scholarly journals Titanium Dioxide Nanoparticles Alter the Cellular Phosphoproteome in A549 Cells

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 185 ◽  
Author(s):  
Mathilde Biola-Clier ◽  
Jean-Charles Gaillard ◽  
Thierry Rabilloud ◽  
Jean Armengaud ◽  
Marie Carriere

TiO2 nanoparticles (NPs) are one of the most produced NPs worldwide and are used in many consumer products. Their impact on human health, especially through inhalation, has been studied for more than two decades. TiO2 is known for its strong affinity towards phosphates, and consequently interaction with cellular phosphates may be one of the mechanisms driving its toxicity. In the present study, we used a phosphoproteomics approach to document the interaction of TiO2-NP with phosphoproteins from A549 human pulmonary alveolar epithelial cells. Cells were exposed to 21 nm anatase/rutile TiO2-NPs, then their phosphopeptides were extracted and analyzed using shotgun proteomics. By comparing the phosphoprotein content, phosphorylation status and phosphorylation sites of exposed cells with that of control cells, our results show that by affecting the phosphoproteome, TiO2-NPs affect cellular processes such as apoptosis, linked with cell cycle and the DNA damage response, TP53 being central to these pathways. Other pathways including inflammation and molecular transport are also affected. These molecular mechanisms of TiO2-NP toxicity have been reported previously, our study shows for the first time that they may derive from phosphoproteome modulation, which could be one of their upstream regulators.

2021 ◽  
Vol 22 (11) ◽  
pp. 6041
Author(s):  
Yoshitoshi Kasuya ◽  
Jun-Dal Kim ◽  
Masahiko Hatano ◽  
Koichiro Tatsumi ◽  
Shuichi Matsuda

Idiopathic pulmonary fibrosis (IPF) is one of the most symptomatic progressive fibrotic lung diseases, in which patients have an extremely poor prognosis. Therefore, understanding the precise molecular mechanisms underlying pulmonary fibrosis is necessary for the development of new therapeutic options. Stress-activated protein kinases (SAPKs), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38) are ubiquitously expressed in various types of cells and activated in response to cellular environmental stresses, including inflammatory and apoptotic stimuli. Type II alveolar epithelial cells, fibroblasts, and macrophages are known to participate in the progression of pulmonary fibrosis. SAPKs can control fibrogenesis by regulating the cellular processes and molecular functions in various types of lung cells (including cells of the epithelium, interstitial connective tissue, blood vessels, and hematopoietic and lymphoid tissue), all aspects of which remain to be elucidated. We recently reported that the stepwise elevation of intrinsic p38 signaling in the lungs is correlated with a worsening severity of bleomycin-induced fibrosis, indicating an importance of this pathway in the progression of pulmonary fibrosis. In addition, a transcriptome analysis of RNA-sequencing data from this unique model demonstrated that several lines of mechanisms are involved in the pathogenesis of pulmonary fibrosis, which provides a basis for further studies. Here, we review the accumulating evidence for the spatial and temporal roles of SAPKs in pulmonary fibrosis.


2012 ◽  
Vol 303 (5) ◽  
pp. L413-L424 ◽  
Author(s):  
Sukhdev S. Brar ◽  
Joel N. Meyer ◽  
Carl D. Bortner ◽  
Bennett Van Houten ◽  
William J. Martin

Alveolar epithelial cells are considered to be the primary target of bleomycin-induced lung injury, leading to interstitial fibrosis. The molecular mechanisms by which bleomycin causes this damage are poorly understood but are suspected to involve generation of reactive oxygen species and DNA damage. We studied the effect of bleomycin on mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) in human alveolar epithelial A549 cells. Bleomycin caused an increase in reactive oxygen species production, DNA damage, and apoptosis in A549 cells; however, bleomycin induced more mtDNA than nDNA damage. DNA damage was associated with activation of caspase-3, cleavage of poly(ADP-ribose) polymerase, and cleavage and activation of protein kinase D1 (PKD1), a newly identified mitochondrial oxidative stress sensor. These effects appear to be mtDNA-dependent, because no caspase-3 or PKD1 activation was observed in mtDNA-depleted (ρ0) A549 cells. Survival rate after bleomycin treatment was higher for A549 ρ0 than A549 cells. These results suggest that A549 ρ0 cells are more resistant to bleomycin toxicity than are parent A549 cells, likely in part due to the depletion of mtDNA and impairment of mitochondria-dependent apoptotic pathways.


2020 ◽  
Vol 16 (1) ◽  
pp. 85-89
Author(s):  
Mahesh M. Gouda ◽  
Ashwini Prabhu ◽  
Varsha Reddy S.V. ◽  
Rafa Jahan ◽  
Yashodhar P. Bhandary

Background: Bleomycin (BLM) is known to cause DNA damage in the Alveolar Epithelial Cells (AECs). It is reported that BLM is involved in the up-regulation of inflammatory molecules such as neutrophils, macrophages, chemokines and cytokines. The complex underlying mechanism for inflammation mediated progression of lung injury is still unclear. This investigation was designed to understand the molecular mechanisms associated with p53 mediated modulation of Plasminogen Activator Inhibitor-I (PAI-I) expression and its regulation by nano-curcumin formulation. Methods: A549 cells were treated with BLM to cause the cellular damage in vitro and commercially available nano-curcumin formulation was used as an intervention. Cytotoxic effect of nano-curcumin was analyzed using Methyl Thiazolyl Tetrazolium (MTT) assay. Protein expressions were analyzed using western blot to evaluate the p53 mediated changes in PAI-I expression. Results: Nano-curcumin showed cytotoxicity up to 88.5 % at a concentration of 20 μg/ml after 48 h of treatment. BLM exposure to the cells activated the phosphorylation of p53, which in turn increased PAII expression. Nano-curcumin treatment showed a protective role against phosphorylation of p53 and PAI-I expression, which in turn regulated the fibro-proliferative phase of injury induced by bleomycin. Conclusion: Nano-curcumin could be used as an effective intervention to regulate the severity of lung injury, apoptosis of AECs and fibro-proliferation during pulmonary injury.


2014 ◽  
Vol 307 (6) ◽  
pp. L449-L459 ◽  
Author(s):  
Seong Chul Kim ◽  
Thomas Kellett ◽  
Shaohua Wang ◽  
Miyuki Nishi ◽  
Nagaraja Nagre ◽  
...  

The molecular mechanisms for lung cell repair are largely unknown. Previous studies identified tripartite motif protein 72 (TRIM72) from striated muscle and linked its function to tissue repair. In this study, we characterized TRIM72 expression in lung tissues and investigated the role of TRIM72 in repair of alveolar epithelial cells. In vivo injury of lung cells was introduced by high tidal volume ventilation, and repair-defective cells were labeled with postinjury administration of propidium iodide. Primary alveolar epithelial cells were isolated and membrane wounding and repair were labeled separately. Our results show that absence of TRIM72 increases susceptibility to deformation-induced lung injury whereas TRIM72 overexpression is protective. In vitro cell wounding assay revealed that TRIM72 protects alveolar epithelial cells through promoting repair rather than increasing resistance to injury. The repair function of TRIM72 in lung cells is further linked to caveolin 1. These data suggest an essential role for TRIM72 in repair of alveolar epithelial cells under plasma membrane stress failure.


2021 ◽  
Vol 12 ◽  
Author(s):  
Pamela Velázquez-Díaz ◽  
Erika Nakajima ◽  
Parand Sorkhdini ◽  
Ashley Hernandez-Gutierrez ◽  
Adam Eberle ◽  
...  

Hermansky-Pudlak Syndrome (HPS) is a rare, genetic, multisystem disorder characterized by oculocutaneous albinism (OCA), bleeding diathesis, immunodeficiency, granulomatous colitis, and pulmonary fibrosis. HPS pulmonary fibrosis (HPS-PF) occurs in 100% of patients with subtype HPS-1 and has a similar presentation to idiopathic pulmonary fibrosis. Upon onset, individuals with HPS-PF have approximately 3 years before experiencing signs of respiratory failure and eventual death. This review aims to summarize current research on HPS along with its associated pulmonary fibrosis and its implications for the development of novel treatments. We will discuss the genetic basis of the disease, its epidemiology, and current therapeutic and clinical management strategies. We continue to review the cellular processes leading to the development of HPS-PF in alveolar epithelial cells, lymphocytes, mast cells, and fibrocytes, along with the molecular mechanisms that contribute to its pathogenesis and may be targeted in the treatment of HPS-PF. Finally, we will discuss emerging new cellular and molecular approaches for studying HPS, including lentiviral-mediated gene transfer, induced pluripotent stem cells (iPSCs), organoid and 3D-modelling, and CRISPR/Cas9-based gene editing approaches.


2013 ◽  
Vol 305 (1) ◽  
pp. L33-L41 ◽  
Author(s):  
Bruce D. Uhal ◽  
Hang Nguyen ◽  
MyTrang Dang ◽  
Indiwari Gopallawa ◽  
Jing Jiang ◽  
...  

Earlier work showed that apoptosis of alveolar epithelial cells (AECs) in response to endogenous or xenobiotic factors is regulated by autocrine generation of angiotensin (ANG) II and its counterregulatory peptide ANG1–7. Mutations in surfactant protein C (SP-C) induce endoplasmic reticulum (ER) stress and apoptosis in AECs and cause lung fibrosis. This study tested the hypothesis that ER stress-induced apoptosis of AECs might also be regulated by the autocrine ANGII/ANG1–7 system of AECs. ER stress was induced in A549 cells or primary cultures of human AECs with the proteasome inhibitor MG132 or the SP-C BRICHOS domain mutant G100S. ER stress activated the ANGII-generating enzyme cathepsin D and simultaneously decreased the ANGII-degrading enzyme ACE-2, which normally generates the antiapoptotic peptide ANG1–7. TAPI-2, an inhibitor of ADAM17/TACE, significantly reduced both the activation of cathepsin D and the loss of ACE-2. Apoptosis of AECs induced by ER stress was measured by assays of mitochondrial function, JNK activation, caspase activation, and nuclear fragmentation. Apoptosis induced by either MG132 or the SP-C BRICHOS mutant G100S was significantly inhibited by the ANG receptor blocker saralasin and was completely abrogated by ANG1–7. Inhibition by ANG1–7 was blocked by the specific mas antagonist A779. These data show that ER stress-induced apoptosis is mediated by the autocrine ANGII/ANG1–7 system in human AECs and demonstrate effective blockade of SP-C mutation-induced apoptosis by ANG1–7. They also suggest that therapeutic strategies aimed at administering ANG1–7 or stimulating ACE-2 may hold potential for the management of ER stress-induced fibrotic lung disorders.


2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Toshifumi Sugizaki ◽  
Ken-ichiro Tanaka ◽  
Teita Asano ◽  
Daisuke Kobayashi ◽  
Yuuki Hino ◽  
...  

AbstractAlveolar epithelial injury induced by reactive oxygen species (ROS) and abnormal collagen production by activated fibroblasts (myofibroblasts) is involved in the onset and exacerbation of idiopathic pulmonary fibrosis (IPF). Compared with alveolar epithelial cells, lung fibroblasts, especially myofibroblasts, exhibit an apoptosis-resistance phenotype (apoptosis paradox) that appears to be involved in IPF pathogenesis. Thus, we screened for chemicals eliciting preferential cytotoxicity of LL29 cells (lung fibroblasts from an IPF patient) compared with A549 cells (human lung alveolar epithelial cell line) from medicines already in clinical use. We identified idebenone, a synthetic analogue of coenzyme Q10 (CoQ10, an antioxidant) that has been used clinically as a brain metabolic stimulant. Idebenone induced cell growth inhibition and cell death in LL29 cells at a lower concentration than in A549 cells, a feature that was not observed for other antioxidant molecules (such as CoQ10) and two IPF drugs (pirfenidone and nintedanib). Administration of idebenone prevented bleomycin-induced pulmonary fibrosis and increased pulmonary ROS levels. Importantly, idebenone also improved pulmonary fibrosis and lung function when administered after the development of fibrosis, whereas administration of CoQ10 similarly prevented bleomycin-induced pulmonary fibrosis, but had no effect after its development. Administration of idebenone, but not CoQ10, suppressed bleomycin-induced increases in lung myofibroblasts. In vitro, treatment of LL29 cells with idebenone, but not CoQ10, suppressed TGF-β–induced collagen production. These results suggest that in addition to antioxidant activity, idebenone exerts inhibitory activity on the function of lung fibroblasts, with the former activity being preventative and the latter therapeutic for bleomycin-induced fibrosis. Thus, we propose that idebenone may be more therapeutically beneficial for IPF patients than current treatments.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 1526-1526
Author(s):  
Yun-Ho Kim ◽  
Young-Hee Kang

Abstract Objectives Thrombin generation is crucial to the regulation of hemostasis and thrombosis and is essential to the pathogenesis of cardiovascular disease and venous thrombosis. Pulmonary embolism is a blockage in one of the pulmonary arteries in your lung caused by blood clots due to risk factors including tobacco use. Astragalin (kaempferol 3-O-glucoside) is a flavonoid present in persimmon leaves and green tea seeds and exhibits diverse activities such as asthma and obstructive pulmonary disease. This study investigated that astragalin encumbered pulmonary inflammation caused by cigarette smoking-induced embolism. Methods Pulmonary embolism was evoked through exposure of BALB/c mice to cigarette smoke for 30 min, five days a week for eight weeks. Mice were orally administrated with 10 or 20 mg/kg astragalin for 8 weeks. For the in vitro studies, 10 U/ml thrombin was loaded to alveolar epithelial A549 cells in the absence and presence of 1–20 μM astragalin. Results Oral supplementation of astragalin reduced tissue factor and urokinase-type plasminogen activator elevated in cigarette smoking-exposed lungs. In addition, 1–20 μM astragalin attenuated the induction of protease activated receptor-1 known as coagulation factor II (thrombin) receptor-like-1, in 10 U/ml thrombin-loaded alveolar epithelial cells. Astragalin curtailed induction of the inflammatory mediators of cyclooxygenase-2, intercellular adhesion molecule-1 and inducible nitric oxide synthase in alveolar cells subjected to thrombin. Furthermore, astragalin inhibited inflammatory signaling entailing MAPK/ERK pathway. Conclusions Astragalin may be a potential agent alleviating pulmonary inflammation induced by cigarette smoking-induced embolism. Funding Sources This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2019R1A6A3A01094891).


2020 ◽  
Vol 2020 ◽  
pp. 1-15 ◽  
Author(s):  
Hao Sun ◽  
Yunfei Jiang ◽  
Yang Song ◽  
Xiaomin Zhang ◽  
Jun Wang ◽  
...  

Objective. Paraquat (PQ), a widely used toxic herbicide, induces lung inflammation through mechanisms that remain incompletely understood. In a previous study, we found that the plasma MUC5B mucin level was implicated in PQ poisoning in patients. Here, we hypothesize that MUC5B is a critical mediator in PQ-induced cell inflammation. Methods. A mouse model of PQ-induced lung injury was used to examine the MUC5B expression level. A549 cells (alveolar epithelial cells line) were exposed to PQ in dose-dependent and time-dependent manners. Cell viability was detected by CCK-8 assays. The expression levels of MUC5B were examined by dot blot enzyme-linked immunosorbent assay (ELISA) and RT-qPCR. Western blotting was used to detect the levels of proteins in the MAPK and NF-κB pathways. Inflammatory factors in the cell culture medium were measured by ELISA. NF-κB and MAPK pathway inhibitors and MUC5B siRNA (siMUC5B) were used to determine the function of MUC5B. Finally, N-acetyl-cysteine (NAC) was added and its regulatory effect on the MAPK-NF-κB-MUC5B pathway was examined in PQ-induced cell inflammation. Results. MUC5B was significantly upregulated accompanying the increases in TNF-α and IL-6 secretion following PQ treatment in mouse and also in A549 cells after treatment with 50 μM PQ at 24 hours. Furthermore, MAPK and NF-κB pathway inhibitors could dramatically decrease the expression of MUC5B and the secretion of TNF-α and IL-6. Importantly, siMUC5B could significantly attenuate the secretion of TNF-α and IL-6 induced by PQ. As expected, the addition of NAC efficiently suppresses the TNF-α and IL-6 secretion stimulated from PQ and also downregulated ERK, JNK, and p65 phosphorylation (ERK/JNK MAPK and NF-κB pathways) as well as MUC5B expression. Conclusion. Our findings suggest that MUC5B participates in the process of PQ-induced cell inflammation and is downstream of the NF-κB and MAPK pathways. NAC can attenuate PQ-induced cell inflammation at least in part by suppressing the MAPK-NF-κB-MUC5B pathway. These results nominate MUC5B as a new biomarker and therapeutic target for PQ-induced lung inflammation.


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