Preproendothelin-1 expression in human mesangial cells : Evidence for a p38 mitogen-activated protein kinase/protein kinases-C-dependent mechanism

• Published in: Journal of the American Society of Nephrology 2001-06, Vol.12 (6), p.1137-1150
• Main Authors: FOSCHI, Marco, SOROKIN, Andrey, PRATT, Phillip, MCGINTY, Ann, LA VILLA, Giorgio, FRANCHI, Franco, DUNN, Michael J
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Blotting, Northern; Calcium - metabolism; Cells, Cultured; Chloramphenicol O-Acetyltransferase - pharmacology; Endothelins - analysis; Endothelins - genetics; Endothelins - metabolism; Endothelium, Vascular - cytology; Endothelium, Vascular - metabolism; Female; Gene Expression Regulation; Genetic Vectors; Glomerular Mesangium - cytology; Humans; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Mitogen-Activated Protein Kinase 11; Mitogen-Activated Protein Kinases - metabolism; Pathology. Cytology. Biochemistry. Spectrometry. Miscellaneous investigative techniques; Protein Kinase C - metabolism; Protein-Tyrosine Kinases - metabolism; Rats; Rats, Sprague-Dawley; RNA, Messenger - genetics; Thrombin - pharmacology; Transfection; Tumor Necrosis Factor-alpha - pharmacology; Up-Regulation; Urinary system
• ISSN: 1046-6673; 1533-3450
• DOI: 10.1681/ASN.V1261137

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.