Coronavirus Anxiety, COVID Anxiety Syndrome and Mental Health: A Test Among Six Countries During March 2021.

The negative impact of the COVID-19 pandemic on mental health outcomes is widely documented. Specifically, individuals experiencing greater degrees of severity in coronavirus anxiety have demonstrated higher levels of generalized anxiety, depression and psychological distress. Yet the pathways in which coronavirus anxiety confers vulnerability are not well known. The present investigation sought to address this gap in the scientific literature by testing the indirect effect of the COVID-19 anxiety syndrome, which centres on the function of detecting and managing the environmental threat of virus exposure and its sequalae. Data were collected during the height of the pandemic (March 2021) and included 5297 adults across six countries. Structural equation modelling techniques revealed that the COVID-19 anxiety syndrome evidenced a statistically significant indirect effect between coronavirus anxiety and generalized anxiety, depression and work/social adjustment. Overall, results suggest there could be public health merit to targeting anxiety related to virus exposure to improve behavioural health for those who are struggling with excessive fear and worry.

The vagus nerve mediates the physiological but not pharmacological effects of PYY3-36 on food intake.

Peptide YY (PYY3-36) is a post-prandially released gut hormone with potent appetite-reducing activity, the mechanism of action of which is not fully understood. Unravelling how this system physiologically regulates food intake may help unlock its therapeutic potential, whilst minimising unwanted effects. Here we demonstrate that germline and post-natal targeted knockdown of the PYY3-36 preferring receptor (neuropeptide Y (NPY) Y2 receptor (Y2R)) in the afferent vagus nerve is required for the appetite inhibitory effects of physiologically-released PYY3-36, but not peripherally administered pharmacological doses. Post-natal knockdown of the Y2R results in a transient body weight phenotype that is not evident in the germline model. Loss of vagal Y2R signalling also results in altered meal patterning associated with accelerated gastric emptying. These results are important for the design of PYY-based anti-obesity agents.

COVID-19: Tail risk and predictive regressions.

The paper focuses on econometrically justified robust analysis of the effects of the COVID-19 pandemic on financial markets in different countries across the World. It provides the results of robust estimation and inference on predictive regressions for returns on major stock indexes in 23 countries in North and South America, Europe, and Asia incorporating the time series of reported infections and deaths from COVID-19. We also present a detailed study of persistence, heavy-tailedness and tail risk properties of the time series of the COVID-19 infections and death rates that motivate the necessity in applications of robust inference methods in the analysis. Econometrically justified analysis is based on heteroskedasticity and autocorrelation consistent (HAC) inference methods, recently developed robust t-statistic inference approaches and robust tail index estimation.

Diabetes self-management during the COVID-19 pandemic and its associations with COVID-19 anxiety syndrome, depression and health anxiety.

INTRODUCTION: The effects of the COVID-19 pandemic on mental health have been profound. Mental health and diabetes self-care are inter-related. We examined whether COVID-19 anxiety, depressive symptoms and health anxiety were associated with domains of diabetes self-management and investigated whether greater COVID-19 anxiety syndrome would independently contribute to suboptimal diabetes self-care. RESEARCH DESIGN AND METHODS: Surveys were sent to people attending diabetes clinics of three London hospitals. Participants completed the Diabetes Self-Management Questionnaire (DSMQ), the COVID-19 Anxiety Syndrome Scale (C-19 ASS), which measures perseveration and avoidant maladaptive coping behaviour, assessed with measures of co-existent depressive symptoms and anxiety, controlling for age, gender and social deprivation. Clinical data, including pre- and post-lockdown HbA1c measures, were obtained from hospital records for 369 respondents, a response rate of 12.8%. RESULTS: Depressive symptom scores were high. Both pre-existing health anxiety and depressive symptoms were independently linked to improvable measures of diabetes care, as was lower socio-economic rank. However, avoidant COVID-19 anxiety responses were independently associated with higher diabetes self-care scores. HbA1c levels improved modestly over the year of UK lockdown in this cohort. CONCLUSION: During the height of lockdown, avoidant coping behaviours characteristic of the COVID-19 anxiety syndrome may in fact work to improve diabetes self-care, at least in the short term. We recommend screening for depressive symptoms and being aware of the significant minority of people with COVID-19 anxiety syndrome who may now find it difficult to re-engage with face-to-face clinic opportunities.

Dysregulation of the Pdx1/Ovol2/Zeb2 axis in dedifferentiated ß-cells triggers the induction of genes associated with epithelial-mesenchymal transition in diabetes.

OBJECTIVE: ß-cell dedifferentiation has been revealed as a pathological mechanism underlying pancreatic dysfunction in diabetes. We previously showed that increased miR-7 levels trigger ß-cell dedifferentiation and diabetes. We used ß-cell-specific miR-7 overexpressing mice (Tg7) to test the hypothesis that loss of ß-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 ß-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 ß-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 ß-cells. These molecular changes are associated with a weakening of ß-cell: ß-cell contacts, increased extracellular matrix (ECM) deposition, and TGFß-dependent islet fibrosis. We found that the mesenchymal reprogramming of ß-cells is explained in part by the downregulation of Pdx1 and its inability to regulate a myriad of epithelial-specific genes expressed in ß-cells. Notable among genes transactivated by Pdx1 is Ovol2, which encodes a transcriptional repressor of the EMT transcription factor Zeb2. Following compromised ß-cell identity, the reduction in Pdx1 gene expression causes a decrease in Ovol2 protein, triggering mesenchymal reprogramming of ß-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 miR-7-mediated ß-cell dedifferentiation induces EMT signalling and a chronic response to tissue injury, which alters the islet microenvironment and predisposes to fibrosis. This research suggests that regulators of EMT signalling may represent novel therapeutic targets for treating ß-cell dysfunction and fibrosis in T2D.

Adverse outcomes in COVID-19 and diabetes: a retrospective cohort study from three London teaching hospitals.

INTRODUCTION: Patients with diabetes mellitus admitted to hospital with COVID-19 have poorer outcomes. However, the drivers of poorer outcomes are not fully elucidated. We performed detailed characterization of patients with COVID-19 to determine the clinical and biochemical factors that may be drivers of poorer outcomes. RESEARCH DESIGN AND METHODS: This is a retrospective cohort study of 889 consecutive inpatients diagnosed with COVID-19 between March 9 and April 22, 2020 in a large London National Health Service Trust. Unbiased multivariate logistic regression analysis was performed to determine variables that were independently and significantly associated with increased risk of death and/or intensive care unit (ICU) admission within 30 days of COVID-19 diagnosis. RESULTS: 62% of patients in our cohort were of non-white ethnic background and the prevalence of diabetes was 38%. 323 (36%) patients met the primary outcome of death/admission to the 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 coexisting ischemic heart disease, increasing age and lower platelet count. CONCLUSIONS: In this large study of a diverse patient population, comorbidity (ie, diabetes with ischemic heart disease; increasing CFS score in older patients) was a major determinant of poor outcomes with COVID-19. Antiplatelet medication should be evaluated in randomized clinical trials among high-risk patient groups.

The type 2 diabetes gene product STARD10 is a phosphoinositide-binding protein that controls insulin secretory granule biogenesis.

OBJECTIVE: Risk alleles for type 2 diabetes at the STARD10 locus are associated with lowered STARD10 expression in the ß-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 ß-cell function are not understood. The aim of this study was to identify the lipids transported and affected by STARD10 in the ß-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 ß-cell for Stard10 (ßStard10KO) 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: ßStard10KO 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 ßStard10KO 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 ßStard10KO islets. CONCLUSION: Our data indicate that STARD10 binds to, and may transport, phosphatidylinositides, influencing membrane lipid composition, insulin granule biosynthesis, and insulin processing.

Leader ß-cells coordinate Ca2+ dynamics across pancreatic islets in vivo.

Pancreatic ß-cells form highly connected networks within isolated islets. Whether this behaviour pertains to the situation in vivo, after innervation and during continuous perfusion with blood, is unclear. In the present study, we used the recombinant Ca2+ sensor GCaMP6 to assess glucose-regulated connectivity in living zebrafish Danio rerio, and in murine or human islets transplanted into the anterior eye chamber. In each setting, Ca2+ waves emanated from temporally defined leader ß-cells, and three-dimensional connectivity across the islet increased with glucose stimulation. Photoablation of zebrafish leader cells disrupted pan-islet signalling, identifying these as likely pacemakers. Correspondingly, in engrafted mouse islets, connectivity was sustained during prolonged glucose exposure, and super-connected 'hub' cells were identified. Granger causality analysis revealed a controlling role for temporally defined leaders, and transcriptomic analyses revealed a discrete hub cell fingerprint. We thus define a population of regulatory ß-cells within coordinated islet networks in vivo. This population may drive Ca2+ dynamics and pulsatile insulin secretion.