Post-reproductive ovaries shift to immune role
Get the Health newsletter
Daily health & science — research, biotech, public health, the studies worth knowing. Free.
- Francesca Duncan at Northwestern University led a study finding that aged mouse ovaries become infiltrated with immune cells, directly challenging the long-held assumption that post-menopausal ovaries sit inert in the body.
- The team analyzed ovaries from young (2 months), reproductively old (18 months), and post-reproductive (24 months) mice, finding that older ovaries lost egg-producing follicles, showed more scarring, and downregulated genes tied to reproduction and hormone production including estradiol.
- Genes linked to inflammation and immune activity became increasingly active with age, and the number of immune cells — including T cells and macrophages — rose in the ovaries as the mice aged.
- In a separate March study on post-menopausal women aged 50 to 75, Duncan's team found ovarian molecular signatures changed 'quite dramatically over the decades,' indicating the organ continues evolving long after fertility ends.
- Duncan characterized the change as an identity shift — ovaries losing their reproductive signature and adopting an immune one — and suspects they may release inflammatory signaling molecules that contribute to 'inflammaging' elsewhere in the body.
- Diana Laird at the University of California, San Francisco, said the findings may help explain the spike in rheumatoid arthritis and other inflammatory conditions seen in post-menopausal women and called for detailed functional studies of the post-reproductive ovary.
Why it matters: If post-menopausal ovaries are active drivers of chronic inflammation and potentially autoimmune conditions like rheumatoid arthritis, it could reshape how researchers approach women's post-reproductive health and even inform decisions about whether to preserve or remove ovaries during surgery after menopause — a practice currently guided by the belief that the organs are largely dormant.
.png)
