Impact of varicocelectomy on the proteome profile of testicular tissues of rats with varicocele

The Evolving Landscape of Male Varicocele Pathophysiology in the Era of Multi-Omics: A Narrative Review of the Current Literature

Male-factor infertility is implicated in over half of the millions of cases of infertility worldwide, and varicoceles are the most common correctable cause of male-factor infertility. The pathophysiologic mechanism for varicoceles is complex and next-generation technologies offer promising insights into the molecular underpinnings of this condition. In this narrative review, we highlight historical and contemporary paradigms associated with varicoceles, with an emphasis on the biological underpinnings of this disease. Specifically, we review the literature describing the underlying causes of varicoceles, discuss the molecular and cellular mechanisms causing pathological changes in some (but not all) men, and highlight key articles regarding the next-generation analyses (e.g., transcriptome, epigenome, proteome, and microbiome) being applied to better understand the condition and its treatment. These data demonstrate an ongoing evolution of the knowledge of varicoceles and the potential for improved personalized care in the future for men with this condition.

Silencing CAMK2D Promotes the Proliferation of Spermatogonia in the Testis of Experimental Varicocele Rats

Varicocele is regarded as the main factor that contributes to male infertility. This study aimed to explore the effect of CAMK2D on spermatogonia in the testis of experimental varicocele rats. The experimental varicocele model was established in rats and treated using different ligation methods. mRNA expression profile analysis was performed on the left testicular tissue isolated from different groups, and differentially expressed genes (DEGs) were analysed by bioinformatics methods and identified by qRT-PCR. The effect of CAMK2D, the screened DEG, on the proliferation of spermatogonia was evaluated by CCK-8 assay. The expression level of the c-kit was measured by the immunofluorescence assay and the expression levels of CAMKII, FOXO1, and β-catenin were detected by qRT-PCR and western blotting. Five DEGs (i.e., TMCC3, FLNB, CAMK2D, OPLAH, and EGR1) were screened using the comprehensive analysis of mRNA high-throughput sequencing data. TMCC3 and FLNB were significantly downregulated, and CAMK2D, OPLAH, and EGR1 were dramatically upregulated in the testicular tissue of varicocele rats. The target DEG CAMK2D was obtained through identification by using qRT-PCR. In vitro assays revealed that the proliferation of spermatogonia was significantly facilitated by the silencing of CAMK2D, which resulted in the downregulation of CAMKII, FOXO1, and β-catenin. In conclusion, silencing CAMK2D facilitated the proliferation of spermatogonia in the testis of experimental varicocele rats.

Identification and verification of key genes in varicocele rats through high-throughput sequencing and bioinformatics analysis

Varicocele (VC) is the most common treatable cause of infertility, but it is difficult to distinguish fertile from infertile VC populations because the pathogenesis is unclear. In order to study the related mechanism of VC causing male sterility, we made VC rat model by surgery, analysed the rat epididymal spermatozoa and used the transcriptome sequencing to compare all the mRNA expression differences in testicular tissue between VC rats and control rats. The differentially expressed genes (DEGs) of testicular tissue were also screened by the limma package in R software (version 3.6.1). The 273 DEGs were identified from the four profile data sets including 124 up-regulated genes and 149 down-regulated genes in the VC group compared to control group. We found that Sod1, Casp9, Atg7, Casp3 and Sirt1 in module 1 had higher degrees of connectivity in the first 10 hub genes. Gene ontology (GO) functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis demonstrated that Sod1, Casp9, Atg7, Casp3 and Sirt1 are enriched in regulation of oxidative stress-induced cell death (GO:1,903,201) and Amyotrophic lateral sclerosis (KEGG:05,014). From the above evidence, we speculate that hypoxia plays an important role in the occurrence and development of VC, and it induced the abnormal expression of autophagy and apoptosis-related proteins may involve in the development of VC-associated infertility. Sod1, Casp9, Atg7, Casp3 and Sirt1 as well as their module are hub genes for VC, which will have attractive applications to provide new treatment targets for VC.