A research team from Nankai University in Tianjin has identified a new biological target linked to female infertility, offering hope for women affected by age-related or unexplained infertility, according to a study published in Cell Reports Medicine last month.

Generally, female fertility declines with age, with the rate of decline accelerating after age 35. But the precise mechanisms behind this process have remained unclear. Professor Liu Lin's team found that after age 34, women's oocytes (egg cells) and surrounding cumulus cells undergo changes marked by excessive ribosomal activity, the cell structures responsible for protein synthesis. This "ribosomal hyperactivity," the researchers say, disrupts normal cell function and contributes to infertility.

Ribosomes are often termed the "protein synthesis factories" within human cells. The study revealed that overactive ribosomes increase protein production but reduce protein stability, which may consequently accelerate ovarian aging and degrade embryonic quality

Li Jie, a member of this research team, said, "Our study demonstrated that abnormalities in ribosomal function are a previously unrecognized factor leading to diminished oocyte quality. Moreover, this phenomenon extends beyond the oocyte itself. We have found that the surrounding cumulus cells would also experience degenerative changes with advancing age. This synchronous deterioration undermines both women's oocyte maturation and embryonic developmental competence."

To counter this, the team tested rapamycin, a drug known to regulate cell growth, in mouse models. The treatment restored protein balance, improved the ovarian microenvironment, and enhanced egg quality.

In follow-up clinical trials, scientists verified that short-term administration of rapamycin enabled patients with previous in vitro fertilization failures to achieve successful pregnancies and deliver healthy infants. This therapeutic approach indicates that short-term oral administration of low-dose rapamycin can potentially intervene in female infertility conditions. And current clinical evidence demonstrates no observed negative impacts on embryonic viability, fetal development, or neonatal outcomes in monitored cases.

Wu Xueqing from Shanxi Children's Hospital said, "These findings are profoundly encouraging for us and patients, inaugurating an entirely novel pathway for comprehending and treating age-associated infertility."

He also pointed out that future research requires large-scale randomized controlled trials. "In the future, we still need to further validate the drug's therapeutic effects and establish optimized treatment addressing individual patient variables and long-term reproductive outcomes," he said.

Zang Yifan contributed to this story.