Untargeted metabolomic profiling of seminal plasma in nonobstructive azoospermia men: A noninvasive detection of spermatogenesis

Abstract

Male factor infertility is involved in almost half of all infertile couples. Lack of the ejaculated sperm owing to testicular malfunction has been reported in 6-10% of infertile men, a condition named nonobstructive azoospermia (NOA). In this study, we investigated untargeted metabolomic profiling of the seminal plasma in NOA men using gas chromatography-mass spectrometry and advance chemometrics. In this regard, the seminal plasma fluids of 11 NOA men with TESE-negative, nine NOA men with TESE-positive and 10 fertile healthy men (as a control group) were collected. Quadratic discriminate analysis (QDA) technique was implemented on total ion chromatograms (TICs) for identification of discriminatory retention times. We developed multivariate classification models using the QDA technique. Our results revealed that the developed QDA models could predict the classes of samples using their TIC data. The receiver operating characteristic curves for these models were >0.88. After recognition of discriminatory retention time's asymmetric penalized least square, evolving factor analysis, correlation optimized warping and alternating least squares strategies were applied for preprocessing and deconvolution of the overlapped chromatographic peaks. We could identify 36 discriminatory metabolites. These metabolites may be considered discriminatory biomarkers for different groups in NOA.

Metabolomic markers of fertility in bull seminal plasma

“…Metabolites, products of metabolic reactions, appear in numerous biochemical pathways [ 42 ] and have been reported as potential biomarkers for male fertility [ 10 , 20 , 25 – 27 ]. At ejaculation, spermatozoa are suspended in the seminal plasma and it marks clear qualitative and quantitative differences in its biochemical composition [ 43 ].…”

Uncovering sperm metabolome to discover biomarkers for bull fertility

“…In addition, organic acids play crucial roles during anabolism by providing C-atom backbones [38]. Studies have previously reported the presence of organic acids in human spermatozoa [31, 32] and seminal plasma of bulls [30] and humans [27, 41, 42]. Fatty acids, in turn, are involved in the structural organization of the sperm membranes, energy metabolism, and signaling molecules [12, 43, 44].…”

Untargeted metabolomic profiling of accessory sex gland fluid from Morada Nova rams

“…Both LC and GC/MS are noninvasive techniques suitable for the discovery of molecular markers of phenotypes and physiological processes as well. In this regard, seminal plasma metabolites identified by GC/MS have been listed as potential markers of nonobstructive azoospermia in men (Gilany et al, 2017) and other studies also confirm the importance of seminal and sperm metabolites for evaluation of subfertility and infertility in humans (Davalieva et al, 2012). Comprehensive analyses of seminal plasma and sperm metabolomes from farm animals are still incipient, but recent reports have shown meaningful associations between seminal fluid metabolites and bull fertility (Kumar, Kroetsch, Blondin, & Anzar, 2015; Velho et al, 2018).…”