| 1. |
- Eliasson, Lena, et al.
(author)
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PKC-dependent stimulation of exocytosis by sulfonylureas in pancreatic beta cells
- 1996
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In: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 271:5250, s. 813-815
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Journal article (peer-reviewed)abstract
- Hypoglycemic sulfonylureas represent a group of clinically useful antidiabetic compounds that stimulate insulin secretion from pancreatic beta cells. The molecular mechanisms involved are not fully understood but are believed to involve inhibition of potassium channels sensitive to adenosine triphosphate (KATP channels) in the beta cell membrane, causing membrane depolarization, calcium influx, and activation of the secretory machinery. In addition to these effects, sulfonylureas also promoted exocytosis by direct interaction with the secretory machinery not involving closure of the plasma membrane KATP channels. This effect was dependent on protein kinase C (PKC) and was observed at therapeutic concentrations of sulfonylureas, which suggests that it contributes to their hypoglycemic action in diabetics.
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| 2. |
- Rigal, Sophie, et al.
(author)
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Normoglycemia and physiological cortisone level maintain glucose homeostasis in a pancreas-liver microphysiological system
- 2024
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In: Communications Biology. - : NATURE PORTFOLIO. - 2399-3642. ; 7:1
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Journal article (peer-reviewed)abstract
- Current research on metabolic disorders and diabetes relies on animal models because multi-organ diseases cannot be well studied with standard in vitro assays. Here, we have connected cell models of key metabolic organs, the pancreas and liver, on a microfluidic chip to enable diabetes research in a human-based in vitro system. Aided by mechanistic mathematical modeling, we demonstrate that hyperglycemia and high cortisone concentration induce glucose dysregulation in the pancreas-liver microphysiological system (MPS), mimicking a diabetic phenotype seen in patients with glucocorticoid-induced diabetes. In this diseased condition, the pancreas-liver MPS displays beta-cell dysfunction, steatosis, elevated ketone-body secretion, increased glycogen storage, and upregulated gluconeogenic gene expression. Conversely, a physiological culture condition maintains glucose tolerance and beta-cell function. This method was reproducible in two laboratories and was effective in multiple pancreatic islet donors. The model also provides a platform to identify new therapeutic proteins, as demonstrated with a combined transcriptome and proteome analysis. A human-cell-based pancreas-liver microphysiological system serves as a preclinical platform for studying glucose-insulin homeostasis and disease mechanisms of glucose dysregulation, offering a tool for identifying targets and testing drugs.
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