Lycium barbarum miR2911-loaded exosomes promote spermatogenic function recovery in rats with non-obstructive azoospermia by regulating Wnt/β-catenin signaling pathways
Objective:To investigate the effect of exosomes loaded with Lycium barbarum miRNA(Lb-miR2911)on spermato-genic function recovery in non-obstructive azoospermia(NOA)rats through cross-regulation of the Wnt/β-catenin signaling pathways.Methods:We established an NOA model in 30 four-week-old male SD rats by intraperitoneal injection of busulfan.At 5 weeks after modeling,we equally randomized the rats into a model control group(MC,untreated),an Lb-miR2911EXO group(Lb-miR2911EXO,treated by intratesticular injection of Lb-miR2911-loaded exosomes),and a sham group(Shame,treated by intratesticular injection of exosomes-empty drug),with another 10 male SD rats taken as normal controls(NC).We observed the uptake and metabolic changes of Lb-miR2911 in the testis tissue of the rats by RNA FISH at 2 and 6 weeks after treatment,detected cell proliferation,spermatogenesis and gene expressions of the Wnt/β-catenin signaling pathways in the testis tissue by Transcriptome sequencing analysis combined with Western blot and RT-PCR at 12 weeks,evaluated the recovery of the spermatogenic function based on the testis tissue morphology and sperm quality,and assessed the organ toxicity of Lb-miR2911 in the tissue and organs of the rats based on histomorphological analysis and the levels of serum TNF-α,IL-1β,Aspartate aminotransferase(AST),Alanine aminotransferase(ALT)and other relevant indi-cators.Results:After 12 weeks of treatment,histomorphological analysis showed regular arrangement of spermatogenic cells at all levels in the testis tissue,with a large number of mature sperm in the tubular lumen,and with significantly higher Johnsen scores,tes-tis weight,testicular index,sperm concentration and sperm motility in the Lb-miR2911EXO than in the sham group(all P<0.05).Compared with the model controls,the Lb-miR2911EXO group exhibited remarkably down-regulated gene expression of DACT3(P<0.05),up-regulated expressions of DVL2 and β-catenin(P<0.05),elevated levels of p-DVL2 and β-catenin(nucleus)proteins(P<0.05),increased expressions of cell proliferation-related genes CCND1,CCNE1 and CCNE2(P<0.05)and spermatogenesis-related genes DMC1,CCR6,JAM2 and KLC3(P<0.05).No pathological changes were observed in the lung,liver and kidney tis-sues of the rats,or in the levels of serum TNF-α,IL-1β,AST,ALT,creatinine and urea nitrogen in the rats treated with Lb-miR2911EXO compared with the normal controls(P>0.05).Conclusion:Lb-miR2911-loaded exosomes promote spermatogenic function recovery in NOA rats through cross-regulation of the DACT3,Wnt and β-catenin signaling pathways.