Neuronal regulation of adult taste stem cells

项目摘要 这项研究将阐明成年味觉干细胞神经调控的分子基础。味道 器官在缺乏神经元输入的情况下退化，这是一个世纪前描述的现象，但 这背后的细胞和分子机制尚未明确。我们建议使用一个组合在 体内和体外方法来确定是否R-spondin-2（Rspo 2），通过其味觉干细胞表达的相互作用， 受体Lgr 5/Lgr 6和/或Znrf 3/Rnf 43，是味觉神经元产生的维持味蕾的因子 完整 在目标1中，我们将确定味蕾维持是否需要Rspo 2。使用功能丧失的方法， 从支配味觉组织的味觉神经元中有条件地去除Rspo 2将有助于确定 味觉神经元产生的Rspo 2是维持味蕾完整性所必需的。相反，在味觉中， 神经横断模型，导致味觉组织去神经支配，我们将确定是否全身供应 通过腺病毒和纯化蛋白的重组Rspo 2足以用于味细胞产生和味蕾 在缺乏味觉神经支配的情况下再生。功能丧失和功能获得将建立 Rspo 2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Rspo 2是否与 用其味觉干细胞表达的受体Lgr 5/Lgr 6和/或Znrf 3/Rnf 43来调节味觉干细胞活性。 我们将使用遗传方法，选择性结合Lgr 5/Lgr 6或Znrf 3/Rnf 43的Rspo 2突变体， 类器官培养和味觉神经横切以确定Rspo 2如何起作用。 接受化疗或放疗的癌症患者经常会出现味觉障碍。失真 或失去味觉会导致食欲不振和营养不良。药物性味觉障碍的机制 目前尚不清楚，但成人味觉干细胞活性失调可能是罪魁祸首。实现目标 这里提出的将是发展减轻味觉障碍的策略的重要步骤 由遭受味觉丧失或味觉扭曲的个体经历。

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.