Cover article: Identification of cell-specific markers of skeletal muscle aging

"Our study provides some insights
into human skeletal muscle aging.
"

A new research paper is published on the cover of Aging (listed as "Aging (Albany NY)" by Medline/PubMed and "Aging-US" by Web of Science), Volume 14, Issue 23
.

Aging is accompanied by a loss of muscle mass and function, called sarcopenia, which causes a variety of diseases and economic burdens
in the human population.
Mechanisms associated with age-related sarcopenia or weakness include inflammation, loss of muscle stem cells, mitochondrial dysfunction, and loss of motor neurons, but whether there are key drivers of sarcopenia is unknown
.

In the new study, researchers performed lower extremity muscle biopsies on 72 young, elderly, and frail human subjects, transcriptome analysis using bulk RNA-seq (N = 72) and mononuclear RNA-seq (N = 17) to gain a deeper understanding of age-related muscle loss
.

"This combined approach reveals changes in gene expression with age and weakness in multiple cell types, including mature skeletal muscle
.
"

Notably, the researchers found that in aging muscle, expression of the MYH8 and PDK4 genes increased, and expression of the IGFN1 gene decreased
.
They used digital spatial analysis to validate changes
in several key genes in fixed human muscle tissue.
The researchers also found a small subset of cells expressing CDKN1A, present only in older samples, consistent with
p21cip1-driven aging in this subpopulation.

"Overall, our findings identify unique cell subsets in senile and oligoskeletal muscle, which will facilitate the development of new therapeutic strategies to combat age-related weakness
.
"