磷酸化转录因子Olig2阶段性调控少突胶质细胞系分化的作用机制

Our recent results indicate that Olig2 displays a stage-specific function on oligodendroglial differentiation which is highly correlated with Olig1 expression, namely Olig2 promotes Olig1 expression and differentiation at oligodendrocyte progenitor cells (OPCs) stage, but inhibits Olig1 expression and maturation at oligodendrocytes (OLs) stage. Combined with the bioinfomatics analysis and documentaries, we hypothesis that phosphorylation status of Olig2 decide the co-factors which it would binding to, and Olig2 in collaborating with co-factors manipulates stage-specific Olig1 expression and oligodendroglial differentiation. In the proposed proposal, using Olig1/2 conditional knock-out mice, OPC culture, Chip-sequence, and point-mutation methods, we first investigate whether Olig1 expression is directly controlled by Olig2, then we will identify the various co-factors by which phosphorylation status of Olig2 cooperate with to manipulate the stage-specific olig1 expression as well as status of oligodendroglial differentiation. Lastly, we would generate Olig2 mutant trangenic mice at indicated phosphorylation sites to reveal the stage-dependent function by Olig2. Our results would clarify mechanisms underlying the stage-specific regulatory function by Olig2, that may provide potential target for novel drug development and therapy strategy.

前期实验证明，转录因子Olig2具有阶段性调控少突胶质细胞系分化的特征，且与Olig1表达高度相关，即在少突胶质前体细胞(OPCs)阶段促进Olig1表达，正向调控分化，而在少突胶质细胞（OLs）阶段，抑制Olig1表达，负向调控分化成熟。结合文献和生物信息学分析，我们推测Olig2的磷酸化状态差异，决定与不同协同转录因子结合，实现阶段性调控Olig1表达和少突胶质系分化。本课题拟采用Olig2/1条件敲基因小鼠，结合离体OPCs培养，Chip-Sequence、点突变等方法，明确Olig2磷酸化状态调控Olig1表达。进一步利用Co-IP、Lusifase等方法证明Olig2磷酸化状态差异能够与不同的转录因子结合，发挥阶段性作用。最后通过点突变转基因小鼠验证Olig2的阶段性调控作用效应。本项目的完成将阐明Olig2阶段性调控作用的机制，为脱髓鞘疾病的治疗策略研究提供新的药物治疗靶点。

前期实验证明,转录因子 Olig2 具有阶段性调控少突胶质细胞系分化的特征,且与 Olig1 表 达高度相关,即在少突胶质前体细胞(OPCs)阶段促进 Olig1 表达,正向调控分化,而在少突 胶质细胞(OLs)阶段,抑制 Olig1 表达,负向调控分化成熟。结合文献和生物信息学分析 我们推测 Olig2 的磷酸化状态差异,决定与不同协同转录因子结合,实现阶段性调控 Olig1 表达和少突胶质系分化。本课题拟采用 Olig2/1 条件敲基因小鼠,结合离体 OPCs 培养, Chip-Sequence、点突变等方法,明确 Olig2 磷酸化状态调控 Olig1 表达。本项目的完成将阐明 Olig2 阶段性调控作用的机制。进一步证明Kappa阿片受体（KOR）是Olig2其下游靶基因，具有调控髓鞘再生的作用，并采用KOR条件敲除小鼠证明KOR是调控少突胶质细胞发育的新受体。本研究结果为脱髓鞘疾病的治疗策略研究提供新的药物治疗靶点和药物。