Abstract: Background　Rheumatoid arthritis-associated interstitial lung disease （RA-ILD） is a common complication of rheumatoid arthritis （RA）， with 20% to 50% of RA patients developing ILD， which increases the risk of mortality. Currently， there is a lack of highly targeted and safe therapeutic agents for this condition. Traditional Chinese medicine has certain advantages in the treatment of RA-ILD， Fengshi Feibi Decoction （FSFBF）， as a commonly used prescription，has proven efficacy， but its mechanism of action remains unclear and urgently requires validation through experimental research. Objective　To investigate the therapeutic efficacy and underlying mechanisms of FSFBF in TNF-α transgenic （TNF-Tg） mice with RA-ILD. Methods　From March 2024 to January 2025， female TNF-Tg mice were used as an RA-ILD model. A total of 24 TNF-Tg mice （2.5 months old） were randomly divided into four groups: model group （TNF-Tg）， low-dose FSFBF group（Low），medium-dose FSFBF group （Middle）， and high-dose FSFBF group （High）. Additionally， six age-matched wild-type（WT）littermates were randomly selected as controls. The TNF-Tg group received normal saline， while the treatment groups received FSFBF via oral gavage at doses of 5.825， 13.65， and 27.3 g·kg-1·day-1， respectively， for 9 weeks. Body weight， ankle joint clinical scores， and forelimb grip strength were recorded. Ankle joint and lung tissues were collected for histological analysis using H&E， Masson's trichrome， and Safranin O-fast green staining. Serum levels of inflammatory cytokines were measured by enzyme linked immunosorbent assay （ELISA）. Immunofluorescence staining was performed to assess macrophage polarization in lung tissues. Quantitative real-time polymerase chain reaction （RT-qPCR） was used to evaluate the relative mRNA expression of inflammatory cytokines in ankle joints and lungs. Results　At 4.5 months of age， body weight in the TNF-Tg group was lower than that in the WT group， while the Low and High groups had higher body weights than the TNF-Tg group; ankle joint clinical scores in the TNF-Tg group were higher than those in the WT group， while the Middle and High groups had lower scores than the TNF-Tg group; forelimb grip strength in the TNF-Tg group was lower than that in the WT group， while the High group had higher grip strength than the TNF-Tg group （P<0.05）. Pathological experimental results showed: The TNF-Tg group had larger ankle joint inflammation areas， lung inflammation areas， and lung type I collagen fibers areas than the WT group; the Middle and High groups had smaller ankle joint inflammation areas than the TNF-Tg group; the Middle group had larger joint cartilage areas than the TNF-Tg group; and the Low， Middle， and High groups had smaller lung inflammation and lung type I collagen fibre areas than the TNF-Tg group （P<0.05）. Immunofluorescence staining results showed that the number of M1 and M2 macrophages in the lungs of the TNF-Tg group was greater than that in the WT group. The number of M1 macrophages in the Low， Middle， and High groups was lower than that in the TNF-Tg group， while the number of M2 macrophages was higher than that in the TNF-Tg group （P<0.05）. ELISA results showed that serum TNF-α， IL-1β and IL-6 levels in the TNF-Tg group were higher than those in the WT group（P<0.05）. The serum TNF-α and IL-1β levels in the Low， Middle， and High groups were lower than those in the TNF-Tg group， and the serum IL-6 levels in the High group was lower than that in the TNF-Tg Group （P<0.05）. RT-qPCR results showed that the relative expression levels of TNF-α and IL-1β in the lungs of mice in the TNF-Tg group were higher than those in the WT group， while the High group was lower than the TNF-Tg group（P<0.05）；The Middle group and High group had lower relative expression levels of IL-1β in the lungs than the TNF-Tg group（P<0.05）；The relative expression levels of TNF-α and IL-1β in the ankle joints of the TNF-Tg group were higher than those in the WT group， while the Low， Middle and High groups were lower than the TNF-Tg group （P<0.05）. Conclusion　FSFBF ameliorates RA-ILD symptoms in TNF-Tg mice by modulating macrophage polarization in the lungs. It alleviates joint inflammation， cartilage degradation， pulmonary inflammation， and alveolar fibrosis. These findings suggest that FSFBF may represent a promising novel therapeutic strategy for the clinical treatment of RA-ILD.

Key words: Rheumatoid arthritis, Interstitial lung disease, Feng Shi Fei Bi Decoction, TNF-Tg mice, Macrophage polarisation

摘要： 背景　类风湿关节炎合并间质性肺疾病（RA-ILD）是类风湿关节炎（RA）的常见并发症，20%~50%的RA患者会继发ILD，使RA患者死亡风险增加。目前临床缺乏安全有效、靶向明确的治疗RA-ILD药物。中医药在RA-ILD治疗中具有一定优势，风湿肺痹方作为常用方剂，其疗效确切，但作用机制尚不明确，需通过实验研究加以验证。目的　探讨FSFBF对肿瘤坏死因子α转基因（TNF-Tg）小鼠RA-ILD的疗效和作用机制。方法　于2024年3月—2025年1月，采用雌性TNF-Tg小鼠作为RA-ILD模型小鼠，将24只2.5月龄TNF-Tg小鼠随机分为模型组（TNF-Tg组）、FSFBF低剂量组（Low组）、FSFBF中剂量组（Middle组）、FSFBF高剂量组（High组），同时随机挑选6只同窝野生型小鼠作为对照组（WT组）。TNF-Tg组给予生理盐水，Low、Middle、High组分别给予5.825、13.65、27.3g·kg-1·d-1 FSFBF灌胃。9周后采集小鼠体质量、踝关节临床评分和前肢抓力数据；取踝关节与肺脏组织进行HE染色、Masson染色、番红固绿染色；使用酶联免疫吸附试验（ELISA）检测小鼠血清炎症因子含量；采用免疫荧光染色标记肺脏巨噬细胞；采用实时荧光定量PCR（RT-qPCR）检测肺脏炎症因子mRNA相对表达量。结果　4.5月龄时，TNF-Tg组体质量低于WT组，Low组、High组高于TNF-Tg组（P<0.05）；TNF-Tg组踝关节临床评分高于WT组，Middle组、High组低于TNF-Tg组（P<0.05）；TNF-Tg组前肢抓力低于WT组，High组高于TNF-Tg组（P<0.05）。病理结果显示：TNF-Tg组踝关节炎症面积、肺脏炎症面积、肺脏I型胶原纤维面积大于WT组，Middle组和High组踝关节炎症面积小于TNF-Tg组，Middle组关节软骨面积大于TNF-Tg组，Low组、Middle组和High组肺脏炎症与肺脏I型胶原纤维面积小于TNF-Tg组（P<0.05）。免疫荧光染色结果显示：TNF-Tg组肺脏M1、M2型巨噬细胞数量大于WT组，Low组、Middle组和High组M1型巨噬细胞数量低于TNF-Tg组，M2型巨噬细胞数量高于TNF-Tg组（P<0.05）。ELISA结果显示：TNF-Tg组血清TNF-α、IL-1β和IL-6水平高于WT组，Low组、Middle组、High组血清TNF-α和IL-1β水平低于TNF-Tg组，High组血清IL-6水平低于TNF-Tg组（P<0.05）。RT-qPCR结果显示：TNF-Tg组小鼠肺脏TNF-α和IL-1β相对表达量高于WT组，High组低于TNF-Tg组（P<0.05）；Middle组和High组肺脏IL-1相对表达量低于TNF-Tg组（P<0.05）；TNF-Tg组小鼠踝关节TNF-α和IL-1β相对表达量高于WT组，Low组、Middle组和High组低于TNF-Tg组（P<0.05）。结论　FSFBF通过调节肺脏巨噬细胞极化，改善TNF-Tg小鼠RA-ILD的症状，减轻关节炎症、软骨破坏、肺脏炎症和肺泡纤维化，FSFBF可能成为临床治疗RA-ILD的新方法。

关键词: 类风湿关节炎, 间质性肺病, 风湿肺痹方, TNF-Tg 小鼠, 巨噬细胞极化