大肠埃希菌和金黄色葡萄球菌对奶牛睾丸间质细胞炎症反应和睾酮分泌的影响

探讨不同数量大肠埃希菌(E.coli)和金黄色葡萄球菌(S.aureus)对奶牛睾丸间质细胞(LCs)炎性因子、类固醇合成快速调节蛋白(StAR)以及睾酮(T)分泌的影响。通过体外培养LCs,选取生长状态良好的第3代LCs进行试验。根据E.coli和S.aureus作用数量,试验各分为6组,即用不同数量的E.coli(0、10~4、10~5、10~6、10~7、10~8 CFU/mL)和不同数量的S.aureus(0、10~4、10~5、10~6、10~7、10~8 CFU/mL)感染LCs。通过实时荧光定量PCR检测相关炎性因子和StAR mRNA表达的变化;用牛睾酮(T)酶联免疫分析(ELISA)试剂盒检测睾酮分泌水平的变化。结果表明,E.coli数量为10~8 CFU/mL和S.aureus数量为10~7 CFU/mL时,IL-6和IL-1βmRNA的表达量最高,与其他组相比较增加极显著(P<0.01);E.coli数量为10~4、10~5、10~6、10~7、10~8 CFU/mL时感染LCs后,StAR mRNA表达量显著低于对照组(P<0.05);S.aureus浓度为10~6、10~7和10~8 CFU/mL时,StAR mRNA的表达量显著低于对照组(P<0.05);分别用E.coli和S.aureus感染LCs 12 h,睾酮分泌量与对照组相比无显著变化(P>0.05)。结果表明,LCs被E.coli和S.aureus感染12 h,能引起LCs的炎症反应,同时抑制StAR mRNA的表达,但对睾酮的分泌无显著影响。

Effects of Escherichia coli and Staphylococcus aureus on Inflammation and Testosterone Secretion in Leydig cells of Cattle

To investigate the effects of different concentrations of E.coli and S.aureus on inflammatory factors,StAR protein gene levels and testosterone(T)secretion in Leydig cells( LCs) of cattle.LCs were cultured in vitro,and the third-generation LCs with good growth status were selected for the experiment.According to the concentrations of E.coli and S.aureus,the experiment was divided into 6 groups:different concentrations of E.coli(0,10~4,10~5,10~6,10~7,10~8 CFU/mL)and different concentrations of S.aureus(0,10~4,10~5,10~6,10~7,10~8 CFU/mL)infected LCs.Changes in the expression of related inflammatory factors and StAR mRNA were detected by RT-qPCR;Changes in testosterone secretion levels were measured using a bovine T ELISA kit.The results showed that the concentration of E.coli was 10~8 CFU/mL and the concentration of S.aureus was 10~7 CFU/mL,the expressions of IL-6 and IL-1β mRNA were the highest,which was significantly increased compared with other groups(P<0.01),and the concentrations of E.coli were 10~4,10~5,10~6, 10~7,10~8CFU/mL,the expression of StAR mRNA was significantly lower than that of the control group(P<0.05).The expression of StAR mRNA was significantly lower than that of the control group when the concentrations of S.aureus were 10~6,10~7 and10~8 CFU/mL(P<0.05),and LCs were infected with E.coli and S.aureus for 12 h,there was no significant change in testosterone secretion compared with the control group(P>0.05).The results showed that LCs infected with E.coli and S.aureus for 12 h could induce the inflammatory reaction of LCs and inhibit the expression of StAR mRNA,but had no significant effect on the secretion of testosterone.