该研究探究了日粮中添加白藜芦醇对牛肌纤维类型和丝氨酸-苏氨酸蛋白激酶(serine-threonine protein kinase，Akt)/叉头盒蛋白O(forkhead box protein O，FoxO)通路信号分子的影响，并进一步以牛肌管细胞为研究对象，验证其分子机制。结果表明，肉牛日粮添加450 mg/kg白藜芦醇显著提高了背最长肌和腰大肌Ⅰ型纤维基因表达(P＜0。05)，降低了 Ⅱ型纤维基因表达(P＜0。05)。进一步分析其分子机制，发现，白藜芦醇显著上调肉牛背最长肌中磷酸酰肌醇3-激酶(phosphatidylinositol3-kinase，PI3 K)和Akt的基因表达水平(P＜0。05)，显著下调FoxO3基因表达水平(P＜0。05)，显著上调了 PI3K、p-Akt/Akt和p-FoxO1/FoxO1蛋白表达(P＜0。05);显著上调肉牛腰大肌PI3K和Akt的基因表达水平(P＜0。05)，显著下调FoxO1和FoxO3基因表达水平(P＜0。05)，显著下调了 FoxO1 和 FoxO3 的蛋白表达水平(P＜0。05)，显著上调了 PI3K、p-Akt、p-FoxO1/FoxO1 和p-FoxO3/FoxO3蛋白表达(P＜0。05)，表明肉牛日粮添加白藜芦醇激活了 Akt/FoxO通路。添加PI3K抑制剂渥曼青霉素(wort-mannin)阻断Akt/FoxO信号通路后，白藜芦醇对牛肌管细胞中肌纤维类型的转化作用和对Akt/FoxO信号通路的激活作用被减弱。研究表明，白藜芦醇可通过激活Akt/FoxO通路促进牛肌纤维类型从Ⅱ型到Ⅰ型的转化。
The study of resveratrol promotes the transformation of bovine muscle fiber types through Akt/FoxO signaling pathway
In order to investigate the effects of dietary resveratrol supplementation on bovine muscle fiber types and serine-threonine protein kinase(Akt)/forkhead box protein O(FoxO)pathway related proteins and genes,this feeding experiment was undertaken.Fur-thermore,bovine myotubes were used to verify its deeply molecular mechanism.The results of muscle fiber types showed that dietary sup-plementation of 450 mg/kg resveratrol significantly increased the gene expression of type Ⅰ fiber(P＜0.05)and decreased the gene ex-pression of type Ⅱ fiber(P＜0.05)in Longissimus dorsi and Psoas major muscle of beef cattle.Furtherly analysis of its molecular mecha-nism,the results showed that resveratrol significantly up-regulated the gene expression levels of phosphatidylinositol 3-kinase(PI3K)and Akt in beef cattle Longissimus dorsi muscle(P＜0.05),significantly down-regulated the FoxO3 gene expression level(P＜0.05),and significantly up-regulated the protein expressions of PI3K,p-Akt/Akt and p-FoxO1/FoxO1(P＜0.05).Additionally,dietary supplemen-tation of resveratrol also significantly up-regulated the gene expression levels of PI3K and Akt in beef cattle Psoas major muscle(P＜0.05),significantly decreased the gene expression levels of FoxO1 and FoxO3(P＜0.05),and significantly down-regulated the protein expression levels of FoxO1 and FoxO3(P＜0.05).At the same time,in resveratrol group,the protein expression levels of PI3K,p-Akt/Akt,p-FoxO1/FoxO1 and p-FoxO3/FoxO3 were significantly up-regulated(P＜0.05),which indicated dietary supplementation of resveratrol could activate the Akt/FoxO pathway.PI3K inhibitors(wortmannin)were added to block the Akt/FoxO signaling pathway.Under this cir-cumstance,the transformation of muscle fiber type and the activation of Akt/FoxO signal pathway in bovine myotubes were weakened by resveratrol.In conclusion,resveratrol can promote the transformation of bovine muscle fiber types from type Ⅱ to type Ⅰ by activating the Akt/FoxO pathway.
万方数据
维普
