Department of Orthopedic Surgery, Loudi Central Hospital, Loudi, Hunan, PR China.
Histol Histopathol. 2024 Apr;39(4):483-496. doi: 10.14670/HH-18-654. Epub 2023 Jul 26.
Both microRNA (miR)-105-5p and SPARCL1 were discovered to be differentially expressed in osteoarthritis (OA), but their roles and exact mechanisms have not been entirely elaborated. This paper sets out to probe the impact of miR-105-5p/SPARCL1 on chondrocyte injury, extracellular matrix degradation, and osteoarthritis progression.
C28/I2 cells were stimulated with IL-1β to construct an OA model. C28/I2 cells were transfected with sh-SPARCL1, oe-SPARCL1, or miR-105-5p mimic before IL-1β induction. CCK-8 assay, flow cytometry, and ELISA were adopted to assess cell viability, apoptosis, and inflammatory factor expression, respectively. The binding relationship of miR-105-5p to SPARCL1 was assessed using dual-luciferase reporter assay. After an OA rat model was established, rats underwent intra-articular injection with ago-miR-105-5p. TUNEL was applied to determine cell apoptosis . mRNA and protein levels were measured by qRT-PCR and western blot, respectively, and .
IL-1β treatment diminished miR-105-5p expression and augmented SPARCL1 expression in C28/I2 cells. miR-105-5p decreased SPARCL1 expression by targeting SPARCL1. miR-105-5p overexpression or SPARCL1 silencing prominently reversed the decrease in viability and the promotion of inflammatory factor production, cartilage matrix degradation, and apoptosis in IL-1β-stimulated C28/I2 cells. Furthermore, upregulation of SPARCL1 nullified the influence of miR-105-5p overexpression on viability, apoptosis, inflammation, and cartilage matrix degradation in IL-1β-stimulated C28/I2 cells. miR-105-5p overexpression ameliorated knee cartilage tissue injury in OA rats.
Conclusively, miR-105-5p exerted suppressive effects on chondrocyte injury, extracellular matrix degradation, and OA progression by targeting SPARCL1.
微小 RNA（miR）-105-5p 和 SPARCL1 在骨关节炎（OA）中均被发现存在差异表达，但它们的作用和确切机制尚未完全阐明。本文旨在探讨 miR-105-5p/SPARCL1 对软骨细胞损伤、细胞外基质降解和 OA 进展的影响。
用白细胞介素-1β（IL-1β）刺激 C28/I2 细胞构建 OA 模型。在诱导 IL-1β 之前，用 sh-SPARCL1、oe-SPARCL1 或 miR-105-5p 模拟物转染 C28/I2 细胞。采用 CCK-8 测定法、流式细胞术和 ELISA 分别评估细胞活力、细胞凋亡和炎性因子表达。通过双荧光素酶报告基因检测评估 miR-105-5p 与 SPARCL1 的结合关系。建立 OA 大鼠模型后，大鼠进行关节内注射 ago-miR-105-5p。采用 TUNEL 法检测细胞凋亡。采用 qRT-PCR 和 Western blot 分别检测 mRNA 和蛋白水平。
IL-1β 处理降低了 C28/I2 细胞中的 miR-105-5p 表达并增加了 SPARCL1 表达。miR-105-5p 通过靶向 SPARCL1 降低 SPARCL1 表达。miR-105-5p 过表达或 SPARCL1 沉默显著逆转了 IL-1β 刺激的 C28/I2 细胞中活力降低和炎性因子产生、软骨基质降解和细胞凋亡的促进作用。此外，上调 SPARCL1 使 miR-105-5p 过表达对 IL-1β 刺激的 C28/I2 细胞中活力、凋亡、炎症和软骨基质降解的影响无效。miR-105-5p 过表达改善了 OA 大鼠的膝关节软骨组织损伤。
总之，miR-105-5p 通过靶向 SPARCL1 对软骨细胞损伤、细胞外基质降解和 OA 进展发挥抑制作用。
