Thongboonkerd Visith, Barati Michelle T, McLeish Kenneth R, Benarafa Charaf, Remold-O'Donnell Eileen, Zheng Shirong, Rovin Brad H, Pierce William M, Epstein Paul N, Klein Jon B
Kidney Disease Program, Department of Medicine, University of Louisville, Louisville, Kentucky, USA.
J Am Soc Nephrol. 2004 Mar;15(3):650-62. doi: 10.1097/01.asn.0000115334.65095.9b.
Diabetes now accounts for >40% of patients with ESRD. Despite significant progress in understanding diabetic nephropathy, the cellular mechanisms that lead to diabetes-induced renal damage are incompletely defined. For defining changes in protein expression that accompany diabetic nephropathy, the renal proteome of 120-d-old OVE26 transgenic mice with hypoinsulinemia, hyperglycemia, hyperlipidemia, and proteinuria were compared with those of background FVB nondiabetic mice (n = 5). Proteins derived from whole-kidney lysate were separated by two-dimensional PAGE and identified by matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) mass spectrometry. Forty-one proteins from 300 visualized protein spots were differentially expressed in diabetic kidneys. Among these altered proteins, expression of monocyte/neutrophil elastase inhibitor was increased, whereas elastase IIIB was decreased, leading to the hypothesis that elastin expression would be increased in diabetic kidneys. Renal immunohistochemistry for elastin of 325-d-old FVB and OVE26 mice demonstrated marked accumulation of elastin in the macula densa, collecting ducts, and pelvicalyceal epithelia of diabetic kidneys. Elastin immunohistochemistry of human renal biopsies from patients with type 1 diabetes (n = 3) showed increased elastin expression in renal tubular cells and the interstitium but not glomeruli. These results suggest that coordinated changes in elastase inhibitor and elastase expression result in increased tubulointerstitial deposition of elastin in diabetic nephropathy. The identification of these coordinated changes in protein expression in diabetic nephropathy indicates the potential value of proteomic analysis in defining pathophysiology.
目前，糖尿病患者占终末期肾病（ESRD）患者的40%以上。尽管在理解糖尿病肾病方面取得了显著进展，但导致糖尿病性肾损伤的细胞机制仍未完全明确。为了确定伴随糖尿病肾病的蛋白质表达变化，将120日龄患有低胰岛素血症、高血糖、高血脂和蛋白尿的OVE26转基因小鼠的肾脏蛋白质组与背景FVB非糖尿病小鼠（n = 5）的进行了比较。从全肾裂解物中提取的蛋白质通过二维聚丙烯酰胺凝胶电泳（PAGE）进行分离，并通过基质辅助激光解吸电离飞行时间（MALDI-TOF）质谱进行鉴定。在300个可见蛋白质斑点中，有41种蛋白质在糖尿病肾脏中差异表达。在这些变化的蛋白质中，单核细胞/中性粒细胞弹性蛋白酶抑制剂的表达增加，而弹性蛋白酶IIIB减少，这导致了糖尿病肾脏中弹性蛋白表达会增加的假设。对325日龄FVB和OVE26小鼠肾脏进行弹性蛋白免疫组织化学检测，结果显示糖尿病肾脏的致密斑、集合管和肾盂上皮中弹性蛋白明显积聚。对1型糖尿病患者（n = 3）的肾活检组织进行弹性蛋白免疫组织化学检测，结果显示肾小管细胞和间质中弹性蛋白表达增加，但肾小球中未增加。这些结果表明，弹性蛋白酶抑制剂和弹性蛋白酶表达的协同变化导致糖尿病肾病中弹性蛋白在肾小管间质的沉积增加。糖尿病肾病中这些蛋白质表达协同变化的鉴定表明了蛋白质组学分析在定义病理生理学方面的潜在价值。
