細胞老化の指標であるテロメア長は加齢とともに短縮し, 心血管死, 感染症死など老化関連疾患と関連する。しかし, これまで健康長寿者におけるテロメア長の報告はきわめて限られていた。本研究では100歳以上の健康長寿者684名, 85-99歳536名, 百寿者の子供とその配偶者167組のテロメア長を測定し, 60-90歳代までは加齢とともにテロメア長が短縮するが, 百歳以降ではテロメアの短縮が起こらず, さらに105歳以上ではテロメアが長い傾向があることを見出した。また, テロメア超は免疫老化の指標であるCD28陽性率と相関した。つまり, テロメア短縮と免疫老化が起こりにくいことが健康長寿者の特徴である可能性を示した。
Leukocyte telomere length (LTL) is an emerging biomarker of aging, and associated with death from cardiovascular and infectious disease. Litte is known about LTL in centenarians. In this study, we measured LTL from 684 centenarians and 167 pairs of their offspring, 536 non-centenarian individual aged between 85-99 years old. we found that LTL actually decreased with age until late 90's, however, centenarians and especially semi-supercentenarians (individuals aged 105 years or older) exhibited longer LTL than expected for their ages. Moreover, centenarians' offspring maintained their LTL compared to non-centenarians. Decrease in percentage of CD28 lymphocyes is known to be associated with age-related decline in immune system (immmunesenescence). Interestingly, LTL in semi-supercentenarians were significantly correlated with CD28(+) lyphocytes. These resluts suggested that maintenance of LTL and immune competence could be hallmark of healthy longevity in humans.
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