title: Comparative proteomic network signatures in seminal plasma of infertile men as a function of reactive oxygen species.
abstract: BACKGROUND
  Reactive oxygen species (ROS) plays a major role in the pathology of male infertility. It is an independent biomarker of sperm function. Seminal plasma is a natural reservoir of antioxidants responsible for the nourishment, protection, capacitation, and motility of sperm within the female reproductive tract resulting in successful fertilization and implantation of the embryo. A comparative proteomic analysis of seminal plasma proteins from fertile men and infertile men with varying levels of ROS was carried out to identify signature proteins involved in ROS-mediated reproductive dysfunction.
  
  
  METHODS
  A total of 42 infertile men presenting with infertility and 17 proven fertile donors were enrolled in the study. ROS levels were measured in the seminal ejaculates by chemiluminescence assay. Infertile men were subdivided into Low ROS (0-<93 RLU/s/10(6) sperm; n = 11), Medium ROS (>93-500 RLU/s/10(6) sperm; n = 17) and High ROS (>500 RLU/s/10(6) sperm; n = 14) groups and compared with fertile men (4-50 RLU/s/10(6) sperm). 4 subjects from fertile group and 4 each from the Low, Medium and High ROS were pooled. 1D gel electrophoresis followed by in-gel digestion and LC/MS-MS in a LTQ-Orbitrap Elite hybrid mass spectrometer system was used for proteome analysis. Identification of differentially expressed proteins (DEPs), their cellular localization and involvement in different pathways were examined utilizing bioinformatics tools.
  
  
  RESULTS
  The results indicate that proteins involved in biomolecule metabolism, protein folding and protein degradation are differentially modulated in all three infertile patient groups in comparison to fertile controls. Membrane metallo-endopeptidase (MME) was uniformly overexpressed (>2 fold) in all infertile groups. Pathway involving 35 focus proteins in post-translational modification of proteins, protein folding (heat shock proteins, molecular chaperones) and developmental disorder was overexpressed in the High ROS group compared with fertile control group. MME was one of the key proteins in the pathway. FAM3D was uniquely expressed in fertile group.
  
  
  CONCLUSIONS
  We have for the first time demonstrated the presence of 35 DEPs of a single pathway that may lead to impairment of sperm function in men with Low, Medium or High ROS levels by altering protein turn over. MME and FAM3D along with ROS levels in the seminal plasma may serve as good markers for diagnosis of male infertility.
authors: American Center for Reproductive Medicine, Department of Urology, Cleveland Clinic, Cleveland, OH 44195 USA.
authors: Ashok
authors: A
authors: Agarwal
authors: American Center for Reproductive Medicine, Department of Urology, Cleveland Clinic, Cleveland, OH 44195 USA.
authors: Ahmet
authors: A
authors: Ayaz
authors: American Center for Reproductive Medicine, Department of Urology, Cleveland Clinic, Cleveland, OH 44195 USA ; Department of Zoology, School of Life Sciences, Ravenshaw University, Cuttack, Odisha 751003 India.
authors: Luna
authors: L
authors: Samanta
authors: American Center for Reproductive Medicine, Department of Urology, Cleveland Clinic, Cleveland, OH 44195 USA.
authors: Rakesh
authors: R
authors: Sharma
authors: Center of Excellence in Genomic Medicine Research, King AbdulAziz University, Jeddah, Saudi Arabia ; KACST Technology Innovation Center in Personalized Medicine at King AbdulAziz University, Jeddah, Saudi Arabia.
authors: Mourad
authors: M
authors: Assidi
authors: Center of Excellence in Genomic Medicine Research, King AbdulAziz University, Jeddah, Saudi Arabia ; KACST Technology Innovation Center in Personalized Medicine at King AbdulAziz University, Jeddah, Saudi Arabia.
authors: Adel M
authors: AM
authors: Abuzenadah
authors: Department of Urology, Cleveland Clinic, Cleveland, OH 44195 USA.
authors: Edmund
authors: E
authors: Sabanegh
keywords: Infertility; Proteome; Reactive oxygen species; Seminal plasma; Sperm function