Project description:Our in vivo Insulin-rtTA;TET-DTA mouse model of severe hyperglycemia revealed that proloned exposure to very high glucose levels inhibits cell cycle entry and progression of pancreatic beta cells. To investigation of the molecular mechanisms responsible for this observation we performed ex vivo experiment on wild-type ICR mouse islets mimiking the in vivo conditions and subjected them to RNAseq analysis.
Project description:Our in vivo Insulin-rtTA;TET-DTA mouse model of severe hyperglycemia revealed that proloned exposure to very high glucose levels inhibits cell cycle entry and progression of pancreatic beta cells. To investigate the molecular mechanisms responsible for this observation and the relevance to human beta cells, we performed an in vitro experiment on EndoC-betaH2 mimiking the in vivo conditions and subjected them to RNAseq analysis.
Project description:The overall goal of this project is to identify transcriptome alteration in fetal islets exposed to transient maternal hyperglycemia from GD20 to GD22.
Project description:Hyperglycemia is an essential factor leading to micro- and macrovascular diabetic complications. Macrophages are key innate immune regulators of inflammation that undergo 2 major directions of functional polarization: classically (M1) and alternatively (M2) activated macrophages. The aim of the study was to examine the effect of hyperglycemia on transcriptional activation of M0, M1 and M2 human macrophages.
Project description:Objective: The loss of insulin-secreting β-cells, ultimately characterizing most diabetes forms, demands the development of cell replacement therapies. The common endpoint for all ex vivo strategies is transplantation into diabetic patients. However, the effects of hyperglycemia environment on the transplanted cells were not yet properly assessed. Thus, the main goal of this study was to characterize global effect of brief and prolonged in vivo hyperglycemia exposure on the cell fate acquisition and maintenance of transplanted human pancreatic progenitors. Methods: To rigorously study the effect of hyperglycemia, in vitro differentiated human induced pluripotent stem cells (hiPSC)-derived pancreatic progenitors were xenotransplanted in normoglycemic and diabetic NSG RIP-DTR mice. The transplants were retrieved after one-week or one-month exposure to overt hyperglycemia and analyzed by large-scale microscopy or global proteomics. For this study we pioneer the use of the NSG RIP-DTR system in the transplantation of hiPSC, making use of its highly reproducible specific and absolute β-cell ablation property in the absence of inflammation or other organ toxicity. Results: Here we show for the first time that besides the presence of an induced oxidative stress signature, the cell fate and proteome landscape response to hyperglycemia was different, involving largely different mechanisms, according to the period spent in the hyperglycemic environment. Surprisingly, brief hyperglycemia exposure increased the bihormonal cell number by impeding the activity of specific islet lineage determinants. Moreover it activated antioxidant and inflammation protection mechanisms signatures in the transplanted cells. In contrast, the prolonged exposure was characterized by decreased numbers of hormone+ cells, low/absent detoxification signature, augmented production of oxygen reactive species and increased apoptosis. Conclusion: Hyperglycemia exposure induced distinct, period-dependent, negative effects on xenotransplanted human pancreatic progenitor, affecting their energy homeostasis, cell fate acquisition and survival.
Project description:Transgenic mice were generated that expressed the inhibitor of apoptosis and mitotic regulator survivin in pancreatic islet beta cells. Control non-transgenic or transgenic islets were then used in a model of islet transplantation in diabetic recipient mice and tested for their ability to correct hyperglycemia and allow long-term engraftment of tranplanted islets in vivo. Control or transgenic islets were analyzed by chip microarray for potential transcriptional changes associated with transgenic expression of survivin, in vivo.
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.
Project description:In order to investigate the effect of in vitro hyperglycemia on gene expression of fpEC, cells were treated with hypergylcemia (25mM) for 24h.