NADP(P)H-oxidasa complex regulation by Hsp70 in vascular smooth muscle cells Losartan efect

GIL LORENZO AF; BOCANEGRA MV; CACCIAMANI VE; BENARDON ME; MIATELLO RM; VALLÉS P

San juan

Congreso; II Reunión Conjunta de Sociedades de Biología de la República Argentina. XXIX Reunión Anual de la Sociedad de Biología de Cuyo; 2011

Sociedades de Biología de la República Argentina y Sociedad de Biología de Cuyo (SBCuyo)

NAD(P)H-OXIDASE COMPLEX REGULA-TION BY HSP70 IN VASCULAR SMOOTH MUSCLE CELLS.LOSARTAN EFFECT Gil Lorenzo AF, Bocanegra MV, Cacciamani VE, Benardon ME, Miatello RM, Vallés P. FCM, UNCuyo. IMBECU, CONICET. Mendoza. gil.andrea@fcm.uncu.edu.ar Involvement of Hsp70 in the regulation of Nox4 and p22 phox NAD(P)H-oxidase subunits by the Rho small GTPases, Cdc42 and Rac signaling pathway after Losartan administration in CMLVs. SHR and WKY VSMC primary cultures from resistance vessels were used. Groups Control (C), Angiotensina II (AII: 100 µmol/L), Losartan (L: 100 µmol/L) y Losartan plus Angiotensina II (L+AII). VSMCs were stimulated with AII for 15, 60, 120, 180 min, 24 and 48 h in the presence or absence of Losartan. Cells remained exposed to Losartan for 45, 90, 150, 210 min or 24 and 48 h. Hsp70 membrane translocation was shown in WKY VSMCs 15 min after AII stimulation, decreasing its expression after Losartan exposure for 60 min. In SHR, membrane translocation of Hsp70 occured after Losartan exposure for 90 min associated with increased Cav-1 expression. SHR Losartan treatment for 90 min showed co-immunoprecipitation of Nox4 with Hsp70, as well as interaction with decreased p22, Cdc42 and Rho in the membrane fraction compared to AII stimulated VSMCs. Moreover, Hsp70 and p22 colocalization by immunofluorescence was shown. Early activation of MAPK ERK1/2 and p38 signaling pathway was demonstrated in AII 15 min cell stimulation, the opposite effect by Losartan treatment for 45 min. Translocated Hsp70 is involved in the negative regulation of Nox4/p22NAD(P)H-oxidase and in RhoA and Cdc42 absence of activation, suggesting Hsp70 involvement in cytoskeleton stabilizationin Losartan VSMCs SHR.