Fig. 4
Effects of the secretome with different concentrations of culture pO2 on the signaling pathways essential for cell proliferation in the mouse liver. a Real-time RT-PCR showing mRNA expression of HIF-1α, STAT3, HGF, and VEGF in the liver specimens of the secretome-injected mice on day 2 after injection. Of the groups, the 1% pO2 group showed the highest mRNA expression of HGF (left) and VEGF (right). b (Left) Western blot analysis of the markers for liver cell proliferation in the mouse liver specimens on day 2 after injection. (Right) Relative densities of each marker. The 1% pO2 secretome group showed the highest expression of HIF-1α, PCNA, HGF, and VEGF. The 1% pO2 secretome group showed the highest expression of p-STAT3 as well as the lowest expression of SOCS3 (a key negative regulator of IL-6/STAT3 signaling). c VEGF immunohistochemistry of liver specimens demonstrating the highest expression of VEGF in the 1% pO2 secretome group on day 2 after injection. Data represent mean ± SD. *p < 0.05 compared to control. Ct control, HGF hepatocyte growth factor, HIF-1α hypoxia-inducible factor-1α, PCNA proliferating cell nuclear antigen, PH partial hepatectomy, S21% secretome of culture 21% pO2, S10% secretome of culture 10% pO2, S5% secretome of culture 5% pO2, S1% secretome of culture 1% pO2, SOCS3 suppressor of cytokine signaling 3, p-STAT3 phospho-signal transducer and activator of transcription 3, VEGF vascular endothelial growth factor