Effect of Silencing Information Regulator on Islet β Cells in High Glucose Environment Through Regulation of Phosphatidylinositol 3 Kinase (PI3K)/Protein Kinase B (AKT)/Nuclear Factor-κ-Gene Binding Pathway

2021 ◽  
Vol 11 (8) ◽  
pp. 1624-1629
Author(s):  
Nali Liu ◽  
Beijing Zhu ◽  
Xin Wei
Keyword(s):  
Cell Proliferation ◽  
Insulin Secretion ◽  
High Glucose ◽  
Islet Cell ◽  
Control Group ◽  
Diabetic Patients ◽  
Phosphatidylinositol 3 Kinase ◽  
Sod Activity ◽  
Sirt1 Expression ◽  
Cell Supernatant

Islet β-cell regeneration is beneficial for treating diabetic patients. Silencing information regulator (SIRT1) has a regulatory role in endocrine diseases. However, SIRT1’s role in islet β cells remains unclear. MIN6 cells were cultured and assigned into control group, high glucose group, and SIRT1 group (treated with SIRT1 agonist, Resveratrol) followed by analysis of SIRT1 expression by Real time PCR and ELISA, cell proliferation by MTT assay, apoptosis activity by Caspase3 activity kit, secretion of TNF-α and IL-2 by ELISA, insulin secretion, ROS and SOD generation and expression of PI3K/Akt/NF-κB signaling by Western blot. SIRT1 mRNA was decreased in high glucose environment and its secretion in cell supernatant was reduced, with inhibited cell proliferation, increased Caspase3 activity and secretion of TNF-α and IL-2, decreased insulin secretion and SOD activity, increased ROS content, pAKT phosphorylation and NF-κB expression. Resveratrol significantly promoted SIRT1 expression and cell proliferation, decreased Caspase3 activity and secretion of TNF-α and IL-2, increased insulin secretion and SOD activity, as well as decreased ROS content, pAKT phosphorylation and NF-κB expression (P <0.05). SIRT1 is decreased in high glucose environment, and SIRT1 expression can inhibit islet cell apoptosis, inhibit oxidative stress and inflammation, and promote islet cell proliferation and insulin secretion by regulating PI3K/Akt/NF-κB signaling.

Effect of Glucose Metabolism-Associated Protein-1 on Exendin-4-Treated Pancreatic Islet Cell Function

2020 ◽  
Vol 10 (7) ◽  
pp. 1015-1021
Author(s):  
Jing Feng ◽  
Cuiwen Kong ◽  
Min Wang ◽  
Yingchuan Xu ◽  
Yingwei Chang
Keyword(s):  
Cell Proliferation ◽  
Glucose Metabolism ◽  
Islet Cell ◽  
Caspase 3 ◽  
Cell Function ◽  
Islet Cells ◽  
Control Group ◽  
Sod Activity ◽  
Fas L ◽  
Islet Cell Function

Exendin-4 regulates blood sugar. Glucose metabolism-associated protein-1 (GMRP-1) regulates islet cell function. Therefore, this paper intends to analyze the effect of GMRP-1 on Exendin-4treated islet cells. The islet cell MIN6 cells were separated into control group, Exendin-4 group, GMRP-1 overexpressing+ Exendin-4 group, and GMRP-1 siRNA+ Exendin-4 group followed by analysis of the expression of GMRP-1 by quantitative real-time PCR and Western blot, cell proliferation by MTT, cell apoptosis by flow cytometry, Bcl-2, Bax, Fas and Fas-L expression by real-time PCR, as well as caspase-3 activity, reactive oxygen species (ROS) and superoxide dismutase (SOD) activity. Exendin-4 and GMRP-1 overexpression+ Exendin-4 significantly increased GMRP-1 expression and promoted cell proliferation, decreased apoptotic rate and Caspase-3 activity, increased Bcl-2 and Fas-L expression, reduced Fas and Bax expression, as well as decreased ROS generation and increased SOD activity (P < 0 05), and the changes in GMRP-1 overexpression+ Exendin-4 group was more significant (P < 0 01). However, GMRP-1 siRNA+ Exendin-4 group significantly down-regulated GMRP-1 expression, decreased MIN6 cell prolifer- ation, increased cell apoptosis and Caspase-3 activity, decreased Bcl-2 and Fas-L expression, elevated Fas and Bax expression, increased ROS content and decreased SOD activity compared to control group and Exendin-4 group (P < 0 05). Up-regulation of GMRP-1 expression promoted Exendin-4-induced proliferation and inhibited apoptosis of islet cells. Down-regulation of GMRP-1 expression reversed Exendin-4's effect on islet cells.

Effect of SIRT1 on Bone Marrow Stromal Stem Cells in High Glucose Environment and Related Mechanisms

2019 ◽  
Vol 9 (9) ◽  
pp. 1238-1244
Author(s):  
Yajun Wang ◽  
Zongjiang Wang ◽  
Honggang Sun ◽  
Jianrong Song ◽  
Chao Xu
Keyword(s):  
Cell Proliferation ◽  
High Glucose ◽  
Caspase 3 ◽  
Pi3k Signaling ◽  
Sod Activity ◽  
Sirt1 Expression ◽  
Alp Activity ◽  
Pi3k Signaling Pathway ◽  
High Glucose Group ◽  
Glucose Group

Silencing information regulator (SIRT1) involves in endocrine diseases. However, whether SIRT1 participates in BMSCs under high glucose environment remains unclear. Rat BMSCs were isolated and divided into control group; high glucose group; and SIRT1 group, in which SIRT1 agonist (Resveratrol) was added to high glucose BMSCs followed by analysis of SIRT1, Bax and Bcl-2 expression by real time PCR and ELISA, cell proliferation by MTT assay, Caspase3 activity, ALP activity, calcification nodule formation by alizarin red staining, changes of ROS and SOD activities, PI3K signaling pathway by Western blot. SIRT1 expression was significantly decreased in BMSCs in high glucose group, with inhibited cell proliferation, increased Caspase 3 activity, Bax expression, and ROS content, decreased Bcl-2 expression, ALP activity, SOD activity, as well as reduced formation of calcified nodules and phosphorylation of PI3K compared to control (P < 0.05). Addition of Resveratrol significantly promoted SIRT1 expression and cell proliferation of BMSCs in high glucose group, decreased Caspase 3 activity, Bax expression, and ROS content, increased Bcl-2 expression, ALP activity, SOD activity, as well as increased formation of calcified nodules and phosphorylation of PI3K (P < 0.05). SIRT1 expression is decreased in BMSCs in high glucose group. Increasing SIRT1 expression in BMSCs under high glucose environment promoted proliferation of BMSCs and the formation of calcified nodules by regulating oxidative stress and activating PI3K signaling pathway.

scholarly journals Identification of a small molecule that stimulates human β-cell proliferation and insulin secretion, and protects against cytotoxic stress in rat insulinoma cells

2019 ◽  
Author(s):  
Hans E. Hohmeier ◽  
Lu Zhang ◽  
Brandon Taylor ◽  
Samuel Stephens ◽  
Peter McNamara ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Insulin Secretion ◽  
Small Molecule ◽  
Islet Cell ◽  
Human Islet ◽  
Luciferase Reporter ◽  
Β Cell ◽  
Cytotoxic Stress ◽  
Insulinoma Cells ◽  
Rat Insulinoma

AbstractA key event in the development of both major forms of diabetes is the loss of functional pancreatic islet β-cell mass. Strategies aimed at enhancing β-cell regeneration have long been pursued, but methods for reliably inducing human β-cell proliferation with full retention of key functions such as glucose-stimulated insulin secretion (GSIS) are still very limited. We have previously reported that overexpression of the homeobox transcription factor Nkx6.1 stimulates β-cell proliferation, while also enhancing GSIS and providing protection against β-cell cytotoxicity through induction of the VGF prohormone. We developed an Nkx6.1 pathway screen by stably transfecting 832/13 rat insulinoma cells with a VGF promoter-luciferase reporter construct, using the resultant cell line to screen a 630,000 compound chemical library. We isolated three compounds with consistent effects to stimulate human islet cell proliferation. Further studies of the most potent of these compounds, GNF-9228, revealed that it selectively activates human β-cell relative to α-cell proliferation and has no effect on δ-cell replication. In addition, pre-treatment, but not short term exposure of human islets to GNF-9228 enhances GSIS. GNF-9228 also protects 832/13 insulinoma cells against ER stress- and inflammatory cytokine-induced cytotoxicity. In contrast to recently emergent Dyrk1a inhibitors that stimulate human islet cell proliferation, GNF-9228 does not activate NFAT translocation. These studies have led to identification of a small molecule with pleiotropic positive effects on islet biology, including stimulation of human β-cell proliferation and insulin secretion, and protection against multiple agents of cytotoxic stress.

scholarly journals Sorafenib Inhibits Tumor Growth and Improves Survival in a Transgenic Mouse Model of Pancreatic Islet Cell Tumors

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Volker Fendrich ◽  
Katja Maschuw ◽  
Johannes Rehm ◽  
Malte Buchholz ◽  
Julia P. Holler ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Treatment Group ◽  
Tumor Progression ◽  
Early Treatment ◽  
Islet Cell ◽  
Control Group ◽  
Islet Cell Tumors ◽  
Pancreatic Islet Cell ◽  
Early Treatment Group ◽  
Late Treatment

Background. The purpose of the study was to evaluate Sorafenib (BAY 43-9006) derived receptor tyrosine kinase inhibition on tumor progression in murine islet cell tumors. Sorafenib is considered to be a potent inhibitor of tumor angiogenesis and neovascularization in various solid tumors. Rip1Tag2 mice were treated in two different groups according to the model of tumor progression: the early treatment group received vehicle or Sorafenib from 10 to 14 weeks of age and the late treatment group from week 12 until death. Tumor surface, tumor cell proliferation, and apoptosis were measured in both treatment groups to assess the in vivo effects of Sorafenib. Survival was recorded for the late treatment group. In the early treatment group Sorafenib led to a dramatic decrease in tumor volume compared to the control group. Apoptosis was significantly augmented and cell proliferation was inhibited. As a single therapy Sorafenib significantly improved survival in the late treatment group.Conclusion. Sorafenib may provide a new paradigm for the therapy of islet cell tumors.

scholarly journals miR-29a Negatively Affects Glucose-Stimulated Insulin Secretion and MIN6 Cell Proliferation via Cdc42/β-Catenin Signaling

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Jing Duan ◽  
Xian-Ling Qian ◽  
Jun Li ◽  
Xing-Hua Xiao ◽  
Xiang-Tong Lu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Insulin Secretion ◽  
High Glucose ◽  
Cell Counting ◽  
Luciferase Reporter ◽  
Enzyme Linked Immunosorbent Assay ◽  
Glucose Stimulation ◽  
Inhibition Of Proliferation ◽  
Glucose Stimulated Insulin Secretion

Background. Diabetes is a progressive metabolic disease characterized by hyperglycemia. Functional impairment of islet β cells can occur to varying degrees. This impairment can initially be compensated for by proliferation and metabolic changes of β cells. Cell division control protein 42 (Cdc42) and the microRNA (miRNA) miR-29 have important roles in β-cell proliferation and glucose-stimulated insulin secretion (GSIS), which we further explored using the mouse insulinoma cell line MIN6. Methods. Upregulation and downregulation of miR-29a and Cdc42 were accomplished using transient transfection. miR-29a and Cdc42 expression was detected by real-time PCR and western blotting. MIN6 proliferation was detected using a cell counting kit assay. GSIS under high-glucose (20.0 mM) or basal-glucose (5.0 mM) stimulation was detected by enzyme-linked immunosorbent assay. The miR-29a binding site in the Cdc42 mRNA 3′-untranslated region (UTR) was determined using bioinformatics and luciferase reporter assays. Results. miR-29a overexpression inhibited proliferation (P<0.01) and GSIS under high-glucose stimulation (P<0.01). Cdc42 overexpression promoted proliferation (P<0.05) and GSIS under high-glucose stimulation (P<0.05). miR-29a overexpression decreased Cdc42 expression (P<0.01), whereas miR-29a downregulation increased Cdc42 expression (P<0.01). The results showed that the Cdc42 mRNA 3′-UTR is a direct target of miR-29a in vitro. Additionally, Cdc42 reversed miR-29a-mediated inhibition of proliferation and GSIS (P<0.01). Furthermore, miR-29a inhibited β-catenin expression (P<0.01), whereas Cdc42 promoted β-catenin expression (P<0.01). Conclusion. By negatively regulating Cdc42 and the downstream molecule β-catenin, miR-29a inhibits MIN6 proliferation and insulin secretion.

scholarly journals Regulation of Dendrobium Polysaccharides on Proliferation and Oxidative Stress of Human Umbilical Vein Endothelial Cells in the High Glucose Environment

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Yajia Li ◽  
Ziqin Cao ◽  
Limin Jia ◽  
Yanfei Huang ◽  
Meilan Shi ◽  
...  
Keyword(s):  
High Glucose ◽  
Calcium Ion ◽  
Umbilical Vein ◽  
Ion Concentration ◽  
Control Group ◽  
Sod Activity ◽  
Intracellular Ros ◽  
Intracellular Calcium Ion ◽  
Umbilical Vein Endothelial Cells ◽  
Calcium Ion Concentration

Backgrounds. Polysaccharides of Dendrobium candidum (PDC) showed a strong antioxidant effect on islet cells while the effects of PDC on human umbilical vein endothelial cells (HUVECs) under the high glucose condition remain unclear. Material and Method. HUVECs were incubated with high glucose (33.3 mmol/L) for 48 hours to induce injury, and cells were treated with PDC (100, 200, and 400 μg/mL) for 48 hours. The tetrazolium blue colorimetric (MTT) assay was used to detect cell proliferation, superoxide dismutase (SOD), and nitric oxide (NO) content in cell supernatants. Flow cytometry was used to detect reactive oxygen species (ROS) and calcium levels. Results. (1) Compared with the control group, the proliferation of HUVECs cells in the high glucose (33.3 mmol/L) group decreased ( P < 0.05 ). The intracellular calcium ion concentration and the intracellular ROS level increased ( P < 0.01 and P < 0.05 ). SOD activity and the level of NO in the culture medium were reduced (P <0.05). (2) Compared with the control group, PDC (50, 100, 200, 400, and 800 μg/mL) did not significantly affect the cell proliferation of HUVECs ( P > 0.05 ). (3) Compared with the high glucose group, the HUVEC cell viability of the high glucose + PDC (100, 200, and 400 μg/mL) group increased while the intracellular calcium ion concentration decreased in a concentration-dependent manner ( P < 0.05 ). Intracellular ROS levels were reduced, while SOD activity and the level of NO in culture fluids increased ( P < 0.05 ). Conclusion. PDC can promote the proliferation of HUVECs in the high glucose environment by reducing oxidative stress injury of HUVECs induced by high glucose.

scholarly journals SAT-LB035 The G Protein-Coupled Estrogen Receptor GPER Plays a Dominant Role in Human Islet Cell Proliferation upon High Glucose

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Sigal Shaklai ◽  
Meital Grafi-Cohen ◽  
Orli Sharon ◽  
Gabi Shefer ◽  
Dalia Somjen ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Estrogen Receptor ◽  
G Protein ◽  
High Glucose ◽  
Islet Cell ◽  
Dominant Role ◽  
Human Islet ◽  
G Protein Coupled

scholarly journals Influence of SGLT2 Inhibitor Treatment on Urine Antioxidant Status in Type 2 Diabetic Patients: A Pilot Study

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Diana Nabrdalik-Leśniak ◽  
Katarzyna Nabrdalik ◽  
Katarzyna Sedlaczek ◽  
Patryk Główczyński ◽  
Hanna Kwiendacz ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Antioxidant Status ◽  
Sglt2 Inhibitor ◽  
Control Group ◽  
Diabetic Patients ◽  
Compensatory Mechanism ◽  
Type 2 Diabetic Patients ◽  
Sod Activity ◽  
Antioxidant Agents

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have been recognized as potent antioxidant agents. Since SGLT2i are nephroprotective drugs, we aimed to examine the urine antioxidant status in patients with type 2 diabetes mellitus (T2DM). One hundred and one subjects participated in this study, including 37 T2DM patients treated with SGLT2i, 31 T2DM patients not using SGLT2i, and 33 healthy individuals serving as a control group. Total antioxidant capacity (TAC), superoxide dismutase (SOD), manganese superoxide dismutase (MnSOD), free thiol groups (R-SH, sulfhydryl groups), and catalase (CAT) activity, as well as glucose concentration, were assessed in the urine of all participants. Urine SOD and MnSOD activity were significantly higher among T2DM patients treated with SGLT2i than T2DM patients without SGLT2i treatment ( p = 0.009 and p = 0.003 , respectively) and to the healthy controls ( p = 0.002 and p = 0.001 , respectively). TAC was significantly lower in patients with T2DM treated with SGLT2i when compared to those not treated and healthy subjects ( p = 0.036 and p = 0.019 , respectively). It could be hypothesized that the mechanism by which SGLT2i provides nephroprotective effects involves improvement of the SOD antioxidant activity. However, lower TAC might impose higher OS (oxidative stress), and elevation of SOD activity might be a compensatory mechanism.

Thiamine pyrophosphate diminishes nitric oxide synthesis in endothelial cells

2020 ◽  
pp. 1-9
Author(s):  
Susana Alcázar-Leyva ◽  
Estrella Zapata ◽  
Demetrio Bernal-Alcántara ◽  
Patricia Gorocica ◽  
Noé Alvarado-Vásquez
Keyword(s):  
Nitric Oxide ◽  
Cell Proliferation ◽  
Endothelial Cells ◽  
High Glucose ◽  
Thiamine Pyrophosphate ◽  
Diabetic Patients ◽  
Protective Agent ◽  
Nitric Oxide Synthesis ◽  
Umbilical Cord Vein ◽  
Cells Cultured

Abstract. Although thiamine pyrophosphate (TPP) is considered a protective agent for endothelial cells, it is still unknown if this is associated with nitric oxide (NO) synthesis. Our aim was to evaluate the synthesis of NO in endothelial cells incubated with TPP and high glucose concentrations. Endothelial cells from the umbilical cord vein from newborns (n = 20), were incubated with 5, 15 or 30 mmol/L glucose, in absence or presence of 0.625 mg/ml of TPP. Our results showed a significant increase in cell proliferation (> 40%; P < 0.05), and cell viability (> 90%; P < 0.001) after 48 h in endothelial cells cultured with glucose plus TPP. Likewise, in the presence of glucose and TPP an important rise in the consumption of glucose by the endothelial cells was observed after 24 h (> 7%; P < 0.001) and 48 h (> 10%; P < 0.05). Additionally, the levels of lactate after incubation with glucose and TPP showed only slight variations after 48 h (P < 0.05). However, these changes were clearly different from those observed in the absence of TPP. Interestingly, we found that the changes mentioned were linked with reduced levels of nitrites both at 24 h (< 171 pmol/μg protein; P < 0.001), and 48 h (< 250 pmol/μg protein; P < 0.05), which was associated with a reduced expression of mRNA of eNOS in endothelial cells incubated with TPP and high glucose. In conclusion, the presence of TPP regulates the consumption of glucose and the synthesis of NO, which would explain its protective effect in the endothelium of diabetic patients.

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