Acute respiratory distress syndrome induction by pulmonary ischemia-reperfusion injury in large animal models

Effects of therapeutic hypercapnia on the expression and function of γδT cells in transplanted lungs in rats

OBJECTIVE

To investigate the effect of therapeutic hypercapnia on the expression and function of gamma delta T (γδ T) cells during ischemia-reperfusion injury (IRI) after lung transplantation.

METHODS

We randomly divided male Wistar rats into three groups (n = 6 in each group), the control group (group N), the IRI group (group I), and the therapeutic hypercapnia group (group H). We then assessed pulmonary edema, neutrophil infiltration, wet-to-dry (W/D) weight ratio, and microscopic histopathology and separately measured the levels of γδT cell surface antigen (TCR) and Interleukin-17 (IL-17) using flow cytometry and enzyme-linked immunosorbent assays (ELISAs).

RESULTS

The infiltration of neutrophils and the expression of TCR and IL-17 were significantly increased in the I group compared to the control, and the biopsy edema in group I was more severe. Arterial partial pressure of oxygen (PaO2) was decreased after reperfusion in group I compared with the control group. W/D weight ratio, neutrophil infiltration, and the expression of TCR and IL-17 decreased drastically in the H group compared to the I group.

CONCLUSION

Our findings suggest that γδ T lymphocytes were directly involved in lung injury. In addition, therapeutic hypercapnia effectively reduced the expression of γδ T cells and IL-17, and this has the potential to become a treatment strategy for IRI and an intervention to improve lung function.

Translational medicine for acute lung injury

Acute lung injury (ALI) is a complex disease with numerous causes. This review begins with a discussion of disease development from direct or indirect pulmonary insults, as well as varied pathogenesis. The heterogeneous nature of ALI is then elaborated upon, including its epidemiology, clinical manifestations, potential biomarkers, and genetic contributions. Although no medication is currently approved for this devastating illness, supportive care and pharmacological intervention for ALI treatment are summarized, followed by an assessment of the pathophysiological gap between human ALI and animal models. Lastly, current research progress on advanced nanomedicines for ALI therapeutics in preclinical and clinical settings is reviewed, demonstrating new opportunities towards developing an effective treatment for ALI.

Therapeutic benefits of nitric oxide in lung transplantation

Lung transplantation is an evolutionary procedure from its experimental origin in the twentieth century and is now recognized as an established and routine life-saving intervention for a variety of end-stage pulmonary diseases refractory to medical management. Despite the success and continuous refinement in lung transplantation techniques, the widespread application of this important life-saving intervention is severely hampered by poor allograft quality offered from donors-after-brain-death. This has necessitated the use of lung allografts from donors-after-cardiac-death (DCD) as an additional source to expand the pool of donor lungs. Remarkably, the lung exhibits unique properties that may make it ideally suitable for DCD lung transplantation. However, primary graft dysfunction (PGD), allograft rejection and other post-transplant complications arising from unavoidable ischemia-reperfusion injury (IRI) of transplanted lungs, increase morbidity and mortality of lung transplant recipients annually. In the light of this, nitric oxide (NO), a selective pulmonary vasodilator, has been identified as a suitable agent that attenuates lung IRI and prevents PGD when administered directly to lung donors prior to donor lung procurement, or to recipients during and after transplantation, or administered indirectly by supplementing lung preservation solutions. This review presents a historical account of clinical lung transplantation and discusses the lung as an ideal organ for DCD. Next, the author highlights IRI and its clinical effects in lung transplantation. Finally, the author discusses preservation solutions suitable for lung transplantation, and the protective effects and mechanisms of NO in experimental and clinical lung transplantation.

Bone Marrow Mesenchymal Stem Cell Exosomal miR-345-3p Ameliorates Cerebral Ischemia-reperfusion Injury by Targeting TRAF6

INTRODUCTION

The purpose of this study was to investigate the effects of bone marrow mesenchymal stem cells (BMSCs) exosomal miR-345-3p and tumor necrosis factor receptorassociated factor 6 (TRAF6) on cerebral ischemia reperfusion (CIR) injury. Exosomes (Exos) derived from BMSCs were isolated and identified. PC12 (rat pheochromocytoma) cells were used to establish an oxygen and glucose deprivation/reoxygenation (OGD/R) model.

METHODS

Cell counting kit-8, TUNEL staining, lactate dehydrogenase staining, RT-qPCR, and western blotting were utilized for analyzing the functions of miR-345-3p about PC12 cells. Dualluciferase reporter experiment was then to confirm the link between miR-345-3p and TRAF6. Finally, using male SD rats, the middle cerebral artery occlusion (MCAO) model was constructed. Regulation of I/R damage in MCAO rats of miR-345-3p and TRAF6 were further explored in the changes of modified neurological severity score, cerebral infarction pictures, relative infarct volume, and histopathological changes. After OGD/R treatment, neuronal apoptosis was dramatically increased. After treatment with exosomal miR-345-3p, OGD/R-induced neuroapoptosis was dramatically inhibited. Exosomal miR-345-3p inhibited OGD/R-induced neuroapoptosis by downregulating the expression of TRAF6. However, the miR-345-3p inhibitor aggravated the changes caused by OGD/R.

RESULTS

The corresponding regulations of miR-345-3p were reversed with TRAF6 overexpression. The animal experiments in vivo further verified that miR-345-3p ameliorated brain I/R injury in MCAO rats by targeting TRAF6.

CONCLUSION

This study found that BMSCs-exosomal miR-345-3p protected against CIR injury by decreasing TRAF6.

Mechanistic Understanding of Lung Inflammation: Recent Advances and Emerging Techniques

Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury characterized by an acute inflammatory response in the lung parenchyma. Hence, it is considered as the most appropriate clinical syndrome to study pathogenic mechanisms of lung inflammation. ARDS is associated with increased morbidity and mortality in the intensive care unit (ICU), while no effective pharmacological treatment exists. It is very important therefore to fully characterize the underlying pathobiology and the related mechanisms, in order to develop novel therapeutic approaches. In vivo and in vitro models are important pre-clinical tools in biological and medical research in the mechanistic and pathological understanding of the majority of diseases. In this review, we will present data from selected experimental models of lung injury/acute lung inflammation, which have been based on clinical disorders that can lead to the development of ARDS and related inflammatory lung processes in humans, including ventilation-induced lung injury (VILI), sepsis, ischemia/reperfusion, smoke, acid aspiration, radiation, transfusion-related acute lung injury (TRALI), influenza, Streptococcus (S.) pneumoniae and coronaviruses infection. Data from the corresponding clinical conditions will also be presented. The mechanisms related to lung inflammation that will be covered are oxidative stress, neutrophil extracellular traps, mitogen-activated protein kinase (MAPK) pathways, surfactant, and water and ion channels. Finally, we will present a brief overview of emerging techniques in the field of omics research that have been applied to ARDS research, encompassing genomics, transcriptomics, proteomics, and metabolomics, which may recognize factors to help stratify ICU patients at risk, predict their prognosis, and possibly, serve as more specific therapeutic targets.

Silymarin/curcumin loaded albumin nanoparticles coated by chitosan as muco-inhalable delivery system observing anti-inflammatory and anti COVID-19 characterizations in oleic acid triggered lung injury and in vitro COVID-19 experiment

Respiratory infected by COVID-19 represents a major global health problem at moment even after recovery from virus corona. Since, the lung lesions for infected patients are still sufferings from acute respiratory distress syndrome including alveolar septal edema, pneumonia, hyperplasia, and hyaline membranes Therefore, there is an urgent need to identify additional candidates having ability to overcome inflammatory process and can enhance efficacy in the treatment of COVID-19. The polypenolic extracts were integrated into moeties of bovine serum albumin (BSA) and then were coated by chitosan as a mucoadhesion polymer. The results of interleukin-6, and c-reactive protein showed significant reduction in group treated by Encap. SIL + CUR (64 ± 0.8 Pg/μL & 6 ± 0.5 μg/μL) compared to group treated by Cham. + CUR (102 ± 0.8 Pg/μL & 7 ± 0.5 μg/μL) respectively and free capsules (with no any drug inside) (148 ± 0.6 Pg/μL & 10 ± 0.6 μg/μL) respectively. Histopathology profile was improved completely. Additionally, encapsulating silymarin showed anti-viral activity in vitro COVID-19 experiment. It can be summarized that muco-inhalable delivery system (MIDS) loaded by silymarin can be used to overcome inflammation induced by oleic acid and to overcome COVID-19.

Bone marrow mesenchymal stem cells-derived exosomal microRNA-124-3p attenuates hypoxic-ischemic brain damage through depressing tumor necrosis factor receptor associated factor 6 in newborn rats

Mesenchymal stem cells (MSCs)-derived exosomes (Exo) are beneficial in the use of brain damages. Restrictively, the mechanism of Exo expressing miR-124-3p in hypoxic-ischemic brain damage (HIBD) is not completely comprehended. Thereupon, this work was put forward to reveal the action of bone marrow MSCs-derived Exo (BMSCs-Exo) expressing miR-124-3p in the illness. BMSCs were isolated and transfected with miR-124-3p agomir. Then, BMSCs-Exo were extracted and identified. The newborn HIBD rats were injected with miR-124-3p-modified BMSCs-Exo or tumor necrosis factor receptor associated factor 6 (TRAF6)-related vectors. Next, neurological functions, neuron pathological and structural damages, oxidative stress and neuronal apoptosis were observed. miR-124-3p and TRAF6 expression was tested, along with their targeting relationship. miR-124-3p was down-regulated, and TRAF6 was up-regulated in newborn HIBD rats. miR-124-3p targeted TRAF6. BMSCs-Exo improved neurological functions, alleviated neuron pathological and structural damages, suppressed oxidative stress and reduced neuronal apoptosis in newborn HIBD rats, whereas BMSCs-Exo-mediated effects were enhanced by restoring miR-124-3p. Silencing TRAF6 attenuated HIBD in newborn rats, but overexpression of TRAF6 reversed the protective role of miR-124-3p-overexpressing BMSCs-Exo. This work makes it comprehensive that up-regulated exosomal miR-124-3p ameliorates HIBD in newborn rats by targeting TRAF6, which replenishes the potential agents for curing HIBD.

Exosomal microRNA-150-5p from bone marrow mesenchymal stromal cells mitigates cerebral ischemia/reperfusion injury via targeting toll-like receptor 5

MicroRNA (miR)-150-5p has been investigated in many studies, while the role of exosomal miR-150-5p from bone arrow mesenchymal stromal cells (BMSCs) on cerebral ischemia/reperfusion (I/R) injury is not fully explored. This research aims to probe the effects of exosomal miR-150-5p from BMSCs on cerebral I/R injury via regulating B-cell translocation gene 2 (TLR5). Bone marrow mesenchymal stem cell-derived exosomes (BMSCs-Exo) were isolated and identified. The middle cerebral artery occlusion (MCAO) rat model was established and treated by BMSCs-Exo. Then, functional assays were conducted to explore neurological function, pathological changes, neuron apoptosis and inflammatory factors in MCAO rats. miR-150-5p and TLR5 expression in rat brain tissues were detected. Then, gain and loss-function assays were conducted to determine the impact of exosomes, miR-150-5p and TLR5 on neurological function, pathological changes, neuron apoptosis and inflammatory factors of MCAO rats. The binding relation between miR-150-5p and TLR5 was validated. It was found that miR-150-5p expression was decreased while TLR5 level was augmented in MCAO rats. BMSCs-Exo could improve neurological function, pathological changes, decelerate neuron apoptosis and reduce inflammatory factors in MCAO rats. Enriched miR-150-5pcould enhance the protective effects of BMSCs-Exo on cerebral I/R injury. The elevated TLR5 reversed the impacts of elevated exosomal miR-150-5p on cerebral I/R injury. TLR5 was targeted by miR-150-5p. This research manifested that exosomal miR-150-5p from BMSCs exerts protective effects on cerebral I/R injury via repressing TLR5. This study provided novel therapeutic targets for the treatment of cerebral I/R injury.

Effects of remifentanil and propofol on distant organ lung injury in an ischemia-reperfusion model

Our aim was to evaluate lung injury due to oxidative stress and antioxidant activity levels in an infrarenal ischemia-reperfusion model and to compare prevention effects of single and combined use of propofol and remifentanil. In this study, a total of 40 adult Wistar Albino rats were randomly divided into five groups of eight rats as SHAM, physiological saline, intraperitoneal propofol, remifentanil, and propofol and remifentanil groups. Blood and tissue samples were obtained after 80 min of reperfusion. The malondialdehyde (MDA) level, a measure of lipid peroxidation, was measured in lung tissue samples and red blood cells; additionally, total oxidant status and total antioxidant capacity of lung tissues were measured and histopathological examination was performed. Distant organ (lung) injury developed due to lower extremity ischemia-reperfusion was created by infrarenal aortic clamping. The lipid peroxidation product MDA and total oxidant levels were increased, but there was insufficient antioxidant protection both in the lung tissues and red blood cells. While propofol prevented this injury consistent with its proposed antioxidant properties; no protective effect of remifentanil was observed. On the contrary, it showed oxidative stress increasing effect. This study concluded that the antioxidant effect of propofol was suppressed by remifentanil in the case of combined use.

Dexmedetomidine preconditioning ameliorates lung injury induced by pulmonary ischemia/reperfusion by upregulating promoter histone H3K4me3 modification of KGF-2

Keratinocyte growth factor (KGF)-2 has been highlighted to play a significant role in maintaining the endothelial barrier integrity in lung injury induced by ischemia-reperfusion (I/R). However, the underlying mechanism remains largely unknown. The aims of this study were to determine whether dexmedetomidine preconditioning (DexP) modulates pulmonary I/R-induced lung injury through the alteration in KGF-2 expression. In our I/R-modeled mice, DexP significantly inhibited pathological injury, inflammatory response, and inflammatory cell infiltration, while promoted endothelial barrier integrity and KGF-2 promoter activity in lung tissues. Bioinformatics prediction and ChIP-seq revealed that I/R significantly diminished the level of H3K4me3 modification in the KGF-2 promoter, which was significantly reversed by DexP. Moreover, DexP inhibited the expression of histone demethylase JMJD3, which in turn promoted the expression of KGF-2. In addition, overexpression of JMJD3 weakened the protective effect of DexP on lung injury in mice with I/R. Collectively, the present results demonstrated that DexP ameliorates endothelial barrier dysfunction via the JMJD3/KGF-2 axis.

Ischemia-Reperfusion Injury in Lung Transplantation

Lung transplantation has been established worldwide as the last treatment for end-stage respiratory failure. However, ischemia–reperfusion injury (IRI) inevitably occurs after lung transplantation. The most severe form of IRI leads to primary graft failure, which is an important cause of morbidity and mortality after lung transplantation. IRI may also induce rejection, which is the main cause of mortality in recipients. Despite advances in donor management and graft preservation, most donor grafts are still unsuitable for transplantation. Although the pulmonary endothelium is the primary target site of IRI, the pathophysiology of lung IRI remains incompletely understood. It is essential to understand the mechanism of pulmonary IRI to improve the outcomes of lung transplantation. Therefore, we reviewed the state-of-the-art in the management of pulmonary IRI after lung transplantation. Recently, the ex vivo lung perfusion (EVLP) system has been clinically introduced worldwide. Various promising therapeutic strategies for the protection of the endothelium against IRI, including EVLP, inhalation therapy with therapeutic gases and substances, fibrinolytic treatment, and mesenchymal stromal cell therapy, are awaiting clinical application. We herein review the latest advances in the field of pulmonary IRI in lung transplantation.

microRNA-223 promotes autophagy to aggravate lung ischemia-reperfusion injury by inhibiting the expression of transcription factor HIF2α

Lung ischemia-reperfusion (I/R) injury severely endangers human health, and recent studies have suggested that certain microRNAs (miRNAs) play important roles in this pathological phenomenon. The current study aimed to ascertain the ability of miR-223 to influence lung I/R injury by targeting hypoxia-inducible factor-2α (HIF2α). First, mouse models of lung I/R injury were established: during surgical procedures, pulmonary arteries and veins and unilateral pulmonary portal vessels were blocked and resuming bilateral pulmonary ventilation, followed by restoration of bipulmonary ventilation. In addition, a lung I/R injury cell model was constructed by exposure to hypoxic reoxygenation (H/R) in mouse pulmonary microvascular endothelial cells (PMVECs). Expression of miR-223, HIF2α and β-catenin in tissues or cells was determined by RT-qPCR and Western blot analysis. Correlation between miR-223 and HIF2α was analyzed by dual luciferase reporter gene assay. Further, lung tissue injury and mouse PMVEC apoptosis was evaluated by HE, TUNEL staining and flow cytometry. Autophagosomes in cells were detected by light chain3 immunofluorescence assay. miR-223 was expressed at a high level while HIF2α/β-catenin was downregulated in tissues and cells with lung I/R injury. Further, miR-223 targeted and repressed HIF2α expression to downregulate β-catenin expression. The miR-223/HIF2α/β-catenin axis aggravated H/R injury in mouse PMVECs and lung I/R injury in mice by enhancing autophagy. Taken together, miR-223 inhibits HIF2α to repress β-catenin, thus contributing to autophagy to complicate lung I/R injury. These findings provide a promising therapeutic target for treating lung I/R injury.

Pulmonary protection of transcutaneous electrical acupoint stimulation in gynecological laparoscopic surgery: A randomized controlled trial

Laparoscopy is performed worldwide due to its limited side effects and optimal treatment efficacy. However, it also has adverse effects, including atelectasis and ischemia-reperfusion injury, due to CO₂ accumulation during ventilation in a head-down position, which may result in severe disorders and adversely affecting postoperative recovery, prolonging hospitalization. The present study was performed to assess whether transcutaneous electrical acupoint stimulation (TEAS) protects against lung injury occurring during gynecological laparoscopic surgery. Patients were randomly allocated to two groups: Control group (received no stimulation) and TEAS group (patients treated with TEAS on BL13, LI4 and LU5). The mean arterial pressure, heart rate and oxygen saturation were recorded at the time-points of arriving in the operating room (T₀), immediately prior to induction of the pneumoperitoneum (T₁), immediately after the end of pneumoperitoneum (T₂) and on leaving the operating room (T₃). Arterial blood gas analysis was performed to record the pH, determine the partial pressure of carbon dioxide and calculate the oxygenation index (OI) at T_0–3. Blood samples were taken from the peripheral vein for determination of the serum concentrations of tumor necrosis factor (TNF)-α and interleukin (IL)-1β at T₀ and T₃. Post-operative pulmonary complications occurring during the first five days after surgery were also recorded. A total of 100 patients were initially enrolled and 80 patients were analysed. The results indicated that the OI in the control group was significantly lower than that in the TEAS group at the T₂ and T₃ time-points. The serum concentrations of TNF-α and IL-1β were significantly increased following surgery, while the extent of these increases was lower in the TEAS group compared with that in the control group. The incidence of post-operative pulmonary complications was significantly lower in the TEAS group. It was therefore indicated that TEAS protect against lung injury as a complication of gynecological laparoscopic surgery. The present study was registered at http://www.clinicaltrials.gov prior to enrollment of the patients (no. NCT02850471).

Orally delivered resveratrol-loaded lipid-core nanocapsules ameliorate LPS-induced acute lung injury via the ERK and PI3K/Akt pathways

Background

Resveratrol (RSV) has attracted interest as an alternative drug for the treatment of acute lung injury (ALI) and other pulmonary diseases, but its poor oral bioavailability is a limitation. In this study, we employed drug delivery nanotechnology to improve the stability, lung localization and efficacy of orally administered resveratrol to control lung damage leading to ALI.

Methods and materials

RSV-loaded lipid-core nanocapsules (RSV-LNCs), prepared by interfacial deposition of biodegradable polymers, were given orally to A/J mice prior to lipopolysaccharide (LPS) intranasal instillation. Inflammatory changes, oxidative stress and lung tissue elastance were assessed 24 h after LPS challenge.

Results

RSV-LNCs (5 mg/kg), given 1, 4, 6 or 12 h but not 24 h before provocation, inhibited LPS-induced leukocyte accumulation in the bronchoalveolar fluid (BALF), whereas unloaded nanocapsules (ULNCs) or free RSV (5 mg/kg) were ineffective. RSV-LNCs (2.5–10 mg/kg) but not ULNCs or RSV improved lung function and prevented total leukocyte and neutrophil accumulation equally in both BALF and lung tissue when given 4 h before LPS challenge. Similar findings were seen concerning the generation of a range of pro-inflammatory cytokines such as IL-6, KC, MIP-1α, MIP-2, MCP-1 and RANTES in lung tissue. In addition, only RSV-LNCs inhibited MDA levels and SOD activity in parallel with blockade of the ERK and PI3K/Akt pathways following LPS provocation.

Conclusion

Nanoformulation of RSV in biodegradable oil-core polymers is an effective strategy to improve the anti-ALI activity of RSV, suggesting that the modified-release formulation of this plant polyphenol may be of great value in clinical conditions associated with ALI and respiratory failure.

The Nox1/Nox4 inhibitor attenuates acute lung injury induced by ischemia-reperfusion in mice

Lung ischemia and reperfusion injury (LIRI) were mediated by several processes including over-production of reactive oxygen species (ROS) and inflammatory activation. ROS generated by nicotinamide adenine dinucletide phosphate (NADPH) oxidase (Nox) may play a pivotal role in pathophysiological changes in a range of disease. However, it was poorly understood in LIRI. Thus, the purpose of our study was to explore whether GKT137831, as a special dual inhibitor of Nox1 and 4, could alleviate LIRI in mice model and explore the minimal dose. According to the protocol, this study was divided into two parts. The first part was to determine the minimal dose of Nox1/4 inhibitor in attenuating LIRI via histopathology and apoptosis analysis. Eighteen C57BL/6J male wild-type mice were randomly divided in to sham, 2.5Nox+sham, 5.0Nox+sham, IR, 2.5Nox+IR and 5.0Nox+IR groups. According to the different group, mice were pretreated with corresponding dose of Nox1/4 inhibitors or normal saline. After LIRI, the results showed 5.0mg/kg Nox1/4 inhibitor could be considered as the minimal dose to alleviate injury by decreasing of lung injury score and the number of TUNEL-positive cells. The second part was to further verify the benefit of 5.0mg/kg Nox1/4 inhibitor in lung protective effects. Thirty-seven C57BL/6J male wild-type mice were divided in to sham, IR and 5.0Nox+IR groups randomly. The results showed that expressions of inflammatory, autophagy cytokines were markedly elevated and PH value was declined after LIRI. However, 5.0 mg/kg Nox1/4 inhibitor significantly attenuated cytokine production as reflected by immunohistochemistry, western blotting and Q-PCR analysis. In conclusion, our findings suggested that 5.0mg/kg Nox1/4 inhibitor contributed to protect lung tissue damage after LIRI via the suppression of inflammatory and autophagy activation.

Lazaroid (U-74389G) ameliorates lung injury due to lipid peroxidation and nitric oxide synthase-dependent reactive oxygen species generation caused by remote systematic ischemia-reperfusion following thoracoabdominal aortic occlusion

INTRODUCTION

Lung ischemia-reperfusion injury after thoracoabdominal aortic occlusion represents a major complication, which increases morbidity and mortality. In the present study we hypothesized that lazaroid U-74389G intravenous administration protects from lung ischemia-reperfusion injury through lipid peroxidation inhibition.

MATERIALS AND METHODS

A total of 24 pigs were randomized in three groups. Group I (n = 8) underwent sham operation, group II (n = 8) underwent thoracoabdominal aortic occlusion for 45min and received placebo and group III (n = 8) received 3 doses of lazaroid (3 mg/kg) 60 and 30min before thoracoabdominal aortic occlusion and at 30min during thoracoabdominal aortic occlusion (duration 45min). Aortic occlusion was performed with aortic balloon-catheters under fluoroscopic guidance. All animals were sacrificed at the 7 t h postoperative day and lung specimens were harvested for molecular analysis.

RESULTS

mRNA levels of leukotrienes LB4 (LTB4R2), LC4 (LTC4S) and nitric oxide synthase (NOS) isoforms including iNOS, nNOS and eNOS were determined with real-time RT-qPCR. Nitric oxide can either induce (iNOS) or inhibit (nNOS and eNOS) lipid peroxidation based on its specific isoform origin. Group III showed significantly reduced mRNA levels of LTB4R2 (-63.7%), LTC4S (-35.9%) and iNOS (-60.2%) when compared with group II (P < 0.05, for all). The mRNA levels of nNOS was significantly increased (+37.4%), while eNOS was slightly increased (+2.1%) in group III when compared with group II (P < 0.05 and P = 0.467 respectively).

CONCLUSION

Lazaroid U-74389G may represent an effective pharmacologic intervention in reducing lung ischemia-reperfusion injury following thoracoabdominal aortic occlusion.

Protective mechanism of sulforaphane in Nrf2 and anti-lung injury in ARDS rabbits

The effect of sulforaphane on nuclear factor erythroid 2-related factor 2 (Nrf2) and its protective mechanism for lung injury in rabbits with acute respiratory distress syndrome (ARDS) were investigated. Thirty rabbits were randomly divided into control (n=10), model (n=10) and experimental groups (n=10). Rabbits in model group and experimental group were treated with femoral venous injection of oleic acid to establish the ARDS model, while those in control group were injected with the same volume of normal saline. The experimental group received intravenous injection of sulforaphane. Twelve hours after modeling, the clinical manifestations and deaths of rabbits in each group were recorded and compared, including blood gas indexes, lung index (LI), alveolar damage coefficient, serum Nrf2 expression, as well as messenger ribonucleic acid (mRNA) and protein expression of Nrf2 in lung tissues. Pink frothy sputum and death were observed in rabbits in model group and experimental group, but the number of such cases in experimental group was smaller than that in the model group (p<0.05). Compared with those in control group, LI and IQA in model group and experimental group were increased, but LI and IQA in the experimental group were significantly decreased compared with those in the model group. Compared with those in the model group, the blood gas indexes (PaO₂, PaCO₂ and SaO₂) in the experimental group were significantly increased (p<0.05). Nrf2 in serum and lung tissues of rabbits in experimental group was significantly increased compared with that in model group (p<0.05). Sulforaphane significantly inhibits ARDS in rabbits and plays a protective role in ARDS through upregulating Nrf2.

Oxidative and nitrosative stress during pulmonary ischemia-reperfusion injury: from the lab to the OR

Oxidative and nitrosative stress are an umbrella term for pathophysiological processes that involve free radical generation during inflammation. In this review, the involvement of reactive oxygen and nitrogen species is evaluated during lung ischemia-reperfusion injury (LIRI) from a surgical point of view. The main biochemical and cellular mechanisms behind free radical generation are discussed, together with surgical procedures that may cause reperfusion injury. Finally, different therapeutic strategies are further explored. A literature search was performed, searching for "lung ischemia reperfusion injury", "reperfusion injury", "large animal model" and different search terms for each section: "surgery", "treatment", "cellular mechanism", or "enzyme". Although reperfusion injury is not an uncommon entity and there is a lot of evidence concerning myocardial ischemia-reperfusion injury, in the lung this phenomenon is less extensively described and studies in large animals are not easy to come by. With increasing number of patients on waiting lists for lung transplant, awareness for this entity should all but rise.

Sulforaphane exerts anti-inflammatory effects against lipopolysaccharide-induced acute lung injury in mice through the Nrf2/ARE pathway

Sulforaphane (1-isothiocyanate-4-methyl sulfonyl butane) is a plant extract (obtained from cruciferous vegetables, such as broccoli and cabbage) and is known to exert anticancer, antioxidant and anti-inflammatory effects. It stimulates the generation of human or animal cells, which is beneficial to the body. The aim of the current study was to determine whether sulforaphane protects against lipopolysaccharide (LPS)‑induced acute lung injury (ALI) through its anti-inflammatory effects, and to investigate the signaling pathways involved. For this purpose, male BALB/c mice were treated with sulforaphane (50 mg/kg) and 3 days later, ALI was induced by the administration of LPS (5 mg/kg) and we thus established the model of ALI. Our results revealed that sulforaphane significantly decreased lactate dehydrogenase (LDH) activity (as shown by LDH assay), the wet-to-dry ratio of the lungs and the serum levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) (measured by ELISA), as well as nuclear factor-κB protein expression in mice with LPS-induced ALI. Moreover, treatment with sulforaphane significantly inhibited prostaglandin E2 (PGE2) production, and cyclooxygenase-2 (COX-2), matrix metalloproteinase-9 (MMP-9) protein expression (as shown by western blot analysis), as well as inducible nitric oxide synthase (iNOS) activity in mice with LPS-induced ALI. Lastly, we noted that pre-treatment with sulforaphane activated the nuclear factor-E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway in the mice with LPS-induced ALI. These findings demonstrate that sulforaphane exerts protective effects against LPS-induced ALI through the Nrf2/ARE pathway. Thus, sulforaphane may be a potential a candidate for use in the treatment of ALI.

Mouse Models of Acute Respiratory Distress Syndrome: A Review of Analytical Approaches, Pathologic Features, and Common Measurements

Acute respiratory distress syndrome (ARDS) is a severe pulmonary reaction requiring hospitalization, which is incited by many causes, including bacterial and viral pneumonia as well as near drowning, aspiration of gastric contents, pancreatitis, intravenous drug use, and abdominal trauma. In humans, ARDS is very well defined by a list of clinical parameters. However, until recently no consensus was available regarding the criteria of ARDS that should be evident in an experimental animal model. This lack was rectified by a 2011 workshop report by the American Thoracic Society, which defined the main features proposed to delineate the presence of ARDS in laboratory animals. These should include histological changes in parenchymal tissue, altered integrity of the alveolar capillary barrier, inflammation, and abnormal pulmonary function. Murine ARDS models typically are defined by such features as pulmonary edema and leukocyte infiltration in cytological preparations of bronchoalveolar lavage fluid and/or lung sections. Common pathophysiological indicators of ARDS in mice include impaired pulmonary gas exchange and histological evidence of inflammatory infiltrates into the lung. Thus, morphological endpoints remain a vital component of data sets assembled from animal ARDS models.

Pathophysiological Approaches of Acute Respiratory Distress syndrome: Novel Bases for Study of Lung Injury

Experimental approaches have been implemented to research the lung damage related-mechanism. These models show in animals pathophysiological events for acute respiratory distress syndrome (ARDS), such as neutrophil activation, reactive oxygen species burst, pulmonary vascular hypertension, exudative edema, and other events associated with organ dysfunction. Moreover, these approaches have not reproduced the clinical features of lung damage. Lung inflammation is a relevant event in the develop of ARDS as component of the host immune response to various stimuli, such as cytokines, antigens and endotoxins. In patients surviving at the local inflammatory states, transition from injury to resolution is an active mechanism regulated by the immuno-inflammatory signaling pathways. Indeed, inflammatory process is regulated by the dynamics of cell populations that migrate to the lung, such as neutrophils and on the other hand, the role of the modulation of transcription factors and reactive oxygen species (ROS) sources, such as nuclear factor kappaB and NADPH oxidase. These experimental animal models reproduce key components of the injury and resolution phases of human ALI/ARDS and provide a methodology to explore mechanisms and potential new therapies.

Applying Biotechnology and Bioengineering to Pediatric Lung Disease: Emerging Paradigms and Platforms

Pediatric lung diseases remain a costly worldwide health burden. For many children with end-stage lung disease, lung transplantation remains the only therapeutic option. Due to the limited number of lungs available for transplantation, alternatives to lung transplant are desperately needed. Recently, major improvements in tissue engineering have resulted in newer technology and methodology to develop viable bioengineered lungs. These include critical advances in lung cell biology, stem cell biology, lung extracellular matrix, microfabrication techniques, and orthotopic transplantation of bioartificial lungs. The goal of this short review is to engage the reader's interest with regard to these emerging concepts and to stimulate their interest to learn more. We review the existing state of the art of lung tissue engineering, and point to emerging paradigms and platforms in the field. Finally, we summarize the challenges and unmet needs that remain to be overcome.