Differential effects of interleukin-13 and interleukin-6 on Jak/STAT signaling and cell viability in pancreatic β-cells

This is an Accepted Manuscript of an article published by Taylor & Francis in islets on 1 March 2013, available online: http://www.tandfonline.com/10.4161/isl.24249Open Access articlePro-inflammatory cytokines are important mediators of β-cell demise in type 1 diabetes, and similar mechanisms are increasingly implicated in type 2 diabetes, where a state of chronic inflammation may persist. It is likely that the actions of anti-inflammatory cytokines are also altered in diabetes. Cytokines are released from immune cells, which may be recruited to the islets in diabetes, but they can also be produced by islet endocrine cells in response to environmental factors, including enteroviral infection. Since enteroviral infection of islet cells may influence the development of diabetes in humans, we examined the actions of two cytokines, IL-13 and IL-6, whose expression are reported to be altered in β-cells during enteroviral infection. Human and rodent islet cells were shown to express receptors for both IL-13 and IL-6, and treatment with either cytokine resulted in the rapid phosphorylation of STAT3 and STAT6. However, while β-cells were protected against a range of cytotoxic insults during exposure to IL-13, treatment with IL-6 enhanced cytotoxicity and western blotting revealed that IL-13 induced one specific isoform of phospho-STAT6 preferentially. Upon incubation with both cytokines together, the isoform of STAT6 that was upregulated by IL-13 alone was again induced, and the effects of IL-6 on β-cell viability were attenuated. Overall, the results suggest that induction of specific isoforms of STAT family transcription factors may underlie the cytoprotective actions of IL-13, and they imply that selective targeting of specific STAT-mediated signaling components could provide a means to ameliorate the loss of β-cell viability in diabetes.Nuffield Foundation - Bursary schemeEuropean Union’s Seventh Framework Programme PEVNET (FP7/2007-2013

Social Interactions as a Source of Information about E-Cigarettes: A Study of U.S. Adult Smokers

The novelty of e-cigarettes and ambiguity about their effects may foster informal sharing of information, such as through social interactions. We aimed to describe smokers’ social interactions about e-cigarettes and their recommendations that others use e-cigarettes. Data were collected from 2149 adult smokers in North Carolina and California who participated in a study of the impact of pictorial cigarette pack warnings. In the previous month, almost half of participants (45%) reported talking to at least one person about e-cigarettes and nearly a third of participants (27%) recommended e-cigarettes to someone else. Smokers recommended e-cigarettes to cut back on smoking (57%), to quit smoking (48%), for health reasons (36%), and for fun (27%). In adjusted analyses, more frequent e-cigarette use, positive views about typical e-cigarette users, and attempting to quit smoking in the past month were associated with recommending e-cigarettes for health reasons (all p < 0.05). Social interactions appear to be a popular method of information-sharing about e-cigarettes among smokers. Health communication campaigns may help to fill in the gaps of smokers’ understanding of e-cigarettes and their long-term effects

Expression of the enteroviral capsid protein VP1 in the islet cells of patients with type 1 diabetes is associated with induction of protein kinase R and downregulation of Mcl-1

The final publication is available at link.springer.com/article/10.1007%2Fs00125-012-2745-4Immunohistochemical staining reveals that the enteroviral capsid protein VP1 is present at higher frequency in the insulin-containing islets of patients with recent-onset type 1 diabetes than in controls. This is consistent with epidemiological evidence suggesting that enteroviral infection may contribute to the autoimmune response in type 1 diabetes. However, immunostaining of VP1 is not definitive since the antibody widely used to detect the protein (Clone 5D8/1) might also cross-react with additional proteins under some conditions. Therefore, we sought to verify that VP1 immunopositivity correlates with additional markers of viral infection

Differential insulitic profiles determine the extent of beta cell destruction and the age at onset of type 1 diabetes

Published onlineJOURNAL ARTICLEType 1 diabetes (T1D) results from a T-cell mediated destruction of pancreatic beta cells following the infiltration of leukocytes (including CD8+, CD4+ and CD20+ cells) into and around pancreatic islets ("insulitis"). Recently, we reported that two distinct patterns of insulitis occur in patients with recent-onset T1D from the UK and that these differ principally in the proportion of infiltrating CD20+ B-cells (designated "CD20Hi" and "CD20Lo" respectively). We have now extended this analysis to include patients from the nPOD (USA) and DiViD (Norway) cohorts and confirm that the two profiles of insulitis occur more widely. Moreover, we show that patients can be directly stratified according to their insulitic profile and that those receiving a diagnosis before the age of 7 years always display the CD20Hi profile. By contrast, individuals diagnosed beyond the age of 13 years are uniformly defined as CD20Lo. This implies that the two forms of insulitis are differentially aggressive and that patients with a CD20Hi profile lose their beta cells at a more rapid rate. In support of this, we also find that the proportion of residual insulin-containing islets (ICIs) increases in parallel with age at onset of T1D. Importantly, those diagnosed in, or beyond, their teenage years retain ∼40% ICIs at diagnosis, implying that a functional deficit rather than absolute beta cell loss may be causal for disease onset in these patients. We conclude that appropriate patient stratification will be critical for correct interpretation of the outcomes of intervention therapies targeted to islet-infiltrating immune cells in T1D

Offspring of mice exposed to a low-protein diet in utero demonstrate changes in mTOR signaling in pancreatic islets of langerhans, associated with altered glucagon and insulin expression and a lower β-cell mass

Low birth weight is a risk factor for gestational and type 2 diabetes (T2D). Since mammalian target of rapamycin (mTOR) controls pancreatic β-cell mass and hormone release, we hypothesized that nutritional insult in utero might permanently alter mTOR signaling. Mice were fed a low-protein (LP, 8%) or control (C, 20%) diet throughout pregnancy, and offspring examined until 130 days age. Mice receiving LP were born 12% smaller and β-cell mass was significantly reduced throughout life. Islet mTOR levels were lower in LP-exposed mice and localized predominantly to α-rather than β-cells. Incubation of isolated mouse islets with rapamycin significantly reduced cell proliferation while increasing apoptosis. mRNA levels for mTORC complex genes mTOR, Rictor and Raptor were elevated at 7 days in LP mice, as were the mTOR and Raptor proteins. Proglucagon gene expression was similarly increased, but not insulin or the immune/metabolic defense protein STING. In human and mouse pancreas STING was strongly associated with islet β-cells. Results support long-term changes in islet mTOR signaling in response to nutritional insult in utero, with altered expression of glucagon and insulin and a reduced β-cell mass. This may contribute to an increased risk of gestational or type 2 diabetes

“My First Thought was Croutons”: Perceptions of Cigarettes and Cigarette Smoke Constituents Among Adult Smokers and Nonsmokers

Understanding what people think about harmful and potentially harmful constituents in cigarettes and cigarette smoke has new urgency given legislation requiring US Food and Drug Administration (FDA) to disclose constituent information. Our study sought to obtain qualitative information on what people think about these constituents and the language they use to talk about them

Brand switching and toxic chemicals in cigarette smoke: A national study

US law requires disclosure of quantities of toxic chemicals (constituents) in cigarette smoke by brand and sub-brand. This information may drive smokers to switch to cigarettes with lower chemical quantities, under the misperception that doing so can reduce health risk. We sought to understand past brand-switching behavior and whether learning about specific chemicals in cigarette smoke increases susceptibility to brand switching

Detection of a low-grade enteroviral infection in the islets of Langerhans of living patients newly diagnosed with type 1 diabetes

Journal ArticleThis is an author-created, uncopyedited electronic version of an article accepted for publication in Diabetes. The American Diabetes Association (ADA), publisher of Diabetes, is not responsible for any errors or omissions in this version of the manuscript or any version derived from it by third parties. The definitive publisher-authenticated version is available in Diabetes, May 2015, vol. 64, no. 5 pp. 1682-1687 in print and online at http://diabetes.diabetesjournals.org/content/64/5/1682.abstractThe Diabetes Virus Detection study (DiViD) is the first to examine fresh pancreatic tissue at the diagnosis of type 1 diabetes for the presence of viruses. Minimal pancreatic tail resection was performed 3-9 weeks after onset of type 1 diabetes in six adult patients (age 24-35 years). The presence of enteroviral capsid protein 1 (VP1) and the expression of class I HLA were investigated by immunohistochemistry. Enterovirus RNA was analyzed from isolated pancreatic islets and from fresh-frozen whole pancreatic tissue using PCR and sequencing. Nondiabetic organ donors served as controls. VP1 was detected in the islets of all type 1 diabetic patients (two of nine controls). Hyperexpression of class I HLA molecules was found in the islets of all patients (one of nine controls). Enterovirus-specific RNA sequences were detected in four of six patients (zero of six controls). The results were confirmed in various laboratories. Only 1.7% of the islets contained VP1(+) cells, and the amount of enterovirus RNA was low. The results provide evidence for the presence of enterovirus in pancreatic islets of type 1 diabetic patients, which is consistent with the possibility that a low-grade enteroviral infection in the pancreatic islets contributes to disease progression in humans.Academy of FinlandSouth-Eastern Norway Regional HealthAuthorityNovo Nordisk FoundationPEVNET (Persistent Virus Infection in Diabetes Network) Study GroupEuropean Union’s Seventh Framework ProgrammeSwedish Medical Research CouncilDiabetes Wellness FoundationJDR

Recommendation report for the implementation of research data management policy and for a sustainable research data management service at the University of Exeter

This is the Open Access and Research Data Management Policy Task and Finish Group's recommendation report for the implementation of research data management policy and a sustainable research data management service at the University of Exeter.JIS