Przemysław Wirstlein

The Impact of Leukemia Inhibitory Factor in Uterine Flushing on the Reproductive Potential of Infertile Women – A Prospective Study

To determine the value of leukemia inhibitory factor (LIF) assessment for predicting the reproductive outcome.

Reduced expression of HOXA10 in the midluteal endometrium from infertile women with minimal endometriosis

Recent human and animal studies have suggested that reduced HOXA10 expression in the implantation window of eutopic endometrium may contribute to infertility in women with endometriosis. Therefore, we examined the HOXA10 transcript, protein and HOXA10 promoter methylation levels in midluteal eutopic endometrium from 17 infertile women with minimal endometriosis and 15 healthy fertile women from a Polish cohort. Real-time quantitative PCR (RQ-PCR) and western blotting analysis revealed significantly lower levels of HOXA10 transcript (P=0.019) and protein (P=0.048) levels in eutopic endometrium from infertile women with endometriosis as compared to healthy fertile women. Moreover, sodium bisulfite sequencing of three HOXA10 CpG islands showed significantly higher methylation levels of genomic DNA from midluteal eutopic endometrium from infertile women with endometriosis as compared to healthy fertile women (P=0.006). We confirmed that DNA hypermethylation can be one of the potential molecular mechanisms silencing HOXA10 expression in the midluteal endometrium associated with infertility in women with endometriosis.

Could the Defects in the Endometrial Extracellular Matrix During the Implantation Be a Cause for Impaired fertility

Assessment of concentration of the metalloproteinase 9 (MMP9), tissue inhibitor of metalloproteinases 1 (TIMP1), urokinase plasminogen activator (uPA) and its receptor (uPAR) and leukaemia inhibitory factor (LIF) in the uterine fluid in women with idiopathic infertility and unknown cause for recurrent miscarriage.

Polymorphic variants of CYP17 and CYP19A and risk of infertility in endometriosis

Endometriosis is recognized as an estrogen‐dependent disease. There are conflicting data demonstrating single nuclear polymorphisms (SNPs) of CYP17 and CYP19 steroidogenic genes as related to endometriosis risk. We assessed the CYP17 5′‐untranslated region ‐34 A/G (rs743572) and CYP19 Ex10 + C1558T (rs10046) SNPs in stage I–II endometriosis.

Expression of HOXA-10 and HOXA-11 in the endometria of women with idiopathic infertility

In fertile women, HOXA-10 and HOXA-11 expression rises during the luteal phase, with the peak occurring during the implantation window, and stays at a high level until the end of the cycle. We evaluated the transcript and protein levels of HOXA-10 and HOXA-11 in the endometria of patients with idiopathic infertility (n = 15) and control patients (n = 10). The amounts of mRNA were determined by reverse transcription and real-time quantitative PCR. The protein levels were evaluated by Western blotting analysis. Using immunohistochemical techniques, we compared the localization of HOXA-10 and HOXA-11 proteins in the implantation window between the study and control groups. We observed statistically significantly decreased HOXA-10 and HOXA-11 transcript levels (p = 0.003, p = 0.012 respectively) in infertile patients compared to controls. There was no significant decrease in HOXA-10 protein levels between these groups (p = 0.074). However, we observed a significantly higher level of HOXA-11 protein in the endometria of infertile patients compared to controls (p = 0.015). HOXA-10 and HOXA-11 proteins were localized in the nuclei of the endometrial stromal cells. Immunohistochemical analyses did not reveal differences between amounts of HOXA-10 and HOXA-11 protein levels in infertility and control groups. Our results suggest that HOXA-10 and HOXA-11 gene expression in the endometrium during the implantation window may not be altered in patients with idiopathic infertility.

No correlation between pinopode formation and LIF and MMP2 expression in endometrium during implantation window.

Implantation depends on two factors - embryo and endometrium. The period of maximal endometrial receptivity is a poorly understood phenomenon. We decided to look at three possible markers of implantation: pinopodes, leukemia inhibitory factor, and matrix metalloproteinase 2 and their correlations. We included in the study 23 idiopathic infertility patients and 21 patients with recurrent spontaneous abortions of unknown etiology. Twenty one fertile patients were also recruited. A biopsy was used for endometrial dating according to the Noyes and Hertig criteria, and assessed for the presence of pinopodes via a scanning electron microscope. Endometria were examined in Real Time-Polymerase Chain Reaction cycles for the mRNA expression of leukemia inhibitory factor (LIF) and matrix metalloproteinase 2 (MMP2). No difference was found in the stage of pinopodes development, nor in the coverage of endometrial surface between the studied groups. The expression level for LIF mRNA was lower in control patients compared to idiopathic infertility and recurrent miscarriage patients. No difference was detected in the expression of MMP2 between all studied groups. No correlation was found between pinopodes development stage and LIF and MMP2 expressions in endometrium. Of the studied factors, LIF and pinopodes show the most promise as potential markers of endometrial receptivity. However, the results achieved suggest that these markers are independent of each other.

Polymorphic variants of folate and choline metabolism genes and the risk of endometriosis-associated infertility.

OBJECTIVE Endometriosis has been considered an epigenetic disease. Single nucleotide polymorphisms (SNPs) located in genes encoding enzymes of the folate and choline metabolism may affect DNA methyltransferase activity. STUDY DESIGN We studied 16 SNPs in 12 folate and choline metabolism genes, including BHMT (rs7356530 and rs3733890), BHMT2 (rs625879), CBS (844ins68), CHDH (rs893363 and rs2289205), CHKA (rs7928739), MTHFD1 (rs2236225), MTHFR (rs1801133), MTR (rs1805087), MTRR (rs1801394), PCYT1A (rs712012 and rs7639752), PEMT (rs4244593 and rs4646406) and TCN (rs1801198) in one hundred and sixty-three infertile women with minimal endometriosis and one hundred and fifty fertile women. RESULTS There were no significant differences between genotype and allele frequencies of these gene variants in infertile women with endometriosis (n=163) and controls (n=150). The lowest, but not statistically significant, p values of the trend test were observed for the CBS 844ins68 and MTR rs1805087 (ptrend=0.0527 and ptrend=0.0771, respectively) polymorphisms. However, the exhaustive multifactor dimensionality reduction analysis revealed an epistatic interaction between rs1801133 of MTHFR and rs4244593 of PEMT in endometriosis-associated infertility (p=0.0240). CONCLUSIONS Our results showed moderate evidence for the contribution of SNPs located in genes encoding folate and choline metabolism enzymes to infertility in women with endometriosis.

Polymorphic variants in vitamin D signaling pathway genes and the risk of endometriosis-associated infertility.

It has recently been reported that vitamin D blood plasma levels are associated with reduced risk of endometriosis. The present study aimed to investigate whether the vitamin D binding protein (GC), vitamin D receptor (VDR), and retinoid X receptor (RXR) gene variants may be genetic risk factors for endometriosis‑associated infertility. The subjects consisted of 154 women with endometriosis‑associated infertility and 347 controls. Using polymerase chain reaction restriction fragment length polymorphism and high resolution melt techniques, the GC rs1155563, rs2298849 and rs7041; RXRA rs10881578, rs10776909 and rs749759; VDR BsmI rs1544410; and FokI rs2228570 single nucleotide polymorphisms (SNPs) were investigated in the patients with endometriosis and the healthy controls. The results indicated that no significant differences were observed between the genotype and allele frequencies of all experimental SNPs in the vitamin D signaling pathway genes in women with endometriosis-associated infertility and controls. However, a significant association was present between the A‑T haplotype, consisting of VDR rs1544410 and rs222857 minor alleles, and endometriosis-associated infertility [OR=1.659 (1.122‑2.453), P=0.011]. The results of the present study suggested that VDR gene variants act as genetic risk factors for endometriosis‑associated infertility.

Polymorphic variants of DNMT3A and the risk of endometriosis

OBJECTIVE Overexpression of DNA methyltransferase 3A (DNMT3A) and aberrant methylation of various genes in eutopic endometrium have been demonstrated in women with endometriosis. We aimed to study whether DNMT3A polymorphisms could be a genetic risk factor for endometriosis and endometriosis-related infertility. STUDY DESIGN We studied 5 SNPs (rs2289195, rs7590760, rs13401241, rs749131 and rs1550117) located in the DNMT3A gene in 357 women with endometriosis and 640 controls. RESULTS We did not observe significant differences between genotype and allele frequencies of rs2289195, rs7590760, rs13401241, rs749131 and rs1550117 SNPs in women with endometriosis, endometriosis-related infertility, and controls. The lowest p values of the trend test were observed for DNMT3A rs1550117 in endometriosis and endometriosis-related infertility (p(trend)=0.049 and p(trend)=0.055, respectively). CONCLUSIONS Our results did not supply evidence for the contribution of SNPs located in DNMT3A to either endometriosis or endometriosis-related infertility.

Assessment of the transcription levels for the complement activation control system in eutopic endometrium in women with two or more consecutive miscarriages of unknown etiology

Human endometrium, deciuda and placenta have been shown to express factors that inhibit the complement activation cascade - decay-accelerating factor (DAF), membrane cofactor protein (MCP) and the C3 complement component. In the following study we have analyzed the transcripts levels for DAF, MCP and heparin-binding epidermal growth factor-like growth factor (HB-EGF), the C3 complement component and receptor for vascular endothelial growth factor (VEGFR1) as markers of endometrial unbalance between factors activating the complement system in women with consecutive miscarriages. Study enrolled 30 women with at least two consecutive miscarriages, and 19 healthly women, that comprised the control group. RNA was isolated from endometrial samples. Transcripts levels of DAF and MCP was higher in women with consecutive miscarriages compared to controls, 0.78 vs 5.08 (p<0.001) and 0.25 vs 0.17 (p=0.001) respectively. In consecutive miscarriages group, DAF and MCP expression was correlated with the C3 expression, with r=0.60; p<0.001 and r= 0.40; p=0.03 respectively. Correlation between DAF and C3 was also noted in controls, 0.70; p=0.001. In women with two or more consecutive miscarriages the analysis proved higher expression of genes that encode proteins that inhibit the complement cascade. Further studies are needed to confirm that this might be a reaction to increased presence of the complement factors, which like C3 that are synthesized in the endometrium.