Abstract |
Lipid rafts reportedly play an important role in modulating the activation of mast cells and granulocytes, the primary effector cells of airway hyperresponsiveness and asthma. Activation is mediated through resident signaling molecules whose activity, in part, may be modulated by the composition of glycosphingolipids (GSLs) in membrane rafts. In this study, we evaluated the impact of inhibiting GSL biosynthesis in mast cells and in the ovalbumin (OVA)-induced mouse model of asthma using either a small molecule inhibitor or anti-sense oligonucleotides (ASOs) directed against specific enzymes in the GSL pathway. Lowering GSL levels in mast cells through inhibition of glucosylceramide synthase (GCS) reduced phosphorylation of Syk tyrosine kinase and phospholipase C gamma 2 (PLC-gamma2) as well as cytoplasmic Ca(2+) levels. Modulating these intracellular signaling events also resulted in a significant decrease in mast cell degranulation. Primary mast cells isolated from a GM3 synthase (GM3S) knockout mouse exhibited suppressed activation-induced degranulation activity further supporting a role of GSLs in this process. In previously OVA-sensitized mice, intra- nasal administration of ASOs to GCS, GM3S or lactosylceramide synthase (LCS) significantly suppressed metacholine-induced airway hyperresponsiveness and pulmonary inflammation to a subsequent local challenge with OVA. However, administration of the ASOs into mice that had been sensitized and locally challenged with the allergen did not abate the consequent pulmonary inflammatory sequelae. These results suggest that GSLs contribute to the initiation phase of the pathogenesis of airway hyperreactivity and asthma and lowering GSL levels may offer a novel strategy to modulate these manifestations.
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Authors | Jozsef Karman, Jennifer L Tedstone, Nathan K Gumlaw, Yunxiang Zhu, Nelson Yew, Craig Siegel, Shuling Guo, Andrew Siwkowski, Melanie Ruzek, Canwen Jiang, Seng H Cheng |
Journal | International immunology
(Int Immunol)
Vol. 22
Issue 7
Pg. 593-603
(Jul 2010)
ISSN: 1460-2377 [Electronic] England |
PMID | 20497953
(Publication Type: Journal Article)
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Chemical References |
- (2-(2',3'-dihydrobenzo(1,4)dioxin-6'-yl)-2-hydroxy-1-pyrrolidin-1-ylmethylethyl)nonanoic acid amide
- Dioxanes
- Glycosphingolipids
- Oligonucleotides, Antisense
- Pyrrolidines
- Ovalbumin
- Glucosyltransferases
- ceramide glucosyltransferase
- Sialyltransferases
- haematoside synthetase
- Protein-Tyrosine Kinases
- Phospholipase C gamma
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Topics |
- Animals
- Asthma
(drug therapy, immunology, pathology, physiopathology)
- Cell Degranulation
(drug effects)
- Dioxanes
(pharmacology)
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Glucosyltransferases
(antagonists & inhibitors)
- Glycosphingolipids
(biosynthesis, immunology)
- Mast Cells
(cytology, drug effects, immunology, pathology)
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Knockout
- Molecular Weight
- Oligonucleotides, Antisense
(administration & dosage, pharmacology)
- Ovalbumin
(immunology)
- Phospholipase C gamma
(antagonists & inhibitors, immunology)
- Phosphorylation
- Protein-Tyrosine Kinases
(antagonists & inhibitors, immunology)
- Pyrrolidines
(pharmacology)
- Sialyltransferases
(immunology)
- Signal Transduction
(immunology)
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