Pancreatic Islets Research Articles

Challenging directions in pediatric diabetes - the place of oxidative stress and antioxidants in systemic decline

Diabetes is a complex condition with a rising global incidence, and its impact is equally evident in pediatric practice. Regardless of whether we are dealing with type 1 or type 2 diabetes, the development of complications following the onset of the disease is inevitable. Consequently, contemporary medicine must concentrate on understanding the pathophysiological mechanisms driving systemic decline and on finding ways to address them. We are particularly interested in the effects of oxidative stress on target cells and organs, such as pancreatic islets, the retina, kidneys, and the neurological or cardiovascular systems. Our goal is to explore, using the latest data from international scientific databases, the relationship between oxidative stress and the development or persistence of systemic damage associated with diabetes in children. Additionally, we highlight the beneficial roles of antioxidants such as vitamins, minerals, polyphenols, and other bioactive molecules; in mitigating the pathogenic cascade, detailing how they intervene and their bioactive properties. As a result, our study provides a comprehensive exploration of the key aspects of the oxidative stress-antioxidants-pediatric diabetes triad, expanding understanding of their significance in various systemic diseases.

Enhanced Insulin Production From Porcine Islets: More Insulin, Less Islets

Clinical pancreatic islet xenotransplantation will most probably rely on genetically modified pigs as donors. Several lines of transgenic pigs carrying one and more often, multiple modifications already exist. The vast majority of these modifications aim to mitigate the host immune response by suppressing major xeno-antigens, or expressing immunomodulatory molecules that act locally at the graft site. While these modifications are essential and have proven beneficial in preclinical trials, ensuring good intrinsic islet secretory function is equally important to achieve normoglycemia in recipients. Neonatal and even adult porcine islets are known for their low secretory response to physiological stimulation, a shortcoming that is often overcome by implanting extremely large numbers of such islets to compensate for insulin requirement incompatibilities between donor pigs and rodent, non-human primate or human recipients. Recent studies have revealed the existence of secretory amplifying pathways in porcine beta-cells previously identified in murine and human cells. Building upon these findings, a new line of transgenic pigs where these pathways are activated specifically in beta-cells has been created. Compared to their wild-type counterparts, islets from these transgenic pigs have proven to be better insulin secretors in their native pancreas environment, in vitro after isolation and most importantly in vivo after transplantation to diabetic mice.

Effects of FGFR2b-ligand signaling on pancreatic branching morphogenesis and postnatal islet function.

Pancreatic development is a complex process vital for maintaining metabolic balance, requiring intricate interactions among different cell types and signaling pathways. Fibroblast growth factor receptors 2b (FGFR2b)-ligands signaling from adjacent mesenchymal cells is crucial in initiating pancreatic development and differentiating exocrine and endocrine cells through a paracrine mechanism. However, the precise critical time window that affects pancreatic development remains unclear. To explore the roles of FGFR2b-ligands and identify the narrow window of time during which FGFR2b-ligand signaling affects pancreatic development, we used an inducible mouse model to control the expression of soluble dominant-negative FGFR2b (sFGFR2b) at various stages of pancreatic development. Our findings revealed a significant effect of FGFR2b-ligand signaling on epithelial morphology, lumen formation, and pancreatic branching during primary and secondary transition stages. Additionally, sFGFR2b expression reduced the number of Pdx1+ progenitor cells and altered the pancreatic islet structure. Furthermore, we examined the effect of mutation in FGF10, an FGFR2b ligand, on embryonic pancreatic β-cell function. FGF10 null mutant embryos exhibited reduced pancreatic size and a decrease number of islet-like structure. Although neonatal mice with haploinsufficiency for FGF10 exhibited abnormal glucose tolerance test results, indicating a potential diabetes predisposition, these abnormalities normalized with age, aligning with observations in wild type mice. Our study underscores the critical role of FGFR2b-ligand signaling in pancreatic development and postnatal islet function, offering insights into potential therapeutic targets for pancreatic disorders.

Adipose Tissue as a Major Launch Spot for Circulating Extracellular Vesicle-Carried MicroRNAs Coordinating Tissue and Systemic Metabolism

Circulating microRNAs (miRNAs), especially transported by extracellular vesicles (EVs), have recently emerged as major new participants in interorgan communication, playing an important role in the metabolic coordination of our tissues. Among these, adipose tissue displays an extraordinary ability to secrete a vast list of EV-carried miRNAs into the circulation, representing new hormone-like factors. Despite the limitations of current methodologies for the unequivocal identification of the origin and destination of EV-carried miRNAs in vivo, recent investigations clearly support the important regulatory role of adipose-derived circulating miRNAs in shaping the metabolism and function of other tissues including the liver, muscle, endocrine pancreas, cardiovascular system, gastrointestinal tract, and brain. Here, we review the most recent findings regarding miRNAs transported by adipose-derived EVs (AdEVs) targeting other major metabolic organs and the implications of this dialog for physiology and pathology. We also review here the current and potential future diagnostic and therapeutic applications of AdEV-carried miRNAs.

Hepatocyte nuclear factor 4-α is necessary for high fat diet-induced pancreatic β-cell mass expansion and metabolic compensations

AimsThis study investigates the role of Hepatocyte Nuclear Factor 4α (HNF4α) in the adaptation of pancreatic β-cells to an HFD-induced obesogenic environment, focusing on β cell mass expansion and metabolic adaptations.Main methodsWe utilized an HNF4α knockout (KO) mouse model, with CRE-recombinase enzyme activation confirmed through tamoxifen administration. KO and Control (CTL) mice were fed an HFD for 20 weeks. We monitored body weight, food intake, glucose tolerance, insulin sensitivity, and insulinemia. Also, to assess structural and metabolic changes, histological analyses of pancreatic islets and liver tissue were conducted.Key findingsKO mice displayed lower fasting blood glucose levels compared to CTL mice after tamoxifen administration, indicating impaired glucose-regulated insulin secretion. HFD-fed KO mice consumed less food but exhibited greater weight gain and perigonadal fat accumulation, reflecting higher energy efficiency. Histological analysis revealed more pronounced liver steatosis and fibrosis in KO mice on HFD. Glucose intolerance and insulin resistance were exacerbated in KO mice, highlighting their inability to adapt to increased metabolic demand. Structural analysis showed that KO mice failed to exhibit HFD-induced β cell mass expansion, resulting in reduced islet diameter and number, confirming the critical role of HNF4α in β cell adaptation.SignificanceThis study demonstrates that HNF4α is essential for the proper metabolic and structural adaptation of pancreatic β-cells in response to an obesogenic environment. The lack of HNF4α impairs β cell functionality, leading to increased susceptibility to glucose intolerance and insulin resistance. These findings underscore the importance of HNF4α in maintaining glucose homeostasis and highlight its potential as a therapeutic target for diabetes management in obesity.

Observation on the Gross and Histology of the Exocrine and Endocrine Pancreas in Large White Yorkshire Pig

Background: Islet transplantation is a potential treatment option for selected patients with type 1 diabetes. The limited supply of human islet from cadavers and poor islet yield remains a significant barrier to progress in the field. So, the use of porcine islets holds great promise for large scale application for the transplantation of the islet. The primary aim of this study was to describe the gross and morphological studies of the porcine pancreas to rule out its similarity to human pancreas. Methods: Pancreas was collected from eight apparently healthy Large White Yorkshire pig (6-7 months of age). The gross and morphological studies were analyzed by using different staining techniques. Result: The pancreas appeared as pale pink triangular lobulated gland located along the dorsal aspect of the abdominal cavity behind the stomach having exocrine and endocrine part. Histologically, two types of acinar cell were identified i.e. active and resting acinar cells. The islets were richly vascularized and were separated from the exocrine acini by a thin layer of collagen, elastic and reticular fibers which were seen extending into the interior of the islets. Mainly three types of cells were observed in islets i.e. alpha (A), beta (B) and delta (D) cells. Epithelial duct and secretory cells showed strong positive reaction for both Periodic acid Schiff (PAS) and Alcian Blue (pH-2.5) whereas islets of Langerhans showed moderate activity for both.

Islet-derived exosomal miR-204 accelerates insulin resistance in skeletal muscle by suppressing sirtuin 1: An in vivo study in a mouse model of high-fat diet-induced obesity.

The interaction between pancreatic islets and skeletal muscle plays a pivotal role in the development of insulin resistance. The present study aimed to elucidate the impact of non-hormonal molecules from islets on the insulin sensitivity of skeletal muscle cells. We developed a mouse model of obesity through a high-fat diet, assessing glucose tolerance and conducting miRNA sequencing on skeletal muscle samples. An in vitro model was established by treating cells with palmitic acid, and exosomes in the supernatant were characterized using scanning electron microscopy and CD63 expression analysis. Intracellular miR-204-5p levels were quantified by RT-PCR. Our in vivo model demonstrated a robust correlation between miR-204-5p level alterations and obesity-induced insulin resistance. Elevated fatty acid levels were observed to increase miR-204-5p in both skeletal muscle and islets. In cellular studies, palmitic acid increased miR-204-5p in MIN-6 islet β-cells but not in C2C12 skeletal muscle cells. Exosomes containing miR-204-5p, secreted by palmitic acid-treated MIN6 cells, were identified through morphological examination, immunoblotting for the exosomal marker CD63, and intraexosomal miR-204-5p level measurement. C2C12 cells were shown to uptake islet-derived miR-204-5p exosomes, as evidenced by the uptake of Exo-Red labeled exosomes. TargetScan analysis identified a highly conserved binding site for miR-204-5p in the 3' UTR of Sirt mRNA. Functional studies indicated that miR-204-5p overexpression reduced glucose consumption and uptake in C2C12 cells, decreased Sirt expression, and impaired insulin signaling, as evidenced by reduced Akt phosphorylation and membrane Glut4 levels. Our findings reveal that miR-204-5p contributes to the development of insulin resistance in obesity and acts as a signaling molecule in the crosstalk between pancreatic islets and skeletal muscle.

Parallel measurement of transcriptomes and proteomes from same single cells using nanodroplet splitting

Single-cell multiomics provides comprehensive insights into gene regulatory networks, cellular diversity, and temporal dynamics. Here, we introduce nanoSPLITS (nanodroplet SPlitting for Linked-multimodal Investigations of Trace Samples), an integrated platform that enables global profiling of the transcriptome and proteome from same single cells via RNA sequencing and mass spectrometry-based proteomics, respectively. Benchmarking of nanoSPLITS demonstrates high measurement precision with deep proteomic and transcriptomic profiling of single-cells. We apply nanoSPLITS to cyclin-dependent kinase 1 inhibited cells and found phospho-signaling events could be quantified alongside global protein and mRNA measurements, providing insights into cell cycle regulation. We extend nanoSPLITS to primary cells isolated from human pancreatic islets, introducing an efficient approach for facile identification of unknown cell types and their protein markers by mapping transcriptomic data to existing large-scale single-cell RNA sequencing reference databases. Accordingly, we establish nanoSPLITS as a multiomic technology incorporating global proteomics and anticipate the approach will be critical to furthering our understanding of biological systems.

β-Cell Secretory Capacity Predicts Metabolic Outcomes over 6 Years following Human Islet Transplantation.

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 cell hormone metabolism and clinical measures of graft function (mixed-meal tolerance test [MMTT] C-peptide, BETA-2 score, and continuous glucose monitoring [CGM]). Eleven individuals received purified human pancreatic islets over one or two intra-portal infusions to achieve insulin-independence and were followed over a median (IQR) 6 (5-7) years. β-cell secretory capacity remained stable over 3-years before declining. Fasting glucagon and proinsulin secretory ratios under glucose-potentiation were inversely correlated with AIRpot. A functional β-cell mass of 40% normal predicted insulin-independence and was strongly predicted by MMTT C-peptide-to-glucose and BETA-2 score. A functional β-cell mass of >20% predicted excellent glycemic outcomes including ≤1% time <60 mg/dL, ≤2% time >180 mg/dL and ≥90% time-inrange 70-180 mg/dL. β-cell replacement approaches should target a functional β-cell mass >40% to provide sufficient islet reserve for sustained insulin-independence. MMTT C-peptide-to-glucose and BETA-2 score can inform changes in functional β-cell mass in the clinical setting.

Cycling alpha cells in regenerative drug-treated human pancreatic islets may serve as key beta cell progenitors.

Diabetes results from an inadequate number of insulin-producing human beta cells. There is currently no clinically available effective means to restore beta cell mass in millions of people with diabetes. Although the DYRK1A inhibitors, either alone or in combination with GLP-1 receptor agonists (GLP-1) or transforming growth factor β (TGF-β) superfamily inhibitors (LY), induce beta cell replication and increase beta cell mass, the precise mechanisms of action remain elusive. Here we perform single-cell RNA sequencing on human pancreatic islets treated with a DYRK1A inhibitor, either alone or with GLP-1 or LY. We identify cycling alpha cells as the most responsive cells to DYRK1A inhibition. Lineage trajectory analyses suggest that cycling alpha cells may serve as precursor cells that transdifferentiate into beta cells. Collectively, in addition to enhancing expression of beta cell phenotypic genes in beta cells, our findings suggest that regenerative drugs may be targeting cycling alpha cells in human islets.

Diacylglycerol kinase ζ is a positive insulin secretion regulator in pancreatic β-cell line MIN6

Some isoforms of diacylglycerol (DAG) kinase (DGK), an enzyme converting DAG into phosphatidic acid, i.e., DGKα, γ and δ, have been reportedly involved in the regulation of pancreatic β-cell function. DGKζ has also been reported to be expressed in rat pancreatic β-cells. However, its function in pancreatic β-cells remains unknown. The present study aimed to elucidate the function of DGKζ in pancreatic β-cells. The expression of DGKζ was detected in the β-cell line MIN6B and mouse pancreatic islets and in the cytoplasmic fraction from MIN6B cells. The knockdown of DGKζ with siRNA significantly decreased glucose-induced insulin secretion in MIN6B cells. The induction of DGKζ expression in MIN6CEon1 cells with a doxycycline-inducible stable expression system significantly increased glucose-induced insulin secretion. In contrast, glucose-induced insulin secretion was not changed when a kinase-dead DGKζ mutant (G356D) was overexpressed in MIN6CEon1 cells, indicating that a mechanism dependent on its kinase activity mediates the facilitatory effect of DGKζ on glucose-induced insulin secretion. Additionally, we revealed that DGKζ overexpression exhibited no effect on cell cycle of MIN6 cells. These results suggest that DGKζ plays a facilitatory role in insulin secretion in pancreatic β-cells.

Role of the Pancreatic Islet Microvasculature in Health and Disease.

The pancreatic islet vasculature comprises microvascular endothelial cells surrounded by mural cells (pericytes). Both cell types support the islet by providing (1) a conduit for delivery and exchange of nutrients and hormones; (2) paracrine signals and extracellular matrix (ECM) components that support islet development, architecture, and endocrine function; and (3) a barrier against inflammation and immune cell infiltration. In type 2 diabetes, the islet vasculature becomes inflamed, showing loss of endothelial cells, detachment, and/or trans-differentiation of pericytes, vessel dilation, and excessive ECM deposition. While most work to date has focused either on endothelial cells or pericytes in isolation, it is very likely that the interaction between these cell types and disruption of that interaction in diabetes are critically important. In fact, dissociation of pericytes from endothelial cells is an early, key feature of microvascular disease in multiple tissues/disease states. Moreover, in beta-cell replacement therapy, co-transplantation with microvessels versus endothelial cells alone is substantially more effective in improving survival and function of the transplanted cells. Ongoing studies, including characterization of islet vascular cell signatures, will aid in the identification of new therapeutic targets aimed at improving islet function and benefiting people living with all forms of diabetes.

The effect of a new phytocomposition based on the cranberry leaf extract and amino acids on the pancreas and liver of rats in the model of diabetes mellitus type 2

In pharmacotherapy of diabetes mellitus type 2 and metabolic syndrome, medicinal plants and amino acids are used as an important preventive and therapeutic supplement to correct disorders that develop against the background of insulin resistance, which determines the relevance of developing new domestic combined antidiabetic herbal medicines. Aim. To study the effect of a phytocomposition based on the polyphenol extract from large-fruited cranberry leaves and amino acids (L-arginine, taurine, glycine) on the state of the liver and pancreas of rats in an experimental model of diabetes mellitus type 2. Materials and methods. Diabetes mellitus type 2 was reproduced by a single injection of rats with a streptozotocin solution in the dose of 65 mg/kg, intraperitoneally with the previous (15 min) intraperitoneal administration of nicotinamide in the dose of 230 mg/kg against the background of obesity (keeping rats on a high-calorie diet for 12 weeks). The pancreatic and hepatoprotective effect of the phytocomposition was studied according to the morphofunctional state of pancreatic β-cells, the content of glycogen and neutral fats in the liver and morphometric indices in the pancreas. Results. The phytocomposition studied had a stimulating effect on regenerative processes in the insulin-producing apparatus of the rat pancreas – the severity of proliferation of small β-cells in pancreatic islets significantly increased compared to the control pathology. The phytocomposition at the morphological level showed hepatoprotective properties considerably reducing the manifestations of the toxic-dystrophic action of diabetogens, significantly restoring fat and carbohydrate metabolism in hepatocytes. Conclusions. The results obtained substantiate the feasibility of further study of the phytocomposition as a promising antidiabetic agent.

Reformed islets: a long-term primary cell platform for exploring mouse and human islet biology

Pancreatic islets are 3D micro-organs that maintain β-cell functionality through cell–cell and cell-matrix communication. While primary islets, the gold standard for in vitro models, have a short culture life of approximately 1–2 weeks, we developed a novel protocol that employs reformed islets following dispersion coupled with a fine-tuned culture environment. Reformed islets exhibit physiological characteristics similar to primary islets, enabling high-resolution imaging and repeated functional assessment. Unlike other in vitro platforms, reformed islets retain an immune population, allowing the study of interactions between β cells and resident and infiltrating immune cells. Analyses showed that reformed islets have a similar composition and cytoarchitecture to primary islets, including macrophages and T cells, and can secrete insulin in response to glucose. Reformed islets exhibited partial dedifferentiation compared to native islets but were otherwise transcriptionally similar. The reformed islets offer a useful platform for studying diabetes pathology and can recapitulate both T1DM and T2DM disease milieus, providing an advantage over other models, such as mouse and human β-cell lines, which lack the input of non-β-endocrine cells and immune cell crosstalk.

Incretin hormones and obesity.

The incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) play critical roles in co-ordinating postprandial metabolism, including modulation of insulin secretion and food intake. They are secreted from enteroendocrine cells in the intestinal epithelium following food ingestion, and act at multiple target sites including pancreatic islets and the brain. With the recent development of agonists targeting GLP-1 and GIP receptors for the treatment of type 2 diabetes and obesity, and the ongoing development of new incretin-based drugs with improved efficacy, there is great interest in understanding the physiology and pharmacology of these hormones.

Toward a cure for diabetes: iPSC and ESC-derived islet cell transplantation trials.

Advancements in regenerative medicine, particularly through the use of induced pluripotent stem cells (iPSCs) and embryonic stem cells (ESCs), are garnering substantial attention as potential solutions to the limited availability of donors, leading to prolonged waiting periods for people with type 1 diabetes who require transplantation of pancreatic islets from deceased donors. The promising outcomes from recent clinical trials suggest that transplantation of iPSC- or ESC-derived islet cells could pave the way for more effective and broadly accessible treatment options. This progress holds potential not only for individuals with type 1 diabetes but may also extend to type 2 diabetes treatment in the future.

Sex-specific regulatory architecture of pancreatic islets from subjects with and without type 2 diabetes.

Patients with type 2 and type 1 diabetes (T2D and T1D) exhibit sex-specific differences in insulin secretion, the mechanisms of which are unknown. We examined sex differences in human pancreatic islets from 52 donors with and without T2D combining single cell RNA-sequencing (scRNA-seq) and single nucleus ATAC-sequencing (snATAC-seq) with assays probing hormone secretion and bioenergetics. In non-diabetic (ND) donors, sex differences in islet cell chromatin accessibility and gene expression predominantly involved sex chromosomes. In contrast, islets from T2D donors exhibited similar sex differences in sex chromosome-encoded differentially expressed genes (DEGs) as ND donors, but also exhibited sex differences in autosomal genes. Comparing β cells from T2D and ND donors, gene enrichment of female β cells showed suppression in mitochondrial respiration, while male β cells exhibited suppressed insulin secretion, suggesting a role for mitochondrial failure in females in the transition to T2D. We finally performed cell type-specific, sex stratified, GWAS restricted to differentially accessible chromatin peaks across T2D, fasting glucose, and fasting insulin traits. We identified that differentially accessible regions overlap with T2D-associated variants in a sex- and cell type-specific manner.

A Tissue-Engineered Construct Based on a Decellularized Scaffold and the Islets of Langerhans: A Streptozotocin-Induced Diabetic Model.

Producing a tissue-engineered pancreas based on a tissue-specific scaffold from a decellularized pancreas, imitating the natural pancreatic tissue microenvironment and the islets of Langerhans, is one of the approaches to treating patients with type 1 diabetes mellitus (T1DM). The aim of this work was to investigate the ability of a fine-dispersed tissue-specific scaffold (DP scaffold) from decellularized human pancreas fragments to support the islets' survival and insulin-producing function when injected in a streptozotocin-induced diabetic rat model. The developed decellularization protocol allows us to obtain a scaffold with a low DNA content (33 [26; 38] ng/mg of tissue, p < 0.05) and with the preservation of GAGs (0.92 [0.84; 1.16] µg/mg, p < 0.05) and fibrillar collagen (273.7 [241.2; 303.0] µg/mg, p < 0.05). Rat islets of Langerhans were seeded in the obtained scaffolds. The rats with stable T1DM were treated by intraperitoneal injections of rat islets alone and islets seeded on the DP scaffold. The blood glucose level was determined for 10 weeks with a histological examination of experimental animals' pancreas. A more pronounced decrease in the recipient rats' glycemia was detected after comparing the islets seeded on the DP scaffold with the control injection (by 71.4% and 51.2%, respectively). It has been shown that the DP scaffold facilitates a longer survival and the efficient function of pancreatic islets in vivo and can be used to engineer a pancreas.

Identifying and validating the key regulatory transcription factor YY1 in the aging process of pancreatic beta cells based on bioinformatics

The aging of pancreatic beta cells is closely associated with various diseases, such as impaired glucose tolerance, yet the underlying regulatory mechanisms remain unclear. In this study, we screened young and aged mouse pancreatic beta cells' high-throughput sequencing data from the GEO public database. Utilizing bioinformatics techniques, we identified the key regulatory factor YY1 in the aging process of pancreatic islets. We observed a significant decrease in the expression of YY1 in a D-gal-induced mouse model of pancreatic aging and an H2O2-induced MIN6 cell model of aging. Moreover, both vivo and vitro models, we found that the YY1 agonist eudesmin (EDN) improved glucose intolerance in mice, alleviated aging of pancreatic beta cells, and downregulated the expression of cell cycle protein P21. Mechanistically, we discovered that EDN inhibited the P38/JNK MAPK pathway in aging cells. In summary, our study confirms the regulatory role of the transcription factor YY1 in the aging process of pancreatic beta cells. This finding may provide a new approach for the clinical treatment of pancreatic aging-related diseases such as impaired glucose tolerance or diabetes.

Tracking insulin- and glucagon-expressing cells in vitro and in vivo using a double reporter human embryonic stem cell line.

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 reporter (INSEGFPGCGmScarlet) hESC line using CRISPR/Cas9. We established robust expression of EGFP and mScarlet fluorescent proteins in insulin- and glucagon-expressing cells respectively without compromising the differentiation or function of these cells. We also showed the insulin- and glucagon-expressing bihormonal population at the maturing endocrine cell stage (Stage 6) of our pancreatic islet differentiation lose insulin expression over time, while maintaining an alpha-like expression profile, suggesting these bihormonal cells are cell autonomously fated to become alpha-like cells. We also demonstrated this cell line can be used to monitor hESC-derived insulin- and glucagonexpressing cells, and hESC-derived islet morphology in vivo by transplanting them into the anterior chamber of the eye in mice. Together, the INSEGFPGCGmScarlet hESC line provides an efficient strategy for tracking populations of hESC-derived beta- and alpha-like cells.