Endocrine Disruptors-induced Testicular Dysplasia And Testicular Impairment Is Mediated By Autophagy

Objective: To investigate the roles of apoptosis and autophagy in testicular impairment induced by cryptorchidism and find the roles of autophagy in BTB toxicity induced by DEHP.Methods: The first stage: Pregnant rats were randomly divided into three groups: group I: non-treated rats were used as controls,group II: injected with drug Flutamide(Flu)25 mg/kg/bw/d from Gestation Day(GD)11–19,group III: intragastric administration of 750 mg/kg/bw/d di-2-ethylhexylphosphate(DEHP)from GD 7-19.The cubs were feed normally and the testes were excised on postnatal day(PND)30.The second stage: Sprague-Dawley rats were developmentally exposed to 0,250 and 500 mg/kg DEHP via intragastric administration from postnatal day(PND)1 to PND 35.Testicular morphology,expressions of BTB junction proteins and autophagy related proteins were detected.In addition,expressions of oxidative stress markers and PI3K、p-Akt、Akt、p-mTOR、mTOR expression were also analyzed.Results: The first stage: EDCs exposure induced cryptorchidism.Cryptorchidism models induced noticeable decreased fertility,significantly reduced sperm count,increased sperm abnormality rate,decreased testosterone and severe testicular damage in histomorphology.Intriguingly,the level of apoptosis marker FAS,Cytochrome C and caspase-3 increased in Flu-induced and DEHP-induced groups.DEHP-induced treatment simultaneously increased the number of autophagosomes and the levels of autophagy marker LC3-II and p62.And significant decrease of autophagy gene(LC3-II and p62)expression is found in Flu-induced rats’ testes.The second stage: Developmental DEHP exposure induced decreasing organ coefficients of immature testes and severe testicular damage in histomorphology.The expressions of junctional proteins were downregulated significantly after DEHP treatment.Intriguingly,DEHP simultaneously increased the number of autophagosomes and the levels of autophagy marker LC3-II and p62,suggesting that the accumulated autophagosomes resulted from impaired autophagy degradation.Moreover,the expressions of HO-1 and SOD levels remarkably decreased after DEHP exposure.PI3 K 、 p-Akt/Akt 、 p-mTOR/mTOR expression decreased.Vitamins E and C could alleviate the DEHP-induced oxidative stress,reverse the autophagy defect and restore the BTB impairment.Conclusion: Deficient autophagy is involved in testicular spermatogenesis damage of EDCs-induced cryptorchidism rats.And this autophagy defect is caused by deficient degradation.Furthermore,DEHP exposure destroys immature testis blood-testis barrier(BTB)integrity through excessive ROS-PI3K/Akt/mTOR mediated autophagy.