Department of Spine Surgery, Hainan General Hospital and Hainan Affiliated Hospital of Hainan Medical University, Haikou, China.
Department of Spine Surgery, Xiangya Hospital of Central-South University, Hunan, 410008, China.
BMC Musculoskelet Disord. 2022 Aug 20;23(1):797. doi: 10.1186/s12891-022-05730-x.
Congenital scoliosis (CS) is a congenital deformity of the spine resulting from abnormal and asymmetrical development of vertebral bodies during pregnancy. However, the etiology and mechanism of CS remain unclear. Epigenetics is the study of heritable variations in gene expression outside of changes in nucleotide sequence. Among these, DNA methylation was described first and is the most characteristic and most stable epigenetic mechanism. Therefore, in this study, we aim to explore the association between genome methylation and CS which are not been studied before.
Two pairs of monozygotic twins were included, with each pair involving one individual with and one without CS. Agilent SureSelect XT Human Methyl-Sequencing was used for genome methylation sequencing. MethylTarget was used to detect methylation levels in target regions. Immunohistochemistry was performed to visualize expression of associated genes in candidate regions.
A total of 75 differentially methylated regions were identified, including 24 with an increased methylation level and 51 with a decreased methylation level in the CS group. Nine of the differentially methylated regions were selected (TNS3, SEMAC3, GPR124, MEST, DLK1, SNTG1, PPIB, DEF8, and GRHL2). The results showed that the methylation level of the promoter region of TNS3 was 0.72 ± 0.08 in the CS group and 0.43 ± 0.06 in the control group (p = 0.00070 < 0.01). There was no significant difference in the degree of methylation of SEMAC3, GPR124, MEST, DLK1, SNTG1, PPIB, DEF8, or GRHL2 between the two groups. Immunohistochemistry showed significantly decreased TNS3 expression in the cartilage of the articular process in CS (CS: 0.011 ± 0.002; control: 0.018 ± 0.006, P = 0.003 < 0.01).
Compared with the control group, high-level methylation of the TNS3 promoter region and low TNS3 expression in the cartilage layer of the articular process characterize CS. Thus, DNA methylation and TNS3 may play important roles in the pathogenesis of CS.
先天性脊柱侧凸（CS）是一种脊柱先天性畸形，是由于妊娠期间椎体的异常和不对称发育所致。然而，CS 的病因和发病机制尚不清楚。表观遗传学是研究基因表达在外显子序列变化之外的可遗传变化。在这些变化中，首先描述了 DNA 甲基化，它是最具特征性和最稳定的表观遗传机制。因此，在这项研究中，我们旨在探索尚未研究过的基因组甲基化与 CS 之间的关联。
纳入了两对同卵双胞胎，每对双胞胎都有一个患有 CS 的个体和一个没有 CS 的个体。使用 Agilent SureSelect XT 人类甲基化测序进行全基因组甲基化测序。使用 MethylTarget 检测目标区域的甲基化水平。免疫组织化学用于可视化候选区域中相关基因的表达。
共鉴定出 75 个差异甲基化区域，其中 CS 组中有 24 个区域的甲基化水平升高，51 个区域的甲基化水平降低。选择了 9 个差异甲基化区域（TNS3、SEMAC3、GPR124、MEST、DLK1、SNTG1、PPIB、DEF8 和 GRHL2）。结果表明，CS 组 TNS3 启动子区域的甲基化水平为 0.72±0.08，对照组为 0.43±0.06（p=0.00070<0.01）。两组间 SEMAC3、GPR124、MEST、DLK1、SNTG1、PPIB、DEF8 或 GRHL2 的甲基化程度无显著差异。免疫组织化学显示 CS 关节突软骨中 TNS3 表达明显降低（CS：0.011±0.002；对照组：0.018±0.006，p=0.003<0.01）。
与对照组相比，TNS3 启动子区域的高甲基化和关节突软骨层中 TNS3 的低表达是 CS 的特征。因此，DNA 甲基化和 TNS3 可能在 CS 的发病机制中起重要作用。
