Dose dependent effects of fructose and glucose on de novo palmitate and glycerol synthesis in an enterocyte cell model

Steenson, S., Shojaee-Moradie, F., Lovegrove, J. A. ORCID: https://orcid.org/0000-0001-7633-9455, Umpleby, A. M., Jackson, K. G. ORCID: https://orcid.org/0000-0002-0070-3203 and Fielding, B. A. (2022) Dose dependent effects of fructose and glucose on de novo palmitate and glycerol synthesis in an enterocyte cell model. Molecular Nutrition and Food Research, 66 (1). ISSN 1613-4125 doi: 10.1002/mnfr.202100456

Abstract/Summary

Scope: Fructose exacerbates post-prandial hypertriacylglycerolaemia. This may be partly due to increased enterocyte de novo lipogenesis (DNL). It is unknown whether this is concentration-dependent or whether fructose has a greater effect on lipid synthesis than glucose. The dose-dependent effects of fructose and glucose on DNL and de novo triacylglycerol (TAG)-glycerol synthesis were investigated in an enterocyte model, Caco-2 cells. Methods and results: Caco-2 cells were treated for 96h with 5mM, 25mM or 50mM fructose or glucose, or 12.5mM fructose/12.5mM glucose mix. DNL was measured following addition of [13C2]-acetate to apical media. In separate experiments, [13C6]-fructose and [13C6]-glucose were used to measure DNL and de novo TAG-glycerol synthesis. DNL from [13C2]-acetate was detected following all treatments, with greater amounts in intracellular than secreted (media) samples (all P <0.05). DNL from [13C6]-fructose and [13C6]-glucose was also measurable. Intracellular synthesis was concentration-dependent for both glucose and fructose tracers (P=0.003, P=0.034, respectively) and was higher with 25mM glucose than 25mM fructose (P=0.025). DNL from fructose and glucose was <1%, but up to 70% of de novo TAG-glycerol was synthesised from glucose or fructose. Conclusion: Fructose is not a major source of DNL in Caco-2 cells but contributes substantially to de novo TAG-glycerol synthesis.