Publications by authors named "Thomas He"

Vibrio diabolicus 3098 is a marine halophile, a member of the . The draft whole-genome sequence is 5.17 Mb and has 4,829 predicted coding sequences divided into two chromosomes and a plasmid.

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Pancreatic β-cells in the islets of Langerhans are key to maintaining glucose homeostasis by secreting the peptide hormone insulin. Insulin is packaged within vesicles named insulin secretory granules (ISGs), which recently have been considered to have intrinsic structures and proteins that regulate insulin granule maturation, trafficking, and secretion. Previously, studies have identified a handful of novel ISG-associated proteins, using different separation techniques.

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A mechanistic connection between aging and development is largely unexplored. Through profiling age-related chromatin and transcriptional changes across 22 murine cell types, analyzed alongside previous mouse and human organismal maturation datasets, we uncovered a transcription factor binding site (TFBS) signature common to both processes. Early-life candidate cis-regulatory elements (cCREs), progressively losing accessibility during maturation and aging, are enriched for cell-type identity TFBSs.

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Aims/hypothesis: Almost all beta cells contact one capillary and insulin granule fusion is targeted to this region. However, there are reports of beta cells contacting more than one capillary. We therefore set out to determine the proportion of beta cells with multiple contacts and the impact of this on cell structure and function.

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Chronic destruction of insulin-producing pancreatic β cells by T cells results in autoimmune diabetes. Similar to other chronic T cell-mediated pathologies, a role for T cell exhaustion has been identified in diabetes in humans and NOD mice. The development and differentiation of exhausted T cells depends on exposure to Ag.

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Introduction: Chronic activation of self-reactive T cells with beta cell antigens results in the upregulation of immune checkpoint molecules that keep self-reactive T cells under control and delay beta cell destruction in autoimmune diabetes. Inhibiting PD1/PD-L1 signaling results in autoimmune diabetes in mice and humans with pre-existing autoimmunity against beta cells. However, it is not known if other immune checkpoint molecules, such as TIGIT, can also negatively regulate self-reactive T cells.

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Article Synopsis
  • - Persistent exposure to antigens leads to the development of exhausted T cells, which are less effective in responding to threats, and this phenomenon typically occurs during chronic infections and cancer, raising questions about its role in autoimmune diabetes.
  • - In a study using nonobese diabetic (NOD) mice, exhausted CD8+ T cells targeting the islet antigen IGRP were found in the pancreas, while more of these cells were preserved in peripheral lymphoid organs.
  • - By creating transgenic NOD mice that express IGRP in cells outside the islet, researchers showed that exposure to IGRP in these extraislet areas resulted in severely exhausted T cells, which ultimately protected the mice from developing diabetes.
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Objective: This multicenter prospective cohort study compared pancreas volume as assessed by MRI, metabolic scores derived from oral glucose tolerance testing (OGTT), and a combination of pancreas volume and metabolic scores for predicting progression to stage 3 type 1 diabetes (T1D) in individuals with multiple diabetes-related autoantibodies.

Research Design And Methods: Pancreas MRI was performed in 65 multiple autoantibody-positive participants enrolled in the Type 1 Diabetes TrialNet Pathway to Prevention study. Prediction of progression to stage 3 T1D was assessed using pancreas volume index (PVI), OGTT-derived Index60 score and Diabetes Prevention Trial-Type 1 Risk Score (DPTRS), and a combination of PVI and DPTRS.

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  • A phase 2 trial investigated the effects of baricitinib, a JAK inhibitor, on β-cell function in patients with early-stage type 1 diabetes, comparing it to a placebo over 48 weeks.
  • Results showed that the baricitinib group had a significantly higher mean C-peptide level, indicating better β-cell function, and required a lower daily insulin dose compared to the placebo group.
  • While baricitinib improved certain measures of insulin production and glycemic control, the overall levels of glycated hemoglobin were similar between both groups, with no notable differences in adverse events reported.
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Tau protein is implicated in the pathogenesis of Alzheimer's disease (AD) and other tauopathies, but its physiological function is in debate. Mostly explored in the brain, tau is also expressed in the pancreas. We further explored the mechanism of tau's involvement in the regulation of glucose-stimulated insulin secretion (GSIS) in islet β-cells, and established a potential relationship between type 2 diabetes mellitus (T2DM) and AD.

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CXCL10 is an IFNγ-inducible chemokine implicated in the pathogenesis of type 1 diabetes. T-cells attracted to pancreatic islets produce IFNγ, but it is unclear what attracts the first IFNγ -producing T-cells in islets. Gut dysbiosis following administration of pathobionts induced CXCL10 expression in pancreatic islets of healthy non-diabetes-prone (C57BL/6) mice and depended on TLR4-signaling, and in non-obese diabetic (NOD) mice, gut dysbiosis induced also CXCR3 chemokine receptor in IGRP-reactive islet-specific T-cells in pancreatic lymph node.

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Article Synopsis
  • * Ongoing research focuses on understanding T-cell responses and developing effective disease-modifying agents that could be useful in the early stages of T1D.
  • * Advanced profiling techniques at the single-cell level aim to discover new biomarkers and improve assays for characterizing antigen-specific T cells, enhancing the ability to predict disease progression and treatment responses.
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Type 1 diabetes is an autoimmune disease with onset from early childhood. The insulin-producing pancreatic beta cells are destroyed by CD8 cytotoxic T cells. The disease is challenging to study mechanistically in humans because it is not possible to biopsy the pancreatic islets and the disease is most active prior to the time of clinical diagnosis.

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Article Synopsis
  • Immune checkpoint inhibitors can effectively treat cancer but are linked to immune-related side effects, including type 1 diabetes (T1D), prompting researchers to explore preventive treatments like JAK1/JAK2 inhibitors.* -
  • In experiments with nonobese diabetic mice, JAK1/JAK2 inhibitors successfully prevented and even reversed diabetes caused by PD-L1 blockade, inhibiting harmful immune cell activity in the pancreas.* -
  • The study demonstrates that JAK1/JAK2 inhibitors might be a viable option for managing diabetes resulting from cancer therapy, without compromising the anti-tumor effectiveness in other models.*
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Type 1 diabetes is a complex disease characterized by the lack of endogenous insulin secreted from the pancreatic β-cells. Although β-cell targeted autoimmune processes and β-cell dysfunction are known to occur in type 1 diabetes, a complete understanding of the cell-to-cell interactions that support pancreatic function is still lacking. To characterize the pancreatic endocrine compartment, we studied pancreata from healthy adult donors and investigated a single cell surface adhesion molecule, desmoglein-2 (DSG2).

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Background: Type 1 diabetes (T1D) places an extraordinary burden on individuals and their families, as well as on the healthcare system. Despite recent advances in glucose sensors and insulin pump technology, only a minority of patients meet their glucose targets and face the risk of both acute and long-term complications, some of which are life-threatening. The JAK-STAT pathway is critical for the immune-mediated pancreatic beta cell destruction in T1D.

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Interferon gamma (IFNγ) is a proinflammatory cytokine implicated in autoimmune diseases. However, deficiency or neutralization of IFNγ is ineffective in reducing disease. We characterize islet antigen-specific T cells in non-obese diabetic (NOD) mice lacking all three IFN receptor genes.

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We present a case of an obese 22-year-old man with activating variant who had neonatal hypoglycemia, re-emerging with hypoglycemia later in life. We investigated him for asymptomatic hypoglycemia with a family history of hypoglycemia. Genetic testing yielded a novel missense class 3 variant that was subsequently found in his mother, sister and nephew and reclassified as a class 4 likely pathogenic variant.

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Article Synopsis
  • * Elevated PNAs were found in the blood of children with T1D and those at risk of developing it, alongside increased markers of inflammation in pancreatic islets of certain mouse models, indicating a link between PNAs and T1D pathogenesis.
  • * PNAs might serve as a potential biomarker for early T1D detection, while a drug called methyl cellobiose sulfate (mCBS) has shown promise in reducing histone-induced damage to islet cells in
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Background & Aims: Pancreatic islet β-cells are factories for insulin production; however, ectopic expression of insulin also is well recognized. The gallbladder is a next-door neighbor to the developing pancreas. Here, we wanted to understand if gallbladders contain functional insulin-producing cells.

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Objectives: Loss of functional β-cell mass is a key factor contributing to poor glycemic control in advanced type 2 diabetes (T2D). We have previously reported that the inhibition of the neuropeptide Y1 receptor improves the islet transplantation outcome in type 1 diabetes (T1D). The aim of this study was to identify the pathophysiological role of the neuropeptide Y (NPY) system in human T2D and further evaluate the therapeutic potential of using the Y1 receptor antagonist BIBO3304 to improve β-cell function and survival in T2D.

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Magnetic resonance imaging (MRI) has detected changes in pancreas volume and other characteristics in type 1 and type 2 diabetes. However, differences in MRI technology and approaches across locations currently limit the incorporation of pancreas imaging into multisite trials. The purpose of this study was to develop a standardized MRI protocol for pancreas imaging and to define the reproducibility of these measurements.

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Pancreatic β cells secrete the hormone insulin into the bloodstream and are critical in the control of blood glucose concentrations. β cells are clustered in the micro-organs of the islets of Langerhans, which have a rich capillary network. Recent work has highlighted the intimate spatial connections between β cells and these capillaries, which lead to the targeting of insulin secretion to the region where the β cells contact the capillary basement membrane.

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