Hsp25 and Hsp70 expression in neonatal obstructive nephropathy

RINALDI TOSI M.; MONTT GUEVARA M.M.; GARRAMUÑO DE VALLES P.; VARGAS ROIG L.M.

Mendoza

Congreso; XXVI Reunión Científica Anual Sociedad de Biología de Cuyo; 2008

Sociedad de Biología de Cuyo

Chronic and complete unilateral obstruction (UUO) in the neonatal rat causes delayed renal maturation, tubular apoptosis, and interstitial inflammation. This obstruction induces oxidative stress in both the obstructed (O) and the contralateral unobstructed (CL) kidney. Experimental evidences have shown that there exists an interrelationship between Hsp25, Hsp70 and redox status. In the present study we examined the expression of these Hsps in control (C), O and CL kidneys. Neonatal rats were subjected to UUO (n=5) within the first 48 h of life. After 14 days of obstruction, animals, were sacrified and their kidneys were decapsulated and removed. The expression of Hsps were studied by immunohistochemistry and western blot. In C (n=4), Hsp25 was observed mainly in the cytoplasm of collecting ducts in inner medulla. Hsp25 expression was not induced in O kidney. In C kidney, Hsp70 expression was observed in the cytoplasm of a high percent of tubular epithelial cells in cortex. The expression of Hsp70 in C kidneys was weakly in most of the tubules in outer medulla, whereas in the papilla intense staining of collecting ducts was noted. In O kidney we did not observe increased expression of Hsp70. In CL (=2) kidneys a high Hsp70 expression was observed in tubular epithelial cells of cortex and in papilla. Conclusion: We demonstrated Hsp70 upregulation in contralateral cortex tubular cells, suggesting a possible cytoprotective role of this chaperone in obstructive nephropathy.