Background

Chronic life stress, such as the stress of caregiving, can promote pathophysiology, but the underlying cellular mechanisms are not well understood. Chronic stress may induce recalibrations in mitochondria leading to either changes in mitochondrial content per cell, or in mitochondrial functional capacity (i.e., quality).

Methods

Here we present a functional index of mitochondrial health (MHI) for human leukocytes that can distinguish between these possibilities. The MHI integrates nuclear- and mitochondrial DNA (mtDNA)-encoded respiratory chain enzymatic activities and mtDNA copy number. We then use the MHI to test the hypothesis that caregiving stress and daily emotional states influence mitochondrial function by comparing healthy mothers of either a child with an autism spectrum disorder (high stress caregivers, n=46) or with a neurotypical child (control group, n=45).

Results

The MHI outperformed individual mitochondrial function measures. Elevated positive mood at night was associated with higher MHI, and nightly positive mood was also a mediator of the association between caregiving and MHI. Moreover, MHI was correlated to positive mood on the days preceding, but not following the blood draw, suggesting for the first time in humans that mitochondria may respond to proximate emotional states within days. Correspondingly, the caregiver group, which had higher perceived stress, lower positive and greater negative daily affect, exhibited lower MHI. This effect was not explained by a mismatch between nuclear and mitochondrial genomes.

Conclusions

Daily mood and chronic caregiving stress are associated with mitochondrial functional capacity. Mitochondrial health may represent a nexus between psychological stress and health.

中文翻译：

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对情绪和护理压力敏感的线粒体健康指数

背景

慢性生活压力，例如护理压力，可以促进病理生理，但其潜在的细胞机制尚不十分清楚。慢性应激可能会诱导线粒体重新校准，从而导致每个细胞的线粒体含量或线粒体功能能力（即质量）发生变化。

方法

在这里，我们介绍了人类白细胞线粒体健康（MHI）的功能指标，可以区分这些可能性。MHI整合了核和线粒体DNA（mtDNA）编码的呼吸链酶活性和mtDNA拷贝数。然后，我们通过MHI来检验假设照顾压力和日常情绪状态会影响线粒体功能的假设，方法是比较自闭症谱系障碍儿童（高压力照顾者，n = 46）或有神经性典型孩子（对照组， n = 45）。

结果

三菱重工（MHI）优于单独的线粒体功能指标。夜间积极情绪升高与MHI升高有关，而夜间积极情绪也是护理与MHI之间联系的中介。此外，在重症监护前（但不是在抽血后），MHI与积极情绪相关，这表明人类首次发现线粒体可能会在几天内对近距离的情绪状态做出反应。相应地，具有较高的感知压力，较低的每日正向情绪和较大的负面每日影响的看护者组表现出较低的MHI。核和线粒体基因组之间的不匹配不能解释这种作用。

结论

日常情绪和慢性护理压力与线粒体功能能力有关。线粒体健康可能代表心理压力与健康之间的联系。