title: Rho proteins play a critical role in cell migration during the early phase of mucosal restitution.
abstract: In the intestine, several growth factors stimulate migration of epithelial cells, contributing to the maintenance of tissue integrity. The Ras-like GTPase Rho regulates a signal transduction pathway linking growth factor receptors to the formation of actin stress fibers and focal adhesions, presumed to be important for motility. Using an in vitro wound-induced migration assay, we have examined the role of Rho GTPases in the migration of IEC-6 and Caco-2 cells, and provide evidence that the Rho GTPases play an essential role in the initial phase of mucosal wound healing. Treatment of the cells with Clostridium difficile toxins A and B, inhibitors of the Rho family GTPases inhibited migration in a dose-dependent fashion. Microinjection of the inhibitory exchange factor Rho-guanine nucleotide dissociation inhibitor (GDI), or Clostridium botulinum C3 ADP-ribosyl transferase (C3) toxin, a Rho-ADP-ribosylating exoenzyme, potently inhibited migration. Microinjection of RhoT19N, a dominant negative form of RhoA, or in vitro ADP-ribosylated RhoA impaired the ability of cells to migrate. Rho-GDI and C3 exoenzyme also inhibited EGF-induced migration of IEC-6 cells. These results demonstrate that Rho is required for endogenous and EGF-induced migration of small intestinal crypt cells, and that Rho proteins are essential elements of a mechanism by which growth factors induce cell migration to restitute mucosal integrity.
authors.affiliation: Department of Physiology and Biophysics, University of Tennessee, College of Medicine, Memphis, Tennessee 38163, USA.
authors.forename: M F
authors.initials: MF
authors.lastname: Santos
authors.forename: S A
authors.initials: SA
authors.lastname: McCormack
authors.forename: Z
authors.initials: Z
authors.lastname: Guo
authors.forename: J
authors.initials: J
authors.lastname: Okolicany
authors.forename: Y
authors.initials: Y
authors.lastname: Zheng
authors.forename: L R
authors.initials: LR
authors.lastname: Johnson
authors.forename: G
authors.initials: G
authors.lastname: Tigyi
mesh_terms: D036002:ADP Ribose Transferases / Q000494:pharmacology; D000818:Animals; D001426:Bacterial Proteins; D001427:Bacterial Toxins / Q000494:pharmacology; D001905:Botulinum Toxins; D002465:Cell Movement / Q000187:drug effects; D003110:Colonic Neoplasms; D004768:Enterotoxins / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D005982:Glutathione Transferase; D020730:Guanine Nucleotide Dissociation Inhibitors; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D007421:Intestine, Small; D007700:Kinetics; D016297:Mutagenesis, Site-Directed; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014407:Tumor Cells, Cultured; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors; D020742:rhoA GTP-Binding Protein
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004768:Enterotoxins; D020730:Guanine Nucleotide Dissociation Inhibitors; D011993:Recombinant Fusion Proteins; D062947:rho-Specific Guanine Nucleotide Dissociation Inhibitors; C041348:tcdA protein, Clostridium difficile; C031815:toxB protein, Clostridium difficile; D004815:Epidermal Growth Factor; D036002:ADP Ribose Transferases; C063007:exoenzyme C3, Clostridium botulinum; D005982:Glutathione Transferase; D001905:Botulinum Toxins; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; D020742:rhoA GTP-Binding Protein