Improving olfactory neuroplasticity through FAK/CNTF signaling

项目摘要 嗅觉上皮(OE)中的嗅觉神经元(OSNs)从基底茎不断更替 细胞并将轴突生长到嗅球以保持嗅觉。未能重组运营工程师 在受伤、感染或衰老后，会导致嗅觉功能障碍，这是一个安全和生活质量问题。不是 治疗方法是可用的。定义调节嗅神经可塑性的信号将揭示新的 改善嗅觉缺陷的治疗目标。睫状神经营养因子(CNTF)在血管内皮细胞高表达 水平基底细胞(HBCs)和嗅鞘细胞(OEC)，同时表达CNTFRα受体 在邻近的神经前体细胞球状基底细胞(GBCS)中。我们发现CNTF被抑制 粘着斑激酶(FAK)及其抑制剂的鼻腔应用通过促进OE神经发生 CNTF。重要的是，FAK抑制剂进一步增强了他巴唑引起的OE损伤后CNTF的表达。 我们将在雄性和雌性小鼠身上使用遗传、药理学和行为方法来测试 FAK抑制通过增加CNTF促进损伤后嗅神经可塑性的假说 表情。目标1将首先确定FAK-CNTF-CNTFRα通路在胆管细胞增殖中的作用 确定FAK抑制是否在HBCs、OEC或两者中诱导CNTF。我们还将确定是否 CNTF是否被释放来激活CNTFRα信号通路，在刺激GBC增殖中，以及FAK是否被抑制 通过这种细胞间机制起作用。为了增加我们发现的相关性，目标2将确定 抑制FAK是否可通过CNTF促进急性OE损伤后嗅神经的再生。因此，我们将 使用他巴唑急性损伤，确定损伤是否增加HbCs和/或OECs的CNTF 导致GBC增殖和神经再生增加。FAK抑制剂治疗急性肾功能衰竭的疗效观察 他巴唑可能存在于HbCs和/或OEC中，我们将进行测试。为了准备更多的研究，我们 将确定FAK抑制剂的最佳剂量，然后测试CNTF是否介导FAK抑制剂的作用 促进急性损伤后OE的神经再生。慢性嗅炎抑制HBC增殖和 增加HBCs中的FAK信号，提示CNTF可能被抑制。扩大与…的关联性 更多类型的嗅觉损伤，Aim 3将使用一种精炼的慢性嗅炎小鼠模型来 确定抑制FAK是否会增加CNTF并促进GBC增殖和嗅觉 神经发生。目的4将确定FAK抑制促进OSN轴突生长和嗅觉的能力 联合应用遗传轴突示踪法研究急性和慢性阻塞性肺损伤后的功能恢复 通过行为测试。该提案将确定FAK和CNTF的作用，并验证其治疗潜力 应用FAK抑制剂改善损伤后的嗅觉功能。FAK抑制剂在癌症临床中耐受性良好 试验和鼻腔给药避免了全身副作用。

Project Summary Olfactory sensory neurons (OSNs) in the olfactory epithelium (OE) are continuously replaced from basal stem cells and grow their axons to the olfactory bulb to maintain the sense of smell. Failure to reconstitute the OE after injury, infection or aging, causes olfactory dysfunction which is a safety and a quality of life issue. No treatments are available. Defining the signals that regulate olfactory neuroplasticity would reveal new therapeutic targets to improve olfactory deficits. Ciliary neurotrophic factor (CNTF) is highly expressed in horizontal basal cells (HBCs) and olfactory ensheathing cells (OECs), while the CNTFRα receptor is expressed in the neighboring neuronal progenitor globose basal cells (GBCs). We found that CNTF is suppressed by focal adhesion kinase (FAK) and that intranasal application of an FAK inhibitor promotes OE neurogenesis via CNTF. Importantly, FAK inhibitor further enhances CNTF expression caused by OE injury with methimazole. We will use genetic, pharmacological, and behavioral approaches in male and female mice to test the hypothesis that FAK inhibition promotes olfactory neuroplasticity following injury by increasing CNTF expression. Aim 1 will define the FAK-CNTF-CNTFRα pathway underlying GBC proliferation by first determining whether FAK inhibition induces CNTF in HBCs, OECs or both. We will also determine whether CNTF is released to activate CNTFRα signaling in stimulating GBC proliferation, and whether FAK inhibition acts through this intercellular mechanism. To increase the relevance of our findings, Aim 2 will determine whether FAK inhibition can increase olfactory neurogenesis via CNTF following acute OE injury. Thus, we will use acute injury with methimazole and determine whether injury increases CNTF in HBCs and/or OECs which leads to increased GBC proliferation and neurogenesis. The effect of FAK inhibitor treatment following methimazole may be within HBCs and/or OECs, something we will test. To prepare for additional studies, we will define an optimal dose of FAK inhibitor and then test whether CNTF mediates the effect of FAK inhibitor to promote OE neurogenesis after acute injury. Chronic olfactory inflammation inhibits HBC proliferation and increases FAK signaling in HBCs, suggesting that CNTF might be suppressed. To broaden the relevance to more types of olfactory injuries, Aim 3 will use a refined chronic olfactory inflammation mouse model to determine whether FAK inhibition increases CNTF and promotes GBC proliferation and olfactory neurogenesis. Aim 4 will determine the ability of FAK inhibition to promote OSN axonal growth and olfactory function recovery following acute and chronic types of OE injury, using genetic axon tracing methods combined with behavioral tests. This proposal will define the role of FAK and CNTF and validate the therapeutic potential of FAK inhibitors to improve olfactory function after injury. FAK inhibitors are well-tolerated in cancer clinical trials and intranasal administration avoids systemic side effects.