FGF7 enhances the expression of ACE2 in human islet organoids aggravating SARS-CoV-2 infection.

The angiotensin-converting enzyme 2 (ACE2) is a primary cell surface viral binding receptor for SARS-CoV-2, so finding new regulatory molecules to modulate ACE2 expression levels is a promising strategy against COVID-19. In the current study, we utilized islet organoids derived from human embryonic stem cells (hESCs), animal models and COVID-19 patients to discover that fibroblast growth factor 7 (FGF7) enhances ACE2 expression within the islets, facilitating SARS-CoV-2 infection and resulting in impaired insulin secretion. Using hESC-derived islet organoids, we demonstrated that FGF7 interacts with FGF receptor 2 (FGFR2) and FGFR1 to upregulate ACE2 expression predominantly in ß cells. This upregulation increases both insulin secretion and susceptibility of ß cells to SARS-CoV-2 infection. Inhibiting FGFR counteracts the FGF7-induced ACE2 upregulation, subsequently reducing viral infection and replication in the islets. Furthermore, retrospective clinical data revealed that diabetic patients with severe COVID-19 symptoms exhibited elevated serum FGF7 levels compared to those with mild symptoms. Finally, animal experiments indicated that SARS-CoV-2 infection increased pancreatic FGF7 levels, resulting in a reduction of insulin concentrations in situ. Taken together, our research offers a potential regulatory strategy for ACE2 by controlling FGF7, thereby protecting islets from SARS-CoV-2 infection and preventing the progression of diabetes in the context of COVID-19.

Spontaneous Akt2 deficiency in a colony of NOD mice exhibiting early diabetes.

Diabetes constitutes a major public health problem, with dramatic consequences for patients. Both genetic and environmental factors were shown to contribute to the different forms of the disease. The monogenic forms, found both in humans and in animal models, specially help to decipher the role of key genes in the physiopathology of the disease. Here, we describe the phenotype of early diabetes in a colony of NOD mice, with spontaneous invalidation of Akt2, that we called HYP. The HYP mice were characterised by a strong and chronic hyperglycaemia, beginning around the age of one month, especially in male mice. The phenotype was not the consequence of the acceleration of the autoimmune response, inherent to the NOD background. Interestingly, in HYP mice, we observed hyperinsulinemia before hyperglycaemia occurred. We did not find any difference in the pancreas' architecture of the NOD and HYP mice (islets' size and staining for insulin and glucagon) but we detected a lower insulin content in the pancreas of HYP mice compared to NOD mice. These results give new insights about the role played by Akt2 in glucose homeostasis and argue for the ß cell failure being the primary event in the course of diabetes.

Poorly controlled type 1 diabetes mellitus seriously impairs female reproduction via immune and metabolic disorders.

RESEARCH QUESTION: Does type 1 diabetes mellitus (T1DM) affect reproductive health of female patients? What is the potential mechanism of reproductive dysfunction in female patients caused by T1DM? DESIGN: Preliminary assessment of serum levels of female hormones in women with or without T1DM. Then histological and immunological examinations were carried out on the pancreas, ovaries and uteri at different stages in non-obese diabetic (NOD) and Institute of Cancer Research (ICR) mice, as well as assessment of their fertility. A protein array was carried out to detect the changes in serum inflammatory cytokines. Furthermore, RNA-sequencing was used to identify the key abnormal genes/pathways in ovarian and uterine tissues of female NOD mice, which were further verified at the protein level. RESULTS: Testosterone levels were significantly increased (P = 0.0036) in female mice with T1DM. Increasing age in female NOD mice was accompanied by obvious lymphocyte infiltration in the pancreatic islets. Moreover, the levels of serum inflammatory factors in NOD mice were sharply increased with increasing age. The fertility of female NOD mice declined markedly, and most were capable of conceiving only once. Furthermore, ovarian and uterine morphology and function were severely impaired in NOD female mice. Additionally, ovarian and uterine tissues revealed that the differentially expressed genes were primarily enriched in metabolism, cytokine-receptor interactions and chemokine signalling pathways. CONCLUSION: T1DM exerts a substantial impairment on female reproductive health, leading to diminished fertility, potentially associated with immune disorders and alterations in energy metabolism.

The therapeutic effects of exosomes the first time isolated from pancreatic islet-derived progenitor cells in the treatment of pancreatic cancer.

Insulinoma is an excessive insulin-released beta cell tumor. Pancreas cancer is one of the deadliest malignant neoplasms. Exosomes are secreted cell membrane vesicles containing a large number of proteins, lipids, and nucleic acids. The aim of this study is to investigate the effects of exosomes on two cell lines of benign and malignant character. For the first time, exosomes were isolated from pancreatic island-derived progenitor cells (PID-PCs) and applied to INS-1 and MiaPaCa-2 cells. In addition, exosomes isolated from PID-PC, MiaPaca-2, and INS-1 cells were characterized in order to compare their sizes with other previously isolated exosomes. Alix, TSG101, CD9, and CD81 were analyzed. The size and concentration of exosomes and the cell viability were detected. The cells were marked with HSP90, HSF-1, Kaspaz-8, Active-Kaspaz-3, Beclin, and p-Bcl-2. The cell cytotoxicity and insulin levels kit were measured. Alix in all exosomes, and PID-PC, MiaPaca-2 cell lysates; TSG101 in PID-PC and MiaPaca-2 cell lysates; CD9 in INS-1 exosomes were detected. The dimensions of isolated exosomes were 103.6 ± 28.6 nm, 100.7 ± 10 nm, and 147.2 ± 12.3 nm for PID-PCs, MiaPaca-2, and INS-1 cells. The cell viability decreased and HSP90 increased in the MiaPaca-2 cells. The HSF-1 was higher in the control MiaPaca-2 cell compared to the control INS-1 cell, and the exosome-treated MiaPaca-2 cell compared to the exosome-treated INS-1 cell. Beclin and p-Bcl-2 were decreased in the exosome-treated MiaPaca-2 cells. The insulin level in the cell lysates increased compared to cell secretion in INS-1 cells. In conclusion, exosomes isolated from the PID-PC caused cell death in the MiaPaca-2 cells in a time- and dose-dependent manner. The IC50 value determined for MiaPaca-2 cells has no effect on cell viability in INS-1 cells, which best mimics pancreatic beta cells and can be used instead of healthy pancreatic beta cells. Isolated exosomes can kill cancer cells without damaging healthy cells.

Effect of Low-Dose Progesterone on Glycemic Metabolism, Morphology and Function of Adipose Tissue and Pancreatic Islets in Diet-Induced Obese Female Mice.

BACKGROUND: Obesity is a worldwide concern due to its global rapid expansion and remarkable impact on individual's health by predisposing to several other diseases. About twice as many women as men suffer from severe obesity and, in fact, there are stages in a woman's life when weight gain and adiposity can result in greater damage to health. For example, obesity triples the chance of a woman developing gestational diabetes. Many hormones promote the metabolic adaptations of pregnancy, including progesterone, whose role in female obesity is still not well known despite being involved in many physiological and pathological processes. METHODS: Here we investigated whether progesterone treatment at low dose can worsen the glucose metabolism and the morpho functional aspects of adipose tissue and pancreas in obese females. Mice were assigned into four groups: normocaloric diet control (NO-CO), high-fat and -fructose diet control (HFF-CO), normocaloric diet plus progesterone (NO-PG) and high-fat and -fructose diet plus progesterone (HFF-PG) for 10 weeks. Infusion of progesterone (0.25 mg/kg/day) was done by osmotic minipump in the last 21 days of protocol. RESULTS: Animals fed a hypercaloric diet exhibited obesity with increased body weight (p < 0.0001), adipocyte hypertrophy (p < 0.0001), hyperglycemia (p = 0.03), and glucose intolerance (p = 0.001). HFF-CO and HFF-PG groups showed lower adiponectin concentration (p < 0.0001) and glucose-stimulated insulin secretion (p = 0.03), without differences in islet size. Progesterone attenuated glucose intolerance in the HFF-PG group (p = 0.03), however, did not change morphology or endocrine function of adipose tissue and pancreatic islets. CONCLUSIONS: Taken together, our results showed that low dose of progesterone does not worsen the effects of hypercaloric diet in glycemic metabolism, morphology and function of adipose tissue and pancreatic islets in female animals. These results may improve the understanding of the mechanisms underlying the pathogenesis of obesity in women and eventually open new avenues for therapeutic strategies and better comprehension of the interactions between progesterone effects and obesity.

Genetic risk converges on regulatory networks mediating early type 2 diabetes.

Type 2 diabetes mellitus (T2D), a major cause of worldwide morbidity and mortality, is characterized by dysfunction of insulin-producing pancreatic islet ß cells1,2. T2D genome-wide association studies (GWAS) have identified hundreds of signals in non-coding and ß cell regulatory genomic regions, but deciphering their biological mechanisms remains challenging3-5. Here, to identify early disease-driving events, we performed traditional and multiplexed pancreatic tissue imaging, sorted-islet cell transcriptomics and islet functional analysis of early-stage T2D and control donors. By integrating diverse modalities, we show that early-stage T2D is characterized by ß cell-intrinsic defects that can be proportioned into gene regulatory modules with enrichment in signals of genetic risk. After identifying the ß cell hub gene and transcription factor RFX6 within one such module, we demonstrated multiple layers of genetic risk that converge on an RFX6-mediated network to reduce insulin secretion by ß cells. RFX6 perturbation in primary human islet cells alters ß cell chromatin architecture at regions enriched for T2D GWAS signals, and population-scale genetic analyses causally link genetically predicted reduced RFX6 expression with increased T2D risk. Understanding the molecular mechanisms of complex, systemic diseases necessitates integration of signals from multiple molecules, cells, organs and individuals, and thus we anticipate that this approach will be a useful template to identify and validate key regulatory networks and master hub genes for other diseases or traits using GWAS data.

Angiotensin-(1-7) Improves Islet ß-cell Dedifferentiation by Activating PI3K/Akt/FoxO1 Pathway.

BACKGROUND: Islet ß-cell dedifferentiation may be the main cause of reduced insulin secretion. Angiotensin-(1-7) [Ang-(1-7)] can attenuate high glucose-induced apoptosis and dedifferentiation of pancreatic ß-cell, but the specific signal transduction pathway and mechanism are not yet clear. OBJECTIVES: This study aimed to investigate the effects of Ang-(1-7) on high glucose-induced islet ß-cell dedifferentiation by activating the phosphatidylinositol-3-kinase/Protein kinase B/ Forkhead box transcription factor O1 (PI3K/Akt/FoxO1) signaling pathway. METHODS: The mouse islet ß-cell line MIN6 cells were passaged and cultured and randomly divided into five groups: control (Con) group, high glucose (HG) group, HG with Ang-(1-7) group, HG with Ang-(1-7) and specific MasR antagonist A-779 group, and HG with Ang-(1-7) and PI3K inhibitor LY294002 group. After 48 hours, glucose-stimulated insulin secretion (GSIS) was detected by Enzyme-Linked Immunosorbent Assay (ELISA). The mRNA and protein expression levels of ß-cell-specific factors (Pancreatic duodenal homeobox-1 (Pdx1), v-maf musculoaponeurotic fibrosarcoma oncogene homolog A(MafA)) and endocrine progenitor cell-specific factors (Octamer binding transcription factor 4(Oct4), Nanog) were measured by Real Time-PCR and Western blot. The factors of protein expression levels of PI3K/Akt/FoxO1 signaling pathway (Akt, p-Akt, Fox- O1, p-FoxO1) were determined by Western blot. RESULTS: We observed for the first time that high glucotoxicity can induce dedifferentiation of pancreatic islet ß-cell, causing a decrease in insulin secretion levels and expression of Pdx1, MafA, p-- FoxO1, and p-Akt and an increase in expression of Oct4 and Nanog. After Ang-(1-7) intervention, insulin secretion levels and expression of Pdx1, MafA, p-FoxO1 and p-Akt were increased, and the levels of Oct4 and Nanog were reduced. However, A-779 and LY294002 could reverse this effect. During these processes, the total Akt and total FoxO1 expression did not change significantly. CONCLUSION: Ang-(1-7) may prevent high glucose-induced pathological dedifferentiation of pancreatic ß-cell by activating the PI3K/Akt/FoxO1 signaling pathway.

Circularity of islets is a distinct marker for the pathological diagnosis of adult non-neoplastic hyperinsulinemic hypoglycemia using surgical specimens.

BACKGROUND: Adult non-neoplastic hyperinsulinemic hypoglycemia (ANHH), also known as adult-onset nesidioblastosis, is a rare cause of endogenous hyperinsulinemic hypoglycemia in adults. This disease is characterized by diffuse hyperplasia of pancreatic endocrine cells and is diagnosed by a pathological examination. While diagnostic criteria for this disease have already been proposed, we established more quantitative criteria for evaluating islet morphology. METHODS: We measured the number, maximum diameter, total area, and circularity (representing how closely islets resemble perfect spheres) of islets contained in representative sections of ANHH (n = 4) and control cases (n = 5) using the NIS-Elements software program. We also measured the average cell size, percentage of cells with enlarged nuclei, and percentage of cells with recognizable nucleoli for each of three representative islets. We also assessed the interobserver diagnostic concordance of ANHH between five experienced and seven less-experienced pathologists. RESULTS: There was no significant difference in the number, maximum diameter, or total area of islets between the two groups, even after correcting for these parameters per unit area. However, the number of islets with low circularity (< 0.71) per total area of the pancreatic parenchyma was significantly larger in ANHH specimens than in controls. We also found that the percentage of cells with recognizable nucleoli was significantly higher in the ANHH group than in the controls. There were no significant differences in the average cell size or the number of cells with enlarged nuclei between the groups. The correct diagnosis rate with the blind test was 47.5% ± 6.12% for experienced pathologists and 50.0% ± 8.63% for less-experienced pathologists, with no significant differences noted. CONCLUSIONS: Low circularity, which indicates an irregular islet shape, referred to as "irregular shape and occasional enlargement of islets" and "lobulated islet structure" in a previous report, is a useful marker for diagnosing ANHH. An increased percentage of recognizable nucleoli, corresponding to "macronucleoli in ß-cells," has potential diagnostic value.

Chronic periodontitis induces the proliferation of pancreatic ß-cells to cause hyperinsulinemia in a rat model.

BACKGROUND AND OBJECTIVE: The purpose of this study was to determine if chronic periodontitis (CP) may induce hyperinsulinemia and may have the effect of on pancreatic ß-cell proliferation in a rat model. MATERIALS AND METHODS: Twelve male Sprague-Dawley rats were divided into two groups: the CP group and the control group (Con group). The following contents were evaluated: pathological changes in periodontal soft and hard tissues; serum lipopolysaccharide (LPS) level, serum fasting insulin (FINS) level, fasting blood glucose (FBG) level, and homeostasis model assessment (HOMA) ß (HOMA-ß) index; histopathological examination of islets; immunohistochemistry of insulin and p-Smad2 expression in islets; immunofluorescence of changes in the relative number of ß-cells and the number of Ki67-positive ß-cells. Western blotting was used to analyze p-Smad2/Smad2 levels. Results were analyzed by two independent samples t tests. RESULTS: Increased serum LPS level, FINS level, and HOMA-ß index were observed in the rats of the CP group; FBG level did not change significantly; histological assessments showed an enlarged islet area, increased insulin content, relatively increased ß-cells, increased Ki67-positive ß-cells, and decreased p-Smad2 expression in islets in the rats of the CP group. CONCLUSION: Our study results link CP-induced hyperinsulinemia with changes in islets, such as islet hyperplasia and compensatory ß-cell proliferation, by using a CP rat model.

Islet hypoplasia of adult offspring rats caused by intrauterine chronic hypoxia is compensated by up-regulation of INS and PDX-1.

BACKGROUND: Intrauterine chronic hypoxia (ICH) can lead to pancreatic dysmetabolism in offspring. This study aimed to determine the changes in islet function of offspring through a rat ICH model and detect the factors affecting islet function. METHODS: Twenty couples of healthy Sprague - Dawley adult rats were randomly mated, and the pregnant rats were randomly allocated to ICH and normal control (NC) groups. Pregnant rats in the ICH group were placed in a hypoxic chamber with 13% oxygen concentration for hypoxia treatment twice a day for 4 h until delivery at 21 days. NC group is inlet with normal air from beginning to end. After delivery, blood was taken from the heart of pregnant rats for blood gas analysis. The weight of the offspring rats was measured at 12 h after birth and 16 weeks after birth. At 16 weeks, the immunohistochemical results of ß-cell total, islet area, insulin (INS), and glucose transporter 2 (GLUT2) proteins were obtained from the islets. The mRNA data of INS and pancreatic and duodenal homeobox 1 (PDX-1) genes were obtained from pancreas. RESULTS: We found the ß-cell total, islet area, and the positive cell area of INS and GLUT2 of offspring rats in ICH group were lower than those of NC group, while the levels of INS and PDX-1 genes were higher in ICH group than in NC group. CONCLUSIONS: ICH can lead to islet hypoplasia in adult male offspring rats. However, this is within the compensatory range.

The pathogenic "symphony" in type 1 diabetes: A disorder of the immune system, ß cells, and exocrine pancreas.

Type 1 diabetes (T1D) is widely considered to result from the autoimmune destruction of insulin-producing ß cells. This concept has been a central tenet for decades of attempts seeking to decipher the disorder's pathogenesis and prevent/reverse the disease. Recently, this and many other disease-related notions have come under increasing question, particularly given knowledge gained from analyses of human T1D pancreas. Perhaps most crucial are findings suggesting that a collective of cellular constituents-immune, endocrine, and exocrine in origin-mechanistically coalesce to facilitate T1D. This review considers these emerging concepts, from basic science to clinical research, and identifies several key remaining knowledge voids.

Human IAPP is a contributor to painful diabetic peripheral neuropathy.

Peripheral neuropathy is a frequent complication of type 2 diabetes mellitus (T2DM). We investigated whether human islet amyloid polypeptide (hIAPP), which forms pathogenic aggregates that damage pancreatic islet ß cells in T2DM, is involved in T2DM-associated peripheral neuropathy. In vitro, hIAPP incubation with sensory neurons reduced neurite outgrowth and increased levels of mitochondrial reactive oxygen species. hIAPP-transgenic mice, which have elevated plasma hIAPP levels without hyperglycemia, developed peripheral neuropathy as evidenced by pain-associated behavior and reduced intraepidermal nerve fiber (IENF) density. Similarly, hIAPP Ob/Ob mice, which have hyperglycemia in combination with elevated plasma hIAPP levels, had signs of neuropathy, although more aggravated. In wild-type mice, intraplantar and intravenous hIAPP injections induced long-lasting allodynia and decreased IENF density. Non-aggregating murine IAPP, mutated hIAPP (pramlintide), or hIAPP with pharmacologically inhibited aggregation did not induce these effects. T2DM patients had reduced IENF density and more hIAPP oligomers in the skin compared with non-T2DM controls. Thus, we provide evidence that hIAPP aggregation is neurotoxic and mediates peripheral neuropathy in mice. The increased abundance of hIAPP aggregates in the skin of T2DM patients supports the notion that hIAPP is a potential contributor to T2DM neuropathy in humans.

Respiratory infections and type 1 diabetes: Potential roles in pathogenesis.

Among the environmental factors associated with type 1 diabetes (T1D), viral infections of the gut and pancreas has been investigated most intensely, identifying enterovirus infections as the prime candidate trigger of islet autoimmunity (IA) and T1D development. However, the association between respiratory tract infections (RTI) and IA/T1D is comparatively less known. While there are significant amounts of epidemiological evidence supporting the role of respiratory infections in T1D, there remains a paucity of data characterising infectious agents at the molecular level. This gap in the literature precludes the identification of the specific infectious agents driving the association between RTI and T1D. Furthermore, the effect of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections on the development of IA/T1D remains undeciphered. Here, we provide a comprehensive overview of the evidence to date, implicating RTIs (viral and non-viral) as potential risk factors for IA/T1D.

Heterogeneity of Islet-Infiltrating IL-21+ CD4 T Cells in a Mouse Model of Type 1 Diabetes.

IL-21 is essential for type 1 diabetes (T1D) development in the NOD mouse model. IL-21-expressing CD4 T cells are present in pancreatic islets where they contribute to T1D progression. However, little is known about their phenotype and differentiation states. To fill this gap, we generated, to our knowledge, a novel IL-21 reporter NOD strain to further characterize IL-21+ CD4 T cells in T1D. IL-21+ CD4 T cells accumulate in pancreatic islets and recognize ß cell Ags. Single-cell RNA sequencing revealed that CD4 T effector cells in islets actively express IL-21 and they are highly diabetogenic despite expressing multiple inhibitory molecules, including PD-1 and LAG3. Islet IL-21+ CD4 T cells segregate into four phenotypically and transcriptionally distinct differentiation states, that is, less differentiated early effectors, T follicular helper (Tfh)-like cells, and two Th1 subsets. Trajectory analysis predicts that early effectors differentiate into both Tfh-like and terminal Th1 cells. We further demonstrated that intrinsic IL-27 signaling controls the differentiation of islet IL-21+ CD4 T cells, contributing to their helper function. Collectively, our study reveals the heterogeneity of islet-infiltrating IL-21+ CD4 T cells and indicates that both Tfh-like and Th1 subsets produce IL-21 throughout their differentiation process, highlighting the important sources of IL-21 in T1D pathogenesis.

Islet-specific CD8+ T cells gain effector function in the gut lymphoid tissues via bystander activation not molecular mimicry.

Type 1 diabetes (T1D) is caused by aberrant activation of autoreactive T cells specific for the islet beta cells. How islet-specific T cells evade tolerance to become effector T cells is unknown, but it is believed that an altered gut microbiota plays a role. Possible mechanisms include bystander activation of autoreactive T cells in the gut or "molecular mimicry" from cross-reactivity between gut microbiota-derived peptides and islet-derived epitopes. To investigate these mechanisms, we use two islet-specific CD8+ T cell clones and the non-obese diabetic mouse model of type 1 diabetes. Both insulin-specific G9C8 cells and IGRP-specific 8.3 cells underwent early activation and proliferation in the pancreatic draining lymph nodes but not in the Peyer's patches or mesenteric lymph nodes. Mutation of the endogenous epitope for G9C8 cells abolished their CD69 upregulation and proliferation, ruling out G9C8 cell activation by a gut microbiota derived peptide and molecular mimicry. However, previously activated islet-specific effector memory cells but not naïve cells migrated into the Peyer's patches where they increased their cytotoxic function. Oral delivery of butyrate, a microbiota derived anti-inflammatory metabolite, reduced IGRP-specific cytotoxic function. Thus, while initial activation of islet-specific CD8+ T cells occurred in the pancreatic lymph nodes, activated cells trafficked through the gut lymphoid tissues where they gained additional effector function via non-specific bystander activation influenced by the gut microbiota.

Multi-omic interactions in the gut of children at the onset of islet autoimmunity.

BACKGROUND: The gastrointestinal ecosystem is a highly complex environment with a profound influence on human health. Inflammation in the gut, linked to an altered gut microbiome, has been associated with the development of multiple human conditions including type 1 diabetes (T1D). Viruses infecting the gastrointestinal tract, especially enteroviruses, are also thought to play an important role in T1D pathogenesis possibly via overlapping mechanisms. However, it is not known whether the microbiome and virome act together or which risk factor may be of greater importance at the time when islet autoimmunity is initiated. RESULTS: Here, we apply an integrative approach to combine comprehensive fecal virome, microbiome, and metaproteome data sampled before and at the onset of islet autoimmunity in 40 children at increased risk of T1D. We show strong age-related effects, with microbial and metaproteome diversity increasing with age while host antibody number and abundance declined with age. Mastadenovirus, which has been associated with a reduced risk of T1D, was associated with profound changes in the metaproteome indicating a functional shift in the microbiota. Multi-omic factor analysis modeling revealed a cluster of proteins associated with carbohydrate transport from the genus Faecalibacterium were associated with islet autoimmunity. CONCLUSIONS: These findings demonstrate the interrelatedness of the gut microbiota, metaproteome and virome in young children. We show a functional remodeling of the gut microbiota accompanies both islet autoimmunity and viral infection with a switch in function in Faecalibacterium occurring at the onset of islet autoimmunity. Video Abstract.

Beyond the "3 Ps": A critical appraisal of the non-endocrine manifestations of multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type 1 (MEN1), an autosomal-dominantly inherited tumor syndrome, is classically defined by tumors arising from the "3 Ps": Parathyroids, Pituitary, and the endocrine Pancreas. From its earliest descriptions, MEN1 has been associated with other endocrine and non-endocrine neoplastic manifestations. High quality evidence supports a direct association between pathogenic MEN1 variants and neoplasms of the skin (angiofibromas and collagenomas), adipose tissue (lipomas and hibernomas), and smooth muscle (leiomyomas). Although CNS tumors, melanoma, and, most recently, breast cancer have been reported as MEN1 clinical manifestations, the published evidence to date is not yet sufficient to establish causality. Well-designed, multicenter prospective studies will help us to understand better the relationship of these tumors to MEN1, in addition to verifying the true prevalence and penetrance of the well-documented neoplastic associations. Nevertheless, patients affected by MEN1 should be aware of these non-endocrine manifestations, and providers should be encouraged always to think beyond the "3 Ps" when treating an MEN1 patient.

Altered microvasculature in pancreatic islets from subjects with type 1 diabetes.

AIMS: The transcriptome of different dissociated pancreatic islet cells has been described in enzymatically isolated islets in both health and disease. However, the isolation, culturing, and dissociation procedures likely affect the transcriptome profiles, distorting the biological conclusions. The aim of the current study was to characterize the cells of the islets of Langerhans from subjects with and without type 1 diabetes in a way that reflects the in vivo situation to the highest possible extent. METHODS: Islets were excised using laser capture microdissection directly from frozen pancreatic tissue sections obtained from organ donors with (n = 7) and without (n = 8) type 1 diabetes. Transcriptome analysis of excised samples was performed using AmpliSeq. Consecutive pancreatic sections were used to estimate the proportion of beta-, alpha-, and delta cells using immunofluorescence and to examine the presence of CD31 positive endothelial regions using immunohistochemistry. RESULTS: The proportion of beta cells in islets from subjects with type 1 diabetes was reduced to 0% according to both the histological and transcriptome data, and several alterations in the transcriptome were derived from the loss of beta cells. In total, 473 differentially expressed genes were found in the islets from subjects with type 1 diabetes. Functional enrichment analysis showed that several of the most upregulated gene sets were related to vasculature and angiogenesis, and histologically, vascular density was increased in subjects with type 1 diabetes. Downregulated in type 1 diabetes islets was the gene set epithelial mesenchymal transition. CONCLUSION: A number of transcriptional alterations are present in islets from subjects with type 1 diabetes. In particular, several gene sets related to vasculature and angiogenesis are upregulated and there is an increased vascular density, suggesting an altered microvasculature in islets from subjects with type 1 diabetes. By studying pancreatic islets extracted directly from snap-frozen pancreatic tissue, this study reflects the in vivo situation to a high degree and gives important insights into islet pathophysiology in type 1 diabetes.

Role of Autophagy in the Pathogenesis of Diabetes and Therapeutic Potential of Autophagy Modulators in the Treatment of Diabetes and Metabolic Syndrome.

Autophagy is critically involved in the maintenance of intracellular nutrient homeostasis and organelle function. Dysregulated autophagy is likely to play a role in the development of metabolic disorders and diabetes because autophagy is critical in the rejuvenation of dysfunctional or stressed endoplasmic reticulum and mitochondria that play a crucial role in the development of diabetes. Indeed, systemic autophagy insufficiency led to the increased tissue lipid content, aggravated metabolic and finally more severe diabetes when metabolic stress was imposed, suggesting that autophagy insufficiency of dysfunction of lysosome, an effector organelle of autophagy, due to aging, genetic predisposition or environmental factors could be an underlying cause of diabetes. Conversely, autophagy enhancer could improve metabolic profile of obese mice by reducing tissue lipid content and ameliorating metabolic inflammation. Furthermore, clearance of human islet amyloid polypeptide (hIAPP) oligomer and amyloid that accumulate in pancreatic islets of > 90% of diabetes patients was also dependent on autophagy. Consistently, autophagy enhancer could improve glucose profile and ß-cell function of transgenic mice expressing amyloidogenic hIAPP in pancreatic ß-cells, which was accompanied by reduced accumulation of hIAPP oligomer or amyloid, ameliorated ß-cell apoptosis and increased ß-cell mass. These results suggest that autophagy enhancer could be a novel therapeutic modality against diabetes associated with lipid overload and human diabetes characterized by islet amyloid accumulation.

3D chromatin maps of the human pancreas reveal lineage-specific regulatory architecture of T2D risk.

Three-dimensional (3D) chromatin organization maps help dissect cell-type-specific gene regulatory programs. Furthermore, 3D chromatin maps contribute to elucidating the pathogenesis of complex genetic diseases by connecting distal regulatory regions and genetic risk variants to their respective target genes. To understand the cell-type-specific regulatory architecture of diabetes risk, we generated transcriptomic and 3D epigenomic profiles of human pancreatic acinar, alpha, and beta cells using single-cell RNA-seq, single-cell ATAC-seq, and high-resolution Hi-C of sorted cells. Comparisons of these profiles revealed differential A/B (open/closed) chromatin compartmentalization, chromatin looping, and transcriptional factor-mediated control of cell-type-specific gene regulatory programs. We identified a total of 4,750 putative causal-variant-to-target-gene pairs at 194 type 2 diabetes GWAS signals using pancreatic 3D chromatin maps. We found that the connections between candidate causal variants and their putative target effector genes are cell-type stratified and emphasize previously underappreciated roles for alpha and acinar cells in diabetes pathogenesis.