Reactive oxygen species-induced TXNIP drives fructose-mediated hepatic inflammation and lipid accumulation through NLRP3 inflammasome activation.

Abstract

AIMS:

Increased fructose consumption predisposes the liver to nonalcoholic fatty liver disease (NAFLD), but the mechanisms are elusive. Thioredoxin-interacting protein (TXNIP) links oxidative stress to NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation and this signaling axis may be involved in fructose-induced NAFLD. Here, we explore the role of reactive oxygen species (ROS)-induced TXNIP overexpression in fructose-mediated hepatic NLRP3 inflammasome activation, inflammation, and lipid accumulation.

RESULTS:

Rats were fed a 10% fructose diet for 8 weeks and treated with allopurinol and quercetin during the last 4 weeks. Five millimolars of fructose-exposed hepatocytes (primary rat hepatocytes, rat hepatic parenchymal cells [RHPCs], HLO2, HepG2) were co-incubated with antioxidants or caspase-1 inhibitor or subjected to TXNIP or NLRP3 siRNA interference. Fructose induced NLRP3 inflammasome activation and pro-inflammatory cytokine secretion, janus-activated kinase 2/signal transducers and activators of transcription 3-mediated inflammatory signaling, and expression alteration of lipid metabolism-related genes in cultured hepatocytes and rat livers. NLRP3 silencing and caspase-1 suppression blocked these effects in primary rat hepatocytes and RHPCs, confirming that inflammasome activation alters hepatocyte lipid metabolism. Hepatocellular ROS and TXNIP were increased in animal and cell models. TXNIP silencing blocked NLRP3 inflammasome activation, inflammation, and lipid metabolism perturbations but not ROS induction in fructose-exposed hepatocytes, whereas antioxidants addition abrogated TXNIP induction and diminished the detrimental effects in fructose-exposed hepatocytes and rat livers.

INNOVATION AND CONCLUSIONS:

This study provides a novel mechanism for fructose-induced NAFLD pathogenesis by which the ROS-TXNIP pathway mediates hepatocellular NLRP3 inflammasome activation, inflammation and lipid accumulation. Antioxidant-based interventions can inhibit the ROS-TXNIP pathway.

• Authors: Xian Zhang, Jian-Hua Zhang, Xu-Yang Chen, Qing-Hua Hu, Ming-Xing Wang, Rui Jin, Qing-Yu Zhang, Wei Wang, Rong Wang, Lin-Lin Kang, Jin-Sheng Li, Meng Li, Ying Pan, Jun-Jian Huang, Ling-Dong Kong
• Journal: Antioxidants & redox signaling (Antioxid Redox Signal) Vol. 22 Issue 10 Pg. 848-70 (Apr 01 2015) ISSN: 1557-7716 [Electronic] United States
• PMID: 25602171 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antioxidants
• Carrier Proteins
• Cell Cycle Proteins
• Cytokines
• Enzyme Inhibitors
• Inflammasomes
• NLR Family, Pyrin Domain-Containing 3 Protein
• Nlrp3 protein, rat
• Reactive Oxygen Species
• TXNIP protein, rat
• Fructose
• Allopurinol
• Quercetin

Topics

• Allopurinol (pharmacology)
• Animals
• Antioxidants (pharmacology)
• Carrier Proteins (metabolism)
• Cell Cycle Proteins
• Cell Line
• Cytokines (metabolism)
• Enzyme Inhibitors (pharmacology)
• Fructose (metabolism)
• Hepatocytes (metabolism)
• Inflammasomes (metabolism)
• Inflammation (metabolism)
• Lipid Metabolism
• Liver (metabolism)
• Male
• NLR Family, Pyrin Domain-Containing 3 Protein
• Non-alcoholic Fatty Liver Disease (metabolism)
• Oxidative Stress (drug effects)
• Quercetin (pharmacology)
• Rats, Sprague-Dawley
• Reactive Oxygen Species (metabolism)