TNFα Enhances Calcium Influx by Interacting with AMPA Receptors in the Spinal Dorsal Horn Neurons
TNFα Enhances Calcium Influx by Interacting with AMPA Receptors in the Spinal Dorsal Horn Neurons
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TNFα 通过与脊髓背角神经元中的 AMPA 受体相互作用来增强钙流入
DOI：
10.1007/s12035-022-03062-4
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发表时间：
2022-10-08
影响因子：
5.1
通讯作者：
Tao, Feng
中科院分区：
文献类型：
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作者：
Li, Changsheng;Liu, Sufang;Tao, Feng
肿瘤坏死因子α（TNF α）是一种促炎细胞因子，与疼痛调节有关。脊髓背角的神经元活动有助于伤害性信息的传递。然而，TNF α如何影响脊髓背角神经元的活性还不完全清楚。在本研究中，我们使用钙成像来表征TNF α调节培养的脊髓背角神经元中钙内流的机制。我们观察到，TNF α孵育引起培养的脊髓背角神经元中特异性细胞内钙指示剂Fura-2的荧光强度增加，并且这种作用被选择性TNF α受体拮抗剂R7050显著抑制，这表明TNF α可以通过激活脊髓背角的TNF α受体来增加钙内流，从而增加神经元的活动。采用免疫荧光双染法，我们发现TNF α受体与α-氨基-3-羟基-5-甲基-4-异恶唑丙酸酯（AMPA）受体亚单位GluA 1在脊髓背角神经元中共表达。我们进一步观察到，1-萘基乙酰精胺（NASPM），一种特异性的钙渗透性AMPA受体阻断剂，处理完全阻断TNF α孵育对培养神经元钙内流的影响。此外，脂多糖（LPS）诱导的钙内流抑制与R7050共孵育。总之，我们的研究结果表明，在脊髓背角的TNF α可以增加钙指示的神经元活动，通过其受体和钙渗透AMPA受体之间的相互作用。
Tumor necrosis factor alpha (TNF alpha) is a proinflammatory cytokine and has been implicated in pain regulation. Neuronal activity in the spinal dorsal horn contributes to nociceptive transmission. However, it is not fully understood how TNF alpha affects the activity of spinal dorsal horn neurons. In the present study, we used calcium imaging to characterize the mechanism by which TNF alpha regulates calcium influx in the cultured spinal dorsal horn neurons. We observed that TNF alpha incubation caused an increase in fluorescent intensity of Fura-2, a specific intracellular calcium indicator, in the cultured spinal dorsal horn neurons, and such effect was significantly inhibited by co-incubation with R7050, a selective TNF alpha receptor antagonist, which suggests that TNF alpha can enhance calcium influx and increase neuronal activity via activating TNF alpha receptors in the spinal dorsal horn. Using double immunofluorescence staining, we showed that TNF alpha receptors were co-expressed with a-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptor subunit GluA1 in the spinal dorsal horn neurons. We further observed that treatment with 1-naphthyl acetyl spermine (NASPM), a specific calcium-permeable AMPA receptor blocker, completely blocked the effect of TNF alpha incubation on calcium influx in the cultured neurons. Moreover, lipopolysaccharide (LPS)-induced calcium influx was inhibited by co-incubation with R7050. Together, our results suggest that TNF alpha in the spinal dorsal horn can increase calcium-indicated neuronal activity through the interaction between its receptor and calcium-permeable AMPA receptors.