Versleijen MWJ, van Esterik JCJ, Roelofs HMJ, van Emst-de Vries SE, Willems PHGM, Wanten GJA. Parenteral medium-chain triglyceride-induced neutrophil activation is not mediated by a Pertussis Toxin sensitive receptor.
Clin Nutr 2008;
28:59-64. [PMID:
18952326 DOI:
10.1016/j.clnu.2008.09.001]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2008] [Revised: 08/28/2008] [Accepted: 09/08/2008] [Indexed: 10/21/2022]
Abstract
BACKGROUND & AIMS
Lipid-induced immune modulation might contribute to the increased infection rate that is observed in patients using parenteral nutrition. We previously showed that emulsions containing medium-chain triglycerides (LCT/MCTs or pure MCTs), but not pure long-chain triglycerides (LCTs), impair neutrophil functions, modulate cell-signaling and induce neutrophil activation in vitro. It has recently been shown that medium-chain fatty acids are ligands for GPR84, a pertussis toxin (PT)-sensitive G-protein-coupled receptor (GPCR). This finding urged us to investigate whether MCT-induced neutrophil activation is mediated by PT-sensitive GPCRs.
METHODS
Neutrophils isolated from blood of healthy volunteers were pre-incubated with PT (0.5-1 microg/mL, 1.5 h) and analyzed for the effect of this pre-incubation on LCT/MCT (2.5 mmol/L)-dependent modulation of serum-treated zymosan (STZ)-induced intracellular Ca(2+) mobilization and on LCT/MCT (5 mmol/L)-induced expression of cell surface adhesion (CD11b) and degranulation (CD66b) markers and oxygen radical (ROS) production.
RESULTS
PT did not inhibit the effects of LCT/MCT on the STZ-induced increase in cytosolic free Ca(2+) concentration. LCT/MCT increased ROS production to 146% of unstimulated cells. However, pre-incubation with PT did not inhibit the LCT/MCT-induced ROS production. Furthermore, the LCT/MCT-induced increase in CD11b and CD66b expression (196% and 235% of unstimulated cells, respectively) was not inhibited by pre-incubation with PT.
CONCLUSION
LCT/MCT-induced neutrophil activation does not involve the action of a PT-sensitive G-protein-coupled receptor.
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