Neuronal regulation of adult taste stem cells

项目总结 这项拟议的研究将阐明成人味觉干细胞神经调节的分子基础。味觉 器官在没有神经元输入的情况下退化，这是一个多世纪前描述的现象，但 这背后的细胞和分子机制还没有很好的定义。我们建议使用合并后的 通过与味觉干细胞的相互作用来确定R-响应蛋白-2(Rsp2)是否在体内和体外表达 受体Lgr5/Lgr6和/或Znrf3/RNF43是维持味蕾的味觉神经元产生的因子 正直。 在目标1中，我们将确定是否需要Rsp2来维持味蕾。使用功能损失方法， 有条件地消融支配味觉组织的味觉神经元的Rsp2将有助于确定 味觉神经元产生的Rsp2是维持味蕾完整性所必需的。相反，在味觉中 导致味觉组织失神经的神经切断模型，我们将确定是否系统供应 腺病毒和纯化蛋白重组的Rsp2足以产生味觉细胞和味蕾 在没有味觉神经支配的情况下再生。功能的丧失和功能的获得将建立 Rsp2在味觉组织维持的神经元调节中的作用。在目标2中，我们将确定Rsp2是否相互作用 通过其味觉干细胞表达的受体Lgr5/Lgr6和/或Znrf3/RNF43来调节味觉干细胞的活性。 我们将使用遗传方法，Rspo2突变体选择性地结合到Lgr5/Lgr6或Znrf3/RNF43，味觉 器官培养和味觉神经横断以确定Rsp2的作用。 接受化疗或放射治疗的癌症患者经常会经历味觉障碍。扭曲 或者失去味觉会导致食欲减退和营养不良。药物引起味觉障碍的机制 目前尚不清楚，但成人味觉干细胞活动的失调可能是罪魁祸首。完成目标 这里提出的将是朝着减轻味觉障碍的策略发展的重要步骤 味觉丧失或味觉扭曲的人所经历的。

PROJECT SUMMARY This proposed research will elucidate the molecular basis of neuronal regulation of adult taste stem cells. Taste organs degenerate in the absence of neuronal input, a phenomenon described more than a century ago, but the cellular and molecular mechanisms underlying this are not well defined. We propose to use a combined in vivo and in vitro approach to determine if R-spondin-2 (Rspo2), via interaction of its taste stem cell-expressed receptors Lgr5/Lgr6 and/or Znrf3/Rnf43, is the gustatory-neuron-produced factor that maintains taste bud integrity. In Aim 1, we will determine if Rspo2 is required for taste bud maintenance. Using a loss-of-function approach, conditional ablation of Rspo2 from gustatory neurons that innervate taste tissue will help determine whether gustatory neuron-produced Rspo2 is necessary to maintain taste bud integrity. Conversely, in a gustatory nerve transection model that leads to taste tissue denervation, we will determine if systemically supplied recombinant Rspo2 via adenovirus and purified protein is sufficient for taste cell generation and taste bud regeneration in the absence of gustatory innervation. The loss-of-function and gain-of-function will establish the role of Rspo2 in neuronal regulation of taste tissue maintenance. In Aim 2, we will determine if Rspo2 interacts with its taste stem cell-expressed receptors Lgr5/Lgr6 and/or Znrf3/Rnf43 to regulate taste stem cell activity. We will use genetic approaches, Rspo2 mutants that selectively bind to Lgr5/Lgr6 or Znrf3/Rnf43, taste organoid culture, and gustatory nerve transection to determine how Rspo2 acts. Cancer patients who receive chemotherapy or radiotherapy often experience taste disturbance. The distortion or loss of taste can lead to appetite loss and malnutrition. The mechanisms for drug-induced taste disturbance are not clear, but dysregulation of adult taste stem cell activity could be the culprit. Accomplishing the aims proposed here will be significant steps toward developing strategies for mitigating taste disturbances experienced by individuals who suffer from taste loss or taste distortion.