MiRNA-451a inhibits airway remodeling by targeting Cadherin 11 in an allergic asthma model of neonatal mice.
MiRNA-451a 通过靶向钙黏蛋白 11 抑制新生小鼠过敏性哮喘模型气道重塑。
- 作者列表："Wang T","Zhou Q","Shang Y
:Airway remodeling happens in childhood asthma, in parallel with, but not necessarily subsequent to, airway inflammation. The differentiation of airway epithelial cells into myofibroblasts via epithelial-mesenchymal-transition (EMT) is one of the mechanisms underlying airway remodeling. This study aimed at identifying novel molecules involved in pediatric asthma-associated airway remodeling. Asthma model was established by challenging C57BL/6 mouse pups with ovalbumin (OVA). We found that the expression of Cadherin 11 (CDH11), a type II cadherin, was increased by OVA treatments in the airway epithelium. Our earlier microarray data suggested miRNA-451a-5p (miRNA-451a) as a potential regulator of CDH11. In contrast to CDH11, miRNA-451a expression decreased in the asthmatic lung. MiRNA-451a was then packaged into a lentivirus vector and systematically given to the asthmatic pups. Our data indicated that OVA-induced infiltration of inflammatory cells, including eosnophils, neutrophils, macrophages and lymphocytes, was reduced by miRNA-451a over-expression. EMT was initiated in asthmatic mice as demonstrated by increased alpha-smooth muscle actin (α-SMA) positive cells present in airway epithelium, which was inhibited by miRNA-451a. CDH11 elevation in vivo was also inhibited by miRNA-451a. Dual-Luciferase analysis further showed CDH11 as a novel valid target of miRNA-451a. Additionally, in vitro, EMT was triggered in human 16HBE airway epithelial cells by pro-fibrotic transforming growth factor β (TGF-β). Corresponding to the anti-EMT effects observed in vivo, miRNA-451a also inhibited TGF-β-induced collagen deposition in cultured airway epithelial cells by targeting in CDH11. In summary, our study demonstrates that the deregulated miRNA-451a-CDH11 axis contributes to airway remodeling in childhood asthma.
: 气道重塑发生在儿童哮喘中，与气道炎症并行，但不一定继发于气道炎症。气道上皮细胞通过上皮间质转化 (EMT) 向肌成纤维细胞分化是气道重塑的机制之一。本研究旨在鉴定参与儿童哮喘相关气道重塑的新型分子。采用卵清蛋白 (OVA) 挑战 C57BL/6 小鼠幼鼠建立哮喘模型。我们发现气道上皮中 OVA 处理增加了钙黏蛋白 11 (CDH11) 的表达，这是一种 II 型钙黏蛋白。我们早期的微阵列数据表明 miRNA-451a-5p (miRNA-451a) 是 cdh11 的潜在调控因子。与 CDH11 相反，miRNA-451a 在哮喘肺组织中表达降低。然后将 MiRNA-451a 包装成慢病毒载体，系统地给予哮喘幼鼠。我们的数据表明，OVA 诱导的炎性细胞浸润，包括嗜酸性粒细胞、中性粒细胞、巨噬细胞和淋巴细胞，通过 miRNA-451a 过表达减少。EMT 在哮喘小鼠中启动，表现为气道上皮中 α-平滑肌肌动蛋白 (α-SMA) 阳性细胞增加，其被 miRNA-451a 抑制。CDH11 在体内的升高也被 miRNA-451a 抑制。双荧光素酶分析进一步表明 CDH11 是 miRNA-451a 的一个新的有效靶点。此外，在体外，促纤维化转化生长因子 β (TGF-β) 在人 16HBE 气道上皮细胞中触发 EMT。与体内观察到的抗 EMT 作用相对应，miRNA-451a 还通过靶向 cdh11 抑制 TGF-β 诱导的气道上皮细胞胶原沉积。总之，我们的研究表明，失调的 miRNA-451a-CDH11 轴有助于儿童哮喘的气道重塑。
METHODS:BACKGROUND AND PURPOSE:A critical role for sphingosine kinase/sphingosine-1-phosphate (S1P) pathway in the control of airway function has been demonstrated in respiratory diseases. Here, we address S1P contribution in a mouse model of mild chronic obstructive pulmonary disease (COPD). EXPERIMENTAL APPROACH:C57BL/6J mice have been exposed to room air or cigarette smoke up to 11 months and killed at different time points. Functional and molecular studies have been performed. KEY RESULTS:Cigarette smoke caused emphysematous changes throughout the lung parenchyma coupled to a progressive collagen deposition in both peribronchiolar and peribronchial areas. The high and low airways showed an increased reactivity to cholinergic stimulation and α-smooth muscle actin overexpression. Similarly, an increase in airway reactivity and lung resistances following S1P challenge occurred in smoking mice. A high expression of S1P, Sph-K2 , and S1P receptors (S1P2 and S1P3 ) has been detected in the lung of smoking mice. Sphingosine kinases inhibition reversed the increased cholinergic response in airways of smoking mice. CONCLUSIONS AND IMPLICATIONS:S1P signalling up-regulation follows the disease progression in smoking mice and is involved in the development of airway hyperresponsiveness. Our study defines a therapeutic potential for S1P inhibitors in management of airways hyperresponsiveness associated to emphysema in smokers with both asthma and COPD.
METHODS::The interim results from this 90-day multi-dose, inhalation toxicology study with life-time post-exposure observation has shown an important fundamental difference in persistence and pathological response in the lung between brake dust derived from brake-pads manufactured with chrysotile, TiO2 or chrysotile alone in comparison to the amphiboles, crocidolite and amosite asbestos. In the brake dust exposure groups no significant pathological response was observed at any time. Slight macrophage accumulation of particles was noted. Wagner-scores, were from 1 to 2 (1 = air-control group) and were similar to the TiO2 group. Chrysotile being biodegradable, shows a weakening of its matrix and breaking into short fibers & particles that can be cleared by alveolar macrophages and continued dissolution. In the chrysotile exposure groups, particle laden macrophage accumulation was noted leading to a slight interstitial inflammatory response (Wagner-score 1-3). There was no peribronchiolar inflammation and occasional very slight interstitial fibrosis. The histopathology and the confocal analyses clearly differentiate the pathological response from amphibole asbestos, crocidolite and amosite, compared to that from the brake dust and chrysotile. Both crocidolite and amosite induced persistent inflammation, microgranulomas, and fibrosis (Wagner-scores 4), which persisted through the post exposure period. The confocal microscopy of the lung and snap-frozen chestwalls quantified the extensive inflammatory response and collagen development in the lung and on the visceral and parietal surfaces. The interim results reported here, provide a clear basis for differentiating the effects from brake dust exposure from those following amphibole asbestos exposure. The subsequent results through life-time post-exposure will follow.
METHODS::The respiratory tract is lined by a pseudo-stratified epithelium from the nose to terminal bronchioles. This first line of defense of the lung against external stress includes five main cell types: basal, suprabasal, club, goblet and multiciliated cells, as well as rare cells such as ionocytes, neuroendocrine and tuft/brush cells. At homeostasis, this epithelium self-renews at low rate but is able of fast regeneration upon damage. Airway epithelial cell lineages during regeneration have been investigated in the mouse by genetic labeling, mainly after injuring the epithelium with noxious agents. From these approaches, basal cells have been identified as progenitors of club, goblet and multiciliated cells, but also of ionocytes and neuroendocrine cells. Single-cell RNA sequencing, coupled to lineage inference algorithms, has independently allowed the establishment of comprehensive pictures of cell lineage relationships in both mouse and human. In line with genetic tracing experiments in mouse trachea, studies using single-cell RNA sequencing (RNAseq) have shown that basal cells first differentiate into club cells, which in turn mature into goblet cells or differentiate into multiciliated cells. In the human airway epithelium, single-cell RNAseq has identified novel intermediate populations such as deuterosomal cells, 'hybrid' mucous-multiciliated cells and progenitors of rare cells. Novel differentiation dynamics, such as a transition from goblet to multiciliated cells have also been discovered. The future of cell lineage relationships in the respiratory tract now resides in the combination of genetic labeling approaches with single-cell RNAseq to establish, in a definitive manner, the hallmarks of cellular lineages in normal and pathological situations.