Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, PR China.
Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou 510405, PR China.
Life Sci. 2019 Jan 1;216:233-245. doi: 10.1016/j.lfs.2018.11.035. Epub 2018 Nov 22.
Tilianin, a naturally occurring flavonoid glycoside, possesses versatile biological activities including antioxidant, anti-inflammatory, energy collecting and anti-hypoxic effects. Little is known about the mechanisms underlying the effect of tilianin against ischemic injury in neuronal cells. We aimed to determine the potential targets and mechanisms of tilianin treatment behind the crosstalk pathways induced by oxygen-glucose deprivation (OGD).
We used an in silico docking model for interaction mode analysis and in vitro models for mechanistic exploration and target verification. Protein changes were measured using cellular immunofluorescence and ELISA techniques.
The ability of tilianin to promote recovery of OGD-induced neurocytotoxic injury was demonstrated by maintenance of cell viability, membrane integrity and nuclear homogeneity. Tilianin treatment was also found to balance the concentrations of proapoptotic and antiapoptotic proteins that had been modified by OGD-induced mitochondrial dysfunction. Of these intersectional cascades, Ca/calmodulin-dependent protein kinase II (CaMKII) was found to bind efficiently with tilianin. This presented a certain binding score along with down-regulation of ox-CaMKII and p-CaMKII in SH-SY5Y cells affected by OGD. Importantly, after utilizing KN93, one specific CaMKII inhibitor, tilianin-mediated neuroprotection against OGD was abolished. This effect was accompanied by upregulation of mitochondrial function. Thus, the beneficial effects of tilianin toward mitochondrion-mediated apoptosis and p38/JNK/NF-κB-associated inflammatory pathways were reversed following CaMKII inhibition.
Our study indicated that attenuation of CaMKII-linked signaling mediated through mitochondria and p38/JNK/NF-κB inflammatory pathways is a key mechanism by which tilianin exerts its neuroprotective effects against cerebral ischemia.
丁香苷是一种天然存在的类黄酮糖苷，具有多种生物活性，包括抗氧化、抗炎、能量收集和抗缺氧作用。关于丁香苷对神经元细胞缺血损伤的作用机制知之甚少。我们旨在确定丁香苷通过氧葡萄糖剥夺（OGD）诱导的交叉途径治疗的潜在靶点和机制。
我们使用计算机对接模型进行相互作用模式分析，以及体外模型进行机制探索和靶标验证。使用细胞免疫荧光和 ELISA 技术测量蛋白质变化。
通过维持细胞活力、膜完整性和核均匀性，证明了丁香苷能够促进 OGD 诱导的神经细胞毒性损伤的恢复。丁香苷处理还发现可以平衡由 OGD 诱导的线粒体功能障碍引起的促凋亡和抗凋亡蛋白浓度。在这些交叉级联中，发现钙/钙调蛋白依赖性蛋白激酶 II（CaMKII）与丁香苷有效结合。这呈现出一定的结合评分，同时下调 OGD 影响的 SH-SY5Y 细胞中的 ox-CaMKII 和 p-CaMKII。重要的是，在用 KN93（一种特定的 CaMKII 抑制剂）处理后，丁香苷对 OGD 的神经保护作用被消除。这种作用伴随着线粒体功能的上调。因此，在用 CaMKII 抑制剂处理后，丁香苷对线粒体介导的细胞凋亡和 p38/JNK/NF-κB 相关炎症途径的有益作用被逆转。
我们的研究表明，通过线粒体和 p38/JNK/NF-κB 炎症途径抑制 CaMKII 相关信号传导是丁香苷发挥其对脑缺血神经保护作用的关键机制。
