STUDY OF LOW DENSITY LIPOPROTEIN RECEPTOR-RELATED PROTEIN-1 (LRP-1) EXPRESSION AND 2-MACROGLOBULIN (alfa2-M) EFFECT ON MURINE MÜLLER

BARCELONA PF; CACERES L; CHIABRANDO GA; RIERA CM; SANCHEZ MC

Pinamar, Buenos Aires Republica Argentina.

Congreso; Congreso Conjunto de SAN 2005 (XX Reunión Anual de Sociedad Argentina de Neuroquímica).; 2005

Sociedad Argentina de Neuroquímica

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.