Spint1 specific knokout in mouse pancreas islet SILAC
Ontology highlight
ABSTRACT:
INSTRUMENT(S): LTQ Orbitrap Velos
ORGANISM(S): Mus Musculus (mouse)
SUBMITTER: 
Lin hsin-hsien
LAB HEAD: Ming-Shyue Lee
PROVIDER: PXD039190 | Pride | 2024-11-01
REPOSITORIES: Pride
Dataset's files
Items per page: 5 1 - 5 of 38 |
Similar Datasets
Project description:Peroxisome proliferator-activated receptor beta/delta protects against obesity by reducing dyslipidemia and insulin resistance via effects in various organs, including muscle, adipose tissue, liver, and heart. However, nothing is known about the function of PPAR-beta in pancreas, a prime organ in the control of glucose metabolism. To gain insight into so far hypothetical functions of this PPAR isotype in insulin production, we specifically ablated Ppar-beta in pancreas. The mutated mice developed a chronic hyperinsulinemia, due to an increase in both beta-cell mass and insulin secretion. Gene expression profiling indicated a broad repressive function of PPAR-beta impacting the vesicular compartment, actin cytoskeleton, and metabolism of glucose and fatty acids. Analyses of insulin release from the islets revealed an increased second-phase glucose-stimulated insulin secretion. Higher levels of PKD, PKC-delta and diacyglycerol in mutated animals lead to an enhanced formation of trans-Golgi network (TGN)-to-plasma-membrane transport carriers in concert with F-actin disassembly, which resulted in increased insulin secretion and its associated systemic effects. Taken together, these results provide evidence for PPAR-beta playing a repressive role on beta-cell growth and insulin exocytosis, which shed new light on its anti-obesity action. Pancreas-specific knock-out animals were generated by breeding mice harbouring a floxed Ppar-beta (PPARbetafl/fl) to mice expressing the Cre transgene under the control of the Pdx1 promoter (Pdx1Cre). Islets from 3 different animals from the knock-out group Pdx1Cre;PPARbetafl/fl and the control littermates group PPARbetafl/fl were compared.
2012-08-30 | E-GEOD-16048 | biostudies-arrayexpress
Project description:Beta-cells produce hybrid insulin peptides (HIPs) by linking insulin fragments to other peptides through peptide bonds. HIPs have unique amino acid sequences and are targeted by autoreactive T cells in type 1 diabetes (T1D). Individuals with recent-onset T1D have significantly higher levels of HIP-reactive T cells in their blood compared to non-diabetic control subjects. HIP-reactive T cells have also been found in the residual pancreatic islets of deceased T1D organ donors. In non-obese diabetic (NOD) mice, a major T1D animal model, several CD4 T cell clones that trigger diabetes have been shown to target HIPs. Through mass spectrometry, a subgroup of HIPs containing N-terminal amine groups of various peptides linked to aspartic acid residues of insulin C-peptide has been detected in NOD islets. Our research reveals that these HIPs form spontaneously in beta-cells via an aspartic anhydride intermediate mechanism. This process leads to the creation of a regular HIP with a standard peptide bond and a HIP-isomer (isoHIP) with an isopeptide bond linked to the carboxylic acid side-chain of the aspartic acid residue. Our mass spectrometric analyses confirmed the presence of both HIP isomers in murine islets, thereby validating the occurrence of this new reaction mechanism in beta-cells. The spontaneous formation of neoepitopes through the development of new peptide bonds within cells may contribute to the pathogenesis of T1D and other autoimmune diseases.
2023-11-16 | PXD041616 | Pride
Project description:Hyperinsulinemia often precedes type 2 diabetes but its role in disease progression is unknown. Palmitoylation, a protein modification implicated in regulated exocytosis, is reversed by acyl-protein thioesterase 1 (APT1). We found altered APT1 biology in pancreatic islets from humans with type 2 diabetes, and APT1 knockdown in nondiabetic human islets caused insulin hypersecretion. Chow fed global and islet specific APT1 knockout mice had enhanced glucose tolerance due to islet autonomous increased glucose-stimulated insulin secretion. APT1 deficiency did not affect islet calcium dynamics but prolonged insulin granule fusion. Using palmitoylation proteomics, we identified Scamp1 as an APT1 substrate that localized to insulin secretory granules. Knockdown of Scamp1 caused insulin hypersecretion. APT1 deficient insulinoma cells subjected to nutrient excess had increased apoptosis, and expression of a mutated Scamp1 incapable of being palmitoylated in APT1 deficient cells rescued insulin hypersecretion and nutrient induced apoptosis. Compared to APT1 sufficient controls, high fat fed islet specific APT1 knockout mice and global APT1 deficient db/db mice showed increased -cell failure. These findings suggest that the depalmitoylation enzyme APT1 is regulated in human islets, and that APT1 deficiency causes insulin hypersecretion leading to -cell failure, modeling the evolution of some forms of human type 2 diabetes.
2023-11-05 | PXD038554 | Pride
Project description:Sulforaphane (SFN), an isothiocyanate found in cruciferous vegetables, is a potent inhibitor of experimental mammary carcinogenesis and may be an effective, safe chemopreventive agent for use in humans. SFN acts in part on the Keap1/Nrf2 pathway to regulate a battery of cytoprotective genes. In this study transcriptomic and proteomic changes in the estrogen receptor negative, non tumorigenic human breast epithelial MCF10A cell line were analyzed following SFN treatment or KEAP1 knockdown with siRNA using microarray and stable isotopic labeling with amino acids in culture (SILAC), respectively. Changes in selected transcripts and proteins were confirmed by PCR and Western blot in MCF10A and MCF12A cells. There was strong correlation between the transcriptomic and proteomic responses in both the SFN treatment (R=0.679, P<0.05) and KEAP1 knockdown (R=0.853, P<0.05) experiments. Common pathways for SFN treatment and KEAP1 knockdown were xenobiotic metabolism and antioxidants, glutathione metabolism, carbohydrate metabolism and NADH/NADPH regeneration. Moreover, these pathways were most prominent in both the transcriptomic and proteomic analyses. The aldo-keto reductase family members, AKR1B10, AKR1C1, AKR1C2 and AKR1C3, as well as NQO1 and ALDH3A1, were highly upregulated at both the transcriptomic and proteomic level. Collectively, these studies served to identify potential biomarkers that can be used in clinical trials to investigate the initial pharmacodynamic action of SFN in the breast. MCF10A cells were treated with SFN or had KEAP1 knocked down by siRNA.
2011-04-22 | E-GEOD-28813 | biostudies-arrayexpress
Project description:Secretion of insulin by pancreatic β cells in response to glucose is central for glucose homeostasis, and dysregulation of this process is a hallmark of the early stages of diabetes. We utilized a tetracycline-inducible approach to investigate the immediate impact of a pulse of Sox17 expression on the insulin secretory pathway. Sox17 gain-of-function animals (Sox17-GOF) were generated using an Ins2-rtTA mouse line and a line in which Sox17 expression is regulated by the tetracycline transactivator (tetO-Sox17). Administering doxycycline to 16-week old mice resulted in Sox17 overexpression in mature β cells in the islets. In order to identify the molecular basis by which Sox17 regulates the secretory pathway in β cells, we performed microarray analysis on isolated islets following a 24-hour pulse of Sox17 overexpression. We chose to analyze a 24 hour pulse of Sox17 for islet pancreas RNA extraction and hybridization on Affymetrix microarrays since it was sufficient to stimulate the insulin secretory pathway without causing changes in islet architecture.
2014-07-31 | E-GEOD-59928 | biostudies-arrayexpress
Project description:Insulin (INS) synthesis and secretion from pancreatic M-NM-2 cells are tightly regulated; their deregulation causes diabetes. Here we map INS-associated loci in human pancreatic islets by 4C and 3C techniques and show that the INS gene physically interacts with the SYT8 gene, located over 300 kb away. This interaction is elevated by glucose and accompanied by increases in SYT8 expression. Inactivation of the INS promoter by promoter-targeting siRNA reduces SYT8 gene expression. SYT8-INS interaction and SYT8 transcription are attenuated by CTCF depletion. Furthermore, SYT8 knockdown decreases insulin secretion in islets. These results reveal a non-redundant role for SYT8 in insulin secretion and indicate that the INS promoter acts from a distance to stimulate SYT8 transcription. This suggests a function for the INS promoter in coordinating insulin transcription and secretion through long-range regulation of SYT8 expression in human islets. Circular Chromosome Conformation Capture (4C)-Seq experiments to profile interactions of INS promoter in human pancreatic islets isolated from two donors: donor 1 and donor 2.
2011-02-22 | E-GEOD-25862 | biostudies-arrayexpress
Project description:The short chain fatty acid (SCFA) receptor (free fatty acid receptor-3; FFAR3) is expressed in pancreatic beta cells; however, its role in insulin secretion is not clearly defined. Here, we examined the role of FFAR3 in insulin secretion. Using islets from global knockout FFAR3 (Ffar3-/-) mice, we explored the role of FFAR3 and ligand-induced FFAR3 signaling on glucose stimulated insulin secretion. RNA sequencing was also performed to gain greater insight into the impact of FFAR3 deletion on the islet transcriptome. First exploring insulin secretion, it was determined that Ffar3-/- islets secrete more insulin in a glucose-dependent manner as compared to wildtype (WT) islets. Next, exploring its primary endogenous ligand, propionate, and a specific agonist for FFAR3, signaling by FFAR3 inhibited glucose-dependent insulin secretion, which occurred through a Gαi/o pathway. To help understand these results, transcriptome analyses by RNA-sequencing of Ffar3-/- and WT islets observed multiple genes with well known roles in islet biology to be altered by genetic knockout of FFAR3. Our data shows that FFAR3 signaling mediates glucose stimulated insulin secretion through Gαi/o sensitive pathway. Future studies are needed to more rigorously define the role of FFAR3 by in vivo approaches. Analysis of total RNA from 3 biological replicates of pancreatic islets isolated from free fatty acid receptor 3 knockout (Ffar3 KO) and wildtype (Ffar3 WT) male mice
2016-07-03 | E-GEOD-67991 | biostudies-arrayexpress
Project description:The goal: Investigate NeuroD function in the mature beta cells. The model: Cross RIP-Cre to NeuroD flox/flox mouse to delete neuroD when insulin gene is activated; The methods: Islets are purified and RNA is extracted to see how the profile of gene expression is altered after neuroD is deleted from the beta cells. The comparison: Compare control with mutant; The hypothesis: Since neuroD is deleted, I would expect that neuroD mRNA will be decreased in the mutant samples; The samples: two types of samples will be submitted including control and conditional knockout (mutant); Flox/+,Ins (F/+,I) is the control and labled as group B; and Flox/-,Ins (F/-,I) is the conditional knockout and labled as group A
2010-03-03 | E-MTAB-152 | biostudies-arrayexpress
Project description:Type 2 diabetes mellitus (T2DM) is a multi-factorial disease characterized by the inability of beta-cells in the endocrine pancreas to produce sufficient amounts of insulin to overcome insulin resistance in peripheral tissue. To investigate the function of miRNAs in T2DM, we sequenced the small RNAs of human islets cells from diabetic and non-diabetic organ donors and identified a cluster of miRNAs in an imprinted locus on human chromosome 14 to be dramatically down-regulated in T2DM islets. These miRNAs are highly and specifically expressed in human beta-cells. The down-regulation of this imprinted locus strongly correlates with increased methylation of its promoter in T2DM islets, providing evidence for an epigenetic modification that contributes to the pathogenesis of T2DM. Targets of the Chr 14q32 cluster of miRNAs were identified by high-throughput sequencing of cross-linked and immunoprecipitated RNA (HITS-CLIP) of Argonaute. We have also identified a unique class of sequences, termed chimeric reads, that represent an in vivo ligation of miRNAs and their targets while in complex with Argonaute, and which allow for the direct identification of miRNA:target relationships in vivo. There are three experiments in this submission. All are in human islets or islet cell types. The first is a comparison of miRNA levels in sorted alpha versus beta cells. There is one replicate for this experiment. The second experiment is to measure the expression of miRNAs in whole islets as a function of glucose levels. There are three levels and one replicate for each condition. The third exeriment is a comparison of whole islets taken from human donors that were suspected/confirmed Type 2 diabetic or considered controls. There are 3 controls and 4 T2D samples.
2013-12-01 | E-GEOD-52314 | biostudies-arrayexpress
Project description:The study was completed to compare expression profiles of primary human beta cells (in the form of adult human islets), to the expression profile of hESC-derived beta-like cells. A HES3 line modified by homologous recombination to express GFP under the insulin promoter allowed us to FACS sort the hESC-derived cells into purified insulin-positive (presumably beta-like cells), and insulin-negative populations. Expression profile of adult human islets from cadaveric donors is compared to insulin-positive and insulin-negative populations of hESC-derived beta-like cells
2012-09-09 | E-GEOD-40709 | biostudies-arrayexpress