Direct Exposure to Ethanol Disrupts Junctional Cell-Cell Contact and Hippo-YAP Signaling in HL-1 Murine Atrial Cardiomyocytes.
Direct Exposure to Ethanol Disrupts Junctional Cell-Cell Contact and Hippo-YAP Signaling in HL-1 Murine Atrial Cardiomyocytes.
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DOI：
10.1371/journal.pone.0136952
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Uemura K
中科院分区：
文献类型：
--
作者：
Noritake K;Aki T;Funakoshi T;Unuma K;Uemura K
心肌细胞直接暴露在乙醇中会导致心脏损伤，如心律失常和细胞凋亡。心肌细胞通过间隙连接盘(ID)相互连接，插入盘由缝隙连接(GJ)、粘着连接和桥粒组成。连接蛋白43(Cx43)是心脏GJ的主要成分，其含量和亚细胞定位的变化据报道与心律失常和随后的损害有关。最近，河马-YAP信号通路将细胞的生理状态与细胞的增殖、分化和凋亡联系在一起，在生理和病理条件下都参与了心脏的动态平衡。本研究旨在探讨细胞间连接通讯、通过细胞骨架组织的机械转导以及HIPPO-YAP通路在乙醇直接暴露所致心脏损伤中的可能作用。使用HL-1小鼠心房心肌细胞，因为这些细胞通过ID形成和随后的同步收缩保持心脏表型。细胞暴露于0.5-2%乙醇中，暴露于2%乙醇48小时后可见明显的细胞凋亡。在2%乙醇中暴露3小时后，已经观察到Cx43水平的下降，这表明该蛋白迅速降解。接触乙醇后，Cx43转位到溶酶体中。细胞骨架组织也被乙醇失调，表现为肌原纤维和中间丝的破坏。与细胞间黏附丧失一致的是，在乙醇处理的细胞中也观察到河马途径效应器YAP的磷酸化降低。综上所述，这些结果提供了证据表明，直接接触乙醇的细胞表现出1)细胞-细胞黏附/通讯受损，2)细胞骨架的机械转导减少，3)HIPPO-YAP途径被抑制。抑制HIPPO-YAP通路信号应能有效地维持乙醇所致心肌细胞内环境的稳定。
Direct exposure of cardiomyocytes to ethanol causes cardiac damage such as cardiac arrythmias and apoptotic cell death. Cardiomyocytes are connected to each other through intercalated disks (ID), which are composed of a gap junction (GJ), adherens junction, and desmosome. Changes in the content as well as the subcellular localization of connexin43 (Cx43), the main component of the cardiac GJ, are reportedly involved in cardiac arrythmias and subsequent damage. Recently, the hippo-YAP signaling pathway, which links cellular physical status to cell proliferation, differentiation, and apoptosis, has been implicated in cardiac homeostasis under physiological as well as pathological conditions. This study was conducted to explore the possible involvement of junctional intercellular communication, mechanotransduction through cytoskeletal organization, and the hippo-YAP pathway in cardiac damage caused by direct exposure to ethanol. HL-1 murine atrial cardiac cells were used since these cells retain cardiac phenotypes through ID formation and subsequent synchronous contraction. Cells were exposed to 0.5–2% ethanol; significant apoptotic cell death was observed after exposure to 2% ethanol for 48 hours. A decrease in Cx43 levels was already observed after 3 hours exposure to 2% ethanol, suggesting a rapid degradation of this protein. Upon exposure to ethanol, Cx43 translocated into lysosomes. Cellular cytoskeletal organization was also dysregulated by ethanol, as demonstrated by the disruption of myofibrils and intermediate filaments. Coinciding with the loss of cell-cell adherence, decreased phosphorylation of YAP, a hippo pathway effector, was also observed in ethanol-treated cells. Taken together, the results provide evidence that cells exposed directly to ethanol show 1) impaired cell-cell adherence/communication, 2) decreased cellular mechanotransduction by the cytoskeleton, and 3) a suppressed hippo-YAP pathway. Suppression of hippo-YAP pathway signaling should be effective in maintaining cellular homeostasis in cardiomyocytes exposed to ethanol.