ABSTRACT
BACKGROUND/AIMS: Osteoarthritis (OA) is a common inflammatory joint disease. miRNAs are associated with OA and functionally implicated in the pathogenesis of the disease. In the present study, we investigated the role of miR-1246 in the lipopolysaccharide (LPS)-induced inflammatory injury of ATDC5 cells. METHODS: ATDC5 cells were cultured and treated with LPS in a series of concentration (0, 1, 5, and 10 µg/ml) for 5 h. The cells were transfected with miR-1246-mimic, inhibitor, si-HNF4γ or negative control, then were assessed for cell viability using CCK8 assay, apoptosis by flow-cytometry and expressions of miR-1246 and pro-inflammatory cytokines by qRT-PCR and western blot analysis. RESULTS: Cell viability was significantly reduced and cell apoptosis was added in ATDC5 cells injured with LPS at the dosage of 5 and 10 µg/ml. Relative mRNA expressions of pro-inflammatory cytokines (IL-1ß, IL-6, IL-8 and TNF-α) were significantly increased. miR-1246 was up-regulated in ATDC5 cells treated with LPS. Moreover, miR-1246 overexpression aggravated LPS-induced decrease in cell viability, increase in apoptosis and overproduction of pro-inflammatory factors. mRNA and protein expressions of HNF4γ were significantly suppressed in cells transfected with miR-124-mimic. Further, miR-1246 knockdown alleviated LPS-induced inflammatory injury by up-regulating the expression of HNF4γ and activation of PI3K/AKT and JAK/STAT pathways. CONCLUSIONS: Suppression of miR-1246 alleviated LPS-induced inflammatory injury in chondrogenic ADTC5 cells by up-regulation of HNF4γ and activation of PI3K/AKT and JAK/STAT pathways. The findings of this study will provide a novel viewpoint regarding miR-1246 target for clinical.
Subject(s)
Chondrogenesis/physiology , Hepatocyte Nuclear Factor 4/metabolism , Inflammation/metabolism , Lipopolysaccharides/pharmacology , MicroRNAs/physiology , Animals , Apoptosis/genetics , Apoptosis/physiology , Cell Line , Cell Survival/genetics , Cell Survival/physiology , Chondrogenesis/genetics , Hepatocyte Nuclear Factor 4/genetics , Inflammation/genetics , Interleukin-1beta/metabolism , Interleukin-6/metabolism , Interleukin-8/metabolism , Mice , MicroRNAs/genetics , Signal Transduction/genetics , Signal Transduction/physiology , Tumor Necrosis Factor-alpha/metabolismABSTRACT
BACKGROUND: MicroRNA-374a (miR-374a) has been implicated in several cancers. However, its role in osteosarcoma (OS) remains unclear. Thus the aim of this study was to investigate its expression and role in progression of OS. METHODS: Quantitative real-time PCR (qRT-PCR) was performed to detect the expression of miR-374a in OS cell lines and tissues. To further understand its role, we restored expression of miR-374a in MG63 cell line by transfection with miR-374a mimics or inhibitors. Effects of miR-374a on cell proliferation on targets were also determined. RESULTS: In the present study, our results showed that miR-374a was significantly up-regulated in both OS cell lines and OS tissues. Over expression of miR-374a markedly accelerated proliferation of OS cells, while its inhibition significantly suppressed cell proliferation. Moreover, Axin2 was identified to be a functional downstream target of miR-374a, and decreased expression of Axin2 could promote OS cell proliferation. CONCLUSION: Our study suggested that miR-374a functions as an oncogene in OS, and the miR-374a/Axin2 axis might represent a potential therapeutic target for OS intervention.