble nutrients and modulate various metabolic pathways through the farnesoid X receptor (FXR) and Takeda G-protein-coupled receptor 5. These receptors are targets for therapy in cholestatic and metabolic diseases. However, dissimilarities in BA metabolism between humans and mice complicate translation of preclinical data. Cytochrome P450 family 2 subfamily c polypeptide 70 (CYP2C70) was recently proposed to catalyze the formation of rodent-specific muricholic acids (MCAs). With CRISPR/Cas9-mediated somatic genome editing, we generated an acute hepatic Cyp2c70 knockout mouse model (Cyp2c70^ako) to clarify the role of CYP2C70 in BA metabolism in vivo and evaluate whether its activity modulates effects of pharmacologic FXR activation on cholesterol homeostasis. In Cyp2c70^ako mice, chenodeoxycholic acid (CDCA) increased at the expense of βMCA, resulting in a more hydrophobic human-like BA pool. Tracer studies demonstrated that, in vivo, CYP2C70 catalyzes the formation of βMCA primarily by sequential 6β-hydroxylation and C7-epimerization of CDCA, generating αMCA as an intermediate metabolite. Physiologically, the humanized BA composition in Cyp2c70^ako mice blunted the stimulation of fecal cholesterol disposal in response to FXR activation compared with WT mice, predominantly due to reduced stimulation of transintestinal cholesterol excretion. Thus, deletion of hepatic Cyp2c70 in adult mice translates into a human-like BA pool composition and impacts the response to pharmacologic FXR activation. This Cyp2c70^ako mouse model may be a useful tool for future studies of BA signaling and metabolism that informs human disease development and treatment.

To ensure fetal lipid supply, maternal blood triglyceride (TG) concentrations are robustly elevated during pregnancy. Interestingly, a lower increase in maternal blood TG concentrations has been observed in some obese mothers. We have shown that high-fat (HF) feeding during pregnancy significantly reduces maternal blood TG levels. Therefore, we performed this study to investigate if and how obesity alters maternal blood TG levels. Maternal obesity was established by prepregnant HF feeding (ppHF), which avoided the dietary effect during pregnancy. We found that maternal blood TG concentrations in ppHF dams were not only remarkably lower than control dams, but the TG peak occurred earlier during gestation. Hepatic TG production and intestinal TG absorption were unchanged in ppHF dams, but systemic lipoprotein lipase (LPL) activity was increased, suggesting that increased blood TG clearance contributes to the decreased blood TG concentrations in ppHF dams. Although significantly higher levels of UCP1 protein were observed in iBAT of ppHF dams, Ucp1 gene deletion did not restore blood TG concentrations in ppHF dams. Expression of the angiopoietin-like protein 4 (ANGPTL4), a potent endogenous LPL inhibitor, was significantly increased during pregnancy. However, the pregnancy-induced elevation of blood TG was almost abolished in Angptl4^-/- dams. Compared with control dams, Angptl4 mRNA levels were significantly lower in iBAT, gWAT and livers of ppHF dams. Importantly, ectopic overexpression of ANGPTL4 restored maternal blood TG concentrations in ppHF dams. Together, these results indicate that ANGPTL4 plays a vital role in increasing maternal blood TG concentrations during pregnancy. Obesity impairs the rise of maternal blood TG concentrations by reducing ANGPTL4 expression in mice.

Invitation Only Research Event

Event participants

Kirsty Brimelow QC, Barrister, Doughty Street Chambers
Miles Jackson, Associate Professor of Law, University of Oxford
Anton Korynevych, Representative of the President of Ukraine for Crimea
Oleksandra Matviychuk, Head of the Board, Centre for Civil Liberties
Taras Tsymbrivksyy, Head, USAID Human Rights in Action Program; Ukrainian Helsinki Human Rights Union

Do you want to become a certified Yoga Teacher? Just join our 200 Hour Yoga Teacher Training in Rishikesh and become a certified Yoga Teacher.

Lila Iké’s latest single, ‘ I Spy’, is flirty and playful with a sultry tone. It’s the kind of song record labels in decades past would compulsorily conflate with bubblegum pop princess images of lollipops, pigtails, ribbons, and skirts with...

When the Braves re-signed Nick Markakis in January, they began leaning toward putting Ender Inciarte in the leadoff spot and moving Ronald Acuna Jr. to the cleanup role. But manager Brian Snitker said Acuna may still get his wish to stay at the top of the lineup.

The Orioles' restocked farm system might inject some excitement into the club's retooled roster.

With improved survival and and ageing population, the number of people living with coronary heart disease in the UK has increased to an estimated 2.3 million. There is increasing evidence that cardiac rehabilitation benefits these patients, and as such it has been included in international clinical guidelines. ​In this podcast, we're joined by...

Doctors considering strike action may worry about the effect on patients. David Metcalfe and colleagues examine the evidence and find that “patients do not come to serious harm during industrial action provided that provisions are made for emergency care.” Read the full analysis: http://www.bmj.com/content/351/bmj.h6231