Spinal caspase-6 regulates AMPA receptor trafficking and dendritic spine plasticity through netrin-1 in postoperative pain after orthopedic surgery for tibial fracture in mice
Spinal caspase-6 regulates AMPA receptor trafficking and dendritic spine plasticity through netrin-1 in postoperative pain after orthopedic surgery for tibial fracture in mice
复制标题
脊髓 caspase-6 通过 netrin-1 调节 AMPA 受体运输和树突棘可塑性，减轻小鼠胫骨骨折骨科手术后的术后疼痛
DOI：
10.1097/j.pain.0000000000002021
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发表时间：
2021-01-01
期刊：
影响因子：
7.4
通讯作者：
Zhang, Linlin
中科院分区：
文献类型：
--
作者：
Cui, Wei;Li, Yize;Zhang, Linlin
慢性术后疼痛阻碍骨折和骨科手术后的功能恢复。最近报道的证据表明，caspase-6是重要的兴奋性突触可塑性和病理性疼痛。同时，netrin-1控制α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体（AMPAR）的突触后募集和突触发生。目前的工作旨在研究caspase-6和netrin-1是否有助于膀胱癌诱导的术后异常性疼痛。通过髓内钉固定建立小鼠胫骨骨折模型，以诱导术后疼痛。然后，检测缩爪阈值、脊髓半胱天冬酶-6活性、netrin-1分泌、AMPAR运输和脊髓形态学。通过Caspase-6抑制和netrin-1的shRNA敲低来阐明异常性疼痛的发病机制及其预防。采用全细胞膜片钳技术观察caspase-6在脊髓AMPAR诱导电流中的作用。骨科手术后胫骨骨折引发持续性术后机械和冷异常性疼痛，伴随脊髓活性caspase-6、netrin-1释放、含GluA 1的AMPAR运输、脊髓密度和背角神经元AMPAR诱导电流增加。半胱天冬酶-6抑制剂减少了膀胱相关的异常性疼痛、netrin-1分泌和GluA 1运输。Netrin-1缺乏损害了神经元引起的异常性疼痛、突触后GluA 1募集和脊柱可塑性。特异性GluA 2缺乏的AMPAR拮抗剂NASPM也剂量依赖性地预防术后疼痛。重组netrin-1可抑制caspase-6介导的脊髓背角术后兴奋性突触AMPAR电流的减少。外源性caspase-6诱导的疼痛超敏反应，逆转netrin-1敲低或共同应用NASPM。因此，脊髓半胱天冬酶-6调制的GluA 1-含有AMPAR激活和脊柱形态通过netrin-1分泌是重要的，在发展中的脊髓相关的术后疼痛的小鼠。
Chronic postoperative pain hinders functional recovery after bone fracture and orthopedic surgery. Recently reported evidence indicates that caspase-6 is important in excitatory synaptic plasticity and pathological pain. Meanwhile, netrin-1 controls postsynaptic recruitment of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and synaptogenesis. The present work aimed to examine whether caspase-6 and netrin-1 contribute to fracture-induced postoperative allodynia. A mouse model of tibial fracture by intramedullary pinning was generated for inducing postoperative pain. Then, paw withdrawal threshold, spinal caspase-6 activity, netrin-1 secretion, AMPAR trafficking, and spine morphology were examined. Caspase-6 inhibition and netrin-1 knockdown by shRNA were performed to elucidate the pathogenetic mechanism of allodynia and its prevention. Whole-cell patch-clamp recording was performed to assess caspase-6's function in spinal AMPAR-induced current. Tibial fractures after orthopedic operation initiated persistent postsurgical mechanical and cold allodynia, accompanied by increased spinal active caspase-6, netrin-1 release, GluA1-containing AMPAR trafficking, spine density, and AMPAR-induced current in dorsal horn neurons. Caspase-6 inhibition reduced fracture-associated allodynia, netrin-1 secretion, and GluA1 trafficking. Netrin-1 deficiency impaired fracture-caused allodynia, postsynaptic GluA1 recruitment, and spine plasticity. The specific GluA2-lacking AMPAR antagonist NASPM also dose dependently prevented postoperative pain. The reduction of fracture-mediated postoperative excitatory synaptic AMPAR current in the dorsal horn by caspase-6 inhibition was compromised by recombinant netrin-1. Exogenous caspase-6 induced pain hypersensitivity, reversing by netrin-1 knockdown or coapplication of NASPM. Thus, spinal caspase-6 modulation of GluA1-containing AMPAR activation and spine morphology through netrin-1 secretion is important in the development of fracture-related postsurgical pain in the mouse.