Reduction in podocyte density as a pathologic feature in early diabetic nephropathy in rodents: Prevention by lipoic acid treatment

被引:83
作者
Siu B. [1 ]
Saha J. [1 ]
Smoyer W.E. [2 ]
Sullivan K.A. [3 ]
Brosius III F.C. [1 ]
机构
[1] Departments of Internal Medicine and Physiology, University of Michigan, 1560 MSRB2, Ann Arbor, MI 48109-0676
[2] Department of Pediatrics, University of Michigan, 8220E MSRB III, Ann Arbor
[3] Department of Neurology, University of Michigan, Ann Arbor, MI 48109-0580
关键词
Diabetic Nephropathy; Podocyte Injury; Podocyte Damage; Podocyte Loss; Podocyte Number;
D O I
10.1186/1471-2369-7-6
中图分类号
学科分类号
摘要
Background: A reduction in the number of podocytes and podocyte density has been documented in the kidneys of patients with diabetes mellitus. Additional studies have shown that podocyte injury and loss occurs in both diabetic animals and humans. However, most studies in animals have examined relatively long-term changes in podocyte number and density and have not examined effects early after initiation of diabetes. We hypothesized that streptozotocin diabetes in rats and mice would result in an early reduction in podocyte density and that this reduction would be prevented by antioxidants. Methods: The number of podocytes per glomerular section and the podocyte density in glomeruli from rats and mice with streptozotocin (STZ)-diabetes mellitus was determined at several time points based on detection of the glomerular podocyte specific antigens, WT-1 and GLEPP1. The effect of insulin administration or treatment with the antioxidant, α-lipoic acid, on podocyte number was assessed. Results: Experimental diabetes resulted in a rapid decline in apparent podocyte number and podocyte density. A significant reduction in podocytes/glomerular cross-section was found in STZ diabetes in rats at 2 weeks (14%), 6 weeks (18%) and 8 weeks (34%) following STZ injection. Similar declines in apparent podocyte number were found in STZ diabetes in C57BL/6 mice at 2 weeks, but not at 3 days after injection. Treatment with α-lipoic acid substantially prevented podocyte loss in diabetic rats but treatment with insulin had only a modest effect. Conclusion: STZ diabetes results in reduction in apparent podocyte number and in podocyte density within 2 weeks after onset of hyperglycemia. Prevention of these effects with antioxidant therapy suggests that this early reduction in podocyte density is due in part to increased levels of reactive oxygen species as well as hyperglycemia. © 2006Siu et al; licensee BioMed Central Ltd.
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页数:11
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共 22 条
[1]  
Mauer S.M., Steffes M.W., Ellis E.N., Sutherland D.E., Brown D.M., Goetz F.C., Structural-functional relationships in diabetic nephropathy, J Clin Invest, 74, pp. 1143-1155, (1984)
[2]  
Pagtalunan M.E., Miller P.L., Jumping-Eagle S., Nelson R.G., Myers B.D., Rennke H.G., Coplon N.S., Sun L., Meyer T.W., Podocyte loss and progressive glomerular injury in type II diabetes, J Clin Invest, 99, pp. 342-348, (1997)
[3]  
Meyer T.W., Bennett P.H., Nelson R.G., Podocyte number predicts long-term urinary albumin excretion in Pima Indians with type II diabetes and microalbuminuria, Diabetologia, 42, pp. 1341-1344, (1999)
[4]  
Wolf G., Chen S., Ziyadeh F.N., From the periphery of the glomerular capillary wall toward the center of disease: Podocyte injury comes of age in diabetic nephropathy, Diabetes, 54, pp. 1626-1634, (2005)
[5]  
Kim Y.H., Goyal M., Kurnit D., Wharram B., Wiggins J., Holzman L., Kershaw D., Wiggins R., Podocyte depletion and glomerulosclerosis have a direct relationship in the PAN-treated rat, Kidney Int, 60, pp. 957-968, (2001)
[6]  
Steffes M.W., Schmidt D., McCrery R., Basgen J.M., Glomerular cell number in normal subjects and in Type 1 diabetic patients, Kidney Int, 59, pp. 2104-2113, (2001)
[7]  
White K.E., Bilous R.W., Marshall S.M., El Nahas M., Remuzzi G., Piras G., De Cosmo S., Viberti G., Podocyte number in normotensive Type 1 diabetic patients with albuminuria, Diabetes, 51, pp. 3083-3089, (2002)
[8]  
Hoshi S., Shu Y., Yoshida F., Inagaki T., Sonoda J., Watanabe T., Nomoto K., Nagata M., Podocyte injury promotes progressive nephropathy in Zucker diabetic fatty rats, Lab Invest, 82, pp. 25-35, (2002)
[9]  
Mifsud S.A., Allen T.J., Bertram J.F., Hulthen U.L., Kelly D.J., Cooper M.E., Wilkinson-Berka J.L., Gilbert R.E., Podocyte foot process broadening in experimental diabetic nephropathy: Amelioration with renin-angiotensin blockade, Diabetologia, 44, pp. 878-882, (2001)
[10]  
Sanden S.K., Wiggins J.E., Goyal M., Riggs L.K., Wiggins R.C., Evaluation of a thick and thin section method for estimation of podocyte number, glomerular volume, and glomerular volume per podocyte in rat kidney with Wilms' tumor-1 protein used as a podocyte nuclear marker, J Am Soc Nephrol, 14, pp. 2484-2493, (2003)