RESUMO
The nuclear bile acid (BA) receptor farnesoid X receptor (FXR) is a major regulator of metabolic/energy homeostasis in peripheral organs. Indeed, enterohepatic-expressed FXR controls metabolic processes (BA, glucose and lipid metabolism, fat mass, body weight). The central nervous system (CNS) regulates energy homeostasis in close interaction with peripheral organs. While FXR has been reported to be expressed in the brain, its function has not been studied so far. We studied the role of FXR in brain control of energy homeostasis by treating wild-type and FXR-deficient mice by intracerebroventricular (ICV) injection with the reference FXR agonist GW4064. Here we show that pharmacological activation of brain FXR modifies energy homeostasis by affecting brown adipose tissue (BAT) function. Brain FXR activation decreases the rate-limiting enzyme in catecholamine synthesis, tyrosine hydroxylase (TH), and consequently the sympathetic tone. FXR activation acts by inhibiting hypothalamic PKA-CREB induction of TH expression. These findings identify a function of brain FXR in the control of energy homeostasis and shed new light on the complex control of energy homeostasis by BA through FXR.
RESUMO
Premature rupture of membranes (PRM) affects 5 to 15% of pregnancies, leading to prematurity and neonatal infection. PRM can be identified by through various amniotic fluid proteins in vaginal secretions. The aim of this study is to compare two immunochromatographic tests based on the detection of insulin-like growth factor binding protein (IGFBP-1) and alpha-foeto protein (AFP) for one of the two tests in cervico-vaginal secretions. Two tests, Actim(®) Prom and Amnioquick(®) Duo were performed on 80 pregnant women with suspected PRM. Amnioquick(®) Duo allows the simultaneous detection of IGFBP-1 and AFP with an automated incubation and reading. The number of positive results is similar (Khi-deux = 0.173, p = 0.6773) for IGFBP-1 between the two tests and there is a good agreement (K = 0.621), with a proportion of negative results of 86%. The number of positive results for AFP is more important in comparison to IGFBP-1. Results positive/positive (Actim(®) Prom/Amnioquick(®)) for IGFBP-1 seems to be related to the time when tests have been performed, that is to say in the last weeks of pregnancy. In conclusion, both tests have similar performance, but there is a risk of false positive results with AFP, this can be explained by the presence of non-visible blood in samples. An automated incubation and reading allows a good reproducibility. Moreover, the computer data storage improve the post-analytical quality.
