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BACKGROUND: Percutaneous coronary intervention (PCI) for calcified coronary artery remains challenging in the drug-eluting stent (DES) era. While recent studies reported the efficacy of orbital atherectomy (OA) combined with DES for calcified lesion, the effectiveness of drug-coated balloon (DCB) following OA has not been fully elucidated. METHODS: Between June 2018 and June 2021, 135 patients who received PCI for calcified de novo coronary lesions with OA were enrolled and divided into two groups; OA followed by DCB (n = 43) if the target lesion achieved acceptable preparation, or second- or third-generation DESs (n = 92) if the target lesion showed suboptimal preparation between June 2018 and June 2021. All patients underwent PCI with optical coherence tomography (OCT) imaging. The primary endpoint was 1-year major adverse cardiac event (MACE), that was a composite of cardiac death, nonfatal myocardial infarction, or target lesion revascularization. RESULTS: Mean age was 73 years and 82% was male. In OCT analysis, maximum calcium plaque was thicker (median: 1050 µm [interquartile range (IQR): 945-1175 µm] vs. 960 µm [808-1100 µm], p = 0.017), calcification arc tended to larger (median: 265° [IQR: 209-360°] vs. 222° [162-305°], p = 0.058) in patients with DCB than in DES, and the postprocedure minimum lumen area was smaller in DCB compared with minimum stent area in DES (median: 3.83 mm2 [IQR: 3.30-4.52 mm2 ] vs. 4.86 mm2 [4.05-5.82 mm2 ], p < 0.001). However, 1 year MACE free rate was not significantly different between 2 groups (90.3% in DCB vs. 96.6% in DES, log-rank p = 0.136). In the subgroup analysis of 14 patients who underwent follow-up OCT imaging, late lumen area loss was lower in patients with DCB than DES, despite lower lesion expansion rate in DCB than DES. CONCLUSIONS: In calcified coronary artery disease, DCB alone strategy (if acceptable lesion preparation was performed with OA) was feasible compared with DES following OA with respect to 1-year clinical outcomes. Our finding indicated using DCB with OA might be reduce late lumen area loss for severe calcified lesion.
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Aterectomia Coronária , Doença da Artéria Coronariana , Stents Farmacológicos , Intervenção Coronária Percutânea , Humanos , Masculino , Idoso , Intervenção Coronária Percutânea/efeitos adversos , Tomografia de Coerência Óptica , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/cirurgia , Resultado do Tratamento , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Doença da Artéria Coronariana/etiologia , Aterectomia , Aterectomia Coronária/efeitos adversosRESUMO
BACKGROUND: The efficacy of direct oral anticoagulants (DOACs) compared with warfarin for the treatment of venous thromboembolism (VTE), and the recurrence of VTE after discontinuation of anticoagulation therapy in research are limited.MethodsâandâResults: This retrospective study enrolled 893 patients with acute VTE between 2011 and 2019. The cohort was divided into the transient risk, unprovoked, continued cancer treatment, and cancer remission groups. The following were compared between DOACs and warfarin: composite outcome of all-cause death, VTE recurrence, bleeding and composite outcome of VTE-related death, recurrence and bleeding. In the continued cancer treatment group, more bleeding was seen in warfarin-treated patients than in patients treated with DOACs (53.2% vs. 31.2%, [P=0.048]). In addition, composite outcome of VTE-related death and recurrence after discontinuation of anticoagulation therapy (n=369) was evaluated. The continued cancer treatment group (multivariate analysis: HR: 3.62, 95% CI: 1.84-7.12, P<0.005) and bleeding-related discontinuation of therapy (HR: 2.60, 95% CI: 1.32-5.13, P=0.006) were independent predictors of the event after discontinuation of anticoagulation therapy. VTE recurrence after discontinuation of anticoagulation therapy in the cancer remission group was 1.6% and a statistically similar occurrence was found in the transient risk group (12.4%) (P=0.754). CONCLUSIONS: DOACs may decrease bleeding incidence in patients continuing to receive cancer treatment. In patients with bleeding-related discontinuation of anticoagulation therapy, VTE recurrence may increase. Discontinuation of anticoagulant therapy might be a treatment option in patients who have completed their cancer treatment.
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Tromboembolia Venosa , Trombose Venosa , Administração Oral , Anticoagulantes/uso terapêutico , Hemorragia/induzido quimicamente , Humanos , Recidiva , Estudos Retrospectivos , Tromboembolia Venosa/tratamento farmacológico , Tromboembolia Venosa/epidemiologia , Trombose Venosa/tratamento farmacológico , Varfarina/uso terapêuticoRESUMO
BACKGROUND AND AIMS: The nutritional risk of patients who undergo atrial fibrillation (AF) ablation varies. Its impact on the recurrence after ablation is unclear. We sought to evaluate the relationship between the nutritional risk and arrhythmia recurrence in patients who undergo AF ablation. METHODS AND RESULTS: We enrolled 538 patients (median 67 years, 69.9% male) who underwent their first AF ablation. Their nutritional risk was evaluated using the pre-procedural geriatric nutritional risk index (GNRI), and the patients were classified into two groups: No-nutritional risk (GNRI ⧠98) and Nutritional risk (GNRI < 98). The primary endpoint was a recurrence of an arrhythmia, and its relationship to the nutritional risk was evaluated. We used propensity-score matching to adjust for differences between patients with a GNRI-based nutritional risk and those without a nutritional risk. A nutritional risk was found in 10.6% of the patients, whereas the remaining 89.4% had no-nutritional risk. During a mean follow-up of 422 days, 91 patients experienced arrhythmia recurrences. The patients with a nutritional risk had a significantly higher arrhythmia recurrence rate both in the entire study cohort (Log-rank p = 0.001) and propensity-matched cohort (Log-rank p = 0.006). In a Cox proportional hazard analysis, the nutritional risk independently predicted arrhythmia recurrences in the entire study cohort (hazard ratio [HR]: 3.91, 95% confidence interval [CI]: 1.84-8.35, p < 0.001) and propensity-matched cohort (HR: 6.49, 95% CI: 1.42-29.8, p = 0.016). CONCLUSION: A pre-procedural malnutrition risk was significantly associated with increased arrhythmia recurrences in patients who underwent AF ablation.
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Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Criocirurgia/efeitos adversos , Avaliação Geriátrica , Desnutrição/diagnóstico , Avaliação Nutricional , Estado Nutricional , Veias Pulmonares/cirurgia , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Feminino , Humanos , Masculino , Desnutrição/complicações , Desnutrição/fisiopatologia , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Veias Pulmonares/fisiopatologia , Recidiva , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do TratamentoRESUMO
Mycotic aneurysms are sometimes seen in patients with infective endocarditis. We report a case of infective endocarditis with multiple mycotic aneurysms. Although antibiotics were effective, mycotic aneurysms appeared in the cerebral, hepatic, and gastroepiploic arteries. A 55-year-old man presented with mitral valve endocarditis due to Streptococcus oralis. Surgical treatment was deferred because of cerebral hemorrhage. After antibiotic initiation, his fever and C-reactive protein levels declined, and blood culture was negative. However, he experienced repeated cerebral hemorrhage and the number of cerebral mycotic aneurysms increased. Additionally, his spleen ruptured and the number of mycotic aneurysms in the hepatic and gastroepiploic arteries increased. After embolization for mycotic aneurysm and mitral valve replacement, no mycotic aneurysms appeared. Regardless of whether laboratory data improve or not, multiple mycotic aneurysms sometimes appear, and cardiac surgery for infection control should be considered in the early phase.
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Aneurisma Infectado , Endocardite Bacteriana , Endocardite , Aneurisma Intracraniano , Endocardite/complicações , Endocardite/tratamento farmacológico , Endocardite Bacteriana/tratamento farmacológico , Humanos , Aneurisma Intracraniano/complicações , Masculino , Pessoa de Meia-IdadeRESUMO
Mammalian cardiomyocytes withdraw from the cell cycle shortly after birth, although it remains unclear how cardiomyocyte cell cycles behave during development. Compared to conventional immunohistochemistry in static observation, time-lapse imaging can reveal comprehensive data in hard-to-understand biological phenomenon. However, there are no reports of an established protocol of successful time-lapse imaging in mammalian heart. Thus, it is valuable to establish a time-lapse imaging system to enable the observation of cell cycle dynamics in living murine cardiomyocytes. This study sought to establish time-lapse imaging of murine heart to study cardiomyocyte cell cycle behavior. The Fucci (fluorescent ubiquitination-based cell cycle indicator) system can effectively label individual G1, S/G2/M, and G1/S-transition phase nuclei red, green and yellow, respectively, in living mammalian cells, and could therefore be useful to visualize the real-time cell cycle transitions in living murine heart. To establish a similar system for time-lapse imaging of murine heart, we first developed an ex vivo culture system, with the culture conditions determined in terms of sample state, serum concentration, and oxygen concentration. The optimal condition (slice culture, oxygen concentration 20%, serum concentration 10%) successfully mimicked physiological cardiomyocyte proliferation in vivo. Time-lapse imaging of cardiac slices from E11.5, E14.5, E18.5, and P1 Fucci-expressing transgenic mice revealed an elongated S/G2/M phase in cardiomyocytes during development. Our time-lapse imaging of murine heart revealed a gradual elongation of the S/G2/M phase during development in living cardiomyocytes.
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Ciclo Celular/fisiologia , Desenvolvimento Embrionário/fisiologia , Miócitos Cardíacos/citologia , Imagem com Lapso de Tempo , Animais , Proliferação de Células , Embrião de Mamíferos , Feminino , Corantes Fluorescentes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microscopia de Fluorescência/métodos , Miócitos Cardíacos/fisiologia , Gravidez , Técnicas de Cultura de Tecidos , UbiquitinaçãoRESUMO
BACKGROUND: There are limited data about determinant factors of target lesion failure (TLF) in lesions after percutaneous coronary intervention (PCI) using a drug-coated balloon (DCB) for de novo coronary artery lesions, including optical coherence tomography (OCT) findings. AIMS: The present study aims to investigate the associated factors of TLF in de novo coronary artery lesions with DCB treatment. METHODS: We retrospectively enrolled 328 de novo coronary artery lesions in 328 patients who had undergone PCI with a DCB. All lesions had been treated without a stent, and both pre- and post-PCI OCT had been carried out. Patients were divided into two groups, with or without TLF, which was defined as a composite of culprit lesion-related cardiac death, myocardial infarction, and target lesion revascularisation, and the associated factors of TLF were assessed. RESULTS: At the median follow-up period of 460 days, TLF events occurred in 31 patients (9.5%) and were associated with patients requiring haemodialysis (HD; 29.0% vs 10.8%), with a severely calcified lesion (median maximum calcium arc 215° vs 104°), and with the absence of OCT medial dissection (16.1% vs 60.9%) as opposed to those without TLF events. In Cox multivariable logistic regression analysis, HD (hazard ratio [HR]: 2.26, 95% confidence interval [CI]: 1.00-5.11; p=0.049), maximum calcium arc (per 90°, HR: 1.34, 95% CI: 1.05-1.72; p=0.02), and the absence of post-PCI medial dissection on OCT (HR: 8.24, 95% CI: 3.15-21.6; p<0.001) were independently associated with TLF. CONCLUSIONS: In de novo coronary artery lesions that received DCB treatment, factors associated with TLF were being on HD, the presence of a severely calcified lesion, and the absence of post-PCI medial dissection.
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Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Tomografia de Coerência Óptica , Humanos , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Doença da Artéria Coronariana/terapia , Doença da Artéria Coronariana/diagnóstico por imagem , Estudos Retrospectivos , Intervenção Coronária Percutânea/efeitos adversos , Intervenção Coronária Percutânea/instrumentação , Intervenção Coronária Percutânea/métodos , Angioplastia Coronária com Balão/instrumentação , Angioplastia Coronária com Balão/efeitos adversos , Angioplastia Coronária com Balão/métodos , Fatores de Risco , Resultado do Tratamento , Vasos Coronários/diagnóstico por imagem , Stents Farmacológicos , Infarto do Miocárdio/etiologiaRESUMO
PURPOSE: The association between the extent of the wire and device bias as assessed by optical coherence tomography (OCT) in the healthy portion of the vessel and the risk of coronary artery injury after orbital atherectomy (OA) has not been fully elucidated. Thus, purpose of this study is to investigate the association between pre-OA OCT findings and post-OA coronary artery injury by OCT. METHODS: We enrolled 148 de novo lesions having calcified lesion required OA (max Ca angle > 90°) in 135 patients who underwent both pre- and post-OA OCT. In pre-OA OCT, OCT catheter contact angle and the presence or absences of guide-wire (GW) contact with the normal vessel intima were assessed. Also, in post-OA OCT, we assessed there was post-OA coronary artery injury (OA injury), defined as disappearance of both of intima and medial wall of normal vessel, or not. RESULTS: OA injury was found in 19 lesions (13%). Pre-PCI OCT catheter contact angle with the normal coronary artery was significantly larger (median 137°; inter quartile range [IQR] 113-169 vs. median 0°; IQR 0-0, P < 0.001) and more GW contact with the normal vessel was found (63% vs. 8%, P < 0.001). Pre-PCI OCT catheter contact angle > 92° and GW contact with the normal vessel intima were associated with post-OA vascular injury (Both: 92% (11/12), Either: 32% (8/25), Neither: 0% (0/111), P < 0.001). CONCLUSION: Pre-PCI OCT findings, such as catheter contact angle > 92° and guide-wire contact to the normal coronary artery, were associated with post-OA coronary artery injury.
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Aterectomia Coronária , Doença da Artéria Coronariana , Intervenção Coronária Percutânea , Calcificação Vascular , Lesões do Sistema Vascular , Humanos , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/terapia , Doença da Artéria Coronariana/patologia , Aterectomia Coronária/efeitos adversos , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/patologia , Intervenção Coronária Percutânea/efeitos adversos , Lesões do Sistema Vascular/diagnóstico por imagem , Lesões do Sistema Vascular/etiologia , Lesões do Sistema Vascular/patologia , Tomografia de Coerência Óptica/métodos , Resultado do Tratamento , Valor Preditivo dos Testes , Aterectomia , Calcificação Vascular/diagnóstico por imagem , Calcificação Vascular/terapia , Calcificação Vascular/patologia , Angiografia CoronáriaRESUMO
Acute myocarditis is a rare but serious complication associated with mRNA-based coronavirus disease 2019 (COVID-19) vaccination. In this article, four COVID-19 mRNA vaccination induced myocarditis cases managed at our tertiary Medical Center have been discussed. Three patients had typical myocarditis. One patient suffered from atrioventricular block and heart failure, which required more intensive treatment, but eventually improved. Additionally, a review of cardiac magnetic resonance imaging (MRI) features related to the diagnosis of myocarditis showed that COVID-19 mRNA vaccine-associated myocarditis tend to have more late-gadolinium enhancement (LGE) accumulation in the inferior lateral wall direction. According to a report by the U.S. Centers for Disease Control and Prevention (CDC), the diagnosis of COVID-19 mRNA vaccine-associated myocarditis is based on clinical symptoms, altered myocardial enzymes, cardiac MRI finding, or histopathology. Cardiac MRI is relatively less invasive than myocardial biopsy and plays an important role in the diagnosis of myocarditis. This review may aid in the diagnosis of COVID-19 mRNA vaccine-associated myocarditis.
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Objectives: To examine the outcomes of anticoagulant therapy for patients with venous thromboembolism (VTE) with active cancer and the outcomes after cancer remission with and without anticoagulant therapy. Materials and Methods: Of the 338 patients with cancer-associated VTE who received anticoagulant therapy, we evaluated therapeutic outcomes over 1 year for 112 patients whose cancers were in remission (cancer remission group) and 226 patients who continued cancer treatment (continued cancer treatment group). Further, the cancer remission group was divided into 89 and 23 patients who completed (completion of anticoagulation group) and continued (continued anticoagulation group) anticoagulant therapy, respectively. Treatment outcomes after completing anticoagulant therapy were compared between these two groups. The follow-up period was 1 year, and the endpoints were all-cause death, VTE recurrence, and bleeding events. Results: The event-free survival rates were 99.1% and 42.9% in the cancer remission and continued cancer treatment groups, respectively. For treatment outcomes after the completion of anticoagulant therapy, the event-free survival rates were 98.9% and 87% in the completion of anticoagulation and continued anticoagulation groups, respectively (log rank, P=0.005). Conclusion: When cancer is in remission, recurrence is low even if anticoagulant therapy is terminated after a certain period.
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Background: Catheter ablation is a standard therapy for frequent premature ventricular complex (PVCs). Predicting their origin from a 12-lead electrocardiogram (ECG) is crucial but it requires specialized knowledge and experience. Objective: The objective of the present study was to develop and evaluate machine learning algorithms that predicted PVC origins from an ECG. Methods: We developed the algorithms utilizing a support vector machine (SVM) and a convolutional neural network (CNN). The training, validating, and testing data consisted of 116 PVCs from 111 patients who underwent catheter ablation. The ECG signals were labeled with the PVC origin, which was confirmed using a 3-dimensional electroanatomical mapping system. We classified the origins into 4 groups: right or left, outflow tract, or other sites. We trained and evaluated the model performance. The testing datasets were also evaluated by board-certified electrophysiologists and an existing classification algorithm. We also developed binary classification models that predicted whether the origin was on the right or left side of the heart. Results: The weighted accuracies of the 4-class classification were as follows: SVM 0.85, CNN 0.80, electrophysiologists 0.73, and existing algorithm 0.86. The precision, recall, and F1 in the machine learning models marked better than physicians and comparable to the existing algorithm. The SVM model scored among the best accuracy in the binary classification (the accuracies were 0.94, 0.87, 0.79, and 0.90, respectively). Conclusion: Artificial intelligence-enabled algorithms that predict the origin of PVCs achieved superior accuracy compared to the electrophysiologists and comparable accuracy to the existing algorithm.
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BACKGROUND: Although long sinus arrest is occasionally observed during atrial fibrillation (AF) catheter ablation when the fibrillation was terminated, its meaning and prognosis have not yet been clearly elucidated. We hypothesized that sinus node recovery time (SNRT) after termination of AF (time from termination of AF to the earliest sinus node activation) could reflect the extent of atrial remodeling, influencing the formation of non-pulmonary vein (non-PV) triggers and post-ablation outcomes. METHOD: The participants were 157 consecutive patients with persistent AF (male: 77.1%, age: 63.3±11.2 years) who underwent catheter ablation. We recorded SNRT after terminating AF by radiofrequency delivery or electrical cardioversion during the first ablation and evaluated the relationships between SNRT and atrial tachyarrhythmia recurrence and between SNRT and non-PV triggers after repeat ablation. RESULTS: Forty-five patients (28.7%) experienced recurrence of atrial tachyarrhythmias. Patients with recurrence had longer SNRTs (1738 ms vs. 1394 ms, p = 0.012). In the multivariate logistic regression analysis, only SNRT ≥2128ms was a significant independent predictor of clinical AF recurrence (hazard ratio 7.48; 95% confidence interval 2.94-19.00; P<0.001). Kaplan-Meier estimator showed that the recurrence-free rate was significantly lower if ≥ 2128ms (log-rank, p<0.001). Thirty-five patients (77.8%) underwent a second ablation. Although there was no difference in the rate of pulmonary vein reconnections (78.6% vs. 71.4%, p = 0.712), non-PV triggers were observed more frequently in the longer SNRT group (57.1% vs. 14.3%, p = 0.012). CONCLUSIONS: Patients with a prolonged SNRT had a higher prevalence of AF recurrence after the first ablation and higher inducibility of non-PV triggers. Measuring SNRT might be used for the stratification of patients with persistent AF.
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Fibrilação Atrial , Idoso , Remodelamento Atrial , Ablação por Cateter , Humanos , Pessoa de Meia-IdadeRESUMO
Andersen-Tawil syndrome (ATS) is a rare inherited channelopathy. The cardiac phenotype in ATS is typified by a prominent U wave and ventricular arrhythmia. An effective treatment for this disease remains to be established. We reprogrammed somatic cells from three ATS patients to generate induced pluripotent stem cells (iPSCs). Multi-electrode arrays (MEAs) were used to record extracellular electrograms of iPSC-derived cardiomyocytes, revealing strong arrhythmic events in the ATS-iPSC-derived cardiomyocytes. Ca2+ imaging of cells loaded with the Ca2+ indicator Fluo-4 enabled us to examine intracellular Ca2+ handling properties, and we found a significantly higher incidence of irregular Ca2+ release in the ATS-iPSC-derived cardiomyocytes than in control-iPSC-derived cardiomyocytes. Drug testing using ATS-iPSC-derived cardiomyocytes further revealed that antiarrhythmic agent, flecainide, but not the sodium channel blocker, pilsicainide, significantly suppressed these irregular Ca2+ release and arrhythmic events, suggesting that flecainide's effect in these cardiac cells was not via sodium channels blocking. A reverse-mode Na+/Ca2+exchanger (NCX) inhibitor, KB-R7943, was also found to suppress the irregular Ca2+ release, and whole-cell voltage clamping of isolated guinea-pig cardiac ventricular myocytes confirmed that flecainide could directly affect the NCX current (INCX). ATS-iPSC-derived cardiomyocytes recapitulate abnormal electrophysiological phenotypes and flecainide suppresses the arrhythmic events through the modulation of INCX.
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SCN5A is abundant in heart and has a major role in INa. Loss-of-function mutation in SCN5A results in Brugada syndrome (BrS), which causes sudden death in adults. It remains unclear why disease phenotype does not manifest in the young even though mutated SCN5A is expressed in the young. The aim of the present study is to elucidate the timing of the disease manifestation in BrS. A gain-of-function mutation in SCN5A also results in Long QT syndrome type 3 (LQTS3), leading to sudden death in the young. Induced pluripotent stem cells (iPSCs) were generated from a patient with a mixed phenotype of LQTS3 and BrS with the E1784K SCN5A mutation. Here we show that electrophysiological analysis revealed that LQTS3/BrS iPSC-derived cardiomyocytes recapitulate the phenotype of LQTS3 but not BrS. Each ß-subunit of the sodium channel is differentially expressed in embryonic and adult hearts. SCN3B is highly expressed in embryonic hearts and iPSC-derived cardiomyocytes. A heterologous expression system revealed that INa of mutated SCN5A is decreased and SCN3B augmented INa of mutated SCN5A. Knockdown of SCN3B in LQTS3/BrS iPSC-derived cardiomyocytes successfully unmasked the phenotype of BrS. Isogenic control of LQTS3/BrS (corrected-LQTS3/BrS) iPSC-derived cardiomyocytes gained the normal electrophysiological properties.
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Mitochondrial diseases are heterogeneous disorders, caused by mitochondrial dysfunction. Mitochondria are not regulated solely by nuclear genomic DNA but by mitochondrial DNA. It is difficult to develop effective therapies for mitochondrial disease because of the lack of mitochondrial disease models. Mitochondrial myopathy, encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is one of the major mitochondrial diseases. The aim of this study was to generate MELAS-specific induced pluripotent stem cells (iPSCs) and to demonstrate that MELAS-iPSCs can be models for mitochondrial disease. We successfully established iPSCs from the primary MELAS-fibroblasts carrying 77.7% of m.3243A>G heteroplasmy. MELAS-iPSC lines ranged from 3.6% to 99.4% of m.3243A>G heteroplasmy levels. The enzymatic activities of mitochondrial respiratory complexes indicated that MELAS-iPSC-derived fibroblasts with high heteroplasmy levels showed a deficiency of complex I activity but MELAS-iPSC-derived fibroblasts with low heteroplasmy levels showed normal complex I activity. Our data indicate that MELAS-iPSCs can be models for MELAS but we should carefully select MELAS-iPSCs with appropriate heteroplasmy levels and respiratory functions for mitochondrial disease modeling.
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Duchenne muscular dystrophy (DMD) is a chronic and life-threatening disease that is initially supported by muscle regeneration but eventually shows satellite cell exhaustion and muscular dysfunction. The life-long maintenance of skeletal muscle homoeostasis requires the satellite stem cell pool to be preserved. Asymmetric cell division plays a pivotal role in the maintenance of the satellite cell pool. Here we show that granulocyte colony-stimulating factor receptor (G-CSFR) is asymmetrically expressed in activated satellite cells. G-CSF positively affects the satellite cell population during multiple stages of differentiation in ex vivo cultured fibres. G-CSF could be important in developing an effective therapy for DMD based on its potential to modulate the supply of multiple stages of regenerated myocytes. This study shows that the G-CSF-G-CSFR axis is fundamentally important for long-term muscle regeneration, functional maintenance and lifespan extension in mouse models of DMD with varying severities.
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Fator Estimulador de Colônias de Granulócitos/farmacologia , Músculo Esquelético/efeitos dos fármacos , Distrofia Muscular de Duchenne/tratamento farmacológico , Receptores de Fator Estimulador de Colônias de Granulócitos/genética , Regeneração/efeitos dos fármacos , Células Satélites de Músculo Esquelético/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Modelos Animais de Doenças , Regulação da Expressão Gênica , Fator Estimulador de Colônias de Granulócitos/genética , Fator Estimulador de Colônias de Granulócitos/metabolismo , Longevidade/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos mdx , Camundongos Knockout , Células Musculares/efeitos dos fármacos , Células Musculares/metabolismo , Células Musculares/patologia , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patologia , Proteína MyoD/genética , Proteína MyoD/metabolismo , Fator de Transcrição PAX7/genética , Fator de Transcrição PAX7/metabolismo , Cultura Primária de Células , Receptores de Fator Estimulador de Colônias de Granulócitos/deficiência , Regeneração/genética , Células Satélites de Músculo Esquelético/metabolismo , Células Satélites de Músculo Esquelético/patologia , Transdução de Sinais , Células-Tronco/metabolismo , Células-Tronco/patologiaRESUMO
Induced pluripotent stem cells (iPSCs) have been proposed as novel cell sources for genetic disease models and revolutionary clinical therapies. Accordingly, human iPSC-derived cardiomyocytes are potential cell sources for cardiomyocyte transplantation therapy. We previously developed a novel generation method for human peripheral T cell-derived iPSCs (TiPSCs) that uses a minimally invasive approach to obtain patient cells. However, it remained unknown whether TiPSCs with genomic rearrangements in the T cell receptor (TCR) gene could differentiate into functional cardiomyocyte in vitro. To address this issue, we investigated the morphology, gene expression pattern, and electrophysiological properties of TiPSC-derived cardiomyocytes differentiated by floating culture. RT-PCR analysis and immunohistochemistry showed that the TiPSC-derived cardiomyocytes properly express cardiomyocyte markers and ion channels, and show the typical cardiomyocyte morphology. Multiple electrode arrays with application of ion channel inhibitors also revealed normal electrophysiological responses in the TiPSC-derived cardiomyocytes in terms of beating rate and the field potential waveform. In this report, we showed that TiPSCs successfully differentiated into cardiomyocytes with morphology, gene expression patterns, and electrophysiological features typical of native cardiomyocytes. TiPSCs-derived cardiomyocytes obtained from patients by a minimally invasive technique could therefore become disease models for understanding the mechanisms of cardiac disease and cell sources for revolutionary cardiomyocyte therapies.
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Células-Tronco Pluripotentes Induzidas/fisiologia , Miócitos Cardíacos/fisiologia , Linfócitos T/fisiologia , Potenciais de Ação/fisiologia , Biomarcadores/metabolismo , Diferenciação Celular , Células Cultivadas , Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Ativação do Canal Iônico/fisiologia , Canais Iônicos/genética , Canais Iônicos/metabolismo , Miócitos Cardíacos/citologia , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/citologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
BACKGROUND: Despite the accumulating genetic and molecular investigations into hypertrophic cardiomyopathy (HCM), it remains unclear how this condition develops and worsens pathologically and clinically in terms of the genetic-environmental interactions. Establishing a human disease model for HCM would help to elucidate these disease mechanisms; however, cardiomyocytes from patients are not easily obtained for basic research. Patient-specific induced pluripotent stem cells (iPSCs) potentially hold much promise for deciphering the pathogenesis of HCM. The purpose of this study is to elucidate the interactions between genetic backgrounds and environmental factors involved in the disease progression of HCM. METHODS AND RESULTS: We generated iPSCs from 3 patients with HCM and 3 healthy control subjects, and cardiomyocytes were differentiated. The HCM pathological phenotypes were characterized based on morphological properties and high-speed video imaging. The differences between control and HCM iPSC-derived cardiomyocytes were mild under baseline conditions in pathological features. To identify candidate disease-promoting environmental factors, the cardiomyocytes were stimulated by several cardiomyocyte hypertrophy-promoting factors. Interestingly, endothelin-1 strongly induced pathological phenotypes such as cardiomyocyte hypertrophy and intracellular myofibrillar disarray in the HCM iPSC-derived cardiomyocytes. We then reproduced these phenotypes in neonatal cardiomyocytes from the heterozygous Mybpc3-targeted knock in mice. High-speed video imaging with motion vector prediction depicted physiological contractile dynamics in the iPSC-derived cardiomyocytes, which revealed that self-beating HCM iPSC-derived single cardiomyocytes stimulated by endothelin-1 showed variable contractile directions. CONCLUSIONS: Interactions between the patient's genetic backgrounds and the environmental factor endothelin-1 promote the HCM pathological phenotype and contractile variability in the HCM iPSC-derived cardiomyocytes.
Assuntos
Cardiomiopatia Hipertrófica/metabolismo , Diferenciação Celular , Endotelina-1/farmacologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Contração Miocárdica/efeitos dos fármacos , Miócitos Cardíacos/efeitos dos fármacos , Miofibrilas/efeitos dos fármacos , Animais , Fenômenos Biomecânicos , Cardiomegalia/genética , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Cardiomegalia/fisiopatologia , Cardiomiopatia Hipertrófica/patologia , Cardiomiopatia Hipertrófica/fisiopatologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Estudos de Casos e Controles , Células Cultivadas , Relação Dose-Resposta a Droga , Interação Gene-Ambiente , Genótipo , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Miofibrilas/metabolismo , Miofibrilas/patologia , Fenótipo , Fatores de Risco , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Transfecção , Disfunção Ventricular/genética , Disfunção Ventricular/metabolismo , Disfunção Ventricular/patologia , Disfunção Ventricular/fisiopatologia , Gravação em VídeoRESUMO
The long QT syndrome type 2 (LQT2) is inheritable life threatening arrhythmic disorder and one of the most common genetic variants in long QT syndrome. There are some indications for treatment of the patients with LQT2 but it is impossible to completely prevent fatal arrhythmia. To develop novel therapy for the patients with LQT2, it has been desired to generate diseasespecific and patient-specific disease model. Human induced pluripotent stem (iPS) cells are somatic cell-derived pluripotent stem cells with infinite proliferation ability and multipotency. Patient-specific iPS cells can be derived from patient somatic cells, have all genomic information encoded in patient's genome including mutation and all SNPs, and can be ideal disease models of the patients. To generate disease model for LQT2 by iPS cells, we should firstly generate iPS cells from the patient with LQT2 and confirm the genomic mutation in iPS cells. In this study, we showed the successful generation of iPS cells from a patient with KCNH2 G603D mutation. The patient specific iPS cells properly expressed stem cell markers, such as NANOG and OCT3/4. We also confirmed that the KCNH2 G603D (G1808A) mutation was taken over in patient specific iPS cells. These patient-specific iPS cells may contribute to the future analysis for disease pathogenesis and drug innovation.
Assuntos
Ácido Aspártico/genética , Canais de Potássio Éter-A-Go-Go/genética , Glicina/genética , Síndrome do QT Longo/genética , Células-Tronco Pluripotentes/classificação , Polimorfismo de Nucleotídeo Único/genética , Adenina , Técnicas de Cultura de Células , Criança , Canal de Potássio ERG1 , Genoma Humano/genética , Guanina , Proteínas de Homeodomínio , Humanos , Síndrome do QT Longo/patologia , Masculino , Proteína Homeobox Nanog , Fator 3 de Transcrição de Octâmero/genética , Análise de Sequência de DNARESUMO
AIMS: Long QT syndrome (LQTS) is an inheritable and life-threatening disease; however, it is often difficult to determine disease characteristics in sporadic cases with novel mutations, and more precise analysis is necessary for the successful development of evidence-based clinical therapies. This study thus sought to better characterize ion channel cardiac disorders using induced pluripotent stem cells (iPSCs). METHODS AND RESULTS: We reprogrammed somatic cells from a patient with sporadic LQTS and from controls, and differentiated them into cardiomyocytes through embryoid body (EB) formation. Electrophysiological analysis of the LQTS-iPSC-derived EBs using a multi-electrode array (MEA) system revealed a markedly prolonged field potential duration (FPD). The IKr blocker E4031 significantly prolonged FPD in control- and LQTS-iPSC-derived EBs and induced frequent severe arrhythmia only in LQTS-iPSC-derived EBs. The IKs blocker chromanol 293B did not prolong FPD in the LQTS-iPSC-derived EBs, but significantly prolonged FPD in the control EBs, suggesting the involvement of IKs disturbance in the patient. Patch-clamp analysis and immunostaining confirmed a dominant-negative role for 1893delC in IKs channels due to a trafficking deficiency in iPSC-derived cardiomyocytes and human embryonic kidney (HEK) cells. CONCLUSIONS: This study demonstrated that iPSCs could be useful to characterize LQTS disease as well as drug responses in the LQTS patient with a novel mutation. Such analyses may in turn lead to future progress in personalized medicine.