Abstract:

Objective To explore the role and mechanism of lncRNA NEAT1 in palmitic acid-induced injury and inflammatory response of LO2 cells by regulating NF-κB signaling pathway. Methods LO2 cells were treated with palmitic acid for 24 h. Oil red O staining and triglyceride （TG） test were done to detect lipid accumulation， CCK8 assay was done for cell viability， and ALT and AST were tested for detecting hepatocyte injury. The expression of lncRNA NEAT1 was detected by RT-qPCR， the expression of inflammatory cytokines TNF-α， IL-1β and IL-6 in intracellular and culture supernatants were determined by RT-qPCR and ELISA and the expression of NF-κB signaling pathway-related proteins was detected by Western blot and immunofluorescence. Results In the palmitic acid-treated LO2 cells， the lipid accumulation was increased， the cell viability was decreased， the levels of ALT and AST were increased. Meanwhile， the expression of inflammatory cytokines TNF-α， IL-1β and IL-6 was increased and the expression of lncRNA NEAT1 was upregulated （P < 0.05）. After overexpression of lncRNA NEAT1， the levels of ALT， AST， TNF-α， IL-1β， IL-6 were even more increased， the cell viability was significantly reduced. Contrarily， inhibition of lncRNA NEAT1 resulted in the opposite effect （P < 0.05）. In addition， NF-κB signaling pathway was activated in the LO2 cells induced by palmitic acid and IKBα expression was decreased and phosphorylation of NF-κB p65 was increased. Then the overexpress of lncRNA NEAT1 further promoted the degradation of IKBα protein and increased NF-κB p65 phosphorylation into the nucleus， and contrarily， inhibition of lncRNA NEAT1 resulted in the opposite effect （P < 0.05）. Conclusion The up-expressed lncRNA NEAT1 in LO2 cells induced by palmitic acid can promote cell injury and inflammatory response by way of activating NF-κB signaling pathway.

Key words: lncRNA NEAT1, metabolic associated fatty liver disease, hepatocyte injury, inflammation, NF-κB signaling pathway