The pathophysiology of recurrent pregnancy loss (RPL) is still unknown in 50% of the cases. Herein we measure the expression of beta3 integrin subunit, a well-known implantation marker, in women with or without RPL and correlate it with the histological dating of the endometrial tissue.

During the menstrual cycle, the endometrium undergoes cyclic changes of cellular proliferation, differentiation, and death, an essential preparation of the endometrium for its interaction with the implanting embryo. In particular, the differentiation of endometrial stromal cells, named decidualization, ensures the formation of a proper feto-maternal interface for a regulated trophoblast invasion and correct placental orientation and growth. Interestingly, autophagy, an intracellular degradation process of great importance for the maintenance of cellular homeostasis, plays an important role in cell proliferation, differentiation, and growth. In the endometrium, increased detection of autophagy markers correlates with the progression of the menstrual cycle. However, until now, it was unknown whether autophagy contributes to the proper function of the endometrium. In this study, we show that autophagy is increased during in vitro decidualization of human endometrial stromal cells. Furthermore, we demonstrate that the knockdowns of two important autophagy-related (ATG) proteins, ATG7 and ATG5, impaired decidualization, confirming a positive role of these proteins and of autophagy for the correct decidualization of human endometrial stromal cells. In conclusion, in this work, we describe a previously unknown functional connection between autophagy and endometrial physiology.

Fragile-X-Mental-Retardation-1- (FMR1)-gene is supposed to be a key gene for ovarian reserve and folliculogenesis. It contains in its 5’-UTR a triplet-base-repeat (CGG), that varies between 26 and 34 in general population. CGG-repeat-lengths with 55–200 repeats (pre-mutation = PM) show instable heredity with a tendency to increase and are associated with premature-ovarian-insufficiency or failure (POI/POF) in about 20%. FMR1-mRNA-expression in leucocytes and granulosa cells (GCs) increases with CGG-repeat-length in PM-carriers, but variable FMR1-expression profiles were also described in women with POI without PM-FMR1 repeat-length. Additionally, associations between low numbers of retrieved oocytes and elevated FMR1-expression levels have been shown in GCs of females with mid-range PM-CGG-repeats without POI. Effects of FMR1-repeat-lengths-deviations (n < 26 or n > 34) below the PM range (n < 55) on ovarian reserve and response to ovarian stimulation remain controversial. We enrolled 229 women undergoing controlled ovarian hyperstimulation for IVF/ICSI-treatment and devided them in three ovarian-response-subgroups: Poor responder (POR) after Bologna Criteria, polycystic ovary syndrome (PCO) after Rotterdam Criteria, or normal responder (NOR, control group). Subjects were subdivided into six genotypes according to their be-allelic CGG-repeat length. FMR1-CGG-repeat-length was determined using ALF-express-DNA-sequencer or ABI 3100/3130 × 1-sequencer. mRNA was extracted from GCs after follicular aspiration and quantitative FMR1-expression was determined using specific TaqMan-Assay and applying the ΔΔCT method. Kruskall-Wallis-Test or ANOVA were used for simple comparison between ovarian reserve (NOR, POR or PCO) and CGG-subgroups or cohort demographic data. All statistical analysis were performed with SPSS and statistical significance was set at p ≤ 0.05. A statistically significant increase in FMR1-mRNA-expression-levels was detected in GCs of PORs with heterozygous normal/low-CGG-repeat-length compared with other genotypes (p = 0.044). Female ovarian response may be negatively affected by low CGG-alleles during stimulation. In addition, due to a low-allele-effect, folliculogenesis may be impaired already prior to stimulation leading to diminished ovarian reserve and poor ovarian response. A better understanding of FMR1 expression-regulation in GCs may help to elucidate pathomechanisms of folliculogenesis disorders and to develop risk-adjusted treatments for IVF/ICSI-therapy. Herewith FMR1-genotyping potentially provides a better estimatation of treatment outcome and allows the optimal adaptation of stimulation protocols in future.