论文部分内容阅读
人表皮干细胞(human keratinocyte stem cells,hKSCs)可作为上皮源性的成体干细胞应用于牙齿再生,但是其诱导效率较低.本研究利用小分子化合物CHIR-99021提高hKSCs的Wnt/β-catenin信号活性,再与具有诱导成牙潜能的小鼠牙胚间充质重组,构建嵌合体,并移植裸鼠肾囊膜下培养20 d.将嵌合体组织切片,并利用组织染色和免疫组化等方法鉴定牙齿结构.结果显示,经FGF8诱导处理的hKSCs与小鼠牙胚间充质构成的嵌合体的成牙率为27.80%,其中成釉率仅为40.00%;经CHIR-99021诱导处理的hKSCs与小鼠牙胚间充质构成的嵌合体的成牙率仅为18.20%,其中成釉率高达100%;而CHIR-99021与FGF8协同作用,则进一步提高嵌合体成牙率至40.00%,其中成釉率也达75.00%.进一步的研究发现,经CHIR-99021处理后,hKSCs的Wnt/β-catenin信号活性明显提高,同时FGF8的表达水平也显著上调.以上结果表明,CHIR-99021可通过上调Wnt/β-catenin信号活性水平,同时促进FGF8表达,与FGF8协同,高效诱导hKSCs分化为具有分泌釉质功能的成釉质细胞.研究结果对利用hKSCs作为上皮来源的成体细胞应用于人类牙齿再生的研究具有重要意义.
Human keratinocyte stem cells (hKSCs) can be used as epithelial-derived adult stem cells for tooth regeneration, but their induction efficiency is low.In this study, hKSCs Wnt / β-catenin signaling activity was enhanced by small molecule compound CHIR-99021 , And then with the tooth germ-induced mouse tooth into embryos to induce mesenchymal reorganization, the construction of chimera, and transplanted in nude mice subrenal subcutaneously cultured for 20 d. Chimera tissue sections and the use of tissue staining and immunohistochemical methods The tooth structure of hKSCs induced by FGF8 and mesenchyme of mouse tooth germ was 27.80%, and the rate of glaze formation was only 40.00%. The hKSCs induced by CHIR-99021 The rate of enamel formation was only up to 100% with the mosaic of mouse tooth germ, which was only 18.20%, while the synergistic effect of CHIR-99021 and FGF8 further enhanced the molar ratio of chimerism to 40.00% The rate of formation of glaze also reached 75.00% .Further study found that, after treatment with CHIR-99021, hKSCs Wnt / β-catenin signal activity was significantly increased, while the expression of FGF8 also significantly upregulated.The above results show that, CHIR-99021 Wnt / |Â-catenin signaling is up-regulated Sex, and promote the expression of FGF8 at the same time, synergize with FGF8 and efficiently induce hKSCs to differentiate into enamel cells with the function of secreting enamel.The results of this study are of great significance for the study of human tooth regeneration using hKSCs as epithelial derived adult cells.