Heparin and structurally related polymers attenuate eotaxin-1 (CCL11) release from human airway smooth muscle.
OBJECTIVE
The glycosaminoglycan heparin has anti-inflammatory activity and is exclusively found in mast cells, which are localized within airway smooth muscle (ASM) bundles of asthmatic airways. Interleukin (IL)-13 induces the production of multiple inflammatory mediators from ASM including the eosinophil chemoattractant chemokine, eotaxin-1. Heparin and related glycosaminoglycan polymers having structurally heterogeneous polysaccharide side chains that varied in molecular weight, sulphation and anionic charge were used to identify features of the heparin molecule linked to anti-inflammatory activity.


METHODS
Cultured human ASM cells were stimulated with interleukin (IL)-13 in the absence or presence of heparin and related polymers. Eotaxin-1 was quantified using chemokine antibody arrays and ELISA.


RESULTS
Unfractionated heparin attenuated IL-13-dependent eotaxin-1 production and this effect was reproduced with low molecular weight heparins (3 and 6 kDa), demonstrating a minimum activity fragment of at least 3 kDa. N-desulphated, 20% re-N-acetylated heparin (anticoagulant) was ineffective against IL-13-dependent eotaxin-1 production compared with 90% re-N-acetylated (anticoagulant) or O-desulphated (non-anticoagulant) heparin, suggesting a requirement for N-sulphation independent of anticoagulant activity. Other sulphated molecules with variable anionic charge and molecular weight exceeding 3 kDa (dextran sulphate, fucoidan, chondroitin sulphate B) inhibited IL-13-stimulated eotaxin-1 release to varying degrees. However, non-sulphated dextran had no effect.


CONCLUSIONS
Inhibition of IL-13-dependent eotaxin-1 release by heparin involved but did not depend upon sulphation, though loss of N-sulphation reduced the attenuating activity, which could be restored by N-acetylation. This anti-inflammatory effect was also partially dependent on anionic charge, but independent of molecular size above 3 kDa and the anticoagulant action of heparin.
Kanabar
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King's College London, Division of Asthma, Allergy & Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK.
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C P
CP
Simcock
D E
DE
Karner
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Mahn
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O'Connor
B J
BJ
Hirst
S J
SJ
D000328:Adult; D000368:Aged; D000838:Anions / Q000737:chemistry; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology*; D000925:Anticoagulants / Q000737:chemistry / Q000494:pharmacology*; D002478:Cells, Cultured; D054413:Chemokine CCL11 / Q000187:drug effects* / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006493:Heparin / Q000737:chemistry / Q000494:pharmacology*; D006495:Heparin, Low-Molecular-Weight / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D018793:Interleukin-13 / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D032389:Myocytes, Smooth Muscle / Q000187:drug effects*; D013431:Sulfates / Q000737:chemistry
D000838:Anions; D000893:Anti-Inflammatory Agents; D000925:Anticoagulants; C515456:CCL11 protein, human; D054413:Chemokine CCL11; D006495:Heparin, Low-Molecular-Weight; D018793:Interleukin-13; D013431:Sulfates; D006493:Heparin