Lipoxin Receptor Agonist Research Articles

Lipoxin receptor agonist and inhibition of LTA4 hydrolase prevent tight junction disruption caused by P. aeruginosa filtrate in airway epithelial cells.

Airway diseases can disrupt tight junction proteins, compromising the epithelial barrier and making it more permeable to pathogens. In people with pulmonary disease who are prone to infection with Pseudomonas aeruginosa, pro-inflammatory leukotrienes are increased and anti-inflammatory lipoxins are decreased. Upregulation of lipoxins is effective in counteracting inflammation and infection. However, whether combining a lipoxin receptor agonist with a specific leukotriene A4 hydrolase (LTA4H) inhibitor could enhance these protective effects has not to our knowledge been investigated. Therefore, we explored the effect of lipoxin receptor agonist BML-111 and JNJ26993135 a specific LTA4H inhibitor that prevents the production of pro-inflammatory LTB4 on tight junction proteins disrupted by P. aeruginosa filtrate (PAF) in human airway epithelial cell lines H441 and 16HBE-14o. Pre-treatment with BML-111 prevented an increase in epithelial permeability induced by PAF and conserved ZO-1 and claudin-1 at the cell junctions. JNJ26993135 similarly prevented the increased permeability induced by PAF, restored ZO-1 and E-cadherin and reduced IL-8 but not IL-6. Cells pre-treated with BML-111 plus JNJ26993135 restored TEER and permeability, ZO-1 and claudin-1 to the cell junctions. Taken together, these data indicate that the combination of a lipoxin receptor agonist with a LTA4H inhibitor could provide a more potent therapy.

Effect of the Lipoxin Receptor Agonist BML-111 on Cigarette Smoke Extract-Induced Macrophage Polarization and Inflammation in RAW264.7 Cells.

Macrophages are known to play a crucial role in the chronic inflammation associated with Chronic Obstructive Pulmonary Disease (COPD). BML-111, acting as a lipoxin A4 (LXA4) receptor agonist, has shown to be effective in protecting against COPD. However, the precise mechanism by which BML-111 exerts its protective effect remains unclear. In order to establish a cell model of inflammation, cigarette smoke extract (CSE) was used on the RAW264.7 cell line. Afterwards, an Enzyme-linked immunosorbent assay (ELISA) kit was employed to measure concentrations of tumor necrosis factor-α (TNF-α), interleukin-1beta (IL-1β), interleukin-18 (IL-18), and interleukin-10 (IL-10) in the cell supernatants of the RAW264.7 cells.In this study, we examined the markers of macrophage polarization using two methods: quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. Additionally, we detected the expression of Notch-1 and Hes-1 through Western blotting. BML-111 effectively suppressed the expression of pro-inflammatory cytokines TNF-α, IL-1β, and IL-18, as well as inflammasome factors NLRP3 and Caspase-1, while simultaneously up-regulating the expression of the anti-inflammatory cytokine IL-10 induced by CSE. Moreover, BML-111 reduced the expression of iNOS, which is associated with M1 macrophage polarization, and increased the expression of Arg-1, which is associated with M2 phenotype. Additionally, BML-111 downregulated the expression of Hes-1 and the ratio of activated Notch-1 to Notch-1 induced by CSE. The effect of BML-111 on inflammation and macrophage polarization was reversed upon administration of the Notch-1 signaling pathway agonist Jagged1. BML-111 has the potential to suppress inflammation and modulate M1/M2 macrophage polarization in RAW264.7 cells. The underlying mechanism may involve the Notch-1 signaling pathway.

BML-111 alleviates inflammatory response of alveolar epithelial cells via miR-494/Slit2/Robo4 signalling axis to improve acute lung injury

Acute lung injury (ALI) is a common, variously induced lung cell injury with high mortality. It is also an early stage of acute respiratory distress syndrome. BML-111 is a lipoxin A4 receptor agonist that plays an important role in inflammation. However, its function on ALI remains unclear. To explore whether BML-111 is involved in ALI and its regulatory molecular mechanism, we constructed an in vitro ALI model by stimulating primary mouse alveolar epithelial cells (AECs) with lipopolysaccharide (LPS). The downstream target of microRNA (miR)-494 was predicted by Targetscan. The apoptosis and expression of inflammatory cytokines were analysed by RT-qPCR, Western blot, and ELISA. BML-111 treatment alleviated LPS-induced apoptosis and the production of inflammatory cytokines, such as tumour necrosis factor α, interleukin (IL)-6, IL-1β, in primary mouse AECs via downregulating miR-494. MiR-494 targeted and downregulated slit guidance ligand 2 (Slit2) in primary mouse AECs. BML-111 activated the Slit2/roundabout guidance receptor 4 (Robo4) axis via downregulating miR-494 to reduce LPS-induced damage in AECs. This study elucidated that miR-494 on BML-111 alleviated LPS-induced ALI in primary mouse AECs via downregulating miR-494 and subsequently activating the Slit2/Robo4 axis. These findings provided a new idea for the prevention and treatment of ALI and respiratory distress syndrome.

Effects of Lipoxin Receptor Agonist BML-111 on Cigarette Smoke Extract-Induced Macrophage Polarization and Inflammation: Involvement of Notch Signaling Pathway

Effects of Lipoxin Receptor Agonist BML-111 on Cigarette Smoke Extract-Induced Macrophage Polarization and Inflammation: Involvement of Notch Signaling Pathway

Specialized pro-resolving mediators prevents cardiac dysfunction by modulating Ca2+ handling and NRF2 axis

Abstract Background and purpose Myocarditis is a severe inflammatory heart disease and a leading cause of sudden death in young adults; but currently no specific treatment is available. Lipoxins and their derivatives promote the resolution of inflammation contributing to recover tissue homeostasis; but their role in cardiac inflammation is poorly understood. Methods and results BML-111, a stable lipoxin A4 receptor agonist, protects against cardiac dysfunction in a murine model of experimental autoimmune myocarditis (EAM) by preventing Ca2+ mishandling. Cardiac proteomic analysis revealed an enhanced cardiac oxidative profile in EAM-induced mice with reduced activation of NRF2, a master antioxidant transcription factor. In vitro analysis showed that 15-epi-lipoxin A4 increased systolic Ca2+ release and sarcoplasmic reticulum (SR)-Ca2+ load in cardiomyocytes isolated from wild-type mice and augmented the rate of SR-Ca2+ uptake by SERCA2a, but failed to induce any functional change in cells from Nrf2−/− mice. BML-111 increased SERCA2a cardiac expression in wild-type mice, and the transcriptional activity of Nrf2 determined SERCA2a expression in human ventricular cells. Human myocarditis-positive myocardium showed a reduced expression of both ATP2A2 (SERCA2a) and NF2L2 (NRF2). Conclusions Our results demonstrated new cardioprotective mechanisms of pro-resolving lipid mediators that may emerge as innovative treatments for myocarditis. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ISCIII [PI17/01344]), Sociedad Española de Cardiología: Proyecto Traslacional 2019Fondo Europeo de Desarrollo Regional (FEDER), FSE, and CIBER-CV, a network funded by ISCIII

Specialized Pro-Resolving Mediators Protect Against Experimental Autoimmune Myocarditis by Modulating Ca <sup>2+</sup> Handling and NRF2 Activation

Myocarditis is a severe inflammatory heart disease and a precursor of dilated cardiomyopathy. Despite progress in the understanding of the disease, there is currently no specific treatment available for myocarditis. Lipoxins and their derivatives promote the resolution of inflammation, and help recover tissue homeostasis; however, their role in cardiac inflammation is poorly understood. BML-111, a stable lipoxin A4 receptor agonist, protects against cardiac dysfunction in a murine model of experimental autoimmune myocarditis (EAM) by preventing Ca2+ mishandling. Enhanced cardiac oxidative profile and reduced activation of NRF2, a master antioxidant transcription factor was revealed in EAM-induced mice. Administration of BML-111 to EAM-induced mice prevented all pathological changes, whereas co-administration of the NRF2 inhibitor luteolin to EAM-treated mice blunted the BML-111-induced activation of NRF2 and the accompanying protective effects on cardiac function and intracellular Ca2+ dynamics. In vitro analysis showed that 15-epi-lipoxin A4 increased systolic Ca2+ release and sarcoplasmic reticulum (SR)-Ca2+ load in cardiomyocytes isolated from wild-type mice and augmented the rate of SR-Ca2+ uptake by SERCA2a (SR Ca2+-ATPase), but failed to induce any functional change in cells from Nrf2-/- knockout mice. Mechanistically, BML-111 increased SERCA2a cardiac expression in wild-type mice, and regulation of the expression of NRF2 determined SERCA2a expression in human ventricular cells. Finally, human myocarditis-positive myocardium showed a reduced expression of both ATP2A2 and NFE2L2 coding genes for SERCA2a and NRF2, respectively. Our results highlight new cardioprotective mechanisms of pro-resolving lipid mediators, emerging as innovative treatments for myocarditis.

The LipoxinA4 receptor agonist BML-111 ameliorates intestinal disruption following acute pancreatitis through the Nrf2-regulated antioxidant pathway

Acute pancreatitis (AP) is characterized by excessive release of pro-inflammatory cytokines and provokes multiorgan dysfunction. Disruption of the intestinal epithelium often occurs during and following acute pancreatitis and may aggravate systemic organ injuries. Although it has been widely investigated, to date, there is no satisfactory clinical therapy to restore the inflammatory damage. BML-111 is an endogenous lipid mediator that is analogous to LipoxinA4. It has been shown that BML-111 has a stable and potent anti-inflammatory ability. However, it is unclear whether BML-111 is involved in the process of relieving acute pancreatitis and its induced intestinal barrier damage, and the underlying mechanism of this effect. Here, we demonstrated that BML-111 could enhance the expression of E-cadherin, alleviate apoptosis, and mitigate the accumulation of reactive oxygen species in intestinal epithelial cells, thereby contributing to the anti-inflammatory efficacy in vitro and in vivo. Mechanistically, BML-111 upregulates the expression of Nrf2, which is a key regulator of the antioxidant response, and activates its downstream HO-1/NQO-1 pathway to protect against oxidative stress-induced cell death and tissue injury, consequently ameliorating pancreatitis and intestinal epithelium injury. In Nrf2-deficient cell and Nrf2-knockout mouse models, the depletion of Nrf2 blocked BML-111-induced antioxidant effects and thus was unable to exert protective effects in tissue. Taken together, BML-111 attenuated AP-related intestinal injury via an Nrf2-dependent antioxidant mechanism. Targeting this pathway is a potential therapeutic approach for AP-related intestinal injury.

Intervention effect of lipoxygen receptor agonist BML-111 on acute liver injury in rats and its mechanism

Objective: To investigate the effect and mechanism of lipoxygen on acute liver injury. Methods: Twenty-four SD rats were randomly divided into 4 groups (n=6): normal control group: subcutaneous injection of olive oil at a dose of 1.8 ml/kg; model group: subcutaneous injection of 40% carbon tetrachloride(CCL4)oil (olive oil as a solvent) at a dose of 3 ml/kg; BML-111 treatment group: Lipoxin receptor agonist BML-111 was injected subcutaneously at a dose of 1 mg/kg, and treated in the same model group after 30 minutes; BOC-2 blocker group: Lipoxin receptor blocker BOC-2 was injected subcutaneously at a dose of 50 μg/kg. After 30 minutes, the treatment was the same as BML-111 group. HE staining was used to observe the pathological changes of liver tissues to judge the liver injury. Serological detection was used to determine the activities of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST); The myeloperoxidase (MPO) activity in rat liver tissue was detected by kit method; the contents of of angiotensin converting enzyme (ACE) , Angiotensin converting enzyme 2 (ACE2), angiotensin II (AngII) and angiotensin 1-7 (Ang- (1-7)) were detected by ELISA. Western Blot was used to detect the protein contents of Ang II and Ang- (1-7) in liver tissue. Results: The treatment group had less liver damage than the model group and the blocker group; BML-111 decreased the levels of ACE and AngII in serum of rats with CCL4 injury (P＜0.01) and increased the levels of ACE2 and Ang- (1 in serum -7) content (P＜0.01). BML-111 increased the content of Ang- (1-7) in liver tissue and decreased the content of AngII in CCL4 injured rat tissue. Conclusion: The results showed that the intervention effect and mechanism of lipoxygen receptor agonist BML-111 on acute liver injury in rats may be related to the regulation of AngII and Ang-(1-7).

The Lipoxin A4 Receptor Agonist BML-111 Alleviates Inflammatory Injury and Oxidative Stress in Spinal Cord Injury.

BackgroundSpinal cord injury (SCI) has a high incidence and causes serious harm. Lipoxin A4 (LXA4) receptor agonist BML-111 was reported to regulate inflammation and oxidative stress. The goal of this study was to assess whether BML-111 could protect against SCI by suppressing inflammation and oxidative stress.Material/MethodsWe developed a rat SCI model, then BML-111 was intraperitoneally injected into SCI rats to observe the BML-111 function. The pathological changes of SCI were observed with hematoxylin and eosin (HE) staining. Motor function of rats were assessed by the modified Tarlov’s scale. ELISA was used to assess the changes in levels of TNF-α, IL-1β, and IL-6. Western blot analysis was performed to assess the expressions of TNF-α, IL-1β, IL-6, Bcl2, Bax, and cleaved caspase3 in spinal cord tissue. TOS and TAS in rat serum were detected by xylenol orange method and ABTS method, respectively. The apoptotic cells in spinal cord tissue were observed with TUNEL assay.ResultsThe results indicated that BML-111 effectively improved the SCI and motor function of rats. BML-111 treatment decreased the levels of TNF-α, IL-1β, and IL-6 in serum and spinal cord tissue, as well as decreasing the levels of TOS and TAS and cell apoptosis.ConclusionsBML-111 alleviated inflammation and oxidative stress in SCI rats.

Lipoxin A4 receptor agonist BML-111 induces autophagy in alveolar macrophages and protects from acute lung injury by activating MAPK signaling

BackgroundAcute lung injury (ALI) is a life-threatening lung disease where alveolar macrophages (AMs) play a central role both in the early phase to initiate inflammatory responses and in the late phase to promote tissue repair. In this study, we examined whether BML-111, a lipoxin A4 receptor agonist, could alter the phenotypes of AM and thus present prophylactic benefits for ALI.MethodsIn vitro, isolated AMs were treated with lipopolysaccharide (LPS) to induce ALI. In response to BML-111 pre-treatment, apoptosis and autophagy of AMs were examined by flow cytometry, and by measuring biomarkers for each process. The potential involvement of MAPK1 and mTOR signaling pathway was analyzed. In vivo, an LPS-induced septic ALI model was established in rats and the preventative significance of BML-111 was assessed. On the cellular and molecular levels, the pro-inflammatory cytokines TNF-α and IL-6 from bronchoalveolar lavage were measured by ELISA, and the autophagy in AMs examined using Western blot.ResultsBML-111 inhibited apoptosis and induced autophagy of AMs in response to ALI inducer, LPS. The enhancement of autophagy was mediated through the suppression of MAPK1 and MAPK8 signaling, but independent of mTOR signaling. In vivo, BML-111 pre-treatment significantly alleviated LPS-induced ALI, which was associated with the reduction of apoptosis, the dampened production of pro-inflammatory cytokines in the lung tissue, as well as the increase of autophagy of AMs.ConclusionsThis study reveals the prophylactic significance of BML-111 in ALI and the underlying mechanism: by targeting the MAPK signaling but not mTOR pathway, BML-111 stimulates autophagy in AMs, attenuates the LPS-induced cell apoptosis, and promotes the resolution of ALI.

BML-111, a lipoxin receptor agonist, protects against acute injury via regulating the renin angiotensin-aldosterone system

BackgroundThe renin angiotensin-aldosterone system (RAAS) and lipoxins (LXs) have similar roles in many processes. We previously reported that BML-111, a Lipoxin receptor agonist, inhibited chronic injury hepatic fibrosis by regulating RAAS, but whether LXs are involved in BML-111-mediated protection from acute injury is unclear still. MethodsWe established models of acute liver/lung injury and confirmed them with histopathology and myeloperoxidase (MPO) measurements. BML-111, a lipoxin receptor agonist, was applied to mimic the effects of LXs. The contents and activities of angiotensin converting enzyme(ACE) and angiotensinconverting enzyme 2 (ACE2) were measured through ELISA and activity assay kits respectively. Angiotensin II (AngII), angiotensin-(1–7) (Ang-1–7), AngII type 1 receptor (AT1R), and Mas receptor were quantified with ELISA and Western blot. ResultsModels of acute injury were established successfully and BML-111 protected LPS-induced acute lung injury and LPS/D-GalN-induced acute liver injury. BML-111 repressed the activity of ACE, but increased the activity of ACE2. BML-111 decreased the expression levels of ACE, AngII, and AT1R, meanwhile increased the levels of ACE2, Ang-(1–7), and Mas. Furthermore, BOC-2, an inhibitor of lipoxin receptor, reversed all the effects. ConclusionBML-111 could protect against acute injury via regulation RAAS.

The anti-inflammatory effect of BML-111 on COPD may be mediated by regulating NLRP3 inflammasome activation and ROS production

The aim of this study is to investigate whether the lipoxin receptor agonist BML-111 exerts a protective effect against inflammation in a mouse model of chronic obstructive pulmonary disease (COPD) by regulating NLRP3 inflammasome activation and reactive oxygen species (ROS) production. In this study, mice were randomly divided into the following five groups: control group (Control), COPD model group (Model), BML-111 low-dose group (Low-BML), BML-111 high-dose group (High-BML) and Dexamethasone group (Dex). NLRP3 involvement and oxidative stress were evaluated. Differential cell counts in the BALF were calculated to obtain a reliable enumeration of each cell type, and the levels of TGF-β, TNF-α, IL-1β, and IL-10 in BALF were evaluated using ELISA. We found that the white blood cell and lymphocyte numbers in the BALF were significantly lower in the High-BML group than in the Model group. ELISA of the BALF showed that BML-111 reduced TGF-β and IL-1β levels to some extent. HE staining showed various degrees of reduction in inflammatory cell infiltration in the bronchopulmonary tissue and blood vessels of the Low-BML, High-BML and Dex groups. Measurement of oxidative stress showed that SOD activity was significantly upregulated and that the increase in MDA content was prevented in the High-BML and Dex groups. According to the Western blotting analysis, the levels of NLRP3, Cleaved-IL-1β and Cleaved-caspase-1 were decreased and Nrf-2 was increased to various extents in the Low-BML, High-BML and Dex groups. Based on these findings, BML-111 may prevent NLRP3 inflammasome activation and inhibit ROS production via upregulation of Nrf-2, thereby exerting an anti-inflammatory effect on COPD model mice.

BML-111 inhibits the inflammatory response and apoptosis of renal tissue in rats with hemorrhagic shock by inhibiting the MAPK pathway.

The effect of lipoxin receptor agonist BML-111 on acute kidney injury and AKI in rats with hemorrhagic shock (HS) and its mechanism were investigated. A model of hemorrhagic shock in Sprague-Dawley (SD) rats was established, and recovered after 30 min of shock. 1 mg/kg BML-111 was intraperitoneally injected at the beginning of resuscitation in group BML-111. The concentration of serum creatinine, serum KIM-1 content, NGAL and inflammatory factors were detected. Renal tissue injury was examined by HE staining; TUNEL staining was used to detect the apoptosis of rat kidney cells. Western blot was performed for the detection of the expression level of MAPK (mitogen-activated protein kinase), Bax, cytochrome C and caspase-3,9 in rat renal tissue. HE staining showed pathological changes in groups group comparing to sham group. BML-111 group had a significant decrease in renal tissue injury. The scores of renal injury in each group were in accordance with the histological changes. The expression level of inflammatory factors in HS group was significantly higher than that in sham group (p<0.05). After BML-111 intervention, the levels of inflammatory factors in renal tissue were significantly lower than those in HS group (p<0.05). Meanwhile, NGAL and KIM-1 also showed the same trend. TUNEL staining showed that compared with sham group, the number of apoptotic cells in renal tissue of HS group increased significantly, and the apoptosis rate of renal tissue cells in group BML-111 decreased significantly. Western blot showed that the expression level of JNK, p38MAPK, and apoptosis-related protein in HS group was significantly increased, whereas the expression level of p38MAPK and JNK in group BML-111 was significantly decreased. BML-111 can reduce the inflammatory response and apoptosis of renal tissue by inhibiting the activation of MAPK signaling pathway in acute renal injury induced by hemorrhagic shock.

BML-111 alleviates acute lung injury through regulating the expression of lncRNA MALAT1

BML-111 is a lipoxin receptor agonist that plays a vital role on inflammation. MALAT1 is reported to mediate lung injury. ALI rat model was established using the method of venous cannula. Pulmonary microvascular endothelial cells (PMVEC) of rats were isolated using immunomagnetic separation method. Hematoxylin-eosin (HE) staining was performed to observe the lung injury degree. Real-time PCR and western blot were performed to detect the genes expression. ELIAS was used to determine the level of TNF-α and IL-6. RNA pull-down and RIP were carried out to affirm the relationship between MALAT1 and TLR4. The lung injury score and lung wet/dry weight ratio was significantly increased in ALI rats, while BML-111 treatment significantly decreased it, the HE staining directly revealed the lung injury. The expression of MALAT1 was decreased, while TLR4 was increased in ALI rats, BML-111 stimulation significantly reversed it. MALAT1 targets TLR4 to regulate its expression. TLR4 regulated the inflammation and cell apoptosis of PMVEC via NF-κB and p38 MAPK signaling pathway. The down-regulated MALAT1 mediates the mechanism of ALI by regulating of NF-κB and p38 MAPK signaling pathways via TLR4, while BML-111 stimulation significantly alleviated the ALI by regulating the expression of MALAT1.

Lipoxin A4 and its analog suppress inflammation by modulating HMGB1 translocation and expression in psoriasis

Psoriasis is a chronic inflammatory skin disease that affects 2–3% of the global population, and there is still no known possibility of a cure. Lipoxin A4 (LXA4), an endogenous lipoxygenase-derived eicosanoid mediator, has potent dual pro-resolving and anti-inflammatory properties. BML-111 (5(S)-6(R)-7-trihydroxyheptanoic acid methyl ester), a lipoxin receptor agonist, has been previously confirmed to be equivalent to LXA4 in the anti-inflammatory processes. High mobility group box 1 (HMGB1) serves as an inflammatory cytokine when secreted extracellularly in psoriatic lesions and is involved in the development of psoriasis. Therefore, we investigated the effects of LXA4 and BML-111 on the HMGB1 signaling cascade and inflammation in lipopolysaccharide (LPS)-induced keratinocytes and imiquimod (IMQ)-induced psoriasiform dermatitis in mice. In the present study, we found that treatment with BML-111 attenuated the development of IMQ-induced psoriasiform dermatitis. Furthermore, treatment with BML-111 and LXA4 inhibited HMGB1 translocation from the nucleus to cytoplasm and downregulated the expression of toll-like receptor 4 (TLR4), receptor for advanced glycation end products (RAGE), p-ERK1/2, nuclear NF-κB p65, and proinflammatory cytokines in vivo and in vitro. Our findings indicate that LXA4 and its analog may be potential therapeutic candidates for psoriasis because of their ability to modulate the translocation and expression of HMGB1.

Pilot application of lipoxin A4 analog and lipoxin A4 receptor agonist in asthmatic children with acute episodes.

Previous studies have demonstrated that lipoxin A4 (LXA4) analogs blocked both airway hyper-responsiveness and pulmonary inflammation in a murine model of asthma. The present pilot study investigated the initial efficacy and safety of inhaled 5(S),6(R)-LXA4 methyl ester and BML-111, a LXA4 agonist, in the treatment of asthmatic children with acute episodes. A total of 50 asthmatic children diagnosed with acute moderate asthma were randomly assigned into groups and subjected to an inhalation challenge with pulmicort (n=10), ventolin (n=10), 5(S),6(R)-LXA4 methyl ester (n=10), BML-111 (n=10) or normal saline as a placebo (n=10). Pulmonary function was assessed prior to and following the challenge. Acute toxicity and safety of the inhaled 5(S),6(R)-LXA4 methyl ester and BML-111 in normal BALB/c mice were investigated prior to the current pilot study conducted in patients. Following the inhalation challenge, pulmonary function parameters in all groups with the exception of the normal saline-treated group indicated an improvement. The efficacies of 5(S),6(R)-LXA4 methyl ester and BML-111 were superior to the efficacy of pulmicort but reduced when compared to the efficacy of ventolin with regard to the improvement of pulmonary function following the inhalation challenge. No clinical adverse events were observed in the enrolled patients. All safety parameters in the full blood counts, routine urine and feces examination, electrocardiogram and liver and kidney function tests at baseline and the end of the current study were within normal limits for all patients. No significant differences in kidney or liver function tests were observed in mice treated with 5(S),6(R)-LXA4 methyl ester and BML-111. Light and electron microscopy demonstrated no airway epithelium or alveolar epithelial cell damage in the treated mice. The present preliminary study of a small sample demonstrates the initial efficacy and safety of inhaled 5(S),6(R)-LXA4 methyl ester and BML-111 in the treatment of asthmatic children with acute moderate episodes, and suggests that an inhaled LXA4 analog and LXA4 receptor agonist may exhibit potential as a novel therapeutic strategy for asthma.

BML-111 Attenuates Renal Ischemia/Reperfusion Injury Via Peroxisome Proliferator-Activated Receptor-α-Regulated Heme Oxygenase-1.

We examine whether BML-111, a lipoxin receptor agonist, inhibits renal ischemia/reperfusion (I/R) injury, and whether peroxisome proliferator-activated receptor-α (PPARα) or heme oxygenase-1 (HO-1) is involved in protective effects of BML-111 on kidney against I/R injury. Rats subjected to renal I/R injury were treated with or without BML-111. Renal histological and immunohistochemical studies were performed. Expressions of phosphorylated p38 mitogen-activated protein kinase (pp38 MAPK), phosphorylated PPARα (pPPARα), and HO-1 were assessed in NRK-52E cells exposed to BML-111. The binding activity of PPARα to peroxisome proliferator-responsive element (PPRE) on HO-1 promoter in the cells was determined. BML-111 treatment resulted in a marked reduction in the severity of histological features of renal I/R injury, and attenuated the rise in renal myeloperoxidase and malondialdehyde, blood urea nitrogen and creatinine, urinary N-acetyl-β-glucosaminidase, and leucine aminopeptidase levels caused by I/R injury. BML-111 stimulated the renal expressions of pPPARα and HO-1, and cellular messenger RNA (mRNA) and protein expressions of pPPARα and HO-1 which were both blocked by GW6471, a selective PPARα antagonist, and ZnPP-IX, a specific inhibitor of HO-1 pretreatment. The pp38 MAPK inhibitor SB203580 blocked the BML-111-induced expressions of pp38 MAPK, pPPARα, and HO-1 in NRK-52E cells. The binding activity of PPARα to PPRE in nuclear extracts of NRK-52E cells was enhanced by treatment of the cells with BML-111, and was suppressed by GW6471 and SB203580. BML-111 protects the kidney against I/R injury via activation of p38 MAPK/PPARα/HO-1 pathway.

BML-111 attenuates acute lung injury in endotoxemic mice

BackgroundBML-111 is a lipoxin receptor agonist that has protective effects in various lung injury models. We tried to elucidate whether BML-111 could mitigate lung injury in a mouse model of endotoxemia and endothelial hyperpermeability in vitro. MethodsThe effect of BML-111 on lung injury was evaluated using C57BL/6 mice and human umbilical vein endothelial cells (HUVECs). Male C57BL/6 mice were intraperitoneally injected with normal saline, BML-111, and/or the lipoxin receptor antagonist Boc-2. Then, either lipopolysaccharide (LPS) or normal saline was given intraperitoneally. Lung injury was assessed by a pathohistologic examination for neutrophil infiltration, pulmonary endothelial permeability, and inflammatory cytokines in lung tissue and bronchoalveolar lavage fluid. HUVECs were treated with or without BML-111 before incubation with LPS for 24 h. Boc-2 was also tested as a novel inhibitor of BML-111. A Transwell assay was used to evaluate the permeability of HUVECs. Junction protein expression was also assessed. ResultsBML-111 significantly improved the mouse survival rate, reduced body weight loss, attenuated the pulmonary pathologic changes, inhibited neutrophil infiltration and proinflammatory cytokine production, and mitigated endothelial hyperpermeability. The decreased expression of junction proteins induced by LPS in lung tissue and endothelial cells were upregulated by BML-111. In addition, BML-111 inhibited the activation of the Akt, ERK1/2, and p38 MAPK signaling pathways. However, the beneficial effects of BML-111 were abolished by Boc-2. ConclusionsBML-111 attenuated lung injury in endotoxemic mice and mitigated endothelial hyperpermeability by upregulating the expression of junction proteins.

Effect of BML-111 on the intestinal mucosal barrier in sepsis and its mechanism of action.

5(S),6(R)-7-trihydroxymethyl heptanoate (BML-111) is an lipoxin A4 receptor agonist, which modulates the immune response and attenuates hemorrhagic shock-induced acute lung injury. However, the role of BML-111 in sepsis and in the intestinal mucosal barrier are not well understood. Therefore, the present study was designed to investigate the effect of BML-111 on the intestinal mucosal barrier in a rat model of sepsis. Furthermore, the molecular mechanism of action of BML-111 was evaluated. The cecal ligation and puncture-induced rat model of sepsis was constructed, and BML-111 was administered at three different doses. The results revealed that BML-111 suppressed the elevation of the pro-inflammatory cytokines tumor necrosis factor-α and interleukin-6, while enhancing the elevation of the anti-inflammatory cytokine transforming growth factor-β in the intestine. In addition, BML-111 significantly upregulated rat defensin-5 mRNA expression levels and downregulated the induction of cell apoptosis as well as caspase-3 activity in the intestine. All these results demonstrated that BML-111 exerted protective effects on the intestinal mucosal barrier in sepsis. Further, it was indicated that alterations in the expression of toll-like receptor (TLR)2 and TLR4 may be one of the molecular mechanisms underlying the protective effect of BML-111. The present study therefore suggested that BML-111 may be a novel therapeutic agent for sepsis.

Roles of lipoxin A4 receptor activation and anti-interleukin-1β antibody on the toll-like receptor 2/mycloid differentiation factor 88/nuclear factor-κB pathway in airway inflammation induced by ovalbumin

Previous studies investigating the role of toll-like receptors (TLRs) in asthma have been inconclusive. It has remained elusive whether the toll-like receptors (TLR2)/mycloid differentiation factor 88 (MyD88)/nuclear factor (NF)-κB signaling pathway is involved in lipoxin A4 (LXA4)-induced protection against asthma. Therefore, the present study investigated whether ovalbumin (OVA)-induced airway inflammation is mediated by upregulation of the TLR2/MyD88/NF-κB signaling pathway, and whether it proceeds via the inhibition of the activation of the LXA4 receptor and anti-interleukin (IL)-1β antibodies. Mice with airway inflammation induced by OVA administration were treated with or without a LXA4 receptor agonist, BML-111 and anti-IL-1β antibody. Serum levels of IL-1β, IL-4, IL-8 and interferon-γ (IFN-γ) were assessed, and levels of IL-1β, IL-4, IL-8 and OVA-immunoglobulin (Ig)E, as well as leukocyte counts in the bronchoalveolar lavage fluid (BALF) were measured. Pathological features and expression of TLR2, MyD88 and NF-κB in the lungs were analyzed. Expression of TLR2 and MyD88, and activation of NF-κB in leukocytes as well as levels of IL-4, IL-6 and IL-8 released from leukocytes exposed to IL-1β were assessed. OVA treatment increased the levels of IL-1β, IL-4 and IL-8 in the serum and BLAF, the number of leukocytes and the levels of OVA-IgE in the BALF, the expression of TLR2 and MyD88, and the activation of NF-κB in the lung. These increments induced by OVA were inhibited by treatment with BML-111 and anti-IL-1β antibodies. Treatment of the leukocytes with BML-111 or TLR2 antibody, or MyD88 or NF-κB inhibitor, all blocked the IL-1β-triggered production of IL-4, IL-6 and IL-8 and activation of NF-κB. Treatment of the leukocytes with BML-111 or TLR2 antibody suppressed IL-1β-induced TLR2 and MyD88 expression. The present study therefore suggested that OVA-induced airway inflammation is mediated by the TLR2/MyD88/NF-κB pathway. IL-1β has a pivotal role in the airway inflammation and upregulation of the TLR2/MyD88/NF-κB pathway induced by OVA. BML-111 and anti-IL-1β antibody restrains the OVA-induced airway inflammation via downregulation of the TLR2/MyD88/NF-κB pathway.