LXR INCREASE GnRH AND MSH EXPRESSION IN THE RAT HYPOTHALAMUS IN VIVO.

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

CABA

Congreso; 2nd FALAN Congress; 2016

IBRO-LARC

Previously we described the expression of LXR receptors in the hypothalamus (HT) and its relation 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 by Western Blot and immunocytochemistry. We studied the expression of GnRH and GHRH (as they present LXRE sequences in their promoter region), the αMSH and NPY in male Sprague-Dawley rats. As a positive control, the cholesterol transporter ABCA1 expression was measured. For in vitro assays, hypothalamic explants were 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 were injected into the third ventricle with either T0 or GW and after 3.5 h or 24 h the HT were taken and processed. Results: No changes were observed in the expression of the neuropeptides by LXR in vitro. The HT explants were viable (measured by LDH) and responded to the treatment with an increased ABCA1 expression. In contrast, T0 and GW significantly increased the expression of GnRH and MSH by LXR treatment in vivo. These results demonstrate that LXR is capable of regulating the expression of GnRH and MSH in the HT in vivo (PIP-0243).