6565 The NF-κB-CXCL1 Axis Mediates the Development of Nonalcoholic Steatohepatitis

Abstract Disclosure: M. Raul: None. Y. Li: None. L. Chen: None. C. Sottas: None. N. Patel: None. A. Zambidis: None. V. Papadopoulos: None. The transcription factor nuclear factor kappa B (NF-κB) plays a crucial role in the pathogenesis of nonalcoholic steatohepatitis (NASH). CXC chemokine, (CXCL1) is one of the most selective and potent chemokines that effectively attracts neutrophils to the site of inflammation or infection, which is also regulated by the NF-κB signaling pathway. In the liver, when NF-κB is activated, it promotes the transcription of CXCL1 to recruit neutrophils to the site of inflammation. Moreover, induced expression of the CXCL1 gene in rat liver was accompanied by neutrophil infiltration, causing hepatic damage and dysfunction. Previous research has shown that NF-κB signaling can influence CXCL1 in vitro. However, the contribution of the NF-κB/CXCL1 axis to the progression of NASH has remained unclear. To verify the regulatory association between NF-κB and CXCL1, we conducted a luciferase assay by transiently transfecting Huh7 cells with a CXCL1-Luciferase plasmid and treating them with varying concentrations of human recombinant NF-κB protein. The results demonstrated a dose-dependent increase in CXCL1-luciferase activity in response to NF-κB, indicating that NF-κB regulates CXCL1 expression. Additionally, TNFɑ (10ng/ml)-induced CXCL1-luciferase activity was significantly and dose-dependently suppressed by celastrol (CEL), a compound known to counteract the TNFα-induced upregulation of NF-κB. To further investigate the regulation of CXCL1 by NF-κB in the liver in vivo, CEL was administered to rats fed with the Gubra-Amylin diet-induced NASH (GAN) diet. Histological studies revealed a substantial reduction in liver lipid accumulation and fibrosis, along with reduced inflammation in white adipose tissue with CEL treatment. As anticipated, NF-κB levels were significantly suppressed in GAN+CEL compared to the GAN+Veh (vehicle)-treated rats. CXCL1 expression was also diminished by the treatment, providing further confirmation of the regulation of CXCL1 by NF-κB in the liver. Moreover, the hallmarks of NASH, including inflammation, lipid accumulation, and fibrosis, were alleviated in the GAN+CEL group compared to the GAN+Veh group. In conclusion, these findings provide compelling evidence supporting the involvement of the NF-κB - CXCL1 signaling pathway in the development of NASH. Presentation: 6/2/2024