School of Veterinary Medicine, Department of Animal, Dairy and Veterinary Sciences, Center for Integrated BioSystems, Utah State University, Logan, UT, 84322, USA.
USDA-ARS Poisonous Plant Research Laboratory, Logan, UT, 84341, USA.
Geroscience. 2022 Aug;44(4):2157-2169. doi: 10.1007/s11357-022-00549-9. Epub 2022 Mar 29.
A critical mediator of evolution is natural selection, which operates by the divergent reproductive success of individuals and results in conformity of an organism with its environment. Reproductive function has evolved to support germline transmission. In mammalian ovaries, this requires healthy, active gonad function, and follicle development. However, healthy follicles do not contribute to germline transmission in a dead animal. Therefore, support of the health and survival of the organism, in addition to fertility, must be considered as an integral part of reproductive function. Reproductive and chronological aging both impose a burden on health and increase disease rates. Tremors are a common movement disorder and are often correlated with increasing age. Muscle quality is diminished with age and these declines are gender-specific and are influenced by menopause. In the current experiments, we evaluated aging-associated and reproduction-influenced changes in motor function, utilizing changes in tremor amplitude and grip strength. Tremor amplitude was increased with aging in normal female mice. This increase in tremor amplitude was prevented in aged female mice that received ovarian tissue transplants, both in mice that received germ cell-containing or germ cell-depleted ovarian tissue. Grip strength was decreased with aging in normal female mice. This decrease in grip strength was prevented in aged female mice that received either germ cell-containing or germ cell-depleted tissue transplants. As expected, estradiol levels decreased with aging in normal female mice. Estradiol levels did not change with exposure to young ovarian tissues/cells. Surprisingly, estradiol levels were not increased in aged females that received ovaries from actively cycling, young donors. Overall, tremor amplitude and grip strength were negatively influenced by aging and positively influenced by exposure to young ovarian tissues/cells in aged female mice, and this positive influence was independent of ovarian germ cells and estradiol levels. These findings provide a strong incentive for further investigation of the influence of ovarian somatic tissue on health. In addition, changes in tremor amplitude may serve as an additional marker of biological age.
进化的一个关键调节者是自然选择，它通过个体繁殖成功率的差异起作用，导致生物体与其环境的一致性。生殖功能已经进化到支持生殖细胞的传递。在哺乳动物的卵巢中，这需要健康、活跃的性腺功能和卵泡发育。然而，在死亡的动物中，健康的卵泡不会促进生殖细胞的传递。因此，除了生育能力外，支持生物体的健康和生存必须被视为生殖功能的一个组成部分。生殖和年龄的增长都会给健康带来负担，并增加疾病的发生率。震颤是一种常见的运动障碍，通常与年龄的增长有关。肌肉质量随年龄的增长而下降，这些下降是性别特异性的，并受绝经的影响。在目前的实验中，我们评估了与衰老相关的和受生殖影响的运动功能变化，利用震颤幅度和握力的变化。在正常雌性小鼠中，震颤幅度随年龄的增长而增加。在接受卵巢组织移植的老年雌性小鼠中，这种震颤幅度的增加得到了预防，无论是接受含有生殖细胞的还是不含生殖细胞的卵巢组织。在正常雌性小鼠中，握力随年龄的增长而下降。在接受含有生殖细胞或不含生殖细胞的组织移植的老年雌性小鼠中，这种握力的下降得到了预防。正如预期的那样，在正常雌性小鼠中，雌二醇水平随年龄的增长而下降。暴露于年轻的卵巢组织/细胞并不会改变雌二醇水平。令人惊讶的是，在接受来自活跃循环的年轻供体的卵巢的老年雌性小鼠中，雌二醇水平并没有升高。总的来说，在老年雌性小鼠中，震颤幅度和握力受到衰老的负面影响，而暴露于年轻的卵巢组织/细胞则产生积极影响，这种积极影响与卵巢生殖细胞和雌二醇水平无关。这些发现为进一步研究卵巢体组织对健康的影响提供了强有力的动力。此外，震颤幅度的变化可能成为生物年龄的另一个附加标志物。
