State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Savaid Medical School, University of Chinese Academy of Sciences, Beijing, China.
Cell Prolif. 2021 Nov;54(11):e13124. doi: 10.1111/cpr.13124. Epub 2021 Sep 25.
Neurodevelopmental diseases are common disorders caused by the disruption of essential neurodevelopmental processes. Recent human exome sequencing and genome-wide association studies have shown that mutations in the subunits of the SWI/SNF (BAF) complex are risk factors for neurodevelopmental diseases. Clinical studies have found that ARID1A (BAF250a) is the most frequently mutated SWI/SNF gene and its mutations lead to mental retardation and microcephaly. However, the function of ARID1A in brain development and its underlying mechanisms still remain elusive.
The present study used Cre/loxP system to generate an Arid1a conditional knockout mouse line. Cell proliferation, cell apoptosis and cell differentiation of NSPCs were studied by immunofluorescence staining. In addition, RNA-seq and RT-PCR were performed to dissect the molecular mechanisms of Arid1a underlying cortical neurogenesis. Finally, rescue experiments were conducted to evaluate the effects of Neurod1 or Fezf2 overexpression on the differentiation of NSPCs in vitro.
Conditional knockout of Arid1a reduces cortical thickness in the developing cortex. Arid1a loss of function inhibits the proliferation of radial glial cells, and increases cell death during late cortical development, and leads to dysregulated expression of genes associated with proliferation and differentiation. Overexpression of Neurod1 or Fezf2 in Arid1a cKO NSPCs rescues their neural differentiation defect in vitro.
This study demonstrates for the first time that Arid1a plays an important role in regulating the proliferation and differentiation of NSPCs during cortical development, and proposes several gene candidates that are worth to understand the pathological mechanisms and to develop novel interventions of neurodevelopment disorders caused by Arid1a mutations.
神经发育疾病是由关键神经发育过程中断引起的常见疾病。最近的人类外显子组测序和全基因组关联研究表明，SWI/SNF（BAF）复合物亚基的突变是神经发育疾病的风险因素。临床研究发现 ARID1A（BAF250a）是最常突变的 SWI/SNF 基因，其突变导致智力迟钝和小头畸形。然而，ARID1A 在大脑发育中的功能及其潜在机制仍不清楚。
本研究使用 Cre/loxP 系统生成了 Arid1a 条件敲除小鼠系。通过免疫荧光染色研究 NSPCs 的细胞增殖、细胞凋亡和细胞分化。此外，进行 RNA-seq 和 RT-PCR 以剖析 ARID1A 对皮质神经发生的潜在分子机制。最后，进行挽救实验以评估 Neurod1 或 Fezf2 过表达对 NSPCs 体外分化的影响。
Arid1a 条件敲除可减少发育中皮质的皮质厚度。Arid1a 功能丧失抑制放射状胶质细胞的增殖，并在皮质晚期发育过程中增加细胞死亡，导致与增殖和分化相关的基因表达失调。Neurod1 或 Fezf2 在 Arid1a cKO NSPCs 中的过表达可挽救其体外神经分化缺陷。
这项研究首次表明，Arid1a 在调节皮质发育过程中 NSPCs 的增殖和分化中起重要作用，并提出了一些值得研究的候选基因，以了解由 Arid1a 突变引起的神经发育障碍的病理机制并开发新的干预措施。
