Guo Si-Nuo, Jiang Xu-Qin, Chen Ning, Song Si-Ming, Fang Yu, Xie Qiu-Meng, Fei Guang-He, Wu Hui-Mei
Anhui Geriatric Institute, Department of Geriatric Respiratory and Critical Care Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, 230022, China.
Key Laboratory of Respiratory Disease research and Medical Transformation of Anhui Province, Hefei, 230022, China.
Heliyon. 2024 Mar 8;10(6):e27471. doi: 10.1016/j.heliyon.2024.e27471. eCollection 2024 Mar 30.
Asthma demonstrates a strong circadian rhythm with disrupted molecular clock. Melatonin which can directly regulate circadian rhythm has been reported to alleviate asthma, but whether this effect is related to its regulation on circadian clock has not yet been known. Here, female C57BL/6 mice were challenged with ovalbumin (OVA) to establish allergic airway inflammation, and were treated with melatonin or Luzindole to investigate whether the expressions of circadian clock proteins were changed in response to OVA and were affected by exogenous/endogenous melatonin. Airway inflammation, mucus secretion, protein expressions of circadian proteins (Bmal1, Per1, Clock, Timeless, Cry1 and Cry2), melatonin biosynthetase (ASMT, AANAT) and melatonin receptor (Mel-1A/B-R) were analyzed accordingly. The results showed that in the successfully established allergic airway inflammation model, inflammatory cells infiltration, expressions of circadian clock proteins in the lung tissues of OVA-challenged mice were all notably up-regulated as compared to that of the vehicle mice. Meanwhile, the protein expression of ASMT and the level of melatonin in the lung tissues were reduced in allergic mice, while the expression of melatonin receptor Mel-1A/B-R was markedly increased. After addition of exogenous melatonin, the OVA-induced airway inflammation was pronouncedly ameliorated, while simultaneously the OVA-induced expressions of Per1 and Clock were further increased. However, a melatonin receptor antagonist Luzindole further augmented the OVA-induced airway inflammation, accompanied with remarkably decreased expressions of Per1, Bmal1, Cry1 and Cry2 but notably increased expression of Timeless. Collectively, our results demonstrated that the expression of circadian clock proteins was increased in the lungs during allergic airway inflammation, and Per1 was a clock protein that can be regulated by both exogenous and endogenous melatonin, suggesting Per1 may be an important potential circadian clock target for melatonin as a negative regulatory factor against Th2-type airway inflammation.
哮喘表现出强烈的昼夜节律，分子时钟紊乱。据报道，可直接调节昼夜节律的褪黑素能缓解哮喘，但这种作用是否与其对昼夜节律时钟的调节有关尚不清楚。在此，用卵清蛋白（OVA）攻击雌性C57BL/6小鼠以建立过敏性气道炎症，并给予褪黑素或鲁辛朵进行治疗，以研究昼夜节律时钟蛋白的表达是否因OVA而改变，以及是否受外源性/内源性褪黑素影响。相应地分析气道炎症、黏液分泌、昼夜节律蛋白（Bmal1、Per1、Clock、Timeless、Cry1和Cry2）、褪黑素生物合成酶（ASMT、AANAT）和褪黑素受体（Mel-1A/B-R）的蛋白表达。结果显示，在成功建立的过敏性气道炎症模型中，与对照组小鼠相比，OVA攻击小鼠肺组织中的炎性细胞浸润、昼夜节律时钟蛋白表达均显著上调。同时，过敏性小鼠肺组织中ASMT的蛋白表达和褪黑素水平降低，而褪黑素受体Mel-1A/B-R的表达明显增加。添加外源性褪黑素后，OVA诱导的气道炎症明显改善，同时OVA诱导的Per1和Clock表达进一步增加。然而，褪黑素受体拮抗剂鲁辛朵进一步加剧了OVA诱导的气道炎症，同时Per1、Bmal1、Cry1和Cry2的表达显著降低，但Timeless的表达明显增加。总体而言，我们的结果表明，在过敏性气道炎症期间，肺中昼夜节律时钟蛋白的表达增加，且Per1是一种可受外源性和内源性褪黑素调节的时钟蛋白，提示Per1可能是褪黑素作为抗Th2型气道炎症负调节因子的一个重要潜在昼夜节律时钟靶点。
