秦川牛宰后成熟期间BSG对MAPK信号通路及细胞凋亡的影响

Effect of Basigin on the Mitogen Activated Protein Kinase Signaling Pathway and Apoptosis in Qinchuan Cattle Muscle during Postmortem Maturation

为探究秦川牛宰后成熟期间基础免疫球蛋白(basigin,BSG)对丝裂原活化蛋白激酶(mitogen activated protein kinase,MAPK)信号通路及细胞凋亡的影响,利用4D-非标记定量组学技术分析BSG及其差异蛋白的变化情况。向宰后秦川牛肉的背最长肌中注射BSG抑制剂衣霉素,通过蛋白质免疫印迹法测定秦川牛肉在4℃贮藏过程中MAPK通路关键蛋白质表达水平,并测定caspase-3的活力变化。研究表明:在秦川牛宰后贮藏期内,BSG的表达量总体呈先上升后下降趋势;利用京都基因与基因组百科全书通路分析发现BSG及其差异蛋白质显著注释于氧化磷酸化通路、钙信号通路、MAPK信号通路,说明BSG通过MAPK途径发挥作用。另外,衣霉素组MAPK通路关键蛋白质的相对表达量均显著下调,说明BSG抑制剂使得MAPK信号通路失活。这为研究BSG对MAPK信号通路影响奠定了很好的基础。在抑制BSG的表达后,衣霉素组caspase-3的活力明显上升,说明细胞凋亡是细胞损伤机制的重要环节,衣霉素作用于BSG的N端结构使蛋白质发生去糖基化作用。通过抑制细胞内蛋白质的折叠使其生物学活性受到抑制,从而诱导细胞凋亡。

In order to explore the effects of basigin(BSG)on the mitogen activated protein kinase(MAPK)signaling pathway and apoptosis in Qinchuan cattle muscle during postmortem maturation,the changes in BSG and related differentially expressed proteins were analyzed by 4D-label free quantification(4D-LFQ).The BSG inhibitor tunicamycin was injected into the longissimus dorsi of Qinchuan cattle after slaughter,and the expression levels of key proteins in the MAPK signaling pathway during storage at 4℃were determined by Western blotting.An apoptosis detection kit was used to determine the change in the activity of caspase-3.The results showed that the expression of BSG increased first and then decreased during the postmortem storage period of Qinchuan cattle muscle.Through Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis,it was found that BSG and related differentially expressed proteins were significantly annotated to the oxidative phosphorylation pathway,calcium signal pathway and MAPK signaling pathway,indicating that BSG played an important role through the MAPK signaling pathway.In addition,for the tunicamycin group,the relative expression of the key proteins in the MAPK signaling pathway was significantly down-regulated,indicating that BSG inactivated the MAPK signaling pathway.This finding lays a good foundation for exploring the effect of BSG on the MAPK signaling pathway.After inhibiting BSG expression,caspase-3 activity in the tunicamycin group increased significantly,indicating that apoptosis was an important link in cell injury mechanism,and tunicamycin acted on the N-terminal structure of BSG to deglycosylate the protein and inhibited the folding of intracellular proteins and consequently their biological activity,thereby inducing cell apoptosis.