老化した細胞が若返る？
Press Release from Dana-Farber Cancer Institute on November 29, 2010.
© Dana-Farber Cancer Institute
研究を主導したRonald Depinho医師
老化による組織の変性を部分的に逆転させる方法がマウスの実験で成功した。染色体の末端にある構造・テロメアが短いことと老化は関連するとされているが，同実験ではテロメアが短いため早く老化するマウスを作成し，テロメアの維持に必要な酵素，テロメラーゼの機能を人為的に再開できるよう工夫した。老化によりマウスの脳，精巣，脾臓は縮小し，認知機能も低下していたが，テロメラーゼ回復後には臓器の大きさや受胎能，認知機能も回復した。正常な老化もテロメラーゼの回復で逆転できるか不明だが，加齢による疾患に効果があると考えられる。（吉田素子）
Scientists Report Partial Reversal of Age-related Degeneration in Aged Mice
Scientists at Dana-Farber Cancer Institute say they have for the first time partially reversed age-related degeneration in mice, resulting in new growth of the brain and testes, improved fertility, and the return of a lost cognitive function.
In a report posted online by the journal Nature in advance of print publication, researchers led by Ronald A. DePinho, MD, said they achieved the milestone in aging science by engineering mice with a controllable telomerase gene. The telomerase enzyme maintains the protective caps called telomeres that shield the ends of chromosomes.
As humans age, low levels of telomerase are associated with progressive erosion of telomeres, which may then contribute to tissue degeneration and functional decline in the elderly.
By creating mice with a telomerase switch, the researchers were able to generate prematurely aged mice. The switch allowed the scientists to find out whether reactivating telomerase in the animals would restore telomeres and mitigate the signs and symptoms of aging.
The work showed a dramatic reversal of many aspects of aging, including reversal of brain disease and infertility.
While human applications remain in the future, the strategy might one day be used to treat conditions such as rare genetic premature aging syndromes in which shortened telomeres play an important role, said DePinho, senior author of the report and the director of Dana-Farber's Belfer Institute of Applied Cancer Science.
"Whether this would impact on normal aging is a more difficult question," he added, "But it is notable that telomere loss is associated with age-associated disorders and thus restoration of telomeres could alleviate such decline."
［単語和訳］
Reversal：逆戻り Age-related：加齢性の Degeneration：（細胞・組織などの）変性 Mice：マウス
Cancer：癌 partially：部分的に resulting in：～をもたらす brain：脳 testes：精巣 fertility：受胎能 cognitive function：認知機能
online：オンラインで in advance of：～に先立って researchers：研究者 milestone：画期的な出来事 aging science：加齢研究 engineering：～を操作すること controllable：制御可能な telomerase：テロメラーゼ gene：遺伝子 enzyme：酵素 protective：保護する telomeres：テロメア chromosomes：染色体
are associated with：～に関連している progressive：進行性の erosion：衰え contribute to：～の一因となる tissue：組織 functional：機能的
generate：～を作り出す prematurely：時期尚早に reactivating：再活性化すること mitigate：～を軽減する symptoms：症状
infertility：不妊
strategy：方法 genetic：遺伝的 premature aging syndromes：早（期）老（化）症候群 play an important role：重要な役割を果たす senior author：主席著者，統括著者 Applied：応用～
notable：注目に値する age-associated：加齢に関連した disorders：疾患 restoration：復元 alleviate：～を軽減する
