正调控域 I 结合因子 1 通过抑制 Kv4.3 通道表达介导小鼠外周神经损伤诱导的痛觉过敏。

Positive Regulatory Domain I-binding Factor 1 Mediates Peripheral Nerve Injury-induced Nociception in Mice by Repressing Kv4.3 Channel Expression.

出版信息

Anesthesiology. 2021 Mar 1;134(3):435-456. doi: 10.1097/ALN.0000000000003654.

Abstract

BACKGROUND

The transcriptional repressor positive regulatory domain I-binding factor 1 (PRDM1) is expressed in adult mouse dorsal root ganglion and regulates the formation and function of peripheral sensory neurons. The authors hypothesized that PRDM1 in the dorsal root ganglion may contribute to peripheral nerve injury-induced nociception regulation and that its mechanism may involve Kv4.3 channel transcriptional repression.

METHODS

Nociception was induced in C57BL/6 mice by applying chronic constriction injury, complete Freund's adjuvant, or capsaicin plantar injection. Nociceptive response was evaluated by mechanical allodynia, thermal hyperalgesia, cold hyperalgesia, or gait analysis. The role of PRDM1 was evaluated by injection of Prdm1 knockdown and overexpression adeno-associated viruses. The interaction of PRDM1 at the Kv4.3 (Kcnd3) promoter was evaluated by chromatin immunoprecipitation assay. Excitability of dorsal root ganglion neurons was evaluated by whole cell patch clamp recordings, and calcium signaling in spinal dorsal horn neurons was evaluated by in vivo two-photon imaging.

RESULTS

Peripheral nerve injury increased PRDM1 expression in the dorsal root ganglion, which reduced the activity of the Kv4.3 promoter and repressed Kv4.3 channel expression (injured vs. uninjured; all P < 0.001). Knockdown of PRDM1 rescued Kv4.3 expression, reduced the high excitability of injured dorsal root ganglion neurons, and alleviated peripheral nerve injury-induced nociception (short hairpin RNA vs. Scram; all P < 0.05). In contrast, PRDM1 overexpression in naive mouse dorsal root ganglion neurons diminished Kv4.3 channel expression and induced hyperalgesia (PRDM1 overexpression vs. control, mean ± SD; n = 13; all P < 0.0001) as evaluated by mechanical allodynia (0.6 ± 0.3 vs. 1.2 ± 0.2 g), thermal hyperalgesia (5.2 ± 1.3 vs. 9.8 ± 1.7 s), and cold hyperalgesia (3.4 ± 0.5 vs. 5.3 ± 0.6 s). Finally, PRDM1 downregulation in naive mice reduced the calcium signaling response of spinal dorsal horn neurons to thermal stimulation.

CONCLUSIONS

PRDM1 contributes to peripheral nerve injury-induced nociception by repressing Kv4.3 channel expression in injured dorsal root ganglion neurons.

摘要

背景

转录抑制因子阳性调节域 I 结合因子 1（PRDM1）在成年小鼠背根神经节中表达，并调节周围感觉神经元的形成和功能。作者假设背根神经节中的 PRDM1 可能参与外周神经损伤诱导的痛觉调节，其机制可能涉及 Kv4.3 通道转录抑制。

方法

通过慢性缩窄性损伤、完全弗氏佐剂或辣椒素足底注射，在 C57BL/6 小鼠中诱导痛觉。通过机械性痛觉过敏、热痛觉过敏、冷痛觉过敏或步态分析评估痛觉反应。通过注射 Prdm1 敲低和过表达腺相关病毒来评估 PRDM1 的作用。通过染色质免疫沉淀分析评估 PRDM1 在 Kv4.3（Kcnd3）启动子上的相互作用。通过全细胞膜片钳记录评估背根神经节神经元的兴奋性，通过体内双光子成像评估脊髓背角神经元的钙信号。

结果

外周神经损伤增加了背根神经节中 PRDM1 的表达，这降低了 Kv4.3 启动子的活性并抑制了 Kv4.3 通道的表达（损伤 vs. 未损伤；均 P < 0.001）。PRDM1 敲低挽救了 Kv4.3 的表达，降低了损伤背根神经节神经元的高兴奋性，并缓解了外周神经损伤诱导的痛觉（短发夹 RNA 与 Scram；均 P < 0.05）。相比之下，PRDM1 在幼稚小鼠背根神经节神经元中的过表达降低了 Kv4.3 通道的表达，并诱导了痛觉过敏（PRDM1 过表达与对照，平均值 ± 标准差；n = 13；均 P < 0.0001），如机械性痛觉过敏（0.6 ± 0.3 对 1.2 ± 0.2 g）、热痛觉过敏（5.2 ± 1.3 对 9.8 ± 1.7 s）和冷痛觉过敏（3.4 ± 0.5 对 5.3 ± 0.6 s）所示。最后，幼稚小鼠中 PRDM1 的下调降低了脊髓背角神经元对热刺激的钙信号反应。