CYP7B1与ER在胆汁淤积孕鼠胎鼠肝脏中的表达

目的 探讨雌激素受体(ERα、ERβ)与胆固醇7α羟化酶(CYP7B1)mRNA在妊娠期肝内胆汁淤积(ICP)孕鼠、胎鼠肝脏中的表达及其意义.方法 对照组孕鼠30只注射精制植物油;研究组孕鼠30只注射17-α-乙炔雌二醇.两组孕鼠分别于妊娠第13天、17天、21天断尾采母鼠血检测,于妊娠第21天抽取母鼠、胎鼠血并提取肝脏组织.应用酶联免疫吸附试验检测两组孕鼠及胎鼠血清中胆酸水平;应用实时定量PCR技术检测两组胎鼠肝脏ERα、ERβ、CYP7B1 mRNA的表达.结果 ①在妊娠第17天、21天研究组母鼠胆汁酸水平明显高于对照组(55.7±3.2μmol/L vs 23.4±1.2μmol/L,t=2.541,P<0.05;61.4±2.4μmol/L vs 25.5±2.1μmol/L,t=2.621,P<0.05);研究组胎鼠胆汁酸水平明显高于对照组(27.4±2.3μmol/L vs 11.5±2.6μmol/L,t=2.631,P<0.05);②研究组胎鼠肝脏CYP7B1 mRNA水平明显高于对照组(2.15±0.01vs 0.25±0.02,t=2.563,P<0.05);③研究组ERα mRNA水平明显高于对照组(0.81±0.02 vs 0.35±0.01,t=2.534,P<0.01).结论 ICP孕鼠胎鼠肝细胞ERα、CYP7B1的表达升高,胆汁酸的合成与代谢调节机制存在障碍,可能是导致ICP胎儿围生儿死亡发生的原因之一.     

Interaction among peroxisome proliferators-activated receptor alpha, cytochrome P450 oxysterol 7α-hydroxylase and estrogen receptor and its association with intrahepatic cholestasis in pregnant rats

Objective To investigate the relationship between interaction of peroxisome proliferators-activated receptor alpha (PPARα), cytochrome P450 oxysterol 7α-hydroxylase (CYP7B1) and estrogen receptor (ER) and intrahepatic cholestasis in pregnant rats. Methods Eighty clean SD pregnant rats were selected and divided into four groups randomly with 20 in each. Since the 13th day of pregnancy,rats in the control group was injected subcutaneously with refined vegetable oil 2.0 ml · kg-1 · d -1 , those in the low-dose, moderate-dose and high-dose groups received 17-α-ethynylestradiol (EE) 1.0 mg · kg-1 · d-1,1.25 mg · kg-1 · d-1 and 1.5 mg · kg-1 · d-1, respectively. All rats were sacrificed at the 21at day of pregnancy and maternal hepatic tissues were collected. The serum levels of alanine aminotransferase(ALT), aspartate transaminase (AST), total bile acid (TBA) and bilirubin (BIL) were determined by enzyme linked immunosorbent assay (ELISA). The mRNA expressions of PPARα, CYP7B1, Erα and Erβ in maternal rat livers were examined by real-time PCR. Results (1) Biochemical indicators: the serum levels of ALT,AST, TBA and BIL were significantly lower in the control group than in the rest 3 groups,respectively [ control group: (41.1 ± 2.8 ) U/L, (44.4 ± 3.6) U/L, (26.4 ± 5.6 ) μmol/L and( 2.8 ± 0.2)U/L;low-dose group: (48.2 ±3.4) U/L,(47.9 ±3.7) U/L,(36.4 ±4.2) μmol/L and (4.2 ±0.2) U/L;moderate-dose group: (70.4 ± 5.3 ) U/L, (68.4 ± 5.6) U/L, (64.3 ± 3.8 ) μmol/L and ( 6.2 ± 1.2)U/L; high-dose group: (72.4 ±7.6) U/L, (70.2 ±3.8) U/L, (72.4 ±7.8) μmol/L and (8.2 ±2.2)U/L, P<0.05], and those in the moderate or high-dose groups were higher than in the low-dose group (P<0.05). (2) mRNA expression of Erα and Erβ: the mRNA expression of Erα in pregnant rat livers increased in a dose-dependent manner, which were all significantly higher than that in the control group,respectively ( low-dose group: 0.76 ± 0.02 ); moderate -dose group: ( 0.99 ± 0.04; high-dose group:1.21 ±0.01 ;control group:0.65 ±0.01, P <0.05), but no difference was found among the 4 groups in the mRNA expression of Erβ ( P > 0.05 ). (3) mRNA expression of CYP7B1 and PPARα: the mRNA expression of CYP7B1 in pregnant rat livers increased from the low-dose group to the high-dose group, and were all higher than that of the control group ( low-dose group: 0.93 ± 0.01; moderate-dose group: 0.99 ±0.06; high-dose group: 1.22 ± 0.04; control group: 0.75 ± 0.02, P < 0.05 ). However, the mRNA expression of PPARα decreased from the low-dose group to the high-dose group, and were all lower than that of the control group (low-dose group: 0.83 ± 0.05; moderate-dose group: 0.71 ± 0.02; high-dose group:0.64 ± 0.03; control group: 1.35 ± 0. 05; P < 0.05 ) . Conclusions The down regulated mRNA expression of PPARα, caused by higher dose of estrogen, may increase the expression of CYP7B1 due to the ineffectiveness of the inhibition of PPARα on CYP7B1, which may further stimulate the Erα activity and then induce intrahepatic cholestasis. Abnormal expression of PPARα, CYP7B1 and ER may play a role in the pathogenesis of estrogen-induced intrahepatic cholestasis.     

Interaction among peroxisome proliferators-activated receptor alpha, cytochrome P450 oxysterol 7α-hydroxylase and estrogen receptor and its association with intrahepatic cholestasis in pregnant rats

Objective To investigate the relationship between interaction of peroxisome proliferators-activated receptor alpha (PPARα), cytochrome P450 oxysterol 7α-hydroxylase (CYP7B1) and estrogen receptor (ER) and intrahepatic cholestasis in pregnant rats. Methods Eighty clean SD pregnant rats were selected and divided into four groups randomly with 20 in each. Since the 13th day of pregnancy,rats in the control group was injected subcutaneously with refined vegetable oil 2.0 ml · kg-1 · d -1 , those in the low-dose, moderate-dose and high-dose groups received 17-α-ethynylestradiol (EE) 1.0 mg · kg-1 · d-1,1.25 mg · kg-1 · d-1 and 1.5 mg · kg-1 · d-1, respectively. All rats were sacrificed at the 21at day of pregnancy and maternal hepatic tissues were collected. The serum levels of alanine aminotransferase(ALT), aspartate transaminase (AST), total bile acid (TBA) and bilirubin (BIL) were determined by enzyme linked immunosorbent assay (ELISA). The mRNA expressions of PPARα, CYP7B1, Erα and Erβ in maternal rat livers were examined by real-time PCR. Results (1) Biochemical indicators: the serum levels of ALT,AST, TBA and BIL were significantly lower in the control group than in the rest 3 groups,respectively [ control group: (41.1 ± 2.8 ) U/L, (44.4 ± 3.6) U/L, (26.4 ± 5.6 ) μmol/L and( 2.8 ± 0.2)U/L;low-dose group: (48.2 ±3.4) U/L,(47.9 ±3.7) U/L,(36.4 ±4.2) μmol/L and (4.2 ±0.2) U/L;moderate-dose group: (70.4 ± 5.3 ) U/L, (68.4 ± 5.6) U/L, (64.3 ± 3.8 ) μmol/L and ( 6.2 ± 1.2)U/L; high-dose group: (72.4 ±7.6) U/L, (70.2 ±3.8) U/L, (72.4 ±7.8) μmol/L and (8.2 ±2.2)U/L, P<0.05], and those in the moderate or high-dose groups were higher than in the low-dose group (P<0.05). (2) mRNA expression of Erα and Erβ: the mRNA expression of Erα in pregnant rat livers increased in a dose-dependent manner, which were all significantly higher than that in the control group,respectively ( low-dose group: 0.76 ± 0.02 ); moderate -dose group: ( 0.99 ± 0.04; high-dose group:1.21 ±0.01 ;control group:0.65 ±0.01, P <0.05), but no difference was found among the 4 groups in the mRNA expression of Erβ ( P > 0.05 ). (3) mRNA expression of CYP7B1 and PPARα: the mRNA expression of CYP7B1 in pregnant rat livers increased from the low-dose group to the high-dose group, and were all higher than that of the control group ( low-dose group: 0.93 ± 0.01; moderate-dose group: 0.99 ±0.06; high-dose group: 1.22 ± 0.04; control group: 0.75 ± 0.02, P < 0.05 ). However, the mRNA expression of PPARα decreased from the low-dose group to the high-dose group, and were all lower than that of the control group (low-dose group: 0.83 ± 0.05; moderate-dose group: 0.71 ± 0.02; high-dose group:0.64 ± 0.03; control group: 1.35 ± 0. 05; P < 0.05 ) . Conclusions The down regulated mRNA expression of PPARα, caused by higher dose of estrogen, may increase the expression of CYP7B1 due to the ineffectiveness of the inhibition of PPARα on CYP7B1, which may further stimulate the Erα activity and then induce intrahepatic cholestasis. Abnormal expression of PPARα, CYP7B1 and ER may play a role in the pathogenesis of estrogen-induced intrahepatic cholestasis.     

产妇血、乳汁和尿中铅、镉含量水平60例分析

[目的] 研究母亲体内铅、镉含量以及与母乳、母尿之间关系,指导孕期保健和母乳喂养. [方法] 应用石墨炉原子吸收仪测定60例产妇血、乳汁和尿中铅与镉含量. [结果] 60例产妇血铅含量平均水平0.497μmol/L,46.6%的产妇血铅高于0.483μmol/L,产妇血铅与母乳铅含量差异有显著性(P<0.05).产妇血铅水平在0.483μmol/L左右时,母乳中铅含量较低.母血中镉含量与母乳中含量基本相同,两者差异无显著性(P>0.05). [结论]应积极开展孕妇血铅水平的监测及预防;母乳中铅含量对婴儿的影响较小,母乳喂养对于婴儿是安全的.     

胆汁酸代谢主要调节核受体和相关基因在胆汁淤积孕鼠肝脏中的表达

目的 探讨法尼醇X受体(FXR)、过氧化物酶增殖体激活受体α(PPAR α)与胆固醇7 α羟化酶(CYP7A1)、胆固醇27 α羟化酶(CYP27A1)、胆固醇12 α羟化酶(CYP8B1)mRNA在妊娠期肝内胆汁淤积孕鼠肝脏中的表达及其意义.方法将60只清洁级SD大鼠自孕第13天均分为3组,对照组:皮下注射精制植物油2.0ml·kg-1·d-1;未治疗组:皮下注射17-α-乙炔雌二醇1.25 mg·kg-1·d-1;治疗组:皮下注射17-α-乙炔雌二醇1.25 mg·kg-1·d-1,孕第17天起给予非诺贝特50 mg·kg-1·d-1灌胃.3组孕鼠分别于妊娠第13、17、21天断尾采血2 ml检测血清生物化学指标,并于妊娠第21天处死,提取肝脏组织.应用酶联免疫吸附法检测3组孕鼠血清中的胆酸水平;用实时定量PCR技术检测各组PPARα、FXR、CYP7A1、CYP27A1、CYP8B1 mRNA的表达量.多组间的比较用方差分析,多组的两两间比较用Student-Newman-Keuls法检验,两组数据间比较用t检验.结果 妊娠第17天,对照组、未治疗组、治疗组的胆汁酸水平分别为(26.6±2.3)μmol/L、(68.7±4.2)μmol/L、(69.5±3.8)μmol/L,未治疗组和治疗组胆汁酸水平与对照组比较,t值分别为2.516、2.642,P值均＜0.05,差异均有统计学意义.治疗组与未治疗组之间胆汁酸水平比较,t=1.835,P＞0.05,差异无统计学意义;妊娠第21天,对照组、未治疗组、治疗组胆汁酸水平分别为(27.1±3.2) mol/L、(69.4±3.7)μmol/L、(48.5±4.8)μmol/L,3组比较,F=7.81,P＜0.05,差异有统计学意义.对照组、未治疗组、治疗组中CYP7A1 mRNA的相对表达量分别为0.75±0.02、1.55±0.03、1.25±0.01,FXR mRNA的相对表达量分别为1.25±0.03、1.75±0.02、1.65±0.05,CYP27A1 mRNA的相对表达量分别为0.65±0.03、2.45±0.01、1.65±0.02,CYP8B1 mRNA的相对表达量分别为1.50±0.02、2.15±0.01、1.75±0.03,PPARαmRNA的相对表达量分别为1.45±0.02、0.85±0.02、1.35±0.01.CYP7A1、FXR、CYP27A1、CYP8B1 mRNA在未治疗组中的表达量与对照组相比,q值分别为6.554、5.613、8.126和6.143,P值均＜0.05,差异均有统计学意义.未治疗组中PPAR α mRNA的表达量与对照组相比,q=6.126,P＜0.01,差异有统计学意义.治疗组中CYP27A1、PPAR α mRNA、CYP8B1 mRNA水平与未治疗组相比,q值分别为6.346、7.231和5.892,P值均＜0.05,差异均有统计学意义.结论胆汁酸的合成与代谢调节机制存在障碍,是导致妊娠期肝内胆汁淤积症发生的原因之一,用PPAR α的激动剂对其有一定疗效.     

雌激素受体及胆汁酸代谢相关基因在胆汁淤积孕鼠胎鼠肝脏中的表达

目的探讨雌激素受体(estrogen receptor,ERα)与胆汁酸代谢相关基因胆固醇7α羟化酶(cholesterol 7α-hydroxylase,CYP7A1)、胆固醇27α羟化酶(cholesterol 27-hydroxylase,CYP27A1)、胆固醇12α羟化酶(cholesterol 12α-hydroxylase,CYP8B1)mRNA在妊娠期肝内胆汁淤积孕鼠胎鼠肝脏中的表达及其意义。方法将60只清洁级SD孕鼠自孕第13天均分为2组:对照组孕鼠皮下注射精制植物油2.0 mL.kg-1.d-1;研究组孕鼠皮下注射17-α-乙炔雌二醇1.25 mg.kg-1.d-1。2组孕鼠分别于妊娠第13、17、21天断尾采母鼠血2 mL检测血清生物化学指标,于妊娠第21天处死。抽取母鼠、胎鼠血并提取母鼠、胎鼠肝脏组织。应用酶联免疫吸附试验检测2组孕鼠以及胎鼠血清中胆酸浓度;应用实时定量PCR技术检测各组胎鼠肝脏ERα、CYP7A1、CYP27A1、CYP8B1的mRNA表达量。结果①胆酸指标比较:在妊娠第17天时对照组、研究组母鼠胆汁酸浓度分别为(24.6±1.3)μmol/L、(58.7±3.2)μmol/L,研究组母鼠胆汁酸浓度明显高于对照组(t=2.462,P<0.05);在妊娠第21天时对照组、研究组母鼠胆汁酸浓度分别为(26.5±3.1)μmol/L、(66.4±2.7)μmol/L,研究组母鼠胆汁酸浓度与妊娠第17天时研究组以及对照组相比(F=5.43,P<0.05),差异有统计学意义。②胎鼠肝脏CYP7A1 mRNA、CYP27A1 mRNA、CYP8B1 mRNA表达:研究组中CYP7A1 mRNA(1.25±0.01)、CYP27A1 mRNA(2.05±0.03)、CYP8B1 mRNA明显高于对照组(0.35±0.02、0.75±0.03、0.85±0.02),P值均<0.05,差异有统计学意义。③胎鼠肝脏雌激素受体的表达:研究组中ERαmRNA(0.75±0.02)明显高于对照组ERαmRNA(0.45±0.01)。结论妊娠期肝内胆汁淤积症(intrahepatic cholestasis of pregnancy,ICP)孕鼠胎鼠肝细胞ER、CYP7A1、CYP27A1、CYP8B1的表达升高,胆汁酸的合成与代谢调节机制存在障碍,可能是导致ICP胎儿围生期死亡发生的原因之一。