哮喘中类固醇抵抗发展的潜在机制仍不清楚。为了确定Janus激酶(JAKs)的激活是否以及其机制参与哮喘类固醇抵抗的发展,分析了第2组固有淋巴细胞(ILC2s)体外增殖和体内哮喘气道炎症的鼠类固醇抗性模型。分选BALB/c小鼠肺中的ILC2s,然后与IL-33,胸腺基质淋巴细胞生成素(TSLP)孵育,和/或含或不含地塞米松的IL-7(10nM),泛JAK抑制剂,delgocitinib(1-10000nM),和/或Bcl-xL抑制剂,navitoclax(1-100nM),然后检测活细胞和凋亡细胞。抗凋亡因子,流式细胞术检测ILC2s中的Bcl-xL。作为一种类固醇抵抗性哮喘模型,卵清蛋白(OVA)致敏的BALB/c小鼠用500μg高剂量的OVA气管内攻击四次。地塞米松(1mg/kg,i.p.),德戈西替尼(3-30mg/kg,p.o.),或navitoclax(30毫克/千克,p.o.)在挑战期间进行了管理。通过流式细胞术分析进入肺的细胞浸润。对气道重塑进行组织学评估。获得了以下结果。(1)当ILC2s与TSLP和/或IL-7一起培养时,细胞增殖伴随着凋亡细胞的减少,并被地塞米松有效抑制。相比之下,当TSLP和IL-7在IL-33存在下进行培养时,增殖反应表现出类固醇抗性.德戈西替尼以浓度依赖性方式抑制类固醇抗性ILC2增殖。(2)IL-33、TSLP、IL-7诱导Bcl-xL过表达,它被德戈西替尼明显抑制,但不是地塞米松。当用navitoclax处理ILC2s时,对地塞米松的不敏感性被显著消除.(3)地塞米松未抑制哮喘模型气道重塑的发展和ILC2s向肺的浸润,但受到德戈西替尼的剂量依赖性抑制。地塞米松和德戈西替尼或navitoclax的联合治疗协同抑制了这些反应。因此,JAK似乎通过上调ILC2s中的Bcl-xL在类固醇抗性的诱导中发挥重要作用。抑制JAKs和Bcl-xL有可能作为激素抵抗哮喘的药物治疗,特别是由ILC2s介导的。
The mechanisms underlying the development of steroid resistance in asthma remain unclear. To establish whether as well as the mechanisms by which the activation of Janus kinases (JAKs) is involved in the development of steroid resistance in asthma, murine steroid-resistant models of the proliferation of group 2 innate lymphoid cells (ILC2s) in vitro and asthmatic airway inflammation in vivo were analysed. ILC2s in the lungs of BALB/c mice were sorted and then incubated with IL-33, thymic stromal lymphopoietin (TSLP), and/or IL-7 with or without dexamethasone (10 nM), the pan-JAK inhibitor, delgocitinib (1-10 000 nM), and/or the Bcl-xL inhibitor, navitoclax (1-100 nM), followed by the detection of viable and apoptotic cells. The anti-apoptotic factor, Bcl-xL was detected in ILC2s by flow cytometry. As a steroid-resistant asthma model, ovalbumin (OVA)-sensitized BALB/c mice were intratracheally challenged with OVA at a high dose of 500 μg four times. Dexamethasone (1 mg/kg, i.p.), delgocitinib (3-30 mg/kg, p.o.), or navitoclax (30 mg/kg, p.o.) was administered during the challenges. Cellular infiltration into the lungs was analysed by flow cytometry. Airway remodelling was histologically evaluated. The following results were obtained. (1) Cell proliferation concomitant with a decrease in apoptotic cells was induced when ILC2s were cultured with TSLP and/or IL-7, and was potently inhibited by dexamethasone. In contrast, when the culture with TSLP and IL-7 was performed in the presence of IL-33, the proliferative response exhibited steroid resistance. Steroid-resistant ILC2 proliferation was suppressed by delgocitinib in a concentration-dependent manner. (2) The culture with IL-33, TSLP, and IL-7 induced the overexpression of Bcl-xL, which was clearly inhibited by delgocitinib, but not by dexamethasone. When ILC2s were treated with navitoclax, insensitivity to dexamethasone was significantly cancelled. (3) The development of airway remodelling and the infiltration of ILC2s into the lungs in the asthma model were not suppressed by dexamethasone, but were dose-dependently inhibited by delgocitinib. Combination treatment with dexamethasone and either delgocitinib or navitoclax synergistically suppressed these responses. Therefore, JAKs appear to play significant roles in the induction of steroid resistance by up-regulating Bcl-xL in ILC2s. The inhibition of JAKs and Bcl-xL has potential as pharmacotherapy for steroid-resistant asthma, particularly that mediated by ILC2s.