Rol of Nerve Growth Factor (NGF) in AT2 receptor signaling in developing rat hindbrain

BLANCO HM, SEGUIN LR, CIUFFO GM

Ciudad de la Punta, San Luis, Argentina

Congreso; XXVII Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2009

Angiotensin II (Ang II) regulates blood pressure and electrolyte balance, by interacting with specific receptors, AT1 and AT2. Besides its classical effects, Ang II is involved in neurite outgrowth and cell migration in NG108-15 cells via AT2 receptor signaling. NGF is a classic growth factor, which induces differentiation and survival of neurons.  The aim of the present study was to investigate whether NGF participates in the signaling pathway mediated by Ang II AT2 receptors during rat development. Membrane preparations (120 mg prot.) from postnatal rat hindbrain (cerebellum and brainstem) (PDN15) were stimulated with Ang II (10-7 M) in combination with the AT1 antagonist losartan (10-6 M), in the presence or not of NGF (100 ng/ml). Proteins were separated by SDS-PAGE and western blots developed with anti-p-Erk 1/2 or anti-py99 antibodies. In our model, NGF induces phosphorylation of Erk1/2 in a time and dose-dependent mode. Similarly, AT2 receptors stimulation induce phosphorylation of  Erk1/2. Our present results are in agreement with previous studies on NG108-15 cell line. Simultaneous stimulation of AT2 and NGF receptors produces a decrease in the phosphorylation level of Erk 1/2. Thus, a possible interaction between both receptors could modulate development and differentiation of the rat hindbrain.