Figure 2

TNFα activates the IKK-β/NF-κB cascade without significant induction of endoplasmic reticulum (ER) stress or apoptosis in rHypoE-7 cells. Ai. The phosphorylation levels of the ER stress marker, elF-2α, were assessed by western blotting after TNFα treatment (10 ng/mL, 2 hr). Relative to vehicle (H₂0) and normalized to β-actin, no significant increase in phospho-elF2α (p-elf2α) was observed (ii) (H₂0: 0.71 ± 0.05 and TNFα: 0.81 ± 0.08 p-elF-2α/βactin, n = 4). B. ER stress levels were also assessed by measuring the mRNA levels of ER stress markers, CHOP and GRP-78, by qRT-PCR (n = 4-10). No significant change was detected relative to vehicle (H₂0) treatment for either CHOP (H₂0; white bar: 0.78 ± 0.11 and TNFα; gray bar: 0.92 ± 0.07 CHOP/histone mRNA, n = 4 to 10) or GRP78 (H₂0: 1.03 ± 0.05 and TNFα: 1.17 ± 0.07 GRP78/histone). C. Bar graph representing the total MTT absorbance (AB_570nm) upon H₂0 or TNFα treatment (10 ng/mL, 2 hr) where no significant change in absorbance could be detected (H₂0; white bar: 0.12 ± 0.002 and TNFα; gray bar: 0.13 ± 0.004 AB_570nm, n = 8 to 16). Data are shown as mean ± SEM.