瘦素对牦牛MEC中SOCS2 mRNA及蛋白水平的表达影响

Effect of leptin on SOCS2 mRNA and protein expression in MEC of yak

【目的】了解瘦素对牦牛乳腺上皮细胞(mammary epithelial cells,MEC)中SOCS2表达的作用特点及催乳素对瘦素功能发挥可能产生的影响。【方法】选取无催乳素及有催乳素(500 ng/mL)刺激时,不同质量浓度瘦素(0、50、100、200、400、800 ng/mL)作用牦牛MEC 48 h,采用RT-qPCR及Western blot技术检测SOCS2在mRNA及蛋白水平的相对表达情况。【结果】无论有无催乳素诱导,SOCS2 mRNA的相对表达水平均随瘦素质量浓度的增大而呈现出先升高后降低的趋势,均在瘦素质量浓度为100 ng/mL时表现出最高的相对表达水平(P<0.05),且催乳素可显著提高其表达水平(P<0.05);而SOCS2蛋白在无催乳素时,除800 ng/mL瘦素显著抑制了其表达水平外(P<0.05),其他质量浓度瘦素下的SOCS2蛋白表达水平均无显著性变化(P>0.05);有催乳素时,其蛋白表达水平则随瘦素质量浓度的增大而先升高后降低,200 ng/mL瘦素时表达量最高(P<0.05)。【结论】瘦素在有无催乳素参与下,对SOCS2 mRNA和蛋白水平表达情况的影响不同,表现为SOCS2在催乳素和瘦素功能发挥时参与影响了不同水平的信号通路机制及不同水平上功能性发挥的差异;并且发现瘦素质量浓度为100 ng/mL时对SOCS2 mRNA的表达量有显著促进作用;200 ng/mL瘦素对SOCS2蛋白表达量提升明显,但高质量浓度瘦素会抑制SOCS2蛋白表达。

【Objective】The study aimed to clarify the characteristics of leptin affecting SOCS2 expres‐sion in yak mammary epithelial cells and the possible effect of prolactin on leptin function.【Method】Yak mammatocyte epithelial cells were treated with the different concentrations of leptin(i.e.,0,50,100,200,400,800 ng/mL)under the condition of without or with prolactin(500 ng/mL)for 48 h,and then the relative expression of SOCS2 in both mRNA and protein levels were detected by using RT-qPCR and Western blot.【Result】The results showed that the relative expression level of SOCS2 mRNA increased firstly and then decreased with increased leptin concentration,and prolactin could significantly increase its expression level(P<0.05)and the relative expression level was the highest when leptin concentration was at 100 ng/mL(P<0.05).For treatments without the prolactin,the 800 ng/mL leptin significantly inhibited SOCS2 protein expression(P<0.05),while no significant change in SOCS2 protein expression was de‐tected at the other leptin concentrations(P>0.05).For the treatments of adding prolactin,the expression of SOCS2 protein increased firstly and then decreased with increased leptin concentration,and the expres‐sion level was the highest at 200 ng/mL leptin(P<0.05).【Conclusion】The effect of leptin on the expres‐sion of SOCS2 mRNA and protein levels was affected by prolactin adding,implying that SOCS2 affects dif‐ferent levels of signaling pathway mechanisms and functional differences at different levels when prolactin and leptin were exerted.The results suggested that the leptin concentration of 100 ng/mL significantly pro‐moted the expression of SOCS2 mRNA,and 200 ng/mL leptin significantly increased the expression of SOCS2 protein,whereas high concentrations of leptin inhibited the expression of SOCS2 protein.