PDF(Pubmed)
Abstract：
Multiple sclerosis (MS) is a chronic and debilitating neurological disease that results in inflammatory demyelination. While endogenous remyelination helps to recover function, this restorative process tends to become less efficient over time. Currently, intense efforts aimed at the mechanisms that promote remyelination are being considered promising therapeutic approaches. The M1 muscarinic acetylcholine receptor (M1R) was previously identified as a negative regulator of oligodendrocyte differentiation and myelination. Here, we validate M1R as a target for remyelination by characterizing expression in human and rodent oligodendroglial cells (including those in human MS tissue) using a highly selective M1R probe. As a breakthrough to conventional methodology, we conjugated a fluorophore to a highly M1R selective peptide (MT7) which targets the M1R in the subnanomolar range. This allows for exceptional detection of M1R protein expression in the human CNS. More importantly, we introduce PIPE-307, a brain-penetrant, small-molecule antagonist with favorable drug-like properties that selectively targets M1R. We evaluate PIPE-307 in a series of in vitro and in vivo studies to characterize potency and selectivity for M1R over M2-5R and confirm the sufficiency of blocking this receptor to promote differentiation and remyelination. Further, PIPE-307 displays significant efficacy in the mouse experimental autoimmune encephalomyelitis model of MS as evaluated by quantifying disability, histology, electron microscopy, and visual evoked potentials. Together, these findings support targeting M1R for remyelination and support further development of PIPE-307 for clinical studies.
摘要：
多发性硬化(MS)是一种导致炎性脱髓鞘的慢性和使人衰弱的神经系统疾病。虽然内源性髓鞘再生有助于恢复功能，随着时间的推移，这种恢复过程的效率往往会降低。目前,针对促进髓鞘再生的机制的努力被认为是有希望的治疗方法。M1毒蕈碱乙酰胆碱受体（M1R）先前被鉴定为少突胶质细胞分化和髓鞘形成的负调节剂。这里,我们通过使用高选择性M1R探针表征人和啮齿动物少突胶质细胞(包括人MS组织中的细胞)中的表达,验证M1R是髓鞘再生的靶标.作为传统方法论的突破，我们将荧光团与高度M1R选择性肽（MT7）缀合，该肽靶向亚纳摩尔范围的M1R。这允许异常检测人CNS中的M1R蛋白表达。更重要的是,我们引入PIPE-307，一种脑渗透剂，具有良好的药物样特性的小分子拮抗剂，选择性靶向M1R。我们在一系列体外和体内研究中评估了PIPE-307，以表征M1R相对于M2-5R的效力和选择性，并确认了阻断该受体以促进分化和髓鞘再生的充分性。Further,PIPE-307在MS的小鼠实验性自身免疫性脑脊髓炎模型中显示出显着疗效，组织学,电子显微镜，和视觉诱发电位。一起,这些发现支持靶向M1R用于髓鞘再生,并支持PIPE-307的进一步开发用于临床研究.
