Lung Myeloperoxidase Activity Research Articles

Harnessing extracellular cold-inducible RNA binding protein by PS-OMe miR130: A promising shield against hemorrhage-induced lung injury.

Hemorrhagic shock (HS) poses a life-threatening condition with the lungs being one of the most susceptible organs to its deleterious effects. Extracellular cold-inducible RNA binding protein has emerged as a pivotal mediator of inflammation, and its release has been observed as a case of HS-induced tissue injury. Previous studies unveiled a promising engineered microRNA, designated PS-OMe miR130, which inhibits extracellular cold-inducible RNA binding protein, thereby safeguarding vital organs. In this study, we hypothesized that PS-OMe miR130 serves as a protective shield against HS-induced lung injury by curtailing the overzealous inflammatory immune response. Hemorrhagic shock was induced in male C57BL6 mice by withdrawing blood via a femoral artery cannula to a mean arterial pressure of 30 mm Hg for 90 minutes. The mice were resuscitated with twice the shed blood volume with Ringer's lactate solution. They were then treated intravenously with either phosphate-buffered saline (vehicle) or 62.5 nmol PS-OMe miR130. At 4 hours later, blood and lungs were harvested. Following PS-OMe miR130 treatment in HS mice, a substantial decrease was observed in serum injury markers including aspartate aminotransferase, alanine transaminase, lactate dehydrogenase, and blood urea nitrogen. Serum interleukin (IL)-6 exhibited a similar reduction. In lung tissues, PS-OMe miR130 led to a significant decrease in the messenger RNA expressions of pro-inflammatory cytokines (IL-6, IL-1β, and tumor necrosis factor α), chemokines (keratinocyte-derived chemokine and macrophage inflammatory protein 2), and an endothelial injury marker, E-selectin. PS-OMe miR130 also produced substantial inhibition of lung myeloperoxidase activity and resulted in a marked reduction in lung injury as evidenced by histological evaluation. This was further confirmed by the observation that PS-OMe miR130 significantly reduced the presence of lymphocyte antigen 6 family member G-positive neutrophils and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive apoptotic cells. PS-OMe miR130 emerges as a potent safeguard against HS-induced lung injury by effectively inhibiting pro-inflammation and injuries, offering a promising therapeutic strategy in such critical clinical condition.

Garlic oil supplementation blocks inflammatory pyroptosis-related acute lung injury by suppressing the NF-κB/NLRP3 signaling pathway via H2S generation.

Acute lung injury (ALI) is a major cause of acute respiratory failure with a high morbidity and mortality rate, and effective therapeutic strategies for ALI remain limited. Inflammatory response is considered crucial for the pathogenesis of ALI. Garlic, a globally used cooking spice, reportedly exhibits excellent anti-inflammatory bioactivity. However, protective effects of garlic against ALI have never been reported. This study aimed to investigate the protective effects of garlic oil (GO) supplementation on lipopolysaccharide (LPS)-induced ALI models. Hematoxylin and eosin staining, pathology scores, lung myeloperoxidase (MPO) activity measurement, lung wet/dry (W/D) ratio detection, and bronchoalveolar lavage fluid (BALF) analysis were performed to investigate ALI histopathology. Real-time polymerase chain reaction, western blotting, and enzyme-linked immunosorbent assay were conducted to evaluate the expression levels of inflammatory factors, nuclear factor-κB (NF-κB), NLRP3, pyroptosis-related proteins, and H2S-producing enzymes. GO attenuated LPS-induced pulmonary pathological changes, lung W/D ratio, MPO activity, and inflammatory cytokines in the lungs and BALF. Additionally, GO suppressed LPS-induced NF-κB activation, NLRP3 inflammasome expression, and inflammatory-related pyroptosis. Mechanistically, GO promoted increased H2S production in lung tissues by enhancing the conversion of GO-rich polysulfide compounds or by increasing the expression of H2S-producing enzymes in vivo. Inhibition of endogenous or exogenous H2S production reversed the protective effects of GO on ALI and eliminated the inhibitory effects of GO on NF-κB, NLRP3, and pyroptotic signaling pathways. Overall, these findings indicate that GO has a critical anti-inflammatory effect and protects against LPS-induced ALI by suppressing the NF-κB/NLRP3 signaling pathway via H2S generation.

An integrated RNA-Seq and network pharmacology approach for exploring the preventive effect of Corydalis bungeana Turcz. Extract and Acetylcorynoline on LPS-induced acute lung injury

Ethnopharmacological relevanceCorydalis bungeana Turcz. (KDD) is a Chinese herbal medicine with anti-inflammatory, lung cleansing, detoxification and other functions. Clinically, it is commonly used to treat respiratory infections. This study uses ALI as the research model, which is consistent with the clinical use of KDD. Acetylcorynoline (AC) is the main alkaloid component of the KDD extracts, and network pharmacology studies suggest that it may be the main active ingredient in the prevention of ALI. Aim of the studyThe aim of this study is to explore the underlying mechanisms and to study the efficacy material basis of KDD in anti-ALI effect by LPS-induced mice and using a combination of RNA sequencing (RNA-Seq) technology and network pharmacology. Materials and methodsEstablish a mouse model of ALI by intraperitoneal injection of LPS (5 mg/kg). The main active ingredients of KDD were identified and analyzed by high performance liquid chromatography with quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) and network pharmacology. IL-18, IL-1β, and IL-6 levels in serum and bronchoalveolar lavage fluid (BALF), lung histopathological changes, and lung myeloperoxidase (MPO) activity were assessed. We investigated the possible molecular mechanisms of KDD and AC in an LPS-induced mouse ALI models with RNA-Seq technology. In addition, the anti-inflammatory effect of AC was verified in vitro by establishing an LPS-stimulated RAW264.7 inflammation model. Molecular docking further validated AC as the efficacy material basis of KDD in anti-ALI. ResultsBased on HPLC-QTOF-MS technology and network pharmacology, KDD is more strongly associated with lung tissue, and that AC may be the main active ingredient of KDD. Subsequently, in vivo experiments results showed that KDD and AC reduced the levels of pro-inflammatory cytokines in serum and BALF, reduced MPO levels and reduced inflammatory damage in the lungs. To elucidate its underlying mechanism, based on RNA-Seq analysis techniques performed in lung tissue, enrichment analysis showed that KDD and AC intervened through the NLR signaling pathway, thereby mitigating LPS-induced ALI. Then, RT-qPCR, IF, WB and other technologies were used to verify the anti-ALI core difference genes of KDD and AC from the gene transcription and protein expression levels of the NLR signaling pathway, and confirmed the anti-ALI. In vitro experimental results also showed that AC has anti-inflammatory effects in RAW264.7. Finally, the biotransformation and molecular docking results also further indicated that AC is the active ingredient of KDD in anti-ALI. ConclusionsStudies have shown that KDD has a good therapeutic effect on ALI, and AC is the main pharmacodynamic material basis for its therapeutic effect in ALI.

Protective effect of oleo-gum resin of Commiphora wightii against elastase-induced chronic obstructive pulmonary disease-linked lung inflammation and emphysema: Isolation and identification of key bioactive phytoconstituent

Ethnopharmacological relevanceOleo-gum resin of Commiphora wightii (Arnott) Bhandari of family Burseraceae, commonly known as ‘guggul’, is a well known Ayurvedic drug used traditionally to treat various disorders including respiratory ailments. However, role of C. wightii in chronic obstructive pulmonary disease (COPD) is not known. AimThe present work was designed to investigate the protective potential of standardized C. wightii extract/and its fractions against elastase-induced COPD-linked lung inflammation and to identify key bioactive constituent(s). Material and methodsC. wightii oleo-gum resin extract was prepared using Soxhlet extraction technique and the resultant extract was standardized on basis of guggulsterone content using HPLC. The extract was partitioned by different solvents in increasing order of polarity. Standardized extract/its partitioned fractions were orally administered to male BALB/c mice 1 h prior to intra-tracheal instillation of elastase (1U/mouse). Anti-inflammatory effect was evaluated by analyzing inflammatory cells and myeloperoxidase activity in lungs. The various fraction(s) were subjected to column chromatography to isolate bioactive compound. Isolated compound was identified using 1H and 13C-NMR and analyzed for assessment of several inflammatory mediators using techniques like ELISA, PCR, and gelatin zymography. ResultsC. wightii extract attenuated elastase-induced lung inflammation in dose-dependent manner and Ethyl acetate fraction (EAF) provided maximum protection. EAF was subjected to column chromatography followed by assessment of bioactivity of each sub-fraction, ultimately leading towards isolation of two compounds i.e. C1 and C2. C1 seems to be the key active principle of C. wightii, as it displayed significant anti-inflammatory activity against elastase induced lung inflammation while C2 largely remains ineffective. C1 was identified as mixture of E− and Z-guggulsterone (GS). Reduction in the elastase induced lung inflammation by GS was associated with downregulation of expression of several COPD linked pro-inflammatory factors such as IL-6/TNF-α/IL-1β/KC/MIP-2/MCP-1/G-CSF as well as normalization of redox imbalance as indicated by levels of ROS/MDA/protein carbonyl/nitrite/GSH etc. Further, 21 days prolonged administration of GS (10 mg/kg b.wt; once daily) protected against elastase-induced emphysema by mitigating expression/activity of MMP-2/-9 and increasing TIMP-1 expression. ConclusionOverall, guggulsterone seems to be the key bioactive constituent responsible for exerting beneficial effects of C. wightii against COPD.

TIPE3 protects mice from lipopolysaccharide-induced acute lung injury

BackgroundAcute lung injury (ALI) is a severe inflammatory disease with high morbidity and mortality in patients and lung transplant recipients. Tumor necrosis factor-α-induced protein 8-like 3 (TIPE3) is one of the members of the TIPE family. While TIPE2 has been demonstrated to be protective against lipopolysaccharide (LPS)-induced ALI, the role of TIPE3 in ALI is currently unidentified. MethodsTo examine the role of TIPE3 in ALI, we pretreated C57BL/6 mice with control or TIPE3-lentivirus in LPS-induced ALI models. The C57BL/6 mice were randomly divided into four groups: control group; ALI-induced group; ALI-induced group with control lentivirus; and ALI-induced group with TIPE3-lentivirus. Additionally, RAW 264.7 cells were used to validate the role and molecular mechanism of TIPE3 signaling in vitro. ResultsAn increased expression of TIPE3 reduced lung histopathological damage in ALI-affected mice. ALI-affected mice treated with TIPE3-lentivirus exhibited reduced lung microvascular permeability, myeloperoxidase (MPO) activity, neutrophil buildup, and inflammation response. Additionally, over-expression of TIPE3 significantly inhibited NF-κB activation and promoted the activation of Liver X receptors alpha (LXRα). In LPS-treated RAW264.7 cells, enforced TIPE3 expression produced anti-inflammatory effects, whereas the LXR inhibitor geranylgeranyl pyrophosphate (GGPP) reversed these effects. ConclusionsTIPE3 protected against LPS-induced ALI by regulating the LXRα/NF-κB signaling pathway. These results suggest that TIPE3 might provide a novel insight into the prevention of ALI.

Angiotensin-(1-7) alleviates acute lung injury by activating the Mas receptor in neutrophil.

Acute lung injury (ALI) is a major cause of mortality and morbidity in the clinic. None of the current pharmacological interventions has achieved a detectable benefit. The renin-angiotensin system (RAS) is a complex humoral system essentially involved in the regulation of ALI. In the RAS family, angiotensin (Ang)-(1-7) was found to provide protection by counteracting the effects of Ang II in various cardiopulmonary disease models. The downstream receptor of Ang-(1-7) is the G protein-coupled receptor (GPCR) Mas. We hypothesize that the Ang-(1-7)-Mas pathway would protect patients from ALI. To establish a 2-hit ALI model, the mice underwent intratracheal instillation of hydrochloric acid followed by ventilator-induced lung injury (VILI). ALI was evaluated based on lung edema, histology, myeloperoxidase activity, and proinflammatory cytokine production. The effects of the infusion or inhalation of Ang-(1-7) and Mas receptor blocker A779 were examined. The human neutrophils were isolated, and Mas receptor expression was examined. The neutrophil responses to platelet-activating factor (PAF) stimulation were tested by measuring the formation of reactive oxygen species (ROS), neutrophil adhesion, and chemotaxis. Next, in the mouse model, the neutrophils were depleted using an anti-ly6G antibody. The infusion or inhalation of Ang-(1-7) protected mice from ALI as evidenced by decreases in lung edema, the histological lung injury score, myeloperoxidase activity, and proinflammatory cytokine production. Such effects were largely blocked by the Mas receptor blocker A779. Mas receptor expression in the neutrophils was identified at both the messenger ribonucleic acid and protein levels. Ang-(1-7) prevented neutrophil responses to PAF stimulation, including the formation of ROS, neutrophil adhesion, and chemotaxis, while A779 alleviated these effects. The importance of neutrophils in ALI was further confirmed by neutrophil depletion using the anti-ly6G antibody; however, A779 partially reversed the protective role of neutrophil depletion in ALI, indicating the critical role of Ang-(1-7)-Mas signaling in other pulmonary cells. Ang-(1-7)/Mas receptor attenuates the key features of ALI by regulating neutrophil activation. Our study provides new evidence of their role in the pathogenesis of ALI and may lead to the development of a promising therapeutic strategy.

The mechanism underlying ICAM-1 and E-selectin-mediated hypertriglyceridemic pancreatitis-associated lung injury

PurposeTo investigate the possible mechanism by which adhesion molecules ICAM-1 and E-selectin mediate hypertriglyceridemic pancreatitis (HTGP)-associated lung injury. MethodsC57BL/6 mice were randomly divided into five groups: control group (Con), severe acute pancreatitis group (SAP), HTGP group (HTGP), A-205804 group (A-205804), and apocynin group (Apo). Serum biochemical markers related to pancreatitis, such as inflammatory cytokines, amylase and lipase, were measured by enzyme-linked immunosorbent assay (ELISA) kits. Hematoxylin and eosin (HE) staining was used to analyze the histopathology changes in the pancreas and lung, and myeloperoxidase (MPO) activity in lung was detected by immunohistochemistry (IHC). Molecules related to NF-κB signaling pathway and adhesion molecules were assessed by western blotting (WB), IHC and immunofluorescence staining. The levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) in lung tissues and serum were measured with reagent kits, respectively. ResultsThe severity of pancreatitis and lung injury in HTGP group was more severe than that in SAP group, and the expression levels of adhesion molecules ICAM-1 and E-selectin in lung tissues of HTGP mice were significantly increased. After HTGP mice were treated with adhesion molecule inhibitor A-205804, the expression of ICAM-1 and E-selectin in A-205804 group significantly decreased, and the lung injury was alleviated. The HTGP group had higher levels of oxidative stress and NF-κB pathway-related protein p-p65 expression compared with the SAP group. Apocynin treatment resulted in suppression of p-p65, ICAM-1, and E-selectin expression. ConclusionIn HTGP, hypertriglyceridemia may exacerbate pancreatitis-related lung injury by regulating oxidative stress and activating the NF-κB proinflammatory pathway to upregulate ICAM-1 and E-selectin levels.

Ivermectin contributes to attenuating the severity of acute lung injury in mice

Ivermectin has been proposed as a potential anti-inflammatory drug in addition to its antiparasitic activity. Here we investigated the potential role of ivermectin in the pathogenesis of acute lung injury (ALI) using the lipopolysaccharide (LPS)- or bleomycin (BLM)-induced mice models. Male C57BL/6 mice were given ivermectin orally every day for the remainder of the experiment at doses of 1 or 2 mg/kg after 24 h of LPS or BLM treatment. Ivermectin reversed severe lung injury caused by LPS or BLM challenge, including mortality, changes in diffuse ground-glass and consolidation shadows on lung CT imaging, lung histopathological scores, lung wet/dry ratio, and protein content in the bronchoalveolar lavage fluid (BALF). Furthermore, ivermectin also reduced total lung BALF inflammatory cells, infiltrating neutrophils, myeloperoxidase activity, and plasma TNF-α and IL-6 levels in mice treated with LPS or BLM. Finally, the mechanism study showed that LPS or BLM administration increased JNK, Erk1/2, and p38 MAPK phosphorylation while decreasing IκBα expression, an inhibitor of NF-κB. However, ivermectin increased IκBα expression but blocked elevated phosphorylated JNK and p38 MAPK, not Erk1/2, in both ALI mice. These findings suggested that ivermectin may alleviate ALI caused by LPS or BLM in mice, partly via lowering the inflammatory response, which is mediated at least by the inhibition of MAPK and NF-κB signaling. Collectively, ivermectin might be used to treat acute lung injury/acute respiratory distress syndrome.

Apremilast ameliorates acute respiratory distress syndrome by inhibiting neutrophil-induced oxidative stress

BackgroundThe pathogenesis of acute respiratory distress syndrome (ARDS) is attributed to the dysregulation of oxidative stress and neutrophil recruitment. We aimed to investigate the anti-inflammatory effects of apremilast on human neutrophils and assess its efficacy for treating ARDS. MethodsWe analysed superoxide anion generation, integrin expression, and adhesion in activated human neutrophils using spectrophotometry, flow cytometry, and immunofluorescence microscopy. Phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) was determined using immunoblotting. A murine lipopolysaccharide (LPS)-induced ARDS model was used to evaluate the therapeutic effects of apremilast. ResultsApremilast significantly decreased superoxide anion production, reactive oxygen species (ROS) generation, cluster of differentiation (CD)11 b expression, and neutrophil adhesion in formyl-l-methionyl-l-leucyl-l-phenylalanine activated human neutrophils. Apremilast elevated cyclic 3′,5′-adenosine monophosphate (cAMP) and protein kinase A (PKA) activity in activated neutrophils. It reduced cellular cAMP-specific phosphodiesterase (PDE) activity and selectively inhibited enzymatic PDE4 activity. The activated cAMP/PKA pathway suppressed the phosphorylation of ERK and JNK as well as Ca2+ mobilization in activated neutrophils. All inhibitory effects of apremilast on activated neutrophils were reversed by a PKA inhibitor. In vivo examinations indicated that apremilast alleviated lung neutrophil infiltration, myeloperoxidase (MPO) activity, pulmonary oedema, and alveolar damage in LPS-induced ARDS. ConclusionApremilast inhibits inflammatory responses after neutrophil activation via cAMP/PKA-dependent inhibition of ERK and JNK activation. Our study revealed apremilast suppresses oxidative stress and chemotaxis by selectively inhibiting PDE4 in neutrophils and thus protects against endotoxin-induced ARDS in mice. Apremilast can be used as an alternative off-label drug in treating acute lung damage.

Jian-Ti-Kang-Yi decoction alleviates poly(I:C)-induced pneumonia by inhibiting inflammatory response, reducing oxidative stress, and modulating host metabolism.

Jian-Ti-Kang-Yi decoction (JTKY) is widely used in the treatment of COVID-19. However, the protective mechanisms of JTKY against pneumonia remain unknown. In this study, polyinosinic-polycytidylic acid (poly(I:C)), a mimic of viral dsRNA, was used to induce pneumonia in mice; the therapeutic effects of JTKY on poly(I:C)-induced pneumonia model mice were evaluated. In addition, the anti-inflammatory and anti-oxidative potentials of JTKY were also investigated. Lastly, the metabolic regulatory effects of JTKY in poly(I:C)-induced pneumonia model mice were studied using untargeted metabolomics. Our results showed that JTKY treatment decreased the wet-to-dry ratio in the lung tissue, total protein concentration, and total cell count of the bronchoalveolar lavage fluid (BALF). Hematoxylin and Eosin (HE) and Masson staining indicated that the JTKY treatment alleviated the pathological changes and decreased the fibrotic contents in the lungs. JTKY treatment also decreased the expression of pro-inflammatory cytokines [interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α)] and increased the levels of immunomodulatory cytokines (IL-4 and IL-10) in the BALF and serum. Flow cytometry analysis showed that the JTKY treatment lowered the ratio of CD86+/CD206+ macrophages in the BALF, decreased inducible nitric oxide synthase (iNOS) level, and increased arginase 1 (Arg-1) level in lung. JTKY also lowered CD11b+Ly6G+ neutrophils in BALF and decreased myeloperoxidase (MPO) activity in lung. Moreover, it also elevated superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and decreased methane dicarboxylic aldehyde (MDA) level in lung. Untargeted metabolomic analysis showed that the JTKY treatment could affect 19 metabolites in lung, such as L-adrenaline, L-asparagine, ornithine, and alpha-ketoglutaric acid. These metabolites are associated with the synthesis and degradation of ketone bodies, butanoate, alanine, aspartate, and glutamate metabolism, and tricarboxylic acid (TCA) cycle processes. In conclusion, our study demonstrated that treatment with JTKY ameliorated poly(I:C)-induced pneumonia. The mechanism of action of JTKY may be associated with the inhibition of the inflammatory response, the reduction of oxidative stress, and the regulation of the synthesis and degradation of ketone bodies, TCA cycle, and metabolism of alanine, aspartate, glutamate, and butanoate processes in lung.

Aurantiamide Acetate Ameliorates Lung Inflammation in Lipopolysaccharide-Induced Acute Lung Injury in Mice.

Purpose Aurantiamide acetate (AA) is a dipeptide derivative with complex pharmacological activities and remarkable effects on preventing and treating various diseases. In the current study, we aimed to investigate whether AA can exert protective effects in a mouse model of ALI induced by LPS. Materials and Methods In this model, mice were given intranasal LPS for 3 days prior to receiving AA (2.5, 5, and 10 mg/kg) via oral gavage. An assessment of histopathological changes was performed by hematoxylin and eosin (HE). Proinflammatory cytokines were detected in bronchoalveolar lavage fluids (BALFs) by enzyme-linked immunosorbent assays (ELISAs). The effects of AA on protein expression of NF-κB and PI3K/AKT signaling pathways were determined by Western blot. In addition, lung wet/dry (W/D) weight ratio, myeloperoxidase (MPO) activity, cell counts, and protein content were also measured. Results According to results, AA pretreatment significantly reduced lung pathological changes, W/D ratio, MPO activity, and protein content. Additionally, AA resulted in a significant reduction in the number of total cells, neutrophils, and proinflammatory cytokines in the BALF after LPS stimulation. The subsequent study revealed that pretreatment with AA dose dependently suppressed LPS-induced activation of NF-κB as well as PI3K/AKT phosphorylation. Conclusion The results indicated that the AA had a protective effect on LPS-induced ALI in mice and could be a potential drug for ALI.

Protective effects of fargesin on cadmium-induced lung injury through regulating aryl hydrocarbon receptor.

Fragesin, a traditional Chinese medicine, has been shown to exert anti-inflammatory effect. The aim of this study was to figure out the possible effectiveness of the fargesin, and to invest the mechanisms by which it works in the cadmium-induced lung injury in mice. Fargesin was given 1 h before cadmium treatment for 7 days. Then, the bronchoalveolar lavage fluid (BALF) were harvested to test inflammatory cells and pro-inflammatory cytokine production. Lung histopathological changes, myeloperoxidase (MPO) activity, and aryl hydrocarbon receptor (AhR) and nuclear factor kappa B (NF-κB) activation were measured. Fargesin dose-dependently reduced inflammatory cells and pro-inflammatory cytokines in BALF, improved lung histopathological injury, and inhibited lung wet/dry ratio and MPO activity. Furthermore, fargesin inhibited cadmium-induced NF-κB activation. In addition, fargesin was found to increase AhR expression. In conclusion, fargesin attenuates cadmium-induced lung injury may be via activating AhR, which subsequently suppressing the inflammatory response.

Abstract P3012: Syndecan 1 Regulates Lung Endothelial Barrier Function In Homeostatic And Injury Conditions

Introduction: Acute lung injury (ALI) is an inflammatory syndrome that may occur secondarily to bacterial infection. Pulmonary edema is a severe complication of ALI and it may result from endothelial barrier disruption. The mechanisms that initiate ALI during bacterial infection remains unresolved. Syndecan 1 (Sdc1) is a heparan sulfate proteoglycan that contributes to endothelial barrier stability and is cleaved during inflammatory processes. Whether Sdc1 contributes to ALI progression is unresolved. Herein we investigated if Sdc1 mediates LPS-induced ALI in mice. Methods: Male and Female Sdc1 knockout (Sdc1KO) and wild type (WT) mice, with 5-8 weeks of age, were injected with lipopolysaccharide (LPS, 10mg/Kg, IP) or PBS and euthanized after 6hr. Bronchoalveolar lavage fluid (BAL) and lung tissue were collected and assessed for myeloperoxidase (MPO) activity, albumin content, RhoA activity using commercially available spectrometric and ELISA kits. Lung edema was assessed by lung wet/dry ratio (W/D). Results and Conclusions: LPS increased lung W/D by 1.5-fold (p=0.0042, n≥5/group) in WT but not Sdc1KO mice. Sdc1KO showed higher basal lung W/D vs WT (Sdc1KO=3.55 vs WT=2.21, p=0.044, n≥5/group). Similarly, a trend increase in basal lung MPO activity was seen in Sdc1KO when compared to WT (p=0.33, n≥5/group). A significant increase in MPO activity was seen in LPS-treated WT (LPS=0.47±0.03 vs. PBS=0.26±0.03, p=0.003) but not LPS-treated Sdc1KO mice (p=0.11; n≥5/group) when compared to matched PBS-treated strain controls. Albumin content was increased by LPS only in WT BAL (LPS=106.9±8.9 vs PBS=63.65±6.15, p=0.03, n≥5/group). LPS increased RhoA activity exclusively in WT lungs. (LPS=0.04±0.002 vs PBS= 0.02±0.003, p=0.04, n≥5/group). A trend increase in RhoA activity was seen in PBS-treated Sdc1KO when compared to PBS-treated WT (p=0.06, n≥4/group). Collectively, our data suggest that Sdc1KO show basal lung endothelial barrier failure. This phenotype is associated with decreased response to LPS. The mechanisms whereby Sdc1 regulate barrier function may involve RhoA-dependent pathway. Sdc1 may participate in lung edema development during ALI.

Pinocembrin Relieves Mycoplasma pneumoniae Infection‑Induced Pneumonia in Mice Through the Inhibition of Oxidative Stress and Inflammatory Response.

Pneumonia is a serious infectious disease with increased morbidity and mortality worldwide. The M. pneumoniae is a major airway pathogen that mainly affects respiratory tract and ultimately leads to the development of pneumonia. The current exploration was aimed to uncover the beneficial properties of pinocembrin against the M. pneumoniae-triggered pneumonia in mice via its anti-inflammatory property. The pneumonia was stimulated to the BALB/c mice via infecting them with M. pneumoniae (100µl) for 2days through nasal drops and concomitantly treated with pinocembrin (10mg/kg) for 3days. The azithromycin (100mg/kg) was used as a standard drug. Then the lung weight, nitric oxide, and myeloperoxidase (MPO) activity was assessed. The content of MDA, GSH, and SOD activity was scrutinized using kits. The total cells and DNA amount present in the bronchoalveolar lavage fluid (BALF) was assessed by standard methods. The IL-1, IL-6, IL-8, TNF-α, and TGF contents in the BALF samples and NF-κB level in the lung tissues were assessed using kits. The lung histopathology was assessed microscopically to detect the histological alterations. The 10mg/kg of pinocembrin treatment substantially decreased the lung weight, nitric oxide (NO) level, and MPO activity. The MDA level was decreased, and GSH content and SOD activity were improved by the pinocembrin treatment. The pinocembrin administered pneumonia animals also demonstrated the decreased total cells, DNA amount, IL-1, IL-6, IL-8, TNF-α, and TGF in the BALF and NF-κB level. The findings of histological studies also witnessed the beneficial role of pinocembrin against M. pneumoniae-infected pneumonia. In conclusion, our findings confirmed that the pinocembrin effectively ameliorated the M. pneumoniae-provoked inflammation and oxidative stress in the pneumonia mice model. Hence, it could be a hopeful therapeutic agent to treat the pneumonia in the future.

The β-catenin/CBP signaling axis participates in sepsis-induced inflammatory lung injury.

Sepsis-induced inflammatory lung injury is a key factor causing failure of the lungs and other organs, as well as death, during sepsis. In the present study, a caecal ligation and puncture (CLP)-induced sepsis model was established to investigate the effect of β-catenin on sepsis-induced inflammatory lung injury and the corresponding underlying mechanisms. C57BL/6 mice were randomly divided into five groups, namely, the sham, CLP, β-catenin knockout (KO) + CLP, XAV-939 + CLP, and ICG-001 + CLP groups; the XAV-939 + CLP and ICG-001 + CLP groups were separately subjected to intraperitoneal injections of the β-catenin inhibitors XAV-939 and ICG-001 for 1 week preoperatively and 2 days postoperatively, respectively. Forty-eight hours after CLP, we measured β-catenin expression in lung tissues and evaluated mouse mortality, histopathological characteristics of hematoxylin and eosin (H&E)-stained lung tissues, serum cytokine (tumor necrosis factor [TNF]-α, interleukin [IL]-10, and IL-1β) levels, lung myeloperoxidase (MPO) activity, and the number of apoptotic cells in the lung tissues. Our results indicated that both the inhibition of β-catenin expression and blockage of β-catenin/CREB-binding protein (CBP) interactions by ICG-001 effectively decreased mouse mortality, alleviated pathological lung injury, and reduced the serum TNF-α, IL-10, and IL-1β levels, in addition to reducing the lung MPO activity and the number of apoptotic cells in lung tissues of the sepsis model mice. Therefore, it can be deduced that the β-catenin/CBP signaling axis participates in regulating sepsis-induced inflammatory lung injury.

Arbutin Alleviates LPS Induced Sepsis Pneumonia in Mice.

The aim of this study was to investigate the effects of arbutin (AR) on lipopolysaccharide (LPS)-induced sepsis pneumonia. LPS-induced mice and A549 cells were used to establish septic pneumonia model. AR significantly decreased lung wet-to-dry weight (W/D) ratio, lung myeloperoxidase (MPO) activity and ameliorated lung histopathological changes. In addition, AR increased super oxide dismutase (SOD) activity, decreased malondialdehyde (MDA) content and levels of cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-β) and interleukin-6 (IL-6) in bronchoalveolar lavage fluid (BALF) in mice. Furthermore, the results demonstrated that AR inhibited the JAK2/STAT3/NF-κB pathway in LPS-induced A549 cells which was further confirmed by siRNA JAK2 experiment. The experimental results indicated that the protective mechanism of AR on sepsis pneumonia might be attributed partly to the inhibition of cytokine production and JAK2/STAT3/NF-κB pathway.

Prone Position Minimizes the Exacerbation of Effort-dependent Lung Injury: Exploring the Mechanism in Pigs and Evaluating Injury in Rabbits

Vigorous spontaneous effort can potentially worsen lung injury. This study hypothesized that the prone position would diminish a maldistribution of lung stress and inflation after diaphragmatic contraction and reduce spontaneous effort, resulting in less lung injury. A severe acute respiratory distress syndrome model was established by depleting surfactant and injurious mechanical ventilation in 6 male pigs ("mechanism" protocol) and 12 male rabbits ("lung injury" protocol). In the mechanism protocol, regional inspiratory negative pleural pressure swing (intrabronchial balloon manometry) and the corresponding lung inflation (electrical impedance tomography) were measured with a combination of position (supine or prone) and positive end-expiratory pressure (high or low) matching the intensity of spontaneous effort. In the lung injury protocol, the intensities of spontaneous effort (esophageal manometry) and regional lung injury were compared in the supine position versus prone position. The mechanism protocol (pigs) found that in the prone position, there was no ventral-to-dorsal gradient in negative pleural pressure swing after diaphragmatic contraction, irrespective of the positive end-expiratory pressure level (-10.3 ± 3.3 cm H2O vs. -11.7 ± 2.4 cm H2O at low positive end-expiratory pressure, P = 0.115; -10.4 ± 3.4 cm H2O vs. -10.8 ± 2.3 cm H2O at high positive end-expiratory pressure, P = 0.715), achieving homogeneous inflation. In the supine position, however, spontaneous effort during low positive end-expiratory pressure had the largest ventral-to-dorsal gradient in negative pleural pressure swing (-9.8 ± 2.9 cm H2O vs. -18.1 ± 4.0 cm H2O, P < 0.001), causing dorsal overdistension. Higher positive end-expiratory pressure in the supine position reduced a ventral-to-dorsal gradient in negative pleural pressure swing, but it remained (-9.9 ± 2.8 cm H2O vs. -13.3 ± 2.3 cm H2O, P < 0.001). The lung injury protocol (rabbits) found that in the prone position, spontaneous effort was milder and lung injury was less without regional difference (lung myeloperoxidase activity in ventral vs. dorsal lung, 74.0 ± 30.9 μm · min-1 · mg-1 protein vs. 61.0 ± 23.0 μm · min-1 · mg-1 protein, P = 0.951). In the supine position, stronger spontaneous effort increased dorsal lung injury (lung myeloperoxidase activity in ventral vs. dorsal lung, 67.5 ± 38.1 μm · min-1 · mg-1 protein vs. 167.7 ± 65.5 μm · min-1 · mg-1 protein, P = 0.003). Prone position, independent of positive end-expiratory pressure levels, diminishes a maldistribution of lung stress and inflation imposed by spontaneous effort and mitigates spontaneous effort, resulting in less effort-dependent lung injury.

Penehyclidine hydrochloride ameliorates renal ischemia reperfusion-stimulated lung injury in mice by activating Nrf2 signaling.

Introduction: Penehyclidine hydrochloride (PHC) is an anticholinergic with anti-inflammatory and anti-oxidation activities. PHC displayed protectivity against renal ischemia reperfusion (RIR) injury. Nevertheless, the precise protectivity of PHC on RIR-induced lung injury remains unknown. Methods: We examined the effects of PHC on RIR-induced lung injury and investigated the underlying mechanism. We induced RIR in mice and administrated PHC to RIR mice. Kidney function was monitored by measuring the blood urea nitrogen (BUN) and creatinine level in serum. We evaluated the lung injury, myeloperoxidase (MPO) activity in lung, pro-inflammatory cytokine level, and oxidative markers in serum and lung tissues. We tested the expression level of nuclear factor erythroid 2-related factor 2 (Nrf-2) and heme oxygenase 1 (HO-1) in lung of RIR mice after PHC treatment. Finally, we evaluated the effects of PHC in RIR Nrf2-/- mice. Results: PHC greatly downregulated the serum levels of BUN, creatinine, IL-6, NO, malondialdehyde (MDA), and matrix metalloproteinase-2. PHC also ameliorated the lung injury, decreased the MPO activity, and suppressed production of IL-6, TNF-α, IFN-γ, MDA, and O2-, while it promoted production of superoxide dismutase (SOD) and catalase (CAT) in lung. PHC improved the production of Nrf2 and HO-1. Conclusion: The protectivity of PHC was absent in Nrf2-/- mice. PHC ameliorated RIR-induced lung injury through Nrf2 pathway.

Capsaicin Protects Against Lipopolysaccharide-Induced Acute Lung Injury Through the HMGB1/NF-κB and PI3K/AKT/mTOR Pathways.

PurposeCapsaicin (8-methyl-N-geranyl-6-nonamide; CAP) is an alkaloid isolated from chili peppers, which has complex pharmacological properties, including beneficial effects against various diseases. The aim of this study was to investigate the role of CAP in lipopolysaccharide (LPS)-induced acute lung injury (ALI), and the possible underlying mechanisms.Materials and MethodsALI was induced by intranasal administration of LPS (0.5 mg/kg), and CAP (1 mg/kg) injected intraperitoneally 3 days before exposure to LPS. Then, the histopathological changes were evaluated by hematoxylin and eosin staining. Enzyme-linked immunosorbent assay and qPCR were used to detect pro-inflammatory cytokines in serum and lung tissue. The expressions of HMGB1/NF-κB, PI3K/AKT/mTOR signaling pathways and apoptosis-associated molecules were determined by Western blot and/or qPCR. In addition, the lung cell apoptosis was analyzed by TUNEL staining, and the expression and location of cleaved caspase-3 were detected by immunofluorescence analysis.ResultsCAP pretreatment significantly protected mice from LPS-induced ALI, with reduced lung wet/dry weight ratio, lung histological damage, myeloperoxidase (MPO) activity, malondialdehyde (MDA) content and pro-inflammatory cytokine levels, and significant increased superoxide dismutase (SOD) activity. In addition, CAP pretreatment significantly inhibited the high-mobility group protein B1 (HMGB1) expression, nuclear factor-kappa B (NF-κB) activation, and the PI3K/AKT/mTOR signaling pathway. Furthermore, mice pre-treated with CAP exhibited reduced apoptosis of lung tissues, with associated down-regulation of caspase-3, cleaved caspase-3, and BAX expression, and up-regulation of BCL-2.ConclusionOur data demonstrate that CAP can protect against LPS-induced ALI by inhibiting oxidative stress, inflammatory responses and apoptosis through down-regulation of the HMGB1/NF-κB and PI3K/AKT/mTOR pathways.

Hypaphorine exerts anti-inflammatory effects in sepsis induced acute lung injury via modulating DUSP1/p38/JNK pathway.

Sepsis is a systemic inflammatory response syndrome attributed to infection, while sepsis-induced acute lung injury (ALI) has high morbidity and mortality. Here, we aimed to explore the specific mechanism of hypaphorine's anti-inflammatory effects in ALI. Lipopolysaccharide (LPS) was adopted to construct ALI model both in vivo and in vitro. BEAS-2B cell viability and apoptosis was testified by the MTT assay and flow cytometry. Reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) were performed to examine the expression of proinflammatory cytokines (IL-1β, IL-6, TNF-α, and IL-18), and Western blot was adopted to examine the expression of the apoptosis-related proteins (Bax, Bcl2, and Caspase3) and the DUSP1/p38/JNK signaling pathway. At the same time, lung injury score, lactate dehydrogenase (LDH) and myeloperoxidase (MPO) activity were monitored. The dry/wet weight method was used to examine lung edema, and the total protein content in BALF was determined to test pulmonary vascular permeability. As the data suggested, hypaphorine inhibited the LPS-mediated apoptosis of alveolar epithelial cells. What is more, hypaphorine attenuated the expression of inflammatory factors (IL-1β, IL-6, TNF-α, and IL-18) and inactivated the p38/JNK signaling pathway through upregulating DUSP1 in a dose-dependent manner. Meanwhile, DUSP1 knockdown weakened the anti-inflammatory effect of hypaphorine on LPS-mediated lung injury. Furthermore, hypaphorine also relieved LPS induced ALI in rats with anti-inflammatory effects. Taken together, hypaphorine prevented LPS-mediated ALI and proinflammatory response via inactivating the p38/JNK signaling pathway by upregulating DUSP1.