Uncovering the Role of Oxidative Imbalance in the Development and Progression of Bronchial Asthma

Protective effect of Lactiplantibacillus plantarum CCFM8661 against heavy metal mixture-induced liver and kidney injury in mice

Human health and the ecological balance are both gravely threatened by heavy metal pollution brought on by global industrialization. Probiotics are thought to represent a novel class of medicinal products for reducing heavy metal toxicity. Though simultaneous poisoning of numerous heavy metals is more prevalent, the majority of current studies on probiotics in the treatment of heavy metal poisoning concentrate on a single heavy metal. Thus, a mouse damage model was created in this investigation using five heavy metals (Pb, Cd, Hg, Cr, and As), and Lactiplantibacillus plantarum CCFM8661 was utilized as an intervention therapy. The oxidative stress markers, including superoxide dismutase (SOD), catalase (CAT), antioxidant capacity (T-AOC), and malondialdehyde (MDA), were evaluated in the blood, liver, and kidney tissues of mice throughout the experiment by tracking changes in body weight. Additionally, the amounts of five heavy metals were measured in the liver and kidney tissues. The alleviation of tissue damage and the detoxifying activity of L. plantarum CCFM8661 in mice with combined heavy metal intoxication were assessed by histopathological examination of liver and kidney tissues. Results revealed that during the test period, L. plantarum CCFM8661 significantly reduced the content of MDA and the contents of Pb, Cd, Hg, Cr, and As in liver and kidney tissues, while also significantly increasing weight gain and the activities of SOD, CAT, and T-AOC in mouse blood, liver, and kidney tissues compared to the model group. Mouse liver and kidney tissue damage from combined heavy metal exposure was considerably lessened by L. plantarum CCFM8661 when compared to the model group, according to H&E staining. This study demonstrates that L. plantarum CCFM8661 may be utilized as a useful intervention for the treatment of combined heavy metal poisoning by efficiently reducing the harm that heavy metals do to the body and maintaining bodily health.

Unraveling the Molecular Regulation of Ferroptosis in Respiratory Diseases

Ferroptosis, a type of programmed cell death that relies on iron, is distinct in terms of its morphological, biochemical and genetic features. Unlike other forms of cell death, such as autophagy, apoptosis, necrosis, and pyroptosis, ferroptosis is primarily caused by lipid peroxidation. Cells that die due to iron can potentially trigger an immune response which intensifies inflammation and causes severe inflammatory reactions that eventually lead to multiple organ failure. In recent years, ferroptosis has been identified in an increasing number of medical fields, including neurological pathologies, chronic liver diseases and sepsis. Ferroptosis has the potential to cause an inflammatory tempest, with many of the catalysts and pathological indications of respiratory ailments being linked to inflammatory reactions. The growing investigation into ferroptosis in respiratory disorders has also garnered significant interest to better understand the mechanism of ferroptosis in these diseases. In this review, the recent progress in understanding the molecular control of ferroptosis and its mechanism in different respiratory disorders is examined. In addition, this review discusses current challenges and prospects for understanding the link between respiratory diseases and ferroptosis.

Determining superoxide dismutase content and catalase activity in mammalian cell lines

Traditional methods for determining superoxide dismutase (SOD) content and catalase (CAT) activity rely on measuring the absorbance of individual tissue (biological) samples using a cuvette and spectrophotometer, rather than cell cultures. Although there are kits available for SOD and CAT assays, these allow for high-throughput analysis of samples and might be too expensive for research laboratories in countries from the Global South, such as South Africa. This paper describes a simple and cost-effective method to determine SOD content and CAT activity in mammalian cell cultures following exposure to environmental chemical mixtures by measuring absorbance in 96-well microplates. Moreover, the equipment used for this method is considered standard for cell culture laboratories, while the reagents and consumables are easily obtainable.•Antioxidant enzyme levels can be measured in vitro in cell cultures.•The supernatant obtained can be used to determine protein concentration, SOD content, and CAT activity.•This method is simple and affordable, allowing for the analysis of multiple samples (up to 32 samples per microplate).

Follow-up of patients with a 5-year survival after paraquat poisoning using computed tomography images and spirometry

OBJECTIVES

The study aimed to examine long-term survival of patients with acute paraquat poisoning using computed tomography (CT) images and spirometry.

METHODS

A total of 36 patients with long-term survival after paraquat poisoning were followed-up and divided into mild (11 patients), moderate (17 patients), and severe (8 patients) paraquat poisoning groups. Differences among the groups were compared using clinical indicators, such as peripheral capillary oxygen saturation, arterial partial pressure of oxygen and 6-min walk test (6-MWT), chest CT, spirometry, and serum immunoglobulin E (IgE).

RESULTS

The 6-MWT distance was significantly shorter in the severe paraquat poisoning group than that in the mild and moderate paraquat poisoning groups. In the mild paraquat poisoning group, CT revealed no obvious lung injury, and spirometry showed normal lung function in most patients. In moderate or severe paraquat poisoning group, CT images showed fibrotic lesions as cord-like high-density shadows, reticulations, and honeycombs. In addition, other pulmonary changes, including bronchiectasis, increased lung transparency, and pulmonary bullae, were discovered. In moderate or severe paraquat poisoning group, obvious obstructive ventilation dysfunction with slight restrictive and diffuse impairment were observed in some patients, with positive bronchial relaxation test and high serum IgE level.

CONCLUSION

In the long-term follow-up, patients with severe paraquat poisoning showed the lowest exercise endurance. In moderate or severe paraquat poisoning group, CT images revealed diversified changes, not only dynamic evolution of pulmonary fibrosis process, but also signs of bronchiectasis, and chronic obstructive pulmonary disease. Some patients with moderate or severe paraquat poisoning developed obstructive ventilatory dysfunction with airway hyperresponsiveness.

Ferroptosis triggers airway inflammation in asthma

Ferroptosis is a regulatory cell death characterized by intracellular iron accumulation and lipid peroxidation that leads to oxidative stress. Many signaling pathways such as iron metabolism, lipid metabolism, and amino acid metabolism precisely regulate the process of ferroptosis. Ferroptosis is involved in a variety of lung diseases, such as acute lung injury, chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis. Increasing studies suggest that ferroptosis is involved in the development of asthma. Ferroptosis plays an important role in asthma. Iron metabolism disorders, lipid peroxidation, amino acid metabolism disorders lead to the occurrence of ferroptosis in airway epithelial cells, and then aggravate clinical symptoms in asthmatic patients. Moreover, several regulators of ferroptosis are involved in the pathogenesis of asthma, such as Nrf2, heme oxygenase-1, mevalonate pathway, and ferroptosis inhibitor protein 1. Importantly, ferroptosis inhibitors improve asthma. Thus, the pathogenesis of ferroptosis and its contribution to the pathogenesis of asthma help us better understand the occurrence and development of asthma, and provide new directions in asthma treatment. This article aimed to review the role and mechanism of ferroptosis in asthma, describing the relationship between ferroptosis and asthma based on signaling pathways and related regulatory factors. At the same time, we summarized current observations of ferroptosis in eosinophils, airway epithelial cells, and airway smooth muscle cells in asthmatic patients.

Involvement of Cu-containing amine oxidases in the development of lung pathology in ovalbumin-induced bronchial asthma in guinea pigs

Bronchial asthma is developed as an immune response to allergen challenges accompanied by inflammation and fibrosis implicated in airway remodeling. To reveal the causative implication of Cu-containing amino oxidases semicarbazide-sensitive amine oxidase (SSAO), DAO and lysyl oxidase (LOX) in BA development we used their irreversible inhibitor semicarbazide and guinea pig model of BA induced by ovalbumin. Semicarbazide was introduced to asthmatic animals via drink or inhalation. At the 16th week after disease induction, the increase in the activity of pro-inflammatory SSAO and DAO in plasma (1.6 and 2 times, respectively) was observed. The introduction of semicarbazide to asthmatic animals via drink or inhalation significantly decreased activities of these enzymes compared to the untreated asthmatic animals. A considerable­ increase in IL-13 content and LOX activity in the lung tissue of asthmatic animals were observed that evidenced airway inflammation and pulmonary fibrosis development. The uptake of semicarbazide by guinea pigs with bronchial asthma led to normalization of LOX activity. Histological studies confirmed that semicarbazide attenuated morphopathological changes in the lungs of asthmatic animals. Thus, the data obtained indicate the direct participation of the studied enzymes in the progression of pathological processes in atopic bronchial asthma as well as the potential use of semicarbazide as a drug in complex anti-asthmatic therapy. Keywords: atopic bronchial asthma, histaminase/diamine oxidase, IL-13, lysyl oxidase, nitric oxide, semicarbazide, semicarbazide sensitive amine oxidase

Phytochemical Profiling, Antioxidant, Antimicrobial and Cholinesterase Inhibitory Effects of Essential Oils Isolated from the Leaves of Artemisia scoparia and Artemisia absinthium

The current studies were focused on the phytochemical profiling of two local wild Artemisia species, Artemisia scoparia and Artemisia absinthium leaves’ essential oils, extracted via the hydro distillation method along with evaluation of their antioxidant as well as antimicrobial effects. The constituents of EOs were identified using a combined gas chromatography-mass spectrometric (GC-MS) technique. A total of 25 compounds in A. scoparia essential oil (EOAS) were identified, and 14 compounds with percentage abundance of >1% were tabulated, the major being tocopherol derivatives (47.55%). A total of nine compounds in Artemisia absinthium essential oil (EOAA) were enlisted (% age > 1%), the majority being oleic acid derivatives (41.45%). Strong antioxidant effects were pronounced by the EOAS in DPPH (IC50 = 285 ± 0.82 µg/mL) and in ABTS (IC50 = 295 ± 0.32 µg/mL) free radical scavenging assays. Both the EOs remained potent in inhibiting the growth of bacterial species; Escherichia coli (55−70%) and Shigella flexneri (60−75%) however remained moderately effective against Bacillus subtilis as well as Staphylococcus aureus. Both EOAS and EOAA strongly inhibited the growth of the tested fungal species, especially Aspergillus species (up to 70%). The oils showed anti-cholinesterase potential by inhibiting both Acetylcholinesterase (AChE; IC50 = 30 ± 0.04 µg/mL (EOAS), 32 ± 0.05 µg/mL (EOAA) and Butyrylcholinesterase (BChE; IC50 = 34 ± 0.07 µg/mL (EOAS), 36 ± 0.03 µg/mL (EOAA). In conclusion, the essential oils of A. scoparia and A. absinthium are promising antioxidant, antimicrobial and anticholinergic agents with a different phytochemical composition herein reported for the first time.

HDM induces distinct immunometabolic phenotype in macrophages in TLR4-dependent manner

Asthma is one of the most common chronic diseases. In many cases it is preceded by the development of an immune response to allergens such as animal fur, dust, pollens and etc. In human population this disease is heterogeneous, and no selective drugs are available at the moment for some endotypes of asthma. The role of the adaptive immune system in the pathogenesis of asthma was extensively studied, while the role of innate immune cells, in particular myeloid cells, was not sufficiently addressed. Myeloid cells, such as macrophages and dendritic cells, are characterized by high plasticity, heterogenicity and ability to undergo polarization in response to various pathogenic stimuli, including those engaging innate immune receptors. Recently, special attention was drawn to the link between polarization of macrophages and cell metabolism. We hypothesized that immunometabolic reprogramming of myeloid cells, in particular, of macrophages and dendritic cells during sensitization with an allergen may affect further immune response and asthma development. To test this hypothesis, we generated distinct types of myeloid cells in vitro from murine bone marrow and analyzed their immunometabolic profiles upon activation with house dust mite extract (HDM) and its key active components. We found that the combination of lipopolysaccharide (LPS) and beta-glucan is sufficient to upregulate proinflammatory cytokine production as well as respiratory and glycolytic capacity of myeloid cells, comparably to HDM. This specific immunometabolic phenotype was associated with altered mitochondrial morphology and possibly with increased ROS production in macrophages. Moreover, we found that both TNF production and metabolic remodeling of macrophages in response to HDM are TLR4-dependent processes. Altogether, these results expand our understanding of molecular mechanisms underlying asthma induction and pathogenesis and may potentially lead to new therapeutic strategies for the treatment of this disease.

Polysaccharides from Platycodonis Radix ameliorated respiratory syncytial virus-induced epithelial cell apoptosis and inflammation through activation of miR-181a-mediated Hippo and SIRT1 pathways

Respiratory syncytial virus (RSV) is the leading cause of bronchiolitis in young children, but there are few safe and effective treatments for this disease. Platycodonis Radix is widely used as an antitussive and expectorant drug for preventing various diseases in lower respiratory tract, in which the polysaccharides are one of the main bioactivity constituents. In this study, the protective effects of the P. Radix polysaccharides (PRP) against RSV-induced bronchiolitis in juvenile mice and RSV-induced apoptosis of epithelial HEp-2 cells were investigated. The results showed that PRP obviously decreased the levels of IL-1β, IL-4, IL-6, TNF-α, IFN-γ and TSLP in lung tissues, and reduced the number of inflammatory cells in bronchoalveolar lavage fluid (BALF) of RSV-infected mice. Furthermore, it reduced the apoptosis of RSV-infected HEp-2 cells and remarkably inhibited the mRNA expressions of RSV L gene, which indicated that PRP affected transcription and replication of RSV in host cells. Compared with that in RSV-infected group, miR-181a-5p in the PRP-treated group presented the highest relative abundance and its expression was violently reduced by approximately 30%. Mechanistically, PRP had the similar effects as miR-181a-5p antagomir on RSV-induced apoptosis and inflammation in HEp-2 cells via upregulating BCL2, MLL3 and SIRT1, which could be reversed by miR-181a-5p mimic. Therefore, it demonstrated that PRP not only protected against RSV-induced lung inflammation in mice but also inhibited apoptosis of RSV-infected HEp-2 cells via suppressing miR-181a-5p and transcriptionally activating Hippo and SIRT1 pathways.

Nutraceuticals and mitochondrial oxidative stress: bridging the gap in the management of bronchial asthma

Asthma is a chronic inflammatory disease primarily characterized by inflammation and reversible bronchoconstriction. It is currently one of the leading causes of morbidity and mortality in the world. Oxidative stress further complicates the pathology of the disease. The current treatment strategies for asthma mainly involve the use of anti-inflammatory agents and bronchodilators. However, long-term usage of such medications is associated with severe adverse effects and complications. Hence, there is an urgent need to develop newer, novel, and safe treatment modalities for the management of asthma. This has therefore prompted further investigations and detailed research to identify and develop novel therapeutic interventions from potent untapped resources. This review focuses on the significance of oxidative stressors that are primarily derived from both mitochondrial and non-mitochondrial sources in initiating the clinical features of asthma. The review also discusses the biological scavenging system of the body and factors that may lead to its malfunction which could result in altered states. Furthermore, the review provides a detailed insight into the therapeutic role of nutraceuticals as an effective strategy to attenuate the deleterious effects of oxidative stress and may be used in the mitigation of the cardinal features of bronchial asthma.

Intermittent Hypoxia-Hyperoxia and Oxidative Stress in Developing Human Airway Smooth Muscle

Premature infants are frequently and intermittently administered supplemental oxygen during hypoxic episodes, resulting in cycles of intermittent hypoxia and hyperoxia. The relatively hypoxic in utero environment is important for lung development while hyperoxia during the neonatal period is recognized as detrimental towards the development of diseases such as bronchopulmonary dysplasia and bronchial asthma. Understanding early mechanisms that link hypoxic, hyperoxic, and intermittent hypoxic-hyperoxic exposures to altered airway structure and function are key to developing advanced therapeutic approaches in the clinic. Changes in oxygen availability can be detrimental to cellular function and contribute to oxidative damage. Here, we sought to determine the effect of oxygen on mitochondria in human fetal airway smooth muscle cells exposed to either 5% O₂, 21% O₂, 40% O₂, or cycles of 5% and 40% O₂ (intermittent hypoxia-hyperoxia). Reactive oxygen species production, altered mitochondrial morphology, and changes in mitochondrial respiration were assessed in the context of the antioxidant N-acetylcysteine. Our findings show developing airway smooth muscle is differentially responsive to hypoxic, hyperoxic, or intermittent hypoxic-hyperoxic exposure in terms of mitochondrial structure and function. Cycling O₂ decreased mitochondrial branching and branch length similar to hypoxia and hyperoxia in the presence of antioxidants. Additionally, hypoxia decreased overall mitochondrial respiration while the addition of antioxidants increased respiration in normoxic and O₂-cycling conditions. These studies show the necessity of balancing oxidative damage and antioxidant defense systems in the developing airway.

Vitamin D has an effect on airway inflammation and Th17/Treg balance in asthmatic mice

Asthma is regarded as a chronic inflammation of the airway. Research has highlighted the significance of Vitamin D in asthma. This study explored the mechanism of vitamin D on asthma. The asthma mouse model was established by ovalbumin (OVA) sensitization and treated with vitamin D (50 or 100 ng/ml). The morphological changes of the airway were observed by HE staining. The serum IgE contents and MDA, ROS, and SOD expressions in the bronchoalveolar lavage fluid (BALF) were detected by ELISA. The Th17 and Treg cells were detected using flow cytometry. The RORγt and Foxp 3 expressions were detected by Reverse transcription quantitative polymerase chain reaction (RT-qPCR). IL-17, IL-10, and TGF-β1 expressions were detected using ELISA. The NF-κB pathway was blocked using the NF-κB pathway inhibitor, Andrographolide sulfonate. The NF-κB pathway-related indexes were detected by western blotting. After blockade of the NF-κB pathway, the IL-17, IL-10, and TGF-G1 expressions were detected. OVA-sensitized asthma induced airway remodeling and elevated IgE content in mice, which was downregulated after vitamin D treatment. MDA and ROS were upregulated and SOD was downregulated in asthmatic mice, while vitamin D inverted the changes. Th17/Treg ratio was imbalanced, RORγt and IL-17 were upregulated, and Foxp 3, IL-10, and TGF-β1 were downregulated after OVA sensitization, while vitamin D treatment inverted these changes and inhibited the NF-κB-p65 phosphorylation level. After blockade of the NF-κB pathway, IL-17 was downregulated and IL-10 and TGF-β1 were upregulated. In conclusion, vitamin D rectified the Th17/Treg balance and alleviated airway inflammation by inhibiting the NF-κB pathway in asthmatic mice.

An Update on the Role of Nrf2 in Respiratory Disease: Molecular Mechanisms and Therapeutic Approaches

Nuclear factor erythroid 2-related factor (Nrf2) is a transcriptional activator of the cell protection gene that binds to the antioxidant response element (ARE). Therefore, Nrf2 protects cells and tissues from oxidative stress. Normally, Kelch-like ECH-associated protein 1 (Keap1) inhibits the activation of Nrf2 by binding to Nrf2 and contributes to Nrf2 break down by ubiquitin proteasomes. In moderate oxidative stress, Keap1 is inhibited, allowing Nrf2 to be translocated to the nucleus, which acts as an antioxidant. However, under unusually severe oxidative stress, the Keap1-Nrf2 mechanism becomes disrupted and results in cell and tissue damage. Oxide-containing atmospheric environment generally contributes to the development of respiratory diseases, possibly leading to the failure of the Keap1-Nrf2 pathway. Until now, several studies have identified changes in Keap1-Nrf2 signaling in models of respiratory diseases, such as acute respiratory distress syndrome (ARDS)/acute lung injury (ALI), chronic obstructive pulmonary disease (COPD), idiopathic pulmonary fibrosis (IPF), and asthma. These studies have confirmed that several Nrf2 activators can alleviate symptoms of respiratory diseases. Thus, this review describes how the expression of Keap1-Nrf2 functions in different respiratory diseases and explains the protective effects of reversing this expression.