TREM1对软骨细胞线粒体动力学及细胞凋亡的影响

Effects of TREM1 on the Mitochondrial Dynamics and Apoptosis of Chondrocytes

目的:探讨髓系细胞表达激发受体分子1(triggering receptor expressed on myeloid cells 1,TREM1)对软骨细胞线粒体动力学及细胞凋亡的影响,以期为骨关节炎治疗提供新的研究方向。方法:使用白细胞介素-1β(Interleukin-1β,IL-1β)刺激ATDC5小鼠软骨细胞以模拟骨关节炎软骨细胞炎症,qPCR检测白介素-6(IL-6)表达以验证炎性软骨细胞诱导情况,同时检测目标基因TREM1的表达。为观测抑制TREM1对炎性软骨细胞的影响,将细胞分为对照组、IL-1β组及IL-1β+LR12(TREM1抑制剂)组,分别通过Mito-Tracker染色、TUNEL染色观察三组细胞的线粒体动力学和凋亡情况。接着探究过表达TREM1对正常ATDC5软骨细胞的影响,设置空载质粒组、TREM1过表达组及过表达TREM1+LR12处理组,使用Mito-Tracker染色及TUNEL染色检测三组细胞线粒体动力学和凋亡情况。此外,PCR Array检测过表达TREM1对软骨细胞代谢的影响。结果:与对照组相比,IL-1β组IL-6基因表达增加,表明炎性软骨细胞造模成功;TREM1在IL-1β处理后的骨关节炎细胞中表达升高,使用TREM1抑制剂(LR12)处理可有效抑制TREM1的表达,且能明显抑制软骨细胞的炎性因子IL-6的表达。IL-1β组软骨细胞的线粒体动力学失衡和凋亡增加,而IL-1β+LR12组上述情况得到改善。另外,与空载质粒组相比,过表达TREM1组出现线粒体动力学失衡和凋亡增加,但在TREM1+LR12组软骨细胞中线粒体失衡和凋亡增加得到缓解。此外,PCR Array发现过表达TREM1可引起ATDC5细胞的代谢紊乱。结论:TREM1可一定程度损害软骨细胞线粒体动力学平衡及促进细胞凋亡,靶向TREM1可能为骨关节炎治疗提供新的方向。

Objective:This study aims to investigate the influence of triggering receptor expressed on myeloid cells 1(TREM1)expression on the mitochondrial dynamics and apoptosis of chondrocytes in order to propose a novel direction for the treatment of osteoarthritis in the future.Methods:Murine chondrocyte ATDC5 cells were stimulated with interleukin-1β(IL-1β)to mimic osteoarthritis-like chondrocyte inflammation,and interleukin-6(IL-6)expression was detected by qPCR to validate the inflammatory chondrocyte model.The expression of the target gene TREM1 was also detected by qPCR.To observe the effect of TREM1 inhibition on inflammatory chondrocytes,the cells were divided into the control group,IL-1βgroup and IL-1β+LR12(TREM1 inhibitor)group.Mito-Tracker staining and TUNEL staining were used to observe the mitochondrial dynamics and apoptosis of the cells.The effects of TREM1 overexpression on normal ATDC5 chondrocytes were then investigated.The cells were divided into the vector group,TREM1overexpression group,and TREM1 overexpression+LR12 group.Mito-Tracker staining and TUNEL staining were used to detect mitochondrial dynamics and apoptosis in all three groups.In addition,PCR Array was used to detect the effects of TREM1overexpression on chondrocyte metabolism.Results:Compared with the control group,the expression of IL-6 was increased in the IL-1βgroup,indicating successful establishment of inflammatory chondrocytes.TREM1 expression was also elevated in IL-1β-treated chondrocytes.However,treatment with an inhibitor of TREM1(LR12)effectively inhibited the expression of TREM1 and significantly inhibited the expression of the inflammatory cytokine IL-6 in chondrocytes.The mitochondrial dynamics imbalance and apoptosis of chondrocytes were increased in the IL-1βgroup compared with the control group,while the above conditions were ameliorated in the IL-1β+LR12 group.In addition,imbalanced mitochondrial dynamics and increased apoptosis were observed in the TREM1overexpression group compared with the vector group,which were alleviated in the TREM1 overexpression+LR12 chondrocytes.In addition,PCR Array results indicated that overexpression of TREM1 caused metabolic disturbances in ATDC5 cells.Conclusion:TREM1,to a certain extent,increases imbalance of mitochondrial dynamics and apoptosis of chondrocytes.Targeting TREM1 may provide a new direction for the treatment of osteoarthritis.