Background

Although platelet-released growth factors (PRGF) can protect cells from inflammation or oxidative stress condition, their therapeutic efficacy for articular cartilage degeneration has been little discussed. The purpose of this study was to investigate the effect of PRGF on human articular chondrocytes under inflammatory conditions.

Methods

Human C-28/I2 chondrocytes were treated with PRGF, the production from liquid-preserved platelet concentrates obtained by platelet apheresis from human volunteers. Cell proliferation/viability, and collagen type (COL) II and SOX9 gene expressions for chondrogenesis were evaluated with different PRGF concentrations. Additionally, in vitro inflammatory condition was mimicked by stimulating the cells with tumor necrosis factor (TNF)-α. Under inflammation, cell viability, TNF-α gene expression, and the protein levels of cytokines including TNF-α, interleukin (IL)-1β and -6, and vascular endothelial growth factor (VEGF) angiogenesis marker, were compared with and without PRGF treatment.

Results

Cell proliferation/viability, and SOX9 and COL II expressions in chondrocytes stimulated with 10% PRGF were significantly higher than without treatment. Cell viability with 10% PRGF was also statistically higher than without treatment under inflammation. The TNF-α gene expression with 10% PRGF was significantly lower than without treatment under inflammation. The protein levels of endogenous TNF-α with 5% PRGF, IL-1β with 10% PRGF, and IL-6 with 5 and 10% PRGF in chondrocytes were significantly lower than untreated ones under inflammation. The VEGF-protein level in chondrocytes stimulated with 20% PRGF was significantly higher than without treatment under inflammation, while there was no significant difference between with 10% PRGF and without treatment.

Conclusions

Our results reveal that optimal PRGF treatment leads to the increase of chondrocyte proliferation/viability and chondrogenic markers, while it increased cell viability but reduced IL-1β and IL-6 expressions under inflammatory condition, suggesting the therapeutic role of PRGF for protection from articular cartilage degeneration through anti-inflammatory effects.

中文翻译：

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血小板释放生长因子保护关节软骨细胞免受炎症影响

背景

虽然血小板释放生长因子 (PRGF) 可以保护细胞免受炎症或氧化应激条件的影响，但它们对关节软骨变性的治疗功效却鲜有讨论。本研究的目的是研究 PRGF 在炎症条件下对人类关节软骨细胞的影响。

方法

人类 C-28/I2 软骨细胞用 PRGF 处理，PRGF 是从人类志愿者的血小板单采术获得的液体保存的血小板浓缩物中产生的。用不同的 PRGF 浓度评估了细胞增殖/活力以及软骨形成的胶原类型 (COL) II 和 SOX9 基因表达。此外，通过用肿瘤坏死因子 (TNF)-α 刺激细胞来模拟体外炎症状况。在炎症条件下，细胞活力、TNF-α 基因表达以及包括 TNF-α、白细胞介素 (IL)-1β 和 -6 以及血管内皮生长因子 (VEGF) 血管生成标志物在内的细胞因子的蛋白质水平，在使用和不使用 PRGF 的情况下进行了比较治疗。

结果

用 10% PRGF 刺激的软骨细胞中的细胞增殖/活力和 SOX9 和 COL II 表达显着高于未处理。在炎症条件下，具有 10% PRGF 的细胞活力在统计学上也高于没有处理的情况。在炎症条件下，10% PRGF 的 TNF-α 基因表达显着低于未处理。在炎症条件下，软骨细胞中含有 5% PRGF 的内源性 TNF-α、含有 10% PRGF 的 IL-1β 和含有 5% 和 10% PRGF 的 IL-6 的蛋白质水平显着低于未处理的软骨细胞。在炎症条件下，20% PRGF 刺激的软骨细胞中 VEGF 蛋白水平显着高于未处理，而 10% PRGF 和未处理之间没有显着差异。

结论

我们的结果表明，最佳 PRGF 治疗导致软骨细胞增殖/活力和软骨形成标志物的增加，同时它增加了细胞活力，但在炎症条件下降低了 IL-1β 和 IL-6 的表达，表明 PRGF 对保护关节软骨的治疗作用通过抗炎作用退化。