Remodeling in asthma and COPD-recent concepts

Recent Advances in Therapeutics and Manufacturing Processes of Recombinant Adeno-Associated Virus for the Treatment of Lung Diseases

Developing delivery vectors capable of transducing genetic material across the lung epithelia and mucus barrier is a major challenge and of great interest to enable gene therapies to treat pulmonary diseases. Recombinant Adeno-associated Viruses (rAAVs) have emerged as attractive candidates among viral and non-viral vectors due to their broad tissue tropism, ability to transduce dividing and quiescent cells, and their safety profile in current human applications. While rAAVs have demonstrated safety in earlier clinical trials for lung disease applications, there are still some limitations regarding rAAV-transgene delivery in pulmonary cells. Thus, further improvements in rAAV engineering are needed to enhance the effectiveness of rAAV-based therapies for lung diseases. Such therapies could benefit patients with chronic lung diseases, such as asthma, chronic obstructive pulmonary disease, pulmonary hypertension, and cystic fibrosis, among others, by regulating hereditary gene mutations or acquired gene deregulations causing these conditions. Alongside therapeutic development, advances in the rAAV production process are essential to meet increasing production demands, while reducing manufacturing costs. This review discusses current challenges and recent advances in the field of rAAV engineering and manufacturing to encourage the clinical development of new pulmonary gene therapy treatments.

Endothelial progenitor cells and chronic obstructive pulmonary disease: From basic research to clinical application

Chronic obstructive pulmonary disease (COPD) is a chronic lung disease characterized by persistent airflow limitation, with vascular endothelial dysfunction being one of its key pathogenic mechanisms. Endothelial progenitor cells (EPCs), a class of progenitor cells capable of vascular repair and regeneration, play a crucial role in the pathogenesis of COPD. In COPD patients, the number and function of circulating EPCs are significantly reduced, which is closely associated with disease severity, lung function decline, acute exacerbations, nutritional status, and comorbidities. Environmental factors such as smoking, nicotine, electronic cigarettes, and particulate matter 2.5 (PM2.5) can markedly impair both the function and quantity of EPCs. The underlying mechanisms may involve the regulation of vascular endothelial growth factor/vascular endothelial growth factor receptor (VEGF/VEGFR), C-X-C motif chemokine ligand 12/C-X-C motif chemokine receptor 4 (CXCL12/CXCR4) signaling pathways, and various cytokine regulations. Moreover, animal studies have shown that intratracheal transplantation of EPCs can significantly improve lung function and pathological changes in emphysema models, suggesting that targeting EPCs may be a promising therapeutic strategy for COPD. Elucidating the molecular mechanisms of EPC mobilization, homing, and dysfunction, and evaluating the efficacy and safety of their clinical application, may offer new insights into the treatment of COPD and other chronic lung diseases.

Transforming growth factor-β1 and SMAD signalling pathway in the small airways of smokers and patients with COPD: potential role in driving fibrotic type-2 epithelial mesenchymal transition

Background

COPD is a common disease characterized by respiratory airflow obstruction. TGF-β1 and SMAD pathway is believed to play a role in COPD pathogenesis by driving epithelial mesenchymal transition (EMT).

Methods

We investigated TGF-β1 signalling and pSmad2/3 and Smad7 activity in resected small airway tissue from patients with; normal lung function and a smoking history (NLFS), current smokers and ex-smokers with COPD GOLD stage 1 and 2 (COPD-CS and COPD-ES) and compared these with normal non-smoking controls (NC). Using immunohistochemistry, we measured activity for these markers in the epithelium, basal epithelium, and reticular basement membrane (RBM). Tissue was also stained for EMT markers E-cadherin, S100A4 and vimentin.

Results

The Staining of pSMAD2/3 was significantly increased in the epithelium, and RBM of all COPD groups compared to NC (p <0.0005). There was a less significant increase in COPD-ES basal cell numbers compared to NC (p= 0.02). SMAD7 staining showed a similar pattern (p <0.0001). All COPD group levels of TGF-β1 in the epithelium, basal cells, and RBM cells were significantly lower than NC (p <0.0001). Ratio analysis showed a disproportionate increase in SMAD7 levels compared to pSMAD2/3 in NLFS, COPD-CS and COPD-ES. pSMAD negatively correlated with small airway calibre (FEF_25-75%; p= 0.03 r= -0.36). EMT markers were active in the small airway epithelium of all the pathological groups compared to patients with COPD.

Conclusion

Activation of the SMAD pathway via pSMAD2/3 is triggered by smoking and active in patients with mild to moderate COPD. These changes correlated to decline in lung function. Activation of the SMADs in the small airways is independent of TGF-β1, suggesting factors other than TGF-β1 are driving these pathways. These factors may have implications for small airway pathology in smokers and COPD through the process of EMT, however more mechanistic work is needed to prove these correlations.

Etanercept Protected Against Cigarette Smoke Extract-Induced Inflammation and Apoptosis of Human Pulmonary Artery Endothelial Cells via Regulating TNFR1

Purpose

Etanercept (ETN), a tumor necrosis factor-α (TNF-α) inhibitor, has been applied in the treatment of many diseases. However, whether it has effects on chronic obstructive pulmonary disease (COPD) and its interaction with tumor necrosis factor receptor 1 (TNFR1) remained unknown.

Methods

Histopathological analysis of lung tissues from non-smokers and smokers with or without COPD was conducted using hematoxylin–eosin (H&E) staining, Van Gieson (VG) staining, and terminal transferase-mediated biotin dUTP nick end labeling (TUNEL). TNF-α content was measured using Immunohistochemistry. Correlation analysis among apoptosis rate, smoke index, the FEV1/FVC ratio, and TNF-α-positive cells was performed. After ETN treatment and transfection of overexpressed or silenced TNFR1, levels of inflammatory cytokines, apoptosis and related genes expressions in cigarette smoke extract (CSE)-treated human pulmonary artery endothelial cells (HPAECs) were detected using enzyme-linked immunosorbent assay (ELISA), Hoechst 33342 staining, flow cytometry, quantitative real-time PCR (qRT-PCR) and Western blot.

Results

Pulmonary arterial remodeling and increased apoptotic and TNF-α⁺ HPAECs were found in lung tissue of smokers with or without COPD, with higher degrees in smokers with COPD. The numbers of apoptotic and TNF-α⁺ HPAECs were positively correlated with smoke index, while the FEV1/FVC ratio was negatively correlated with apoptotic HPAECs. In HPAECs, ETN downregulated the expressions of proteins related to CSE-induced apoptosis and the TNF receptor family, decreased CSE-induced cell apoptosis and inflammatory cytokine levels, and inhibited TNFR1 expression and p65 phosphorylation. Overexpressed TNFR1 reversed the effects of ETN on CSE-treated HPAECs, whereas silencing TNFR1 did the opposite.

Conclusion

ETN protected HPAECs against CSE-induced inflammation and apoptosis via downregulating TNFR1, thus providing a potential therapy for smoking-induced COPD.

Mini Review (Part I): An Experimental Concept on Exercise and Ischemic Conditioning in Stroke Rehabilitation

Stroke remains a leading cause of adult death and disability. Poststroke rehabilitation is vital for reducing the long-term sequelae of brain ischemia. Recently, physical exercise training has been well established as an effective rehabilitation tool, but its efficacy depends on exercise parameters and the patient's capacities, which are often altered following a major cerebrovascular event. Thus, ischemic conditioning as a rehabilitation intervention was considered an “exercise equivalent,” but the investigation is still in its relative infancy. In this mini-review, we discuss the potential for physical exercise or ischemic conditioning and its relation to angiogenesis, neurogenesis, and plasticity in stroke rehabilitation. This allows the readers to understand the context of the research and the application of ischemic conditioning in poststroke rehabilitation.

Air Pollution and Allergic Airway Diseases: Social Determinantsand Sustainability in the Control and Prevention

Air pollution, global warming and climate change are the major contributing factors in causing the increase prevalence of allergic airway diseases like asthma and allergic rhinitis and they will be the defining issues for health system in the twenty-first century. Asthma is an early onset non-communicable environmental disease with global epidemic and contributes a greatest psycho socio economic burden. Nearly 8 million global deaths are from air pollution. Over one billion population are the sufferers during 2015 and will increase to 4 billion by 2050. Air pollution not only triggers the asthma episodes but also changes the genetic pattern in initiating the disease process. Over the years our concept of management of allergic airway disease has changed from control of symptoms to prevention of the disease. To achieve this we need positive development on clean air policies with standard norms, tracking progress, monitoring and evaluation, partnership and conventions with local and global authorities. We do have challenges to overcome like rapid urbanization, lack of multisectorial policy making, lack of finance for research and development and lack of monitoring exposure to health burden from air pollution. We need to prioritize our strategy by sustainable, safe, human settlement, cities, sustainable energy, industrialization, and research. The measures to be adopted are highlighted in this review article. With effective measures by all stake holders we can reduce air pollution and prevent the global warming by 2030, along with 194 countries as adopted by WHO in May 2015.