Osteopontin induces vascular endothelial growth factor expression in articular cartilage through PI3K/AKT and ERK1/2 signaling

  • Authors:
    • Jun Xu
    • Yu Yi
    • Lin Li
    • Weiguo Zhang
    • Jianhua Wang
  • View Affiliations

  • Published online on: June 22, 2015     https://doi.org/10.3892/mmr.2015.3975
  • Pages: 4708-4712
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Abstract

The expression of osteopontin (OPN) and vascular endothelial growth factor (VEGF) are associated with the severity of cartilage destruction in osteoarthritis. However, the biological connection between OPN and VEGF in osteoarthritis remains to be elucidated. The present study was performed to investigate the effect of OPN on VEGF expression in articular cartilage. Rat articular chondrocytes were isolated and cultured in monolayer conditions, and they were treated with OPN for different time periods (0, 2, 8, 12 or 24 h) and dosages (0, 0.1, 0.25 or 0.5 µM). VEGF expression was assessed by reverse transcription‑quantitative polymerase chain reaction and western blotting. The activation of the phosphoinositide 3‑kinase (PI3K)/AKT and extracellular signal‑regulated kinase (ERK)1/2 pathway was analyzed by detecting the expression of pPI3K, pAKT and pERK1/2. To inhibit the PI3K/AKT and ERK1/2 pathway, LY294002 and PD98059 were used, respectively or in combination. It was identified that OPN increased the expression of VEGF in a dose‑ and time‑dependent manner. The PI3K/AKT and ERK1/2 pathways were activated following OPN stimulation and the effect was concomitant with the upregulation of VEGF. Finally, the regulation of VEGF was inhibited by LY294002 and PD98059, and their combination exhibited a synergistic effect. In conclusion, these findings suggest that OPN may directly upregulate VEGF expression through the PI3K/AKT and ERK1/2 pathway. Further studies are required to reveal the mechanism of action of OPN on cartilage angiogenesis and cartilage destruction.
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September-2015
Volume 12 Issue 3

Print ISSN: 1791-2997
Online ISSN:1791-3004

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Spandidos Publications style
Xu J, Yi Y, Li L, Zhang W and Wang J: Osteopontin induces vascular endothelial growth factor expression in articular cartilage through PI3K/AKT and ERK1/2 signaling. Mol Med Rep 12: 4708-4712, 2015
APA
Xu, J., Yi, Y., Li, L., Zhang, W., & Wang, J. (2015). Osteopontin induces vascular endothelial growth factor expression in articular cartilage through PI3K/AKT and ERK1/2 signaling. Molecular Medicine Reports, 12, 4708-4712. https://doi.org/10.3892/mmr.2015.3975
MLA
Xu, J., Yi, Y., Li, L., Zhang, W., Wang, J."Osteopontin induces vascular endothelial growth factor expression in articular cartilage through PI3K/AKT and ERK1/2 signaling". Molecular Medicine Reports 12.3 (2015): 4708-4712.
Chicago
Xu, J., Yi, Y., Li, L., Zhang, W., Wang, J."Osteopontin induces vascular endothelial growth factor expression in articular cartilage through PI3K/AKT and ERK1/2 signaling". Molecular Medicine Reports 12, no. 3 (2015): 4708-4712. https://doi.org/10.3892/mmr.2015.3975