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Cristina Barlassina

Publications and source records attributed to Cristina Barlassina.

16 recordsLinked to original sources
PubMed2006

The 460Trp allele of alpha-adducin increases carotid intima-media thickness in young adult males.

BACKGROUND: The 460Trp allele of the alpha-adducin gene (ADD1), which is involved in a form of salt-sensitive hypertension, has been associated with patterns of target organ damage. OBJECTIVES: As carotid artery intima-media thickness (IMT) largely depends upon unknown genetic factors, besides being associated to conventional risk factors, we tested the association of the 460Trp allele of ADD1 with IMT in a well-characterized sample of young healthy normotensive subjects, to assess the role of ADD1 polymorphism without overlapping effects of age or already elevated blood pressure. METHODS: Anthropometric measurements, blood pressure (BP), and carotid artery wall IMT (high-resolution sonography and digitalized morphometry) were obtained in 420 healthy normotensive Caucasian university students. Genotypes for ADD1 were detected by automated genomic polymerase chain reaction (PCR). RESULTS: ADD1 genotypes were evenly distributed between genders. IMT was significantly larger in carriers of the 460Trp allele of ADD1, while a significant gender x ADD1 interaction (P = 0.02) demonstrated that IMT was increased only in males carrying the 460Trp allele (P < 0.001). No significant association was found in females. CONCLUSIONS: The 460Trp allele of ADD1 contributes substantially to increase carotid IMT, in a male hormonal milieu only, at least in the young age range.

Adult↗
PubMed2006

Alpha-adducin and angiotensin-converting enzyme polymorphisms in hypertension: evidence for a joint influence on albuminuria.

BACKGROUND: A single-nucleotide polymorphism (Gly460Trp) within the alpha-adducin gene (ADD1) may influence several renal phenotypes, including salt sensitivity, susceptibility to renal failure, the renal haemodynamics and confer a worse cardiovascular risks profile. However, its relationship with microalbuminuria, a marker of early renal and cardiovascular damage and an independent predictor of morbid events in hypertension, is unknown. For this reason, we related the ADD1 genetic polymorphism to urine albumin levels and other clinical variables in essential hypertensive men. The angiotensin-converting enzyme (ACE) insertion/deletion (ID) polymorphism was also evaluated because of its interactive potential with the ADD1 genotype. METHODS: Albuminuria (three overnight collections), echocardiographic left ventricular mass index, blood pressure, body mass index, renal function, glucose and lipids were measured in 238 genetically unrelated, never treated, uncomplicated Caucasian essential hypertensive men. Polymerase chain reaction or a 5' nuclease assay were used to characterize the ACE ID and ADD1 Gly460Trp variants, respectively. RESULTS: Microalbuminuria (albuminuria >or= 15 microg/min) was more frequent in patients with the ACE DD variant, but only in those with a ADD1 Gly460Gly background. In contrast, urine albumin did not differ by ACE ID genotype in the presence of mutated ADD1 Trp alleles. ADD1 polymorphisms per se were not associated with albuminuria. Cardiovascular, renal, metabolic parameters were homogeneously distributed among different genetic backgrounds. CONCLUSIONS: ACE DD and ADD1 Gly460Gly polymorphisms may jointly influence albuminuria in hypertensive men, 460Gly homozygosis facilitating or, possibly, the 460Trp allele mitigating the noxious renal impact of the ACE DD genotype. The data highlight further the complex pathophysiological implications of microalbuminuria in hypertension.

Adult↗
PubMed2005

Role of the adducin family genes in human essential hypertension.

OBJECTIVE: In both humans and rats, polymorphisms of the alpha adducin (ADD1) gene are involved in renal sodium handling, essential hypertension and some of its organ complications. Adducin functions within cells as a heterodimer composed of various combinations of three subunits that are coded by three genes (ADD1, 2, 3) each located on a different chromosome. DESIGN: These characteristics provide the biochemical basis for investigating epistatic interactions among these loci. METHODS: We examined the three adducin gene polymorphisms and their association with ambulatory blood pressure (ABPM) and with plasma levels of renin activity (PRA), endogenous ouabain (EO), in 512 newly discovered and never-treated hypertensive patients. RESULTS: Relative to carriers of the wild type (Gly/Gly) ADD1 gene, patients carrying the mutated Trp ADD1 allele had higher blood pressure (systolic blood pressure (SBP) 143.2 +/- 1.0 versus 140.6 +/- 0.6 mmHg P = 0.027 and diastolic blood pressure (DBP) 94.2 +/- 0.77 versus 92.3 +/- 0.5 mmHg, P = 0.03), lower PRA and EO, consistent with the hypothesis of the renal sodium retaining effect of the Trp allele. Polymorphisms in the ADD2 and ADD3 genes taken alone were not associated with these variables. However, the differences in SBP and DBP between the two ADD1 genotypes were greatest in carriers of the ADD3 G allele (around + 8 mmHg). The significance of the interaction between ADD1 and ADD3 ranged between P = 0.020 to P = 0.006 according to the genetic model applied. CONCLUSIONS: The interaction of ADD1 and ADD3 gene variants in humans is statistically associated with variation in blood pressure, suggesting the presence of epistatic effects among these loci.

Adult↗
PubMed2004

Association between aldosterone synthase (CYP11B2) polymorphism and left ventricular mass in human essential hypertension.

OBJECTIVES: The aim of our study was to evaluate the relationship between aldosterone synthase gene polymorphism and cardiac dimensions in essential hypertension. BACKGROUND: Higher aldosterone synthase messenger ribonucleic acid levels in the human heart are accompanied by increased intracardiac aldosterone production, a phenomenon that is associated with cardiac fibrosis and hypertrophy. Recent evidence suggests that a polymorphism (-344C/T) in the promoter region of the aldosterone synthase gene is associated with increased constitutive aldosterone production. METHOD: Relationships between M-mode echocardiographic cardiac dimensions and aldosterone synthase -344C/T polymorphism were studied in 210 never-treated, middle-aged patients (age 41.6 +/- 1.4 years) affected by mild to moderate essential hypertension. Among these patients, 48 had the genotype -C344C, 97 had -C344T, and 65 had -T344T. Patients in the three groups were similar in terms of age, gender, body mass index, and blood pressure. RESULTS: Left ventricular (LV) mass and thickness were positively correlated with the number of T alleles: LV mass (CC, CT, and TT, respectively: 168 +/- 6.9, 179 +/- 5.2, and 193 +/- 6.9 g; p = 0.03), LV septal thickness (0.99 +/- 0.02, 1.03 +/- 0.02, and 11.08 +/- 0.03 cm, p = 0.04), PWT (0.93 +/- 0.03, 0.95 +/- 0.01, and 1.03 +/- 0.02 cm; p = 0.002), and relative wall thickness (38.3 +/- 1.2%, 38.8 +/- 0.8%, and 42.8 +/- 1.1%; p = 0.004). This trend was confirmed by linear regression, suggesting a "major gene" behavior for the T allele. Multiple regression analysis showed that this effect was independent of anthropometric and clinical factors, including adrenal aldosterone. CONCLUSIONS: Our data suggest that -344C/T polymorphism affects LV mass and thickness in essential hypertension, independent of adrenal aldosterone. A role for intracardiac aldosterone synthesis is hypothesized.

Adult↗
PubMed2003

Expression analysis of the human adducin gene family and evidence of ADD2 beta4 multiple splicing variants.

Adducin is a cytoskeleton heterodimeric protein. Its subunits are encoded by three related genes (ADD1, ADD2, and ADD3) which show alternative spliced variants. Adducin polymorphisms are involved in blood pressure regulation in humans and rats. We have analyzed mRNA distribution of ADD gene family in human tissues and cells with Real-Time TaqMan RT-PCR. Whereas ADD1 is ubiquitously distributed, ADD3 is more expressed in kidney medulla and cortex than in fetal kidney, while in adult liver it is less abundant than in fetal liver. ADD2 beta1 and beta4 variants show the same pattern of distribution with the highest expression in brain, fetal liver, and kidney. Conventional RT-PCR identified new beta4 variants. Beta4a is characterized by an in-frame insertion of 21 nucleotides upstream exon 15 predicting a 7 amino acids longer protein with a similar C-terminus region. It is coexpressed with beta1 and beta4 in several tissues. Fetal kidney shows further beta4b, beta4c and beta4d variants containing internal exon deletions that enormously modify the predicted NH(2) and central regions. Our findings could help one to understand the functional role of adducin variants in specific tissues and cells.

Amino Acid Sequence↗
PubMed2003

ACE and alpha-adducin polymorphism as markers of individual response to diuretic therapy.

Renin-angiotensin system reactivity and the constitutive capacity of the renal tubule to reabsorb sodium play a role in the individual response to diuretic therapy; therefore we evaluated the blood pressure (BP) response to hydrochlorothiazide in 87 never-treated individuals with mild essential hypertension, according to ACE gene I/D and alpha-adducin Gly460Trp polymorphism. These genotypes where chosen because previous data showed their interaction in determining the BP response to salt probably was the result of their involvement in the activation of the renin-angiotensin system (ACE) and in the constitutive capacity of the kidney to reabsorb sodium (alpha-adducin) (treatment for 2 months). BP was measured after 3 run-in visits and after the first and second months of treatment by means of a standardized procedure. Data were analyzed by ANOVA, t test, and multivariate ANOVA for repeated measures (covarying for gender, age, and body mass index). Although basal mean BP (MBP) was similar in the different ACE and alpha-adducin genotypes, patients carrying at least one I allele of ACE and one 460Trp allele of alpha-adducin had the largest MBP decrease with treatment (12.7+/-1.9 mm Hg), the effect of the combination of genotypes being additive but not epistatic. These patients had an odds ratio of 15.75 of being a responder to hydrochlorothiazide compared with patients with Gly460Gly+DD, with the least MBP decrease (3.4+/-1.7 mm Hg). Alpha-adducin and ACE I/D polymorphism may be useful to predict the interindividual degree of response to hydrochlorothiazide; the analysis of the combination of the 2 genotypes increases the accuracy of the prediction of response to the drug.

Antihypertensive Agents↗
PubMed2003

Genetic polymorphism of the renin-angiotensin-aldosterone system and arterial hypertension in the Italian population: the GENIPER Project.

OBJECTIVE: To detect the association of single polymorphisms of the renin-angiotensin-aldosterone system (RAAS), or different combinations thereof, with hypertension. DESIGN AND METHODS: The GENIPER database is the result of a collaborative effort of 13 Italian research centres to collect genomic DNA in subjects well characterized in terms of blood pressure status. A total of 2461 subjects (normotensive = 611; hypertensive = 1850) were selected and genotyped for the angiotensin-converting enzyme insertion/deletion (ACE I/D), angiotensinogen (AGT) T/C704, angiotensin receptor type 1 (AT1) A/C1166 and aldosterone synthase (ALDO) T/C-344 genetic variants. RESULTS: Allele frequencies were homogeneous over the Italian territory, with the relevant exception of the ACE I/D, the D allele being significantly less frequent in the northern region (61%) than in the rest of the country (67%; P < 0.0001). When comparing allele and genotype distributions in normotensives and hypertensives, the latter presented a small but statistically significant increase of the C allele of AGT T/C704, the A allele of AT1 A/C1166 and the T allele of ALDO T/C-344 polymorphisms (P = 0.018, P = 0.037 and P = 0.015, respectively), with similar trends all over the country. A step-wise logistic regression analysis confirmed these findings, by entering in the model as independent predictors of blood pressure status of AGT T/C704 (P = 0.013), ALDO T/C-344 (P = 0.032) and AT1 A/C1166 polymorphisms (P = 0.075), but not ACE I/D (P = 0.996). We also found some evidence of an additive effect of individual genetic variants of the RAAS, modulating at different levels the same functional pathway, on the risk of developing hypertension, but no synergistic interaction was observed. CONCLUSIONS: Our results suggest that some allelic variants of RAAS genes carry a small but identifiable risk of developing arterial hypertension.

Databases, Genetic↗
PubMed2003

Endothelial nitric oxide synthase polymorphisms are associated with type 2 diabetes and the insulin resistance syndrome.

Endothelial nitric oxide synthase (eNOS) variants were previously demonstrated in cardiovascular disease. To evaluate whether eNOS gene variants are associated with insulin resistance and type 2 diabetes, we evaluated polymorphisms in Exon7 (E298D), intron 18 (IVS18 + 27A-->C), and intron 23 (IVS23 + 10G-->T) in 159 type 2 diabetic patients without macrovascular complications and in 207 healthy control subjects. Samples for all hormonal and metabolic variables were obtained after an overnight fast. The D298 and IVS18 + 27C alleles, but not the IVS23 + 10G-->T variant, were significantly more frequent in type 2 diabetic patients than in control subjects. The two- and three-loci haplotype analysis showed that there is a statistically significant association between the eNOS variants and type 2 diabetes. No significant differences were observed in the clinical characteristics of type 2 diabetic patients according to genotypes (except for visceral obesity [waist-to-hip ratio], which was significantly more present in D298 homozygotes). Healthy control subjects homozygous for both D298 and IVS18 + 27C presented higher insulin, C-peptide, and nitric oxide levels, as well as higher HOMA (homeostasis model assessment) values than the double wild-type homozygotes, with values superimposable on those found in type 2 diabetic patients. In conclusion, we described a significant association between eNOS gene polymorphisms and type 2 diabetes, suggesting a new genetic susceptibility factor for hyperinsulinemia, insulin resistance, and type 2 diabetes.

Cardiovascular Diseases↗
PubMed2002

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗
PubMed2002

Association between hypertension and variation in the alpha- and beta-adducin genes in a white population.

BACKGROUND: The substitution of tryptophan for glycine at amino acid 460 (Gly460Trp polymorphism) of the alpha-subunit of the heterodimeric cytoskeleton protein adducin increases renal sodium reabsorption and may be involved in the pathophysiology of essential hypertension. In the present study, we investigated in multivariate analyses whether the risk of hypertension was associated with the C1797T polymorphism of the beta-adducin gene. METHODS: A total of 1848 subjects randomly selected from a white population were genotyped. Study nurses measured blood pressure at the participants' homes. RESULTS: The frequencies of the alpha-adducin Trp and beta-adducin T alleles were 0.23 and 0.11, respectively. In men (N = 904), the beta-adducin T allele was not associated with hypertension [adjusted relative risk (RR) vs. CC homozygotes 0.94, P = 0.77], but T allele carriers had lower plasma renin activity (PRA) and 24-hour urinary aldosterone excretion (P < 0.04). In all women (N = 944), beta-adducin T allele carriers had a higher risk of hypertension than CC homozygotes (RR 1.81, CI 1.18-2.77, P = 0.007), but similar PRA and 24-hour urinary aldosterone excretion (P> 0.29). In 345 post-menopausal women and 190 users of oral contraceptives, the RRs of hypertension were 2.47 (CI 1.34-4.64, P = 0.003) and 2.56 (CI 0.83-7.86, P = 0.10), respectively. For systolic pressure in women, there was a significant interaction (P = 0.02) between the alpha- and beta-adducin polymorphisms. Only in female carriers of the mutated alpha-adducin Trp allele was the systolic pressure significantly higher in beta-adducin T allele carriers compared with CC homozygotes (+3.8 mm Hg, P = 0.02). Furthermore, in the presence of the mutated alpha-adducin Trp allele, the RRs associated with the beta-adducin T allele were 2.35 (P = 0.01) in all women, 2.92 (P = 0.03) in post-menopausal subjects, and 3.79 (P = 0.09) in users of oral contraceptives. CONCLUSIONS: The 1797T allele of the beta-adducin gene is associated with increased risk of hypertension in post-menopausal women and in users of oral contraceptives, particularly in the presence of the mutated alpha-adducin Trp allele. We hypothesize that inhibition of the renin-aldosterone system in men and absence of such a compensatory mechanism in women may explain, at least to some extent, the sexual dimorphism of the blood pressure phenotype in relation to the C1797T beta-adducin polymorphism.

Adolescent↗
PubMed2002

Carotid and femoral intima-media thickness in relation to three candidate genes in a Caucasian population.

BACKGROUND: In a Caucasian population, the prevalence and incidence of hypertension, renal function and large artery stiffness were significantly correlated with polymorphisms in the genes encoding the angiotensin-converting enzyme (ACE I/D), aldosterone synthase (-C344T) and the cytoskeleton protein alpha-adducin (Gly460Trp). OBJECTIVE: This study investigated intima-media thickening, a precursor of atherosclerosis, in relation to these genetic polymorphisms. METHODS: Carotid and femoral intima-media thickness were assessed with a wall-track system in 380 subjects enrolled in a population study. Subjects were genotyped for the presence of the ACE D, aldosterone synthase -344T and alpha-adducin 460Trp alleles. The statistical analysis allowed for confounders, interactions among genes, and the non-independence of the phenotypes within families. RESULTS: The sample included 188 men (49.5%). Mean age was 39.8 years. Intima-media thickness of the carotid and femoral arteries averaged 575 and 719 microm, respectively. Intima-media thickness of the femoral-but not carotid-artery increased with the number of ACE D alleles. The effect of ACE genotype on femoral intima-media thickness was confined to carriers of the 460Trp allele and the -344T allele. Expressed as a percentage of the population mean, the mean differences between II and DD homozygotes averaged 13.4% (95% CI 5.6-21.2%) in all subjects, 21.2% (8.0-34.5%) in carriers of the 460Trp allele, 15.4% (4.1-26.8%) in carriers of the -344T allele, and 25.2% (10.7-39.7%) if the 460Trp and -344T alleles were both present. CONCLUSION: This study shows that a relationship exists between the intima-media thickness of the large muscular femoral artery and the ACE gene. This relationship is only apparent in the presence of either the alpha-adducin 460Trp or the aldosterone synthase -344T allele. These findings may have clinical implications for the assessment of genetic cardiovascular risk.

Adolescent↗
PubMed2002

Genetics of essential hypertension: from families to genes.

Family studies demonstrated the contribution of genetic factors to the development of primary hypertension. However, the transition from this phenomenologic-biometric approach to the molecular-genetic one is more difficult. This last approach is mainly based on the Mendel paradigm; that is, the dissection of the poligenic complexity of hypertension is brought about on the assumption that the individual genetic variants underlying the development of hypertension must be more frequent in hypertensive patients than in controls and must cosegregate with hypertension in families. The validity of these assumptions was clearly demonstrated in the so-called monogenic form of hypertension. However, because of the network of the feedback mechanisms regulating BP, it is possible that that the same gene variant may have an opposite effect on BP according to the genetic and environmental backgrounds. Independent groups of observations (acute BP response to saline infusion, incidence of hypertension in a population follow-up of 9 yr, age-related changes on BP) discussed in this review suggest a positive answer to this question. Therefore the impact of a given genetic variant on BP level must be evaluated within the context of the appropriate genetic epistatic interactions. A negative finding or a minor genetic effect in a general population may become a major gene effect in a subset of people with the appropriate genetic and environmental backgrounds.

Blood Pressure↗
PubMed2002

alpha-Adducin 460Trp allele is associated with erythrocyte Na transport rate in North Sardinian primary hypertensives.

Erythrocyte membrane alterations mirror those of vascular smooth muscle and renal tubular cell membrane. The interaction between adducin and Na-K pump is the most likely biochemical mechanism responsible for the increased tubular Na reabsorption and hypertension in Milan hypertensive strain (MHS) rats. To substantiate this hypothesis in humans, we tested to see if alpha-adducin Gly460Trp genotype is associated with erythrocyte sodium transport rate in a new cohort of n=268 never-treated North Sardinian primary hypertensives. Plasma renin activity and blood pressure response to hydrochlorothiazide were also measured to evaluate the relationship between sodium transport rate and two intermediate phenotypes with a higher degree of genetic complexity. Na-K pump, Na-K-Cl cotransport, and Li-Na countertransport at V(max) were faster (P<0.0001), whereas intracellular Na concentration was lower (P<0.0001) in patients carrying one or two 460Trp alleles. Such behavior was mirrored by opposite changes of intracellular Na concentration. Plasma renin activity and blood pressure response to diuretic treatment, on the other hand, showed a weaker association with the sodium transport rate. In conclusion, our findings are consistent with the hypothesis that the Gly460Trp alpha-adducin polymorphism may affect renal Na handling through an alteration in ion transport across the cell membrane mirrored by erythrocytes. These results may also have clinical relevance because the Gly460Trp alpha-adducin polymorphism may explain, at least in part, the variability of blood pressure response to diuretics in primary hypertensive patients.

Alleles↗
PubMedDate not supplied

Genetics of human arterial hypertension.

Although everybody agrees that each individual's blood pressure variance is under substantial genetic control, its quantitative estimates vary from 35 to 70%, according to the different experimental designs. The problem is that, in spite of such substantial contribution, the discovery of the "genes that cause hypertension" has been quite discouraging. This is indeed caused by the multifactorial nature of the disease and no improvement is to be expected without dissecting hypertension in its major pathogenetic pathways. As a paradigm of such a dissection, we present the data on adducin system, that proved to be relevant for a common form of salt sensitive in humans and the genetic hypertension of MHS rats.

Animals↗