The objectives of this study are to identify the mechanism of mitochondrial dysfunction during cerebral ischemic/reperfusion (I/R) injury and the therapeutic potential of tetrahydrocurcumin (THC) to mitigate mitochondrial dysfunction in experimental stroke model. In our study, 8-10 weeks old male C57BL/6 wild-type mice were subjected to middle cerebral artery occlusion (MCAO) for 40 min, followed by reperfusion for 72 h. THC (25mg/kg-BW/day) was injected intraperitoneally once daily for 3 days after 4 h of ischemia. The experimental groups were: (i) sham, (ii) I/R and (iii) I/R + THC. We noticed that THC treatment in ischemic mice significantly improved the functional capacity and motor co-ordination along with reduced neuroscore, infarct volume, brain edema and microvascular leakage in brain parenchyma. The study revealed that level of total homocysteine (tHcy), homocysteine metabolizing enzymes, mitochondrial oxidative stress were significantly altered in I/R mice compared to sham. We also observed alteration in mitochondrial transition pore, ATP production and O2 consumption in the ischemic brain as compared to sham. Further, elevated matrix metalloproteinases-9 (MMP-9) activity and reduced tight junction protein expressions intensified the brain vascular impairment in I/R mice compared to sham. Interestingly, we found that levels of mitophagy markers, fusion and fission proteins were significantly altered. However THC treatment in I/R mice almost normalized the above functional and molecular changes. Mechanistic study demonstrated that DNA Methyltransferase 1 (DNMT1) expression was higher and was associated with reduced mitochondrial tissue inhibitor of metalloproteinases 2 (TIMP-2) expression through hyper-methylation of CpG island of TIMP-2 promoter in I/R mice compared to sham. However, administration of epigenetic inhibitor, 5-Azacytidine (5-Aza) abrogated I/R induced hyper-methylation of TIMP-2 promoter and maintaining the extracellular matrix (ECM) integrity. In conclusion, this study suggests that THC epigenetically ameliorates mitochondrial dysfunction in brain vasculature during Ischemic Stroke.

中文翻译：

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四氢姜黄素表观遗传学上减轻缺血性中风期间脑血管中的线粒体功能障碍。

这项研究的目的是确定脑缺血/再灌注（I / R）损伤期间线粒体功能障碍的机制，以及四氢姜黄素（THC）减轻实验性卒中模型中线粒体功能障碍的治疗潜力。在我们的研究中，对8-10周龄的雄性C57BL / 6野生型小鼠进行大脑中动脉闭塞（MCAO）40分钟，然后再灌注72 h。缺血4小时后，每天一次腹膜内注射THC（25mg / kg-BW /天），持续3天。实验组是：（i）假，（ii）I / R和（iii）I / R + THC。我们注意到，在缺血小鼠中进行THC治疗可显着改善其功能能力和运动协调能力，并降低神经实质，梗塞体积，脑水肿和脑实质中的微血管渗漏。研究表明，与假手术相比，I / R小鼠的总同型半胱氨酸（tHcy），同型半胱氨酸代谢酶，线粒体氧化应激水平显着改变。我们还观察到与假手术相比，缺血性脑中线粒体过渡孔，ATP产生和O2消耗发生了变化。此外，与假手术相比，升高的基质金属蛋白酶9（MMP-9）活性和减少的紧密连接蛋白表达增强了I / R小鼠的脑血管损伤。有趣的是，我们发现线粒体标志物，融合蛋白和裂变蛋白的水平发生了显着变化。但是，在I / R小鼠中进行THC处理几乎可以使上述功能和分子变化正常化。机理研究表明，与假手术相比，I / R小鼠中DNA甲基转移酶1（DNMT1）的表达更高，并且与TIMP-2启动子的CpG岛的超甲基化有关，与线粒体组织金属蛋白酶2（TIMP-2）的表达降低有关。 。但是，表观遗传抑制剂5-氮杂胞苷（5-Aza）的使用取消了I / R诱导的TIMP-2启动子超甲基化，并维持了细胞外基质（ECM）的完整性。总之，这项研究表明，THC在表观遗传学上改善了缺血性中风期间脑血管中的线粒体功能障碍。5-氮杂胞苷（5-Aza）消除了I / R诱导的TIMP-2启动子超甲基化，并维持了细胞外基质（ECM）的完整性。总之，这项研究表明，THC在表观遗传学上改善了缺血性中风期间脑血管中的线粒体功能障碍。5-氮杂胞苷（5-Aza）消除了I / R诱导的TIMP-2启动子超甲基化，并维持了细胞外基质（ECM）的完整性。总之，这项研究表明，THC在表观遗传学上改善了缺血性中风期间脑血管中的线粒体功能障碍。