Rho kinase blockade prevents inflammation via nuclear factor kappa B inhibition: evidence in Crohn's disease and experimental colitis.
OBJECTIVE
Rho proteins are involved in the regulation of several cellular functions. Data from in vitro studies suggest that RhoA could be involved in the inflammatory response. We investigated the role of RhoA and its downstream effector Rho kinase in intestinal inflammation.


METHODS
Activation of RhoA was assessed by pull-down assays. A specific inhibitor of Rho kinase, Y-27632, was used to examine the role of Rho kinase in inflammatory response in vivo and in vitro by molecular biology and by immunological and biochemical approaches.


RESULTS
Increased activation of RhoA was found in inflamed intestinal mucosa of patients with Crohn's disease and of rats with 2,4,6-trinitrobenzene sulfonic acid-induced colitis. Oral administration of Y-27632 in rats significantly reduced the colonic inflammation. In vitro, activation of RhoA alone was sufficient to induce tumor necrosis factor production. Y-27632 inhibited production of tumor necrosis factor-alpha and interleukin-1 beta by lamina propria and peripheral blood mononuclear cells. Rho kinase inhibition prevented nuclear factor kappa B activation and I-kappa B phosphorylation and degradation. We showed that Rho kinase associates with and activates I-kappa B kinase alpha and that Y-27632 prevents I-kappa B kinase activation.


CONCLUSIONS
Our study provides the first evidence that Rho kinase activates I-kappa B kinase and, thus, nuclear factor kappa B, suggesting a key role of Rho kinase in inflammatory responses and intestinal inflammation. Specific inhibition of Rho kinase may be a promising approach for the treatment of patients with Crohn's disease.
Segain
Jean-Pierre
JP
INSERM U-539, Department of Gastroenterology, and Centre d'Investigation Clinique, Centre Hospitalier Universitaire, Hotel Dieu, Nantes, France. Jean-Pierre.Segain@sante.univ-nantes.fr
Raingeard de la Blétière
Diane
D
Sauzeau
Vincent
V
Bourreille
Arnaud
A
Hilaret
Gréory
G
Cario-Toumaniantz
Chrystelle
C
Pacaud
Pierre
P
Galmiche
Jean-Paul
JP
Loirand
Gervaise
G
D000293:Adolescent; D000328:Adult; D000368:Aged; D000577:Amides / Q000008:administration & dosage*; D000818:Animals; D002478:Cells, Cultured; D003092:Colitis / Q000188:drug therapy / Q000276:immunology / Q000378:metabolism; D003424:Crohn Disease / Q000188:drug therapy* / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D051550:I-kappa B Kinase; D007413:Intestinal Mucosa / Q000201:enzymology / Q000276:immunology; D047908:Intracellular Signaling Peptides and Proteins; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D011446:Prospective Studies; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D011725:Pyridines / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014302:Trinitrobenzenesulfonic Acid; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
D000577:Amides; D016207:Cytokines; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D016328:NF-kappa B; D011725:Pyridines; C108830:Y 27632; D014302:Trinitrobenzenesulfonic Acid; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; C496559:CHUK protein, human; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; D020742:rhoA GTP-Binding Protein