Figure 1.

Activation of the UPR target genes in degenerated NPCs. (a) Transmission electron microscopy (TEM) images of endoplasmic reticulum (ER) in N-NPCs and D-NPCs. The morphology of ERs was showed with white arrows. The results showed more dilated and abundant ERs in D-NPCs. (b) The expressions of the UPR target genes (PERK, GRP78, and CHOP) in N-NPCs and D-NPCs were determined by real-time PCR. The results were normalized to GAPDH mRNA expression. (c) Western blot analysis showed the protein levels of PERK, GRP78, and CHOP in N-NPCs and D-NPCs. β-Actin was used as an internal control. The representative results were from three independent experiments. The error bars represent the SD from the mean values. ∗P < 0.05, ∗∗P < 0.01.