Co-opting Lef-1 and miR-26b activities to regulate dental stem cells and their progeny

项目摘要 组织特异性再生需要祖细胞的功能，这些细胞可以分化来修复疾病或 受伤的组织。受影响的组织可能含有干细胞，它们的生长和图案是由 转录因子和信号通路。从干细胞壁龛中提取的干细胞有助于 在许多不同的器官中再生成熟的组织类型，包括气管、肺和牙齿 其他。这些生态位是在发育中的胚胎中形成的，必须通过对称的方式在一生中保持 产生子代多能干细胞的细胞分裂。细胞的另一个同样重要的行为 在干细胞的生态位中，是通过不对称细胞分裂产生分化的子细胞，然后 取代再生器官中受损的细胞，以使器官继续发挥作用。 然而，特定的microRNAs(MiRs)在这些过程中的作用尚不清楚。MIR已经成为 被认为在干细胞分化中发挥了作用。对miR表达进行合作的能力 重新编程和控制原始细胞向不同细胞类型的分化将是必要的重要工具 创造人造器官和修复疾病组织，拯救了数百万人的生命和公共资金。 我们推测mir-26b在一定程度上调节上下切牙的干细胞生态位。 调节Lef-1的表达，这一机制可能在许多容纳干细胞的组织中是共同的 利基市场。因此，在E14.5之前没有miR-26b的表达允许Lef-1在口腔中表达 上皮(胎盘)和Lacl(干细胞龛)在发育过程中。然而，在E14.5之后，miR-26b 牙齿上皮细胞中的表达限制Lef-1的表达，然后其他因子(Sox2)调节干细胞 维修。为了确定Lef-1和miR-26b在发育过程中如何影响基因表达 我们将追求三个目标：1)利用我们的小鼠模型来了解体内干细胞的增殖 并用miR-26b OE挽救Lef-1 OE表型。 明确miR-26b OE在牙齿发育中的作用；2)验证miR-26b、Lef-OE之间的分子相互作用。 3)分离培养的牙源性上皮细胞。 WT、Lef-1 OE、miR-26b OE和拯救小鼠，利用RNA-Seq、ChIP-Seq鉴定新的遗传途径。和 单电池序列

Project Summary Tissue specific regeneration requires the function of progenitor cells that can differentiate to repair diseased or injured tissues. Affected tissues can contain stem cells and their growth and patterning are controlled by transcription factors and signaling pathways. Stem cells derived from stem cell niches contribute to the regeneration of mature tissue types in many different organs, including the trachea, lungs and teeth, amongst others. These niches are formed in developing embryos, and must be maintained throughout life by symmetric cellular divisions that produce daughter pluripotent stem cells. Another equally important behavior of the cells in a stem cell niche is the production of differentiated daughter cells by asymmetric cell division, which then take the place of damaged cells in regenerative organs, in order to allow the organ to continue to function. However, the roles of specific microRNAs (miRs) in these processes are unclear. miRs have become appreciated as playing a role in stem cell differentiation. The ability to coopt miR expression in order to reprogram and control the differentiation of naive cells into different cell types will be an important tool required to create artificial organs and repair diseased tissues, saving millions of lives and public dollars. We hypothesize that miR-26b is acting in part to regulate the stem cell niche of the lower and upper incisor by regulating Lef-1 expression, and that this mechanism may be common to many tissues that house stem cell niches. Thus, the absence of miR-26b expression prior to E14.5 allows Lef-1 expression in the oral epithelium (placode) and LaCL (stem cell niche) during development. However, after E14.5, miR-26b expression in the dental epithelium restricts Lef-1 expression and then other factors (Sox2) regulate stem cell maintenance. In order to determine how Lef-1 and miR-26b is affecting gene expression during development and cells we will pursue three aims: 1) to use our murine models to understand in vivo stem cell proliferation and differentiation by Lef-1 and miR-26b OE; and use miR-26b OE to rescue the Lef-1 OE phenotype and define the role of miR-26b OE in dental development; 2) validate molecular interactions between miR-26b, Lef- 1 and known factors involved in DESC proliferation and differentiation; 3) isolate the dental epithelial cells from WT, Lef-1 OE, miR-26b OE and rescue mice to identify new genetic pathways using RNA-Seq, ChIP-Seq. and Single cell Seq.