2 April 2020

29 April 2020

Campylobacter jejuni is a major cause of food-borne gastroenteritis. Proteomics by label-based two-dimensional liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) identified proteins associated with growth in 0.1% sodium deoxycholate (DOC, a component of gut bile salts), and system-wide validation was performed by data-independent acquisition (DIA-SWATH-MS). LC-MS/MS quantified 1326 proteins (~82% of the predicted C. jejuni proteome), of which 1104 were validated in additional biological replicates by DIA-SWATH-MS. DOC resulted in a profound proteome shift with 512 proteins showing significantly altered abundance. Induced proteins were associated with flagellar motility and antibiotic resistance; and these correlated with increased DOC motility and resistance to polymyxin B and ciprofloxacin. DOC also increased human Caco-2 cell adherence and invasion. Abundances of proteins involved in nutrient transport were altered by DOC and aligned with intracellular changes to their respective carbon sources. DOC increased intracellular levels of sulfur-containing amino acids (cysteine and methionine) and the dipeptide cystine (Cys-Cys), which also correlated with reduced resistance to oxidative stress. A DOC induced transport protein was Cj0025c, which has sequence similarity to bacterial Cys-Cys transporters. Deletion of cj0025c (cj0025c) resulted in proteome changes consistent with sulfur starvation, as well as attenuated invasion, reduced motility, atypical morphology, increased antimicrobial susceptibility and poor biofilm formation. Targeted metabolomics showed cj0025c was capable of utilizing known C. jejuni amino and organic acid substrates commensurate with wild-type. Medium Cys-Cys levels however, were maintained in cj0025c relative to wild-type. A toxic Cys-Cys mimic (selenocystine) inhibited wild-type growth, but not cj0025c. Provision of an alternate sulfur source (2 mM thiosulfate) restored cj0025c motility. Our data confirm that Cj0025c is a Cys-Cys transporter that we have named TcyP consistent with the nomenclature of homologous proteins in other species.

Invitation Only Research Event

Event participants

Archbishop Yevstraty (Zoria) of Chernihiv, Deputy Head of Department for External Church Relations, Ukrainian Orthodox Church (Orthodox Church of Ukraine)

X-linked adrenoleukodystrophy (X-ALD) is an inherited disorder caused by deleterious mutations in the ABCD1 gene. The ABCD1 protein transports very long-chain FAs (VLCFAs) from the cytosol into the peroxisome where the VLCFAs are degraded through β-oxidation. ABCD1 dysfunction leads to VLCFA accumulation in individuals with X-ALD. FAs are activated by esterification to CoA before metabolic utilization. However, the intracellular pools and metabolic profiles of individual acyl-CoA esters have not been fully analyzed. In this study, we profiled the acyl-CoA species in fibroblasts from X-ALD patients and in ABCD1-deficient HeLa cells. We found that hexacosenoyl (26:1)-CoA, but not hexacosanoyl (26:0)-CoA, was the most abundantly concentrated among the VLCFA-CoA species in these cells. We also show that 26:1-CoA is mainly synthesized from oleoyl-CoA, and the metabolic turnover rate of 26:1-CoA was almost identical to that of oleoyl-CoA in both WT and ABCD1-deficient HeLa cells. The findings of our study provide precise quantitative and metabolic information of each acyl-CoA species in living cells. Our results suggest that VLCFA is endogenously synthesized as VLCFA-CoA through a FA elongation pathway and is then efficiently converted to other metabolites, such as phospholipids, in the absence of ABCD1.

Membrane-bound proteins have been proposed to mediate the transport of long-chain FA (LCFA) transport through the plasma membrane (PM). These proposals are based largely on reports that PM transport of LCFAs can be blocked by a number of enzymes and purported inhibitors of LCFA transport. Here, using the ratiometric pH indicator (2',7'-bis-(2-carboxyethyl)-5-(and-6-)-carboxyfluorescein and acrylodated intestinal FA-binding protein-based dual fluorescence assays, we investigated the effects of nine inhibitors of the putative FA transporter protein CD36 on the binding and transmembrane movement of LCFAs. We particularly focused on sulfosuccinimidyl oleate (SSO), reported to be a competitive inhibitor of CD36-mediated LCFA transport. Using these assays in adipocytes and inhibitor-treated protein-free lipid vesicles, we demonstrate that rapid LCFA transport across model and biological membranes remains unchanged in the presence of these purported inhibitors. We have previously shown in live cells that CD36 does not accelerate the transport of unesterified LCFAs across the PM. Our present experiments indicated disruption of LCFA metabolism inside the cell within minutes upon treatment with many of the "inhibitors" previously assumed to inhibit LCFA transport across the PM. Furthermore, using confocal microscopy and a specific anti-SSO antibody, we found that numerous intracellular and PM-bound proteins are SSO-modified in addition to CD36. Our results support the hypothesis that LCFAs diffuse rapidly across biological membranes and do not require an active protein transporter for their transmembrane movement.

Severity: Medium Description: PROC IMPORT contains a stack-corruption vulnerability. Potential Impact: Under certain circumstances (with use of the DBM

Severity: Medium Description: PROC EXPORT contains a stack-corruption vulnerability. Potential Impact: Under certain circumstances, the use of PROC EXP

Using the NCR form of a surrogate pair as an input string to the UNICODE function does not convert the string to the appropriate display character.

You can create create a Databricks table by using PROC SQL, but you cannot insert data into the table. PROC APPEND cannot create a new table or append data to an existing table.

If your SAS Visual Analytics report contains many sections and objects, you might encounter performance problems when you are editing the report.   A hot fix is planned for this issue.

When you attempt to save a report distribution in SAS Visual Analytics Designer, you might see the error shown in the following display:  imgalt="" src="{fusion_65868_1_distributionerror.png}" />

Sulfur is essential for biological processes such as amino acid biogenesis, iron–sulfur cluster formation, and redox homeostasis. To acquire sulfur-containing compounds from the environment, bacteria have evolved high-affinity uptake systems, predominant among which is the ABC transporter family. Theses membrane-embedded enzymes use the energy of ATP hydrolysis for transmembrane transport of a wide range of biomolecules against concentration gradients. Three distinct bacterial ABC import systems of sulfur-containing compounds have been identified, but the molecular details of their transport mechanism remain poorly characterized. Here we provide results from a biochemical analysis of the purified Escherichia coli YecSC-FliY cysteine/cystine import system. We found that the substrate-binding protein FliY binds l-cystine, l-cysteine, and d-cysteine with micromolar affinities. However, binding of the l- and d-enantiomers induced different conformational changes of FliY, where the l- enantiomer–substrate-binding protein complex interacted more efficiently with the YecSC transporter. YecSC had low basal ATPase activity that was moderately stimulated by apo FliY, more strongly by d-cysteine–bound FliY, and maximally by l-cysteine– or l-cystine–bound FliY. However, at high FliY concentrations, YecSC reached maximal ATPase rates independent of the presence or nature of the substrate. These results suggest that FliY exists in a conformational equilibrium between an open, unliganded form that does not bind to the YecSC transporter and closed, unliganded and closed, liganded forms that bind this transporter with variable affinities but equally stimulate its ATPase activity. These findings differ from previous observations for similar ABC transporters, highlighting the extent of mechanistic diversity in this large protein family.

Numerous zinc ectoenzymes are metalated by zinc and activated in the compartments of the early secretory pathway before reaching their destination. Zn transporter (ZNT) proteins located in these compartments are essential for ectoenzyme activation. We have previously reported that ZNT proteins, specifically ZNT5–ZNT6 heterodimers and ZNT7 homodimers, play critical roles in the activation of zinc ectoenzymes, such as alkaline phosphatases (ALPs), by mobilizing cytosolic zinc into these compartments. However, this process remains incompletely understood. Here, using genetically-engineered chicken DT40 cells, we first determined that Zrt/Irt-like protein (ZIP) transporters that are localized to the compartments of the early secretory pathway play only a minor role in the ALP activation process. These transporters included ZIP7, ZIP9, and ZIP13, performing pivotal functions in maintaining cellular homeostasis by effluxing zinc out of the compartments. Next, using purified ALP proteins, we showed that zinc metalation on ALP produced in DT40 cells lacking ZNT5–ZNT6 heterodimers and ZNT7 homodimers is impaired. Finally, by genetically disrupting both ZNT5 and ZNT7 in human HAP1 cells, we directly demonstrated that the tissue-nonspecific ALP-activating functions of both ZNT complexes are conserved in human cells. Furthermore, using mutant HAP1 cells, we uncovered a previously-unrecognized and unique spatial regulation of ZNT5–ZNT6 heterodimer formation, wherein ZNT5 recruits ZNT6 to the Golgi apparatus to form the heterodimeric complex. These findings fill in major gaps in our understanding of the molecular mechanisms underlying zinc ectoenzyme activation in the compartments of the early secretory pathway.

Pathogenic bacteria of the genera Mycobacterium and Corynebacterium cause severe human diseases such as tuberculosis (Mycobacterium tuberculosis) and diphtheria (Corynebacterium diphtheriae). The cells of these species are surrounded by protective cell walls rich in long-chain mycolic acids. These fatty acids are conjugated to the disaccharide trehalose on the cytoplasmic side of the bacterial cell membrane. They are then transported across the membrane to the periplasm where they act as donors for other reactions. We have previously shown that transient acetylation of the glycolipid trehalose monohydroxycorynomycolate (hTMCM) enables its efficient transport to the periplasm in Corynebacterium glutamicum and that acetylation is mediated by the membrane protein TmaT. Here, we show that a putative methyltransferase, encoded at the same genetic locus as TmaT, is also required for optimal hTMCM transport. Deletion of the C. glutamicum gene NCgl2764 (Rv0224c in M. tuberculosis) abolished acetyltrehalose monocorynomycolate (AcTMCM) synthesis, leading to accumulation of hTMCM in the inner membrane and delaying its conversion to trehalose dihydroxycorynomycolate (h2TDCM). Complementation with NCgl2764 normalized turnover of hTMCM to h2TDCM. In contrast, complementation with NCgl2764 derivatives mutated at residues essential for methyltransferase activity failed to rectify the defect, suggesting that NCgl2764/Rv0224c encodes a methyltransferase, designated here as MtrP. Comprehensive analyses of the individual mtrP and tmaT mutants and of a double mutant revealed strikingly similar changes across several lipid classes compared with WT bacteria. These findings indicate that both MtrP and TmaT have nonredundant roles in regulating AcTMCM synthesis, revealing additional complexity in the regulation of trehalose mycolate transport in the Corynebacterineae.

Infants born to mothers with obesity have a greater risk for childhood obesity and metabolic diseases; however, the underlying biological mechanisms remain poorly understood. We used a Japanese macaque model to investigate whether maternal obesity combined with a western-style diet (WSD) impairs offspring muscle insulin action. Adult females were fed a control or WSD prior to and during pregnancy through lactation, and offspring subsequently weaned to a control or WSD. Muscle glucose uptake and signaling were measured ex vivo in fetal (n=5-8/group) and juvenile offspring (n=8/group). In vivo signaling was evaluated after an insulin bolus just prior to weaning (n=4-5/group). Maternal WSD reduced insulin-stimulated glucose uptake and impaired insulin signaling at the level of Akt phosphorylation in fetal muscle. In juvenile offspring, insulin-stimulated glucose uptake was similarly reduced by both maternal and post-weaning WSD and corresponded to modest reductions in insulin-stimulated Akt phosphorylation relative to controls. We conclude that maternal WSD leads to a persistent decrease in offspring muscle insulin-stimulated glucose uptake even in the absence of increased offspring adiposity or markers of systemic insulin resistance. Switching offspring to a healthy diet did not reverse the effects of maternal WSD on muscle insulin action suggesting earlier interventions may be warranted.

Multidrug resistance (MDR) in cancer arises from cross-resistance to structurally- and functionally-divergent chemotherapeutic drugs. In particular, MDR is characterized by increased expression and activity of ATP-binding cassette (ABC) superfamily transporters. Sphingolipids are substrates of ABC proteins in cell signaling, membrane biosynthesis, and inflammation, for example, and their products can favor cancer progression. Glucosylceramide (GlcCer) is a ubiquitous glycosphingolipid (GSL) generated by glucosylceramide synthase, a key regulatory enzyme encoded by the UDP-glucose ceramide glucosyltransferase (UGCG) gene. Stressed cells increase de novo biosynthesis of ceramides, which return to sub-toxic levels after UGCG mediates incorporation into GlcCer. Given that cancer cells seem to mobilize UGCG and have increased GSL content for ceramide clearance, which ultimately contributes to chemotherapy failure, here we investigated how inhibition of GSL biosynthesis affects the MDR phenotype of chronic myeloid leukemias. We found that MDR is associated with higher UGCG expression and with a complex GSL profile. UGCG inhibition with the ceramide analog d-threo-1-(3,4,-ethylenedioxy)phenyl-2-palmitoylamino-3-pyrrolidino-1-propanol (EtDO-P4) greatly reduced GSL and monosialotetrahexosylganglioside levels, and co-treatment with standard chemotherapeutics sensitized cells to mitochondrial membrane potential loss and apoptosis. ABC subfamily B member 1 (ABCB1) expression was reduced, and ABCC-mediated efflux activity was modulated by competition with nonglycosylated ceramides. Consistently, inhibition of ABCC-mediated transport reduced the efflux of exogenous C6-ceramide. Overall, UGCG inhibition impaired the malignant glycophenotype of MDR leukemias, which typically overcomes drug resistance through distinct mechanisms. This work sheds light on the involvement of GSL in chemotherapy failure, and its findings suggest that targeted GSL modulation could help manage MDR leukemias.

Mariam Alatrach
Apr 1, 2020; 69:681-688
Pathophysiology

Invitation Only Research Event

Invitation Only Research Event

A gofundme account has been launched with the hope of keeping animals feed and to preserve endangered wildlife at the Hope Zoo in St Andrew. Curator, Joey Brown, organiser of the fundraiser, indicated that as a non-profit organisation,...

The Earthquake Unit at the University of the West Indies is reporting that a minor quake hit a section of Portland this morning. The unit says the 2.8 quake occurred about 9:13 and had an epicentre near Spring Garden. It had a focal depth of five...

Jamaica’s senior men’s ice hockey team’s historic championship win at last year’s Amerigol LATAM Cup is memorialised in a Canadian sports yearbook published earlier this year. The team copped the championship in its first international outing...

Invitation Only Research Event

Event participants

Archbishop Yevstraty (Zoria) of Chernihiv, Deputy Head of Department for External Church Relations, Ukrainian Orthodox Church (Orthodox Church of Ukraine)

Research Event

Event participants

Dr Fatima Denton, Director, Special Initiatives Division, UN Economic Commission for Africa
Dr Chukwumerije Okereke, Associate Professor, University of Reading
Douglas Brew, Director External Affairs, Communications and Sustainable Living for Africa, Unilever
Chair: Bob Dewar, Associate Fellow, Africa Programme, Chatham House

Industries across the world face uncertainty, as no one entity can absolutely declare when or if economies will revert to normal in the wake of COVID-19. The local entertainment industry suffers the same uncertainty – and to address it, the Jamaica...

The current orthodoxy is that home is the best and preferred place of death for most people, but in this podcast, Kristian Pollock a sociologist from Nottingham University questions these assumptions and calls for greater attention to improving the experience of dying in hospital and elsewhere. Read the full...

All doctors, irrespective of their specialty or the setting in which they work, will care for patients who die. Around half of all deaths occur in hospitals. Evidence suggests that the quality of communication around this process is poorer in hospitals than in other settings, according to responses from relatives who have experienced bereavement....

We at The BMJ care about food, and if our listener stats are to be believed, so do you. In this podcast we’re looking at quality as an important driver of a good diet. At our recent food conference - Food For Thought - hosted in Zurich by Swiss Re we brought researchers in many fields of nutritional science together. We asked people with...

Last week we heard about how evidence in policy making is imperilled - but today we’re hearing about a plan to make evidence about health central to all aspects of government. Laura Webber, director of public health modelling at the UK Health Forum, Susie Morrow, chair of the Wandsworth Living Streets Group and Brian Ferguson, chief economist at...

Brits have a reputation as Europe’s boozers - and for good reason, with alcohol consumption higher than much of the rest of the continent. That reputation is extended to our young people too - but is it still deserved? Joanna Inchley, senior research fellow at the University of St Andrews, explains new research on decreasing drinking -...

You’ll have read in a clinical trial “Most patients had an acceptable adverse-event profile.” Or that a drug “has a manageable and mostly reversible safety profile.” And that “the tolerability was good overall.” In this podcast, Bishal Gyawali (@oncology_bg) joins us to describe what events those terms were actually describing in cancer drug...

Helen talks about new research on prevention of recurrent VTE - and Carl things the evidence goes further, and we can extend prophylaxis for a year. 13.00 - CRP testing for antibiotic prescription in COPD exacerbations, should we start doing it in primary care settings - and what will that mean. We also hear from Chris Butler, one of the...

The NHS Practitioner Health Programme - once only for doctors in London, now it’s being rolled out across the NHS to provide the largest, publicly funded, comprehensive physician health service, in the world. However, while helping the individual is essential, systemic change needs to be made to support doctors in our healthcare system. Clare...

Michael West is professor of organisational psychology, at Lancaster University, and co-author of a new GMC report into the wellbeing of NHS staff. The review he led together with the clinical psychiatrist Denise Coia, focused on primary interventions related to workplace factors and the systems that doctors work in, rather than secondary...

How can we help frontline clinicians? Sometimes medics may feel uneasy or even guilty and that they could be doing more. That was what a junior doctor in Abergavenny in Wales felt and she did something about it. In this podcast, we speak to Josie Cheetham about how she started her initiative to provide support boxes in hospitals for her...

Tatsuya Hayashi
Aug 1, 1998; 47:1369-1373
Rapid Publications

PORT OF SPAIN, Trinidad, CMC – The Trinidad and Tobago government Saturday said it had uncovered a plot by persons to defraud the state and that a new mechanism would be put in place Monday in providing rental assistance to people impacted by...

THE EDITOR, Madam: THE JAMAICAN economy has been underperforming for the last 40 years, during which economic growth averaged approximately one per cent per annum. One of the main reasons for this poor performance is the non-competitive nature of...

In 2020, when information is literally glued to our fingertips, technological innovations fill the stratosphere, the economy is reeling. Under the catastrophic effects of the coronavirus pandemic, one has no choice but to be creative – be creative...

25 November 2014

This paper accompanies a series of assessments on China, France, Japan, the Netherlands, the UK, the US and Vietnam, providing details on how the estimates of the level of illegality of imports of wood-based products into those countries were derived.

Research Event

Event participants

HE Dr Kayode Fayemi, Minister of Solid Minerals Development, Nigeria
HE Aminu Bello Masari, Governor of Katsina State, Nigeria
Chair: Chi Onwurah MP, Vice Chair, All Party Parliamentary Group on Nigeria

GEORGETOWN, Guyana (AP): Four months after Guyana became one of the world’s newest crude oil exporters, the South American country says it is already reaping the rewards with about $60 million in payments. The money is linked to Guyana’s...

Members Event

Event participants

Rory Stewart, Member of Parliament for Penrith and The Border (2010-19); Secretary of State for International Development (2019)

Chair: Daniel Bruce, Chief Executive, Transparency International UK

Research Event