J.A. Martínez-Conejero

A GENOMIC DIAGNOSTIC TOOL FOR HUMAN ENDOMETRIAL RECEPTIVITY BASED ON THE TRANSCRIPTOMIC SIGNATURE

OBJECTIVE To create a genomic tool composed of a customized microarray and a bioinformatic predictor for endometrial dating and to detect pathologies of endometrial origin. To define the transcriptomic signature of human endometrial receptivity. DESIGN Two cohorts of endometrial samples along the menstrual cycle were used: one to select the genes to be included in the customized microarray (endometrial receptivity array [ERA]), and the other to be analyzed by ERA to train the predictor for endometrial dating and to define the transcriptomic signature. A third cohort including pathological endometrial samples was used to train the predictor for pathological classification. SETTING Healthy oocyte donors and patients. PATIENT(S) Healthy fertile women (88) and women with implantation failure (5) or hydrosalpinx (2). INTERVENTION(S) Human endometrial biopsies. MAIN OUTCOME MEASURE(S) The gene expression of endometrial biopsies. RESULT(S) The ERA included 238 selected genes. The transcriptomic signature was defined by 134 genes. The predictor showed a specificity of 0.8857 and sensitivity of 0.99758 for endometrial dating, and a specificity of 0.1571 and a sensitivity of 0.995 for the pathological classification. CONCLUSION(S) This diagnostic tool can be used clinically in reproductive medicine and gynecology. The transcriptomic signature is a potential endometrial receptivity biomarkers cluster.

Endometrial receptivity is affected in women with high circulating progesterone levels at the end of the follicular phase: a functional genomics analysis

BACKGROUND Elevated serum progesterone levels at the end of the follicular phase in controlled ovarian stimulation (COS) leads to a poorer ongoing pregnancy rate in IVF cycles due to reduced endometrial receptivity. The objective of this study was to use microarray technology to compare endometrial gene expression profiles at the window of implantation according to the levels of circulating progesterone. METHODS For this prospective cohort study, microarray data were obtained from endometrial biopsies from 12 young healthy oocyte donors undergoing COS with pituitary suppression by either gonadotrophin-releasing hormone (GnRH) agonists or antagonists, and recombinant FSH. On the day of recombinant chorionic gonadotrophin (rCG) administration, six women had serum progesterone levels (P) >1.5 ng/ml (study group) and six had serum P levels <1.5 ng/ml (control group). Endometrial samples were collected using a Pipelle catheter 7 days after the rCG injection. RESULTS Using the parametric test, we identified 140 genes significantly dysregulated (64 up- and 76 down-regulated) in the study group endometria compared with the control endometria, regardless of the GnRH analogue employed. These genes are related to cell adhesion, developmental processes, the immune system and others, which are all required for normal endometrial function development. Of the 25 gene targets previously proposed as markers for endometrial receptivity, 13 appeared over-regulated in the study group. CONCLUSIONS Our results reveal that elevated progesterone levels on the day of rCG administration can induce significant alterations in the gene expression profile of the endometrium.

Human Endometrial Side Population Cells Exhibit Genotypic, Phenotypic and Functional Features of Somatic Stem Cells

During reproductive life, the human endometrium undergoes around 480 cycles of growth, breakdown and regeneration should pregnancy not be achieved. This outstanding regenerative capacity is the basis for womens cycling and its dysfunction may be involved in the etiology of pathological disorders. Therefore, the human endometrial tissue must rely on a remarkable endometrial somatic stem cells (SSC) population. Here we explore the hypothesis that human endometrial side population (SP) cells correspond to somatic stem cells. We isolated, identified and characterized the SP corresponding to the stromal and epithelial compartments using endometrial SP genes signature, immunophenotyping and characteristic telomerase pattern. We analyzed the clonogenic activity of SP cells under hypoxic conditions and the differentiation capacity in vitro to adipogenic and osteogenic lineages. Finally, we demonstrated the functional capability of endometrial SP to develop human endometrium after subcutaneous injection in NOD-SCID mice. Briefly, SP cells of human endometrium from epithelial and stromal compartments display genotypic, phenotypic and functional features of SSC.

Endometrial gene expression analysis at the time of embryo implantation in women with unexplained infertility

Successful embryo implantation depends on the quality of the embryo, as well as on the receptivity of the endometrium. The aim of this study was to investigate the endometrial gene expression profile in women with unexplained infertility in comparison with fertile controls at the time of embryo implantation in order to find potential predictive markers of uterine receptivity and to identify the molecular mechanisms of infertility. High-density oligonucleotide gene arrays, comprising 44 000 gene targets, were used to define the endometrial gene expression profile in infertile (n = 4) and fertile (n = 5) women during the mid-secretory phase (day LH + 7). Microarray results were validated using real-time PCR. Analyses of expression data were carried out using non-parametric methods. Hierarchical clustering and principal component analysis showed a clear distinction in endometrial gene expression between infertile and fertile women. In total we identified 145 significantly (>3-fold change) up-regulated and 115 down-regulated genes in infertile women versus controls. Via Database for Annotation, Visualization and Integrated Discovery functional analysis we detected a substantial number of dysregulated genes in the endometria of infertile women, involved in cellular localization (21.1%) and transport (18.8%) and transporter activity (13.1%) and with major localization in extracellular regions (19.2%). Ingenuity Pathways Analysis of the gene list showed dysregulation of gene pathways involved in leukocyte extravasation signalling, lipid metabolism and detoxification in the endometria of infertile women. In conclusion, endometrial gene expression in women with unexplained infertility at the time of embryo implantation is markedly different from that in fertile women. These results provide new information on genes and pathways that may have functional significance as regards to endometrial receptivity and subsequent embryo implantation.

Microarray analysis in sperm from fertile and infertile men without basic sperm analysis abnormalities reveals a significantly different transcriptome

Sperm analysis following World Health Organization guidelines is unable to explain the molecular causes of male infertility when basic sperm parameters are within a normal range and women do not present gynecologic pathology. Consequently, there is a need for accurate diagnostic tools in this area, and microarray technology emerges as promising. We present, for the first time, preliminary results of a comparison of sperm mRNA expression profiles between fertile and infertile men with normal semen parameters, discovering profound discrepancies between groups, with potential diagnostic and therapeutic possibilities.

The accuracy and reproducibility of the endometrial receptivity array is superior to histology as a diagnostic method for endometrial receptivity

OBJECTIVE To compare the accuracy and reproducibility of the endometrial receptivity array (ERA) versus standard histologic methods. DESIGN A comparative prospective study (May 2008-May 2012). SETTING University-affiliated infertility clinic. PATIENT(S) Eighty-six healthy oocyte donors, regularly cycling, aged 20-34 years with a body mass index (BMI) of 19-25 kg/m(2). INTERVENTION(S) Endometrial biopsies were collected throughout the menstrual cycle. For the accuracy study, 79 samples were grouped into two cohorts: the training set (n = 79) for ERA machine-learning training and dating, and a dating subset (n = 49) for comparison between histologic and ERA dating. For the reproducibility study, seven women underwent ERA testing and it was repeated in the same patients on the same day of their cycle 29-40 months later. MAIN OUTCOME MEASURE(S) Concordance of histologic and ERA dating related to LH as a reference, and interobserver variability between pathologists were statistically analyzed by the quadratic weighted Kappa index. The ERA reproducibility was tested and its gene expression visualized by principal component analysis. RESULT(S) For each pathologist, concordance against LH peak yielded values of 0.618 (0.446-0.791) and 0.685 (0.545-0.824). Interobserver variability between pathologists yielded a Kappa index of 0.622 (0.435-0.839). Concordance for ERA dating against LH peak showed a value of 0.922 (0.815-1.000). Reproducibility of the ERA test was 100% consistent. CONCLUSION(S) The ERA is more accurate than histologic dating and is a completely reproducible method for the diagnosis of endometrial dating and receptivity status.

MicroRNAs miR-30b, miR-30d, and miR-494 Regulate Human Endometrial Receptivity

MicroRNAs (miRNAs) act as important epigenetic posttranscriptional regulators of gene expression. We aimed to gain more understanding of the complex gene expression regulation of endometrial receptivity by analyzing miRNA signatures of fertile human endometria. We set up to analyze miRNA signatures of receptive (LH + 7, n = 4) versus prereceptive (LH + 2, n = 5) endometrium from healthy fertile women. We found hsa-miR-30b and hsa-miR-30d to be significantly upregulated, and hsa-miR-494 and hsa-miR-923 to be downregulated in receptive endometrium. Three algorithms (miRanda, PicTar, and TargetScan) were used for target gene prediction. Functional analyses of the targets using Ingenuity Pathways Analysis and The Database for Annotation, Visualization and Integrated Discovery indicated roles in transcription, cell proliferation and apoptosis, and significant involvement in several relevant pathways, such as axon guidance, Wnt/β-catenin, ERK/MAPK, transforming growth factor β (TGF-β), p53 and leukocyte extravasation. Comparison of predicted miRNA target genes and our previous messenger RNA microarray data resulted in a list of 12 genes, including CAST, CFTR, FGFR2, and LIF that could serve as a panel of genes important for endometrial receptivity. In conclusion, we suggest that a subset of miRNAs and their target genes may play important roles in endometrial receptivity.

Endometrial gene expression in the window of implantation is altered in obese women especially in association with polycystic ovary syndrome.

OBJECTIVE To determine whether luteal phase endometrial transcriptome is altered in obese women during the window of implantation (WOI), considering the presence of infertility, fat distribution and association with polycystic ovary syndrome (PCOS). DESIGN Prospective study. SETTING University-affiliated infertility clinic, between May 2007 and March 2009. PATIENT(S) One control group of women with normal weight (n=4), and four study groups of obese women (n=6 each one) according to the association with infertility, PCOS, and ovarian stimulation. INTERVENTION(S) The endometrium was biopsied 7 days after LH surge or hCG administration in 28 women. MAIN OUTCOME MEASURE(S) Endometrial gene expression during the WOI. RESULT(S) One hundred and fifty-one genes were dysregulated in obese groups compared with controls. This dysregulation was more pronounced when infertility was associated. The biologic processes of these genes belonged mainly to development and regulation of different biological functions such as transcription and biosynthesis. The molecular functions overrepresented were transcription and peptide receptor activity. The endometrium of obese women with PCOS showed dysregulated genes related to biologic processes such as development, morphogenesis, and the immune system, as well as different molecular functions such as protein binding, binding, growth factor activity, and carboxylic acid transmembrane transporter activity. Some of these genes have been previously related to implantation and unexplained infertility. CONCLUSION(S) Obese women present a different endometrial gene expression than controls during the WOI, which is more pronounced when infertility or polycystic ovary syndrome are associated.

Differential transcriptomic profile in spermatozoa achieving pregnancy or not via ICSI

Basic sperm analysis is limited as a method of estimating pregnancy. This study’s objective was use of microarray technology to differentiate the gene expressions of spermatozoa that achieved pregnancy in an intracytoplasmic sperm injection (ICSI)cycle in an oocyte donation programme with those that did not achieve pregnancy. A study of nested cases and controls was designed to evaluate fresh and frozen spermatozoa from infertile males undergoing ICSI with donor oocytes. The global genome expression of pooled samples from each group (achieving pregnancy versus those that didn’t, from fresh or frozen spermatozoa)was compared using microarray analysis. The level of expression of some of the transcripts from fresh spermatozoa was shown to differ for those that achieved pregnancy versus those that didn’t. Additionally, exclusively expressed transcripts were identified for both outcome groups. Analysis of frozen spermatozoa didn’t reveal differential expression, but exclusively expressed transcripts were detected. Lists of the transcripts were systematically analysed using different databases in order to provide information about them and their relationship with male fertility. The results revealed profound differences between the expression profiles of spermatozoa that resulted in pregnancy versus those that didn’t. These differences may explain ICSI failure associated with male factor infertility.

Adenomyosis does not affect implantation, but is associated with miscarriage in patients undergoing oocyte donation

OBJECTIVE To evaluate the effect of adenomyosis on endometrial gene expression and its correlation with clinical outcome. DESIGN Transcriptomic analysis of the endometrium of women with adenomyosis during the window of implantation. Retrospective matched cohort study of the impact of adenomyosis on oocyte donation (OD) outcome. SETTING University-affiliated infertility clinic (2005-2009). PATIENT(S) Endometrial samples were analyzed using microarrays in women with adenomyosis and healthy controls. The clinical study included three groups: adenomyosis, endometriosis, and control. INTERVENTION(S) Endometrial biopsies in natural cycles 7 days after the LH peak; controlled ovarian stimulation in donors; ET in recipients after replacement therapy. MAIN OUTCOME MEASURE(S) Differentially expressed genes; implantation, pregnancy, miscarriage, and term pregnancy rates in OD. RESULT(S) There is a similar endometrial gene expression pattern in both the adenomyosis group and controls, and nonparametric tests revealed 34 dysregulated genes in adenomyosis patients but none belonged to the group of window of implantation genes. Implantation in OD did not differ among the three groups. However, miscarriage was significantly higher in the adenomyosis group vs. the adenomyosis + endometriosis and control groups. Term pregnancy rate was also significantly lower in the adenomyosis group compared with others. CONCLUSION(S) Clinical and molecular data show that implantation is not affected by adenomyosis, but the higher miscarriage rates associated with this condition lead to lower term pregnancy rates, indicating a clear negative effect on the final outcome of OD.