scholarly journals Epithelial Ablation of Miro1/Rhot1 GTPase Augments Lung Inflammation by Cigarette Smoke

2021 ◽  
Vol 28 (4) ◽  
pp. 501-512
Author(s):  
Shikha Sharma ◽  
Qixin Wang ◽  
Thivanka Muthumalage ◽  
Irfan Rahman
Keyword(s):  
Quality Control ◽  
Cigarette Smoke ◽  
Inflammatory Mediators ◽  
Calcium Binding ◽  
Lung Inflammation ◽  
Inflammatory Responses ◽  
Inflammatory Cells ◽  
Mitochondrial Quality Control ◽  
Lung Epithelial ◽  
Notable Increase

Mitochondrial quality control is sustained by Miro1 (Rhot1), a calcium-binding membrane-anchored GTPase during mitophagy. The exact mechanism that operates the interaction of Miro1 with mitophagy machinery and their role in cigarette smoke (CS)-induced mitochondrial dysfunction that often results in lung inflammation is unclear. We hypothesized that Miro1 plays an important role in regulating mitophagy machinery and the resulting lung inflammation by CS exposure to mice. The lung epithelial Rhot1fl/fl (WT) and Rhot1CreCC10 mice were exposed to mainstream CS for 3 days (acute) and 4 months (chronic). Acute CS exposure showed a notable increase in the total inflammatory cells, macrophages, and neutrophils that are associated with inflammatory mediators. Chronic exposure showed increased infiltration of neutrophils versus air controls. The effects of acute and chronic CS exposure were augmented in the Rhot1CreCC10 group, indicating that epithelial Miro1 ablation led to the augmentation of inflammatory cell infiltration with alteration in the inflammatory mediators. Thus, Rhot1/Miro1 plays an important role in regulating CS-induced lung inflammatory responses with implications in mitochondrial quality control.

scholarly journals Epithelial Ablation of Miro1/Rhot1 GTPase Leads to Mitochondrial Dysfunction and Lung Inflammation by Cigarette Smoke

2021 ◽  
Author(s):  
Shikha Sharma ◽  
Qixin Wang ◽  
Thivanka Muthumalage ◽  
Irfan Rahman
Keyword(s):  
Quality Control ◽  
Mitochondrial Dysfunction ◽  
Cigarette Smoke ◽  
Calcium Binding ◽  
Lung Inflammation ◽  
Inflammatory Cells ◽  
Mouse Lung ◽  
Control Mechanisms ◽  
Histopathological Changes ◽  
Mitochondrial Quality Control

Cigarette smoke (CS) exposure results in lung damage and inflammation through mitochondrial dysfunction. Mitochondria quality control is sustained by Miro1 (Rhot1), a calcium-binding membrane-anchored GTPase by its interaction with PINK1/Parkin during mitophagy. However, the exact mechanism that operates this interaction of mitophagy machinery in Miro1 degradation and CS-induced mitochondrial dysfunction that results in lung inflammation remains unclear. We hypothesized that mitochondrial Miro1 plays an important role in regulating mitophagy machinery and resulting lung inflammation by CS in mouse lung. We showed a role of Miro1 in CS-induced mitochondrial dysfunction and quality control mechanisms. The Rhot1Fl/Fl (WT) and lung epithelial cell-specific Rhot1 KO were exposed to mainstream CS for 3 days (acute) and 4 months (chronic). The cellular infiltration, cytokines, and lung histopathology were studied for the inflammatory response in the lungs. Acute CS exposure showed a notable increase in the total inflammatory cells, macrophages, and neutrophils associated with inflammatory mediators and Miro1 associated mitochondrial quality control proteins Parkin and OPA1. Chronic exposure showed an increase infiltration of total inflammatory cells and neutrophils versus air controls. Histopathological changes, such as pulmonary macrophages and neutrophils were increased in CS exposed mice. The epithelial Miro1 ablation led to augmentation of inflammatory cell infiltration with alteration in the levels of pro-inflammatory cytokines and histopathological changes. Thus, CS induces disruption of mitochondrial quality control mechanisms, and Rhot1/Miro1 mediates the process of CS-induced mitochondrial dysfunction ensuing lung inflammatory responses.

scholarly journals Epithelial Ablation of Miro1/Rhot1 GTPase Leads to Mitochondrial Dysfunction and Lung Inflammation by Cigarette Smoke

2021 ◽  
Author(s):  
Shikha Sharma ◽  
Qixin Wang ◽  
Thivanka Muthumalage ◽  
Irfan Rahman
Keyword(s):  
Quality Control ◽  
Mitochondrial Dysfunction ◽  
Cigarette Smoke ◽  
Calcium Binding ◽  
Lung Inflammation ◽  
Inflammatory Cells ◽  
Mouse Lung ◽  
Control Mechanisms ◽  
Histopathological Changes ◽  
Mitochondrial Quality Control

Cigarette smoke (CS) exposure results in lung damage and inflammation through mitochondrial dysfunction. Mitochondria quality control is sustained by Miro1 (Rhot1), a calcium-binding membrane-anchored GTPase by its interaction with PINK1/Parkin during mitophagy. However, the exact mechanism that operates this interaction of mitophagy machinery in Miro1 degradation and CS-induced mitochondrial dysfunction that results in lung inflammation remains unclear. We hypothesized that mitochondrial Miro1 plays an important role in regulating mitophagy machinery and resulting lung inflammation by CS in mouse lung. We showed a role of Miro1 in CS-induced mitochondrial dysfunction and quality control mechanisms. The Rhot1Fl/Fl (WT) and lung epithelial cell-specific Rhot1 KO were exposed to mainstream CS for 3 days (acute) and 4 months (chronic). The cellular infiltration, cytokines, and lung histopathology were studied for the inflammatory response in the lungs. Acute CS exposure showed a notable increase in the total inflammatory cells, macrophages, and neutrophils associated with inflammatory mediators and Miro1 associated mitochondrial quality control proteins Parkin and OPA1. Chronic exposure showed an increase infiltration of total inflammatory cells and neutrophils versus air controls. Histopathological changes, such as pulmonary macrophages and neutrophils were increased in CS exposed mice. The epithelial Miro1 ablation led to augmentation of inflammatory cell infiltration with alteration in the levels of pro-inflammatory cytokines and histopathological changes. Thus, CS induces disruption of mitochondrial quality control mechanisms, and Rhot1/Miro1 mediates the process of CS-induced mitochondrial dysfunction ensuing lung inflammatory responses.

Attenuation of bleomycin-induced pneumopathy in mice by a caspase inhibitor

2001 ◽  
Vol 280 (2) ◽  
pp. L316-L325 ◽  
Author(s):  
Kazuyoshi Kuwano ◽  
Ritsuko Kunitake ◽  
Takashige Maeyama ◽  
Naoki Hagimoto ◽  
Masayuki Kawasaki ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Lung Inflammation ◽  
Caspase 3 ◽  
Fas Ligand ◽  
Inflammatory Cells ◽  
Lung Epithelial Cells ◽  
Caspase Inhibitor ◽  
Hydroxyproline Content ◽  
Caspase 1 ◽  
Lung Epithelial

Caspases have been implicated in the effector process of apoptosis in several systems including the Fas-Fas ligand pathway. We previously demonstrated that excessive apoptosis of lung epithelial cells and the Fas-Fas ligand pathway were essential in the pathogenesis of bleomycin-induced pneumopathy in mice. Therefore, the purpose of this study was to investigate whether a caspase inhibitor could prevent the development of this model. The expression of caspase-1 and caspase-3 was upregulated on lung epithelial cells, alveolar macrophages, and infiltrating inflammatory cells in this model. We demonstrated that a broad-spectrum caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, decreased the caspase-1- and caspase-3-like activity, the number of apoptotic cells, the pathological grade of lung inflammation and fibrosis, and the hydroxyproline content in lung tissues in this model. We conclude that caspase inhibitors could be a new therapeutic approach against lung injury and pulmonary fibrosis.

scholarly journals Receptor-mediated mitophagy regulates EPO production and protects against renal anemia

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Guangfeng Geng ◽  
Jinhua Liu ◽  
Changlu Xu ◽  
Yandong yan Pei ◽  
Linbo Chen ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Quality Control ◽  
Therapeutic Strategy ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Renal Anemia ◽  
Inflammatory Factors ◽  
Oxygen Species ◽  
Mitochondrial Quality Control ◽  
Hematopoietic Disorders

Erythropoietin (EPO) drives erythropoiesis and is secreted mainly by the kidney upon hypoxic or anemic stress. The paucity of EPO production in renal EPO-producing cells (REPs) causes renal anemia, one of the most common complications of chronic nephropathies. Although mitochondrial dysfunction is commonly observed in several renal and hematopoietic disorders, the mechanism by which mitochondrial quality control impacts renal anemia remains elusive. In this study, we showed that FUNDC1, a mitophagy receptor, plays a critical role in EPO-driven erythropoiesis induced by stresses. Mechanistically, EPO production is impaired in REPs in Fundc1-/- mice upon stresses, and the impairment is caused by the accumulation of damaged mitochondria, which consequently leads to the elevation of the reactive oxygen species (ROS) level and triggers inflammatory responses by up-regulating proinflammatory cytokines. These inflammatory factors promote the myofibroblastic transformation of REPs, resulting in the reduction of EPO production. We therefore provide a link between aberrant mitophagy and deficient EPO generation in renal anemia. Our results also suggest that the mitochondrial quality control safeguards REPs under stresses, which may serve as a potential therapeutic strategy for the treatment of renal anemia.

scholarly journals Lung epithelial C/EBPβ is necessary for the integrity of inflammatory responses to cigarette smoke

2011 ◽  
Vol 5 ◽  
pp. 5-5
Author(s):  
Abraham B. Roos ◽  
Lukas Didon ◽  
Jenny L. Barton ◽  
Gordon J. Gaschler ◽  
Carla M.T. Bauer ◽  
...  
Keyword(s):  
Cigarette Smoke ◽  
Inflammatory Responses ◽  
Lung Epithelial

scholarly journals Lung Epithelial TRPA1 Transduces the Extracellular ROS into Transcriptional Regulation of Lung Inflammation Induced by Cigarette Smoke: The Role of Influxed Ca2+

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
An-Hsuan Lin ◽  
Meng-Han Liu ◽  
Hsin-Kuo Ko ◽  
Diahn-Warng Perng ◽  
Tzong-Shyuan Lee ◽  
...  
Keyword(s):  
Nadph Oxidase ◽  
Cigarette Smoke ◽  
Lung Inflammation ◽  
Lung Epithelial Cells ◽  
Wild Type ◽  
Intracellular Ros ◽  
Lung Epithelial ◽  
Intracellular Ca ◽  
Acetyl Cysteine

The mechanism underlying the inflammatory role of TRPA1 in lung epithelial cells (LECs) remains unclear. Here, we show that cigarette smoke extract (CSE) sequentially induced several events in LECs. The Ca2+influx was prevented by decreasing extracellular reactive oxygen species (ROS) with the scavenger N-acetyl-cysteine, removing extracellular Ca2+with the chelator EGTA, or treating with the TRPA1 antagonist HC030031. NADPH oxidase activation was abolished by its inhibitor apocynin, EGTA, or HC030031. The increased intracellular ROS was halted by apocynin, N-acetyl-cysteine, or HC030031. The activation of the MAPKs/NF-κB signaling was suppressed by EGTA, N-acetyl-cysteine, or HC030031. IL-8 induction was inhibited by HC030031 or TRPA1 siRNA. Additionally, chronic cigarette smoke (CS) exposure in wild-type mice induced TRPA1 expression in LECs and lung tissues. In CS-exposuretrpa1−/−mice, the increased BALF level of ROS was similar to that of CS-exposure wild-type mice; yet lung inflammation was lessened. Thus, in LECs, CSE may initially increase extracellular ROS, which activate TRPA1 leading to an increase in Ca2+influx. The increased intracellular Ca2+contributes to activation of NADPH oxidase, resulting in increased intracellular ROS, which activate the MAPKs/NF-κB signaling leading to IL-8 induction. This mechanism may possibly be at work in mice chronically exposed to CS.

scholarly journals Dual interleukin-17A/F deficiency protects against acute and chronic response to cigarette smoke exposure in mice

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hiroo Wada ◽  
Masuo Nakamura ◽  
Shin-Ichi Inoue ◽  
Akihiko Kudo ◽  
Tomoko Hanawa ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Cigarette Smoke ◽  
Inflammatory Responses ◽  
Inflammatory Cells ◽  
Smoke Exposure ◽  
Cigarette Smoke Exposure ◽  
Inflammatory Protein ◽  
Interleukin 17A ◽  
Macrophage Colony ◽  
Environmental Air

AbstractIL-17A and IL-17F are both involved in the pathogenesis of neutrophilic inflammation observed in COPD and severe asthma. To explore this, mice deficient in both Il17a and Il17f and wild type (WT) mice were exposed to cigarette smoke or environmental air for 5 to 28 days and changes in inflammatory cells in bronchoalveolar lavage (BAL) fluid were determined. We also measured the mRNA expression of keratinocyte derived chemokine (Kc), macrophage inflammatory protein-2 (Mip2), granulocyte–macrophage colony stimulating factor (Gmcsf) and matrix metalloproteinase-9 (Mmp9 ) in lung tissue after 8 days, and lung morphometric changes after 24 weeks of exposure to cigarette smoke compared to air-exposed control animals. Macrophage counts in BAL fluid initially peaked at day 8 and again on day 28, while neutrophil counts peaked between day 8 and 12 in WT mice. Mice dual deficient with Il17a and 1l17f showed similar kinetics with macrophages and neutrophils, but cell numbers at day 8 and mRNA expression of Kc, Gmcsf and Mmp9 were significantly reduced. Furthermore, airspaces in WT mice became larger after cigarette smoke exposure for 24 weeks, whereas this was not seen dual Il17a and 1l17f deficient mice. Combined Il17a and Il17f deficiency resulted in significant attenuation of neutrophilic inflammatory response and protection against structural lung changes after long term cigarette smoke exposure compared with WT mice. Dual IL-17A/F signalling plays an important role in pro-inflammatory responses associated with histological changes induced by cigarette smoke exposure.

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