RESUMO
AIMS: Long-QT syndromes (LQTS) are mostly autosomal-dominant congenital disorders associated with a 1:1000 mutation frequency, cardiac arrest, and sudden death. We sought to use cardiomyocytes derived from human-induced pluripotency stem cells (hiPSCs) as an in vitro model to develop and evaluate gene-based therapeutics for the treatment of LQTS. METHODS AND RESULTS: We produced LQTS-type 2 (LQT2) hiPSC cardiomyocytes carrying a KCNH2 c.G1681A mutation in a IKr ion-channel pore, which caused impaired glycosylation and channel transport to cell surface. Allele-specific RNA interference (RNAi) directed towards the mutated KCNH2 mRNA caused knockdown, while leaving the wild-type mRNA unaffected. Electrophysiological analysis of patient-derived LQT2 hiPSC cardiomyocytes treated with mutation-specific siRNAs showed normalized action potential durations (APDs) and K(+) currents with the concurrent rescue of spontaneous and drug-induced arrhythmias (presented as early-afterdepolarizations). CONCLUSIONS: These findings provide in vitro evidence that allele-specific RNAi can rescue diseased phenotype in LQTS cardiomyocytes. This is a potentially novel route for the treatment of many autosomal-dominant-negative disorders, including those of the heart.
Assuntos
Canais de Potássio Éter-A-Go-Go/genética , Síndrome do QT Longo/genética , Miócitos Cardíacos/fisiologia , Células-Tronco Pluripotentes/fisiologia , Interferência de RNA/fisiologia , Canal de Potássio ERG1 , Fenômenos Eletrofisiológicos/genética , Expressão Gênica/genética , Técnicas de Silenciamento de Genes , Terapia Genética , Humanos , Síndrome do QT Longo/fisiopatologia , Síndrome do QT Longo/terapia , Mutação de Sentido Incorreto/genética , Fenótipo , TransfecçãoRESUMO
OBJECTIVE: To evaluate the association between hypercarbia in the first 24 h of life and clinical outcomes in infants with congenital diaphragmatic hernia (CDH). STUDY DESIGN: Retrospective review of patients entered into the CDHSG registry between 2007-2014. Half of the identified patients were analyzed to identify the PaCO2 value most predictive of mortality. Prediction models for outcomes of death, ECMO, and respiratory support at 30 days of life (DOL) were developed using PaCO2. Remaining half of data was used for validation of study findings. RESULTS: 1878 and 1875 patients were analyzed in the testing and validation groups. Lowest PaCO2≥60 mmHg in the first DOL is highly predictive of death prior to discharge. Prediction models including this variable demonstrate good discrimination for outcomes of death, ECMO, and respiratory support (AUC 0.8808, 0.8279, 0.8065). CONCLUSION: Lowest PaCO2 in the first DOL is an independent risk factor of mortality and morbidity in CDH.
Assuntos
Dióxido de Carbono/sangue , Hérnias Diafragmáticas Congênitas/mortalidade , Hérnias Diafragmáticas Congênitas/terapia , Oxigenação por Membrana Extracorpórea/mortalidade , Feminino , Hérnias Diafragmáticas Congênitas/sangue , Humanos , Recém-Nascido , Modelos Logísticos , Masculino , Morbidade , Análise Multivariada , Valor Preditivo dos Testes , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença , Texas/epidemiologiaRESUMO
A scalable and cost-effective synthetic polymer substrate that supports robust expansion and subsequent multilineage differentiation of human pluripotent stem cells (hPSCs) with defined commercial media is presented. This substrate can be applied to common cultureware and used off-the-shelf after long-term storage. Expansion and differentiation of hPSCs are performed entirely on the polymeric surface, enabling the clinical potential of hPSC-derived cells to be realized.
Assuntos
Técnicas de Cultura de Células/instrumentação , Diferenciação Celular/fisiologia , Células-Tronco Pluripotentes/fisiologia , Polímeros , Adesão Celular/fisiologia , Linhagem Celular , Linhagem da Célula , Meios de Cultura , Imunofluorescência , Ensaios de Triagem em Larga Escala , Humanos , Análise em MicrossériesRESUMO
In September 2003, legislation approved in Denmark legalized work on surplus human embryos from IVF for clinical purposes to establish human embryonic stem (ES) cell cultures. The aim of this study was to establish such stem cell lines. Fresh surplus embryos were donated after informed consent from the donors. Embryos were cultured into blastocysts and using the immunosurgery procedure, inner cell masses were isolated and cultured on irradiated human foreskin fibroblasts in KnockOut D-MEM supplemented with KnockOut Serum Replacement, bFGF, and LIF. Within a period of 12 months, 198 embryos were donated. Four isolated inner cell masses developed into putative ES cell lines, CLS1, CLS2, CLS3, CLS4, which have now been continuously cultured for eight months, corresponding to 30 passages. These cells expressed markers for undifferentiated human ES cells: stage-specific embryonic antigen-4, tumour-related antigen (TRA)-1-60, TRA-1-81, OCT4, NANOG, SOX2, and FGF4. The cells expressed high levels of telomerase activity, had a normal karyotype, and have been successfully cryopreserved and thawed. Finally, the cells displayed the potential to differentiate in vitro into cell types originating from all three germ layers. It is thought that the cell lines described in this study are the first human ES cells established in Denmark.