细菌脂多糖通过MAPK/ERK1/2信号通路影响成骨细胞活性和凋亡  

Bacterial lipopolysaccharide affects osteoblast activity and apoptosis via MAPK/ERK1/2 signaling pathway

作　　者：孙勃[1] 刘士波[1] 王培(指导)[1] 薛鑫鑫[1] 高云峰[1] 付世杰[1] SUN Bo;LIU Shi-Bo;WANG Pei;XUE Xin-Xin;GAO Yun-Feng;FU Shi-Jie(Hand and Foot Surgery,Affiliated Hospital of Chengde Medical,Chengde 067000,China)

机构地区：[1]承德医学院附属医院手足外科,承德067000

出　　处：《中国免疫学杂志》2020年第7期799-803,共5页Chinese Journal of Immunology

摘　　要：目的:探讨细菌脂多糖(LPS)通过丝裂原活化蛋白激酶/细胞外调节蛋白激酶(MAPK/ERK1/2)信号通路对成骨细胞活性和凋亡的影响。方法:将小鼠前体成骨细胞MC3T3-E1随机分为对照组、LPS组、LPS+U0126组,对照组不给予LPS处理,LPS组给予10 mmol/L LPS处理,LPS+U0126组给予10 mmol/L LPS和25μmol/L ERK1/2激酶抑制剂U0126处理。采用噻唑蓝(MTT)测定细胞活性,采用流式细胞术测定细胞凋亡,采用硝基苯磷酸二钠基质动力学方法测定碱性磷酸酶(ALP),采用放射免疫法测定骨钙素(BGP)活性,采用Hochest 33258染色观察细胞核形态,采用Western blot测定活化型细胞半胱氨酸天冬氨酸特异性蛋白酶3型(C-Caspase 3)、Bcl-2相关X蛋白(Bax)、B淋巴细胞瘤-2基因(Bcl-2)、ERK1/2、磷酸化ERK1/2(p-ERK1/2)蛋白水平。结果:与对照组比较,LPS组和LPS+U0126组MC3T3-E1细胞活性、ALP和BGP活性降低(P<0.05),细胞凋亡率升高(P<0.05),C-Caspase 3、Bax、p-ERK1/2蛋白水平升高(P<0.05),Bcl-2蛋白水平降低(P<0.05);与LPS组比较,LPS+U0126组MC3T3-E1细胞活性、ALP和BGP活性升高(P<0.05),细胞凋亡率降低(P<0.05),C-Caspase 3、Bax、p-ERK1/2蛋白水平降低(P<0.05),Bcl-2蛋白水平升高(P<0.05)。对照组细胞核正常;LPS组细胞凋亡形态数量明显增多;LPS+U0126组凋亡形态细胞数量较LPS组减少。结论:LPS可通过抑制MAPK/ERK1/2信号通路抑制成骨细胞活性,诱导成骨细胞凋亡。Objective:To investigate the effects of bacterial lipopolysaccharide(LPS)on osteoblast activity and apoptosis via mitogen-activated protein kinase/extracellular regulated protein kinase(MAPK/ERK1/2)signaling pathway.Methods:The mouse precursor osteoblast MC3T3-E1 was randomly divided into control group,LPS group and LPS+U0126 group.The MC3T3-E1 of the control group was not given LPS treatment.The MC3T3-E1 of the LPS group was treated with 10 mmol/L LPS.The MC3T3-E1 of the LPS+U0126 group was treated with 10 mmol/L LPS and 25μmol/L ERK1/2 kinase inhibitor U0126.The cell viability was determined by thiazole blue(MTT).The apoptosis was measured by flow cytometry.The alkaline phosphatase(ALP)was determined by nitrobenzene phosphate disodium matrix kinetic method and the activity of osteocalcin(BGP)was determined by radioimmunoassay.The morphology of the nucleus was observed by Hochest 33258 staining.The Western blot was used to detect activated cell caspase-3(C-Caspase 3),Bcl-2 related X protein(Bax),B lymphocyte tumor-2 gene(Bcl-2),ERK1/2,phosphorylated ERK1/2(p-ERK1/2)protein levels.Results:Compared with the control group,the activity of MC3T3-E1 cells and the activity of ALP and BGP were decreased(P<0.05),the apoptosis rate was increased(P<0.05),the C-Caspase 3,Bax,p-ERK1/2 protein levels were increased(P<0.05),the Bcl-2 protein level was decreased(P<0.05)in LPS group and LPS+U0126 group.Compared with the LPS group,the activity of MC3T3-E1 cells and the activity of ALP and BGP were increased(P<0.05),the apoptosis rate was decreased(P<0.05),the levels of C-Caspase 3,Bax and p-ERK1/2 protein were decreased(P<0.05),the Bcl-2 protein level was elevated(P<0.05)in LPS+U0126 group.The MC3T3-E1 cells of the control group had normal nuclei.The number of apoptotic morphological cells in the LPS group were increased significantly.The number of apoptotic morphological cells in the LPS+U0126 group was lower than that in the LPS group.Conclusion:LPS can inhibit osteoblast activity and induce osteoblast apoptosis by inhibiting

关 键 词：细菌脂多糖 丝裂原活化蛋白激酶 细胞外调节蛋白激酶 成骨细胞 活性 凋亡 

分 类 号：R780.2[医药卫生—口腔医学]