The Mitochondrial-Derived Peptide MOTS-c Improves Bioenergetics in Aging-Associated Granulosa Cells and Oocytes.

As women age, the quality of their eggs declines, which is a major contributor to age-related infertility. Eggs are supported by neighboring "helper" cells called granulosa cells, which act like a support crew that supplies the egg with the energy it needs to mature. These helper cells contain mitochondria, tiny energy-generating structures often called the cell's "powerhouses," and with age these powerhouses become less efficient, leaving eggs with less support than they need. This study tested whether MOTS-c, a small molecule naturally produced by mitochondria, could restore the function of these aging helper cells. In laboratory experiments using aged human granulosa cells and eggs from aged mice, MOTS-c boosted energy production and helped maintain cell structure, and was associated with improved egg maturation compared with untreated aged eggs, although treated eggs did not fully reach the maturation levels seen in young mice. These findings are from laboratory and animal experiments, not from women, and this study did not test whether MOTS-c affects fertilization, embryo development, or live birth. Further research is needed before any conclusions can be drawn about its relevance to human fertility.