A new Drosophila model of astrocyte calcium signaling in chronic pain

项目总结 慢性神经性疼痛是一种严重影响生活质量的破坏性疾病。更好 因此，了解急性神经损伤如何转变为慢性神经病理性疼痛是一个关键的创举 疼痛研究。过渡到神经病理性疼痛通常涉及中枢敏感化，其中伤害性感觉 中枢神经系统中的网络对感觉输入变得高度敏感。在中枢敏化过程中 星形胶质细胞变得高度反应，释放兴奋性和突触生成因子，这是 伤害性网络敏化。这些星形胶质细胞的功能受钙信号调节；然而， 神经病理性疼痛中星形胶质细胞所需的特定的钙信号机制还知之甚少。 星形胶质细胞钙信号涉及遍及整个细胞体和微域的体细胞钙瞬变 钙信号定位于细小的星形细胞突起。我们对这些不同星形胶质细胞的功能理解 产生这些信号的机制和通道的复杂性限制了这些信号 哺乳动物星形胶质细胞。我们的建议将直接解决这个问题，方法是利用 果蝇星形胶质细胞证明体细胞钙瞬变是由瞬时受体介导的 TrpML通道介导潜在(Trp)通道、水开关(Wtrw)和微域钙信号。 这第一次为我们提供了从基因上分离体细胞和微域钙信号的方法。 我们将把它与新开发的成年果蝇中枢神经病理性疼痛模型结合起来。在……里面 目的1，我们将确定抑制wtrw和trpm1如何影响神经病理性疼痛的发生。 成年果蝇。在目标2中，我们将直接分析成年果蝇的体细胞和微域钙信号 急性损伤后的星形胶质细胞。这些实验将使我们能够清楚地定义特定的钙信号 星形胶质细胞中驱动神经病理性疼痛的机制。这将是我们的一个重要突破 了解神经病理性疼痛的病因，并可能为新的疼痛治疗发展提供信息。

PROJECT SUMMARY Chronic neuropathic pain is a devastating condition that significantly impacts quality of life. Better understanding of how acute nerve injury transitions to chronic neuropathic pain is therefore a key initiative of pain research. Transition to neuropathic pain frequently involves central sensitization, where nociceptive networks in the central nervous system become hypersensitized to sensory inputs. During central sensitization astrocytes become highly reactive and release excitatory and synaptogenic factors that are required for nociceptive network sensitization. These astrocyte functions are regulated by Ca2+ signaling; however, the specific Ca2+ signaling mechanisms required in astrocytes for neuropathic pain are poorly understood. Astrocyte Ca2+ signaling involves somatic Ca2+ transients that traverse the entire cell body, and microdomain Ca2+ signals localized to thin astrocytic processes. Our functional understanding of these distinct astrocyte Ca2+ signals is limited by the complexity of mechanisms and channels that generate these signals in mammalian astrocytes. Our proposal will directly address this by taking advantage of recent seminal findings in Drosophila astrocytes demonstrating that somatic Ca2+ transients are mediated by the transient receptor potential (Trp) channel Waterwitch (Wtrw) and microdomain Ca2+ signals are mediated by TrpML channels. This provides us the means, for the first time, to genetically separate somatic and microdomain Ca2+ signals. We will combine this with a newly developed, adult Drosophila model of centrally mediated neuropathic pain. In Aim 1, we will determine how suppression of wtrw and trpml affects the development of neuropathic pain in adult Drosophila. In Aim 2, we will directly analyze somatic and microdomain Ca2+ signals in adult Drosophila astrocytes following acute injury. These experiments will allow us to clearly define the specific Ca2+ signaling mechanisms in astrocytes that drive neuropathic pain. This will represent an important breakthrough in our understanding of neuropathic pain etiology and may inform new pain therapeutic development.