title: Fluid-shear-stress-induced translocation of aquaporin-2 and reorganization of actin cytoskeleton in renal tubular epithelial cells.
abstract: In vivo, renal tubular epithelial cells are exposed to luminal fluid shear stress (FSS) and a transepithelial osmotic gradient. In this study, we used a simple collecting-duct-on-a-chip to investigate the role of an altered luminal microenvironment in the translocation of aquaporin-2 (AQP2) and the reorganization of actin cytoskeleton (F-actin) in primary cultured inner medullary collecting duct (IMCD) cells of rat kidney. Immunocytochemistry demonstrated that 3 h of exposure to luminal FSS at 1 dyn cm(-2) was sufficient to induce depolymerization of F-actin in those cells. We observed full actin depolymerization after 5 h exposure and substantial re-polymerization within 2 h of removing the luminal FSS, suggesting that the process is reversible and the fluidic environment regulates the reorganization of intracellular F-actin. We demonstrate that several factors (i.e., luminal FSS, hormonal stimulation, transepithelial osmotic gradient) collectively exert a profound effect on the AQP2 trafficking in the collecting ducts, which is associated with actin cytoskeletal reorganization.
authors.affiliation: Interdisciplinary Program in Nano-Science and Technology, Seoul National University, Seoul, Korea. sky4u@snu.ac.kr
authors.forename: Kyung-Jin
authors.initials: KJ
authors.lastname: Jang
authors.forename: Hye Sung
authors.initials: HS
authors.lastname: Cho
authors.forename: Do Hyun
authors.initials: DH
authors.lastname: Kang
authors.forename: Won Gyu
authors.initials: WG
authors.lastname: Bae
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Kwon
authors.forename: Kahp-Yang
authors.initials: KY
authors.lastname: Suh
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D051399:Aquaporin 2 / Q000378:metabolism*; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D007150:Immunohistochemistry; D007685:Kidney Tubules, Collecting / Q000166:cytology / Q000378:metabolism*; D046210:Microfluidic Analytical Techniques / Q000379:methods; D021381:Protein Transport; D051381:Rats; D013314:Stress, Mechanical
chemical_list: D000199:Actins; D051399:Aquaporin 2