类风湿性关节炎（RA）是一种自身免疫性疾病，导致慢性关节炎症。骨侵蚀是RA最严重的病理情况,也是关节变形和功能障碍的主要原因。蜂胶针注射（MAI）是一种有效的中医治疗RA的方法。本研究旨在调查MAI对RA骨侵蚀的影响，并阐明其潜在的机制。以胶原诱导关节炎（CIA）小鼠模型作为实验对象。对患有CIA的小鼠每隔一天进行一次MAI处理，持续处理28天。通过体重、关节炎指数（AI）得分、肿胀关节计数（SJC）得分和后足厚度评估MAI对关节疾病的影响。通过显微CT观察踝关节的放射学改变，通过病理染色观察组织学变化。评估MAI的毒性，包括器官组织学变化、脾指数、血清丙氨酸转氨酶（ALT）、门冬氨酸转氨酶（AST）和肌酐（Crea）水平。通过酶联免疫吸附试验（ELISA）确定细胞因子表达水平，评估CIA小鼠的免疫功能。MAI处理显著改善了CIA小鼠的临床症状，包括后足厚度、AI得分和肿胀足关节数量（大多数P<0.05甚至<0.01）。根据组织病理学分析，MAI改善了炎性细胞浸润、滑膜增生、滑膜形成和骨侵蚀（全部P<0.01）。显微CT和酒石酸阻滞性酸性磷酸酶（TRAP）染色（P<0.01）还表明, MAI通过减少破骨细胞的形成缓解骨侵蚀。MAI不仅可以缓解免疫促进作用（高剂量MAI组[P<0.05]），而且对肝脏或肾脏没有副作用（P>0.05）。此外, 它降低了白细胞介素(IL)-6和肿瘤坏死因子-α(TNF-α)的血清水平，增加了白细胞介素-4和白细胞介素-10的血清水平（大多数P<0.05甚至<0.01）。转录组测序结果表明，MAI影响了相关于核因子κB配体/核因子κB（RANKL/NF-κB）通路的破骨细胞分化通路基因的表达。根据我们的发现，MAI可以抑制关节炎症，抑制RANKL/NF-κB介导的破骨细胞分化，拯救CIA小鼠的骨侵蚀，表明MAI可能是一种治疗RA的潜在物质。2023年《医学与外科定量成像》.版权所有.

Rheumatoid arthritis (RA) is an autoimmune disease leading to chronic joint inflammation. Bone erosion is the most serious pathological condition of RA and the main cause of joint deformities and disability. Melittin acupoint injection (MAI) is an effective traditional Chinese medicine (TCM) method for RA treatment. This study aimed to investigate the effect of MAI on RA bone erosion and to elucidate the underlying mechanism.A collagen-induced arthritis (CIA) mouse model was established as the experimental subject. MAI was administrated once every other day for 28 days to mice with CIA. The effects of MAI on joint diseases were assessed by body weight, arthritis index (AI) score, swollen joint count (SJC) score, and hind paw thickness. Ankle radiological changes were captured by micro-computed tomography (micro-CT) and histological changes were observed by pathological staining. Organ histological changes, spleen index, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatinine (Crea) levels of serum were tested to evaluate the toxicity of MAI. Cytokine expression levels were confirmed by enzyme-linked immunosorbent assay (ELISA) to evaluate the immunity of CIA mice.MAI administration markedly improved the clinical signs of CIA in mice, including hind paw thickness, AI, and the number of swollen paw joints (most of them P<0.05 or even <0.01). According to histopathological analysis, MAI ameliorated inflammatory cell infiltration, synovial hyperplasia, pannus formation, and bone erosion (all P<0.01). Micro-CT and tartrate-resistant acid phosphatase (TRAP) staining (P<0.01) also revealed that MAI could relieve bone erosion via reducing the formation of osteoclasts. Not only could MAI relieve the immunological boost [P<0.05 for the high-dose MAI (HM) group], but also it had no liver or kidney side effects (P>0.05). In addition, it decreased the serum levels of interleukin (IL)-6 and tumor necrosis factor-α (TNF-α) and increased the serum levels of IL-4 and IL-10 (the majority of P<0.05 or even <0.01). Transcriptome sequencing results indicated that MAI affected the expression of osteoclast differentiation pathway genes, which was connected with the receptor activator of the nuclear factor κB ligand/nuclear factor kappa B (RANKL/NF-κB) pathway.Based on our findings, MAI could suppress joint inflammation and inhibit RANKL/NF-κB-mediated osteoclast differentiation to rescue bone erosion in CIA mice, suggesting that MAI can be a potentially therapeutic substance for RA.2023 Quantitative Imaging in Medicine and Surgery. All rights reserved.