c-Jun氨基末端激酶在邻苯二甲酸二(2-乙基)己酯诱导的尿道下裂大鼠阴茎组织中的表达

目的研究c-Jun氨基末端激酶(c-Jun N-terminal kinase,JNK)在邻苯二甲酸二(2-乙基)己酯[di(-2-ethyl-hexyl)phthalate,DEHP]诱导的尿道下裂大鼠阴茎组织中的表达变化,探讨尿道下裂发生的机制。方法将孕12 d(gestation day,GD12)的SD孕鼠随机分为2组:实验组[将DEHP溶于1.5 ml大豆油中灌胃大鼠,750 mg/(kg.d)]和对照组(以1.5 ml大豆油灌胃大鼠),每组20只,自GD12～GD19连续每天定时给药1次。各组分别取10只孕鼠正常分娩,雄性仔鼠出生后30 d,计数每窝产雄性活仔数,称量体重,并测量肛门生殖器距离(anogenital distance,AGD),逐个检查雄鼠的阴茎弯曲度和尿道开口部位,判断有无尿道下裂;其余孕鼠在怀孕第20天行剖宫产取出胎鼠,采用实时定量PCR(qPCR)和免疫组化法分别检测雄性胎鼠阴茎组织中JNK1和JNK2 mRNA和蛋白的表达水平。结果雄性仔鼠出生后30 d,实验组与对照组比较,每窝产雄性活仔数、雄性仔鼠的体重及AGD均有明显减少或缩短(P均<0.001);实验组尿道下裂发生率约为30.6%。与对照组比较,实验组胎鼠阴茎组织中JNK1和JNK2mRNA的水平明显增加(P<0.05),磷酸化JNK1和JNK2蛋白的表达水平有增加的趋势。结论 DEHP诱导的先天性尿道下裂可能与胎鼠阴茎组织中JNK通路异常表达有关。

Expression of c-Jun N-terminal kinase in hypospadiac penis of fetal rats induced by maternal exposure to di-(2-ethylhexyl) phthalate

Objective To investigate the expression of c-Jun N-terminal kinase(JNK)in the hypospadiac penis of fetal rats induced by maternal exposure to di(-2-ethylhexyl)phthalate(DEHP)in order to explore the etiology of hypospadias.Methods Pregnant rats of 12 gestation days(GD12) were randomly divided into test and control groups,20 for each.The rats in test group were treated with DEHP dissolved in 1.5 ml soybean oil by lavage at a dosage of 750 mg /(kg.d),while those in control group with 1.5 ml soybean oil,once a day from GD12 to GD19.Half of rats in each group were raised to postnatal day(PND) 30,and live male pups were counted and weighed,of which anogenital distance(AGD) were measured,and the hypospadias was observed.Fetal rats of the rest pregnant rats were obtained on GD20 by caesare an section,and determined for expression levels of JNK 1/2 mRNA and protein by real-time quantitative PCR(qPCR) and immunochemical assay respectively.Results On PND30,the number,body weight and AGD of live male pups in test group decreased significantly as compared with those in control group(each P < 0.001),while the incidence rate of hypospadias was about 30.6%.However,compared with those in control group,the expression levels of JNK1 and JNK2 mRNAs in penis of fetal rats in test groups increased significantly(P < 0.05),while the expression levels of JNK1 and JNK2 proteins showed increasing tendencies(P < 0.05).Conclusion DEHP-induced congenital hypospadias might be associated with the abnormal expression of JNK signal pathway in hypospadiac penis of fetal rats.