Sox2ot在妊娠前母源性糖尿病引起的神经管发育缺陷中的作用和机制研究

Pregestational maternal diabetes (PGMD) induces neural tube defects (NTDs). China is a high-risk country for PGMD-induced NTDs. There is currently no effective treatment for this disease. Sox2 overlapping transcript (Sox2ot) is a brain-enriched lncRNA and highly expressed in the neuroepithelium during embryonic development. Our study firstly demonstrates that Sox2ot is suppressed by PGMD in the developing embryo during neurulation, and Sox2ot knockout leads to NTDs. However, the inhibitory mechanism of Sox2ot by PGMD and downstream signaling of Sox2ot deficiency-induced NTDs is unclear. We will investigate the molecular mechanisms by which PGMD inhibits Sox2ot expression from the perspective of transcription factors and miRNAs. Meanwhile, we will determine in vivo and in vitro that Sox2ot deficiency inhibits the proliferation and differentiation and induces apoptosis of neuroepithelial cells by down-regulating Pax3 expression, which results in NTDs. Finally, we will demonstrate that restoration of Sox2ot expression inhibits PGMD-induced NTDs via constructing Sox2ot transgenic mice. Thus, this study will elucidate the mechanism of PGMD-induced NTDs from the perspective of lncRNA and provide a novel target for the treatment of this disease.

妊娠前母源性糖尿病（PGMD）诱导神经管发育缺陷（NTDs）。我国是PGMD诱导NTDs的高风险国家，目前无有效的治疗方法。Sox2ot是在胚胎神经上皮及脑中高表达的长非编码RNA（lncRNA）。本课题组首次发现PGMD抑制神经胚形成阶段胚胎中Sox2ot的表达，并且Sox2ot敲除诱导了NTDs。但是PGMD抑制Sox2ot表达机制以及Sox2ot缺乏导致NTDs的下游信号不清楚。本课题将从转录因子和miRNA的角度探索PGMD抑制Sox2ot表达的分子机制。然后从体内体外水平探索Sox2ot缺乏通过下调Pax3抑制神经上皮细胞的增值和分化以及诱导神经上皮细胞凋亡来诱导NTDs。最后通过构建Sox2ot转基因小鼠证实恢复Sox2ot的表达可以抑制PGMD诱导的NTDs。最终，本课题将从lncRNA的全新视角阐明PGMD诱导NTDs的机制，为此疾病的治疗提供新的靶点。

SRY-box转录因子2(SRY-box transcription factor 2, Sox2)重叠转录本(Sox2ot)是一种进化上保守的长链非编码RNA。Sox2ot内含子区域包含胚胎干细胞多能性的主要调节因子Sox2基因。Sox2ot主要在发育中的神经上皮细胞中表达。本研究表明妊娠前母源性糖尿病通过上调miR-27a和miR-200b抑制发育的胚胎中的Sox2ot水平。Sox2ot敲除从转录水平抑制Pax3表达。Sox2ot是Pax3转录复合物的辅助因子，Sox2ot缺陷降低了转录因子与Pax3启动子之间的结合从而抑制Pax3的表达。进一步研究表明，Sox2ot敲除通过Pax3抑制神经干细胞增殖和分化，促进神经干细胞凋亡。神经上皮特异性的过表达Sox2ot通过上调Pax3并随后恢复神经干细胞增殖和分化以及抑制神经干细胞凋亡来改善妊娠前母源性糖尿病引起的神经管发育缺陷。总之，本研究表明Sox2ot可能是治疗妊娠前母源性糖尿病引起的神经管发育缺陷的潜在治疗靶点。