バイカリンは、アレルギー性鼻炎におけるオートファジーを阻害することにより、Treg/Th17細胞のアンバランスを調節する

Baicalin regulates Treg/Th17 cell imbalance by inhibiting autophagy in allergic rhinitis.

• Jing Li
• Xiaoyan Lin
• Xiang Liu
• Zhiqi Ma
• Yong Li

抄録

背景:

バイカリンは抗酸化作用や抗アレルギー作用など多くの生物学的特性を有している。本研究では、バイカリンのアレルギー性鼻炎（AR）に対する効果とその潜在的な作用機序を探ることを目的とした。

BACKGROUND: Baicalin has many biological properties such as anti-oxidation and anti-allergy. The current study aimed to explore the effect of Baicalin on allergic rhinitis (AR) and its potential mechanism of action.

方法:

METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated by density gradient centrifugation. Expression levels of Th17 and Treg cells-related proteins in nasal mucosa and peripheral blood cells were detected by real-time quantitative PCR, flow cytometry and Western blot. The mice were randomly divided into Control, ovalbumin (OVA), l-Baicalin, H-Baicalin, DSGC, 3-MA, and H-Baicalin + Rapa groups. Changes of allergic rhinitis conditions and eosinophil infiltration of the mice were detected and scored by Diff-Quik staining, and histological changes were observed by Hematoxylin & Eosin (H&E) staining and Periodate Schiff (PAS) staining. Serological changes, expression levels of interleukin-17A (IL-17A), interleukin-10 (IL-10), eosinophilic cationic protein (ECP) and anti-OVA-specific antibodies were detected by Enzyme-linked immunosorbent assay (ELISA).

結果:

臨床例を解析した結果、AR患者はTh17/Tregのバランスが崩れ、オートファジーが活性化していたが、バイカリンはTh17/Treg細胞のバランスを回復させ、in vitroではオートファジーを抑制した。さらに、バイカリンは鼻汁液の様々な炎症細胞の浸潤を減少させ、上皮細胞の損傷を防止し、鼻粘膜の厚さと粘液分泌を改善した。また、バイカリンはマウス抗OVA特異的抗体レベルのバランスやTh17/Treg関連サイトカインの発現を調節した。

RESULTS: Clinical case analysis found that AR patients had a Th17/Treg imbalance and activated autophagy, however, Baicalin restored Th17/Treg cell balance and inhibited autophagy in vitro. in vivo experiments demonstrated that Baicalin inhibited OVA-induced allergic nasal symptoms and the activation of autophagy pathway, which was the same as the regulation of 3-MA, while Rapa could weaken the effects of H-baicalin. Moreover, Baicalin reduced the infiltration of different inflammatory cells of the nasal lavage fluid, prevented the damages to epithelial cells, and improved nasal mucosal thickness and mucus secretion. In addition, Baicalin regulated the balance of mouse anti-OVA-specific antibody levels and expressions of Th17/Treg-associated cytokines.

結論:

今回の研究により、バイカリンがAR治療に使用できることが明らかになり、オートファジーを阻害してTh17/Treg細胞の分化を調節することで効果を発揮することが明らかになりました。

CONCLUSION: Our study revealed that Baicalin can be used to treat AR, and the effect is realized through inhibiting autophagy to regulate Th17/Treg cell differentiation.

Copyright © 2020. Published by Elsevier Ltd.