刺猬信号通路在氟中毒大鼠肝脏中表达及意义

目的探讨刺猬信号通路(Hh)在慢性氟中毒大鼠肝脏损伤中作用及机制。方法选择健康成年SD大鼠36只,按体重随机分为对照组、低、高剂量染氟组(饮水中含氟量分别为5、50 mg/L),每组12只(雌雄各半),饲养6个月后检测大鼠尿氟、骨氟含量;应用自动生化分析仪检测大鼠肝功能;免疫组织化学(IHC)、Western blot和逆转录PCR(RT- PCR)法检测大鼠肝脏组织中印度刺猬蛋白(Ihh)、跨膜蛋白(Smo)、胶质瘤相关癌基因(Gli1)蛋白和mRNA表达;试剂盒法检测肝组织中总超氧化物歧化酶(T-SOD)、谷胱甘肽过氧化物酶(GSH-Px)和谷氨酰胺合成酶(GS)活力及脂质过氧化物(LPO)含量。结果与对照组比较,染氟组大鼠尿氟、骨氟含量、高剂量染氟组大鼠血清谷丙转氨酶、谷草转氨酶活性[分别为(73.42±6.98)、(161.08±8.59)U/L]明显增加,高剂量染氟组大鼠肝组织中Ihh、Smo、Gli1蛋白和mRNA的表达[分别为(71.41±4.18)、(83.83±5.26)、(81.14±25.44)及(1.20±0.17)、(3.13±0.19)、(5.35±0.52)]明显增加,高剂量染氟组大鼠肝组织中T-SOD、GSH-Px、GS活性[(5.08±0.64)、(5.53±0.83)、(19.22±1.84)U/mgprot]明显降低, LPO含量[(10.29±1.81)μmol/gprot]升高,差异均有统计学意义(P<0.05)。结论Hh信号通路与氧化应激可能共同参与慢性氟中毒所致肝脏损伤发病过程。

Expressions of protein and mRNA relevant to hedgehog signaling pathway in liver of fluorosis rats

ObjectiveTo explore the role of hedgehog(Hh) signaling pathway in excessive fluorine-induced liver injury in rats.MethodsThirty-six healthy Sprague-Dawley(SD) rats were randomly divided into three groups(6 males and 6 females in each group):a control group and two low- and high-dose fluorine groups exposed to 5,50 mg/L fluorine in drinking water.After 6 months,urine and bone fluorine contents were detected using fluorine ion electrode method.Indicators of liver function were determined with automatic blood chemical analyzer.The protein and mRNA expressions of Indian hedgehog(Ihh),smoothened protein(Smo),and glioma-associated oncogene homolog 1(Gli1) were detected with immunocytochemistry,Western blot,and real-time-PCR.The activity of total superoxide dismutase(T-SOD), glutathione peroxidase(GSH-PX), glutamine synthetase(GS), and the content of lipid peroxide(LPO) were determined with oxidative stress kit.ResultsCompared with the control group,urine and bone fluoride contents of the fluorine exposure groups increased;the rats in high-dose fluorine exposure group showed significantly increased activity of serum alanine transaminase(73.42±6.98 U/L),aspartate transaminase(161.08±8.59 U/L),increased protein and mRNA expressions of Ihh(71.41±4.18 and 1.20±0.17),Smo(83.83±5.26 and 3.13±0.19),Gli1(81.14±25.44 and 5.35±0.52),and increased content of LPO(10.29±1.81 μmol/gprot) and significantly decreased activity of SOD(5.08±0.64 U/mgprot),GSH-PX(5.53±0.83 U/mgprot),and GS(19.22±1.84 U/mgprot)(all P<0.05).ConclusionHh signaling pathway and oxidative stress may be involved in the pathogenesis of fluorosis liver injury.