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1.
Physiol Rev ; 99(1): 79-114, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30328784

RESUMO

The discovery of somatic cell nuclear transfer proved that somatic cells can carry the same genetic code as the zygote, and that activating parts of this code are sufficient to reprogram the cell to an early developmental state. The discovery of induced pluripotent stem cells (iPSCs) nearly half a century later provided a molecular mechanism for the reprogramming. The initial creation of iPSCs was accomplished by the ectopic expression of four specific genes (OCT4, KLF4, SOX2, and c-Myc; OSKM). iPSCs have since been acquired from a wide range of cell types and a wide range of species, suggesting a universal molecular mechanism. Furthermore, cells have been reprogrammed to iPSCs using a myriad of methods, although OSKM remains the gold standard. The sources for iPSCs are abundant compared with those for other pluripotent stem cells; thus the use of iPSCs to model the development of tissues, organs, and other systems of the body is increasing. iPSCs also, through the reprogramming of patient samples, are being used to model diseases. Moreover, in the 10 years since the first report, human iPSCs are already the basis for new cell therapies and drug discovery that have reached clinical application. In this review, we examine the generation of iPSCs and their application to disease and development.


Assuntos
Diferenciação Celular/fisiologia , Células-Tronco Pluripotentes Induzidas/citologia , Modelos Biológicos , Células-Tronco Pluripotentes/classificação , Animais , Terapia Baseada em Transplante de Células e Tecidos , Células Cultivadas , Humanos , Fator 4 Semelhante a Kruppel
2.
Br J Haematol ; 205(4): 1430-1443, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39187468

RESUMO

Structural variations involving enhancer hijacking induce aberrant oncogene expression and cause tumorigenesis. A rare translocation, t(3;8)(q26.2;q24), is associated with MECOM and MYC rearrangement, causing myeloid neoplasms with a dismal prognosis. The most recent World Health Organization classification recognises myeloid neoplasms with MECOM rearrangement as acute myeloid leukaemia (AML) with defining genetic abnormalities. Recently, the increasing use of induced pluripotent stem cell (iPSC) technology has helped elucidate the pathogenic processes of haematological malignancies. However, its utility for investigating enhancer hijacking in myeloid neoplasms remains unclear. In this study, we generated iPSC lines from patients with myelodysplastic syndromes (MDS) harbouring t(3;8)(q26.2;q24) and differentiated them into haematopoietic progenitor cells to model the pathophysiology of MDS with t(3;8)(q26.2;q24). Our iPSC model reproduced the primary patient's MECOM expression changes and histone H3 lysine 27 acetylation (H3K27ac) patterns in the MECOM promoter and MYC blood enhancer cluster (BENC). Furthermore, we revealed the apoptotic effects of the bromodomain and extra-terminal motif (BET) inhibitor on iPSC-derived MDS cells by suppressing activated MECOM. Our study demonstrates the usefulness of iPSC models for uncovering the precise mechanism of enhancer hijacking due to chromosomal structural changes and discovering potential therapeutic drug candidates for cancer treatment.


Assuntos
Cromossomos Humanos Par 3 , Células-Tronco Pluripotentes Induzidas , Síndromes Mielodisplásicas , Translocação Genética , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/metabolismo , Cromossomos Humanos Par 3/genética , Cromossomos Humanos Par 8/genética , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Rearranjo Gênico , Masculino , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Azepinas/farmacologia , Feminino
3.
Int Heart J ; 65(2): 367-370, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38479845

RESUMO

Papillary fibroelastoma (PFE) is a benign tumor that arises mostly from left-sided valves. PFE can cause stroke, and surgical resection may be needed. Lambl's excrescence (LE) is a filiform valvular lesion and is considered a possible cause of stroke. A 79-year-old man with light-headedness and left-sided hemiparesis was diagnosed with stroke. Transesophageal echocardiography (TEE) revealed a round-shaped mobile mass in the left ventricular outflow tract (LVOT), which was considered the cause of the stroke. Surgical resection was performed transaortically, and during surgery, a mass was incidentally detected on the noncoronary cusp (NCC), which was also resected followed by aortic valve replacement. Pathology confirmed that the mass in the LVOT was a PFE and that the filiform mass on the NCC was LE. We herein report a rare case of PFE in the LVOT and coexisting LE on the NCC. A careful examination via TEE helps to identify other possible causes of stroke hidden behind the obvious cause.


Assuntos
Fibroelastoma Papilar Cardíaco , Neoplasias Cardíacas , Doenças das Valvas Cardíacas , Acidente Vascular Cerebral , Masculino , Humanos , Idoso , Doenças das Valvas Cardíacas/complicações , Fibroelastoma Papilar Cardíaco/complicações , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Valva Aórtica/patologia , Acidente Vascular Cerebral/complicações , Ecocardiografia Transesofagiana , Neoplasias Cardíacas/diagnóstico , Neoplasias Cardíacas/diagnóstico por imagem
4.
J Cardiovasc Electrophysiol ; 34(2): 337-344, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36423234

RESUMO

INTRODUCTION: Spatial characteristics of localized sources of persistent atrial fibrillation (AF) identified by unipolar-based panoramic mapping software (CARTOFINDER) remain unclear. We evaluated spatial characteristics of bi-atrial AF localized sources in relation to complex fractionated atrial electrocardiograms (CFAEs) and atrial low voltage area (LVAs) (≤0.35 mV during AF). METHODS AND RESULTS: Twenty consecutive patients with persistent AF underwent bi-atrial voltage, CFAE, and CARTOFINDER mapping before the beginning of ablation (18 [90%] patients, initial procedure; 2 [10%] patients, repeat procedure). CFAEs were recorded using the interval confidence level (ICL) mode and defined as sites with a confidence level of ≥80% of maximal ICL number. We elucidated the following: (1) differences in the rate of AF localized sources and CFAEs inside or outside the atrial LVAs; (2) distribution of AF localized sources and CFAEs; and (3) distance between the closest points of AF localized sources and CFAEs. A total of 270 AF localized sources and 486 CFAEs were identified in 20 patients. AF localized sources were confirmed more often outside atrial LVAs than CFAEs (71% vs. 46% outside LVA, p < .001). AF localized sources and CFAEs were diffusely distributed without any tendency in bi-atria. Mean distance between closest AF localized sources and CFAEs was 22 ± 8 mm. CONCLUSION: AF localized sources identified by CARTOFINDER are different therapeutic targets as compared to CFAEs and could be confirmed both inside and outside atrial LVAs.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Humanos , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/cirurgia , Algoritmos , Eletrocardiografia/métodos
5.
Int J Mol Sci ; 24(13)2023 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-37445782

RESUMO

The mechanisms behind reported decreases in plasma insulin and glucagon during hemodialysis (HD) are not clear. Here, we investigated these mechanisms during HD treatment and the characteristics of insulin and glucagon removal when using two super high-flux membranes. In an experimental study, clearance, adsorption rates, and reduction rates of insulin and glucagon were investigated when using cellulose triacetate (CTA) and polysulfone (PS) membranes in a closed circuit using bovine blood. In a clinical study, 20 diabetes patients with end-stage kidney disease who were stable on HD were randomly selected for two HD sessions with two different membranes. At 1 h after the initiation of HD, insulin and glucagon clearance were measured, and the reduction rates were also investigated. In the experimental study, the PS membrane showed significantly higher clearance, adsorption rates, and reduction rates of insulin and glucagon compared with the CTA membrane. Although glucagon was detected in the ultrafiltration fluids in both membranes, insulin was absent in the PS membrane. In the clinical study, both membranes showed significant reductions in plasma insulin and glucagon at each time point. The PS membrane showed significantly higher insulin clearance and reduction rates compared with the CTA membrane. The two membranes showed no significant difference in glucagon clearance, but the glucagon reduction rate was significantly higher with the PS membrane. Our findings show that HD with the two super high-flux membranes used removes significant amounts of glucoregulatory peptide hormones from plasma in patients with diabetes and end-stage kidney disease, potentially affecting their glucose metabolism.


Assuntos
Diabetes Mellitus , Falência Renal Crônica , Humanos , Animais , Bovinos , Diálise Renal , Glucagon , Cinética , Falência Renal Crônica/terapia , Insulina , Insulina Regular Humana , Membranas Artificiais
6.
Haematologica ; 106(6): 1581-1590, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32439725

RESUMO

Leukocytes that lack HLA allelic expression are frequently detected in patients with acquired aplastic anemia (AA) who respond to immunosuppressive therapy (IST), although the exact mechanisms underlying the HLA loss and HLA allele repertoire likely to acquire loss-of-function mutations are unknown. We identified a common nonsense mutation at position 19 (c.19C>T, p.R7X) in exon 1 (Exon1mut) of different HLA-A and -B alleles in HLA-lacking granulocytes from AA patients. A droplet digital PCR (ddPCR) assay capable of detecting as few as 0.07% Exon1mut HLA alleles in total DNA revealed the mutation was present in 29% (101/353) of AA patients, with a median allele frequency of 0.42% (range, 0.071% to 21.3%). Exon1mut occurred in only 12 different HLA-A (n=4) and HLA-B (n=8) alleles, including B*40:02 (n=31) and A*02:06 (n=15), which correspond to 4 HLA supertypes (A02, A03, B07, and B44). The percentages of patients who possessed at least one of these 12 HLA alleles were significantly higher in the 353 AA patients (92%, P.


Assuntos
Anemia Aplástica , Códon sem Sentido , Alelos , Anemia Aplástica/genética , Éxons , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Humanos
7.
Circ Res ; 125(6): 653-658, 2019 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-31465267

RESUMO

Long-QT syndrome, a frequently fatal inherited arrhythmia syndrome caused by genetic variants (congenital) or drugs (acquired), affects 1 in 2000 people worldwide. Its sentinel event is often sudden cardiac death, which makes preclinical diagnosis by genetic testing potentially life-saving. Unfortunately, clinical experience with genetic testing has shown that it is difficult to correctly identify genetic variants as disease causing. These current deficiencies in accurately assigning pathogenicity led to the discovery of increasing numbers of rare variants classified as variant of uncertain significance. To overcome these challenges, new technologies such as clustered regularly interspaced short palindromic repeats (CRISPR) genome editing can be combined with human induced pluripotent stem cell-derived cardiomyocytes to provide a new approach to decipher pathogenicity of variants of uncertain significance and to better predict arrhythmia risk. To that end, the overarching goal of our network is to establish the utility of induced pluripotent stem cell-based platforms to solve major clinical problems associated with long-QT syndrome by determining how to (1) differentiate pathogenic mutations from background genetic noise, (2) assess existing and novel variants associated with congenital and acquired long-QT syndrome, and (3) provide genotype- and phenotype- guided risk stratification and pharmacological management of long-QT syndrome. To achieve these goals and to further advance the use of induced pluripotent stem cells in disease modeling and drug discovery, our team of investigators for this Leducq Foundation Transatlantic Networks of Excellence proposal will work together to (1) improve differentiation efficiency, cellular maturation, and lineage specificity, (2) develop new assays for high throughput cellular phenotyping, and (3) train young investigators to clinically implement patient-specific genetic modeling.


Assuntos
Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Células-Tronco Pluripotentes Induzidas/transplante , Síndrome do QT Longo/genética , Síndrome do QT Longo/terapia , Medicina de Precisão/métodos , Canalopatias/diagnóstico , Canalopatias/genética , Canalopatias/terapia , Humanos , Síndrome do QT Longo/diagnóstico , Medicina de Precisão/tendências
8.
Circ J ; 85(3): 323-329, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33518695

RESUMO

Due to the COVID-19 pandemic, the 84thAnnual Meeting of the Japanese Circulation Society (JCS) was held in a web-based format for the first time in its history as "The Week for JCS 2020" from Monday, July 27 to Sunday, August 2, 2020. All sessions, including general abstracts, were streamed live or on-demand. The main theme of the meeting was "Change Practice!" and the aim was to organize the latest findings in the field of cardiovascular medicine and discuss how to change practice. The total number of registered attendees was over 16,800, far exceeding our expectations, and many of the sessions were viewed by far more people than at conventional face-to-face scientific meetings. At this conference, the power of online information dissemination was fully demonstrated, and the evolution of online academic meetings will be a direction that cannot be reversed in the future. The meeting was completed with great success, and we express our heartfelt gratitude to all affiliates for their enormous amount of work, cooperation, and support.


Assuntos
Cardiologia/organização & administração , Congressos como Assunto/organização & administração , Sociedades Científicas/organização & administração , Telecomunicações/organização & administração , Cardiologia/tendências , Doenças Cardiovasculares/diagnóstico por imagem , Doenças Cardiovasculares/terapia , Congressos como Assunto/estatística & dados numéricos , Congressos como Assunto/tendências , Humanos , Japão , Pesquisa , Inquéritos e Questionários , Telecomunicações/estatística & dados numéricos , Telecomunicações/tendências
9.
Arch Toxicol ; 95(12): 3633-3650, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34657219

RESUMO

It has been nearly 15 years since the discovery of human-induced pluripotent stem cells (iPSCs). During this time, differentiation methods to targeted cells have dramatically improved, and many types of cells in the human body can be currently generated at high efficiency. In the cardiovascular field, the ability to generate human cardiomyocytes in vitro with the same genetic background as patients has provided a great opportunity to investigate human cardiovascular diseases at the cellular level to clarify the molecular mechanisms underlying the diseases and discover potential therapeutics. Additionally, iPSC-derived cardiomyocytes have provided a powerful platform to study drug-induced cardiotoxicity and identify patients at high risk for the cardiotoxicity; thus, accelerating personalized precision medicine. Moreover, iPSC-derived cardiomyocytes can be sources for cardiac cell therapy. Here, we review these achievements and discuss potential improvements for the future application of iPSC technology in cardiovascular diseases.


Assuntos
Doenças Cardiovasculares/fisiopatologia , Células-Tronco Pluripotentes Induzidas/citologia , Miócitos Cardíacos/citologia , Animais , Cardiotoxicidade/etiologia , Cardiotoxicidade/fisiopatologia , Doenças Cardiovasculares/terapia , Diferenciação Celular/fisiologia , Terapia Baseada em Transplante de Células e Tecidos/métodos , Humanos , Tecnologia/métodos
10.
Hum Mol Genet ; 26(9): 1670-1677, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28335032

RESUMO

Calmodulin is a ubiquitous Ca2+ sensor molecule encoded by three distinct calmodulin genes, CALM1-3. Recently, mutations in CALM1-3 have been reported to be associated with severe early-onset long-QT syndrome (LQTS). However, the underlying mechanism through which heterozygous calmodulin mutations lead to severe LQTS remains unknown, particularly in human cardiomyocytes. We aimed to establish an LQTS disease model associated with a CALM2 mutation (LQT15) using human induced pluripotent stem cells (hiPSCs) and to assess mutant allele-specific ablation by genome editing for the treatment of LQT15. We generated LQT15-hiPSCs from a 12-year-old boy with LQTS carrying a CALM2-N98S mutation and differentiated these hiPSCs into cardiomyocytes (LQT15-hiPSC-CMs). Action potentials (APs) and L-type Ca2+ channel (LTCC) currents in hiPSC-CMs were analyzed by the patch-clamp technique and compared with those of healthy controls. Furthermore, we performed mutant allele-specific knockout using a CRISPR-Cas9 system and analyzed electrophysiological properties. Electrophysiological analyses revealed that LQT15-hiPSC-CMs exhibited significantly lower beating rates, prolonged AP durations, and impaired inactivation of LTCC currents compared with control cells, consistent with clinical phenotypes. Notably, ablation of the mutant allele rescued the electrophysiological abnormalities of LQT15-hiPSC-CMs, indicating that the mutant allele caused dominant-negative suppression of LTCC inactivation, resulting in prolonged AP duration. We successfully recapitulated the disease phenotypes of LQT15 and revealed that inactivation of LTCC currents was impaired in CALM2-N98S hiPSC model. Additionally, allele-specific ablation using the latest genome-editing technology provided important insights into a promising therapeutic approach for inherited cardiac diseases.


Assuntos
Calmodulina/genética , Calmodulina/metabolismo , Células-Tronco Pluripotentes Induzidas/fisiologia , Síndrome do QT Longo/genética , Potenciais de Ação , Alelos , Arritmias Cardíacas/genética , Diferenciação Celular/genética , Linhagem Celular , Fenômenos Eletrofisiológicos , Sistema de Condução Cardíaco , Humanos , Síndrome do QT Longo/metabolismo , Masculino , Mutação de Sentido Incorreto , Miócitos Cardíacos/citologia , Técnicas de Patch-Clamp
11.
Circ Res ; 120(12): 1958-1968, 2017 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-28596174

RESUMO

Induced pluripotent stem cells (iPSCs) are reprogrammed cells that have features similar to embryonic stem cells, such as the capacity of self-renewal and differentiation into many types of cells, including cardiac myocytes. Although initially the reprogramming efficiency was low, several improvements in reprogramming methods have achieved robust and efficient generation of iPSCs without genomic insertion of transgenes. iPSCs display clonal variations in epigenetic and genomic profiles and cellular behavior in differentiation. iPSC-derived cardiac myocytes (iPSC cardiac myocytes) recapitulate phenotypic differences caused by genetic variations, making them attractive human disease models, and are useful for drug discovery and toxicology testing. In addition, iPSC cardiac myocytes can help with patient stratification in regard to drug responsiveness. Furthermore, they can be used as source cells for cardiac regeneration in animal models. Here, we review recent progress in iPSC technology and its applications to cardiac diseases.


Assuntos
Cardiopatias/terapia , Células-Tronco Pluripotentes Induzidas/transplante , Miócitos Cardíacos/transplante , Transplante de Células-Tronco/métodos , Animais , Diferenciação Celular/fisiologia , Linhagem Celular , Reprogramação Celular/fisiologia , Cardiopatias/diagnóstico , Cardiopatias/fisiopatologia , Humanos , Células-Tronco Pluripotentes Induzidas/fisiologia , Miócitos Cardíacos/fisiologia , Transplante de Células-Tronco/tendências , Fatores de Tempo
12.
Biochem Biophys Res Commun ; 505(4): 1251-1256, 2018 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-30333092

RESUMO

Many studies have shown the feasibility of in vivo cardiac transplantation of human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) in animal experiments. However, nano-structural confirmation of the successful incorporation of the engrafted iPSC-CMs including electron microscopy (EM) has not been accomplished, partly because identification of graft cells in EM has proven to be difficult. Using APEX2, an engineered ascorbate peroxidase imaging tag, we successfully localized and analyzed the fine structure of sarcomeres and the excitation contraction machinery of iPSC-CMs 6 months after their engraftment in infarcted mouse hearts. APEX2 made iPSC-CMs visible in multiple imaging modalities including light microscopy, X-ray microscopic tomography, transmission EM, and scanning EM. EM tomography allowed assessment of the differentiation state of APEX2-positive iPSC-CMs and analysis of the fine structure of the sarcomeres including T-tubules and dyads.


Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Miocárdio/citologia , Miócitos Cardíacos/transplante , Animais , Diferenciação Celular , Linhagem Celular , Linhagem da Célula , DNA Liase (Sítios Apurínicos ou Apirimidínicos)/genética , Coração/anatomia & histologia , Humanos , Masculino , Camundongos , Sondas Moleculares , Infarto do Miocárdio/patologia , Miocárdio/ultraestrutura , Miócitos Cardíacos/citologia
13.
Am J Nephrol ; 47(6): 406-414, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29874654

RESUMO

BACKGROUND: Serum phosphate and vitamin D receptor activator regulate fibroblast growth factor 23 (FGF23), and iron may modulate FGF23 metabolism. The aim of the present study was to elucidate the effects of ferric citrate hydrate and lanthanum carbohydrate on serum FGF23 levels in hemodialysis patients. METHODS: This prospective, open-label, multicenter study enrolled 60 patients on hemodialysis treated with lanthanum carbonate. Patients were randomly assigned to 2 groups: those switching from lanthanum carbonate to ferric citrate hydrate (ferric citrate group, n = 30) or those continuing lanthanum carbonate (control group, n = 30). Patients were monitored for 24 weeks. Endpoints included changes in FGF23, phosphate, and the dose of erythropoiesis stimulating agent (ESA), erythropoietin responsiveness index (ERI), and adverse events. RESULTS: FGF-23 levels were significantly lower in the ferric citrate group compared with the levels in the control group (change from baseline -6,160 vs. -1,118 pg/mL; p = 0.026). There were no significant changes in serum calcium, phosphate, and intact parathyroid hormone levels in either group. The ferric citrate group had significantly increased serum iron, ferritin, and transferrin saturation. Hemoglobin levels were significantly elevated, and the dose of ESA was significantly decreased in the ferric citrate group but not in the control group. ERI and the dose of intravenous saccharated ferric oxide were significantly lower in the ferric citrate group compared with those of the control group (p = 0.015 and p = 0.002). CONCLUSION: In patients on hemodialysis, 24-week treatment with ferric citrate hydrate resulted in significant reduction in FGF23 and ERI independently of serum phosphate level.


Assuntos
Eritropoetina/uso terapêutico , Compostos Férricos/farmacologia , Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Fatores de Crescimento de Fibroblastos/sangue , Lantânio/farmacologia , Diálise Renal , Feminino , Fator de Crescimento de Fibroblastos 23 , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento
14.
J Cardiovasc Electrophysiol ; 28(5): 489-497, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28188960

RESUMO

INTRODUCTION: Catheter ablation can terminate persistent atrial fibrillation (AF). However, atrial tachycardia (AT) often arises after termination of AF. METHODS AND RESULTS: Of 215 patients who underwent index stepwise ablation for persistent AF, 141 (66%) patients (64 ± 9 years) in whom AF terminated during the ablation procedure were studied. If AF converted into AT, ablation for AT was subsequently performed. ATs were categorized as focal or macroreentrant AT. We assessed whether type of AT occurring after conversion of AF during the ablation procedure was associated with freedom from atrial tachyarrhythmia (AF or AT) during follow-up. Sinus rhythm was directly restored from AF in 37 patients, while 34, 37, and 33 patients had focal AT alone, a mix of focal and macroreentrant AT, and macroreentrant AT alone after termination of AF, respectively. Arrhythmia-free survival rates at 1 year after the index procedure were 30%, 34%, 61%, and 59% in the patients with focal AT alone, a mix of focal AT and macroreentrant AT, macroreentrant AT alone, and direct restoration of sinus rhythm, respectively (P = 0.004). Type of AT occurring during the index procedure was associated with type of recurrent AT (P = 0.03), but the origin of focal AT occurring during the index ablation differed from that of the recurrent AT in 85% of patients. CONCLUSION: In patients who had AF termination by ablation, occurrence of focal AT during the ablation procedure was associated with worse clinical outcome than occurrence of macroreentrant AT, likely due to ATs arising from other foci during follow-up.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Sistema de Condução Cardíaco/cirurgia , Taquicardia Supraventricular/etiologia , Potenciais de Ação , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Intervalo Livre de Doença , Eletrocardiografia Ambulatorial , Técnicas Eletrofisiológicas Cardíacas , Feminino , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Recidiva , Reoperação , Estudos Retrospectivos , Fatores de Risco , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/fisiopatologia , Taquicardia Supraventricular/cirurgia , Fatores de Tempo , Resultado do Tratamento
15.
Circ J ; 81(12): 1783-1791, 2017 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-28637969

RESUMO

BACKGROUND: TheSCN5Agene encodes the α subunit of the cardiac voltage-gated sodium channel, NaV1.5. The missense mutation, D1275N, has been associated with a range of unusual phenotypes associated with reduced NaV1.5 function, including cardiac conduction disease and dilated cardiomyopathy. Curiously, the reported biophysical properties ofSCN5A-D1275N channels vary with experimental system.Methods and Results:First, using a human embryonic kidney (HEK) 293 cell-based heterologous expression system, theSCN5A-D1275N channels showed similar maximum sodium conductance but a significantly depolarizing shift of activation gate (+10 mV) compared to wild type. Second, we generated human-induced pluripotent stem cells (hiPSCs) from a 24-year-old female who carried heterozygousSCN5A-D1275N and analyzed the differentiated cardiomyocytes (CMs). AlthoughSCN5Atranscript levels were equivalent between D1275N and control hiPSC-CMs, both the total amount of NaV1.5 and the membrane fractions were reduced approximately half in the D1275N cells, which were rescued by the proteasome inhibitor MG132 treatment. Electrophysiological assays revealed that maximum sodium conductance was reduced to approximately half of that in control hiPSC-CMs in the D1275N cells, and maximum upstroke velocity of action potential was lower in D1275N, which was consistent with the reduced protein level of NaV1.5. CONCLUSIONS: This study successfully demonstrated diminished sodium currents resulting from lower NaV1.5 protein levels, which is dependent on proteasomal degradation, using a hiPSC-based model forSCN5A-D1275N-related sodium channelopathy.


Assuntos
Canalopatias/genética , Células-Tronco Pluripotentes Induzidas/citologia , Mutação de Sentido Incorreto , Canal de Sódio Disparado por Voltagem NAV1.5/genética , Eletrofisiologia Cardíaca , Células HEK293 , Humanos , Miócitos Cardíacos/citologia , Canal de Sódio Disparado por Voltagem NAV1.5/análise , Complexo de Endopeptidases do Proteassoma/metabolismo , Sódio/metabolismo
16.
Methods ; 101: 43-55, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-26707206

RESUMO

The potential use of induced pluripotent stem cells (iPSCs) in personalized regenerative medicine applications may be augmented by transgenics, including the expression of constitutive cell labels, differentiation reporters, or modulators of disease phenotypes. Thus, there is precedence for reproducible transgene expression amongst iPSC sub-clones with isogenic or diverse genetic backgrounds. Using virus or transposon vectors, transgene integration sites and copy numbers are difficult to control, and nearly impossible to reproduce across multiple cell lines. Moreover, randomly integrated transgenes are often subject to pleiotropic position effects as a consequence of epigenetic changes inherent in differentiation, undermining applications in iPSCs. To address this, we have adapted popular TALEN and CRISPR/Cas9 nuclease technologies in order to introduce transgenes into pre-defined loci and overcome random position effects. AAVS1 is an exemplary locus within the PPP1R12C gene that permits robust expression of CAG promoter-driven transgenes. Gene targeting controls transgene copy number such that reporter expression patterns are reproducible and scalable by ∼2-fold. Furthermore, gene expression is maintained during long-term human iPSC culture and in vitro differentiation along multiple lineages. Here, we outline our AAVS1 targeting protocol using standardized donor vectors and construction methods, as well as provide practical considerations for iPSC culture, drug selection, and genotyping.


Assuntos
Cromossomos Humanos Par 19/genética , Engenharia Genética , Células-Tronco Pluripotentes Induzidas/fisiologia , Sequência de Bases , Sistemas CRISPR-Cas , Diferenciação Celular , Linhagem Celular , Clonagem Molecular , Dependovirus , Genes Reporter , Loci Gênicos , Vetores Genéticos , Proteínas de Fluorescência Verde/biossíntese , Proteínas de Fluorescência Verde/genética , Humanos , Parvovirinae/genética , Regiões Promotoras Genéticas , Transfecção , Transgenes
17.
Rinsho Ketsueki ; 58(7): 787-791, 2017.
Artigo em Japonês | MEDLINE | ID: mdl-28781275

RESUMO

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal stem cell diseases characterized by inefficient hematopoiesis and poor prognosis. There are currently no useful tools for identifying new therapeutic targets of MDS mainly because of a lack of good disease models. Although massive parallel sequencing studies have revealed several MDS-specific genomic alterations that are different from those of de novo acute myeloid leukemia (AML), the relationships between the genetic architecture and pathophysiology in MDS remain poorly understood. We successfully generated multiple iPS cell lines (MDS-iPSC lines) from several patients with either MDS or secondary AML that progressed from MDS. We assessed the hematopoietic differentiation potential of the established MDS-iPSC lines and identified stage-specific maturation defects with graded severity. The MDS-iPSC lines could be a useful tool for elucidating the subclonal diversity, pathogenesis, and clonal evolution of MDS as well as for identifying new therapeutic compounds.


Assuntos
Síndromes Mielodisplásicas/genética , Animais , Técnicas de Reprogramação Celular , Desenho de Fármacos , Genoma Humano , Humanos , Células-Tronco Pluripotentes Induzidas
18.
J Mol Cell Cardiol ; 92: 158-62, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26876450

RESUMO

Cardiac progenitor cells (CPCs) are a crucial source of cells in cardiac development and regeneration. However, reported CPCs are heterogeneous, and no gene has been identified to transiently mark undifferentiated CPCs throughout heart development. Here we show that Spalt-like gene 1 (Sall1), a zing-finger transcription factor, is expressed in undifferentiated CPCs giving rise to both left and right ventricles. Sall1 was transiently expressed in precardiac mesoderm contributing to the first heart field (left ventricle precursors) but not in the field itself. Similarly, Sall1 expression was maintained in the second heart field (outflow tract/right ventricle precursors) but not in cardiac cells. In vitro, high levels of Sall1 at mesodermal stages enhanced cardiomyogenesis, whereas its continued expression suppressed cardiac differentiation. Our study demonstrates that Sall1 marks CPCs in an undifferentiated state and regulates cardiac differentiation. These findings provide fundamental insights into CPC maintenance, which can be instrumental for CPC-based regenerative medicine.


Assuntos
Diferenciação Celular/genética , Ventrículos do Coração/crescimento & desenvolvimento , Células-Tronco/metabolismo , Fatores de Transcrição/genética , Animais , Regulação da Expressão Gênica no Desenvolvimento , Ventrículos do Coração/metabolismo , Humanos , Camundongos , Miocárdio/metabolismo , Fatores de Transcrição/biossíntese , Fatores de Transcrição/metabolismo
19.
Int J Mol Sci ; 17(5)2016 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-27120597

RESUMO

Compared with glycated hemoglobin (HbA1c), glycated albumin (GA) is superior in estimating glycemic control in diabetic patients on hemodialysis (HD). However, the better index for assessment of glycemic control in diabetic patients on peritoneal dialysis (PD) and the impact of protein loss on GA are unknown. Twenty diabetic patients on HD were matched by age, sex, and baseline postprandial plasma glucose (PG) levels to 20 PD patients. PG, HbA1c, GA, and serum albumin levels were measured for six months. Protein loss in PD patients was estimated by measuring the protein concentration in the peritoneal dialysate and by 24 h urine collection. Although PG and HbA1c did not differ significantly between the groups, the PD group had significantly lower GA (17.8% versus 20.8%, p < 0.001) and GA/HbA1c ratio (2.95% versus 3.45%, p < 0.0001) than the HD group. Although the PG level correlated significantly with the GA levels in both groups, it was not correlated with the HbA1c levels in both groups. HbA1c level was negatively associated with erythropoiesis-stimulating agent (ESA) dose in both groups, whereas GA was not significantly associated with serum albumin, hemoglobin concentration, ESA dose, and protein loss. Multiple regression analysis identified GA as the only independent factor associated with PG in PD patients. Our results suggested that GA was not significantly associated with protein loss, hemoglobin, serum albumin, and ESA dose. Although GA might underestimate glycemic status, it provided a significantly better measure for estimating glycemic control than HbA1c, even in PD patients.


Assuntos
Diabetes Mellitus Tipo 2/patologia , Hemoglobinas Glicadas/análise , Albumina Sérica/análise , Idoso , Glicemia/análise , Feminino , Produtos Finais de Glicação Avançada , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Diálise Peritoneal , Estudos Prospectivos , Análise de Regressão , Diálise Renal , Albumina Sérica Glicada
20.
Circ Res ; 113(1): 13-5, 2013 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-23788502

RESUMO

A new report demonstrates direct cardiac reprogramming in human cells for the first time and points to the possibility of moving this technology toward clinical applications.


Assuntos
Transdiferenciação Celular/fisiologia , Fibroblastos/citologia , Regulação da Expressão Gênica/fisiologia , Miócitos Cardíacos/citologia , Fenótipo , Humanos
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