Figure 6.

Overexpression of PNPLA3 M148M activated ER stress signal IRE‐1α‐JNK‐c‐Jun inflammatory pathway. A, PNPLA3 M148M overexpression increased TNF‐α expression in a NF‐kB independent way. HepG2 cells were stably infected with lentiviral PNPLA3 M148M (LV‐148M), lentiviral PNPLA3 I148I (LV‐148I) and mock lentivirus (LV‐Mock), respectively. Nucleoprotein and cytoplasmic protein were extracted after infection to measure protein expressions of nuclear NF‐kB, PNPLA3 and TNF‐α by Western blotting (left panel). RNA was extracted to measure PNPLA3 and TNF‐α mRNA levels by real‐time PCR (right panel). The real‐time PCR results are presented as the mean ± SD from three independent experiments. #P < .05 compared with LV‐Mock; *P < .05 compared with LV‐148M. B, PNPLA3 M148M but not I148I overexpression activated IRE‐1α‐JNK‐c‐Jun pathway. HepG2 cells were stably transfected with LV‐148M, LV‐148I and LV‐Mock, respectively. Cytoplasmic protein was extracted to measure protein expressions of IRE‐1α, total and phosphorylation JNK1/2, and c‐Jun by Western blotting (left panel). The relative band intensities (right panel) in Western blots (n = 2) were determined using ImageJ and normalized to β‐actin. Statistical significance was performed by one‐way ANOVA. Data are presented as the mean ± SD. *P < .05 compared with LV‐Mock