RESUMEN
In the present study, we showed that the dorsal root ganglion (DRG) in the mouse embryo contains pluripotent stem cells (PSCs) that have developmental capacities equivalent to those of embryonic stem (ES) cells and induced pluripotent stem cells. Mouse embryonic DRG cells expressed pluripotency-related transcription factors [octamer-binding transcription factor 4, SRY (sex determining region Y)-box containing gene (Sox) 2, and Nanog] that play essential roles in maintaining the pluripotency of ES cells. Furthermore, the DRG cells differentiated into ectoderm-, mesoderm- and endoderm-derived cells. In addition, these cells produced primordial germ cell-like cells and embryoid body-like spheres. We also showed that the combination of leukemia inhibitor factor/bone morphogenetic protein 2/fibroblast growth factor 2 effectively promoted maintenance of the pluripotency of the PSCs present in DRGs, as well as that of neural crest-derived stem cells (NCSCs) in DRGs, which were previously shown to be present there. Furthermore, the expression of pluripotency-related transcription factors in the DRG cells was regulated by chromodomain helicase DNA-binding protein 7 and Sox10, which are indispensable for the formation of NCSCs, and vice versa. These findings support the possibility that PSCs in mouse embryonic DRGs are NCSCs.
RESUMEN
Neural crest-derived stem cells (NCSCs) are tissue-specific stem cells derived from multipotent neural crest cells. NCSCs are present in some adult tissues such as dorsal root ganglia, sciatic nerve, and bone marrow. However, little is known about the formation mechanisms of these cells. We have shown that BMP2/Wnt3a signaling and a chromatin remodeler, CHD7, in mice help to maintain the multipotency of neural crest cells and lead to the formation of NCSCs. In the present study, we analyzed a regulatory gene cascade in the formation of mouse NCSCs. The inhibition of FoxD3 expression significantly suppressed the expression of Sox10, which is an indispensable transcription factor for mouse NCSC formation, in the presence of BMP2/Wnt3a. CHD7, Oct3/4, Sox2, and Nanog occupied multiple conserved regions of mouse FoxD3, mE1, mE2, and mE3, in a BMP2/Wnt3a-dependent manner. Furthermore, siRNA of CHD7, Oct3/4, Sox2, and Nanog significantly suppressed FoxD3 expression. The inhibition of histone H3K4 mono- or trimethylation also repressed FoxD3 expression. The present data suggest that CHD7, Oct3/4, Sox2, and Nanog directly induce FoxD3 expression when stimulated by BMP2/Wnt3a signaling, that FoxD3 promotes Sox10 expression, and that histone H3K4 methylation plays important roles in this process of mouse NCSC formation.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Factores de Transcripción Forkhead/genética , Factores de Transcripción Forkhead/metabolismo , Proteína Homeótica Nanog/metabolismo , Cresta Neural/citología , Cresta Neural/metabolismo , Células-Madre Neurales/citología , Células-Madre Neurales/metabolismo , Factor 3 de Transcripción de Unión a Octámeros/metabolismo , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Factores de Transcripción SOXB1/metabolismo , Animales , Secuencia de Bases , Sitios de Unión/genética , Proteína Morfogenética Ósea 2/metabolismo , Células Cultivadas , Secuencia Conservada , Proteínas de Unión al ADN/antagonistas & inhibidores , Proteínas de Unión al ADN/genética , Regulación del Desarrollo de la Expresión Génica , Técnicas de Silenciamiento del Gen , Redes Reguladoras de Genes , Histonas/metabolismo , Metilación , Ratones , Proteína Homeótica Nanog/antagonistas & inhibidores , Proteína Homeótica Nanog/genética , Cresta Neural/embriología , Factor 3 de Transcripción de Unión a Octámeros/antagonistas & inhibidores , Factor 3 de Transcripción de Unión a Octámeros/genética , Factor de Transcripción SOX9/metabolismo , Factores de Transcripción SOXB1/antagonistas & inhibidores , Factores de Transcripción SOXB1/genética , Factores de Transcripción SOXE/metabolismo , Proteína Wnt3A/metabolismoRESUMEN
We analyzed roles of two chromatin remodelers, Chromodomain Helicase DNA-binding protein 7 (CHD7) and SWItch/Sucrose NonFermentable-B (SWI/SNF-B), and Bone Morphogenetic Protein (BMP)/Wnt signaling in the maintenance of the multipotency of mouse trunk neural crest cells, leading to the formation of mouse neural crest-derived stem cells (mouse NCSCs). CHD7 was expressed in the undifferentiated neural crest cells and in the dorsal root ganglia (DRG) and sciatic nerve, typical tissues containing NCSCs. BMP/Wnt signaling stimulated the expression of CHD7 and participated in maintaining the multipotency of neural crest cells. Furthermore, the promotion of CHD7 expression maintained the multipotency of these cells. The inhibition of CHD7 and SWI/SNF-B expression significantly suppressed the maintenance of the multipotency of these cells. In addition, BMP/Wnt treatment promoted CHD7 expression and caused the increase of the percentage of multipotent cells in DRG. Thus, the present data suggest that the chromatin remodelers as well as BMP/Wnt signaling play essential roles in the maintenance of the multipotency of mouse trunk neural crest cells and in the formation of mouse NCSCs.