Immunopathology Lab, School of Bio Sciences and Technology, Vellore Institute of Technology (VIT), Vellore 632 014, Tamilnadu, India.
Immunopathology Lab, School of Bio Sciences and Technology, Vellore Institute of Technology (VIT), Vellore 632 014, Tamilnadu, India.
Life Sci. 2018 Aug 15;207:284-295. doi: 10.1016/j.lfs.2018.06.013. Epub 2018 Jun 15.
Bone erosion induced by enhanced osteoclast formation is a debilitating pathological phenomenon in rheumatoid arthritis (RA). Recent finding has revealed that ferulic acid is associated with reduced osteoclast differentiation and bone erosion. However, the underlying mechanism through which ferulic acid inhibited osteoclast differentiation and bone erosion still remains to be elucidated. This study assessed the therapeutic effects of ferulic acid on osteoclast differentiation and bone erosion by targeting RANKL dependent NF-κB pathway.
RAW 264.7 monocyte/macrophage cells were left untreated/treated with 25, 50 and 100 μM ferulic acid prior to stimulation with/without RANKL and M-CSF. Osteoclast differentiation and formation was assessed by SEM and TRAP analysis whereas its functional activity of bone erosion was determined by pit formation assay. Crucial transcription factors (NF-κBp-65, NFATc1 and c-Fos) and osteoclast specific genes (TRAP, MMP-9 and Cathepsin K) were evaluated by quantitative RT-PCR. Further, the protein level expression of NF-κBp-65, NFAtc1, c-Fos and MMP-9 was assessed using western blot analysis.
Our results demonstrated that ferulic acid significantly attenuated RANKL induced osteoclast differentiation as evidenced from SEM and TRAP staining analysis. A remarkable decrease in the bone resorption activity of osteoclasts was also noticed upon ferulic acid treatment. In addition, the down-regulation of RANKL induced NF-κB activation and its associated downstream factors like NFATc1, c-Fos, TRAP, Cathepsin K and MMP-9 was also observed upon ferulic acid treatment.
Thus, our findings evidence the anti-stimulatory and anti-resorptive role of ferulic acid via the inhibition of RANKL dependent NF-κB signalling pathway.
破骨细胞形成增强导致的骨侵蚀是类风湿关节炎（RA）的一种使人虚弱的病理性现象。最近的研究发现，阿魏酸与破骨细胞分化减少和骨侵蚀有关。然而，阿魏酸抑制破骨细胞分化和骨侵蚀的潜在机制仍有待阐明。本研究通过靶向 RANKL 依赖性 NF-κB 通路评估了阿魏酸对破骨细胞分化和骨侵蚀的治疗作用。
RAW 264.7 单核/巨噬细胞在未经处理/用 25、50 和 100μM 阿魏酸处理后，用/不用 RANKL 和 M-CSF 刺激。通过 SEM 和 TRAP 分析评估破骨细胞分化和形成，通过陷窝形成测定法确定其骨侵蚀的功能活性。通过定量 RT-PCR 评估关键转录因子（NF-κBp-65、NFATc1 和 c-Fos）和破骨细胞特异性基因（TRAP、MMP-9 和组织蛋白酶 K）。进一步，使用 Western blot 分析评估 NF-κBp-65、NFAtc1、c-Fos 和 MMP-9 的蛋白水平表达。
我们的结果表明，阿魏酸显著抑制了 RANKL 诱导的破骨细胞分化，这从 SEM 和 TRAP 染色分析中得到证实。在用阿魏酸处理时，也观察到破骨细胞的骨吸收活性显著降低。此外，在用阿魏酸处理时，还观察到 RANKL 诱导的 NF-κB 激活及其相关下游因子如 NFATc1、c-Fos、TRAP、组织蛋白酶 K 和 MMP-9 的下调。
因此，我们的研究结果表明，阿魏酸通过抑制 RANKL 依赖性 NF-κB 信号通路发挥抗刺激和抗吸收作用。
