Fig. 1.

HepaRG cells secrete more acute-phase proteins upon IL1b treatment than HepG2 cells, but viability in serum-free medium limits the collection window to 12 h.A, secretomics analysis of IL1b-treated HepG2 cells. All identified proteins are depicted with their mean log₂ fold change (n = 3) against the time-matched controls at the indicated time points. Proteins passing the significance thresholds (p(Benjamini-Hochberg) < 0.05 and log₂ fold change > 2× SD of the individual treatment) are colored in orange, acute-phase response proteins are colored in purple, and acute-phase proteins passing the significance thresholds are indicated as triangles. IL1b is colored in blue and indicated with name. 2-fold increase in abundance is indicated by horizontal bars. B, heatmap of all proteins significantly secreted in HepG2 cells upon IL1b treatment for at least one time point. Displayed are mean log₂ fold changes to the respective time-matched control. Statistically significant changes as described in (A) are denoted with asterisks (∗) in the respective cells. Bold names label known acute-phase proteins. C, same as (A) for differentiated HepaRG cells. D, same as (B) for proteins significantly secreted in HepaRG cells upon IL1b treatment. Due to the large number of significant proteins, only those proteins are displayed which show a log₂ fold change >1.5. E, determination of LDH levels in the supernatant of HepaRG cells cultured in serum-free medium using a enzymatic assay at multiple time points (each time point in n = 3). Percentage of cell death is determined as percentage to the maximal LDH activity by lysing the cells with Triton X-100 at time point 0 h. F, light microscopic examination of differentiated HepaRG cells kept in serum-free medium for up to 72 h. White arrows denote areas with disruptions of the monolayer. LDH, lactate dehydrogenase.