Antioxidant, Anti-inflammatory and Testosterone Therapy Reinforces Spermatogonial Stem Cells Self-renewal in Experimentally-induced Varicocele; Possible Mechanisms

Background: The varicocele (VCL) has been known as oneof the infertility problems in ۱۵-۲۰% of the male population,which severely affects the spermatogenesis via inducing oxidative,inflammatory stresses and suppressing testicular endocrinepotential. Thus, the antioxidant, anti-inflammatory and testosteroneboosting chemicals (herbal and/or synthetic) have beenconsidered as the alternative therapeutic methods. Thus, theVCL-induced damages can be divided into a-failed endocrinenetwork between Leydig and Sertoli cells, b-the cytokinesinducedeffects on transcriptional factors and encoding genes,c-the oxidative stress-related molecular changes at cell cyclemachinery.Materials and Methods: To analyze mentioned three mechanisms,the experimental VCL was induced in Wistar rats, thenthe animals were divided into VCL-sole and antioxidant, antiinflammatoryand testosterone treated VCL-induced groups.Following ۲ months, the animals were euthanized and the testicularglial cell line-derived neurotrophic (GDNF), its receptorsGfrα۱ and C-ret, the encoding active genes of spermatogonialstem cells (SSCs) self-renewal Bcl-۶b and Etv۵, and genesinvolving in cell cycle machinery including, Cylin D۱, CDK-۴,p۲۱, and the inflammatory mediators, tumor necrosis factor-α(TNF-α), interleukin-۶ (IL-۶), cyclooxygenases (COX-II)and nitric oxide (NO), and the homeostatic factors heat shockprotein۷۰-۲ (Hsp۷۰-۲), E۲f۱ expressions, serum levels of testosteroneand inhibin B, the testicular total antioxidant capacity(TAC), malondialdehyde (MDA), glutathione peroxidase(GSH-px), superoxide dismutase (SOD), catalase, total thiolmolecules (TTM) were investigated, using different RT-PCR,immunohistochemical, western blot and ELISA methods. thegerminal cells DNA fragmentation was assessed using TUNELstaining. Moreover, the sperm parameters including, spermcount, viability, motility, DNA integrity, chromatin condensationwere assessed. All results were compared between VCLsoleand treatment groups.Results: Observations revealed that, administrating antioxidantand anti-inflammatory chemicals in association with testosteroneboosting agents significantly ameliorates the VCL-impairedLeydig-Sertoli network, amplify the VCL-diminished GDNF,Gfrα۱, C-ret, Bcl-۶b and Etv۵ expression, and finally throughthis mechanism promote the SSCs self-renewal. Moreover, weshowed that promoting the testicular endocrine and antioxidantsystem remarkably down regulates the DNA fragmentation,suppresses the p۲۱ expression, amplifies the Cyclin D۱and CDK-۴ expression, and through this mechanism promotescell cycle progression in SSCs. More observations revealed aremarkable reduction in inflammatory madiators expression/synthesis/activity in treated groups. the animals in antioxidantand anti-inflammatory chemicals-treated groups exhibited enhancedtesticular Hsp۷۰, TAC, GSH-px, SOD, catalase andTTM levels and represented diminished E۲f۱ and apoptosis indicesverus VCL-sole group. Finally, the VCL-treated groupsexhibited improved sperm parameters compared to VCL-solegroup.Conclusion: The antioxidant and anti-inflammatory therapiesin association with testosterone boosting agents (in sole and simultaneousform of administration) promote the Leydig-Sertolicells physiologic interactions, which in turn a- amplifies theSertoli-related niche factors expression/synthesis and affect onSSCs self-renewal, b- downregulates the inflammatory mediatorsexpression/synthesis and affect on SSCs self-renewal, creducesDNA fragmentation both at germ cells and sperm levelsand amplies the homeostatic factors Hsp۷۰-۲ expression andsuppresses the E۲f۱ protein level and d- improves the spermparameters resulting in enhanced fertilization potential.

کلیدواژه ها:

Varicocele ، Spermatoginial Stem Cells ، Self-Renewal ، Cell Cycle