Angiotensin I converting enzyme and angiotensinogen gene polymorphisms related to 24-h blood pressure in paediatric type I diabetes mellitus

The aim of this study was to evaluate two putative predictive genetic markers for hypertension in children and adolescents with diabetes mellitus. Ambulatory blood pressure measurements were performed in 199 patients with type I diabetes mellitus (mean age 16.5 years, mean duration of diabetes 7.7 years) and compared to those of 1141 healthy children. The local allele frequencies were established based on a control population consisting of 181 healthy subjects. The allele frequencies of the angiotensinogen gene M235T polymorphism was nearly identical in insulin-dependent diabetes mellitus patients (MM 33%, MT 51%, TT 16%) and controls (MM 35%, MT 49%, TT 16%). In contrast, the genotype distribution of the angiotensin I converting enzyme gene insertion/deletion (I/D) polymorphism was different between patients with type I diabetes mellitus (DD 26%, ID 49%, II 25%) and the control group (DD 37%, ID 44%, II 19%) (P = 0.04). Relative nocturnal systolic and diastolic pressures in patients with diabetes were higher than in healthy age- and height-matched controls; no association was found with the angiotensinogen gene M235T polymorphism. Relative nocturnal diastolic blood pressure was higher in patients homozygous for the I allele of the angiotensin I converting enzyme gene. Conclusion Nocturnal systolic and diastolic blood pressure is higher in patients with type I diabetes than in healthy children. The formerly described, but controversial, association of the M235T polymorphism with arterial hypertension could not be confirmed in this study. Received: 4 February 1998 / Accepted: 15 June 1998     

血管紧张素原及载脂蛋白E基因多态性与冠心病关系的研究

目的：研究血管紧张素原(AGT)基因M235T多态性及载脂蛋白E(ApoE)基因多态性与中国人群冠心病的关联。方法:分别用PCR—RFLP技术检测了129例冠心病患者及90例健康人AGT及ApoE基因型。结果：(1)冠心病组ε3/4基因型及ε4等位基因频率显著高于健康对照组，ε3/3基因型及ε3等位基因频率则显著低于对照组;(2)AGT各基因型及等位基因频率在两组间无显著差异;(3)携带ε4等位基因的不同AGT基因型在两组间也无显著差异。结论:(1)ε4等位基因是冠心病的遗传易患因子；(2)AGT基因与冠心病发病无显著关联，与ApoE基因间也无协同作用。     

应用等位基因特异性PCR检测血管紧张素原基因突变

目的:建立检测血管紧张素原(angiotensinogen,AGT)基因2种常见突变的等位基因特异性PCR技术。方法:应用针对AGT基因T174M和M235T这2种常见的突变位点设计的等位基因特异性PCR技术,对海南汉、黎族人群中AGT基因突变类型进行了检测,同时对经上述等位基因特异性PCR检测的样本进行序列测定。结果:在海南汉、黎族人群中,T174M突变位点可检测出TT、TM、MM 3种基因型,M235T突变位点可检测出MM、MT、TT 3种基因型,用等位基因特异性PCR鉴定的AGT基因突变的基因分型结果与序列测定结果完全符合。结论:等位基因特异性PCR技术操作简便,重复性和稳定性好,可作为鉴定AGT基因突变类型的可行方法。     

藏族原发性高血压的遗传学研究

目的　探讨遗传因素在藏族原发性高血压 (EH)发病中的作用 ,以及血管紧张素Ⅱ的惟一前体物血管紧张素原 (AGT)基因变异是否参与EH发病。方法　以藏族 35 3例EH患者和 317名正常血压对照者为对象进行病例 对照相关研究。根据相似家系结构的指示对照和指示病例 1∶1配比分析 ,按Falconer公式计算藏族EH的遗传度。以聚合酶链反应 (PCR)和PCR产物的限制性片段长度多态性分析方法 ,分析AGT基因M2 35T多态性和 5′调控区 6A→G变异与藏族EH遗传易感的相关性。结果　 (1)藏族EH先证者 (指示病例 )一级亲属受累率为 43.3% ,EH遗传度为 77.2 %± 13 3%。(2 )EH患者血浆肾素活性 (μg·L-1·h-1)为 1.95± 0 .11,血管紧张素Ⅱ水平 (ng/L)为 72 .6± 4.6 ,均明显高于对照组 (分别为 1.5 9± 0 .11和 5 1.7± 4.6 ,P <0 .0 5 )。 (3)EH组AGT基因 5′调控区 6G等位基因频率 (0 .36 )明显高于对照组 (0 .2 7) (χ2 =9.35 ,P <0 .0 1) ,并与血管紧张素Ⅱ水平呈弱相关 ,而M2 35T多态性与EH易感无明显相关 (P >0 .0 5 )。结论　遗传因素在藏族EH发病中起重要作用 ,AGT基因可能是其重要易感基因之一     

Effect of GPE-AGT nanoparticle shRNA transfection system mediated RNAi on early atherosclerotic lesion

Objective

To investigate the effects of RNA interference targeting AGT on early atherosclerotic lesion in the hypertensive state.

Methods

Hypertension and atherosclerosis rats were treated with GPE nanoparticles carrying AGT shRNA. Systolic blood pressure and heart rate were measured for 2 consecutive weeks. Three days after treatment, the mRNA and protein expressions of AGT in the liver were measured by PCR and western blot assay, respectively. The blood levels of AGT and Ang II were determined by ELISA. H&E staining and electron microscopy were performed.

Results

Three days after AGT shRNA treatment, the mRNA and protein expressions of AGT in the liver were markedly reduced and the blood levels of AGT and Ang II dramatically decreased as compared to the remaining 3 groups (P < 0.05). Three days after AGT shRNA treatment, the blood pressure was reduced by 27 ± 4mmHg when compared with that at baseline (P < 0.05). About 11 days after AGT shRNA treatment, the blood pressure began to increase. The blood pressure remained unchanged in the remaining 3 groups. Microscopy showed the atherosclerotic lesions were markedly attenuated in AGT shRNA treated rats but the liver and kidney functions remained stable (P > 0.05) when compared with the remaining 3 groups.

Conclusion

Transfection with GPE nanoparticle carrying AGT shRNA can stably lower the blood pressure and improve the atherosclerotic lesions which lead to the delayed development of early atherosclerotic lesions in hypertension rats with concomitant atherosclerosis.     

血管紧张素原基因（GT）重复多态性与藏族原发性高血压

目的探讨血管紧张素原基因(GT)3′-端(GT)重复多态性与藏族原发性高血压(EH)易感相关性。方法导入基于群体的病例-对照相关分析。病例组360例(M/F=168/192);对照组380人(M/F=177/203)。平均年龄分别为51.4±14.5岁和47.8±12.4岁。应用荧光标记dctp参入PCR扩增和基因扫描技术检测各片段长度及基因型。结果藏族血管紧张素基因3′-端(GT)重复序列在10种主要等位基因(频率>1%),从小到大依次称为A1(162bp),A2,A……,A10(180bp)。重复次数依次为(GT)≥1.5,(GT)16……(GT)≥24。分布频率从1.7%～27.5%;A4(GT18)为常见等位基因。高血压组A7(GT21)频率较对照组明显升高(11.3%:5.9%,χ2=5.02,P=0.023,OR=2.01,95%CI:1.05～1.87)。结论 AGT基因3′-端(GT)n多态性与藏族EH易感相关,而与汉族EH无关联。     

肾素-血管紧张素系统双基因多态性与高血压合并舒张性心力衰竭的关系

目的探讨中国南方部分汉族高血压患者肾素一血管紧张素系统中血管紧张素转换酶（ACE）及血管紧张素原（AGT）双基因多态性与舒张性心力衰竭发病的关系。方法应用聚合酶链反应及限制性片断长度多态性技术,对432例高血压患者的ACE基因插入／缺失（I／D）及AGTM235T多态性进行检测。将其中207例合并舒张性心力衰竭者作为病例组,其余225例心功能正常者作为对照组。结果①病例组DD基因型及D等位基因的频率均高于对照组;②病例组TT基因型及T等位基因的频率与对照组比较差异无统计学意义;③联合分析ACE与ACT基因多态性显示,两组中同时具有DD型ACE基因及TT型AGT基因的频率分别为29．0％及14．9％,前者明显高于后者。结论DD型ACE基因可能是该地区高血压患者舒张性心力衰竭发病的遗传危险因素,ACE和AGT基因在慢性心力衰竭的发生中具有协同作用。     

肾素-血管紧张素系统双基因多态性与老年人冠心病慢性心力衰竭的关系

目的:探讨中国南方部分汉族人群的老年冠心病患者中,肾素-血管紧张素系统中的关键成分即血管紧张素转换酶(ACE)及血管紧张素原(AGT)双基因多态性与慢性心力衰竭(心衰)发病的关系.方法:应用聚合酶链反应及限制性片断长度多态性技术,对396例老年冠心病患者的ACE基因插入/缺失(I/D)及AGT基因M235T多态性进行检测.将其中196例合并慢性心衰患者作为病例组,其余200例心功能正常者作为对照组.结果:①病例组DD基因型频率及D等位基因频率均高于对照组;②病例组TT基因型频率及T等位基因频率均高于对照组;③联合分析ACE与AGT基因多态性显示,两组中同时具有DD型ACE基因及TT型AGT基因的频率分别为28.6%及15.0%,前者明显高于后者.结论:DD型ACE基因及TT型AGT基因可能是中国南方部分汉族老年冠心病慢性心衰患者发病的遗传危险因素,ACE和AGT基因在慢性心衰的发生中具有协同作用.     

Perinatal profile of ventricular overload markers in congenital diaphragmatic hernia

Background

In congenital diaphragmatic hernia (CDH), pulmonary hypertension increases right ventricle (RV) afterload, which could impair heart function and contribute to poor outcome for most affected infants. Nevertheless, the real significance of vascular pulmonary alterations in perinatal hemodynamics is largely unknown. It is defined that ventricular pressure overload induces increased myocardium gene expression of B-type natriuretic peptide (BNP) and components of the renin-angiotensinogen and endothelin (ET)-1 systems. Our aim was to evaluate perinatal myocardium expression of these genes associated with ventricular pressure overload in a nitrofen-induced CDH rat model.

Methods

In the nitrofen-induced CDH rat model, fetuses from dated pregnant Sprague-Dawley rats at 15.5, 17.5, 19.5 and 21.5 days postcoitum as well as newborn pups were assigned to 3 experimental groups: control, nitrofen (exposed to nitrofen, without CDH), and CDH (exposed to nitrofen, with CDH). Myocardial samples collected from the RV and left ventricle (LV) were processed for quantification of messenger RNA (mRNA) of BNP, angiotensinogen, and ET-1.

Results

The perinatal expression of BNP, angiotensinogen, and ET-1 mRNA in the RV and LV of the control group revealed daily changes. During gestation, the expression of BNP and angiotensinogen mRNA underwent significant oscillation compared with control in both nitrofen-exposed fetuses, although we cannot identify significant differences between the nitrofen and CDH groups. After birth, we found a significant increasing expression of all studied genes only in the RV of CDH pups.

Conclusions

Perinatal myocardial quantification of BNP, angiotensinogen, and ET-1 mRNA levels suggests that both nitrofen-exposed and control pups revealed prenatal variations of expression of the studied genes. Moreover, CDH is associated with significant molecular alterations only in the RV after birth.