scholarly journals Inhibition of Notch activity promotes pancreatic cytokeratin 5-positive cell differentiation to beta cells and improves glucose homeostasis following acute pancreatitis

2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Xiaoyi Zhang ◽  
Jing Tao ◽  
Jia Yu ◽  
Ning Hu ◽  
Xuanzhe Zhang ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Beta Cell ◽  
Beta Cells ◽  
Glucose Homeostasis ◽  
Cell Injury ◽  
Cell Loss ◽  
Notch Activity ◽  
Endocrine Insufficiency ◽  
Cytokeratin 5 ◽  
Notch Inhibition

AbstractSome individuals develop prediabetes and/or diabetes following acute pancreatitis (AP). AP-induced beta-cell injury and the limited regenerative capacity of beta cells might account for pancreatic endocrine insufficiency. Previously, we found that only a few pancreatic cytokeratin 5 positive (Krt5+) cells differentiated into beta cells in the murine AP model, which was insufficient to maintain glucose homeostasis. Notch signaling determines pancreatic progenitor differentiation in pancreas development. This study aimed to examine whether Notch signaling inhibition could promote pancreatic Krt5+ cell differentiation into beta cells and improve glucose homeostasis following AP. Pancreatic tissues from patients with acute necrotizing pancreatitis (ANP) were used to evaluate beta-cell injury, Krt5+ cell activation and differentiation, and Notch activity. The murine AP model was induced by cerulein, and the effect of Notch inhibition on Krt5+ cell differentiation was evaluated both in vivo and in vitro. The results demonstrated beta-cell loss in ANP patients and AP mice. Krt5+ cells were activated in ANP pancreases along with persistently elevated Notch activity, which resulted in the formation of massive duct-like structures. AP mice that received Notch inhibitor showed that impaired glucose tolerance was reversed 7 and 15 days following AP, and increased numbers of newborn small islets due to increased differentiation of Krt5+ cells to beta cells to some extent. In addition, Krt5+ cells isolated from AP mice showed increased differentiation to beta cells by Notch inhibition. Collectively, these findings suggest that beta-cell loss contributes to pancreatic endocrine insufficiency following AP, and inhibition of Notch activity promotes pancreatic Krt5+ cell differentiation to beta cells and improves glucose homeostasis. The findings from this study may shed light on the potential treatment of prediabetes/diabetes following AP.

scholarly journals β-cells operate collectively to help maintain glucose homeostasis

2019 ◽  
Author(s):  
Boris Podobnik ◽  
Dean Korošak ◽  
Maša Skelin Klemen ◽  
Andraž Stožer ◽  
Jurij Dolenšek ◽  
...  
Keyword(s):  
Beta Cell ◽  
Beta Cells ◽  
Glucose Homeostasis ◽  
Cell Activity ◽  
Cell Communication ◽  
Calcium Oscillations ◽  
Homeostatic Function ◽  
Entire Cell ◽  
Collective Phenomenon ◽  
Gap Junctional

Residing in the islets of Langerhans in the pancreas, beta cells contribute to glucose homeostasis by managing the body’s insulin supply. A circulating hypothesis has been that healthy beta cells heavily engage in cell-to-cell communication to perform their homeostatic function. We provide strong evidence in favor of this hypothesis in the form of (i) a dynamical network model that faithfully mimics fast calcium oscillations in response to above-threshold glucose stimulation and (ii) empirical data analysis that reveals a qualitative shift in the cross-correlation structure of measured signals below and above the threshold glucose concentration. Combined together, these results point to a glucose-induced transition in beta-cell activity thanks to increasing coordination through gap-junctional signaling and paracrine interactions. The model further suggests how the conservation of entire cell-cell conductance, observed in coupled but not uncoupled beta cells, emerges as a collective phenomenon. An overall implication is that improving the ability to monitor beta-cell signaling should offer means to better understand the pathogenesis of diabetes mellitus.

scholarly journals Flavonoids Identification and Pancreatic Beta-Cell Protective Effect of Lotus Seedpod

Antioxidants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 658 ◽  
Author(s):  
Ming-Shih Lee ◽  
Charng-Cherng Chyau ◽  
Chi-Ping Wang ◽  
Ting-Hsuan Wang ◽  
Jing-Hsien Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Beta Cell ◽  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Cell Injury ◽  
Pancreatic Beta Cell ◽  
B Cell Lymphoma ◽  
Pancreatic Cell ◽  
Traditional Chinese Herbal Medicine ◽  
Lotus Seedpod

Oxidative stress is highly associated with the development of diabetes mellitus (DM), especially pancreatic beta-cell injury. Flavonoids derived from plants have caused important attention in the prevention or treatment of DM. Lotus seedpod belongs to a traditional Chinese herbal medicine and has been indicated to possess antioxidant, anti-age, anti-glycative, and hepatoprotective activities. The purpose of this study was to demonstrate the pancreatic beta-cell protective effects of lotus seedpod aqueous extracts (LSE) against oxidative injury. According to HPLC/ESI-MS-MS method, LSE was confirmed to have flavonoids derivatives, especially quercetin-3-glucuronide (Q3G). In vitro, LSE dose-dependently improved the survival and function of rat pancreatic beta-cells (RIN-m5F) from hydrogen peroxide (H2O2)-mediated loss of cell viability, impairment of insulin secretion, and promotion of oxidative stress. LSE showed potential in decreasing the H2O2-induced occurrence of apoptosis. In addition, H2O2-triggered acidic vesicular organelle formation and microtubule-associated protein light chain 3 (LC3)-II upregulation, markers of autophagy, were increased by LSE. Molecular data explored that antiapoptotic and autophagic effects of LSE, comparable to that of Q3G, might receptively be mediated via phospho-Bcl-2-associated death promoter (p-Bad)/B-cell lymphoma 2 (Bcl-2) and class III phosphatidylinositol-3 kinase (PI3K)/LC3-II signal pathway. In vivo, LSE improved the DM symptoms and pancreatic cell injury better than metformin, a drug that is routinely prescribed to treat DM. These data implied that LSE induces the autophagic signaling, leading to protect beta-cells from oxidative stress-related apoptosis and injury.

scholarly journals TCF7L2 in mouse pancreatic beta cells plays a crucial role in glucose homeostasis by regulating beta cell mass

Diabetologia ◽  
2013 ◽  
Vol 57 (3) ◽  
pp. 542-553 ◽  
Author(s):  
Iseki Takamoto ◽  
Naoto Kubota ◽  
Keizo Nakaya ◽  
Katsuyoshi Kumagai ◽  
Shinji Hashimoto ◽  
...  
Keyword(s):  
Beta Cell ◽  
Beta Cells ◽  
Glucose Homeostasis ◽  
Crucial Role ◽  
Pancreatic Beta Cells ◽  
Cell Mass ◽  
Beta Cell Mass

scholarly journals LncRNA LEGLTBC Functions as a ceRNA to Antagonize the Effects of miR-34a on the Downregulation of SIRT1 in Glucolipotoxicity-Induced INS-1 Beta Cell Oxidative Stress and Apoptosis

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Xiang Kong ◽  
Chong-xiao Liu ◽  
Guo-dong Wang ◽  
Hui Yang ◽  
Xin-ming Yao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetes Mellitus ◽  
Beta Cell ◽  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Cell Injury ◽  
Cell Damage ◽  
High Serum ◽  
Cell Dysfunction ◽  
Beta Cell Damage

Type 2 diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose and/or high serum free fatty acids. Chronic hyperlipidemia causes the dysfunction of pancreatic beta cells, which is aggravated in the presence of hyperglycemia (glucolipotoxicity). Long noncoding RNAs (lncRNAs) have been suggested to play key roles in type 1 diabetes mellitus development. However, their roles in glucolipotoxicity-induced beta cell dysfunction are not fully understood. In the present study, we identified the differentially expressed lncRNAs in INS-1 cells exposed to high glucose and palmitate (HG/PA). Among the dysregulated lncRNAs, NONRATT003679.2 (low expression in glucolipotoxicity-treated beta cells (LEGLTBC)) was involved in glucolipotoxicity-evoked rat islet beta cell damage. LEGLTBC functioned as a molecular sponge of miR-34a in INS-1 cells. Additionally, SIRT1 was identified as a target of miR-34a and LEGLTBC promoted SIRT1 expression by sponging miR-34a. The upregulation of LEGLTBC attenuated HG/PA-induced INS-1 cell injury through the promotion of SIRT1-mediated suppression of ROS accumulation and apoptosis. This is the first study to comprehensively identify the lncRNA expression profiling of HG/PA-treated INS-1 beta cells and to demonstrate that LEGLTBC functions as a competing endogenous RNA and regulates miR-34a/SIRT1-mediated oxidative stress and apoptosis in INS-1 cells undergoing glucolipotoxicity.

scholarly journals Inherent Beta Cell Dysfunction Contributes to Autoimmune Susceptibility

Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 512
Author(s):  
Yong Kyung Kim ◽  
Lori Sussel ◽  
Howard W. Davidson
Keyword(s):  
Insulin Secretion ◽  
Beta Cell ◽  
Beta Cells ◽  
Pancreatic Beta Cell ◽  
Cell Loss ◽  
The Body ◽  
Beta Cell Dysfunction ◽  
Metabolic Characteristics ◽  
Cell Dysfunction ◽  
Glucose Stimulated Insulin Secretion

The pancreatic beta cell is a highly specialized cell type whose primary function is to secrete insulin in response to nutrients to maintain glucose homeostasis in the body. As such, the beta cell has developed unique metabolic characteristics to achieve functionality; in healthy beta cells, the majority of glucose-derived carbons are oxidized and enter the mitochondria in the form of pyruvate. The pyruvate is subsequently metabolized to induce mitochondrial ATP and trigger the downstream insulin secretion response. Thus, in beta cells, mitochondria play a pivotal role in regulating glucose stimulated insulin secretion (GSIS). In type 2 diabetes (T2D), mitochondrial impairment has been shown to play an important role in beta cell dysfunction and loss. In type 1 diabetes (T1D), autoimmunity is the primary trigger of beta cell loss; however, there is accumulating evidence that intrinsic mitochondrial defects could contribute to beta cell susceptibility during proinflammatory conditions. Furthermore, there is speculation that dysfunctional mitochondrial responses could contribute to the formation of autoantigens. In this review, we provide an overview of mitochondrial function in the beta cells, and discuss potential mechanisms by which mitochondrial dysfunction may contribute to T1D pathogenesis.

scholarly journals Characterization of the endocrine pancreas in Type 1 Diabetes: islet size is maintained but islet number is markedly reduced

2018 ◽  
Author(s):  
Peter Seiron ◽  
Anna Wiberg ◽  
Lars Krogvold ◽  
Frode Lars Jahnsen ◽  
Knut Dahl-Jørgensen ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Beta Cell ◽  
Beta Cells ◽  
Cell Mass ◽  
Beta Cell Mass ◽  
Cell Loss ◽  
Recent Onset ◽  
Islet Size ◽  
Pancreas Volume

AbstractInsulin deficiency in type 1 diabetes (T1D) is generally considered a consequence of specific beta-cell loss. Since healthy pancreatic islets consist of ~65% beta cells, this would lead to reduced islet size if the beta cells are not replaced by other cells or tissue. The number of islets per pancreas volume (islet density) would not be affected.In this study, we compared the islet density, size, and size distribution in subjects with recent-onset or long-standing T1D, with that in matched non-diabetic subjects. Results show that subjects with T1D, regardless of disease duration, had a dramatically reduced islet number per mm2, while the islet size was similar in all groups. Insulin-negative islets in T1D subjects were dominated by glucagon-positive cells that frequently had lost the alpha-cell transcription factor ARX while instead expressing PDX1, normally expressed in beta cells.Based on our findings, we propose that failure during childhood to establish a sufficient islet number to reach the beta-cell mass needed to cope with episodes of increased insulin demand contributes to T1D susceptibility. Exhaustion induced by relative lack of beta cells could then potentially drive beta-cell dedifferentiation to alpha-cells, explaining the preserved islet size observed in T1D compared to controls.

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