Ac2-26 Reduced Lung Injury After Cardiopulmonary Bypass via the AKT1/GSK3ß/eNOS Pathway.

INTRODUCTION: Cardiopulmonary bypass (CPB) leads to severe inflammation and lung injury. Our previous study showed that Ac2-26 (an active n-terminal peptide of Annexin A1) can reduce acute lung injury. The aim of this study was to evaluate the effect of Ac2-26 on lung injury in CPB rats. METHODS: Forty rats were randomly divided into the sham, CPB, Ac, Ac/serine/threonine kinase 1 (AKT1), and Ac/ glycogen synthase kinase (GSK)-3ß groups. The rats in the sham group only received anesthesia, intubation, and cannulation. The rats in the other 4 groups received the standard CPB procedure. The rats in the CPB, Ac, Ac/AKT1, and Ac/GSK3ß groups were immediately injected with saline, Ac2-26 (1 mg/kg), Ac2-26 combined with short hairpin RNA (AKT1), or Ac2-26 combined with a GSK3ß inhibitor after CPB. At 12 h after the end of CPB, the PaO2/ fraction of inspired oxygen ratio, wet/dry weight ratio and protein content in the bronchoalveolar lavage fluid (BALF) were recorded. The numbers of macrophages and neutrophils in the BALF and blood were determined. Cytokine levels in the blood and BALF were investigated. Lung tissue histology and apoptosis were estimated. The expression of nuclear factor kappa- B, AKT1, GSK3ß, endothelial nitric oxide synthase and apoptosis-related proteins was analyzed. The survival of all the rats was recorded. RESULTS: Compared with the rats in the sham group, all the parameters examined worsened in the rats that received CPB. Compared with those in the CPB group, Ac2-26 significantly improved pulmonary capillary permeability, reduced cytokine levels, and decreased histological scores and apoptosis. The protective effect of Ac2-26 on lung injury was significantly reversed by AKT1 short hairpin RNA or a GSK3ß inhibitor. CONCLUSIONS: Ac2-26 significantly reduced lung injury and inflammation after CPB. The protective effect of Ac2-26 mainly depended on the AKT1/GSK3ß/endothelial nitric oxide synthase pathway.

Ac2-26 activated the AKT1/GSK3ß pathway to reduce cerebral neurons pyroptosis and improve cerebral function in rats after cardiopulmonary bypass.

BACKGROUND: Cardiopulmonary bypass (CPB) results in brain injury, which is primarily caused by inflammation. Ac2-26 protects against ischemic or hemorrhage brain injury. The present study was to explore the effect and mechanism of Ac2-26 on brain injury in CPB rats. METHODS: Forty-eight rats were randomized into sham, CPB, Ac, Ac/AKT1, Ac/GSK3ßi and Ac/AKT1/GSK3ßa groups. Rats in sham group only received anesthesia and in the other groups received standard CPB surgery. Rats in the sham and CPB groups received saline, and rats in the Ac, Ac/AKT1, Ac/GSK3ßi and Ac/AKT1/GSK3ßa groups received Ac2-26 immediately after CPB. Rats in the Ac/AKT1, Ac/GSK3ßi and Ac/AKT1/GSK3ßa groups were injected with shRNA, inhibitor and agonist of GSK3ß respectively. The neurological function score, brain edema and histological score were evaluated. The neuronal survival and hippocampal pyroptosis were assessed. The cytokines, activity of NF-κB, S100 calcium-binding protein ß(S100ß) and neuron-specific enolase (NSE), and oxidative were tested. The NLRP3, cleaved-caspase-1 and cleaved-gadermin D (GSDMD) in the brain were also detected. RESULTS: Compared to the sham group, all indicators were aggravated in rats that underwent CPB. Compared to the CPB group, Ac2-26 significantly improved neurological scores and brain edema and ameliorated pathological injury. Ac2-26 reduced the local and systemic inflammation, oxidative stress response and promoted neuronal survival. Ac2-26 reduced hippocampal pyroptosis and decreased pyroptotic proteins in brain tissue. The protection of Ac2-26 was notably lessened by shRNA and inhibitor of GSK3ß. The agonist of GSK3ß recovered the protection of Ac2-26 in presence of shRNA. CONCLUSIONS: Ac2-26 significantly improved neurological function, reduced brain injury via regulating inflammation, oxidative stress response and pyroptosis after CPB. The protective effect of Ac2-26 primarily depended on AKT1/ GSK3ß pathway.

Inhibition of DNA methylation attenuates lung ischemia-reperfusion injury after lung transplantation.

OBJECTIVE: DNA methylation plays an important role in inflammation and oxidative stress. This study aimed to investigate the effect of inhibiting DNA methylation on lung ischemia-reperfusion injury (LIRI). METHODS: We adopted a completely random design for our study. Thirty-two rats were randomized into the sham, LIRI, azathioprine (AZA), and pluripotin (SC1) groups. The rats in the LIRI, AZA, and SC1 groups received left lung transplantation and intravenous injection of saline, AZA, and SC1, respectively. After 24 hours of reperfusion, histological injury, the arterial oxygen partial pressure to fractional inspired oxygen ratio, the wet/dry weight ratio, protein and cytokine concentrations in lung tissue, and DNA methylation in lung tissue were evaluated. The pulmonary endothelium that underwent hypoxemia and reoxygenation was treated with AZA or SC1. Endothelial apoptosis, chemokines, reactive oxygen species, nuclear factor-κB, and apoptotic proteins in the endothelium were studied. RESULTS: Inhibition of DNA methylation by AZA attenuated lung injury, inflammation, and the oxidative stress response, but SC1 aggravated LIRI injury. AZA significantly improved endothelial function, suppressed apoptosis and necrosis, reduced chemokines, and inhibited nuclear factor-κB. CONCLUSIONS: Inhibition of DNA methylation ameliorates LIRI and apoptosis and improves pulmonary function via the regulation of inflammation and oxidative stress.

Diannexin Can Ameliorate Acute Respiratory Distress Syndrome in Rats by Promoting Heme Oxygenase-1 Expression.

BACKGROUND: The recombinant protein diannexin can inhibit platelet-mediated events, which contribute to acute respiratory distress syndrome (ARDS). Here, we investigated the effect of diannexin and its effect on heme oxygenase-1 (HO-1) in ARDS. METHODS: A total of 32 rats were randomized into sham, ARDS, diannexin (D), and diannexin+HO-1 inhibitor (DH) groups. Alveolar-capillary permeability was evaluated by testing the partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) ratio, lung wet/dry weight ratio, and protein levels in the lung. Inflammation was assessed by measuring cytokine levels in the bronchial alveolar lavage fluid (BALF) and serum and nuclear factor-κB (NF-κB) in the lung tissue. Inducible nitric oxide synthase (iNOS), malondialdehyde (MDA), and myeloperoxidase (MPO) were measured to evaluate the oxidative stress response. Lung tissue pathology and apoptosis were also evaluated. We measured HO-1 expression in the lung tissue to investigate the effect of diannexin on HO-1 in ARDS. RESULTS: Compared with the ARDS group, diannexin improved PaO2/FiO2, lung wet/dry weight ratio, and protein levels in the BALF and decreased levels of cytokines and NF-κB in the lung and serum. Diannexin inhibited the oxidative stress response and significantly ameliorated pathological lung injury and apoptosis. The partial reversal of diannexin effects by a HO-1 inhibitor suggests that diannexin may promote HO-1 expression to ameliorate ARDS. CONCLUSIONS: We showed that diannexin can improve alveolar-capillary permeability, inhibit the oxidative stress response and inflammation, and protect against ARDS-induced lung injury and apoptosis.

Corrigendum to "Desflurane Attenuates Ventilator-Induced Lung Injury in Rats with Acute Respiratory Distress Syndrome".

[This corrects the article DOI: 10.1155/2018/7507314.].

Endothelial Progenitor Cells Attenuate Ventilator-Induced Lung Injury with Large-Volume Ventilation.

Ventilator-induced lung injury (VILI) is a common complication that results from treatment with mechanical ventilation (MV) in acute respiratory distress syndrome (ARDS) patients. The present study investigated the effect of endothelial progenitor cell (EPC) transplantation on VILI. Wistar rats were divided into three groups (n = 8): sham (S), VILI model (V) induced by tidal volume ventilation (17 mL/kg), and VILI plus EPC transplantation (VE) groups. The lung PaO2/FiO2 ratio, pulmonary wet-to-dry (W/D) weight ratio, number of neutrophils, total protein, neutrophil elastase level, and inflammatory cytokines in bronchoalveolar lavage fluid (BALF) and serum were examined. Furthermore, the histological and apoptotic analysis, and lung tissue protein expression analysis of Bax, Bcl-2, cleaved caspase-3, matrix metalloproteinase (MMP)-9, total nuclear factor kappa B (total-NF-κB), phosphorylated NF-κB (phospho-NF-κB) and myosin light chain (MLC) were performed. The ventilation-induced decrease in PaO2/FiO2 ratio, and the increase in W/D ratio and total protein concentration were prevented by the EPC transplantation. The EPC transplantation (VE group) significantly attenuated the VILI-induced increased expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-8, MMP-9, phospho-NF-κB and MLC, neutrophil elastase levels and neutrophil counts in BALF. In addition, the anti-inflammatory factor IL-10 increased in the VE group. Furthermore, pulmonary histological injury and apoptosis (TUNEL-positive cells, increase in Bax and cleaved caspase-3) were considerably diminished by the EPC transplantation. The EPC transplantation ameliorated the VILI. The mechanism may be primarily through the improvement of epithelial permeability, inhibition of local and systemic inflammation, and reduction in apoptosis.

Ac2-26 ameliorates lung ischemia-reperfusion injury via the eNOS pathway.

BACKGROUND: Lung ischemia-reperfusion injury (LIRI) is a major complication after lung transplantation. Annexin A1 (AnxA1) ameliorates inflammation in various injured organs. This study aimed to determine the effects and mechanism of AnxA1 on LIRI after lung transplantation. METHODS: Thirty-two rats were randomized into sham, saline, Ac2-26 and Ac2-26/L groups. Rats in the saline, Ac2-26 and Ac2-26/L groups underwent left lung transplantation and received saline, Ac2-26, and Ac2-26/L-NIO, respectively. After 24 h of reperfusion, serum and transplanted lung tissues were examined. RESULTS: The partial pressure of oxygen (PaO2) was increased in the Ac2-26 group compared to that in the saline group but was decreased by L-NIO treatment. In the Ac2-26 group, the wet-to-dry (W/D) weight ratios, total protein concentrations, proinflammatory factors and inducible nitric oxide synthase levels were notably decreased, but the concentrations of anti-inflammatory factors and endothelial nitric oxide synthase levels were significantly increased. Ac2-26 attenuated histological injury and cell apoptosis, and this improvement was reversed by L-NIO. CONCLUSIONS: Ac2-26 reduced LIRI and improved alveoli-capillary permeability by inhibiting oxygen stress, inflammation and apoptosis. The protective effect of Ac2-26 on LIRI largely depended on the endothelial nitric oxide synthase pathway.

Adrenomedullin Reduces Secondary Injury and Improves Outcome in Rats with Fluid Percussion Brain Injury.

OBJECTIVE: Traumatic brain injury (TBI) is a devastating neurologic injury and remains a major cause of death in the world. Secondary injury after TBI is associated with long-term disability in patients with TBI. This study evaluated adrenomedullin (AM) on secondary injury and neurologic functional outcome in rats after TBI. METHODS: Forty-eight Sprague Dawley rats were randomly assigned into 3 groups: sham, TBI, and TBI with AM groups. TBI was induced by fluid percussion injury, and AM was intravenously injected. Neurologic function was examined at 2, 3, and 7 days after TBI. Enzyme-linked immunosorbent assay was used to test tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-8 levels in the brain. Brain edema and blood-brain barrier (BBB) permeability in brain tissue were tested. Western blot was used to examine the expression of aquaporin-4, phosphorylated myosin light-chain, and cleaved caspase-3. Terminal deoxynucleotidyl transferase dUTP nick end labeling was used to test the apoptosis. RESULTS: Compared with the sham group, TNF-α, IL-1ß, and IL-6 levels, brain edema, BBB permeability, neurologic examination scores, terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cells, and expression of aquaporin-4, phosphorylated myosin light-chain, and cleaved caspase-3 significantly increased in the TBI group. AM treatment significantly inhibited TBI-induced effects. CONCLUSIONS: AM can improve neurologic function and ameliorate brain injury in rats with TBI. AM exerts its neuroprotective effect via its anti-inflammatory and antiapoptotic effect.

Endothelial Colony-forming Cells Attenuate Ventilator-induced Lung Injury in Rats with Acute Respiratory Distress Syndrome.

BACKGROUND: Mechanical ventilation (MV) can cause ventilator-induced lung injury (VILI). AIM OF THE STUDY: This study investigated whether endothelial colony-forming cells (ECFC) could inhibit VILI in a rat model of acute respiratory distress syndrome (ARDS). METHODS: Male Wistar rats received the femoral artery and venous cannulation (sham group) or were injected intravenously with 500 µg/kg lipopolysaccharide to induce ARDS. The ARDS rats were subjected to MV. Immediately after the MV, the rats were randomized and injected intravenously with vehicle (ARDS group) or ECFC (ECFC group, n = 8 per group). The oxygen index, lung wet-to-dry weight (W/D) ratios, cytokine protein levels in serum or bronchoalveolar lavage fluid (BALF), neutrophil counts, neutrophil elastase and total protein levels in BALF, histology and cell apoptosis in the lung were detected. The protein levels of endothelin-1, inducible nitric oxide synthase (iNOS), endothelial NOS, matrix metalloproteinase (MMP)-9, Bax, Bcl-2, gelsolin, cleaved caspase-3, phosphorylated NF-κBp65 and myosin light chain (MLC) in the lung were analyzed. RESULTS: Compared with the ARDS group, treatment with ECFC significantly increased the oxygen index, and decreased the lung W/D ratios and injury, and the numbers of apoptotic cells in the lungs, neutrophils counts, total protein and elastase concentrations in BALF of rats. ECFC treatment significantly minimized the protein levels of pro-inflammatory cytokines in BALF and serum, but increased interleukin 10 in rats. Furthermore, ECFC treatment significantly reduced the protein levels of endothelin-1, iNOS, Bax, Gelsolin, MMP-9, cleaved caspase-3, phosphorylated NF-κBp65 and MLC, but enhanced eNOS and Bcl-2 in the lungs of rats. CONCLUSIONS: Therefore, ECFC attenuated inflammation, cell apoptosis and VILI in ARDS rats.

Desflurane Attenuates Ventilator-Induced Lung Injury in Rats with Acute Respiratory Distress Syndrome.

Ventilator-induced lung injury aggravates the existing lung injury. This study investigated the effect of desflurane on VILI in a rat model of acute respiratory distress syndrome. Forty-eight rats were randomized into a sham (S) group, control (C) group, lipopolysaccharide/ventilation (LV) group, lipopolysaccharide/ventilation/desflurane (LVD) group, or lipopolysaccharide/low ventilation with and without desflurane (LLV and LLVD) groups. Rats in the S group received anesthesia only. Rats in the LV and LVD groups received lipopolysaccharide and were ventilated with a high tidal volume. Rats in LLV and LLVD groups were treated as the LV and LVD groups and ventilated with a low tidal volume. PaO2/FiO2, lung wet-to-dry weight ratios, concentrations of inflammatory factors in serum and BALF, histopathologic analysis of lung tissue, and levels of nuclear factor- (NF-) κB protein in lung tissue were investigated. PaO2/FiO2 was significantly increased by desflurane. Total cell count, macrophages, and neutrophils in BALF and proinflammatory factors in BALF and serum were significantly decreased by desflurane, while IL-10 was increased. The histopathological changes and levels of NF-κB protein in lung tissue were decreased by desflurane. The results indicated that desflurane ameliorated VILI in a rat model of acute respiratory distress syndrome.

Parecoxib reduced ventilation induced lung injury in acute respiratory distress syndrome.

BACKGROUND: Cyclooxygenase-2 (COX-2) contributes to ventilation induced lung injury (VILI) and acute respiratory distress syndrome (ARDS). The objective of present study was to observe the therapeutic effect of parecoxib on VILI in ARDS. METHODS: In this parallel controlled study performed at Harbin Medical University, China between January 2016 and March 2016, 24 rats were randomly allocated into sham group (S), volume ventilation group/ARDS (VA), parecoxib/volume ventilation group/ARDS (PVA). Rats in the S group only received anesthesia; rats in the VA and PVA group received intravenous injection of endotoxin to induce ARDS, and then received ventilation. Rats in the VA and PVA groups were treated with intravenous injection of saline or parecoxib. The ratio of arterial oxygen pressure to fractional inspired oxygen (PaO2/FiO2), the wet to dry weight ratio of lung tissue, inflammatory factors in serum and bronchoalveolar lavage fluid (BALF), and histopathologic analyses of lung tissue were examined. In addition, survival was calculated at 24 h after VILI. RESULTS: Compared to the VA group, in the PVA group, PaO2/FiO2 was significantly increased; lung tissue wet to dry weight ratio; macrophage and neutrophil counts, total protein and neutrophil elastase levels in BALF; tumor necrosis factor-α, interleukin-1ß, and prostaglandin E2 levels in BALF and serum; and myeloperoxidase (MPO) activity, malondialdehyde levels, and Bax and COX-2 protein levels in lung tissue were significantly decreased, while Bcl-2 protein levels were significantly increased. Lung histopathogical changes and apoptosis were reduced by parecpxib in the PVA group. Survival was increased in the PVA group. CONCLUSIONS: Parecoxib improves gas exchange and epithelial permeability, decreases edema, reduces local and systemic inflammation, ameliorates lung injury and apoptosis, and increases survival in a rat model of VILI.

Budesonide Attenuates Ventilator-induced Lung Injury in a Rat Model of Inflammatory Acute Respiratory Distress Syndrome.

BACKGROUND AND AIMS: Patients with acute respiratory distress syndrome (ARDS) are particularly susceptible to ventilator-induced lung injury (VILI). This study investigated the effect of budesonide on VILI in a rat model of inflammatory ARDS. METHODS: Forty eight rats were randomized into three groups (n = 16 each): sham group (S), endotoxin/ventilation group (LV), endotoxin/ventilation/budesonide group (LVB). Rats in the S group received anesthesia only. Rats in the LV and LVB groups received endotoxin to simulate ARDS and were mechanically ventilated for 4 h (tidal volume 30 mL/kg). Rats in the LVB group received budesonide 1 mg, and rats in the LV group received saline in airway. PaO2/FiO2, lung wet-to-dry weight ratios, inflammatory factors in serum and bronchoalveolar lavage fluid (BALF), histopathologic analysis of lung tissue, and survival were examined. RESULTS: PaO2/FiO2 was significantly increased in rats in the LVB group compared to the LV group. Total cell count, macrophages, and neutrophils in BALF, and levels of intercellular adhesion molecule (ICAM)-1, tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-8 in BALF and serum were significantly decreased in rats in the LVB group compared to the LV group, whereas levels of IL-10 in BALF and serum were significantly increased. Histopathological changes of lung injury and apoptosis were reduced, and survival was increased in rats in the LVB group compared to the LV group. CONCLUSIONS: Budesonide ameliorated VILI in a rat model of inflammatory ARDS.

Budesonide ameliorates lung injury induced by large volume ventilation.

BACKGROUND: Ventilation-induced lung injury (VILI) is a health problem for patients with acute respiratory dysfunction syndrome. The aim of this study was to investigate the effectiveness of budesonide in treating VILI. METHODS: Twenty-four rats were randomized to three groups: a ventilation group, ventilation/budesonide group, and sham group were ventilated with 30 ml/kg tidal volume or only anesthesia for 4 hor saline or budesonide airway instillation immediately after ventilation. The PaO2/FiO2and wet-to-dry weight ratios, protein concentration, neutrophil count, and neutrophil elastase levels in bronchoalveolar lavage fluid (BALF) and the levels of inflammation-related factors were examined. Histological evaluation of and apoptosis measurement inthe lung were conducted. RESULTS: Compared with that in the ventilation group, the PaO2/FiO2 ratio was significantly increased by treatment with budesonide. The lung wet-to-dry weight ratio, total protein, neutrophil elastase level, and neutrophilcount in BALF were decreased in the budesonide group. The BALF and plasma tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, intercellular adhesion molecule (ICAM)-1, and macrophage inflammatory protein (MIP)-2 levels were decreased, whereas the IL-10 level was increased in the budesonide group. The phosphorylated nuclear factor (NF)-kBlevels in lung tissue were inhibited by budesonide. The histological changes in the lung and apoptosis were reduced by budesonide treatment. Bax, caspase-3, and cleaved caspase-3 were down-regulated, and Bcl-2 was up-regulated by budesonide. CONCLUSIONS: Budesonide ameliorated lung injury induced by large volume ventilation, likely by improving epithelial permeability, decreasing edema, inhibiting local and systemic inflammation, and reducing apoptosis in VILI.