ANG II AT RECEPTORS INDUCE APOPTOSIS IN HELA CELLS

MANZUR, MARIA J; CIUFFO, GM

Potrero de los Funes, San Luis

Congreso; XLVI reunión anual de SAIB; 2011

Soc. Arg. de Invest. Bioqca. y Biol. Molecular

Manzur MJ1, Beron W2, Kotler ML3, Ciuffo GM1. 1IMIBIO,CONICET UNSL. San Luis; 2IHEM-CONICET, UNCuyo; 3Lab. de Apoptosis, Fac. de Cs Exactas UBA. E-mail: mjmanzu@unsl.edu.ar The signal transduction mechanism of Ang II AT receptors in tissue 2 remodeling and organogenesis remains unclear. Apoptosis is a mechanism involved in tissue differentiation. The aim of this project was to study apoptosis induction mediated by AT in 2 response to Ang II. HeLa cells over-expressing Ang II AT receptors 2 alone or together with RhoA WT or its mutants, were used as a model to study the signaling events triggering apoptosis. Apoptosis was evaluated by means of nuclear condensation, F-actin disassembly, caspases 3 and 8 cleavage and caspase 3/7 activation. In HeLa-AT cells, cleavage of caspases 3 and 8 increased in a time 2 dependent manner after 30 min stimulation. Caspase cleavage appeared earlier in cells co-expressing the constitutively active mutant of RhoA while the effect was absent in cells expressing the dominant negative RhoA N19. We also studied p38MAPK participation in the signaling pathway activated by AT and found 2 that inhibition with SB203580 increased apoptosis. To characterize the pathway, we determined JNK phosphorylation and FAK cleavage by western blot. Cleavage of FAK was time-dependent in Hela-AT cells induced with Ang II. Co-expression of RhoA 2 isoforms modulates FAK cleavage. The present results support a central role of RhoA in the signaling pathway of Ang II AT 2 receptors in apoptosis induction, with participation of JNK, p38MAPK and FAK.