Attenuation of cartilage degeneration via silencing Postn gene in mouse chondroprogenitor cell line ATDC5 cells

Abstract

Objective To investigate the expression of Periostin (Postn) in osteoarthritic cartilage and explore its influence and machanism in cartilage degeneration. Methods C57/BL6 mice were randomly divided into two groups: experimental group and control group, the right knee joints of experimental gruop were underwent destabilization of the medial meniscus (DMM) surgery, while that of control group were only incised skin and joint capsule. Safranin O-fast green and Toluidine Blue staining were used to examinate the change of articular cartilage, and immunohistochemistry staining was used to detect the expression of Postn in articular cartilage. We induced ATDC5 mouse chondrogenic cells to osteoarthritis with interleukin (IL)-1β, and real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) was used to detect the levels of osteoarthritic related factors after silencing Postn gene via small interfering RNA (siRNA) oligo. Results In animal experiments, the thickness of articular cartilage was obviously decreased (DMM 4 w vs. Sham 4 w, P=0.000; DMM 8 w vs. Sham 8 w, P=0.001), International Society for the study of osteoarthritis (OARSI) scoring was obviously increased (DMM 4 w vs. Sham 4 w, P=0.005; DMM 8 w vs. Sham 8 w, P=0.002) and the rates of Postn positive cells were obviously increased in DMM groups compared to Sham groups (DMM 4 w vs. Sham 4 w, P=0.000; DMM 8 w vs. Sham 8 w, P=0.004). In vivo experiment, Postn (1.65±0.23, P=0.008), matrix metalloproteinase-13 (MMP-13, 1.75±0.24, P=0.005), a disintegrin and metalloproteinase with thrombospondin motifs 5 protein (ADAMTS-5, 4.63±1.58, P=0.017), vascular endothelial growth factor (VEGF, 6.24±0.90, P=0.001) and Runt related transcription factor 2 protein (Runx2, 1.54±0.14, P=0.003) were up-regulated in IL-1β+ siScramble group compared to NC group, while no statistics difference was observed in collagen type X, alpha 1 (COL10a1, 1.12±0.12, P=0.161). Postn (0.51±0.17, P=0.002), MMP-13 (0.79±0.09, P=0.003), ADAMTS-5 (0.90±0.11, P=0.015), VEGF (1.04±0.62, P=0.001), Runx2 (0.82±0.14, P=0.003), COL10a1 (0.77±0.11, P=0.020) were differently down-regulated in IL-1β+ siPostn group compared to IL-1β+ siScramble group. Conclusion Postn was elevated in osteoarthritic articular cartilage in DMM model. Silencing Postn gene in ATDC5 chondrogenic cells could attenuate cartilage degeneration. Key words: Osteoarhtitis; Postn; Small interfering RNA; Articular cartilage