Vasoactive intestinal peptide suppresses the NLRP3 inflammasome activation in lipopolysaccharide-induced acute lung injury mice and macrophages.
血管活性肠肽抑制脂多糖诱导的急性肺损伤小鼠和巨噬细胞中 NLRP3 炎症小体的活化。
- 作者列表："Zhou Y","Zhang CY","Duan JX","Li Q","Yang HH","Sun CC","Zhang J","Luo XQ","Liu SK
:Vasoactive intestinal peptide (VIP) is a neuropeptide that exerts anti-inflammatory functions. We have reported that VIP mediated by lentivirus attenuates acute lung injury (ALI) in lipopolysaccharide (LPS)-induced murine model. However, the exact role of VIP in uncontrolled inflammation during ALI is largely unknown. Accumulating evidence indicates that the NLRP3 inflammasome has a critical role during ALI. In this study, we investigated the effects of VIP on the activation of NLRP3 inflammasome during the development of ALI in mice. Seven days after the intratracheal injection of VIP-lentivirus, a murine ALI model was induced by intratracheal injection of LPS. VIP-lentivirus significantly reduced the expression of NLRP3 inflammasome components in lung tissue, including NLRP3, pro-caspase-1, pro-IL-1β, and pro-IL-18. VIP-lentivirus also inhibited the formation of caspase-1 p10 and the maturation of IL-1β and IL-18. In vitro, exogenous VIP pre-treatment inhibited the priming of NLRP3 inflammasome in murine primary peritoneal macrophages, indicated by down-regulation of expression of NLRP3 inflammasome components. VIP pre-treatment effectively prevented the LPS-induced degradation of I-κB and the synthesis of the downstream of NF-κB, including TNF-α and IL-17A. Furthermore, VIP pre-treatment pronouncedly suppressed the autoproteolysis of caspase-1 and the secretion of IL-1β and IL-18 induced by LPS plus ATP in macrophages. In addition, VIP inhibited the generation of reactive oxygen species in macrophages by decreasing NOX1 and NOX2 expression. These findings illustrate one mechanism that VIP attenuates ALI induced by LPS through inhibiting the activation of the NLRP3 inflammasome and encourage further studies assessing the therapeutic potential of VIP to ALI.
: 血管活性肠肽 (VIP) 是一种发挥抗炎功能的神经肽。我们报道了慢病毒介导的 VIP 可减轻脂多糖 (LPS) 诱导的小鼠急性肺损伤 (ALI)。然而，VIP 在 ALI 过程中不受控制的炎症中的确切作用在很大程度上是未知的。越来越多的证据表明，NLRP3 炎症小体在 ALI 过程中具有关键作用。在本研究中，我们研究了 VIP 对小鼠 ALI 发育过程中 NLRP3 炎症小体激活的影响。气管内注射 VIP-慢病毒后 7 天，通过气管内注射 LPS 诱导小鼠 ALI 模型。VIP-慢病毒显著降低肺组织中 NLRP3 炎性体成分的表达，包括 NLRP3 、 pro-caspase-1 、 pro-il-1 β 和 pro-IL-18。VIP-慢病毒也抑制 caspase-1 p10 的形成和 il-1 β 和 IL-18 的成熟。在体外，外源性 VIP 预处理抑制小鼠原代腹腔巨噬细胞 NLRP3 炎性体的启动，表现为 NLRP3 炎性体成分表达下调。VIP 预处理有效地阻止了 LPS 诱导的 I-κ b 降解和 NF-κ b 下游的合成，包括 TNF-α 和 IL-17A。此外，VIP 预处理可明显抑制 LPS 加 ATP 诱导的巨噬细胞 caspase-1 自身蛋白酶解及 il-1 β 和 IL-18 的分泌。此外，VIP 通过降低 NOX1 和 NOX2 表达抑制巨噬细胞内活性氧的生成。这些发现说明了 VIP 通过抑制 NLRP3 炎症小体的激活减轻 LPS 诱导的 ALI 的一种机制，并鼓励进一步研究评估 VIP 对 ALI 的治疗潜力。
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.