目的  基于活性氧（ROS）/硫氧还蛋白结合蛋白（TXNIP）/核苷酸结合寡聚化结构域样受体蛋白3（NLRP3）通路探讨山柰酚（Kae）对白细胞介素（IL）-1β诱导的软骨细胞炎性损伤的作用及机制。 方法  SD大鼠随机分为假手术组（sham）、骨关节炎（OA）组、Kae组，利用前交叉韧带切断术建立膝骨OA模型，采用2.5 mg/L Kae干预（关节腔内注射100 μl，每周1次）3周后，以2’,7’-二氯二氢荧光素二乙酸酯（H2DCFDA）荧光探针、Western blotting分别检测大鼠软骨组织ROS水平以及ROS/TXNIP/NLRP3通路相关蛋白表达；以番红O-固绿染色进行软骨组织病理检测。将人关节软骨细胞随机分为对照（Ctrl）组、IL-1β组、IL-1β+Kae组、IL-1β+三甲基胺-N-氧化物（TMAO）组、IL-1β+Kae+TMAO组，以IL-1β、Kae与ROS激活剂TMAO分组干预后以CCK-8法、EdU染色检测细胞增殖；测定细胞乳酸脱氢酶（LDH）释放量；以流式细胞术检测细胞凋亡；以免疫荧光染色检测细胞增殖蛋白（Ki67）、Bax/Bcl-2比值以及胶原蛋白Ⅱ型α1链（COL2a1）、基质金属蛋白酶13（MMP13）表达；ELISA检测细胞炎性因子释放量；以H2DCFDA荧光探针、Western blotting分别检测细胞ROS水平以及ROS/TXNIP/NLRP3通路相关蛋白表达。 结果  Kae可减轻OA大鼠软骨组织退变损伤，并降低其Mankin评分，ROS水平以及TXNIP、NLRP3、Caspase-1、IL-1β蛋白相对表达（P＜0.05）。与Ctrl组比较，IL-1β组细胞活力、EdU阳性率、Ki67与COL2a1阳性比例降低（P＜0.05），LDH释放量、凋亡率、Bax/Bcl-2比值、MMP13阳性比例、肿瘤坏死因子-α（TNF-α）、IL-6、IL-8与IL-18释放量、ROS水平、TXNIP、NLRP3、Caspase-1与IL-1β蛋白相对表达升高（P＜0.05）。Kae可改善IL-1β诱导的软骨细胞上述改变，而TMAO可加重IL-1β诱导的软骨细胞上述改变。TMAO可逆转Kae对IL-1β诱导的软骨细胞炎性损伤的减轻作用。 结论  Kae可减轻IL-1β诱导的人关节软骨细胞炎性损伤，可能是通过抑制ROS/TXNIP/NLRP3通路激活实现的。

Objective  To explore the effect and mechanism of kaempferol (Kae) on interleukin (IL)-1β-induced inflammatory damage of chondrocytes based on the reactive oxygen species (ROS)/thioredoxin-interacting protein (TXNIP)/nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) pathway.  Methods  SD rats were randomly divided into sham operation(sham) group, osteoarthritis (OA) group and Kae group. The OA model was established by anterior cruciate ligament transection. After 3 weeks of intervention with 2.5 mg/L Kae (100 μl intra-articular injection, once a week), the ROS level and the expression of ROS/TXNIP/NLRP3 pathway proteins in rat cartilage tissue were detected using the 2’,7’-Dichlorodihydrofluorescein diacetate (H2DCFDA) fluorescent probe and Western blotting, respectively. Pathological examination of cartilage tissue was performed using safranin O-fast green staining. Human articular chondrocytes were randomly classified into the control (Ctrl) group, the IL-1β group, the IL-1β+Kae group, the IL-1β+ trimethylamine N-oxide (TMAO) group, and the IL-1β+Kae+TMAO group. After treatment with IL-1β, Kae and ROS activator TMAO, CCK-8 assay and EdU staining were used to detect the cell proliferation. Measured the release of cellular lactate dehydrogenase (LDH). Flow cytometry was used to measure apoptosis. Immunofluorescence staining was used to detect the expression of cell proliferative protein (Ki67). The ratio of Bcl-2 and the expression of collagen type Ⅱ α1 chain (COL2a1) and matrix metalloprotein 13 (MMP13). ELISA was used to determine the release of cellular inflammatory factors. The ROS level and the expression of ROS/TXNIP/NLRP3 pathway proteins of cells were detected using the H2DCFDA fluorescent probe and Western blotting.  Results  Kae alleviated the degeneration and damage of cartilage tissue in OA rats, and reduced their Mankin scores, ROS levels, the relative expression of TXNIP, NLRP3, cysteine-containing aspartate-specific proteases 1 (Caspase-1) and IL-1β proteins (P<0.05). Compared with the Ctrl group, the IL-1β group reduced cell viability, EdU positivity rate, Ki67 and COL2a1 positivity ratios (P<0.05), and increased LDH release, apoptosis rate, Bax/Bcl-2 ratio, MMP13 positivity ratio, tumor necrosis factor-α (TNF-α), IL-6, IL-8 and IL-18 releases, ROS level, TXNIP, NLRP3, Caspase-1 and IL-1β protein relative expression (P<0.05). Kae ameliorated the aforementioned pathological changes in IL-1β induced chondrocytes, whereas TMAO exacerbated these changes. TMAO reversed the mitigating effect of Kae on the inflammatory damage in IL-1β induced chondrocytes.   Conclusion  Kae can reduce IL-1β-induced inflammatory damage to human articular chondrocytes, which may be achieved by inhibiting the activation of the ROS/TXNIP/NLRP3 pathway.