Section of Forensic Genetics, Department of Forensic Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
Department of Cardiothoracic Surgery, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark.
Sci Rep. 2024 Oct 24;14(1):25170. doi: 10.1038/s41598-024-76027-3.
Investigating DNA methylation (DNAm) in cardiac tissues is vital for epigenetic research in cardiovascular diseases (CVDs). During cardiac surgery, biopsies may not be immediately stored due to a lack of human or technical resources at the collection site. Assessing DNAm stability in cardiac samples left in suboptimal conditions is crucial for applying DNAm analysis. We investigated the stability of DNAm in human cardiac tissues kept at 4 °C and 22 °C for periods of 1, 7, 14, and 28 days (exposed samples) using the Illumina Infinium MethylationEPIC v1.0 BeadChip Array. We observed high correlations between samples analysed immediately after tissue collection and exposed ones (R > 0.992). Methylation levels were measured as β-values and median absolute β-value differences (|∆β|) ranged from 0.0093 to 0.0119 in all exposed samples. Pairwise differentially methylated position (DMP) analysis revealed no DMPs under 4 °C (fridge temperature) exposure for up to 28 days and 22 °C (room temperature) exposure for one day, while 3,437, 6,918, and 3,824 DMPs were observed for 22 °C samples at 7, 14, and 28 days, respectively. This study provides insights into the stability of genome-wide DNAm, showing that cardiac tissue can be used for reliable DNAm analysis even when stored suboptimally after surgery.
研究心脏组织中的 DNA 甲基化（DNAm）对于心血管疾病（CVDs）的表观遗传学研究至关重要。在心脏手术期间，由于采集现场缺乏人力或技术资源，活检可能无法立即储存。评估在不理想条件下保存的心脏样本中的 DNAm 稳定性对于应用 DNAm 分析至关重要。我们使用 Illumina Infinium MethylationEPIC v1.0 BeadChip Array 研究了在 4°C 和 22°C 下保存 1、7、14 和 28 天（暴露样本）的人心肌组织中 DNAm 的稳定性。我们观察到在组织采集后立即分析的样本和暴露样本之间的高度相关性（R > 0.992）。甲基化水平以β值表示，所有暴露样本的中位绝对β值差异（|∆β|）范围为 0.0093 至 0.0119。成对差异甲基化位置（DMP）分析显示，在 4°C（冰箱温度）暴露长达 28 天和 22°C（室温）暴露一天的情况下，没有 DMP；而在 22°C 样本中，分别在 7、14 和 28 天时观察到 3,437、6,918 和 3,824 个 DMP。这项研究提供了关于全基因组 DNAm 稳定性的见解，表明即使在手术后以不理想的方式储存，心脏组织也可以用于可靠的 DNAm 分析。
