Endoplasmic Reticulum Stress Induction and ERK1/2 Activation Contribute to Nefazodone-Induced Toxicity in Hepatic Cells

In this report, using biochemical and molecular analyses, we characterized the molecular mechanisms underlying the hepatotoxicity of nefazodone. We found that nefazodone induced endoplasmic reticulum (ER) stress in HepG2 cells, as the expression of typical ER stress markers, including CHOP, ATF-4, and p-eIF2α, was significantly increased, and splicing of XBP1 was observed. Nefazodone-suppressed protein secretion was evaluated using a Gaussia luciferase reporter assay that measures ER stress. The ER stress inhibitors (4-phenylbutyrate and salubrinal) and knockdown of ATF-4 gene attenuated nefazodone-induced ER stress and cytotoxicity. Nefazodone activated the MAPK signaling pathway, as indicated by increased phosphorylation of JNK, ERK1/2, and p38. Inhibition of ERK1/2 reduced ER stress caused by nefazodone. Taken together, our findings suggest that ER stress contributes to nefazodone-induced toxicity in HepG2 cells and that the MAPK signaling pathway plays an important role in ER stress.

Source: Toxicological Sciences - December 4, 2016 Category: Toxicology Authors: Ren, Z., Chen, S., Zhang, J., Doshi, U., Li, A. P., Guo, L. Tags: Nefazodone Causes Endoplasmic Reticulum Stress and Hepatic Cell Toxicity Source Type: research