Effect of HBO on the expression of GPR177 and Wnt3a. Protein levels of GPR177 were up-regulated after HBO treatment in the cell lysates (1.67 ± 0.05-fold, p < 0.01, A) and the effect of HBO was reduced through GPR177 siRNA treatment (1.67 ± 0.05-fold vs. 0.69 ± 0.07-fold, p < 0.01, A). The amounts of Wnt3a in the cell lysates (1.89 ± 0.09-fold, p < 0.05, B) and conditioned culture medium (I vs. IH, *p < 0.05, C) were both up-regulated after HBO treatment. However, the effect of HBO on secreted Wnt3a was reduced (IH vs. IH + siRNA, *p < 0.05, C), but the intracellular Wnt3a levels were not affected (IH/I vs. IH + siRNA/I, p > 0.05, B) by GPR177 siRNA treatment. Each bar represents the value of the mean ± SD and analyzed by Student t-test (I, induction; IH, induction + HBO).