肌肉生长抑制素(MSTN)对猪前体脂肪细胞增殖和成脂分化的影响

Effect of myostatin on proliferation and adipogenic differentiation of preadipocytes of swines

为探讨肌肉生长抑制素(MSTN)对猪前体脂肪细胞增殖和成脂分化的影响,本研究以原代培养的断奶猪前体脂肪细胞为研究对象,分别以0 ng/mL(对照组)、25、50和100 ng/mL的MSTN重组蛋白处理细胞,采用油红O染色和提取法定量分析细胞内脂肪生成和成脂分化程度,使用荧光定量PCR和Western blot分析脂肪细胞分化标志基因过氧化物酶体增殖物激活受体-γ(PPAR-γ)、脂肪合成关键酶脂肪酸合成酶(FAS)和乙酰辅酶A羧化酶(ACC)的表达,探讨MSTN调控猪前体脂肪细胞成脂分化可能的分子机制。结果显示,处理48 h后,与对照组细胞相比,25和50 ng/mL MSTN处理对细胞增殖活力无显著影响,而100 ng/mL MSTN可显著提高猪前体脂肪细胞增殖活力。油红O染色及提取结果表明,MSTN呈剂量依赖性抑制猪前体脂肪细胞的成脂分化。进一步研究表明,与0 ng/mL MSTN组细胞相比,100 ng/mL MSTN处理组细胞中MSTN表达量显著升高,而PPAR-γ、FAS和ACC的mRNA和蛋白表达均显著降低。研究表明,MSTN抑制猪前体脂肪细胞的成脂分化,效果呈剂量依赖性,此抑制作用可能是通过抑制PPAR-γ的表达,进而抑制脂肪的合成来实现的。

In order to investigate the effect of myostatin(MSTN) on the proliferation and adipogenic differentiation of porcine preadipocytes, the preadipocytes from weaned piglets were primarily cultured in vitro and treated with 0 ng/mL(the control group), 25, 50 and 100 ng/mL MSTN recombinant protein, respectively. The intracellular lipogenesis and adipogenic differentiation were quantitatively analyzed by oil red O staining and extraction. RT-qPCR and western blot were used to analyze the expression of adipogenic differentiation marker gene peroxisome proliferator-activated receptor gamma(PPAR-γ), fat synthesis key enzymes fatty acid synthase(FAS) and acetyl-CoA carboxylase(ACC), so as to investigate the potential molecular mechanism of MSTN on the adipogenic differentiation of porcine preadipocytes. The results showed that after treatment for 48 h, 25 and 50 ng/mL MSTN had no significant effect on cell proliferation viability when compared with control cells, while 100 ng/mL MSTN significantly increased the proliferative viability of porcine preadipocytes. The results of oil red O staining and extraction showed that MSTN inhibited the adipogenic differentiation of porcine preadipocytes in a dose-dependent manner. Further study showed that, compared with the 0 ng/mL MSTN treated cells, the expression of MSTN was significantly up-regulated in the 100 ng/mL MSTN group, while their mRNA and protein expression of PPAR-γ, FAS and ACC were all significantly down-regulated. In summary, MSTN inhibited the differentiation of porcine preadipocytes in a dose-dependent manner, which might be achieved by inhibiting the expression of PPAR-γ and thus suppressing fat synthesis. These results provided a theoretical foundation for the improvement of meat quality in animal husbandry.