G-Rh4 improves pancreatic β-cells dysfunction in vivo and in vitro by increased expression of Nrf2 and its target genes

2021 ◽  
Vol 148 ◽  
pp. 111925
Author(s):  
Yao Liu ◽  
Jianjun Deng ◽  
Daidi Fan
Keyword(s):  
Target Genes ◽  
Β Cells ◽  
Pancreatic Β Cells

scholarly journals Targeted delivery of antisense oligonucleotides to pancreatic β-cells

2018 ◽  
Vol 4 (10) ◽  
pp. eaat3386 ◽  
Author(s):  
C. Ämmälä ◽  
W. J. Drury ◽  
L. Knerr ◽  
I. Ahlstedt ◽  
P. Stillemark-Billton ◽  
...  
Keyword(s):  
Targeted Delivery ◽  
Target Genes ◽  
Cell Types ◽  
Cell Type Specificity ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Glucagon Like Peptide 1 ◽  
Novel Therapeutic

Antisense oligonucleotide (ASO) silencing of the expression of disease-associated genes is an attractive novel therapeutic approach, but treatments are limited by the ability to deliver ASOs to cells and tissues. Following systemic administration, ASOs preferentially accumulate in liver and kidney. Among the cell types refractory to ASO uptake is the pancreatic insulin-secreting β-cell. Here, we show that conjugation of ASOs to a ligand of the glucagon-like peptide-1 receptor (GLP1R) can productively deliver ASO cargo to pancreatic β-cells both in vitro and in vivo. Ligand-conjugated ASOs silenced target genes in pancreatic islets at doses that did not affect target gene expression in liver or other tissues, indicating enhanced tissue and cell type specificity. This finding has potential to broaden the use of ASO technology, opening up novel therapeutic opportunities, and presents an innovative approach for targeted delivery of ASOs to additional cell types.

scholarly journals LncRNA MALAT1 Regulates iPSC-derived Β-cell Differentiation by Targeting the miR-15b-5p/Ihh Axis

2020 ◽  
Author(s):  
Yao Wang ◽  
Xinxing Lin ◽  
Jin Lv ◽  
Jiachen Zhu ◽  
Haowen Fan ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Cell Therapy ◽  
Target Genes ◽  
Differentially Expressed ◽  
Luciferase Reporter ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Lncrna Malat1

Abstract Background: iPSCs-derived β-like cell differentiation provides a novel strategy for type 1 diabetes treatment. Clarifying the regulatory mechanisms of lncRNAs in β-like cells derived from induced pluripotent stem cells (iPSCs) is not only significant for understanding the development of pancreas or pancreatic β cells, but also helpful for improving the quality of β-like cells for stem cell therapy.Methods: β-like cells derived from iPSCs followed a three-step protocol. RNA-sequencing was carried out to screen the differentially expressed lncRNAs which was probably involved in the differentiation of pancreatic β cells. Bioinformatics was performed to analyze the putative target genes of significantly differentially expressed lncRNAs. LncRNA Malat1 was chosen for further research. Lentivirus victor, siRNA victor, antagomir victor and mimic victor were constructed for overexpression of lncRNA Malat1, knockdown of lncRNA Malat1, knockdown of miR-15b-5p and overexpression of miR-15b-5p respectively. Quantitative Real-Time PCR (qRT-PCR), Western Blot and Immunofluorescence (IF) staining were carried out to detect the functions of pancreatic β cells at mRNA and protein level separately. Cytoplasmic and nuclear RNA fractionation and Fluorescence in situ hybridization (FISH) were to ventilate the subcellar location of lncRNA Malat1 in β-like cells. Flow cytometry and ELISA were performed to examine differentiation efficiency and function of insulin secretion from β-like cells after being stimulated with different concentrations of glucose. Structural interactions between lncRNA Malat1 and miR-15b-5p and between miR-15b-5p and Ihh were detected by Dual luciferase reporter assay (LRA).Results: We found that expression of lncRNA Malat1 was on the decline during the differentiation and overexpression of this lncRNA obviously impaired the differentiation and maturation of β-like cells derived from iPSCs in vitro and in vivo. Localized to the cytoplasm, lncRNA Malat1 could function as a competing endogenous RNA (ceRNA) of miR-15b-5p to regulate the expression of Ihh according the bioinformatic prediction, mechanistic analysis and downstream experiments.Conclusion: This study built an unreported regulatory network of lncRNA Malat1 and miR-15b-5p/Ihh axis during differentiation of iPSCs into β-like cells. Except for acting as a proverbial oncogene promoting tumorigenesis, lncRNA Malat1 may provide effective and novel molecule for diabetes cell therapy in the future.

scholarly journals LncRNA Malat1 regulates iPSC-derived β-cell differentiation by targeting the miR-15b-5p/Ihh axis

2021 ◽  
Author(s):  
Yao Wang ◽  
Xinxing Lin ◽  
Jin Lv ◽  
Jiachen Zhu ◽  
Haowen Fan ◽  
...  
Keyword(s):  
Stem Cell ◽  
Target Genes ◽  
Induced Pluripotent Stem Cell ◽  
Luciferase Reporter ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Protein Levels ◽  
Lncrna Malat1

Abstract Background: Differentiation of induced pluripotent stem cell (iPSC)-derived β-like cells is a novel strategy for treatment of type 1 diabetes. Elucidation of the regulatory mechanisms of long noncoding RNAs (lncRNAs) in β-like cells derived from iPSCs is important for understanding the development of the pancreas and pancreatic β-cells and may improve the quality of β-like cells for stem cell therapy.Methods: β-like cells were derived from iPSCs in a three-step protocol. RNA sequencing and bioinformatics analysis were carried out to screen the differentially expressed lncRNAs and identify the putative target genes separately. LncRNA Malat1 was chosen for further research. Series of loss and gain of functions experiments were performed to study the biological function of this lncRNA. Quantitative real-time PCR (qRT-PCR), Western blot analysis and immunofluorescence (IF) staining were carried out to separately detect the functions of pancreatic β-cells at the mRNA and protein levels. Cytoplasmic and nuclear RNA fractionation and fluorescence in situ hybridization (FISH) were used to determine the subcellar location of lncRNA Malat1 in β-like cells. Flow cytometry and enzyme-linked immunosorbent assays (ELISAs) were performed to examine the differentiation and insulin secretion of β-like cells after stimulation with different glucose concentrations. Structural interactions between lncRNA Malat1 and miR-15b-5p and between miR-15b-5p and Ihh were detected by dual luciferase reporter assays (LRAs).Results: We found that the expression of lncRNA Malat1 declined during differentiation, and overexpression of this lncRNA notably impaired the differentiation and maturation of β-like cells derived from iPSCs in vitro and in vivo. Localized to the cytoplasm, lncRNA Malat1 could function as a competing endogenous RNA (ceRNA) of miR-15b-5p to regulate the expression of Ihh according to bioinformatics prediction, mechanistic analysis and downstream experiments.Conclusion: This study established an unreported regulatory network of lncRNA Malat1 and the miR-15b-5p/Ihh axis during the differentiation of iPSCs into β-like cells. In addition to acting as an oncogene promoting tumorigenesis, lncRNA Malat1 may be an effective and novel target for treatment of diabetes in the future.

scholarly journals Treatment With Naringenin Elevates the Activity of Transcription Factor Nrf2 to Protect Pancreatic β-Cells From Streptozotocin-Induced Diabetes in vitro and in vivo

2019 ◽  
Vol 9 ◽  
Author(s):  
Rashmi Rajappa ◽  
Dornadula Sireesh ◽  
Magesh B. Salai ◽  
Kunka M. Ramkumar ◽  
Suryanarayanan Sarvajayakesavulu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Streptozotocin Induced Diabetes

scholarly journals Protein Kinase CK2 Controls CaV2.1-Dependent Calcium Currents and Insulin Release in Pancreatic β-cells

2020 ◽  
Vol 21 (13) ◽  
pp. 4668
Author(s):  
Rebecca Scheuer ◽  
Stephan Ernst Philipp ◽  
Alexander Becker ◽  
Lisa Nalbach ◽  
Emmanuel Ampofo ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Calcium Currents ◽  
Insulin Biosynthesis ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Voltage Dependent ◽  
Regulatory Impact ◽  
Kinase Ck2

The regulation of insulin biosynthesis and secretion in pancreatic β-cells is essential for glucose homeostasis in humans. Previous findings point to the highly conserved, ubiquitously expressed serine/threonine kinase CK2 as having a negative regulatory impact on this regulation. In the cell culture model of rat pancreatic β-cells INS-1, insulin secretion is enhanced after CK2 inhibition. This enhancement is preceded by a rise in the cytosolic Ca2+ concentration. Here, we identified the serine residues S2362 and S2364 of the voltage-dependent calcium channel CaV2.1 as targets of CK2 phosphorylation. Furthermore, co-immunoprecipitation experiments revealed that CaV2.1 binds to CK2 in vitro and in vivo. CaV2.1 knockdown experiments showed that the increase in the intracellular Ca2+ concentration, followed by an enhanced insulin secretion upon CK2 inhibition, is due to a Ca2+ influx through CaV2.1 channels. In summary, our results point to a modulating role of CK2 in the CaV2.1-mediated exocytosis of insulin.

Pannexin-2-deficiency sensitizes pancreatic β-cells to cytokine-induced apoptosis in vitro and impairs glucose tolerance in vivo

2017 ◽  
Vol 448 ◽  
pp. 108-121 ◽  
Author(s):  
Lukas A. Berchtold ◽  
Michela Miani ◽  
Thi A. Diep ◽  
Andreas N. Madsen ◽  
Valentina Cigliola ◽  
...  
Keyword(s):  
Glucose Tolerance ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Induced Apoptosis

scholarly journals Hyperinsulinemia promotes HMGB1 release leading to inflammation induced systemic insulin resistance: An interplay between pancreatic beta-cell and peripheral organs

2019 ◽  
Author(s):  
Abhinav Choubey ◽  
Aditya K Kar ◽  
Khyati Girdhar ◽  
Tandrika Chattopadhyay ◽  
Surbhi Dogra ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Pancreatic Beta Cell ◽  
Underlying Mechanism ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Extracellular Milieu ◽  
Peripheral Organs ◽  
Systemic Insulin Resistance

SummaryInsulin resistance results from several pathophysiologic mechanisms, including chronic tissue inflammation and defective insulin signaling. Pancreatic β-cells hypersecretion (hyperinsulinemia), is a central hallmark of peripheral insulin resistance. However, the underlying mechanism by which hyperinsulinemia perpetuates towards the development of insulin resistance remains unclear and is still a bigger therapeutic challenge. Here, we found hyperinsulinemia triggers inflammation and insulin resistance by stimulating TLR4-driven inflammatory cascades. We show that hyperinsulinemia activates the TLR4 signaling through HMGB1, an endogenous TLR4 ligand emanating from hyperinsulinemia exposed immune cells and peripheral organs like adipose tissue and liver. Further, our observation suggests hyperinsulinemia ensuring hyperacetylation, nuclear-to-cytoplasmic shuttling and release of HMGB1 into the extracellular space. HMGB1 was also found to be elevated in serum of T2DM patients. We found that extracellular HMGB1 plays a crucial role to promote proinflammatory responses and provokes systemic insulin resistance. Importantly, in-vitro and in-vivo treatment with naltrexone, a TLR4 antagonist led to an anti-inflammatory phenotype with protection from hyperinsulinemia mediated insulin resistance. In-vitro treatment with naltrexone directly enhanced SIRT1 activity, blocked the release of HMGB1 into extracellular milieu, suppressed release of proinflammatory cytokines and ultimately led to insulin-sensitizing effects. These observations elucidate a regulatory network between pancreatic β-cells, macrophage and hepatocytes and assign an unexpected role of TLR4 - HMGB1 signaling axis in hyperinsulinemia mediated systemic insulin resistance.Graphical Abstract

scholarly journals Downregulation of lncRNA TUG1 Affects Apoptosis and Insulin Secretion in Mouse Pancreatic β Cells

2015 ◽  
Vol 35 (5) ◽  
pp. 1892-1904 ◽  
Author(s):  
Dan-dan Yin ◽  
Er-bao Zhang ◽  
Liang-hui You ◽  
Ning Wang ◽  
Lin-tao Wang ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Cell Function ◽  
Annexin V ◽  
Pancreatic Tissue ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Lncrna Tug1

Background: Increasing evidence indicates that long noncoding RNAs (IncRNAs) perform specific biological functions in diverse processes. Recent studies have reported that IncRNAs may be involved in β cell function. The aim of this study was to characterize the role of IncRNA TUG1 in mouse pancreatic β cell functioning both in vitro and in vivo. Methods: qRT-PCR analyses were performed to detect the expression of lncRNA TUG1 in different tissues. RNAi, MTT, TUNEL and Annexin V-FITC assays and western blot, GSIS, ELISA and immunochemistry analyses were performed to detect the effect of lncRNA TUG1 on cell apoptosis and insulin secretion in vitro and in vivo. Results: lncRNA TUG1 was highly expressed in pancreatic tissue compared with other organ tissues, and expression was dynamically regulated by glucose in Nit-1 cells. Knockdown of lncRNA TUG1 expression resulted in an increased apoptosis ratio and decreased insulin secretion in β cells both in vitro and in vivo . Immunochemistry analyses suggested decreased relative islet area after treatment with lncRNA TUG1 siRNA. Conclusion: Downregulation of lncRNA TUG1 expression affected apoptosis and insulin secretion in pancreatic β cells in vitro and in vivo. lncRNA TUG1 may represent a factor that regulates the function of pancreatic β cells.

scholarly journals Protection of pancreatic β-cells by exendin-4 may involve the reduction of endoplasmic reticulum stress; in vivo and in vitro studies

2007 ◽  
Vol 193 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Shin Tsunekawa ◽  
Naoki Yamamoto ◽  
Katsura Tsukamoto ◽  
Yuji Itoh ◽  
Yukiko Kaneko ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Death ◽  
Er Stress ◽  
Islet Cells ◽  
Binding Protein ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells

The aim of this study was to investigate the in vivo and in vitro effects of exendin-4, a potent glucagon-like peptide 1 agonist, on the protection of the pancreatic β-cells against their cell death. In in vivo experiments, we used β-cell-specific calmodulin-overexpressing mice where massive apoptosis takes place in their β-cells, and we examined the effects of chronic treatment with exendin-4. Chronic and s.c. administration of exendin-4 reduced hyperglycemia. The treatment caused significant increases of the insulin contents of the pancreas and islets, and retained the insulin-positive area. Dispersed transgenic islet cells lived only shortly, and several endoplasmic reticulum (ER) stress-related molecules such as immunoglobulin-binding protein (Bip), inositol-requiring enzyme-1α, X-box-binding protein-1 (XBP-1), RNA-activated protein kinase-like endoplasmic reticulum kinase, activating transcription factor-4, and C/EBP-homologous protein (CHOP) were more expressed in the transgenic islets. We also found that the spliced form of XBP-1, a marker of ER stress, was also increased in β-cell-specific calmodulin-overexpressing transgenic islets. In the quantitative real-time PCR analyses, the expression levels of Bip and CHOP were reduced in the islets from the transgenic mice treated with exendin-4. These findings suggest that excess of ER stress occurs in the transgenic β-cells, and the suppression of ER stress and resultant protection against cell death may be involved in the anti-diabetic effects of exendin-4.

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