MiR-7a is regulated in beta-cell dysfunction and couples early and late stages of pancreatic beta-cell differentiation to insulin secretion
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE48195 | GEO | 2015/06/30
SECONDARY ACCESSION(S): PRJNA209133
REPOSITORIES: GEO
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Project description:Transcriptional and posttranscriptional regulatory networks play a crucial role in the maintenance and adaptation of pancreatic beta-cell function. In this study we show that the levels of the prototypic neuroendocrine miRNA-7 are regulated in islets of obese, diabetic and aged mouse models. Using gain- and loss-of-function models we demonstrate that miR-7 regulates crucial members of the endocrine pancreatic transcriptional network controlling differentiation and insulin synthesis. Importantly, it also directly regulates key proteins in the insulin granule secretory machinery. These results reveal an interconnecting miR-7 genomic circuit that influences beta-cell differentiation, insulin synthesis and release and define a role for miR-7 as an endocrine checkpoint to stabilize beta-cell function during metabolic stress. These findings have implications for miR-7 inhibitors as potential therapies for type 2 diabetes and neurodegenerative diseases. Either miR-7a2 or miR-7b were over-expressed in MIN6 cells using an adenoviral vector. The miR-7a infection was performed in duplicates. In addition, a GFP over-expression in MIN6 using the same viral vector served as control. We also explored the consequence of miR-7a2 deletion in pancreatic beta-cells by generating a beta-cells specific miR-7a2 knock-out using the Lox/Cre system in a C57BL/6 background. We profiled gene expression in mutant and wild-type (control) islets.
2015-06-30 | E-GEOD-48195 | biostudies-arrayexpress
Project description:Adult beta cells in the pancreas are the sole source of insulin in our body. Beta cell loss or increased demand for insulin, impose metabolic challenges because adult beta cells are generally quiescent and infrequently re-enter the cell division cycle. miR-17-92/106b is a family of proto-oncogene microRNAs, that regulate proliferation in normal tissues and in cancer. Here, we employ mouse genetics to demonstrate a critical role for miR-17-92/106b in glucose homeostasis and in controlling insulin secretion. Mass spectrometry analysis was performed on miR-17-92LoxP/LoxP;106-25-/- MEF lysate, without or with CRE-Adenovirus. miR-17-92LoxP/LoxP;106-25+/+ MEFs with GFP-Adenovirus served as controls. We demonstrate that miR-17-92/106b regulate the adult beta cell mitotic checkpoint and that miR-17-92/106b deficiency results in reduction in beta cell mass in-vivo. Furthermore, protein kinase A (PKA) is a new relevant molecular pathway downstream of miR-17-92/106b in control of adult beta cell division and glucose homeostasis. Therefore, contributes to the understanding of proto-oncogene miRNAs in the normal, untransformed endocrine pancreas, and illustrates new genetic means for regulation of beta cell mitosis and function by non-coding RNAs.
2019-06-17 | PXD012610 | Pride
Project description:Pancreatic β cell dysfunction greatly contributes to the pathogenesis of type 2 diabetes. MiR-21 has been shown to be induced in the islets of glucose intolerant patients and type 2 diabetic mice. However, the role of miR-21 in the regulation of pancreatic β cell function remains largely elusive. In the current study, we studied the pathway by which miR-21 regulates glucose-stimulated insulin secretion utilizing mice lacking miR-21 in their β cells (miR-21βKO). We found that miR-21βKO mice developed glucose intolerance due to impaired glucose-stimulated insulin secretion. Mechanistic studies revealed that miR-21 enhances glucose uptake and subsequently promotes insulin secretion by up-regulating Glut2 expression in a miR-21-Pdcd4-AP-1 dependent pathway. Over-expression of Glut2 in knockout islets resulted in rescue of the impaired glucose-stimulated insulin secretion. Furthermore, we demonstrated that delivery of miR-21 into the pancreas of type 2 diabetic db/db mice is able to promote Glut2 expression and significantly reduce blood glucose level. Taking together, our results reveal that miR-21 in islet β cell promotes insulin secretion and support a role for miR-21 in the adaptation of pancreatic β cell function in type 2 diabetes.
2022-05-16 | GSE191194 | GEO
Project description:β-cells are a type of endocrine cell found in pancreatic islets that synthesize, store and release insulin. Destruction of these cells in type 1 diabetes leads to a lifelong dependence on exogenous insulin administration for survival. Here we employ RNA-seq to examine the promotion of β-like cell regeneration with EZH2 inhibition in pancreatic ductal epithelial cells and exocrine cells isolated from type 1 diabetic donor tissue.
2024-01-10 | GSE247275 | GEO
Project description:Several miRNAs have tissue-specific patterns consistent with crucial functions in many biological processes and are candidate biomarkers of disease. Yet, there is limited knowledge about the role of pancreas-specific miRNAs in pancreatic pathologies. Here, we show that miR-216a is a conserved, pancreas-specific miRNA with important roles in pancreatic islet and acinar cells. By profiling miRNAs from human islets and subsequent systematic tissue analysis we found that miR-216a is highly enriched in endocrine and exocrine pancreas. Deletion of miR-216a in mice lead to a reduction in islet size, β-cell mass and insulin levels. RNA-sequencing indicated that cell cycle and proliferation were the most significantly regulated biological processes in miR-216 knockout pancreata. miR-216a was induced by TGF-β signalling and inhibition of miR-216a increased apoptosis and decreased cell proliferation in both β- and exocrine cells. Deletion of miR-216a in the pancreatic cancer prone mouse line Kras G12D ;Ptf1a CreER reduced the propensity of pancreatic cancer precursor lesions. Notably, circulating miR-216a levels were elevated in both mice and humans with pancreatic cancer. Collectively, our study gives insights into how β-cell mass and acinar cell growth are modulated by a pancreas-specific miRNA but also suggests miR-216a as a promising biomarker for diagnosis of pancreatic diseases.
2021-10-22 | GSE159970 | GEO
Project description:Several miRNAs have tissue-specific patterns consistent with crucial functions in many biological processes and are candidate biomarkers of disease. Yet, there is limited knowledge about the role of pancreas-specific miRNAs in pancreatic pathologies. Here, we show that miR-216a is a conserved, pancreas-specific miRNA with important roles in pancreatic islet and acinar cells. By profiling miRNAs from human islets and subsequent systematic tissue analysis we found that miR-216a is highly enriched in endocrine and exocrine pancreas. Deletion of miR-216a in mice lead to a reduction in islet size, β-cell mass and insulin levels. RNA-sequencing indicated that cell cycle and proliferation were the most significantly regulated biological processes in miR-216 knockout pancreata. miR-216a was induced by TGF-β signalling and inhibition of miR-216a increased apoptosis and decreased cell proliferation in both β- and exocrine cells. Deletion of miR-216a in the pancreatic cancer prone mouse line Kras G12D ;Ptf1a CreER reduced the propensity of pancreatic cancer precursor lesions. Notably, circulating miR-216a levels were elevated in both mice and humans with pancreatic cancer. Collectively, our study gives insights into how β-cell mass and acinar cell growth are modulated by a pancreas-specific miRNA but also suggests miR-216a as a promising biomarker for diagnosis of pancreatic diseases.
2021-10-22 | GSE159844 | GEO
Project description:The gastrointestinal (GI) epithelium is a highly regenerative tissue with the potential to provide a renewable source of insulin+ cells using cellular reprogramming. Here, we describe the antral stomach as a previously unrecognized source highly amenable to conversion into functional insulin-secreting cells. Native antral endocrine cells share a surprising degree of transcriptional similarity with pancreatic beta-cells. Expression of beta-cell reprogramming factors in vivo converts antral cells efficiently into insulin+ cells with close molecular and functional resemblance to beta-cells. Our data further indicate that the intestine-expressed Cdx2 acts as a molecular barrier for beta-cell conversion. Induced GI insulin+ cells can suppress hyperglycemia over at least 6 months and they regenerate rapidly after ablation from the native stem-cell compartment. Transplantation of bioengineered stomach mini-organs also produced insulin+ cells and suppressed hyperglycemia. These studies demonstrate the potential of developing engineered stomach tissue as a renewable source of functional beta-cells for glycemic control. Total RNA extracted from primary mouse tissues: Stomach (3 replicates), Duodenum (3 replicates) and Colon (2 replicates)
2016-01-09 | E-GEOD-76686 | biostudies-arrayexpress
Project description:Lifestyle intervention including exercise restores glucose homeostasis and pancreatic β-cell function in type 2 diabetes (T2D). However, exercise compliance is a challenge. Novel alternative or adjuvant approaches are necessary. During exercise, the contracting skeletal muscle acts as endocrine organ via the secretion and endocrine signaling of functional proteins. We postulated that contracting skeletal muscle secretes proteins that target pancreatic β-cells and regulate insulin secretion and glucose metabolism. To test this hypothesis, we used an in vitro cell-based skeletal muscle contraction system to uncover proteins released in the muscle secretome. Using an RNAseq screen, we identified growth differentiation factor 15 (GDF15) as a lead candidate. β-cells, human pancreatic islets, and C57BL/6J mice exposed to acute GDF15 treatment exhibited increased glucose-stimulated insulin secretion, and the mechanism involved activation of the insulin release pathway. Chronic GDF15 treatment in db/db mice reduced insulin resistance and preserved pancreatic PDX-1 expression. Consistently, plasma GDF15 increased concurrently with C-peptide prior to the onset of chronic hyperglycemia in humans with pre-diabetes. In addition, in humans with T2D, exercise-induced GDF15 was associated with enhanced β-cell function. These findings support GDF15 as a potential therapeutic target for type 2 diabetes and associated co-morbidities.
2022-10-31 | GSE139872 | GEO
Project description:Aims: establishment of reference samples to investigate gene expression selective for endocrine or ductal-exocrine cells within the adult human pancreas. To this end, human islet endocrine cells, FACS-enriched in insulin+ cells, (n=3) and human exocrine ductal cells (n=2) are compared on Affymetrix HG133A platform with duplicate hybridizations of a panel of other primary human tissues. The microarray analysis was performed on 3 pools of human beta cell-enriched cell fractions, isolated from 10 non-selected donor organs, and 2 pools of duct cell-enriched fractions obtained from 6 non-selected donor pancreases. The cells were suspension-cultured for 2-3 weeks along standard procedures and with no specific treatment prior to FACS-sorting and RNA extraction. The average composition of human beta cell-preparations was 55 ± 13% insulin+ cells, 13±8% glucagon+ cells and 21 ±7% non-granulated cells. Pancreatic duct cells-enriched preparations contained 85 ±7% cytokeratin 19+ cells with 4 ± 1% insulin+ cells and 6 ±4% glucagon+ cells and were isolated as described by Heimberg H. et al.( Diabetes 2001,49: 571-579 ). Pancreatic cell mRNA profiles were compared to those of a panel of other human primary tissues (n=2 biological replicates). This dataset is part of the TransQST collection.
2011-07-21 | E-GEOD-30803 | biostudies-arrayexpress
Project description:AIMS/HYPOTHESIS: Manoeuvres aimed at increasing beta cell mass have been proposed as regenerative medicine strategies for diabetes treatment. Raf-1 kinase inhibitor protein 1 (RKIP1) is a common regulatory node of the mitogen-activated protein kinase (MAPK) and nuclear factor κB (NF-κB) pathways and therefore may be involved in regulation of beta cell homeostasis. The aim of this study was to investigate the involvement of RKIP1 in the control of beta cell mass and function. METHODS: Rkip1 (also known as Pebp1) knockout (Rkip1 (-/-)) mice were characterised in terms of pancreatic and glucose homeostasis, including morphological and functional analysis. Glucose tolerance and insulin sensitivity were examined, followed by assessment of glucose-induced insulin secretion in isolated islets and beta cell mass quantification through morphometry. Further characterisation included determination of endocrine and exocrine proliferation, apoptosis, MAPK activation and whole genome gene expression assays. Capacity to reverse a diabetic phenotype was assessed in adult Rkip1 (-/-) mice after streptozotocin treatment. RESULTS: Rkip1 (-/-) mice exhibit a moderately larger pancreas and increased beta cell mass and pancreatic insulin content, which correlate with an overall improvement in whole body glucose tolerance. This phenotype is established in young postnatal stages and involves enhanced cellular proliferation without significant alterations in cell death. Importantly, adult Rkip1 (-/-) mice exhibit rapid reversal of streptozotocin-induced diabetes compared with control mice. CONCLUSIONS/INTERPRETATION: These data implicate RKIP1 in the regulation of pancreatic growth and beta cell expansion, thus revealing RKIP1 as a potential pharmacological target to promote beta cell regeneration. Pancreatic gene expression of Rkip-1 (Raf kinase inhibitor 1) knockout (KO) and wild type (WT) mice, including three biological replicates in each group.
2012-11-19 | E-GEOD-31150 | biostudies-arrayexpress