Project description:The neural crest (NC) is a transient dynamic structure of ectodermal origin, found in early vertebrate embryos. The multipotential NC cells migrate along well defined routes, differentiate to various cells types including melanocytes and participate in the formation of various permanent tissues. Abnormal development of NC cells causes several human diseases M-bM-^@M-^S neurocristopathies. As there is only limited information about the molecular mechanisms controlling early events in melanocyte specification and development, we exploited the AMV v-Myb transcriptional regulator, which directs differentiation of in vitro chicken NC cells to the melanocyte lineage. This activity is strictly dependent on v-Myb specifically binding to the Myb recognition DNA element (MRE). The two tamoxifen-inducible v-myb alleles were constructed, one which recognizes the MRE and one which does not. These were activated in ex-ovo NC cells, and the expression profiles of resulting cells were analyzed using Affymetrix microarrays and RT-PCR. These approaches revealed up-regulation of the BMP antagonist gremlin 2 mRNA, and down-regulation of mRNAs encoding several epithelial genes including KRT19 as very early events following the activation of melanocyte differentiation by v-Myb. Comparison of gene expression profiles of chicken neural crest cells constitutively expressing 4-OH-tamoxifen inducible v-myb with mutated leucine zipper region or a version with an additional point mutation (N118D) in the DNA-binding domain. Three biological replicates were analyzed for each group.
Project description:The neural crest (NC) is a transient dynamic structure of ectodermal origin, found in early vertebrate embryos. The multipotential NC cells migrate along well defined routes, differentiate to various cells types including melanocytes and participate in the formation of various permanent tissues. Abnormal development of NC cells causes several human diseases – neurocristopathies. As there is only limited information about the molecular mechanisms controlling early events in melanocyte specification and development, we exploited the AMV v-Myb transcriptional regulator, which directs differentiation of in vitro chicken NC cells to the melanocyte lineage. This activity is strictly dependent on v-Myb specifically binding to the Myb recognition DNA element (MRE). The two tamoxifen-inducible v-myb alleles were constructed, one which recognizes the MRE and one which does not. These were activated in ex-ovo NC cells, and the expression profiles of resulting cells were analyzed using Affymetrix microarrays and RT-PCR. These approaches revealed up-regulation of the BMP antagonist gremlin 2 mRNA, and down-regulation of mRNAs encoding several epithelial genes including KRT19 as very early events following the activation of melanocyte differentiation by v-Myb.
Project description:INK4A expression in leukemic cells transformed by the v-Myb oncoprotein depends on the integrity of the v-Myb leucine zipper region
Project description:The neural crest is a highly plastic stem cell population that represents a notable exception to the germ layer theory. Despite being of ectodermal origin, these cells can differentiate into skeletal derivatives like cartilage and bone, tissues that are typically formed by mesoderm. The inductive program that endows the neural crest with these unique properties is still poorly understood. Here, we report that Smad2/3-mediated TGFβ signaling endows cranial neural crest cells with enhanced developmental potential. Our results show that TGFβ signaling modulates neural crest axial identity and directly activates the gene circuits that support skeletal differentiation. Cooperation between TGFβ and low levels of WNT-signaling in the embryonic head activates cranial-specific cis-regulatory elements of anterior genes. Activation of the TGFβ pathway allowed reprogramming of trunk neural crest cells to adopt an anterior identity and led to the development of an improved protocol for the generation of human cranial neural crest cells. Our findings indicate TGFβ signaling is required for the specification of cranial neural crest cells, endowing them with the potential to give rise to the craniofacial skeleton.
Project description:The neural crest is a highly plastic stem cell population that represents a notable exception to the germ layer theory. Despite being of ectodermal origin, these cells can differentiate into skeletal derivatives like cartilage and bone, tissues that are typically formed by mesoderm. The inductive program that endows the neural crest with these unique properties is still poorly understood. Here, we report that Smad2/3-mediated TGFβ signaling endows cranial neural crest cells with enhanced developmental potential. Our results show that TGFβ signaling modulates neural crest axial identity and directly activates the gene circuits that support skeletal differentiation. Cooperation between TGFβ and low levels of WNT-signaling in the embryonic head activates cranial-specific cis-regulatory elements of anterior genes. Activation of the TGFβ pathway allowed reprogramming of trunk neural crest cells to adopt an anterior identity and led to the development of an improved protocol for the generation of human cranial neural crest cells. Our findings indicate TGFβ signaling is required for the specification of cranial neural crest cells, endowing them with the potential to give rise to the craniofacial skeleton.
Project description:The neural crest is a highly plastic stem cell population that represents a notable exception to the germ layer theory. Despite being of ectodermal origin, these cells can differentiate into skeletal derivatives like cartilage and bone, tissues that are typically formed by mesoderm. The inductive program that endows the neural crest with these unique properties is still poorly understood. Here, we report that Smad2/3-mediated TGFβ signaling endows cranial neural crest cells with enhanced developmental potential. Our results show that TGFβ signaling modulates neural crest axial identity and directly activates the gene circuits that support skeletal differentiation. Cooperation between TGFβ and low levels of WNT-signaling in the embryonic head activates cranial-specific cis-regulatory elements of anterior genes. Activation of the TGFβ pathway allowed reprogramming of trunk neural crest cells to adopt an anterior identity and led to the development of an improved protocol for the generation of human cranial neural crest cells. Our findings indicate TGFβ signaling is required for the specification of cranial neural crest cells, endowing them with the potential to give rise to the craniofacial skeleton.
Project description:The neural crest is a highly plastic stem cell population that represents a notable exception to the germ layer theory. Despite being of ectodermal origin, these cells can differentiate into skeletal derivatives like cartilage and bone, tissues that are typically formed by mesoderm. The inductive program that endows the neural crest with these unique properties is still poorly understood. Here, we report that Smad2/3-mediated TGFβ signaling endows cranial neural crest cells with enhanced developmental potential. Our results show that TGFβ signaling modulates neural crest axial identity and directly activates the gene circuits that support skeletal differentiation. Cooperation between TGFβ and low levels of WNT-signaling in the embryonic head activates cranial-specific cis-regulatory elements of anterior genes. Activation of the TGFβ pathway allowed reprogramming of trunk neural crest cells to adopt an anterior identity and led to the development of an improved protocol for the generation of human cranial neural crest cells. Our findings indicate TGFβ signaling is required for the specification of cranial neural crest cells, endowing them with the potential to give rise to the craniofacial skeleton.