Department of Rheumatology, Qilu Hospital of Shandong University, Jinan, China.
Department of Rheumatology and Clinical Immunology, The Affiliated Hospital of Qingdao University, Qingdao, China.
J Cell Biochem. 2018 Dec;119(12):10165-10175. doi: 10.1002/jcb.27357. Epub 2018 Aug 26.
Osteoarthritis is the most frequent chronic bone-joint disease in middle-aged and older people worldwide. This study investigated the effects of long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on lipopolysaccharide (LPS)-induced murine chondrogenic ATDC5 cell inflammatory injury. Cell viability and apoptosis were assessed using cell counting kit-8 assay and annexin V-phycoerythrin (PE) staining, respectively. The expression levels of interleukin-1β (IL)-1β, IL-6, IL-8, tumor necrosis factor α (TNF-α), MALAT1, and microRNA-19b (miR)-19b were measured using quantitative reverse-transcription polymerase chain reaction. Enzyme-linked immunosorbent assay was conducted to detect the concentrations of IL-1β, IL-6, IL-8, and TNF-α in culture supernatant of ATDC5 cells. Expressions of key factors involved in cell apoptosis, proinflammatory response, Wnt/β-catenin, and nuclear factor κB (NF-κB) pathways were analyzed using Western blot analysis. We found that LPS treatment remarkably induced ATDC5 cell apoptosis and inflammatory injury. MALAT1 was upregulated in LPS-stimulated ATDC5 cells. Overexpression of MALAT1 significantly reversed the LPS-induced ATDC5 cell inflammatory injury, while suppression of MALAT1 had opposite effects. Further results showed that MALAT1 positively regulated the expression of miR-19b in ATDC5 cells. Knockdown of miR-19b reversed the protective effect of MALAT1 on LPS-induced ATDC5 cells. In addition, MALAT1 reduced LPS-induced Wnt/β-catenin and NF-κB pathways activation in ATDC5 cells by upregulating miR-19. To conclude, our research verified that MALAT1 alleviated LPS-induced ATDC5 cell inflammatory injury by upregulating miR-19b and inactivating Wnt/β-catenin and NF-κB pathways. This finding will be helpful for further understanding the critical roles of MALAT1 and miR-19b in osteoarthritis and may provide possible targets for osteoarthritis diagnosis and treatment.
骨关节炎是全球中老年人最常见的慢性骨关节疾病。本研究探讨了长链非编码 RNA 转移相关肺腺癌转录本 1（MALAT1）对脂多糖（LPS）诱导的鼠软骨细胞 ATDC5 炎性损伤的影响。通过细胞计数试剂盒-8 检测和 Annexin V-藻红蛋白（PE）染色分别评估细胞活力和细胞凋亡。采用定量逆转录聚合酶链反应检测白细胞介素 1β（IL-1β）、白细胞介素 6（IL-6）、白细胞介素 8（IL-8）、肿瘤坏死因子 α（TNF-α）、MALAT1 和微小 RNA-19b（miR-19b）的表达水平。采用酶联免疫吸附试验检测 ATDC5 细胞培养上清液中 IL-1β、IL-6、IL-8 和 TNF-α的浓度。采用 Western blot 分析检测细胞凋亡、促炎反应、Wnt/β-catenin 和核因子 κB（NF-κB）通路关键因子的表达。结果发现，LPS 处理显著诱导 ATDC5 细胞凋亡和炎症损伤。LPS 刺激的 ATDC5 细胞中 MALAT1 上调。过表达 MALAT1 显著逆转了 LPS 诱导的 ATDC5 细胞炎症损伤，而抑制 MALAT1 则产生相反的效果。进一步的结果表明，MALAT1 正向调节 ATDC5 细胞中 miR-19b 的表达。敲低 miR-19b 逆转了 MALAT1 对 LPS 诱导的 ATDC5 细胞的保护作用。此外，MALAT1 通过上调 miR-19 降低 LPS 诱导的 ATDC5 细胞中 Wnt/β-catenin 和 NF-κB 通路的激活。综上所述，本研究证实 MALAT1 通过上调 miR-19b 并抑制 Wnt/β-catenin 和 NF-κB 通路，减轻 LPS 诱导的 ATDC5 细胞炎症损伤。这一发现有助于进一步了解 MALAT1 和 miR-19b 在骨关节炎中的关键作用，并为骨关节炎的诊断和治疗提供可能的靶点。
