Aging Regulates Receptivity by Modulating the Expression of Osteopontin and HOXA10 in the Human Endometrium

Background/Objectives: Aging is increasingly recognized as a key determinant of changes in human tissue and cellular function. Women's age, in particular, has been associated with reduced oocyte quality and negatively correlated with the expression of genes involved in endometrial decidualization and cellular function. The ability of endometrial cells to interact and allow the invasion of the growing embryo is defined as endometrial receptivity. Investigating age-related differences in human endometrial receptivity may expand our understanding of factors contributing to infertility. Methods: Stromal cells were isolated and cultured from endometrial pipelle biopsies (n = 28) obtained from female donors at the proliferative phase of the menstrual cycle. Protein and mRNA expression of the receptivity modulators OPN, CD44, and HOXA10 were analyzed by Western blot and real-time PCR, respectively. Results: Data presented a linear decrease in mRNA expression of OPN and HOXA10 (p = 0.0066, R² = 0.3018 and p = 0.0036, R² = 0.529, respectively) with women's increasing age, and a similar trend was evident at the protein level (OPN, p < 0.05; HOXA10, p < 0.01). Further analysis of the data included separating the samples into three age groups: 25-35 years, 36-40 years, and 41-46 years. ANOVA revealed a significant decrease in OPN and HOXA10 mRNA expression (p = 0.03158 and p = 0.02578, respectively). CD44 expression did not differ with age. Conclusions: OPN and HOXA10 are negatively correlated with increasing maternal age. These findings suggest that age-related alterations in key endometrial receptivity modulators may contribute to impaired implantation and could represent potential targets for diagnostic or therapeutic strategies in human implantation failure.