Spironolactone ameliorates podocytic adhesive capacity via restoring integrin α3 expression in streptozotocin-induced diabetic rats

Abstract

Podocyte responses to various injuries include detachment from the glomerular basement membrane (GBM) with impaired adhesion ability. Growing evidence suggests inappropriately enhanced aldosterone levels in glomeruli may contribute to podocytic injury and subsequently glomerulosclerosis in diabetic nephropathy (DN). In the present study, we aimed to investigate podocytic integrin α3 expression and urinary podocyte excretion in streptozotocin (STZ)-induced diabetic rats, and to evaluate their responses to spironolactone (SPL). STZ-induced male diabetic Wistar rats were treated with vehicle (the STZ group, n=7), or spironolactone (the STZ+SPL group, n=6) for 12 weeks, six additional rats of similar body weight serving as control. Urine specimens were obtained for measurement of urine albumin concentration and urinary podocyte quantitation upon completion of the 12 weeks. Urinary podocyte excretion was quantified by immunofluorescence and expression of integrin α3 was detected by immunohistochemistry and Western blotting. At 12 weeks, rats given STZ alone revealed an increase in blood glucose and were unaffected by spironolactone, whereas the STZ+SPL group showed considerable improvement in urine albumin and podocyte excretion, as well as up-regulation of integrin α3. Our results suggest that spironolactone ameliorates impaired podocytic adhesion capacity and prevents STZ-induced DN progression.

Keywords

spironolactone integrin podocyte diabetic nephropathy

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References

Mauer M. , Zinman B. , Gardiner R. , et al. ACE-I and ARBs in early diabetic nephropathy. J Renin Angiotensin Aldosterone Syst 2002;3:262-269.

Susztak K. , Raff AC , Schiffer M. , and Böttinger EP Glucose-induced reactive oxygen species cause apoptosis of podocytes and podocyte depletion at the onset of diabetic nephropathy . Diabetes 2006;55:225-233.

Lehman DM , Leach RJ , Johnson-Pais T. , et al. Evaluation of tight junction protein 1 encoding zona occludens 1 as a candidate gene for albuminuria in a Mexican American population. Exp Clin Endocrinol Diabetes 2006;114:432-437.

Toyoda M. , Najafian B. , Kim Y. , Caramori ML , and Mauer M. Podocyte detachment and reduced glomerular capillary endothelial fenestration in human type 1 diabetic nephropathy. Diabetes 2007;56:2155-2160.

Whiteside C. , Prutis K. , Cameron R. , and Thompson J. Glomerular epithelial detachment, not reduced charge density, correlates with proteinuria in Adriamycin and puromycin nephrosis . Lab Invest 1989;61:650-660.

Yu D. , Petermann A. , Kunter U. , Rong S. , Shankland SJ , and Floege J. Urinary podocyte loss is a more specific marker of ongoing glomerular damage than proteinuria. J Am Soc Nephrol 2005;16:1733-1741.

Hynes R. Integrins: Versatility, modulation and signaling in cell adhesion . Cell 1992;69:11-25.

Kitsiou PV , Tzinia AK , Stetler-Stevenson WG , et al. Glucose-induced changes in integrins and matrix-related functions in cultured human glomerular epithelial cells. Am J Physiol Renal Physiol 2003;284:F671-F679.

Cha DR , Kang YS , Han SY , et al. Role of aldosterone in diabetic nephropathy. Nephrology (Carlton) 2005;10(Suppl): S37-S39.

10.

Good DW Nongenomic actions of aldosterone on the renal tubule. Hypertension 2007;49:728-739.

11.

Shibata S. , Nagase M. , Yoshida S. , Kawachi H. , and Fujita T. Podocyte as the target for aldosterone: roles of oxidative stress and Sgk1 . Hypertension 2007;49:355-364.

12.

Rossing K. , Schjoedt KJ , Smidt UM , Boomsma F. , and Parving HH Beneficial effects of adding spironolactone to recommended antihypertensive treatment in diabetic nephropathy: a randomized, double-masked, cross-over study. Diabetes Care 2005;28:2106-2112.

13.

Nakamura T. , Ushiyama C. , Shimada N. , et al. Effect of the antiplatelet drug dilazep dihydrochloride on urinary podocytes in patients in the early stage of diabetic nephropathy. Diabetes Care 2000;23:1168-1171.

14.

Inada A. , Nagai K. , Arai H. , et al. Establishment of a diabetic mouse model with progressive diabetic nephropathy. Am J Pathol 2005;167:327-336.

15.

White KE , Bilous RW Estimation of podocyte number: a comparison of methods. Kidney Int 2004;66:663-667.

16.

Sato A. , Hayashi K. , Naruse M. , and Saruta T. Effectiveness of aldosterone blockade in patients with diabetic nephropathy . Hypertension 2003;41:64-68.

17.

Siragy HM , Xue C. Local renal aldosterone production induces inflammation and matrix formation in kidneys of diabetic rats. Exp Physiol 2008 ;93:817-824.

18.

Fujisawa G. , Okada K. , Muto S. , et al. Spironolactone prevents early renal injury in streptozotocin-induced diabetic rats. Kidney Int 2004;66:1493-1502.

19.

Sato A. , Hayashi K. , and Saruta T. Antiproteinuric effects of mineralocorticoid receptor blockade in patients with chronic renal disease. Am J Hypertens 2005;18:44-49.

20.

Schjoedt KJ , Rossing K. , and Juhl TR Beneficial impact of spironolactone on nephrotic range albuminuria in diabetic nephropathy. Kidney Int 2006;70:536-542.

21.

Guo C. , Martinez-Vasquez D. , and Mendez GP Mineralocorticoid receptor antagonist reduces renal injury in rodent models of types 1 and 2 diabetes mellitus. Endocrinology 2006;147:5363-5373.

22.

Gross ML , El-Shakmak A. , Szabo A. , et al. ACE-inhibitors but not endothelin receptor blockers prevent podocyte loss in early diabetic nephropathy. Diabetologia 2003;46:856-868.

23.

Pagtalunan ME , Miller PL , Jumping-Eagle S. , et al. Podocyte loss and progressive glomerular injury in type II diabetes. J Clin Invest 1997;99:342-348.

24.

Meyer TW , Bennett PH , and Nelson RG Podocyte number predicts long-term urinary albumin excretion in Pima Indians with type II diabetes and microalbuminuria. Diabetologia 1999;42:1341-1344.

25.

Vogelmann SU , Nelson WJ , Myers BD , and Lemley KV Urinary excretion of viable podocytes in health and renal disease. Am J Physiol Renal Physiol 2003;285:F40-F48.

26.

Petermann AT , Pippin J. , Krofft R. , et al. Viable podocytes detach in experimental diabetic nephropathy: potential mechanism underlying glomerulosclerosis. Nephron Exp Nephrol 2004;98:e114-e123.

27.

Aberdam D. , Galliano MF , Vailly J. , et al. Herlitz’s junctional epidermolysis bullosa is genetically linked to mutations in the nicein/kalinin (laminin 5) LAMC2 gene. Nat Genet 1994; 6:299-304.

28.

Cosio FG Cell-matrix adhesion receptors: relevance in glomerular pathology . Am J Kidney Dis 1992;20:294-305.

29.

Rahilly M. , Fleming S. Differential expression of integrin alpha chains by renal epithelial cells . J Pathol 1992;167:327-334.

30.

Chen HC , Chen CA , Guh JY , Chang JM , Shin SJ , and Lai YH Altering expression of alpha3beta1 integrin on podocytes of human and rats with diabetes. Life Sci 2000;67:2345-2353.

31.

Zatz R. , Meyer TW , Rennke HG , and Brenner BM Predominance of hemodynamic rather than metabolic factors in the pathogenesis of diabetic glomerulopathy. Proc Natl Acad Sci U S A 1985;82:5963-5967.

32.

Forbes JM , Fukami K. , and Cooper ME Diabetic nephropathy: where hemodynamics meets metabolism. Exp Clin Endocrinol Diabetes 2007;115:69-84.

33.

Seyer-Hansen K. Renal hypertrophy in experimental diabetes: some functional aspects. J Diabetes Complications 1987;1:7-10.

34.

Ingram AJ , Scholey JW Stress-responsive signal transduction mechanisms in glomerular cells . Curr Opin Nephrol Hypertens 2000;9:49-55.

35.

Dessapt CBM , Hayward A. , Viberti G. , and Gnudi L. TGFß1 and mechanical stretch reduce murine podocyte adhesion to extracellular matrix substrate and modulate ß1 integrin expression/maturation in vitro. Diabetologia 2005;48(Suppl 1): A28(abstract).

36.

Kojima K. , Matsui K. , and Nagase M. Protection of alpha(3) integrin-mediated podocyte shape by superoxide dismutase in the puromycin aminonucleoside nephrosis rat. Am J Kidney Dis 2000;35:1175-1185.

37.

Cortinovis M. , Perico N. , Cattaneo D. , Remuzzi G. , and Cortinovis M. Aldosterone and progression of kidney disease. Ther Adv Cardiovasc Dis 2009;3:133-143.