Department of Agrobioscience, Graduate School of Agricultural Science, Kobe University, Kobe 657-8501, Japan.
Central Research Institute, ITO EN, Ltd., 21 Mekami, Makinohara, Shizuoka 421-0516, Japan.
Biomolecules. 2020 Feb 9;10(2):258. doi: 10.3390/biom10020258.
A previous study revealed that fucoidan inhibited mast cell degranulation through the upregulation of galectin-9 in blood. The purpose of this study is to elucidate its mechanism using ovalbumin (OVA) induced anaphylaxis model mice (BALB/c, Female, 5-week-old) and mast cell line (RBL-2H3 cells). Oral administration of fucoidan after sensitization with OVA/Al(OH) inhibited reduction of rectal temperature induced by activation of mast cells. Fucoidan increased galectin-9 mRNA expression only in colonic epithelial cells. These results suggested that fucoidan could suppress the allergic symptoms in sensitized mice by inducing galectin-9 production from colonic epithelial cells. In addition, to check the influence of galectin 9 on the degranulation of mast cells, RBL-2H3 cell lines were treated directly with recombinant galectin-9. As expected, galectin-9 inhibited degranulation of RBL-2H3 cells pre-bound with IgE. Moreover, the residual amounts of IgE on RBL-2H3 cells were decreased by an addition of galectin-9. It was demonstrated that galectin-9 could remove IgE even if IgE was already bound to mast cells and suppress the mast cells degranulation induced by antigen. This study shows that fucoidan might become an effective therapeutic agent for patients already developed type I allergic diseases.
先前的研究表明，岩藻聚糖硫酸酯通过上调血液中的半乳糖凝集素-9（Galectin-9）来抑制肥大细胞脱颗粒。本研究旨在使用卵清蛋白（OVA）诱导的过敏反应模型小鼠（BALB/c，雌性，5 周龄）和肥大细胞系（RBL-2H3 细胞）来阐明其机制。OVA/Al(OH) 致敏后，岩藻聚糖硫酸酯的口服给药抑制了肥大细胞活化引起的直肠温度降低。岩藻聚糖硫酸酯仅增加结肠上皮细胞中的 Galectin-9 mRNA 表达。这些结果表明，岩藻聚糖硫酸酯可通过诱导结肠上皮细胞产生 Galectin-9 来抑制致敏小鼠的过敏症状。此外，为了检查 Galectin-9 对肥大细胞脱颗粒的影响，直接用重组 Galectin-9 处理 RBL-2H3 细胞系。正如预期的那样，Galectin-9 抑制了预先与 IgE 结合的 RBL-2H3 细胞的脱颗粒。此外，Galectin-9 的添加减少了 RBL-2H3 细胞上剩余的 IgE。结果表明，Galectin-9 即使 IgE 已经与肥大细胞结合，也可以去除 IgE 并抑制抗原诱导的肥大细胞脱颗粒。本研究表明，岩藻聚糖硫酸酯可能成为已经发生 I 型过敏疾病的患者的有效治疗剂。
