Objective OA is a chronic disease characterized by cartilage degeneration and inflammation, with no approved disease-modifying drugs. This study aimed to identify pathogenic genes and elucidate their mechanism in OA. Methods We systematically identified pathogenic genes combined sing-cell and bulk transcriptome profiles of cartilage tissues in OA. Adenovirus carrying the serpin peptidase inhibitor clade E member 2 (serpinE2) or exogenous serpinE2 was injected into monosodium iodoacetate (MIA)-induced OA-model rats. Histological analysis, immunohistochemistry and Alcian blue staining were performed. In vitro, immunofluorescence, quantitative real-time PCR (RT-qPCR), ELISA and western blot assays were performed. Results serpinE2 exhibited elevated expression and hypomethylation, showing a positive association with collagen pathway activities in patients with OA. Silencing serpinE2 aggravated MIA-induced knee cartilage degeneration in OA-model rats. Conversely, the intra-articular injection of exogenous serpinE2 ameliorated articular cartilage degeneration, reduced pain-related behavioural responses and relieve synovitis in MIA-induced OA-model rats. Exogenous serpinE2 not only attenuated the elevation of NLRP3, IL-1β and caspase1 expression levels but also restored the reduction in cell viability induced by lipopolysaccharide (LPS) in chondrocytes. Mechanistically, we found that exogenous serpinE2 inhibited LPS-induced reactive oxygen species (ROS) release and NF-κB signalling activation. Conclusions serpinE2 plays a protective role in cartilage and synovium tissues, suggesting that serpinE2 gene transfer or molecules that upregulate serpinE2 expression could be therapeutic candidates for OA.

中文翻译：

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丝氨酸蛋白酶抑制剂 E2 通过靶向 NF-κB 信号传导来防止骨关节炎中的软骨组织破坏和炎症


目的 OA 是一种以软骨退化和炎症为特征的慢性疾病，尚无已获批的疾病缓解药物。本研究旨在鉴定致病基因并阐明它们在 OA 中的机制。方法 我们系统地鉴定了 OA 中软骨组织单细胞和大量转录组谱的致病基因。将携带丝球蛋白酶抑制剂进化枝 E 成员 2 （serpinE2） 或外源性丝球蛋白 E2 的腺病毒注射到碘乙酸单钠 （MIA） 诱导的 OA 模型大鼠体内。进行组织学分析、免疫组化和 Alcian 蓝染色。在体外，进行免疫荧光、定量实时 PCR （RT-qPCR）、ELISA 和 western blot 检测。结果 serpinE2 表现出高表达和低甲基化，与 OA 患者的胶原蛋白通路活性呈正相关。沉默 serpinE2 加重了 MIA 诱导的 OA 模型大鼠膝关节软骨变性。相反，关节内注射外源性丝氨酸蛋白酶 E2 改善了关节软骨变性，减少了与疼痛相关的行为反应，并缓解了 MIA 诱导的 OA 模型大鼠的滑膜炎。外源丝滑菌素 E2 不仅减轻了 NLRP3 、 IL-1β 和 caspase1 表达水平的升高，还恢复了软骨细胞中脂多糖 （LPS） 诱导的细胞活力降低。从机制上讲，我们发现外源性 serpinE2 抑制 LPS 诱导的活性氧 （ROS） 释放和 NF-κB 信号激活。结论 丝氨酸蛋白酶 E2 在软骨和滑膜组织中起保护作用，提示丝氨酸蛋白酶 E2 基因转移或上调丝氨酸蛋白酶 E2 表达的分子可能是 OA 的治疗候选者。