Deficiency in Outer Dense Fiber 1 Is a Marker and Potential Driver of Idiopathic Male Infertility

Abstract

Globally, ϳ1 in 15 men of reproductive age are infertile, yet the precise mechanisms underlying their gamete failure are unknown. Although a semen analysis is performed to determine fertilizing potential, the diagnostic suitability of this analysis has been questioned in several reports, as many men, classified as infertile according to their semen analysis, subsequently turn out to be fertile. Herein, we have used a quantitative (phospho)-proteomic analysis, using enrichment on titanium dioxide followed by ion-trap mass spectrometry (LC-MS/MS), to compare the semen of infertile versus fertile males. One protein, namely outer dense fiber 1 (ODF1), was dramatically reduced in infertile males. Using specific antibodies, we then screened the gametes of a cohort of suspected infertile men and demonstrated a reduction in the amount of ODF1 compared with fertile controls. Stress treatment of sperm deficient in ODF1 caused the head to decapitate, suggesting why these gametes fail to initiate fertilization. Interestingly, electron micrographs of ODF1-deficient spermatozoa revealed an abnormal connecting piece, indicating several developmental defects with both the implantation plate and the thin laminated fibers. In some cases, the implantation plate appeared to be reduced in size or was overburdened by granular material near the connecting piece. Hence, a strong reduction ODF1 is a marker of idiopathic male infertility and a potential driver of this condition. Molecular & Cellular Proteomics 15: 10.1074/ mcp.M116.060343, 3685-3693, 2016.Globally, in excess of 80 million people suffer from infertility (1), with ϳ1 in every seven couples so affected (2). In at least half of these cases, a defect in one or more aspects of sperm function appears to be the cause (2). Understanding the contribution of each partner to a couple's infertility is critical in determining how this situation can be optimally addressed. In the case of the male, a semen analysis focusing on sperm motility, concentration, and morphology is often performed to determine the fertilizing potential. A set of guidelines for evaluating semen quality was originally published by the World Health Organization (WHO) in 1980 (3). However, so inadequate were these criteria in predicting infertility that revised values had to be released in 1987, 1992, 1999, and again in 2010 (4). Although a semen analysis is the best predictive test we have to date, it clearly falls short of a true diagnosis (5, 6). Indeed, several studies have shown that men with sperm numbers (7-9), morphology (8, 10), and motility (11-17) below the thresholds outlined by the WHO can be fertile. Furthermore, there are many instances of men with normal sperm parameters that are infertile (13, 18 -20). Thus, these traditional diagnostic tests are limited in the information they generate and are poor predictors of male-factor infertility.In order to define the cause of male infertility, attempts have been made to identify changes in the proteomic composition of normal and infertile spermatozoa (20...

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Mass Spectrometry Reveals New Insights into the Production of Superoxide Anions and 4‐Hydroxynonenal Adducted Proteins in Human Sperm

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“…The secondary goat anti‐rabbit immunoglobulin G horseradish peroxidase (HRP) conjugate was used at a concentration of 1:1000 in TBS containing 1% (w/v) BSA and 0.1% (v/v) Tween‐20. Stripping of the blots was performed as described elsewhere, and they were blotted again with anti‐α‐Τubulin (1:1000) as a mean of loading control …”

ODF1, sperm flagelar protein is expressed in kidney collecting ducts of rats

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