激活的肺动脉成纤维细胞Piezo1通道通过活化p38-MAPK促进IL-6分泌诱发肺动脉高压的研究

目的 利用大鼠肺动脉成纤维细胞探讨机械敏感Piezo1通道与IL-6分泌的关系，分析Piezo1通道在肺动脉高压（PAH）发展过程中的作用机制。方法 利用组织块法获取成年SD大鼠肺动脉组织并分离培养肺动脉成纤维细胞；将细胞分为对照组和流体剪切力组，用流体剪切力系统在12 dyn/cm2条件下培养流体剪切力组细胞24 h，对照组不做额外处理；利用Western blot和PCR技术分别检测对照组和流体剪切力组细胞Piezo1蛋白和mRNA水平；将肺动脉成纤维细胞分为PBS组、Yoda1组和Yoda1+Dooku1组并分别加入10 μM PBS、Yoda1和Yoda1+Dooku1培养24 h，24 h后利用检测各组细胞IL-6蛋白和mRNA水平；取Yoda1组细胞分为PBS组、ERK抑制剂组、JNK抑制剂组和p38MAPK抑制剂组分别加入PBS、ERK抑制剂(PD98059，10 μM)、JNK抑制剂（SP600125，10 μM）和p38 MAPK抑制剂（SB203580，5 μM），培养24 h后检测IL-6 mRNA水平；在PBS组、Yoda1组和Yoda1+Dooku1组细胞进行对应处理10 min后检测磷酸化p38 MAPK蛋白水平。结果 成功分离培养大鼠肺动脉成纤维细胞；12 dyn/cm2流体剪切力环境培养24 h后，相较于对照组，流体剪切力组细胞中Piezo1蛋白和mRNA水平均显著升高（P＜0.05）。PBS组、Yoda1组和Yoda1+Dooku1组细胞培养24 h后，相较于PBS组和Yoda1+Dooku1组，Yoda1组细胞IL-6蛋白和mRNA水平均显著增高（P＜0.05），相较于PBS组，Yoda1+Dooku1组细胞IL-6蛋白和mRNA水平差异无统计学意义（P＞0.05）。相较于PBS组、ERK抑制剂组和JNK抑制剂组，p38 MAPK抑制剂组IL-6 mRNA水平受到抑制而显著降低（P＜0.05），但PBS组、ERK抑制剂组和JNK抑制剂组IL-6 mRNA水平两两相比差异均无统计学意义（P＞0.05）。PBS组、Yoda1组和Yoda1+Dooku1组细胞培养10 min后各组磷酸化p38 MAPK水平显示，相较于PBS组，Yoda1组磷酸化p38水平显著升高（P＜0.05），而Yoda1+Dooku1组磷酸化p38水平差异无统计学意义（P＞0.05）。结论 血管内流体剪切力改变可上调并激活肺动脉成纤维细胞Piezo1的表达，介导Ca2+ 内流活化p38 MAPK通路促进IL-6的分泌，进一步导致血管重塑，加快PAH进程

The activated pulmonary artery fibroblast Piezo1 induce pulmonary arterial hypertension by activating p38-MAPK and promote IL-6 secretion

Objective To explore the relationship between Piezo1 and IL-6 secretion in rat pulmonary artery fibroblasts and clarify the mechanism of Piezo1 channel in the development of pulmonary arterial hypertension.Methods Pulmonary artery tissue of adult SD rats was obtained and pulmonary artery fibroblasts were isolated and cultured through tissue block method. The cells were divided into control group and fluid shear force group. The fluid shear force system was used to culture the fluid shear force group cells for 24h under the condition of 12dyn/cm2, and no additional treatment was done in the control group. The levels of Piezo1 protein and mRNA in the control group and the fluid shear force group were detected by Western blot and PCR. Pulmonary artery fibroblasts was divided into the PBS group, Yoda1 and Yoda1+Dooku1 group, and add 10 μM PBS, Yoda1 and Yoda1+Dooku1 respectively. After 24 hours of cultivation, the IL-6 protein and mRNA level in each group was measured; Yoda1 group cell was divided into four groups and PBS (10 μl), ERK inhibitor (PD98059, 10 μM), JNK inhibitor (SP600125, 10 μM)and p38 MAPK inhibitor (SB203580, 5 M), and the IL-6 mRNA level was measured 24h after the treatment. The level of p-p38 MAPK protein was detected in PBS group, Yoda1 group and Yoda1+Dooku1 group 10min after the treatment. Results Pulmonary artery fibroblasts were isolated and cultured successfully. After a 24h culture in 12dyn/cm2 fluid shear force condition, both Piezo1 protein and mRNA levels were significantly increased in the fluid shear force group compared with the control group (P＜0.05)After a 24h cell culture in PBS group, Yoda1 group and Yoda1+Dooku1 group, IL-6 protein and mRNA levels in Yoda1 group were significantly increased compared with PBS group and Yoda1+Dooku1 group (P＜0.05) However, there were no significant differences in IL-6 protein and mRNA levels in Yoda1+Dooku1 group compared with PBS group (P＞0.05) PBS, ERK inhibitor, JNK inhibitor and p38 MAPK inhibitor were added into Yoda1 group and cultured for 24h. Compared with PBS, ERK inhibitor and JNK inhibitor groups, IL-6 mRNA level in the p38 MAPK inhibitor group was inhibited and significantly decreased (P＜0.05)However, there was no significant difference in IL-6 mRNA level between PBS group, ERK inhibitor group and JNK inhibitor group (P＞0.05)Phosphorylated p38 MAPK level in PBS group, Yoda1 group and Yoda1+Dooku1 group showed that compared with the PBS group, the phosphorylated p38 level in Yoda1 group was significantly higher than that in PBS group (P＜0.05), and there was no significant difference in phosphorylated p38 in Yoda1+Dooku1 group (P＞0.05) Conclusion The expression of Piezo1 can be up-regulated and activated in pulmonary artery fibroblasts, bring a Ca2+ flow and activating the p38 MAPK pathway, to promote IL-6 secretion. It leads to vascular remodeling and accelerate the process of pulmonary hypertension