Effect of HBO on the expression of VPS35 and Wnt3a. Protein levels of VPS35 were up-regulated after HBO treatment in the cell lysates (1.86 ± 0.11-fold, p < 0.01, A) and the effect of HBO was reduced by VPS35 siRNA treatment (1.86 ± 0.11-fold vs. 1.22 ± 0.04-fold, p < 0.05, A). The amounts of Wnt3a in the cell lysates (1.46 ± 0.03-fold, p < 0.05, B) and conditioned culture medium (I vs. IH, **p < 0.01, C) were both up-regulated after HBO treatment. The effect of HBO on secreted Wnt3a was reduced (IH vs. IH + siRNA,**p < 0.01, C) but the intracellular Wnt3a levels were not affected (IH/I vs. IH + siRNA/I, p > 0.05, B) by VPS35 siRNA treatment. GPR177 level was reduced (0.46 ± 0.11-fold, p < 0.01, D) when VPS35 was suppressed (0.38 ± 0.07-fold, p < 0.01, D) by VPS35 siRNA treatment. Each bar represents the value of the mean ± SD and analyzed by Student t-test (I, induction; IH, induction + HBO).