title: Sirt1 and mir-9 expression is regulated during glucose-stimulated insulin secretion in pancreatic β-islets.
abstract: MicroRNA mir-9 is speculated to be involved in insulin secretion because of its ability to regulate exocytosis. Sirt1 is an NAD-dependent protein deacetylase and a critical factor in the modulation of cellular responses to altered metabolic flux. It has also been shown recently to control insulin secretion from pancreatic β-islets. However, little is known about the regulation of Sirt1 and mir-9 levels in pancreatic β-cells, particularly during glucose-dependent insulin secretion. In this article, we report that mir-9 and Sirt1 protein levels are actively regulated in vivo in β-islets during glucose-dependent insulin secretion. Our data also demonstrates that mir-9 targets and regulates Sirt1 expression in insulin-secreting cells. This targeting is relevant in pancreatic β-islets, where we show a reduction in Sirt1 protein levels when mir-9 expression is high during glucose-dependent insulin secretion. This functional interplay between insulin secretion, mir-9 and Sirt1 expression could be relevant in diabetes. It also highlights the crosstalk between an NAD-dependent protein deacetylase and microRNA in pancreatic β-cells.
authors.affiliation: Department of Biological Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India.
authors.forename: Deepti
authors.initials: D
authors.lastname: Ramachandran
authors.forename: Upasana
authors.initials: U
authors.lastname: Roy
authors.forename: Swati
authors.initials: S
authors.lastname: Garg
authors.forename: Sanchari
authors.initials: S
authors.lastname: Ghosh
authors.forename: Sulabha
authors.initials: S
authors.lastname: Pathak
authors.forename: Ullas
authors.initials: U
authors.lastname: Kolthur-Seetharam
mesh_terms: D000818:Animals; D001483:Base Sequence; D005786:Gene Expression Regulation; D005947:Glucose / Q000494:pharmacology*; D057809:HEK293 Cells; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism* / Q000502:physiology; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D041681:NIH 3T3 Cells; D016415:Sequence Alignment; D056564:Sirtuin 1 / Q000235:genetics / Q000378:metabolism*
chemical_list: D007328:Insulin; C551804:MIRN9 microRNA, mouse; D035683:MicroRNAs; D056564:Sirtuin 1; D005947:Glucose