Lipoproteins Upregulate High Affinity FC Receptors in Human Monocytes

Esfahani, Mohammad Reza; Bigler, Robert D.; Alfieri, John L.; Gressen, E.; Lund‐Katz, Sissel; Scerbo, L.

doi:10.1006/bbrc.1993.1261

Cited by 4 publications

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This may represent a positive feedback mechanism enhancing receptor-mediated uptake and relate to energy requirements of the cell [28]. Signalling by lipoproteins is not confined to LPL: both VLDL and LDL upregulate expression of high-affinity Fc receptors in monocytes [29]. Macrophages possess many cell surface receptors offering potential routes of uptake for lipoprotein particles, including the VLDL/apo-E receptor [30], scavenger receptors (e.g.…”

Section: Discussionmentioning

confidence: 99%

Utilisation of Fatty Acid and Triacylglycerol by Rat Macrophages: the Effect of Endotoxin

Hui‐Kang

Evans²

2002

Cell Physiol Biochem

View full text Add to dashboard Cite

Background/Aims: Plasma very-low-density lipoprotein (VLDL) concentrations are increased during sepsis/endotoxaemia and VLDL may be substrates for the activated immune system. Lipid substrate utilisation by quiescent and activated macrophages was therefore examined. Methods: Rat R2 macrophages were incubated with oleate or rat VLDL, with or without lipopolysaccharide (LPS) stimulation. The metabolic fate of the lipids was examined. Results: Macrophages utilised both oleate and (control) VLDL-triacylglycerol (TAG) to a similar extent. Most was deposited as cellular lipid; about 10% of oleate was oxidised compared to 25% of cVLDL-TAG. LPS significantly increased oleate oxidation and its deposition as cellular lipid (mostly as TAG) at 48hrs but abolished both oxidation and storage of VLDL-TAG. VLDL produced during endotoxaemia (eVLDL) was assimilated by the unstimulated macrophage to a greater extent than oleate or cVLDL-TAG and selectively stored as cellular lipids (no oxidation); LPS decreased eVLDL utilisation. VLDL-TAG utilisation was decreased by the lipoprotein lipase (LPL) inhibitor terahydrolipstatin. LPL activity was greater in oleate than in VLDL incubations, but was increased by incubation with eVLDL. LPS had no effect (oleate, cVLDL) or increased (eVLDL) LPL activity. Conclusion: VLDL represented an efficient substrate for the macrophage. However under conditions of sepsis/endotoxaemia eVLDL utilisation was limited and directed away from oxidation, suggesting that the increased plasma TAG (eVLDL) concentrations resulting from sepsis is not a respiratory fuel for the macrophage but may supply cellular lipid.

show abstract

Section: Discussionmentioning

confidence: 99%