Neuron-Keratinocyte Communication in the Epidermis in Normal and Diabetic Wound Healing

项目概要/摘要： 伤口愈合不良是胰岛素抵抗型糖尿病的主要健康问题。糖尿病神经变性 有助于延迟愈合，并与基底角质形成细胞迁移减少有关。 伤口床提高了对神经元和角质形成细胞之间通讯的理解， 对于伤口修复至关重要，可能会导致新的干预措施。皮肤感觉神经现在被认为 包括以不同标志物和功能为特征的几种亚型。识别神经元亚型 参与伤口愈合可能提供线索，新的治疗方向。探索特定的影响 神经元-角质形成细胞通信对伤口愈合的影响，我们将首先消融健康人中的特定神经元亚群。 小鼠皮肤使用白喉毒素受体的基因表达，并将评估 夹板伤我们将通过化学发生学引入和 激活刺激性设计受体（DREADDs），我们希望如果在一个特定的环境中激活它， 神经亚群对正常愈合很重要。我们已经证明，神经退化的结果， 神经元过度兴奋和将抑制性DREADDs引入大多数感觉神经中， 糖尿病小鼠模型既抑制了这种兴奋，又逆转了神经退化，尽管 对愈合的影响是未知的。基于这一观察，我们将把这些抑制性DREADD引入到 糖尿病小鼠中的特定神经元亚群，以描述对愈合的影响，以及一种或多种亚型 是退化和愈合损伤的关键。这些在健康和糖尿病小鼠中的研究将 允许我们捕获未受伤和受伤边缘皮肤用于进行转录组学分析。我们尤其 将评估G蛋白偶联受体（GPCR）表达的变化。这些GPCR的激活， 选择性激动剂应复制所观察到的DREADD的作用。我们预计，这些研究将 使用高通量技术在角质形成细胞中发现涉及小分子药物的靶点， 评估钙信号、迁移、增殖和毒性。最佳候选人将在培养的 3D人类糖尿病伤口模型和随后在我们的2型糖尿病小鼠模型中寻找新的 促进伤口愈合。这些拟议的研究将增加我们对这一作用的理解， 神经传入亚群在糖尿病与正常伤口愈合中的作用。此外，通过确定负责人 在糖尿病伤口愈合过程中改变的神经和基因表达模式的子集，我们可以筛选 和先进的临床前试验的新的小分子，可以局部应用，以促进愈合的 糖尿病伤口

Project Summary/Abstract: Poor wound healing is a major health issue in insulin-resistant diabetes. Degeneration of nerves in diabetes contributes to the delay in healing and is associated with reduction in basal keratinocyte migration across the wound bed. Improved understanding of the communication between neurons and keratinocytes, which is critical for wound repair, may lead to new interventions. Cutaneous sensory nerves are now recognized to comprise several subtypes characterized by different markers and functions. Identifying the neuron subtype(s) involved in wound healing may provide clues to new therapeutic directions. To explore the impact of specific neuron-keratinocyte communication on wound healing, we will initially ablate specific neuron subsets in healthy mouse skin using genetic expression of diphtheria toxin receptors and will evaluate the impact on healing of splinted wounds. We will confirm subgroup neurons involvement by chemogenetically introducing and activating stimulatory designer receptors (DREADDs), which we expect to accelerate healing if activated in a nerve subset that is important for normal healing. We have shown that nerve degeneration results from neuronal hyperexcitability and that introducing inhibitory DREADDs into the majority of sensory nerves in a mouse model of diabetes both suppresses this excitation and reverses the nerve degeneration, although the impact on healing is unexplored. Building on this observation, we will introduce these inhibitory DREADDs into specific neuronal subsets in diabetic mice to delineate the impact on healing and whether one or more subtype of neurons is key to the degeneration and healing impairment. These studies in healthy and diabetic mice will allow us to capture unwounded and wound edge skin for conducting transcriptomic analysis. In particular, we will evaluate changes in expression of G-protein coupled receptors (GPCRs). Activation of these GPCRs with selective agonists should replicate the observed effects of DREADDs. We anticipate that these studies will implicate targets in keratinocytes for small molecule drug discovery using high throughput technology to assess calcium signals, migration, proliferation, and toxicity. Best candidates will be tested topically in cultured 3D human diabetic wound models and subsequently in our type 2 diabetic mouse models towards finding new interventions to promote wound healing. These proposed studies will increase our understanding of the role that nerve afferent subsets play in diabetic vs. normal wound healing. Furthermore, by identifying responsible subsets of nerves and gene expression patterns that are altered during diabetic wound healing, we can screen and advance preclinical trials of new small molecules that can be applied topically to promote healing of diabetic wounds.