背景:邻苯二甲酸二丁酯(DBP),一种常用的增塑剂,已经发现与过敏性疾病的持续高患病率密切相关,特别是过敏性哮喘。先前的动物实验表明,暴露于DBP可以通过触发降钙素基因相关肽(CGRP)的产生而使哮喘恶化。肺组织中的神经肽。然而,CGRP辅助下DBP加重过敏性哮喘的确切神经免疫机制和病理生理学尚不清楚.
目的:本研究从神经-免疫相互作用的角度探讨DBP加重哮喘的潜在病理生理机制。
结果:C57BL/6小鼠口服暴露于不同浓度(0.4、4、40mg/kg)的DBP28天。然后用OVA敏化它们并用OVA雾化7次连续激发。探讨DBP是否加重OVA诱导小鼠的过敏性哮喘,我们分析了气道高反应性和肺组织病理学.探讨JNC细胞对JNC和TRPV1神经元的激活及CGRP的释放,我们测量了TRPV1通道的水平,钙向内流动,和下游神经肽CGRP。结果显示,TRPV1的表达,向内的钙通量,40DBP+OVA组肺组织中CGRP水平显著升高,提示JNC细胞释放CGRP。为了抵消CGRP介导的DBP的有害作用,我们使用了olceepant(也称为BIBN-4096),CGRP受体特异性拮抗剂。结果显示,40DBP+OVA+催黄剂导致TRPV1显著减少,钙向内流动,和CGRP在肺组织中的表达与40DBP+OVA相比,进一步支持olceepant的功效。此外,我们还进行了ILC2流式分选,观察到神经肽CGRP激活的ILC2细胞作为关键效应细胞在DBP诱导的神经免疫正反馈调节中具有至关重要的作用.最后,我们检测了CGRP的蛋白表达,GATA3和P-GATA3,发现CGRP和P-GATA3在40DBP+OVA组中显著上调,提示GATA3是CGRP激活ILC2的关键调节因子。
结论:上述研究表明,DBP可以加重过敏性哮喘,导致气道炎症。这种恶化是通过JNC中TRPV1的激活而发生的,导致CGRP的释放。CGRP的过度释放通过GATA磷酸化诱导ILC2的活化进一步促进Th2细胞因子的释放。因此,这一过程有助于气道炎症和过敏性哮喘的发展。Th2细胞因子产生的增加也触发了IgE的产生,它与JNC神经元上的FcεRI相互作用,从而介导神经免疫正反馈调节。
Dibutyl phthalate (DBP), a commonly used plasticizer, has been found to be strongly linked to a consistently high prevalence of allergic diseases, particularly allergic asthma. Previous animal experiments have demonstrated that exposure to DBP can worsen asthma by triggering the production of calcitonin gene-related peptide (CGRP), a neuropeptide in the lung tissue. However, the precise neuroimmune mechanism and pathophysiology of DBP-exacerbated allergic asthma with the assistance of CGRP remain unclear.
The present study was to investigate the potential pathophysiological mechanism in DBP-exacerbated asthma from the perspective of neural-immune interactions.
C57BL/6 mice were orally exposed to different concentrations (0.4, 4, 40 mg/kg) of DBP for 28 days. They were then sensitized with OVA and nebulized with OVA for 7 consecutive excitations. To investigate whether DBP exacerbates allergic asthma in OVA induced mice, we analyzed airway hyperresponsiveness and lung histopathology. To investigate the activation of JNC and TRPV1 neurons and the release of CGRP by JNC cells, we measured the levels of TRPV1 channels, calcium inward flow, and downstream neuropeptide CGRP. Results showed that TRPV1 expression, inward calcium flux, and CGRP levels were significantly elevated in the lung tissues of the 40DBP + OVA group, suggesting the release of CGRP by JNC cells. To counteract the detrimental effects of DBP mediated by CGRP, we employed olcegepant (also known as BIBN-4096), a CGRP receptor specific antagonist. Results revealed that 40DBP + OVA + olcegepant led to notable decreases in TRPV1, calcium inward flow, and CGRP expression in lung tissues compare with 40DBP + OVA, further supporting the efficacy of olcegepant. Additionally, we also conducted ILC2 flow sorting and observed that neuropeptide CGRP-activated ILC2 cells have a crucial role as key effector cells in DBP-induced neuroimmune positive feedback regulation. Finally, we examined the protein expression of CGRP, GATA3 and P-GATA3, and found that significant upregulations of CGRP and P-GATA3 in the 40DBP + OVA group, suggest that GATA3 acted as a key regulator of CGRP-activated ILC2.
The aforementioned studies indicate that exposure to DBP can exacerbate allergic asthma, leading to airway inflammation. This exacerbation occurs through the activation of TRPV1 in JNC, resulting in the release of CGRP. The excessive release of CGRP further promotes the release of Th2 cytokines by inducing the activation of ILC2 through GATA phosphorylation. Consequently, this process contributes to the development of airway inflammation and allergic asthma. The increased production of Th2 cytokines also triggers the production of IgE, which interacts with FcεRI on JNC neurons, thereby mediating neuro-immune positive feedback regulation.