Loss of ovarian hormones modulates nucleic acid content of circulating extracellular vesicles in response to acute exercise
Loss of ovarian hormones (i.e., menopause) leads to negative effects on metabolic health. While exercise offers significant benefits, it seems to be insufficient to completely reverse these changes. The mechanisms by which exercise conveys the effects throughout the body are still poorly understood. Extracellular vesicles (EVs) are released into circulation during exercise. EVs carry small non-coding RNAs (sRNAs), such as microRNAs (miRs), which are proposed as mediators of the effects of exercise. In this study, we examined the effect of loss of ovarian hormones and acute exercise in the sRNA cargo of EV and HDL particles in female rats. We show for the first time that loss of ovarian hormones affects specifically the nucleic acid cargo of circulating EVs. In addition, we show that the loss of ovarian hormones diminishes the miR response to acute exercise in EV particles. The study sample consisted of 40 female Wistar Hans rats. Half of the rats (n=20) underwent ovariectomy (OVX), resulting in the loss of ovarian hormones and the other half (n=20) was predisposed to sham surgery without the removal of ovaries. In both groups, half of the rats (n=10) performed maximal running test (max) to induce an acute exercise stimulus and the other 10 served as control. Hence, there were 4 groups of rats, with 10 rats in each group: sham/control, sham/max, OVX/control, and OVX/max.