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

项目摘要/摘要： 伤口愈合不良是胰岛素抵抗糖尿病的一个主要健康问题。糖尿病患者的神经变性 有助于延迟愈合，并与减少基础角质形成细胞在 伤口床。提高了对神经元和角质形成细胞之间的交流的理解，这是 对伤口修复至关重要，可能会导致新的干预措施。皮肤感觉神经现在被认为是 包括具有不同标记和功能的几个亚型。确定神经元亚型(S) 参与伤口愈合可能为新的治疗方向提供线索。探索具体的影响 关于伤口愈合的神经元-角质形成细胞通讯，我们将首先消融健康人特定的神经元亚群 利用小鼠皮肤白喉毒素受体的基因表达，将评估其对皮肤愈合的影响 夹板上的伤口。我们将通过化学方法引入和证实亚群神经元的参与。 激活刺激性设计受体(DREADD)，我们预计如果在 对正常愈合很重要的神经亚群。我们已经证明，神经退化是由 神经元的过度兴奋性和将抑制性DREADDS引入大多数感觉神经的作用 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 对治愈的影响尚不清楚。在此观察的基础上，我们将把这些抑制性DREADD引入 糖尿病小鼠特定神经元亚群对愈合的影响以及是一种还是多种亚型 神经元的损伤是退化和修复损伤的关键。这些对健康和糖尿病小鼠的研究将 允许我们捕获未受伤和受伤的边缘皮肤进行转录分析。特别是，我们 将评估G蛋白偶联受体(GPCRs)表达的变化。通过以下方式激活这些GPCR 选择性激动剂应复制DREADDS的观察效果。我们预期这些研究将会 利用高通量技术在角质形成细胞中发现小分子药物的潜在靶点 评估钙信号、迁移、增殖和毒性。最好的候选人将在培养中接受局部测试 3D人糖尿病创面模型以及随后在我们的2型糖尿病小鼠模型中发现新的 促进伤口愈合的干预措施。这些拟议的研究将增加我们对这一角色的理解 神经传入亚群在糖尿病和正常伤口愈合中起作用。此外，通过确定责任 在糖尿病伤口愈合过程中改变的神经亚群和基因表达模式，我们可以筛选 并推进新的小分子的临床前试验，这些小分子可以局部应用来促进皮肤溃疡的愈合 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.