The interaction between Hertwig＇s epithelial root sheath （HERS） and the adjacent mesenchyme is vitally important in mouse tooth root development. We previously generated odontoblast-specific Ctnnbl （encodingβ-cat...The interaction between Hertwig＇s epithelial root sheath （HERS） and the adjacent mesenchyme is vitally important in mouse tooth root development. We previously generated odontoblast-specific Ctnnbl （encodingβ-catenin） deletion mice, and demon- strated that odontoblast β-catenin signaling regulates odontoblast proliferation and differentiation. However, the role of odon- toblast β-catenin signaling in regulation of HERS behavior has not been fully investigated. Here, using the same odonto- blast-specific Ctnnbl deletion mice, we found that ablation of β-catenin signaling in odontoblasts led to aberrant HERS for- mation. Mechanistically, odontoblast-specific Ctnnbl deletion resulted in elevated bone morphogenetic protein 7 （Bmp7） ex- pression and reduced expression of noggin andfollistatin, both of which encode extracellular inhibitors of BMPs. Furthermore, the levels of phosphorylated Smadl/5/8 were increased in HERS cells. In vitro tissue culture confirmed that BMP7 treatment disrupted the HERS structure. Taken together, we demonstrated that odontoblast f3-catenin signaling may act through regula- tion of BMP signaling to maintain the integrity of HERS cells.展开更多
Paracrine pathway activities are being increasingly recognized as instrumental regulatory mechanisms of epithelial-stromal interactions that play important roles in physiological and pathological self-renewal of stem ...Paracrine pathway activities are being increasingly recognized as instrumental regulatory mechanisms of epithelial-stromal interactions that play important roles in physiological and pathological self-renewal of stem cells and in the initiation and maintenance of neoplastic tumor development.Stromal-specific Hedgehog(Hh)responses and epithelial-associated Wnt pathway activities have been recently appreciated as important factors in stem cell self-renewal and carcinogenesis.Furthermore,Hh and Wnt pathways frequently crosstalk with each other to regulate the growth of epithelial cells in a context-dependent manner.Because small molecule modulators of Hh and Wnt pathway activities are readily available,emerging roles of Hh-Wnt pathway crosstalk in epithelial-stromal interactions will shed light on the development of regenerative and anti-cancer medicines.展开更多
基金supported by grants from the State Key Program of the National Natural Science Foundation of China(81030018)the National Basic Research Program of China(2012CB966904)the National Natural Science Foundation of China(30900863,81241062)
文摘The interaction between Hertwig＇s epithelial root sheath （HERS） and the adjacent mesenchyme is vitally important in mouse tooth root development. We previously generated odontoblast-specific Ctnnbl （encodingβ-catenin） deletion mice, and demon- strated that odontoblast β-catenin signaling regulates odontoblast proliferation and differentiation. However, the role of odon- toblast β-catenin signaling in regulation of HERS behavior has not been fully investigated. Here, using the same odonto- blast-specific Ctnnbl deletion mice, we found that ablation of β-catenin signaling in odontoblasts led to aberrant HERS for- mation. Mechanistically, odontoblast-specific Ctnnbl deletion resulted in elevated bone morphogenetic protein 7 （Bmp7） ex- pression and reduced expression of noggin andfollistatin, both of which encode extracellular inhibitors of BMPs. Furthermore, the levels of phosphorylated Smadl/5/8 were increased in HERS cells. In vitro tissue culture confirmed that BMP7 treatment disrupted the HERS structure. Taken together, we demonstrated that odontoblast f3-catenin signaling may act through regula- tion of BMP signaling to maintain the integrity of HERS cells.
文摘Paracrine pathway activities are being increasingly recognized as instrumental regulatory mechanisms of epithelial-stromal interactions that play important roles in physiological and pathological self-renewal of stem cells and in the initiation and maintenance of neoplastic tumor development.Stromal-specific Hedgehog(Hh)responses and epithelial-associated Wnt pathway activities have been recently appreciated as important factors in stem cell self-renewal and carcinogenesis.Furthermore,Hh and Wnt pathways frequently crosstalk with each other to regulate the growth of epithelial cells in a context-dependent manner.Because small molecule modulators of Hh and Wnt pathway activities are readily available,emerging roles of Hh-Wnt pathway crosstalk in epithelial-stromal interactions will shed light on the development of regenerative and anti-cancer medicines.
