Liu Lu, Chen Manli, Lin Kun, Xiang Xuwu, Yang Jing, Zheng Yueying, Xiong Xiaoxing, Zhu Shengmei
Department of Anesthesiology, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, China.
Front Cell Dev Biol. 2021 Feb 2;8:594283. doi: 10.3389/fcell.2020.594283. eCollection 2020.
Transient receptor potential canonical 6 (TRPC6) channel is an important non-selective cation channel with a variety of physiological roles in the central nervous system. Evidence has shown that TRPC6 is involved in the process of experimental stroke; however, the underlying mechanisms remain unclear. In the present study, the role of astrocytic TRPC6 was investigated in an oxygen-glucose deprivation cell model and middle cerebral artery occlusion (MCAO) mouse model of stroke. HYP9 (a selective TRPC6 agonist) and SKF96365 (SKF; a TRPC antagonist) were used to clarify the exact functions of TRPC6 in astrocytes after ischemic stroke. TRPC6 was significantly downregulated during ischemia/reperfusion (IR) injury in cultured astrocytes and in cortices of MCAO mice. Application of HYP9 alleviated the brain infarct lesion, astrocytes population, apoptosis, and interleukin-6 (IL-6) and IL-1β release in mouse cortices after ischemia. HYP9 dose-dependently inhibited the downregulation of TRPC6 and reduced astrocytic apoptosis, cytotoxicity and inflammatory responses in IR insult, whereas SKF aggravated the damage . In addition, modulation of TRPC6 channel diminished IR-induced Ca entry in astrocytes. Furthermore, decreased Ca entry due to TRPC6 contributed to reducing nuclear factor kappa light chain enhancer of activated B cells (NF-κB) nuclear translocation and phosphorylation. Overexpression of astrocytic TRPC6 also attenuated apoptosis, cytotoxicity, inflammatory responses, and NF-κB phosphorylation in modeled ischemia in astrocytes. The results of the present study indicate that the TRPC6 channel can act as a potential target to reduce both inflammatory responses and apoptosis in astrocytes during IR injury, subsequently attenuating ischemic brain damage. In addition, we provide a novel view of stroke therapy by targeting the astrocytic TRPC6 channel.
瞬时受体电位经典型6（TRPC6）通道是一种重要的非选择性阳离子通道，在中枢神经系统中具有多种生理作用。有证据表明，TRPC6参与实验性中风的过程；然而，其潜在机制仍不清楚。在本研究中，在氧糖剥夺细胞模型和大脑中动脉闭塞（MCAO）小鼠中风模型中研究了星形胶质细胞TRPC6的作用。使用HYP9（一种选择性TRPC6激动剂）和SKF96365（SKF；一种TRPC拮抗剂）来阐明缺血性中风后TRPC6在星形胶质细胞中的确切功能。在培养的星形胶质细胞和MCAO小鼠的皮质中，TRPC6在缺血/再灌注（IR）损伤期间显著下调。应用HYP9可减轻缺血后小鼠皮质中的脑梗死病变、星形胶质细胞数量、细胞凋亡以及白细胞介素-6（IL-6）和IL-1β释放。HYP9剂量依赖性地抑制TRPC6的下调，并减少IR损伤中星形胶质细胞的凋亡、细胞毒性和炎症反应，而SKF则加重损伤。此外，调节TRPC6通道可减少IR诱导的星形胶质细胞中的Ca内流。此外，由于TRPC6导致的Ca内流减少有助于减少活化B细胞核因子κB轻链增强子（NF-κB）的核转位和磷酸化。星形胶质细胞TRPC6的过表达也减轻了星形胶质细胞模型缺血中的细胞凋亡、细胞毒性、炎症反应和NF-κB磷酸化。本研究结果表明，TRPC6通道可作为一个潜在靶点，以减少IR损伤期间星形胶质细胞中的炎症反应和细胞凋亡，随后减轻缺血性脑损伤。此外，我们通过靶向星形胶质细胞TRPC6通道提供了一种中风治疗的新观点。
