MechanoBiology Laboratory, Department of Orthopaedic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.
PLoS One. 2013 Jun 28;8(6):e67303. doi: 10.1371/journal.pone.0067303. Print 2013.
Platelet-rich plasma (PRP) containing hepatocyte growth factor (HGF) and other growth factors are widely used in orthopaedic/sports medicine to repair injured tendons. While PRP treatment is reported to decrease pain in patients with tendon injury, the mechanism of this effect is not clear. Tendon pain is often associated with tendon inflammation, and HGF is known to protect tissues from inflammatory damages. Therefore, we hypothesized that HGF in PRP causes the anti-inflammatory effects. To test this hypothesis, we performed in vitro experiments on rabbit tendon cells and in vivo experiments on a mouse Achilles tendon injury model. We found that addition of PRP or HGF decreased gene expression of COX-1, COX-2, and mPGES-1, induced by the treatment of tendon cells in vitro with IL-1β. Further, the treatment of tendon cell cultures with HGF antibodies reduced the suppressive effects of PRP or HGF on IL-1β-induced COX-1, COX-2, and mPGES-1 gene expressions. Treatment with PRP or HGF almost completely blocked the cellular production of PGE2 and the expression of COX proteins. Finally, injection of PRP or HGF into wounded mouse Achilles tendons in vivo decreased PGE2 production in the tendinous tissues. Injection of platelet-poor plasma (PPP) however, did not reduce PGE2 levels in the wounded tendons, but the injection of HGF antibody inhibited the effects of PRP and HGF. Further, injection of PRP or HGF also decreased COX-1 and COX-2 proteins. These results indicate that PRP exerts anti-inflammatory effects on injured tendons through HGF. This study provides basic scientific evidence to support the use of PRP to treat injured tendons because PRP can reduce inflammation and thereby reduce the associated pain caused by high levels of PGE2.
富含血小板的血浆 (PRP) 含有肝细胞生长因子 (HGF) 和其他生长因子，广泛用于骨科/运动医学以修复受伤的肌腱。虽然 PRP 治疗被报道可减轻肌腱损伤患者的疼痛，但这种效果的机制尚不清楚。肌腱疼痛通常与肌腱炎症有关，而 HGF 已知可保护组织免受炎症损伤。因此，我们假设 PRP 中的 HGF 引起抗炎作用。为了验证这一假设，我们在兔肌腱细胞的体外实验和小鼠跟腱损伤模型的体内实验中进行了实验。我们发现，PRP 或 HGF 的添加降低了体外肌腱细胞用 IL-1β处理后 COX-1、COX-2 和 mPGES-1 的基因表达。此外，用 HGF 抗体处理肌腱细胞培养物可降低 PRP 或 HGF 对 IL-1β诱导的 COX-1、COX-2 和 mPGES-1 基因表达的抑制作用。PRP 或 HGF 的治疗几乎完全阻断了 PGE2 的细胞产生和 COX 蛋白的表达。最后，将 PRP 或 HGF 注射到体内受伤的小鼠跟腱中，可减少腱组织中 PGE2 的产生。然而，注射血小板贫乏的血浆 (PPP) 不会降低受伤肌腱中的 PGE2 水平，但 HGF 抗体的注射抑制了 PRP 和 HGF 的作用。此外，注射 PRP 或 HGF 也降低了 COX-1 和 COX-2 蛋白。这些结果表明，PRP 通过 HGF 对受伤的肌腱发挥抗炎作用。这项研究为 PRP 治疗受伤的肌腱提供了基本的科学依据，因为 PRP 可以减轻炎症，从而减少由高水平 PGE2 引起的相关疼痛。
