RESUMO
Recent advances in somatic cell reprogramming have highlighted the plasticity of the somatic epigenome, particularly through demonstrations of direct lineage reprogramming of adult mouse and human fibroblasts to induced pluripotent stem cells (iPSCs) and induced neurons (iNs) under defined conditions. However, human cells appear to be less plastic and have a higher epigenetic hurdle for reprogramming to both iPSCs and iNs. Here, we show that SH2B adaptor protein 1ß (SH2B1) can enhance neurite outgrowth of iNs reprogrammed from human fibroblasts as early as day 14, when combined with miR124 and transcription factors BRN2 and MYT1L (IBM) under defined conditions. These SH2B1-enhanced iNs (S-IBM) showed canonical neuronal morphology, and expressed multiple neuronal markers, such as TuJ1, NeuN, and synapsin, and functional proteins for neurotransmitter release, such as GABA, vGluT2, and tyrosine hydroxylase. Importantly, SH2B1 accelerated mature process of functional neurons and exhibited action potentials as early as day 14; without SH2B1, the IBM iNs do not exhibit action potentials until day 21. Our data demonstrate that SH2B1 can enhance neurite outgrowth and accelerate the maturation of human iNs under defined conditions. This approach will facilitate the application of iNs in regenerative medicine and in vitro disease modeling.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Células-Tronco Neurais/metabolismo , Neuritos/metabolismo , Neurogênese , Neurônios/metabolismo , Medicina Regenerativa/métodos , Potenciais de Ação , Proteínas Adaptadoras de Transdução de Sinal/genética , Biomarcadores/metabolismo , Forma Celular , Células Cultivadas , Reprogramação Celular , Genótipo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Fatores do Domínio POU/genética , Fatores do Domínio POU/metabolismo , Fenótipo , Fatores de Tempo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , TransfecçãoRESUMO
Cell-based therapy could aid in alleviating symptoms or even reversing the progression of neurodegenerative diseases and nerve injuries. Fibroblast growth factor 1 (FGF1) has been shown to maintain the survival of neurons and induce neurite outgrowth. Accumulating evidence suggests that combination of FGF1 and cell-based therapy is promising for future therapeutic application. Neural stem cells (NSCs), with the characteristics of self-renewal and multipotency, can be isolated from embryonic stem cells, embryonic ectoderm, and developing or adult brain tissues. For NSC clinical application, several critical problems remain to be resolved: (1) the source of NSCs should be personalized; (2) the isolation methods and protocols of human NSCs should be standardized; (3) the clinical efficacy of NSC transplants must be evaluated in more adequate animal models; and (4) the mechanism of intrinsic brain repair needs to be better characterized. In addition, the ideal imaging technique for tracking NSCs would be safe and yield high temporal and spatial resolution, good sensitivity and specificity. Here, we discuss recent progress and future development of cell-based therapy, such as NSCs, induced pluripotent stem cells, and induced neurons, in neurodegenerative diseases and peripheral nerve injuries.
