title: Role of phospholipase Cgamma-induced activation of protein kinase Cepsilon (PKCepsilon) and PKCbetaI in epidermal growth factor-mediated protection of tight junctions from acetaldehyde in Caco-2 cell monolayers.
abstract: Epidermal growth factor (EGF) protects the intestinal epithelial tight junctions from acetaldehyde-induced insult. The role of phospholipase Cgamma (PLCgamma) and protein kinase C (PKC) isoforms in the mechanism of EGF-mediated protection of tight junction from acetaldehyde was evaluated in Caco-2 cell monolayers. EGF-mediated prevention of acetaldehyde-induced decrease in transepithelial electrical resistance and an increase in inulin permeability, and subcellular redistribution of occludin and ZO-1 was attenuated by reduced expression of PLCgamma1 by short hairpin RNA. EGF induced a rapid activation of PLCgamma1 and PLC-dependent membrane translocation of PKCepsilon and PKCbetaI. Inhibition of PKC activity or selective interference of membrane translocation of PKCepsilon and PKCbetaI by RACK interference peptides attenuated EGF-mediated prevention of acetaldehyde-induced increase in inulin permeability and redistribution of occludin and ZO-1. BAPTA-AM and thapsigargin blocked EGF-induced membrane translocation of PKCbetaI and attenuated EGF-mediated prevention of acetaldehyde-induced disruption of tight junctions. EGF-induced translocation of PKCepsilon and PKCbetaI was associated with organization of F-actin near the perijunctional region. This study shows that PLCgamma-mediated activation of PKCepsilon and PKCbetaI and intracellular calcium is involved in EGF-mediated protection of tight junctions from acetaldehyde-induced insult.
authors.affiliation: Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163.
authors.forename: Takuya
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163.
authors.forename: Ankur
authors.initials: A
authors.lastname: Seth
authors.affiliation: Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee 38163. Electronic address: rkrao@physio1.utmem.edu.
authors.forename: Radhakrishna
authors.initials: R
authors.lastname: Rao
mesh_terms: D000079:Acetaldehyde / Q000737:chemistry / Q000494:pharmacology*; D018938:Caco-2 Cells; D002462:Cell Membrane / Q000378:metabolism; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry; D008954:Models, Biological; D062793:Occludin; D010455:Peptides / Q000737:chemistry; D051966:Phospholipase C gamma / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D064546:Protein Kinase C beta; D051744:Protein Kinase C-epsilon / Q000378:metabolism*; D021381:Protein Transport; D019108:Tight Junctions
chemical_list: D008565:Membrane Proteins; C568985:OCLN protein, human; D062793:Occludin; D010455:Peptides; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D004533:Egtazic Acid; D004815:Epidermal Growth Factor; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D051744:Protein Kinase C-epsilon; D051966:Phospholipase C gamma; D000079:Acetaldehyde