Acute Lung Injury In Rats Research Articles

Acetate, a gut bacterial product, ameliorates ischemia-reperfusion induced acute lung injury in rats

Recent data suggest that short-chain fatty acids (SCFAs), the major fermentation product from gut microbial degradation of dietary fiber, have protective effects against renal ischemia–reperfusion (IR) injury, colitis, and allergic asthma. However, the effect of SCFAs on acute lung injury (ALI) caused by IR is still unclear. In this study, we examine whether SCFAs have protective effects against IR-induced ALI and explore possible protective mechanisms. IR-induced ALI was established by 40 min ischemia followed by 60 min reperfusion in isolated perfused rat lungs. Rats were randomly assigned to one of six groups: control, control + acetate (400 mg/kg), IR, and IR + acetate at one of three dosages (100, 200, 400 mg/kg). Bronchoalveolar lavage fluids (BALF) and lung tissues were obtained and analyzed at the end of the experiment. In vitro, mouse lung epithelial cells (MLE-12) subjected to hypoxia-reoxygenation (HR) were pretreated with acetate (25 mmol/L) and GPR41 or GPR43 siRNA. Acetate decreased lung weight gain, lung weight/body weight ratios, wet/dry weight ratios, pulmonary artery pressure, and protein concentration of the BALF in a dose-dependent manner for IR-induced ALI. Acetate also significantly inhibited the production of TNF-α, IL-6 and CINC-1 in the BALF. Moreover, acetate treatment restored suppressed IκB-α levels and reduced nuclear NF-κB p65 levels in lung tissues. In addition, acetate mitigated IR-induced apoptosis and tight junction disruption in injured lung tissue. In vitro analyses showed that acetate attenuated NF-κB activation and KC/CXCL-1 levels in MLE-12 cells exposed to HR. The protective effects of acetate in vitro were significantly abrogated by GPR41 or GPR43 siRNA. Acetate ameliorates IR-induced acute lung inflammation and its protective mechanism appears to be via the GPR41/43 signaling pathway. Based on our findings, acetate may provide a novel adjuvant therapeutic approach for IR-induced lung injury.

Identification of the key ferroptosis-related genes involved in sepsis progression and experimental validation in vivo.

Background: Ferroptosis has a vital role in sepsis, but the mechanism is not known. Understanding the mechanism of ferroptosis during sepsis will aid in developing improved therapeutic strategies. Methods: We used the Gene Expression Omnibus database and FerrDb database to obtain ferroptosis-related differentially expressed genes (DEGs) between sepsis patients and healthy volunteers (HVs). Analyses of PPI networks, functional enrichment, as well as use of the MCODE algorithm were used to identify key ferroptosis-related DEGs. Expression of key ferroptosis-related DEGs was verified using: GSE57065 and GSE65682 datasets; rats in which ferroptosis was induced with erastin; sepsis-induced acute lung injury (siALI) rats. The effects of acupoint catgut embedding (ACE) on ferroptosis and expression of key ferroptosis-related DEGs in the lungs of siALI rats were also observed. A Cox proportional hazard model was used to verify the effect of key ferroptosis-related DEGs on the survival of sepsis patients. Cytoscape was used to construct ceRNA networks and gene–transcription factor networks. Results: Between sepsis patients and HVs, we identified 33 ferroptosis-related DEGs. According to analyses of PPI networks and the MCODE algorithm, we obtained four modules, of which the most significant module contained nine ferroptosis-related DEGs. Functional-enrichment analyses showed that four of the nine DEGs were enriched in the MAPK signaling pathway: MAPK14, VEGFA, TGFBR1, and DUSP1. We verified expression of these four genes in GSE57065 and GSE65682 datasets and ferroptosis rats. In addition, expression of these four genes and that of the oxidative-stress indicators GSSG and MDA was upregulated, and glutathione peroxidase-4 (GPX4) expression was downregulated, in siALI rats, but ACE reversed these changes. The Cox proportional hazard model showed that survival of sepsis patients in the high-risk group was shorter than that in the low-risk group. We found that the XIST−hsa-let-7b-5p−TGFBR1/DUSP1 ceRNA network and transcription factor E2F1 may be important regulators of these four DEGs. Conclusion: Our results suggest that MAPK14, VEGFA, TGFBR1, and DUSP1 may be key regulatory targets of ferroptosis in sepsis, and that ACE pretreatment may be antioxidant treatment for sepsis and alleviate ferroptosis. These findings provide a basis for further ferroptosis-related study in sepsis and provide new targets for its treatment.

Antioxidant Biodegradable Covalent Cyclodextrin Frameworks as Particulate Carriers for Inhalation Therapy against Acute Lung Injury.

Drug therapies for acute lung injury (ALI) are far from satisfactory, primarily because drugs cannot specifically target the lungs. Direct delivery of drugs to the deep alveolar regions by inhalation administration is crucial for the treatment of ALI. However, conventional inhalable carriers such as lactose and mannitol are generally inactive. Therefore, the use of a novel pharmacologically active carrier for pulmonary delivery may produce synergetic effects in treating ALI. Considering the pathophysiological environment of ALI, which typically featured excessive reactive oxygen species (ROS) and acute inflammation, we synthesized a novel kind of biodegradable and ROS-sensitive cross-linked covalent cyclodextrin frameworks (OC-COF) with uniform inhalable particle size to treat ALI. OC-COF was devised to incorporate H2O2-scavenging peroxalate ester linkages, which could hydrolyze and eliminate ROS generated in inflammatory sites. Ligustrazine (LIG), an antioxidant and anti-inflammatory natural compound, was loaded into OC-COF and evaluated as a dry powder inhaler (LIG@OC-COF) in vitro and in vivo, showing favorable aerodynamic properties and prominent antioxidant and anti-inflammatory capacities for the synergistic effects of OC-COF and LIG. In ALI rats, inhalation of LIG@OC-COF with a one-fifth LIG dose significantly alleviated the inflammation, oxidant stress, and lung damage. Western blot analysis demonstrated that LIG@OC-COF protected the lungs by regulating the Nrf2/NF-κB signaling pathway. In summary, this study provides a novel ROS-responsive material as an inhalable particulate carrier for the improved treatment of ALI and other medical conditions.

Aspirin eugenol ester alleviates lipopolysaccharide-induced acute lung injury in rats while stabilizing serum metabolites levels.

Aspirin eugenol ester (AEE) was a novel drug compound with aspirin and eugenol esterified. AEE had various pharmacological activities, such as anti-inflammatory, antipyretic, analgesic, anti-oxidative stress and so on. In this study, it was aimed to investigate the effect of AEE on the acute lung injury (ALI) induced by lipopolysaccharide (LPS) in rats. In vitro experiments evaluated the protective effect of AEE on the LPS-induced A549 cells. The tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-1β (IL-1β) were measured in the cell supernatant. The Wistar rats were randomly divided into five groups (n = 8): control group, model group (LPS group), LPS + AEE group (AEE, 54 mg·kg−1), LPS + AEE group (AEE, 108 mg·kg−1), LPS + AEE group (AEE, 216 mg·kg−1). The lung wet-to-dry weight (W/D) ratio and immune organ index were calculated. WBCs were counted in bronchoalveolar lavage fluid (BALF) and total protein concentration was measured. Hematoxylin-Eosin (HE) staining of lung tissue was performed. Glutathione (GSH), glutathione peroxidase (GPx), catalase (CAT), antioxidant superoxide dismutase (SOD), total antioxidant capacity (T-AOC), lactate dehydrogenase (LDH), C-reactive protein (CRP), myeloperoxidase (MPO), malondialdehyde (MDA), macrophage mobility inhibitory factor (MIF), TNF-α, IL-6, and IL-1β activity were measured. The metabolomic analysis of rat serum was performed by UPLC-QTOF-MS/MS. From the results, compared with LPS group, AEE improved histopathological changes, reduced MDA, CRP, MPO, MDA, and MIF production, decreased WBC count and total protein content in BALF, pro-inflammatory cytokine levels, immune organ index and lung wet-dry weight (W/D), increased antioxidant enzyme activity, in a dose-dependent manner. The results of serum metabolomic analysis showed that the LPS-induced ALI caused metabolic disorders and oxidative stress in rats, while AEE could ameliorate it to some extent. Therefore, AEE could alleviate LPS-induced ALI in rats by regulating abnormal inflammatory responses, slowing down oxidative stress, and modulating energy metabolism.

Protective effect of breviscapine on acute lung injury in rats with infectious shock

Acute lung injury (ALI), during the progression of infectious shock, leads to systemic inflammatory response syndromewith increased pulmonary capillary membrane permeability due to pulmonary inflammation and uncontrolled inflammatoryresponses. It may cause fatality in patients. Here, we evaluated the protective effect of breviscapine on ALI in rats withinfectious shock. Sprague-Dawley (SD) rats were assigned into Sham, model [lipopolysaccharide (LPS) group], andbreviscapine treatment groups (LPS + breviscapine group) and weighed. The lung coefficient, and the wet-to-dry weightratio (W/D) and moisture content of lung tissues were calculated. The pathological changes of the lung tissues were detectedusing hematoxylin-eosin (HE) staining, and the protein expressions of interleukin-1 beta (IL-1β), IL-6, and tumor necrosisfactor-alpha (TNF-α) were determined by enzyme-linked immunosorbent assay. Western blotting was conducted to measurethe protein expressions of toll-like receptor-9 (TLR-9) and nuclear factor-kappa B (NF-κB) (p65). Compared with LPSgroup, breviscapine significantly lowered the lung coefficient and the W/D and moisture content of lung tissues, relieved thepathological changes of lung tissues, reduced the protein expression levels of IL-1β, IL-6, and TNF-α, weakened theactivation of NF-κB (p65) in lung tissues, and repressed the protein expressions of TLR-9 and NF-κB (p65).

Protective effect of forsythiaside A on acute lung injury in septic rats

To observe the protective effect of forsythiaside A on acute lung injury (ALI) in septic rats. Male Sprague-Dawley (SD) rats were randomly divided into normal control group, sham operation group, sepsis model group, and forsythiaside A intervention group, with 10 rats in each group. The rats in the normal control group did not receive any intervention; the rats in the sham operation group only underwent abdominal surgery; and those in the model group and forsythiaside A intervention group received cecal ligation and puncture (CLP) to establish the sepsis rat model. The rats in the forsythiaside A intervention group were given 75 mL/kg of forsythiaside A within 0.5 hour after operation, and repeated after 6 hours. The rats in the sham operation group and model group were given the same amount of normal saline at the same time points. The lung tissues were collected for pathological examination 12 hours after operation. The lung homogenate was prepared, and enzyme-linked immunosorbent assay (ELISA) was used to detect tumor necrosis factor-α (TNF-α), interleukins (IL-1β, IL-6). The activity of superoxide dismutase (SOD) was detected by xanthine oxidase method, and the content of malonaldehyde (MDA) was detected by colorimetry. The expression of nuclear factor-κB p65 (NF-κB p65) was detected by Western blotting. There was no significant pathological change of lung tissue in both normal control group and sham operation group, and there was no significant difference in each parameter between the two groups. The rats in the model group had interstitial infiltration of inflammatory cells, alveolar structure destruction, alveolar septum thicken, extensive alveolar hemorrhage, telangiectasia; the levels of TNF-α, IL-1β, IL-6, MDA and NF-κB p65 protein expression in lung tissue were significantly higher than those in the normal control group and sham operation group [TNF-α (ng/L): 132.81±16.15 vs. 45.08±5.98, 46.10±6.72, IL-1β (ng/L): 137.32±15.22 vs. 51.03±7.89, 50.92±8.13; IL-6 (ng/L): 138.39±14.28 vs. 51.68±7.03, 52.48±7.36; MDA (kU/g): 1.79±0.13 vs. 0.96±0.05, 0.97±0.05; NF-κB p65 protein (NF-κB p65/GAPDH): 2.82±0.23 vs. 1.76±0.12, 1.82±0.13; all P < 0.05], the activity of SOD decreased significantly (kU/g: 45.90±5.46 vs. 92.11±10.13, 93.36±10.56, both P < 0.05). The changes in lung histopathology in the forsythiaside A intervention group were obviously improved as compared with the model group, which showed less inflammatory cell infiltration, less alveolar septum thickening, less bleeding and more intact structures; the levels of TNF-α, IL-1β, IL-6, MDA and the expression of NF-κB p65 protein in lung tissue were significantly lower than those in the model group [TNF-α (ng/L): 72.48±9.78 vs. 132.81±16.15, IL-1β (ng/L): 83.85±12.46 vs. 137.32±15.22, IL-6 (ng/L): 81.88±11.89 vs. 138.39±14.28, MDA (kU/L): 1.29±0.09 vs. 1.79±0.13, NF-κB p65 protein (NF-κB p65/GAPDH): 2.29±0.19 vs. 2.82±0.23, all P < 0.05], SOD activity increased significantly (kU/g: 66.03±7.98 vs. 45.90±5.46, P < 0.05). Forsythiaside A can effectively alleviate ALI in septic rats. The mechanism may be related to down-regulate the expression of NF-κB p65 and reduce the level of inflammatory factors and free radicals in lung tissue, thereby against acute lung injury in septic rats.

Protective effect of N-acetylcysteine on acute lung injury in septic rats by inhibiting inflammation, oxidation, and apoptosis.

Objective(s):Acute lung injury (ALI) is a common comorbidity in patients with sepsis, and finding drugs that can effectively reduce its mortality is a hot spot in current research. The purpose of this study is to explore the protective mechanism of N-acetylcysteine (NAC) on ALI in septic rats.Materials and Methods:We used NAC to intervene in septic rats to evaluate the plasma inflammatory factors and lung tissue pathological damage. Biochemical methods were used to determine the levels of oxidases in lung tissue, the expression of inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) proteins, and observed lung tissue cell apoptosis.Results:NAC pretreatment decreased the mortality of septic rats, improved lung tissue pathological damage, reduced the levels of tumor necrosis factor-α, interleukin-1β, interleukin-6, interleukin-8, and malondialdehyde, and increased activity of superoxide dismutase, glutathione peroxidase, and catalase. Moreover, NAC pretreatment significantly decreased iNOS protein expression and increased eNOS protein expression in lung tissue. Meanwhile, NAC significantly decreased the number of apoptosis and the levels of Bax and Caspase-3 mRNA and increased the level of Bcl-2 mRNA in the lung tissue of septic rats. Conclusion:NAC protects ALI in septic rats by inhibiting inflammation, oxidative stress, and apoptosis.

Shp2 in Alveolar Macrophages Regulates Macrophage I Phenotype in Acute Lung Injury.

Macrophage play important role in acute lung injury (ALI). This study aims to explore the possible role of Shp2 in regulating macrophage 1 (M1) in ALI progression. ALI was induced in rats by intravenous injection of lipopolysacharide (LPS). Lentivirus was used to knock down Shp2 expression. Lungs from LPS-induced ALI rats were evaluated by H&amp;E staining and wet/dry lung weight ratio (W/D ratio) measurement. The expression of inflammatory cytokines IL-1β, TNF-α and IL-6 in bronchoalveolar lavage fluid were detected by ELISA. The expressions of M1 biomarker (iNOS) and macrophage 2 (M2) biomarker (Arg-1) in lung tissues and macrophages were measured by immunofluorescence and western blot. The ratio of M2/M1 was detected by flow cytometry. Inflammatory cytokines were highly expressed in ALI rat models, in which elevated expression of iNOS and decreased Arg-1 expression were detected. Shp2 was found to be highly expressed in lung tissues of ALI rat models. LPS treatment in NR8383 cells lead to increased M1 phenotype and elevated expression of Shp2. Suppression on Shp2 expression can counteract the LPS-induced effect and further attenuate ALI progression. Evidence collected from ALI rat and cell models showed that suppression Shp2 expression in macrophages can inhibit M1 phenotype to attenuate ALI progression.

Salidroside attenuates sepsis-associated acute lung injury through PPP1R15A mediated endoplasmic reticulum stress inhibition

BackgroundThis study explored the role and mechanism of salidroside in sepsis-associated acute lung injury (ALI). MethodSepsis-associated ALI in rats was induced by cecal ligation and perforation method, while lipopolysaccharide (LPS) was used to stimulate cell model. After the treatment of salidroside and dexamethasone (DEX), hematoxylin and eosin staining was applied to evaluate the rat lung injury. Next, the number of total cells and neutrophils in rat bronchoalveolar lavage fluid (BALF) was counted, and the lung wet/dry (W/D) ratio and water content were measured. The neutrophil elastase activity and inflammatory factor levels in BALF were detected by Elastase Assay kit and ELISA. The expressions of PPP1R15A and endoplasmic reticulum (ER) stress-related genes were detected by quantitative reverse transcription polymerase chain reaction and western blot. And the effects of silenced PPP1R15A and tauroursodeoxycholic acid (TUDCA) on cell viability, apoptosis and endoplasmic reticulum (ER) stress were determined by cell counting kit-8 assay, flow cytometry and western blot. ResultThe lung injury, inflammation and edema in sepsis model rats were alleviated by salidroside and DEX, meanwhile salidroside increased the viability and inhibited apoptosis in LPS-treated cells. The expression of PPP1R15A was decreased in sepsis models and increased by salidroside, and salidroside down-regulated the ER stress-related protein expressions in vitro and in vivo. Silenced PPP1R15A reversed the effect of salidroside on cell viability, apoptosis and ER stress, whereas TUDCA could counteract the above effect of silenced PPP1R15A. ConclusionSalidroside targeted PPP1R15A to ameliorate lung injury in sepsis through inhibiting ER stress.

PMN Apoptosis Induced by SNHG11 through the Inhibition of Endotoxin-induced Acute Lung Injury NF-κB Pathway.

This study aimed to investigate the impacts of small nucleolar RNA host gene 11 (SNHG11) on nuclear factor kappa-B (NF-κB) pathway polymorphonuclear neutrophils (PMN) apoptosis in rats with endotoxin-induced acute lung injury (ALI). Forty rats were the experimental subjects. They were randomly grouped as a control group (Group C), an endotoxin group (Group E), an inhibitor group (Group I), and an activator group (Group A), with 10 rats in each group. The endotoxin-educed ALI rat model was built. Arterial Blood Gas Test (ABGT) was performed, and the Wet/Dry (W/D) ratio of lung weight was determined. The pathological variations in rat pulmonary tissues were scrutinized and scored. PMN in peripheral blood was isolated; its apoptosis was assessed, and its total NF-κB p65 and p-NF-κB p65 expressions were assessed. The expression of SNHG11 mRNA in pulmonary tissues was assessed. Results: Compared to Group C, the W/D ratios and pathological scores of Group E, Group I, and Group A boosted notably (P <0.05), while their ABGT indicators and PMN apoptosis rates dropped (P <0.05). Compared to Group E and Group I, the W/D ratio and pathological score of Group A dropped notably (P <0.05), while its ABGT indicators and PMN apoptosis rate boosted (P <0.05). Compared to Group C, the p-NF-κB p65 and SNHG11 expressions boosted in Group E, Group I, and Group A (P <0.05); compared to Group E and Group I, the p-NF-κB p65 and SNHG11 expressions in Group A dropped (P <0.05). SNHG11 could relieve endotoxin-induced ALI, which might be associated with the acceleration of PMN apoptosis and the inhibition of the NF-κB pathway.

Effects of non-muscle myosin Ⅱ silenced bone marrow-derived mesenchymal stem cells transplantation on lung extracellular matrix in rats after endotoxin/lipopolysaccharide-induced acute lung injury

Effects of non-muscle myosin Ⅱ silenced bone marrow-derived mesenchymal stem cells transplantation on lung extracellular matrix in rats after endotoxin/lipopolysaccharide-induced acute lung injury

MicroRNA-145-5p attenuates acute lung injury via targeting ETS2.

The protective effect of microRNA (miR)-145-5p in acute lung injury (ALI) has been discovered previously. Thus, in this study, we attempted to further investigate the mechanism of miR-145-5p in ALI through the downstream E26 transformation-specific proto-oncogene 2 (ETS2)/transforming growth factor β1 (TGF-β1)/Smad pathway. A lipopolysaccharide (LPS)-induced ALI rat model was established. The expression of miR-145-5p in ALI rat lung tissues was up-regulated. Afterward, pathological damage in the lung tissue, the wet/dry (W/D) ratio, apoptosis, and serum inflammatory factor contents were observed. miR-145-5p, ETS2, TGF-β1, Smad2/3, and phosphorylated Smad2/3 levels were measured in rats. miR-145-5p expression was down-regulated, ETS2 expression was up-regulated, and the TGF-β1/Smad pathway was activated in LPS-exposed rats. Overexpression of miR-145-5p inactivated the TGF-β1/Smad pathway and attenuated ALI, as reflected by relieved pathological damage, a decreased W/D ratio, reduced apoptosis, and suppressed inflammatory response. In contrast, loss of miR-145-5p or elevated ETS2 levels worsened ALI and activated the TGF-β1/Smad pathway. Moreover, elevation of ETS2 diminished miR-145-5p-mediated protection against ALI. Evidently, miR-145-5p negatively regulates ETS2 expression and inactivates the TGF-β1/Smad pathway to ameliorate ALI in rats.

RGD-Hydrogel Improves the Therapeutic Effect of Bone Marrow-Derived Mesenchymal Stem Cells on Phosgene-Induced Acute Lung Injury in Rats

Mesenchymal stem cells (MSCs) have promising potential in the treatment of various diseases, such as the therapeutic effect of bone marrow-derived MSCs for phosgene-induced acute lung injury (P-ALI). However, MSC-related therapeutics are limited due to poor cell survival, requiring appropriate MSC delivery systems to maximise therapeutic capacity. Biomaterial RGD-hydrogel is a potential cell delivery vehicle as it can mimic the natural extracellular matrix and provide cell adhesion support. The application of RGD-hydrogel in the MSC treatment of respiratory diseases is scarce. This study reports that RGD-hydrogel has good biocompatibility and can increase the secretion of Angiopoietin-1, hepatocyte growth factor, epidermal growth factor, vascular endothelial cell growth factor, and interleukin-10 in vitro MSCs. The hydrogel-encapsulated MSCs could further alleviate P-ALI and show better cell survival in vivo. Overall, RGD-hydrogel could improve the MSC treatment of P-ALI by modulating cell survival and reparative activities. It is exciting to see more and more ways to unlock the therapeutic potential of MSCs.

Metformin Regulates Alveolar Macrophage Polarization to Protect Against Acute Lung Injury in Rats Caused by Paraquat Poisoning.

This study explored the role of metformin (MET) in regulating the polarization of alveolar macrophages to protect against acute lung injury (ALI) in rats caused by paraquat (PQ) poisoning. The in vivo studies showed that the 35 mg/kg dose of MET increased the survival rate of rats, alleviated pathological damages to the lungs and their systemic inflammation, promoted the reduction of the pro-inflammatory factors interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels, and increased the anti-inflammatory factor IL-10 levels in the rat serum. At the same time, the MET intervention decreased the expression of M1 macrophage marker iNOS in the lungs of the PQ-poisoned rats while increasing the M2 macrophage marker, Arg1, expression. In vitro, the concentration of MET > 10 mmol/L affected NR8383 viability adversely and was concentration-dependent; however, no adverse impact on NR8383 viability was observed at MET ≤ 10 mmol/L concentration, resisting the reducing effect of PQ on NR8383 vitality. The PQ-induced NR8383 model with MET intervention showed significantly reduced secretions of IL-6 and TNF-α in NR8383, and lowered expressions of M1 macrophage markers iNOS and CD86. Additionally, MET increased IL-10 secretion and the M2 macrophage markers, Arg1 and Mrcl, expressions. Therefore, we speculate that MET could regulate alveolar macrophage polarization to protect against PQ-poisoning caused ALI.

Paeoniflorin Can Improve Acute Lung Injury Caused by Severe Acute Pancreatitis through Nrf2/ARE Pathway.

Objective To evaluate the potential therapeutic effect of paeoniflorin on acute lung injury induced by severe acute pancreatitis (SAP) and to initially explore the possible protective mechanisms of paeoniflorin. Method The SAP lung injury rat model was established by retrograde injection of 5% sodium taurocholate to the cholangiopancreatic duct. H&E staining was used to detect pathological changes in rat lung tissue. W/D ratio method, serum amylase (AMY), and lipase activity were used to assess the degree of lung injury in rats. Oxidation indicators such as LDH, MDA, and SOD in lung tissue were measured. Levels of inflammatory factors TNF-α, IL-6, and IL-10 were measured in bronchoalveolar lavage fluid (BALF). At the same time, Western blot was used to detect the expression of related proteins in the Nrf2/ARE signaling pathway. Results In SAP rats, paeoniflorin treatment could significantly alleviate lung injury conditions such as pulmonary edema and inflammatory cell infiltration in lung tissue and reduce serum amylase and lipase activities. Paeoniflorin can reduce the content of LDH and MDA in lung tissue and increase the content of SOD. In addition, ELISA results showed that paeoniflorin could inhibit the levels of TNF-α and IL-6 in BALF and upregulate the levels of IL-10. Paeoniflorin could upregulate the expression of Nrf2/ARE signaling pathway proteins Cyt-Nrf2, HO-1, and NQO1 in lung tissue of SAP rats. Conclusion Paeoniflorin may improve acute lung injury in rats with severe pancreatitis by inhibiting inflammation and oxidative stress response. These effects may be related to activating the Nrf2/ARE signaling pathway.

Protection of toll-like receptor 9 against lipopolysaccharide-induced inflammation and oxidative stress of pulmonary epithelial cells via MyD88-mediated pathways.

Acute lung injury (ALI) caused by lipopolysaccharide (LPS) is a common, severe clinical syndrome. Injury caused by inflammation and oxidative stress in vascular endothelial and alveolar epithelial cells is a vital process in the pathogenesis of ALI. Toll-like receptor 9 (TLR9) is highly expressed in LPS-induced ALI rats. In this study, Beas-2B human pulmonary epithelial cells and A549 alveolar epithelial cells were stimulated by LPS, resulting in the upregulation of TLR9 in a concentrationdependent manner. Furthermore, TLR9 overexpression and interference vectors were transfected before LPS administration to explore the role of TLR9 in LPS-induced ALI in vitro. The findings revealed that inhibition of TLR9 reduced inflammation and oxidative stress while suppressing apoptosis of LPS-induced Beas-2B and A549 cells, whereas TLR9 overexpression aggravated these conditions. Moreover, TLR9 inhibition resulted in downregulated protein expression of myeloid differentiation protein 88 (MyD88) and activator activator protein 1 (AP-1), as well as phosphorylation of nuclear factor-?B (NF-kappaB), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (MAPK). The phosphorylation of extracellular-regulated protein kinases 1/2 was upregulated compared to that of cells subjected to only LPS administration, and this was reversed by TLR9 overexpression. These results indicate that inhibition of TLR9 plays a protective role against LPS-induced inflammation and oxidative stress in Beas-2B and A549 cells, possibly via the MyD88/NF-kappaB and MyD88/MAPKs/AP-1 pathways.

Berberine Suppresses Leukocyte Adherence by Downregulating CX3CL1 Expression and Shedding and ADAM10 in Lipopolysaccharide-Stimulated Vascular Endothelial Cells.

Berberine exerts therapeutic effects in inflammation-associated diseases. In a lipopolysaccharide (LPS)-induced endotoxemic acute lung injury (ALI) rat model, berberine alleviated lung injury through different anti-inflammatory mechanisms; however, treatment effects on CX3CL1 expression and shedding remain to be examined. As these processes play important roles in promoting the binding of leukocytes to the endothelium, the CX3CL1/CX3CR1 axis and its related pathways may serve as potential targets for the clinical treatment of ALI. The anti-inflammatory effects of berberine were investigated in LPS-stimulated rats, human umbilical cord vein endothelial cells (HUVECs), and THP-1 monocytic cells. Cx3cl1 expression in rat pulmonary tissues was examined using immunohistochemistry. CX3CL1, CX3CR1, RELA, STAT3, and ADAM10 levels were examined using Western blotting. CX3CL1 and ADAM10 mRNA levels were examined using quantitative real-time polymerase chain reaction. Soluble fractalkine levels in LPS-stimulated rats and HUVECs were examined using the enzyme-linked immunosorbent assay. Berberine significantly mitigated the LPS-induced upregulation of fractalkine and soluble fractalkine in rats and cultured HUVECs. Berberine mitigated the LPS-induced activation of the NF-κB and STAT3 signaling pathways. In THP-1 cells, berberine mitigated the LPS-induced upregulation of CX3CR1. Furthermore, the membrane expression of ADAM10 in LPS-stimulated HUVECs was suppressed by the berberine treatment. Berberine dose-dependently inhibited the LPS-induced activation of the CX3CL1/CX3CR1 axis and fractalkine shedding through ADAM10. These findings reveal a novel molecular mechanism underlying the inhibitory effect of berberine on monocyte adherence to the endothelium during inflammation.

Verdiperstat attenuates acute lung injury by modulating MPO/μ-calpain/β-catenin signaling

Verdiperstat, a myeloperoxidase (MPO) inhibitor, is a well-known drug used for the treatment of multisystem atrophy. However, its therapeutic effect on acute lung injury (ALI) remains to be elucidated. In this study, the effect of verdiperstat on lipopolysaccharide (LPS)-induced two-hit rat ALI model was studied in vivo. Subsequently, to explore the anti-ALI mechanism of verdiperstat, an LPS-induced injury in human pulmonary microvascular endothelial cells (HMs) was studied in vitro. The continuous administration of verdiperstat at 120 mg/kg for 3 days exerted a protective effect on the LPS-induced two-hit rat ALI model, as reflected by the change in the lung coefficient and lung pathology scores from 0.72 to 0.61 and 6.08 to 4.37, respectively. Furthermore, the values of protective adhesion protein VE-cadherin and tight junction protein claudin 5 changed from 0.42 to 0.97 and 0.25 to 0.72, but MPO, the ratio of N-μ-calpain to μ-calpain, and the distribution of β-catenin in the nucleus changed from 3.04 to 2.17, 0.62 to 0.38 and 2.25 to 0.76, respectively. LPS-induced HMs in vitro also showed similar results, including lower MPO and the distribution of β-catenin in the nucleus, but higher VE-cadherin claudin 5 and N-μ-calpain. Moreover, MPO inhibition resulted in lower μ-calpain activation and lower β-catenin in the nucleus. Our cumulative results suggest that verdiperstat alleviates ALI by strengthening VE-cadherin and claudin 5 through the inhibition of MPO/μ-calpain/β-catenin activation.

Dexmedetomidine Attenuates LPS-Induced Acute Lung Injury in Rats by Activating the Nrf2/ARE Pathway.

Background To investigate the effect of dexmedetomidine (Dex) on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats and its mechanism. Methods Eighteen SD rats were randomly divided into 3 groups (6 rats in each group): control group (intratracheal instillation of saline), ALI group (intratracheal instillation of 5 mg/kg LPS), and ALI-Dex group (tail vein injection of 50 μg/kg/h Dex + intratracheal instillation of LPS). Subsequently, the water content of lung tissues was assessed using the wet-dry (W/D) ratio and the histopathological changes of lung tissues using H&E staining. Further activities of ROS, SOD, and GSH-Px in lung tissues of rats were measured by an automatic biochemistry analyzer. ELISA was performed to detect TNF-α, IL-1β, and IL-6 expression in alveolar lavage fluid (BALF) and Western blot to detect the expression of Nrf2/ARE pathway-related proteins. Results After Dex treatment, a reduction in water content in lung tissue and an improvement of lung injury were found in the ALI rats. Compared with the ALI group, rats in the ALI-Dex group had decreased ROS activity and increased activities of SOD and GSH-Px in lung tissues. Dex-treated rats were also associated with a decrease in TNF-α, IL-1β, and IL-6 expression in alveolar lavage fluid (BALF). Additionally, increased expression levels of HO-1 and NQO1 in lung tissues and elevated expression of Nrf2 in the nucleus were shown in the ALI-Dex group compared with the ALI group. Conclusion Dex alleviates LPS-induced ALI by activating the Nrf2/ARE signaling pathway.

A new approach to sepsis treatment by rasagiline: a molecular, biochemical and histopathological study.

We aimed to investigate the effects of rasagiline on acute lung injury that develops in the sepsis model induced with the cecal ligation and puncture in rats. The rats were separated into the following six groups, Group 1: Sham, Group 2: Sham + Rasagiline 4mg/kg, Group 3: Sepsis, Group 4: Sepsis + Rasagiline 1mg/kg, Group 5: Sepsis + Rasagiline 2mg/kg, Group 6: Sepsis + Rasagiline 4mg/kg. A total of four holes were opened with a 16-gauge needle through the cecum distal to the point of ligation. Rasagiline treatment increased glutathione level and superoxide dismutase activity while decreased the malondialdehyde level after the sepsis. There was a statistically significant improvement in the doses of 2mg/kg and 4mg/kg. Rasagiline also increased Tnf-α, IL1β, IL6, NF-κβand HMGB1 gene expressions in dose-dependent at 2mg/kg and 4mg/kg doses. In increased doses, rasagiline prevent the development of edema, the formation of inflammation, and hemorrhage. Rasagiline exerts both antioxidant and anti-inflammatory effects on the cecal ligation and puncture induced acute lung injury in rats.