MiR-300 Serves as Potential Biomarker to Screen Knee Osteoarthritis Patients by Targeting TNFα

BACKGROUND: This study mainly explored the serum level of miR-300 with the risk of knee OA, thereby evaluating their diagnostic ability for treatment of knee osteoarthritis (KOA) patients. METHODS: In the current study, we evaluated the level of TNFα in KOA patients and HCs. The serum was used to quantify the level of TNF-α by way of a sandwich enzyme-linked immunosorbent assay. Dual luciferase reporter assay was carried out to identify the possible target gene of miR-300. RESULTS: In line with previous studies, our data showed that serum TNFα level was increased along with K/L grades and WOMAC scoring, suggesting TNFα induced inflammatory responses correlating with the severity of KOA. We also showed that serum miR-300 level was increased with the severity of KOA according to X ray examination and K/L grades. Furthermore, we showed that serum miR-300 level positively correlated with K/L grades, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain scoring and WOMAC function scoring. Bioinformatic predictions showed a conserved binding site of miR-300 in the 3'UTR of IκBα. We then carried out a dual luciferase reporter assay and found miR-300 significantly suppressed pmirGLO-IκBα-3'UTR luciferase activity. CONCLUSIONS: Serum miR-300 is increased with the severity of KOA according to X-ray examination and K/L grades, thereby reflecting the severity of KOA and the degree of cartilage damage. Therefore, it could be used as a potential biomarker to screen KOA patients from healthy controls.