Cervical mucus (CM) is a viscous fluid that is produced by the cervical glands and functions as a uterine cervix plug. Its viscosity decreases during ovulation, providing a window for non-invasive sampling. This study focuses on proteomic characterization of CM to evaluate its potential as a non-invasively acquired source of biomarkers and in understanding of molecular (patho)physiology of the female genital tract. The first objective of this work was to optimize experimental workflow for CM processing and the second was to assess differences in the proteomic composition of CM during natural ovulatory cycles obtained from intrauterine insemination (IUI) cycles and in vitro fertilization (IVF) cycles with controlled ovarian hyperstimulation. Proteomic analysis of CM samples revealed 4370 proteins involved in processes including neutrophil degranulation, cellular stress responses, and hemostasis. Differential expression analysis revealed 199 proteins enriched in IUI samples and 422 enriched in IVF. The proteins enriched in IUI were involved in phosphatidic acid synthesis, responses to external stimulus, and neutrophil degranulation, while those enriched in IVF samples were linked to neutrophil degranulation, formation of a cornified envelope and hemostasis. Subsequent analyses clarified the protein composition of the CM and how it is altered by hormonal stimulation of the uterus.

Department of Gynecology and Obstetrics Masaryk University Brno Obilni trh 11 625 00 Brno Czech Republic

Department of Gynecology and Obstetrics University Hospital Brno Obilni trh 11 625 00 Brno Czech Republic

Department of Gynecology and Obstetrics University Hospital in Olomouc 1 P Pavlova 6 779 00 Olomouc Czech Republic

Department of Gynecology and Obstetrics University Hospital in Olomouc Faculty of Medicine and Dentistry Palacký University in Olomouc Hněvotínská 3 779 00 Olomouc Czech Republic

Laboratory of Experimental Medicine Institute of Molecular and Translational Medicine Faculty of Medicine and Dentistry Palacký University Hněvotínská 5 779 00 Olomouc Czech Republic

Laboratory of Experimental Medicine University Hospital in Olomouc Hněvotínská 5 779 00 Olomouc Czech Republic

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