Department of Rheumatology and Immunology, the First Affiliated Hospital of China Medical University, Shenyang, China.
Clin Exp Rheumatol. 2019 Sep-Oct;37(5):820-825. Epub 2019 Feb 11.
Angiogenesis in bone and osteogenesis appear to be closely linked, suggesting the existence of molecular crosstalk between pro-angiogenic molecules and osteoblasts. The pro-angiogenic molecules vascular endothelial growth factor (VEGF) with its receptors Flt-1, Flk-1 and fibroblast growth factor (FGF)-2 play a crucial role in born formation, an early and critical event in the pathogenesis of rheumatoid arthritis (RA). Interleukin (IL)-35 is demonstrated to be an anti-inflammatory cytokine in RA. However, the mechanisms involved are not fully understood. This study aims to investigate whether IL-35 has an impact on angiogenesis in osteoblasts and its related signalling pathway in RA.
The effects of IL-35 on osteoblasts proliferation, apoptosis and pro-angiogenic molecules mRNA and protein were examined using osteoblast-like MC3T3E1 cells in vitro. The effects of IL-35 on proliferation and apoptosis were examined using cell counting kit-8 (CCK-8) assay and flow cytometry, respectively. Pro-angiogenic molecules expression were assessed by real time PCR and ELISA, respectively. The signalling pathway between IL-35, bone formation, angiogenesis and signalling pathway was also investigated.
IL-35 promoted osteoblasts proliferation and inhibited apoptosis in a dose-dependent manner in vitro. IL-35 increased basal and TNF-α induced pro-angiogenic molecules expression by osteoblasts. Blocking the Th17/IL-17 signalling pathway with plumbagin inhibited the pro-angiogenic effects of IL-35 in osteoblasts.
These results suggested that IL-35 promotes bone formation and angiogenesis by fostering osteoblasts proliferation, inhibiting apoptosis and upregulating pro-angiogenic molecules through Th17/IL-17 related-signalling pathway. Our findings extend the current understanding of mechanisms modulating bone formation and angiogenesis in RA.
骨骼中的血管生成和成骨似乎密切相关，这表明促血管生成分子与成骨细胞之间存在分子串扰。促血管生成分子血管内皮生长因子(VEGF)及其受体 Flt-1、Flk-1 和成纤维细胞生长因子(FGF)-2 在骨形成中起着至关重要的作用，骨形成是类风湿关节炎(RA)发病机制中的早期和关键事件。白细胞介素(IL)-35 被证明是 RA 中的一种抗炎细胞因子。然而，其涉及的机制尚不完全清楚。本研究旨在探讨 IL-35 是否对 RA 中成骨细胞的血管生成及其相关信号通路有影响。
体外使用成骨样 MC3T3E1 细胞研究 IL-35 对成骨细胞增殖、凋亡和促血管生成分子 mRNA 和蛋白的影响。使用细胞计数试剂盒-8(CCK-8)检测 IL-35 对增殖的影响，通过流式细胞术检测凋亡，分别用实时 PCR 和 ELISA 检测促血管生成分子的表达。还研究了 IL-35、骨形成、血管生成和信号通路之间的信号通路。
IL-35 在体外以剂量依赖性方式促进成骨细胞增殖并抑制凋亡。IL-35 增加了基础和成纤维细胞生长因子(TNF)-α诱导的促血管生成分子在成骨细胞中的表达。用白花丹醌阻断 Th17/IL-17 信号通路抑制了 IL-35 对成骨细胞的促血管生成作用。
这些结果表明，IL-35 通过促进成骨细胞增殖、抑制凋亡和上调促血管生成分子，促进骨形成和血管生成，通过 Th17/IL-17 相关信号通路。我们的发现扩展了调节 RA 中骨形成和血管生成的机制的当前理解。
