上海口腔医学 ›› 2019, Vol. 28 ›› Issue (3): 259-263.doi: 10.19439/j.sjos.2019.03.007

• 论著 • 上一篇    下一篇

内质网应激关键因子PREK在应力加载下成肌细胞凋亡中的作用及机制

嵇国平1, 田一宏2, 刘美希2, 沈莹1, 沈刚3   

  1. 1.上海恒正口腔门诊部,上海200040;
    2.青岛大学附属医院正畸科,青岛 山东 266555;
    3.上海拜博口腔医院,拜博口腔医疗集团 正畸学科联合体,上海 200001
  • 收稿日期:2019-03-08 修回日期:2019-05-25 出版日期:2019-06-25 发布日期:2019-08-09
  • 通讯作者: 沈刚,E-mail:gangshen@orthosh.com
  • 作者简介:嵇国平(1974-),男,博士, E-mail:gpji741009@163.com

The role and mechanism of endoplasmic reticulum stress key factor PREK in myoblast apoptosis under stress loading

JI Guo-ping1, TIAN Yi-hong2, LIU Mei-xi2, SHEN Ying1, SHEN Gang3   

  1. 1. Shanghai Hengzheng Dental Clinic. Shanghai 200040;
    2. Department of Orthodontics, School and Hospital of Stomatology, Qingdao University. Qingdao 266555, Shandong Province;
    3. Shanghai ByBo Dental Hospital,United Orthodontic Institutions, ByBo Dental Group. Shanghai 200001, China
  • Received:2019-03-08 Revised:2019-05-25 Online:2019-06-25 Published:2019-08-09

摘要: 目的 研究周期性张应力对L6大鼠成肌细胞凋亡的影响,探讨蛋白激酶R样内质网激酶(protein kinase R-like ER kinase,PERK)在这一过程中的作用及机制。方法 构建L6细胞力学刺激模型,加载参数为细胞拉伸形变率15%,频率10个循环/min,每循环包括3 s拉伸及3 s舒张,加力时间为2、6、12、24 h,以不加力组为对照组。应用DAPI染色观察各组细胞凋亡情况;应用实时荧光定量PCR检测各组PERK、CHOP mRNA的表达;应用Western免疫印迹检测各组PERK、p-PERK的表达变化。加入PERK抑制剂后重复实验,检测各组细胞凋亡情况,PERK、CHOP mRNA 的表达变化及p-PERK的蛋白表达变化。采用SPSS17.0软件包进行统计学分析。结果 DAPI染色显示,L6大鼠成肌细胞在周期性应力诱导下发生凋亡,24 h时达到凋亡最大值。PERK被抑制后,加力组的细胞凋亡程度与对照组无显著差别。RT-PCR 结果显示,随着加力时间的延长,CHOP mRNA 的表达逐渐增加;PERK mRNA 表达无差异。Western免疫印迹结果显示,p-PERK蛋白表达水平随加力时间延长而逐渐升高,总蛋白PERK的表达无明显变化;加入PERK抑制剂后,CHOP的mRNA表达与对照组无显著差异,p-PERK蛋白表达与对照组无显著差异。结论 内质网应激关键因子PERK参与了周期性应力条件下的成肌细胞凋亡,其作用机制可能与PERK磷酸化有关。

关键词: PERK, 周期性应力, 内质网应激, 成肌细胞凋亡

Abstract: PURPOSE: This study was aimed to figure out the way that cyclic-stretch influenced the apoptosis of myoblasts and evaluate the importance of PERK and its possible mechanism involved. Methods: L6 rat myoblasts were cultured in vitro and mechanical stimulation model was constructed successfully. The myoblasts were imposed tension for 0, 2, 6, 12 and 24 hours respectively by multi-channel cell stress loading system. The force value was 15% cell deformation and the frequency was 10 cycles/min. Each cycle was consisted of stretch for 3 seconds and relaxation for 3 seconds, and the group without tension was used as the control group. The apoptotic myoblasts were dyed by DAPI and observed through fluorescence microscopy to detect the apoptosis rate; the mRNA levels of PERK and CHOP in different groups were detected by real-time PCR and protein levels of PERK and p-PERK in different groups were detected by Western blot. PERK inhibitor was used to clear the role of PERK in apoptosis induced by cyclic-stretch and clarify the relationship between the endoplasmic reticulum stress and apoptosis induced by cyclic-stretch. SPSS 17.0 software package was used to analyze the data statistically. Results: DAPI nuclear stain showed that cyclical tensile stress can induce apoptosis in vitro cultured myoblast. Apoptosis rate showed a trend of rising gradually over time, peaked at 24 h. After dealt with the inhibitor of PERK, the apoptosis rate of the 24 h group under the cyclic stretch showed no difference compared with the control. The results of real- time PCR showed that the mRNA of CHOP was increased with the extension loading time, while the mRNA of PERK showed no difference compared with the control. Western blot results showed that the protein level of p-PERK was increased with the extension of loading time, while the expression of PERK showed no difference compared with the control group. When PERK inhibitor added, the mRNA level of CHOP along with the protein expression level of p-PERK showed no significant difference compared to the control. Conclusions: PERK signaling pathway is involved in the apoptosis of myoblasts induced by cyclic stretch, and the possible mechanism may be closely related to the phosphorylation of PERK.

Key words: PERK, Cyclic stress, Endoplasmic reticulum stress, Myoblast apoptosis

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