Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences and Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China.
Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming, Yunnan, China.
Neuropsychopharmacology. 2019 Aug;44(9):1552-1561. doi: 10.1038/s41386-019-0346-3. Epub 2019 Feb 16.
Recent European genome-wide association studies (GWAS) have revealed strong statistical correlations between MDD and numerous zero-to-high linked variants in the genomic region containing major histocompatibility complex (MHC) genes (MHC region), but the underlying biological mechanisms are still unclear. To better understand the roles of this genomic region in the neurobiology of MDD, we applied a convergent functional genomics approach to integrate GWAS data of MDD relevant biological phenotypes, gene-expression analyses results obtained from brain samples, and genetic analyses of independent Chinese MDD samples. We observed that independent MDD risk variants in the MHC region were also significantly associated with the relevant biological phenotypes in the predicted directions, including the emotional and cognitive-related phenotypes. Gene-expression analyses further revealed that mRNA expression levels of several MHC region genes in the human brain were associated with MDD risk SNPs and diagnostic status. For instance, a brain-enriched gene ZNF603P consistently showed lower mRNA levels in the individuals carrying MDD risk alleles and in MDD patients. Remarkably, we further found that independent MDD risk SNPs in the MHC region likely converged to affect the mRNA level(s) of the same gene(s), and Europeans and Han Chinese populations have a substantial shared genetic and molecular basis underlying MDD risk associations in the MHC region. These results highlighted several potential pivotal genes at the MHC region in the pathogenesis of MDD. Their common impacts on multiple psychiatric relevant phenotypes also implicated the neurological processes shared by different psychological processes, such as mood and/or cognition, shedding lights on their potential biological mechanisms.
最近的欧洲全基因组关联研究(GWAS)揭示了重度抑郁症(MDD)与包含主要组织相容性复合体(MHC)基因的基因组区域(MHC 区域)中众多零到高关联变异之间存在强烈的统计学相关性,但潜在的生物学机制仍不清楚。为了更好地理解这个基因组区域在 MDD 神经生物学中的作用,我们应用了一种会聚的功能基因组学方法,整合了与 MDD 相关的生物表型的 GWAS 数据、来自大脑样本的基因表达分析结果,以及独立的中国 MDD 样本的遗传分析。我们观察到 MHC 区域中的独立 MDD 风险变异也与预测方向上的相关生物学表型显著相关,包括情绪和认知相关表型。基因表达分析进一步揭示了人类大脑中几个 MHC 区域基因的 mRNA 表达水平与 MDD 风险 SNP 和诊断状态相关。例如,一个在大脑中丰富表达的基因 ZNF603P 在携带 MDD 风险等位基因的个体和 MDD 患者中表现出较低的 mRNA 水平。值得注意的是,我们还发现 MHC 区域中的独立 MDD 风险 SNP 可能汇聚到影响相同基因的 mRNA 水平,欧洲人和汉族人群在 MHC 区域的 MDD 风险关联中具有实质性的共享遗传和分子基础。这些结果突出了 MHC 区域中几个潜在的关键基因在 MDD 发病机制中的作用。它们对多个精神相关表型的共同影响也暗示了不同心理过程(如情绪和/或认知)所共有的神经过程,为它们的潜在生物学机制提供了线索。