Myeloperoxidase inhibition decreases morbidity and oxidative stress in mice with cystic fibrosis-like lung inflammation

8-Iso-prostaglandin F2α as a biomarker of type 2 low airway inflammation and remodeling in adult asthma

BACKGROUND

Although 8-iso-prostaglandin F2a has been proposed as a potential biomarker for oxidative stress in airway diseases, its specific role in asthma remains poorly understood.

OBJECTIVE

To evaluate the diagnostic potential of 8-iso-prostaglandin F2a in assessing airway inflammation, airway remodeling, airway hyperresponsiveness, and oxidative stress in asthma.

METHODS

Blood and urine concentrations of 8-iso-prostaglandin F2a were quantified using liquid chromatography-tandem mass spectrometry in 128 adults with asthma who had maintained antiasthma medications. Their correlations with clinical data, sputum cell counts, lung function parameters, and serum markers of epithelial/neutrophil activity and airway remodeling were then analyzed.

RESULTS

The urinary 8-iso-prostaglandin F2a concentrations were significantly higher in patients with noneosinophilic asthma than in those with eosinophilic asthma (P < .05). The area under the curve was 0.678, indicating moderate diagnostic accuracy for noneosinophilic asthma. There were significant correlations with neutrophilic inflammation markers and airway remodeling markers (all P < .05). Negative correlations were observed with forced expiratory volume in 1 second (%), forced expiratory volume in 1 second/forced vital capacity, forced expiratory flow at 25% to 75% of forced vital capacity, and serum club cell protein 16 levels (all P < .05). High 8-iso-prostaglandin F2a concentrations were also noted in obese and smoking subgroups (all P < .05). However, the serum 8-iso-prostaglandin F2a concentrations were not correlated with these asthma-related parameters.

CONCLUSION

Urinary 8-iso-prostaglandin F2a concentrations are a potential biomarker for phenotyping severe asthma, particularly noneosinophilic asthma, offering oxidative stress-induced epithelial inflammation/remodeling as an additional target in asthma management.

Novel quinazoline sulfonamide-based scaffolds modulate methicillin-resistant Staphylococcus aureus (MRSA) pneumonia in immunodeficient irradiated model: Regulatory role of TGF-β

A library of new quinazoline pharmacophores bearing benzenesulfonamide moiety was designed and synthesized. Compounds 3a-n were screened for their in vitro antimicrobial activity against eight multidrug-resistant clinical isolates. Compounds 3d and 3n exhibited prominent antibacterial activity, specifically against MRSA. After exhibiting relative in vitro and in vivo safety, compound 3n was selected to assess its anti-inflammatory activity displaying promising COX-2 inhibitory activity compared to Ibuprofen. In vivo experimental MRSA pneumonia model was conducted on immunodeficient (irradiated) mice to reveal the antimicrobial and anti-inflammatory responses of compound 3n compared to azithromycin (AZ). Treatment with compound 3n (10 and 20 mg/kg) as well as AZ resulted in a significant decrease in bacterial counts in lung tissues, suppression of serum C-reactive protein (CRP), lung interleukin-6 (IL-6), myeloperoxidase activity (MPO) and transforming growth factor-β (TGF-β). Compound 3n showed a non-significant deviation of lung TGF-β1 from normal values which in turn controlled the lung inflammatory status and impacted the histopathological results. Molecular docking of 3n showed promising interactions inside the active sites of TGF-β and COX-2. Our findings present a new dual-target quinazoline benzenesulfonamide derivative 3n, which possesses significant potential for treating MRSA-induced pneumonia in an immunocompromised state.

Sumatriptan mitigates bleomycin-induced lung fibrosis in male rats: Involvement of inflammation, oxidative stress and α-SMA

INTRODUCTION

Idiopathic pulmonary fibrosis (IPF) is a fibrotic lung condition that produces symptoms including coughing which may cause by excessive accumulation of scar tissue inflammatory and oxidative stress exacerbation. Sumatriptan, utilized for migraine treatment as a selective 5-HT1B/1D receptor agonist, has demonstrated significant anti-inflammatory and antioxidant properties in multiple preclinical investigations. Operating primarily on serotonin receptors, sumatriptan leverages the diverse physiological functions of serotonin, playing a pivotal role in regulating both inflammation and oxidative stress which is particularly relevant in the context of IPF.

MATERIALS & METHODS

Thirty-five male Wistar rats were divided to five group, including: Sham (without IPF induction), control (BLM 5 mg/kg, intraperitoneally), and three fibrosis group with sumatriptan (0.5, 1, and 3 mg/kg, i.p. for 2 weeks) administration. IPF was induced by injection of BLM (single dose, 5 mg/kg intratracheally). Lung tissues were separated for measurement of myeloperoxidase (MPO) as an oxidative stress hallmark, and tumor necrosis factor-α (TNF-α), interleukin-1β (IL-β), and transforming growth factor-β (TGF-β) as inflammatory markers as well as alpha smooth muscle actin (α-SMA). Also, for histological investigations, tissue damages were assessed by Hematoxylin-eosin (H&E) and Masson's trichrome staining method.

RESULTS

BLM-induced fibrosis could increase α-SMA, MPO, TNF-α, IL-1β, and TGF-β, while treatment with sumatriptan has reversed the α-SMA, MPO, and IL-1β levels. Moreover, the results of H&E and Masson's trichrome staining indicated that sumatriptan (1 and 3 mg/kg) reduced tissue damages, alveolar wall thickness, collagen accumulation, and pulmonary fibrosis induced by BLM.

CONCLUSION

According to the data achieved from this study, Sumatriptan appears to have therapeutic benefits in IPF, possibly via reducing α-SMA as well as inflammation and the toxicity caused by oxidative stress.

Umbelliferone reduces inflammation and ligature-induced osteoclastic alveolar bone resorption in mice

AIMS

This study aimed to investigate the effects of Umbelliferone (UMB) on the inflammation underlying alveolar bone resorption in mouse periodontitis.

METHODS

Male Swiss mice subjected to a ligature of molars were grouped as non-treated (NT), received UMB (15, 45, or 135 mg/kg) or saline daily for 7 days, respectively, and were compared with naïve mice as control. Gingival tissues were evaluated by myeloperoxidase (MPO) activity and interleukin-1β level by ELISA. The bone resorption was directly assessed on the region between the cement-enamel junction and the alveolar bone crest. Microscopically, histomorphometry of the furcation region, immunofluorescence for nuclear factor-kappa B (NF-ĸB), and immunohistochemistry for tartrate-resistant acid phosphatase (TRAP), and cathepsin K (CTSK) were performed. Systemically, body mass variation and leukogram were analyzed.

RESULTS

Periodontitis significantly increased MPO activity, interleukin-1β level, and NF-ĸB+ immunofluorescence, and induced severe alveolar bone and furcation resorptions, besides increased TRAP+ and CTSK+ cells compared with naïve. UMB significantly prevented the inflammation by reducing MPO activity, interleukin-1β level, and NF-ĸB+ intensity, besides reduction of resorption of alveolar bone and furcation area, and TRAP+ and CTSK+ cells compared with the NT group. Periodontitis or UMB treatment did not affect the animals systemically.

CONCLUSION

UMB improved periodontitis by reducing inflammation and bone markers.

The Roles of Neutrophil-Derived Myeloperoxidase (MPO) in Diseases: The New Progress

Myeloperoxidase (MPO) is a heme-containing peroxidase, mainly expressed in neutrophils and, to a lesser extent, in monocytes. MPO is known to have a broad bactericidal ability via catalyzing the reaction of Cl- with H2O2 to produce a strong oxidant, hypochlorous acid (HOCl). However, the overproduction of MPO-derived oxidants has drawn attention to its detrimental role, especially in diseases characterized by acute or chronic inflammation. Broadly speaking, MPO and its derived oxidants are involved in the pathological processes of diseases mainly through the oxidation of biomolecules, which promotes inflammation and oxidative stress. Meanwhile, some researchers found that MPO deficiency or using MPO inhibitors could attenuate inflammation and tissue injuries. Taken together, MPO might be a promising target for both prognostic and therapeutic interventions. Therefore, understanding the role of MPO in the progress of various diseases is of great value. This review provides a comprehensive analysis of the diverse roles of MPO in the progression of several diseases, including cardiovascular diseases (CVDs), neurodegenerative diseases, cancers, renal diseases, and lung diseases (including COVID-19). This information serves as a valuable reference for subsequent mechanistic research and drug development.

Myeloperoxidase-Sensitive Magnetic Resonance Imaging Assesses Inflammatory Activation State in Experimental Mouse Acute Gout

BACKGROUND

A novel myeloperoxidase-activatable manganese-based (MPO-Mn) MRI probe may enable the activation state of inflammatory foci to be detected and monitored noninvasively.

PURPOSE

To evaluate the inflammatory response in a mouse model of acute gout using MPO as an imaging biomarker and a potential therapeutic target.

STUDY TYPE

Prospective.

ANIMAL MODEL

A total of 40 male Swiss mice with monosodium urate crystals induced acute gout.

FIELD STRENGTH/SEQUENCE

A 3.0 T/T1-weighted imaging with 2D fast spoiled gradient recalled echo and T2-weighted imaging with fast recovery fast spin-echo sequences.

ASSESSMENT

The difference in contrast-to-noise ratio between left hind limb (lesion) and right hind limb (internal reference) (ΔCNR), and normalized signal-to-noise ratio (nSNR) on the right hind limb were calculated and compared. The expression level and activity of myeloperoxidase (MPO) were analyzed using western blotting and spectrophotometric quantitation activity assay. MPO-positive cell infiltration and lesion volume were evaluated using immunofluorescence staining and T2-weighted images, respectively.

STATISTICAL TESTS

Student's t test. A P-value less than 0.05 was considered to be statistically significant.

RESULTS

MPO-Mn resulted in a significantly higher ΔCNR than Gd-DTPA (22.54 ± 1.86 vs. 13.90 ± 2.22) but lower nSNR on the reference right hind limb (1.08 ± 0.07 vs. 1.21 ± 0.08). Compared to the nontreatment group, MPO-inhibition resulted in a significantly reduced contrast enhancement at the lesion (17.81 ± 1.58 vs. 22.96 ± 3.12), which was consistent with a remission of the inflammatory response, as evidenced by a substantial reduction of lesion volume (0.55 ± 0.16 mm3 /g vs. 1.14 ± 0.15 mm3 /g), myeloperoxidase expression level (0.98 ± 0.09 vs. 1.48 ± 0.19) and activity (0.75 ± 0.12 vs. 1.12 ± 0.07), and inflammatory cell recruitment.

DATA CONCLUSION

MPO-Mn MRI has potential to evaluate the activation state of inflammatory foci in the experimental model of acute gout.

EVIDENCE LEVEL

1.

TECHNICAL EFFICACY

Stage 1.

Loss of CFTR function in macrophages alters the cell transcriptional program and delays lung resolution of inflammation

Cystic fibrosis (CF) is an autosomal recessive genetic disorder caused by mutations in the CF Transmembrane-conductance Regulator (CFTR) gene. The most severe pathologies of CF occur in the lung, manifesting as chronic bacterial infection, persistent neutrophilic inflammation, and mucopurulent airway obstruction. Despite increasing knowledge of the CF primary defect and the resulting clinical sequelae, the relationship between the CFTR loss of function and the neutrophilic inflammation remains incompletely understood. Here, we report that loss of CFTR function in macrophages causes extended lung inflammation. After intratracheal inoculation with Pseudomonas aeruginosa, mice with a macrophage-specific Cftr-knockout (Mac-CF) were able to mount an effective host defense to clear the bacterial infection. However, three days post-inoculation, Mac-CF lungs demonstrated significantly more neutrophil infiltration and higher levels of inflammatory cytokines, suggesting that Mac-CF mice had a slower resolution of inflammation. Single-cell RNA sequencing revealed that absence of CFTR in the macrophages altered the cell transcriptional program, affecting the cell inflammatory and immune responses, antioxidant system, and mitochondrial respiration. Thus, loss of CFTR function in macrophages influences cell homeostasis, leading to a dysregulated cellular response to infection that may exacerbate CF lung disease.

Natural Targeting Potent ROS-Eliminating Tungsten-Based Polyoxometalate Nanodots for Efficient Treatment of Pulmonary Hypertension

Pulmonary hypertension (PH) is a disease of pulmonary artery stenosis and blockage caused by abnormal pulmonary artery smooth muscle cells (PASMCs), with high morbidity and mortality. High levels of reactive oxygen species (ROS) in pulmonary arteries play a crucial role in inducing phenotypic switch and abnormal proliferation of PASMCs. However, antioxidants are rarely approved for the treatment of PH because of a lack of targeting and low bioavailability. In this study, the presence of an enhanced permeability and retention effect (EPR)-like effect in the pulmonary arteries of PH is revealed by tissue transmission electron microscopy (TEM). Subsequently, for the first time, tungsten-based polyoxometalate nanodots (WNDs) are developed with potent elimination of multiple ROS for efficient treatment of PH thanks to the high proportion of reduced W5+ . WNDs are effectively enriched in the pulmonary artery by intravenous injection because of the EPR-like effect of PH, and significantly prevent the abnormal proliferation of PASMCs, greatly improve the remodeling of pulmonary arteries, and ultimately improve right heart function. In conclusion, this work provides a novel and effective solution to the dilemma of targeting ROS for the treatment of PH.

The Epithelial Sodium Channel-An Underestimated Drug Target

Epithelial sodium channels (ENaC) are part of a complex network of interacting biochemical pathways and as such are involved in several disease states. Dependent on site and type of mutation, gain- or loss-of-function generated symptoms occur which span from asymptomatic to life-threatening disorders such as Liddle syndrome, cystic fibrosis or generalized pseudohypoaldosteronism type 1. Variants of ENaC which are implicated in disease assist further understanding of their molecular mechanisms in order to create models for specific pharmacological targeting. Identification and characterization of ENaC modifiers not only furthers our basic understanding of how these regulatory processes interact, but also enables discovery of new therapeutic targets for the disease conditions caused by ENaC dysfunction. Numerous test compounds have revealed encouraging results in vitro and in animal models but less in clinical settings. The EMA- and FDA-designated orphan drug solnatide is currently being tested in phase 2 clinical trials in the setting of acute respiratory distress syndrome, and the NOX1/ NOX4 inhibitor setanaxib is undergoing clinical phase 2 and 3 trials for therapy of primary biliary cholangitis, liver stiffness, and carcinoma. The established ENaC blocker amiloride is mainly used as an add-on drug in the therapy of resistant hypertension and is being studied in ongoing clinical phase 3 and 4 trials for special applications. This review focuses on discussing some recent developments in the search for novel therapeutic agents.

Protective role of FBXL19 in Streptococcus pneumoniae-induced lung injury in pneumonia immature mice

OBJECTIVE

Streptococcus pneumoniae (Spn) is a common pathogen for pediatric pneumonia and leads to severe lung injury. This study is conducted to analyze the role of F-box and leucine rich repeat protein 19 (FBXL19) in Spn-induced lung injury in immature mice.

METHODS

Immature mice were infected with Spn to record the survival rates and bacterial loads in bronchoalveolar lavage fluid. Levels of FBXL19 and FOXM1 in lung tissues were determined via real-time quantitative polymerase chain reaction or Western blotting. After the interference of FBXL19, its impacts on lung inflammatory injury were appraised by the lung wet/dry weight ratio, myeloperoxidase activity, hematoxylin and eosin staining, and enzyme-linked immunosorbent assay. The binding of FBXL19 to forkhead box M1 (FOXM1) in mouse lung epithelial cells was determined. After MG132 treatment, the protein and ubiquitination levels of FOXM1 were measured. The functional rescue experiments were performed to analyze the role of FOXM1 in FBXL19-regulated lung injury.

RESULTS

FBXL19 was downregulated while FOXM1 was upregulated in lung tissues of Spn-infected immature mice. Overexpression of FBXL19 reduced the degree of lung injury and inflammation. FBXL19 can bind to FOXM1 to reduce its protein level via ubiquitination degradation. MG132 reduced the ubiquitination and increased the protein level of FOXM1. Overexpression of FOXM1 reversed the protective role of FBXL19 overexpression in lung injury of Spn immature mice.

CONCLUSION

FBXL19 was downregulated by Spn and FBXL19 overexpression alleviated lung injury by inducing ubiquitination and degradation of FOXM1 in Spn immature mice.

Non-Canonical Functions of Myeloperoxidase in Immune Regulation, Tissue Inflammation and Cancer

Myeloperoxidase (MPO) is one of the most abundantly expressed proteins in neutrophils. It serves as a critical component of the antimicrobial defense system, facilitating microbial killing via generation of reactive oxygen species (ROS). Interestingly, emerging evidence indicates that in addition to the well-recognized canonical antimicrobial function of MPO, it can directly or indirectly impact immune cells and tissue responses in homeostatic and disease states. Here, we highlight the emerging non-canonical functions of MPO, including its impact on neutrophil longevity, activation and trafficking in inflammation, its interactions with other immune cells, and how these interactions shape disease outcomes. We further discuss MPO interactions with barrier forming endothelial and epithelial cells, specialized cells of the central nervous system (CNS) and its involvement in cancer progression. Such diverse function and the MPO association with numerous inflammatory disorders make it an attractive target for therapies aimed at resolving inflammation and limiting inflammation-associated tissue damage. However, while considering MPO inhibition as a potential therapy, one must account for the diverse impact of MPO activity on various cellular compartments both in health and disease.

Betaine ameliorates acute sever ulcerative colitis by inhibiting oxidative stress induced inflammatory pyroptosis

SCOPE

Betaine rich in beet is used as an important source of human nutrition. Here we aimed to explore whether betaine supplementation can protect against acute sever ulcerative colitis (ASUC) and the underlying mechanism METHODS AND RESULTS: : ASUC model was induced by dextran sulfate sodium (DSS), and effects of betaine as a methyl donor on ASUC were evaluated. Betaine mitigated the changes, e.g., elevated DAI, weight lose, spleen enlargement, colon shortening and disordered colonic mucosa. We then verified the protective effects of betaine on colonic barrier integrity in ASUC through examining tight junction proteins by western blot and immunofluorescence. Spectrophotometry method and western blot confirmed that betaine can decrease levels of oxidative markers (MDA, MPO, NOS and COX2), and promote expressions of antioxidant proteins (GSH, NRF2, CAT and SOD1). Further, betaine prevented colonic inflammatory pyroptosis by blocking expressions of NLRP3 inflammasome complex (NLRP3, ASC and cleaved-caspase 1), N terminal-GSDMD, and release of relevant inflammatory factors.

CONCLUSION

Betaine inhibits colonic oxidative stress induced inflammatory pyroptosis to alleviate ASUC, which shows therapeutic potential against colitis and other acute inflammatory disorder. This article is protected by copyright. All rights reserved.

Cystic Fibrosis and Oxidative Stress: The Role of CFTR

There is substantial evidence in the literature that patients with cystic fibrosis (CF) have higher oxidative stress than patients with other diseases or healthy subjects. This results in an increase in reactive oxygen species (ROS) and in a deficit of antioxidant molecules and plays a fundamental role in the progression of chronic lung damage. Although it is known that recurrent infection–inflammation cycles in CF patients generate a highly oxidative environment, numerous clinical and preclinical studies suggest that the airways of a patient with CF present an inherently abnormal proinflammatory milieu due to elevated oxidative stress and abnormal lipid metabolism even before they become infected. This could be directly related to cystic fibrosis transmembrane conductance regulator (CFTR) deficiency, which appears to produce a redox imbalance in epithelial cells and extracellular fluids. This review aims to summarize the main mechanism by which CFTR deficiency is intrinsically responsible for the proinflammatory environment that characterizes the lung of a patient with CF.

Neutrophil extracellular traps in chronic lung disease: implications for pathogenesis and therapy

Neutrophilic inflammation has a key role in the pathophysiology of multiple chronic lung diseases. The formation of neutrophil extracellular traps (NETs) has emerged as a key mechanism of disease in neutrophilic lung diseases including asthma, COPD, cystic fibrosis and, most recently, bronchiectasis. NETs are large, web-like structures composed of DNA and anti-microbial proteins that are able to bind pathogens, prevent microbial dissemination and degrade bacterial virulence factors. The release of excess concentrations of proteases, antimicrobial proteins, DNA and histones, however, also leads to tissue damage, impaired mucociliary clearance, impaired bacterial killing and increased inflammation. A number of studies have linked airway NET formation with greater disease severity, increased exacerbations and overall worse disease outcomes across the spectrum of airway diseases. Treating neutrophilic inflammation has been challenging in chronic lung disease because of the delicate balance between reducing inflammation and increasing the risk of infections through immunosuppression. Novel approaches to suppressing NET formation or the associated inflammation are in development and represent an important therapeutic target. This review will discuss the relationship between NETs and the pathophysiology of cystic fibrosis, asthma, COPD and bronchiectasis, and explore the current and future development of NET-targeting therapies.

NETs contribute to the pathophysiology of chronic lung disease. Immunomodulating therapies that may reduce inflammatory mediators and NET formation, without compromising bacterial clearance, offer a new treatment path for patients. https://bit.ly/3fyJC6I

Therapeutic enzymes as non-conventional targets in cardiovascular impairments:A Comprehensive Review

Over the last few decades, substantial progress has been made towards the understanding of cardiovascular diseases (CVDs). In-depth mechanistic insights have also provided opportunities to explore novel therapeutic targets and treatment regimens to be discovered. Therapeutic enzymes are an example of such opportunities. The balanced functioning of such enzymes protects against a variety of CVDs while on the other hand, even a small shift in the normal functioning of these enzymes may lead to deleterious outcomes. Owing to the great versatility of these enzymes, inhibition and activation are key regulatory approaches to counter the onset and progression of several cardiovascular impairments. While cardiovascular remedies are already available in excess and of course they are efficacious, a comprehensive description of novel therapeutic enzymes to combat CVDs is the need of the hour. In light of this, the regulation of the functional activity of these enzymes also opens a new avenue for the treatment approaches to be employed. This review describes the importance of non-conventional enzymes as potential candidates in several cardiovascular disorders while highlighting some of the recently targeted therapeutic enzymes in CVDs.

Current and novel therapeutic strategies for the management of cystic fibrosis

Introduction: Cystic fibrosis (CF), is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and affects thousands of people throughout the world. Lung disease is the leading cause of death in CF patients. Despite the advances in treatments, the management of CF mainly targets symptoms. Recent CFTR modulators however target common mutations in patients, alleviating symptoms of CF. Unfortunately, there is still no approved treatments for patients with rare mutations to date.Areas covered: This paper reviews current treatments of CF that mitigate symptoms and target genetic defects. The use of gene and drug delivery systems such as viral or non-viral vectors and nano-compounds to enhance CFTR expression and the activity of antimicrobials against chronic pulmonary infections respectively, will also be discussed.Expert opinion: Nano-compounds tackle biological barriers to drug delivery and revitalize antimicrobials, anti-inflammatory drugs and even genes delivery to CF patients. Gene therapy and gene editing are of particular interest because they have the potential to directly target genetic defects. Nanoparticles should be formulated to more specifically target epithelial cells, and biofilms. Finally, the development of more potent gene vectors to increase the duration of gene expression and reduce inflammation is a promising strategy to eventually cure CF.

Plants derived therapeutic strategies targeting chronic respiratory diseases: Chemical and immunological perspective

The apparent predicament of the representative chemotherapy for managing respiratory distress calls for an obligatory deliberation for identifying the pharmaceuticals that effectively counter the contemporary intricacies associated with target disease. Multiple, complex regulatory pathways manifest chronic pulmonary disorders, which require chemotherapeutics that produce composite inhibitory effect. The cost effective natural product based molecules hold a high fervor to meet the prospects posed by current respiratory-distress therapy by sparing the tedious drug design and development archetypes, present a robust standing for the possible replacement of the fading practice of poly-pharmacology, and ensure the subversion of a potential disease relapse. This study summarizes the experimental evidences on natural products moieties and their components that illustrates therapeutic efficacy on respiratory disorders.

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Plant derived therapeutics for managing chronic respiratory disorders.

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Activity of natural product based molecules on key regulatory pathways of COPD.

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Preclinical evidence for the efficacy of natural product moieties.

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Clinical significance of plant derived molecules in pulmonary distress.