Protein Fingerprinting of Seminal Plasma Reveals Dysregulation of Exosome-Associated Proteins in Infertile Men with Unilateral Varicocele

Abstract

Purpose Aberrant expression of seminal plasma proteins are associated with altered homeostasis that may affect the fertilizing ability of spermatozoa. However, the precise roles of seminal exosomes on sperm function remain unclear. The objective of this study was to identify the differentially expressed proteins (DEPs) associated with varicocele-mediated infertility by comparing seminal plasma protein profile of unilateral varicocele patients with proven fertile donors. Materials and Methods Semen samples were obtained from 10 proven fertile donors with normal semen parameters and 33 infertile patients with unilateral varicocele. For proteomic analysis, 5 samples from each group were pooled and run in triplicate. Key DEPs (ANXA2, TF, CD63, KIF5B, SEMG1) associated with the exosome function were selected by bioinformatic tools and validated using Western blotting. Results A total of 47 seminal plasma proteins were differentially expressed in unilateral varicocele patients compared to fertile donors. Validation of exosome-associated DEPs in unilateral varicocele patients (n=7) and fertile donors (n=7) revealed significant upregulation of ANXA2 (p=0.0016) and downregulation of KIF5B (p=0.009). The main upstream regulators of the DEPs in seminal plasma of unilateral varicocele group were androgen receptor, YB1 and NRF2. Conclusions This is the first report to identify DEPs in seminal plasma of unilateral varicocele patients compared to fertile donors. Based on the detection of DEPs associated with exosomal function, Western blotting was used to validate the presence of defective exosome machinery in seminal plasma of unilateral varicocele patients. KIF5B and ANXA2 can be utilized as potential biomarkers of infertility in unilateral varicocele patients.

The Effect of Schisandra chinensis Baillon on Cross-Talk between Oxidative Stress, Endoplasmic Reticulum Stress, and Mitochondrial Signaling Pathway in Testes of Varicocele-Induced SD Rat

“…Oxidative stress is a well-known mechanism for testicular dysfunction in VC-induced infertility, which acts by damaging sperm membrane, proteins, and DNA known to be associated with fertility [33,34]. Results of our study showed upregulation of MDA and ROS/RNS levels in VC rats, in consensus with previous findings [7].…”

Exosome Composition and Seminal Plasma Proteome: A Promising Source of Biomarkers of Male Infertility

“…On the other hand, CDC42 and SEMG2 can be useful candidate biomarkers for primary infertility and APP for secondary infertility. A dysregulated expression of semenogelins has also been reported in SP of men with abnormal semen parameters [ 111 , 117 ] and varicocele [ 120 , 126 , 146 ], confirming the importance of these proteins as markers of infertility. Importantly, this study shows that seminal proteins might permit the identification of the main cause associated with primary and secondary infertility [ 114 ].…”

“…Of particular interest, there was an overexpression of ANXA2 and CDC42 and an underexpression of SEMG2 in men with primary infertility and an overexpression of ANXA2 and amyloid precursor protein (APP) in secondary infertility. The overexpression of ANXA2 in both primary and secondary infertility, and the results of earlier studies, showing an altered expression of this protein in SP and prostasomes of subfertile or infertile men [ 89 , 146 , 147 ] suggest its potential utility as a biomarker for both primary and secondary infertility. On the other hand, CDC42 and SEMG2 can be useful candidate biomarkers for primary infertility and APP for secondary infertility.…”

“…Differences in the seminal proteome profile of patients with unilateral and bilateral varicocele have also been described [ 112 ]. Panner Selvam et al [ 146 ] observed a dysregulation of exosome-associated proteins in patients with unilateral varicocele, compared to fertile controls, with an overexpression of ANXA2 and an underexpression of kinesin-1 heavy chain (KIF5B). Compared to unilateral varicocele patients, inflammatory response pathways were dysregulated in bilateral varicocele, with an underexpression of alpha-1-acid glycoprotein 1 (ORM1), alpha-1-acid glycoprotein 2 (ORM2), SERPINA1, GGT1, apolipoprotein D (APOD) and FN1, and an overexpression of ECM1, polymeric immunoglobulin receptor (PIGR) and ALDR.…”

Sperm and Seminal Plasma Proteomics: Molecular Changes Associated with Varicocele-Mediated Male Infertility

“…Recently, we have identified the alterations in seminal plasma proteins associated with exosome functions in varicocele patients. Exosome-associated proteins ANXA2 and KIF5B may serve as potential protein biomarkers of exosomal dysfunction and exosome-mediated infertility in varicocele patients [ 74 ].…”