Blockage to PAR affects the phosphorylation of ERK 1/2 and FN secretion by thrombin-treated MSCs. SCH79797 (SCH) and FSLLRY-NH2 (FSL) were added into MSC culture in the presence of thrombin (TH, 4 U/ml). The cells were harvested at the indicated time points and the phosphorylated status of ERK 1/2 and NFκB p65 was revealed by Western blotting (A). MSC culture was maintained for 48 hours and the supernatants were collected for FN detection by ELISA (B). Data are shown as means ± SE (n = 3). *compared with control group (thrombin- and inhibitors- free), *P <0.05, **P <0.01; # compared with thrombin 4 U/ml treated group, #P <0.05, ##P <0.01. FN, Fibronectin; MSCs, Mesenchymal stem cells; NFκB, Nuclear factor kappa B.