title: Vasopressin-mediated mitogenic signaling in intestinal epithelial cells.
abstract: The role of G protein-coupled receptors and their ligands in intestinal epithelial cell signaling and proliferation is poorly understood. Here, we demonstrate that arginine vasopressin (AVP) induces multiple intracellular signal transduction pathways in rat intestinal epithelial IEC-18 cells via a V(1A) receptor. Addition of AVP to these cells induces a rapid and transient increase in cytosolic Ca(2+) concentration and promotes protein kinase D (PKD) activation through a protein kinase C (PKC)-dependent pathway, as revealed by in vitro kinase assays and immunoblotting with an antibody that recognizes autophosphorylated PKD at Ser(916). AVP also stimulates the tyrosine phosphorylation of the nonreceptor tyrosine kinase proline-rich tyrosine kinase 2 (Pyk2) and promotes Src family kinase phosphorylation at Tyr(418), indicative of Src activation. AVP induces extracellular signal-related kinase (ERK)-1 (p44(mapk)) and ERK-2 (p42(mapk)) activation, a response prevented by treatment with mitogen-activated protein kinase kinase (MEK) inhibitors (PD-98059 and U-0126), specific PKC inhibitors (GF-I and Ro-31-8220), depletion of Ca(2+) (EGTA and thapsigargin), selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (tyrphostin AG-1478, compound 56), or the selective Src family kinase inhibitor PP-2. Furthermore, AVP acts as a potent growth factor for IEC-18 cells, inducing DNA synthesis and cell proliferation through ERK-, Ca(2+)-, PKC-, EGFR tyrosine kinase-, and Src-dependent pathways.
authors.affiliation: Department of Medicine, School of Medicine, University of California-Los Angeles, 900 Veteran Ave., Los Angeles, CA 90095, USA.
authors.forename: Terence
authors.initials: T
authors.lastname: Chiu
authors.forename: Steven S
authors.initials: SS
authors.lastname: Wu
authors.forename: Chintda
authors.initials: C
authors.lastname: Santiskulvong
authors.forename: Pisit
authors.initials: P
authors.lastname: Tangkijvanich
authors.forename: Hal F
authors.initials: HF
authors.lastname: Yee
authors.forename: Enrique
authors.initials: E
authors.lastname: Rozengurt
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism* / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects; D016895:Culture Media, Serum-Free; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D051418:Focal Adhesion Kinase 2; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism*; D048369:MAP Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D051381:Rats; D017483:Receptors, Vasopressin / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D016895:Culture Media, Serum-Free; D004791:Enzyme Inhibitors; D017483:Receptors, Vasopressin; D001127:Arginine Vasopressin; C089212:protein kinase D; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; D051418:Focal Adhesion Kinase 2; C496054:Ptk2b protein, rat; D019061:src-Family Kinases; D017346:Protein Serine-Threonine Kinases; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; D048369:MAP Kinase Kinase 1; D020929:Mitogen-Activated Protein Kinase Kinases; D002118:Calcium