scholarly journals Preconditioning with rHMGB1 ameliorates lung ischemia–reperfusion injury through inhibiting alveolar macrophages pyroptosis via Keap1/Nrf-2/HO-1 signal pathway

2020 ◽  
Author(s):  
Lin Fei ◽  
Xiao Jingyuan ◽  
Liang Fangte ◽  
Dai Huijun ◽  
Ye Liu ◽  
...  

Abstract Background Lung ischemia-reperfusion injury (LIRI) is a common and complex pathophysiological process that can lead to poor patient outcomes. Inflammasome-dependent macrophage pyroptosis contributes to organ damage caused by ischemia-reperfusion (I/R). Oxidative stress reaction and antioxidant enzymes also play an important role in LIRI. This experiment was conducted to investigate whether preconditioning with rHMGB1 could ameliorate LIRI and explore the mechanisms of its protective effect in a lung I/R mice model. Methods Adult male mice were anesthetized and the left hilus pulmonis was clamped for 60 min, followed by 120 min of reperfusion. rHMGB1 was performed by intraperitoneal injection at 2 h before anesthesia. Brusatol (Nrf-2 antagonist) was given intraperitoneally every other day for a total of five times before surgery. Measurements of pathohistological lung tissue damage, pulmonary wet/dry (W/D) ratios, inflammatory mediators were performed to assess the extent of lung injury after I/R. Alveolar macrophages (AMs) pyroptosis were evaluated by LDH release, caspase-1 expression in flow cytometry, GSDMD expression in immunofluorescent staining. Measurement of the products of oxidative Stress (ROS, MDA, 15-F2t-Isoprostane) and the antioxidant enzymes (SOD, GSH-PX, CAT) were performed. Results Preconditioning with rHMGB1 significantly ameliorated I/R-induced lung injury through measuring the morphology, wet/dry weight ratio, the expressions of IL-1β, IL-6, NF-κB, HMGB1 in lung tissue. rHMGB1 preconditioning remarkably alleviated AMs pyroptosis induced by lung I/R. rHMGB1 preconditioning significantly reduced oxidative stress and restored the activity of antioxidative enzymes. In addition, rHMGB1 preconditioning mediated the activity of Keap1/Nrf-2/HO-1 pathway in LIRI. Furthermore, inhibiting Keap1/Nrf-2/HO-1 pathway through brusatol administration could aggravate lung tissue damage and inflammatory response after lung I/R. Also, brusatol administration could suppresse the antioxidant and anti-pyroptosis effects of rHMGB1 preconditioning in LIRI. Conclusions rHMGB1 preconditioning protects against LIRI through suppressing AMs pyroptosis. The mechanism is partially explained by inhibiting oxidative stress and improving the activity of antioxidative enzymes via Keap1/Nrf-2/HO-1 pathway.

2020 ◽  
Author(s):  
Lin Fei ◽  
Xiao Jingyuan ◽  
Liang Fangte ◽  
Dai Huijun ◽  
Ye Liu ◽  
...  

Abstract Background: Lung ischemia-reperfusion injury (LIRI) is a common and complex pathophysiological process that can lead to poor patient outcomes. Inflammasome-dependent macrophage pyroptosis contributes to organ damage caused by ischemia-reperfusion (I/R). Oxidative stress reaction and antioxidant enzymes also play an important role in LIRI. This experiment was conducted to investigate whether preconditioning with rHMGB1 could ameliorate LIRI and explore the mechanisms of its protective effect in a lung I/R mice model. Methods: Adult male mice were anesthetized and the left hilus pulmonis was clamped for 60 min, followed by 120 min of reperfusion. rHMGB1 was performed by intraperitoneal injection at 2 h before anesthesia. Brusatol (Nrf2 antagonist) was given intraperitoneally every other day for a total of five times before surgery. Measurements of pathohistological lung tissue damage, pulmonary wet/dry (W/D) ratios and inflammatory mediators were performed to assess the extent of lung injury after I/R. Alveolar macrophages (AMs) pyroptosis were evaluated by LDH release, caspase-1 expression in flow cytometry, GSDMD expression in immunofluorescent staining. The products of oxidative Stress (ROS, MDA, 15-F2t-Isoprostane) and the antioxidant enzymes (SOD, GSH-PX, CAT) were detected.Results: Preconditioning with rHMGB1 significantly ameliorated I/R-induced lung injury through measuring the morphology, wet/dry weight ratio, the expressions of IL-1β, IL-6, NF-κB and HMGB1 in lung tissue. rHMGB1 preconditioning remarkably alleviated AMs pyroptosis induced by lung I/R. rHMGB1 preconditioning significantly reduced oxidative stress and restored the activity of antioxidative enzymes. In addition, rHMGB1 preconditioning mediated the activity of Keap1/Nrf2/HO-1 pathway in LIRI. Furthermore, inhibiting Keap1/Nrf2/HO-1 pathway through brusatol administration could aggravate lung tissue damage and inflammatory response after lung I/R. And these effects by brusatol administration could be alleviated by rHMGB1 preconditioning in LIRI .Conclusions : rHMGB1 preconditioning protects against LIRI through suppressing AMs pyroptosis. The molecular mechanism could be partially explained by inhibiting oxidative stress and improving the activity of antioxidative enzymes via Keap1/Nrf2/HO-1 pathway upon rHMGB1 preconditioning.


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.


2021 ◽  
Author(s):  
Yun Ding ◽  
Pengjie Tu ◽  
Yiyong Chen ◽  
Yangyun Huang ◽  
Xiaojie Pan ◽  
...  

Abstract Background Cytochrome P450 epoxygenase 2J2 (CYP2J2) metabolizes arachidonic acid to epoxyeicosatrienoic acids (EETs), which exert anti-inflammatory, anti-apoptotic, pro-proliferative, and antioxidant effects on the cardiovascular system. However, the role of CYP2J2 and EETs in pulmonary arterial hypertension (PAH) with lung ischemia-reperfusion injury (LIRI) remains unclear. In the present study, we investigated the effects of CYP2J2 overexpression and exogenous EETs on PAH with LIRI in vitro and in vivo.Methods CYP2J2 gene was transfected into rat lung tissue by recombinant adeno-associated virus (rAAV) to increase the levels of EETs in serum and lung tissue. A rat model of PAH with LIRI was constructed by tail vein injection of monocrotaline (50 mg/kg) for 4 weeks, followed by clamping of the left pulmonary hilum for 1 h and reperfusion for 2 h. In addition, we established a cellular model of human pulmonary artery endothelial cells (HPAECs) with TNF-α combined with hypoxic reoxygenation (anoxia for 8 h and reoxygenation for 16 h) to determine the effect and mechanism of exogenous EETs.Results CYP2J2 overexpression significantly reduced the inflammatory response, oxidative stress and apoptosis associated with lung injury in PAH with LIRI. In addition, exogenous EETs suppressed inflammatory response and reduced intracellular reactive oxygen species (ROS) production and inhibited apoptosis in a tumor necrosis factor alpha (TNF-α) combined hypoxia-reoxygenation model of HPAECs. Our further studies revealed that the anti-inflammatory effects of CYP2J2 overexpression and EETs might be mediated by PPARγ pathway; the anti-apoptotic effects might be mediated by the PI3K/Ak pathway.Conclusions CYP2J2 overexpression and EETs protect against PAH with LIRI via anti-inflammation, anti-oxidative stress and anti-apoptosis, suggesting that increased levels of EETs may be a promising strategy for the prevention and treatment of PAH with LIRI.


Cells ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1421 ◽  
Author(s):  
Thomas S. Weiss ◽  
Madeleine Lupke ◽  
Rania Dayoub ◽  
Edward K. Geissler ◽  
Hans J. Schlitt ◽  
...  

Hepatic ischemia reperfusion injury (IRI) is a major complication in liver resection and transplantation. Here, we analyzed the impact of recombinant human augmenter of liver regeneration (rALR), an anti-oxidative and anti-apoptotic protein, on the deleterious process induced by ischemia reperfusion (IR). Application of rALR reduced tissue damage (necrosis), levels of lipid peroxidation (oxidative stress) and expression of anti-oxidative genes in a mouse IRI model. Damage associated molecule pattern (DAMP) and inflammatory cytokines such as HMGB1 and TNFα, were not affected by rALR. Furthermore, we evaluated infiltration of inflammatory cells into liver tissue after IRI and found no change in CD3 or γδTCR positive cells, or expression of IL17/IFNγ by γδTCR cells. The quantity of Gr-1 positive cells (neutrophils), and therefore, myeloperoxidase activity, was lower in rALR-treated mice. Moreover, we found under hypoxic conditions attenuated ROS levels after ALR treatment in RAW264.7 cells and in primary mouse hepatocytes. Application of rALR also led to reduced expression of chemo-attractants like CXCL1, CXCL2 and CCl2 in hepatocytes. In addition, ALR expression was increased in IR mouse livers after 3 h and in biopsies from human liver transplants with minimal signs of tissue damage. Therefore, ALR attenuates IRI through reduced neutrophil tissue infiltration mediated by lower expression of key hepatic chemokines and reduction of ROS generation.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yong Li ◽  
Hongbo Zhang ◽  
Zhanhu Li ◽  
Xiaoju Yan ◽  
Yuan Li ◽  
...  

Abstract Background Myocardial ischemia reperfusion injury (MIRI) is defined as tissue injury in the pathological process of progressive aggravation in ischemic myocardium after the occurrence of acute coronary artery occlusion. Research has documented the involvement of microRNAs (miRs) in MIRI. However, there is obscure information about the role of miR-130a-5p in MIRI. Herein, this study aims to investigate the effect of miR-130a-5p on MIRI. Methods MIRI mouse models were established. Then, the cardiac function and hemodynamics were detected using ultrasonography and multiconductive physiological recorder. Functional assays in miR-130a-5p were adopted to test the degrees of oxidative stress, mitochondrial functions, inflammation and apoptosis. Hematoxylin and eosin (HE) staining was performed to validate the myocardial injury in mice. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) was employed to assess the expression patterns of miR-130a-5p, high mobility group box (HMGB)2 and NF-κB. Then, dual-luciferase reporter gene assay was performed to elucidate the targeting relation between miR-130a-5p and HMGB2. Results Disrupted structural arrangement in MIRI mouse models was evident from HE staining. RT-qPCR revealed that overexpressed miR-130a-5p alleviated MIRI, MIRI-induced oxidative stress and mitochondrial disorder in the mice. Next, the targeting relation between miR-130a-5p and HMGB2 was ascertained. Overexpressed HMGB2 annulled the protective effects of miR-130a-5p in MIRI mice. Additionally, miR-130a-5p targets HMGB2 to downregulate the nuclear factor kappa-B (NF-κB) axis, mitigating the inflammatory injury induced by MIRI. Conclusion Our study demonstrated that miR-130a-5p suppresses MIRI by down-regulating the HMGB2/NF-κB axis. This investigation may provide novel insights for development of MIRI treatments.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Aleksandra Kezic ◽  
Ivan Spasojevic ◽  
Visnja Lezaic ◽  
Milica Bajcetic

Kidney ischemia/reperfusion injury emerges in various clinical settings as a great problem complicating the course and outcome. Ischemia/reperfusion injury is still an unsolved puzzle with a great diversity of investigational approaches, putting the focus on oxidative stress and mitochondria. Mitochondria are both sources and targets of ROS. They participate in initiation and progression of kidney ischemia/reperfusion injury linking oxidative stress, inflammation, and cell death. The dependence of kidney proximal tubule cells on oxidative mitochondrial metabolism makes them particularly prone to harmful effects of mitochondrial damage. The administration of antioxidants has been used as a way to prevent and treat kidney ischemia/reperfusion injury for a long time. Recently a new method based on mitochondria-targeted antioxidants has become the focus of interest. Here we review the current status of results achieved in numerous studies investigating these novel compounds in ischemia/reperfusion injury which specifically target mitochondria such as MitoQ, Szeto-Schiller (SS) peptides (Bendavia), SkQ1 and SkQR1, and superoxide dismutase mimics. Based on the favorable results obtained in the studies that have examined myocardial ischemia/reperfusion injury, ongoing clinical trials investigate the efficacy of some novel therapeutics in preventing myocardial infarct. This also implies future strategies in preventing kidney ischemia/reperfusion injury.


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