Rho proteins play a critical role in cell migration during the early phase of mucosal restitution.
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.
Santos
M F
MF
Department of Physiology and Biophysics, University of Tennessee, College of Medicine, Memphis, Tennessee 38163, USA.
McCormack
S A
SA
Guo
Z
Z
Okolicany
J
J
Zheng
Y
Y
Johnson
L R
LR
Tigyi
G
G
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
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