膽汁酸經(jīng)典合成途徑的基因調(diào)節(jié)研究
發(fā)布時間：2018-09-01 08:21
【摘要】： 第一部分高膽固醇攝入對膽汁酸經(jīng)典合成途徑中基因調(diào)節(jié)的影響 [目的]檢測短期(2天)和較長期(2周)高膽固醇攝入新西蘭白兔血清膽固醇、膽汁酸水平及肝臟膽汁酸經(jīng)典合成途徑限速酶CYP7A1、核受體FXR和LXR的激活狀態(tài),揭示短期和較長期高膽固醇攝入對膽汁酸合成的不同影響,探討核受體不同的激活狀態(tài)對膽汁酸合成不同的基因調(diào)節(jié)機制。 [方法]將36只新西蘭兔隨機分為4組:2天對照組、2天膽固醇組、2周對照組和2周膽固醇組,每組各9只。其中對照組分別喂飼普通兔糧2天及2周,高膽固醇組分別喂飼含2%膽固醇兔糧2天及2周,喂飼結(jié)束后測定血清總膽固醇、低密度脂蛋白和膽汁酸水平并測定肝臟CYP7A1活性及CYP7A1 mRNA、FXR的靶基因SHP mRNA、BSEP mRNA和LXR的靶基因ABCA1 mRNA、CETPmRNA。 [結(jié)果]2天對照組和2周對照組各項指標無差異(P＞0.05)。高膽固醇組的血清總膽固醇、低密度脂蛋白水平均較對照組升高,且2周高膽固醇組高于2天高膽固醇組(P＜0.05);2天高膽固醇組血清膽汁酸水平與對照組相比無變化(P＞0.05),而2周高膽固醇組血清膽汁酸水平較對照組升高(P＜0.05);2天高膽固醇組肝臟CYP7A1活性及CYP7A1mRNA均較對照組升高(P＜0.05),而2周高膽固醇組肝臟CYP7A1活性及CYP7A1mRNA均較對照組降低(P＜0.05);2天高膽固醇組肝臟SHPmRNA、BSEP mRNA與對照組相比無變化(P＞0.05),而2周高膽固醇組肝臟SHPmRNA、BSEP mRNA均較對照組升高(P＜0.05);高膽固醇組肝臟ABCA1mRNA、CETP mRNA均較對照組升高,且2周高膽固醇組高于2天高膽固醇組(P＜0.05)。 [結(jié)論]高膽固醇攝入使血清總膽固醇、低密度脂蛋白水平升高。短期高膽固醇攝入可激活肝臟LXR受體繼而使CYP7A1活性增加,膽汁酸合成增加;此時體內(nèi)膽汁酸水平尚未升高故肝臟FXR受體活性不變。當較長期的高膽固醇攝入后,體內(nèi)膽汁酸水平升高從而激活FXR受體;盡管LXR仍被進一步激活,但FXR對CYP7A1的抑制作用強于LXR對CYP7A1激活作用,CYP7A1活性下降,膽汁酸合成減少。 第二部分考來烯胺對膽汁酸經(jīng)典合成途徑的基因調(diào)節(jié)及其降低血清膽固醇的機制 [目的]研究考來烯胺對膽汁酸經(jīng)典合成途徑的基因調(diào)節(jié)及其降低血清膽固醇的作用機制。 [方法]20只新西蘭兔隨機分為考來烯胺組和對照組,每組10只�？紒硐┌方M每天予考來烯胺混懸液20ml灌胃共2周;對照組每天予20ml蒸餾水灌胃共2周。實驗結(jié)束后抽血測定血清總膽固醇、低密度脂蛋白和膽汁酸水平并測定肝臟CYP7A1活性及CYP7A1 mRNA、SHP mRNA、BSEP mRNA和LDL-R mRNA。 [結(jié)果]考來烯胺組血清總膽固醇水平和低密度脂蛋白水平較對照組下降(P＜0.05);考來烯胺組血清膽汁酸水平與對照組差異無統(tǒng)計學(xué)意義(P＞0.05);考來烯胺組CYP7A1活性及mRNA較對照組升高(P＜0.05);考來烯胺組SHPmRNA和BSEP mRNA均較對照組下降(P＜0.05);考來烯胺組LDL mRNA較對照組升高(P＜0.05)。 [結(jié)論]考來烯胺使回流入肝的膽汁酸減少,FXR失活從而對CYP7A1的抑制減弱,CYP7A1活性增高,膽汁酸經(jīng)典途徑合成增加,彌補經(jīng)腸道丟失的膽汁酸并消耗了肝內(nèi)的LDL,肝臟攝取循環(huán)LDL增加,使血清LDL下降。 第三部分考來烯胺對高膽固醇攝入新西蘭兔膽汁酸-膽固醇代謝的影響 [目的]研究考來烯胺對長期(4周)高膽固醇攝入新西蘭兔經(jīng)典途徑膽汁酸合成及膽固醇代謝的影響。 [方法]將30只新西蘭兔隨機分為對照組、高膽固醇血癥模型組和考來烯胺組,每組10只。對照組給予普通兔糧,每天予20ml蒸餾水灌胃4周;模型組給予高膽固醇兔糧,每天予20ml蒸餾水灌胃4周;考來烯胺組給予高膽固醇兔糧,每天予考來烯胺混懸液20ml灌胃4周。4周后抽血測定血清總膽固醇、低密度脂蛋白、膽汁酸水平并測定肝臟HMGCoA還原酶活性、CYP7A1活性及CYP7A1mRNA、SHP mRNA、BSEP mRNA和LDL-R mRNA。 [結(jié)果]模型組、考來烯胺組血清總膽固醇及低密度脂蛋白均較對照組上升(P＜0.01);考來烯胺組血清總膽固醇及低密度脂蛋白均較模型組下降(P＜0.01)。模型組、考來烯胺組血清膽汁酸水平較對照組上升(P＜0.01),模型組和考來烯胺組血清膽汁酸水平差異無統(tǒng)計學(xué)意義(P＜0.01)。模型組CYP7A1活性及mRNA較對照組降低(P＜0.01);考來烯胺組CYP7A1活性及mRNA組較模型組升高(P＜0.01)。模型組HMGCoA還原酶活性較對照組降低(P＜0.01);考來烯胺組HMGCoA還原酶活性較模型組升高(P＜0.01)但與對照組差異無統(tǒng)計學(xué)意義(P＞0.05)。模型組肝臟SHPmRNA和BSEPmRNA均較對照組升高(P＜0.01);考來烯胺組肝臟SHP mRNA和BSEP mRNA均較對照組升高(P＜0.01)且較模型組下降(P＜0.01)。模型組LDL mRNA較對照組下降(P＜0.01);考來烯胺組LDL mRNA較對照組和模型組升高(P＜0.01)。 [結(jié)論]長期高膽固醇攝入新西蘭兔肝臟FXR被激活,CYP7A1活性及其mRNA、HMGCoA還原酶活性、LDL mRNA下降,血清膽固醇、低密度脂蛋白和膽汁酸升高;同時應(yīng)用考來烯胺可降低FXR活性,CYP7A1活性及其mRNA、HMGCoA還原酶活性、LDL mRNA升高,從而降低血清膽固醇、低密度脂蛋白而膽汁酸水平不變。
[Abstract]:Part 1 the effect of high cholesterol intake on gene regulation in classical synthesis pathway of bile acids
[Objective] To detect the activation of CYP7A1, FXR and LXR in serum cholesterol, bile acid level and classical bile acid synthesis pathway of New Zealand white rabbits fed with high cholesterol for short (2 days) and longer (2 weeks), reveal the different effects of short-term and long-term high cholesterol intake on bile acid synthesis and explore the different stimulation of nuclear receptors. The regulation of bile acid synthesis by living state is different.
[Methods] Thirty-six New Zealand rabbits were randomly divided into 4 groups: 2-day control group, 2-day cholesterol group, 2-week control group and 2-week cholesterol group, 9 rabbits in each group. The activity of CYP7A1, CYP7A1 mRNA, target gene SHP mRNA of FXR, BSEP mRNA, target gene ABCA1 mRNA of LXR and CETP mRNA were measured.
[Results] There was no significant difference in serum total cholesterol and low density lipoprotein levels between 2-day control group and 2-week control group (P > 0.05). The level of serum bile acid in cholesterol group was higher than that in control group (P < 0.05), the activity of CYP7A1 and the expression of CYP7A1 mRNA in liver of two-day high cholesterol group were higher than that in control group (P < 0.05), while the activity of CYP7A1 and the expression of CYP7A1 mRNA in liver of two-week high cholesterol group were lower than that in control group (P < 0.05). The hepatic SHP mRNA and BSEP mRNA in two-week hypercholesterolemic group were higher than those in control group (P < 0.05), while the hepatic ABCA1 mRNA and CETP mRNA in two-week hypercholesterolemic group were higher than those in two-day hypercholesterolemic group (P < 0.05).
[Conclusion] High cholesterol intake can increase serum total cholesterol and low density lipoprotein levels.Short-term high cholesterol intake can activate liver LXR receptor and then increase CYP7A1 activity and bile acid synthesis.The activity of liver FXR receptor remains unchanged after long-term high cholesterol intake. Although LXR is still further activated, FXR has a stronger inhibitory effect on CYP7A1 than LXR does on CYP7A1. CYP7A1 activity decreases and bile acid synthesis decreases.
Part II Gene regulation of classical bile acid synthesis pathway by colineamine and its mechanism of lowering serum cholesterol
[Objective] To study the gene regulation of classical bile acid biosynthesis pathway by colineamine and its mechanism of lowering serum cholesterol.
[Methods] Twenty New Zealand rabbits were randomly divided into two groups, 10 rabbits in each group. Colineamine group was given colineamine suspension 20 ml daily for 2 weeks while control group was given 20 ml distilled water for 2 weeks. P7A1 mRNA, SHP mRNA, BSEP mRNA and LDL-R mRNA.
[Results] The levels of serum total cholesterol and low density lipoprotein in the colineamine group were lower than those in the control group (P < 0.05); the levels of serum bile acid in the colineamine group were not significantly different from those in the control group (P > 0.05); the activities of CYP7A1 and mRNA in the colineamine group were higher than those in the control group (P < 0.05); the SHP mRNA and BSEP mRNA in the colineamine group were higher than those in the control group (P < 0.05). Decrease (P < 0.05); LDL mRNA in the test group was higher than that in the control group (P < 0.05).
[Conclusion] Colineamine decreases bile acid reflux into the liver, inactivates FXR and thus reduces the inhibition of CYP7A1, increases the activity of CYP7A1, enhances the synthesis of bile acid via classical pathway, compensates for the loss of bile acid through the intestine and consumes LDL in the liver, increases LDL uptake by the liver, and decreases serum LDL.
The third part is the effect of enolamine on bile acid cholesterol metabolism in New Zealand rabbits with high cholesterol intake.
[Objective] To study the effects of colineamine on bile acid synthesis and cholesterol metabolism in New Zealand rabbits fed with high cholesterol for 4 weeks.
[Methods] Thirty New Zealand rabbits were randomly divided into control group, hypercholesterolemia model group and colineamine group with 10 rabbits in each group. Serum total cholesterol, low density lipoprotein (LDL), bile acid (bile acid) levels were measured and liver HMGCoA reductase activity, CYP7A1 activity, CYP7A1 mRNA, SHP mRNA, BSEP mRNA and LDL-R mRNA were measured after the suspension was given 20 ml for 4 weeks.
[Results] The serum total cholesterol and low density lipoprotein in the model group were higher than those in the control group (P < 0.01), while the serum total cholesterol and low density lipoprotein in the model group were lower than those in the model group (P < 0.01). There was no significant difference in bile acid level (P < 0.01). CYP7A1 activity and mRNA in model group were lower than those in control group (P < 0.01); CYP7A1 activity and mRNA in colineamine group were higher than those in model group (P < 0.01). HMGCoA reductase activity in model group was lower than that in control group (P < 0.01); HMGCoA reductase activity in colineamine group was higher than that in model group (P < 0.01). There was no significant difference between the model group and the control group (P > 0.05). The hepatic SHP mRNA and BSEP mRNA in the model group were higher than those in the control group (P < 0.01); the hepatic SHP mRNA and BSEP mRNA in the colineamine group were higher than those in the control group (P < 0.01) and lower than those in the model group (P < 0.01). And the model group increased (P < 0.01).
[Conclusion] Liver FXR activity, CYP7A1 activity and its mRNA, HMGCoA reductase activity, LDL mRNA decreased, serum cholesterol, LDL protein and bile acid increased in New Zealand rabbits fed with high cholesterol for a long time, while the activity of FXR, CYP7A1 activity and its mRNA, HMGCoA reductase activity, LDL mRNA increased, and serum cholesterol, LDL mRNA decreased with the application of colineamine. Cholesterol, low density lipoprotein and bile acid level remained unchanged.
【學(xué)位授予單位】：復(fù)旦大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2008
【分類號】：R341
本文編號：2216630
[Abstract]:Part 1 the effect of high cholesterol intake on gene regulation in classical synthesis pathway of bile acids
[Objective] To detect the activation of CYP7A1, FXR and LXR in serum cholesterol, bile acid level and classical bile acid synthesis pathway of New Zealand white rabbits fed with high cholesterol for short (2 days) and longer (2 weeks), reveal the different effects of short-term and long-term high cholesterol intake on bile acid synthesis and explore the different stimulation of nuclear receptors. The regulation of bile acid synthesis by living state is different.
[Methods] Thirty-six New Zealand rabbits were randomly divided into 4 groups: 2-day control group, 2-day cholesterol group, 2-week control group and 2-week cholesterol group, 9 rabbits in each group. The activity of CYP7A1, CYP7A1 mRNA, target gene SHP mRNA of FXR, BSEP mRNA, target gene ABCA1 mRNA of LXR and CETP mRNA were measured.
[Results] There was no significant difference in serum total cholesterol and low density lipoprotein levels between 2-day control group and 2-week control group (P > 0.05). The level of serum bile acid in cholesterol group was higher than that in control group (P < 0.05), the activity of CYP7A1 and the expression of CYP7A1 mRNA in liver of two-day high cholesterol group were higher than that in control group (P < 0.05), while the activity of CYP7A1 and the expression of CYP7A1 mRNA in liver of two-week high cholesterol group were lower than that in control group (P < 0.05). The hepatic SHP mRNA and BSEP mRNA in two-week hypercholesterolemic group were higher than those in control group (P < 0.05), while the hepatic ABCA1 mRNA and CETP mRNA in two-week hypercholesterolemic group were higher than those in two-day hypercholesterolemic group (P < 0.05).
[Conclusion] High cholesterol intake can increase serum total cholesterol and low density lipoprotein levels.Short-term high cholesterol intake can activate liver LXR receptor and then increase CYP7A1 activity and bile acid synthesis.The activity of liver FXR receptor remains unchanged after long-term high cholesterol intake. Although LXR is still further activated, FXR has a stronger inhibitory effect on CYP7A1 than LXR does on CYP7A1. CYP7A1 activity decreases and bile acid synthesis decreases.
Part II Gene regulation of classical bile acid synthesis pathway by colineamine and its mechanism of lowering serum cholesterol
[Objective] To study the gene regulation of classical bile acid biosynthesis pathway by colineamine and its mechanism of lowering serum cholesterol.
[Methods] Twenty New Zealand rabbits were randomly divided into two groups, 10 rabbits in each group. Colineamine group was given colineamine suspension 20 ml daily for 2 weeks while control group was given 20 ml distilled water for 2 weeks. P7A1 mRNA, SHP mRNA, BSEP mRNA and LDL-R mRNA.
[Results] The levels of serum total cholesterol and low density lipoprotein in the colineamine group were lower than those in the control group (P < 0.05); the levels of serum bile acid in the colineamine group were not significantly different from those in the control group (P > 0.05); the activities of CYP7A1 and mRNA in the colineamine group were higher than those in the control group (P < 0.05); the SHP mRNA and BSEP mRNA in the colineamine group were higher than those in the control group (P < 0.05). Decrease (P < 0.05); LDL mRNA in the test group was higher than that in the control group (P < 0.05).
[Conclusion] Colineamine decreases bile acid reflux into the liver, inactivates FXR and thus reduces the inhibition of CYP7A1, increases the activity of CYP7A1, enhances the synthesis of bile acid via classical pathway, compensates for the loss of bile acid through the intestine and consumes LDL in the liver, increases LDL uptake by the liver, and decreases serum LDL.
The third part is the effect of enolamine on bile acid cholesterol metabolism in New Zealand rabbits with high cholesterol intake.
[Objective] To study the effects of colineamine on bile acid synthesis and cholesterol metabolism in New Zealand rabbits fed with high cholesterol for 4 weeks.
[Methods] Thirty New Zealand rabbits were randomly divided into control group, hypercholesterolemia model group and colineamine group with 10 rabbits in each group. Serum total cholesterol, low density lipoprotein (LDL), bile acid (bile acid) levels were measured and liver HMGCoA reductase activity, CYP7A1 activity, CYP7A1 mRNA, SHP mRNA, BSEP mRNA and LDL-R mRNA were measured after the suspension was given 20 ml for 4 weeks.
[Results] The serum total cholesterol and low density lipoprotein in the model group were higher than those in the control group (P < 0.01), while the serum total cholesterol and low density lipoprotein in the model group were lower than those in the model group (P < 0.01). There was no significant difference in bile acid level (P < 0.01). CYP7A1 activity and mRNA in model group were lower than those in control group (P < 0.01); CYP7A1 activity and mRNA in colineamine group were higher than those in model group (P < 0.01). HMGCoA reductase activity in model group was lower than that in control group (P < 0.01); HMGCoA reductase activity in colineamine group was higher than that in model group (P < 0.01). There was no significant difference between the model group and the control group (P > 0.05). The hepatic SHP mRNA and BSEP mRNA in the model group were higher than those in the control group (P < 0.01); the hepatic SHP mRNA and BSEP mRNA in the colineamine group were higher than those in the control group (P < 0.01) and lower than those in the model group (P < 0.01). And the model group increased (P < 0.01).
[Conclusion] Liver FXR activity, CYP7A1 activity and its mRNA, HMGCoA reductase activity, LDL mRNA decreased, serum cholesterol, LDL protein and bile acid increased in New Zealand rabbits fed with high cholesterol for a long time, while the activity of FXR, CYP7A1 activity and its mRNA, HMGCoA reductase activity, LDL mRNA increased, and serum cholesterol, LDL mRNA decreased with the application of colineamine. Cholesterol, low density lipoprotein and bile acid level remained unchanged.
【學(xué)位授予單位】：復(fù)旦大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2008
【分類號】：R341
【共引文獻】
相關(guān)碩士學(xué)位論文 前1條
1 呂國平;FXR激動劑高通量藥物篩選模型的建立及應(yīng)用[D];河北師范大學(xué);2007年
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