Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
Sci Adv. 2023 Jan 27;9(4):eade7002. doi: 10.1126/sciadv.ade7002.
Microglia are important mediators of neuroinflammation, which underlies neuropathic pain. However, the molecular checkpoints controlling microglial reactivity are not well-understood. Here, we investigated the role of Orai1 channels for microglia-mediated neuroinflammation following nerve injury and find that deletion of Orai1 in microglia attenuates Ca signaling and the production of inflammatory cytokines by proalgesic agonists. Conditional deletion of Orai1 attenuated microglial proliferation in the dorsal horn, spinal cytokine levels, and potentiation of excitatory neurotransmission following peripheral nerve injury. These cellular effects were accompanied by mitigation of pain hyperalgesia in microglial Orai1 knockout mice. A small-molecule Orai1 inhibitor, CM4620, similarly mitigated allodynia in male mice. Unexpectedly, these protective effects were not seen in female mice, revealing sexual dimorphism in Orai1 regulation of microglial reactivity and hyperalgesia. Together, these findings indicate that Orai1 channels are key regulators of the sexually dimorphic role of microglia for the neuroinflammation that underlies neuropathic pain.
小胶质细胞是神经炎症的重要介质,而神经炎症是神经性疼痛的基础。然而,控制小胶质细胞反应的分子检查点还没有被很好地理解。在这里,我们研究了 Orai1 通道在神经损伤后小胶质细胞介导的神经炎症中的作用,发现小胶质细胞中 Orai1 的缺失可减弱疼痛敏化激动剂引起的 Ca 信号和炎性细胞因子的产生。Orai1 的条件性缺失可减轻背角小胶质细胞的增殖、脊髓细胞因子水平以及外周神经损伤后的兴奋性神经传递的增强。这些细胞效应伴随着小胶质细胞 Orai1 敲除小鼠疼痛超敏反应的减轻。一种小分子 Orai1 抑制剂 CM4620 也可减轻雄性小鼠的痛觉过敏。出乎意料的是,这些保护作用在雌性小鼠中并未出现,这表明 Orai1 对小胶质细胞反应性和痛觉过敏的调节存在性别二态性。总之,这些发现表明 Orai1 通道是小胶质细胞在神经性疼痛的神经炎症中发挥性别二态作用的关键调节因子。