Kupffer cells play a crucial role in monocrotaline-induced liver injury by producing TNF-α. (28th February 2022)

• Record Type: Journal Article
• Authors: Cao, Yuhan; Liu, Meng; Wu, Shouyan; Xu, Junjiu; Wang, Wenjie; Qi, Xinming; Ren, Jin; Sun, Jianhua; Chen, Jing; Gong, Likun
• Is Part Of: Toxicology. Volume 468(2022)
• Publication Date: 2022-02-28
• Subjects: Monocrotaline -- Kupffer cells -- Necrosis -- Hepatotoxicity; Toxicology -- Periodicals; Chemicals -- Physiological effect -- Periodicals; 615.9005
• DOI: 10.1016/j.tox.2022.153101
• Languages: English
• ISSNs: 0300-483X

Abstract

Graphical abstract: Abstract: Monocrotaline (MCT), an unsaturated pyrrolizidine alkaloid (PA) in plants, is mainly toxic to the lung and liver of mammals. As a commonly used tool for liver injury model, the mechanism of MCT hepatoxicity has still not been fully clarified. Kupffer cells (KCs) are the liver-resident macrophages and have various responses to different toxicants and liver damage. However, the role of KCs in MCT-induced liver injury remains controversial. In current work, we investigated the effects of KCs on MCT-induced liver injury, especially on MCT-induced hepatocyte death. KCs were depleted in Balb/c mice by liposome-entrapped clodronate (Lip/Clo) (0.2 mL/mouse, i.p.) or GdCl3 (0.7 mg/kg, i.p.) before MCT administration (300 mg/kg, i.p.), we found that the Lip/Clo group showed higher efficiency in KCs depletion and stronger hepatoprotective effects against MCT. We also found TNF-α was remarkably decreased after KCs depletion, the experiment of administering anti-TNF-α antibody (20 μg/mouse, i.p.) to MCT-treated animals generated the similar results. To further elaborate the function of KCs, we compared the ALT levels released from co-culturing murine hepatic parenchymal cells (HPCs) and RAW264.7 cells with that from HPCs alone. After the treatment of MCT, the released ALT levels in co-culture system were shown to be dependent on the number of RAW264.7 cells, while the anti-TNF-α antibody could suppress it. Finally, we discovered RIPK3/MLKL pathway might be activated by TNF-α released from KCs, and subsequently induced hepatocyte necrosis. Noteworthy, the known mechanisms including ER stress and NF-κB pathways were also found to be involved in the activation of KCs. In conclusion, our study reveals a further mechanism to MCT-induced hepatoxicity mediated directly by KCs via producing TNF-α.