Insulin reduces endoplasmic reticulum stress-induced apoptosis by decreasing mitochondrial hyperpolarization and caspase-12 in INS-1 pancreatic ß-cells.

Pancreatic ß-cell mass is a critical determinant of insulin secretion. Severe endoplasmic reticulum (ER) stress causes ß-cell apoptosis; however, the mechanisms of progression and suppression are not yet fully understood. Here, we report that the autocrine/paracrine function of insulin reduces ER stress-induced ß-cell apoptosis. Insulin reduced the ER-stress inducer tunicamycin- and thapsigargin-induced cell viability loss due to apoptosis in INS-1 ß-cells. Moreover, the effect of insulin was greater than that of insulin-like growth factor-1 at physiologically relevant concentrations. Insulin did not attenuate the ER stress-induced increase in unfolded protein response genes. ER stress did not induce cytochrome c release from mitochondria. Mitochondrial hyperpolarization was induced by ER stress and prevented by insulin. The protonophore/mitochondrial oxidative phosphorylation uncoupler, but not the antioxidants N-acetylcysteine and α-tocopherol, exhibited potential cytoprotection during ER stress. Both procaspase-12 and cleaved caspase-12 levels increased under ER stress. The caspase-12 inhibitor Z-ATAD-FMK decreased ER stress-induced apoptosis. Caspase-12 overexpression reduced cell viability, which was diminished in the presence of insulin. Insulin decreased caspase-12 levels at the post-translational stages. These results demonstrate that insulin protects against ER stress-induced ß-cell apoptosis in this cell line. Furthermore, mitochondrial hyperpolarization and increased caspase-12 levels are involved in ER stress-induced and insulin-suppressed ß-cell apoptosis.

Scaling Insulin-Producing Cells by Multiple Strategies.

In the quest to combat insulin-dependent diabetes mellitus (IDDM), allogenic pancreatic islet cell therapy sourced from deceased donors represents a significant therapeutic advance. However, the applicability of this approach is hampered by donor scarcity and the demand for sustained immunosuppression. Human induced pluripotent stem cells are a game-changing resource for generating synthetic functional insulin-producing ß cells. In addition, novel methodologies allow the direct expansion of pancreatic progenitors and mature ß cells, thereby circumventing prolonged differentiation. Nevertheless, achieving practical reproducibility and scalability presents a substantial challenge for this technology. As these innovative approaches become more prominent, it is crucial to thoroughly evaluate existing expansion techniques with an emphasis on their optimization and scalability. This manuscript delineates these cutting-edge advancements, offers a critical analysis of the prevailing strategies, and underscores pivotal challenges, including cost-efficiency and logistical issues. Our insights provide a roadmap, elucidating both the promises and the imperatives in harnessing the potential of these cellular therapies for IDDM.

Redoxisome Update: TRX and TXNIP/TBP2-Dependent Regulation of NLRP-1/NLRP-3 Inflammasome.

Recent studies have provided evidence for the direct binding of thioredoxin-1 (TRX1) to a component of inflammasome complex NLR family pyrin domain containing 1 (NLRP-1). This interaction suggests a potential role for TRX1 in the regulation of the NLRP-1 inflammasome. Furthermore, the NLRP-3 inflammasome is known to bind TRX1 and its inhibitor, TRX-binding protein-2/TRX-interacting protein/vitamin D3 upregulated protein-1 (TBP2/TXNIP/VDUP-1). This binding forms a redox-sensitive complex, termed the "Redoxisome," as described previously. However, the specific functions of NLRP-1 within the redoxisome complex remain undefined. Antioxid. Redox Signal. 40, 595-597.

Stem Cell-Derived Islets for Type 2 Diabetes.

Since the discovery of insulin a century ago, insulin injection has been a primary treatment for both type 1 (T1D) and type 2 diabetes (T2D). T2D is a complicated disea se that is triggered by the dysfunction of insulin-producing ß cells and insulin resistance in peripheral tissues. Insulin injection partially compensates for the role of endogenous insulin which promotes glucose uptake, lipid synthesis and organ growth. However, lacking the continuous, rapid, and accurate glucose regulation by endogenous functional ß cells, the current insulin injection therapy is unable to treat the root causes of the disease. Thus, new technologies such as human pluripotent stem cell (hPSC)-derived islets are needed for both identifying the key molecular and genetic causes of T2D and for achieving a long-term treatment. This perspective review will provide insight into the efficacy of hPSC-derived human islets for treating and understanding T2D. We discuss the evidence that ß cells should be the primary target for T2D treatment, the use of stem cells for the modeling of T2D and the potential use of hPSC-derived islet transplantation for treating T2D.

Adapting Physiology in Functional Human Islet Organogenesis.

Generation of three-dimensional (3D)-structured functional human islets is expected to be an alternative cell source for cadaveric human islet transplantation for the treatment of insulin-dependent diabetes. Human pluripotent stem cells (hPSCs), such as human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs), offer infinite resources for newly synthesized human islets. Recent advancements in hPSCs technology have enabled direct differentiation to human islet-like clusters, which can sense glucose and secrete insulin, and those islet clusters can ameliorate diabetes when transplanted into rodents or non-human primates (NHPs). However, the generated hPSC-derived human islet-like clusters are functionally immature compared with primary human islets. There remains a challenge to establish a technology to create fully functional human islets in vitro, which are functionally and transcriptionally indistinguishable from cadaveric human islets. Understanding the complex differentiation and maturation pathway is necessary to generate fully functional human islets for a tremendous supply of high-quality human islets with less batch-to-batch difference for millions of patients. In this review, I summarized the current progress in the generation of 3D-structured human islets from pluripotent stem cells and discussed the importance of adapting physiology for in vitro functional human islet organogenesis and possible improvements with environmental cues.

Estrogen-Related Receptor γ Maintains Pancreatic Acinar Cell Function and Identity by Regulating Cellular Metabolism.

BACKGROUND & AIMS: Mitochondrial dysfunction disrupts the synthesis and secretion of digestive enzymes in pancreatic acinar cells and plays a primary role in the etiology of exocrine pancreas disorders. However, the transcriptional mechanisms that regulate mitochondrial function to support acinar cell physiology are poorly understood. Here, we aim to elucidate the function of estrogen-related receptor γ (ERRγ) in pancreatic acinar cell mitochondrial homeostasis and energy production. METHODS: Two models of ERRγ inhibition, GSK5182-treated wild-type mice and ERRγ conditional knock-out (cKO) mice, were established to investigate ERRγ function in the exocrine pancreas. To identify the functional role of ERRγ in pancreatic acinar cells, we performed histologic and transcriptome analysis with the pancreas isolated from ERRγ cKO mice. To determine the relevance of these findings for human disease, we analyzed transcriptome data from multiple independent human cohorts and conducted genetic association studies for ESRRG variants in 2 distinct human pancreatitis cohorts. RESULTS: Blocking ERRγ function in mice by genetic deletion or inverse agonist treatment results in striking pancreatitis-like phenotypes accompanied by inflammation, fibrosis, and cell death. Mechanistically, loss of ERRγ in primary acini abrogates messenger RNA expression and protein levels of mitochondrial oxidative phosphorylation complex genes, resulting in defective acinar cell energetics. Mitochondrial dysfunction due to ERRγ deletion further triggers autophagy dysfunction, endoplasmic reticulum stress, and production of reactive oxygen species, ultimately leading to cell death. Interestingly, ERRγ-deficient acinar cells that escape cell death acquire ductal cell characteristics, indicating a role for ERRγ in acinar-to-ductal metaplasia. Consistent with our findings in ERRγ cKO mice, ERRγ expression was significantly reduced in patients with chronic pancreatitis compared with normal subjects. Furthermore, candidate locus region genetic association studies revealed multiple single nucleotide variants for ERRγ that are associated with chronic pancreatitis. CONCLUSIONS: Collectively, our findings highlight an essential role for ERRγ in maintaining the transcriptional program that supports acinar cell mitochondrial function and organellar homeostasis and provide a novel molecular link between ERRγ and exocrine pancreas disorders.

Heterogeneity of Diabetes: ß-Cells, Phenotypes, and Precision Medicine: Proceedings of an International Symposium of the Canadian Institutes of Health Research's Institute of Nutrition, Metabolism and Diabetes and the U.S. National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases.

One hundred years have passed since the discovery of insulin-an achievement that transformed diabetes from a fatal illness into a manageable chronic condition. The decades since that momentous achievement have brought ever more rapid innovation and advancement in diabetes research and clinical care. To celebrate the important work of the past century and help to chart a course for its continuation into the next, the Canadian Institutes of Health Research's Institute of Nutrition, Metabolism and Diabetes and the U.S. National Institutes of Health's National Institute of Diabetes and Digestive and Kidney Diseases recently held a joint international symposium, bringing together a cohort of researchers with diverse interests and backgrounds from both countries and beyond to discuss their collective quest to better understand the heterogeneity of diabetes and thus gain insights to inform new directions in diabetes treatment and prevention. This article summarizes the proceedings of that symposium, which spanned cutting-edge research into various aspects of islet biology, the heterogeneity of diabetic phenotypes, and the current state of and future prospects for precision medicine in diabetes.

Advances in Pancreatic Islet Transplantation Sites for the Treatment of Diabetes.

Diabetes is a complex disease that affects over 400 million people worldwide. The life-long insulin injections and continuous blood glucose monitoring required in type 1 diabetes (T1D) represent a tremendous clinical and economic burdens that urges the need for a medical solution. Pancreatic islet transplantation holds great promise in the treatment of T1D; however, the difficulty in regulating post-transplantation immune reactions to avoid both allogenic and autoimmune graft rejection represent a bottleneck in the field of islet transplantation. Cell replacement strategies have been performed in hepatic, intramuscular, omentum, and subcutaneous sites, and have been performed in both animal models and human patients. However more optimal transplantation sites and methods of improving islet graft survival are needed to successfully translate these studies to a clinical relevant therapy. In this review, we summarize the current progress in the field as well as methods and sites of islet transplantation, including stem cell-derived functional human islets. We also discuss the contribution of immune cells, vessel formation, extracellular matrix, and nutritional supply on islet graft survival. Developing new transplantation sites with emerging technologies to improve islet graft survival and simplify immune regulation will greatly benefit the future success of islet cell therapy in the treatment of diabetes.

Bisphenol A derivatives act as novel coactivator-binding inhibitors for estrogen receptor ß.

Bisphenol A and its derivatives are recognized as endocrine disruptors based on their complex effects on estrogen receptor (ER) signaling. While the effects of bisphenol derivatives on ERα have been thoroughly evaluated, how these chemicals affect ERß signaling is less well understood. Herein, we sought to identify novel ERß ligands using a radioligand competitive binding assay to screen a chemical library of bisphenol derivatives. Many of the compounds identified showed intriguing dual activities as both ERα agonists and ERß antagonists. Docking simulations of these compounds and ERß suggested that they bound not only to the canonical binding site of ERß but also to the coactivator binding site located on the surface of the receptor, suggesting that they act as coactivator-binding inhibitors (CBIs). Receptor-ligand binding experiments using WT and mutated ERß support the presence of a second ligand-interaction position at the coactivator-binding site in ERß, and direct binding experiments of ERß and a coactivator peptide confirmed that these compounds act as CBIs. Our study is the first to propose that bisphenol derivatives act as CBIs, presenting critical insight for the future development of ER signaling-based drugs and their potential to function as endocrine disruptors.

Immune Protection of Stem Cell-Derived Islet Cell Therapy for Treating Diabetes.

Insulin injection is currently the main therapy for type 1 diabetes (T1D) or late stage of severe type 2 diabetes (T2D). Human pancreatic islet transplantation confers a significant improvement in glycemic control and prevents life-threatening severe hypoglycemia in T1D patients. However, the shortage of cadaveric human islets limits their therapeutic potential. In addition, chronic immunosuppression, which is required to avoid rejection of transplanted islets, is associated with severe complications, such as an increased risk of malignancies and infections. Thus, there is a significant need for novel approaches to the large-scale generation of functional human islets protected from autoimmune rejection in order to ensure durable graft acceptance without immunosuppression. An important step in addressing this need is to strengthen our understanding of transplant immune tolerance mechanisms for both graft rejection and autoimmune rejection. Engineering of functional human pancreatic islets that can avoid attacks from host immune cells would provide an alternative safe resource for transplantation therapy. Human pluripotent stem cells (hPSCs) offer a potentially limitless supply of cells because of their self-renewal ability and pluripotency. Therefore, studying immune tolerance induction in hPSC-derived human pancreatic islets will directly contribute toward the goal of generating a functional cure for insulin-dependent diabetes. In this review, we will discuss the current progress in the immune protection of stem cell-derived islet cell therapy for treating diabetes.

Immune-evasive human islet-like organoids ameliorate diabetes.

Islets derived from stem cells hold promise as a therapy for insulin-dependent diabetes, but there remain challenges towards achieving this goal1-6. Here we generate human islet-like organoids (HILOs) from induced pluripotent stem cells and show that non-canonical WNT4 signalling drives the metabolic maturation necessary for robust ex vivo glucose-stimulated insulin secretion. These functionally mature HILOs contain endocrine-like cell types that, upon transplantation, rapidly re-establish glucose homeostasis in diabetic NOD/SCID mice. Overexpression of the immune checkpoint protein programmed death-ligand 1 (PD-L1) protected HILO xenografts such that they were able to restore glucose homeostasis in immune-competent diabetic mice for 50 days. Furthermore, ex vivo stimulation with interferon-γ induced endogenous PD-L1 expression and restricted T cell activation and graft rejection. The generation of glucose-responsive islet-like organoids that are able to avoid immune detection provides a promising alternative to cadaveric and device-dependent therapies in the treatment of diabetes.

TXNIP/TBP-2: A Master Regulator for Glucose Homeostasis.

Identification of thioredoxin binding protein-2 (TBP-2), which is currently known as thioredoxin interacting protein (TXNIP), as an important binding partner for thioredoxin (TRX) revealed that an evolutionarily conserved reduction-oxidation (redox) signal complex plays an important role for pathophysiology. Due to the reducing activity of TRX, the TRX/TXNIP signal complex has been shown to be an important regulator for redox-related signal transduction in many types of cells in various species. In addition to its role in redox-dependent regulation, TXNIP has cellular functions that are performed in a redox-independent manner, which largely rely on their scaffolding function as an ancestral α-Arrestin family. Both the redox-dependent and -independent TXNIP functions serve as regulatory pathways in glucose metabolism. This review highlights the key advances in understanding TXNIP function as a master regulator for whole-body glucose homeostasis. The potential for therapeutic advantages of targeting TXNIP in diabetes and the future direction of the study are also discussed.

FXR Regulates Intestinal Cancer Stem Cell Proliferation.

Increased levels of intestinal bile acids (BAs) are a risk factor for colorectal cancer (CRC). Here, we show that the convergence of dietary factors (high-fat diet) and dysregulated WNT signaling (APC mutation) alters BA profiles to drive malignant transformations in Lgr5-expressing (Lgr5+) cancer stem cells and promote an adenoma-to-adenocarcinoma progression. Mechanistically, we show that BAs that antagonize intestinal farnesoid X receptor (FXR) function, including tauro-ß-muricholic acid (T-ßMCA) and deoxycholic acid (DCA), induce proliferation and DNA damage in Lgr5+ cells. Conversely, selective activation of intestinal FXR can restrict abnormal Lgr5+ cell growth and curtail CRC progression. This unexpected role for FXR in coordinating intestinal self-renewal with BA levels implicates FXR as a potential therapeutic target for CRC.

Vitamin D Switches BAF Complexes to Protect ß Cells.

A primary cause of disease progression in type 2 diabetes (T2D) is ß cell dysfunction due to inflammatory stress and insulin resistance. However, preventing ß cell exhaustion under diabetic conditions is a major therapeutic challenge. Here, we identify the vitamin D receptor (VDR) as a key modulator of inflammation and ß cell survival. Alternative recognition of an acetylated lysine in VDR by bromodomain proteins BRD7 and BRD9 directs association to PBAF and BAF chromatin remodeling complexes, respectively. Mechanistically, ligand promotes VDR association with PBAF to effect genome-wide changes in chromatin accessibility and enhancer landscape, resulting in an anti-inflammatory response. Importantly, pharmacological inhibition of BRD9 promotes PBAF-VDR association to restore ß cell function and ameliorate hyperglycemia in murine T2D models. These studies reveal an unrecognized VDR-dependent transcriptional program underpinning ß cell survival and identifies the VDR:PBAF/BAF association as a potential therapeutic target for T2D.

ERRγ Preserves Brown Fat Innate Thermogenic Activity.

Brown adipose tissue (BAT) adaptively transfers energy from glucose and fat into heat by inducing a gene network that uncouples mitochondrial electron transport. However, the innate transcription factors that enable the rapid adaptive response of BAT are unclear. Here, we identify estrogen-related receptor gamma (ERRγ) as a critical factor for maintaining BAT identity. ERRγ is selectively expressed in BAT versus WAT, in which, in the absence of PGC1α, it drives a signature transcriptional network of thermogenic and oxidative genes in the basal (i.e., thermoneutral) state. Mice lacking ERRγ in adipose tissue (ERRγKO mice) display marked downregulation of BAT-selective genes that leads to a pronounced whitening of BAT. Consistent with the transcriptional changes, the thermogenic capacity of ERRγKO mice is severely blunted, such that they fail to survive an acute cold challenge. These findings reveal a role for ERRγ as a critical thermoneutral maintenance factor required to prime BAT for thermogenesis.

No Association between the Polymorphism rs6943555 in the AUTS2 Gene and Personality Traits in Japanese University Students.

OBJECTIVE: The autism susceptibility candidate 2 (AUTS2) gene has been implicated in multiple neurological disorders. Several recent studies have revealed that the polymorphism rs6943555 in the AUTS2 gene is broadly associated with human mental function and behavior. Therefore, in the present study we investigated whether the polymorphism rs6943555 is associated with human personality traits in Japanese university students. In addition, our previous study reported that the AUTS2 rs6943555-rs9886351 haplotype is associated with alcohol dependence. As a preliminary analysis, we also examined whether the AUTS2 haplotypes are related to personality traits. METHODS: After written informed consent had been obtained from the participants, two AUTS2 polymorphisms were analyzed, and personality was assessed using the Temperament and Character Inventory (TCI) in 190 university students. In addition, in order to exclude the influence of the results for students with mental health problems, we gave the Patient Health Questionnaire-9 (PHQ-9) to all subjects. RESULTS: In all the subjects, there was a main effect of the polymorphism rs6943555 genotype on reward dependence (p=0.038) and cooperativeness (p=0.031), although the significance was lost on Bonferroni correction. Similarly, on analysis that excluded the subjects with PHQ-9 scores≥10, no significant association with any TCI dimension score among the rs6943555 genotypes was seen. There was no effect of the rs6943555-rs9886351 haplotypes on the TCI dimension scores. CONCLUSION: This study suggests that the polymorphism AUTS2 rs6943555 is not associated with personality traits. Further large-scale studies with more subjects using other self-report questionnaires are needed.

A phase 2 randomized study of TAS-102 versus topotecan or amrubicin in patients requiring second-line chemotherapy for small cell lung cancer refractory or sensitive to frontline platinum-based chemotherapy.

OBJECTIVES: TAS-102 is an oral combination treatment comprised of an antimetabolite, trifluridine, a thymidine-based nucleoside analog, and tipiracil hydrochloride, at a molar ratio of 1:0.5. This antimetabolite has demonstrated efficacy in clinical trials, including a global phase 3 trial in metastatic colorectal cancer. As this agent has shown activity greater than cisplatin in small cell lung cancer xenograft mouse models, the objective of this study was to evaluate TAS-102 in the second-line treatment of small cell lung cancer. METHODS: This was a multicenter, open-label, two-arm, randomized phase 2 study designed to compare oral TAS-102 (35mg/m(2)/dose twice daily) versus control (topotecan or amrubicin). Patients requiring second-line chemotherapy for treatment of small cell lung cancer, either refractory or sensitive to frontline platinum-based chemotherapy, were enrolled. RESULTS: Eighteen patients were enrolled. Eight of nine patients receiving TAS-102 discontinued treatment due to progressive disease and one patient died due to clinical progression during the safety follow-up. Unplanned interim futility considerations were made, and the study was terminated early because it was unlikely that superiority of TAS-102 versus comparator could be demonstrated. Six control patients discontinued therapy due to progressive disease and one due to an adverse event. Median progression-free survival was 1.4 months (range 0.9-1.8) versus 2.7 months (range 1.0-6.8) for TAS-102 and control, respectively, with a hazard ratio of 3.76 (80% CI, 1.68-8.40) favoring control. The most common adverse events with TAS-102 were neutropenia, diarrhea, anemia, anorexia, and fatigue, each in three patients. CONCLUSION: TAS-102 showed no evidence of activity in second-line small cell lung cancer.

ERRγ Is Required for the Metabolic Maturation of Therapeutically Functional Glucose-Responsive ß Cells.

Pancreatic ß cells undergo postnatal maturation to achieve maximal glucose-responsive insulin secretion, an energy intensive process. We identify estrogen-related receptor γ (ERRγ) expression as a hallmark of adult, but not neonatal ß cells. Postnatal induction of ERRγ drives a transcriptional network activating mitochondrial oxidative phosphorylation, the electron transport chain, and ATP production needed to drive glucose-responsive insulin secretion. Mice deficient in ß cell-specific ERRγ expression are glucose intolerant and fail to secrete insulin in response to a glucose challenge. Notably, forced expression of ERRγ in iPSC-derived ß-like cells enables glucose-responsive secretion of human insulin in vitro, obviating in vivo maturation to achieve functionality. Moreover, these cells rapidly rescue diabetes when transplanted into ß cell-deficient mice. These results identify a key role for ERRγ in ß cell metabolic maturation, and offer a reproducible, quantifiable, and scalable approach for in vitro generation of functional human ß cell therapeutics.