MicroRNA-24 promotes pancreatic beta cells toward dedifferentiation to avoid endoplasmic reticulum stress-induced apoptosis

AbstractCurrent research indicates that beta cell loss in type 2 diabetes may be attributed to beta cell dedifferentiation rather than apoptosis; however, the mechanisms by which this occurs remain poorly understood. Our previous study demonstrated that elevation of microRNA-24 (miR-24) in a diabetic setting caused beta cell dysfunction and replicative deficiency. In this study, we focused on the role of miR-24 in beta cell apoptosis and dedifferentiation under endoplasmic reticulum (ER) stress conditions. We found that miR-24 overabundance protected beta cells from thapsigargin-induced apoptosis at the cost of accelerating the impairment of glucose-stimulated insulin secretion (GSIS) and enhancing the presence of dedifferentiation markers. Ingenuity® Pathway Analysis (IPA) revealed that elevation of miR-24 had an inhibitory effect on XBP1 and ATF4, which are downstream effectors of two key branches of ER stress, by inhibiting its direct target, Ire1α. Notably, elevated miR-24 initiated another pathway that targeted Mafa and decreased GSIS function in surviving beta cells, thus guiding their dedifferentiation under ER stress conditions. Our results demonstrated that the elevated miR-24, to the utmost extent, preserves beta cell mass by inhibiting apoptosis and inducing dedifferentiation. This study not only provides a novel mechanism by which miR-24 dominates beta cell turnover under persistent metabolic stress but also offers a therapeutic consideration for treating diabetes by inducing dedifferentiated beta cells to re-differentiation.

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Phenylpropenoic acid glucoside augments pancreatic beta cell mass in high-fat diet-fed mice and protects beta cells from ER stress-induced apoptosis

Molecular Nutrition & Food Research ◽

10.1002/mnfr.201400211 ◽

2014 ◽

Vol 58 (10) ◽

pp. 1980-1990 ◽

Cited By ~ 20

Author(s):

Iris Mathijs ◽

Daniel A. Da Cunha ◽

Eddy Himpe ◽

Laurence Ladriere ◽

Nireshni Chellan ◽

...

Keyword(s):

Beta Cell ◽

Er Stress ◽

Beta Cells ◽

High Fat Diet ◽

Pancreatic Beta Cell ◽

Cell Mass ◽

Beta Cell Mass ◽

High Fat ◽

Induced Apoptosis ◽

Pancreatic Beta Cell Mass

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Multi-Organ Crosstalk with Endocrine Pancreas: A Focus on How Gut Microbiota Shapes Pancreatic Beta-Cells

Biomolecules ◽

10.3390/biom12010104 ◽

2022 ◽

Vol 12 (1) ◽

pp. 104

Author(s):

Elisa Fernández-Millán ◽

Carlos Guillén

Keyword(s):

Beta Cell ◽

Beta Cells ◽

Cell Biology ◽

Pancreatic Beta Cells ◽

Metabolic Diseases ◽

Cell Function ◽

Cell Mass ◽

Beta Cell Mass ◽

Short Chain Fatty Acids

Type 2 diabetes (T2D) results from impaired beta-cell function and insufficient beta-cell mass compensation in the setting of insulin resistance. Current therapeutic strategies focus their efforts on promoting the maintenance of functional beta-cell mass to ensure appropriate glycemic control. Thus, understanding how beta-cells communicate with metabolic and non-metabolic tissues provides a novel area for investigation and implicates the importance of inter-organ communication in the pathology of metabolic diseases such as T2D. In this review, we provide an overview of secreted factors from diverse organs and tissues that have been shown to impact beta-cell biology. Specifically, we discuss experimental and clinical evidence in support for a role of gut to beta-cell crosstalk, paying particular attention to bacteria-derived factors including short-chain fatty acids, lipopolysaccharide, and factors contained within extracellular vesicles that influence the function and/or the survival of beta cells under normal or diabetogenic conditions.

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Bergenin protects pancreatic beta cells against cytokine-induced apoptosis in INS-1E cells

PLoS ONE ◽

10.1371/journal.pone.0241349 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0241349

Author(s):

Sajid Ali Rajput ◽

Munazza Raza Mirza ◽

M. Iqbal Choudhary

Keyword(s):

Insulin Secretion ◽

Beta Cell ◽

Beta Cells ◽

Proinflammatory Cytokines ◽

Cell Apoptosis ◽

Pancreatic Beta Cells ◽

Cell Function ◽

Beta Cell Apoptosis ◽

Atp Levels ◽

Induced Apoptosis

Beta cell apoptosis induced by proinflammatory cytokines is one of the hallmarks of diabetes. Small molecules which can inhibit the cytokine-induced apoptosis could lead to new drug candidates that can be used in combination with existing therapeutic interventions against diabetes. The current study evaluated several effects of bergenin, an isocoumarin derivative, in beta cells in the presence of cytokines. These included (i) increase in beta cell viability (by measuring cellular ATP levels) (ii) suppression of beta cell apoptosis (by measuring caspase activity), (iii) improvement in beta cell function (by measuring glucose-stimulated insulin secretion), and (iv) improvement of beta cells mitochondrial physiological functions. The experiments were carried out using rat beta INS-1E cell line in the presence or absence of bergenin and a cocktail of proinflammatory cytokines (interleukin-1beta, tumor necrosis factor-alpha, and interferon- gamma) for 48 hr. Bergenin significantly inhibited beta cell apoptosis, as inferred from the reduction in the caspase-3 activity (IC50 = 7.29 ± 2.45 μM), and concurrently increased cellular ATP Levels (EC50 = 1.97 ± 0.47 μM). Bergenin also significantly enhanced insulin secretion (EC50 = 6.73 ± 2.15 μM) in INS-1E cells, presumably because of the decreased nitric oxide production (IC50 = 6.82 ± 2.83 μM). Bergenin restored mitochondrial membrane potential (EC50 = 2.27 ± 0.83 μM), decreased ROS production (IC50 = 14.63 ± 3.18 μM), and improved mitochondrial dehydrogenase activity (EC50 = 1.39 ± 0.62 μM). This study shows for the first time that bergenin protected beta cells from cytokine-induced apoptosis and restored insulin secretory function by virtue of its anti-inflammatory, antioxidant and anti-apoptotic properties. To sum up, the above mentioned data highlight bergenin as a promising anti-apoptotic agent in the context of diabetes.

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Update on the Protective Molecular Pathways Improving Pancreatic Beta-Cell Dysfunction

Mediators of Inflammation ◽

10.1155/2013/750540 ◽

2013 ◽

Vol 2013 ◽

pp. 1-14 ◽

Cited By ~ 14

Author(s):

Alessandra Puddu ◽

Roberta Sanguineti ◽

François Mach ◽

Franco Dallegri ◽

Giorgio Luciano Viviani ◽

...

Keyword(s):

Beta Cell ◽

Beta Cells ◽

Pancreatic Beta Cells ◽

Cell Function ◽

Pancreatic Beta Cell ◽

Cell Mass ◽

Beta Cell Mass ◽

Beta Cell Dysfunction ◽

Molecular Pathways ◽

Cell Dysfunction

The primary function of pancreatic beta-cells is to produce and release insulin in response to increment in extracellular glucose concentrations, thus maintaining glucose homeostasis. Deficient beta-cell function can have profound metabolic consequences, leading to the development of hyperglycemia and, ultimately, diabetes mellitus. Therefore, strategies targeting the maintenance of the normal function and protecting pancreatic beta-cells from injury or death might be crucial in the treatment of diabetes. This narrative review will update evidence from the recently identified molecular regulators preserving beta-cell mass and function recovery in order to suggest potential therapeutic targets against diabetes. This review will also highlight the relevance for novel molecular pathways potentially improving beta-cell dysfunction.

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Dynamic Regulation of JAK-STAT Signaling Through the Prolactin Receptor Predicted by Computational Modeling

Cellular and Molecular Bioengineering ◽

10.1007/s12195-020-00647-8 ◽

2020 ◽

Author(s):

Ryland D. Mortlock ◽

Senta K. Georgia ◽

Stacey D. Finley

Keyword(s):

Experimental Data ◽

Beta Cell ◽

Beta Cells ◽

Pancreatic Beta Cells ◽

Prolactin Receptor ◽

Cell Mass ◽

Beta Cell Mass ◽

Receptor Internalization ◽

Proliferative Potential ◽

Stat Signaling

Abstract Introduction The expansion of insulin-producing beta cells during pregnancy is critical to maintain glucose homeostasis in the face of increasing insulin resistance. Prolactin receptor (PRLR) signaling is one of the primary mediators of beta cell expansion during pregnancy, and loss of PRLR signaling results in reduced beta cell mass and gestational diabetes. Harnessing the proliferative potential of prolactin signaling to expand beta cell mass outside of the context of pregnancy requires quantitative understanding of the signaling at the molecular level. Methods A mechanistic computational model was constructed to describe prolactin-mediated JAK-STAT signaling in pancreatic beta cells. The effect of different regulatory modules was explored through ensemble modeling. A Bayesian approach for likelihood estimation was used to fit the model to experimental data from the literature. Results Including receptor upregulation, with either inhibition by SOCS proteins, receptor internalization, or both, allowed the model to match experimental results for INS-1 cells treated with prolactin. The model predicts that faster dimerization and nuclear import rates of STAT5B compared to STAT5A can explain the higher STAT5B nuclear translocation. The model was used to predict the dose response of STAT5B translocation in rat primary beta cells treated with prolactin and reveal possible strategies to modulate STAT5 signaling. Conclusions JAK-STAT signaling must be tightly controlled to obtain the biphasic response in STAT5 activation seen experimentally. Receptor up-regulation, combined with SOCS inhibition, receptor internalization, or both is required to match experimental data. Modulating reactions upstream in the signaling can enhance STAT5 activation to increase beta cell survival.

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Mechanisms involved in the beta-cell mass increase induced by chronic sucrose feeding to normal rats

Journal of Endocrinology ◽

10.1677/joe.0.1740225 ◽

2002 ◽

Vol 174 (2) ◽

pp. 225-231 ◽

Cited By ~ 16

Author(s):

H Del Zotto ◽

CL Gomez Dumm ◽

S Drago ◽

A Fortino ◽

GC Luna ◽

...

Keyword(s):

Body Weight ◽

Beta Cell ◽

Beta Cells ◽

Cell Mass ◽

Beta Cell Mass ◽

Serum Glucose ◽

Beta Cell Apoptosis ◽

Cell Replication ◽

Replication Rate ◽

Endocrine Tissue

The aim of the present study was to clarify the mechanisms by which a sucrose-rich diet (SRD) produces an increase in the pancreatic beta-cell mass in the rat. Normal Wistar rats were fed for 30 weeks either an SRD (SRD rats; 63% wt/wt), or the same diet but with starch instead of sucrose in the same proportion (CD rats). We studied body weight, serum glucose and triacylglycerol levels, endocrine tissue and beta-cell mass, beta-cell replication rate (proliferating cell nuclear antigen; PCNA), islet neogenesis (cytokeratin immunostaining) and beta-cell apoptosis (propidium iodide). Body weight (g) recorded in the SRD rats was significantly (P<0.05) larger than that of the CD group (556.0+/-8.3 vs 470.0+/-13.1). Both serum glucose and triacylglycerol levels (mmol/l) were also significantly higher (P<0.05) in SRD than in CD rats (serum glucose, 8.11+/-0.14 vs 6.62+/-0.17; triacylglycerol, 1.57+/-0.18 vs 0.47+/-0.04). The number of pancreatic islets per unit area increased significantly (P<0.05) in SRD rats (3.29+/-0.1 vs 2.01+/-0.2). A significant increment (2.6 times) in the mass of endocrine tissue was detected in SRD animals, mainly due to an increase in the beta-cell mass (P=0.0025). The islet cell replication rate, measured as the percentage of PCNA-labelled beta cells increased 6.8 times in SRD rats (P<0.03). The number of apoptotic cells in the endocrine pancreas decreased significantly (three times) in the SRD animals (P=0.03). The cytokeratin-positive area did not show significant differences between CD and SRD rats. The increase of beta-cell mass induced by SRD was accomplished by an enhanced replication of beta cells together with a decrease in the rate of beta-cell apoptosis, without any evident participation of islet neogenesis. This pancreatic reaction was unable to maintain serum glucose levels of these rats at the level measured in CD animals.

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Wisp1 is a circulating factor that stimulates proliferation of adult mouse and human beta cells

Nature Communications ◽

10.1038/s41467-020-19657-1 ◽

2020 ◽

Vol 11 (1) ◽

Author(s):

Rebeca Fernandez-Ruiz ◽

Ainhoa García-Alamán ◽

Yaiza Esteban ◽

Joan Mir-Coll ◽

Berta Serra-Navarro ◽

...

Keyword(s):

Beta Cell ◽

Beta Cells ◽

Pancreatic Beta Cells ◽

Cell Mass ◽

Beta Cell Mass ◽

Beta Cell Proliferation ◽

Cell Replication ◽

Trophic Effect ◽

Beta Cell Replication

AbstractExpanding the mass of pancreatic insulin-producing beta cells through re-activation of beta cell replication has been proposed as a therapy to prevent or delay the appearance of diabetes. Pancreatic beta cells exhibit an age-dependent decrease in their proliferative activity, partly related to changes in the systemic environment. Here we report the identification of CCN4/Wisp1 as a circulating factor more abundant in pre-weaning than in adult mice. We show that Wisp1 promotes endogenous and transplanted adult beta cell proliferation in vivo. We validate these findings using isolated mouse and human islets and find that the beta cell trophic effect of Wisp1 is dependent on Akt signaling. In summary, our study reveals the role of Wisp1 as an inducer of beta cell replication, supporting the idea that the use of young blood factors may be a useful strategy to expand adult beta cell mass.

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Insulin mutations impair beta-cell development in a patient-derived iPSC model of neonatal diabetes

eLife ◽

10.7554/elife.38519 ◽

2018 ◽

Vol 7 ◽

Cited By ~ 37

Author(s):

Diego Balboa ◽

Jonna Saarimäki-Vire ◽

Daniel Borshagovski ◽

Mantas Survila ◽

Päivi Lindholm ◽

...

Keyword(s):

Beta Cell ◽

Er Stress ◽

Cell Mass ◽

Gene Mutations ◽

Beta Cell Mass ◽

Neonatal Diabetes ◽

Beta Cell Apoptosis ◽

Beta Cell Proliferation ◽

Sequencing Analysis ◽

Mtorc1 Signaling

Insulin gene mutations are a leading cause of neonatal diabetes. They can lead to proinsulin misfolding and its retention in endoplasmic reticulum (ER). This results in increased ER-stress suggested to trigger beta-cell apoptosis. In humans, the mechanisms underlying beta-cell failure remain unclear. Here we show that misfolded proinsulin impairs developing beta-cell proliferation without increasing apoptosis. We generated induced pluripotent stem cells (iPSCs) from people carrying insulin (INS) mutations, engineered isogenic CRISPR-Cas9 mutation-corrected lines and differentiated them to beta-like cells. Single-cell RNA-sequencing analysis showed increased ER-stress and reduced proliferation in INS-mutant beta-like cells compared with corrected controls. Upon transplantation into mice, INS-mutant grafts presented reduced insulin secretion and aggravated ER-stress. Cell size, mTORC1 signaling, and respiratory chain subunits expression were all reduced in INS-mutant beta-like cells, yet apoptosis was not increased at any stage. Our results demonstrate that neonatal diabetes-associated INS-mutations lead to defective beta-cell mass expansion, contributing to diabetes development.

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