Fig. 6
nCeO2 induced cell proliferation and fibroblastic nodule formation are attenuated with chemical inhibition of TGFβ receptor signaling. NHLFs were treated as indicated for 48 h. Cells receiving the TGFβ receptor inhibitor SB431542 (SB) were treated for 3 h with 1 μM of inhibitor prior to the addition of the nanoparticles. Chemical inhibition of the TGFβ receptor reversed the nCeO2-induced increase in cell proliferation (a) and fibroblastic nodule formation (b) at both of the tested nanoparticle doses. (c) Collagen I staining demonstrated that inhibition of the TGFβ receptor decreased the nCeO2-induced increase in collagen I production from NHLFs. (d) Western blot analysis and corresponding densitometry further confirmed that the SB inhibitor reversed the nCeO2-induced increase in collagen I production. Statistical significance is indicated as *p < 0.05, **p < 0.01, and ***p < 0.001 compared to non-treated (NT) conditions or compared to other treatments as indicated in D; #p < 0.05, ##p < 0.01, and ###p < 0.001 compared to the same treatment condition without inhibitor