The Infertility Protein Screening And Verification In Seminal Plasma Of Patients With Varicocele

Object: In recent years,more and more men suffer from infertility,male infertility has become a hot spot of social concern.Varicocele is one of the most common causes of male infertility,with about 40% of adult men with primary infertility and 80% with secondary infertility with varicocele.Some studies have found that varicocele causes blood stasis,which may affect the temperature regulation of testis,change the microenvironment of spermatogenesis,and then affect spermatogenesis.On the other hand,the varicose vein causes chronic hypoxia and excessive reactive oxygen species in spermatogenic cells,resulting in excessive sperm apoptosis and the decrease in the number of spermatozoa.Although varicocele affects fertility,but not all patients with varicocele are infertile,but the mechanism of infertility remains unclear.Proteomics,as an advanced research technique,can study the protein function and metabolic process in cells or tissues at a molecular level.Isotope labeling relative and absolute quantification technology(iTRAQ)has been widely used in scientific research,especially in the field of protein related diseases,with high sensitivity and specificity.Semen consists of sperm and seminal plasma,which is the secretion of glands such as epididymis,prostate,seminal vesicle,urethra,etc.It is rich in protein and various chemical components,and is a biochemical marker of potential male infertility and reproductive system diseases.It may be helpful in the diagnosis and treatment of male infertility.The molecular function of differential protein was studied in order to understand the molecular mechanism of male infertility caused by varicocele,and the differential expression protein was verified by Western blot.To obtain the protein markers of infertility caused by varicocele,and to provide help for the clinical treatment of male infertility.Methods: 30 semen samples from patients with varicocele and infertility,25 semen samples from normal fertile men and 40 semen samples from patients with left varicocele were collected.Seminal plasma was extracted as experimental samples.iTRAQ technique was used.The seminal plasma samples of patients with varicocele combined with infertility were labeled with iTRAQ kit.The seminal plasma samples of normal fertility group were labeled with seminal plasma.The data of MS were analyzed by Proteome Discoverer 1.3 software.The differentially expressed proteins were screened by up-regulating ≥ 1.5 times and down-regulating ≤ 0.7 standard.The molecular functional analysis of these proteins was carried out,and the proteins that could be used as markers of infertility were selected,respectively,in varicocele with infertility.Western blot test was carried out in seminal plasma of normal fertility and patients with left varicocele.The gray value of the obtained image was analyzed by image pro plus 7.0 software to analyze the expression of differentially expressed proteins in different groups.Results: A total of 39 differentially expressed proteins were identified,of which 22 were up-regulated and 17 were down-regulated.There are 14 kinds of proteins,including protein binding,catalytic activity and structural molecular activity.Heat shock protein 70(Hsp70)、Bcl2-associated x protein(Bax)、recombinant human s100 calcium binding protein A12(S100A12)proteins that were up-regulated for verification.Western blot confirmed that hsp70、Bax and S100A12 protein expressed the highest in varicocele with infertility group,followed by simple varicocele group,and the lowest expression in normal fertility group.Conclusion: The potential sterility protein in seminal plasma of patients with varicocele is mainly induced by affecting protein binding,catalytic activity and structural molecular activity.The abnormal expression of HSP70 、 BAX and S100A12 proteins was significantly correlated with varicocele and infertility,and could be used as a marker of infertility in patients with varicocele.It is recommended that patients with varicocele,especially those with fertility requirements,be treated actively to protect their fertility.