Kanabar V, Page C P, Simcock D E, Karner C, Mahn K, O'Connor B J, Hirst S J
King's College London, Division of Asthma, Allergy & Lung Biology, MRC and Asthma UK Centre in Allergic Mechanisms of Asthma, London, UK.
Br J Pharmacol. 2008 Jun;154(4):833-42. doi: 10.1038/bjp.2008.109. Epub 2008 Apr 21.
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.
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.
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.
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.
糖胺聚糖肝素具有抗炎活性，且仅存在于肥大细胞中，肥大细胞定位于哮喘气道的气道平滑肌（ASM）束内。白细胞介素（IL）-13可诱导ASM产生多种炎症介质，包括嗜酸性粒细胞趋化因子嗜酸性粒细胞趋化蛋白-1。肝素及相关糖胺聚糖聚合物具有结构上异质的多糖侧链，其分子量、硫酸化程度和阴离子电荷各不相同，用于确定与抗炎活性相关的肝素分子特征。
在不存在或存在肝素及相关聚合物的情况下，用白细胞介素（IL）-13刺激培养的人ASM细胞。使用趋化因子抗体阵列和酶联免疫吸附测定法对嗜酸性粒细胞趋化蛋白-1进行定量。
未分级肝素可减弱IL-13依赖性嗜酸性粒细胞趋化蛋白-1的产生，低分子量肝素（3和6 kDa）也有此作用，表明最小活性片段至少为3 kDa。与90%重新N-乙酰化（抗凝剂）或O-去硫酸化（非抗凝剂）肝素相比，N-去硫酸化、20%重新N-乙酰化肝素（抗凝剂）对IL-13依赖性嗜酸性粒细胞趋化蛋白-1的产生无效，提示N-硫酸化的需求与抗凝活性无关。其他具有可变阴离子电荷且分子量超过3 kDa的硫酸化分子（硫酸葡聚糖、岩藻依聚糖、硫酸软骨素B）不同程度地抑制IL-13刺激的嗜酸性粒细胞趋化蛋白-1释放。然而，非硫酸化葡聚糖无作用。
肝素对IL-13依赖性嗜酸性粒细胞趋化蛋白-1释放的抑制作用涉及但不依赖于硫酸化，尽管N-硫酸化的丧失会降低其减弱活性，而N-乙酰化可恢复该活性。这种抗炎作用也部分依赖于阴离子电荷，但与3 kDa以上的分子大小及肝素的抗凝作用无关。
