Alteration of cellular lipids and lipid metabolism markers in RTL-W1 cells exposed to model endocrine disrupters

• RTL-W1 cells express genes involved in lipid metabolism: CD36, FATP1, FAS, LPL, PPARβ.
• Gene expression was up/down-regulated after exposure to selected endocrine disrupters.
• Cellular lipids were altered by exposure to model endocrine disrupters.
• BPA and DEHP acted as obesogens by increasing cell’s triacylglycerols.
• DEHP, NP and TBT induced significant changes in membrane lipids.

This work investigates the suitability of the rainbow trout liver cell line (RTL-W1) as an in-vitro model to study the ability of model endocrine disrupters, namely TBT, TPT, 4-NP, BPA and DEHP, to act as metabolic disrupters by altering cellular lipids and markers of lipid metabolism. Among the tested compounds, BPA and DEHP significantly increased the intracellular accumulation of triacylglycerols (TAGs), while all the compounds -apart from TPT-, altered membrane lipids – phosphatidylcholines (PCs) and plasmalogen PCs – indicating a strong interaction of the toxicants with cell membranes and cell signaling. RTL-W1 expressed a number of genes involved in lipid metabolism that were modulated by exposure to BPA, TBT and TPT (up-regulation of FATP1 and FAS) and 4-NP and DEHP (down-regulation of FAS and LPL). Multiple and complex modes of action of these chemicals were observed in RTL-W1 cells, both in terms of expression of genes related to lipid metabolism and alteration of cellular lipids. Although further characterization is needed, this might be a useful model for the detection of chemicals leading to steatosis or other diseases associated with lipid metabolism in fish.