Attenuation Of Acute Lung Injury Research Articles

Budesonide and N-acetylcysteine inhibit activation of the NLRP3 inflammasome by regulating miR-381 to alleviate acute lung injury caused by the pyroptosis-mediated inflammatory response.

The anti-inflammatory effects of budesonide (BUN) and N-acetylcysteine (NAC) attenuate acute lung injury (ALI). The aim of this study was to investigate the effects of combination therapy consisting of BUN and NAC on ALI and the underlying mechanisms. In vitro and in vivo models of ALI were generated by LPS induction. Western blotting was used to detect the expression levels of pyroptosis-related proteins and inflammation-related factors, and RT-qPCR was used to detect the expression of miR-381. Cell proliferation and apoptosis were detected by CCK-8 and flow cytometry, respectively. ELISA was used to detect the levels of inflammation-related factors. HE staining was used to detect lung injury. The results showed that LPS effectively induced pyroptosis in cells and promoted the expression of pyroptosis-related proteins (Caspase1, Gasdermin D and NLRP3) and inflammatory cytokines (TNF-α, IL-6 and IL-1β). The combination of BUN and NAC significantly alleviated LPS-induced pyroptosis and inflammation. In addition, the combination of BUN and NAC effectively promoted miR-381 expression. Transfection of miR-381 mimics effectively alleviated LPS-induced pyroptosis and inflammation, while transfection of miR-381 inhibitors had the opposite effect. miR-381 negatively regulates NLRP3 expression. Treatment with a miR-381 inhibitor or pc-NLRP3 reversed the effects of the combination of BUN and NAC. In a mouse model of ALI, the combination of BUN and NAC effectively improved lung injury, while treatment with a miR-381 inhibitor or pc-NLRP3 effectively reversed this effect. Overall, this study revealed that BUN+NAC inhibits the activation of NLRP3 by regulating miR-381, thereby alleviating ALI caused by pyroptosis-mediated inflammation.

Stellate Ganglion Block Attenuates LPS-Induced Acute Lung Injury by Activating Sirt3 Regulation of Oxidative Stress and Inflammation.

Stellate ganglion blocks (SGBs) has been applied in clinics to alleviate pain-related syndromes for almost a century. In recent years, it has been reported that SGB can attenuate acute lung injury (ALI) in animals. However, the details of these molecular mechanisms remain complex and unclear. In this study, rats were randomly divided into four groups: group C (receiving no treatment), group NS (receiving the intratracheal instillation of normal saline), group L (receiving the intratracheal instillation of LPS) and group LS (receiving SGB after the intratracheal instillation of LPS). The pathological damage of lung tissue, arterial blood gases, the differentiation of alveolar macrophages (AMs) and inflammatory cytokines (IL-1β, IL-6, IL-10) were detected. Furthermore, the oxidative stress indexes (ROS, CYP-D, T-SOD, Mn-SOD and CAT) in serum and the levels of Sirt3 signaling-associated proteins (JAK2/STAT3, NF-κb p65, CIRP and NLRP3) in the lungs were measured. The results revealed that SGB could attenuate lung tissue damage, improve pulmonary oxygenation, promote the differentiation of AMs to the M2 phenotype, decrease the secretion of IL-1β and IL-6, and increase the secretion of IL-10. Meanwhile, SGB was found to inhibit the production of ROS and CYP-D, and enhance the activities of T-SOD, Mn-SOD and CAT. Furthermore, SGB upregulated Sirt3 and downregulated JAK2/STAT3 and NF-κb p65 phosphorylation, CIRP and NLRP3. Our work revealed that SGB could attenuate LPS-induced ALI by activating the Sirt3-mediated regulation of oxidative stress and pulmonary inflammation; this may shed new light upon the protection of SGB and provide a novel prophylactic strategy for LPS-induced ALI.

Pyruvate Kinase M2 Nuclear Translocation Regulate Ferroptosis-Associated Acute Lung Injury in Cytokine Storm

Cytokine storm (CS) is linked with macrophage dysfunction and acute lung injury (ALI), which can lead to patient mortality. Glycolysis is preferentially exploited by the pro-inflammatory macrophages, in which pyruvate kinase M2 (PKM2) is a critical enzyme. The mechanism underlying the link between CS and ALI involves cell death, with the recently discovered programmed cell death known as ferroptosis being involved. However, the relationship between the glycolysis and ferroptosis in the context of CS-related ALI remains unclear. CS-associated ALI induced by poly I:C (10 mg/kg, i.v) and LPS (5 mg/kg, i.p) (IC: LPS) exhibit significant ferroptosis. Ferrostatin-1 (ferroptosis inhibitor) treatment attenuated IC:LPS‑induced mortality and lung injury. Moreover, Alveolar macrophage (AM) from IC:LPS model exhibited enhanced glycolysis and PKM2 translocation. The administration of ML-265(PKM2 monomer/dimer inhibitor) resulted in the formation of a highly active tetrameric PKM2, leading to improved survival and attenuation of ALI. Furthermore, ML-265 treatment decreased ferroptosis and restored the balance between anaerobic glycolysis and oxidative phosphorylation. Notably, in patients with lung infection, intracellular expression level of PKM2 were correlated with circulating inflammation. Enhanced ferroptosis and PKM2 nuclear translocation was noticed in CD14+ blood monocytes of lung infection patients with CS. In conclusion, PKM2 is a key regulatory node integrating metabolic reprograming with intra-nuclear function for the regulation of ferroptosis. Targeting PKM2 could be explored as a potential means in the future to prevent or alleviate hyper-inflammatory state or cytokines storm syndrome with aberrant ferroptotic cell death.

Cannabinoids Receptors in COVID-19: Perpetrators and Victims.

COVID-19 is caused by SARS-CoV-2 and leads to acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and extrapulmonary manifestations in severely affected cases. However, most of the affected cases are mild or asymptomatic. Cannabinoids (CBs) such as tetrahydrocannabinol (THC) and cannabidiol (CBD), which act on G-protein-coupled receptors called CB1 and CB2, have anti-inflammatory effects. Many published studies show that CBs are effective in various inflammatory disorders, viral infections, and attenuation of ALI and ARDS. Therefore, the present narrative review aimed to summarize the possible immunological role of CBs in COVID-19. The effects of CBs are controversial, although they have beneficial effects via CB2 receptors and adverse effects via CB1 receptors against ALI, ARDS, and hyperinflammation, which are hallmarks of COVID-19. The present narrative review has shown that CBs effectively manage ALI and ARDS by suppressing pro-inflammatory cytokines, which are common in COVID-19. Therefore, CBs may be used to manage COVID-19 because of their potent anti-inflammatory effects, suppressing pro-inflammatory cytokines and inhibiting inflammatory signaling pathways.

The Substitution of Fifty Percent of Combustible Tobacco Smoke Exposure With Either Electronic Cigarettes or Heated tobacco Products Did Not Attenuate Acute Lung Injury in an Animal Model.

To reduce the harmful health effects of combustible cigarette smoke (CS), some (CS) users attempt to substitute CS with electronic cigarettes (ECIG) and/or heated tobacco products (HTP). In this animal study, we evaluated the acute effects of substituting CS consumption with ECIG or HTP thus mimicking the dual users' approach, on the lungs of a mouse model. C57BL/6 mice were divided into Control, ECIG, HTP, CS, ECIG + CS, HTP + CS, and HTP + ECIG groups. Animals were exposed for 3 hours in AM and PM sessions to either air, CS, ECIG, or HTP for seven days. Lung injury was assessed by: wet to dry (W/D) ratio, albumin concentration in bronchoalveolar lavage fluid, expression of IL-1β, IL-6, and TNF-α, histopathology examination, reactive oxygen species (ROS) production, and assessment of cellular apoptosis. W/D ratio was significantly increased in mice exposed to CS only. Albumin leak and expression of IL-1β, IL-6, and TNF-a were elevated in CS, ECIG + CS, and HTP + CS. Histological examination revealed significant inflammatory cells infiltration, as well as collagen deposit in CS, ECIG + CS, HTP + CS. ROS production was significantly increased in CS, ECIG + CS, HTP + CS. Finally, cell death was also significantly increased in CS, ECIG + CS, and HTP + CS. In this animal model, substituting 50% of daily CS exposure by either ECIG or HTP exposure did not result in significant attenuation of acute lung injury.

Local Delivery of Azithromycin Nanoformulation Attenuated Acute Lung Injury in Mice.

Humanity has suffered from the coronavirus disease 2019 (COVID-19) pandemic over the past two years, which has left behind millions of deaths. Azithromycin (AZ), an antibiotic used for the treatment of several bacterial infections, has shown antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as against the dengue, Zika, Ebola, and influenza viruses. Additionally, AZ has shown beneficial effects in non-infective diseases such as cystic fibrosis and bronchiectasis. However, the systemic use of AZ in several diseases showed low efficacy and potential cardiac toxicity. The application of nanotechnology to formulate a lung delivery system of AZ could prove to be one of the solutions to overcome these drawbacks. Therefore, we aimed to evaluate the attenuation of acute lung injury in mice via the local delivery of an AZ nanoformulation. The hot emulsification-ultrasonication method was used to prepare nanostructured lipid carrier of AZ (AZ-NLC) pulmonary delivery systems. The developed formulation was evaluated and characterized in vitro and in vivo. The efficacy of the prepared formulation was tested in the bleomycin (BLM) -mice model for acute lung injury. AZ-NLC was given by the intratracheal (IT) route for 6 days at a dose of about one-eighth oral dose of AZ suspension. Samples of lung tissues were taken at the end of the experiment for immunological and histological assessments. AZ-NLC showed an average particle size of 453 nm, polydispersity index of 0.228 ± 0.07, zeta potential of -30 ± 0.21 mV, and a sustained release pattern after the initial 50% drug release within the first 2 h. BLM successfully induced a marked increase in pro-inflammatory markers and also induced histological changes in pulmonary tissues. All these alterations were significantly reversed by the concomitant administration of AZ-NLC (IT). Pulmonary delivery of AZ-NLC offered delivery of the drug locally to lung tissues. Its attenuation of lung tissue inflammation and histological injury induced by bleomycin was likely through the downregulation of the p53 gene and the modulation of Bcl-2 expression. This novel strategy could eventually improve the effectiveness and diminish the adverse drug reactions of AZ. Lung delivery could be a promising treatment for acute lung injury regardless of its cause. However, further work is needed to explore the stability of the formulation, its pharmacokinetics, and its safety.

23-O-acetylshengmanol-3-O-α-L-arabinoside alleviates lipopolysaccharide-induced acute lung injury through inhibiting IκB/NF-κB and MAPK/AP-1 signaling pathways

Ethnopharmacological relevanceCimicifuga foetida L. is a well-established traditional Chinese medicine with heat-clearing and detoxifying effects and has good therapeutic effect on oral mucosal ulcer and pharyngitis. The rhizome of this herb is rich in triterpenoid glycosides, including 23-O-acetylshengmanol-3-o-α-L-arabinoside (DA). Aim of the studyWhether and how DA attenuates acute lung injury (ALI) are unclear. Accordingly, we focused on its anti-inflammatory effects and underlying molecular mechanisms in lipopolysaccharide (LPS)-stimulated ALI mice and RAW264.7 cells. Materials and methodsThe model of ALI mice was established by exposed intratracheal instillation of LPS. Lung pathological changes were evaluated by hematoxylin and eosin staining. Pulmonary function was assessed by whole-body plethysmography. Total protein content in bronchoalveolar lavage fluid (BALF) was detected by bicinchoninic acid method. Wet/dry lung ratio was used to evaluate the degree of pulmonary edema in mice. The levels of pro-inflammatory mediators were measured using enzyme-linked immunosorbent assay. The relative expression of pro-inflammatory gene mRNA was examined by RT-qPCR. The expression of inflammatory-related proteins was detected by Western blot. RAW264.7 cells were used to test the anti-inflammatory effects of DA in vitro. Cytotoxicity was assessed using a MTT assay. Nitric oxide production was measured by Griess assay. The production and expression of inflammatory mediators and the protein levels of inflammatory signaling molecules in the NF-κB and MAPK pathways were measured. Furthermore, immunofluorescence staining was used to analyze the expression of p-IκBα, p-ERK, and p-p38 in lung macrophages and the nuclear translocation of NF-κB p65 and AP-1 in cells. ResultsDA evidently alleviated histopathological changes and ameliorated pulmonary edema. Moreover, DA could reduce excessive inflammatory reaction in lung tissue as manifested by the reduction of proinflammatory mediators (IL-1β, IL-6, TNF-α, MCP-1, iNOS, and COX-2) in BALF, serum, and lung tissues. Further, DA inhibited the activation of the NLRP3/caspase-1 pathway in the lung. DA reduced the production and expression of the proinflammatory mediators above in RAW264.7 cells. Mechanistically, DA remarkably blocked the nuclear translocation of NF-κB p65, suppressed IκBα phosphorylation, and markedly reduced the nuclear translocation of AP-1 and the phosphorylation of ERK and p38. ConclusionsThe findings demonstrated that DA exerts anti-inflammatory effects in LPS-stimulated ALI mice and macrophages by downregulating the NLRP3/caspase-1 signaling pathway in lung tissue and the IκB/NF-κB and MAPKs/AP-1 pathways in macrophages, suggesting that DA may be promising in ALI treatment.

Mesenchymal Stem Cells Attenuate Acute Lung Injury in Mice Partly by Suppressing Alveolar Macrophage Activation in a PGE2-Dependent Manner.

Mesenchymal stem cells (MSCs) have been demonstrated to attenuate acute lung injury (ALI). We also found that they can suppress the activation of alveolar macrophages (AMs), which can partly account for their therapeutic effects. MSCs do not inherently own immunosuppressive effects, when co-cultured with inflammatory immune cells, MSCs can be activated by inflammatory cytokines and meanwhile exert immunosuppressive effects. In order to further research, RNA sequencing (RNA-seq) of MSCs cultured before and after co-culturing with activated macrophages was performed. The data suggested a total of 5268 differentially expressed genes (DEGs) along the process. We used the data of 2754 upregulated DEGs to develop a signaling network of genes and the transcription factors targeting them in order to predict the altered functions of MSCs after exposure to inflammatory stimuli. This constructed network revealed some critical target genes and potential roles of MSCs under inflammatory conditions. According to the network, Ptgs2 was assumed to be an important gene participating in the immunosuppressive effects of MSCs. We also identified significant increases in the expression of COX2 protein and the secretion of PGE2 from MSCs. The use of the COX2 inhibitor NS-398 restrained the secretion of PGE2 and reversed the suppression of macrophage activation by MSCs in vitro. In addition, a selective antagonist of PGE2 binding receptor (EP4 receptor), GW627368X, also reversed the inhibitory effects of MSCs on AMs and the protective effects in ALI mouse. In summary, the therapeutic effects of MSCs on ALI partly occur through suppressing AM activation via PGE2 binding to EP4 receptor.

Suppression of NLRP3 Inflammasome by Erythropoietin via the EPOR/JAK2/STAT3 Pathway Contributes to Attenuation of Acute Lung Injury in Mice.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common and devastating clinical disorders with high mortality and no specific therapy. An excessive inflammatory response results in the progression of ALI/ARDS, and the NLRP3 inflammasome is a key participant in inflammation. Erythropoietin (EPO), which is clinically used for anemia, reportedly exerts pleiotropic effects in ALI. However, whether EPO could protect against lipopolysaccharide (LPS)-induced ALI by regulating the NLRP3 inflammasome and its underlying mechanisms remain poorly elucidated. This study aimed to explore whether the therapeutic effects of EPO rely on the suppression of the NLRP3 inflammasome and the specific mechanisms in an LPS-induced ALI mouse model. ALI was induced in C57BL/6 mice by intraperitoneal (i.p.) injection of LPS (15 mg/kg). EPO was administered intraperitoneally at 5 U/g after LPS challenge. The mice were sacrificed 8 h later. Our findings indicated that application of EPO markedly diminished LPS-induced lung injury by restoring histopathological changes, lessened lung wet/dry (W/D) ratio, protein concentrations in bronchoalveolar lavage fluid (BALF) and myeloperoxidase (MPO) levels. Meanwhile, EPO evidently decreased interleukin-1β (IL-1β) and interleukin-18 (IL-18) secretion, the expression of NLRP3 inflammasome components including pro-IL-1β, NLRP3, and cleaved caspase-1 as well as phosphorylation of nuclear factor-κB (NF-κB) p65, which may be associated with activation of EPO receptor (EPOR), phosphorylation of Janus-tyrosine kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3). However, all the beneficial effects of EPO on ALI and modulation NLRP3 inflammasome were remarkably abrogated by the inhibition of EPOR/JAK2/STAT3 pathway and knockout (KO) of NLRP3 gene. Taken together, this study indicates that EPO can effectively attenuate LPS-induced lung injury in mice by suppressing the NLRP3 inflammasome, which is dependent upon activation of EPOR/JAK2/STAT3 signaling and inhibition of the NF-κB pathway.

Didox ameliorates sepsis induced acute lung injury via down regulation of IL-33 signaling pathway in mice

Background: Sepsis very well define as life-threatening medical condition and may be characterize as dangerous condition described by dysregulated inflammation. The objective of this study is investigating the effects of pre-treatment with didox in attenuation of acute lung injury caused by sepsis through down regulation of IL-33 pathway. Method and materials: A total of 30 Adult male of Swiss Albino mice were used for the study, with weights ranged between 30 g - 35 g. The experimental animal subjected to cecal ligation and puncture (CLP) and pretreated with 200mg /Kg i.p. of didox 1 hour before sepsis induced. The lung tissue for histopathology examination and proinflammatory markers level (IL-1β, IL-33 and MCP-1) beside serum samples were analyzed by enzyme-linked immunosorbent assay (ELISA). ApHOX analyzer (Nova Biomedical, Waltham, USA) used for the determination of blood gases as indication to lung function in mice groups. Results: When compared the data of different mice sets with the sham collection, levels of serum and lung tissues IL-1β and MCP-1 are showed significant (p<0.001) increased within control and vehicle groups. Sepsis induction set also shows significant (p<0.001) increase in serum IL-33 which cause impairment of lung functions expressed as a significant reduction in partial pressure values for oxygen (pO2) and as well as a significant elevation in partial pressure values for carbon dioxide (pCO2). These changes are consistent with histopathologic examination which shows severe pulmonary damage as compared to sham set. All these changes were counteracted by administration of didox. Conclusions: Our results revealed didox have been shown to decrease sepsis-induced acute lung injury through interfering with inflammatory mediators (IL-1β, IL-33 and MCP-1) and down regulation of IL-33 signaling pathway. How to Cite this Article Pubmed Style NASSER GHALY YOUSIF, ALI NAJAH AL-KHAYYAT, ZAINAB ABD OLKADHIM, NAJAH R. HADI, SARA N. ALTIMIMI, AHMAD ALTIMIMI. ameliorates sepsis induced acute lung injury via down regulation of IL-33 signaling pathway in SRP. 2020; 11(1): 96-107. doi:10.5530/srp.2020.1.15 Web Style NASSER GHALY YOUSIF, ALI NAJAH AL-KHAYYAT, ZAINAB ABD OLKADHIM, NAJAH R. HADI, SARA N. ALTIMIMI, AHMAD ALTIMIMI. ameliorates sepsis induced acute lung injury via down regulation of IL-33 signaling pathway in http://www.sysrevpharm.org/?mno=82743 [Access: March 29, 2021]. doi:10.5530/srp.2020.1.15 AMA (American Medical Association) Style NASSER GHALY YOUSIF, ALI NAJAH AL-KHAYYAT, ZAINAB ABD OLKADHIM, NAJAH R. HADI, SARA N. ALTIMIMI, AHMAD ALTIMIMI. ameliorates sepsis induced acute lung injury via down regulation of IL-33 signaling pathway in SRP. 2020; 11(1): 96-107. doi:10.5530/srp.2020.1.15 Vancouver/ICMJE Style NASSER GHALY YOUSIF, ALI NAJAH AL-KHAYYAT, ZAINAB ABD OLKADHIM, NAJAH R. HADI, SARA N. ALTIMIMI, AHMAD ALTIMIMI. ameliorates sepsis induced acute lung injury via down regulation of IL-33 signaling pathway in SRP. (2020), [cited March 29, 2021]; 11(1): 96-107. doi:10.5530/srp.2020.1.15 Harvard Style NASSER GHALY YOUSIF, ALI NAJAH AL-KHAYYAT, ZAINAB ABD OLKADHIM, NAJAH R. HADI, SARA N. ALTIMIMI, AHMAD ALTIMIMI (2020) ameliorates sepsis induced acute lung injury via down regulation of IL-33 signaling pathway in SRP, 11 (1), 96-107. doi:10.5530/srp.2020.1.15 Turabian Style NASSER GHALY YOUSIF, ALI NAJAH AL-KHAYYAT, ZAINAB ABD OLKADHIM, NAJAH R. HADI, SARA N. ALTIMIMI, AHMAD ALTIMIMI. 2020. ameliorates sepsis induced acute lung injury via down regulation of IL-33 signaling pathway in Systematic Reviews in Pharmacy, 11 (1), 96-107. doi:10.5530/srp.2020.1.15 Chicago Style NASSER GHALY YOUSIF, ALI NAJAH AL-KHAYYAT, ZAINAB ABD OLKADHIM, NAJAH R. HADI, SARA N. ALTIMIMI, AHMAD ALTIMIMI. Didox ameliorates sepsis induced acute lung injury via down regulation of IL-33 signaling pathway in mice. Systematic Reviews in Pharmacy 11 (2020), 96-107. doi:10.5530/srp.2020.1.15 MLA (The Modern Language Association) Style NASSER GHALY YOUSIF, ALI NAJAH AL-KHAYYAT, ZAINAB ABD OLKADHIM, NAJAH R. HADI, SARA N. ALTIMIMI, AHMAD ALTIMIMI. Didox ameliorates sepsis induced acute lung injury via down regulation of IL-33 signaling pathway in mice. Systematic Reviews in Pharmacy 11.1 (2020), 96-107. Print. doi:10.5530/srp.2020.1.15 APA (American Psychological Association) Style NASSER GHALY YOUSIF, ALI NAJAH AL-KHAYYAT, ZAINAB ABD OLKADHIM, NAJAH R. HADI, SARA N. ALTIMIMI, AHMAD ALTIMIMI (2020) ameliorates sepsis induced acute lung injury via down regulation of IL-33 signaling pathway in Systematic Reviews in Pharmacy, 11 (1), 96-107. doi:10.5530/srp.2020.1.15

Vasoactive intestinal peptide suppresses the NLRP3 inflammasome activation in lipopolysaccharide-induced acute lung injury mice and macrophages

Vasoactive intestinal peptide (VIP) is a neuropeptide that exerts anti-inflammatory functions. We have reported that VIP mediated by lentivirus attenuates acute lung injury (ALI) in lipopolysaccharide (LPS)-induced murine model. However, the exact role of VIP in uncontrolled inflammation during ALI is largely unknown. Accumulating evidence indicates that the NLRP3 inflammasome has a critical role during ALI. In this study, we investigated the effects of VIP on the activation of NLRP3 inflammasome during the development of ALI in mice. Seven days after the intratracheal injection of VIP-lentivirus, a murine ALI model was induced by intratracheal injection of LPS. VIP-lentivirus significantly reduced the expression of NLRP3 inflammasome components in lung tissue, including NLRP3, pro-caspase-1, pro-IL-1β, and pro-IL-18. VIP-lentivirus also inhibited the formation of caspase-1 p10 and the maturation of IL-1β and IL-18. In vitro, exogenous VIP pre-treatment inhibited the priming of NLRP3 inflammasome in murine primary peritoneal macrophages, indicated by down-regulation of expression of NLRP3 inflammasome components. VIP pre-treatment effectively prevented the LPS-induced degradation of I-κB and the synthesis of the downstream of NF-κB, including TNF-α and IL-17A. Furthermore, VIP pre-treatment pronouncedly suppressed the autoproteolysis of caspase-1 and the secretion of IL-1β and IL-18 induced by LPS plus ATP in macrophages. In addition, VIP inhibited the generation of reactive oxygen species in macrophages by decreasing NOX1 and NOX2 expression. These findings illustrate one mechanism that VIP attenuates ALI induced by LPS through inhibiting the activation of the NLRP3 inflammasome and encourage further studies assessing the therapeutic potential of VIP to ALI.

Dexmedetomidine Attenuates Acute Lung Injury Induced by Heatstroke and Improve Outcome.

Dexmedetomidine (DEX) has been demonstrated to inhibit inflammatory response and protect against multiorgan injury in various scenarios. The objectives of the present study were to ascertain whether DEX is able to attenuate acute lung injury (ALI) under heatstroke (HS), and to explore the underlying mechanism. Male C57BL/6 mice were exposed to ambient temperature of 39.5 ± 0.2°C until core temperature reach 43°C. DEX or 0.9% saline was injected i.p. immediately. At the end of the experiment, bronchoalveolar lavage fluid (BALF) and lung tissue were harvested. HS induce ALI and pulmonary dysfunction, while DEX treatment could significantly inhibit lung injury and improve respiratory dysfunction under HS. The overall effect was beneficial and improved the 72 h cumulative survival rate of mice with HS. Furthermore, HS significantly elevated the levels of cytokines in BALF, as well as increased the activity of toll-like receptor 4 (TLR4)/MyD88/nuclear factor-κB (NFκB) signaling pathway in lung tissue, while DEX treatment could inhibit such effects. Finally, DEX could upregulate the expression of caveolin 1 downregulated by HS, which may contribute to the inhibition of TLR4/MyD88/NFκB signaling pathway. In conclusion, the present results indicated that DEX may protect against lung inflammatory response and injury under HS via TLR4/MyD88/NFκB signaling pathway, and caveolin-1 may participate in the effects.

Adiponectin deficiency induces mitochondrial dysfunction and promotes endothelial activation and pulmonary vascular injury.

Adiponectin (APN), an adipocyte-derived adipokine, has been shown to limit lung injury originating from endothelial cell (EC) damage. Previously we reported that obese mice with low circulatory APN levels exhibited pulmonary vascular endothelial dysfunction. This study was designed to investigate the cellular and molecular mechanisms underlying the pulmonary endothelium-dependent protective effects of APN. Our results demonstrated that in APN-/- mice, there was an inherent state of endothelium mitochondrial dysfunction that could contribute to endothelial activation and increased susceptibility to LPS-induced acute lung injury (ALI). We noted that APN-/- mice showed decreased expression of mitochondrial biogenesis regulatory protein peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) and its downstream proteins nuclear respiratory factor 1, transcription factor A, mitochondrial, and Sirtuin (Sirt)3 and Sirt1 expression in whole lungs and in freshly isolated lung ECs from these mice at baseline and subjected to LPS-induced ALI. We further showed that treating APN-/- mice with PGC-1α activator pyrroloquinoline quinone enhances mitochondrial biogenesis and function in lung endothelium and attenuation of ALI. These results suggest that the pulmonary endothelium-protective properties of APN are mediated, at least in part, by an enhancement of mitochondrial biogenesis through a mechanism involving PGC-1α activation.-Shah, D., Torres, C., Bhandari, V. Adiponectin deficiency induces mitochondrial dysfunction and promotes endothelial activation and pulmonary vascular injury.

Effect of tranexamic acid administration on acute traumatic coagulopathy in rats with polytrauma and hemorrhage.

Trauma and hemorrhagic shock can lead to acute traumatic coagulopathy (ATC) that is not fully reversed by prehospital resuscitation as simulated with a limited volume of fresh whole blood (FWB) in a rat model. Tranexamic Acid (TXA) is used as an anti-fibrinolytic agent to reduce surgical bleeding if administered prior to or during surgery, and to improve survival in trauma if given early after trauma. It is not clear from the existing clinical literature whether TXA has the same mechanism of action in both settings. This study sought to explore the molecular mechanisms of TXA activity in trauma and determine whether administration of TXA as a supplement to FWB resuscitation could attenuate the established ATC in a rat model simulating prehospital resuscitation of polytrauma and hemorrhagic shock. In a parallel in-vitro study, the effects on clotting assays of adding plasmin at varying doses along with either simultaneous addition of TXA or pre-incubation with TXA were measured, and the results suggested that maximum anti-fibrinolytic effect of TXA on plasmin-induced fibrinolysis required pre-incubation of TXA and plasmin prior to clot initiation. In the rat model, ATC was induced by polytrauma followed by 40% hemorrhage. One hour after trauma, the rats were resuscitated with FWB collected from donor rats. Vehicle or TXA (10mg/kg) was given as bolus either before trauma (TXA-BT), or 45min after trauma prior to resuscitation (TXA-AT). The TXA-BT group was included to contrast the coagulation effects of TXA when used as it is in elective surgery vs. what is actually feasible in real trauma patients (TXA-AT group). A single dose of TXA prior to trauma significantly delayed the onset of ATC from 30min to 120min after trauma as measured by a rise in prothrombin time (PT). The plasma d-dimer as well as plasminogen/fibrinogen ratio in traumatized liver of TXA-BT were significantly lower as compared to vehicle and TXA-AT. Wet/dry weight ratio and leukocytes infiltration of lungs were significantly decreased only if TXA was administrated later, prior to resuscitation (TXA-AT). In conclusion: Limited prehospital trauma resuscitation that includes FWB and TXA may not correct established systemic ATC, but rather may improve overall outcomes of resuscitation by attenuation of acute lung injury. By contrast, TXA given prior to trauma reduced levels of fibrinolysis at the site of tissue injury and circulatory d-dimer, and delayed development of coagulopathy independent of reduction of fibrinogen levels following trauma. These findings highlight the importance of early administration of TXA in trauma, and suggest that further optimization of dosing protocols in trauma to exploit TXA’s various sites and modes of action may further improve patient outcomes.

Hydrogen-Rich Saline Attenuates Acute Lung Injury Induced by Limb Ischemia/Reperfusion via Down-Regulating Chemerin and NLRP3 in Rats.

Limb ischemia/reperfusion (LI/R) injury is associated with high morbidity and mortality. The hypothesis of this study is that hydrogen-rich solution could attenuateacute lung injury and improve mortality via chemerin and NLRP3 after LI/R in rats. A rat model of LI/R was performed by clamping the bilateral femoral arteries for 3 h followed by reperfusion. Hydrogen-rich saline (HRS) was administered intraperitoneally (10 mL/kg or 2.5 mL/kg) when the atraumatic micro clips were released. The rats were euthanized at 2 h after reperfusion and then the arterial blood and lung specimens were harvested for further analyses. Meanwhile, survival rate was observed. The results showed that HRS improved the survival rate and attenuated pulmonary edema, injury, and apoptosis. HRS also decreased the levels of tumor necrosis factor-α, interleukin-6, myeloperoxidase and malondialdehyde, and increased the activity of superoxide dismutase in serum and lung after the LI/R event. HRS downregulated the expression of chemerin and NLRP3 in lung. The study demonstrated that chemerin and NLRP3 could serve as important response factors that were involved in the lung injury following LI/R. HRS could significantly attenuate LI/R-mediated acute lung injury, at least in part, by inhibiting the activated chemerin/NLRP3 signaling pathway.

DL-3-n-butylphthalide attenuates lipopolysaccharide-induced acute lung injury via SIRT1-dependent and -independent regulation of Nrf2

The acute respiratory distress syndrome (ARDS), a devastating clinical syndrome, is one of the most severe complications of acute lung injury (ALI). Despite of decades of clinical trials and supportive ventilation strategies, the incidence and mortality of ALI/ARDS remain high. DL-3-n-butylphthalide (NBP) is a synthesized raceme of L-3-n-butylphthalide which has been approved to possess various activities. In the current study, we aimed to investigate the effect of NBP on ALI in lipopolysaccharide (LPS)-treated mice. We found that 10 mg/kg and 50 mg/kg NBP significantly prevented LPS-induced increase of W/D ratio of lung, histological injury of lung, infiltration of inflammatory cells, release of pro-inflammatory cytokines and chemokines, and oxidative damage. Sirtuin 1 (SIRT1) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression was increased by NBP in lung of LPS-treated mice. Knockout of SIRT1 significantly aggravated LPS-induced ALI. Moreover, the absence of SIRT1 notably inhibited NBP-induced protective effects against LPS-induced increase of W/D ratio of lung, histological injury of lung, infiltration of inflammatory cells, release of pro-inflammatory cytokines and chemokines, and oxidative damage. However, knockout of SIRT1 did not completely inhibit NBP-induced upregulation of Nrf2 and attenuation of ALI. The results demonstrated that NBP could activate Nrf2 antioxidant signaling in a SIRT1-dependent and SIRT1-independent manner, resulting in the amelioration of oxidative stress, inflammation and pulmonary edema. The data highlights the importance of SIRT1/Nrf2 signaling in the protective effects of NBP.

Exogenous ghrelin ameliorates acute lung injury by modulating the nuclear factor κB inhibitor kinase/nuclear factor κB inhibitor/nuclear factor κB pathway after hemorrhagic shock

Previous studies have shown that ghrelin, a peptide produced in the stomach, attenuates acute lung injury (ALI) in various animal models, and that some of these effects are associated with inhibition of the nuclear factor κB signaling pathway. This study investigated whether ghrelin exerts beneficial effects on hemorrhagic shock (HS)-induced ALI by modulating nuclear factor κB inhibitor kinase/nuclear factor κB inhibitor/nuclear factor κB (IKK/IκBα/NF-κB) pathway activity. HS was induced in male SD rats by withdrawing blood to a mean arterial pressure (MAP) of 40 mm Hg for 1 h; rats then received ghrelin (10 nmol/kg) or vehicle intravenously and were resuscitated with the shed blood and an equal volume of Ringer lactate solution followed by observation for 2 h. After resuscitation, samples were collected and analyzed for lung histopathology, wet to dry weight ratio (W/D), bronchoalveolar lavage fluid (BALF) protein, neutrophil infiltration, plasma inflammatory cytokines (TNF-α and IL-6), and cytoplasmic phosphorylated IKKβ, IκBα, phosphorylated IκBα and nuclear NF-κB expression. Compared to those in the two sham groups, lung injury, W/D, BALF protein, neutrophil infiltration, plasma TNF-α and IL-6 levels, and IKK/IκBα/NF-κB pathway activation were significantly increased in HS rats. After ghrelin administration, all parameters analyzed were decreased compared to those without ghrelin in HS rats. Moreover, ghrelin alleviated the decreased MAP after resuscitation compared to that in HS rats. Exogenous ghrelin attenuates the inflammatory response and acute lung injury after HS. These beneficial effects appear to be mediated through inhibition of IKK/IκBα/NF-κB signaling.

Sulfur dioxide reduces lipopolysaccharide-induced acute lung injury in rats.

IntroductionRecent studies suggested that sulfur dioxide (SO2) can be produced endogenously by pulmonary vessels and attenuate acute lung injury (ALI) with vasorelaxant effects. This study was conducted to determine whether SO2 can inhibit lung inflammation and relax pulmonary arteries via inhibition of the mitogen-activated protein kinase (MAPK) pathway.Material and methodsForty-eight adult male Sprague Dawley rats (250~300 g) were randomly divided into six treatment groups: control (n = 8), control + SO2 (n = 8), control + L-aspartic acid-β-hydroxamate (HDX) (n = 8), LPS (n = 8), LPS + SO2 (n = 8) and LPS + HDX (n = 8).ResultsSix hours after LPS treatment, rats exhibited elevated pulmonary artery hypertension (PAH), marked pulmonary structure injury with elevated pulmonary myeloperoxidase (MPO) activity and increased expression of intercellular adhesion molecule 1 (ICAM-1) and CD11b, along with decreased pulmonary SO2 production and reduced pulmonary aspartate aminotransferase (AAT) activity. Pretreatment with SO2 saline solution significantly reduced, while HDX (AAT inhibitor) aggravated, the pathogenesis of LPS-induced ALI. Moreover, SO2 saline solution significantly down-regulated expression of Raf-1, MEK-1 and phosphorylated ERK (p-ERK). It also prevented pulmonary hypertension in association with an up-regulated SO2/AAT pathway. However, HDX advanced pulmonary hypertension and inflammatory responses in the lung were associated with a down-regulated SO2/AAT pathway.ConclusionsOur results suggest that SO2 markedly relieved inflammatory responses, in association with Raf-1, MEK-1 and p-ERK during ALI induced by LPS. The down-regulation of the SO2/AAT pathway may be involved in the mechanism(s) of LPS-induced lung injury.

Connexin 43-Mediated Mitochondrial Transfer of iPSC-MSCs Alleviates Asthma Inflammation.

SummaryWe previously identified an immunomodulatory role of human induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (MSCs) in asthmatic inflammation. Mitochondrial transfer from bone marrow MSCs to epithelial cells can result in the attenuation of acute lung injury in mice. However, the effects of mitochondrial transfer from iPSC-MSCs to epithelial cells in asthma and the mechanisms underlying these effects are unclear. We found that iPSC-MSC transplantation significantly reduced T helper 2 cytokines, attenuated the mitochondrial dysfunction of epithelial cells, and alleviated asthma inflammation in mice. Tunneling nanotubes (TNTs) were formed between iPSC-MSCs and epithelial cells, and mitochondrial transfer from iPSC-MSCs to epithelial cells via TNTs was observed both in vitro and in mice. Overexpression or silencing of connexin 43 (CX43) in iPSC-MSCs demonstrated that CX43 plays a critical role in the regulation of TNT formation by mediating mitochondrial transfer between iPSC-MSCs and epithelial cells. This study provides a therapeutic strategy for targeting asthma inflammation.

Up-regulation of SFTPB expression and attenuation of acute lung injury by pulmonary epithelial cell-specific NAMPT knockdown.

Although a deficiency of surfactant protein B (SFTPB) has been associated with lung injury, SFTPB expression has not yet been linked with nicotinamide phosphoribosyltransferase (NAMPT), a potential biomarker of acute lung injury (ALI). The effects of Nampt in the pulmonary epithelial cell on both SFTPB expression and lung inflammation were investigated in a LPS-induced ALI mouse model. Pulmonary epithelial cell-specific knockdown of Nampt gene expression, achieved by the crossing of Nampt gene exon 2 floxed mice with mice expressing epithelial-specific transgene Cre or by the use of epithelial-specific expression of anti-Nampt antibody cDNA, significantly attenuated LPS-induced ALI. Knockdown of Nampt expression was accompanied by lower levels of bronchoalveolar lavage (BAL) neutrophil infiltrates, total protein and TNF-α levels, as well as lower lung injury scores. Notably, Nampt knockdown was also associated with significantly increased BAL SFTPB levels relative to the wild-type control mice. Down-regulation of NAMPT increased the expression of SFTPB and rescued TNF-α-induced inhibition of SFTPB, whereas overexpression of NAMPT inhibited SFTPB expression in both H441 and A549 cells. Inhibition of NAMPT up-regulated SFTPB expression by enhancing histone acetylation to increase its transcription. Additional data indicated that these effects were mainly mediated by NAMPT nonenzymatic function via the JNK pathway. This study shows that pulmonary epithelial cell-specific knockdown of NAMPT expression attenuated ALI, in part, via up-regulation of SFTPB expression. Thus, epithelial cell-specific knockdown of Nampt may be a potential new and viable therapeutic modality to ALI.-Bi, G., Wu, L., Huang, P., Islam, S., Heruth, D. P., Zhang, L. Q., Li, D.-Y., Sampath, V., Huang, W., Simon, B. A., Easley, R. B., Ye, S. Q. Up-regulation of SFTPB expression and attenuation of acute lung injury by pulmonary epithelial cell-specific NAMPT knockdown.