Glutathione Peroxidase in Stable Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-analysis

Insights into the Role of Glutathione Peroxidase 3 in Non-Neoplastic Diseases

Reactive oxygen species (ROSs) are byproducts of normal cellular metabolism and play pivotal roles in various physiological processes. Disruptions in the balance between ROS levels and the body's antioxidant defenses can lead to the development of numerous diseases. Glutathione peroxidase 3 (GPX3), a key component of the body's antioxidant system, is an oxidoreductase enzyme. GPX3 mitigates oxidative damage by catalyzing the conversion of hydrogen peroxide into water. Beyond its antioxidant function, GPX3 is vital in regulating metabolism, modulating cell growth, inducing apoptosis and facilitating signal transduction. It also serves as a significant tumor suppressor in various cancers. Recent studies have revealed aberrant expression of GPX3 in several non-neoplastic diseases, associating it with multiple pathological processes. This review synthesizes the current understanding of GPX3 expression and regulation, highlighting its extensive roles in noncancerous diseases. Additionally, this paper evaluates the potential of GPX3 as a diagnostic biomarker and explores emerging therapeutic strategies targeting this enzyme, offering potential avenues for future clinical treatment of non-neoplastic conditions.

Chronic Obstructive Pulmonary Disease Adverse Event Signals Associated with Potential Inhibitors of Glutathione Peroxidase 1: A Sequence Symmetry Analysis

BACKGROUND AND OBJECTIVE

Prior molecular modelling analysis identified several medicines as potential inhibitors of glutathione peroxidase 1 (GPx1) which may contribute to development or progression of chronic obstructive pulmonary disease (COPD). This study investigates 40 medicines (index medicines) for signals of COPD development or progression in a real-world dataset.

METHODS

Sequence symmetry analysis (SSA) was conducted using a 10% extract of Australian Pharmaceutical Benefits Scheme (PBS) claims data between January 2013 and September 2019. Patients must have been initiated on an index medicine and a medicine for COPD development or progression within 12 months of each other. Sequence ratios were calculated as the number of patients who initiated an index medicine followed by a medicine for COPD development or progression divided by the number who initiated the index medicine second. An adjusted sequence ratio (aSR) was calculated which accounted for changes in prescribing trends. Adverse drug event signals (ADEs) were identified where the aSR lower 95% confidence interval (CI) was greater than 1.

RESULTS

Twenty-one of 40 (53%) index medicines had at least one ADE signal of COPD development or progression. Signals of COPD development, as identified using initiation of tiotropium, were observed for atenolol (aSR 1.32, 95% CI 1.23-1.42) and naproxen (aSR 1.14, 95% CI 1.06-1.23). Several signals of COPD progression were observed, including initiation of fluticasone propionate/salmeterol following initiation of atenolol (aSR 1.44, 95% CI 1.30-1.60) and initiation of aclidinium/formoterol following initiation of naproxen (aSR 2.21, 95% CI 1.34-3.65).

CONCLUSION

ADE signals were generated for several potential GPx1 inhibitors; however, further validation of signals is required in large well-controlled observational studies.

Oxidative Stress and Air Pollution: Its Impact on Chronic Respiratory Diseases

Redox regulation participates in the control of various aspects of metabolism. Reactive oxygen and nitrogen species participate in many reactions under physiological conditions. When these species overcome the antioxidant defense system, a distressed status emerges, increasing biomolecular damage and leading to functional alterations. Air pollution is one of the exogenous sources of reactive oxygen and nitrogen species. Ambient airborne particulate matter (PM) is important because of its complex composition, which includes transition metals and organic compounds. Once in contact with the lungs' epithelium, PM components initiate the synthesis of inflammatory mediators, macrophage activation, modulation of gene expression, and the activation of transcription factors, which are all related to the physiopathology of chronic respiratory diseases, including cancer. Even though the pathophysiological pathways that give rise to the development of distress and biological damage are not fully understood, scientific evidence indicates that redox-dependent signaling pathways are involved. This article presents an overview of the redox interaction of air pollution inside the human body and the courses related to chronic respiratory diseases.

S-allylmercapto-N-acetylcysteine ameliorates pulmonary fibrosis in mice via Nrf2 pathway activation and NF-κB, TGF-β1/Smad2/3 pathway suppression

Pulmonary fibrosis (PF) is a chronic lung disease characterised by alveolar inflammatory injury, alveolar septal thickening, and eventually fibrosis. Patients with severe Coronavirus Disease 2019 (COVID-19) may have left a certain degree of pulmonary fibrosis. PF is commonly caused by oxidative imbalance and inflammatory damage. S-allylmercapto-N-acetylcysteine (ASSNAC) exhibits anti-oxidative and anti-inflammatory effects in other diseases. However, the pharmacodynamics of ASSNAC remain unclear for PF. This investigation aimed to evaluate the efficacy and mechanism of ASSNAC against PF. The PF model was established by TGF-β1 stimulating HFL-1 cells in vitro. ASSNAC exhibited the potential to inhibit fibroblast transformation into myofibroblasts. Also, in the PF mice model with bleomycin (BLM), the sodium salt of ASSNAC (ASSNAC-Na) inhalation was treated. ASSNAC remarkably improved mice's lung tissue structure and collagen deposition. The important indicator proteins of PF, collagen Ⅰ, collagen Ⅲ, and α-SMA significantly decreased in the ASSNAC treated groups. Besides, ASSNAC attenuated oxidative stress by reversing glutathione (GSH), superoxide dismutase (SOD) levels and interfering with Nrf2/NOX4 signaling pathways. ASSNAC showed an anti-inflammatory effect by reducing the number of inflammatory cells and inflammatory cytokines, such as TNF-α and IL-6, and blocking the NF-κB signaling pathway. ASSNAC inhibited fibroblast differentiation by blocking the TGF-β1/Smad2/3 signaling pathway. This study implicates that ASSNAC alleviates pulmonary fibrosis through fighting against oxidative stress, reducing inflammation and inhibiting fibroblast differentiation.

Glutathione: A Samsonian life-sustaining small molecule that protects against oxidative stress, ageing and damaging inflammation

Many local and systemic diseases especially diseases that are leading causes of death globally like chronic obstructive pulmonary disease, atherosclerosis with ischemic heart disease and stroke, cancer and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causing coronavirus disease 19 (COVID-19), involve both, (1) oxidative stress with excessive production of reactive oxygen species (ROS) that lower glutathione (GSH) levels, and (2) inflammation. The GSH tripeptide (γ- L-glutamyl-L-cysteinyl-glycine), the most abundant water-soluble non-protein thiol in the cell (1-10 mM) is fundamental for life by (a) sustaining the adequate redox cell signaling needed to maintain physiologic levels of oxidative stress fundamental to control life processes, and (b) limiting excessive oxidative stress that causes cell and tissue damage. GSH activity is facilitated by activation of the Kelch-like ECH-associated protein 1 (Keap1)-Nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) redox regulator pathway, releasing Nrf2 that regulates expression of genes controlling antioxidant, inflammatory and immune system responses. GSH exists in the thiol-reduced (>98% of total GSH) and disulfide-oxidized (GSSG) forms, and the concentrations of GSH and GSSG and their molar ratio are indicators of the functionality of the cell. GSH depletion may play a central role in inflammatory diseases and COVID-19 pathophysiology, host immune response and disease severity and mortality. Therapies enhancing GSH could become a cornerstone to reduce severity and fatal outcomes of inflammatory diseases and COVID-19 and increasing GSH levels may prevent and subdue these diseases. The life value of GSH makes for a paramount research field in biology and medicine and may be key against systemic inflammation and SARS-CoV-2 infection and COVID-19 disease. In this review, we emphasize on (1) GSH depletion as a fundamental risk factor for diseases like chronic obstructive pulmonary disease and atherosclerosis (ischemic heart disease and stroke), (2) importance of oxidative stress and antioxidants in SARS-CoV-2 infection and COVID-19 disease, (3) significance of GSH to counteract persistent damaging inflammation, inflammaging and early (premature) inflammaging associated with cell and tissue damage caused by excessive oxidative stress and lack of adequate antioxidant defenses in younger individuals, and (4) new therapies that include antioxidant defenses restoration.

The Emerging Clinical Significance of the Red Cell Distribution Width as a Biomarker in Chronic Obstructive Pulmonary Disease: A Systematic Review

There is an intense focus on the identification of novel biomarkers of chronic obstructive pulmonary disease (COPD) to enhance clinical decisions in patients with stable disease and acute exacerbations (AECOPD). Though several local (airway) and circulatory inflammatory biomarkers have been proposed, emerging evidence also suggests a potential role for routine haematological parameters, e.g., the red cell distribution width (RDW). We conducted a systematic literature search in PubMed, Web of Science, and Scopus, from inception to April 2022, for articles investigating the diagnostic and prognostic role of the RDW in stable COPD and AECOPD. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist. Significant associations between the RDW and the presence and severity of disease, outcomes (mortality, hospital readmission), and other relevant clinical parameters (right heart failure, pulmonary arterial hypertension) were reported in 13 out of 16 studies in stable COPD (low risk of bias in 11 studies), and 17 out of 21 studies of AECOPD (low risk of bias in 11 studies). Pending further research, our systematic review suggests that the RDW might be useful, singly or in combination with other parameters, for the diagnosis and risk stratification of patients with stable COPD and AECOPD (PROSPERO registration number: CRD42022348304).