Gene expression profiling of cumulus cells from women with adenomyosis disclose differential pattern to endometriosis: striking the chord for evaluation of a biomarker

Abstract Study question Can metabolic picture of cumulus cell (CC) assess assisted reproductive technology outcome/s in women with adenomyosis/endometriosis and have implications on treatment decisions? Summary answer The differentially expressed genes between uterine pathologies explain the functional gap to identify diagnostic/prognostic markers of CC and further dissect molecular contribution to oocyte maturation. What is known already A healthy intra-follicular environment supports achievement of oocyte developmental competence (ODC) largely via coordinated CC-follicular fluid (FF) crosstalk. Lately, promising studies document CC of endometriosis are involved in important pathways for ODC like oxidative phosphorylation, metabolism, mitochondrial function and acetylation to name a few. Similar presentation/s of adenomyosis to other gynecological diseases including endometriosis makes the diagnosis difficult. Given that the functional integrities of CCs are susceptible to concurrent pathological conditions, understanding the influence of CCs on oocyte quality compared to routine morphological analysis in presence of deleterious systemic or pelvic conditions may impact clinical decisions. Study design, size, duration Twenty-eight consented patients undergoing IVF-ICSI between January to December 2021at Institute of Reproductive Medicine, Kolkata were enrolled. CCs obtained and corresponding oocyte maturation was assessed. They were sub-stratified (n = 9) according to uterine pathologies: adenomyosis (Group A), and endometriosis (Group B) as diagnosed by transvaginal ultrasound (TVUS). Counterpart/s of male sub-fertility, defined by World Health Organization criteria (5th edition) was treated as control (Group C; n = 10). CC from mature MII and immature GV oocytes were compared. Participants/materials, setting, methods CCs collected following oocyte-denudation were evaluated by Trypan Blue viability test. Patient age and embryo development were recorded with respect to each cumulus complex. Real Time-quantitative polymerase-chain-reaction (qRTPCR) was performed for glycolysis (PFKP, PKM2, ALDOA, LDHA, TPI1), cholesterol-biosynthesis (CYP51, MVK, PMVK, EBP) and extracellular-matrix (PTGS2, PTX3, TNFAIP6, VCAN) related gene/s known to have important functions in cumulus expansion and metabolism. Patient characteristics and gene expression were correlated by Spearman’s correlation. P < 0.05 was considered statistically significant. Main results and the role of chance A significant higher (p < 0.001) age (A vs B: 35.77±2.33 vs 25.88± 1.76; A vs C: 35.77±2.33 vs 31.9±1.98) and increased number of oocytes retrieved (A vs B: 11.22±1.56 vs 8.55±0.88) was documented in adenomyosis cohort. Immature oocytes from Group A expressed enhanced cholesterol/steroid biosynthesis, with significant (A vs B; p < 0.01) up-regulation of CYP51, MVK, PMVK, EBP in spite of hyper-estrogenic environment in peripheral blood. On contrary, significant attenuation (p < 0.01) of cholesterol biosynthesis was documented in endometriosis cohort compared to control. Expression of PTGS2, PTX3 and VCAN was down-regulated (p < 0.001) (which together mediate cumulus expansion and oocyte maturation, as well as corpus luteum formation and maintenance and reduce spindle abnormalities) in both Group A and B. Expression/s of CC-PFKP and PKM2 was lower in immature compared to mature oocytes (B vs C; p < 0.01) in endometriosis making the duo responsible for follicular/oocyte growth, and embryonic development. This supports the role in promoting cumulus expansion and oocyte competence. Expression levels of other genes including ALDOA, LDHA, TPI1, and TNFAIP6 were not associated with oocyte maturity, and fertilization in either cohort/s. Interestingly, levels of VCAN, TNFAIP6, PTX3 changed significantly as a function of the subject’s age and embryo development. Limitations, reasons for caution Our findings are limited by the relatively small sample size and inherent biological variability of human samples. Several yet known or unknown factors are presumably involved in the implantation process of adenomyosis and/or endometriosis. Multi-centric systematic studies are needed to corroborate these findings and account for the probable confounding factors. Wider implications of the findings A differential metabolic dependence of CC play essential role in oocyte competence in adenomyosis influencing cumulus expansion and oocyte maturation. This would be useful to do further studies to know how molecular interface of implantation capacity with live-birth rate would be affected to complement embryonic morphological assessment/s. Trial registration number Not Applicable