Advanced oxidation protein products induce mesangial cell perturbation through PKC-dependent activation of NADPH oxidase.
Mesangial deposition of extracellular matrix (ECM) is a hallmark of several glomerular diseases including diabetic nephropathy. Accumulation of advanced oxidation protein products (AOPPs) has been found in diabetes and chronic kidney disease and linked to mesangial ECM deposition and progressive glomerulosclerosis in these disorders. Although emerging evidence implicates AOPPs as the renal pathogenic factors, the underlying mechanisms have not been investigated. Here, using cultured rat mesangial cells (MCs) as a model, we identify AOPPs as the important mediators for activation of MC NADPH oxidase. Exposure of MCs to AOPPs, through membrane-associated phosphorylation of PKCalpha, induced rapid phosphorylation of cytosolic p47(phox) and its membrane translocation, enhanced interaction of p47(phox) with the membrane components p22(phox) and Nox4, and increased expression of these key regulatory subunits of NADPH oxidase. Challenge with AOPPs triggered cytosolic superoxide generation, resulting in upregulation of fibronectin and collagen IV genes and proteins and overexpression of TGF-beta1 via a PKC-NADPH oxidase-dependent pathway, as these downstream events were blocked by the inhibitors of PKC, inhibitors of NADPH oxidase, or the cytosolic superoxide scavenger. These data provide new information for understanding the molecular basis underlying AOPP-induced MC perturbation and might be a central step toward development of new interventions.
Wei
Xiao Fan
XF
Div. of Nephrology, Nanfang Hospital, 1838 North Guangzhou Ave., Guangzhou 510515, China.
Zhou
Qiu Gen
QG
Hou
Fan Fan
FF
Liu
Bei Yi
BY
Liang
Min
M
D000818:Animals; D002478:Cells, Cultured; D024141:Collagen Type IV / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004789:Enzyme Activation; D005109:Extracellular Matrix / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D050527:Mesangial Cells / Q000201:enzymology*; D019255:NADPH Oxidases / Q000378:metabolism*; D018384:Oxidative Stress; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D013481:Superoxides / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000276:immunology / Q000378:metabolism; D015854:Up-Regulation
D024141:Collagen Type IV; D005353:Fibronectins; D053773:Transforming Growth Factor beta1; D013481:Superoxides; D019255:NADPH Oxidases; D011493:Protein Kinase C