Pancreatic Inflammation Redirects Acinar to β Cell Reprogramming

Development, regeneration, and physiological expansion of functional β-cells: Cellular sources and regulators

Pancreatic regeneration is a complex process observed in both normal and pathological conditions. The aim of this review is to provide a comprehensive understanding of the emergence of a functionally active population of insulin-secreting β-cells in the adult pancreas. The renewal of β-cells is governed by a multifaceted interaction between cellular sources of genetic and epigenetic factors. Understanding the development and heterogeneity of β-cell populations is crucial for functional β-cell regeneration. The functional mass of pancreatic β-cells increases in situations such as pregnancy and obesity. However, the specific markers of mature β-cell populations and postnatal pancreatic progenitors capable of increasing self-reproduction in these conditions remain to be elucidated. The capacity to regenerate the β-cell population through various pathways, including the proliferation of pre-existing β-cells, β-cell neogenesis, differentiation of β-cells from a population of progenitor cells, and transdifferentiation of non-β-cells into β-cells, reveals crucial molecular mechanisms for identifying cellular sources and inducers of functional cell renewal. This provides an opportunity to identify specific cellular sources and mechanisms of regeneration, which could have clinical applications in treating various pathologies, including in vitro cell-based technologies, and deepen our understanding of regeneration in different physiological conditions.

Polyester Nanoparticles with Controlled Topography for Peroral Drug Delivery Using Insulin as a Model Protein

Receptor-mediated polyester drug delivery systems have tremendous potential for improving the clinical performance of existing pharmaceutical drugs. Despite significant progress made in this area, it remains unclear how and to what extent the polyester nanoparticle surface topography would affect the in vitro, ex vivo and in vivo performance of a drug, and if there exists a correlation between in vitro and in vivo, as well as healthy versus pathophysiological states. Herein, we report a systematic investigation of the interactions between ligands and receptors as a function of the linker length, two-carbon (2C) versus four-carbon (4C). The in vitro, ex vivo and in vivo in healthy models validate the hypothesis that 4C has better reach and binding to the receptors. The results indicate that 4C offered better performance over 2C in vivo in improving the oral bioavailability of insulin (INS) by 1.1-fold (3.5-fold compared to unfunctionalized nanoparticles) in a healthy rat model. Similar observations were made in pathophysiological models; however, the effects were less prominent compared to those in healthy models. Throughout, ligand decorated nanoparticles outperformed unfunctionalized nanoparticles. Finally, a semimechanistic pharmacokinetic and pharmacodynamic (PKPD) model was developed using the experimental data sets to quantitatively evaluate the effect of P2Ns-GA on oral bioavailability and efficacy of insulin. The study presents a sophisticated oral delivery system for INS or hydrophilic therapeutic cargo, highlighting the significant impact on bioavailability that minor adjustments to the surface chemistry can have.

Hepatic insulin synthesis increases in rat models of diabetes mellitus type 1 and 2 differently

Insulin-positive (+) cells (IPCs), detected in multiple organs, are of great interest as a probable alternative to ameliorate pancreatic beta-cells dysfunction and insulin deficiency in diabetes. Liver is a potential source of IPCs due to it common embryological origin with pancreas. We previously demonstrated the presence of IPCs in the liver of healthy and diabetic rats, but detailed description and analysis of the factors, which potentially can induced ectopic hepatic expression of insulin in type 1 (T1D) and type 2 diabetes (T2D), were not performed. In present study we evaluate mass of hepatic IPCs in the rat models of T1D and T2D and discuss factors, which may stimulate it generation: glycaemia, organ injury, involving of hepatic stem/progenitor cell compartment, expression of transcription factors and inflammation. Quantity of IPCs in the liver was up by 1.7-fold in rats with T1D and 10-fold in T2D compared to non-diabetic (ND) rats. We concluded that ectopic hepatic expression of insulin gene is activated by combined action of a number of factors, with inflammation playing a decision role.

Arjunolic acid modulate pancreatic dysfunction by ameliorating pattern recognition receptor and canonical Wnt pathway activation in type 2 diabetic rats

BACKGROUND

Arjunolic acid (AA) is a potent phytochemical with multiple therapeutics effects. In this study, AA is evaluated on type 2 diabetic (T2DM) rats to understand the mechanism of β-cell linkage with Toll-like receptor 4 (TLR-4) and canonical Wnt signaling. However, its role in modulating TLR-4 and canonical Wnt/β-catenin crosstalk on insulin signaling remains unclear during T2DM. Aim The current study is aimed to examine the potential role of AA on insulin signaling and TLR-4-Wnt crosstalk in the pancreas of type 2 diabetic rats.

METHOD

Multiple methods were used to determine molecular cognizance of AA in T2DM rats, when treated with different dosage levels. Histopathological and histomorphometry analysis was conducted using masson trichrome and H&E stains. While, protein and mRNA expressions of TLR-4/Wnt and insulin signaling were assessed using automated Western blotting (jess), immunohistochemistry, and RT-PCR.

RESULTS

Histopathological findings revealed that AA had reversed back the T2DM-induced apoptosis and necrosis caused to rats pancreas. Molecular findings exhibited prominent effects of AA in downregulating the elevated level of TLR-4, MyD88, NF-κB, p-JNK, and Wnt/β-catenin by blocking TLR-4/MyD88 and canonical Wnt signaling in diabetic pancreas, while IRS-1, PI3K, and pAkt were all upregulated by altering the NF-κB and β-catenin crosstalk during T2DM.

CONCLUSION

Overall results, indicate that AA has potential to develop as an effective therapeutic in the treatment of T2DM associated meta-inflammation. However, future preclinical research at multiple dose level in a long-term chronic T2DM disease model is warranted to understand its clinical relevance in cardiometabolic disease.

Acinar cells and the development of pancreatic fibrosis

Pancreatic fibrosis is caused by excessive deposition of extracellular matrixes of collagen and fibronectin in the pancreatic tissue as a result of repeated injury often seen in patients with chronic pancreatic diseases. The most common causative conditions include inborn errors of metabolism, chemical toxicity and autoimmune disorders. Its pathophysiology is highly complex, including acinar cell injury, acinar stress response, duct dysfunction, pancreatic stellate cell activation, and persistent inflammatory response. However, the specific mechanism remains to be fully clarified. Although the current therapeutic strategies targeting pancreatic stellate cells show good efficacy in cell culture and animal models, they are not satisfactory in the clinic. Without effective intervention, pancreatic fibrosis can promote the transformation from pancreatitis to pancreatic cancer, one of the most lethal malignancies. In the normal pancreas, the acinar component accounts for 82% of the exocrine tissue. Abnormal acinar cells may activate pancreatic stellate cells directly as cellular source of fibrosis or indirectly via releasing various substances and initiate pancreatic fibrosis. A comprehensive understanding of the role of acinar cells in pancreatic fibrosis is critical for designing effective intervention strategies. In this review, we focus on the role of and mechanisms underlying pancreatic acinar injury in pancreatic fibrosis and their potential clinical significance.

Epigenetic modulation of cell fate during pancreas development

Epigenetic modifications to DNA and its associated proteins affect cell plasticity and cell fate restrictions throughout embryonic development. Development of the vertebrate pancreas is characterized by initial is an over-lapping expression of a set of transcriptional regulators in a defined region of the posterior foregut endoderm that collectively promote pancreas progenitor specification and proliferation. As development progresses, these transcription factors segregate into distinct pancreatic lineages, with some being maintained in specific subsets of terminally differentiated pancreas cell types throughout adulthood. Here we describe the progressive stages and cell fate restrictions that occur during pancreas development and the relevant known epigenetic regulatory events that drive the dynamic expression patterns of transcription factors that regulate pancreas development. In addition, we highlight how changes in epigenetic marks can affect susceptibility to pancreas diseases (such as diabetes), adult pancreas cell plasticity, and the ability to derive replacement insulin-producing β cells for the treatment of diabetes.

Exocrine-Endocrine Crosstalk: The Influence of Pancreatic Cellular Communications on Organ Growth, Function and Disease

Diabetes mellitus, a disease that affects nearly 536.6 million people worldwide, is characterized by the death or dysfunction of insulin-producing beta cells of the pancreas. The beta cells are found within the islets of Langerhans, which are composed of multiple hormone-producing endocrine cells including the alpha (glucagon), delta (somatostatin), PP (pancreatic polypeptide), and epsilon (ghrelin) cells. There is direct evidence that physical and paracrine interactions between the cells in the islet facilitate and support beta cell function. However, communication between endocrine and exocrine cells in the pancreas may also directly impact beta cell growth and function. Herein we review literature that contributes to the view that "crosstalk" between neighboring cells within the pancreas influences beta cell growth and function and the maintenance of beta cell health.

Pancreatic Organoids for Regenerative Medicine and Cancer Research

In recent years, the development of ex vivo organoid cultures has gained substantial attention as a model to study regenerative medicine and diseases in several tissues. Diabetes and pancreatic ductal adenocarcinoma (PDAC) are the two major devastating diseases affecting the pancreas. Suitable models for regenerative medicine in diabetes and to accurately study PDAC biology and treatment response are essential in the pancreatic field. Pancreatic organoids can be generated from healthy pancreas or pancreatic tumors and constitute an important translational bridge between in vitro and in vivo models. Here, we review the rapidly emerging field of pancreatic organoids and summarize the current applications of the technology to tissue regeneration, disease modelling, and drug screening.

Effects of hypothyroidism on the female pancreas involve the regulation of estrogen receptors

This study aimed to investigate the impact of short-time hypothyroidism on the expression of aromatase, estrogen receptors (ERα, β), and GPR30 in the pancreas of female rabbits. The formation of new islets and the expression of insulin, GLUT4, and lactate dehydrogenase (LDH) were also analyzed. This purpose is based on actions that thyroid hormones and estrogens have on β-cells differentiation, acinar cell function, and insulin secretion. Twelve Chinchilla-breed adult virgin female rabbits were divided into control (n = 6) and hypothyroid (n = 6; methimazole 10 mg/kg for 30 days) groups. In the complete pancreas, expressions of aromatase and estrogen receptors, as well as proinsulin, GLUT4, and LDH were determined by western blot. Characteristics of islets were measured in slices of the pancreas with immunohistochemistry for insulin. Islet and acinar cells express aromatase, ERα, ERβ, and GPR30. Hypothyroidism increased the expression of ERα and diminished that for aromatase, ERβ, and GPR30 in the pancreas. It also promoted a high number of extra small islets (new islets) and increased the expression of proinsulin and GLUT4 in the pancreas. Our results show that actions of thyroid hormones and estrogens on β-cells neogenesis, acinar cell function, and synthesis and secretion of insulin are linked. Thus, the effects of hypothyroidism on the pancreas could include summatory actions of thyroid hormones plus estrogens. Our findings indicate the importance of monitoring estrogen levels and actions on the pancreas of hypothyroid women, particularly when serum estrogen concentrations are affected such as menopausal, pregnant, and those with contraceptive use.

Accelerated Generation of Extra-Islet Insulin-Producing Cells in Diabetic Rats, Treated with Sodium Phthalhydrazide

β-cells dysfunction plays an important role in the pathogenesis of type 2 diabetes (T2D), partially may be compensated by the generation of extra-islet insulin-producing cells (IPCs) in pancreatic acini and ducts. Pdx1 expression and inflammatory level are suggested to be involved in the generation of extra-islet IPCs, but the exact reasons and mechanisms of it are unclear. Macrophages are key inflammatory mediators in T2D. We studied changes in mass and characteristics of extra-islet IPCs in rats with a streptozotocin-nicotinamide model of T2D and after i.m. administration of 20 daily doses of 2 mg/kg b.w. sodium aminophthalhydrazide (APH). Previously, we found that APH modulates macrophage production and increases the proliferative activity of pancreatic β-cells. Expressions of insulin and Pdx1, as well as F4/80 (macrophage marker), were detected at the protein level by immunohistochemistry analysis, the concentration of pro- and anti-inflammatory cytokines in blood and pancreas—by ELISA. Diabetic rats treated with APH showed an increasing mass of extra-islet IPCs and the content of insulin in them. The presence of Pdx1⁺ cells in the exocrine pancreas also increased. F4/80⁺ cell reduction was accompanied by increasing TGF-β1 content. Interestingly, during the development of diabetes, the mass of β-cells decreased faster than the mass of extra-islet IPCs, and extra-islet IPCs reacted to experimental T2D differently depending on their acinar or ductal location.

Molecular signaling in pancreatic ductal metaplasia: emerging biomarkers for detection and intervention of early pancreatic cancer

Pancreatic ductal metaplasia (PDM) is the transformation of potentially various types of cells in the pancreas into ductal or ductal-like cells, which eventually replace the existing differentiated somatic cell type(s). PDM is usually triggered by and manifests its ability to adapt to environmental stimuli and genetic insults. The development of PDM to atypical hyperplasia or dysplasia is an important risk factor for pancreatic intraepithelial neoplasia (PanIN) and pancreatic ductal adenocarcinoma (PDA). Recent studies using genetically engineered mouse models, cell lineage tracing, single-cell sequencing and others have unraveled novel cellular and molecular insights in PDM formation and evolution. Those novel findings help better understand the cellular origins and functional significance of PDM and its regulation at cellular and molecular levels. Given that PDM represents the earliest pathological changes in PDA initiation and development, translational studies are beginning to define PDM-associated cell and molecular biomarkers that can be used to screen and detect early PDA and to enable its effective intervention, thereby truly and significantly reducing the dreadful mortality rate of PDA. This review will describe recent advances in the understanding of PDM biology with a focus on its underlying cellular and molecular mechanisms, and in biomarker discovery with clinical implications for the management of pancreatic regeneration and tumorigenesis.

Sca-1 is a marker for cell plasticity in murine pancreatic epithelial cells and induced by IFN-β in vitro

BACKGROUND & AIMS

Sca-1 is a surface marker for murine hematopoietic stem cells (HSCs) and type-I interferon is a key regulator for Lin^-Sca-1⁺ HSCs expansion through Ifnar/Stat-1/Sca-1-signaling. In this study we aimed to characterize the role and regulation of Sca-1⁺ cells in pancreatic regeneration.

METHODS

To characterize Sca-1 in vivo, immunohistochemistry and immunofluorescence staining of Sca-1 was conducted in normal pancreas, in cerulein-mediated acute pancreatitis, and in Kras-triggered cancerous lesions. Ifnar/Stat-1/Sca-1-signaling was studied in type-I IFN-treated epithelial explants of adult wildtype, Ifnar^-/-, and Stat-1^-/- mice. Sca-1 induction was analyzed by gene expression and FACS analysis. After isolation of pancreatic epithelial Lin^-Sca-1⁺cells, pancreatosphere-formation and immunofluorescence-assays were carried out to investigate self-renewal and differentiation capabilities.

RESULTS

Sca-1⁺ cells were located in periacinar and periductal spaces and showed an enrichment during cerulein-induced acute pancreatitis (23.2/100 μm² ± 4.9 SEM) and in early inflammation-mediated carcinogenic lesions of the pancreas of Kras^G12D mice (35.8/100 μm² ± SEM 1.9) compared to controls (3.6/100 μm² ± 1.3 SEM). Pancreatic Lin^-Sca-1⁺ cells displayed a small population of 1.46% ± 0.12 SEM in FACS. In IFN-β treated pancreatic epithelial explants, Sca-1 expression was increased, and Lin^-Sca-1⁺ cells were enriched in vitro (from 1.49% ± 0.36 SEM to 3.85% ± 0.78 SEM). Lin^-Sca-1⁺ cells showed a 12 to 51-fold higher capacity for clonal self-renewal compared to Lin^-Sca-1^- cells and generated cells express markers of the acinar and ductal compartment.

CONCLUSIONS

Pancreatic Sca-1⁺ cells enriched during parenchymal damage showed a significant capacity for cell renewal and in vitro plasticity, suggesting that corresponding to the type I interferon-dependent regulation of Lin^-Sca-1⁺ hematopoietic stem cells, pancreatic Sca-1⁺ cells also employ type-I-interferon for regulating progenitor-cell-homeostasis.

Acinar to ductal cell trans-differentiation: A prelude to dysplasia and pancreatic ductal adenocarcinoma

Pancreatic cancer (PC) is the deadliest neoplastic epithelial malignancies and is projected to be the second leading cause of cancer-related mortality by 2024. Five years overall survival being ~10%, mortality and incidence rates are disturbing. Acinar to ductal cell metaplasia (ADM) encompasses cellular reprogramming and phenotypic switch-over, making it a cardinal event in tumor initiation. Differential cues and varied regulatory factors drive synchronous functions of metaplastic cell populations leading to multiple cell fates and physiological outcomes. ADM is a precursor for developing early pre-neoplastic lesions further progressing into PC due to oncogenic signaling. Hence delineating molecular events guiding tumor initiation may provide cues for regenerative medicine and precision onco-medicine. Therefore, understanding PC pathogenesis and early diagnosis are crucial. We hereby provide a timely overview of the current progress in this direction and future perspectives we foresee unfolding in the best interest of patient well-being and better clinical management of PC.

Dynamic flux balance analysis of whole-body metabolism for type 1 diabetes

Type 1 diabetes (T1D) mellitus is a systemic disease triggered by a local autoimmune inflammatory reaction in insulin-producing cells that induce organ-wide, long-term metabolic effects. Mathematical modeling of the whole-body regulatory bihormonal system has helped to identify therapeutic interventions but is limited to a coarse-grained representation of metabolism. To extend the depiction of T1D, we developed a whole-body model of organ-specific regulation and metabolism that highlighted chronic inflammation as a hallmark of the disease, identified processes related to neurodegenerative disorders and suggested calcium channel blockers as adjuvants for diabetes control. In addition, whole-body modeling of a patient population allowed for the assessment of between-individual variability to insulin and suggested that peripheral glucose levels are degenerate biomarkers of the internal metabolic state. Taken together, the organ-resolved, dynamic modeling approach enables modeling and simulation of metabolic disease at greater levels of coverage and precision and the generation of hypothesis from a molecular level up to the population level.

Signaling pathways and proteins targeted by antidiabetic chalcones

Chalcones have shown a broad spectrum of biological activities with clinical potential against various diseases. The biological activities are mainly attributed to the presence of α, β-unsaturated carbonyl system, perceived as potential Michael acceptors. In this review, we discussed the antioxidant potential of chalcones and elucidated the mechanisms of pathways and proteins such as carbohydrate digestive enzymes (α-amylase and α-glucosidase), aldose reductase, SGLT-2, and Nrf2 that are targeted by antidiabetic chalcones. In addition to their insulin mimetic potential, we explore the major molecular targets of chalcones and discuss the biochemical and therapeutic implication of modulating these targets. Finally, we dwell on the opulence of the literature and envisage how RNA interference-mediated gene silencing technique and in silico molecular docking could be exploited in the search for novel and more efficacious antidiabetic chalcones.

Advances and complications of regenerative medicine in diabetes therapy

The rapid development of technologies in regenerative medicine indicates clearly that their common application is not a matter of if, but of when. However, the regeneration of beta-cells for diabetes patients remains a complex challenge due to the plurality of related problems. Indeed, the generation of beta-cells masses expressing marker genes is only a first step, with maintaining permanent insulin secretion, their protection from the immune system and avoiding pathological modifications in the genome being the necessary next developments. The prospects of regenerative medicine in diabetes therapy were promoted by the emergence of promising results with embryonic stem cells (ESCs). Their pluripotency and proliferation in an undifferentiated state during culture have ensured the success of ESCs in regenerative medicine. The discovery of induced pluripotent stem cells (iPSCs) derived from the patients’ own mesenchymal cells has provided further hope for diabetes treatment. Nonetheless, the use of stem cells has significant limitations related to the pluripotent stage, such as the risk of development of teratomas. Thus, the direct conversion of mature cells into beta-cells could address this issue. Recent studies have shown the possibility of such transdifferentiation and have set trends for regeneration medicine, directed at minimizing genome modifications and invasive procedures. In this review, we will discuss the published results of beta-cell regeneration and the advantages and disadvantages illustrated by these experiments.

Pancreatic β cell regeneration: To β or not to β

Diabetes is a major worldwide health problem which results from the loss and/or dysfunction of pancreatic insulin-producing β cells in the pancreas. Therefore, there is great interest in understanding the endogenous capacity of β cells to regenerate under normal or pathological conditions, with the goal of restoring functional β cell mass in patients with diabetes. Here, we summarize the current status of β cell regeneration research, which has been broadly divided into three in vivo mechanisms: 1. proliferation of existing β cells; 2. neogenesis of β cells from adult ductal progenitors; and 3. transdifferentiation of other cell types into β cells. We discuss the evidence and controversies for each mechanism in mice and humans, as well as the prospect of using these approaches for the treatment of diabetes.

The Beta Cell in Type 2 Diabetes

PURPOSE OF REVIEW

This review summarizes the alterations in the β-cell observed in type 2 diabetes (T2D), focusing on changes in β-cell identity and mass and changes associated with metabolism and intracellular signaling.

RECENT FINDINGS

In the setting of T2D, β-cells undergo changes in gene expression, reverting to a more immature state and in some cases transdifferentiating into other islet cell types. Alleviation of metabolic stress, ER stress, and maladaptive prostaglandin signaling could improve β-cell function and survival. The β-cell defects leading to T2D likely differ in different individuals and include variations in β-cell mass, development, β-cell expansion, responses to ER and oxidative stress, insulin production and secretion, and intracellular signaling pathways. The recent recognition that some β-cells undergo dedifferentiation without dying in T2D suggests strategies to revive these cells and rejuvenate their functionality.

Human duct cells contribute to β cell compensation in insulin resistance

The identification of new sources of β cells is an important endeavor with therapeutic implications for diabetes. Insulin resistance, in physiological states such as pregnancy or in pathological states such as type 2 diabetes (T2D), is characterized by a compensatory increase in β cell mass. To explore the existence of a dynamic β cell reserve, we superimposed pregnancy on the liver-specific insulin receptor-KO (LIRKO) model of insulin resistance that already exhibits β cell hyperplasia and used lineage tracing to track the source of new β cells. Although both control and LIRKO mice displayed increased β cell mass in response to the relative insulin resistance of pregnancy, the further increase in mass in the latter supported a dynamic source that could be traced to pancreatic ducts. Two observations support the translational significance of these findings. First, NOD/SCID-γ LIRKO mice that became pregnant following cotransplantation of human islets and human ducts under the kidney capsule showed enhanced β cell proliferation and an increase in ductal cells positive for transcription factors expressed during β cell development. Second, we identified duct cells positive for immature β cell markers in pancreas sections from pregnant humans and in individuals with T2D. Taken together, during increased insulin demand, ductal cells contribute to the compensatory β cell pool by differentiation/neogenesis.

Regenerative medicine and cell-based approaches to restore pancreatic function

The pancreas is a complex organ with exocrine and endocrine components. Many pathologies impair exocrine function, including chronic pancreatitis, cystic fibrosis and pancreatic ductal adenocarcinoma. Conversely, when the endocrine pancreas fails to secrete sufficient insulin, patients develop diabetes mellitus. Pathology in either the endocrine or exocrine pancreas results in devastating economic and personal consequences. The current standard therapy for treating patients with type 1 diabetes mellitus is daily exogenous insulin injections, but cell sources of insulin provide superior glycaemic regulation and research is now focused on the goal of regenerating or replacing β cells. Stem-cell-based models might be useful to study exocrine pancreatic disorders, and mesenchymal stem cells or secreted factors might delay disease progression. Although the standards that bioengineered cells must meet before being considered as a viable therapy are not yet established, any potential therapy must be acceptably safe and functionally superior to current therapies. Here, we describe progress and challenges in cell-based methods to restore pancreatic function, with a focus on optimizing the site for cell delivery and decreasing requirements for immunosuppression through encapsulation. We also discuss the tools and strategies being used to generate exocrine pancreas and insulin-producing β-cell surrogates in situ and highlight obstacles to clinical application.

Systematic single-cell analysis provides new insights into heterogeneity and plasticity of the pancreas

BACKGROUND

Diabetes mellitus is characterized by loss or dysfunction of insulin-producing β-cells in the pancreas, resulting in failure of blood glucose regulation and devastating secondary complications. Thus, β-cells are currently the prime target for cell-replacement and regenerative therapy. Triggering endogenous repair is a promising strategy to restore β-cell mass and normoglycemia in diabetic patients. Potential strategies include targeting specific β-cell subpopulations to increase proliferation or maturation. Alternatively, transdifferentiation of pancreatic islet cells (e.g. α- or δ-cells), extra-islet cells (acinar and ductal cells), hepatocytes, or intestinal cells into insulin-producing cells might improve glycemic control. To this end, it is crucial to systematically characterize and unravel the transcriptional program of all pancreatic cell types at the molecular level in homeostasis and disease. Furthermore, it is necessary to better determine the underlying mechanisms of β-cell maturation, maintenance, and dysfunction in diabetes, to identify and molecularly profile endocrine subpopulations with regenerative potential, and to translate the findings from mice to man. Recent approaches in single-cell biology started to illuminate heterogeneity and plasticity in the pancreas that might be targeted for β-cell regeneration in diabetic patients.

SCOPE OF REVIEW

This review discusses recent literature on single-cell analysis including single-cell RNA sequencing, single-cell mass cytometry, and flow cytometry of pancreatic cell types in the context of mechanisms of endogenous β-cell regeneration. We discuss new findings on the regulation of postnatal β-cell proliferation and maturation. We highlight how single-cell analysis recapitulates described principles of functional β-cell heterogeneity in animal models and adds new knowledge on the extent of β-cell heterogeneity in humans as well as its role in homeostasis and disease. Furthermore, we summarize the findings on cell subpopulations with regenerative potential that might enable the formation of new β-cells in diseased state. Finally, we review new data on the transcriptional program and function of rare pancreatic cell types and their implication in diabetes.

MAJOR CONCLUSION

Novel, single-cell technologies offer high molecular resolution of cellular heterogeneity within the pancreas and provide information on processes and factors that govern β-cell homeostasis, proliferation, and maturation. Eventually, these technologies might lead to the characterization of cells with regenerative potential and unravel disease-associated changes in gene expression to identify cellular and molecular targets for therapy.