IL-34/CSF1R途径在遗传性弥漫性白质脑病合并轴索球样变中的关键作用

Hereditary diffuse leukoencephalopathy with spheroids (HDLS) in humans is a rare autosomal dominant encephalopathy, mutations in the colony-stimulating factor 1 receptor gene (CSF-1R) were identified as the genetic cause of HDLS recently. Our preliminary work indicated that IL-34/CSF1R pathway could be deeply involved the pathogenesis of the progressive demyelinating disease. With the supportive data that haploinsufficiency can cause dysfuncion of microglia (MG) and oligodendrocytes (OL) in HDLS, we have found that the central role of IL-34/CSF1R signaling pathway in MG regulating the dysfunction of myelinating of OL. We propose the hypothesis that the IL-34/CSF1R play key role in HDLS pathogenesis via neuron-microglia-oligodendrocyte network in CNS, and further to investigate the new disease-modify treatment strategy by targeting IL-34/CSF1R with CRISPR technique.

遗传性弥漫性白质脑病合并轴索球样变(Hereditary Diffuse Leukoencephalopathy with Spheroids, HDLS)是一种罕见的常染色体显性遗传脑病，系集落刺激因子-1受体(colony-stimulating factor-1 receptor, CSF1R)基因突变导致。我们前期工作提示IL-34/CSF1R途径密切参与HDLS进行性脱髓鞘损害病理过程；国外研究提示小胶质细胞(MG)-寡突胶质细胞(OL)功能异常与单倍体不足有关，支持预实验发现IL-34/CSF1R途径在MG调节髓鞘形成中的核心机制。我们提出此假说：IL-34/CSF1R途径在HDLS发病中关键作用主要经由神经元-小胶质细胞-寡突胶质细胞的网络而实现。并进一步探索CRISPR技术修复IL-34/CSF1R途径的病因治疗策略。

我们在报道集落刺激因子-1 受体(colony-stimulating factor-1 receptor, CSF1R)基因突变导致的遗传性弥漫性白质脑病合并轴索球样变(Hereditary Diffuse Leukoencephalopathy with Spheroids, HDLS)这种罕见的常染色体显性遗传脑病基础上，通过系列研究揭示：（1）CSF1R突变导致MG细胞功能异常及外泌体双向调控机制：CSF1R野生型过表达对细胞周期无显著影响，突变型过表达会使细胞周期产生明显的G2/M阻滞。对比正常人血清及过表达CSF1R突变基因的BV-2细胞外泌体，证实exosome-突变CSF1R对共培养的神经元，星形胶质细胞有毒性。而年轻的过表达CSF1R野生型BV-2细胞的外泌体，可以促进寡突胶质细胞的髓鞘修复。（2）抑制CSF1R突变诱导MG炎性转化可改善AD转基因鼠病理学：CSF1R通过调控转录因子CREB1激活TNFα-NALP3炎症途径CSF1R上调，CREB1下调，TNFα-NALP3炎症途径激活。而GW2580(CSF1R抑制剂)可以调节MG-AC交互作用：GW2580通过抑制MG可以抑制AC表面tmTNFα表达，及降低sTNFα(炎性因子)的释放。提示GW2580通过MG-AC交互作用可能参与MG极化和对AC炎性诱导，从而参与了Aβ的代谢；（3）CAR-T靶向MG-CSF1R实现高效持续改善阿尔兹海默病(AD)转基因鼠病理学，根据抗CSF1R的小鼠scFv序列，制备第二代CAR-T细胞，包装病毒后转导活化T细胞，通过对慢病毒后转导人CSF1R全长基因构建CSF1R稳定过表达肺癌A549细胞特异性杀伤作用的验证二代CSF1R.CAR-T构建成功。给予CSF1R.CAR-T干预3月龄及6月龄APPswe/PS1dE9转基因鼠，Aβ免疫组化显示，Aβ阳性斑块清除效应存在及早干预效果更明显的趋势。