Gsta4 restricts apoptosis in differentiating adult oligodendrocytes via Fas/Casp8/Bid-axis during homeostasis and remyelination

Arrest of oligodendrocyte (OL) differentiation and remyelination following myelin damage in Multiple Sclerosis (MS) are associated with disease progression but the underlying mechanism are elusive. We show that Glutathione S-transferase 4α (Gsta4) is highly expressed during adult OL differentiation and that its loss prevents differentiation into myelinating OLs. Also, Gsta4 appeared to be a novel target for Clemastine, in clinical trial for MS. Over-expression of Gsta4 reduced the expression of Fas and activity along the mitochondria-associated Casp8/Bid-axis in adult pre-OLs from the corpus callosum, together promoting enhanced pre-OL survival during differentiation. The Gsta4-mediated input on apoptosis during adult OL differentiation was further verified in the LPC and EAE model, where Casp8 were reduced in pre-OLs with high Gsta4 expression in an immune response-independent fashion. Our results place Gsta4 as a key regulator of intrinsic mechanisms beneficial for OL differentiation and remyelination, and as a possible target for future MS therapies. GSTA4 transgenenic mice compared with WT at D0, D10 and D15 of EAE. P9560_104 was run on 2 lanes and was demultiplexed using an index-

多发性硬化（Multiple Sclerosis, MS）患者髓鞘损伤后，少突胶质细胞（oligodendrocyte, OL）的分化与髓鞘再生过程受阻，该现象与疾病进展密切相关，但其潜在分子机制仍不明确。本研究发现，谷胱甘肽S-转移酶4α（Glutathione S-transferase 4α, Gsta4）在成年OL分化阶段呈高表达，其基因缺失会阻碍细胞向具有髓鞘形成能力的OL分化。此外，Gsta4被鉴定为氯马斯汀（Clemastine）的全新靶点，而氯马斯汀目前正处于多发性硬化的临床试验中。在来自胼胝体（corpus callosum）的成年少突胶质前体细胞（pre-OLs）中，过表达Gsta4可下调Fas蛋白的表达，并抑制线粒体关联的Casp8/Bid通路活性，从而在分化过程中提升pre-OLs的存活能力。Gsta4介导的成年OL分化阶段抗凋亡调控作用，在溶血磷脂酰胆碱（LPC）和实验性自身免疫性脑脊髓炎（EAE）模型中得到进一步验证：在免疫非依赖的调控模式下，高表达Gsta4的pre-OLs内Casp8的表达水平显著降低。本研究结果表明，Gsta4是调控OL分化与髓鞘再生的关键内源性调节因子，有望成为未来多发性硬化治疗的潜在靶点。本研究将GSTA4转基因小鼠与野生型（Wild Type, WT）小鼠在EAE造模后的第0天（D0）、第10天（D10）及第15天（D15）进行对比分析。P9560_104样本在2个泳道完成电泳，并通过索引进行解多路复用。