HepG2 cells stimulated by THP-1-conditioned medium: a potential in vitro model of systemic inflammation–induced hepatic alterations

TL;DR

This study creates an in vitro model using HepG2 cells and THP-1-conditioned medium to study how systemic inflammation affects liver metabolism and lipoprotein changes.

Contribution

A novel in vitro model is developed to study inflammation-induced hepatic metabolic changes under conditions mimicking systemic inflammation.

Findings

Short-term exposure to THP-1-conditioned medium altered inflammatory gene and transcription factor mRNA expression in HepG2 cells.

Lipoprotein-associated gene expression was significantly modified at different time points following exposure.

The model showed no effect on HepG2 cell viability after 24 hours of exposure.

Abstract

Chronic inflammatory diseases are associated with qualitative and quantitative changes in lipid and lipoprotein metabolism, including high density lipoproteins (HDLs), increasing patients´ susceptibility to atherosclerosis and cardiovascular mortality. Given the liver’s central role in lipoprotein metabolism and systemic inflammation, we aimed to develop and investigate an in vitro model of inflammation-induced hepatic metabolic changes.

To better approximate in vivo conditions, where systemic inflammation exposes the liver to a complex environment rich in cytokines and inflammatory mediators, we exposed human hepatocarcinoma HepG2 cells to conditioned media (CM) from THP-1-derived macrophages using phorbol-12-myristate-13-acetate (PMA) and lipopolysaccharide (LPS). The effect of CM on mRNA expression in HepG2 was tested by quantitative real-time PCR or protein expression by Western blot analysis. Even short-term exposure to CM (2–4 h) led to a significant change in the mRNA expression of inflammatory genes and several transcription factors (e.g., TNF-α, NF-κB, PPARα, and LRH-1). This change was accompanied by alternations in the expression of lipoprotein-associated genes at different time points (e.g. SAA, LDLr, ApoA1, ABCA1, PON1, and PCSK9). After 24 h of exposure, no effect on HepG2 viability was observed.

In our model, we observed several significant inflammation-induced changes in hepatic lipoprotein metabolism, making it a valuable in vitro system for further mechanistic studies.

The online version contains supplementary material available at 10.1007/s11033-026-11641-0.

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