Osteoarthritis

PVT1[LncRNA]

miR-146a[miRNA]

COL2A1[mRNA]

Cartilage Tissue

Mus musculus (mouse)

J Bone Miner Metab. 2021 Jul;39(4):534-546. doi: 10.1007/s00774-020-01199-7. Epub 2021 Feb 10.

LncPVT1 promotes cartilage degradation in diabetic OA mice by downregulating miR-146a and activating TGF-b/SMAD4 signaling.

Western blot;Luciferase reporter assay;

INTRODUCTION: To investigate the role of LncRNA PVT1 (plasmacytoma variant translocation 1) in hyperglycemia-triggered cartilage damage using the diabetic osteoarthritis (OA) mice model. MATERIALS AND METHODS: Streptozotocin (STZ) was used to induce mouse diabetes. Knee OA model was induced through transection of anterior cruciate ligament (ACLT). Severity of arthritis was assessed histologically by Safranin O-Fast Green Staining using Mankin Scores. LncRNA PVT1 and miR-146a were detected by real-time polymerase chain reaction (PCR) in cartilage tissue. Moreover, the interaction among PVT1, miR-146a, and SMAD4 was examined by luciferase reporter assays. Mice were injected intra-articularly with ad-siRNA-PVT1 and ad-siRNA scramble control. Articular concentrations of TNF-a, IL-1, IL-6 and TGF-b1 were determined using enzyme-linked immunosorbent assay. Levels of type II Collagen (COL2A1), TGF-b1, p-SMAD2, SMAD2, p-SMAD3, SMAD3, SMAD4 and nuclear SMAD4 were detected by western blot analysis. RESULTS: PVT1 expression was significantly increased, whereas miR-146a was markedly decreased in diabetic OA mice than in non-diabetic OA and control. Increased PVT1 expression in diabetic OA mice was significantly associated with Mankin score and reduced miR-146a as well as Collagen alpha-1(II) (COL2A1) expressions. In vivo, intra-articular injection of ad-siRNA-PVT1 efficiently increased miR-146a and COL2A1 expressions, alleviated joint inflammation, decreased the expression of pro-inflammatory mediators, and suppressed TGF-b/SMAD4 pathway in diabetic OA mice. CONCLUSIONS: Our results demonstrate LncRNA PVT1 is involved in cartilage degradation in diabetic OA and correlated with disease severity. Efficiency of ad-siRNA-PVT1 in controlling joint inflammation in diabetic OA mice is associated with the suppression of the expression of miR-146a, pro-inflammatory cytokines and activation of TGF-b/SMAD4 pathway.