Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Single-cell RNA sequencing enables transcriptomic analysis of iPSC-derived beta-cells in a model of neonatal diabetes caused by insulin mutations.

ABSTRACT: Insulin gene mutations are a leading cause of neonatal diabetes. They can lead to proinsulin misfolding and its retention in endoplasmic reticulum (ER). This results in increased ER-stress suggested to trigger beta-cell apoptosis. In humans, the mechanisms underlying beta-cell failure remain unclear. Here we show that misfolded proinsulin impairs developing beta-cell proliferation without increasing apoptosis. We generated iPSCs from diabetics carrying insulin mutations, engineered isogenic CRISPR-Cas9 mutation-corrected lines and differentiated them to beta-like cells using a 3D-suspension differentiation protocol. Single-cell RNA-sequencing analysis showed increased ER-stress and reduced proliferation in INS-mutant beta-like cells compared with corrected controls. Upon transplantation to mice, INS-mutant grafts presented reduced insulin secretion and aggravated ER-stress. Cell size, mTORC1 signaling, and respiratory chain subunit expression were all reduced in INS-mutant beta-like cells, yet apoptosis was not increased at any stage. Our results demonstrate that neonatal diabetes-associated INS-mutations lead to defective beta-cell mass expansion, contributing to diabetes development.

ORGANISM(S): Homo sapiens

PROVIDER: GSE115257 | GEO | 2018/12/01

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Progressive ER stress over time due to human insulin gene mutation contributes to pancreatic β-cell dysfunction, islet inflammation and compensatory responses

Project description:Heterozygous human INS gene mutations are known to promote ER stress, leading to β-cell dysfunction and neonatal diabetes. Recent literature challenged the long-standing notion that neonatal diabetes occurs due to ER stress-induced β-cell apoptosis. Importantly, mechanisms of β-cell failure during the disease progression and why the other wild-type (WT) INS allele is unable to function still remain unclear. Here, our computational modelling studies, short-term and long-term expression studies in β-cells revealed the presence of ER stress, organelle changes and insulin processing defects, resulting in decreased insulin secretion but not insulin secretory capacity. By nine weeks of expression of mutant INS, dominant negative effects of mutant INS were evident and β-cell insulin secretory capacity declined. INS+/C109Y patient-derived β-like cells and single cell RNA-Sequencing analyses then revealed compensatory upregulation in genes involved in insulin secretion, processing and inflammatory response. Our results provide deeper insights into the mechanisms of β-cell failure during INS mutation-mediated diabetes disease progression. Decreasing CHOP-10, sXBP1 or inflammatory response could be avenues to restore the function of the remaining WT INS allele.

2021-10-03 | GSE141319 | GEO

Pancreatic β cell SERCA2 deficiency leads to impaired proinsulin processing and reduced ER to Golgi protein trafficking

Project description:Impaired proinsulin processing is observed in both type 1 and type 2 diabetes. We have previously shown that reductions in endoplasmic reticulum (ER) calcium (Ca2+) in the pancreatic β cell arising from impaired activity of the Sarcoendoplasmic Reticulum Ca2+ ATPase (SERCA) pump are associated with increased proinsulin secretion. However, the mechanisms responsible for reduced proinsulin processing in the context of SERCA2 deficiency remain incompletely understood. To test this, we developed mice with β cell specific SERCA2 deletion (βS2KO mice) and S2KO INS1 cells. βS2KO mice exhibited age-dependent glucose intolerance and reduced glucose-stimulated insulin secretion without evidence of impaired insulin sensitivity. ER Ca2+ levels in islets from βS2KO mice were significantly reduced, while serum proinsulin/insulin (PI/I) ratios and whole pancreas PI/I content were elevated. Immunoblot analysis of βS2KO islets and S2KO INS-1 cells revealed reduced active forms of the proinsulin processing enzymes, PC1/3, PC2 and CPE. Restoration of SERCA2b via adenoviral transduction in S2KO INS1 cells was sufficient to restore PC1/3 and PC2 maturation and enzyme activity. Brefeldin A treatment in INS1 cells recapitulated the impairments in PC1/3 and PC2 maturation observed in S2KO cells, suggesting a disturbance in protein trafficking between the ER and Golgi. Consistent with this, trafficking assays were performed using a vesicular stomatitis virus G (VSVG) protein construct and revealed a significantly slower rate of VSVG movement from the ER to the Golgi in S2KO INS1 cells. Moreover, pancreas sections from βS2KO mice showed increased co-localization of proinsulin and ProPC2 in the early compartments of the secretory pathway. Taken together, these data suggest that loss of SERCA2 activity and ER Ca2+ loss in the pancreatic β cell leads to impaired proinsulin processing via reduced maturation and trafficking of proinsulin processing enzymes.

2023-10-11 | GSE207498 | GEO

Proinsulin degradation and presentation of a proinsulin B-chain autoantigen involves ER-associated protein degradation (ERAD)-enzyme UBE2G2

Project description:Type 1 diabetes (T1D) is characterized by HLA class I-mediated presentation of autoantigens on the surface of pancreatic β-cells. Recognition of these autoantigens by CD8¬¬+ T cells results in the destruction of pancreatic β-cells and, consequently, insulin deficiency. Most epitopes presented at the surface of β-cells derive from the insulin precursor molecule proinsulin. The intracellular processing pathway(s) involved in the generation of these peptides are poorly defined. In this study, we show that a proinsulin B-chain antigen (PPIB5-14) originates from proinsulin molecules that are processed by ER-associated protein degradation (ERAD) and thus originate from ER-resident proteins. Furthermore, screening genes encoding for E2 ubiquitin conjugating enzymes, we identified UBE2G2 to be involved in proinsulin degradation. These results indicate that insulin-derived peptides, presented by HLA-class I molecules at the cell surface, originate from ER-resident proinsulin that has been dislocated to the cytosol for subsequent degradation. These insights into the pathway involved in the generation of insulin-derived peptides emphasize the importance of proinsulin processing in the ER to T1D pathogenesis and identify novel targets for future therapies that may cure or even prevent T1D.

2024-03-20 | PXD049996 | Pride

Expression data of rat insulinoma cells induced with ER stress +/- IRE1 inhibitor treatment

Project description:The Akita mutation (C96Y) in the insulin gene results in early onset diabetes in both humans and mice. Expression of the mutant proinsulin (C96Y) causes endoplasmic reticulum (ER) stress in pancreatic ?-cells and consequently the cell activates the unfolded protein response (UPR). Since the proinsulin is terminally misfolded however, the ER stress is irremediable and chronic activation of the UPR eventually activates apoptosis in the cell population. We used microarray gene expression arrays to analyze the IRE1-dependent activation of genes in response to misfolded proinsulin expression in an inducible mutant proinsulin (C96Y) insulinoma cell line by inhibiting the IRE1 endoribonucleas activity with a specific inhibitor, 4u8c. Insulinoma cells with doxycycline inducible C96Y-proinsulin expression were either untreated, treated with doxycycline alone or treated with dox and 4u8c. This was done with two biological replicates.

2014-07-16 | E-GEOD-58866 | biostudies-arrayexpress

Proteomics analysis of rough endoplasmic reticulum in pancreatic beta cells

Project description:Pancreatic beta cells have well-developed endoplasmic reticulum (ER) to accommodate for the massive production and secretion of insulin. ER homeostasis is vital for normal beta cell function. Perturbation of ER homeostasis contributes to beta cell dysfunction in both type 1 and type 2 diabetes. To systematically identify the molecular machinery responsible for proinsulin biogenesis and maintenance of beta cell ER homeostasis, a widely used mouse pancreatic beta cell line, MIN6 cell was used to purify rough ER. Two different purification schemes were utilized. In each experiment, the ER pellets were solubilized and analyzed by one dimensional SDS-PAGE coupled with HPLC-MS/MS. A total of 1467 proteins were identified in three experiments with ≥95% confidence, among which 1117 proteins were found in at least two separate experiments. Gene ontology analysis revealed a comprehensive profile of known and novel players responsible for proinsulin biogenesis and ER homeostasis. This dataset defines a molecular environment in the ER for proinsulin synthesis, folding and export and laid a solid foundation for further characterizations of altered ER homeostasis under diabetes-causing conditions.

2015-04-15 | PXD001081 | Pride

Expression data of rat insulinoma cells induced with ER stress +/- IRE1 inhibitor treatment

Project description:The Akita mutation (C96Y) in the insulin gene results in early onset diabetes in both humans and mice. Expression of the mutant proinsulin (C96Y) causes endoplasmic reticulum (ER) stress in pancreatic -cells and consequently the cell activates the unfolded protein response (UPR). Since the proinsulin is terminally misfolded however, the ER stress is irremediable and chronic activation of the UPR eventually activates apoptosis in the cell population. We used microarray gene expression arrays to analyze the IRE1-dependent activation of genes in response to misfolded proinsulin expression in an inducible mutant proinsulin (C96Y) insulinoma cell line by inhibiting the IRE1 endoribonucleas activity with a specific inhibitor, 4u8c.

2014-07-16 | GSE58866 | GEO

Identify proinsulin regulators using CRISPR screen and mouse genetics [CRISPR screen]

Project description:Proinsulin is the precursor of insulin in pancreatic beta cells. Altered proinsulin and proinsulin to insulin ratio mark beta cell dysfunction, predictuing disease progression into type 1 and type 2 diabetes. Of essential role for beta cell function, knowledge about proinsulin production and its role in disease are currently very limited. Using genome wide CRISPR screen, we identified 84 proinsulin regulators including classical protein convertases Pcsk1 and Cpe, and novel factors like Pdia6. Among the list 29 proinsulin regulators were trajectory genes involved in disease progression in obesity and type 2 diabetes in humans. In vivo mouse genetics study revealed unique genetic architecture and quantitative trait loci (QTLs) modulating plasma proinsulin levels. Integrative analyzing and mapping of the QTL signals directly pinpointed to proinsulin regulators identified from the CRISPR screen, which in return greatly improved resolution of the mouse genetic study. 4 out of 5 overlapped genes can be individually validated. Knocking down the leading hits Pdia6 leads to decreased proinsulin content and remarkable loss of proinsulin granules in beta cells. Consequently, proinsulin secretion was greatly decreased. Mechanistically, protein translation rate was greatly impaired after knocking down Pdia6. Our study demonstrated the power of combining in vitro functional genomics with in vivo mouse genetics study to identify proinsulin regulatory network in pancreatic beta cells.

2023-11-15 | GSE245845 | GEO

Identify proinsulin regulators using CRISPR screen and mouse genetics [RNA-Seq]

2023-11-15 | GSE245844 | GEO

Transcription profiling of rat insulinoma-beta (INS-1E) cells exposed to the cytokines IL-1-beta and IFN-gamma for six different lengths of time and with or without the inducible NO synthase blocker NMA

Project description:Locally released cytokines contribute to beta cell dysfunction and apoptosis in Type 1 diabetes. In vitro exposure of insulin producing INS-1E cells to the cytokines interleukin (IL)-1beta + interferon (IFN) gamma leads to a significant increase in apoptosis. To characterize the genetic networks implicated in beta cell dysfunction and apoptosis and its dependence on nitric oxide (NO) production, we performed a time course analysis using the Affymetrix RG U34A microarry. INS-1E cells were exposed in duplicate to IL-1beta + IFN-gamma for six different time points (1, 2, 4, 8, 12, and 24 h) with or without the inducible NO synthase blocker.

2006-06-14 | E-CBIL-10 | biostudies-arrayexpress

Saturated fatty acids promotes β-cell toxicity by disabling intracellular lipid droplet formation through S-acylation of FIT2

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

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data