Control of Somatic Stem Cell Proliferation by Oct4

描述（由申请人提供）：本提案的总体目标是了解成体祖细胞中多能维持转录因子Oct4诱导增殖的分子机制，同时以细胞类型特异性的方式维持未分化状态。我们将使用含有强力霉素诱导的表达Oct4转基因的小鼠模型系统来解决这个问题。这种转基因在体内的激活会迅速导致皮肤和肠道干细胞的增生，但对其他类型的细胞没有明显的影响。我们将使用基因阵列技术鉴定肠上皮中Oct4靶基因和结合伙伴，然后进行稳定的、基于慢病毒的RNA干扰，以确定这些靶基因和协调节蛋白在Oct4激活后观察到的增生表型中的功能贡献。经过验证的Oct4协同调节因子最终将与Oct4一起引入纤维细胞（通常对Oct4的促增殖、抗分化作用难以耐受），最终目的是重新激活分化体细胞的多能状态。这一建议将描述可能被操纵以增强再生医学的分子机制。

DESCRIPTION (provided by applicant): The overall goal of this proposal is to gain an understanding of the molecular mechanisms by which the pluripotency-maintaining transcription factor Oct4 induces proliferation while simultaneously maintaining an undifferentiated state in a cell-type specific manner in adult progenitor cells. We will address this question using a mouse model system harboring a doxycycline-inducible, Oct4 expressing transgene. Activation of this transgene in vivo rapidly results in hyperplasia in skin and intestinal stem cells, but has no discernable effect in other cell types. We will use gene array technology to identify Oct4 target genes and binding partners in the intestinal epithileum followed by stable, lentiviral-based RNA interference to determine the functional contribution of these target genes and coregulatory proteins to the hyperplastic phenotype observed in response to Oct4 activation. Validated Oct4 coregulatory factors will ultimately be introduced along with Oct4 into fibrobiasts (normally refractory to the pro-proliferative, anti-differentiative effects of Oct4) for the ultimate purpose of reactivating a state of pluripotency in differentiated somatic cells. This proposal will delineate molecular mechanisms that can potentially be manipulated to enhance regenerative medicine.