Institute of Genetics and Biophysics "A. Buzzati-Traverso", National Research Council (C.N.R.), 80131 Naples, Italy.
Department of Pharmacy, School of Medicine and Surgery, University of Naples Federico II, 80131 Naples, Italy.
Int J Mol Sci. 2022 Jun 23;23(13):6961. doi: 10.3390/ijms23136961.
The development of midbrain dopaminergic (DA) neurons requires a fine temporal and spatial regulation of a very specific gene expression program. Here, we report that during mouse brain development, the microRNA (miR-) 204/211 is present at a high level in a subset of DA precursors expressing the transcription factor Lmx1a, an early determinant for DA-commitment, but not in more mature neurons expressing Th or Pitx3. By combining different in vitro model systems of DA differentiation, we show that the levels of Lmx1a influence the expression of miR-204/211. Using published transcriptomic data, we found a significant enrichment of miR-204/211 target genes in midbrain dopaminergic neurons where Lmx1a was selectively deleted at embryonic stages. We further demonstrated that miR-204/211 controls the timing of the DA differentiation by directly downregulating the expression of Nurr1, a late DA differentiation master gene. Thus, our data indicate the Lmx1a-miR-204/211-Nurr1 axis as a key component in the cascade of events that ultimately lead to mature midbrain dopaminergic neurons differentiation and point to miR-204/211 as the molecular switch regulating the timing of Nurr1 expression.
中脑多巴胺能 (DA) 神经元的发育需要精细的时空调节特定基因表达程序。在这里，我们报告在小鼠大脑发育过程中，microRNA (miR-) 204/211 在表达转录因子 Lmx1a 的一组 DA 前体细胞中高水平表达，Lmx1a 是 DA 决定的早期决定因素，但不在表达 Th 或 Pitx3 的更成熟神经元中表达。通过结合不同的体外 DA 分化模型系统，我们表明 Lmx1a 的水平影响 miR-204/211 的表达。利用已发表的转录组数据，我们发现 miR-204/211 的靶基因在中脑多巴胺能神经元中显著富集，其中 Lmx1a 在胚胎阶段被选择性缺失。我们进一步证明，miR-204/211 通过直接下调晚期 DA 分化主基因 Nurr1 的表达来控制 DA 分化的时间。因此，我们的数据表明 Lmx1a-miR-204/211-Nurr1 轴作为最终导致成熟中脑多巴胺能神经元分化的事件级联中的关键组成部分，并指出 miR-204/211 是调节 Nurr1 表达时间的分子开关。
