Gene expression data of islets from WT and βRapKO mice
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE84404 | GEO | 2016/07/15
SECONDARY ACCESSION(S): PRJNA329108
REPOSITORIES: GEO
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Project description:The mechanistic target of rapamycin mTORC1 is a key regulator of cell metabolism and autophagy. Despite widespread clinical use of mTOR inhibitors, the role of mTORC1 in renal tubular function and kidney homeostasis remains elusive. By utilizing constitutive and inducible deletion of conditional Raptor alleles in renal tubular epithelial cells, we discovered that mTORC1 deficiency caused a marked concentrating defect, loss of tubular cells and slowly progressive renal fibrosis. Transcriptional profiling revealed that mTORC1 maintains renal tubular homeostasis by controlling mitochondrial metabolism and biogenesis as well as transcellular transport processes involved in counter-current multiplication and urine concentration. Although mTORC2 partially compensated the loss of mTORC1, exposure to ischemia and reperfusion injury exaggerated the tubular damage in mTORC1-deficient mice, and caused pronounced apoptosis, diminished proliferation rates and delayed recovery. These findings identify mTORC1 as an essential regulator of tubular energy metabolism and as a crucial component of ischemic stress responses. Pharmacological inhibition of mTORC1 likely affects tubular homeostasis, and may be particularly deleterious if the kidney is exposed to acute injury. Furthermore, the combined inhibition of mTORC1 and mTORC2 may increase the susceptibility to renal damage. Raptor fl/fl*KspCre and Raptor fl/fl animals were sacrificed at P14 before the development of an overt functional phenotype. Kidneys were split in half and immediately snap frozen in liquid nitrogen.
2014-06-09 | E-GEOD-54417 | biostudies-arrayexpress
Project description:Maternal low-protein diet increases the susceptibility of offspring to type 2 diabetes. An insult to the pancreas during development can have long-term consequences on β-cell mass and function. Because nutrients and growth factors signaling converge on mTOR, we hypothesized that mTOR plays a central role in β-cell programming during fetal development. In this study, we revealed that newborns of dams exposed to low-protein diet (LP0.5) throughout pregnancy exhibited decreased insulin levels, β-cell fraction, and mTOR signaling. Adult LP0.5 offspring demonstrated enhanced insulin sensitivity but remained glucose intolerant due to an insulin secretory defect and not reduced β-cell mass. The insulin secretory defect was distal to Ca2+ influx, at the level of proinsulin biosynthesis and insulin content. LP0.5 islets exhibited reduced mTOR protein and increased expression of specific microRNAs. The reductions in mTOR protein and insulin secretion in LP0.5 islets were restored to normal by blockade of microRNAs 199a-3p and 342. Finally, transient activation of mTORC1 signaling in β-cells during the last week of pregnancy rescued the neonatal β-cell fraction defect and metabolic abnormalities in LP0.5 mice. These findings identify a major role of microRNAs and mTOR in β-cell programing by maternal low-protein diet. To investigate which microRNAs are altered in islets isolated from 2-3 months old male offspring of dams fed low-protein diet (LP0.5) or control diet throughout pregnancy
2014-07-11 | GSE59279 | GEO
Project description:Raptor deficient mice showed diabetic phenotype, to dissect the effect of hyperglycemia, we isolated euglycemic 2-week-old β cells to perform microarray. To determine the influence of Raptor deficiency on β cells independent of hyperglycemia, we hace employed whole transcriptome expression profiling as a discovery platform to identify differentially expressed genes compared with wild type controls. We isolated mice islets, then disgested them into single cells by 0.25% EDTA, and sorted for GFP by FACS.
2020-03-05 | GSE140224 | GEO
Project description:Pancreatic islet endocrine cell and endothelial cell (EC) interactions mediated by vascular endothelial growth factor-A (VEGF-A) signaling are important for islet endocrine cell differentiation and the formation of highly vascularized islets. To dissect how VEGF-A signaling modulates intra-islet vasculature and innervation, islet microenvironment, and β cell mass, we transiently increased VEGF-A production by β cells. VEGF-A induction dramatically increased the number of intra-islet ECs but led to β cell loss. After withdrawal of the VEGF-A stimulus, β cell mass, function, and islet structure normalized as a result of a robust, but transient, burst in proliferation of pre-existing β cells. Bone marrow-derived macrophages (MΦs) recruited to the site of β cell injury were crucial for the β cell proliferation, which was independent of pancreatic location and circulating factors such as glucose. Identification of the signals responsible for the proliferation of adult, terminally differentiated β cells will improve strategies aimed at β cell regeneration and expansion. Examination of RNA profiles from isolated whole islets from RIP-rtTA; TetO-VEGF-A mice with no doxycycline (Dox) treatment (3 samples) and after 1 week of Dox (3 sample); and islet-derived macrophages (3 samples) and endothelial cells (3 samples) isolated from dispersed purified islets from RIP-rtTA; TetO-VEGF-A mice after 1 week Dox treatment by fluorescence-activated cell sorting using antibodies against CD11b and CD31, respectively.
2015-09-01 | E-GEOD-72546 | biostudies-arrayexpress
Project description:Naïve T cells respond to antigen stimulation by exiting from quiescence into clonal expansion and functional differentiation, but the control mechanism is elusive. Here we describe that Raptor/mTORC1-dependent metabolic reprogramming is a central determinant of this transitional process. Loss of Raptor abrogates T cell priming and Th2 cell differentiation, although Raptor function is less important for continuous proliferation of actively cycling cells. mTORC1 coordinates multiple metabolic programs in T cells including glycolysis, lipid synthesis and oxidative phosphorylation to mediate antigen-triggered exit from quiescence. mTORC1 further links glucose metabolism to the initiation of Th2 differentiation by orchestrating cytokine receptor expression and cytokine responsiveness. Activation of Raptor/mTORC1 integrates T cell receptor (TCR) and CD28 co-stimulatory signals in antigen-stimulated T cells. Our studies identify a Raptor/mTORC1-dependent pathway linking signal-dependent metabolic reprogramming to quiescence exit, and this in turn coordinates lymphocyte activation and fate decisions in adaptive immunity. We used microarrays to explore the gene expression profiles differentially expressed in CD4+ T-cells from wild-type (WT) and CD4(cre) x Raptor(fl/fl) mice before and after stimulation with anti CD3/CD28 antibodies.
2014-01-27 | E-GEOD-51668 | biostudies-arrayexpress
Project description:The mechanistic target of rapamycin (mTOR) pathway integrates diverse environmental inputs, including immune signals and metabolic cues, to direct T cell fate decisions1. Activation of mTOR, comprised of mTORC1 and mTORC2 complexes, delivers an obligatory signal for proper activation and differentiation of effector CD4+ T cells2,3, whereas in the regulatory T cell (Treg) compartment, the Akt-mTOR axis is widely acknowledged as a crucial negative regulator of Treg de novo differentiation4-8 and population expansion9. However, whether mTOR signaling affects the homeostasis and function of Tregs remains largely unexplored. Here we show that mTORC1 signaling is a pivotal positive determinant of Treg function. Tregs have elevated steady-state mTORC1 activity compared to naïve T cells. Signals via T cell receptor (TCR) and IL-2 provide major inputs for mTORC1 activation, which in turn programs suppressive function of Tregs. Disruption of mTORC1 through Treg-specific deletion of the essential component Raptor leads to a profound loss of Treg suppressive activity in vivo and development of a fatal early-onset inflammatory disorder. Mechanistically, Raptor/mTORC1 signaling in Tregs promotes cholesterol/lipid metabolism, with the mevalonate pathway particularly important for coordinating Treg proliferation and upregulation of suppressive molecules CTLA-4 and ICOS to establish Treg functional competency. In contrast, mTORC1 does not directly impact the expression of Foxp3 or anti- and pro-inflammatory cytokines in Tregs, suggesting a non-conventional mechanism for Treg functional regulation. Lastly, we provide evidence that mTORC1 maintains Treg function partly through inhibiting the mTORC2 pathway. Our results demonstrate that mTORC1 acts as a fundamental ‘rheostat’ in Tregs to link immunological signals from TCR and IL-2 to lipogenic pathways and functional fitness, and highlight a central role of metabolic programming of Treg suppressive activity in immune homeostasis and tolerance. We used microarrays to explore the gene expression profiles differentially expressed in regulatory T-cells from wild-type and CD4(cre) x Raptor(fl/fl) mice
2013-06-24 | E-GEOD-46693 | biostudies-arrayexpress
Project description:Maternal low-protein diet increases the susceptibility of offspring to type 2 diabetes. An insult to the pancreas during development can have long-term consequences on ?-cell mass and function. Because nutrients and growth factors signaling converge on mTOR, we hypothesized that mTOR plays a central role in ?-cell programming during fetal development. In this study, we revealed that newborns of dams exposed to low-protein diet (LP0.5) throughout pregnancy exhibited decreased insulin levels, ?-cell fraction, and mTOR signaling. Adult LP0.5 offspring demonstrated enhanced insulin sensitivity but remained glucose intolerant due to an insulin secretory defect and not reduced ?-cell mass. The insulin secretory defect was distal to Ca2+ influx, at the level of proinsulin biosynthesis and insulin content. LP0.5 islets exhibited reduced mTOR protein and increased expression of specific microRNAs. The reductions in mTOR protein and insulin secretion in LP0.5 islets were restored to normal by blockade of microRNAs 199a-3p and 342. Finally, transient activation of mTORC1 signaling in ?-cells during the last week of pregnancy rescued the neonatal ?-cell fraction defect and metabolic abnormalities in LP0.5 mice. These findings identify a major role of microRNAs and mTOR in ?-cell programing by maternal low-protein diet. To investigate which microRNAs are altered in islets isolated from 2-3 months old male offspring of dams fed low-protein diet (LP0.5) or control diet throughout pregnancy Pancreatic islets were isolated from 2-3 months old male offspring of dams fed low-protein diet (LP0.5) or control diet throughout pregnancy. Islets were isolated by collagenase digestion. The pancreas was perfused via the common duct with 1 mg/ml collagenase XI (Sigma-Aldrich) in HBSS (Life Technologies). Pancreatic digestion was carried out at 37 °C for 15 min, after which cold HBSS with 2.5% FBS (Life Technologies) was added. The suspension was centrifuged at 1000 rpm for 30s, washed 3 times with HBSS with 2.5% FBS, resuspended in RPMI complete media (RPMI 1640 with 5 mM Glucose, 10% FBS,100 IU/ml penicillin, 100 g/ml streptomycin) and poured onto a 70 µm cell strainer (BD Falcon, BD Biosciences). Islets were rinsed and handpicked. Islets were allowed to recover overnight in RPMI complete media before RNA isolation using MirVana Kit (Life Technologies).
2014-07-11 | E-GEOD-59279 | biostudies-arrayexpress
Project description:Complex molecular mechanisms ensure cellular homeostasis between nutrient sensing and energy metabolism. Strong evidence from many laboratories supports a role for the hexosamine biosynthetic pathway (HBP) and its end product, UDP-GlcNAc, as important nutrient sensors. Isotopic photocleavable tagging for O-GlcNAc profiling (isoPTOP) was performed for quantitative and site specific identification of O-GlcNAcylation upon glucose mediated nutrient fluctuation. Mammalian target of Rapamycin complex 1（mTORC1）is a metabolic hub, which can sense the availability of various nutrients. We found that Raptor, the scaffold of the mTORC1 complex, is O-GlcNAcylated at T700. Our finding provides a novel mechanism that UDP-GlcNAc mediates glucose signal to mTORC1 by O-GlcNAcylating Raptor at T700 to regulate mTORC1 activity and cell growth.
2023-08-03 | PXD039536 | Pride
Project description:During pregnancy, pancreatic islets undergo structural and functional changes that lead to enhance insulin release in response to increased insulin demand, which is rapidly reversed at parturition. One of the most important changes is expansion of pancreatic β-cell mass mainly by increased proliferation of β cells. We used microarrays to detail the global programme of gene expression and identified distinct up- or down-regulated genes during pregnancy.
2010-06-04 | GSE22125 | GEO
Project description:Pathways that stimulate β-cell regeneration remain of great clinical interest, yet effective therapeutic avenues that promote survival or reconstitution of β-cell mass remain elusive. Utilizing a mouse model with inducible β-cell apoptosis followed by adiponectin-mediated regeneration, we aimed to identify key molecules boosting β-cell viability. Within the regenerating pancreatic islets, we examined changes within the transcriptome, and observed an extensive upregulation of genes encoding proteins involved in lipid transport and metabolism. The most prominent targets were further confirmed by quantitative PCR and immunofluorescence. Among the upstream regulators predicted by pathway analysis of the transcriptome, we detected enhanced levels of two key transcription factors, HNF4α and PPARα. Enhanced leptin levels in circulation may also contribute to the anti-lipotoxic program in islets. In summary, our data suggest that improving local lipid metabolism as an important anti-lipotoxic phenomenon to boost β-cell regeneration, primarily mediated by adiponectin’s action on the β-cells directly as well as on the adipocyte. RNA profiles of pancreatic islets isolated from PANIC-ATTAT mice crossed with adiponectin wild-type (P-Adn+/+) or the overexpressing transgene (P-AdnTg/+) at 5 weeks after initial dimerizer administration.
2015-01-09 | E-GEOD-64787 | biostudies-arrayexpress