Andrabi Syed Suhail, Parvez Suhel, Tabassum Heena
Department of Medical Elementology and Toxicology, Jamia Hamdard (Hamdard University), New Delhi 110062, India.
Department of Biochemistry, Jamia Hamdard (Hamdard University), New Delhi 110062, India
Dis Model Mech. 2017 Jun 1;10(6):787-796. doi: 10.1242/dmm.025692. Epub 2017 Mar 31.
Organelle damage and increases in mitochondrial permeabilization are key events in the development of cerebral ischemic tissue injury because they cause both modifications in ATP turnover and cellular apoptosis/necrosis. Early restoration of blood flow and improvement of mitochondrial function might reverse the situation and help in recovery following an onset of stroke. Mitochondria and related bioenergetic processes can be effectively used as pharmacological targets. Progesterone (P4), one of the promising neurosteroids, has been found to be neuroprotective in various models of neurological diseases, through a number of mechanisms. This influenced us to investigate the possible role of P4 in the mitochondria-mediated neuroprotective mechanism in an ischemic stroke model of rat. In this study, we have shown the positive effect of P4 administration on behavioral deficits and mitochondrial health in an ischemic stroke injury model of transient middle cerebral artery occlusion (tMCAO). After induction of tMCAO, the rats received an initial intraperitoneal injection of P4 (8 mg/kg body weight) or vehicle at 1 h post-occlusion followed by subcutaneous injections at 6, 12 and 18 h. Behavioral assessment for functional deficits included grip strength, motor coordination and gait analysis. Findings revealed a significant improvement with P4 treatment in tMCAO animals. Staining of isolated brain slices from P4-treated rats with 2,3,5-triphenyltetrazolium chloride (TTC) showed a reduction in the infarct area in comparison to the vehicle group, indicating the presence of an increased number of viable mitochondria. P4 treatment was also able to attenuate mitochondrial reactive oxygen species (ROS) production, as well as block the mitochondrial permeability transition pore (mPTP), in the tMCAO injury model. In addition, it was also able to ameliorate the altered mitochondrial membrane potential and respiration ratio in the ischemic animals, thereby suggesting that P4 has a positive effect on mitochondrial bioenergetics. In conclusion, these results demonstrate that P4 treatment is beneficial in preserving the mitochondrial functions that are altered in cerebral ischemic injury and thus can help in defining better therapies.
细胞器损伤和线粒体通透性增加是脑缺血组织损伤发展过程中的关键事件,因为它们会导致ATP周转的改变以及细胞凋亡/坏死。早期恢复血流和改善线粒体功能可能会扭转这种情况,并有助于中风发作后的恢复。线粒体及相关生物能量过程可有效用作药物靶点。孕酮(P4)是一种有前景的神经甾体,已发现它通过多种机制在各种神经疾病模型中具有神经保护作用。这促使我们研究P4在大鼠缺血性中风模型中线粒体介导的神经保护机制中的可能作用。在本研究中,我们已证明在短暂性大脑中动脉闭塞(tMCAO)的缺血性中风损伤模型中,给予P4对行为缺陷和线粒体健康具有积极作用。诱导tMCAO后,大鼠在闭塞后1小时接受首次腹腔注射P4(8毫克/千克体重)或溶剂,随后在6、12和18小时进行皮下注射。对功能缺陷的行为评估包括握力、运动协调性和步态分析。结果显示,tMCAO动物经P4治疗后有显著改善。用氯化三苯基四氮唑(TTC)对P4处理的大鼠分离的脑切片进行染色,结果显示与溶剂组相比梗死面积减小,表明存活线粒体数量增加。在tMCAO损伤模型中,P4治疗还能够减弱线粒体活性氧(ROS)的产生,并阻断线粒体通透性转换孔(mPTP)。此外,它还能够改善缺血动物中改变的线粒体膜电位和呼吸比率,从而表明P4对线粒体生物能量学具有积极作用。总之,这些结果表明,P4治疗有助于维持脑缺血损伤中改变的线粒体功能,因此有助于确定更好的治疗方法。