Jin Xiaogao, Wang Yanlin
Department of Anesthesiology and Perioperative Medicine, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, 450007, People's Republic of China.
Department of Anesthesiology, The Affiliated Hospital of Guilin Medical University, Guilin, Guangxi Zhuang Autonomous Region, 541000, People's Republic of China.
J Inflamm Res. 2021 Mar 22;14:981-993. doi: 10.2147/JIR.S292137. eCollection 2021.
Evidence indicate that adiponectin may exert pro-inflammatory effects on inflammatory cells. We have found that adiponectin knockout decreased inflammatory reaction and tubular damage in the ischemia-reperfusion kidney in APN-knockout mice. Globular adiponectin and full-length adiponectin (g-APN and f-APN) were used in this study to investigate the effects of adiponectin on proinflammatory cytokines production and migration in Raw 264.7 cells.
Proinflammatory cytokines production was detected by real-time RT-PCR. NF-kappaB activation was interrupted through Ad-DN-IκBα or SN-50 to confirm how g-APN induces proinflammatory cytokines production. The siRNA against AdipoR1 and AdipoR2 was investigated to uncover the signaling pathway that may involve in NF-kappaB activation and migration in Raw 264.7 cells.
g-APN, not f-APN, was found triggering the production of inflammatory cytokine MIP-2, IL-6, TNFα, and MCP-1 in Raw 264.7 cells. NF-kappaB Inhibition by Ad-DN-IκBα expression or cell-permeable NF-κB inhibitor SN-50 could decrease NF-kappaB nuclear translocation and subsequently decrease inflammatory cytokine expression triggered by globular ANP. However, AdipoR1 and AdipoR2 were not found involved in NF-kappaB activation in this study. Full-length APN, not g-APN, was involved in the promotion of macrophage migration. The migration induced by full-length APN could be inhibited by knockdown of AdipoR1 expression with siRNA. The migration effect could also be inhibited by PIKγ inhibitor, AS-605240.
These results suggested that full-length adiponectin increases macrophage migration through Adiponectin-AdipoR1-PIKgamma signaling pathway. However, NF-κB activation induced by g-APN in this study was independent of AdipoR1 or AdipoR2. The exact signaling pathway of NF-κB activation by adiponectin should be further studied to find a new anti-inflammatory target.
有证据表明脂联素可能对炎症细胞发挥促炎作用。我们发现脂联素基因敲除可减少 APN 基因敲除小鼠缺血再灌注肾中的炎症反应和肾小管损伤。本研究使用球状脂联素和全长脂联素（g-APN 和 f-APN）来研究脂联素对 Raw 264.7 细胞中促炎细胞因子产生和迁移的影响。
通过实时 RT-PCR 检测促炎细胞因子的产生。通过 Ad-DN-IκBα 或 SN-50 阻断 NF-κB 激活，以确认 g-APN 如何诱导促炎细胞因子的产生。研究针对 AdipoR1 和 AdipoR2 的 siRNA，以揭示可能参与 Raw 264.7 细胞中 NF-κB 激活和迁移的信号通路。
发现 g-APN 而非 f-APN 可触发 Raw 264.7 细胞中炎性细胞因子 MIP-2、IL-6、TNFα 和 MCP-1 的产生。通过 Ad-DN-IκBα 表达或细胞可渗透的 NF-κB 抑制剂 SN-50 抑制 NF-κB，可减少 NF-κB 核转位，并随后减少球状 ANP 触发的炎性细胞因子表达。然而，在本研究中未发现 AdipoR1 和 AdipoR2 参与 NF-κB 激活。全长 APN 而非 g-APN 参与促进巨噬细胞迁移。用 siRNA 敲低 AdipoR1 表达可抑制全长 APN 诱导的迁移。PIKγ 抑制剂 AS-605240 也可抑制迁移作用。
这些结果表明全长脂联素通过脂联素-AdipoR1-PIKγ 信号通路增加巨噬细胞迁移。然而，本研究中 g-APN 诱导的 NF-κB 激活独立于 AdipoR1 或 AdipoR2。应进一步研究脂联素激活 NF-κB 的确切信号通路，以寻找新的抗炎靶点。
