DRD1转录调控对精神分裂症发生的作用及法医学应用

The relation and mechanism between schizophrenia and dopaminergic nervous system disorders is controversial. Our study found that the genetic polymorphisms of DRD1 gene could influence the expression of DRD1, which resulted to the incidence of schizophrenia. However, the detail of regulation mechanism is unclear. The association between rs4532 and rs5326 loci and schizophrenia were observed in case-control study in schizophrenia patients from China Northern Han population. The luciferase reporter assay showed that different haplotypes DRD1 gene promoter region presented different transcriptional activity. Thus, the assumption was proposed that the change of the activity of the transcriptional promoter region might be due to the occurrence of SNP variances, which changed the binding between GCR，Ap-1 and Pax-6 transcription factors/ microRNA and DNA-binding domains, thereby altered the transcriptional activity. We intend to build mutational vectors containing different SNP loci, perform luciferase reporter gene assay, EMSA, CHIP to clarify the relationship between the SNP of DRD1 and transcriptional activity and the molecular mechanisms. These information may provide a potential indicator for the occurrence of schizophrenia and forensic psychiatric assessment.

精神分裂症与多巴胺能神经系统紊乱的关系和机制备受争议。在中国北方汉族群体精神分裂症患者的病例-对照研究中，我们发现DRD1基因启动子区rs4532和rs5326多态性位点与精神分裂症的发生具有关联性。在荧光素酶报告基因分析中，DRD1基因启动子区的各单倍型具有不同的转录活性。这说明DRD1基因遗传多态性可能通过影响DRD1的表达来参与精神分裂症的发生，但具体调控机制尚不清楚。通过生物信息学分析，我们推测启动子区转录活性的改变可能是由于SNP位点改变了GCR，Ap-1和Pax-6等转录因子和DNA结构域的结合，或者是影响miR-302等microRNA与RNA片段的结合，进而改变转录活性。我们拟构建含不同SNP位点的突变载体，通过荧光素酶报告基因分析、EMSA和CHIP等方法，阐明SNP位点与DRD1转录活性的关系及分子机制，为精神分裂症的发生和法医司法精神病学鉴定提供潜在的参考指标。

精神分裂症与多巴胺能神经系统紊乱的关系和机制备受争议。在中国北方汉族群体精神分裂症患者的病例-对照研究中，我们发现DRD1基因启动子区rs4532和rs5326多态性位点与精神分裂症的发生具有关联性。在荧光素酶报告基因分析中，DRD1基因启动子区的各单倍型具有不同的转录活性。随后我们构建含有不同启动子区长度片段的报告基因载体，发现-113至+250bp区域（转录起始位点为+1）是DRD1基因的核心启动子区。通过EMSA实验发现5'-gggacgcgcgggcggggtgggctgtgccccgcgggaaccccgccggcctgtgcgcttgctg-3'是转录因子可能结合的区域。Rs100788661位点的碱基改变可以影响荧光素酶的表达，但T/C等位基因的改变并未影响DNA-蛋白复合体的形成。此外，转录因子（CREB1，TFAP2B和SP1）可以在HEK293细胞中调控内源性DRD1的表达。miRNA-15a，miRNA-15b和miRNA-16可以结合3’UTR（-12~+154bp）参与DRD1的转录后调控。此外，-12至+154bp片段的缺失显着增加了荧光素酶的表达，但不增加mRNA的表达。在HEK293，U87，SK-N-SH和SH-SY5Y细胞系中，miRNA-15a，miRNA-15b和miRNA16可以影响内源性DRD1的表达。