Elena Sticchi

Maternal-Fetal Flow, Negative Events, and Preeclampsia: Role of ACE I/D Polymorphism

Abstract—The risk for an adverse pregnancy outcome is markedly higher in women with history of preeclampsia. This may stem from impaired placentation in early gestation and from high impedance to flow in uteroplacental circulation. The renin-angiotensin system is one of the mediators of the remodeling of spiral arteries throughout pregnancy. The D allele of the Insertion/Deletion (I/D) polymorphism in the ACE gene has been associated with higher ACE activity, accounting for 47% of the total phenotypic variance of serum enzyme levels. To investigate whether the ACE I/D polymorphism affects maternal uteroplacental and fetal umbilical circulation and the pregnancy outcome in women with a history of preeclampsia, 106 women underwent Doppler examination of uterine arteries resistance index and umbilical artery pulsatility index at the 16th, 20th, and 24th weeks of gestation and were genotyped for the I/D polymorphism. This study found a difference in genotype distribution (P =0.0002) and allele frequency (P <0.0001) between women with and those without preeclampsia recurrence and fetal growth restriction as well as an association (P =0.0007) between DD genotype and risk of recurrent preeclampsia or fetal growth restriction. At the 16th, 20th, and 24th weeks, uterine artery resistance indexes were significantly lower in II, higher in DD, and intermediate in ID genotype carriers, whereas the umbilical artery pulsatility index values were significantly higher in the DD group in comparison to ID and II genotypes. The current study shows that the ACE I/D polymorphism affects uteroplacental and umbilical flows and the recurrence of an adverse pregnancy outcome in women with history of preeclampsia.

High prevalence of polymorphisms of angiotensin-converting enzyme (I/D) and endothelial nitric oxide synthase (Glu298Asp) in patients with systemic sclerosis

PURPOSE Systemic sclerosis is characterized by progressive microvascular occlusion and fibrosis and by an imbalance in the fibrinolytic system. In vivo and in vitro studies suggest that the renin-angiotensin system partly regulates vascular fibrinolytic balance. Angiotensin II increases the production and secretion of plasminogen activator inhibitor-1, while angiotensin-converting enzyme (ACE) contributes to reduced production of tissue plasminogen activator and endothelial nitric oxide synthesis by bradykinin degradation. The aim of our study was to investigate the effects of ACE insertion/deletion (I/D) and endothelial nitric oxide synthase (eNOS) Glu298Asp (G894-->T) and T-786-->C polymorphisms in patients with systemic sclerosis. SUBJECTS AND METHODS We studied 73 consecutive patients (47 with limited and 26 with diffuse cutaneous systemic sclerosis) and 112 control subjects. ACE I/D and eNOS polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis. RESULTS The ACE I/D and the eNOS G894-->T polymorphisms were more common in patients than in controls (for the ACE D allele: odds ratio [OR] = 3.4; 95% confidence interval [CI]: 1.5 to 7.9; P = 0.003; for the eNOS T allele: OR = 1.9; 95% CI: 1.0 to 3.4; P = 0.04). There was no association between the eNOS T-786-->C polymorphism and systemic sclerosis. CONCLUSIONS Our findings of an increased risk of systemic sclerosis in ACE D and eNOS 894T allele carriers suggest that these polymorphisms may contribute to the pathogenesis of the disease.

Angiotensin-Converting Enzyme and Endothelial Nitric Oxide Synthase Polymorphisms in Patients with Atrial Fibrillation

GENSINI, F., et al.; Angiotensin‐Converting Enzyme and Endothelial Nitric Oxide Synthase Polymorphisms in Patients with Atrial Fibrillation. Experimental studies have shown a significant increase in angiotensin‐converting enzyme (ACE) expression in atrial tissue of AF patients. ACE regulates the synthesis of endothelial nitric oxide (NO), which modulates autonomic nervous activity involved in the development of AF. The aim of the study was to evaluate the prevalence of ACE insertion/deletion and endothelial NO synthase (eNOS) T‐786C, G894T, and 4a/4b polymorphisms in 148 patients with persistent AF, compared with 210 control subjects. ACE insertion/deletion polymorphism genotype distribution and allele frequency were significantly different between patients and controls ( P < 0.0001 and P < 0.0001 , respectively). ACE DD genotype was significantly associated with the risk of AF (OR DD/ID + II = 3.24, P < 0.0001) . Analysis of eNOS polymorphisms showed no significant difference in genotype distribution and allele frequency between patients and controls. The results suggest a possible role of ACE DD genotype as a predisposing factor to AF and a pathophysiological mechanism of ACE inhibition in reducing the incidence of AF in patients with left ventricular dysfunction. (PACE 2003; 26[Pt. II]:295–298)

Genetic analysis of 56 polymorphisms in 17 genes involved in methionine metabolism in patients with abdominal aortic aneurysm

Background: Previous studies suggested an association between abdominal aortic aneurysm (AAA) and hyperhomocysteinaemia, a complex trait determined by genetic and environmental factors. Our hypothesis was that polymorphisms in genes directly or indirectly involved in methionine metabolism may contribute to AAA susceptibility. Method: We studied 56 polymorphisms in MTHFR, MTR, MTRR, CBS, MTHFD1, SLC19A1, NNMT, TCN2, AHCY, BHMT, BHMT2, FOLH1, TYMS, ENOSF1, SHMT1, PON1, PON2 genes according to their demonstrated/putative function, localisation in promoter or regulatory and coding regions and/or heterozygosity values >0.300. Polymorphisms were evaluated by using a primer extension based microarray technology in 423 AAA patients and 423 matched controls. Results: All polymorphisms resulted in Hardy–Weinberg equilibrium in patients and controls. At the multiple logistic regression analysis adjusted for traditional cardiovascular risk factors (sex, age, hypertension, smoking habit, dyslipidaemia, diabetes) and chronic obstructive pulmonary disease (COPD), rs8003379 MTHFD1 (odds ratio (OR) 0.41, 95% confidence interval (CI) 0.26 to 0.65) and rs326118 MTRR (OR 0.47, 95% CI 0.29 to 0.77) polymorphisms resulted in independent susceptibility factor for AAA. Conclusions: After haplotype reconstruction, logistic regression analyses adjusted for traditional risk factors and COPD showed a significant association among AAA and AHCY, FOLH1, MTHFD1, MTR, NNMT, PON1 and TYMS haplotypes. Our findings offer new insights into the pathogenesis of AAA.

ACE DD genotype: an independent predisposition factor to venous thromboembolism.

Background The renin angiotensin system affects haemostasis through different mechanisms; data on the possible role of angiotensin‐converting enzyme I/D polymorphism in the pathogenesis of deep venous thrombosis are conflicting, and no information is available regarding the A1166C polymorphism of the angiotensin type 1 receptor gene. In order to investigate this issue, angiotensin‐converting enzyme and AT1R polymorphisms were genotyped in 336 consecutive venous thromboembolism patients and 378 controls.

Polymorphisms of genes involved in extracellular matrix remodeling and abdominal aortic aneurysm

BACKGROUND Abdominal aortic aneurysm (AAA) has a multifactorial etiology and the relevance of genetic factors is getting increasing interest, in particular those related to the destructive remodeling of extracellular matrix. METHODS We performed a candidate gene association study of polymorphisms in genes coding matrix metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs), and elastin (ELN) in AAA. DNA samples from 423 AAA patients and 423 controls were genotyped for 12 polymorphisms in 10 genes: MMP1 (-1607G/GG), MMP2 (-735C/T; -1306C/T; -1575 G/A), MMP3 (5A/6A), MMP9 (-1562C/T), MMP10 (A180G), MMP-12 (-82A/G), MMP-13 (-77A/G), TIMP1 (C434T), TIMP3 (-1296T/C), and ELN (G1355A). RESULTS Genotype distribution was significantly different between patients and controls for the following polymorphisms: -1306C/T MMP2; 5A/6A MMP3; -77A/G MMP-13; G1355A ELN; and C434T TIMP1. In a multivariable logistic regression analysis adjusted for traditional cardiovascular risk factors and chronic obstructive pulmonary disease, -1306C/T MMP2 (odds ratios [OR] = 0.55 [95% confidence interval, CI .34-.85], P < .007) and G1355A ELN (OR = 0.64 ([95% CI .41-.99], P = .046) polymorphisms resulted in independent protective factors for abdominal aortic aneurysm (AAA), whereas 5A/6A MMP3 (OR = 1.82 [95% CI 1.04-3.12], P = .034) and -77 A/G MMP-13 (OR = 2.14 [95% CI 1.18-3.86], P = .012) polymorphisms resulted in independent risk factors for AAA. In a multivariable logistic regression analysis adjusted for traditional cardiovascular factors and chronic obstructive pulmonary disease, the prevalence of the contemporary presence of three or four genetic risk conditions was a strong and independent determinant of AAA disease (OR = 2.96, 95% CI 1.67-5.24, P < .0001). For those polymorphisms independently associated with AAA in this study (-1306C/T MMP2, 5A/6A MMP3, -77A/G MMP-13, and G1355A ELN polymorphisms), we performed a meta-analysis of the available data (this paper and literature data). We found a significant association with an increased risk of AAA for MMP3 (AAA patients n = 1258, controls n = 1406: OR = 1.48 [95% CI = 1.23-1.78], I(2) = 0%) and MMP-13 (AAA patients n = 800, controls n = 843: OR = 1.37 [95% CI = 1.04-1.82], I(2) = 25%) polymorphisms and a trend that did not reach the statistical significance, toward a decreased risk of AAA for MMP2 (AAA patients n = 1090, controls n = 1077: OR = 0.83 [95% CI = .60-1.15], I(2) =7 1%) and ELN (AAA patients n = 904, controls n = 1069: OR = 0.79 [95% CI = .53-1.18], I(2) = 72%) polymorphisms. CONCLUSIONS These findings suggest that polymorphisms in MMP2, MMP3, MMP-13, and ELN genes may independently contribute to the pathogenesis of AAA.

Endothelial nitric oxide synthase gene influences the risk of pre-eclampsia, the recurrence of negative pregnancy events, and the maternal-fetal flow.

Objectives Pre-eclampsia is associated with vascular endothelial dysfunction, adverse pregnancy outcome and cardiovascular disease in later life. An inadequate nitric oxide availability related to polymorphisms in the endothelial nitric oxide synthase gene (eNOS) might predispose to the disease. Methods We investigated the role of eNOS T-786C, G894T and 4a4b polymorphisms in predisposing to both pre-eclampsia and the recurrence of negative pregnancy events, per se and in the presence of angiotensin-converting enzyme (ACE) DD genotype, and investigated their influence on maternal–fetal flow in 106 non-thrombophilic women with a history of pre-eclampsia, compared with 106 women with a history of normal pregnancy. Results No association between eNOS polymorphisms and predisposition to pre-eclampsia was found; nevertheless, the contemporary presence of eNOS 894TT and −786CC genotypes represented a susceptibility factor to the disease. In 48 out of 106 women, documented complications (pre-eclampsia and fetal growth restriction) were present in the current pregnancy. The eNOS 894TT genotype influenced the risk of recurrence of negative events (odds ratio = 5.45), particularly in contemporary women homozygous for both eNOS 894TT and ACE DD genotypes (odds ratio = 11.4). Throughout the pregnancy, a progressive alteration of maternal–fetal flow indices was found in women carrying the eNOS 894TT genotype, and this effect was strengthened in women with the contemporary presence of the ACE DD genotype. Conclusions An original finding is the increased risk of pre-eclampsia and recurrence of pregnancy negative events, probably by modulating the maternal–fetal flow, in women homozygous for the eNOS 894T allele previously analyzed for the ACE I/D polymorphism.

ACE and TGFBR1 genes interact in influencing the susceptibility to abdominal aortic aneurysm

A role of ACE I/D polymorphism in the pathogenesis of abdominal aortic aneurysm (AAA) has been demonstrated, possibly due to the effect of angiotensin II on vascular tissue remodelling. Angiotensin II exerts profibrogenic effects through the local induction of TGF-beta. Dysregulated TGF-beta signalling may result from mutations in TGFBR1 and TGFBR2 genes, thus resulting in degenerative changes in the vessel wall. We performed a case-control study in order to investigate the role of TGFBR1 9A6A polymorphism as predisposing factor to AAA per se, and in the presence of ACE DD and AT1R 1166 CC genotypes in 201 AAA patients (mean age+/-S.D., 71.5+/-6.9) referred to the Unit of Vascular Surgery of the University of Florence, compared with 252 healthy controls (mean age+/-S.D., 70.6+/-8.6). A significant difference in genotype distribution and allele frequency between patients and controls was found for ACE, but not for AT1R and TGFBR1 polymorphisms. At univariate analysis a significant association between ACE DD, but not AT1R CC and TGFBR1 6A allele, and the susceptibility to the disease was found [ACE DD OR=1.86 (95% CI 1.26-2.76), p=0.002]. After adjustment for age, gender, traditional cardiovascular risk factors, and CAD, PAD and CVD, ACE DD genotype still affected the susceptibility to AAA [OR=2.13 (95% CI 1.06-4.28), p=0.03], and the contemporary presence of ACE DD genotype and TGFBR1 6A allele, increased the predisposition to the disease [OR=5.09 (95% CI 1.44-18.02), p=0.01]. This study, which demonstrates an interaction between ACE and TGFBR1 genes in predisposing to AAA, may provide further information on the mechanisms contributing to AAA susceptibility, and offer a topic for future larger studies.

Marfan syndrome: current perspectives

Marfan syndrome (MFS) is a pleiotropic connective tissue disease inherited as an autosomal dominant trait, due to mutations in the FBN1 gene encoding fibrillin 1. It is an important protein of the extracellular matrix that contributes to the final structure of a microfibril. Few cases displaying an autosomal recessive transmission are reported in the world. The FBN1 gene, which is made of 66 exons, is located on chromosome 15q21.1. This review, after an introduction on the clinical manifestations that leads to the diagnosis of MFS, focuses on cardiovascular manifestations, pharmacological and surgical therapies of thoracic aortic aneurysm and/or dissection (TAAD), mechanisms underlying the progression of aneurysm or of acute dissection, and biomarkers associated with progression of TAADs. A Dutch group compared treatment with losartan, an angiotensin II receptor-1 blocker, vs no other additional treatment (COMPARE clinical trial). They observed that losartan reduces the aortic dilatation rate in patients with Marfan syndrome. Later on, they also reported that losartan exerts a beneficial effect on patients with Marfan syndrome carrying an FBN1 mutation that causes haploinsufficiency (quantitative mutation), while it has no significant effect on patients displaying dominant negative (qualitative) mutations. Moreover, a French group in a 3-year trial compared the administration of losartan vs placebo in patients with Marfan syndrome under treatment with beta-receptor blockers. They observed that losartan decreases blood pressure but has no effect on aortic diameter progression. Thus, beta-receptor blockers remain the gold standard therapy in patients with Marfan syndrome. Three potential biochemical markers are mentioned in this review: total homocysteine, serum transforming growth factor beta, and lysyl oxidase. Moreover, markers of oxidative stress measured in plasma, previously correlated with clinical features of Marfan syndrome, may be explored as potential biomarkers of clinical severity.

Multilocus analysis in candidate genes ACE, AGT, and AGTR1 and predisposition to peripheral arterial disease: Role of ACE D/-240T haplotype

OBJECTIVE Peripheral arterial disease (PAD) is a common manifestation of systemic atherosclerosis. Apart from traditional cardiovascular risk factors, several novel biologic mediators and genetic predisposing factors appear relevant in determining the atherogenetic process leading to PAD. Genes encoding for renin angiotensin system (RAS) components have been proposed as candidate in atherosclerosis. This study investigated four polymorphisms in angiotensinogen (AGT), angiotensin converting enzyme (ACE), and angiotensin II receptor type 1 (AGTR1), genes of RAS, in both predicting PAD and modulating the severity of the disease. METHODS The ACE I/D and -240A>T, AGT M235T, and AGTR1 1166A>C polymorphisms were analyzed in 281 PAD patients and in 485 controls comparable for age and sex. RESULTS The ACE D and -240T alleles both significantly influenced the predisposition to PAD. The ACE D, but not -240 T, allele remained associated with PAD after Bonferroni correction (P = .004) and adjustment for cardiovascular risk factors (P = .03). The ACE D allele influenced PAD predisposition with a dose-dependent effect (odds ratio for ACE ID vs II genotype, 1.77; P = .006; ACE DD vs II genotype, 2.15; P = .001). The haplotype reconstruction analysis for the ACE gene showed that the D/-240T haplotype significantly and independently influenced the predisposition to PAD (P = .02). In 190 PAD patients with no additional atherosclerotic localizations (isolated PAD), a significant association between ACE D and -240T alleles and PAD was observed. Only the ACE D allele remained associated with isolated PAD after Bonferroni correction (P = .02) and after adjustment for cardiovascular risk factors (P = .02). The haplotype reconstruction analysis for the ACE gene showed that the D/-240T, but not the D/-240A haplotype significantly influenced the predisposition to PAD (P = .0003). No influence of the polymorphisms analyzed on the severity of the disease, according to Rutherford categories, was found. CONCLUSIONS The present study contributes data to highlight the role of the ACED/-240T haplotype in predisposing to PAD, also in the absence of other atherosclerotic comorbidities.