INVESTIGADORES
BOCANEGRA Maria Victoria
artículos
Título:
Heat Shock Protein 70 and CHIP Promote Nox4 Ubiquitination and Degradation within the Losartan Antioxidative Effect in Proximal Tubule Cells
Autor/es:
GIL LORENZO ANDREA FERNANDA; COSTANTINO VALERIA VICTORIA; LOPEZ APPIOLAZA MARTIN; CACCIAMANI VALERIA; BENARDON MARIA EUGENIA; BOCANEGRA VICTORIA; GARRAMUÑO DE VALLES PATRICIA
Revista:
CELLULAR PHYSIOLOGY AND BIOCHEMISTRY : INTERNATIONAL JOURNAL OF EXPERIMENTAL CELLULAR PHYSIOLOGY, BIOCHEMISTRY, AND PHARMACOLOGY.
Editorial:
KARGER
Referencias:
Lugar: Basel; Año: 2015 vol. 36 p. 2183 - 2197
ISSN:
1015-8987
Resumen:
Angiotensin II/Angiotensin II type 1 receptor (AT1R) effects are dependen ton ROS production stimulated by NADPH oxidase activation. Hsp70 regulates a diverse set ofsignaling pathways through their interactions with proteins. CHIP is a E3 ubiquitin ligase that targets proteins for polyubiquitination and degradation. Aim: We study whether Hsp70/CHIPcontribute to the negative regulation of Nox4 after AT1R blockage. Methods/Results: Primary culture of proximal tubule cells (PTCs) from SHR and WKY were stimulates with Angiotensin II (AII) or treated with Losartan (L) or Losartan plus Angiotensin II (l+AII). Losartan decreased AT1R and Nox4 while enhancing caveolin-1 and Hsp70 protein expression in SHR PTCs. Immunoprecipitation and immunofluorescence proved interaction and colocalization of increased Hsp70/CHIP with decreased Nox4 in SHR PTCs (L) vs (AII). Hsp72 knocdown resulted in enhanced Nox4 protein levels, NADPH oxidase activity and ROS generation in (L+AII) revealing that Losartan was unable to abrogate AII effects on Nox4 expression and oxidative activity. Moreover, MG132 exposed PTCs (L) demonstrated blocked ubiquitinated Nox4 degradation and increased colocalization of Nox4/Ubiquitin by innmunofluorescence. Conversely, Hsp72 depletion reduced Nox4/Ubiquitin colocalization causing Nox4 upregulation due to proteosomal degradation inhibition, although Losartan treatment. Conclusion: Our study demonstrates that Hsp70 and CHIP mediates the ubiquitination and proteosomal degradation of Nox4 as part of the antioxidative effect of Losartan in SHR.
