目的:探讨NF-КB,血管紧张素Ⅱ-1型受体(ATIR)在非酒精性脂肪肝病(NAFLD)发病中的作用及其机制。方法:采用改良高脂饮食建立大鼠NAFLD模型,随机分为正常组普通饲料喂养,模型组高脂饮食喂养,干预组高脂饮食饲养10周后吡咯烷二硫基甲酸酯(...目的:探讨NF-КB,血管紧张素Ⅱ-1型受体(ATIR)在非酒精性脂肪肝病(NAFLD)发病中的作用及其机制。方法:采用改良高脂饮食建立大鼠NAFLD模型,随机分为正常组普通饲料喂养,模型组高脂饮食喂养,干预组高脂饮食饲养10周后吡咯烷二硫基甲酸酯(PDTC)腹腔注射4周,分别于10、14周处死各组大鼠,观察肝组织病理学形态;测定血管紧张素浓度;检测NF-KB蛋白、肝脏AT1R在肝细胞中的表达情况。结果:肝组织病理结果提示正常组肝组织结构正常;模型组大鼠肝组织出现脂肪变性并随造模时间的延长而加重,10、14周大鼠肝脏可见气球样变及程度不等的肝细胞坏死和小叶内炎症、腺泡内散在点灶状坏死,部分可见点灶状坏死成片,门管区轻中度炎症。14周大鼠出现胶原纤维生成。免疫组化结果提示模型组大鼠肝细胞内可见NF-КB明显活化,而且随造模时间延长,其表达随之增多;干预组表达低于同期模型组,但高于正常组。放免法结果提示模型组、干预组血管紧张素浓度均高于正常组,且随着造模时间的延长,其浓度逐渐增多;干预组血管紧张素浓度低于同时期模型组但高于正常组。RT-PCR法显示:AT1Rm RNA表达量在模型组中随着造模时间的延长,表达量逐渐增加,且均明显高于同时间段正常组;干预组表达低于同时期模型组但高于正常组。结论:NAFLD肝组织随着疾病程度加重,NF-КB活性增强,抑制其活性可降低NAFLD大鼠肝组织AT1R m RNA表达。展开更多
Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarge...Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarged cardiomyocyte.Effective intervention targets for abnormally enlarged cardiomyocyte remain to be identified.Previous studies have shown that the cellular shape and size can be regulated by the actin related protein 2/3(Arp2/3)complex,which is an actin-binding protein complex involved in the actin nucleation and assembly.However,the roles of the Arp2/3 complex in cardiomyocyte hypertrophy remain unknown.Here our study identifies its novel roles in the occurrence and development of cardiomyocyte hypertrophy.We found that mRNA levels of all subunits from the Arp2/3 complex are significantly upregulated(P<0.05)in the angiotensin Ⅱ(Ang Ⅱ)-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy.Further studies showed that siRNA-directed ARPC 2 silencing inhibits the reactivation of fetal genes and enlargement of cardiomyocyte area induced by Ang Ⅱ in neonatal rat primary cardiomyocytes(NRCMs)and H9c2 cells(P<0.05).In addition,the upstream activators of the Arp2/3 complex including SH3 protein interacting with Nck,90 kD(SPIN90)and Ras-related C3 botulinum toxin substrate 1(Rac1)/WASp family Verprolin-homologous protein-2(WAVE-2)are upregulated(P<0.05)in Ang Ⅱ-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy,indicating the excessive activation of the Arp2/3 complex.We further show that CK666,a specific Arp2/3 complex inhibitor,prevents the reactivation of fetal genes and the enlargement of cardiomyocyte area induced by Ang Ⅱ in NRCMs and H9c2 cells(P<0.05).Our results reveal that the Arp2/3 complex plays a crucial role in Ang Ⅱ-induced cardiomyocyte hypertrophy,which is beneficial to further studies about the molecular mechanisms by which the Arp2/3 complex regulates pathological cardiac hypertrophy.展开更多
文摘目的:探讨NF-КB,血管紧张素Ⅱ-1型受体(ATIR)在非酒精性脂肪肝病(NAFLD)发病中的作用及其机制。方法:采用改良高脂饮食建立大鼠NAFLD模型,随机分为正常组普通饲料喂养,模型组高脂饮食喂养,干预组高脂饮食饲养10周后吡咯烷二硫基甲酸酯(PDTC)腹腔注射4周,分别于10、14周处死各组大鼠,观察肝组织病理学形态;测定血管紧张素浓度;检测NF-KB蛋白、肝脏AT1R在肝细胞中的表达情况。结果:肝组织病理结果提示正常组肝组织结构正常;模型组大鼠肝组织出现脂肪变性并随造模时间的延长而加重,10、14周大鼠肝脏可见气球样变及程度不等的肝细胞坏死和小叶内炎症、腺泡内散在点灶状坏死,部分可见点灶状坏死成片,门管区轻中度炎症。14周大鼠出现胶原纤维生成。免疫组化结果提示模型组大鼠肝细胞内可见NF-КB明显活化,而且随造模时间延长,其表达随之增多;干预组表达低于同期模型组,但高于正常组。放免法结果提示模型组、干预组血管紧张素浓度均高于正常组,且随着造模时间的延长,其浓度逐渐增多;干预组血管紧张素浓度低于同时期模型组但高于正常组。RT-PCR法显示:AT1Rm RNA表达量在模型组中随着造模时间的延长,表达量逐渐增加,且均明显高于同时间段正常组;干预组表达低于同时期模型组但高于正常组。结论:NAFLD肝组织随着疾病程度加重,NF-КB活性增强,抑制其活性可降低NAFLD大鼠肝组织AT1R m RNA表达。
文摘Pathological cardiac hypertrophy is an early and significant cardiac structural characteristic that contributes to the onset and progression of heart failure(HF).Its mainly structural feature is the abnormally enlarged cardiomyocyte.Effective intervention targets for abnormally enlarged cardiomyocyte remain to be identified.Previous studies have shown that the cellular shape and size can be regulated by the actin related protein 2/3(Arp2/3)complex,which is an actin-binding protein complex involved in the actin nucleation and assembly.However,the roles of the Arp2/3 complex in cardiomyocyte hypertrophy remain unknown.Here our study identifies its novel roles in the occurrence and development of cardiomyocyte hypertrophy.We found that mRNA levels of all subunits from the Arp2/3 complex are significantly upregulated(P<0.05)in the angiotensin Ⅱ(Ang Ⅱ)-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy.Further studies showed that siRNA-directed ARPC 2 silencing inhibits the reactivation of fetal genes and enlargement of cardiomyocyte area induced by Ang Ⅱ in neonatal rat primary cardiomyocytes(NRCMs)and H9c2 cells(P<0.05).In addition,the upstream activators of the Arp2/3 complex including SH3 protein interacting with Nck,90 kD(SPIN90)and Ras-related C3 botulinum toxin substrate 1(Rac1)/WASp family Verprolin-homologous protein-2(WAVE-2)are upregulated(P<0.05)in Ang Ⅱ-induced neonatal rat primary and H9c2 cardiomyocyte hypertrophy,indicating the excessive activation of the Arp2/3 complex.We further show that CK666,a specific Arp2/3 complex inhibitor,prevents the reactivation of fetal genes and the enlargement of cardiomyocyte area induced by Ang Ⅱ in NRCMs and H9c2 cells(P<0.05).Our results reveal that the Arp2/3 complex plays a crucial role in Ang Ⅱ-induced cardiomyocyte hypertrophy,which is beneficial to further studies about the molecular mechanisms by which the Arp2/3 complex regulates pathological cardiac hypertrophy.
