Aerosolized human extracellular superoxide dismutase prevents hyperoxia-induced lung injury

Wedelolactone inhibits ferroptosis and alleviates hyperoxia-induced acute lung injury via the Nrf2/HO-1 signaling pathway

Hyperoxia-induced acute lung injury (HALI) is a complication of oxygen therapy. Ferroptosis is a vital factor in HALI. This paper was anticipated to investigate the underlying mechanism of wedelolactone (WED) on ferroptosis in HALI. The current study used hyperoxia to injure two models, one HALI mouse model and one MLE-12 cell injury model. We found that WED treatment attenuated HALI by decreasing the lung injury score and lung wet/dry (W/D) weight ratio and alleviating pathomorphological changes. Then, the inflammatory reaction and apoptosis in HALI mice and hyperoxia-mediated MLE-12 cells were inhibited by WED treatment. Moreover, WED alleviated ferroptosis with less iron accumulation and reversed expression alterations of ferroptosis markers, including MDA, GSH, GPX4, SLC7A11, FTH1, and TFR1 in hyperoxia-induced MLE-12 cells in vitro and in vivo. Nrf2-KO mice and Nrf2 inhibitor (ML385) decreased WED's ability to protect against apoptosis, inflammatory response, and ferroptosis in hyperoxia-induced MLE-12 cells. Collectively, our data highlighted the alleviatory role of WED in HALI by activating the Nrf2/HO-1 pathway.

Disruption of extracellular redox balance drives persistent lung fibrosis and impairs fibrosis resolution

Lung fibrosis is a devastating outcome of various diffuse parenchymal lung diseases. Despite rigorous research efforts, the mechanisms that propagate its progressive and nonresolving nature remain enigmatic. Oxidative stress has been implicated in the pathogenesis of lung fibrosis. However, the role of extracellular redox state in disease progression and resolution remains largely unexplored. Here, we show that compartmentalized control over extracellular reactive oxygen species (ROS) by aerosolized delivery of recombinant extracellular superoxide dismutase (ECSOD) suppresses an established bleomycin-induced fibrotic process in mice. Further analysis of publicly available microarray, RNA-seq and single-cell RNAseq datasets reveals a significant decrease in ECSOD expression in fibrotic lung tissues that can be spontaneously restored during fibrosis resolution. Therefore, we investigate the effect of siRNA-mediated ECSOD depletion during the established fibrotic phase on the self-limiting nature of the bleomycin mouse model. Our results demonstrate that in vivo knockdown of ECSOD in mouse fibrotic lungs impairs fibrosis resolution. Mechanistically, we demonstrate that transforming growth factor (TGF)-β1 downregulates endogenous ECSOD expression, leading to the accumulation of extracellular superoxide via Smad-mediated signaling and the activation of additional stores of latent TGF-β1. In addition, depletion of endogenous ECSOD during the fibrotic phase in the bleomycin model induces an apoptosis-resistant phenotype in lung fibroblasts through unrestricted Akt signaling. Taken together, our data strongly support the critical role of extracellular redox state in fibrosis persistence and resolution. Based on these findings, we propose that compartment-specific control over extracellular ROS may be a potential therapeutic strategy for managing fibrotic lung disorders.

Aerosol Delivery of a Novel Recombinant Modified Superoxide Dismutase Protein Reduces Oxidant Injury and Attenuates Escherichia coli Induced Lung Injury in Rats

Background: Acute respiratory distress syndrome (ARDS) is a life-threatening respiratory failure syndrome with diverse etiologies characterized by increased permeability of alveolar-capillary membranes, pulmonary edema, and acute onset hypoxemia. During the ARDS acute phase, neutrophil infiltration into the alveolar space results in uncontrolled release of reactive oxygen species (ROS) and proteases, overwhelming antioxidant defenses and causing alveolar epithelial and lung endothelial injury. Objectives: To investigate the therapeutic potential of a novel recombinant human Cu-Zn-superoxide dismutase (SOD) fusion protein in protecting against ROS injury and for aerosolized SOD delivery to treat Escherichia coli induced ARDS. Methods: Fusion proteins incorporating human Cu-Zn-SOD (hSOD1), with (pep1-hSOD1-his) and without (hSOD1-his) a fused hyaluronic acid-binding peptide, were expressed in E. coli. Purified proteins were evaluated in in vitro assays with human bronchial epithelial cells and through aerosolized delivery to the lung of an E. coli-induced ARDS rat model. Results: SOD proteins exhibited high SOD activity in vitro and protected bronchial epithelial cells from oxidative damage. hSOD1-his and pep1-hSOD1-his retained SOD activity postnebulization and exhibited no adverse effects in the rat. Pep1-hSOD1-his administered through instillation or nebulization to the lung of an E. coli-induced pneumonia rat improved arterial oxygenation and lactate levels compared to vehicle after 48 hours. Static lung compliance was improved when the pep1-hSOD1-his protein was delivered by instillation. White cell infiltration to the lung was significantly reduced by aerosolized delivery of protein, and reduction of cytokine-induced neutrophil chemoattractant-1, interferon-gamma, and interleukin 6 pro-inflammatory cytokine concentrations in bronchoalveolar lavage was observed. Conclusions: Aerosol delivery of a novel recombinant modified SOD protein reduces oxidant injury and attenuates E. coli induced lung injury in rats. The results provide a strong basis for further investigation of the therapeutic potential of hSOD1 in the treatment of ARDS.

Release of extracellular superoxide dismutase into alveolar fluid protects against acute lung injury and inflammation in Staphylococcus aureus pneumonia

Acute respiratory distress syndrome (ARDS) remains a significant cause of morbidity and mortality in critically ill patients. Oxidative stress and inflammation play a crucial role in the pathogenesis of ARDS. Extracellular superoxide dismutase (EC-SOD) is abundant in the lung and is an important enzymatic defense against superoxide. Human single-nucleotide polymorphism in matrix binding region of EC-SOD leads to the substitution of arginine to glycine at position 213 (R213G) and results in release of EC-SOD into alveolar fluid, without affecting enzyme activity. We hypothesized that R213G EC-SOD variant protects against lung injury and inflammation via the blockade of neutrophil recruitment in infectious model of methicillin-resistant S. aureus (MRSA) pneumonia. After inoculation with MRSA, wild-type (WT) mice had impaired integrity of alveolar-capillary barrier and increased levels of IL-1β, IL-6, and TNF-α in the broncho-alveolar lavage fluid (BALF), while infected mice expressing R213G EC-SOD variant maintained the integrity of alveolar-capillary interface and had attenuated levels of proinflammatory cytokines. MRSA-infected mice expressing R213G EC-SOD variant also had attenuated neutrophil numbers in BALF and decreased expression of neutrophil chemoattractant CXCL1 by the alveolar epithelial ATII cells, compared with the infected WT group. The decreased neutrophil numbers in R213G mice were not due to increased rate of apoptosis. Mice expressing R213G variant had a differential effect on neutrophil functionality-the generation of neutrophil extracellular traps (NETs) but not myeloperoxidase (MPO) levels were attenuated in comparison with WT controls. Despite having the same bacterial load in the lung as WT controls, mice expressing R213G EC-SOD variant were protected from extrapulmonary dissemination of bacteria.

Protective effect and mechanism of loganin and morroniside on acute lung injury and pulmonary fibrosis

BACKGROUND

Loganin and morroniside are two iridoid glycosides with anti-inflammatory, antioxidant and anti-tumor effects. Whether they have effect on acute lung injury and pulmonary fibrosis are still unknown.

PURPOSE

To explore the potential effects of loganin and morroniside against acute lung cancer and pulmonary fibrosis, and the underlying molecular mechanism.

STUDY DESIGN AND METHODS

Cell and animal models of acute lung injury were established by the induction of LPS. After intervention with loganin and morroniside, the pathological symptom of lung tissue was assessed, pro-inflammatory factors in cells and lung tissues were detected, NF- κB/STAT3 signaling pathway related proteins were detected by western blotting. Mice pulmonary fibrosis model was induced by bleomycin, pathological symptom was assessed by HE and Masson staining. Fibrosis related indicators were detected by qPCR or western blot. CD4+/CD8+ was detected by flow cytometry.

RESULTS

Loganin and morroniside relieved the pathological symptom of lung tissue in acute lung injury, pro-inflammatory factors such as IL-6, IL-1β, TNF-α mRNA were inhibited. Expression of p-p65 and STAT3 in lung tissues were also downregulated. In addition, loganin and morroniside downregulated the expression of collagen fiber, hydroxyproline and TGF-β1, collagen I and α-SMA mRNA in lung tissues of pulmonary fibrosis model. This study proved that loganin and morroniside have protective effect on acute lung injury and pulmonary fibrosis, and may provide theoretical basis for the development of new clinical drugs.

Aspirin Attenuates Hyperoxia-Induced Acute Respiratory Distress Syndrome (ARDS) by Suppressing Pulmonary Inflammation via the NF-κB Signaling Pathway

Acute respiratory distress syndrome (ARDS) is a common destructive syndrome with high morbidity and mortality rates. Currently, few effective therapeutic interventions for ARDS are available. Clinical trials have shown that the effectiveness of aspirin is inconsistent. The contribution of platelets to the inflammatory response leading to the development of ARDS is increasingly recognized. The antiplatelet agent aspirin reportedly exerts a protective effect on acid- and hyperoxia-induced lung injury in murine models. Our previous study showed that pretreatment with aspirin exerts protective effects on hyperoxia-induced lung injury in mice. However, the mechanisms and therapeutic efficacy of aspirin in the posttreatment of hyperoxia-induced acute lung injury (ALI) remain unclear. In this study, we used a homozygous NF-κB-luciferase^+/+ transgenic mouse model and treated mice with low-dose (25 μg/g) or high-dose (50 μg/g) aspirin at 0, 24, and 48 h after exposure to hyperoxia (inspired oxygen fraction (FiO₂) > 95%). Hyperoxia-induced lung injury significantly increased the activation of NF-κB in the lung and increased the levels of macrophages infiltrating the lung and reactive oxygen species (ROS), increased the HO-1, NF-κB, TNF-α, IL-1β, and IL-4 protein levels, and reduced the CC10, SPC, eNOS, Nrp-1, and IκBα protein levels in the lung tissue. Pulmonary edema and alveolar infiltration of neutrophils were also observed in the lung tissue of mice exposed to hyperoxia. However, in vivo imaging revealed that posttreatment with aspirin reduced luciferase expression, suggesting that aspirin might reduce NF-κB activation. Posttreatment with aspirin also reduced hyperoxia-induced increases in the numbers of lung macrophages, intracellular ROS levels, and the expression of TNF-α, IL-1β, and IL-4; it also increased CC10, SPC and Nrp-1 levels compared with hyperoxia exposure alone. Lung histopathology also indicated that the aspirin posttreatment significantly reduced neutrophil infiltration and lung edema compared with hyperoxia exposure alone. Aspirin effectively induces an anti-inflammatory response in a model of hyperoxia-induced lung injury. Thus, aspirin may have potential as a novel treatment for hyperoxia-induced ALI.

Remifentanil ameliorates lung injury in neonate rats with acute respiratory distress by down-regulating TIMP1 expression

Acute respiratory distress syndrome (ARDS) is a critical clinical disease characterized by diffuse inflammation of lung parenchyma and refractory hypoxemia. Remifentanil has been reported to act as an anti-inflammatory antioxidant in a variety of diseases. However, whether Remifentanil has a protective effect in ARDS and its mechanism remains to be further studied. This study was designed to investigate the effects of Remifentanil on ARDS in neonate rats. In this study, we established the model of acute respiratory distress in neonate rats. To study the effects of Remifentanil on ARDS through a series of in vitro and in vivo experiments. Furthermore, the overexpression vector of recombinant tissue inhibitors of metalloproteinase 1 (TIMP1) was injected into the neonate rat before the operation to explore the effect of TIMP-1 overexpression on acute respiratory distress rats through the above experiments. Remifentanil reduced lung injury in rats with acute respiratory distress, reduced inflammation, oxidative stress and tissue cell apoptosis in rats with acute respiratory distress. Remifentanil inhibited the expression of TIMP-1 in rats with acute respiratory distress, and TIMP-1 overexpression inhibited the protective effect of Remifentanil on rats with acute respiratory distress. Remifentanil can reduce lung injury and inflammatory response in young mice with acute respiratory distress and play a protective role by down-regulating the expression of TIMP-1.

Anti-Inflammatory and Reactive Oxygen Species Suppression through Aspirin Pretreatment to Treat Hyperoxia-Induced Acute Lung Injury in NF-κB-Luciferase Inducible Transgenic Mice

Acute lung injury (ALI), a common cause of morbidity and mortality in intensive care units, results from either direct intra-alveolar injury or indirect injury following systemic inflammation and oxidative stress. Adequate tissue oxygenation often requires additional supplemental oxygen. However, hyperoxia causes lung injury and pathological changes. Notably, preclinical data suggest that aspirin modulates numerous platelet-mediated processes involved in ALI development and resolution. Our previous study suggested that prehospital aspirin use reduced the risk of ALI in critically ill patients. This research uses an in vivo imaging system (IVIS) to investigate the mechanisms of aspirin’s anti-inflammatory and antioxidant effects on hyperoxia-induced ALI in nuclear factor κB (NF-κB)–luciferase transgenic mice. To define mechanisms through which NF-κB causes disease, we developed transgenic mice that express luciferase under the control of NF-κB, enabling real-time in vivo imaging of NF-κB activity in intact animals. An NF-κB-dependent bioluminescent signal was used in transgenic mice carrying the luciferase genes to monitor the anti-inflammatory effects of aspirin. These results demonstrated that pretreatment with aspirin reduced luciferase expression, indicating that aspirin reduces NF-κB activation. In addition, aspirin reduced reactive oxygen species expression, the number of macrophages, neutrophil infiltration and lung edema compared with treatment with only hyperoxia treatment. In addition, we demonstrated that pretreatment with aspirin significantly reduced the protein levels of phosphorylated protein kinase B, NF-κB and tumor necrosis factor α in NF-κB–luciferase^+/+ transgenic mice. Thus, the effects of aspirin on the anti-inflammatory response and reactive oxygen species suppressive are hypothesized to occur through the NF-κB signaling pathway. This study demonstrated that aspirin exerts a protective effect for hyperoxia-induced lung injury and thus is currently the drug conventionally used for hyperoxia-induced lung injury.

Thiol-Redox Regulation in Lung Development and Vascular Remodeling

Significance: Redox homeostasis is finely tuned and governed by distinct intracellular mechanisms. The dysregulation of this either by external or internal events is a fundamental pathophysiologic base for many pulmonary diseases. Recent Advances: Based on recent discoveries, it is increasingly clear that cellular redox state and oxidation of signaling molecules are critical modulators of lung disease and represent a final common pathway that leads to poor respiratory outcomes. Critical Issues: Based on the wide variety of stimuli that alter specific redox signaling pathways, improved understanding of the disease and patient-specific alterations are needed for the development of therapeutic targets. Further Directions: For the full comprehension of redox signaling in pulmonary disease, it is essential to recognize the role of reactive oxygen intermediates in modulating biological responses. This review summarizes current knowledge of redox signaling in pulmonary development and pulmonary vascular disease.

Kefir peptides alleviate particulate matter <4 μm (PM4.0)-induced pulmonary inflammation by inhibiting the NF-κB pathway using luciferase transgenic mice

Kefir peptides, generated by kefir grain fermentation of milk proteins, showed positive antioxidant effects, lowered blood pressure and modulated the immune response. In this study, kefir peptide was evaluated regarding their anti-inflammatory effects on particulate matter <4 μm (PM_4.0)-induced lung inflammation in NF-κB-luciferase^+/+ transgenic mice. The lungs of mice under 20 mg/kg or 10 mg/kg PM_4.0 treatments, both increased significantly the generation of reactive oxygen species (ROS) and inflammatory cytokines; increased the protein expression levels of p-NF-κB, NLRP3, caspase-1, IL-1β, TNF-α, IL-6, IL-4 and α-SMA. Thus, we choose the 10 mg/kg of PM_4.0 for animal trials; the mice were assigned to four treatment groups, including control group (saline treatment), PM_4.0 + Mock group (only PM_4.0 administration), PM_4.0 + KL group (PM_4.0 + 150 mg/kg low-dose kefir peptide) and PM_4.0 + KH group (PM_4.0 + 500 mg/kg high-dose kefir peptide). Data showed that treatment with both doses of kefir peptides decreased the PM_4.0-induced inflammatory cell infiltration and the expression of the inflammatory mediators IL-lβ, IL-4 and TNF-α in lung tissue by inactivating NF-κB signaling. The oral administrations of kefir peptides decrease the PM_4.0-induced lung inflammation process through the inhibition of NF-κB pathway in transgenic luciferase mice, proposing a new clinical application to particulate matter air pollution-induced pulmonary inflammation.

Role of PLD-PKCζ signaling axis in p47phox phosphorylation for activation of NADPH oxidase by angiotensin II in pulmonary artery smooth muscle cells

We sought to determine the mechanism by which angiotensin II (ANGII) stimulates NADPH oxidase-mediated superoxide (O₂ ^.- ) production in bovine pulmonary artery smooth muscle cells (BPASMCs). ANGII-induced increase in phospholipase D (PLD) and NADPH oxidase activities were inhibited upon pretreatment of the cells with chemical and genetic inhibitors of PLD2, but not PLD1. Immunoblot study revealed that ANGII treatment of the cells markedly increases protein kinase C-α (PKC-α), -δ, -ε, and -ζ levels in the cell membrane. Pretreatment of the cells with chemical and genetic inhibitors of PKC-ζ, but not PKC-α, -δ, and -ε, attenuated ANGII-induced increase in NADPH oxidase activity without a discernible change in PLD activity. Transfection of the cells with p47phox small interfering RNA inhibited ANGII-induced increase in NADPH oxidase activity without a significant change in PLD activity. Pretreatment of the cells with the chemical and genetic inhibitors of PLD2 and PKC-ζ inhibited ANGII-induced p47phox phosphorylation and subsequently translocation from cytosol to the cell membrane, and also inhibited its association with p22phox (a component of membrane-associated NADPH oxidase). Overall, PLD-PKCζ-p47phox signaling axis plays a crucial role in ANGII-induced increase in NADPH oxidase-mediated O₂ ^.- production in the cells.

Serum and urinary SOD3 in patients with type 2 diabetes: comparison with early chronic kidney disease patients and association with development of diabetic nephropathy

Extracellular superoxide dismutase 3 (SOD3), one member of the antioxidant defense system and a superoxide scavenger, has been noted to be downregulated in the kidneys of diabetic mice and is characterized by a heparin-binding domain that can anchor the protein to the endothelium and extracellular matrix. The association of the serum and urinary SOD3 levels with diabetic nephropathy in different stages has never been evaluated. It remains unclear how urinary SOD3 changes in different renal diseases. We recruited 98 Taiwanese patients with type 2 diabetes and 10 patients with early chronic kidney disease (CKD) into this study. Biochemical analyses were performed, including evaluation of the serum SOD3, urinary SOD3, urinary albumin, urinary vascular endothelial growth factor (VEGF), and urinary angiotensinogen (ANG). The Kruskal-Wallis rank sum test was used to compare various parameters among the three groups of patients: early CKD, diabetes alone, and diabetes with CKD. Results showed that lower serum and urinary SOD3 levels were observed in the group of patients with diabetes alone. Higher serum and urinary SOD3 levels were observed in the group of patients with diabetes and CKD, which had higher albuminuria and serum creatinine levels. The serum SOD3 levels were significantly positively correlated with renal function, according to the serum creatinine level. The urinary levels of SOD3 were significantly correlated with other urinary biomarkers such as urinary ANG and VEGF. Furthermore, albuminuria can positively predict the serum SOD3 level for the ratio of urinary albumin to urinary creatinine (ACR) >1,190.769 mg/g and the urinary SOD3 level for ACR ≥300 mg/g.

Ferritin-based drug delivery systems: Hybrid nanocarriers for vascular immunotargeting

Ferritin subunits of heavy and light polypeptide chains self-assemble into a spherical nanocage that serves as a natural transport vehicle for metals but can include diverse cargoes. Ferritin nanoparticles are characterized by remarkable stability, small and uniform size. Chemical modifications and molecular re-engineering of ferritin yield a versatile platform of nanocarriers capable of delivering a broad range of therapeutic and imaging agents. Targeting moieties conjugated to the ferritin external surface provide multivalent anchoring of biological targets. Here, we highlight some of the current work on ferritin as well as examine potential strategies that could be used to functionalize ferritin via chemical and genetic means to enable its utility in vascular drug delivery.

The extracellular isoform of superoxide dismutase has a significant impact on cardiovascular ischaemia and reperfusion injury during cardiopulmonary bypass

OBJECTIVES

Cardiac surgery with cardiopulmonary bypass (CPB) provokes ischaemia and reperfusion injury (IRI). Superoxide is a main mediator of IRI and is detoxified by superoxide dismutases (SODs). Extracellular SOD (SOD3) is the prevailing isoform in the cardiovascular system. Its mutation is associated with elevated risk for ischaemic heart disease as epidemiological and experimental studies suggest. We investigated the influence of SOD3 on IRI in the context of CPB and hypothesized a protective role for this enzyme.

METHODS

Mutant rats with loss of SOD3 function induced by amino acid shift, SOD3-E124D, (SOD3 mutant; n = 9) were examined in a model of CPB with deep hypothermic circulatory arrest provoking global IRI and compared with SOD3 competent controls (n = 8) as well as sham animals (n = 7). SOD3 plasma activity was photometrically measured with a diazo dye-forming reagent. Activation of cardioprotective rescue pathways (p44-42 MAPK and STAT3), cleavage of PARP-1, expression of SOD isoforms (SOD1, 2 and 3) and nitric oxide metabolism were analysed on the protein level by western blot. To evaluate whether SOD3 inactivity directly affects the myocardium, we isolated adult cardiac myocytes, which underwent hypoxia prior to protein analyses.

RESULTS

Relative SOD3 plasma activity in SOD3 mutant rats was significantly decreased by at least 50% compared with that in SOD3 competent controls (prior to euthanasia P = 0.008). Effectively, physiological parameters [heart rate and mean arterial pressure (MAP)] indicated a trend toward impaired handling of ischaemia and reperfusion in SOD3 mutants: after reperfusion, mean heart rate was 46 bpm lower (P = 0.083) and MAP 8 mmHg lower (P = 0.288) than that in SOD competent controls. Decreased SOD3 activity led to reduced activation of cardioprotective rescue pathways in vivo and in vitro: relative activation of p44-42 MAPK (P = 0.074) and STAT3 (P = 0.027) was more than 30% decreased in heart and aortic tissue of SOD3 mutants (activity normalized to sham control as 1). After CPB, cleavage of PARP-1 was doubled in the control group (P = 0.017), but increased 3-fold in SOD3 mutants (P = 0.002). Furthermore, 3-nitrotyrosine as a measure of decreased nitric oxide bioavailability and other SOD isoforms (SOD1 and 2) were increased.

CONCLUSIONS

Collectively, SOD3 has a significant cardioprotective role in cases of IRI and directly affects the myocardium as hypothesized. Exploration of intervention strategies targeting SOD3 may provide therapeutic options against IRI and associated systemic inflammation.

Intravenous superoxide dismutase as a protective agent to prevent impairment of lung function induced by high tidal volume ventilation

Background

Positive-pressure mechanical ventilation is essential in assisting patients with respiratory failure in the intensive care unit and facilitating oxygenation in the operating room. However, it was also recognized as a primary factor leading to hospital-acquired pulmonary dysfunction, in which pulmonary oxidative stress and lung inflammation had been known to play important roles. Cu/Zn superoxide dismutase (SOD) is an important antioxidant, and possesses anti-inflammatory capacity. In this study, we aimed to study the efficacy of Cu/Zn SOD, administered intravenously during high tidal volume (HTV) ventilation, to prevent impairment of lung function.

Methods

Thirty-eight male Sprague-Dawley rats were divided into 3 groups: 5 h ventilation with (A) low tidal volume (LTV; 8 mL/kg; n = 10), (B) high tidal volume (HTV; 18 mL/kg; n = 14), or (C) HTV and intravenous treatment of Cu/Zn SOD at a dose of 1000 U/kg/h (HTV + SOD; n = 14). Lung function was evaluated both at baseline and after 5-h ventilation. Lung injury was assessed by histological examination, lung water and protein contents in the bronchoalveolar lavage fluid (BALF). Pulmonary oxidative stress was examined by concentrations of methylguanidine (MG) and malondialdehyde (MDA) in BALF, and antioxidative activity by protein expression of glutathione peroxidase-1 (GPx-1) in the lung. Severity of lung inflammation was evaluated by white blood cell and differential count in BALF, and protein expression of inducible nitric oxide synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α), matrix metalloproteinase-9 (MMP-9), and mRNA expression of nuclear factor-κB (NF-κB) in the lung. We also examined protein expression of surfactant protein (SP)-A and D and we measured hourly changes in serum nitric oxide (NO) level.

Results

Five hours of LTV ventilation did not induce a major change in lung function, whereas 5 h of HTV ventilation induced apparent combined restrictive and obstructive lung disorder, together with increased pulmonary oxidative stress, decreased anti-oxidative activity and increased lung inflammation (P < 0.05). HTV ventilation also decreased SP-A and SP-D expression and suppressed serum NO level during the time course of ventilation. Cu/Zn SOD administered intravenously during HTV ventilation effectively reversed associated pulmonary oxidative stress and lung inflammation (P < 0.05); moreover, it preserved SP-A and SP-D expressions in the lung and increased serum nitric oxide (NO) level, enhancing vascular NO bioavailability.

Conclusions

HTV ventilation can induce combined restrictive and obstructive lung disorders. Intravenous administration of Cu/Zn SOD during HTV ventilation can prevent lung function impairment and lung injury via reducing pulmonary oxidative stress and lung inflammation, preserving pulmonary surfactant expression, and enhancing vascular NO bioavailability.

Kefir peptides prevent high-fructose corn syrup-induced non-alcoholic fatty liver disease in a murine model by modulation of inflammation and the JAK2 signaling pathway

OBJECTIVE

In recent years, people have changed their eating habits, and high-fructose-containing bubble tea has become very popular. High-fructose intake has been suggested to be a key factor that induces non-alcoholic fatty liver disease (NAFLD). Kefir, a fermented milk product composed of microbial symbionts, has demonstrated numerous biological activities, including antibacterial, antioxidant and immunostimulating effects. The present study aims to evaluate the effects of kefir peptides on high-fructose-induced hepatic steatosis and the possible molecular mechanism.

RESULTS

An animal model of 30% high-fructose-induced NAFLD in C57BL/6J mice was established. The experiment is divided into the following six groups: (1) normal: H₂O drinking water; (2) mock: H₂O+30% fructose; (3) KL: low-dose kefir peptides (50 mg kg^-1)+30% fructose; (4) KM: medium-dose kefir peptides (100 mg kg^-1)+30% fructose; (5) KH: high-dose kefir peptides (150 mg kg^-1)+30% fructose; and (6) CFM: commercial fermented milk (100 mg kg^-1)+30% fructose. The results show that kefir peptides improve fatty liver syndrome by decreasing body weight, serum alanine aminotransferase, triglycerides, insulin and hepatic triglycerides, cholesterol, and free fatty acids as well as the inflammatory cytokines (TNF-α, IL-6 and IL-1β) that had been elevated in fructose-induced NAFLD mice. In addition, kefir peptides markedly increased phosphorylation of AMPK to downregulate its targeted enzymes, ACC (acetyl-CoA carboxylase) and SREBP-1c (sterol regulatory element-binding protein 1), and inhibited de novo lipogenesis. Furthermore, kefir peptides activated JAK2 to stimulate STAT3 phosphorylation, which can translocate to the nucleus, and upregulated several genes, including the CPT1 (carnitine palmitoyltransferase-1) involved in fatty acid oxidation.

CONCLUSION

Our data have demonstrated that kefir peptides can improve the symptoms of NAFLD, including body weight, energy intake, inflammatory reaction and the formation of fatty liver by activating JAK2 signal transduction through the JAK2/STAT3 and JAK2/AMPK pathways in the high-fructose-induced fatty liver animal model. Therefore, kefir peptides may have the potential for clinical application for the prevention or treatment of clinical metabolic syndrome.

Lung tumorigenesis induced by human vascular endothelial growth factor (hVEGF)-A165 overexpression in transgenic mice and amelioration of tumor formation by miR-16

Many studies have shown that vascular endothelial growth factor (VEGF), especially the human VEGF-A₁₆₅ (hVEGF-A₁₆₅) isoform, is a key proangiogenic factor that is overexpressed in lung cancer. We generated transgenic mice that overexpresses hVEGF-A₁₆₅ in lung-specific Clara cells to investigate the development of pulmonary adenocarcinoma. In this study, three transgenic mouse strains were produced by pronuclear microinjection, and Southern blot analysis indicated similar patterns of the foreign gene within the genomes of the transgenic founder mice and their offspring. Accordingly, hVegf-A₁₆₅ mRNA was expressed specifically in the lung tissue of the transgenic mice. Histopathological examination of the lung tissues of the transgenic mice showed that hVEGF-A₁₆₅ overexpression induced bronchial inflammation, fibrosis, cysts, and adenoma. Pathological section and magnetic resonance imaging (MRI) analyses demonstrated a positive correlation between the development of pulmonary cancer and hVEGF expression levels, which were determined by immunohistochemistry, qRT-PCR, and western blot analyses. Gene expression profiling by cDNA microarray revealed a set of up-regulated genes (hvegf-A₁₆₅, cyclin b1, cdc2, egfr, mmp9, nrp-1, and kdr) in VEGF tumors compared with wild-type lung tissues. In addition, overexpressing hVEGF-A₁₆₅ in Clara cells increases CD105, fibrogenic genes (collagen α1, α-SMA, TGF-β1, and TIMP1), and inflammatory cytokines (IL-1, IL-6, and TNF-α) in the lungs of hVEGF-A₁₆₅-overexpressing transgenic mice as compared to wild-type mice. We further demonstrated that the intranasal administration of microRNA-16 (miR-16) inhibited lung tumor growth by suppressing VEGF expression via the intrinsic and extrinsic apoptotic pathways. In conclusion, hVEGF-A₁₆₅ transgenic mice exhibited complex alterations in gene expression and tumorigenesis and may be a relevant model for studying VEGF-targeted therapies in lung adenocarcinoma.

Ghrelin attenuates sepsis-associated acute lung injury oxidative stress in rats

This study investigated the effect of ghrelin on oxidative stress in septic rat lung tissue. Male Sprague-Dawley rats were divided into sham-operation, sepsis, and ghrelin groups. Sepsis was induced by cecal ligation and puncture. Ghrelin was administered intraperitoneally at 3 and 15 h post-operation. Bronchoalveolar lavage was performed to collect alveolar macrophages (AMs). Inducible nitric oxide synthase (iNOS) messenger RNA (mRNA) expression in alveolar macrophages and iNOS protein levels were measured by reverse transcription PCR (RT-PCR) and Western blot. Pulmonary pathology was analyzed and nitrotyrosine expression was examined by immunohistochemistry. Plasma superoxide dismutase (SOD) and lung wet/dry weight were measured. In the sepsis group, iNOS mRNA expression in AMs was 1.33 ± 0.05, 1.44 ± 0.08, and 1.57 ± 0.11 at 6, 12, and 20 h post-surgery, respectively, and were higher compared with the sham-operation group (p<0.05). No increase was observed at longer time points. iNOS mRNA expression in the sepsis group was lower compared with the ghrelin group (2.27 ± 0.37) (p<0.05) at 20 h post-surgery. iNOS protein levels in the ghrelin group (0.87 ± 0.03, p<0.05) were lower than in the sepsis group at 20 h. Ghrelin group pathological scores were lower than in the sepsis group (p<0.05). Plasma SOD was slightly non-significantly decreased in the ghrelin group. No difference was observed in lung wet/dry weight ratios between sepsis and ghrelin groups. iNOS mRNA expression in AMs was elevated between 6 and 20 h after cecal ligation and puncture (CLP), but did not progress. Ghrelin attenuated pulmonary iNOS protein expression and tended to increase plasma SOD activity. Ghrelin suppressed pulmonary nitrosative stress in septic rats, but did not improve lung wet/dry weight ratios.

Protective effect of fu-qi granule on carbon tetrachloride-induced liver fibrosis in rats

AIM: To investigate the efficacy of fu-qi granule (FQG) on carbon tetrachloride (CCl₄) induced liver fibrosis in rats and the underlying mechanisms.

METHODS: Sixty rats were randomly divided into six groups: normal control group, CCl₄ induced liver fibrosis group, AnluoHuaxianWan group and three treatment groups of FQG. Treatment of rats with intraperitoneal injection of carbon tetrachloride solution at 0.3 mL per 100 g body weigh twice a week for 8 wk. The normal control group the rats were given the media (olive oil) at the same time. In the first 2 wk, rats were raised with feedstuff (80% corn meal, 20% lard, 0.5% cholesterol). Serum samples were collected for alanine transaminase, aspartate aminotransferase, alkaline phosphatase, albumin, total protein assay and typical histopathological changes was observed in Hematoxylin-eosin staining sections. Smooth muscle alpha actin (α-SMA) was analyzed with immunohistochemistry. Mammalian target of rapamycin (mTOR) and hypoxia-inducible factor-1 (HIF-1α) expressions were detected by Western blotting. Tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) and matrix metalloproteinases-9 (MMP-9) were measured with semi-quantitative reverse transcriptase-polymerase chain reaction.

RESULTS: FQG significantly reduced the serum levels of alanine transaminase, aspartate aminotransferase, alkaline phosphatase and increased the serum contents of albumin, total protein in rats with liver fibrosis. Moreover, FQG promoted extracellular matrix degradation by increasing MMP-9 and inhibiting TIMP-1 and α-SMA. mTOR and HIF-1α expression in liver significantly decreased in the rats treated with FQG.

CONCLUSION: The results indicated that FQG significantly reverse fibrosis induced by CCl₄, which should be developed as a new and promising preparation for the prevention of liver fibrosis.

Comparison of solid-state-cultured and wood-cultured Antrodia camphorata in anti-inflammatory effects using NF-κB/luciferase inducible transgenic mice

PURPOSE

Antrodia camphorata (AC), a highly valued polypore mushroom native only to Taiwan, has been traditionally used as a medicine for the treatment of food and drug intoxication, diarrhea, abdominal pain, hypertension, skin itching, and cancer. In this study, both of solid-state-cultured AC (S-AC) and wood-cultured AC (W-AC) were evaluated the anti-inflammatory effects on hyperoxia-induced lung injury in NF-κB-luciferase(+/+) transgenic mice.

METHODS

The homozygous transgenic mice (NF-κB-luciferase(+/+)) were randomly assigned to four groups for treatment (n = 6) including Normoxia/DMSO group, Hyperoxia/DMSO group, Hyperoxia/S-AC group, and Hyperoxia/W-AC group. After 72 h of hyperoxia, we examined the bioluminescence images, reactive oxygen species (ROS), the mRNA and protein expression levels of inflammation factors, and histopathological analyses of the lung tissues.

RESULTS

Hyperoxia-induced lung injury significantly increased the generation of ROS, the mRNA levels of IL-6, TNF-α, IL-1β and IL-8, and the protein expression levels of IKKα/β, iNOS and IL-6. Pulmonary edema and alveolar infiltration of neutrophils was also observed in the hyperoxia-induced lung tissue. However, treatment with either S-AC or W-AC obviously decreased hyperoxia-induced generation of ROS and the expression of IL-6, TNF-α, IL-1β, IL-8, IKKα/β and iNOS compared to hyperoxia treatment alone. Lung histopathology also showed that treatment with either S-AC or W-AC significantly reduced neutrophil infiltration and lung edema compared to treatment with hyperoxia treated alone. To find out their major compounds, eburicoic acid and dehydroeburicoic acid were both isolated and identified from S-AC and W-AC by using HPLC, MS, and NMR spectrometry.

CONCLUSIONS

These results demonstrated that methanolic extracts both of S-AC and W-AC have excellent anti-inflammatory activities and thus have great potential as a source for natural health products.

Ameliorative effects of docosahexaenoic acid on the toxicity induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in cultured rat hepatocytes

The 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is an environmental contaminant toxicant that mediates carcinogenic effects associated with oxidative DNA damage. Docosahexaenoic acid (DHA) with antioxidant functions has many biochemical, cellular, and physiological functions for cells. The present study assessed, for the first time, the ameliorative effect of DHA in alleviating the toxicity of TCDD on primary cultured rat hepatocytes (HEPs). In vitro, isolated HEPs were incubated with TCDD (5 and 10 μM) in the presence and absence of DHA (5, 10, and 20 μM) for 48 h. The cell viability was detected by 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) release. DNA damage was analyzed by liver micronucleus assay and 8-oxo-2-deoxyguanosine (8-OH-dG) level. In addition, total antioxidant capacity (TAC) and total oxidative stress (TOS) were assessed to determine the oxidative injury in HEPs. The results of MTT and LDH assays showed that TCDD decreased cell viability but not DHA. On the basis of increasing treatment concentrations, the dioxin caused significant increases of micronucleated HEPs and 8-OH-dG as compared to control culture. TCDD also led to significant increases in TOS content. On the contrary, in cultures treated with DHA, the level of TAC was significantly increased during treatment in a concentration-dependent fashion. DHA showed therapeutic potential against TCDD-mediated cell viability and DNA damages. As conclusion, this study provides the first evidence that DHA has protective effects against TCDD toxicity on primary cultured rat hepatocytes.

MicroRNA and mRNA expression profiling in rat acute respiratory distress syndrome

Background

Acute respiratory distress syndrome (ARDS) is characterized by pulmonary epithelial injury and extensive inflammation of the pulmonary parenchyma. Systematic analyses of microRNA (miRNA) and mRNA expression profiling in ARDS provide insights into understanding of molecular mechanisms of the pathogenesis of ARDS. The objective of this study was to identify miRNA and mRNA interactions in a rat model of ARDS by combining miRNA and mRNA microarray analyses.

Methods

Rat model of ARDS was induced by saline lavage and mechanical ventilation. The expression profiles of both mRNAs and miRNAs in rat ARDS model were performed by microarray analyses. Microarray data were further verified by quantitative RT-PCR. Functional annotation on dys-regulated mRNAs and miRNAs was carried out by bioinformatics analysis.

Results

The expression of 27 miRNAs and 37 mRNAs were found to be significantly changed. The selected miRNAs and genes were further verified by quantitative real-time PCR. The down-regulated miRNAs included miR-24, miR-26a, miR-126, and Let-7a, b, c, f. The up-regulated miRNAs were composed of miR-344, miR-346, miR-99a, miR-127, miR-128b, miR-135b, and miR-30a/b. Gene ontology and functional annotation analyses indicated that up-regulated mRNAs, such as Apc, Timp1, and Sod2, were involved in the regulation of apoptosis. Bioinformatics analysis showed the inverse correlation of altered miRNAs with the expression of their predicted target mRNAs. While Sod2 was inversely correlated with Let-7a, b, c, f., Ebf1 and Apc were inversely correlated with miR-24 and miR-26a, respectively. miR-26a, miR-346, miR-135b, miR-30a/b, miR-344, and miR-18a targeted multiple altered mRNAs. Gabrb1, Sod2, Eif2ak1, Fbln5, and Tspan8 were targeted by multiple altered miRNAs.

Conclusion

The expressions of miRNAs and mRNAs were altered in a rat model of ARDS. The identified miRNA-mRNA pairs may play critical roles in the pathogenesis of ARDS.

Oxidative Stress and Therapeutic Development in Lung Diseases

Oxidative stress has many implications in the pathogenesis of lung diseases. In this review, we provide an overview of Reactive Oxygen Species (ROS) and nitrogen (RNS) species and antioxidants, how they relate to normal physiological function and the pathophysiology of different lung diseases, and therapeutic strategies. The production of ROS/RNS from endogenous and exogenous sources is first discussed, followed by antioxidant systems that restore oxidative balance and cellular homeostasis. The contribution of oxidant/antioxidant imbalance in lung disease pathogenesis is also discussed. An overview of therapeutic strategies is provided, such as augmenting NO bioactivity, blocking the production of ROS/RNS and replacement of deficient antioxidants. The limitations of current strategies and failures of clinical trials are then addressed, followed by discussion of novel experimental approaches for the development of improved antioxidant therapies.

Aerosolized bovine lactoferrin reduces lung injury and fibrosis in mice exposed to hyperoxia

This study investigated the ability of aerosolized bovine lactoferrin (bLF) to protect the lungs from injury induced by chronic hyperoxia. Female CD-1 mice were exposed to hyperoxia (FiO2 = 80 %) for 7 days to induce lung injury and fibrosis. The therapeutic effects of bLF, administered via an aerosol delivery system, on the chronic lung injury induced by this period of hyperoxia were measured by bronchoalveolar lavage, lung histology, cell apoptosis, and inflammatory cytokines in the lung tissues. After exposure to hyperoxia for 7 days, the survival of the mice was significantly decreased to 20 %. The protective effects of bLF against hyperoxia were further confirmed by significant reductions in lung edema, total cell numbers in bronchoalveolar lavage fluid, inflammatory cytokines (IL-1β and IL-6), pulmonary fibrosis, and apoptotic DNA fragmentation. The aerosolized bLF protected the mice from oxygen toxicity and increased the survival fraction to 66.7 % in the hyperoxic model. The results support the use of an aerosol therapy with bLF in intensive care units to reduce oxidative injury in patients with severe hypoxemic respiratory failure or chronic obstructive pulmonary disease.

High-frequency ultrasound imaging to evaluate liver fibrosis progression in rats and yi guan jian herbal therapeutic effects

The animals used in liver fibrosis studies must usually be sacrificed. Ultrasound has been demonstrated to have the ability to diagnose hepatic fibrosis and cirrhosis in experimental small-animal models. However, few studies have used high-frequency ultrasound (HFU, 40 MHz) to monitor changes in the rat liver and other hollow organs longitudinally. In this study, liver fibrosis was induced by administering dimethylnitrosamine (DMN) in SD rats, aged 8 weeks, for three consecutive days per week for up to 4 weeks. A Chinese herbal medicine Yi Guan Jian (YGJ) was orally administered (1.8 g/kg daily) to DMN-induced liver fibrosis rats for 2 weeks. Compared with the normal control rats, rats treated with DMN for either 2 weeks or 4 weeks had significantly lower body weights, liver indexes and elevation of hydroxyproline, GOT, and GPT contents. YGJ herbal treatment remarkably prevented rats from DMN-induced liver fibrosis. The HFU scoring results among the normal controls, 2-week DMN-treated rats, 4-week DMN-treated rats, and combined 2-week YGJ therapy with 4-week DMN-treated rats also reached statistical significance. Thus, HFU is an accurate tool for the longitudinal analysis of liver fibrosis progression in small-animal models, and the YGJ may be useful in reversing the development of hepatic fibrosis.

Amniotic fluid stem cells from EGFP transgenic mice attenuate hyperoxia-induced acute lung injury

High concentrations of oxygen aggravate the severity of lung injury in patients requiring mechanical ventilation. Although mesenchymal stem cells have been shown to effectively attenuate various injured tissues, there is limited information regarding a role for amniotic fluid stem cells (AFSCs) in treating acute lung injury. We hypothesized that intravenous delivery of AFSCs would attenuate lung injury in an experimental model of hyperoxia-induced lung injury. AFSCs were isolated from EGFP transgenic mice. The in vitro differentiation, surface markers, and migration of the AFSCs were assessed by specific staining, flow cytometry, and a co-culture system, respectively. The in vivo therapeutic potential of AFSCs was evaluated in a model of acute hyperoxia-induced lung injury in mice. The administration of AFSCs significantly reduced the hyperoxia-induced pulmonary inflammation, as reflected by significant reductions in lung wet/dry ratio, neutrophil counts, and the level of apoptosis, as well as reducing the levels of inflammatory cytokine (IL-1β, IL-6, and TNF-α) and early-stage fibrosis in lung tissues. Moreover, EGFP-expressing AFSCs were detected and engrafted into a peripheral lung epithelial cell lineage by fluorescence microscopy and DAPI stain. Intravenous administration of AFSCs may offer a new therapeutic strategy for acute lung injury (ALI), for which efficient treatments are currently unavailable.

Ingestion of milk containing the Dp2 peptide, a dust mite allergen, protects mice from allergic airway inflammation and hyper-responsiveness

Background

Allergen-specific immunotherapy has been demonstrated to have potential for the treatment of allergic diseases. Transgenic animals are currently the best available bioreactors to produce recombinant proteins, which can be secreted in milk. It has not been clearly demonstrated whether milk from transgenic animals expressing recombinant allergens has immunomodulatory effects on allergic asthma.

Methods

We aimed to determine whether the oral administration of milk containing a mite allergen can down-regulate allergen-specific airway inflammation. Transgenic CD-1 mice that express a recombinant group 2 allergen from Dermatophagoides pteronyssinus (Dp2) in their milk were generated using an embryonic gene-microinjection technique. Mouse pups were fed transgenic Dp2-containing milk or wild-type milk. Subsequently, these mice were sensitized and challenged with Dp2 to induce allergic airway inflammation.

Results

Upon sensitization and challenge, mice fed transgenic Dp2 milk had decreased T-helper 2 (Th2) and increased T-helper 1 (Th1) responses in the airway compared with mice fed wild-type milk. Moreover, pre-treatment with transgenic Dp2 milk attenuated airway inflammation and decreased airway hyper-responsiveness.

Conclusions

This study provides new evidence that oral administration of transgenic milk containing the Dp2 allergen down-regulated and moderately protected against allergic airway inflammation. Milk from transgenic animals expressing allergens may have potential use in the prevention of allergic asthma.

Metallothionein-induced zinc partitioning exacerbates hyperoxic acute lung injury

Hypozincemia, with hepatic zinc accumulation at the expense of other organs, occurs in infection, inflammation, and aseptic lung injury. Mechanisms underlying zinc partitioning or its impact on extrahepatic organs are unclear. Here we show that the major zinc-binding protein, metallothionein (MT), is critical for zinc transmigration from lung to liver during hyperoxia and preservation of intrapulmonary zinc during hyperoxia is associated with an injury-resistant phenotype in MT-null mice. Particularly, lung-to-liver zinc ratios decreased in wild-type (WT) and increased significantly in MT-null mice breathing 95% oxygen for 72 h. Compared with female adult WT mice, MT-null mice were significantly protected against hyperoxic lung injury indicated by reduced inflammation and interstitial edema, fewer necrotic changes to distal airway epithelium, and sustained lung function at 72 h hyperoxia. Lungs of MT-null mice showed decreased levels of immunoreactive LC3, an autophagy marker, compared with WT mice. Analysis of superoxide dismutase (SOD) activity in the lungs revealed similar levels of manganese-SOD activity between strains under normoxia and hyperoxia. Lung extracellular SOD activity decreased significantly in both strains at 72 h of hyperoxia, although there was no difference between strains. Copper-zinc-SOD activity was ~4× higher under normoxic conditions in MT-null compared with WT mice but was not affected in either group by hyperoxia. Collectively the data suggest that genetic deletion of MT-I/II in mice is associated with compensatory increase in copper-zinc-SOD activity, prevention of hyperoxia-induced zinc transmigration from lung to liver, and hyperoxia-resistant phenotype strongly associated with differences in zinc homeostasis during hyperoxic acute lung injury.

A Chinese herbal medicine, Gexia-Zhuyu Tang (GZT), prevents dimethylnitrosamine-induced liver fibrosis through inhibition of hepatic stellate cells proliferation

ETHNOPHARMACOLOGICAL EVIDENCE

Gexia-Zhuyu Tang (GZT), also called Gexiazhuyu decoction (GXZYD), is a traditional Chinese herbal medicine for chronic liver diseases such as cirrhosis and liver fibrosis.

AIM OF THE STUDY

In this study, we have investigated the affects of GZT on a rat model of dimethylnitrosamine (DMN)-induced liver fibrosis.

MATERIALS AND METHODS

In this study, the protective effects of GZT on DMN-induced liver fibrosis were measured using a rat model. Following 5 weeks of DMN-treatment (8 mg/kg, i.p., given 3 consecutive days each week), oral administration of GZT at 1.8 g/kg daily via oral gavage for 2weeks beginning at week 13.

RESULTS

Both body and liver weights were significantly decreased. The reductions in body and liver weights corresponded with increasing liver damage severity. Furthermore, GZT-treatment remarkably decreased the levels of serum GOT (glutamate oxaloacetate transaminase) and GPT (glutamic pyruvic transaminase), and the mRNA expression levels of collagen alpha-1(I) and alpha-smooth muscle actin (alpha-SMA) in DMN-induced hepatic fibrosis. In addition, hepatic stellate cells (HSCs) play a major role in various types of liver fibrosis through initial myofibroblast transformation. The proliferation of HSCs was inhibited by GZT. Treatment with GZT also induced HSC apoptosis in a dose- and time-dependent manner. GZT treatment induced HSC apoptosis by facilitating Ca(2+) release from the mitochondria within 6h. Subsequently, caspases 3 and 12 were elevated by 72 h after treatment.

CONCLUSIONS

Our studies indicate that GZT exhibited both hepatoprotective and antifibrogenic effects in DMN-induced hepatic injury. These findings suggest that GZT may be useful in preventing the development of hepatic fibrosis.

Synergistic protection against hyperoxia-induced lung injury by neutrophils blockade and EC-SOD overexpression

Background

Oxygen may damage the lung directly via generation of reactive oxygen species (ROS) or indirectly via the recruitment of inflammatory cells, especially neutrophils. Overexpression of extracellular superoxide dismutase (EC-SOD) has been shown to protect the lung against hyperoxia in the newborn mouse model. The CXC-chemokine receptor antagonist (Antileukinate) successfully inhibits neutrophil influx into the lung following a variety of pulmonary insults. In this study, we tested the hypothesis that the combined strategy of overexpression of EC-SOD and inhibiting neutrophil influx would reduce the inflammatory response and oxidative stress in the lung after acute hyperoxic exposure more efficiently than either single intervention.

Methods

Neonate transgenic (Tg) (with an extra copy of hEC-SOD) and wild type (WT) were exposed to acute hyperoxia (95% FiO₂ for 7 days) and compared to matched room air groups. Inflammatory markers (myeloperoxidase, albumin, number of inflammatory cells), oxidative markers (8-isoprostane, ratio of reduced/oxidized glutathione), and histopathology were examined in groups exposed to room air or hyperoxia. During the exposure, some mice received a daily intraperitoneal injection of Antileukinate.

Results

Antileukinate-treated Tg mice had significantly decreased pulmonary inflammation and oxidative stress compared to Antileukinate-treated WT mice (p < 0.05) or Antileukinate-non-treated Tg mice (p < 0.05).

Conclusion

Combined strategy of EC-SOD and neutrophil influx blockade may have a therapeutic benefit in protecting the lung against acute hyperoxic injury.

Synchronizing allelic effects of opposing quantitative trait loci confirmed a major epistatic interaction affecting acute lung injury survival in mice

Increased oxygen (O₂) levels help manage severely injured patients, but too much for too long can cause acute lung injury (ALI), acute respiratory distress syndrome (ARDS) and even death. In fact, continuous hyperoxia has become a prototype in rodents to mimic salient clinical and pathological characteristics of ALI/ARDS. To identify genes affecting hyperoxia-induced ALI (HALI), we previously established a mouse model of differential susceptibility. Genetic analysis of backcross and F₂ populations derived from sensitive (C57BL/6J; B) and resistant (129X1/SvJ; X1) inbred strains identified five quantitative trait loci (QTLs; Shali1-5) linked to HALI survival time. Interestingly, analysis of these recombinant populations supported opposite within-strain effects on survival for the two major-effect QTLs. Whereas Shali1 alleles imparted the expected survival time effects (i.e., X1 alleles increased HALI resistance and B alleles increased sensitivity), the allelic effects of Shali2 were reversed (i.e., X1 alleles increased HALI sensitivity and B alleles increased resistance). For in vivo validation of these inverse allelic effects, we constructed reciprocal congenic lines to synchronize the sensitivity or resistance alleles of Shali1 and Shali2 within the same strain. Specifically, B-derived Shali1 or Shali2 QTL regions were transferred to X1 mice and X1-derived QTL segments were transferred to B mice. Our previous QTL results predicted that substituting Shali1 B alleles onto the resistant X1 background would add sensitivity. Surprisingly, not only were these mice more sensitive than the resistant X1 strain, they were more sensitive than the sensitive B strain. In stark contrast, substituting the Shali2 interval from the sensitive B strain onto the X1 background markedly increased the survival time. Reciprocal congenic lines confirmed the opposing allelic effects of Shali1 and Shali2 on HALI survival time and provide unique models to identify their respective quantitative trait genes and to critically assess the apparent bidirectional epistatic interactions between these major-effect loci.

Inhaled neutrophil elastase inhibitor reduces oleic acid-induced acute lung injury in rats

RATIONALE

Neutrophil elastases (NE) play an important role in the pathogenesis of acute lung injury (ALI). NE activities are significantly increased in serums and lungs of patients or animals with ALI. Intravenous infusion (IV) of Sivelestat, an NE inhibitor, can reduce ALI. Through inhalation, drugs reach lungs directly and in high concentration. We hypothesized that inhaled Sivelestat would alleviate oleic acid (OA)-induced ALI in rats.

METHODS

Rats were anesthetized and mechanically ventilated, and then ALI was induced by OA injection. One hour later, the animals were randomized to receive either Sivelestat (3 mg/kg/h) or saline inhalation. The effect of Sivelestat IV (3 mg/kg/h) was also investigated. All animals were ventilated and observed for 6 h.

RESULTS

OA injection increased NE activities in lung tissues and serums. The increase of NE activities in lung tissues and serums markedly reduced by 77%, and 29%, respectively, by the inhalation of Sivelestat; and 53.8%, and 80%, respectively, by Sivelestat IV. Additionally, inhaled Sivelestat resulted in ameliorated lung injury by reducing edema and infiltration of neutrophils in the lung, improved oxygenation and survival.

CONCLUSIONS

An over increased NE activity in lungs may play a vital effect in the pathogenesis of OA-induced ALI in rats. Topical application of nebulized Sivelestat, an NE inhibitor, may reduce OA-induced ALI in rats. Sivelestat inhalation can be developed as a novel treatment for ALI.