Effects of Low-Level Laser Irradiation in Cultured Synovial Cells

低强度激光照射（LLLI）对颞下颌关节（TMJ）疾病的即时效应，如抗炎和缓解疼痛已有报道。然而，基于分子的机制尚未阐明。滑膜细胞被认为在炎症的发展和持续中起病理作用。本研究观察了IL-1β对滑膜细胞分泌细胞因子的影响，并探讨了IL-1 β对滑膜细胞分泌细胞因子的影响。采用生长法培养细胞。用IL-1β处理细胞，同时行LLLI。ELISA试剂盒检测条件培养液中细胞因子含量。LLLI可显著降低早期IL-6、8和MCP-1的产生。研究低激光照射对Ⅱ型胶原诱导关节炎（CIA）大鼠足跖炎症、骨和软骨破坏的预防或治疗作用。预防性或治疗性低强度激光照射显著抑制了后爪肿胀和关节破坏的增加。预防性治疗组和治疗性治疗组23 d时的肿胀抑制指数（%）分别为58.1%、54.4%。结果表明，低强度激光照射能有效抑制CIA大鼠的炎症反应、骨和软骨的损伤，从而提高对类风湿关节炎的治疗效果。

Immediate effects of low-level laser irradiation (LLLI), such as anti-inflammation and relieving pain against temporomandibular joint(TMJ) disorders, have been reported. However, the molecular based mechanisms are not elucidated yet. Synovial cells are believed to play pathological roles in the development and continuation of inflammation. Cytokine, such as Interleukin(IL)-6,8 and monocyte chemoattractant protein(MCP)-1,has been found in synovial fluid from patients with TMJ synovitis as well as IL-1β.The purpose of this study is examined the effect of LLLI on cytokines production stimulated in human synovial cells treated with IL-1β. The cells were cultured using outgrowth method. The confluent-stage cells were treated with IL-1β as the same time, LLLI was performed to the cells. The amounts of cytokines in conditioned medium were measured by ELISA kit. LLLI significantly reduced the production of IL-6, 8 and MCP-1 in early time. These findings suggest that LLLI may have anti-inflammatory effect on TMJ disorder through the reduction of cytokines production.To determine the effect of prophylactic or therapeutic treatment with low-laser irradiation on paw inflammation, bone and cartilage destruction in type II collagen-induced arthritis(CIA) model in rats. The low-level laser irradiation at prophylactic or therapeutic treatment significantly suppressed the increase in hindpaw swelling and joint destruction. In the prophylactic and therapeutic treatment group at 23 days, swelling inhibition index (%) was respectively 58.1%, 54.4%. The low-level laser irradiation suppressed radiographic changes in hindpaw.These results show that low-level laser irradiation is effective in suppressing inflammation, damage to bone and cartilage in rat CIA, and may increase efficacy of therapy for rheumatoid arthritis.