CYP19A1基因单核苷酸多态性在中国汉族女性型秃发中的功能学研究

Female pattern hair loss is a multifactorial disease, which is closely related with the pathogenesis of androgen. This research is mainly concerned with the aromatase gene(CYP19A1 gene), the number and activity of the enzyme determines the ratio of estrogen and androgen levels. In our previous studies we have found that the allele frequencies and distributions of rs6493497 and rs7176005 were significantly different between FPHL and control subjects and GG and CC homozygote genotype may increase the risk of female pattern hair loss. The two SNPs located in the CYP19A1 gene promoter sequences, in conjunction with the promoter, enhancer, or other protein plays an important role. The 8 transcription factors of FOXC1, FOXL1, BRCA1, HNF1B, MZF_5-13, MZF_1-4, YY1 and SOX9 were predicted to combine with the two sites by protien structure analysis in silico. We now conduct a functional study of the two loci, in order to find which transcription factor and further investigate the role of the transcription factor, and the signal pathway it may takes.

女性型秃发是一种多因素疾病，其中雄激素与其发病有着重要关系。本次研究主要关注芳香化酶基因，该酶数量与活性在一定程度上决定着体内雌、雄激素水平的比例。本课题组前期研究发现CYP19A1基因rs6493497、rs7176005位点与中国汉族人群女性型秃发相关，且这两个位点间连锁完全不平衡。本课题组认为GG、CC野生纯合子基因型可能增加女性型秃发的患病风险，突变型具有保护意义。位点位于CYP19A1基因的启动子序列，与之结合的启动子、增强子或其它蛋白对芳香化酶数量或活性的调控起到了关键的作用。通过前期研究发现FOXC1、FOXL1、BRCA1、HNF1B、MZF_5-13、MZF_1-4、YY1、SOX9这8个转录因子具有与该两位点结合的能力。本课题组拟进一步对这两个位点的功能学进行深入研究，以期发现这8个转录因子对突变点的作用，对有阳性发现的转录因子进行进一步的信号通路研究。

目的：我们以前报道过CYP19A1启动子序列的两个单核苷酸多态性（SNPs）与中国女性型秃发（FPHL）相关，rs6493497 GG/rs7176005 CC可能增加FPHL的发病风险。在模拟预测中，SOX9和HNF1B有望提高野生型RS7176005 C的结合强度。在此，我们研究了SOX9和HNF1B在芳香化酶转录调控和毛囊干细胞（HFSCs）稳态中的作用。.方法：我们对10例FPHL患者进行rs6493497/rs7176005基因分型，并评估了头皮组织中CYP19A1/SOX9/HNF1B的mRNA水平与CYP19A1 SNP分型之间的潜在相关性。通过芯片序列和荧光素酶报告分析，揭示SOX9和HNF1B是否直接作用于RS7176005T/C并调节芳香化酶的转录。以体外培养的HFSCs为研究对象，研究了双氢睾酮是否对SOX9、HNF1B和Wnt/β-catenin表达及活性产生影响。同时观察HFSCs的自我更新和分化情况。.结果：在FPHL头皮组织中，CYP19A1单核苷酸多态性与CYP19A1/HNF1B和SOX9相关上游信号分子的mRNA水平有关。芯片序列显示SOX9和HNF1B与rs7176005 C的结合率高于rs7176005 T（分别为0.459%vs0.197%，0.525%vs0.147%）。SOX9和HNF1B直接下调rs7176005 C-HFSCs中芳香化酶的转录。双氢睾酮的刺激可提高HFSCs中SOX9和HNF1B的表达，抑制HFSCs的自我更新和分化。Wnt/β-catenin或雄激素拮抗剂可通过抑制SOX9促进HFSCs的更新和分化。.结论：本研究探讨了SOX9和HNF1B在芳香化酶转录调控和HFSCs稳态中的作用，有助于了解CYP19A1基因在FPHL中的可能致病机制。

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