Loss-of-function (LOF) mutations in KATP channels cause hyperexcitability and insulin hypersecretion, resulting in congenital hyperinsulinism (CHI). Paradoxically, despite the initial insulin hypersecretion, many CHI cases, as well as KATP knockout (KO) animals, eventually ‘crossover’ to undersecretion and even diabetes. Here we confirm that Sur1 KO islets exhibit higher intracellular [Ca2+] ([Ca2+]i)

Lipedema is a lipodystrophic disease that is typically characterized by a marked increase in lower-body subcutaneous adipose tissue that is purported to have increased inflammation and fibrosis, impaired microvascular/lymphatic circulation and to be resistant to reduction by weight loss therapy. However, these outcomes have not been adequately studied. We evaluated body composition, insulin sensitivity

Despite elucidation of the molecular genetic basis of several lipodystrophy syndromes, molecular defects in some ultra-rare subtypes of familial lipodystrophies remain unidentified. We analyzed whole exome sequencing (WES) data of four affected and two unaffected females from an undiagnosed autosomal dominant familial partial lipodystrophy (FPL) pedigree and identified only one novel heterozygous variant

Transplanted islet functional β-cell mass is measured by the β-cell secretory capacity derived from the acute insulin response to glucose-potentiated arginine (AIRpot), however, data are limited beyond one-year post-transplant for individuals with type 1 diabetes. We evaluated changes in β-cell secretory capacity in a single-center longitudinal analysis and examined relationships with measures of islet

The biomarkers connecting obesity and cardiometabolic diseases are not fully understood. We aimed to (i) evaluate the associations between body mass index (BMI), waist circumference (WC), and ∼5,000 plasma proteins (SomaScan v4), (ii) identify protein signatures of BMI and WC, and (iii) evaluate the associations between the protein signatures and cardiometabolic health including metabolically unhealthy

The accumulation of mitochondria in thermogenic adipose tissue (i.e., brown and beige fat) increases energy expenditure, which can aid in alleviating obesity and metabolic disorders. However, recent studies have shown that knocking out key proteins required to maintain mitochondrial function inhibits the energy expenditure in thermogenic fat, and yet the knockout mice are unexpectedly protected from

Murine pancreatic endocrinogenesis has been extensively studied, but human data remain scarce due to limited sample availability. Here, we first built a large collection of human embryonic and fetal pancreases covering the first trimester of pregnancy to explore human endocrinogenesis. Using an experimental pipeline combining in toto staining, tissue clearing, and light-sheet fluorescence microscopy

Glucose tolerance improves significantly upon consuming a second, identical meal later in the day (second meal phenomenon). We previously established that morning hyperinsulinemia primes the liver for increased afternoon hepatic glucose uptake (HGU). Although the route of insulin delivery is an important determinant of the mechanisms by which insulin regulates liver glucose metabolism (direct hepatic

Thermogenesis of brown adipose tissues (BAT) provides metabolic benefits against pathological conditions such as Type 2 diabetes, obesity, cardiovascular diseases, and cancer. The thermogenic function of BAT relies on mitochondria, but whether mitochondrial remodeling is required for the beneficial effects of BAT remains unclear. We have recently identified FAM210A as a BAT-enriched mitochondrial protein

Glucose-stimulated beta-cells exhibit synchronized calcium dynamics across the islet that recruit beta-cells to enhance insulin secretion. Compared to calcium dynamics, the formation and cell-to-cell propagation of electrical signals within the islet are poorly characterized. To determine factors that influence the propagation of electrical activity across the islet underlying calcium oscillations

The gold standard for assessing the function of human islets or β-like cells derived from stem cells involves their engraftment under the kidney capsule of hyperglycemic, immunodeficient mice. Current models, such as Streptozotocin (STZ) treatment of severely immunodeficient mice or the NRG-Akita strain are limited due to unstable and variable hyperglycemia and/or high morbidity of these models. To

Dysregulation and loss of immune tolerance towards pancreatic β-cell autoantigens are features of type 1 diabetes (T1D). Until recently, life-long insulin injection was the only approved treatment for T1D, and this does not address the underlying disease pathology. Antigen-specific immunotherapy (ASI) seeks to restore tolerance and holds potential as a new therapeutic strategy for treating autoimmune

Human embryonic stem cell (hESC)-derived pancreatic alpha and beta cells can be used to develop cell replacement therapies to treat diabetes. However, recent published differentiation protocols yield varying amounts of alpha and beta cells amidst heterogeneous cell populations. To visualize and isolate hESC-derived alpha and beta cells, we generated a GLUCAGON-2AmScarlet and INSULIN-2A-EGFP dual fluorescent

The obesity diagnosis by body mass index (BMI) exhibits considerable interindividual heterogeneity in metabolic phenotypes and risk of developing type 2 diabetes (T2D). We investigated the association of proteomic signature of BMI and T2D and examined whether the proteomic signature of BMI improves prediction of T2D risk. This study included 41,427 adults in the UK Biobank who were free of T2D at baseline

Glucagon-like peptide 1 receptor (GLP-1R) agonists fail to reduce weight and improve glucose control in a sizable minority of people with type 2 diabetes. We hypothesized that stimulation of the hypothalamic-pituitary-adrenal (HPA) axis by GLP-1R agonists, thus inducing cortisol secretion, could explain this unresponsiveness to GLP-1R agonists. To assess the effects of GLP-1R agonist treatment on the

Identified genetic loci for C-peptide and age at diagnosis (AAD) in individuals with type 1 diabetes (T1D) explain only a small proportion of their variation. Here, we aimed to perform large metagenome-wide association studies (GWAS) of C-peptide and AAD in T1D; and to identify the HLA allele/haplotypes associated with C-peptide and AAD. 7,252 and 7,923 European individuals with T1D were included in

Embedded in the Developmental Origins of Health and Disease hypothesis, maternal hyperglycemia in utero, from pre-existing diabetes or gestational diabetes mellitus, predisposes the offspring to excess adiposity and heightened risk of prediabetes and type 2 diabetes development. This transmission creates a vicious cycle increasing the presence of diabetes from one generation to another, leading to

Maternally inherited diabetes and deafness (MIDD) is a monogenic mitochondrial disorder caused by a pathogenic variant in the MT-TL1 gene encoding for a leucine transfer RNA. We propose a new hypothesis that explains how the MT-TL1 variant causes impaired glucose tolerance and diabetes in MIDD. We suggest that diabetes in MIDD primarily depends on a variable combination of insulin resistance and impaired

High-affinity islet autoantibodies predict type 1 diabetes in mice and humans and implicate germinal centers (GCs) in type 1 diabetes pathogenesis. T follicular helper (Tfh) cells are increased in type 1 diabetic individuals and alterations in Tfh-like cells in the peripheral blood predicted individual responses to abatacept. Tfh cells support GC responses and depend on the transcriptional repressor

Resolving metabolic heterogeneity in patients with type 2 diabetes mellitus (T2DM) gives them access to precision medicine. Despite ethnic diversity in pathophysiological processes in individuals with T2DM, studies on subtypes of diabetes related to clinical characteristics in Asians are insufficient. This study aims to identify metabolic patterns in middle-aged patients with T2DM in Republic of Korea

Roux-en-Y gastric bypass (RYGB) has been shown to inhibit β-cell apoptosis, but the underlying mechanisms are not yet fully understood. Cytochrome c oxidase subunit 6A2 (COX6A2) is expressed in β-cells. Here, we sought to investigate the role of COX6A2 in β-cell apoptosis, especially following RYGB. We found that RYGB significantly reduced β-cell apoptosis, accompanied by decreased COX6A2 expression

MG53 is predominantly expressed in striated muscles. The role of MG53 in diabetes mellitus has been gradually elucidated but is still full of controversy. Some reports have indicated that MG53 is upregulated in animal models with metabolic disorders, and that muscle-specific MG53 upregulation is sufficient to induce whole-body insulin resistance and metabolic syndrome through targeting both the insulin

Shared medical appointments (SMAs) for diabetes and group prenatal care (GPC) for pregnant patients, have emerged as innovative care delivery models. They have the potential to transform diabetes care by overcoming many of the time limitations of traditional one-on-one clinical visits. There is compelling evidence that SMAs improve glycemic control for non-pregnant patients with diabetes, GPC reduces

Small glycemic increments (≤0.5 mmol/L) can exert suppressive actions on endogenous glucose production (EGP) however it is unclear if this is an insulin dependent or independent process. Here, we performed a low-rate glucose infusion in control participants without diabetes and in people with type 1 diabetes (T1D) to better understand this phenomenon. Glucose kinetics, hormones and metabolites were

Smoking is widely regarded as a risk factor for type 2 diabetes, as nicotine contributes to insulin resistance by desensitizing the insulin receptors in muscle, liver, or fat. Little is known, however, about the immediate regulation of islet hormonal output by nicotine, an agonist of ionotropic cholinergic receptors. We investigated this by imaging cytosolic Ca2+ dynamics in mouse and human islets

Diabetic vasculopathy, encompassing complications such as diabetic retinopathy, represents a significant source of morbidity, with inflammation playing a pivotal role in the progression of these complications. This study investigates the influence of m6A modification and the m6A demethylase FTO on macrophage polarization and its subsequent effects on diabetic microvasculopathy. We found that diabetes

Diabetes can lead to cell-type-specific responses in the retina, including vascular lesions, glial dysfunction and neurodegeneration, all of which contribute to retinopathy. However, the molecular mechanisms underlying these cell type-specific responses, and the cell types that are sensitive to diabetes have not been fully elucidated. Employing single cell transcriptomics, we profiled the transcriptional

Type 1 diabetes treatment stands at a crucial and exciting crossroad since the 2022 U.S. Food and Drug Administration (FDA) approval of teplizumab to delay disease development. In this Perspective article, we discuss four major conceptual and practical issues that emerged as key to further advance type 1 diabetes research and therapies. First, collaborative networks leveraging the synergy between the

Diabetic keratopathy (DK) is a common chronic metabolic disorder that causes ocular surface complications. Among various therapeutic approaches, local delivery of nerve growth factor (NGF) remains the most effective treatment for DK. However, achieving a sustained therapeutic effect with NGF and the frequent drug delivery burden remain challenging during clinical practice. Here, we developed a novel

We examined the effect of increased plasma ketones on left ventricular (LV) function, myocardial glucose uptake (MGU), and myocardial blood flow (MBF) in type 2 diabetes (T2DM) patients with heart failure (HF). Three groups (I,II,III) of T2DM (12 per group) with LV ejection fraction ≤50% received incremental infusions of β-OH-B for 3-6 hours to raise plasma β-OH-B concentration throughout the physiologic

Immediate early response 3 interacting-protein 1 (IER3IP1) is an endoplasmic reticulum resident protein, highly expressed in pancreatic cells and the developing brain cortex. Homozygous mutations in IER3IP1 have been found in individuals with microcephaly and neonatal diabetes, yet the underlying mechanism causing beta cell failure remains unclear. Here, we utilized differentiation of genome edited-stem

Incidences of childhood obesity and type 2 diabetes (T2D) are climbing at alarming rates. Evidence points to prenatal exposures to maternal obesity and gestational diabetes mellitus (GDM) as key contributors to these upward trends. Children born to mothers with these conditions face higher risks of obesity and T2D, beyond genetic or shared environmental factors. The underpinnings of this maternal-fetal

The prevalence of type 2 diabetes (T2D) varies among populations of different race/ethnicity. The influence of genetically-proxied lipoprotein cholesterol (LDL-C) lowering through proprotein convertase subtilisin/kexin 9 (PCSK9) and HMG-CoA Reductase (HMGCR) on T2D in non-European populations is not well established.A drug-target Mendelian randomization (MR) approach was used to assess the effects

Early, intensive glycemic control in T2D patients is associated with long-term benefits on cardiovascular disease (CVD) development. Evidence on benefits of achieving HbA1c targets close to normal values is scant. Subjects with newly-diagnosed T2D, without CVD at baseline, were identified in an Italian clinical registry (N=251,339). We adopted three definitions of early exposure periods (0–1, 0–2 and

Lesioned fascicles (LF) in the sciatic nerves of individuals with diabetic neuropathy (DN) correlate with clinical symptom severity. This study aimed to characterize the structural and molecular composition of these lesions to better understand DN pathogenesis. Sciatic nerves from amputees with and without type 2 diabetes (T2D) were examined using ex vivo magnetic resonance neurography, in vitro imaging

There is evidence that 1-h plasma glucose (PG) during the 75-g oral glucose tolerance test (OGTT) is superior to 2-h PG in predicting diabetes. We aimed to investigate the characteristics of insulin sensitivity and β-cell function behind this observation. After age, sex and BMI matching, 496 subjects selected from 3965 non-diabetic individuals at high risk of type 2 diabetes in a tertiary medical center

The Ventromedial hypothalamic nucleus (VMN) maintains healthy metabolic function through several important roles. Collectively, homeostasis is maintained via intermingled cells within the VMN that raise blood glucose, lower blood glucose, and stimulate energy expenditure when needed. This perspective discusses the defining factors for the VMN cell types that govern distinct functions induced by the

Exploring the mechanisms underlying abnormal glycemic traits is important for deciphering type 2 diabetes and characterizing novel drug targets. This study aimed to decipher the causal associations of circulating proteins with fasting glucose (FG), 2-h glucose after an oral glucose challenge (2hGlu), fasting insulin (FI), and glycated hemoglobin (HbA1c) using large-scale proteome-wide Mendelian randomization

The brain coordinates the homeostatic defense of multiple metabolic variables, including blood glucose levels, in the context of ever-changing external and internal environments. The biologically defended level of glycemia (BDLG) is the net result of brain modulation of insulin-dependent mechanisms in cooperation with the islet, and insulin-independent mechanisms through direct innervation and neuroendocrine

Increased arcuate proopiomelanocortin (POMC) neuron activity improves glucose metabolism and reduces appetite, facilitating weight loss. We recently showed that arcuate POMC neurons are activated by exercise. However, the role of excitatory glutamatergic input in these neurons and the metabolic outcomes of exercise remains undefined. To investigate this, we developed a mouse model with NMDA receptors

There are key differences between the central nervous system (CNS) (brain and spinal cord) and peripheral nervous system (PNS), such as glial cell types, whether there is protection by the blood-brain barrier, modes of synaptic connections, etc. However, there are many more similarities between these two arms of the nervous system, including neuronal structure and function, neuroimmune and neurovascular

Translocational regulation of proinsulin biosynthesis in pancreatic β-cells is unknown, although several studies have reported an important accessory role for the Translocon-Associated Protein complex to assist preproinsulin delivery into the endoplasmic reticulum via the heterotrimeric Sec61 translocon (comprised of α, β, and γ subunits). The actual protein-conducting channel is the α–subunit encoded

Excessive iron accumulation in metabolic organs such as the adipose tissue, liver, and skeletal muscle is associated with increased diabetes risk. Tissue-resident macrophages serve multiple roles including managing inflammatory tone and regulating parachymal iron homeostasis; thus protecting against metabolic dysfunction upon iron overload. The scavenger receptor CD163 is uniquely present on tissue-resident

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

The prevalence of Type 2 Diabetes (T2D) poses a significant health challenge yet the contribution of air pollutants to T2D epidemics remains understudied. Several studies demonstrated a correlation between exposure to volatile organic compounds (VOCs) in indoor/outdoor environments, and T2D. Here, we conducted the first meta-analysis, establishing a robust association between exposure to benzene, a

Diabetic nephropathy (DN) is the leading cause of end-stage renal disease and effective treatment modalities that fully address its molecular etiology are lacking. Prior studies support that the stress response protein REDD1 (Regulated in Development and DNA Damage 1) contributes to the development of diabetic complications. This study investigated a potential role for REDD1 expression in podocytes

Hypothalamic innate immune responses to dietary fats underpin the pathogenesis of obesity, in which microglia play a critical role. Progranulin (PGRN) is an evolutionarily -conserved secretory protein containing seven-and-a-half granulin (GRN) motifs. It is cleaved into GRNs by multiple proteases. In the central nervous system, PGRN is highly expressed in microglia. To investigate the role of microglia-derived

Muscle sn-1,2-diacylglycerol (DAG) and C18:0 ceramide accumulation in sarcolemmal and mitochondrial compartments have been proposed to regulate muscle insulin sensitivity. Here, we evaluated whether weight loss-induced improvements in insulin sensitivity were associated with changes in muscle sn-1,2-DAG and ceramide content in people with obesity and type 2 diabetes. We measured skeletal muscle insulin

Our objective is to test a single dose of the phosphoinositide-3-kinase (PI3K) inhibitor alpelisib as a tool for acute modeling of insulin resistance in healthy volunteers. This single-center, double-blind, phase 1 clinical trial randomized healthy adults to take a single oral dose of alpelisib 300 mg (n = 5) or placebo (n = 6) at bedtime, followed by measurement of glucose, insulin, and C-peptide

Melanocortin-4-receptor (Mc4r) is a G protein-coupled receptor (GPCR) that controls systemic energy balance by regulating food intake and energy expenditure. Although the detailed molecular mechanism remains unclear, the activation of cAMP signaling in Mc4r-expressing cells reportedly suppresses food intake and increases energy expenditure. cAMP-responsive element-binding protein-regulated transcriptional

In the abstract cited above, author Nadine El Kalach was inadvertently omitted from the author list. The full, correct author list is as follows: Nadine El Kalach, Emmanuel F. Julceus, Caroline Rudisill, Faisal Malik, Kate Flory, Edward A. Frongillo, Katherine A. Sauder, Jason A. Mendoza, and Angela D. Liese. All authors approve the addition and the order of the revised author list. The authors apologize

Evaluation of insulin secretory capacity is essential to understand the pathophysiological condition of individuals with diabetes and to assess the efficacy of drugs used in treatment of the disease. The 1 mg intravenous glucagon stimulation test (GST) is widely used to evaluate residual β cell function; we previously reported that GST assessment of insulin secretory capacity is useful in assessing

Pancreatic β-cell dysfunction caused by obesity can be associated with alterations in the levels of microRNAs (miRNAs). However, the role of miRNAs in such processes remains elusive. Here, we show that pancreatic islet miR-27a-5p, which is markedly increased in obese mice and impairs insulin secretion, is mainly delivered by visceral adipocyte-derived extracellular vesicles (EVs). Depleting miR-27a-5p

Diabetic retinopathy (DR) is one of the most common complications of diabetes mellitus which is associated with visual loss and blindness worldwide. However, the effective treatments for both early- and late-stage DR remains lacking. A streptozotocin (STZ)-induced diabetic mice model and high glucose (HG)-treated Müller cell model were established. M1/M2 microglia polarization was assessed by immunofluorescence

Leptin is a homeostatic regulatory element that signals the presence of adipocyte energy stores, reduces food intake, and increases energy expenditure. Similarly, serotonin (5- HT), a signaling molecule found in both the central and peripheral nervous systems, also controls food intake. Using neuronal tract-tracing, pharmacological and optogenetics approaches, and in vivo microdialysis, combined with

The approval of teplizumab to delay the onset of type 1 diabetes is an important inflection point in the decades long pursuit to treat the cause of the disease rather than its symptoms. NIDDK convened a workshop of the Diabetes Mellitus Interagency Coordinating Committee titled “Evolving Concepts in Pathophysiology, Screening, and Prevention of Type 1 Diabetes” to review this accomplishment and identify

Diabetic peripheral neuropathy (DPN) affects around 50% of the 500 million people with type 2 diabetes worldwide and is considered disabling and irreversible. The present study was undertaken to assess the effect of metformin on peripheral neuropathy outcomes in type 2 diabetes. 69 type 2 diabetes participants receiving metformin were recruited and underwent clinical assessment, peripheral nerve ultrasound

The translocon-associated protein-δ (TRAPδ) plays a role in insulin biosynthesis within pancreatic β cells. However, its pathophysiological significance in maintaining islet β cell function and glucose homeostasis remains unclear. In this study, we generated a mouse model featuring pancreatic β cell-specific deletion of TRAPδ (TRAPδ βKO). Our findings revealed that TRAPδ βKO resulted in decreased circulating

Excessive macrophage extracellular traps (METs) formation has been implicated in several autoimmune disease pathogenesis; however, its impact on Type 1 Diabetes (T1D) and related mechanisms remains enigmatic. Here, we demonstrated the pivotal role of peptidyl arginine deiminase 4 (PAD4) in driving profuse METs formation and macrophage M1 polarization in intestinal inflammation of non-obese diabetic

We postulated that T2D predisposes to exocrine pancreatic diseases through (epi)genetic mechanisms. We explored the methylome (methylationEPIC arrays) of the exocrine pancreas of 141 donors, assessing the impact of T2D. Epigenome-wide association study (EWAS) for T2D identified a hypermethylation in an enhancer of the Pancreatic-Lipase-Related-Protein 1 (PNLIPRP1) gene, associated with decreased PNLIPRP1