Metabolomic profiling of HepG2/C3A liver-on-chip model exposed to oleic acid, palmitic acid and oleic/palmitic acids mixture.

Metabolic dysfunction associated steatotic liver disease (MASLD) is one of the most predominant liver disorders. MASLD is associated with dietary intake of fatty acids. Among them, oleic (OA) and palmitic (PA) acids are the most abundant. Furthermore, OA was reported to have an hepatoprotective effect against PA toxicity on primary hepatocytes and liver cell lines. In this work, to characterize the mechanisms related to fatty acids exposure, we analyzed the metabolomic signatures of HepG2/C3A using advanced organ-on-chip technology. The cells were exposed for 2 to 7 days to OA, PA and OA/PA mixture. The cell secretions were analyzed using GC-MS spectrometry to reveal their metabolomic signatures. We were able to identify a common HepG2/C3A response to OA, PA and OA/PA deciphering the FFAs global perturbations including the nitrogen metabolism, after 7 days of treatments. Then, we extracted the specificity of each treatment. We found that OA altered intracellular lipid secretion, while OA/PA shifted metabolism from the lipid production to their consumption. PA exposure induced changes consistent with a perturbation in oxidative stress, energy metabolism and a high oxalic acid production. Nicotinamide levels increased in all treatments, indicating a potential