Division of Female Pelvic Medicine and Reconstructive Surgery, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0863, USA.
Department of Bioengineering and Sanford Consortium for Regenerative Medicine, University of California San Diego, La Jolla, USA.
Ann Biomed Eng. 2021 Aug;49(8):1836-1847. doi: 10.1007/s10439-021-02748-5. Epub 2021 Mar 8.
Age-related pelvic floor muscle (PFM) dysfunction is a critical defect in the progression to pelvic floor disorders (PFDs). Despite dramatic prevalence of PFDs in older women, the underlying pathophysiology of age-related PFM dysfunction remains poorly understood. Using cadaveric specimens, we quantified aging effects on functionally relevant PFM properties and compared PFMs with the appendicular muscles from the same donors. PFMs, obturator internus, and vastus lateralis were procured from younger (N = 4) and older (N = 11) donors with known obstetrical and medical history. Our findings demonstrate that PFMs undergo degenerative, rather than atrophic, alterations. Importantly, age-related fibrotic degeneration disproportionally impacts PFMs compared to the appendicular muscles. We identified intramuscular lipid accumulation as another contributing factor to the pathological alterations of PFMs with aging. We observed a fourfold decrease in muscle stem cell (MuSC) pool of aged relative to younger PFMs, but the MuSC pool of appendicular muscles from the same older donors was only twofold lower than in younger group, although these differences were not statistically significant. Age-related degeneration appears to disproportionally impact PFMs relative to the appendicular muscles from the same donors. Knowledge of tissue- and cell-level changes in aged PFMs is essential to promote our understanding of the mechanisms governing PFM dysfunction in older women.
与年龄相关的盆底肌肉（PFM）功能障碍是盆底功能障碍（PFD）进展的关键缺陷。尽管老年女性中 PFD 的患病率很高，但与年龄相关的 PFM 功能障碍的潜在病理生理学仍知之甚少。我们使用尸体标本定量评估了年龄对 PFM 功能相关特性的影响，并比较了来自同一供体的 PFM 与四肢肌肉的特性。我们从年轻（N=4）和老年（N=11）供体中获取了 PFM、闭孔内肌和股外侧肌，这些供体具有已知的产科和病史。我们的研究结果表明，PFM 经历的是退行性而非萎缩性改变。重要的是，与四肢肌肉相比，与年龄相关的纤维变性退变不成比例地影响 PFM。我们发现，肌肉内脂质积累是 PFM 随年龄发生病理性改变的另一个促成因素。与年轻的 PFM 相比，我们观察到老年 PFM 中的肌肉干细胞（MuSC）池减少了四倍，但来自同一老年供体的四肢肌肉的 MuSC 池仅比年轻组低两倍，尽管这些差异没有统计学意义。与来自同一供体的四肢肌肉相比，与年龄相关的退行性变似乎不成比例地影响 PFM。了解老年 PFM 中的组织和细胞水平变化对于促进我们对老年女性 PFM 功能障碍相关机制的理解至关重要。
