Transforming growth factor-beta1 regulation of laminin gamma1 and fibronectin expression and survival of mouse mesangial cells.
The transforming growth factor-beta (TGF-beta) 1 is a mediator of extracellular matrix (ECM) gene expression in mesangial cells and the development of diabetic glomerulopathy. Here, we investigate the effects of TGF-beta1 on laminin gamma1 and fibronectin polypeptide expression and cell survival in mouse mesangial cells (MES-13). TGF-beta1 (10 ng/ml) stimulates laminin-gamma1 and fibronectin expression approximately two-fold in a time-dependent manner (0-48 h). TGF-beta1 treatment also retards laminin-gamma1 mobility on SDS-gels, and tunicamycin, an inhibitor of the N-linked glycosylation, blocks the mobility shift. TGF-beta1 increases the binding of laminin gamma1 to WGA-agarose and the binding is abolished by tunicamycin suggesting that laminin gamma1 is modified by N-linked glycosylation. TGF-beta1 also elevates fibronectin glycosylation but its mobility is not altered. The degradation of laminin gamma1 and fibronectin proteins is reduced by their glycosylation. In addition, TGF-beta1 enhances mesangial cell viability and metabolic activities initially (0-24 h); however, eventually leads to cell death (24-48 h). TGF-beta1 elevates pro-apoptotic caspase-3 activity and decrease cell cycle progression factor cyclin D1 expression, which parallels cell death. These results indicate that TGF-beta1 plays an important role in ECM expression, protein glycosylation and demise of mesangial cells in the diabetic glomerular mesangium.
Jiang
Yan
Y
Department of Internal Medicine/Nephrology, Detroit, MI 48201, USA.
Cheng
Davis W
DW
Crook
Errol D
ED
Singh
Lalit P
LP
D000818:Animals; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D016923:Cell Death / Q000187:drug effects; D002478:Cells, Cultured; D003513:Cycloheximide / Q000037:antagonists & inhibitors / Q000378:metabolism; D004004:Dichlororibofuranosylbenzimidazole / Q000037:antagonists & inhibitors / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism*; D005786:Gene Expression Regulation; D006031:Glycosylation / Q000187:drug effects; D007797:Laminin / Q000378:metabolism*; D050527:Mesangial Cells / Q000166:cytology / Q000378:metabolism; D051379:Mice; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000378:metabolism / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1; D014415:Tunicamycin / Q000037:antagonists & inhibitors / Q000378:metabolism
D005353:Fibronectins; D007797:Laminin; C508961:Tgfb1 protein, mouse; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C089141:laminin gamma 1; D014415:Tunicamycin; D004004:Dichlororibofuranosylbenzimidazole; D003513:Cycloheximide; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases