Barrere-Cain Rio, Allard Patrick
Institute for Society & Genetics, University of California, Los Angeles, Los Angeles, CA, USA.
Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA, USA.
Epigenet Insights. 2020 Aug 5;13:2516865720947014. doi: 10.1177/2516865720947014. eCollection 2020.
We live in a complex chemical environment where there are an estimated 350 000 chemical compounds or mixtures commercially produced. A strong body of literature shows that there are time points during early development when an organism's epigenome is particularly sensitive to chemicals in its environment. What is less understood is how gene-environment and epigenetic-environment interactions change with age. This question is bidirectional: (1) how do chemicals in the environment affect the aging process and (2) how does aging affect an organism's response to its chemical environment? The study of gene-environment interactions with age is especially important because, in many parts of the world, older individuals are a large and rapidly growing proportion of the population and because aging is a process universal to most of the animal kingdom. Epigenetics has emerged as a crucial framework for studying aging as epigenetic pathways, often triggered by environmental stimuli, have been shown to be essential regulators of the aging process. In this perspective article, we delineate the connection between aging, epigenetics, and environmental exposures. We discuss why it is essential to consider age when researching how an organism interacts with its environment. We describe recent advances in understanding how the chemical environment affects aging and the gap in research on how age affects an organism's response to the environment. Finally, we highlight how model organisms and network approaches can help fill this crucial gap. Taken together, systemic changes that occur in the epigenome with age indicate that adult organisms cannot be treated as a homogeneous population and that there are discrete mechanisms modulating the aging epigenome that we do not yet understand.
我们生活在一个复杂的化学环境中，据估计有35万种化合物或混合物在商业上生产。大量文献表明，在早期发育过程中存在一些时间点，此时生物体的表观基因组对其环境中的化学物质特别敏感。人们对基因-环境和表观遗传-环境相互作用如何随年龄变化了解较少。这个问题是双向的：（1）环境中的化学物质如何影响衰老过程，（2）衰老如何影响生物体对其化学环境的反应？研究基因-环境与年龄的相互作用尤为重要，因为在世界许多地区，老年人在人口中所占比例很大且正在迅速增长，而且衰老在大多数动物王国中是一个普遍的过程。表观遗传学已成为研究衰老的关键框架，因为表观遗传途径通常由环境刺激触发，已被证明是衰老过程的重要调节因子。在这篇观点文章中，我们阐述了衰老、表观遗传学和环境暴露之间的联系。我们讨论了在研究生物体如何与其环境相互作用时考虑年龄为何至关重要。我们描述了在理解化学环境如何影响衰老方面的最新进展以及在研究年龄如何影响生物体对环境反应方面的研究差距。最后，我们强调模型生物和网络方法如何有助于填补这一关键差距。综上所述，表观基因组随年龄发生的系统性变化表明，成年生物体不能被视为一个同质群体，并且存在一些我们尚未理解的调节衰老表观基因组的离散机制。
