Department of Anesthesiology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, P. R. China.
Department of Anesthesiology, Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, P. R. China.
Transl Res. 2023 Dec;262:44-59. doi: 10.1016/j.trsl.2023.07.008. Epub 2023 Jul 26.
Liver transplantation is the ultimate treatment option for end-stage liver failure. However, liver graft injury remains a challenge. This study aimed to investigate the role of connexin32 (Cx32) in liver graft injury and elucidate its mechanism of action. Through detecting liver graft samples from 6 patients, we observed that changes in the Cx32 level coincided with liver graft injury. Therefore, we established autologous orthotopic liver transplantation (AOLT) models using Cx32-knockout and wild-type mice and hypoxia/reoxygenation (H/R) and lipopolysaccharide (LPS) pretreatment models using alpha mouse liver 12 (AML12) cells, to explore Cx32 mechanisms in liver graft injury. Following in vivo and in vitro Cx32 knockout, oxidative stress and inflammatory response were inhibited through the regulation of PKC-α/NF-κB/NLRP3 and Nrf2/NOX4/ROS signaling pathways, thereby reducing Bak/Bax-related apoptosis and ameliorating liver graft injury. When the Cx32-based gap junction (GJ) was blocked with 2-aminoethoxydiphenyl borate (2-APB), ROS transfer was attenuated between neighboring cells, exacerbated oxidative stress and inflammatory response were prevented, and aggravation of liver graft injury was mitigated. These results highlight the dual regulation mechanism of Cx32 in liver graft injury. Through interaction with PKC-α, Cx32 regulated the NF-κB/NLRP3 and Nrf2/NOX4/ROS signaling pathways, thus directly triggering oxidative stress and inflammatory response. Simultaneously, mass-produced ROS were transferred to neighboring cells through Cx32 channels, for which oxidative stress and the inflammatory response were aggravated indirectly. Finally, Bak/Bax-related apoptosis was activated, thereby worsening liver graft injury. Our findings propose Cx32 as a dual mechanistic factor for oxidative stress and inflammatory signaling pathways in regulating cell apoptosis on liver graft injury, which suggests a promising therapeutic targets for liver graft injury.
肝移植是治疗终末期肝功能衰竭的最终选择。然而，肝移植物损伤仍然是一个挑战。本研究旨在探讨连接蛋白 32（Cx32）在肝移植物损伤中的作用，并阐明其作用机制。通过检测 6 名患者的肝移植物样本，我们观察到 Cx32 水平的变化与肝移植物损伤一致。因此，我们使用 Cx32 敲除和野生型小鼠建立了自体原位肝移植（AOLT）模型，并使用α鼠肝 12（AML12）细胞建立了缺氧/复氧（H/R）和脂多糖（LPS）预处理模型，以探讨 Cx32 在肝移植物损伤中的机制。在体内和体外 Cx32 敲除后，通过调节蛋白激酶 C-α/NF-κB/NLRP3 和 Nrf2/NOX4/ROS 信号通路，抑制氧化应激和炎症反应，从而减少 Bak/Bax 相关凋亡，改善肝移植物损伤。当用 2-氨基乙氧基二苯硼酸盐（2-APB）阻断基于 Cx32 的缝隙连接（GJ）时，相邻细胞之间的 ROS 转移减弱，氧化应激和炎症反应加剧得到预防，肝移植物损伤得到缓解。这些结果强调了 Cx32 在肝移植物损伤中的双重调节机制。通过与蛋白激酶 C-α相互作用，Cx32 调节 NF-κB/NLRP3 和 Nrf2/NOX4/ROS 信号通路，从而直接引发氧化应激和炎症反应。同时，大量产生的 ROS 通过 Cx32 通道转移到相邻细胞，从而间接加剧氧化应激和炎症反应。最后，激活了 Bak/Bax 相关凋亡，从而加重了肝移植物损伤。我们的研究结果表明，Cx32 是调节肝移植物损伤中细胞凋亡的氧化应激和炎症信号通路的双重机制因素，这为肝移植物损伤提供了有希望的治疗靶点。
