Exploring Epithelial-Mesenchymal Transition Signals in Endometriosis Diagnosis and In Vitro Fertilization Outcomes

Abstract

Endometriosis (EMS) pathogenesis has been related to the release of inflammatory mediators in peritoneal fluid, creating an altered microenvironment that leads to low-grade oocyte/embryos and to the reduction of implantation rates. The Epithelial-Mesenchymal Transition (EMT), an inflammation-related process, can be a further contributing factor to EMS. This study aimed to investigate, among various cytokines and EMT markers (Cadherins, TGF-β, HIF-1α), diagnostic markers of EMS and prognostic factors of in vitro fertilization (IVF) outcomes. Herein, EMS patients manifested higher serum levels of the inflammatory molecules IL-6, IL-8, and IL-12 and a decrease in the concentrations of the anti-inflammatory IL-10. Moreover, biochemical markers associated with the EMT process were more elevated in serum and follicular fluid (FF) of EMS patients than in controls. At the end, the number of good-quality embryos was inversely related to serum IL-6 and EMT markers. Interestingly, serum IL-6 and FF IL-10 concentrations differentiated EMS patients from controls. Finally, serum IL-8 and E-Cadherin levels, as well as FF IL-10, predicted positive IVF outcome with great accuracy. Our data confirm the pivotal role of inflammatory mediators (i.e., IL-6 and IL-10) in EMS pathogenesis and suggest that EMT-related markers are elevated in EMS patients and can be predictive of IVF outcome.

Keywords: EMT; endometriosis; follicular fluid; inflammatory cytokines.

Figure 5

ROC analyses. ROC analyses of serum (a,c) and FF (b,d) parameters were performed to assess the ability to discriminate EMS patients from controls or to predict IVF outcome. AUROC, area under the receiving operating characteristic curve, and CI, confidence interval, are shown in Table 4.

Figure 5

ROC analyses. ROC analyses of serum (a,c) and FF (b,d) parameters were performed to assess the ability to discriminate EMS patients from controls or to predict IVF outcome. AUROC, area under the receiving operating characteristic curve, and CI, confidence interval, are shown in Table 4.

Figure 1

Protein levels of proinflammatory IL-6 (a), IL-8 (b), IL-12 (c), and anti-inflammatory IL-10 (d) in serum samples from control women and EMS patients. All interleukins were quantified using commercial ELISA kits (Cloud-Clone ELISA kit). The data are reported as the mean values ± SD of three independent experiments, each performed in duplicate. Statistical analysis was performed by unpaired t-test: ** p < 0.01, *** p < 0.001 versus control.

Figure 2

Protein levels of proinflammatory IL-6 (a), IL-8 (b), IL-12 (c), and anti-inflammatory IL-10 (d) in follicular fluid (FF) samples from control women and EMS patients. The data are reported as the mean values ± SD of three independent experiments each performed in duplicate. Statistical analysis was performed by unpaired t-test: *** p < 0.001 versus control.

Figure 2

Protein levels of proinflammatory IL-6 (a), IL-8 (b), IL-12 (c), and anti-inflammatory IL-10 (d) in follicular fluid (FF) samples from control women and EMS patients. The data are reported as the mean values ± SD of three independent experiments each performed in duplicate. Statistical analysis was performed by unpaired t-test: *** p < 0.001 versus control.

Figure 3

Evaluation of EMT markers (E-cadherin, N-cadherin) and EMT-related inflammatory markers (TGF-β, HIF-1α, and NF-kB) in serum samples from control and EMS patients (Endo). E-cadherin (a), N-cadherin (b), TGF-β (c), HIF-1α (d), and NF-kB (e) levels were assessed by homemade ELISA kits. Data are the mean ± SD of two different experiments, each performed in duplicate. Statistical analysis was performed by unpaired t-test: * p < 0.05, ** p < 0.01, *** p < 0.001 versus control.

Figure 3

Evaluation of EMT markers (E-cadherin, N-cadherin) and EMT-related inflammatory markers (TGF-β, HIF-1α, and NF-kB) in serum samples from control and EMS patients (Endo). E-cadherin (a), N-cadherin (b), TGF-β (c), HIF-1α (d), and NF-kB (e) levels were assessed by homemade ELISA kits. Data are the mean ± SD of two different experiments, each performed in duplicate. Statistical analysis was performed by unpaired t-test: * p < 0.05, ** p < 0.01, *** p < 0.001 versus control.

Figure 4

Evaluation of EMT markers (E-cadherin, N-cadherin) and EMT-related inflammatory markers (TGF-β, HIF-1α, and NF-kB) in FF samples from control and EMS patients. E-cadherin (a), N-cadherin (b), TGF-β (c), HIF-1α (d), and NF-kB (e) levels were assessed by homemade ELISA kits. Data are the mean ± SD of two different experiments, each performed in duplicate. Statistical analysis was performed by unpaired t-test: * p < 0.05, ** p < 0.01, *** p < 0.001 versus control.