Suppression of early experimental osteoarthritis by in vivo delivery of the adenoviral vector-mediated NF-κBp65-specific siRNA.

Lianxu Chen, Lin Lin, Haijun Wang, Xuelei Wei, Xin Fu, Jiying Zhang and Changlong Yu.* 

Institute of Sports Medicine, Peking University Third Hospital, No.49, North Garden Road, Haidian District, Beijing 100083, P.R.China  北京大学第三医院运动医学科陈连旭

Objective:  This study was to use adenoviral vector-mediated NF-κBp65-specific siRNA (Ad-siRNA) to suppress the progression of early experimental osteoarthritis, and therefore to explore a new gene therapy for OA. 

Methods: Reverse transcription polymerase chain reaction (RT-PCR) were performed to confirm the silencing effect of Ad-siRNA in cultured rat chondrocytes. Transection of the medial collateral ligament plus partial medial meniscectomy was operated in the knee of rats to establish osteoarthritis model. Histological analysis was made to assess the morphological change of cartilage and synovium, and enzyme-linked immunosorbent assay (ELISA) was made to measure the expression of cytokines in synovial fluid. The silencing effect of Ad-siRNA on NF-κBp65 in cartilage and synovium of knee was measured with Western blot and the activation of NF-κB was measured with electrophoretic mobility shift assays (EMSA). 

Results: Ad-siRNA can inhibit the activation of NF-κB and the expression of NF-κBp65 in cartilage and synovium of the knee, restrain the induction of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in synovial fluid, alleviate the inflammation of synovium and reduce the degradation of cartilage in early phase of experimental osteoarthritis. 

Conclusions: Ad-siRNA can suppress the progression of the early experimental osteoarthritis which suggests that Ad-siRNA has potential to be a useful preventive and therapeutic agent for OA. 

Key words: siRNA, NF-κBp65, adenoviral vector, IL-1β, TNF-α, osteoarthritis. 

Running title: siRNA suppress the progression of experimental OA.