4月1日,從遺傳學(xué)角度研究衰老機(jī)制的一組英國科學(xué)家在《公共科學(xué)圖書館·綜合》（PLoS ONE）網(wǎng)站撰文指出,，他們針對實(shí)驗室蠕蟲進(jìn)行的研究表明,，DAF-16基因同壽命、免疫力密切相關(guān),。由于很多動物和人體內(nèi)都擁有DAF-16基因,，該發(fā)現(xiàn)有助于更好地了解影響人類衰老和免疫功能的原因。
全球各地的人們正在大踏步邁向衰老,，給健康和社會保障體系提出了巨大挑戰(zhàn),。丹麥科學(xué)家去年進(jìn)行的一項研究發(fā)現(xiàn)，富裕國家出生的嬰兒中,，有一半將可以慶祝其百歲誕辰,。科學(xué)家急切渴望能夠找到令人衰老的原因,，據(jù)此研發(fā)出藥物幫助人們盡可能長壽,，并在有生之年保持健康,。
英國伯明翰大學(xué)的羅賓·梅爾領(lǐng)導(dǎo)了這項研究。梅爾團(tuán)隊比較了4種關(guān)系密切的蠕蟲的壽命,、抗藥性以及免疫力情況,，他們發(fā)現(xiàn)，這4種蠕蟲體內(nèi)的DAF-16基因的活性存在巨大的差異,。
更重要的是,，DAF-16活性的差異同壽命、抵抗力和免疫力相輔相成：DAF-16的活性越高,，蠕蟲的壽命越長,，抗感染的免疫力越好。梅爾表示,，這表明,，免疫力和衰老密切相關(guān)。物種之間的DAF-16基因的活性的差異對衰老和健康具有非常重要的影響,，這或許可以解釋人與人之間的壽命為何不同,。
梅爾稱，DAF-16在體內(nèi)大多數(shù)細(xì)胞中都很活躍,，它們同人體內(nèi)的FoxO家族調(diào)節(jié)基因非常類似,，科學(xué)家認(rèn)為FOXO家族在動物細(xì)胞的分化、生長,、增殖,、代謝、免疫及衰老調(diào)節(jié)方面具有多樣性功能,。
英國生物技術(shù)和生物科學(xué)研究協(xié)會負(fù)責(zé)人道格拉斯·凱爾表示,，這個發(fā)現(xiàn)將幫助科學(xué)家理解決定人類衰老的相關(guān)機(jī)制。(生物谷Bioon.com)
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生物谷推薦原文出處：
PLoS ONE doi:10.1371/journal.pone.0009978
Phenotypic Covariance of Longevity, Immunity and Stress Resistance in the Caenorhabditis Nematodes
Francis R. G. Amrit, Claudia M. L. Boehnisch, Robin C. May*
Background
Ageing, immunity and stresstolerance are inherent characteristics of all organisms. In animals, these traits are regulated, at least in part, by forkhead transcription factors in response to upstream signals from the Insulin/Insulin–like growth factor signalling (IIS) pathway. In the nematode Caenorhabditis elegans, these phenotypes are molecularly linked such that activation of the forkhead transcription factor DAF-16 both extends lifespan and simultaneously increases immunity and stress resistance. It is known that lifespan varies significantly among the Caenorhabditis species but, although DAF-16 signalling is highly conserved, it is unclear whether this phenotypic linkage occurs in other species. Here we investigate this phenotypic covariance by comparing longevity, stress resistance and immunity in four Caenorhabditis species.
Methodology/Principal Findings
We show using phenotypic analysis of DAF-16 influenced phenotypes that among four closely related Caenorhabditis nematodes, the gonochoristic species (Caenorhabditis remanei and Caenorhabditis brenneri) have diverged significantly with a longer lifespan, improved stress resistance and higher immunity than the hermaphroditic species (C. elegans and Caenorhabditis briggsae). Interestingly, we also observe significant differences in expression levels between the daf-16 homologues in these species using Real-Time PCR, which positively correlate with the observed phenotypes. Finally, we provide additional evidence in support of a role for DAF-16 in regulating phenotypic coupling by using a combination of wildtype isolates, constitutively active daf-16 mutants and bioinformatic analysis.
Conclusions
The gonochoristic species display a significantly longer lifespan (p<0.0001) and more robust immune and stress response (p<0.0001, thermal stress; p<0.01, heavy metal stress; p<0.0001, pathogenic stress) than the hermaphroditic species. Our data suggests that divergence in DAF-16 mediated phenotypes may underlie many of the differences observed between these four species of Caenorhabditis nematodes. These findings are further supported by the correlative higher daf-16 expression levels among the gonochoristic species and significantly higher lifespan, immunity and stress tolerance in the constitutively active daf-16 hermaphroditic mutants,。
