Lipid effects on neutrophil calcium signaling induced by opsonized particles: platelet activating factor is only part of the story

• Published in: Clinical nutrition (Edinburgh, Scotland) Scotland), 2004-08, Vol.23 (4), p.623-630
• Main Authors: Wanten, Geert, Kusters, Anneke, van Emst-de Vries, Sjenet E, Tool, Anton, Roos, Dirk, Naber, Ton, Willems, Peter
• Format: Article
• Language: English
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Calcium - metabolism; Calcium signaling; Calcium Signaling - drug effects; Emergency and intensive care: metabolism and nutrition disorders. Enteral and parenteral nutrition; Emulsions; Fat Emulsions, Intravenous - chemistry; Fat Emulsions, Intravenous - pharmacology; Fish Oils; Humans; Immune response; Intensive care medicine; Lipids; Medical sciences; Neutrophil; Neutrophil Activation; Neutrophils - metabolism; Nutrition; Olive Oil; Plant Oils; Platelet Activating Factor - metabolism; Platelet Membrane Glycoproteins - antagonists & inhibitors; Receptors, G-Protein-Coupled - antagonists & inhibitors; Soybean Oil; Zymosan - pharmacology
• ISSN: 0261-5614; 1532-1983
• DOI: 10.1016/j.clnu.2003.10.014

Background & methods: Total parenteral nutrition is frequently used in clinical practice to improve the nutritional status of patients. However, the risk for infectious complications remains a drawback in which immune-modulating effects of the lipid component may play a role. To characterize these lipid effects we investigated neutrophil activation by opsonized yeast particles under influence of lipid emulsions derived from fish oil (VLCT), olive oil (LCT-MUFA), soybean oil (LCT), and a physical mixture of coconut and soybean oil (LCT-MCT). Results: Serum-treated zymosan (STZ) evoked a biphasic increase in cytosolic Ca 2+ concentration ([Ca 2+] c) with an initial slow rise that turned into a second fast rise until a plateau was reached. LCT-MCT (5 mM) pretreatment markedly increased the rate of [Ca 2+] c rise during the initial phase, abolished the second phase and lowered the plateau. These effects of LCT-MCT were mimicked by the protein kinase C (PKC) activating phorbol ester PMA. LCT, LCT-MUFA and VLCT, on the other hand, decreased the rate of [Ca 2+] c rise during both phases and lowered the plateau. The platelet-activating factor (PAF) receptor antagonist WEB 2086 inhibited the second phase, demonstrating that PAF acts as an intercellular messenger in STZ-induced Ca 2+ mobilization, but did not interfere with the stimulatory effect of LCT-MCT or PMA on the initial rate of [Ca 2+] c rise. Conclusions: Structurally different lipids act only in part through PAF to distinctively modulate neutrophil calcium signaling in response to activation by opsonized particles.