ABSTRACT

Chronic kidney disease (CKD) related cardiovascular disease (CVD) is characterized by vascular remodelling with well-established structural and functional changes in the vascular wall such as arterial stiffness, matrix deposition, and calcification. These phenotypic changes resemble pathology seen in ageing, and are likely to be mediated by sustained alterations in gene expression, which may be caused by epigenetic changes such as tissue-specific DNA methylation. We aimed to investigate tissue specific changes in DNA methylation that occur in CKD-related CVD. Genome-wide DNA methylation changes were examined in bisulphite converted genomic DNA isolated from the vascular media of CKD and healthy arteries. Methylation-specific PCR was used to validate the array data, and the association between DNA methylation and gene and protein expression was examined. The DNA methylation age was compared to the chronological age in both cases and controls. Three hundred and nineteen differentially methylated regions (DMR) were identified spread across the genome. Pathway analysis revealed that DMRs associated with genes were involved in embryonic and vascular development, and signalling pathways such as TGFβ and FGF. Expression of top differentially methylated gene HOXA5 showed a significant negative correlation with DNA methylation. Interestingly, DNA methylation age and chronological age were highly correlated, but there was no evidence of accelerated age-related DNA methylation in the arteries of CKD patients. In conclusion, we demonstrated that differential DNA methylation in the arterial tissue of CKD patients represents a potential mediator of arterial pathology and may be used to uncover novel pathways in the genesis of CKD-associated complications.

摘要

慢性肾病 (CKD) 相关的心血管疾病 (CVD) 的特征是血管重塑，血管壁的结构和功能发生了成熟的变化，例如动脉僵硬、基质沉积和钙化。这些表型变化类似于衰老中的病理学，并且可能由基因表达的持续变化介导，这可能是由组织特异性 DNA 甲基化等表观遗传变化引起的。我们旨在研究发生在 CKD 相关 CVD 中的 DNA 甲基化的组织特异性变化。在从 CKD 和健康动脉的血管介质中分离的亚硫酸氢盐转化的基因组 DNA 中检查全基因组 DNA 甲基化变化。甲基化特异性 PCR 用于验证阵列数据，并检查了DNA甲基化与基因和蛋白质表达之间的关联。在病例和对照中，将 DNA 甲基化年龄与实际年龄进行了比较。鉴定了 319 个差异甲基化区域 (DMR)，分布在整个基因组中。通路分析显示，与基因相关的 DMR 参与胚胎和血管发育，以及 TGFβ 和 FGF 等信号通路。顶部差异甲基化基因的表达HOXA5与DNA甲基化呈显着负相关。有趣的是，DNA 甲基化年龄和实足年龄高度相关，但没有证据表明 CKD 患者的动脉中与年龄相关的 DNA 甲基化加速。总之，我们证明 CKD 患者动脉组织中的差异 DNA 甲基化代表了动脉病理学的潜在介质，可用于揭示 CKD 相关并发症发生的新途径。