ACTN3R577X polymorphism and long-term survival in patients with chronic heart failure

Abstract Background Previous studies have shown the occurrence of actinin-3 deficiency in the presence of the R577X polymorphism in the ACTN3 gene. Our hypothesis is that this deficiency, by interfering with the function of skeletal muscle fiber, can result in a worse prognosis in patients with chronic heart failure. Methods A prospective cohort study was conducted from 2002 to 2004. The eligibility criteria included diagnosis of chronic heart failure stage C from different etiologies. We excluded all patients with concomitant disease that could be related to poor prognosis. ACTN3 rs1815739 (R577X) polymorphism was detected by high resolution melting analysis. Survival curves were calculated with the Kaplan-Meier method and evaluated with the log-rank statistic. The relationship between the baseline variables and the composite end-point of all-cause death was assessed using a Cox proportional hazards survival model. Results A total of 463 patients were included in this study. The frequency of the ACTN3 577X variant allele was 39.0%. The LVEF mean was 45.6 ± 18.7% and the most common etiology of this study was hypertensive. After a follow-up of five years, 239 (51.6%) patients met the pre-defined endpoint. Survival curves showed higher mortality in patients carrying RX or XX genotypes compared with patients carrying RR genotype (p = 0.01). Conclusion R577X polymorphism in the ACTN3 gene was independently associated with worse survival in patients with chronic heart failure. Further studies are necessary to ensure its use as a marker of prognosis for this syndrome

Human Saphenous Vein Organ Culture Under Controlled Hemodynamic Conditions

INTRODUCTION: Saphenous vein grafting is still widely used to revascularize ischemic myocardium. The effectiveness of this procedure is limited by neointima formation and accelerated atherosclerosis, which frequently leads to graft occlusion. A better understanding of this process is important to clarify the mechanisms of vein graft disease and to aid in the formulation of strategies for prevention and/or therapeutics. OBJECTIVE: To develop an ex vivo flow system that allows for controlled hemodynamics in order to mimic arterial and venous conditions. METHODS: Human saphenous veins were cultured either under venous (flow: 5 ml/min) or arterial hemodynamic conditions (flow: 50 ml/min, pressure: 80 mmHg) for 1-, 2- and 4-day periods. Cell viability, cell density and apoptosis were compared before and after these intervals using MTT, Hoeschst 33258 stain, and TUNEL assays, respectively. RESULTS: Fresh excised tissue segments were well preserved prior to the study. Hoechst 33258 and MTT stains showed progressive losses in cell density and cell viability in veins cultured under arterial hemodynamic conditions from 1 to 4 days, while no alterations were observed in veins cultured under venous conditions. Although the cell density from 1-day cultured veins under arterial conditions was similar to that of freshly excised veins, the TUNEL assay indicated that most of these cells were undergoing apoptosis. CONCLUSION: The results observed resemble the events taking place during early in vivo arterial-vein grafting and provide evidence that an ex vivo perfusion system may be useful for the identification of new therapeutic targets that ameliorate vein graft remodeling and increase graft patency over time

Exercise Training Can Prevent Cardiac Hypertrophy Induced by Sympathetic Hyperactivity with Modulation of Kallikrein-Kinin Pathway and Angiogenesis

Sympathetic hyperactivity induces adverse effects in myocardial. Recent studies have shown that exercise training induces cardioprotection against sympathetic overload; however, relevant mechanisms of this issue remain unclear. We analyzed whether exercise can prevent pathological hypertrophy induced by sympathetic hyperactivity with modulation of the kallikrein-kinin and angiogenesis pathways. Male Wistar rats were assigned to non-trained group that received vehicle; non-trained isoproterenol treated group (Iso, 0.3 mg kg(-1) day(-1)); and trained group (Iso+Exe) which was subjected to sympathetic hyperactivity with isoproterenol. the Iso rats showed hypertrophy and myocardial dysfunction with reduced force development and relaxation of muscle. the isoproterenol induced severe fibrosis, apoptosis and reduced myocardial capillary. Interestingly, exercise blunted hypertrophy, myocardial dysfunction, fibrosis, apoptosis and capillary decreases. the sympathetic hyperactivity was associated with high abundance of ANF mRNA and beta-MHC mRNA, which was significantly attenuated by exercise. the tissue kallikrein was augmented in the Iso+Exe group, and kinin B-1 receptor mRNA was increased in the Iso group. Moreover, exercise induced an increase of kinin B-2 receptor mRNA in myocardial. the myocardial content of eNOS, VEGF, VEGF receptor 2, pAkt and Bcl-2 were increased in the Iso+Exe group. Likewise, increased expression of pro-apoptotic Bad in the Iso rats was prevented by prior exercise. Our results represent the first demonstration that exercise can modulate kallikrein-kinin and angiogenesis pathways in the myocardial on sympathetic hyperactivity. These findings suggest that kallikrein-kinin and angiogenesis may have a key role in protecting the heart.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)National Council for Scientific and TechnologicalUniv Nove Julho Uninove, Programa Posgrad Ciencias Reabilitacao, São Paulo, BrazilUniversidade Federal de São Paulo Unifesp, São Paulo, BrazilUniv São Paulo, São Paulo, BrazilUniv Nove Julho Uninove, Programa Posgrad Med, São Paulo, BrazilUniversidade Federal de São Paulo Unifesp, São Paulo, BrazilFAPESP: 2009/54225-8National Council for Scientific and Technological: 477458/2009-2National Council for Scientific and Technological: 479395/2012-8Web of Scienc

Cell therapy prevents structural, functional and molecular remodeling of remote non-infarcted myocardium

Background/objectives: Therapy using bone marrow (BM) cells has been tested experimentally and clinically due to the potential ability to restore cardiac function by regenerating lost myocytes or increasing the survival of tissues at risk after myocardial infarction (MI). in this study we aimed to evaluate whether BM-derived mononuclear cell (MNC) implantation can positively influence the post-MI structural remodeling, contractility and Ca(2+)-handling proteins of the remote non-infarcted tissue in rats.Methods and results: After 48 h of MI induction, saline or BM-MNC were injected. Six weeks later, MI scars were slightly smaller and thicker, and cardiac dilatation was just partially prevented by cell therapy. However, the cardiac performance under hemodynamic stress was totally preserved in the BM-MNC treated group if compared to the untreated group, associated with normal contractility of remote myocardium as analyzed in vitro. the impaired post-rest potentiation of contractile force, associated with decreased protein expression of the sarcoplasmic reticulum Ca2+-ATPase and phosphorylated-phospholamban and overexpression of Na(+)/Ca(2+) exchanger, were prevented by BM-MNC, indicating preservation of the Ca(2+) handling. Finally, pathological changes on remodeled remote tissue such as myocyte hypertrophy, interstitial fibrosis and capillary rarefaction were also mitigated by cell therapy.Conclusions: BM-MNC therapy was able to prevent cardiac structural and molecular remodeling after MI, avoiding pathological changes on Ca(2+)-handling proteins and preserving contractile behavior of the viable myocardium, which could be the major contributor to the improvements of global cardiac performance after cell transplantation despite that scar tissue still exists. (C) 2013 Elsevier Ireland Ltd. All rights reserved.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Universidade Federal de São Paulo, Dept Med, São Paulo, BrazilUniv Estadual Campinas, Dept Struct & Funct Biol, Campinas, SP, BrazilUniv São Paulo, Inst Heart, BR-05508 São Paulo, BrazilUniv São Paulo, Inst Biomed Sci, BR-05508 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, São Paulo, BrazilWeb of Scienc

A continuous fluorescent assay for the determination of plasma and tissue angiotensin I-converting enzyme activity

A continuous assay using internally quenched fluorescent peptides with the general sequence Abz-peptidyl-(Dnp)P-OH (Abz = ortho-aminobenzoic acid; Dnp = 2,4-dinitrophenyl) was optimized for the measurement of angiotensin I-converting enzyme (ACE) in human plasma and rat tissues. Abz-FRK(Dnp)P-OH, which was cleaved at the Arg-Lys bond by ACE, was used for the enzyme evaluation in human plasma. Enzymatic activity was monitored by continuous recording of the fluorescence (lambdaex = 320 nm and lambdaem = 420 nm) at 37ºC, in 0.1 M Tris-HCl buffer, pH 7.0, with 50 mM NaCl and 10 µM ZnCl2. The assays can be performed directly in the cuvette of the fluorimeter and the hydrolysis followed for 5 to 10 min. ACE measurements in the plasma of 80 healthy patients with Hip-His-Leu and with Abz-FRK(Dnp)P-OH correlated closely (r = 0.90, P < 0.001). The specificity of the assay was demonstrated by the complete inhibition of hydrolysis by 0.5 µM lisinopril or captopril. Abz-FRK(Dnp)P-OH cleavage by ACE was monitored in rat lung, kidney, heart, and liver homogenates in the presence of a cocktail of inhibitors containing trans-epoxy-succinyl-L-leucylamido-(4-guanido)-butene, pepstatin, phenyl-methylsulfonyl fluoride, N-tosyl-L-phenylalanyl-chloromethyl ketone, and N-tosyl-lysyl-chloromethyl ketone to prevent undesirable hydrolysis. ACE activity in lung, heart and kidney homogenates, but not in liver homogenates, was completely abolished by 0.5 µM lisinopril or captopril. The advantages of the method are the procedural simplicity and the high sensitivity providing a rapid assay for ACE determinations.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de BiofísicaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de MedicinaUniversidade de São Paulo Faculdade de Medicina Instituto do CoraçãoUniversidade de São Paulo Escola de Educação Física e Esporte Laboratório de Bioquímica da Atividade MotoraUNIFESP, EPM, Depto. de BiofísicaUNIFESP, EPM, Depto. de MedicinaSciEL

Quality of life scores differs between genotypic groups of patients with suspected hereditary hemochromatosis

Background: Hereditary hemochromatosis (HH) encompasses a group of autosomal recessive disorders mainly characterized by enhanced intestinal absorption of iron and its accumulation in parenchymal organs. HH diagnosis is based on iron biochemical and magnetic resonance imaging (MRI) assessment, and genetic testing. Questionnaires, such as SF-36 (short form health survey), have been increasingly used to assess the impact of diseases on the patient's quality of life (QL). In addition, different genotypes are identified as results of genetic tests in patients with suspected primary iron overload. In the present study, our aim was to evaluate whether domains of QL are different according to genotypic groups in patients suspected of HH. Methods: Seventy-nine patients with primary iron overload were included and two genotypic groups were formed (group 1: homozygous genotype for the HFE p.Cys282Tyr mutationgroup 2: other genotypes). Results: Group 1 had higher means of plasma transferrin saturation (86 +/- 19%) and serum ferritin (1669 +/- 1209 ng/mL) compared to group 2 (71 +/- 12%, 1252 +/- 750 ng/mL, respectivelyp = 0.001). Four domains were significantly different among groups 1 and 2: physical functioning (p = 0.03), bodily pain (p = 0.03), vitality (p = 0.02) and social functioning (p = 0.01). Conclusions: Our main finding was that patients with p. Cys282Tyr homozygosity had a worse QL scenario assessed by SF-36, compared with patients with iron overload without the same genotype. Being aware of this relationship between genotypes and QL might be helpful in the overall management of patients suspected of hereditary hemochromatosis.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) [2013/09295-3]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Brazil [2013/20614-3]Univ Sao Paulo, Heart Inst InCor, Lab Genet & Mol Cardiol, Med Sch, Av Doutor Eneas de Carvalho Aguiar 44, BR-05403900 Sao Paulo, SP, BrazilSanta Casa Med Sch, Hematol & Hemotherapy Sect, Sao Paulo, BrazilAcad Ciencia & Tecnol, Sao Jose Do Rio Preto, BrazilFundacao Pro Sangue, Hemoctr Sao Paulo, Sao Paulo, SP, BrazilUniv Sao Paulo, Sao Paulo, SP, BrazilUniv Sao Paulo, Med Sch, Hosp Clin, Hematol Serv, Sao Paulo, BrazilUniv Sao Paulo, Med Sch, Hosp Clin, Hematol & Hemotherapy Discipline, Sao Paulo, BrazilUniv Rennes, Pontchaillou Univ Hosp, Liver Dis Unit, Rennes, FranceNatl Reference Ctr Rare Iron Overload Dis Genet O, Rennes, FranceUniv Fed Sao Paulo UNIFESP, Dept Pharmacol, Sao Paulo, BrazilUniv Fed Sao Paulo UNIFESP, Dept Pharmacol, Sao Paulo, BrazilCAPES: 2013/09295-3FAPESP: 2013/20614-3Web of Scienc

Impact of diabetes mellitus on arterial stiffness in a representative sample of an urban Brazilian population

Background\ud Independent of other cardiovascular (CV) risk factors, increased arterial stiffness has been established as a predictor of morbidity and mortality. The main aim of this study was to investigate the impact of diabetes on arterial stiffness in a representative sample of an urban Brazilian population plus Amerindians.\ud \ud Methods\ud A total of 1,415 individuals from the general population were randomly selected plus 588 Amerindians from a native community in Brazil. In addition, a sub-sample of 380 individuals from the general population had 5-year follow-up data. Pulse wave velocity (PWV) was measured with a non-invasive automatic device (Complior, Colson; Garges les Gonesses, France) and increased arterial stiffness was defined as PWV ≥ 12 m/s.\ud \ud Results\ud In the overall group, diabetic individuals had higher frequencies of increased arterial stiffness and hypertension. They also had higher values of PWV, body mass index, total cholesterol, triglycerides, systolic and diastolic blood pressures compared to non-diabetic individuals (p < 0.01). In an analysis stratified by hypertension, PWV values and increased arterial stiffness frequency were higher in diabetic individuals in both groups (hypertensive and non-hypertensive) (p < 0.05). Furthermore, higher risk for increased arterial stiffness was observed in the diabetic individuals from the overall group (OR = 2.27; CI = 1.47-3.52, p < 0.001) and from the hypertensive group (OR = 2.70; CI = 1.58-4.75, p < 0.001), adjusted for covariates. Regarding the ethnic stratification, diabetic individuals from Amerindian, White, and Mulatto (mixed-race) groups had higher PWV values and a greater frequency of increased arterial stiffness compared to non-diabetic individuals. Both diabetic and non-diabetic individuals had higher PWV values after 5 years. There was no significant difference in the 5-year PWV progression in diabetic compared to non-diabetic individuals.\ud \ud Conclusions\ud These results confirm, in a sample of Brazilian population, that the presence of diabetes is associated with increased arterial stiffness and it may contribute in part to increased cardiovascular risk in diabetic patients.PCJL Santos is the recipient of a fellowship from FAPESP, Proc. 2010-17465-8, Brazil. The technical assistance of the Laboratory of Genetics and Molecular Cardiology group, Heart Institute group is gratefully acknowledged

SLCO1B1 rs4149056 polymorphism associated with statin-induced myopathy is differently distributed according to ethnicity in the Brazilian general population: Amerindians as a high risk ethnic group

Background\ud Recent studies reported the association between SLCO1B1 polymorphisms and the development of statin-induced myopathy. In the scenario of the Brazilian population, being one of the most heterogeneous in the world, the main aim here was to evaluate SLCO1B1 polymorphisms according to ethnic groups as an initial step for future pharmacogenetic studies.\ud \ud Methods\ud One hundred and eighty-two Amerindians plus 1,032 subjects from the general urban population were included. Genotypes for the SLCO1B1 rs4149056 (c.T521C, p.V174A, exon 5) and SLCO1B1 rs4363657 (g.T89595C, intron 11) polymorphisms were detected by polymerase chain reaction followed by high resolution melting analysis with the Rotor Gene 6000® instrument.\ud \ud Results\ud The frequencies of the SLCO1B1 rs4149056 and rs4363657 C variant allele were higher in Amerindians (28.3% and 26.1%) and were lower in African descent subjects (5.7% and 10.8%) compared with Mulatto (14.9% and 18.2%) and Caucasian descent (14.8% and 15.4%) ethnic groups (p < 0.001 and p < 0.001, respectively). Linkage disequilibrium analysis show that these variant alleles are in different linkage disequilibrium patterns depending on the ethnic origin.\ud \ud Conclusion\ud Our findings indicate interethnic differences for the SLCO1B1 rs4149056 C risk allele frequency among Brazilians. These data will be useful in the development of effective programs for stratifying individuals regarding adherence, efficacy and choice of statin-type.PCJLS is recipient from fellowship from FAPESP, Proc. 2010-17465-8, Brazil. The technical assistance of the Laboratory of Genetics and Molecular Cardiology group, Heart Institute group is gratefully acknowledged