脊髓损伤(SCI)的恢复与少突胶质祖细胞(OPC)分化受阻密切相关,最终导致无法产生新形成的髓磷脂。为了解决这个问题,基于药物的方法可能是最实用和可行的方法,可能适用于SCI患者的临床治疗。在我们之前的研究中,我们发现氯马斯汀治疗保留了髓鞘的完整性,减少轴突的损失,并提高了SCI模型中的功能恢复。氯马斯汀作为毒蕈碱乙酰胆碱受体的拮抗剂(毒蕈碱受体,MR)从一系列可以增强少突胶质细胞分化和髓鞘包裹的抗毒蕈碱药物中鉴定出来。然而,氯马斯汀通过MR对SCI中OPC分化的影响及其潜在机制尚不清楚.为了探索这种可能性,建立大鼠SCI模型。为了研究氯马斯汀是否可以通过MR促进SCI中OPCs的分化,在损伤后7天(dpi)或14dpi检测到OPC和成熟OL的表达。在14dpi而不是7dpi时,显示了氯马斯汀对促进OPC分化的显着作用。在用MR激动剂西维美林治疗前,氯马斯汀对OPC分化的积极作用被部分破坏.进一步的研究表明,氯马斯汀增加了细胞外信号调节激酶1/2(p-ERK1/2)的磷酸化水平和转录因子的表达,Myrf和Olig2.为了确定氯马斯汀之间的关系,ERK1/2信令,指定的转录因子,和OPC差异化,ERK1/2信号受到U0126的干扰。氯马斯汀抑制SCI大鼠ERK1/2,降低p-ERK1/2、Myrf、Olig2和成熟的OLs,提示ERK1/2是氯马斯汀促进OPC分化所必需的,并且特定的转录因子可能受到ERK1/2活性的影响。此外,西维美林预注射后,氯马斯汀对调节p-ERK1/2水平的影响受到限制,这进一步证明了氯马斯汀的作用是由MRs介导的。总之,我们的数据表明氯马斯汀,由MRs介导,通过激活ERK1/2信号在Myrf和Olig2的增强下促进OPC分化,并为SCI恢复提供了新的治疗前景。
The recovery of spinal cord injury (SCI) is closely associated with the obstruction of oligodendrocyte progenitor cell (OPC) differentiation, which ultimately induces the inability to generate newly formed myelin. To address the concern, drug-based methods may be the most practical and feasible way, possibly applying to clinical therapies for patients with SCI. In our previous study, we found that clemastine treatment preserves myelin integrity, decreases the loss of axons, and improves functional recovery in the SCI model. Clemastine acts as an antagonist of the muscarinic acetylcholine receptor (muscarinic receptor, MR) identified from a string of anti-muscarinic drugs that can enhance oligodendrocyte differentiation and myelin wrapping. However, the effects of clemastine on OPC differentiation through MRs in SCI and the underlying mechanism remain unclear. To explore the possibility, a rat model of SCI was established. To investigate if clemastine could promote the differentiation of OPCs in SCI via MR, the expressions of OPC and mature OL were detected at 7 days post injury (dpi) or at 14 dpi. The significant effect of clemastine on encouraging OPC differentiation was revealed at 14 dpi rather than 7 dpi. Under pre-treatment with the MR agonist cevimeline, the positive role of clemastine on OPC differentiation was partially disrupted. Further studies indicated that clemastine increased the phosphorylation level of extracellular signal-regulated kinase 1/2 (p-ERK1/2) and the expressions of transcription factors, Myrf and Olig2. To determine the relationship among clemastine, ERK1/2 signaling, specified transcription factors, and OPC differentiation, the ERK1/2 signaling was disturbed by U0126. The inhibition of ERK1/2 in SCI rats treated with clemastine decreased the expressions of p-ERK 1/2, Myrf, Olig2, and mature OLs, suggesting that ERK1/2 is required for clemastine on promoting OPC differentiation and that specified transcription factors may be affected by the activity of ERK1/2. Moreover, the impact of clemastine on modulating the level of p-ERK 1/2 was restricted following cevimeline pre-injecting, which provides further evidence that the role of clemastine was mediated by MRs. Altogether, our data demonstrated that clemastine, mediated by MRs, promotes OPC differentiation under the enhancement of Myrf and Olig2 by activating ERK1/2 signaling and suggests a novel therapeutic prospect for SCI recovery.