PhD Scientific Days 2021

MO_I_P: Molecular Sciences I. Posters

Characterization of the CDAA-induced non-alcoholic steatohepatitis model: sex-specific differences in inflammation, fibrosis, and cholesterol metabolism in middle-aged mice

Text of the abstract

Background: Non-alcoholic steatohepatitis (NASH) - associated with type 2 diabetes mellitus, dyslipidemias and most importantly with obesity - shows a worldwide increase of incidence. NASH displays sex-specific differences in epidemiology and phenotypes; however, the molecular differences between sexes is still unknown.
Aims: We aimed to compare in a mouse model of NASH the inflammatory, fibrotic processes and cholesterol metabolism, focusing on PCSK9 and its targets, in a sex-specific manner.
Methods: We fed 10 months old male and female C57Bl/6J mice with choline deficient L-amino acid defined or choline sufficient control diet. After 8 weeks of diet, the animals were sacrificed, organ samples and blood were collected. We performed histologic analysis to determine morphologic changes and the extent of fibrosis; immunhistochemistry to assess immune cell infiltrations; qRT-PCR to quantify the expression level of inflammatory, fibrotic and cholesterol metabolism-related genes; Western blot to evaluate the protein levels of Interleukin-1ß and different inflammasomes; ELISA to determine the circulating level of PCSK9 and biochemical measurements.
Results: We found that, male and female animals developed similar degree of steatosis, but fibrosis was more marked in males with NASH phenotype. On the other hand, females expressed higher levels of pro-inflammatory Il1b and Ifng; and showed increased activation of NLRP3 inflammasome and correspondingly increased Interleukin 1 cleavage. Both sex showed increased neutrophil infiltration and crown-like structure formation in CDAA-fed group. Clec4f positive Kuppfer cell population decreased during NASH development in female mice.
Conclusion: This study is the first preclinical demonstration that there are important sex-specific differences in NASH development. Our finding highlights the need of sex-dependent treatment in metabolic diseases such as non-alcoholic steatohepatitis.
Funding: This study was supported by the European Union’s Horizon 2020 Research and Innovation Programme no.739593., NVKP_16-1-2016-2017, HCEMM, TKP/ITM/NKFIH, OTKA-FK-134751, EFOP-3.6.3-VEKOP-16-2017-0009.

University and Doctoral School

Semmelweis University, Doctoral School of Pharmaceutical Sciences