Project description:Aging-related degeneration of pancreatic islet cells contributes to impaired glucose tolerance and diabetes. Endocrine cells age heterogeneously, complicating the effort to unravel the molecular drives underlying endocrine aging. To overcome these obstacles, we undertook single-cell RNA sequencing of pancreatic islet cells obtained from young and aged non-diabetic cynomolgus monkeys. Despite sex differences and increased single-cell level transcriptional variations, aged β-cells showed increased unfolded protein response (UPR) along with the accumulation of protein aggregates. We observed transcriptomic dysregulation of UPR components linked to canonical ATF6 and IRE1 signaling, comprising adaptive UPR during pancreatic aging. Notably, we found age-related β-cell-specific upregulation of HSP90B1, an ER-located chaperone, impeded high glucose-induced insulin secretion. Our work decodes aging-associated transcriptomic changes that underlie pancreatic islet functional decay at the single-cell resolution and indicates that targeting UPR components may prevent loss of proteostasis, suggesting an avenue for therapies to delay β-cell aging and prevent aging-related diabetes.
Project description:Mouse pancreatic islet scRNA-seq integrated atlas encompassing different ages, sexes, chemical stress leading to dedifferentiation, and diabetes models with corresponding treatments. Two datasets (sub-series) were newly generated for the atlas.
Project description:The aim of the present study was to explore the transcriptome of pancreatic islets and, based on this information, to prepare a comprehensive and open access inventory of insulin-producing ?-cell gene expression, the beta-Cell Gene Atlas (BCGA). INS-1 cells, primary rat beta-cells (>87% beta-cells) and non-beta-cells (<3% beta cells, mostly alpha) were isolated by FACS mediated purification of two different rat islet preparations.
Project description:comparison of mRNA expression in the islets of 3- and 12-month old male Wistar rats Aging is a risk factor for a majority of metabolic diseases including type 2 diabetes. During aging pancreatic beta-cell function decreases leading to impaired insulin secretion and proliferation and to an increase in apoptosis. Impairment of pancreatic beta cell functions and survival has been linked to gene expression changes. The aim of our study was to obtain a global expression profile of microRNAs and mRNAs of pancreatic islets of 3 and 12 month old male Wistar rats in order to identify the changes occurring during aging.
Project description:Molecular mechanisms of ovarian aging and female age-related fertility decline remain unclear. We surveyed the single-cell transcriptomic landscape of ovaries from young and aged non-human primates (NHPs) and identified seven ovarian cell types with distinct gene expression signatures, including oocyte and six types of ovarian somatic cells. In-depth dissection of gene expression dynamics of oocytes revealed four subtypes at sequential and stepwise developmental stages. Further analysis of cell type-specific aging-associated transcriptional changes uncovered the disturbance of antioxidant signaling specific to early-stage oocytes and granulosa cells, indicative of oxidative damage as a crucial factor in ovarian functional decline with age. Additionally, inactivated antioxidative pathways, increased reactive oxygen species and apoptosis were observed in granulosa cells from aged women. This study provides comprehensive understanding of the cell type-specific mechanisms underlying primate ovarian aging at single-cell resolution, revealing new diagnostic biomarkers and potential therapeutic targets for age-related human ovarian disorders.
Project description:comparison of microRNA expression in the islets of 3- and 12-months old male Wistar rats Aging is a risk factor for a majority of metabolic diseases including type 2 diabetes. During aging pancreatic beta-cell function decreases leading to impaired insulin secretion and proliferation and to an increase in apoptosis. Impairment of pancreatic beta cell functions and survival has been linked to gene expression changes. The aim of our study was to obtain a global expression profile of microRNAs and mRNAs of pancreatic islets of 3 and 12 month old male Wistar rats in order to identify the changes occurring during aging.
Project description:loss of Men1 in mouse pancreatic islet cells alters the epigenetic landscape of a subset of target genes. H3K4me3 ChIP-seq from either mouse pancreatic islets or mouse pancreatic islet tumors harvested at different stages.
Project description:Type 1 diabetes is an autoimmune destruction of pancreatic islet beta cell disease, and it is important to find new alternative source of the islet beta cells to replace the damaged cells. Human embryonic stem (hES) cells possess unlimited self-renewal and pluripotency and thus have the potential to provide an unlimited supply of different cell types for tissue replacement. The hES-T3 cells with normal female karyotype were first differentiated into embryoid bodies and then induced to generate the pancreatic islet-like cell clusters, which expressed pancreatic islet cell-specific markers of insulin, glucagon and somatostatin. The expression profiles of microRNAs and mRNAs from the pancreatic islet-like cell clusters were further analyzed and compared with those of undifferentiated hES-T3 cells and differentiated embryoid bodies. MicroRNAs negatively regulate the expression of protein-coding mRNAs. The pancreatic islet-like cell clusters were found to exhibit very high expression of microRNAs miR-186, miR-199a and miR-339, which down-regulated the expression of LIN28, PRDM1, CALB1, GCNT2, RBM47, PLEKHH1, RBPMS2 and PAK6. Therefore, these microRNAs are very likely to play important regulatory roles in the differentiation of pancreatic islet cells and early embryonic development. In this investigation, both miRNA and mRNA expression profiles from the pancreatic islet-like cell clusters differentiated from hES-T3 cells (T3pi) were quantitatively determined and compared with those of undifferentiated hES-T3 cells grown on mouse embryonic fibroblast (MEF) feeder (T3ES) and embryoid bodies differentiated from hES-T3 cells (T3EB). Several target genes of pancreatic islet cell-specific miRNAs were identified. ***This submission represents the mRNA expression component of the study only***