School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, University Walk, Bristol, United Kingdom.
PLoS One. 2019 Apr 11;14(4):e0213331. doi: 10.1371/journal.pone.0213331. eCollection 2019.
Interruption of blood supply to the heart is a leading cause of death and disability. However, the molecular events that occur during heart ischemia, and how these changes prime consequent cell death upon reperfusion, are poorly understood. Protein SUMOylation is a post-translational modification that has been strongly implicated in the protection of cells against a variety of stressors, including ischemia-reperfusion. In particular, the SUMO2/3-specific protease SENP3 has emerged as an important determinant of cell survival after ischemic infarct. Here, we used the Langendorff perfusion model to examine changes in the levels and localisation of SUMOylated target proteins and SENP3 in whole heart. We observed a 50% loss of SENP3 from the cytosolic fraction of hearts after preconditioning, a 90% loss after ischemia and an 80% loss after ischemia-reperfusion. To examine these effects further, we performed ischemia and ischemia-reperfusion experiments in the cardiomyocyte H9C2 cell line. Similar to whole hearts, ischemia induced a decrease in cytosolic SENP3. Furthermore, shRNA-mediated knockdown of SENP3 led to an increase in the rate of cell death upon reperfusion. Together, our results indicate that cardiac ischemia dramatically alter levels of SENP3 and suggest that this may a mechanism to promote cell survival after ischemia-reperfusion in heart.
心肌血液供应中断是死亡和残疾的主要原因。然而，心肌缺血过程中发生的分子事件，以及这些变化如何在再灌注时引发随后的细胞死亡，目前还了解甚少。蛋白 SUMO 化是一种翻译后修饰，它强烈参与了细胞对多种应激源（包括缺血再灌注）的保护。特别是 SUMO2/3 特异性蛋白酶 SENP3 已成为缺血性梗死后细胞存活的重要决定因素。在这里，我们使用 Langendorff 灌注模型来研究 SUMO 化靶蛋白和 SENP3 在整个心脏中的水平和定位的变化。我们观察到，预适应后，SENP3 从心脏胞质部分丢失 50%，缺血后丢失 90%，缺血再灌注后丢失 80%。为了进一步研究这些影响，我们在心肌细胞 H9C2 系中进行了缺血和缺血再灌注实验。与整个心脏相似，缺血诱导胞质 SENP3 减少。此外，SENP3 的 shRNA 介导敲低导致再灌注时细胞死亡的速率增加。总之，我们的结果表明，心肌缺血会显著改变 SENP3 的水平，并表明这可能是促进缺血再灌注后心脏细胞存活的一种机制。
