Abnormalities of the Exocrine Pancreas in Type 1 Diabetes

Impaired islet function and normal exocrine enzyme secretion occur with low inter-regional variation in type 1 diabetes

Histopathological heterogeneity in the human pancreas is well documented; however, functional evidence at the tissue level is scarce. Herein, we investigate in situ glucose-stimulated islet and carbachol-stimulated acinar cell secretion across the pancreas head (PH), body (PB), and tail (PT) regions in donors without diabetes (ND; n = 15), positive for one islet autoantibody (1AAb+; n = 7), and with type 1 diabetes (T1D; <14 months duration, n = 5). Insulin, glucagon, pancreatic amylase, lipase, and trypsinogen secretion along with 3D tissue morphometrical features are comparable across regions in ND. In T1D, insulin secretion and beta-cell volume are significantly reduced within all regions, while glucagon and enzymes are unaltered. Beta-cell volume is lower despite normal insulin secretion in 1AAb+, resulting in increased volume-adjusted insulin secretion versus ND. Islet and acinar cell secretion in 1AAb+ are consistent across the PH, PB, and PT. This study supports low inter-regional variation in pancreas slice function and, potentially, increased metabolic demand in 1AAb+.

The Extra-Islet Pancreas Supports Autoimmunity in Human Type 1 Diabetes

In autoimmune Type 1 diabetes (T1D), immune cells infiltrate and destroy the islets of Langerhans - islands of endocrine tissue dispersed throughout the pancreas. However, the contribution of cellular programs outside islets to insulitis is unclear. Here, using CO-Detection by indEXing (CODEX) tissue imaging and cadaveric pancreas samples, we simultaneously examine islet and extra-islet inflammation in human T1D. We identify four sub-states of inflamed islets characterized by the activation profiles of CD8 + T cells enriched in islets relative to the surrounding tissue. We further find that the extra-islet space of lobules with extensive islet-infiltration differs from the extra-islet space of less infiltrated areas within the same tissue section. Finally, we identify lymphoid structures away from islets enriched in CD45RA + T cells - a population also enriched in one of the inflamed islet sub-states. Together, these data help define the coordination between islets and the extra-islet pancreas in the pathogenesis of human T1D.

Single-cell transcriptomics reveals a role for pancreatic duct cells as potential mediators of inflammation in diabetes mellitus

Introduction

Inflammation of the pancreas contributes to the development of diabetes mellitus. Although it is well-accepted that local inflammation leads to a progressive loss of functional beta cell mass that eventually causes the onset of the disease, the development of islet inflammation remains unclear.

Methods

Here, we used single-cell RNA sequencing to explore the cell type-specific molecular response of primary human pancreatic cells exposed to an inflammatory environment.

Results

We identified a duct subpopulation presenting a unique proinflammatory signature among all pancreatic cell types.

Discussion

Overall, the findings of this study point towards a role for duct cells in the propagation of islet inflammation, and in immune cell recruitment and activation, which are key steps in the pathophysiology of diabetes mellitus.

Impaired islet function with normal exocrine enzyme secretion is consistent across the head, body, and tail pancreas regions in type 1 diabetes

Histopathological heterogeneity in human pancreas has been well documented; however, functional evidence at the tissue level is scarce. Herein we investigated in situ glucose-stimulated islet and carbachol-stimulated acinar cell secretion across the pancreas head (PH), body (PB), and tail (PT) regions in no diabetes (ND, n=15), single islet autoantibody-positive (1AAb+, n=7), and type 1 diabetes donors (T1D, <14 months duration, n=5). Insulin, glucagon, pancreatic amylase, lipase, and trypsinogen secretion along with 3D tissue morphometrical features were comparable across the regions in ND. In T1D, insulin secretion and beta-cell volume were significantly reduced within all regions, while glucagon and enzymes were unaltered. Beta-cell volume was lower despite normal insulin secretion in 1AAb+, resulting in increased volume-adjusted insulin secretion versus ND. Islet and acinar cell secretion in 1AAb+ were consistent across PH, PB and PT. This study supports low inter-regional variation in pancreas slice function and potentially, increased metabolic demand in 1AAb+.

Integrating multi-omics data to analyze the potential pathogenic mechanism of CTSH gene involved in type 1 diabetes in the exocrine pancreas

Type 1 diabetes (T1D) is an autoimmune disease caused by the destruction of insulin-producing pancreatic islet beta cells. Despite significant advancements, the precise pathogenesis of the disease remains unknown. This work integrated data from expression quantitative trait locus (eQTL) studies with Genome wide association study (GWAS) summary data of T1D and single-cell transcriptome data to investigate the potential pathogenic mechanisms of the CTSH gene involved in T1D in exocrine pancreas. Using the summary data-based Mendelian randomization (SMR) approach, we obtained four potential causative genes associated with T1D: BTN3A2, PGAP3, SMARCE1 and CTSH. To further investigate these genes'roles in T1D development, we validated them using a scRNA-seq dataset from pancreatic tissues of both T1D patients and healthy controls. The analysis showed a significantly high expression of the CTSH gene in T1D acinar cells, whereas the other three genes showed no significant changes in the scRNA-seq data. Moreover, single-cell WGCNA analysis revealed the strongest positive correlation between the module containing CTSH and T1D. In addition, we found cellular ligand-receptor interactions between the acinar cells and different cell types, especially ductal cells. Finally, based on functional enrichment analysis, we hypothesized that the CTSH gene in the exocrine pancreas enhances the antiviral response, leading to the overexpression of pro-inflammatory cytokines and the development of an inflammatory microenvironment. This process promotes β cells injury and ultimately the development of T1D. Our findings offer insights into the underlying pathogenic mechanisms of T1D.

Observing exocrine pancreas metabolism using a novel pancreas perfusion technique in combination with hyperpolarized [1-13 C]pyruvate

In a clinical setting, ex vivo perfusions are routinely used to maintain and assess organ viability prior to transplants. Organ perfusions are also a model system to examine metabolic flux while retaining the local physiological structure, with significant success using hyperpolarized (HP) 13 C NMR in this context. We use a novel exocrine pancreas perfusion technique via the common bile duct to assess acinar cell metabolism with HP [1-13 C]pyruvate. The exocrine component of the pancreas produces digestive enzymes through the ductal system and is often neglected in research on the pancreas. Real-time production of [1-13 C]lactate, [1-13 C]alanine, [1-13 C]malate, [4-13 C]malate, [1-13 C]aspartate, and H13 CO3 - was detected. The appearance of these resonances indicates flux through both pyruvate dehydrogenase and pyruvate carboxylase. We studied excised pancreata from C57BL/6J mice and NOD.Rag1-/- .AI4α/β mice, a commonly used model of Type 1 Diabetes (T1D). Pancreata from the T1D mice displayed increased lactate to alanine ratio without changes in oxygen consumption, signifying increased cytosolic NADH levels. The mass isotopologue analysis of the extracted pancreas tissue using gas chromatography-mass spectrometry revealed confirmatory 13 C enrichment in multiple TCA cycle metabolites that are products of pyruvate carboxylation. The methodology presented here has the potential to provide insight into mechanisms underlying several pancreatic diseases, such as diabetes, pancreatitis, and pancreatic cancer.

Pancreatic Ubap2 deletion regulates glucose tolerance, inflammation, and protection from cerulein-induced pancreatitis

Ubiquitin-binding associated protein 2 (UBAP2) is reported to promote macropinocytosis and pancreatic adenocarcinoma (PDAC) growth, however, its role in normal pancreatic function remains unknown. We addressed this knowledge gap by generating UBAP2 knockout (U2KO) mice under a pancreas-specific Cre recombinase (Pdx1-Cre). Pancreatic architecture remained intact in U2KO animals, but they demonstrated slight glucose intolerance compared to controls. Upon cerulein challenge to induce pancreatitis, U2KO animals had reduced levels of several pancreatitis-relevant cytokines, amylase and lipase in the serum, reduced tissue damage, and lessened neutrophil infiltration into the pancreatic tissue. Mechanistically, cerulein-challenged U2KO animals revealed reduced NF-κB activation compared to controls. In vitro promoter binding studies confirmed the reduction of NF-κB binding to its target molecules supporting UBAP2 as a new regulator of inflammation in pancreatitis and may be exploited as a therapeutic target in future to inhibit pancreatitis.

Abnormal acinar-β-cell crosstalk in type 2 diabetes

Cellular crosstalk plays a vital role in maintaining pancreas homeostasis. Recently, in Cell Metabolism, Basile et al. demonstrated that aberrant upregulation of acinar-cell-specific pancreatic elastase CELA3B within endocrine islets reduces β-cell viability in type 2 diabetes (T2D). This identifies detrimental acinar-β-cell crosstalk as a novel pathogenic mechanism in diabetes.

Are we missing pancreatic exocrine insufficiency in 'at-risk' groups? Prospective assessment of the current practice and yield of faecal elastase testing in patients with diabetes mellitus, HIV and/or high alcohol intake

There is cumulative evidence that pancreatic exocrine insufficiency (PEI) is under-recognised and can occur in patients with 'at-risk' conditions. Thus, we aimed to assess the current practice and yield of requesting faecal elastase (FEL-1), an indicator of PEI, in patients with 'at-risk' conditions. We prospectively recruited patients attending secondary care clinics with diabetes mellitus (DM), people living with HIV (PLHIV) and inpatients admitted to hospital with high alcohol intake (HAI). All patients underwent testing with FEL-1. Those patients with PEI (FEL-1 <200 μg/g) were contacted and offered a follow-up review in gastroenterology clinic. In total, 188 patients were recruited (HAI, n=78; DM, n=64; and PLHIV, n=46). Previous FEL-1 testing had not been performed in any of the patients. The return rate of samples was 67.9% for patients with HAI, 76.6% for those with DM and 56.5% for those with PLHIV. The presence of PEI was shown in 20.4% of patients with DM, 15.4% of patients with PLHIV and 22.6% in those with HAI. Diarrhoea and bloating were the most reported symptoms in followed-up patients with low FEL-1 (31.8% and 22.7% of patients, respectively). Follow-up computed tomography (CT) scans in those patients with PEI identified chronic pancreatitis changes in 13.6% and pancreatic atrophy in 31.8% of patients. These results suggest that there is a lack of testing for PEI in 'at-risk' groups. Our findings also suggest that using FEL-1 to test for PEI in patients with DM, PLHIV and HAI has a significant impact, although further studies are required to validate these findings.

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

Type 1 diabetes (T1D) is widely considered to result from the autoimmune destruction of insulin-producing β 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.

Pancreatic draining lymph nodes (PLNs) serve as a pathogenic hub contributing to the development of type 1 diabetes

Type 1 diabetes (T1D) is a chronic, progressive autoinflammatory disorder resulting from the breakdown of self-tolerance and unrestrained β cell-reactive immune response. Activation of immune cells is initiated in islet and amplified in lymphoid tissues, especially those pancreatic draining lymph nodes (PLNs). The knowledge of PLNs as the hub of aberrant immune response is continuously being replenished and renewed. Here we provide a PLN-centered view of T1D pathogenesis and emphasize that PLNs integrate signal inputs from the pancreas, gut, viral infection or peripheral circulation, undergo immune remodeling within the local microenvironment and export effector cell components into pancreas to affect T1D progression. In accordance, we suggest that T1D intervention can be implemented by three major ways: cutting off the signal inputs into PLNs (reduce inflammatory β cell damage, enhance gut integrity and control pathogenic viral infections), modulating the immune activation status of PLNs and blocking the outputs of PLNs towards pancreatic islets. Given the dynamic and complex nature of T1D etiology, the corresponding intervention strategy is thus required to be comprehensive to ensure optimal therapeutic efficacy.

Proteome Mapping of the Human Pancreatic Islet Microenvironment Reveals Endocrine-Exocrine Signaling Sphere of Influence

The need for a clinically accessible method with the ability to match protein activity within heterogeneous tissues is currently unmet by existing technologies. Our proteomics sample preparation platform, named microPOTS (Microdroplet Processing in One pot for Trace Samples), can be used to measure relative protein abundance in micron-scale samples alongside the spatial location of each measurement, thereby tying biologically interesting proteins and pathways to distinct regions. However, given the smaller pixel/voxel number and amount of tissue measured, standard mass spectrometric analysis pipelines have proven inadequate. Here we describe how existing computational approaches can be adapted to focus on the specific biological questions asked in spatial proteomics experiments. We apply this approach to present an unbiased characterization of the human islet microenvironment comprising the entire complex array of cell types involved while maintaining spatial information and the degree of the islet's sphere of influence. We identify specific functional activity unique to the pancreatic islet cells and demonstrate how far their signature can be detected in the adjacent tissue. Our results show that we can distinguish pancreatic islet cells from the neighboring exocrine tissue environment, recapitulate known biological functions of islet cells, and identify a spatial gradient in the expression of RNA processing proteins within the islet microenvironment.

CT imaging shows specific pancreatic abnormalities in persons with cystic fibrosis related diabetes

Cystic fibrosis related diabetes (CFRD) is observed in 20-50% of adults with cystic fibrosis (CF). Pancreas abnormalities on imaging, e.g. pancreas lipomatosis, are frequent in subjects with CF. We hypothesized that specific abnormalities may characterize patients with CFRD. We performed a retrospective study comparing the computed tomography (CT) of participants with CF with or without diabetes ("CFRD" and "CF control" groups). We classified the pancreas on imaging according to 3 categories: normal, partial lipomatosis and complete lipomatosis of the pancreas. We also assessed the presence or absence of pancreatic calcifications. Forty-one CFRD and 53 CF control participants were included. Only 2% of the patients with CFRD had a normal pancreas, as compared with 30% of the participants from the CF control group (p = 0.0016). Lipomatosis was more frequent in subjects with CFRD and was related to exocrine pancreatic insufficiency (EPI) and to severe CFTR mutations (classes I to III). Nine participants with diabetes (22%) presented with pancreatic calcifications, versus none of the control participants (p = 0.0003). In conclusion, pancreas imaging was almost always abnormal in subjects with CFRD, while it was normal in a third of the CF control subjects. Pancreatic calcifications were specific of subjects with CFRD.

Integrated Physiology of the Exocrine and Endocrine Compartments in Pancreatic Diseases: Workshop Proceedings

The Integrated Physiology of the Exocrine and Endocrine Compartments in Pancreatic Diseases workshop was a 1.5-day scientific conference at the National Institutes of Health (Bethesda, MD) that engaged clinical and basic science investigators interested in diseases of the pancreas. This report provides a summary of the proceedings from the workshop. The goals of the workshop were to forge connections and identify gaps in knowledge that could guide future research directions. Presentations were segregated into six major theme areas, including 1) pancreas anatomy and physiology, 2) diabetes in the setting of exocrine disease, 3) metabolic influences on the exocrine pancreas, 4) genetic drivers of pancreatic diseases, 5) tools for integrated pancreatic analysis, and 6) implications of exocrine-endocrine cross talk. For each theme, multiple presentations were followed by panel discussions on specific topics relevant to each area of research; these are summarized here. Significantly, the discussions resulted in the identification of research gaps and opportunities for the field to address. In general, it was concluded that as a pancreas research community, we must more thoughtfully integrate our current knowledge of normal physiology as well as the disease mechanisms that underlie endocrine and exocrine disorders so that there is a better understanding of the interplay between these compartments.

Type 1 Diabetes: A Disorder of the Exocrine and Endocrine Pancreas

Type 1 diabetes has historically been described as an endocrine (β-cell) specific autoimmune disease. However, a substantial reduction (20-50%) in pancreas organ size and subclinical to symptomatic exocrine pancreatic insufficiency are present at diagnosis and may begin even prior to the development of islet autoimmunity. The mechanisms of exocrine loss in type 1 diabetes are not well understood, but leading hypotheses include developmental defects, β-cell loss resulting in exocrine atrophy, or autoimmune or inflammatory destruction of exocrine cells. Inflammatory changes including acute and chronic pancreatitis, exocrine T cell infiltration and classical complement activation, and serum exocrine autoantibodies within type 1 diabetes individuals suggest that an autoimmune or inflammatory process may contribute to exocrine pancreatic dysfunction. Exocrine pancreas atrophy primarily occurs prior to the onset of clinical disease. Indeed, recent work implicates exocrine-specific alterations in gene and protein expression as key in type 1 diabetes development. Measures of exocrine size and function could be useful additions in the prediction of disease onset and in identifying potential therapeutic responders to disease therapies, however, this is an underdeveloped area of research. Additionally, exocrine pancreatic insufficiency is underdiagnosed in individuals with type 1 diabetes and individualized treatment protocols are lacking. Much work remains to be done in this area, but we can definitively say that type 1 diabetes is a disorder of both the exocrine and endocrine pancreas likely from the start.

Alterations of oral microbiota and impact on the gut microbiome in type 1 diabetes mellitus revealed by integrated multi-omic analyses

BACKGROUND

Alterations to the gut microbiome have been linked to multiple chronic diseases. However, the drivers of such changes remain largely unknown. The oral cavity acts as a major route of exposure to exogenous factors including pathogens, and processes therein may affect the communities in the subsequent compartments of the gastrointestinal tract. Here, we perform strain-resolved, integrated meta-genomic, transcriptomic, and proteomic analyses of paired saliva and stool samples collected from 35 individuals from eight families with multiple cases of type 1 diabetes mellitus (T1DM).

RESULTS

We identified distinct oral microbiota mostly reflecting competition between streptococcal species. More specifically, we found a decreased abundance of the commensal Streptococcus salivarius in the oral cavity of T1DM individuals, which is linked to its apparent competition with the pathobiont Streptococcus mutans. The decrease in S. salivarius in the oral cavity was also associated with its decrease in the gut as well as higher abundances in facultative anaerobes including Enterobacteria. In addition, we found evidence of gut inflammation in T1DM as reflected in the expression profiles of the Enterobacteria as well as in the human gut proteome. Finally, we were able to follow transmitted strain-variants from the oral cavity to the gut at the individual omic levels, highlighting not only the transfer, but also the activity of the transmitted taxa along the gastrointestinal tract.

CONCLUSIONS

Alterations of the oral microbiome in the context of T1DM impact the microbial communities in the lower gut, in particular through the reduction of "mouth-to-gut" transfer of Streptococcus salivarius. Our results indicate that the observed oral-cavity-driven gut microbiome changes may contribute towards the inflammatory processes involved in T1DM. Through the integration of multi-omic analyses, we resolve strain-variant "mouth-to-gut" transfer in a disease context. Video Abstract.

Re-Enlightenment of Fulminant Type 1 Diabetes under the COVID-19 Pandemic

Fulminant type 1 diabetes (FT1D) is a subtype of type 1 diabetes (T1D) that is characterized by the rapid progression to diabetic ketoacidosis against the background of rapid and almost complete pancreatic islet destruction. The HbA1c level at FT1D onset remains normal or slightly elevated despite marked hyperglycemia, reflecting the rapid clinical course of the disease, and is an important marker for diagnosis. FT1D often appears following flu-like symptoms, and there are many reports of its onset being linked to viral infections. In addition, disease-susceptibility genes have been identified in FT1D, suggesting the involvement of host factors in disease development. In most cases, islet-related autoantibodies are not detected, and histology of pancreatic tissue reveals macrophage and T cell infiltration of the islets in the early stages of FT1D, suggesting that islet destruction occurs via an immune response different from that occurring in autoimmune type 1 diabetes. From 2019, coronavirus disease 2019 (COVID-19) caused by the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spread worldwide and became a serious problem. Reports on the association between SARS-CoV-2 and T1D are mixed, with some suggesting an increase in T1D incidence due to the COVID-19 pandemic. When discussing the association between COVID-19 and T1D, it is also necessary to focus on FT1D. However, it is not easy to diagnose this subtype without understanding the concept. Therefore, authors hereby review the concept and the latest findings of FT1D, hoping that the association between COVID-19 and T1D will be adequately evaluated in the future.

Exocrine and Endocrine Inflammation Increases Cellular Replication in the Pancreatic Duct Compartment in Type 1 Diabetes

Context

We recently demonstrated increased cellular proliferation in the pancreatic ductal gland (PDG) compartment of organ donors with type 1 diabetes, suggesting that PDGs may harbor progenitor cells capable of pancreatic regeneration.

Objective

We evaluated the impact of diabetes and pancreatic inflammation on PDG and interlobular duct (ILD) cellular proliferation and profiles.

Methods

Endocrine hormone expression (insulin, glucagon, somatostatin, pancreatic polypeptide) and proliferating Ki67+ cells were localized within the PDG and ILD compartments by multicolor immunohistochemistry in cross-sections from the head, body, and tail regions of pancreata from those with (n = 31) or without type 1 diabetes (n = 43). Whole-slide scanned images were analyzed using digital pathology.

Results

Type 1 diabetes donors with insulitis or histologically identified pancreatitis had increased cellular replication in the ILD and PDG compartments. Interestingly, while cellular proliferation within the pancreatic ductal tree was significantly increased in type 1 diabetes (PDG mean = 3.36%, SEM = 1.06; ILD mean = 2.78%, SEM = 0.97) vs nondiabetes(ND) subjects without pancreatic inflammation (PDG mean = 1.18%, SEM = 0.42; ILD mean = 0.74%, SEM = 0.15, P < 0.05), robust replication was also observed in ND donors with pancreatitis (PDG mean = 3.52%, SEM = 1.33; ILD mean = 2.18%, SEM = 0.54, P < 0.05). Few polyhormonal cells were present in the ILD (type 1 diabetes = 0.04 ± 0.02%; ND = 0.08 ± 0.03%, P = 0.40) or PDG compartment (type 1 diabetes = 0.02 ± 0.01%; ND = 0.08 ± 0.13%, P = 0.63).

Conclusion

These data suggest that increased pancreatic ductal cell replication is associated with sustained pancreatic inflammation; however, as replicating cells were hormone-negative, PDGs do not appear to represent a compelling endogenous source of hormone-positive endocrine cells.

The Contribution of Neutrophils and NETs to the Development of Type 1 Diabetes

Type 1 diabetes (T1D) is an autoimmune disease resulting from the destruction of insulin-producing beta cells in pancreatic islets. T lymphocytes are the claimed pathogenic effectors but abnormalities of other immune cell types, including neutrophils, also characterize T1D development. During human T1D natural history, neutrophils are reduced in the circulation, while accumulate in the pancreas where release of neutrophil extracellular traps (NETs), or NETosis, is manifest. Recent-onset T1D patients also demonstrate activated circulating neutrophils, associated with a unique neutrophil gene signature. Neutrophils can bind to platelets, leading to the formation of platelet-neutrophil aggregates (PNAs). PNAs increase in the circulation during the development of human T1D and provide a mechanism for neutrophil activation and mobilization/recruitment to the pancreas. In non-obese diabetic or NOD mice, T1D autoimmunity is accompanied by dynamic changes in neutrophil numbers, activation state, PNAs and/or NETosis/NET proteins in the circulation, pancreas and/or islets. Such properties differ between stages of T1D disease and underpin potentially indirect and direct impacts of the innate immune system in T1D pathogenesis. Supporting the potential for a pathogenic role in T1D, NETs and extracellular histones can directly damage isolated islets in vitro, a toxicity that can be prevented by small polyanions. In human T1D, NET-related damage can target the whole pancreas, including both the endocrine and exocrine components, and contribute to beta cell destruction, providing evidence for a neutrophil-associated T1D endotype. Future intervention in T1D could therefore benefit from combined strategies targeting T cells and accessory destructive elements of activated neutrophils.

Antidiabetic effects of Scrophularia striata ethanolic extract via suppression of Pdx1 and Ins1 expression in pancreatic tissues of diabetic rats

One of the factors that causes severe metabolic imbalance and abnormal changes in many tissues, especially in the pancreas, is the pathological disease of diabetes mellitus. Therefore, in this study, the therapeutic effects of Scrophularia striata were investigated using an animal model in the control of diabetic injury and pancreatic complications caused by diabetes. A total of 66 rats (weight 220–250 g) were randomly divided into: Healthy Control group (rats without diabetes receiving Propylene glycol as solvent); Diabetic control group; 3 experimental healthy groups (receiving the extract with doses of 100, 200 and 400 mg/kg bw/day); 3 treatment groups; and3 pretreatment groups. Diabetes was induced in rats by intraperitoneal STZ (60 mg/kg bw). FBS, HbA1c and insulin were measured after 4 weeks. Pdx1 and Ins1 gene expression was assessed by RT-PCR. The histological evaluation was also performed with H&E staining. The data were analyzed by SPSS ver20 using ANOVA and Tukey tests. By treatment with S. striata ethanolic extract, these factors were close to the normal range. The expression of the Pdx1 and Ins1 genes increased in the treated rats with S. striata extract. Analysis of the obtained data indicates the effect of S. striata in improving the complications of diabetes in rats and can be considered for therapeutic purposes.

Single-cell multi-omics analysis of human pancreatic islets reveals novel cellular states in type 1 diabetes

Type 1 diabetes (T1D) is an autoimmune disease in which immune cells destroy insulin-producing beta cells. The aetiology of this complex disease is dependent on the interplay of multiple heterogeneous cell types in the pancreatic environment. Here, we provide a single-cell atlas of pancreatic islets of 24 T1D, autoantibody-positive and nondiabetic organ donors across multiple quantitative modalities including ~80,000 cells using single-cell transcriptomics, ~7,000,000 cells using cytometry by time of flight and ~1,000,000 cells using in situ imaging mass cytometry. We develop an advanced integrative analytical strategy to assess pancreatic islets and identify canonical cell types. We show that a subset of exocrine ductal cells acquires a signature of tolerogenic dendritic cells in an apparent attempt at immune suppression in T1D donors. Our multimodal analyses delineate cell types and processes that may contribute to T1D immunopathogenesis and provide an integrative procedure for exploration and discovery of human pancreatic function.

Neutrophils and their role in the aetiopathogenesis of type 1 and type 2 diabetes

Multiple and complex aetiological processes underlie diabetes mellitus, which invariably result in the development of hyperglycaemia. Although there are two prevalent distinct forms of the disease, that is, type 1 and type 2 diabetes, accumulating evidence indicates that these syndromes share more aetiopathological mechanisms than originally thought. This compels a rethinking of the approaches to prevent and treat the different manifestations of what eventually becomes a hyperglycaemic state. This review aims to address the involvement of neutrophils, the most abundant type of granulocytes involved in the initiation of the acute phase of inflammation, in the aetiopathogenesis of diabetes mellitus, with a focus on type 1 and type 2 diabetes. We review the evidence that neutrophils are the first leucocytes to react to and accumulate inside target tissues of diabetes, such as the pancreas and insulin-sensitive tissues. We then review available data on the role of neutrophils and their functional alteration, with a focus on NETosis, in the progression towards clinical disease. Finally, we review potential approaches as secondary and adjunctive treatments to limit neutrophil-mediated damage in the prevention of the progression of subclinical disease to clinical hyperglycaemia.

Metaproteomics Approach and Pathway Modulation in Obesity and Diabetes: A Narrative Review

Low-grade inflammatory diseases revealed metabolic perturbations that have been linked to various phenotypes, including gut microbiota dysbiosis. In the last decade, metaproteomics has been used to investigate protein composition profiles at specific steps and in specific healthy/pathologic conditions. We applied a rigorous protocol that relied on PRISMA guidelines and filtering criteria to obtain an exhaustive study selection that finally resulted in a group of 10 studies, based on metaproteomics and that aim at investigating obesity and diabetes. This batch of studies was used to discuss specific microbial and human metaproteome alterations and metabolic patterns in subjects affected by diabetes (T1D and T2D) and obesity. We provided the main up- and down-regulated protein patterns in the inspected pathologies. Despite the available results, the evident paucity of metaproteomic data is to be considered as a limiting factor in drawing objective considerations. To date, ad hoc prepared metaproteomic databases collecting pathologic data and related metadata, together with standardized analysis protocols, are required to increase our knowledge on these widespread pathologies.

Pancreatic exocrine insufficiency in diabetes is associated with autonomic dysfunction

OBJECTIVES

Pancreatic exocrine insufficiency (PEI) is prevalent in diabetes. Pathophysiological theories imply autoimmune destruction, lack of trophic effects of insulin or impaired neuronal stimulation, but the relationship between PEI and autonomic dysfunction is largely unknown. In a pilot study, we aimed to investigate if patients with diabetes and PEI had impaired autonomic function.

METHODS

We measured faecal elastase in 59 patients with type 1 or 2 diabetes, using a cut-off-value <200 μg/g to define PEI. Based on faecal elastase results, patients were stratified into matched case (n = 8) and control groups (n = 13). We used heart rate variability, baroreflex sensitivity and orthostatic hypotension tests to assess autonomic dysfunction.

RESULTS

All baroreflex sensitivity parameters were reduced in cases with PEI compared with controls (all p < .05). The heart rate variability parameters root mean square of successive RR interval differences (p = .05) and high frequency (p = .04) were also reduced. We found no difference in orthostatic hypotension between the groups.

CONCLUSIONS

In this first-of-its-kind study, we found that diabetes patients with PEI had reduced autonomic function compared with matched controls. Although numbers are small, results support the hypothesis that autonomic dysfunction could be a contributor to PEI in diabetes.

Exploring the Interplay Between Oral Diseases, Microbiome, and Chronic Diseases Driven by Metabolic Dysfunction in Childhood

Oral childhood diseases, such as caries and gingivitis, have much more than a local impact on the dentition and tooth surrounding tissues, which can affect systemic conditions. While the mouth is frequently exposed to microbial stressors that can contribute to an inflammatory state in the entire body, chronic disorders can also interfere with oral health. Sharing common risk factors, a dynamic interplay can be driven between 1. dental caries, gingivitis, and type I diabetes mellitus, 2. early childhood caries and obesity, and 3. caries and cardiovascular diseases. Considering that there are ~2.2 billion children worldwide and that childhood provides unique opportunities for intervention targeting future health promotion, this review is of prime importance and aimed to explore the relationship between the oral microbiome and oral chronic diseases driven by metabolic dysfunction in childhood.

Sonographic Evaluation of the Pancreas in Type 1 Diabetes Mellitus: A Case-control Study

BACKGROUND

Pancreas is a vital insulin-producing gland, and it is subjected to various disorders which produce alteration in the morphology and function. Ultrasound (US) of the pancreas is sensitive for evaluating the gland and provides the accurate diagnosis of pancreatic diseases. The aim of this study is to determine whether there were alterations in pancreatic size and echogenicity in type 1 diabetes mellitus (DM).

METHODS

A total of 100 patients with Type-1 DM (insulin dependent) were examined using the ultrasonography. They were compared to 22 healthy controls. Measurements of the pancreas were performed on type 1 diabetic patients and controls.

RESULTS

Pancreatic diameters of the head, body, and tail of the pancreas were reduced in Type 1 DM versus controls (1.78 vs. 1.80 cm, 95% confidence interval [CI]: -0.147 -0.099, P = 0.699 for the head of the pancreas; and 1.093 vs. 1.13 cm: 95% CI: -2.97-1.196, P = 0.484 for the body of the pancreas; 1.12 vs. 1.46 cm, 95% CI: -0.491-0.194, P < 0.001 for the tail of the pancreas). The echogenicity of the pancreas in patients with Type 1 DM increased significantly as the duration of the disease increased (P = 0.015).

CONCLUSION

Individuals with Type 1 DM have reduced pancreatic size in comparison with controls. Patients with Type 1 DM have increased echogenicity of the pancreas as the duration of the disease increased.

Serum trypsin-like immunoreactivity in dogs with diabetes mellitus

Background

Concurrent exocrine pancreatic dysfunction and decreased pancreatic organ size are common findings in various stages of human type 1 diabetes mellitus (DM). Exocrine pancreatic insufficiency (EPI) is incompletely described in diabetic dogs.

Objective

To compare canine trypsin‐like immunoreactivity (cTLI) of diabetic dogs with that of healthy controls. A secondary aim was to evaluate the correlation between duration of DM and cTLI.

Animals

Thirty client‐owned diabetic dogs and thirty client‐owned control dogs.

Methods

Cross‐sectional study. Diabetic and healthy control dogs were included if they had no clinical evidence of pancreatitis and if serum samples obtained after food was withheld were available. Serum cTLI was measured at a reference laboratory and compared between groups. Canine pancreatic lipase immunoreactivity (cPLI) was analyzed concurrently as an indicator of pancreatitis.

Results

The median cTLI concentration in all diabetic dogs (36.4 μg/L [range, 7.0‐288 μg/L]) did not differ from control dogs (28.7 μg/L [range, 12.8‐58.6 μg/L]) (P = .07; difference −7.8 μg/L [95% Confidence Interval (CI), −23.5 to 0.6 μg/L]). There was still no difference in cTLI between groups after exclusion of dogs with cPLI consistent with pancreatitis (n = 8 diabetic dogs). There was no correlation between cTLI and DM duration in all diabetic dogs (r = −0.07, [95% CI, −0.43 to 0.3], P = .7).

Conclusions and Clinical Importance

There was no evidence of EPI as evaluated using cTLI in this cohort of diabetic dogs, but concurrent increases in cPLI suggest cTLI might not be the optimal indicator of exocrine pancreatic dysfunction in dogs with DM.

Whole-Slide Image Analysis of Human Pancreas Samples to Elucidate the Immunopathogenesis of Type 1 Diabetes Using the QuPath Software

Type 1 diabetes is a chronic disease of the pancreas characterized by the loss of insulin-producing beta cells. Access to human pancreas samples for research purposes has been historically limited, restricting pathological analyses to animal models. However, intrinsic differences between animals and humans have made clinical translation very challenging. Recently, human pancreas samples have become available through several biobanks worldwide, and this has opened numerous opportunities for scientific discovery. In addition, the use of new imaging technologies has unraveled many mysteries of the human pancreas not merely in the presence of disease, but also in physiological conditions. Nowadays, multiplex immunofluorescence protocols as well as sophisticated image analysis tools can be employed. Here, we described the use of QuPath—an open-source platform for image analysis—for the investigation of human pancreas samples. We demonstrate that QuPath can be adequately used to analyze whole-slide images with the aim of identifying the islets of Langerhans and define their cellular composition as well as other basic morphological characteristics. In addition, we show that QuPath can identify immune cell populations in the exocrine tissue and islets of Langerhans, accurately localizing and quantifying immune infiltrates in the pancreas. Therefore, we present a tool and analysis pipeline that allows for the accurate characterization of the human pancreas, enabling the study of the anatomical and physiological changes underlying pancreatic diseases such as type 1 diabetes. The standardization and implementation of these analysis tools is of critical importance to understand disease pathogenesis, and may be informative for the design of new therapies aimed at preserving beta cell function and halting the inflammation caused by the immune attack.

Interpreting type 1 diabetes risk with genetics and single-cell epigenomics

Genetic risk variants that have been identified in genome-wide association studies of complex diseases are primarily non-coding1. Translating these risk variants into mechanistic insights requires detailed maps of gene regulation in disease-relevant cell types2. Here we combined two approaches: a genome-wide association study of type 1 diabetes (T1D) using 520,580 samples, and the identification of candidate cis-regulatory elements (cCREs) in pancreas and peripheral blood mononuclear cells using single-nucleus assay for transposase-accessible chromatin with sequencing (snATAC-seq) of 131,554 nuclei. Risk variants for T1D were enriched in cCREs that were active in T cells and other cell types, including acinar and ductal cells of the exocrine pancreas. Risk variants at multiple T1D signals overlapped with exocrine-specific cCREs that were linked to genes with exocrine-specific expression. At the CFTR locus, the T1D risk variant rs7795896 mapped to a ductal-specific cCRE that regulated CFTR; the risk allele reduced transcription factor binding, enhancer activity and CFTR expression in ductal cells. These findings support a role for the exocrine pancreas in the pathogenesis of T1D and highlight the power of large-scale genome-wide association studies and single-cell epigenomics for understanding the cellular origins of complex disease.

Diabetes mellitus induced by immune checkpoint inhibitors: type 1 diabetes variant or new clinical entity? Review of the literature

Immune Check-Point Inhibitors (CPIs) have improved long-term patients' outcomes in several advanced cancers. Diabetes mellitus induced by CPIs (CPI-DM) is considered the second most frequent endocrine CPIs' side effects with a variable prevalence up to 2%. The aim of our study was to identify CPI-DM characteristics and differences from the classical form of diabetes. Therefore, we conducted a structured Pubmed® search collecting publications dated from January 2015 to December 2019. A total of 642 citations were identified and 121 publications met our study criteria. We analyzed 200 case reports, including our 3 cases under publication. The majority of CPI-DM occurred with anti-Programmed cell Death-1 in monotherapy or in combination, although few cases with Programmed cell Death Ligand-1 and Cytotoxic T Lymphocyte Antigen 4 were reported. Generally, CPI-DM arose early (an average of 9 weeks after CPIs starting), but also after the end of CPIs treatment. In all patients, CPI-DM has an acute onset and in 67.5% of cases diabetic ketoacidosis occurs. C-peptide levels were usually and permanently compromised, requiring lifelong insulin therapy. Moreover, autoimmunity and genetic profile was not always helpful. In particular, anti-glutamic acid decarboxylase (anti-GAD) antibodies and Human Leukocyte Antigen (HLA) DR4 were present in only 43.0% and 51.3% of cases respectively. In 51.0% of subjects a mild exocrine impairment coexisted. In short, though CPI-DM has similarities to type 1 diabetes mellitus, it represents a new, largely unknown, clinical entity. In addition, as CPI-DM is a relative frequent side-effect under CPI, a close monitoring of the glucose levels and early signs and symptoms of diabetes in patients affected by neoplasm is recommended.

Deoxyhypusine synthase, an essential enzyme for hypusine biosynthesis, is required for proper exocrine pancreas development

Pancreatic diseases including diabetes and exocrine insufficiency would benefit from therapies that reverse cellular loss and/or restore cellular mass. The identification of molecular pathways that influence cellular growth is therefore critical for future therapeutic generation. Deoxyhypusine synthase (DHPS) is an enzyme that post-translationally modifies and activates the mRNA translation factor eukaryotic initiation factor 5A (eIF5A). Previous work demonstrated that the inhibition of DHPS impairs zebrafish exocrine pancreas development; however, the link between DHPS, eIF5A, and regulation of pancreatic organogenesis remains unknown. Herein we identified that the conditional deletion of either Dhps or Eif5a in the murine pancreas results in the absence of acinar cells. Because DHPS catalyzes the activation of eIF5A, we evaluated and uncovered a defect in mRNA translation concomitant with defective production of proteins that influence cellular development. Our studies reveal a heretofore unappreciated role for DHPS and eIF5A in the synthesis of proteins required for cellular development and function.

Histological and transcriptional characterization of the pancreatic acinar tissue in type 1 diabetes

INTRODUCTION

Despite a reduced function and volume of the exocrine pancreas in type 1 diabetes, the acinar cells remain understudied in type 1 diabetes research. The hypothesis of this study is that the acinar tissue is altered in subjects with type 1 diabetes compared with subjects without diabetes.

RESEARCH DESIGN AND METHODS

The cell density, expression of digestive enzymes, and transcriptome of acinar tissue at varying distances from islets were analyzed using histology, immunostaining, and AmpliSeq RNA sequencing of laser capture microdissected tissue. Pancreases examined were from organ donors with or without type 1 diabetes.

RESULTS

We demonstrate preserved acinar nuclei density and find no support of acinar atrophy in type 1 diabetes. Staining for digestive enzymes (amylase, lipase, and trypsin) demonstrated an evenly distributed expression in the exocrine parenchyma; although occasional amylase-negative regions appeared in tissue that had been formalin-fixed and paraffin-embedded, this phenomenon was not evident in frozen tissue. Gene set enrichment analysis of whole transcriptome data identified transcriptional alterations in type 1 diabetes that were present in the acinar tissue independent of the distance from islets. Among these, the two most enriched gene sets were Myc Targets V2 and Estrogen Response Early.

CONCLUSION

Taken together, these new data emphasize the involvement of the entire pancreas in type 1 diabetes pathology. The alteration of the gene sets Myc Targets V2 and Estrogen Response Early is a possible link to the increased incidence of pancreatic cancer in type 1 diabetes.

Uncovering Pathways to Personalized Therapies in Type 1 Diabetes

The goal of personalized medicine is to match the right drugs to the right patients at the right time. Personalized medicine has been most successful in cases where there is a clear genetic linkage between a disease and a therapy. This is not the case with type 1 diabetes (T1D), a genetically complex immune-mediated disease of β-cell destruction. Researchers over decades have traced the natural history of disease sufficiently to use autoantibodies as predictive biomarkers for disease risk and to conduct successful clinical trials of disease-modifying therapy. Recent studies, however, have highlighted heterogeneity associated with progression, with nonuniform rate of insulin loss and distinct features of the peri-diagnostic period. Likewise, there is heterogeneity in immune profiles and outcomes in response to therapy. Unexpectedly, from these studies demonstrating perplexing complexity in progression and response to therapy, new biomarker-based principles are emerging for how to achieve personalized therapies for T1D. These include therapy timed to periods of disease activity, use of patient stratification biomarkers to align therapeutic target with disease endotype, pharmacodynamic biomarkers to achieve personalized dosing and appropriate combination therapies, and efficacy biomarkers for "treat-to-target" strategies. These principles provide a template for application of personalized medicine to complex diseases.

Arrest in the Progression of Type 1 Diabetes at the Mid-Stage of Insulitic Autoimmunity Using an Autoantigen-Decorated All-trans Retinoic Acid and Transforming Growth Factor Beta-1 Single Microparticle Formulation

Type 1 diabetes (T1D) is a disorder of impaired glucoregulation due to lymphocyte-driven pancreatic autoimmunity. Mobilizing dendritic cells (DC) in vivo to acquire tolerogenic activity is an attractive therapeutic approach as it results in multiple and overlapping immunosuppressive mechanisms. Delivery of agents that can achieve this, in the form of micro/nanoparticles, has successfully prevented a number of autoimmune conditions in vivo. Most of these formulations, however, do not establish multiple layers of immunoregulation. all-trans retinoic acid (RA) together with transforming growth factor beta 1 (TGFβ1), in contrast, has been shown to promote such mechanisms. When delivered in separate nanoparticle vehicles, they successfully prevent the progression of early-onset T1D autoimmunity in vivo. Herein, we show that the approach can be simplified into a single microparticle formulation of RA + TGFβ1 with surface decoration with the T1D-relevant insulin autoantigen. We show that the onset of hyperglycemia is prevented when administered into non-obese diabetic mice that are at the mid-stage of active islet-selective autoimmunity. Unexpectedly, the preventive effects do not seem to be mediated by increased numbers of regulatory T-lymphocytes inside the pancreatic lymph nodes, at least following acute administration of microparticles. Instead, we observed a mild increase in the frequency of regulatory B-lymphocytes inside the mesenteric lymph nodes. These data suggest additional and potentially-novel mechanisms that RA and TGFβ1 could be modulating to prevent progression of mid-stage autoimmunity to overt T1D. Our data further strengthen the rationale to develop RA+TGFβ1-based micro/nanoparticle “vaccines” as possible treatments of pre-symptomatic and new-onset T1D autoimmunity.

Impaired exocrine pancreatic function in different stages of type 1 diabetes

INTRODUCTION

Aim of this study was to investigate the pancreatic exocrine function in patients with type 1 diabetes (T1D) by multiple non-invasive tests.

RESEARCH DESIGN AND METHODS

The study is a single-center, cross-sectional study of pancreatic exocrine function in adult patients with new-onset or long-standing T1D and healthy controls.

RESULTS

Healthy controls, new-onset T1D, and long-standing T1D were similar for age at the time of the study, gender and body mass index (BMI) categories. Age of onset of T1D patients with long-standing disease was younger than that of patients with new-onset T1D (p<0.001). As expected, the three groups differed for C-peptide and hemoglobin A1c (HbA1c) levels. Lipase activity measured by ¹³C-mixed triglyceride breath test was reduced progressively, although not significantly, from controls to recent-onset T1D and long-standing T1D participants. Fecal elastase-1 was significantly lower in participants with T1D, either new onset or long standing. Pancreatic amylase, lipase, retinol binding protein and prealbumin were significantly different across the groups, with a significant trend toward lower values in long-standing T1D and intermediate values in new-onset T1D, while no differences were observed for total amylase. The markers of impaired exocrine function tests (fecal elastase-1, serum pancreatic amylase and lipase) and of nutritional status (retinol binding protein and prealbumin levels) correlated with the reduction of fasting and urinary C-peptide.

CONCLUSIONS

Our results confirm that exocrine pancreatic impairment is a feature of T1D, with low fecal elastase-1, serum pancreatic amylase and lipase as specific markers, associated with reduced levels of nutritional indexes. Moreover, the evidence of more advanced insufficiency in long-standing disease reflects the chronic nature of this process, and its correlation with the residual β-cell function suggests parallel pathways for the impairment of the endocrine and exocrine pancreatic function.

Neutrophil-Associated Inflammatory Changes in the Pre-Diabetic Pancreas of Early-Age NOD Mice

A growing body of evidence indicates that neutrophils are the first major leukocyte population accumulating inside the pancreas even before the onset of a lymphocytic-driven impairment of functional beta cells in type 1 diabetes mellitus (T1D). In humans, pancreata from T1D deceased donors exhibit significant neutrophil accumulation. We present a time course of previously unknown inflammatory changes that accompany neutrophil and neutrophil elastase accumulation in the pancreas of the non-obese diabetic (NOD) mouse strain as early as 2 weeks of age. We confirm earlier findings in NOD mice that neutrophils accumulate as early as 2 weeks of age. We also observe a concurrent increase in the expression of neutrophil elastase in this time period. We also detect components of neutrophil extracellular traps (NET) mainly in the exocrine tissue of the pancreas during this time as well as markers of vascular pathology as early as 2 weeks of age. Age- and sex-matched C57BL/6 mice do not exhibit these features inside the pancreas. When we treated NOD mice with inhibitors of myeloperoxidase and neutrophil elastase, two key effectors of activated neutrophil activity, alone or in combination, we were unable to prevent the progression to hyperglycemia in any manner different from untreated control mice. Our data confirm and add to the body of evidence demonstrating neutrophil accumulation inside the pancreas of mice genetically susceptible to T1D and also offer novel insights into additional pathologic mechanisms involving the pancreatic vasculature that have, until now, not been discovered inside the pancreata of these mice. However, inhibition of key neutrophil enzymes expressed in activated neutrophils could not prevent diabetes. These findings add to the body of data supporting a role for neutrophils in the establishment of early pathology inside the pancreas, independently of, and earlier from the time at onset of lymphocytic infiltration. However, they also suggest that inhibition of neutrophils alone, acting via myeloperoxidase and neutrophil elastase only, in the absence of other other effector cells, is insufficient to alter the natural course of autoimmune diabetes, at least in the NOD model of the disease.

Exocrine Pancreas Dysfunction in Type 1 Diabetes

OBJECTIVE

Type 1 diabetes (T1D) is characterized by autoimmune β-cell destruction, but exocrine pancreas abnormalities may also play a role in the disease pathophysiology. Herein, we review the current evidence of exocrine damage in T1D and discuss its underlying pathophysiology, clinical evaluation, and treatment.

METHOD

Extensive literature search was performed for "type 1 diabetes" and "exocrine dysfunction" on PubMed and Google Scholar databases.

RESULTS

T1D pancreata are significantly smaller than controls, both in weight and volume. T cells, dendritic cells, neutrophils, and products of complement activation are seen in T1D exocrine tissues. Exocrine pancreas fibrosis, arteriosclerosis, fatty infiltration, and acinar atrophy are also observed on histology. Pancreatic exocrine insufficiency (PEI) can be assessed through direct exocrine testing, fecal elastase concentration, and measurement of serum exocrine enzymes. The prevalence of PEI in T1D varies by modality and study but is consistently greater than controls. The clinical relevance of PEI in T1D is debatable, as many patients with laboratory evidence of PEI are asymptomatic. However, in PEI-symptomatic patients reported benefits of pancreatic enzyme replacement therapy (PERT) include relief of gastrointestinal symptoms, improved quality of life, better glycemic control, and optimal nutrition.

CONCLUSION

Exocrine pancreas abnormalities often occur in T1D. Whether exocrine dysfunction occurs simultaneously with β-cell destruction, as a result of β-cell loss, or as a combination of both remains to be definitively answered. In T1D with gastrointestinal complaints, PEI should be evaluated, usually via fecal elastase measurements. PERT is recommended for T1D patients with symptoms and laboratory evidence of PEI.

ABBREVIATIONS

AAb+ = autoantibody positive; AAb- = autoantibody negative; FEC = fecal elastase concentration; PEI = pancreatic exocrine insufficiency; PERT = pancreatic enzyme replacement therapy; PP = pancreatic polypep-tide; T1D = type 1 diabetes.

Pancreatic Tissue Proteomics Unveils Key Proteins, Pathways, and Networks Associated with Type 1 Diabetes

PURPOSE

Type 1 diabetes (T1D) is characterized by autoimmune mediated self-destruction of the pancreatic islet beta cells and the resultant insulin deficiency. However, little is known about the underlying molecular pathogenesis at the pancreatic tissue level given the limited availability of clinical specimens.

EXPERIMENTAL DESIGN

Quantitative proteomic studies is performed on age-matched T1D and healthy cadaveric pancreatic tissues (n = 18 each) using TMT 10plex-based isobaric labeling and BoxCar-based label-free LC-MS/MS approaches. ELISA is used to validate the differentially expressed proteins (DEPs).

RESULTS

Overall, the two quantitative proteomics approaches identified 8824 proteins, of which 261 are DEPs. KEGG pathway and functional network analyses of the DEPs reveal dysregulations to pancreatic exocrine function, complement coagulation cascades, and extracellular matrix receptor interaction pathways in T1D. A selected list of the DEPs associated with pathways, subnetworks, and plasma proteome of T1D are validated using ELISA.

CONCLUSIONS AND CLINICAL RELEVANCE

Integrating labeling and label-free approaches improve the confidence in quantitative profiling of pancreatic tissue proteome, which furthers the understanding of the dysregulated pathways and functional subnetworks associated with T1D pathogenesis and may aid to develop diagnostic and therapeutic strategies for T1D.

Management of endocrine immune-related adverse events of immune checkpoint inhibitors: an updated review

Immune checkpoint inhibitors (ICIs) belong to a new group of anticancer drugs targeting T-cell proteins involved in the activation of immune response toward malignancies. Their introduction into clinical practice was a milestone in modern cancer treatment. However, the significant advantage of ICIs over conventional chemotherapy in terms of therapeutic efficacy is accompanied by new challenges related to specific side effects. ICI-induced immune system activation could lead to the loss of self-tolerance, presenting as autoimmune inflammation and dysfunction of various tissues and organs. Thus, the typical side effects of ICIs include immune-related adverse events (irAEs), among which endocrine irAEs, affecting numerous endocrine glands, have been commonly recognized. This review aimed to outline the current knowledge regarding ICI-induced endocrine disorders from a clinical perspective. We present updated information on the incidence and clinical development of ICI-induced endocrinopathies, including the most frequent thyroiditis and hypophysitis, the rarely observed insulin-dependent diabetes mellitus and primary adrenal insufficiency, and the recently described cases of hypoparathyroidism and lipodystrophy. Practical guidelines for monitoring, diagnosis, and treatment of ICI-related endocrine toxicities are also offered. Rising awareness of endocrine irAEs among oncologists, endocrinologists, and other health professionals caring for patients receiving ICIs could contribute to better safety and efficacy. As immunotherapy becomes widespread and approved for new types of malignancies, increased incidences of endocrine irAEs are expected in the future.

Pancreatic atrophy after gastrectomy for gastric cancer

PURPOSE

To investigate the phenomenon of pancreatic atrophy after gastrectomy for gastric cancer, using computed tomography (CT) volumetry.

METHODS

The subjects of this retrospective study were 77 patients who underwent distal gastrectomy (DG) or total gastrectomy (TG) for pStage I gastric cancer in 2014. The relative pancreatic volume ratio was assessed preoperatively, and then 1 and 5 years postoperatively and the results were compared between surgical procedures RESULTS: A total of 14 patients underwent TG with Roux-en-Y (RY) reconstruction, 24 underwent DG with Billroth-I (BI) reconstruction, and 39 underwent DG with RY reconstruction. We observed that the pancreatic volume continued to decrease over the 5 years after DG or TG. Furthermore, the incidence of pancreatic atrophy 5 years postoperatively was significantly greater after TG than after DG. In patients who underwent DG, a greater incidence of pancreatic atrophy was observed after RY reconstruction than after BI reconstruction, 5 years postoperatively.

CONCLUSION

The pancreatic volume continued to decrease after DG and TG for gastric cancer 5 years after treatment. TG was associated with a significantly greater incidence of pancreatic atrophy than DG 5 years postoperatively, as was RY reconstruction vs. BI reconstruction after DG.

Changes in pancreatic exocrine function in young at-risk children followed to islet autoimmunity and type 1 diabetes in the ENDIA study

BACKGROUNDS

We aimed to monitor pancreatic exocrine function longitudinally in relation to the development of islet autoimmunity (IA) and type 1 diabetes (T1D) in at-risk children with a first-degree relative with T1D, who were followed prospectively in the Environmental Determinants of Islet Autoimmunity (ENDIA) study.

METHODS

Fecal elastase-1 (FE-1) concentration was measured longitudinally in 85 ENDIA children from median age 1.0 (IQR 0.7,1.3) year. Twenty-eight of 85 children (progressors) developed persistent islet autoantibodies at median age of 1.5 (IQR 1.1,2.5) years, of whom 11 went on to develop clinical diabetes. The other 57 islet autoantibody-negative children (non-progressors) followed similarly were age and gender-matched with the progressors. An adjusted linear mixed model compared FE-1 concentrations in progressors and non-progressors.

RESULTS

Baseline FE-1 did not differ between progressors and non-progressors, or by HLA DR type or proband status. FE-1 decreased over time in progressors in comparison to non-progressors (Wald statistic 5.46, P = .02); in some progressors the fall in FE-1 preceded the onset of IA.

CONCLUSIONS

Pancreatic exocrine function decreases in the majority of young at-risk children who progress to IA and T1D.

Innate Viral Sensor MDA5 and Coxsackievirus Interplay in Type 1 Diabetes Development

Type 1 diabetes (T1D) is a polygenic autoimmune disease characterized by immune-mediated destruction of insulin-producing β-cells. The concordance rate for T1D in monozygotic twins is ≈30-50%, indicating that environmental factors also play a role in T1D development. Previous studies have demonstrated that enterovirus infections such as coxsackievirus type B (CVB) are associated with triggering T1D. Prior to autoantibody development in T1D, viral RNA and antibodies against CVB can be detected within the blood, stool, and pancreata. An innate pathogen recognition receptor, melanoma differentiation-associated protein 5 (MDA5), which is encoded by the IFIH1 gene, has been associated with T1D onset. It is unclear how single nucleotide polymorphisms in IFIH1 alter the structure and function of MDA5 that may lead to exacerbated antiviral responses contributing to increased T1D-susceptibility. Binding of viral dsRNA via MDA5 induces synthesis of antiviral proteins such as interferon-alpha and -beta (IFN-α/β). Viral infection and subsequent IFN-α/β synthesis can lead to ER stress within insulin-producing β-cells causing neo-epitope generation, activation of β-cell-specific autoreactive T cells, and β-cell destruction. Therefore, an interplay between genetics, enteroviral infections, and antiviral responses may be critical for T1D development.

Decreased pancreatic acinar cell number in type 1 diabetes

AIMS/HYPOTHESIS

Individuals with longstanding and recent-onset type 1 diabetes have a smaller pancreas. Since beta cells represent a very small portion of the pancreas, the loss of pancreas volume in diabetes is primarily due to the loss of pancreatic exocrine mass. However, the structural changes in the exocrine pancreas in diabetes are not well understood.

METHODS

To characterise the pancreatic endocrine and exocrine compartments in diabetes, we studied pancreases from adult donors with type 1 diabetes compared with similarly aged donors without diabetes. Islet cell mass, islet morphometry, exocrine mass, acinar cell size and number and pancreas fibrosis were assessed by immunohistochemical staining. To better understand possible mechanisms of altered pancreas size, we measured pancreas size in three mouse models of insulin deficiency.

RESULTS

Pancreases from donors with type 1 diabetes were approximately 45% smaller than those from donors without diabetes (47.4 ± 2.6 vs 85.7 ± 3.7 g), independent of diabetes duration or age of onset. Diabetic donor pancreases had decreased beta cell mass (0.061 ± 0.025 vs 0.94 ± 0.21 g) and reduced total exocrine mass (42.0 ± 4.9 vs 96.1 ± 6.5 g). Diabetic acinar cells were similar in size but fewer in number compared with those in pancreases from non-diabetic donors (63.7 ± 8.1 × 10⁹ vs 121.6 ± 12.2 × 10⁹ cells/pancreas), likely accounting for the difference in pancreas size. Within the type 1 diabetes exocrine tissue, there was a greater degree of fibrosis. The pancreases in three mouse models of insulin deficiency were similar in size to those in control mice.

CONCLUSIONS/INTERPRETATION

Pancreases from donors with type 1 diabetes are smaller than normal donor pancreases because exocrine cells are fewer in number rather than smaller in size; these changes occur early in the disease process. Our mouse data suggest that decreased pancreas size in type 1 diabetes is not directly caused by insulin deficiency, but the precise mechanism responsible remains unclear.

Large-scale electron microscopy database for human type 1 diabetes

Autoimmune β-cell destruction leads to type 1 diabetes, but the pathophysiological mechanisms remain unclear. To help address this void, we created an open-access online repository, unprecedented in its size, composed of large-scale electron microscopy images ('nanotomy') of human pancreas tissue obtained from the Network for Pancreatic Organ donors with Diabetes (nPOD; www.nanotomy.org). Nanotomy allows analyses of complete donor islets with up to macromolecular resolution. Anomalies we found in type 1 diabetes included (i) an increase of 'intermediate cells' containing granules resembling those of exocrine zymogen and endocrine hormone secreting cells; and (ii) elevated presence of innate immune cells. These are our first results of mining the database and support recent findings that suggest that type 1 diabetes includes abnormalities in the exocrine pancreas that may induce endocrine cellular stress as a trigger for autoimmunity.

From immunohistological to anatomical alterations of human pancreas in type 1 diabetes: New concepts on the stage

The histological analysis of human pancreatic samples in type 1 diabetes (T1D) has been proven essential to move forward in the evaluation of in situ events characterizing T1D. Increasing availability of pancreatic tissues collected from diabetic multiorgan donors by centralized biorepositories, which have shared tissues among researchers in the field, has allowed a deeper understanding of T1D pathophysiology, using novel immunohistological and high-throughput methods. In this review, we provide a comprehensive update of the main recent advancements in the characterization of cellular and molecular events involving endocrine and exocrine pancreas as well as the immune system in the onset and progression of T1D. Additionally, we underline novel elements, which provide evidence that T1D pathological changes affect not only islet β-cells but also the entire pancreas.

High residual C-peptide likely contributes to glycemic control in type 1 diabetes

BACKGROUNDResidual C-peptide is detected in many people for years following the diagnosis of type 1 diabetes; however, the physiologic significance of low levels of detectable C-peptide is not known.METHODSWe studied 63 adults with type 1 diabetes classified by peak mixed-meal tolerance test (MMTT) C-peptide as negative (<0.007 pmol/mL; n = 15), low (0.017-0.200; n = 16), intermediate (>0.200-0.400; n = 15), or high (>0.400; n = 17). We compared the groups' glycemia from continuous glucose monitoring (CGM), β cell secretory responses from a glucose-potentiated arginine (GPA) test, insulin sensitivity from a hyperinsulinemic-euglycemic (EU) clamp, and glucose counterregulatory responses from a subsequent hypoglycemic (HYPO) clamp.RESULTSLow and intermediate MMTT C-peptide groups did not exhibit β cell secretory responses to hyperglycemia, whereas the high C-peptide group showed increases in both C-peptide and proinsulin (P ≤ 0.01). All groups with detectable MMTT C-peptide demonstrated acute C-peptide and proinsulin responses to arginine that were positively correlated with peak MMTT C-peptide (P < 0.0001 for both analytes). During the EU-HYPO clamp, C-peptide levels were proportionately suppressed in the low, intermediate, and high C-peptide compared with the negative group (P ≤ 0.0001), whereas glucagon increased from EU to HYPO only in the high C-peptide group compared with negative (P = 0.01). CGM demonstrated lower mean glucose and more time in range for the high C-peptide group.CONCLUSIONThese results indicate that in adults with type 1 diabetes, β cell responsiveness to hyperglycemia and α cell responsiveness to hypoglycemia are observed only at high levels of residual C-peptide that likely contribute to glycemic control.FUNDINGFunding for this work was provided by the Leona M. and Harry B. Helmsley Charitable Trust, the National Center for Advancing Translational Sciences, and the National Institute of Diabetes and Digestive and Kidney Diseases.

Better HbA1c during the first years after diagnosis of type 1 diabetes is associated with residual C peptide 10 years later

OBJECTIVE

To identify the factors associated with residual C peptide production at least 10 years after diagnosis in children and adolescents with type 1 diabetes.

RESEARCH DESIGN AND METHODS

73 children and adolescents (<25 years), born in 1988-2005, diagnosed with type 1 diabetes were included during the 4-year study period (2013-2016). At least 10 years after diagnosis, we measured any remaining C peptide concentration using an ultrasensitive C peptide ELISA (≥1.17 pmol/L). The average hemoglobin A1c (HbA1c) was calculated during each of the 10 years after diagnosis and further grand average was calculated for the entire study period.

RESULTS

C peptide was detectable in 38% of participants. The C peptide concentration was 4.3±5.3 pmol/L. At onset of type 1 diabetes, participants were on average approximately 5 years of age, and their average HbA1c was 9.4% (79 mmol/mol). During the first 3 years after diagnosis, HbA1c was lower in the group with detectable C peptide at follow-up ≥10 years later. Moreover, detectable C peptide was more common among female participants. Body mass index SD scores had not increased since the 1-year follow-up, but were higher in patients with measurable C peptide. Nine participants (12%) had been diagnosed with celiac disease and two (3%) with hypothyreosis. Eighteen (25%) participants had retinopathy.

CONCLUSIONS

Children and adolescents with detectable C peptide after more than 10 years of diabetes duration were predominantly female and had better HbA1c than others during the first 3 years after diagnosis.

Immune checkpoint inhibitors and type 1 diabetes mellitus: a case report and systematic review

OBJECTIVE

To better define the rare adverse event (AE) of diabetes mellitus associated with immune checkpoint inhibitors (ICIs).

DESIGN AND METHODS

We report the case of a lung cancer patient with diabetic ketoacidosis (DKA) and autoimmune thyroiditis during pembrolizumab treatment. We provide a systematic review of all published cases (PubMed/Web of Science/Cochrane, through November 2018) of autoimmune diabetes mellitus related to blockade of the cytotoxic T-lymphocyte antigen 4 (CTLA-4)-, programmed cell death 1 (PD-1) receptor or its ligand (PD-L1) or combination (ICI) therapy.

RESULTS

Our literature search identified 90 patient cases (our case excluded). Most patients were treated with anti-PD-1 or anti-PD-L1 as monotherapy (79%) or in combination with CTLA-4 blockade (15%). On average, diabetes mellitus was diagnosed after 4.5 cycles; earlier for combination ICI at 2.7 cycles. Early-onset diabetes mellitus (after one or two cycles) was observed during all treatment regimens. Diabetic ketoacidosis was present in 71%, while elevated lipase levels were detected in 52% (13/25). Islet autoantibodies were positive in 53% of patients with a predominance of glutamic acid decarboxylase antibodies. Susceptible HLA genotypes were present in 65% (mostly DR4). Thyroid dysfunction was the most frequent other endocrine AE at 24% incidence in this patient population.

CONCLUSION

ICI-related diabetes mellitus is a rare but often life-threatening metabolic urgency of which health-care professionals and patients should be aware. Close monitoring of blood glucose and prompt endocrine investigation in case of hyperglycemia is advisable. Predisposing factors such as HLA genotype might explain why some individuals are at risk.

New Evidence of Exocrine Pancreatopathy in Pre-symptomatic and Symptomatic Type 1 Diabetes

PURPOSE OF REVIEW

Type 1 diabetes (T1D) is one of the most frequent chronic autoimmune diseases in humans, characterized by the lack of insulin production resulting in high blood glucose levels and lifelong requirement of exogenous insulin administration for survival. It is now recognized that the autoimmune process begins years before the clinical onset, in a stage called pre-symptomatic T1D, in which the presence of β-cell-specific autoantibodies is detectable. Our aim is to review evidence for T1D as a "whole-pancreas disease," featured by both endocrine and exocrine pancreas alterations already at early disease stages.

RECENT FINDINGS

In this review, we discuss a series of recent observations indicating that in genetically predisposed individuals, structural and functional abnormalities as well as immune cell infiltration of the exocrine pancreas are already present in the pre-symptomatic stages of the disease. Despite T1D being considered a β-cell-specific disease, numerous reports point to the presence of exocrine pancreas subclinical abnormalities occurring during disease development. These observations challenge the long-standing idea that T1D exocrine damage exists as a mere consequence of disease progression and provide further explanation of mechanisms underlying T1D pathogenesis.

Islet-immune interactions in type 1 diabetes: the nexus of beta cell destruction

Recent studies in Type 1 Diabetes (T1D) support an emerging model of disease pathogenesis that involves intrinsic β-cell fragility combined with defects in both innate and adaptive immune cell regulation. This combination of defects induces systematic changes leading to organ-level atrophy and dysfunction of both the endocrine and exocrine portions of the pancreas, ultimately culminating in insulin deficiency and β-cell destruction. In this review, we discuss the animal model data and human tissue studies that have informed our current understanding of the cross-talk that occurs between β-cells, the resident stroma, and immune cells that potentiate T1D. Specifically, we will review the cellular and molecular signatures emerging from studies on tissues derived from organ procurement programs, focusing on in situ defects occurring within the T1D islet microenvironment, many of which are not yet detectable by standard peripheral blood biomarkers. In addition to improved access to organ donor tissues, various methodological advances, including immune receptor repertoire sequencing and single-cell molecular profiling, are poised to improve our understanding of antigen-specific autoimmunity during disease development. Collectively, the knowledge gains from these studies at the islet-immune interface are enhancing our understanding of T1D heterogeneity, likely to be an essential component for instructing future efforts to develop targeted interventions to restore immune tolerance and preserve β-cell mass and function.