Deciphering biomarkers of endometriosis by proteomic analysis of eutopic endometrium in infertile patients

Endometriosis is associated with infertility. The aim of this study was to examine the overall proteomic changes of eutopic endometrium in infertile women with endometriosis.

Tandem mass tags combined with multidimensional liquid chromatography and mass spectrometry analyses were used to screen the proteomic profiles of eutopic endometrium from infertile patients with endometriosis (N = 4), compared with that from patients without endometriosis (N = 4). Quantitative proteomic analysis, functional categories and significant pathway analysis were investigated subsequently.

In total, 6.698 proteins were identified, among which 5,812 proteins were quantified. Compared with controls, proteomic analysis showed some differentially expressed proteins: 16 up-regulated proteins and 23 down-regulated proteins. Bioinformatics analysis indicated that differentially expressed proteins were involved in humoral immune response pathways, antimicrobial humoral response and regulation of nitric oxide biosynthetic process. Besides, our results showed that alpha-1-acid glycoprotein 2, complement factor B and zinc transporter Zip14 were important resources for investigating potential mechanism of infertility in infertile women with endometriosis.

This study provided a reference proteome map of eutopic endometrium from infertile women with endometriosis. The long-term benefits of using those markers to stratify clinical treatment warrant further investigation.