(Journal Article): Glycated albumin induces superoxide generation in mesangial cells
 
Yoo C, Song C, Kim B, Hong H, Lee H (Department of Pathology, Seoul National University College of Medicine, Seoul, South Korea, hyunsoon@plaza.snu.ac.kr )
 
IN: Cell Physiol Biochem 2004; 14(4-6):361-368
Impact Factor(s) of Cell Physiol Biochem: 2.853 (2001)

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ABSTRACT: Background/Aims: Reactive oxygen species are involved in the pathogenesis of diabetic nephropathy. Amadori-modified glycated albumin modulates signaling pathways in mesangial cells that contribute to the development of diabetic nephropathy. However, the effects of glycated albumin on mesangial cell superoxide (O(2)(-)) production are unknown. Thus, we examined whether glycated albumin induces mesangial cell O(2)(-) generation and whether increased O(2)(-) production elicits cell growth. Methods: Quiescent human mesangial cells (HMC) were exposed to bovine serum albumin (BSA) or glycated BSA (Gly-BSA) with or without diphenylene iodonium (DPI) or apocynin, inhibitors of NAD(P)H oxidase, GF109203X (GFX), a protein kinase C (PKC) inhibitor. Results: Gly-BSA increased PKC activity, particularly PKC-alpha and -alpha1, within 15 min of incubation with HMC, which decreased to the control value at 2 h. Gly-BSA incubated with HMC increased O(2)(-) production by 2 times vis-a-vis BSA-treated cells. The Gly-BSA-induced increased O(2)(-) generation was suppressed by DPI or GFX. Gly-BSA significantly increased mesangial [(3)H]-leucine incorporation, whereas these processes were abrogated by DPI, apocynin or GFX. Conclusions: Gly-BSA induces PKC/NAD(P)H oxidase-dependent O(2)(-) production in HMC, which in turn results in cell hypertrophy. Thus, O(2)(-) induced by glycated albumin might cause mesangial cell alterations in diabetes participating in the pathophysiology of diabetic nephropathy.