title: Matrix-independent stimulation of human tubular epithelial cell migration by Rho kinase inhibitors.
abstract: Proximal tubular epithelial cells differ from other epithelial cells in the expression of N-cadherin as major adherens junction protein instead of E-cadherin. Migration of proximal epithelial cells (HKC-8) was analyzed by scratch wounding and by a barrier assay, which allowed determination of migration velocity on different extracellular matrices. Migration velocity was about threefold higher on fibronectin compared to collagen IV. The differential migration velocity was reflected by the orientation of F-actin stress fibers. TGF-beta activated secretion of fibronectin and thus increased migration on collagen IV, but did not further promote migration on fibronectin. Pharmacological inhibition of Rho kinases (ROCKs) by Y-27632, hydroxyfasudil and H-1152, or siRNA against ROCKs significantly increased migration velocity independently of the extracellular matrix. Cells at the migration front showed long filopodia, which could not be mimicked by overexpression of consitutively active Cdc42, indicative of a more complex regulation of F-actin structures. N-cadherin was reorganized from tight zipper-like structures into loosened cell-cell contacts upon incubation with Y-27632, but HKC-8 cells still migrated as cohort. Migration through single cell pores in a modified Boyden chamber assay was also stimulated by ROCK inhibitors. ROCK inhibitors enhanced migration of primary cultures of renal tubular cells which consisted of proximal and distal tubular cells expressing N-cadherin and E-cadherin, respectively. There was no indication of a switch in cadherin expression in these cells or a preferential migration of N-cadherin expressing cells. Pharmacologic inhibition of ROCKs may thus favor repair processes in renal tubules by increasing the migratory capacity of tubular epithelial cells.
authors.affiliation: Department of Nephrology and Hypertension, Medical Clinic 4, University Hospital of Erlangen, Erlangen, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Kroening
authors.forename: Jana
authors.initials: J
authors.lastname: Stix
authors.forename: Christof
authors.initials: C
authors.lastname: Keller
authors.forename: Cedric
authors.initials: C
authors.lastname: Streiff
authors.forename: Margarete
authors.initials: M
authors.lastname: Goppelt-Struebe
mesh_terms: D000199:Actins / Q000378:metabolism; D000577:Amides / Q000494:pharmacology; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects*; D048430:Cell Shape / Q000187:drug effects; D004847:Epithelial Cells / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D055785:Gene Knockdown Techniques; D006801:Humans; D007687:Kidney Tubules, Proximal / Q000166:cytology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors*
chemical_list: D000199:Actins; D000577:Amides; D015820:Cadherins; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D016212:Transforming Growth Factor beta; C108830:Y 27632; D054460:rho-Associated Kinases