Santhanasabapathy Rajasekaran, Sudhandiran Ganapasam
Department of Biochemistry, Cell Biology Laboratory, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu, India.
Department of Biochemistry, Cell Biology Laboratory, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu, India.
Brain Res. 2015 Sep 16;1620:42-56. doi: 10.1016/j.brainres.2015.04.043. Epub 2015 Apr 29.
Neuronal apoptosis occurs as a sequel of oxidative stress associated with various neuropathies. In this study, we have investigated the protective effect of farnesol, a sequisterpene on lipopolysaccharide (LPS) induced neurodegeneration through modulation of intrinsic apoptotic cascade in the cortex and hippocampus of Swiss albino mice. Intraperitoneal (i.p.) injection of LPS (250 μg/kg b.wt. for 7 days) resulted in elevated levels of lipid peroxidation, protein carbonyls and 8-Hydroxydeoxyguanosine (8OHdG), with subsequent depletion in the antioxidant status and severe histological aberrations. These anomalies were accompanied by increased expressions of pro-apoptotic Bax, caspase-3 and p53 with decrease in anti-apoptotic Bcl-2. Farnesol treatment (100mg/kg b.wt.) ameliorated LPS-induced oxidative stress by enhancing the antioxidant defense system as evident from the increased levels of SOD, CAT, GSH and GST and exhibited protected cellular morphology manifested from histopathological and nissl staining analyses. Farnesol treatment also reduced the expulsion of cytochrome c from mitochondria and downregulated caspase 3 activation as revealed by immunoblot analysis. Furthermore, farnesol treatment reduced the expression of Bax and antagonized LPS-induced decrease in anti-apoptotic Bcl-2. Results of this study show that farnesol exerts neuroprotective effect by regulating intrinsic apoptotic cascade through its antioxidant effect during LPS-induced neurodegeneration.
神经元凋亡是与各种神经病变相关的氧化应激的结果。在本研究中,我们研究了法尼醇(一种倍半萜烯)通过调节瑞士白化小鼠皮质和海马中的内在凋亡级联反应,对脂多糖(LPS)诱导的神经变性的保护作用。腹腔注射LPS(250μg/kg体重,持续7天)导致脂质过氧化、蛋白质羰基化和8-羟基脱氧鸟苷(8OHdG)水平升高,随后抗氧化状态降低和严重的组织学异常。这些异常伴随着促凋亡蛋白Bax、半胱天冬酶-3和p53表达增加,抗凋亡蛋白Bcl-2表达减少。法尼醇处理(100mg/kg体重)通过增强抗氧化防御系统改善了LPS诱导的氧化应激,这从超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽(GSH)和谷胱甘肽S-转移酶(GST)水平升高可以明显看出,并且组织病理学和尼氏染色分析显示其具有保护细胞形态的作用。免疫印迹分析显示,法尼醇处理还减少了细胞色素c从线粒体的释放,并下调了半胱天冬酶3的激活。此外,法尼醇处理降低了Bax的表达,并拮抗了LPS诱导的抗凋亡蛋白Bcl-2的减少。本研究结果表明,在LPS诱导的神经变性过程中,法尼醇通过其抗氧化作用调节内在凋亡级联反应,从而发挥神经保护作用。