RESUMO
Amylin (islet amyloid polypeptide) and vaspin (visceral adipose tissue specific serpin) are gut and adipocyte hormones involved in the regulation of body weight homeostasis. The aim of this study was to examine whether amylin and vaspin are expressed in human and rat placenta, as well as their regulation by nutritional status. Our results demonstrate that amylin and vaspin are localized in both human and rat placenta. In the rat term placenta vaspin was demonstrated in the trophoblast of the fetal villi, the labyrinth. Vaspin immunostaining in human placenta was localized in cytotrophoblast and syncytiotrophoblast in the first trimester placentas while in the third trimester vaspin was localized in the syncytiotrophoblast. Regarding amylin, rat placenta of 16 days of gestational age showed an intense immunostaining, mainly localized in the labyrinth. On the other hand, in the human third trimester placenta amylin immunoreactivity was intense in the syncytiotrophoblast of the chorionic villi and in decidual cells. Furthermore, placental amylin and vaspin showed an opposite pattern of expression during pregnancy, with vaspin showing the highest expression level at the end and amylin at the beginning of pregnancy. Finally, food restriction also has contrary effects on their expression, increasing vaspin but decreasing amylin placental mRNA and protein levels. Taken together, our results demonstrate that vaspin and amylin are modulated by energy status in the placenta, which suggests that these proteins may be involved in the regulation of placental metabolic functions.
Assuntos
Amiloide/genética , Expressão Gênica , Avaliação Nutricional , Placenta/metabolismo , Serpinas/genética , Animais , Feminino , Humanos , Imuno-Histoquímica , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Gravidez , Primeiro Trimestre da Gravidez , RNA Mensageiro/metabolismo , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
Evidence suggests that the adipocyte-derived hormone resistin (RSTN) directly regulates both feeding and peripheral metabolism through, so far, undefined hypothalamic-mediated mechanisms. Here, we demonstrate that the anorectic effect of RSTN is associated with inappropriately decreased mRNA expression of orexigenic (agouti-related protein and neuropeptide Y) and increased mRNA expression of anorexigenic (cocaine and amphetamine-regulated transcript) neuropeptides in the arcuate nucleus of the hypothalamus. Of interest, RSTN also exerts a profound nutrition-dependent inhibitory effect on hypothalamic fatty acid metabolism, as indicated by increased phosphorylation levels of both AMP-activated protein kinase and its downstream target acetyl-coenzyme A carboxylase, associated with decreased expression of fatty acid synthase in the ventromedial nucleus of the hypothalamus. In addition, we also demonstrate that chronic central RSTN infusion results in decreased body weight and major changes in peripheral expression of lipogenic enzymes, in a tissue-specific and nutrition-dependent manner. Thus, in the fed state central RSTN is associated with induced expression of fatty acid synthesis enzymes and proinflammatory cytokines in liver, whereas its administration in the fasted state does so in white adipose tissue. Overall, our results indicate that RSTN controls feeding and peripheral lipid metabolism and suggest that hepatic RSTN-induced insulin resistance may be mediated by central activation of de novo lipogenesis in liver.
Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Hipotálamo/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Resistina/farmacologia , Proteína Relacionada com Agouti/genética , Proteína Relacionada com Agouti/metabolismo , Fenômenos Fisiológicos da Nutrição Animal/efeitos dos fármacos , Animais , Ingestão de Alimentos/efeitos dos fármacos , Jejum/metabolismo , Hipotálamo/metabolismo , Injeções Intraventriculares , Resistência à Insulina/fisiologia , Lipogênese/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neuropeptídeo Y/genética , Neuropeptídeo Y/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Resistina/administração & dosagem , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/genética , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Fatores de TempoRESUMO
Nicotine has marked effects on sleep, arousal and body weight. However, the neuronal mechanisms underlying these actions are not fully understood. Neuropeptide S (NPS) is a recently discovered neuropeptide regulating sleep, anxiety and feeding. Here, we examined the effect of acute and chronic nicotine treatment on the expression of NPS and its receptor (NPS-R) in the hypothalamus and brainstem of rats by using real-time PCR. Our results showed that chronic nicotine treatment induced significant changes in NPS and NPS-R expression whereas acute treatment exclusively induces a marked increase in the mRNA levels of NPS-R in the brainstem. Interestingly, we detected no changes in the expression levels of other set of genes present both in hypothalamus and brainstem. Overall, these data suggest that NPS system is specifically regulated by nicotine in the rat hypothalamus and brainstem.