Abstract
Background
Fine particulate matter (PM2.5) is a ubiquitous air pollutant, and it has been reported to be closely associated with lung inflammatory injury. In this study, the potential ...molecular mechanisms underlying PM2.5-induced cellular inflammation in human bronchial epithelial (BEAS-2B) cells were investigated.
Materials and methods
Ambient PM2.5 particulates from Suzhou, China, were collected and re-suspended in ultrapure water. Cellular damages, characterized by oxidative stress, mitochondrial injury, and inflammatory cytokine production, were determined in 24 h PM2.5-treated BEAS-2B cells with or without 3-methyladenine (3-MA; autophagy inhibitor) pretreatment. Biomarkers related to oxidative damage, inflammatory injury and autophagy signaling pathways were also measured.
Results
Uptake of PM2.5 in BEAS-2B cells induced cellular oxidative damage, mitochondrial injury, and inflammatory responses as indicated by a significant decrease in GSH/GSSG ratio, increased MDA content, dilated mitochondria with loss and rupture of crista, and production of inflammatory cytokines. Activation of Nrf-2/TXNIP-mediated NF-κB and Bnip3L/NIX-dependent mitophagy signaling pathways, as well as accumulation of autophagosomes and autolysosomes, were also observed. A 6 h pretreatment of 3-MA increased PM2.5-induced oxidative damage and cellular inflammation as indicated by increasing protein levels of HO-1, TXNIP, Bnip3L/NIX and IL-8 gene expression.
Conclusions
PM2.5 induced cellular inflammatory injury by oxidative stress, mitochondrial dysfunction, and mitophagy initiation. Although induction of Bnip3L/NIX-mediated mitophagy in BEAS-2B cells appeared to confer protection in response to PM2.5, dysfunction of autophagic flux may be a critical contributor to defective mitophagy and cellular inflammatory response.
Abstract
In this study, two synthetic methods for the synthesis of a hitherto unknown class of heterocyclic diastereo- and enantiopure
S
,
O
-acetals are described. Method A involves a chemoselective ...monohalogenation of sulfoximines and method B a stereoselective ring opening of sulfonimidates with a carbenoid as the key step, both followed by a base-induced cyclization of the
S
-(halomethyl)sulfoximine intermediates. The absolute configuration of the resulting 3-oxo-1,3λ
6
,4-oxathiazines has been confirmed by X-ray structural analysis. Furthermore, the first experiments exploring the reactivity of the new compounds are described.
The opinion of Mr. Justice Francis of the English High Court which denied the parents of Charlie Gard, who had been born with an extremely rare mutation of a genetic disease, the right to take their ...child to the United States for a proposed experimental treatment occasioned world wide attention including that of the Pope, President Trump, and the US Congress.
The case raise anew a debate as old as the foundation of Western medicine on who should decide and on what standard when there is a conflict between a family and the treating physicians over a possible treatment. This paper will explore the different approaches of the British and American courts on the issue and the various proposals from that of John Rawls in his A Theory of Justice to a processed-based approach for resolving such disputes.
Abstract
Fine particulate matter, a major air pollutant across the world, causes a series of pulmonary diseases. Vitamin D is a typical vitamin with emerging roles in inflammation and fibrosis. ...Different situations and diseases need different doses and modes of vitamin D administration, which challenges the existing vitamin D supplementary rules. Thus, studies of vitamin D applications and their mechanisms in various diseases are important for its future therapeutic applications. In this study, the therapeutic application of vitamin D3 in chronic particle-exposure-associated lung fibrosis and tissue remodeling was investigated. In vivo studies showed that vitamin D3 significantly attenuated fibrosis effects by decreasing α-smooth muscle actin-regulated extracellular matrix deposition and restoring expressions of E-cadherin and N-cadherin. With the importance of activated macrophage in the regulation of local epithelium and fibroblast in the process of tissue fibrosis, two separate in vitro systems of co-culture of macrophages with lung epithelium or fibroblast were built. The results confirmed that vitamin D3 promoted the proliferation of lung epithelium and depressed the fibrosis effects of fibroblasts as well. In addition, our results indicated that the therapeutic effects of vitamin D3 were through Nrf2 signals. Our work provides convincing experimental evidence for vitamin D therapeutic application to promote tissue repair and improve particle-associated lung fibrosis.
Bacterial cellulose was combined with wood cellulose papers in order to obtain biomaterials with increased barrier properties. For this purpose, different parameters were assessed: two producing ...bacterial strains (
Komagataeibacter xylinus
and
Gluconacetobacter sucrofermentans
), two paper supports to hold bacterial cellulose (filter paper and eucalyptus paper), two kinds of combined biomaterials (composite and bilayer) and two drying temperatures (90 °C and room temperature). Papers with increased barrier properties (100° of water contact angle, 1220 s of water drop test and air permeability < 1 µm (Pa s)
−1
) were obtained by the addition of bacterial cellulose to each paper support. However, due to the lower initial barrier properties of filter paper, higher improvements were produced with this paper. In addition, bacterial cellulose provided smoother surfaces with higher gloss without a detrimental effect on physical properties. Higher resistance to water absorption was obtained with
K. xylinus
possibly explained by its longer size fibers than
G. sucrofermentans
, as analysed by SEM. Smoothness and gloss were specially increased in the bilayer biomaterial although resistance to air and water were further improved in the composite. In this biomaterial drying at high temperature had a detrimental effect. SEM analysis of the products obtained showed the intimate contact among fibers of bacterial cellulose and wood paper. Results obtained show the contribution of bacterial cellulose to improve the properties of paper and its potential for the design of new added value paper products from biomass.
Graphical abstract
PDF
