Saturated fatty acids induced genes and ISR target genes in pancreatic beta cells
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE49647 | GEO | 2015/08/01
SECONDARY ACCESSION(S): PRJNA214595
REPOSITORIES: GEO
Similar Datasets
Project description:To identify the genes induced by lipotoxicity and integrated stress response in pancreatic beta cells, we have employed whole genome microarray expression in panvreatic beta cell line MIN6m9 cells. First microarray analysis : Wild type MIN6m9 cells were treated with Palmitate, Oleate or negative control condition. Second microarray analysis : Wild type and Fv2E-PERK transgened MIN6m9 cells were treated with mock or artificial dimerizer AP20187(AP) in various time course.
2015-08-01 | E-GEOD-49647 | biostudies-arrayexpress
Project description:Pancreatic beta-cell dysfunction and death are central in the pathogenesis of type 2 diabetes. Saturated fatty acids cause beta-cell failure and contribute to diabetes development in genetically predisposed individuals. Here we used RNA-sequencing to map transcripts expressed in five palmitate-treated human islet preparations, observing 1,325 modified genes. Palmitate induced fatty acid metabolism and endoplasmic reticulum (ER) stress. Functional studies identified novel mediators of adaptive ER stress signaling. Palmitate modified genes regulating ubiquitin and proteasome function, autophagy and apoptosis. Inhibition of autophagic flux and lysosome function contributed to lipotoxicity. Palmitate inhibited transcription factors controlling beta-cell phenotype including PAX4 and GATA6. 59 type 2 diabetes candidate genes were expressed in human islets, and 11 were modified by palmitate. Palmitate modified expression of 17 splicing factors and shifted alternative splicing of 3,525 transcripts. Ingenuity Pathway Analysis of modified transcripts and genes confirmed that top changed functions related to cell death. DAVID analysis of transcription binding sites in palmitate-modified transcripts revealed a role for PAX4, GATA and the ER stress response regulators XBP1 and ATF6. This human islet transcriptome study identified novel mechanisms of palmitate-induced beta-cell dysfunction and death. The data point to crosstalk between metabolic stress and candidate genes at the beta-cell level. 5 human islet of Langerhans preparations examined under 2 conditions (control and palmitate treatment)
2014-01-09 | E-GEOD-53949 | biostudies-arrayexpress
Project description:Pancreatic beta-cell dysfunction and death are central in the pathogenesis of type 2 diabetes. Saturated fatty acids cause beta-cell failure and contribute to diabetes development in genetically predisposed individuals. Here we used RNA-sequencing to map transcripts expressed in five palmitate-treated human islet preparations, observing 1,325 modified genes. Palmitate induced fatty acid metabolism and endoplasmic reticulum (ER) stress. Functional studies identified novel mediators of adaptive ER stress signaling. Palmitate modified genes regulating ubiquitin and proteasome function, autophagy and apoptosis. Inhibition of autophagic flux and lysosome function contributed to lipotoxicity. Palmitate inhibited transcription factors controlling beta-cell phenotype including PAX4 and GATA6. 59 type 2 diabetes candidate genes were expressed in human islets, and 11 were modified by palmitate. Palmitate modified expression of 17 splicing factors and shifted alternative splicing of 3,525 transcripts. Ingenuity Pathway Analysis of modified transcripts and genes confirmed that top changed functions related to cell death. DAVID analysis of transcription binding sites in palmitate-modified transcripts revealed a role for PAX4, GATA and the ER stress response regulators XBP1 and ATF6. This human islet transcriptome study identified novel mechanisms of palmitate-induced beta-cell dysfunction and death. The data point to crosstalk between metabolic stress and candidate genes at the beta-cell level.
2014-01-09 | GSE53949 | GEO
Project description:The pancreatic beta cell function failure is the core event of type 2 diabetes mellitus. High levels of free fatty acid and glucose are two main factor that induced pancreatic beta cell function failure. Long term exposure to palmitate can induced pancreatic beta cell apoptoss and impaired insulin secretion in vivo and in vitro, called lipotoxicity. The lipotoxicity often coupled with high glucose, their combination form called glucolipotoxcity. We carried out temporal transcriptome and proteome studies investigating the evolution of molecular events in Ins1 cells stimulated by palmitate for different times. And through compared the transcriptome and proteome between lipotoxicity and glucolipotoxicity explain the mechanism of glucolipotoxicity more harmfull to beta cell.
2019-04-27 | GSE98272 | GEO
Project description:Protein phosphatase 2A (PP2A) is one of the most common serine/threonine phosphatases in mammalian cells and primarily functions to regulate cell signaling, glycolipid metabolism, and apoptosis. Its PP2A catalytic subunit (PP2Ac) plays an important role in its function. Nonetheless, at present, there are only a few reports on the regulatory role of PP2Ac in pancreatic β-cells under lipotoxicity. Mouse pancreatic insulinoma (MIN6) cells were transfected by lentiviruses to generate PP2Ac knockdown cells and incubated with palmitate (PA) to establish the lipotoxicity model. Serine/Threonine Phosphatase Assay System kit, Cell Counting Kit-8 (CCK-8), flow cytometry, enzyme-linked immunosorbent assay (ELISA), Western Blotting (WB) and other techniques were used to measure PP2A activity, cell viability, apoptosis, oxidative stress, and insulin secretion. An animal model of lipotoxicity with knockdown of PP2Ac was established by a high-fat diet (HFD) after using adeno-associated viruses (AAV) to interfere with PP2Ac expression in mouse pancreatic tissues. Serine/Threonine Phosphatase Assay System kit, ELISA, pancreatic tissue immunofluorescence and other techniques were used to measure PP2A activity in pancreatic tissue, serum insulin level and the proliferation of mouse pancreatic β-cells. We found that PP2Ac knockdown inhibited lipotoxicity-induced PP2A hyperactivation, increased the resistance of pancreatic β-cells to lipotoxicity, decreased PA-induced apoptosis in MIN6 cells, protected the function of both the endoplasmic reticulum (ER) and mitochondria, and improved insulin secretion. By mRNA sequencing and Western blotting analysis, we hypothesized that the protective effects of PP2Ac knockdown in MIN6 cells may be mediated by the MAPK pathway. Moreover, the results obtained from animal experiments suggest that the specific knockdown of pancreatic PP2Ac could effectively attenuate HFD-induced insulin resistance and reduce the compensatory proliferation of pancreatic β-cells in mice. The present study revealed the effects and mechanisms of interfering with PP2Ac gene expression on pancreatic β-cells in vivo and in vitro, which might provide insights for the treatment of type 2 diabetes in the clinic.
2023-09-13 | GSE242538 | GEO
Project description:Pancreatic β-cell failure induced by WFS1 deficiency is manifested in wolfram syndrome (WS). The lack of a suitable human model in WS has hampered the progress in developing new treatments. Here, human pluripotent stem cell derived pancreatic β cells (SC-β cells) harboring WFS1-deficiency and mouse model of β cell-specific Wfs1 knockout were applied to model β-cell failure in WS. Single-cell RNA sequencing of WFS1-deficient SC-β cells revealed two cell fates along pseudotime trajectory including maturation and stress branch. WFS1 deficiency blocked β-cell fate trajectory to maturation but pushed it towards stress trajectory leading to β-cell failure.
2024-01-30 | GSE235331 | GEO
Project description:Probing the Global Cellular Responses to Lipotoxicity Caused by Saturated Fatty Acids
| PRJNA515481 | ENA
Project description:Recent studies have identified a cholestatic variant of nonalcoholic fatty liver disease (NAFLD) with portal inflammation and ductular reaction. Based on reports of biliary damage, as well as increased circulating free fatty acids (FFAs) in NAFLD, we hypothesized the involvement of cholangiocyte lipoapoptosis as a mechanism of cellular injury. Here, we demonstrate that the saturated FFAs palmitate and stearate induced robust and rapid cell death in cholangiocytes. Palmitate and stearate induced cholangiocyte lipoapoptosis in a concentration-dependent manner in multiple cholangiocyte-derived cell lines. The mechanism of lipoapoptosis relied on the activation of caspase 3/7 activity. There was also a significant up-regulation of the proapoptotic BH3-containing protein, PUMA. In addition, palmitate-induced cholangiocyte lipoapoptosis involved a time-dependent increase in the nuclear localization of forkhead family of transcription factor 3 (FoxO3). We show evidence for posttranslational modification of FoxO3, including early (6 hours) deacetylation and dephosphorylation that coincide with localization of FoxO3 in the nuclear compartment. By 16 hours, nuclear FoxO3 is both phosphorylated and acetylated. Knockdown studies confirmed that FoxO3 and its downstream target, PUMA, were critical for palmitate- and stearate-induced cholangiocyte lipoapoptosis. Interestingly, cultured cholangiocyte-derived cells did not accumulate appreciable amounts of neutral lipid upon FFA treatment.Our data show that the saturated FFAs palmitate and stearate induced cholangiocyte lipoapoptosis by way of caspase activation, nuclear translocation of FoxO3, and increased proapoptotic PUMA expression. These results suggest that cholangiocyte injury may occur through lipoapoptosis in NAFLD and nonalcoholic steatohepatitis patients.
| S-EPMC4553418 | biostudies-literature
Project description:Palm and coconut oils are linked to cardiovascular disease and diabetes because of their high saturated fatty acid (SFA) content but exactly how exogenous SFAs, but not unsaturated fatty acids (UFA), are toxic to cells remains unknown. In insulin-producing, β-cells of the Islets of Langerhans, loss of which exacerbates diabetes, we found that SFAs but not UFAs were toxic because they disable a highly conserved lipid droplet biogenesis machinery. We show that palmitate (a major SFA of these oils), but not palmitoleic or oleic, S-acylates the highly conserved ER-resident FITM2 protein, required for lipid coalescence and droplet budding from the ER. The S-acylation marks FITM2 for ubiquitination and proteosomal degradation, leaving SFAs within the ER instead safe sequestration within lipid droplets. ER-stress ensues with rapid induction of ER stress leading to β-cell apoptosis. Specific deletion of FITM2 in β-cells disrupts calcium signaling and key β-cell TFs and exacerbates high fat diet-induced ER stress and diabetes. Rescue by overexpression ameliorates ER-stress and β-cell apoptosis thus demonstrating an important link between lipid species and cell ability to sequester them away from the ER in the form of lipid droplets.
2021-07-08 | GSE133939 | GEO
Project description:PP2Ac knockdown attenuates lipotoxicity-induced pancreatic β-cell dysfunction and apoptosis
| PRJNA1013896 | ENA