Park Dong-Ju, Jeon Seong-Jun, Kang Ju-Bin, Koh Phil-Ok
Department of Anatomy, College of Veterinary Medicine, Research Institute of Life Science, Gyeongsang National University, 501 Jinjudaero, Jinju 660-701, South Korea.
Department of Anatomy, College of Veterinary Medicine, Research Institute of Life Science, Gyeongsang National University, 501 Jinjudaero, Jinju 660-701, South Korea.
Neuroscience. 2020 Mar 15;430:47-62. doi: 10.1016/j.neuroscience.2020.01.015. Epub 2020 Jan 23.
Calcium acts as a second messenger that mediates physiologic functions, such as metabolism, cell proliferation, and apoptosis. Hippocalcin is a neuronal calcium sensor protein that regulates intracellular calcium concentration. Moreover, it prevents neuronal cell death from oxidative stress. Quercetin has excellent antioxidant properties and preventative effects. We studied modulation of hippocalcin expression by quercetin treatment in cerebral ischemic injury and glutamate-induced neuronal cell damage. Focal cerebral ischemia was induced by permanent middle cerebral artery occlusion (pMCAO). Male Sprague-Dawley rats were injected with vehicle or quercetin (10 mg/kg) 1 h prior to pMCAO, and cerebral cortical tissues were isolated 24 h after pMCAO. Quercetin improved pMCAO-induced neuronal movement deficit and infarction. pMCAO induced a decrease in hippocalcin expression in the cerebral cortex. However, quercetin treatment attenuated this pMCAO-induced decrease. In cultured hippocampal cells, glutamate excitotoxicity dramatically increased the intracellular calcium concentration, whereas quercetin alleviated intracellular calcium overload. Moreover, Western blot and immunocytochemical studies showed reduction of hippocalcin expression in glutamate-exposed cells. Quercetin prevented this glutamate-induced decrease. Furthermore, caspase-3 expression in hippocalcin siRNA transfection conditions is higher than caspase-3 expression in un-transfection conditions. Quercetin treatment attenuated the increase of caspase-3. Taken together, these results suggest that quercetin exerts a preventative effect through attenuation of intracellular calcium overload and restoration of down-regulated hippocalcin expression during ischemic injury.
钙作为一种第二信使，介导诸如代谢、细胞增殖和细胞凋亡等生理功能。海马钙蛋白是一种调节细胞内钙浓度的神经元钙传感蛋白。此外，它可防止神经元细胞因氧化应激而死亡。槲皮素具有出色的抗氧化特性和预防作用。我们研究了槲皮素处理对脑缺血损伤和谷氨酸诱导的神经元细胞损伤中海马钙蛋白表达的调节作用。通过永久性大脑中动脉闭塞（pMCAO）诱导局灶性脑缺血。雄性Sprague-Dawley大鼠在pMCAO前1小时注射溶剂或槲皮素（10mg/kg），并在pMCAO后24小时分离大脑皮质组织。槲皮素改善了pMCAO诱导的神经元运动缺陷和梗死。pMCAO导致大脑皮质中海马钙蛋白表达下降。然而，槲皮素处理减弱了pMCAO诱导的这种下降。在培养的海马细胞中，谷氨酸兴奋性毒性显著增加细胞内钙浓度，而槲皮素减轻了细胞内钙超载。此外，蛋白质免疫印迹和免疫细胞化学研究表明，暴露于谷氨酸的细胞中海马钙蛋白表达减少。槲皮素阻止了这种谷氨酸诱导的下降。此外，在海马钙蛋白小干扰RNA转染条件下，半胱天冬酶-3的表达高于未转染条件下的表达。槲皮素处理减弱了半胱天冬酶-3的增加。综上所述，这些结果表明，槲皮素通过减轻细胞内钙超载和恢复缺血损伤期间下调的海马钙蛋白表达发挥预防作用。
