Inhibition of calpain reduces cell apoptosis by suppressing mitochondrial fission in acute viral myocarditis.
Inhibition of calpain reduces cell apoptosis by suppressing mitochondrial fission in acute viral myocarditis.
复制标题
抑制钙蛋白酶通过抑制急性病毒性心肌炎中的线粒体裂变来减少细胞凋亡
DOI：
10.1007/s10565-021-09634-9
复制
发表时间：
2022-06
影响因子：
6.1
通讯作者：
中科院分区：
文献类型：
--
作者：
心肌细胞凋亡是病毒性心肌炎（VMC）发生发展的关键，VMC是年轻人心脏性猝死的主要原因之一。我们以前的研究表明，钙蛋白酶活性升高参与了VMC的发病机制。本研究旨在进一步探讨其机制。用柯萨奇病毒B3（CVB 3）感染新生大鼠心肌细胞（NRCMs）和过表达钙蛋白酶抑制蛋白（calpastatin）的转基因小鼠建立VMC模型。流式细胞术、TUNEL染色和Western blotting检测细胞凋亡。采用超声心动图测量心脏功能。使用ATP测定、JC-1和MitoSOX测量线粒体功能。线粒体形态学观察采用MitoTracker染色和透射电镜。共定位的动力蛋白相关蛋白1（Drp-1）在线粒体进行了检查，使用免疫荧光。采用蛋白质印迹法测定Drp-1在Ser 637位点的磷酸化水平。我们发现CVB 3感染损害线粒体功能，表现为线粒体ROS产生增加，ATP产生减少和线粒体膜电位降低，诱导心肌细胞凋亡和损伤，以及心肌功能降低。通过PD 150606治疗和钙蛋白酶抑制蛋白过表达抑制钙蛋白酶，减弱了CVB 3感染的这些作用。此外，CVB 3诱导的线粒体功能障碍与Drp-1在线粒体外膜的积累和随后的线粒体分裂增加有关。钙蛋白酶切割激活钙调神经磷酸酶A，使Drp-1在Ser 637位点脱磷酸化，促进其在线粒体中的积累，导致线粒体分裂和功能障碍。总之，钙蛋白酶抑制剂通过减少线粒体分裂，从而抑制心肌细胞凋亡来减弱CVB 3诱导的心肌炎。激活的钙蛋白酶切割钙调神经磷酸酶A并将其转化为活性形式，该活性形式可以在Ser 637位点使Drp-1去磷酸化。然后，活性Drp-1从细胞质易位到线粒体并引发过度的线粒体分裂。最终，线粒体动力学的平衡被打破，细胞凋亡发生。
Cardiomyocyte apoptosis is critical for the development of viral myocarditis (VMC), which is one of the leading causes of cardiac sudden death in young adults. Our previous studies have demonstrated that elevated calpain activity is involved in the pathogenesis of VMC. This study aimed to further explore the underlying mechanisms. Neonatal rat cardiomyocytes (NRCMs) and transgenic mice overexpressing calpastatin were infected with coxsackievirus B3 (CVB3) to establish a VMC model. Apoptosis was detected with flow cytometry, TUNEL staining, and western blotting. Cardiac function was measured using echocardiography. Mitochondrial function was measured using ATP assays, JC-1, and MitoSOX. Mitochondrial morphology was observed using MitoTracker staining and transmission electron microscopy. Colocalization of dynamin-related protein 1 (Drp-1) in mitochondria was examined using immunofluorescence. Phosphorylation levels of Drp-1 at Ser637 site were determined using western blotting analysis. We found that CVB3 infection impaired mitochondrial function as evidenced by increased mitochondrial ROS production, decreased ATP production and mitochondrial membrane potential, induced myocardial apoptosis and damage, and decreased myocardial function. These effects of CVB3 infection were attenuated by inhibition of calpain both by PD150606 treatment and calpastatin overexpression. Furthermore, CVB3-induced mitochondrial dysfunction was associated with the accumulation of Drp-1 in the outer membrane of mitochondria and subsequent increase in mitochondrial fission. Mechanistically, calpain cleaved and activated calcineurin A, which dephosphorylated Drp-1 at Ser637 site and promoted its accumulation in the mitochondria, leading to mitochondrial fission and dysfunction. In summary, calpain inhibition attenuated CVB3-induced myocarditis by reducing mitochondrial fission, thereby inhibiting cardiomyocyte apoptosis.Graphical abstractCalpain is activated by CVB3 infection. Activated calpain cleaves calcineurin A and converts it to active form which could dephosphorylate Drp-1 at Ser637 site. Then, the active Drp-1 translocates from the cytoplasm to mitochondria and triggers excessive mitochondrial fission. Eventually, the balance of mitochondrial dynamics is broken, and apoptosis occurs.
登录
查看更多内容
影响因子：
9.5
作者：
通讯作者：
--
DOI：
10.1016/j.bbamcr.2014.12.040
发表时间：
2015-10
期刊：
Biochimica et biophysica acta
影响因子：
--
作者：
Khan M;Syed GH;Kim SJ;Siddiqui A
通讯作者：
Siddiqui A
影响因子：
4.3
作者：
Li, Weiwei;Yang, Jiancheng;Hu, Jianmin
通讯作者：
Hu, Jianmin
DOI：
10.1073/pnas.1321114111
发表时间：
2014-04-29
影响因子：
11.1
作者：
Kim, Seong-Jun;Syed, Gulam H.;Siddiqui, Aleem
通讯作者：
Siddiqui, Aleem
影响因子：
5
作者：
Ebermann, Linda;Wika, Sylwia;Doerner, Andrea
通讯作者：
Doerner, Andrea