Hospital of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong Province, China; Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong Province, China; Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong Province, China.
Zhujiang New Town Dental Clinic, Guangzhou, Guangdong Province, China.
Exp Cell Res. 2024 Oct 1;442(2):114249. doi: 10.1016/j.yexcr.2024.114249. Epub 2024 Sep 12.
Temporomandibular joint osteoarthritis (TMJ-OA) is characterized by the degradation of the extracellular matrix (ECM) in cartilage and the apoptosis of chondrocytes, which is caused by inflammation and disruptions of chondrocyte metabolism and inflammation. Lipoxin A4 (LXA4), a specialized pro-resolving mediator, has been shown to inhibit inflammation and regulate the balance between ECM synthesis and degradation. However, the therapeutic effects of LXA4 on TMJ-OA and its underlying mechanisms remain unclear. Interleukin-1 beta (IL-1β)-induced chondrocyte and surgically induced TMJ-OA rat models were established in this study. The viability of chondrocytes treated with LXA4 was evaluated with the cell counting kit-8 (CCK-8) assay, while protein levels were assessed by western blot analysis, and the apoptosis rate was evaluated with terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end labelling (TUNEL) staining. Histological analysis was conducted to evaluate the impact of LXA4 on cartilage degradation in TMJ-OA rat models. In vitro, the qRT-PCR and western blot analysis demonstrated that LXA4 facilitated the upregulation of collagen proteins (Collagen II) and decreased expression of matrix metalloproteinases (MMP-3, and MMP-13) associated with ECM modulation. LXA4 enhanced the TMJ-OA chondrocyte viability and decreased apoptotic rate. In vivo, histology and immunohistochemistry (IHC) analysis revealed that intraperitoneal injection of LXA4 contributed to the amelioration of chondrocyte injuries and deceleration of TMJ-OA. Transcriptomic sequencing revealed that cAMP signaling pathway was up-regulated and NF-κB signaling pathway was down-regulated in LXA4 treated group. LXA4 inhibited the phosphorylation of P65 and inhibitor of nuclear factor kappa B (IκBα) proteins while enhancing the phosphorylation PKA and CREB. This study demonstrates the potential of LXA4 as a therapeutic agent for suppressing chondrocyte catabolism and apoptosis by increasing PKA/CREB activity and decreasing NF-κB signaling.
颞下颌关节骨关节炎（TMJ-OA）的特征是软骨细胞外基质（ECM）降解和软骨细胞凋亡，这是由炎症和软骨细胞代谢及炎症失衡引起的。脂氧素 A4（LXA4）作为一种专门的促解决介质，已被证明能抑制炎症并调节 ECM 合成和降解之间的平衡。然而，LXA4 对 TMJ-OA 的治疗效果及其潜在机制尚不清楚。本研究建立了白细胞介素-1β（IL-1β）诱导的软骨细胞和手术诱导的 TMJ-OA 大鼠模型。用细胞计数试剂盒-8（CCK-8）法评估 LXA4 处理的软骨细胞活力，用 Western blot 分析评估蛋白水平，用末端脱氧核苷酸转移酶（TdT）介导的 dUTP 缺口末端标记（TUNEL）染色评估凋亡率。进行组织学分析以评估 LXA4 对 TMJ-OA 大鼠模型中软骨降解的影响。在体外，qRT-PCR 和 Western blot 分析表明，LXA4 促进了与 ECM 调节相关的胶原蛋白蛋白（Collagen II）的上调和基质金属蛋白酶（MMP-3 和 MMP-13）的下调。LXA4 增强了 TMJ-OA 软骨细胞的活力并降低了凋亡率。在体内，组织学和免疫组织化学（IHC）分析表明，LXA4 的腹腔注射有助于改善软骨细胞损伤和减缓 TMJ-OA。转录组测序显示，LXA4 处理组的 cAMP 信号通路上调，NF-κB 信号通路下调。LXA4 抑制 P65 和核因子 kappa B（IκBα）蛋白的磷酸化，同时增强 PKA 和 CREB 的磷酸化。这项研究表明，LXA4 具有通过增加 PKA/CREB 活性和降低 NF-κB 信号来抑制软骨细胞分解代谢和凋亡的潜力，可作为治疗剂。
