Adipophilin通过ERK1/2-AP-1途径诱导炎症因子的表达

目的:观察巨噬细胞中脂肪分化相关蛋白(adipophilin)对炎症因子表达的影响,阐明adipophilin促进巨噬细胞炎症因子表达的机制。方法:将已构建成功的adipophilin稳定高、低表达逆转录病毒载体转染入PA317包装细胞,制备adipophilin高和低表达的RAW264.7细胞;收集已转染成功的各组细胞上清液,用ELISA方法检测IL-6、TNF-α、MCP-1等炎症因子在细胞培养液中的浓度。Western blot检测各组细胞AP-1、p-AP-1、ERK1/2及p-ERK1/2的蛋白水平;用ERK1/2抑制剂PD98059或AP-1抑制剂curcumin孵育细胞,检测各组细胞中以上指标的变化情况。结果:高表达adipophilin的细胞上清液中炎症因子IL-6、MCP-1和TNF-α浓度明显增高,adipophilin siRNA组细胞中的炎症因子降低;高表达adipophilin的细胞中p-ERK1/2和p-AP-1的蛋白水平增高,adipophilin siRNA组则减少;ERK1/2抑制剂PD98059使AP-1蛋白活性明显下调;给予AP-1抑制剂curcumin后,细胞培养液中的IL-6、MCP-1和TNF-α浓度明显下降。结论:Adipophilin在RAW264.7巨噬细胞中能够促进炎症因子的表达。

Adipophilin induces expression of inflammatory factors through ERK1/2-AP-1 signaling pathway

AIM: To observe the effects of adipose differentiation-related protein (adipophilin) on the expression of inflammatory factors in RAW264.7 macrophage and to clarify the related mechanism. METHODS: The cell models with high expression and low expression of adipophilin were constructed by transfecting PA317 packaging cells with stable high or low expression adipophilin retroviral vectors into the RAW264.7 cells. The concentrations of IL-6, MCP-1 and TNF-α in the cell culture medium were detected by ELISA. The protein levels of AP-1, p-AP-1, ERK1/2 and p-ERK1/2 were measured by Western blot. The protein levels of adipophilin, p-ERK1/2 and p-AP-1 and the releases of the inflammatory factors in the RAW264.7 cells treated with or without ERK1/2 inhibitor PD98059 or AP-1 inhibitor curcumin were determined. RESULTS: The RAW264.7 cells with high expression of adipophilin had higher levels of IL-6, MCP-1 and TNF-α, and higher protein levels of p-AP-1 and p-ERK1/2 than those in the cells with low expression of adipophilin. ERK1/2 inhibitor had no significant effect on the expression of adipophilin, but the protein expression of ERK1/2 and AP-1 was significantly inhibited (P<0.05). The administration of AP-1 inhibitor curcumin had no significant effect on the protein expression of adipophilin and ERK1/2, but the protein expression of AP-1 was significantly inhibited (P<0.05). At the same time, the releases of inflammatory factors IL-6, MCP-1 and TNF-α were significantly decreased. CONCLUSION: Adipophilin may regulate the expression of inflammatory factors through ERK1/2-AP-1 pathway in RAW264.7 macrophages.