Infertility Study of Sperm Protein Profile in Men With and Without Varicocele Using Two-Dimensional Gel Electrophoresis Hani Hosseinifar, Hamid Gourabi, Ghasem Hosseini Salekdeh, Mehdi Alikhani, Shahab Mirshahvaladi, Marjan Sabbaghian, Tahereh Modarresi, and Mohmmad Ali Sadighi Gilani OBJECTIVE To compare the sperm protein profile between men with and without varicocele. METHODS The present study was designed as a case-control study. The research patients were recruited from the Infertility Unit of the Royan Institute in 2009. We included 20 sperm samples from normozoospermic men without varicocele (control group) and 20 sperm samples from oligozoo- spermic patients with varicocele, grade 3 (varicocele group) in the present study. The sperm protein profile in the 2 groups was characterized using 2-dimensional gel electrophoresis. Differences in protein expression were established using gel analysis software, and protein identification was performed using mass spectroscopy analysis. RESULTS In the varicocele group, we noted 15 consistent differences in protein expression (1, spots missing; 12, less abundant; and 2, more abundant) compared with the control group (P  .01). The findings revealed that heat shock proteins, mitochondrial proteins, and cytoskeleton proteins are the proteins mainly affected by varicocele disease. CONCLUSION To our knowledge, the present study is a novel study, with few studies describing the correlation between sperm protein in men with and without varicocele obtained using a 2-dimensional proteomic approach. It could be an important prerequisite to the development of diagnostic tests to predict varicocelectomy outcomes in patients with varicocele and abnormal findings on a spermogram in the clinical environment. UROLOGY 81: 293–300, 2013. © 2013 Elsevier Inc. I nfertility affects about 15% of couples trying to be- come pregnant. Impaired fertility of the male factor is causative in 20% of infertile couples and contributory in up to another 30%-40%. Although human male infertility is an important medical problem, the etiology of most cases remains unknown. 1,2 Varicocele is the most commonly seen and correctable cause of male factor infertility. Al- though the incidence of varicocele in the general male population is approximately 15%, it is implicated as a factor in about one third of infertile men. 3 Studies of unselected fertile men with and without varicocele have shown significant differences in the standard se- men parameters, such as sperm count, motility, and morphology, between these 2 groups. 4 Varicocele com- promises cooling of the arterial blood and thus main- taining the scrotal temperatures closer to the body temperature. 5 A varicocele is an abnormal dilation of the pampiniform plexus, the complex network of veins that drain the testes. 6 At present, the pathogenetic and molecular mecha- nisms by which varicoceles induce testicular dysfunction and infertility are not completely understood. Proteomics is a key area of emerging research in the postgenomic era. 7 Advances in 2-dimensional electro- phoresis for the separation of proteins and mass spectrom- etry (MS), in particular, for peptide sequencing to facil- itate protein identification has led to this field rapidly expanding throughout biomedical research. The avail- ability of proteomic 2-dimensional maps from sperm cells and the identification of the sperm proteome should facilitate the identification of proteins that are over- or underexpressed in association with male infertility. A reasonable hypothesis is that changes in proteomic com- position might be responsible for the functional differ- ences associated with an important proportion of cases of male infertility. Although several studies have been published of sperm proteome, 8,9 no studies have been published of research Financial Disclosure: The authors declare that they have no relevant financial interests. From the Departments of Genetics and Andrology, Reproductive Biomedicine Re- search Centre, Royan Institute for Reproductive Biomedicine and Department of Molecular Systems Biology, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran Reprint requests: Mohmmad Ali Sadighi Gilani, M.D., Department of Andrology, Reproductive Biomedicine Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran. E-mail: masadighi@gmail.com Submitted: March 7, 2012, accepted (with revisions): June 13, 2012 © 2013 Elsevier Inc. 0090-4295/13/$36.00 293 All Rights Reserved http://dx.doi.org/10.1016/j.urology.2012.06.027