It has been fifteen years since the first compelling demonstration of clearance of senescent cells in mice. That study paved the way for the transformation of the research community into one convinced of the relevance of cellular senescence to degenerative aging. It also helped to change the culture of aging research more generally, one of the important contributions to a shift in attitudes that has led to a research and development community that understands the treatment of aging as a medical condition to be a practical, desirable goal. Here, discuss the role of cellular senescence in muscle aging specifically; how it contributes to harm and lost function, and what might be done about it.
Cellular senescence is increasingly recognized as a pivotal mechanism driving skeletal muscle aging and the development of sarcopenia, a condition characterized by the progressive loss of muscle mass, strength, and function. This review synthesizes recent evidence detailing the accumulation of senescent cells in aged skeletal muscle, including muscle stem cells (MuSCs), fibro-adipogenic progenitors (FAPs), immune cells, endothelial cells, and even post-mitotic myofibers. Senescence in these cell types impairs regenerative signaling, disrupts niche homeostasis, and propagates chronic inflammation.
Emerging therapeutic strategies, termed senotherapeutics, aim to counteract these effects through senolytics (which eliminate senescent cells) and senomorphics (which modulate the senescence-associated secretory phenotype), as promising interventions to restore muscle function and delay sarcopenia. We will also discuss the remaining challenges and future directions for studying senescence in skeletal muscle.
