DNA methylation stability in cardiac tissues kept at different temperatures and time intervals

Area of Science:

• Epigenetics
• Cardiovascular Research
• Genomics

Background:

• DNA methylation (DNAm) analysis is crucial for understanding cardiovascular diseases (CVDs).
• Cardiac biopsies collected during surgery may face storage delays due to resource limitations.
• Assessing DNAm stability under suboptimal conditions is essential for practical application.

Purpose of the Study:

• To investigate the stability of genome-wide DNAm in human cardiac tissues stored at different temperatures and durations.
• To determine the impact of delayed storage on DNAm integrity for future epigenetic studies.

Main Methods:

• Human cardiac tissues were stored at 4°C and 22°C for up to 28 days.
• DNA methylation was analyzed using the Illumina Infinium MethylationEPIC v1.0 BeadChip Array.
• Correlations and differentially methylated positions (DMPs) were assessed.

Main Results:

• High correlations (R² > 0.992) were observed between immediately analyzed and stored samples.
• No significant DNAm changes occurred at 4°C for 28 days or 22°C for 1 day.
• Significant DMPs emerged at 22°C after 7, 14, and 28 days, with thousands of changes observed.

Conclusions:

• Cardiac tissue DNAm is remarkably stable at 4°C for extended periods (28 days).
• Short-term storage at room temperature (22°C for 1 day) also preserves DNAm integrity.
• These findings support the feasibility of DNAm analysis from cardiac samples stored suboptimally post-surgery.