RESUMEN
Sexual dimorphism exists in energy balance, but the underlying mechanisms remain unclear. Here we show that the female mice have more pro-opiomelanocortin (POMC) neurons in the arcuate nucleus of hypothalamus than males, and female POMC neurons display higher neural activities, compared to male counterparts. Strikingly, deletion of the transcription factor, TAp63, in POMC neurons confers "male-like" diet-induced obesity (DIO) in female mice associated with decreased POMC neural activities; but the same deletion does not affect male mice. Our results indicate that TAp63 in female POMC neurons contributes to the enhanced POMC neuron functions and resistance to obesity in females. Thus, TAp63 in POMC neurons is one key molecular driver for the sexual dimorphism in energy homeostasis.
Asunto(s)
Neuronas/metabolismo , Fosfoproteínas/fisiología , Proopiomelanocortina/metabolismo , Caracteres Sexuales , Transactivadores/fisiología , Animales , Núcleo Arqueado del Hipotálamo/metabolismo , Peso Corporal , Metabolismo Energético/fisiología , Estrógenos/metabolismo , Femenino , Homeostasis , Hipotálamo/metabolismo , Masculino , Ratones , Obesidad/metabolismo , Receptores de Leptina/metabolismo , Factores SexualesRESUMEN
AIM: Polypeptide from Chlamys farreri (PCF, molecular mass is 879) is a new marine polypeptide compound isolated from Chlamys farreri. This study investigates the possible protective roles and the mechanism of PCF against ultraviolet B (UVB)-induced apoptosis in murine thymocytes. METHODS: The rate of apoptosis and caspase-3 activation was measured by flow cytometry. The expression of stress-response genes c-fos and c-jun was observed by RT-PCR. Western blot analysis was performed to determine the release of cytochrome c. RESULTS: It was found that UVB induced murine thymocyte death. The cells treated with UVB showed an increase in cytochrome c release, caspase-3 activity, as well as in the expression of c-fos and c-jun. In addition, all were involved in UVB-induced cell apoptosis. CONCLUSION: Our present observations pointed to the ability of PCF to avert UVB-induced apoptosis in thymocytes by modulating c-fos and c-jun expression, cytochrome c release, and the consequent activation of caspase-3, which were essential components of the UV-induced cell apoptotic pathway. The results suggested that PCF is a promising protective substance against UV radiation.
Asunto(s)
Materia Medica/farmacología , Pectinidae/química , Péptidos/farmacología , Timo/citología , Rayos Ultravioleta , Animales , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Western Blotting , Caspasa 3/metabolismo , Células Cultivadas , Citocromos c/metabolismo , Activación Enzimática/efectos de los fármacos , Activación Enzimática/efectos de la radiación , Citometría de Flujo , Expresión Génica/efectos de los fármacos , Expresión Génica/efectos de la radiación , Genes fos/genética , Genes jun/genética , Materia Medica/aislamiento & purificación , Ratones , Péptidos/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transducción de Señal/efectos de los fármacos , Transducción de Señal/efectos de la radiación , Timo/efectos de los fármacos , Timo/efectos de la radiaciónRESUMEN
AIM: To investigate the role of motilin in paraventricular nucleus (PVN) of hypothalamus on the regulation of gastric motility and the mechanism. METHODS: Immunohistochemistry and microinjection of motilin into PVN were used to observe motilin neural cells in PVN, the neural path between PVN and dorsal vagal complex (DVC) and the changes of gastric motility in conscious rats. RESULTS: (1) There were motilin immunoreactive-cells in PVN and a significant increase was found in groups of fasting and HCL-perfusion into duodenum. (2) HRP-positive cells were found in PVN after microinjection HRP into dorsal nucleus of vagal nerve. It proved that there was neural relationship between PVN and DVC. (3) The amplitude and frequency of gastric motility increased significantly by microinjection motilin into PVN in conscious rats. The effects produced by motilin could be abolished by vagotomy. CONCLUSION: All these results presented imply that motilin in PVN may increase gastric motility through PVN-DVC-Vagal nerve axis.