Different effects of acetyl-CoA carboxylase inhibitor TOFA on airway inflammation and airway resistance in a mice model of asthma
乙酰辅酶a 羧化酶抑制剂 TOFA 对哮喘小鼠气道炎症和气道阻力的不同作用
- 作者列表："Zhu, Fang-fang","Wang, Yi-min","He, Guang-zhen","Chen, Yi-fei","Gao, Ya-dong
Background and objective Acetyl CoA carboxylase (ACC) regulates the differentiation of Th1, Th2, Th17 cells and Treg cells, which play a critical role in airway inflammation of asthma. Here we investigated the role of ACC in the pathogenesis of asthma. Methods Chicken Ovalbumin-sensitized and -challenged mice were divided into three groups, PBS group, DMSO (solvent of TOFA) group and ACC inhibitor 5-tetradecyloxy-2-furoic acid (TOFA) + DMSO group. Airway inflammation was assessed with histology, percentages of CD4^+T cell subsets in lung and spleen was assessed with flow cytometry, and airway responsiveness was assessed with FinePointe RC system. The expression of characteristic transcription factors of CD4^+T cell subsets was evaluated with real-time PCR. Cytokine levels in bronchoalveolar lavage fluid (BALF) and serum was determined with ELISA. Results In asthma mice, the expression of ACC increased, while the expression of phosphorylated ACC (pACC) decreased. TOFA had no significant effect on pACC expression. TOFA reduced serum IgE, airway inflammatory cells infiltration and goblet cell hyperplasia, but dramatically increased airway responsiveness. TOFA significantly reduced the percentages of Th1, Th2, Th17 cells in lung and spleen, the expression of GATA3 and RORγt in lung, and IFN-γ, IL-4, IL-17A levels in BALF and serum. TOFA had no significant effect on the percentage of Treg cells, IL-10 level and the expression of T-bet and Foxp3. Conclusion Acetyl-CoA carboxylase inhibitor TOFA might have a distinct effect on asthmatic airway inflammation and airway hyperresponsiveness.
背景与目的乙酰辅酶a 羧化酶 (ACC) 调节 Th1 、 Th2 、 Th17 细胞和 Treg 细胞的分化，在哮喘气道炎症中发挥关键作用。在这里，我们调查了 ACC 在哮喘发病机制中的作用。方法鸡卵清蛋白致敏和激发小鼠分为 3 组，PBS 组、 DMSO (TOFA 溶剂) 组和 ACC 抑制剂 5-十四氧基-2-糠酸 (TOFA) + DMSO 组。用组织学评估气道炎症，用流式细胞术评估肺和脾脏中 CD4 ^ + T 细胞亚群的百分比，用 FinePointe RC 系统评估气道反应性。用 real-time PCR 评价 CD4 ^ + T 细胞亚群特征性转录因子的表达。用 ELISA 法测定支气管肺泡灌洗液 (BALF) 和血清中细胞因子水平。结果在哮喘小鼠中，ACC 的表达增加，而磷酸化 ACC (pACC) 的表达减少。TOFA 对 pACC 表达无显著影响。TOFA 降低血清 IgE 、气道炎症细胞浸润和杯状细胞增生，但显著增加气道反应性。TOFA 显著降低肺和脾脏中 Th1 、 Th2 、 Th17 细胞百分比，肺 GATA3 和 ror γ t 表达，BALF 和血清中 IFN-γ 、 IL-4 、 IL-17A 水平。TOFA 对 Treg 细胞百分比、 IL-10 程度和 T-bet 、 foxp3 表达无显著影响。结论乙酰辅酶a 羧化酶抑制剂 TOFA 可能对哮喘气道炎症和气道高反应性有明显的影响。
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.