Ethanol-induced mitogen activated protein kinase activity mediated through protein kinase C.
The aim of this study was to determine the pathway(s) by which ethanol activates mitogen-activated protein kinase (MAPK) signaling and to determine the role of Ca2+ in the signaling process. MAPK signaling was determined by assessing MAPK activity, measuring phosphorylated extracellular signaling-regulated kinase (pp 44 ERK-1 and pp 42 ERK-2) expression and ERK activity by measuring ERK-2-dependent phosphorylation of a synthetic peptide as a MAPK substrate in rat vascular smooth muscle cells. Ethanol activated extracellular signal-regulated kinase expression (ERK 1 and 2) could be observed when vascular smooth muscle cells (VSMCs) were stimulated for 5 min or less, but was inhibited when cells are treated for 10 min or more with 1-16 mM of ethanol. Maximum ethanol-induced MAPK activity was observed within 5 min with 4 or 8 mM. Ethanol stimulated MAPK activity was blocked by the protein kinase C (PKC) inhibitor (GF109203X) and epidermal growth factor (EGF) receptor antagonist (PD153035) by 41 +/- 24 and 34 +/- 12.3%, respectively. The calcium channel blocker, diltiazem and the chelating agent, BAPTA, reduced the activation of MAPK activity by ethanol, significantly. The data demonstrate that ethanol-stimulated MAPK expression is mediated partially through both the EGF-receptor and PKC intermediates and that activation through the PKC intermediate is calcium-dependent.
Washington
B
B
Biomedical Research Center, Tennessee State University, Nashville, TN 37209, USA. bwashington@tnstate.edu
Mtshali
C
C
Williams
S
S
Smith
H
H
Li
J D
JD
Shaw
B
B
Gwathmey
J
J
D000818:Animals; D001011:Aorta / Q000166:cytology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D000431:Ethanol / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000096:biosynthesis / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000431:Ethanol; D011493:Protein Kinase C; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases