Adaptive unfolded protein response promotes cell survival in rifampicin-treated L02 cells

Abstract

An important concept in drug-induced liver injury (DILI) is adaptation, which means the injury reverses with the continuation of the drug. The mechanism of adaption of drugs remains enigmatic, adaptive unfolded protein response (UPR) is possibly involved. We once observed adaptation phenomenon of rifampicin (RFP) in animal models, in this study, we investigate the effects of RFP on adaptive UPR in L02 cells, and after inhibiting UPR by using 4-phenylbutyrate (4-PBA), the change of cell viability and cell apoptosis in RFP-treated cells. We found that with the concentration of RFP increased and the treatment time was prolonged, the glucose-regulated protein 78 (GRP78), a hallmark of the UPR, was upregulated, and was dose- and time-dependent. RFP also activates the p-eukaryotic initiation factor 2α (eIF2α) protein expression. 4-PBA decreased GRP78 and p-eIF2α protein expression levels. Moreover, FCA showed that cell apoptosis rate obviously increased, and MTT assay showed that cell survival rate obviously decreased, this indicates that after inhibiting the UPR, the cell damage increased, which shows that the UPR is an adaptation mechanism to protect cells against injury induced by RFP. This also proves that when the degree of UPR induced by RFP is relatively mild, adaptive UPR is helpful for cell survival.

Induction of ER Stress by an AAV5 BDD FVIII Construct Is Dependent on the Strength of the Hepatic-Specific Promoter

“… 11 Induction of an adaptive UPR is a protective mechanism, shielding cells against injury. 19 However, overactivation or chronic prolongation of UPR may lead to apoptosis and loss of hepatocytes. 10 Several pathways can contribute to ER stress-mediated apoptosis, including inositol-requiring enzyme 1α (IRE1α), apoptosis signal-regulating kinase 1, c-Jun N-terminal kinases signaling, CHOP regulation of B cell lymphoma 2 (BCL2) protein family members and apoptotic genes, ER-localized BCL2-associated X protein, BCL2 homologous antagonist killer, and glycogen synthase kinase 3β (GSK3β).…”

Effects of medium‐ and long‐chain fatty acids on acetaminophen‐ or rifampicin‐induced hepatocellular injury

“…As the concentration of AP or RFP increased and the treatment time was prolonged, the cell viability decreased in a dose-and time-dependent manner (Figure 1a,b). The IC50 values for RFP were reported to be 548.91 and 234.96 µM in 24 and 48 hr, respectively, in LO2 cells (Zhang & Xu, 2018). Other studies found that the IC50 value for RFP in 24 hr was 530.33 µM and established cell injury model by treatment with 10 mM AP for 24 hr (Wu et al, 2016; Yuan-Jing, Wei, Jian-Ping, Yu-Xia, & Zi-Ling, 2016).…”

Application of 3D Hepatic Plate-Like Liver Model for Statin-Induced Hepatotoxicity Evaluation

“…hy926 cell lines and the microfluidic device mentioned earlier, and the fabrication process and materials formula used in this study were the same with our previous study. As an immortalized hepatocyte line, L-02 cells have been proven to be suitable for toxicity assessments and bioartificial liver establishment ( Kouam et al, 2017 ; Zhang and Xu, 2018 ). In this study, we designed four control systems, i.e., two-dimensional co-culture (2D), collagen sandwich co-culture (CS), 3D hybrid hydrogel fiber (3D-H) co-culture systems and primary human hepatocytes (PHHs).…”