Institute of Pharmacology and Clinical Pharmacy, Goethe University, 60438 Frankfurt am Main, Germany.
Albert Einstein College of Medicine, Department of Biochemistry, Bronx, NY 10461, USA.
Free Radic Biol Med. 2021 May 20;168:155-167. doi: 10.1016/j.freeradbiomed.2021.03.021. Epub 2021 Mar 28.
Previous studies suggested that reactive oxygen species (ROS) produced by NADPH oxidase 4 (Nox4) affect the processing of neuropathic pain. However, mechanisms underlying Nox4-dependent pain signaling are incompletely understood. In this study, we aimed to identify novel Nox4 downstream interactors in the nociceptive system. Mice lacking Nox4 specifically in sensory neurons were generated by crossing Advillin-Cre mice with Nox4 mice. Tissue-specific deletion of Nox4 in sensory neurons considerably reduced mechanical hypersensitivity and neuronal action potential firing after peripheral nerve injury. Using a proteomic approach, we detected various proteins that are regulated in a Nox4-dependent manner after injury, including the small calcium-binding protein S100A4. Immunofluorescence staining and Western blot experiments confirmed that S100A4 expression is massively up-regulated in peripheral nerves and dorsal root ganglia after injury. Furthermore, mice lacking S100A4 showed increased mechanical hypersensitivity after peripheral nerve injury and after delivery of a ROS donor. Our findings suggest that S100A4 expression is up-regulated after peripheral nerve injury in a Nox4-dependent manner and that deletion of S100A4 leads to an increased neuropathic pain hypersensitivity.
先前的研究表明，NADPH 氧化酶 4（Nox4）产生的活性氧（ROS）会影响神经病理性疼痛的处理。然而，Nox4 依赖性疼痛信号转导的机制尚不完全清楚。在这项研究中，我们旨在确定疼痛系统中 Nox4 下游的新相互作用蛋白。通过将 Advillin-Cre 小鼠与 Nox4 小鼠杂交，生成了特异性在感觉神经元中缺失 Nox4 的小鼠。感觉神经元中 Nox4 的组织特异性缺失可显著减轻周围神经损伤后的机械性超敏反应和神经元动作电位发放。通过蛋白质组学方法，我们检测到各种受 Nox4 调控的蛋白，包括小钙结合蛋白 S100A4。免疫荧光染色和 Western blot 实验证实，S100A4 的表达在外周神经和背根神经节损伤后大量上调。此外，S100A4 缺失的小鼠在周围神经损伤后和 ROS 供体给药后表现出机械性超敏反应增加。我们的研究结果表明，S100A4 的表达在外周神经损伤后以 Nox4 依赖性方式上调，并且 S100A4 的缺失导致神经病理性疼痛超敏反应增加。
