RESUMO
BACKGROUND: Microvascular obstruction (MVO) is associated with greater infarct size, adverse left-ventricular (LV) remodeling and reduced ejection fraction following ST-elevation myocardial infarction (STEMI). We hypothesized that patients with MVO may constitute a subgroup of patients that would benefit from intracoronary stem cell delivery with bone marrow mononuclear cells (BMCs) given previous findings that BMCs tended to improve LV function only in patients with significant LV dysfunction. METHODS AND RESULTS: We analyzed the cardiac MRIs of 356 patients (303 M, 53 F) with anterior STEMIs who received autologous BMCs or placebo / control as part of 4 randomized clinical trials that included the Cardiovascular Cell Therapy Research Network (CCTRN) TIME trial and its pilot, the multicenter French BONAMI trial and SWISS-AMI trials. A total of 327 patients had paired imaging data at 1 year. All patients received 100 to 150 million intracoronary autologous BMCs or placebo / control 3 to 7 days following primary PCI and stenting. LV function, volumes, infarct size and MVO were assessed prior to infusion of BMCs and 1 year later. Patients with MVO (n = 210) had reduced LVEF and much greater infarct size and LV volumes compared to patients without MVO (n = 146) (P < .01). At 12 months, patients with MVO who received BMCs had significantly greater recovery of LVEF compared to those patients with MVO who received placebo (absolute difference = 2.7%; P < .05). Similarly, left-ventricular end-diastolic (LVEDVI) and end-systolic volume indices (LVESVI) demonstrated significantly less adverse remodeling in patients with MVO who received BMCs compared to placebo. In contrast, no improvement in LVEF or LV volumes was observed in those patients without MVO who received BMCs compared to placebo. CONCLUSIONS: The presence of MVO on cardiac MRI following STEMI identifies a subgroup of patients who benefit from intracoronary stem cell therapy.
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Infarto do Miocárdio , Intervenção Coronária Percutânea , Infarto do Miocárdio com Supradesnível do Segmento ST , Disfunção Ventricular Esquerda , Humanos , Infarto do Miocárdio com Supradesnível do Segmento ST/terapia , Infarto do Miocárdio com Supradesnível do Segmento ST/complicações , Volume Sistólico , Infarto do Miocárdio/complicações , Transplante de Medula Óssea/métodos , Disfunção Ventricular Esquerda/complicações , Resultado do TratamentoRESUMO
Ryanodine receptors are responsible for the massive release of calcium from the sarcoplasmic reticulum that triggers heart muscle contraction. Maurocalcin (MCa) is a 33 amino acid peptide toxin known to target skeletal ryanodine receptor. We investigated the effect of MCa and its analog MCaE12A on isolated cardiac ryanodine receptor (RyR2), and showed that they increase RyR2 sensitivity to cytoplasmic calcium concentrations promoting channel opening and decreases its sensitivity to inhibiting calcium concentrations. By measuring intracellular Ca2+ transients, calcium sparks and contraction on cardiomyocytes isolated from adult rats or differentiated from human-induced pluripotent stem cells, we demonstrated that MCaE12A passively penetrates cardiomyocytes and promotes the abnormal opening of RyR2. We also investigated the effect of MCaE12A on the pacemaker activity of sinus node cells from different mice lines and showed that, MCaE12A improves pacemaker activity of sinus node cells obtained from mice lacking L-type Cav1.3 channel, or following selective pharmacologic inhibition of calcium influx via Cav1.3. Our results identify MCaE12A as a high-affinity modulator of RyR2 and make it an important tool for RyR2 structure-to-function studies as well as for manipulating Ca2+ homeostasis and dynamic of cardiac cells.
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Cálcio/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Venenos de Escorpião/farmacologia , Nó Sinoatrial/efeitos dos fármacos , Potenciais de Ação/efeitos dos fármacos , Animais , Sinalização do Cálcio/efeitos dos fármacos , Citoplasma/efeitos dos fármacos , Citoplasma/metabolismo , Homeostase , Humanos , Masculino , Camundongos , Camundongos Knockout , Miócitos Cardíacos/metabolismo , Células-Tronco Pluripotentes , Ratos , Ratos Wistar , Retículo Sarcoplasmático/efeitos dos fármacos , Retículo Sarcoplasmático/metabolismo , Venenos de Escorpião/química , Nó Sinoatrial/citologia , Nó Sinoatrial/fisiologia , SuínosRESUMO
IKr current, a major component of cardiac repolarization, is mediated by human Ether-à-go-go-Related Gene (hERG, Kv11.1) potassium channels. The blockage of these channels by pharmacological compounds is associated to drug-induced long QT syndrome (LQTS), which is a life-threatening disorder characterized by ventricular arrhythmias and defects in cardiac repolarization that can be illustrated using cardiomyocytes derived from human-induced pluripotent stem cells (hiPS-CMs). This study was meant to assess the modification in hiPS-CMs excitability and contractile properties by BeKm-1, a natural scorpion venom peptide that selectively interacts with the extracellular face of hERG, by opposition to reference compounds that act onto the intracellular face. Using an automated patch-clamp system, we compared the affinity of BeKm-1 for hERG channels with some reference compounds. We fully assessed its effects on the electrophysiological, calcium handling, and beating properties of hiPS-CMs. By delaying cardiomyocyte repolarization, the peptide induces early afterdepolarizations and reduces spontaneous action potentials, calcium transients, and contraction frequencies, therefore recapitulating several of the critical phenotype features associated with arrhythmic risk in drug-induced LQTS. BeKm-1 exemplifies an interesting reference compound in the integrated hiPS-CMs cell model for all drugs that may block the hERG channel from the outer face. Being a peptide that is easily modifiable, it will serve as an ideal molecular platform for the design of new hERG modulators displaying additional functionalities.
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Cálcio/metabolismo , Canal de Potássio ERG1/antagonistas & inibidores , Miócitos Cardíacos/efeitos dos fármacos , Bloqueadores dos Canais de Potássio/farmacologia , Potássio/metabolismo , Venenos de Escorpião/farmacologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Antiarrítmicos/farmacologia , Canais de Cálcio/metabolismo , Diferenciação Celular , Canal de Potássio ERG1/metabolismo , Células HEK293 , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/metabolismo , Transporte de Íons , Síndrome do QT Longo/metabolismo , Síndrome do QT Longo/fisiopatologia , Modelos Biológicos , Miócitos Cardíacos/citologia , Miócitos Cardíacos/metabolismo , Técnicas de Patch-Clamp , Fenetilaminas/farmacologia , Piperidinas/farmacologia , Piridinas/farmacologia , Sulfonamidas/farmacologiaRESUMO
Mesenchymal stem cell (MSC) immunosuppressive functions make them attractive candidates for anti-inflammatory therapy in allergic asthma. However, the mechanisms by which they ensure therapeutic effects remain to be elucidated. In an acute mouse model of house dust mite (Der f)-induced asthma, one i.v. MSC injection was sufficient to normalize and stabilize lung function in Der f-sensitized mice as compared to control mice. MSC injection decreased in vivo airway responsiveness and decreased ex vivo carbachol-induced bronchial contraction, maintaining bronchial expression of the inhibitory type 2 muscarinic receptor. To evaluate in vivo MSC survival, MSCs were labeled with PKH26 fluorescent marker prior to i.v. injection, and 1 to 10 days later total lungs were digested to obtain single-cell suspensions. 91.5 ± 2.3% and 86.6 ± 6.3% of the recovered PKH26(+) lung cells expressed specific macrophage markers in control and Der f mice, respectively, suggesting that macrophages had phagocyted in vivo the injected MSCs. Interestingly, only PKH26(+) macrophages expressed M2 phenotype, while the innate PKH26(-) macrophages expressed M1 phenotype. Finally, the remaining 0.5% PKH26(+) MSCs expressed 10- to 100-fold more COX-2 than before injection, suggesting in vivo MSC phenotype modification. Together, the results of this study indicate that MSCs attenuate asthma by being phagocyted by lung macrophages, which in turn acquire a M2 suppressive phenotype. Stem Cells 2016;34:1836-1845.
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Asma/patologia , Macrófagos/metabolismo , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais/metabolismo , Fagocitose , Animais , Asma/complicações , Asma/fisiopatologia , Broncoconstrição , Polaridade Celular , Modelos Animais de Doenças , Hipersensibilidade/complicações , Hipersensibilidade/patologia , Hipersensibilidade/fisiopatologia , Inflamação/complicações , Inflamação/patologia , Inflamação/fisiopatologia , Injeções Intravenosas , Pulmão/patologia , Camundongos Endogâmicos BALB C , Fenótipo , Pyroglyphidae/fisiologia , Hipersensibilidade Respiratória/complicações , Hipersensibilidade Respiratória/patologia , Hipersensibilidade Respiratória/fisiopatologiaRESUMO
RATIONALE: The meta-Analysis of Cell-based CaRdiac study is the first prospectively declared collaborative multinational database, including individual data of patients with ischemic heart disease treated with cell therapy. OBJECTIVE: We analyzed the safety and efficacy of intracoronary cell therapy after acute myocardial infarction (AMI), including individual patient data from 12 randomized trials (ASTAMI, Aalst, BOOST, BONAMI, CADUCEUS, FINCELL, REGENT, REPAIR-AMI, SCAMI, SWISS-AMI, TIME, LATE-TIME; n=1252). METHODS AND RESULTS: The primary end point was freedom from combined major adverse cardiac and cerebrovascular events (including all-cause death, AMI recurrance, stroke, and target vessel revascularization). The secondary end point was freedom from hard clinical end points (death, AMI recurrence, or stroke), assessed with random-effects meta-analyses and Cox regressions for interactions. Secondary efficacy end points included changes in end-diastolic volume, end-systolic volume, and ejection fraction, analyzed with random-effects meta-analyses and ANCOVA. We reported weighted mean differences between cell therapy and control groups. No effect of cell therapy on major adverse cardiac and cerebrovascular events (14.0% versus 16.3%; hazard ratio, 0.86; 95% confidence interval, 0.63-1.18) or death (1.4% versus 2.1%) or death/AMI recurrence/stroke (2.9% versus 4.7%) was identified in comparison with controls. No changes in ejection fraction (mean difference: 0.96%; 95% confidence interval, -0.2 to 2.1), end-diastolic volume, or systolic volume were observed compared with controls. These results were not influenced by anterior AMI location, reduced baseline ejection fraction, or the use of MRI for assessing left ventricular parameters. CONCLUSIONS: This meta-analysis of individual patient data from randomized trials in patients with recent AMI revealed that intracoronary cell therapy provided no benefit, in terms of clinical events or changes in left ventricular function. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01098591.
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Transplante de Medula Óssea , Infarto do Miocárdio/cirurgia , Miocárdio/patologia , Regeneração , Função Ventricular Esquerda , Idoso , Transplante de Medula Óssea/efeitos adversos , Transplante de Medula Óssea/mortalidade , Transtornos Cerebrovasculares/etiologia , Transtornos Cerebrovasculares/mortalidade , Distribuição de Qui-Quadrado , Bases de Dados Factuais , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Modelos de Riscos Proporcionais , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Recuperação de Função Fisiológica , Recidiva , Fatores de Risco , Volume Sistólico , Fatores de Tempo , Resultado do Tratamento , Remodelação VentricularRESUMO
PURPOSE: Cardiac cell therapy is a promising treatment for acute myocardial infarction (AMI), leading to cardiac function improvement. However, whether it translates into quality of life (QoL) improvement is unclear. We hypothesized that administration of bone marrow cells (BMC) to patients with AMI improves QoL. METHODS: In the multicenter BONAMI trial (NCT00200707), patients with reperfused AMI and decreased myocardial viability were randomized to intracoronary autologous BMC infusion (n = 52) or state-of-the-art therapy (n = 49). QoL data, derived from the Minnesota Living with Heart Failure questionnaire (MLHFQ), were obtained 1, 3, and 12 months after AMI and analyzed using a Rasch-family model. RESULTS: Using this model, QoL improved over time in the BMC group (p = 0.025) but not in the control group. Furthermore, the BMC-group patients displayed a better QoL than the control-group patients at 3 and 12 months post-AMI (p = 0.034 and p = 0.003, respectively). These findings were not detected when analyzing MLHFQ data using a standard method. Cardiac function, myocardial viability, mortality, and number of major adverse cardiac events did not differ between treatment groups. CONCLUSION: Our results suggest that BMC therapy can improve QoL, stressing the need for confirmation trials and for systematic QoL assessment in cardiac cell therapy trials .
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Células da Medula Óssea/metabolismo , Infarto do Miocárdio/psicologia , Perfil de Impacto da Doença , Doença Aguda , Células da Medula Óssea/citologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Resultado do TratamentoRESUMO
Patients with HIV present with a higher prevalence of QT prolongation, of which molecular bases are still not clear. Among HIV proteins, Tat serves as a transactivator that stimulates viral genes expression and is required for efficient HIV replication. Tat is actively secreted into the blood by infected T-cells and affects organs such as the heart. Tat has been shown to alter cardiac repolarization in animal models but how this is mediated and whether this is also the case in human cells is unknown. In the present study, we show that Tat transfection in heterologous expression systems led to a decrease in hERG (underlying cardiac IKr) and human KCNE1-KCNQ1 (underlying cardiac IKs) currents and to an acceleration of their deactivation. This is consistent with a decrease in available phosphatidylinositol-(4,5)-bisphosphate (PIP2). A mutant Tat, unable to bind PIP2, did not reproduce the observed effects. In addition, WT-Tat had no effect on a mutant KCNQ1 which is PIP2-insensitive, further confirming the hypothesis. Twenty-four-hour incubation of human induced pluripotent stem cells-derived cardiomyocytes with Wild-type Tat reduced IKr and accelerated its deactivation. Concordantly, this Tat incubation led to a prolongation of the action potential (AP) duration. Events of AP alternans were also recorded in the presence of Tat, and were exacerbated at a low pacing cycle length. Altogether, these data obtained on human K+ channels both in heterologous expression systems and in human cardiomyocytes suggest that Tat sequesters PIP2, leading to a reduction of IKr and IKs, and provide a molecular mechanism for QT prolongation in HIV-infected patients.
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Potenciais de Ação , Fosfatidilinositol 4,5-Difosfato/metabolismo , Produtos do Gene tat do Vírus da Imunodeficiência Humana/metabolismo , Animais , Células COS , Diferenciação Celular , Linhagem Celular , Canal de Potássio ERG1/metabolismo , Fenômenos Eletrofisiológicos , Expressão Gênica , Células HEK293 , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Canal de Potássio KCNQ1/metabolismo , Miócitos Cardíacos/citologia , Miócitos Cardíacos/fisiologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Transfecção , Produtos do Gene tat do Vírus da Imunodeficiência Humana/genéticaRESUMO
PURPOSE: Few data are available regarding the relation of left ventricular (LV) mechanical dyssynchrony to remodelling after acute myocardial infarction (MI) and stem cell therapy. We evaluated the 1-year time course of both LV mechanical dyssynchrony and remodelling in patients enrolled in the BONAMI trial, a randomized, multicenter controlled trial assessing cell therapy in patients with reperfused MI. METHODS: Patients with acute MI and ejection fraction (EF) ≤ 45 % were randomized to cell therapy or to control and underwent thallium single-photon emission computed tomography (SPECT), radionuclide angiography, and echocardiography at baseline, 3 months, and 1 year. Eighty-three patients with a comprehensive 1-year follow-up were included. LV dyssynchrony was assessed by the standard deviation (SD) of the LV phase histogram using radionuclide angiography. Remodelling was defined as a 20 % increase in LV end-systolic volume index (LVESVI) at 1 year. RESULTS: At baseline, LVEF, wall motion score index, and perfusion defect size were significantly impaired in the 43 patients (52 %) with LV remodelling (all p < 0.001), without significant increase in LV mechanical dyssynchrony. During follow-up, there was a progressive increase in LV SD (p = 0.01). Baseline independent predictors of LV remodelling were perfusion SPECT defect size (p = 0.001), LVEF (p = 0.01) and a history of hypertension (p = 0.043). Bone marrow cell therapy did not affect the time-course of LV remodelling and dyssynchrony. CONCLUSIONS: LV remodelling 1 year after reperfused MI is associated with progressive LV dyssynchrony and is related to baseline infarct size and ejection fraction, without impact of cell therapy on this process.
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Transplante de Medula Óssea/efeitos adversos , Infarto do Miocárdio/terapia , Imagem de Perfusão do Miocárdio , Tomografia Computadorizada de Emissão de Fóton Único , Disfunção Ventricular Esquerda , Remodelação Ventricular , Adulto , Idoso , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico por imagem , Compostos Radiofarmacêuticos , Radioisótopos de TálioRESUMO
AIMS: The objective of the present analysis was to systematically examine the effect of intracoronary bone marrow cell (BMC) therapy on left ventricular (LV) function after ST-segment elevation myocardial infarction in various subgroups of patients by performing a collaborative meta-analysis of randomized controlled trials. METHODS AND RESULTS: We identified all randomized controlled trials comparing intracoronary BMC infusion as treatment for ST-segment elevation myocardial infarction. We contacted the principal investigator for each participating trial to provide summary data with regard to different pre-specified subgroups [age, diabetes mellitus, time from symptoms to percutaneous coronary intervention, infarct-related artery, LV end-diastolic volume index (EDVI), LV ejection fraction (EF), infarct size, presence of microvascular obstruction, timing of cell infusion, and injected cell number] and three different endpoints [change in LVEF, LVEDVI, and LV end-systolic volume index (ESVI)]. Data from 16 studies were combined including 1641 patients (984 cell therapy, 657 controls). The absolute improvement in LVEF was greater among BMC-treated patients compared with controls: [2.55% increase, 95% confidence interval (CI) 1.83-3.26, P < 0.001]. Cell therapy significantly reduced LVEDVI and LVESVI (-3.17 mL/m², 95% CI: -4.86 to -1.47, P < 0.001; -2.60 mL/m², 95% CI -3.84 to -1.35, P < 0.001, respectively). Treatment benefit in terms of LVEF improvement was more pronounced in younger patients (age <55, 3.38%, 95% CI: 2.36-4.39) compared with older patients (age ≥ 55 years, 1.77%, 95% CI: 0.80-2.74, P = 0.03). This heterogeneity in treatment effect was also observed with respect to the reduction in LVEDVI and LVESVI. Moreover, patients with baseline LVEF <40% derived more benefit from intracoronary BMC therapy. LVEF improvement was 5.30%, 95% CI: 4.27-6.33 in patients with LVEF <40% compared with 1.45%, 95% CI: 0.60 to 2.31 in LVEF ≥ 40%, P < 0.001. No clear interaction was observed between other subgroups and outcomes. CONCLUSION: Intracoronary BMC infusion is associated with improvement of LV function and remodelling in patients after ST-segment elevation myocardial infarction. Younger patients and patients with a more severely depressed LVEF at baseline derived most benefit from this adjunctive therapy.
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Transplante de Medula Óssea/métodos , Infarto do Miocárdio/terapia , Adulto , Idoso , Volume Cardíaco/fisiologia , Humanos , Pessoa de Meia-Idade , Infarto do Miocárdio/fisiopatologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Volume Sistólico/fisiologia , Resultado do Tratamento , Disfunção Ventricular Esquerda/fisiopatologia , Disfunção Ventricular Esquerda/terapia , Função Ventricular Esquerda/fisiologiaRESUMO
AIMS: Intracoronary administration of autologous bone marrow cells (BMCs) leads to a modest improvement in cardiac function, but the effect on myocardial viability is unknown. The aim of this randomized multicentre study was to evaluate the effect of BMC therapy on myocardial viability in patients with decreased left ventricular ejection fraction (LVEF) after acute myocardial infarction (AMI) and to identify predictive factors for improvement of myocardial viability. METHODS AND RESULTS: One hundred and one patients with AMI and successful reperfusion, LVEF ≤45%, and decreased myocardial viability (resting Tl201-SPECT) were randomized to either a control group (n = 49) or a BMC group (n = 52). Primary endpoint was improvement of myocardial viability 3 months after AMI. Baseline mean LVEF measured by radionuclide angiography was 36.3 ± 6.9%. Bone marrow cell infusion was performed 9.3 ± 1.7 days after AMI. Myocardial viability improved in 16/47 (34%) patients in the BMC group compared with 7/43 (16%) in the control group (P = 0.06). The number of non-viable segments becoming viable was 0.8 ± 1.1 in the control group and 1.2 ± 1.5 in the BMC group (P = 0.13). Multivariate analysis including major post-AMI prognostic factors showed a significant improvement of myocardial viability in BMC vs. control group (P = 0.03). Moreover, a significant adverse role for active smoking (P = 0.04) and a positive trend for microvascular obstruction (P = 0.07) were observed. CONCLUSION: Intracoronary autologous BMC administration to patients with decreased LVEF after AMI was associated with improvement of myocardial viability in multivariate-but not in univariate-analysis. A large multicentre international trial is warranted to further document the efficacy of cardiac cell therapy and better define a group of patients that will benefit from this therapy. CLINICAL TRIAL REGISTRATION INFORMATION: URL: http://www.clinicaltrials.gov. Unique identifier NCT00200707.
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Transplante de Medula Óssea/métodos , Leucócitos Mononucleares/transplante , Infarto do Miocárdio/terapia , Adolescente , Adulto , Idoso , Angiografia Coronária , Vasos Coronários , Feminino , Humanos , Angiografia por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Volume Sistólico/fisiologia , Tomografia Computadorizada de Emissão de Fóton Único , Transplante Autólogo , Resultado do Tratamento , Disfunção Ventricular Esquerda/patologia , Disfunção Ventricular Esquerda/fisiopatologia , Adulto JovemRESUMO
Catecholamine-induced QT prolongation (CIQTP) is an inherited cardiac disease characterized by a normal baseline ECG and a risk of sudden cardiac death by ventricular arrhythmia due to a QT prolongation that only appears during catecholergic stimulation, especially mental stress. Induced pluripotent stem cells (hiPSCs) were generated from peripheral blood mononuclear cells collected from two CIQTP-affected patients from two different families. These two hiPSC lines are a valuable model to study biological alterations due to CIQTP.
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Human heart development is governed by transcription factor (TF) networks controlling dynamic and temporal gene expression alterations. Therefore, to comprehensively characterize these transcriptional regulations, day-to-day transcriptomic profiles were generated throughout the directed cardiac differentiation, starting from three distinct human- induced pluripotent stem cell lines from healthy donors (32 days). We applied an expression-based correlation score to the chronological expression profiles of the TF genes, and clustered them into 12 sequential gene expression waves. We then identified a regulatory network of more than 23,000 activation and inhibition links between 216 TFs. Within this network, we observed previously unknown inferred transcriptional activations linking IRX3 and IRX5 TFs to three master cardiac TFs: GATA4, NKX2-5 and TBX5. Luciferase and co-immunoprecipitation assays demonstrated that these five TFs could (1) activate each other's expression; (2) interact physically as multiprotein complexes; and (3) together, finely regulate the expression of SCN5A, encoding the major cardiac sodium channel. Altogether, these results unveiled thousands of interactions between TFs, generating multiple robust hypotheses governing human cardiac development.
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Redes Reguladoras de Genes , Coração , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica , Diferenciação Celular/genéticaRESUMO
Studies on animal models have shown that Irx5 is an important regulator of cardiac development and that it regulates ventricular electrical repolarization gradient in the adult heart. Mutations in IRX5 have also been linked in humans to cardiac conduction defects. In order to fully characterize the role of IRX5 during cardiac development and in cardiomyocyte function, we generated three genetically-modified human induced pluripotent stem cell lines: two knockout lines (heterozygous and homozygous) and a knockin HA-tagged line (homozygous).
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Células-Tronco Pluripotentes Induzidas , Animais , Sistemas CRISPR-Cas/genética , Heterozigoto , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Homozigoto , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Miócitos Cardíacos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is an exercise and emotional stress-induced life-threatening inherited heart rhythm disorder, characterized by an abnormal cellular calcium homeostasis. Most reported cases have been linked to mutations in the gene encoding the type 2 ryanodine receptor gene, RYR2. We generated induced pluripotent stem cells (hiPSCs) from peripheral blood mononuclear cells (PBMC) from three CPVT-affected patients, two of them carrying p.R4959Q mutation and one carrying p.Y2476D mutation. These generated hiPSC lines are a useful model to study pathophysiological consequences of RYR2 dysfunction in humans and the molecular basis of CPVT.
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Células-Tronco Pluripotentes Induzidas , Cálcio/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Leucócitos Mononucleares/metabolismo , Mutação/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Taquicardia VentricularRESUMO
Four human induced pluripotent stem cell (hiPSC) lines have been generated from healthy control European donors, and validated. This resource represents a useful tool for stem cell-based research, as references for developmental studies and disease modeling linked to any type of human tissue and organ, in an ethnical-, sex- and age-matched context. They providea reliable in-vitro model for single cell- and tissue-based investigations, and are also a valuable tool for genome editing-based studies.
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INTRODUCTION: COVID-19 sequelae are numerous and multisystemic, and how to evaluate those symptomatic patients is a timely issue. Klok et al proposed the Post-COVID-19 Functional Status (PCFS) Scale as an easy tool to evaluate limitations related to persistent symptoms. Our aim was to analyse PCFS Scale ability to detect functional limitations and its correlation with quality of life in a cohort of patients, 2-9 months after hospitalisation for COVID-19 hypoxemic pneumonia. METHODS: PCFS Scale was evaluated in 121 patients together with quality of life and dyspnoea questionnaires, pulmonary function tests and CT scans. RESULTS: We observed a high correlation with multiple questionnaires (Short Form-36, Hospital Anxiety and Depression Scale, modified Medical Research Council, end Borg Six-Minute Walk Test), making the PCFS Scale a quick and global tool to evaluate functional limitations related to various persistent symptoms following COVID-19 pneumonia. DISCUSSION: The PCFS Scale seems to be a suitable instrument to screen for patients who will require careful follow-up after COVID-19 hypoxemic pneumonia even in the absence of pulmonary sequelae.
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COVID-19 , Pneumonia , COVID-19/complicações , Estado Funcional , Humanos , Pneumonia/diagnóstico , Qualidade de Vida , SARS-CoV-2RESUMO
AIMS: Several inherited arrhythmic diseases have been linked to single gene mutations in cardiac ion channels and interacting proteins. However, the mechanisms underlying most arrhythmias, are thought to involve altered regulation of the expression of multiple effectors. In this study, we aimed to examine the role of a transcription factor (TF) belonging to the Iroquois homeobox family, IRX5, in cardiac electrical function. METHODS AND RESULTS: Using human cardiac tissues, transcriptomic correlative analyses between IRX5 and genes involved in cardiac electrical activity showed that in human ventricular compartment, IRX5 expression strongly correlated to the expression of major actors of cardiac conduction, including the sodium channel, Nav1.5, and Connexin 40 (Cx40). We then generated human-induced pluripotent stem cells (hiPSCs) derived from two Hamamy syndrome-affected patients carrying distinct homozygous loss-of-function mutations in IRX5 gene. Cardiomyocytes derived from these hiPSCs showed impaired cardiac gene expression programme, including misregulation in the control of Nav1.5 and Cx40 expression. In accordance with the prolonged QRS interval observed in Hamamy syndrome patients, a slower ventricular action potential depolarization due to sodium current reduction was observed on electrophysiological analyses performed on patient-derived cardiomyocytes, confirming the functional role of IRX5 in electrical conduction. Finally, a cardiac TF complex was newly identified, composed by IRX5 and GATA4, in which IRX5 potentiated GATA4-induction of SCN5A expression. CONCLUSION: Altogether, this work unveils a key role for IRX5 in the regulation of human ventricular depolarization and cardiac electrical conduction, providing therefore new insights into our understanding of cardiac diseases.
Assuntos
Potenciais de Ação , Arritmias Cardíacas/genética , Doenças Ósseas/genética , Ventrículos do Coração/metabolismo , Proteínas de Homeodomínio/genética , Hipertelorismo/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Deficiência Intelectual/genética , Mutação com Perda de Função , Miócitos Cardíacos/metabolismo , Miopia/genética , Fatores de Transcrição/genética , Animais , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/fisiopatologia , Doenças Ósseas/metabolismo , Doenças Ósseas/fisiopatologia , Células Cultivadas , Conexinas/genética , Conexinas/metabolismo , Fator de Transcrição GATA4/genética , Fator de Transcrição GATA4/metabolismo , Frequência Cardíaca , Proteínas de Homeodomínio/metabolismo , Humanos , Hipertelorismo/metabolismo , Hipertelorismo/fisiopatologia , Deficiência Intelectual/metabolismo , Deficiência Intelectual/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Miopia/metabolismo , Miopia/fisiopatologia , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Canal de Sódio Disparado por Voltagem NAV1.5/metabolismo , Fatores de Transcrição/metabolismo , Transcriptoma , Proteína alfa-5 de Junções ComunicantesRESUMO
Cell-based therapies have great potential for the treatment of cardiovascular diseases. Recently, using a transgenic mouse model Roell et al. reported that cardiac engraftment of connexin43 (Cx43)-overexpressing myoblasts in vivo prevents post-infarct arrhythmia, a common cause of death in patients following heart attack. We carried out a similar study but in a clinically relevant context via transplantation of autologous connexin43-overexpressing myoblasts in infarcted rats. Seven days after coronary ligation, rats were randomized into three groups: a control group injected with myoblasts, a null group injected with myoblasts transduced with an empty lentivirus vector (null) and a Cx43 group injected with myoblasts transduced with a lentivirus vector encoding connexin43. In contrast to Roell's report, arrhythmia occurrence was not statistically different between groups (58%, 64% and 48% for the control (n= 12), null (n= 14) and Cx43 (n= 23) groups, respectively, P= 0.92). Using ex vivo intramural monophasic action potential recordings synchronous electrical activity was observed between connexin43-overexpressing myoblasts and host cardiomyocytes, whereas such synchrony did not occur in the null-transduced group. This suggests that ex vivo connexin43 gene transfer and expression in myoblasts improved intercellular electrical coupling between myoblasts and cardiomyocytes. However, in our model such electrical coupling was not sufficient to decrease arrhythmia induction. Therefore, we would suggest a note of caution on the use of combined Cx43 gene and cell therapy to prevent post-infarct arrhythmias in heart failure patients.
Assuntos
Arritmias Cardíacas/patologia , Conexina 43/biossíntese , Regulação da Expressão Gênica , Ventrículos do Coração/metabolismo , Mioblastos Esqueléticos/citologia , Potenciais de Ação , Animais , Modelos Animais de Doenças , Citometria de Fluxo , Técnicas de Transferência de Genes , Insuficiência Cardíaca/patologia , Masculino , Mioblastos Esqueléticos/metabolismo , Infarto do Miocárdio/patologia , Ratos , Ratos WistarRESUMO
Long-term survivors after allogeneic hematopoietic stem cell transplantation (allo-HSCT) are at high risk for treatment-related adverse events, that may worsen physical capacity and may induce fatigue and disability. The aims of this prospective study were to evaluate exercise capacity in allotransplant survivors and its relationship with fatigue and disability. Patient-reported outcomes and exercise capacity were evaluated in 71 non-relapse patients 1 year after allo-HSCT, using validated questionnaires, cardiopulmonary exercise testing (CPET) with measure of peak oxygen uptake (peakVO2) and deconditioning, pulmonary function testing, echocardiography and 6-min walk test. A high proportion (75.4%) of allo-HSCT survivors showed abnormal cardiopulmonary exercise testing parameters as compared to predicted normal values, including 49.3% patients who exhibited moderate to severe impairment in exercise capacity and 37.7% patients with physical deconditioning. PeakVO2 values were not accurately predicted by 6-min walk distances (r = 0.53). Disability and fatigue were strongly associated with decreased peakVO2 values (p = 0.002 and p = 0.008, respectively). Exercise capacity was reduced in most allo-HSCT long-term survivors. Because reduced exercise capacity was associated with fatigue, disability and a decrease in quality of life, cardiopulmonary exercise testing should be performed in every patient who reports fatigue and disability.
Assuntos
Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Sobreviventes , Adulto , Idoso , Exercício Físico , Teste de Esforço , Fadiga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , Testes de Função Respiratória , Inquéritos e Questionários , Transplante Homólogo/efeitos adversos , Adulto JovemRESUMO
BACKGROUND: Small scale clinical trials suggested the feasibility and the efficacy of autologous myoblast transplantation to improve ventricular function after myocardial infarction. However, these trials were hampered by unexpected episodes of life-threatening ventricular tachyarrhythmias (VT). We investigated cardiac electrical stability after myoblast transplantation to the myocardium. METHODS AND RESULTS: Seven days after coronary ligation, Wistar rats were randomized into 3 groups: a control group receiving no further treatment, a vehicle group injected with culture medium into the infarcted myocardium, and a myoblast group injected with autologous myoblasts. Holter monitoring did not discriminate the myoblast from the vehicle groups. Programmed Electrical Stimulation (PES) was performed to evaluate further a cardiac substrate for arrhythmia susceptibility. The occurrence of sustained VT during PES was similar in control and vehicle groups (5/17 and 4/19 rats, respectively; p=0.50). In contrast, 13/20 rats (65%) from the myoblast group showed at least one episode of sustained VT during PES (p<0.05 and p<0.005 versus control and vehicle groups). As a further control group, rats injected with autologous bone marrow mononuclear cells into the infarcted myocardium did not show increased susceptibility to PES. CONCLUSIONS: In an infarcted rat model, myoblast transplantation but not bone marrow mononuclear cells or myocardial injection per se induces electrical ventricular instability. Because ventricular arrhythmias are life-threatening disorders, we suggest that such preclinical evaluation should be conducted for any new source of cells to be injected into the myocardium.