Developmental Biology Program, Stanley Manne Children's Research Institute, Division of Pediatric Neurosurgery, Ann and Robert H. Lurie Children's Hospital of Chicago, Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
Department of Neurosurgery, Japanese Red Cross Medical Center, Shibuya-Ku, Tokyo, Japan.
Stem Cells. 2016 Nov;34(11):2721-2732. doi: 10.1002/stem.2421. Epub 2016 Jun 28.
Prenatal folic acid (FA) supplementation prevents neural tube defects. Folate receptor alpha (FRα) is critical for embryonic development, including neural crest (NC) development. Previously we showed that FRα translocates to the nucleus in response to FA, where it acts as a transcription factor. In this study, we examined if FA through interaction with FRα regulates stem cell characteristics of cranial neural crest cells (CNCCs)-critical for normal development. We hypothesized that FRα upregulates coding genes and simultaneously downregulates non-coding miRNA which targets coding genes in CNCCs. Quantitative RT-PCR and chromatin immunoprecipitation showed that FRα upregulates Oct4, Sox2, and Klf4 by binding to their cis-regulator elements-5' enhancer/promoters defined by H3K27Ac and p300 occupancy. FA via FRα downregulates miRNAs, miR-138 and miR-let-7, which target Oct4 and Trim71 (an Oct4 downstream effector), respectively. Co-immunoprecipitation data suggests that FRα interacts with the Drosha-DGCR8 complex to affect pre-miRNA processing. Transfecting anti-miR-138 or anti-miR-let-7 into non-proliferating neural crest cells (NCCs) derived from Splotch (Sp ), restored their proliferation potential. In summary, these results suggest a novel pleiotropic role of FRα: (a) direct activation of Oct4, Sox2, and Klf4 genes; and (b) repression of biogenesis of miRNAs that target these genes or their effector molecules. Stem Cells 2016;34:2721-2732.
产前叶酸（FA）补充可预防神经管缺陷。叶酸受体α（FRα）对于胚胎发育至关重要，包括神经嵴（NC）发育。我们之前表明，FRα 在 FA 的作用下转位到细胞核，在细胞核中作为转录因子起作用。在这项研究中，我们研究了 FA 是否通过与 FRα 的相互作用调节颅神经嵴细胞（CNCCs）的干细胞特性，这对正常发育至关重要。我们假设 FRα 通过上调编码基因，同时下调非编码 miRNA 来调节 CNCCs 中的编码基因。定量 RT-PCR 和染色质免疫沉淀显示，FRα 通过与它们的顺式调节元件结合来上调 Oct4、Sox2 和 Klf4，顺式调节元件由 H3K27Ac 和 p300 占据。FA 通过 FRα 下调 miR-138 和 miR-let-7，它们分别靶向 Oct4 和 Trim71（Oct4 的下游效应物）。共免疫沉淀数据表明，FRα 与 Drosha-DGCR8 复合物相互作用以影响前 miR 的加工。将抗 miR-138 或抗 miR-let-7 转染到源自 Splotch（Sp）的非增殖性神经嵴细胞（NCCs）中，恢复了它们的增殖潜力。总之，这些结果表明 FRα 具有新的多效性作用：（a）直接激活 Oct4、Sox2 和 Klf4 基因；和（b）抑制靶向这些基因或其效应分子的 miRNA 的生物发生。干细胞 2016；34:2721-2732.
