Ghrelin alleviates traumatic brain injury-induced acute lung injury through pyroptosis/NF-κB pathway.
Ghrelin 通过焦亡/NF-κ b 通路减轻创伤性脑损伤诱导的急性肺损伤
- 作者列表："Shao XF","Li B","Shen J","Wang QF","Chen SS","Jiang XC","Qiang D
:Acute lung injury (ALI) is one of the severe complications in patients with traumatic brain injury (TBI), contributing to the high mortality. Ghrelin has protective effects against various inflammatory diseases, but the effects of Ghrelin on TBI-induced ALI and its mechanisms remain unknown. In this study, Ghrelin administration was performed on the mice with TBI, then histological change in cortex and lung tissues, lung vascular permeability and macrophage number in bronchoalveolar lavage fluid (BALF) were examined, respectively. Simultaneously, the alterations of proinflammatory factors and pyroptosis-related proteins in lung tissues were detected. As a result, TBI-induced ALI was ameliorated after Ghrelin treatment, which was demonstrated by improved histology, reduced lung vascular permeability, and peripheral macrophage number. Furthermore, Ghrelin decreased the mRNA levels of proinflammatory factors (IL-1β, IL-6, TNF-α and IL-18), the protein levels of pyroptosis-related proteins (NLRP3, Caspase1-P20, HMGB1 and Gasdermin D), and the phosphorylation levels of NF-κB in lung tissues. These results showed that Ghrelin attenuating TBI-induced ALI might be via ameliorating inflammasome-induced pyroptosis by blocking NF-κB signal, which are important for the prevention and treatment of TBI-induced ALI.
急性肺损伤 (ALI) 是创伤性脑损伤 (TBI) 患者的严重并发症之一，病死率高。Ghrelin 对多种炎症性疾病具有保护作用，但 Ghrelin 对 TBI 诱导的 ALI 的影响及其机制尚不清楚。本研究对 TBI 小鼠进行 Ghrelin 治疗，检测皮层和肺组织的组织学变化，支气管肺泡灌洗液 (BALF) 中肺血管通透性和巨噬细胞数量。分别。同时检测肺组织中促炎因子和焦亡相关蛋白的变化。结果，Ghrelin 治疗后 TBI 诱导的 ALI 得到改善，表现为组织学改善、肺血管通透性降低和外周巨噬细胞数量减少。此外，Ghrelin 降低了促炎因子 (il-1 β 、 IL-6 、 TNF-α 和 IL-18) 的 mRNA 水平、焦亡相关蛋白 (NLRP3 、 Caspase1-P20 、 HMGB1 和 Gasdermin D)，以及肺组织中 NF-κ b 的磷酸化水平。这些结果表明，Ghrelin 减轻 TBI 诱导的 ALI 可能是通过阻断 NF-κ b 信号来改善炎性体诱导的焦亡，这对于预防和治疗 TBI 诱导的 ALI 具有重要意义。
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.