Study of Low Density Lipoprotein Receptor-Related Protein-1 (LRP-1) expression and alpha-2-macroglobulin (a2-M) effect of murine Muller cells.

BARCELONA PABLO; CÁCERES LEANDRO; CHIABRANDO GUSTAVO; RIERA CLELIA; SÑANCHEZ MARÍA CECILIA

Pinamar

Congreso; XLI Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB) 2005. X Congreso de la Panamerican Association for Biochemistry and Molecular Biology (PABMB) 2005. XX Reunión Anual de la Sociedad Argentina de Neuroquí; 2005

SAIB

STUDY OF LOW DENSITY LIPOPROTEIN RECEPTOR-RELATED PROTEIN-1 (LRP-1) EXPRESSION AND a2-MACROGLOBULIN (a2-M) EFFECT ON MURINE MÜLLER CELLS. Barcelona PF, Cáceres LC, Chiabrando GA, Riera CM, Sánchez MC. Dpto. Bioq. Clínica-CIBICI (CONICET), Facultad de Ciencias Quimicas. UNC. pbarcelona@mail.fcq.unc.edu.ar Müller cells (MC) constitute the main glial cells of the retina, which are involved in retinal neovascularization. Althrough MC facilitates the neovascularization in hypoxic conditions, the molecular mechanisms of this event has not been established. Previously we demonstrated that the a2-M/LRP-1 system is expressed in rat retinas with ischemia-induced neovascularization. In addition, we also showed that a2-M activates (ERK)-MAPK pathway and cellular proliferation in cells expressing LRP-1. Herein we investigated the LRP-1 expression and analyzed the a2-M effect on intracellular signaling pathways in primary cultures of MC, which were isolated from C57BL6 mice. MC were characterized by immunofluorescence detecting specific protein (CRALBP). LRP-1 expression was detected by Western blotting and immunocytochemistry. (ERK)-MAPK and PKB pathways were analyzed by Western blotting in MC cultured in presence of a2-M. We showed that nearly 95-100% of cells expressed CRALPB and LRP-1. In addition, a2-M generated ERK1/2 phosphorylation. Nevertheless, a2-M no promoted PKB (Akt phosphorylation) activation. In conclusion, we demonstrated that LRP-1 is expressed in murine MC, which can mediate intracellular signaling pathway activation by a2-M. Thus, we proposed that a2-M/LRP-1 system is implicated in the retinal neovascularization.