Dual-regulation by Cx32 in hepatocyte to trigger and worsen liver graft injury
Dual-regulation by Cx32 in hepatocyte to trigger and worsen liver graft injury
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DOI：
10.1016/j.trsl.2023.07.008
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发表时间：
2023-10-31
影响因子：
7.8
通讯作者：
Yuan，Dongdong
中科院分区：
文献类型：
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作者：
Huang，Fei;Deng，Zhizhao;Yuan，Dongdong
肝移植是终末期肝衰竭的最终治疗选择。然而，肝移植损伤仍然是一个挑战。本研究旨在探讨连接蛋白32（Cx32）在肝移植损伤中的作用并阐明其作用机制。通过检测6例患者的肝移植样本，我们观察到Cx32水平的变化与肝移植损伤相一致。因此，我们利用Cx32敲除和野生型小鼠建立了自体原位肝移植（AOLT）模型，并利用α小鼠肝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在肝移植损伤中的机制。体内和体外 Cx32 敲除后，通过调节 PKC-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 相关细胞凋亡，改善肝移植损伤。当用2-氨基乙氧基二苯基硼酸酯（2-APB）阻断基于Cx32的间隙连接（GJ）时，邻近细胞之间的ROS转移减弱，防止氧化应激和炎症反应加剧，并减轻肝移植损伤的加重。这些结果凸显了Cx32在肝移植损伤中的双重调节机制。通过与PKC-α的相互作用，Cx32调节NF-κB/NLRP3和Nrf2/NOX4/ROS信号通路，从而直接触发氧化应激和炎症反应。同时，大量产生的ROS通过Cx32通道转移至邻近细胞，间接加剧氧化应激和炎症反应。最后，Bak/Bax相关的细胞凋亡被激活，从而加重肝移植损伤。我们的研究结果表明，Cx32 作为氧化应激和炎症信号通路的双重机制因子，可调节肝移植损伤中的细胞凋亡，这为肝移植损伤提供了一个有前景的治疗靶点。
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.