Fig. 3

Blue light-induced morphological changes of intracellular organelles and the subsequent activation of stress signaling pathways in 661W cells. (A) Representative images of mitochondria (MitoTracker, red), lysosomes (Lamp1, cyan), ER (calnexin, green), and nuclei (DAPI, blue) in 661W cells incubated without (Control) or with either 2 or 8 h of exposure to blue light. Enlarged views of the boxed regions are shown in the upper right corners. Arrowheads indicate fragmented mitochondria. Bar = 20 μm. (B) Representative images of immunoblots in whole cell lysates obtained from 661W cells at the indicated times under the condition with blue light irradiation. (C, D) The graph represents the relative protein level of ATF4 (C, normalized by β-actin) and the phosphorylation of S6 ribosomal protein (S6RP; D) (E) Representative images of immunoblots in the cytosolic and nuclear fractions. (F, G) The graph displays the relative levels of ATF4 (F) and Nrf2 (G), which are normalized by cJun. Bar graph shows the mean ± SEM. (n = 6). **P < 0.01, ***P < 0.001, Tukey’s test vs. 0 h