title: Involvement of RhoA/ROCK in insulin secretion of pancreatic β-cells in 3D culture.
abstract: Cell-cell contacts and interactions between pancreatic β-cells and/or other cell populations within islets are essential for cell survival, insulin secretion, and functional synchronization. Three-dimensional (3D) culture systems supply the ideal microenvironment for islet-like cluster formation and functional maintenance. However, the underlying mechanisms remain unclear. In this study, mouse insulinoma 6 (MIN6) cells were cultured in a rotating 3D culture system to form islet-like aggregates. Glucose-stimulated insulin secretion (GSIS) and the RhoA/ROCK pathway were investigated. In the 3D-cultured MIN6 cells, more endocrine-specific genes were up-regulated, and GSIS was increased to a greater extent than in cells grown in monolayers. RhoA/ROCK inactivation led to F-actin remodeling in the MIN6 cell aggregates and greater insulin exocytosis. The gap junction protein, connexin 36 (Cx36), was up-regulated in MIN6 cell aggregates and RhoA/ROCK-inactivated monolayer cells. GSIS dramatically decreased when Cx36 was knocked down by short interfering RNA and could not be reversed by RhoA/ROCK inactivation. Thus, the RhoA/ROCK signaling pathway is involved in insulin release through the up-regulation of Cx36 expression in 3D-cultured MIN6 cells.
authors.affiliation: Stem Cell and Regenerative Medicine Laboratory, Beijing Institute of Transfusion Medicine, Beijing, 100850, China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Liu
authors.forename: Fang
authors.initials: F
authors.lastname: Yan
authors.forename: Hailei
authors.initials: H
authors.lastname: Yao
authors.forename: Mingyang
authors.initials: M
authors.lastname: Chang
authors.forename: Jinhua
authors.initials: J
authors.lastname: Qin
authors.forename: Yali
authors.initials: Y
authors.lastname: Li
authors.forename: Yunfang
authors.initials: Y
authors.lastname: Wang
authors.forename: Xuetao
authors.initials: X
authors.lastname: Pei
mesh_terms: D000818:Animals; D018929:Cell Culture Techniques; D002460:Cell Line; D017630:Connexins / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D005947:Glucose / Q000494:pharmacology; D007091:Image Processing, Computer-Assisted; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D050417:Insulin-Secreting Cells / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism*; D051379:Mice; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*; D000097004:Gap Junction delta-2 Protein
chemical_list: D017630:Connexins; D005947:Glucose; D007328:Insulin; D047428:Protein Kinase Inhibitors; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein; D000097004:Gap Junction delta-2 Protein