Abstract: PURPOSE: To explore the effect of transforming growth factor β3 (TGF-β3) on IL-6 expression in inflammatory MG63, and the mechanism by which TGF-β3 exert its anti-inflammatory effect. METHODS: Cell line MG63 was stimulated by 20 μg/mL lipopolysaccharide of Porphyromonas endodontalis (P.e-LPS) to establish the inflammatory model of osteoblast. TGF-β3 or TGFβ1 varying from 5 to 20 ng/mL was added together with P.e-LPS for 24 h, then the mRNA expression of IL-6 was detected by real-time PCR, the role of TGF-β3 on IL-6 protein was further verified by ELISA. MG63 was pretreated with 10 ng/mL TGF-β3 for 30 min in RPMI 1640 medium without fetal bovine serum (FBS), then the cells were cultured for another 20 min with 20 μg/mL P.e-LPS, the phosphorylation level of ERK1/2 was measured by Western blot. Statistical analysis was performed using one-way ANOVA with SPSS13.0 software package. RESULTS: The results of real-time PCR revealed that, when MG63 was treated with 20 μg/mL P.e-LPS alone, the mRNA expression of IL-6 increased significantly(P<0.01). When TGF-β1 was added with P.e-LPS, it could barely decrease IL-6 prominently at the highest concentration (P<0.05).Whereas, the inhibition effect of TGF-β3 on IL-6 was dramatic (P<0.01), ELISA results showed that 10-20 ng/mL TGF-β3 blocked the IL-6 expression at protein level (P<0.05). 20 μg/mL P.e-LPS promoted the phosphorylation level of ERK1/2 in MG63(P<0.01), while with 10 ng/mL TGF-β3, the effect of P.e-LPS on ERK1/2 was blocked(P<0.05). CONCLUSIONS: TGF-β3 is more potent than TGF-β1 in inhibiting MG63, and ERK1/2 is involved in its anti-inflammatory effect.

Key words: Transforming growth factor β, 3, Osteoblast, Inflammation, IL-6