Department of Integrative Biology and Physiology, Medical School, University of Minnesota, Minneapolis, Minnesota.
Lillehei Heart Institute, Medical School, University of Minnesota, Minneapolis, Minnesota.
Am J Physiol Cell Physiol. 2022 Jun 1;322(6):C1123-C1137. doi: 10.1152/ajpcell.00429.2021. Epub 2022 Apr 20.
The size of the satellite cell pool is reduced in estradiol (E)-deficient female mice and humans. Here, we use a combination of in vivo and in vitro approaches to identify mechanisms, whereby E deficiency impairs satellite cell maintenance. By measuring satellite cell numbers in mice at several early time points postovariectomy (Ovx), we determine that satellite cell numbers decline by 33% between 10 and 14 days post-Ovx in tibialis anterior and gastrocnemius muscles. At 14 days post-Ovx, we demonstrate that satellite cells have a reduced propensity to transition from G/G to S and G/M phases, compared with cells from ovary-intact mice, associated with changes in two key satellite cell cycle regulators, and . Further, freshly isolated satellite cells treated with E in vitro have 62% greater cell proliferation and require less time to complete the first division. Using clonal and differentiation assays, we measured 69% larger satellite cell colonies and enhanced satellite cell-derived myoblast differentiation with E treatment compared with vehicle-treated cells. Together, these results identify a novel mechanism for preservation of the satellite cell pool by E via promotion of satellite cell cycling.
卫星细胞池的大小在雌激素(E)缺乏的雌性小鼠和人类中减少。在这里,我们使用体内和体外相结合的方法来确定 E 缺乏如何损害卫星细胞的维持。通过在卵巢切除(Ovx)后几个早期时间点测量小鼠中的卫星细胞数量,我们确定在前肌和比目鱼肌中,卫星细胞数量在 Ovx 后 10 至 14 天减少了 33%。在 Ovx 后 14 天,我们证明与来自卵巢完整的小鼠的细胞相比,卫星细胞从 G/G 向 S 和 G/M 期的转变的倾向降低,这与两个关键的卫星细胞周期调节剂和的变化有关。此外,体外用 E 处理的新分离的卫星细胞具有 62%更高的细胞增殖能力,并且需要更少的时间来完成第一次分裂。通过克隆和分化测定,我们测量到用 E 处理的卫星细胞集落增大 69%,并且与用载体处理的细胞相比,增强了卫星细胞衍生的成肌细胞分化。总之,这些结果确定了 E 通过促进卫星细胞循环来保存卫星细胞池的新机制。