P-401 Aging affects endometrial receptivity factors. Can DHEA modulate this age-related effect?

Abstract

Abstract Study question Identification of age-related gene expression differences of the human endometrium during its receptive period – Dehydroepiandrosterone (DHEA) effects. Summary answer Decrease in expression of OPN and HOXA10, receptivity markers, between increasing female age groups in primary human endometrial cells was presented. DHEA altered gene expression. What is known already The increased infertility noted in the world population, has been related to increasing maternal age. Our previous work points out the role of women’s age in endometrial cell function. Endometrial proliferation and differentiation are two important steps that lead to increased cell receptivity during the window of implantation. Optimal receptivity is achieved also through changes inexpression of several factors throughout the endometrial cycle. It is well known that androgen levels, in the female reproductive system, decrease with increasing age.Therefore, DHEA an androgen precursor, found to be reduced with age is thought to be a candidate for infertility treatment. Study design, size, duration Maternal age has not been previously directly correlated with endometrial receptivity factors. We studied 39 endometrial samples divided in three different women’s age groups (25-35 years, 36-40 years and 41-46years) and changes in the mRNA and protein expression of osteopontin (OPN), CD44 and HOXA10 in human endometrium stromal cells were analyzed, in vitro. DHEA was added on stromal cells (decidualized or not) in order to observe changes in mRNA expression. Participants/materials, setting, methods Pipelle endometrial biopsies (secretory phase) were collected from ovulating, fertile, Caucasian women volunteers aged 25–46 years. Stromal cells were isolated. These samples were divided into three age groups: 25-35 years, 36-40 years and 41-46 years. Protein and mRNA expression of receptivity modulators OPN, CD44 and HOXA10 were analyzed using Real-time PCR and Western blot analysis, respectively. Stromal cells were decidualized in vitrousing bromo-8-cAMP in order to observe DHEA effects. Main results and the role of chance Data presented showed a statistically significant decrease (p ≤ 0.05) in OPN expression levels with increasing age groups. Women included in age group of 41-45y presented a significant downregulation of OPN expression compared to younger age group 25-35y (p ≤ 0.01).CD44 expressiondid not differ with age. Furthermore, a statistically significant decrease (p ≤ 0.05) was evident in HOXA10 expression levels with increasing age. Women belonging to the age group 41-45y expression presented with significant HOXA10 downregulation compared to younger age group 25-35y (p ≤ 0.05). Analysis of OPN protein levels showed that cell-extracted OPN decreased from theage of 33y, while the secreted protein gradually decreased from the age of 38y. CD44 protein expression, similarly to the mRNA expression did not show differences with age. HOXA10 protein expression was found to be decreased mainly after the age of41y. DHEA changed, with statistical significance, the expression of decidualization marker IGFBP and OPN in decidualized stromal cells. Overall, our results support our hypothesis as expected, but we must also consider specific cases where older women have the same results as younger ones and the opposite, so factors that are specific for each individual must be further investigated. Limitations, reasons for caution It must be pointed out that there is a plethora of characterized molecules like cytokines and immune cells that also participate in the optimal receptivity status of the endometrium – leading to a successful implantation procedure – that future studies need to examine, as well, in relation to women’s age. Wider implications of the findings Human endometrial aging can affect embryo receptivity markers and therefore, receptivity. Further investigation of receptivity factors that change with the age could be a useful pool in identifying targets for diagnosis and therapy of human implantation failure. Also, DHEA must be further investigated as a tool for infertility therapy. Trial registration number not applicable