Activation of GPR40 attenuates neuroinflammation and improves neurological function via PAK4/CREB/KDM6B pathway in an experimental GMH rat model.
Activation of GPR40 attenuates neuroinflammation and improves neurological function via PAK4/CREB/KDM6B pathway in an experimental GMH rat model.
复制标题
DOI：
10.1186/s12974-021-02209-9
复制
发表时间：
2021-07-18
影响因子：
9.3
通讯作者：
Tang J
中科院分区：
文献类型：
--
作者：
Xiao J;Cai T;Fang Y;Liu R;Flores JJ;Wang W;Gao L;Liu Y;Lu Q;Tang L;Zhang JH;Lu H;Tang J
生发基质出血（GMH）是指生发基质中未成熟血管破裂，随后出血进入室管膜下区和大脑侧脑室。由此形成的血凝块已被确定为继发性脑损伤的致病因素，它引发了一系列复杂的并行和顺序有害机制，包括神经炎症。孤儿G蛋白偶联受体40（GPR40），一种游离脂肪酸（FFA）受体1，已被证明在激活时具有抗炎作用，并能改善中风动物模型的预后。我们旨在研究GPR40在GMH后的抗炎作用及其潜在机制。
通过脑实质内注射细菌胶原酶在7日龄大鼠幼崽中诱导GMH模型。GPR40激动剂GW9508在GMH诱导后1小时、25小时和49小时经鼻给药。针对GPR40、PAK4和KDM6B的CRISPR在GMH诱导前48小时通过脑室内注射给药。通过负趋地性、右反射、转棒试验、足失误试验、莫里斯水迷宫、免疫荧光染色、蛋白质印迹和尼氏染色分别评估神经学评分、小胶质细胞极化和脑形态。
结果表明，GW9508在短期（24小时、48小时、72小时）和长期（第21 - 27天）改善了GMH后的神经学和形态学结果。然而，一种选择性GPR40拮抗剂GW1100消除了治疗的神经保护作用。GW9508治疗在GMH诱导后24小时增加了脑室周围区域M2小胶质细胞的数量并减少了M1小胶质细胞的数量。GW9508上调了PAK4、CREB的磷酸化以及KDM6B、CD206、IL - 10的蛋白水平，同时炎症标志物IL - 1β和TNF - α下调。机制研究表明，GPR40、PAK4和KDM6B的敲低逆转了GW9508带来的神经保护作用。这一证据表明小胶质细胞中的GPR40/PAK4/CREB/KDM6B信号通路在GMH后神经炎症的减轻中起作用。
总之，本研究表明GPR40的激活通过激活PAK4/CREB/KDM6B信号通路减轻了GMH诱导的神经炎症，并且M2小胶质细胞可能是这种作用的主要介质。因此，GPR40可能作为减少GMH后炎症反应的潜在靶点，从而改善短期和长期的神经学结果。
Germinal matrix hemorrhage (GMH) is defined by the rupture of immature blood vessels in the germinal matrix, where subsequent hemorrhage enters the subependymal zone and the cerebral lateral ventricles. The consequent blood clot has been identified as the causative factor of secondary brain injury, which triggers a series of complex parallel and sequential harmful mechanisms, including neuroinflammation. The orphan G-protein-coupled receptor 40 (GPR40), a free fatty acid (FFA) receptor 1, has been shown to exert anti-inflammatory effects when activated and improved outcomes in animal models of stroke. We aimed to investigate the anti-inflammatory effects of GPR40 and its underlying mechanisms after GMH. GMH model was induced in 7-day-old rat pups by an intraparenchymal injection of bacterial collagenase. GPR40 agonist, GW9508, was administered intranasally 1 h, 25 h, and 49 h after GMH induction. CRISPR targeting GPR40, PAK4, and KDM6B were administered through intracerebroventricular injection 48 h before GMH induction. Neurologic scores, microglia polarization, and brain morphology were evaluated by negative geotaxis, right reflex, rotarod test, foot fault test, Morris water maze, immunofluorescence staining, Western blots, and nissl staining respectfully. The results demonstrated that GW9508 improved neurological and morphological outcomes after GMH in the short (24 h, 48 h, 72h) and long-term (days 21–27). However, the neuroprotective effects of treatment were abolished by GW1100, a selective GPR40 antagonist. GW9508 treatment increased populations of M2 microglia and decreased M1 microglia in periventricular areas 24 h after GMH induction. GW9508 upregulated the phosphorylation of PAK4, CREB, and protein level of KDM6B, CD206, IL-10, which was also met with the downregulation of inflammatory markers IL-1β and TNF-α. The mechanism study demonstrated that the knockdown of GPR40, PAK4, and KDM6B reversed the neuroprotective effects brought on by GW9508. This evidence suggests that GPR40/PAK4/CREB/KDM6B signaling pathway in microglia plays a role in the attenuation of neuroinflammation after GMH. In conclusion, the present study demonstrates that the activation of GPR40 attenuated GMH-induced neuroinflammation through the activation of the PAK4/CREB/KDM6B signaling pathway, and M2 microglia may be a major mediator of this effect. Thus, GPR40 may serve as a potential target in the reduction of the inflammatory response following GMH, thereby improving neurological outcomes in the short- and long-term.
登录
查看更多内容
影响因子：
6.9
作者：
Jackson, Ladonya;Dong, Guangkuo;Ergul, Adviye
通讯作者：
Ergul, Adviye
影响因子：
3.5
作者：
Ma, Dexuan;Lu, Li;Yamashima, Tetsurnori
通讯作者：
Yamashima, Tetsurnori
影响因子：
9.3
作者：
Cherry JD;Olschowka JA;O'Banion MK
通讯作者：
O'Banion MK
DHA促进转染GPR40基因的大鼠神经干细胞的神经元分化
影响因子：
2.9
作者：
Ma, Dexuan;Zhang, Minmin;Zhou, Liangfu
通讯作者：
Zhou, Liangfu
影响因子：
9.3
作者：
Dragano NRV;Solon C;Ramalho AF;de Moura RF;Razolli DS;Christiansen E;Azevedo C;Ulven T;Velloso LA
通讯作者：
Velloso LA