Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China.
Institute of Neuroscience, Key Laboratory of Molecular Neurobiology of Ministry of Education and the Collaborative Innovation Center for Brain Science, Naval Medical University, Shanghai 200433, China.
J Adv Res. 2024 May;59:111-127. doi: 10.1016/j.jare.2023.06.013. Epub 2023 Jun 26.
Ectopic expression of transcription factor-mediated in vivo neuronal reprogramming provides promising strategy to compensate for neuronal loss, while its further clinical application may be hindered by delivery and safety concerns. As a novel and attractive alternative, small molecules may offer a non-viral and non-integrative chemical approach for reprogramming cell fates. Recent definitive evidences have shown that small molecules can convert non-neuronal cells into neurons in vitro. However, whether small molecules alone can induce neuronal reprogramming in vivo remains largely unknown.
To identify chemical compounds that can induce in vivo neuronal reprogramming in the adult spinal cord.
Immunocytochemistry, immunohistochemistry, qRT-PCR and fate-mapping are performed to analyze the role of small molecules in reprogramming astrocytes into neuronal cells in vitro and in vivo.
By screening, we identify a chemical cocktail with only two chemical compounds that can directly and rapidly reprogram cultured astrocytes into neuronal cells. Importantly, this chemical cocktail can also successfully trigger neuronal reprogramming in the injured adult spinal cord without introducing exogenous genetic factors. These chemically induced cells showed typical neuronal morphologies and neuron-specific marker expression and could become mature and survive for more than 12 months. Lineage tracing indicated that the chemical compound-converted neuronal cells mainly originated from post-injury spinal reactive astrocytes.
Our proof-of-principle study demonstrates that in vivo glia-to-neuron conversion can be manipulated in a chemical compound-based manner. Albeit our current chemical cocktail has a lowreprogramming efficiency, it will bring in vivo cell fate reprogramming closer to clinical application in brain and spinal cord repair. Future studies should focus on further refining our chemical cocktail and reprogramming approach to boost the reprogramming efficiency.
转录因子介导的异位体内神经元重编程为补偿神经元缺失提供了有前景的策略，但其进一步的临床应用可能受到传递和安全性问题的阻碍。作为一种新颖且有吸引力的替代方法，小分子可能为细胞命运重编程提供非病毒和非整合的化学方法。最近的明确证据表明，小分子可以将非神经元细胞体外转化为神经元。然而，小分子是否可以单独诱导体内神经元重编程在很大程度上仍然未知。
鉴定可在成年脊髓中诱导体内神经元重编程的化学化合物。
通过免疫细胞化学、免疫组织化学、qRT-PCR 和命运图谱分析，研究小分子在体外和体内将星形胶质细胞重编程为神经元细胞中的作用。
通过筛选，我们确定了一种含有仅两种化学化合物的化学鸡尾酒，可以直接且快速地将培养的星形胶质细胞重编程为神经元细胞。重要的是，这种化学鸡尾酒还可以成功地在受伤的成年脊髓中触发神经元重编程，而无需引入外源性遗传因素。这些化学诱导的细胞表现出典型的神经元形态和神经元特异性标志物表达，并能成熟并存活超过 12 个月。谱系追踪表明，化学化合物转化的神经元细胞主要来源于损伤后脊髓反应性星形胶质细胞。
我们的原理验证研究表明，体内胶质细胞到神经元的转化可以通过化学化合物的方式进行操纵。尽管我们目前的化学鸡尾酒的重编程效率较低，但它将使体内细胞命运重编程更接近脑和脊髓修复的临床应用。未来的研究应集中于进一步改进我们的化学鸡尾酒和重编程方法，以提高重编程效率。
