中国神经再生研究(英文版)

中国神经再生研究(英文版) ›› 2023, Vol. 18 ›› Issue (7): 1613-1622.doi: 10.4103/1673-5374.361516

• 原著:神经损伤修复保护与再生 • 上一篇    下一篇

BRAF V600E通过ERK和JNK分别诱导小胶质细胞增生和神经元死亡

  

  • 出版日期:2023-07-15 发布日期:2023-01-12
  • 基金资助:
    美国国立卫生研究院支持；国家自然科学基金，以及Michael J. Fox帕金森研究基金会（MJFF）

Oncogenic BRAFV600E induces microglial proliferation through extracellular signal-regulated kinase and neuronal death through c-Jun N-terminal kinase

Qing Ye1, 2, Pranay Srivastava1, 3, Nasser Al-Kuwari1, Xiqun Chen1, 3, *   

  1. 1Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA; 2Department of Neurology, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China; 3Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD, USA
  • Online:2023-07-15 Published:2023-01-12
  • Contact: Xiqun Chen, MD, PhD, xchen17@mgh.harvard.edu.
  • Supported by:
    This work was supported by the National Institutes of Health, No. R01NS102735 (to XC); the National Natural Science Foundation of China, No. 82073072 (to XC), and the Michael J. Fox Foundation for Parkinson’s Research (MJFF) and the Aligning Science Across Parkinson’s Initiative (ASAP), No. ASAP-000312 (to XC).

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摘要：

BRAF中激活的V600E是多种组织来源的癌症中常见的驱动突变，包括黑色素瘤和胶质瘤。BRAFV600E还涉及神经变性。为了解BRAFV600E对中枢神经系统三种主要细胞类型（神经元、星形胶质细胞和小胶质细胞）的细胞死亡和增殖的影响特征。采用了多种原代培养物（原代皮质混合培养）和胶质细胞（BV2）和神经元（SH-SY5Y）的细胞系。以慢病毒或逆转录病毒介导BRAFV600E和BRAFWT的表达。通过siRNA阻断下游效应器（ERK1/2和JNK1/2）。通过KEGG分析了帕金森病患者的基因表达数据。在星形胶质细胞和小胶质细胞中，BRAFV600E通过激活的ERK介导的，而不是JNK诱导小胶质细胞的增殖作用。表达BRAFV600E的小胶质细胞的条件培养基介质诱导神经元死亡。在神经元细胞中，BRAFV600E通过JNK而不是ERK直接诱导神经元死亡。实验结果进一步表明，BRAF相关基因在帕金森病患者的路径中富集。研究确定了在同一BRAF突变激活后，在分裂的胶质细胞和神经元中由不同的下游效应器介导的不同后果，以及BRAF激活的小胶质细胞和神经元细胞死亡之间的因果关系。研究结果说明BRAF在神经元中的失调或其对胶质细胞影响可能是其在神经退行性疾病中发挥重要作用的机制。

https://orcid.org/0000-0001-8582-8891 (Xiqun Chen)

Abstract: Activating V600E in v-Raf murine sarcoma viral oncogene homolog B (BRAF) is a common driver mutation in cancers of multiple tissue origins, including melanoma and glioma. BRAFV600E has also been implicated in neurodegeneration. The present study aims to characterize BRAFV600E during cell death and proliferation of three major cell types of the central nervous system: neurons, astrocytes, and microglia. Multiple primary cultures (primary cortical mixed culture) and cell lines of glial cells (BV2) and neurons (SH-SY5Y) were employed. BRAFV600E and BRAFWT expression was mediated by lentivirus or retrovirus. Blockage of downstream effectors (extracellular signal-regulated kinase 1/2 and JNK1/2) were achieved by siRNA. In astrocytes and microglia, BRAFV600E induces cell proliferation, and the proliferative effect in microglia is mediated by activated extracellular signal-regulated kinase, but not c-Jun N-terminal kinase. Conditioned medium from BRAFV600E-expressing microglia induced neuronal death. In neuronal cells, BRAFV600E directly induces neuronal death, through c-Jun N-terminal kinase but not extracellular signal-regulated kinase. We further show that BRAF-related genes are enriched in pathways in patients with Parkinson’s disease. Our study identifies distinct consequences mediated by distinct downstream effectors in dividing glial cells and in neurons following the same BRAF mutational activation and a causal link between BRAF-activated microglia and neuronal cell death that does not require physical proximity. It provides insight into a possibly important role of BRAF in neurodegeneration as a result of either dysregulated BRAF in neurons or its impact on glial cells.

Key words: astrocytes, cell death, cell proliferation, inflammation, microglia, mutation, neurons, v-Raf murine sarcoma viral oncogene homolog B (BRAF)