Potential role of Angiotensin II and NGF in Neuro2a cell´s differentiation.

BLANCO H; ALVAREZ SE; CIUFFO GM

Mendoza

Congreso; XXVIII Reunión Anual de la Sociedad de Biología de Cuyo; 2010

In addition to regulate blood pressure, Angiotensin II (Ang II) modulates cell growth by interacting with specific receptors, called AT1 and AT2. It has been shown that Ang II-induced Erk1/2 activation is essential for neurite outgrowth and cell migration in NG108-15 cells. Nerve Growth Factor (NGF) also modulates neurite outgrowth and induces differentiation of neurons, which prompted us to examine the possible crosstalk between NGF and Ang II receptors in regulating Erk1/2 phosphorylation and neurite outgrowth. To this end, Neuro2a cells, which express both AT1 and AT2 receptors as determined by RT-PCR and western blotting, were pretreated with the AT1 antagonist Losartan (10-5 M) or with the AT2 antagonist PD123319 (10-5 M) for 40 min before stimulation with NGF (100 ng/ml), or with Ang II (10-7 M) for 5 min. Cell lysates were prepared, proteins resolved by SDS-PAGE and western blots developed with anti-p-Erk 1/2 antibodies. As expected, NGF induces phosphorylation of Erk1/2 in a time dependent manner. Likewise, Ang II stimulation induces phosphorylation of Erk1/2, which is dependent on AT2 receptor activation. Preliminary results also suggest that Ang II promotes Neuro2a differentiation. Currently, our efforts are focused in identifying the intracellular signaling pathways involved in this process, with special emphasis in those related to Ang II and NGF crosstalk.