Characterizing the mechanism of thiazolidinedione-induced hepatotoxicity: An in vitro model in mitochondria.
OBJECTIVE
To characterize the mechanism of action of thiazolidinedione (TZD)-induced liver mitochondrial toxicity caused by troglitazone, rosiglitazone, and pioglitazone in HepaRG cells.


METHODS
Human hepatoma cells (HepaRG) were treated with troglitazone, rosiglitazone, or pioglitazone (12.5, 25, and 50μM) for 48h. The Seahorse Biosciences XF24 Flux Analyzer was used to measure mitochondrial oxygen consumption. The effect of TZDs on reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were detected by flow cytometry. The mitochondrial ultrastructure of HepaRG cells was observed under a transmission electrical microscope (TEM). mtDNA content was evaluated by real-time PCR, and ATP content and mitochondrial respiratory chain (MRC) complex I, II, III, IV activity were measured via chemiluminescence. Results were considered statistically significant at p<0.05.


RESULTS
Among the three drugs, troglitazone exhibited the highest potency, followed by rosiglitazone, and then pioglitazone. The TZDs caused varying degrees of mitochondrial respiratory function disorders including decreases in oxygen consumption, MRC activity, and ATP level, and an elevation in ROS level. TZD treatment resulted in mtDNA content decline, reduction in MMP, and alterations of mitochondrial structure.


CONCLUSIONS
All investigated TZDs show a certain degree of mitochondrial toxicity, with troglitazone exhibiting the highest potency. The underlying mechanism of TZD-induced hepatotoxicity may be associated with alterations in mitochondrial respiratory function disorders, oxidative stress, and changes in membrane permeability. These parameters may be used early in drug development to further optimize risk:benefit profiles.
State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Beijing 100850, PR China.
Dan
D
Hu
State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Beijing 100850, PR China.
Chun-qi
CQ
Wu
State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Beijing 100850, PR China; Guang Dong Pharmaceutical University, Guangzhou 510006, PR China.
Ze-jun
ZJ
Li
State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Beijing 100850, PR China.
Yue
Y
Liu
State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Beijing 100850, PR China.
Xing
X
Fan
State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Beijing 100850, PR China. Electronic address: wangquanjunbeijing@163.com.
Quan-jun
QJ
Wang
State Key Laboratory of Toxicology and Medical Countermeasures, Institute of Pharmacology and Toxicology, Academy of Military Medical Sciences, 27 Taiping Road, Beijing 100850, PR China. Electronic address: dingrigao@nic.bmi.ac.cn.
Ri-gao
RG
Ding
D045744:Cell Line, Tumor; D002839:Chromans / Q000633:toxicity; D004272:DNA, Mitochondrial / Q000235:genetics; D004579:Electron Transport / Q000187:drug effects; D006801:Humans; D007004:Hypoglycemic Agents / Q000633:toxicity; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D000077205:Pioglitazone; D017382:Reactive Oxygen Species / Q000378:metabolism; D000077154:Rosiglitazone; D045162:Thiazolidinediones / Q000633:toxicity*; D000077288:Troglitazone
D002839:Chromans; D004272:DNA, Mitochondrial; D007004:Hypoglycemic Agents; D017382:Reactive Oxygen Species; D045162:Thiazolidinediones; D000077154:Rosiglitazone; C089946:2,4-thiazolidinedione; D000077288:Troglitazone; D000077205:Pioglitazone
Mitochondrial respiration; Mitochondrial toxicity; TZDs; Ultrastructure alterations; mtDNA