For their studies, the research team, led by Sangita Choudhury, Ph.D., and August Yue Huang, Ph.D., from the Department of Genetics and Genomics at Boston Children's Hospital, sequenced the entire genome of 56 individual heart muscle cells obtained from 12 individuals across a wide range of ages. The individuals had died from causes unrelated to heart disease. Using bioinformatics analyses, the team compared the number of mutations that were not inherited and looked for mutation patterns.

They observed that the older the cells were, the more single nucleotide variations occurred in the DNA of the heart muscle cells. According to the researchers, this is often caused by oxidative damage due to the energy consumption caused by the permanent pumping action of the heart. Normally, this damage can be corrected by the body's own repair enzymes, but only as long as the enzymes themselves are not affected by the mutation and thus no longer work properly. Although heart cells do not divide, there are a particularly large number of mutations in the heart compared to other organs.

In the end, this can lead to the occurrence of heart disease.

The scientists have published their findings in the journal Nature Aging:
Choudhury, S., Huang, A.Y., Kim, J. et al. Somatic mutations in single human cardiomyocytes reveal age-associated DNA damage and widespread oxidative genotoxicity. Nat Aging 2, 714-725 (2022). https://doi.org/10.1038/s43587-022-00261-5

Source:
https://www.eurekalert.org/news-releases/961716