RESUMO
Mimecan encodes a secretory protein that is secreted into the human serum as two mature proteins with molecular masses of 25 and 12 kDa. We found 12-kDa mimecan to be a novel satiety hormone mediated by the upregulation of the expression of interleukin (IL)-1ß and IL-6 in the hypothalamus. Mimecan was found to be expressed in human pituitary corticotroph cells and was up-regulated by glucocorticoids, while the secretion of adrenocorticotropic hormone (ACTH) in pituitary corticotroph AtT-20 cells was induced by mimecan. However, the effects of mimecan in adrenal tissue on the hypothalamic-pituitary-adrenal (HPA) axis functions remain unknown. We demonstrated that the expression of mimecan in adrenal tissues is significantly downregulated by hypoglycemia and scalded stress. It was down-regulated by ACTH, but upregulated by glucocorticoids through in vivo and in vitro studies. We further found that 12-kDa mimecan fused protein increased the corticosterone secretion of adrenal cells in vivo and in vitro. Interestingly, compared to litter-mate mice, the diurnal rhythm of corticosterone secretion was disrupted under basal conditions, and the response to restraint stress was stronger in mimecan knockout mice. These findings suggest that mimecan stimulates corticosterone secretion in the adrenal tissues under basal conditions; however, the down-regulated expression of mimecan by increased ACTH secretion after stress in adrenal tissues might play a role in maintaining the homeostasis of an organism's responses to stress.
Assuntos
Expressão Gênica/fisiologia , Sistema Hipotálamo-Hipofisário/metabolismo , Sistema Hipófise-Suprarrenal/metabolismo , Estresse Fisiológico/fisiologia , Glândulas Suprarrenais/metabolismo , Hormônio Adrenocorticotrópico/sangue , Animais , Glucocorticoides/metabolismo , Hipotálamo/metabolismo , Camundongos , Camundongos Knockout , Hipófise/metabolismoRESUMO
This study was to investigate the effect of zinc pectin oligosaccharides chelate (Zn-POS) on growth performance, serum enzyme activities, tissue zinc accumulation, metallothionein (MT) concentrations, and gene expression of zinc transporters (ZnT) in broilers. Five hundred forty 1-d-old Arbor Acres broiler chicks were randomly assigned to 5 dietary groups with 6 replicates of 18 birds per replicate. The diets were formulated with the same supplemental Zn level (80 mg/kg diet) but different amount of the Zn-POS: 0, 200, 400, 600, and 800 mg Zn-POS/kg diet. ZnSO4 was used to adjust to the desired amount of the Zn (80 mg/kg) in the Zn-POS diets. Broilers were fed with the experimental diets for 42 d including the starter (days 1 to 21) and grower (days 22 to 42) phases. Our results showed that dietary supplementation of Zn-POS linearly and quadratically increased (P < 0.05) the average daily gain and gain-to-feed ratio during 22 to 42 d and 1 to 42 d as well as body weight on day 42, whereas reduced (P < 0.05) the sum of mortality and lag abnormalities in broilers on day 42. Besides, serum alkaline phosphatase and copper-zinc superoxide dismutase activities increased (P < 0.05) linearly and quadratically in response to dietary Zn-POS supplemental level on day 42. Dietary Zn-POS supplementation increased Zn accumulation in serum (linear, P < 0.05), liver (linear, P < 0.05), and pancreas (linear and quadratic, P < 0.05). In addition, Zn-POS supplementation linearly and quadratically increased (P < 0.01, P < 0.05, respectively) MT concentrations in liver and pancreas of broilers. Pancreatic mRNA levels of MT, ZnT-1, and ZnT-2 increased (P < 0.05) linearly and quadratically, and the mRNA expression of metal response element-binding transcription factor-1 increased linearly (P < 0.05), in response to dietary Zn-POS supplementation. In conclusion, supplementation of Zn-POS in the diet increases Zn enrichment in the metabolic organs such as liver and pancreas and promotes productive performance in broilers.
Assuntos
Ração Animal/análise , Galinhas/fisiologia , Suplementos Nutricionais/análise , Zinco/farmacologia , Animais , Peso Corporal , Galinhas/crescimento & desenvolvimento , Dieta/veterinária , Feminino , Regulação da Expressão Gênica , Fígado/metabolismo , Masculino , Proteínas de Membrana Transportadoras/metabolismo , Metalotioneína/análise , Minerais/metabolismo , Oligossacarídeos/metabolismo , Pâncreas/metabolismo , Pectinas , Distribuição Aleatória , Glycine max , Zinco/metabolismoRESUMO
OBJECTIVE: To study the neuroprotective effect of water extracts of American Ginseng (WEAG) on Abeta25-35-induced SH-SY5Y cells apoptosis in Alzheimer's Disease cellular model. METHODS: The optimal concentration and treating time of Abeta25-35 for Alzheimer's Disease cellular model as well as those of WEAG were measured by flow cytometer. In addition, the cell viability was measured by MTT test and the morphology of SH-SY5Y cells was observed by Hoechst 33258 staining. RESULTS: Treated by Abeta25-35 50 micromol/L 72 h later, SH-SY5Y cells turned rounder, aggregated and were positively stained with fluorochrome Hoechst 33258. Cells displayed a typical sub-diploid peak in flow cytometry, and the percentage of apoptosis reaches (37.30 +/- 0.69)% (P < 0.05 as compared with the control group) (1.56 +/- 0.80)%. When incubated with Abeta 50 micromol/L and different doses (0.5, 1, 5 mg/ml) of WEAG for 72h, the characteristics of apoptosis as measured by FCM dose-dependently declined to (16.71 +/- 1.08)%, (10.52 +/- 2.11)% and (3.39 +/- 1.65)%, respectively (P < 0.05 as compared with the model group). CONCLUSION: Water extracts of American Ginseng have markedly neuroprotective effects on SH-SY5Y cells apoptosis induced by Abeta25-35.