LXR INCREASE GnRH AND αMSH EXPRESSION IN THE RAT HYPOTHALAMUS IN VIVO

SUAREZ, L.; KRUSE, M.S.; COIRINI, H.

Ciudad Autonoma de Buenos Aires

Congreso; Second FALAN Congress; 2016

Sociedad Argentina de Investigacion en Neurociencias

Previously we described the expressionof LXR receptorsin the hypothalamus (HT) and itsrelation with the metabolism.Here, we evaluated the action of LXR activation on the expression of neuropeptides produced in the HT in vitro and in vivo byWestern Blot. We studiedthe expression of GnRH and GHRH (as theypresent LXRE sequences in their promoter region), the αMSH and NPYin male Sprague-Dawleyrats. As a positive control, the cholesterol transporter ABCA1 expression was also measured. For in vitro assays, hypothalamic explantswere treated with two different synthetic LXR agonists T0901317(T0) or GW3965(GW) for 2, 4, 6 and 8 h. For in vivo tests, the animals wereinjected into the third ventricle with either T0 orGW and after3.5 h or 24 h theHT were taken and processed. Results: No changeswere observed in the expressionof the neuropéptidos by LXR in vitro. The HTexplants were viable (measuredby LDH) andresponded to the treatment with an increasedABCA1 expression. In contrast, T0and GW significantly increased theexpression of GnRHand aMSHby LXR treatment in vivo.These results demonstrate that LXRis capable to regulate the expression of GnRH and aMSHin the HT in vivo (PIP-0243)