Expression of signaling pathway of mammalian target of rapamycin in articular cartilage cell induced by interleukin 1β

Abstract

Objective: To observe effect of interleukin(IL)-1β on the expression of signaling pathway of mammalian target of rapamycin(mTOR) of articular cartilage. Methods: Articular cartilage of rats was isolated under sterile technique, cells were digested by type Ⅱ collagenase and trypsin and cultured in vitro, pre-culture the Ⅱ cells for three days, different concentrations of IL-1β were added for 24 hours.The cells were stained with toluidine blue and HE, to observe morphological changes of cells.RT-PCR was used to detect the mRNA expression of typeⅡcollagen gene, aggrecan gene, mTOR gene and P70S6K gene, Western blotting was used to detect the expression of protein related to mTOR. Results: With increasing concentrations of IL-1β, the phenotype of cells appeared polygon into a spindle, the mRNA expression of gene of type Ⅱ collagen (the control group: 0.821±0.014; 1 ng/ml: 0.614±0.014; 10 ng/ml: 0.549±0.009; 100 ng/ml: 0.520±0.008), aggrecan(0.867±0.005; 0.857±0.001; 0.554±0.008; 0.538±0.004) and mTOR(0.845±0.015; 0.785±0.009; 0.569±0.025; 0.518±0.014) reduced, but P70S6K(0.465±0.024; 0.566±0.022; 0.663±0.022; 0.896±0.015) increased by PCR .Expression of protein detected by Western blotting was similar to the trend of PCR. Conclusion: mTOR signaling pathway may play an important role on the degeneration of articular cartilage, regulating mTOR signaling pathway may provides a new idea of delaying the degeneration process of cells.