加齢：高齢者の心臓における体細胞変異の同定

The somatic mutations that accumulate in the human heart with age are identified in a paper in Nature Aging. The findings may help us to understand how the function of the heart declines with age.

The DNA of cells that make up the human body, including the heart, accumulate errors — or somatic mutations — as we age. Although some somatic mutations appear to have little effect, others, for example, underlie the development of cancer or are likely to contribute to physiological ageing. The accumulation of somatic mutations in heart muscle cells may contribute to a decline in cellular function. However, researchers are yet to obtain data concerning these mutations.

Christopher Walsh and colleagues profile somatic single-nucleotide variants — whereby a single nucleotide in the DNA sequence is mutated — in human heart muscle cells from 12 individuals aged between 0.4 and 82 years old, using single-cell whole-genome sequencing. The authors reveal that heart muscle cells show mutational signatures that are indicative of oxidative DNA damage and failed DNA repair mechanisms, as well as an increase in base substitutions — all of which accumulate with age.

Further research will be needed to determine whether the identified processes have a causal role in heart ageing and how they may impair heart function.