scholarly journals Endotoxin stabilizes protein arginine methyltransferase 4 (PRMT4) protein triggering death of lung epithelia

2021 ◽  
Vol 12 (9) ◽  
Author(s):  
Yandong Lai ◽  
Xiuying Li ◽  
Tiao Li ◽  
Toru Nyunoya ◽  
Kong Chen ◽  
...  

AbstractLung epithelial cell death is a prominent feature of acute lung injury and acute respiratory distress syndrome (ALI/ARDS), which results from severe pulmonary infection leading to respiratory failure. Multiple mechanisms are believed to contribute to the death of epithelia; however, limited data propose a role for epigenetic modifiers. In this study, we report that a chromatin modulator protein arginine N-methyltransferase 4/coactivator-associated arginine methyltransferase 1 (PRMT4/CARM1) is elevated in human lung tissues with pneumonia and in experimental lung injury models. Here PRMT4 is normally targeted for its degradation by an E3 ubiquitin ligase, SCFFBXO9, that interacts with PRMT4 via a phosphodegron to ubiquitinate the chromatin modulator at K228 leading to its proteasomal degradation. Bacterial-derived endotoxin reduced levels of SCFFBXO9 thus increasing PRMT4 cellular concentrations linked to epithelial cell death. Elevated PRMT4 protein caused substantial epithelial cell death via caspase 3-mediated cell death signaling, and depletion of PRMT4 abolished LPS-mediated epithelial cell death both in cellular and murine injury models. These findings implicate a unique molecular interaction between SCFFBXO9 and PRMT4 and its regulation by endotoxin that impacts the life span of lung epithelia, which may play a key role in the pathobiology of tissue injury observed during critical respiratory illness.

2013 ◽  
Vol 305 (2) ◽  
pp. C182-C189 ◽  
Author(s):  
Jutaro Fukumoto ◽  
Itsuko Fukumoto ◽  
Prasanna Tamarapu Parthasarathy ◽  
Ruan Cox ◽  
Bao Huynh ◽  
...  

Inspiration of a high concentration of oxygen, a therapy for acute lung injury (ALI), could unexpectedly lead to reactive oxygen species (ROS) production and hyperoxia-induced acute lung injury (HALI). Nucleotide-binding domain and leucine-rich repeat PYD-containing protein 3 (NLRP3) senses the ROS, triggering inflammasome activation and interleukin-1β (IL-1β) production and secretion. However, the role of NLRP3 inflammasome in HALI is unclear. The main aim of this study is to determine the effect of NLRP3 gene deletion on inflammatory response and lung epithelial cell death. Wild-type (WT) and NLRP3−/− mice were exposed to 100% O2 for 48–72 h. Bronchoalveolar lavage fluid and lung tissues were examined for proinflammatory cytokine production and lung inflammation. Hyperoxia-induced lung pathological score was suppressed in NLRP3−/− mice compared with WT mice. Hyperoxia-induced recruitment of inflammatory cells and elevation of IL-1β, TNFα, macrophage inflammatory protein-2, and monocyte chemoattractant protein-1 were attenuated in NLRP3−/− mice. NLRP3 deletion decreased lung epithelial cell death and caspase-3 levels and a suppressed NF-κB levels compared with WT controls. Taken together, this research demonstrates for the first time that NLRP3-deficient mice have suppressed inflammatory response and blunted lung epithelial cell apoptosis to HALI.


2019 ◽  
Vol 3 (3) ◽  
pp. 432-445 ◽  
Author(s):  
William Bain ◽  
Tolani Olonisakin ◽  
Minting Yu ◽  
Yanyan Qu ◽  
Mei Hulver ◽  
...  

Abstract Thrombocytopenia is associated with worse outcomes in patients with acute respiratory distress syndrome, which is most commonly caused by infection and marked by alveolar–capillary barrier disruption. However, the mechanisms by which platelets protect the lung alveolar–capillary barrier during infectious injury remain unclear. We found that natively thrombocytopenic Mpl−/− mice deficient in the thrombopoietin receptor sustain severe lung injury marked by alveolar barrier disruption and hemorrhagic pneumonia with early mortality following acute intrapulmonary Pseudomonas aeruginosa (PA) infection; barrier disruption was attenuated by platelet reconstitution. Although PA infection was associated with a brisk neutrophil influx, depletion of airspace neutrophils failed to substantially mitigate PA-triggered alveolar barrier disruption in Mpl−/− mice. Rather, PA cell-free supernatant was sufficient to induce lung epithelial cell apoptosis in vitro and in vivo and alveolar barrier disruption in both platelet-depleted mice and Mpl−/− mice in vivo. Cell-free supernatant from PA with genetic deletion of the type 2 secretion system, but not the type 3 secretion system, mitigated lung epithelial cell death in vitro and lung injury in Mpl−/− mice. Moreover, platelet releasates reduced poly (ADP ribose) polymerase cleavage and lung injury in Mpl−/− mice, and boiling of platelet releasates, but not apyrase treatment, abrogated PA supernatant–induced lung epithelial cell cytotoxicity in vitro. These findings indicate that while neutrophil airspace influx does not potentiate infectious lung injury in the thrombocytopenic host, platelets and their factors protect against severe pulmonary complications from pathogen-secreted virulence factors that promote host cell death even in the absence of overt infection.


2021 ◽  
Vol 22 (3) ◽  
pp. 1215
Author(s):  
Mi Ho Jeong ◽  
Mi Seon Jeon ◽  
Ga Eun Kim ◽  
Ha Ryong Kim

Airway epithelial cell death contributes to the pathogenesis of lung fibrosis. Polyhexamethylene guanidine phosphate (PHMG-p), commonly used as a disinfectant, has been shown to be strongly associated with lung fibrosis in epidemiological and toxicological studies. However, the molecular mechanism underlying PHMG-p-induced epithelial cell death is currently unclear. We synthesized a PHMG-p–fluorescein isothiocyanate (FITC) conjugate and assessed its uptake into lung epithelial A549 cells. To examine intracellular localization, the cells were treated with PHMG-p–FITC; then, the cytoplasmic organelles were counterstained and observed with confocal microscopy. Additionally, the organelle-specific cell death pathway was investigated in cells treated with PHMG-p. PHMG-p–FITC co-localized with the endoplasmic reticulum (ER), and PHMG-p induced ER stress in A549 cells and mice. The ER stress inhibitor tauroursodeoxycholic acid (TUDCA) was used as a pre-treatment to verify the role of ER stress in PHMG-p-induced cytotoxicity. The cells treated with PHMG-p showed apoptosis, which was inhibited by TUDCA. Our results indicate that PHMG-p is rapidly located in the ER and causes ER-stress-mediated apoptosis, which is an initial step in PHMG-p-induced lung fibrosis.


2016 ◽  
Vol 54 (5) ◽  
pp. 697-706 ◽  
Author(s):  
Haranatha R. Potteti ◽  
Subbiah Rajasekaran ◽  
Senthilkumar B. Rajamohan ◽  
Chandramohan R. Tamatam ◽  
Narsa M. Reddy ◽  
...  

Shock ◽  
2004 ◽  
Vol 21 ◽  
pp. 27
Author(s):  
L. Mantell ◽  
E. J. Miller ◽  
T. Sakuragi ◽  
J. Romashko ◽  
H. Zhu ◽  
...  

2020 ◽  
Vol 21 (15) ◽  
pp. 5356
Author(s):  
Rushikesh Deshpande ◽  
Chunbin Zou

Pseudomonas aeruginosa is an important opportunistic pathogen responsible for the cause of acute lung injury and acute respiratory distress syndrome. P. aeruginosa isthe leading species isolated from patients with nosocomial infection and is detected in almost all the patients with long term ventilation in critical care units. P. aeruginosa infection is also the leading cause of deleterious chronic lung infections in patients suffering from cystic fibrosis as well as the major reason for morbidity in people with chronic obstructive pulmonary disease. P. aeruginosa infections are linked to diseases with high mortality rates and are challenging for treatment, for which no effective remedies have been developed. Massive lung epithelial cell death is a hallmark of severe acute lung injury and acute respiratory distress syndrome caused by P. aeruginosa infection. Lung epithelial cell death poses serious challenges to air barrier and structural integrity that may lead to edema, cytokine secretion, inflammatory infiltration, and hypoxia. Here we review different types of cell death caused by P. aeruginosa serving as a starting point for the diseases it is responsible for causing. We also review the different mechanisms of cell death and potential therapeutics in countering the serious challenges presented by this deadly bacterium.


Sign in / Sign up

Export Citation Format

Share Document