急性缺氧条件下 Galectin-3 通过 TRPC1/4 介导肺血管内皮细胞动力学
- 作者列表："Li Y","Chen X","Zeng X","Chen S","Yang X","Zhang L
:Galectin-3 (Gal-3) has been implicated in various biological functions, yet little is known about its role in regulating the dynamics of pulmonary vascular endothelial cells. Gal-3 was shown to be increased in hypoxic model rats by sequencing analysis. We exposed pulmonary vessel endothelial cells (PVECs) to hypoxia or Gal-3 stimulation, following which cell apoptosis and autophagy were measured with the relevant methods. The results demonstrated that hypoxia elevated nuclear factor-κB (NF-κB) activity and Gal-3 expression. Gla-3 decreased the expression of Bcl-2, Alix, Beclin-1, Atg5, and LC3A/B. The messenger RNA and protein levels of transient receptor potential channel 1/4 (TRPC1/4) and calpain were reduced after Gal-3 treatment. Gal-3 also activated protein kinase B/glycogen synthase kinase-3 β/mammalian target of rapamycin signaling pathways in PVECs. These results suggest that a hypoxia-mediated increase in Gal-3 promotes apoptosis and inhibits autophagy by inhibiting the TRPC1/4 pathway and activating the protein kinase B/glycogen synthase kinase-3 β/mammalian target of rapamycin signaling pathway in PVECs. Furthermore, these results may provide us with a new direction to explore the pathogenesis of pulmonary artery hypertension.
Galectin-3 (Gal-3) 与多种生物学功能有关，但对其调节肺血管内皮细胞动力学的作用知之甚少。测序分析显示缺氧模型大鼠 Gal-3 升高。我们将肺血管内皮细胞 (PVECs) 暴露于缺氧或 Gal-3 刺激下，然后用相关方法测定细胞凋亡和自噬。结果表明，缺氧可提高核因子-κ b (NF-κ b) 活性，Gal-3 表达。Gla-3 下降 Bcl-2 、 Alix 、 Beclin-1 、 Atg5 和 LC3A/B 的表达。瞬时受体电位通道 1/4 (TRPC1/4) 和钙蛋白酶的信使 RNA 和蛋白水平在 Gal-3 处理后降低。Gal-3 还激活了 PVECs 中的蛋白激酶 B/糖原合成酶激酶-3 β/哺乳动物雷帕霉素靶蛋白信号通路。这些结果表明，缺氧介导的 Gal-3 增加通过抑制 TRPC1/4 通路和激活蛋白激酶 B/糖原合成酶激酶-3 β/哺乳动物靶蛋白来促进细胞凋亡和抑制自噬。雷帕霉素信号通路在 PVECs 中的作用。这些结果可能为探讨肺动脉高压的发病机制提供新的方向。
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.