PreproEndothelin-1 expression in human mesangial cells: evidence for a p38 mitogen-activated protein kinase/protein kinases-C-dependent mechanism.
Endothelin-1 (ET-1) has been implicated in the pathogenesis of renal inflammation. This study investigated the mechanisms underlying the synergistic upregulation of preproET-1 gene expression in human mesangial cells after co-stimulation with thrombin and tumor necrosis factor alpha (TNFalpha). Whereas thrombin induced a moderate upregulation of preproET-1 mRNA, co-stimulation with TNFalpha resulted in a strong and protracted upregulation of this mRNA species. Thrombin+TNFalpha-induced upregulation of preproET-1 expression was found to require p38 mitogen-activated protein kinase and protein kinases C, whereas activation of extracellular signal-regulated kinase, c-Jun-N-terminal kinase, or intracellular Ca(2+) release were not required. Actinomycin D chase experiments suggested that enhanced stability of preproET-1 mRNA did not account for the increase in transcript levels. PreproET-1 promoter analysis demonstrated that the 5'-flanking region of preproET-1 encompassed positive regulatory elements engaged by thrombin. Negative modulation of thrombin-induced activation exerted by the distal 5' portion of preproET-1 promoter (-4.4 kbp to 204 bp) was overcome by co-stimulation with TNFalpha, providing a possible mechanism underlying the synergistic upregulation of preproET-1 expression by these two agonists. In conclusion, human mesangial cell expression of preproET-1 may be increased potently in the presence of two common proinflammatory mediators, thereby providing a potential mechanism for ET-1 production in inflammatory renal disease.
Foschi
Marco
M
Medical College of Wisconsin, Milwaukee, Wisconsin.|Department of Internal Medicine, University of Florence, Florence, Italy.
Sorokin
Andrey
A
Medical College of Wisconsin, Milwaukee, Wisconsin.
Pratt
Phillip
P
Medical College of Wisconsin, Milwaukee, Wisconsin.
McGinty
Ann
A
Medical College of Wisconsin, Milwaukee, Wisconsin.
Villa
Giorgio LA
G
Department of Internal Medicine, University of Florence, Florence, Italy.
Franchi
Franco
F
Department of Internal Medicine, University of Florence, Florence, Italy.
Dunn
Michael J
MJ
Medical College of Wisconsin, Milwaukee, Wisconsin.
D000818:Animals; D015152:Blotting, Northern; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000494:pharmacology; D016232:Endothelins / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D005822:Genetic Vectors; D005920:Glomerular Mesangium / Q000166:cytology*; D006801:Humans; D008297:Male; D048290:Mitogen-Activated Protein Kinase 11; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013917:Thrombin / Q000494:pharmacology; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D015854:Up-Regulation
D016232:Endothelins; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D015500:Chloramphenicol O-Acetyltransferase; D011505:Protein-Tyrosine Kinases; D011493:Protein Kinase C; D048290:Mitogen-Activated Protein Kinase 11; D020928:Mitogen-Activated Protein Kinases; D013917:Thrombin; D002118:Calcium