scholarly journals Resetting proteostasis with ISRIB prevents pulmonary fibrosis

Author(s):  
Satoshi Watanabe ◽  
Nikolay S. Markov ◽  
Ziyan Lu ◽  
Raul Piseaux Aillon ◽  
Saul Soberanes ◽  
...  

AbstractAging is among the most important risk factors for the development of pulmonary fibrosis. We found that a small molecule that specifically inhibits translational inhibition induced by activation of the integrated stress response (ISRIB) attenuated the severity of pulmonary fibrosis in young and old mice. The more severe fibrosis in old compared to young mice was associated with increased recruitment of pathogenic monocyte-derived alveolar macrophages. Using genetic lineage tracing and transcriptomic profiling we found that ISRIB modulates stress response signaling in alveolar epithelial cells resulting in decreased apoptosis and decreased recruitment of pathogenic monocyte-derived alveolar macrophages. These data support multicellular model of fibrosis involving epithelial cells, pathogenic monocyte-derived alveolar macrophages and fibroblasts. Inhibition of the integrated stress response in the aging lung epithelium ameliorates pulmonary fibrosis by preventing the prolonged recruitment of monocyte-derived alveolar macrophages.

Author(s):  
Teresa Rubio-Tomás ◽  
Beatriz Aguilar-Bravo ◽  
Pau Sancho-Bru

Medicina ◽  
2019 ◽  
Vol 55 (4) ◽  
pp. 83 ◽  
Author(s):  
Francesco Salton ◽  
Maria Volpe ◽  
Marco Confalonieri

Idiopathic pulmonary fibrosis (IPF) is a serious disease of the lung, which leads to extensive parenchymal scarring and death from respiratory failure. The most accepted hypothesis for IPF pathogenesis relies on the inability of the alveolar epithelium to regenerate after injury. Alveolar epithelial cells become apoptotic and rare, fibroblasts/myofibroblasts accumulate and extracellular matrix (ECM) is deposited in response to the aberrant activation of several pathways that are physiologically implicated in alveologenesis and repair but also favor the creation of excessive fibrosis via different mechanisms, including epithelial–mesenchymal transition (EMT). EMT is a pathophysiological process in which epithelial cells lose part of their characteristics and markers, while gaining mesenchymal ones. A role for EMT in the pathogenesis of IPF has been widely hypothesized and indirectly demonstrated; however, precise definition of its mechanisms and relevance has been hindered by the lack of a reliable animal model and needs further studies. The overall available evidence conceptualizes EMT as an alternative cell and tissue normal regeneration, which could open the way to novel diagnostic and prognostic biomarkers, as well as to more effective treatment options.


2019 ◽  
Vol 87 (5) ◽  
Author(s):  
Amanda L. Dragan ◽  
Richard C. Kurten ◽  
Daniel E. Voth

ABSTRACTHuman Q fever is caused by the intracellular bacterial pathogenCoxiella burnetii. Q fever presents with acute flu-like and pulmonary symptoms or can progress to chronic, severe endocarditis. After human inhalation,C. burnetiiis engulfed by alveolar macrophages and transits through the phagolysosomal maturation pathway, resisting the acidic pH of lysosomes to form a parasitophorous vacuole (PV) in which to replicate. Previous studies showed thatC. burnetiireplicates efficiently in primary human alveolar macrophages (hAMs) inex vivohuman lung tissue. AlthoughC. burnetiireplicates in most cell typesin vitro, the pathogen does not grow in non-hAM cells of human lung tissue. In this study, we investigated the interaction betweenC. burnetiiand other pulmonary cell types apart from the lung environment.C. burnetiiformed a prototypical PV and replicated efficiently in human pulmonary fibroblasts and in airway, but not alveolar, epithelial cells. Atypical PV expansion in alveolar epithelial cells was attributed in part to defective recruitment of autophagy-related proteins. Further assessment of theC. burnetiigrowth niche showed that macrophages mounted a robust interleukin 8 (IL-8), neutrophil-attracting response toC. burnetiiand ultimately shifted to an M2-polarized phenotype characteristic of anti-inflammatory macrophages. Considering our findings together, this study provides further clarity on the uniqueC. burnetii-lung dynamic during early stages of human acute Q fever.


1988 ◽  
Vol 25 (4) ◽  
pp. 297-303 ◽  
Author(s):  
W. Chen ◽  
M. R. Alley ◽  
B. W. Manktelow ◽  
D. Hopcroft ◽  
R. Bennett

Eight colostrum-deprived lambs were inoculated intratracheally with ovine isolates of Bordetella parapertussis. Fluids obtained by bronchoalveolar lavage had a large increase in total cell counts 24 hours after inoculation; up to 93% of cells were neutrophils. From 3 days after inoculation, the number of alveolar macrophages in lavage samples was markedly increased. From 5 days onwards, many alveolar macrophages had moderate to severe cytoplasmic vacuolation. Topographically, tracheal and bronchial epithelium was covered by a large amount of inflammatory exudate 24 hours after inoculation. Later, the tracheobronchial epithelium showed focal extrusions from ciliated cells, which were occasionally associated with B. parapertussis organisms. Ultrastructurally, cytopathological changes associated with B. parapertussis infection were mild focal degeneration of airway epithelium with slight loss of cilia, moderate to severe degeneration of type I and type II alveolar epithelial cells, and focal inflammation in the lungs. These results suggest that the primary targets of B. parapertussis infection are alveolar macrophages and the epithelial cells of bronchioles and alveoli.


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