scholarly journals Nrf2 attenuates ferroptosis-mediated IIR-ALI by modulating TERT and SLC7A11

2021 ◽  
Vol 12 (11) ◽  
Author(s):  
Hui Dong ◽  
Yangyang Xia ◽  
Shanliang Jin ◽  
Chaofan Xue ◽  
Yanjun Wang ◽  
...  

AbstractAcute lung injury (ALI) carries a mortality rate of ~50% and is a hot topic in the world of critical illness research. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a critical modulator of intracellular oxidative homeostasis and serves as an antioxidant. The Nrf2-related anti-oxidative stress is strongly associated with ferroptosis suppression. Meanwhile, telomerase reverse transcriptase (TERT), the catalytic portion of the telomerase protein, is reported to travel to the mitochondria to alleviate ROS. In our study, we found that TERT was significantly reduced in lung tissue of Nrf2−/− mice in the model of intestinal ischemia/reperfusion-induced acute lung injury (IIR-ALI). In addition, MDA levels showed marked increase, whereas GSH and GPX4 levels fell drastically in ALI models. Moreover, typical-related structural changes were observed in the type II alveolar epithelial cells in the IIR model. We further employed the scanning transmission X-ray microscopy (STXM) to examine Fe levels and distribution within cells. Based on our observations, massive aggregates of Fe were found in the MLE-12 cells upon OGD/R (oxygen and glucose deprivation/reperfusion) induction. Additionally, Nrf2 silencing dramatically reduced TERT and SLC7A11 levels, and further exacerbated cellular injuries. In contrast, TERT-overexpressing cells exhibited marked elevation in SLC7A11 levels and thereby inhibited ferroptosis. Collectively, these data suggest that Nrf2 can negatively regulate ferroptosis via modulation of TERT and SLC7A11 levels. The conclusion from this study brings insight into new candidates that can be targeted in future IIR-ALI therapy.

2018 ◽  
Vol 46 (2) ◽  
pp. 781-792 ◽  
Author(s):  
DongDong Chai ◽  
Lei Zhang ◽  
SiWei Xi ◽  
YanYong Cheng ◽  
Hong Jiang ◽  
...  

Background/Aims: Nuclear erythroid 2-related factor-2 (Nrf2) is a major stress-response transcription factor that has been implicated in regulating ischemic angiogenesis. We investigated the effects of Nrf2 in regulating revascularization and modulating acute lung injury. Methods: The expression of Nrf2 and sirtuin1 (Sirt1) was assessed in lung tissue by western blotting and immunofluorescence staining after intestinal ischemia/reperfusion (IIR) in Nrf2–/– and wild-type (WT) mice. The involvement of Nrf2 in angiogenesis, cell viability, and migration was investigated in human pulmonary microvascular endothelial cells (PMVECs). Additionally, the influence of Nrf2 expression on NOX pathway activation was measured in PMVECs after oxygen–glucose deprivation/reoxygenation. Results: We found activation and nuclear accumulation of Nrf2 in lung tissue after IIR. Compared to IIR in WT mice, IIR in Nrf2–/– mice significantly enhanced leukocyte infiltration and collagen deposit, and inhibited endothelial cell marker CD31 expression. Nrf2 upregulation and translocation into the nucleus stimulated by Sirt1 overexpression exhibited remission of histopathologic changes and enhanced CD31 expression. Nrf2 knockdown repressed non-phagocytic cell oxidase 4 (NOX4), hypoxia-inducible factor (HIF-1α) and vascular endothelial growth factor (VEGF) expression after IIR. Nrf2 upregulation by Sirt1 enhances NOX4, HIF-1α and VEGF expression after IIR in WT mice. Furthermore, Nrf2 knockdown suppressed cell viability, capillary tube formation and cell migration in PMVECs after oxygen–glucose deprivation/reoxygenation and also inhibited NOX4, HIF-1 and VEGF expression. Moreover, NOX4 knockdown in PMVECs decreased the levels of VEGF, HIF-1α and angiogenesis. Conclusion: Nrf2 stimulation by Sirt1 plays an important role in sustaining angiogenic potential through NOX4-mediated gene regulation.


2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Zhuanzhuan Qiang ◽  
Hui Dong ◽  
Yangyang Xia ◽  
Dongdong Chai ◽  
Rong Hu ◽  
...  

Acute lung injury (ALI) has gained increased attention in the field of critical illness research and is associated with a fatality rate of approximately 50%. Nuclear factor erythroid 2-related factor2 (Nrf2) is a key regulator of intracellular oxidation homeostasis and also functions as an antioxidant. It has been reported that Nrf2 associated antioxidant stress is closely related to ferroptosis inhibition. Signal transducer and activator of transcription 3 (STAT3) is activated into phosphorylated STAT3 (pSTAT3) in response to tissue damage and serves as a warning signal to enhance the inflammatory response. In this study, an intestinal ischemia/reperfusion-induced acute lung injury (IIR-ALI) model was established in C57BL/6 mice to investigate the role of Nrf2 in regulating IIR-ALI-associated ferroptosis. Compared with those in the IIR-ALI group, the injection of Fe (15 mg/kg) or ferrostatin-1 (5 mg/kg) (ferroptosis promoter and inhibitor, respectively) via the tail vein could aggravate or alleviate lung injury and pulmonary edema, respectively. Nrf2 was increased in IIR-ALI and promoted the phosphorylation of STAT3 to amplify downstream signals. An in vitro oxygen-glucose deprivation and reoxygenation (OGD-R) model was established in MLE12 cells to imitate the ischemia/reperfusion condition. The cells were transfected with lentiviruses to increase or downregulate the levels of STAT3. We found that Nrf2 and STAT3 played key roles in ferroptosis by regulating SLC7A11, which improved the pathological processes associated with ALI.


2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Ying Jiang ◽  
Zhen Zhou ◽  
Qing-tao Meng ◽  
Qian Sun ◽  
Wating Su ◽  
...  

Objective. Intestinal ischemia reperfusion (II/R) injury plays a critical role in remote organ dysfunction, such as lung injury, which is associated with nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. In the present study, we tested whether ginsenoside Rb1 attenuated II/R induced lung injury by Nrf2/HO-1 pathway.Methods. II/R injury was induced in male C57BL/6J mice by 45 min of superior mesenteric artery (SMA) occlusion followed by 2 hours of reperfusion. Ginsenoside Rb1 was administrated prior to reperfusion with or without ATRA (all-transretinoic acid, the inhibitor of Nrf2/ARE signaling pathway) administration before II/R.Results. II/R induced lung histological injury, which is accompanied with increased levels of malondialdehyde (MDA), interleukin- (IL-) 6, and tumor necrosis factor- (TNF-)αbut decreased levels of superoxide dismutase (SOD) and IL-10 in the lung tissues. Ginsenoside Rb1 reduced lung histological injury and the levels of TNF-αand MDA, as well as wet/dry weight ratio. Interestingly, the increased Nrf2 and HO-1 expression induced by II/R in the lung tissues was promoted by ginsenoside Rb1 treatment. All these changes could be inhibited or prevented by ATRA.Conclusion. Ginsenoside Rb1 is capable of ameliorating II/R induced lung injuries by activating Nrf2/HO-1 pathway.


2021 ◽  
Vol 263 ◽  
pp. 291
Author(s):  
Georgia Kostopanagiotou ◽  
Efthimios Avgerinos ◽  
Konstantinos Kostopanagiotou ◽  
Nikolaos Arkadopoulos ◽  
Ioanna Andreadou ◽  
...  

2021 ◽  
Author(s):  
Can Jin ◽  
Shucheng Zhang ◽  
Linlin Wu ◽  
Bohan Li ◽  
Meimei Shi ◽  
...  

Abstract Rationale: It is unclear whether removing the danger-associated molecular patterns (DAMPs) of gut lymph (GL) in the rats of gut ischemia-reperfusion injury (GIRI) model may reduce the distant organ lung injury.Objective: To determine whether oXiris gut lymph purification (GLP) may remove the DAMPs of GL in the rats’ model of acute lung injury (ALI) caused by GIRI.Methods: The experimental rats were divided into four groups: Sham group, GIRI group, GIRI + gut lymph drainage (GLD) group, and GIRI + GLP group. After successful modeling, the lung tissue samples of rats in each group were taken for hematoxylin-eosin (HE) staining and detection of expression levels of apoptotic indexes. The level of DAMPs was detected in blood and lymph. We observed its microstructure of type II alveolar epithelial cells (AECⅡ), and detected the expression level of apoptosis indexes.Measurements and Main Results: GIRI-induced destruction of alveolar structure, thickened alveolar walls, inflammatory cell infiltration emerged in the GIRI group, HMGB-1 and IL-6 levels significantly increased, and HSP70 and IL-10 levels reduced in lymph and serum. Compared with GIRI group, the lung tissue damage in GIRI + GLP group significantly improved, the expression level of HMGB-1 and IL-6 in the lymph and serum reduced, and HSP70 and IL-10 increased. The organelle structure of AECII in GIRI + GLP group was significantly improved compared with the GIRI group. Conclusions: oXiris GLP blocks the key link between DAMPs and mononuclear phagocyte system to inhibit inflammation and cell apoptosis, thereby reducing ALI induced by GIRI.


2018 ◽  
Vol 17 (7) ◽  
pp. 975-983 ◽  
Author(s):  
Luiz Philippe da Silva Sergio ◽  
Andrezza Maria Côrtes Thomé ◽  
Larissa Alexsandra da Silva Neto Trajano ◽  
Andre Luiz Mencalha ◽  
Adenilson de Souza da Fonseca ◽  
...  

Acute lung injury (ALI) is defined as hyperinflammation that could occur from sepsis and lead to pulmonary permeability and edema, making them life-threatening diseases.


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