New Rat Model of Advanced NASH Mimicking Pathophysiological Features and Transcriptomic Signature of The Human Disease

Abstract

Non-alcoholic steatohepatitis (NASH) is a major cause of chronic liver disease. However, most available animal models fail to reflect the whole spectrum of the disease. Liver fibrosis and portal hypertension are the strongest prognostic markers in advanced NASH. We herein aimed at developing a new model of NASH in male rats, obtained using a multi-hit protocol that combines the administration of a high fat and high-cholesterol diet with CCl4 and phenobarbital. Following this protocol, rats showed the full characteristics of advanced human NASH after 10 weeks and NASH with cirrhosis by 24 weeks. Specifically, our NASH rats exhibited: steatosis and metabolic syndrome, lipotoxicity, hepatocellular ballooning necrosis, inflammation and importantly, marked hepatic fibrosis and significant portal hypertension. Furthermore, a whole transcriptomic analysis of liver tissue from our rat model using next generation sequencing was compared with human NASH and illustrated the similarity of this pre-clinical model with the human disease. Pathway enrichment analysis showed that NASH animals shared a relevant number of central pathways involved in NASH pathophysiology, such as those related with cell death, as well as inflammatory or matrix remodeling. The present study defines a pre-clinical model of moderate and advanced NASH that mimics the human disease, including pathophysiologic characteristics and transcriptomic signature.

A Nutraceutical Rich in Docosahexaenoic Acid Improves Portal Hypertension in a Preclinical Model of Advanced Chronic Liver Disease

“…Liver tissue samples were fixed in 4% formaldehyde (Sigma), embedded in paraffin, sectioned, and processed for immunofluorescence as previously described [20]. Liver sections were incubated with a primary antibody against CD68 (1:100, MCA341R, Bio-Rad), a secondary Alexa Fluor 555 antibody (1:300, Life technologies), and 40,6-diamino-2-fenilindol (DAPI) (1:1000, Sigma, Kawasaki, Japan) and mounted in Fluoromount G medium.…”

Transcriptional Regulation in Non-Alcoholic Fatty Liver Disease

“…The same strategy was applied to predict the changes in the activity of transcription factors in mouse models of NAFLD/NASH. We performed IPA upstream activity prediction analysis for publicly available liver transcriptome data from mouse models of steatosis that were established by feeding high caloric diets [ 18 , 207 ] as well as mouse models of NASH that were established by feeding an MCD diet [ 207 ], NASH diet, or a combination of high caloric diets coupled with CCl 4 treatment [ 18 , 208 ]. Additionally, we included the observations of a previously published STZ-induced NASH and HCC model (STAM) [ 7 ].…”

The Mitochondrial Trigger in an Animal Model of Nonalcoholic Fatty Liver Disease

“…Due to the recent epidemiclike diffusion of NAFLD, several NAFLD/NASH animal models, mostly mice and rats, have been developed to help dissect the disease’s pathogenetic process [ 20 , 21 , 22 ]. Such models can be divided into diet-induced, genetic, or derived by combining different interventions [ 23 ].…”