Imperial College London

DrVictoriaSalem

Faculty of EngineeringDepartment of Bioengineering

Clinical Senior Lecturer in Diabetes and Endocrinology
 
 
 
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v.salem

 
 
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Commonwealth BuildingHammersmith Campus

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Summary

 

Publications

Publication Type
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74 results found

Yaganoglu S, Kalyviotis K, Vagena-Pantoula C, Jülich D, Gaub BM, Welling M, Lopes T, Lachowski D, Tang SS, Del Rio Hernandez A, Salem V, Müller DJ, Holley SA, Vermot J, Shi J, Helassa N, Török K, Pantazis Pet al., 2023, Author Correction: Highly specific and non-invasive imaging of Piezo1-dependent activity across scales using GenEPi., Nat Commun, Vol: 14

Journal article

Pantazis P, Pantazis P, Yaganoglu S, Konstantinos K, Vagena-Pantoula C, Julich D, Gaub B, Welling M, Lopes T, Lachowski D, Tang SS, Del Rio Hernandez A, Salem V, Muller D, Holley S, Vermot J, Shi J, Helassa N, Török Ket al., 2023, Highly specific and non-invasive imaging of Piezo1-dependent activity across scales using GenEPi, Nature Communications, Vol: 14, Pages: 1-16, ISSN: 2041-1723

Mechanosensing is a ubiquitous process to translate external mechanical stimuliinto biological responses. Piezo1 ion channels are directly gated by mechanical forces and playan essential role in cellular mechanotransduction. However, readouts of Piezo1 activity aremainly examined by invasive or indirect techniques, such as electrophysiological analyses andcytosolic calcium imaging. Here, we introduce GenEPi, a genetically-encoded fluorescentreporter for non-invasive optical monitoring of Piezo1-dependent activity. We demonstrate thatGenEPi has high spatiotemporal resolution for Piezo1-dependent stimuli from the single-celllevel to that of the entire organism. GenEPi reveals transient, local mechanical stimuli in theplasma membrane of single cells, resolves repetitive contraction-triggered stimulation ofbeating cardiomyocytes within microtissues, and allows for robust and reliable monitoring of Piezo1-dependent activity in vivo. GenEPi will enable non-invasive optical monitoring ofPiezo1 activity in mechanochemical feedback loops during development, homeostaticregulation, and disease.

Journal article

Alhakami A, Salem V, Alateeq D, Nikčević AV, Marci T, Palmieri S, Spada MM, Mansueto Get al., 2023, The Arab COVID-19 Anxiety Syndrome Scale (C-19ASS): COVID-19 anxiety syndrome and psychological symptoms in the Saudi Arabian population., Clin Psychol Psychother

INTRODUCTION: The COVID-19 Anxiety Syndrome Scale (C-19ASS) is a reliable scale assessing dysfunctional coping strategies activated in response to COVID-19 fear and threat. The present study aimed to provide a validation of the Arabic version of the C-19ASS and to explore the association between the C-19ASS and psychological symptoms syndrome. METHOD: In Study 1, a community sample of 404 participants completed the Arabic version of the C-19ASS and results were subjected to an exploratory factor analysis. In Study 2, a community sample of 903 participants completed the Arabic version of the C-19ASS and a series of measures assessing depressed mood and anhedonia, generalized anxiety and health anxiety. Internal consistency, construct validity and incremental validity were assessed. Associations between C-19ASS and psychological symptoms were assessed. RESULTS: Factor analysis identified a two-factor solution (i.e., C-19ASS-Perseveration and C-19ASS-Avoidance), and confirmatory factor analysis suggested a two-factor model best fits the data. The Arabic version of the C-19ASS showed good internal consistency, good construct and incremental validity. COVID-19 anxiety syndrome was associated with more severe anxiety symptoms, depressive symptoms and health anxiety. Females had higher levels of COVID-19 anxiety syndrome than males. Participants diagnosed with COVID-19, and those who had experienced loss as a consequence of COVID-19, had higher levels of COVID-19 anxiety syndrome (Perseveration). CONCLUSIONS: The Arabic version of the C-19ASS appears to be a reliable and valid measure of the COVID-19 anxiety syndrome. The COVID-19 anxiety syndrome could be a suitable therapeutic target to improve psychological recovery during the COVID-19 pandemic among Arabs.

Journal article

Tomas Catala A, Bitsi S, Manchanda Y, El Eid L, Oqua A, Mohamed N, Hansen B, Suba K, Rutter G, Jones B, Salem Vet al., 2023, Divergent acute versus prolonged pharmacological GLP-1R responses in adult beta cell-specific β-arrestin 2 knockout mice, Science Advances, Vol: 9, Pages: 1-23, ISSN: 2375-2548

The glucagon-like peptide-1 receptor (GLP-1R) is a major type 2 diabetes therapeutic target. Stimulated GLP-1Rs are rapidly desensitized by β-arrestins, scaffolding proteins that not only terminate G protein interactions but also act as independent signaling mediators. Here, we have assessed in vivo glycemic responses to the pharmacological GLP-1R agonist exendin-4 in adult β cell–specific β-arrestin 2 knockout (KO) mice. KOs displayed a sex-dimorphic phenotype consisting of weaker acute responses that improved 6 hours after agonist injection. Similar effects were observed for semaglutide and tirzepatide but not with biased agonist exendin-phe1. Acute cyclic adenosine 5′-monophosphate increases were impaired, but desensitization reduced in KO islets. The former defect was attributed to enhanced β-arrestin 1 and phosphodiesterase 4 activities, while reduced desensitization co-occurred with impaired GLP-1R recycling and lysosomal targeting, increased trans-Golgi network signaling, and reduced GLP-1R ubiquitination. This study has unveiled fundamental aspects of GLP-1R response regulation with direct application to the rational design of GLP-1R–targeting therapeutics.

Journal article

Salem V, Hirani D, Lloyd C, Regan L, Peters Cet al., 2022, Why are women still leaving academic medicine? A qualitative study within a London Medical School, BMJ Open, Vol: 12, ISSN: 2044-6055

Objectives: To identify factors that influenced women who chose to leave academic medicine.Design and main outcome measures: Independent consultants led a focus group of women in medicine who had left academia after completion of their postgraduate research degree at Imperial College London Faculty of Medicine. Thematic analysis was performed on the transcribed conversations.Participants and setting: Nine women physicians who completed a postgraduate degree (MD or PhD) at a large London Medical School and Academic Health Sciences Centre, Imperial College London, but did not go on to pursue a career in academic medicine.Results: Influences to leave clinical academia were summarised under eight themes—career intentions, supervisor support, institutional human resources support, inclusivity, work–life balance, expectations, mentors and role models, and pregnancy and maternity leave.Conclusion: The women in our focus group reported several factors contributing to their decision to leave clinical academia, which included lack of mentoring tailored to specific needs, low levels of acceptance for flexible working to help meet parental responsibilities and perceived explicit gender biases. We summarise the multiple targeted strategies that Imperial College London has implemented to promote retention of women in academic medicine, although more research needs to be done to ascertain the most effective interventions.

Journal article

Misky A, Shah R, Meeran K, Kingsbury M, Sam A, Salem Vet al., 2022, Understanding concepts of generalism and specialism amongst medical students at a research-intensive London Medical School, BMC Medical Education, Vol: 22, Pages: 1-11, ISSN: 1472-6920

BackgroundMany prominent UK medical organisations have identified a need for more generalist clinicians to address the complex requirements of an aging society. We sought to clarify attitudes towards “Specialists” and “Generalists” amongst medical students and junior doctors at Imperial College School of Medicine.MethodsA survey exploring medical students’ beliefs was followed up by qualitative analysis of focus groups of medical students and Imperial-graduate foundation year doctors.ResultsFirst year medical students associated specialists with academia and higher income, and generalists with ease of training and job availability. Senior (Years 5/6) medical students associated specialists even more firmly with broader influence and academic work, whilst generalists were assigned lower prestige but the same workload as specialists. The medicalstudent focus group discussed concepts of Generalism pertaining only to Primary Care. In contrast, the foundation year doctor focus group revealed that Generalism was now seen to include some hospital care, and the perception that generalists sat lower in a knowledge hierarchy had been challenged.ConclusionPerceptions that Generalism is associated with lower prestige in the medical profession are already present at the very start of medical school and seem to be reinforced during undergraduate training. In early postgraduate clinical practice, the perceived knowledge and prestige hierarchy lessens. These findings can help inform curriculum redesign and the promotion of Generalism as a rewarding career aspiration.

Journal article

Salem V, AlHusseini N, Razack HIA, Naoum A, Sims OT, Alqahtani SAet al., 2022, Prevalence, risk factors, and interventions for obesity in Saudi Arabia: A systematic review, OBESITY REVIEWS, Vol: 23, ISSN: 1467-7881

Journal article

Eng PC, Distaso W, Durreshahwar H, Shaikhali Y, Narendranathan D, Cassin-Scott R, Misra S, Hill NE, Tharakan G, Oliver NS, Tan TM, Izzi-Engbeaya C, Salem Vet al., 2022, The benefit of dexamethasone in patients with COVID-19 infection is preserved in patients with diabetes., Diabetes, Obesity and Metabolism: a journal of pharmacology and therapeutics, Vol: 24, Pages: 1385-1389, ISSN: 1462-8902

Dexamethasone significantly reduces mortality1 and is now standard treatment for patients with COVID-19 who require supplemental oxygen and/or mechanical ventilation. However, supraphysiological doses of glucocorticoids may exacerbate dysglycaemia and precipitate hyperglycaemic complications, particularly in those with or at risk of Type 2 diabetes2. The RECOVERY trial1 reported a low incidence of hyperglycaemic complications (2/1996, 0.1%), although the real-world incidence is likely to be much higher3. Type 2 diabetes itself increases the risk of severe COVID-194, and hyperglycaemia independently predicts poor outcomes5. We investigated the possibility that patients with diabetes may derive less survival benefit from steroid therapy in the setting of severe COVID-19 infection

Journal article

Izzi-Engbeaya C, Salem V, 2021, Commentary: 'Diversity of invited speakers at endocrinology conferences', CLINICAL ENDOCRINOLOGY, ISSN: 0300-0664

Journal article

Kim A, Knudsen JG, Madara JC, Benrick A, Hill TG, Kadir LA, Kellard JA, Mellander L, Miranda C, Lin H, James T, Suba K, Spigelman AF, Wu Y, MacDonald PE, Asterholm IW, Magnussen T, Christensen M, Vilsboll T, Salem V, Knop FK, Rorsman P, Lowell BB, Briant LJBet al., 2021, Arginine-vasopressin mediates counter-regulatory glucagon release and is diminished in type 1 diabetes, eLife, Vol: 10, Pages: 1-29, ISSN: 2050-084X

Insulin-induced hypoglycemia is a major treatment barrier in type-1 diabetes (T1D). Accordingly, it is important that we understand the mechanisms regulating the circulating levels of glucagon. Varying glucose over the range of concentrations that occur physiologically between the fed and fuel-deprived states (8 to 4 mM) has no significant effect on glucagon secretion in the perfused mouse pancreas or in isolated mouse islets (in vitro), and yet associates with dramatic increases in plasma glucagon. The identity of the systemic factor(s) that elevates circulating glucagon remains unknown. Here, we show that arginine-vasopressin (AVP), secreted from the posterior pituitary, stimulates glucagon secretion. Alpha-cells express high levels of the vasopressin 1b receptor (V1bR) gene (Avpr1b). Activation of AVP neurons in vivo increased circulating copeptin (the C-terminal segment of the AVP precursor peptide) and increased blood glucose; effects blocked by pharmacological antagonism of either the glucagon receptor or V1bR. AVP also mediates the stimulatory effects of hypoglycemia produced by exogenous insulin and 2-deoxy-D-glucose on glucagon secretion. We show that the A1/C1 neurons of the medulla oblongata drive AVP neuron activation in response to insulin-induced hypoglycemia. AVP injection increased cytoplasmic Ca2+ in alpha-cells (implanted into the anterior chamber of the eye) and glucagon release. Hypoglycemia also increases circulating levels of AVP/copeptin in humans and this hormone stimulates glucagon secretion from human islets. In patients with T1D, hypoglycemia failed to increase both copeptin and glucagon. These findings suggest that AVP is a physiological systemic regulator of glucagon secretion and that this mechanism becomes impaired in T1D.

Journal article

de Jesus DS, Mak TCS, Wang Y-F, von Ohlen Y, Bai Y, Kane E, Chabosseau P, Chahrour CM, Distaso W, Salem V, Tomas A, Stoffel M, Rutter GA, Latreille Met al., 2021, Dysregulation of the Pdx1/Ovol2/Zeb2 axis in dedifferentiated β-cells triggers the induction of genes associated with epithelial-mesenchymal transition in diabetes, Molecular Metabolism, Vol: 53, ISSN: 2212-8778

OBJECTIVE: β-cell dedifferentiation has been revealed as a pathological mechanism underlying pancreatic dysfunction in diabetes. We previously showed that increased miR-7 levels trigger β-cell dedifferentiation and diabetes. We used β-cell-specific miR-7 overexpressing mice (Tg7) to test the hypothesis that loss of β-cell identity triggered by miR-7 overexpression alters islet gene expression and islet microenvironment in diabetes. METHODS: We performed bulk and single-cell RNA sequencing (RNA-seq) in islets obtained from β-cell-specific miR-7 overexpressing mice (Tg7). We carried out loss- and gain-of-function experiments in MIN6 and EndoC-bH1 cell lines. We analysed previously published mouse and human T2D data sets. RESULTS: Bulk RNA-seq revealed that β-cell dedifferentiation is associated with the induction of genes associated with epithelial-to-mesenchymal transition (EMT) in prediabetic (2-week-old) and diabetic (12-week-old) Tg7 mice. Single-cell RNA-seq (scRNA-seq) indicated that this EMT signature is enriched specifically in β-cells. These molecular changes are associated with a weakening of β-cell: β-cell contacts, increased extracellular matrix (ECM) deposition, and TGFβ-dependent islet fibrosis. We found that the mesenchymal reprogramming of β-cells is explained in part by the downregulation of Pdx1 and its inability to regulate a myriad of epithelial-specific genes expressed in β-cells. Notable among genes transactivated by Pdx1 is Ovol2, which encodes a transcriptional repressor of the EMT transcription factor Zeb2. Following compromised β-cell identity, the reduction in Pdx1 gene expression causes a decrease in Ovol2 protein, triggering mesenchymal reprogramming of β-cells through the induction of Zeb2. We provided evidence that EMT signalling associated with the upregulation of Zeb2 expression is a molecular feature of islets in T2D subjects. CONCLUSIONS: Our study indicates that m

Journal article

Akalestou E, Suba K, Lopez-Noriega L, Georgiadou E, Chabosseau P, Gallie A, Wretlind A, Legido-Quigley C, Leclerc I, Salem V, Rutter GAet al., 2021, Intravital imaging of islet Ca2+ dynamics reveals enhanced beta cell connectivity after bariatric surgery in mice (vol 12, 5165, 2021), Nature Communications, Vol: 12, Pages: 1-1, ISSN: 2041-1723

Journal article

Salem V, McDonagh J, Avis E, Eng PC, Smith S, Murphy KGet al., 2021, Scientific medical conferences can be easily modified to improve female inclusion: a prospective study., The Lancet Diabetes and Endocrinology, Vol: 9, Pages: 556-559, ISSN: 2213-8595

Journal article

Akalestou E, Suba K, Lopez-Noriega L, Georgiadou E, Chabosseau P, Gallie A, Wretlind A, Quigley C, Leclerc I, Salem V, Rutter GAet al., 2021, Intravital imaging of islet Ca2+ dynamics reveals enhanced beta cell connectivity after bariatric surgery in mice, Nature Communications, Vol: 12, Pages: 1-13, ISSN: 2041-1723

Bariatric surgery improves both insulin sensitivity and secretion and can induce diabetes remission. However, the mechanisms and time courses of these changes, particularly the impact on β cell function, are difficult to monitor directly. In this study, we investigated the effect of Vertical Sleeve Gastrectomy (VSG) on β cell function in vivo by imaging Ca2+ dynamics in islets engrafted into the anterior eye chamber. Mirroring its clinical utility, VSG in mice results in significantly improved glucose tolerance, and enhanced insulin secretion. We reveal that these benefits are underpinned by augmented β cell function and coordinated activity across the islet. These effects involve changes in circulating GLP-1 levels which may act both directly and indirectly on the β cell, in the latter case through changes in body weight. Thus, bariatric surgery leads to time-dependent increases in β cell function and intra-islet connectivity which are likely to contribute to diabetes remission.

Journal article

Israni A, Jones B, Salem V, Bravis Vet al., 2021, IMPACT OF PCSK9 INHIBITORS ON HYPERCHOLESTEROLAEMIC PATIENTS AT A TERTIARY CENTRE LIPID, Publisher: ELSEVIER IRELAND LTD, Pages: E176-E176, ISSN: 0021-9150

Conference paper

Marzook A, Chen S, Pickford P, Lucey M, Wang Y, Corrêa Jr IR, Broichhagen J, Hodson DJ, Salem V, Rutter GA, Tan TM, Bloom SR, Tomas A, Jones Bet al., 2021, Evaluation of efficacy- versus affinity-driven agonism with biased GLP-1R ligands P5 and exendin-F1, Biochemical Pharmacology, Vol: 190, Pages: 1-12, ISSN: 0006-2952

The glucagon-like peptide-1 receptor (GLP-1R) is an important regulator of glucose homeostasis and has been successfully targeted for the treatment of type 2 diabetes. Recently described biased GLP-1R agonists with selective reductions in β-arrestin versus G protein coupling show improved metabolic actions in vivo. However, two prototypical G protein-favouring GLP-1R agonists, P5 and exendin-F1, are reported to show divergent effects on insulin secretion. In this study we aimed to resolve this discrepancy by performing a side-by-side characterisation of these two ligands across a variety of in vitro and in vivo assays. Exendin-F1 showed reduced acute efficacy versus P5 for several readouts, including recruitment of mini-G proteins, G protein-coupled receptor kinases (GRKs) and β-arrestin-2. Maximal responses were also lower for both GLP-1R internalisation and the presence of active GLP-1R-mini-Gs complexes in early endosomes with exendin-F1 treatment. In contrast, prolonged insulin secretion in vitro and sustained anti-hyperglycaemic efficacy in mice were both greater with exendin-F1 than with P5. We conclude that the particularly low acute efficacy of exendin-F1 and associated reductions in GLP-1R downregulation appear to be more important than preservation of endosomal signalling to allow sustained insulin secretion responses. This has implications for the ongoing development of affinity- versus efficacy-driven biased GLP-1R agonists as treatments for metabolic disease.

Journal article

Imbernon M, Saponaro C, Helms HCC, Zubiaga L, Bitsi S, Duquenne M, Tomas A, Chen S, Salem V, Deligia E, Gmyr V, Denis R, Kerr-Conte J, Chao DHM, Beiroa D, Steals B, Pattou F, Pfrieger F, Brodin B, Jones B, Luquet S, Bonner C, Prevot Vet al., 2021, Tanycytes Control the Hypothalamic Uptake and Metabolic Actions of Liraglutide, Publisher: WILEY, Pages: E237-E237, ISSN: 0894-1491

Conference paper

Salem V, Demetriou L, Behary P, Alexiadou K, Scholtz S, Tharakan G, Miras A, Purkayastha S, Ahmed A, Bloom S, Wall M, Dhillo W, Tan Tet al., 2021, Weight loss by low calorie diet versus gastric bypass surgery in people with diabetes results in divergent brain activation patterns: an functional MRI study, Diabetes Care, Vol: 44, Pages: 1842-1851, ISSN: 0149-5992

OBJECTIVE: Weight loss achieved with very-low-calorie diets (VLCDs) can produce remission of type 2 diabetes (T2D), but weight regain very often occurs with reintroduction of higher calorie intakes. In contrast, bariatric surgery produces clinically significant and durable weight loss, with diabetes remission that translates into reductions in mortality. We hypothesized that in patients living with obesity and prediabetes/T2D, longitudinal changes in brain activity in response to food cues as measured using functional MRI would explain this difference.RESEARCH DESIGN AND METHODS: Sixteen participants underwent gastric bypass surgery, and 19 matched participants undertook a VLCD (meal replacement) for 4 weeks. Brain responses to food cues and resting-state functional connectivity were assessed with functional MRI pre- and postintervention and compared across groups.RESULTS: We show that Roux-en-Y gastric bypass surgery (RYGB) results in three divergent brain responses compared with VLCD-induced weight loss: 1) VLCD resulted in increased brain reward center food cue responsiveness, whereas in RYGB, this was reduced; 2) VLCD resulted in higher neural activation of cognitive control regions in response to food cues associated with exercising increased cognitive restraint over eating, whereas RYGB did not; and 3) a homeostatic appetitive system (centered on the hypothalamus) is better engaged following RYGB-induced weight loss than VLCD.CONCLUSIONS: Taken together, these findings point to divergent brain responses to different methods of weight loss in patients with diabetes, which may explain weight regain after a short-term VLCD in contrast to enduring weight loss after RYGB.

Journal article

Chabosseau PL, Martinez-Sanchez A, Leclerc I, Salem V, Rutter GAet al., 2021, Repetitive Ca2+Waves Emanate from a Stable Leader Cell in Mouse Islets, 81st Virtual Scientific Sessions of the American-Diabetes-Association (ADA), Publisher: AMER DIABETES ASSOC, ISSN: 0012-1797

Conference paper

Salem V, Demetriou L, Behary P, Alexiadou K, Miras A, Scoltz S, Purkayastha S, Ahmed S, Dhillo W, Tan Tet al., 2021, Weight loss by low-calorie diet versus gastric bypass surgery in people with diabetes results in divergent brain activation patterns which may explain differences in long-term outcomes: an FMRI study, The Diabetes UK Professional Conference 2021, Publisher: Wiley, Pages: 1-1, ISSN: 0742-3071

Objective: Clinically significant weight loss can produce remission of type 2 diabetes. Bariatric surgery (specifically, Roux-en-Y gastric bypass, RYGB) produces durable weight loss that translates into reductions in mortality. In contrast, weight regain is very common after very low-calorie diets (VLCD). No study has investigated longitudinal changes in brain activity using functional MRI in patients living with obesity and prediabetes/type 2 diabetes to explain this difference.Methods: Visual food cue responses and resting state connectivity was assessed with functional MRI pre- and post-intervention and compared between 16 participants who underwent gastric bypass surgery and 19 age, gender, and disease stage matched participants who undertook a VLCD for 4 weeks.Results: Brain responses to RYGB-induced weight loss diverge from those induced by VLCD in three domains: (i) dieting resulted in increased responsiveness to visual food cues in reward areas whereas after RYGB this was reduced; (ii) dieting therefore engaged greater activation of brain regions involved in cognitive control, associated with the need to exercise increased restraint over eating; and (iii) a homeostatic appetitive system (centred on the hypothalamus) was better engaged following RYGB-induced weight loss than dieting.Conclusion: This study provides a holistic view of multiple divergent brain responses to different methods of weight loss in patients with diabetes, which may explain weight regain after a short-term VLCD in contrast with the enduring weight loss after RYGB.

Conference paper

Misra S, Khozoee B, Huang-Jiawei P, Mitsaki K, Reddy M, Salem V, Tan T, Tharakan G, Gable D, Bravis V, Valabhji Jet al., 2021, Comparison of diabetic ketoacidosis in adults, during the SARS-CoV-2 outbreak and over the same time period for the 3 preceding years, Diabetes Care, Vol: 44, Pages: e29-e31, ISSN: 0149-5992

Journal article

Izzi-Engbeaya C, Distaso W, Amin A, Kenkre J, Abdel-Malek M, Hope D, Oliver N, Misra S, Tan T, Hill N, Salem Vet al., 2021, Adverse outcomes in COVID-19 and diabetes – a retrospective cohort study from three London Teaching hospitals, BMJ Open Diabetes Research and Care, Vol: 9, Pages: 1-10, ISSN: 2052-4897

INTRODUCTION: Patients with diabetes mellitus admitted to hospital with COVID-19 have poorer outcomes. However, the drivers for this are not fully elucidated. We performed detailed characterisation of COVID-19 patients to determine clinical and biochemical factors that may be the drivers of poorer outcomes. RESEARCH DESIGN AND METHODS: Retrospective cohort study of 889 consecutive inpatients diagnosed with COVID-19 between 9th March 2020 and 22nd April 2020 in a large London NHS Trust. Unbiased multivariate logistic regression analysis was performed to determine variables that were independently and significantly associated with increased risk of death and/or ICU admission within 30 days of COVID-19 diagnosis. RESULTS: 62% of patients in our cohort were of non-White ethnic backgrounds and the diabetes prevalence was 38%. 323 (36%) patients met the primary outcome of death/admission to the intensive care unit (ICU) within 30 days of COVID-19 diagnosis. Male gender, lower platelet count, advancing age and higher Clinical Frailty Scale (CFS) score (but not diabetes) independently predicted poor outcomes on multivariate analysis. Antiplatelet medication was associated with a lower risk of death/ICU admission. Factors that were significantly and independently associated with poorer outcomes in patients with diabetes were co-existing ischaemic heart disease, increasing age and lower platelet count. CONCLUSIONS: In this large study of a diverse patient population, comorbidity (i.e. diabetes with ischaemic heart disease; increasing CFS score in older patients) were major determinants of poor outcomes with COVID-19. Antiplatelet medication should be evaluated in randomised clinical trials amongst high-risk patient groups.

Journal article

Jones B, Fang Z, Chen S, Manchanda Y, Bitsi S, Pickford P, David A, Shchepinova MM, Corrêa Jr IR, Hodson DJ, Broichhagen J, Tate EW, Reimann F, Salem V, Rutter GA, Tan T, Bloom SR, Tomas Aet al., 2020, Ligand-specific factors influencing GLP-1 receptor post-endocytic trafficking and degradation in pancreatic beta cells, International Journal of Molecular Sciences, Vol: 212, Pages: 1-24, ISSN: 1422-0067

The glucagon-like peptide-1 receptor (GLP-1R) is an important regulator of blood glucose homeostasis. Ligand-specific differences in membrane trafficking of the GLP-1R influence its signalling properties and therapeutic potential in type 2 diabetes. Here, we have evaluated how different factors combine to control the post-endocytic trafficking of GLP-1R to recycling versus degradative pathways. Experiments were performed in primary islet cells, INS-1 832/3 clonal beta cells and HEK293 cells, using biorthogonal labelling of GLP-1R to determine its localisation and degradation after treatment with GLP-1, exendin-4 and several further GLP-1R agonist peptides. We also characterised the effect of a rare GLP1R coding variant, T149M, and the role of endosomal peptidase endothelin-converting enzyme-1 (ECE-1), in GLP1R trafficking. Our data reveal how treatment with GLP-1 versus exendin-4 is associated with preferential GLP-1R targeting towards a recycling pathway. GLP-1, but not exendin-4, is a substrate for ECE-1, and the resultant propensity to intra-endosomal degradation, in conjunction with differences in binding affinity, contributes to alterations in GLP-1R trafficking behaviours and degradation. The T149M GLP-1R variant shows reduced signalling and internalisation responses, which is likely to be due to disruption of the cytoplasmic region that couples to intracellular effectors. These observations provide insights into how ligand- and genotype-specific factors can influence GLP-1R trafficking.

Journal article

Hameed S, Salem V, Alessimii H, Scholtz S, Dar O, Miras AD, Meeran K, Bloom SR, Ahmed AR, Purkayastha S, Chahal H, Tan Tet al., 2020, Imperial Satiety Protocol: A new non-surgical weight-loss programme, delivered in a health care setting, produces improved clinical outcomes for people with obesity, Diabetes, Obesity and Metabolism: a journal of pharmacology and therapeutics, Vol: 23, Pages: 270-275, ISSN: 1462-8902

‘Imperial Satiety Protocol’ (I-SatPro) is a new multifaceted approach to weight loss for people with obesity (PwO), encompassing dietary advice, time-restricted eating, physical activity and coaching to support behaviour change. Participants (n = 84) attended fortnightly I-SatPro group sessions for 30 weeks, with 70% of participants completing. On completion at 30 weeks, the mean weight loss was 15.2 ± 1.1 kg (13.2 ± 0.8% from baseline, P < .0001), which was maintained to 52 weeks (16.6 ± 1.5 kg, 14.1 ± 1.2%, P < .0001). Weight loss was not associated with reduced energy expenditure. In participants with type 2 diabetes and pre-diabetes (n = 16), glycated haemoglobin fell from 50 to 43 mmol/mol (P < .01). Systolic blood pressure fell by 12 mmHg (P < .0001). Triglycerides fell by 0.37 mmol/L (P < .01) and high-density lipoprotein rose by 0.08 mmol/L (P < .01). Short Form-36 (SF-36) functioning and wellbeing scores increased in all domains post I-SatPro intervention. For selected PwO, I-SatPro delivers clinically meaningful weight loss, and the potential for long-term health and wellbeing improvements.

Journal article

Muniangi-Muhitu H, Akalestou E, Salem V, Misra S, Oliver NS, Rutter GAet al., 2020, Covid-19 and diabetes: a complex bidirectional relationship, Frontiers in Endocrinology, Vol: 11, ISSN: 1664-2392

Covid-19 is a recently-emerged infectious disease caused by the novel severe acute respiratory syndrome coronavirus SARS-CoV2. SARS-CoV2 differs from previous coronavirus infections (SARS and MERS) due to its high infectivity (reproduction value, R0, typically 2-4) and pre- or asymptomatic transmission, properties that have contributed to the current global Covid-19 pandemic. Identified risk factors for disease severity and death from SARS-Cov2 infection include older age, male sex, diabetes, obesity and hypertension. The reasons for these associations are still largely obscure. Evidence is also emerging that SARS-CoV2 infection exacerbates the underlying pathophysiology of hyperglycemia in people with diabetes. Here, we discuss potential mechanisms through which diabetes may affect the risk of more severe outcomes in Covid-19 and, additionally, how diabetic emergencies and longer term pathology may be aggravated by infection with the virus. We consider roles for the immune system, the observed phenomenon of microangiopathy in severe Covid-19 infection and the potential for direct viral toxicity on metabolically-relevant tissues including pancreatic beta cells and targets of insulin action.

Journal article

Carrat GR, Haythorne E, Tomas A, Haataja L, Müller A, Arvan P, Piunti A, Cheng K, Huang M, Pullen TJ, Georgiadou E, Stylianides T, Amirruddin NS, Salem V, Distaso W, Cakebread A, Heesom KJ, Lewis PA, Hodson DJ, Briant LJ, Fung ACH, Sessions RB, Alpy F, Kong APS, Benke PI, Torta F, Keong Teo AK, Leclerc I, Solimena M, Wigley DB, Rutter GAet al., 2020, The type 2 diabetes gene product STARD10 is a phosphoinositide-binding protein that controls insulin secretory granule biogenesis, Molecular Metabolism, Vol: 40, ISSN: 2212-8778

OBJECTIVE: Risk alleles for type 2 diabetes at the STARD10 locus are associated with lowered STARD10 expression in the β-cell, impaired glucose-induced insulin secretion, and decreased circulating proinsulin:insulin ratios. Although likely to serve as a mediator of intracellular lipid transfer, the identity of the transported lipids and thus the pathways through which STARD10 regulates β-cell function are not understood. The aim of this study was to identify the lipids transported and affected by STARD10 in the β-cell and the role of the protein in controlling proinsulin processing and insulin granule biogenesis and maturation. METHODS: We used isolated islets from mice deleted selectively in the β-cell for Stard10 (βStard10KO) and performed electron microscopy, pulse-chase, RNA sequencing, and lipidomic analyses. Proteomic analysis of STARD10 binding partners was executed in the INS1 (832/13) cell line. X-ray crystallography followed by molecular docking and lipid overlay assay was performed on purified STARD10 protein. RESULTS: βStard10KO islets had a sharply altered dense core granule appearance, with a dramatic increase in the number of "rod-like" dense cores. Correspondingly, basal secretion of proinsulin was increased versus wild-type islets. The solution of the crystal structure of STARD10 to 2.3 Å resolution revealed a binding pocket capable of accommodating polyphosphoinositides, and STARD10 was shown to bind to inositides phosphorylated at the 3' position. Lipidomic analysis of âStard10KO islets demonstrated changes in phosphatidylinositol levels, and the inositol lipid kinase PIP4K2C was identified as a STARD10 binding partner. Also consistent with roles for STARD10 in phosphoinositide signalling, the phosphoinositide-binding proteins Pirt and Synaptotagmin 1 were amongst the differentially expressed genes in βStard10KO islets. CONCLUSION: Our data indicate that STARD10 binds to, and may transp

Journal article

Rutter GA, Ninov N, Salem V, Hodson DJet al., 2020, Comment on Satin et al. "Take Me To Your Leader": An Electrophysiological Appraisal of the Role of Hub Cells in Pancreatic Islets. Diabetes 2020;69:830-836, DIABETES, Vol: 69, Pages: E10-E11, ISSN: 0012-1797

Journal article

Suba K, Patel Y, Alonso AM, Ukwuoma M, Kalogianni V, Leclerc I, Owen B, Rutter GA, Bloom SR, Salem Vet al., 2020, Clinical care and other categories posters: Hypoglycaemia, Publisher: WILEY, Pages: 25-25, ISSN: 0742-3071

Conference paper

Ali UT, Suba K, Bitsi S, Alonso AM, Patel Y, Leclerc I, Rutter GA, Rothery S, Tomas A, Salem Vet al., 2020, Improving islet transplantation success by increasing expression of the epidermal growth factor receptor (EGFR), Publisher: WILEY, Pages: 36-36, ISSN: 0742-3071

Conference paper

Hartley O, Hameed S, Reddy M, Tharakan G, Salem Vet al., 2020, An audit of the management of hyperosmolar diabetic emergencies on an acute medical unit, Publisher: WILEY, Pages: 71-71, ISSN: 0742-3071

Conference paper

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