Proteomic signature of menstrual blood mesenchymal stromal cells and their extracellular vesicles in women with unexplained infertility

Abstract

Research question Can the proteome of menstrual blood mesenchymal stem cells, their extracellular vesicles (EVs), or EV-depleted supernatant be employed for personalized identification of altered cellular processes in women with unexplained infertility (uIF), enabling their stratification into etiopathogenetic endotypes? Design For MenSCs isolation, menstrual blood was collected from 12 fertile healthy volunteers (control) and 8 patients with uIF. MenSC EVs were isolated using Iodixanol Density Gradient Centrifugation, quantified by flow cytometry and characterized according to MISEV guidelines by TEM, flow cytometry and Western blot. Proteome was analysed using mass spectrometry and bioinformatic tools. Results Mesenchymal marker expression and phenotype of MenSCs isolated from fertile and uIF female menstrual blood did not differ between the groups. MenSCs- derived EVs were successfully isolated from the conditioned media and characterised as corresponding to MISEV guidelines. The comprehensive proteomic analysis of MenSCs, MenSC EVs and EV-depleted MenSC supernatant showed significant changes in proteome in all those sample types of uIF, mainly implying compromised cell adhesion, immune response, fibrosis and altered metabolism. These findings were validated by western blot and demonstrated the relevance and potential of the proposed biomarkers in understanding and identifying endotypes of uIF. Conclusions We observed proteome changes in cell adhesion, immune and inflammatory processes, and protein metabolism in diverse menstrual blood samples of uIF group. The proteins responsible for these processes may be used as biomarkers to stratify patients into distinct molecular endotypes characterized by altered adhesion, immune response, fibrosis, and metabolism, which may lead to the development of personalized treatment approaches for women with uIF.