Vahidinia Zeinab, Khassafi Negar, Tameh Abolfazl Azami, Karimian Mohammad, Zare-Dehghanani Zahra, Moradi Fatemeh, Joghataei Mohammad Taghi
Department of Anatomy, Faculty of Medicine, Iran University of Medical Sciences, Tehran, Iran.
Anatomical Sciences Research Center, Institute for Basic Sciences, Kashan University of Medical Sciences, Kashan, Iran.
J Stroke Cerebrovasc Dis. 2022 Jun;31(6):106331. doi: 10.1016/j.jstrokecerebrovasdis.2022.106331. Epub 2022 Mar 18.
Calcitriol has been revealed to exert neuroprotective effects in ischemic stroke; however, its role and the underlying mechanisms in brain injury induced by ischemia are not well known. The purpose of this study was to determine the neuroprotective effects of calcitriol pretreatment and to assess the possible neuroprotective function of nuclear factor erythroid 2-related factor 2 (Nrf2)/ heme oxygenase-1 (HO-1) signalling pathway against brain ischemia/reperfusion (I/R) injury in the rat models which was followed by a bioinformatics approach.
The experimental I/R model induction was performed in male Wistar rats for 1 h followed by 23 h reperfusion. Calcitriol was administered intraperitoneally for 7 days prior to stroke. Following ischemia induction 24 h later, neurobehavioral deficits and infarction volume were examined. Oxidative stress was assessed by measurement of malondialdehyde (MDA), nitric oxide (NO) and total antioxidant capacity (TAC). The protein and mRNA expression of HO-1 and Nrf2 were determined by western blot and reverse transcription polymerase chain reaction (RT-PCR), respectively. A molecular docking approach was applied to identify the interaction value of Keap1 with calcitriol.
Our data demonstrated that calcitriol significantly decreased infarction volume and ameliorated neurological deficits in brain I/R. MDA and NO levels were decreased and TAC level was elevated significantly after calcitriol pretreatment. Furthermore, calcitriol upregulated the expression of HO-1 and Nrf2 protein and mRNA in ischemic brain. Molecular modelling demonstrated that calcitriol could interact with the pocket of Keap1 by an appropriate binding energy.
The results indicate that calcitriol protects the brain against I/R injury. This effect may pass through inhibition of oxidative stress and Nrf2/HO-1 pathway activation and this may arise by interaction of Keap1 and calcitriol.
已发现骨化三醇在缺血性卒中中发挥神经保护作用；然而，其在缺血性脑损伤中的作用及潜在机制尚不清楚。本研究旨在确定骨化三醇预处理的神经保护作用，并通过生物信息学方法评估核因子红细胞2相关因子2（Nrf2）/血红素加氧酶-1（HO-1）信号通路对大鼠脑缺血/再灌注（I/R）损伤的可能神经保护功能。
在雄性Wistar大鼠中诱导实验性I/R模型，缺血1小时后再灌注23小时。在卒中前7天腹腔注射骨化三醇。24小时后诱导缺血，检测神经行为缺陷和梗死体积。通过测量丙二醛（MDA）、一氧化氮（NO）和总抗氧化能力（TAC）评估氧化应激。分别通过蛋白质印迹法和逆转录聚合酶链反应（RT-PCR）测定HO-1和Nrf2的蛋白质和mRNA表达。应用分子对接方法确定Keap1与骨化三醇的相互作用值。
我们的数据表明，骨化三醇显著降低了脑I/R中的梗死体积并改善了神经功能缺损。骨化三醇预处理后，MDA和NO水平降低，TAC水平显著升高。此外，骨化三醇上调了缺血脑中HO-1和Nrf2蛋白质及mRNA的表达。分子建模表明，骨化三醇可以通过适当的结合能与Keap1的口袋相互作用。
结果表明，骨化三醇可保护脑免受I/R损伤。这种作用可能通过抑制氧化应激和激活Nrf2/HO-1途径实现，这可能是由于Keap1与骨化三醇的相互作用所致。
