SARS-CoV-2 (COVID-19) Adhesion Site Protein Upregulation in Small Airways, Type 2 Pneumocytes, and Alveolar Macrophages of Smokers and COPD - Possible Implications for Interstitial Fibrosis.

Background: Smokers and patients with COPD are highly susceptible to SARS-CoV-2 infection, leading to severe COVID-19. Methods: This cross-sectional study involved resected lung tissues from 16 patients with GOLD stage I or II COPD; of which 8 were current smokers COPD (COPD-CS), and 8 ex-smokers COPD (COPD-ES), 7 normal lung function smokers (NLFS), 9 patients with small airways disease (SAD), and 10 were never-smoking normal controls (NC). Immunostaining for ACE2, Furin, and TMPRSS2 was performed and analysed for percent expression in small airway epithelium (SAE) and counts for positively and negatively stained type 2 pneumocytes and alveolar macrophages (AMs) were done using Image ProPlus V7.0. Furthermore, primary small airway epithelial cells (pSAEC) were analysed by immunofluorescence after exposure to cigarette smoke extract (CSE). Results: ACE2, Furin, and TMPRSS2 expression significantly increased in SAE and type 2 pneumocytes in all the subjects (except Furin for NLFS) compared to NC (p < 0.001). Similar significance was observed for ACE2 positive AM (p < 0.002), except COPD-ES, which decreased in ACE2 positive AMs (p < 0.003). Total type 2 pneumocytes and AMs significantly increased in the pathological groups compared to NC (p < 0.01), except SAD (p = 0.08). However, AMs are significantly reduced in COPD-ES (p < 0.003). Significant changes were observed for tissue co-expression of Furin and TMPRSS2 with ACE2 in SAE, type 2 pneumocytes and AMs. These markers also negatively correlated with lung function parameters, such as FEV1/FVC % predicted, FEF25-75%, DLCO% predicted. A strong co-localisation and expression for ACE2 (p < 0.0001), Furin (p < 0.01), and TMPRSS2 (p < 0.0001) was observed in pSAEC treated with 1% CSE than controls. Discussion: The increased expression of ACE2, TMPRSS2 and Furin, in the SAE, type 2 pneumocytes and AMs of smokers and COPD are detrimental to lung function and proves that these patient groups could be more susceptible to severe COVID-19 infection. Increased type 2 pneumocytes suggest that these patients are vulnerable to developing post-COVID-19 interstitial pulmonary fibrosis or fibrosis in general. There could be a silently developing interstitial pathology in smokers and patients with COPD. This is the first comprehensive study to report such changes.

Clinical features and mechanistic insights into drug repurposing for combating COVID-19.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) emerged from Wuhan in China before it spread to the entire globe. It causes coronavirus disease of 2019 (COVID-19) where mostly individuals present mild symptoms, some remain asymptomatic and some show severe lung inflammation and pneumonia in the host through the induction of a marked inflammatory 'cytokine storm'. New and efficacious vaccines have been developed and put into clinical practice in record time, however, there is a still a need for effective treatments for those who are not vaccinated or remain susceptible to emerging SARS-CoV-2 variant strains. Despite this, effective therapeutic interventions against COVID-19 remain elusive. Here, we have reviewed potential drugs for COVID-19 classified on the basis of their mode of action. The mechanisms of action of each are discussed in detail to highlight the therapeutic targets that may help in reducing the global pandemic. The review was done up to July 2021 and the data was assessed through the official websites of WHO and CDC for collecting the information on the clinical trials. Moreover, the recent research papers were also assessed for the relevant data. The search was mainly based on keywords like Coronavirus, SARS-CoV-2, drugs (specific name of the drugs), COVID-19, clinical efficiency, safety profile, side-effects etc.This review outlines potential areas for future research into COVID-19 treatment strategies.

Electronic cigarettes: Modern instruments for toxic lung delivery and posing risk for the development of chronic disease.

Following the emergence of electronic cigarette, or vaping product use associated lung injury (EVALI) in 2019 in the US, regulation of e-cigarettes has become globally tighter and the collective evidence of the detrimental effects of vaping has grown. The danger of cellular distress and altered homeostasis is heavily associated with the modifiable nature of electronic cigarette devices. An array of harmful chemicals and elevated concentrations of metals have been detected in e-cigarette aerosols which have been linked to various pathogeneses. Vaping is linked to increased inflammation, altered lipid homeostasis and mitochondrial dysfunction whilst also increasing microbial susceptibility whilst the long-term damage is yet to be observed. The scientific evidence is mounting and highlighting that, along with traditional tobacco cigarette smoking, electronic cigarette vaping is not a safe practice.

Electronic Cigarette Aerosol Is Cytotoxic and Increases ACE2 Expression on Human Airway Epithelial Cells: Implications for SARS-CoV-2 (COVID-19).

Tobacco smoking has emerged as a risk factor for increasing the susceptibility to infection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) via increased expression of angiotensin-converting enzyme-2 (ACE2) in the lung, linked to coronavirus disease 2019 (COVID-19) development. Given the modifiable nature of electronic cigarettes and the delivery of high concentrations of nicotine, we investigate whether electronic cigarette vaping has the potential to increase susceptibility to SARS-CoV-2 infection. We exposed BEAS-2B cells (bronchial epithelium transformed with Ad12-SV40 2B) and primary small airway epithelial cells (SAECs) to electronic cigarette aerosol condensates produced from propylene glycol/vegetable glycerin or commercially bought e-liquid (±added nicotine) and cigarette smoke extract to investigate if electronic cigarette exposure, like cigarette smoke, increases the expression of ACE2 in lung epithelial cells. In BEAS-2B cells, cytotoxicity (CCK-8), membrane integrity (LDH), and ACE2 protein expression (immunofluorescence) were measured for both 4- and 24 h treatments in BEAS-2B cells and 4 h in SAECs; ACE2 gene expression was measured using quantitative polymerase chain reaction (qPCR) for 4 h treatment in BEAS-2B cells. Nicotine-free condensates and higher concentrations of nicotine-containing condensates were cytotoxic to BEAS-2B cells. Higher LDH release and reduced membrane integrity were seen in BEAS-2B cells treated for 24 h with higher concentrations of nicotine-containing condensates. ACE2 protein expression was observably increased in all treatments compared to cell controls, particularly for 24 h exposures. ACE2 gene expression was significantly increased in cells exposed to the locally bought e-liquid condensate with high nicotine concentration and cigarette smoke extract compared with cell controls. Our study suggests that vaping alone and smoking alone can result in an increase in lung ACE2 expression. Vaping and smoking are avoidable risk factors for COVID-19, which, if avoided, could help reduce the number of COVID-19 cases and the severity of the disease. This is the first study to utilize electronic cigarette aerosol condensates, novel and developed in our laboratory, for investigating ACE2 expression in human airway epithelial cells.

Dysregulation of endocytic machinery and ACE2 in small airways of smokers and COPD patients can augment their susceptibility to SARS-CoV-2 (COVID-19) infections.

Lungs of smokers and chronic obstructive pulmonary disease (COPD) are severely compromised and are susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) attack. The dangerous combination of enhanced SARS-CoV-2 attachment receptor protein ACE2 along with an increase in endocytic vacuoles will enable viral attachment, entry, and replication. The objective of the study was to identify the presence of SARS-CoV-2 host attachment receptor angiotensin-converting enzyme-2 (ACE2) along with endocytic vacuoles, early endosome antigen-1 (EEA1), late endosome marker RAB7, cathepsin-L, and lysosomal associated membrane protein-1 (LAMP-1) as lysosome markers in the airways of smokers and COPD patients. The study design was cross-sectional and involved lung resections from 39 patients in total, which included 19 patients with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I or GOLD stage II COPD, of which 9 were current smokers with COPD (COPD-CS) and 10 were ex-smokers with COPD (COPD-ES), 10 were normal lung function smokers, and 10 were never-smoking normal controls. Immunostaining for ACE2, EEA1, RAB7, and cathepsin-L was done. A comparative description for ACE2, EEA1, RAB7, and cathepsin-L expression pattern is provided for the patient groups. Furthermore, staining intensity for LAMP-1 lysosomes was measured as the ratio of the LAMP-1-stained areas per total area of epithelium or subepithelium, using Image ProPlus v7.0 software. LAMP-1 expression showed a positive correlation to patient smoking history while in COPD LAMP-1 negatively correlated to lung function. The active presence of ACE2 protein along with endocytic vacuoles such as early/late endosomes and lysosomes in the small airways of smokers and COPD patients provides evidence that these patient groups could be more susceptible to COVID-19.

The ER Stress/UPR Axis in Chronic Obstructive Pulmonary Disease and Idiopathic Pulmonary Fibrosis.

Cellular protein homeostasis in the lungs is constantly disrupted by recurrent exposure to various external and internal stressors, which may cause considerable protein secretion pressure on the endoplasmic reticulum (ER), resulting in the survival and differentiation of these cell types to meet the increased functional demands. Cells are able to induce a highly conserved adaptive mechanism, known as the unfolded protein response (UPR), to manage such stresses. UPR dysregulation and ER stress are involved in numerous human illnesses, such as metabolic syndrome, fibrotic diseases, and neurodegeneration, and cancer. Therefore, effective and specific compounds targeting the UPR pathway are being considered as potential therapies. This review focuses on the impact of both external and internal stressors on the ER in idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) and discusses the role of the UPR signaling pathway activation in the control of cellular damage and specifically highlights the potential involvement of non-coding RNAs in COPD. Summaries of pathogenic mechanisms associated with the ER stress/UPR axis contributing to IPF and COPD, and promising pharmacological intervention strategies, are also presented.

In utero Exposure to Nicotine Containing Electronic Cigarettes Increases the Risk of Allergic Asthma in Female Offspring.

E-cigarettes (eCig) are being considered as an alternative to quit cigarette smoking while their long-term effect on lung pathophysiology are unknown. Maternal eCig-vaping may be promoted and considered as a safer cigarette smoking-replacement during pregnancy thus needing further assessment. Using murine models of in utero vaping and allergic asthma with complementary in vitro experiments we tested whether maternal eCig vaping enhances features of allergic asthma in offspring. Female BALB/c mice were exposed to either eCig vapor (± nicotine) or room air. Female offspring from these mothers were subjected to an ovalbumin (OVA)-induced allergic asthma model. Lung function and airway inflammation was assessed. Tissues were histologically assessed with H&E, Periodic Acid-Schiff and Masson's trichrome. Mitochondrial homeostasis protein expression was measured using immunohistochemistry while human airway smooth muscle (ASM) and Beas-2B cells were used to further measure cellular function and mitochondrial respiration. Allergen-challenge in mice lead to significant increase in airway inflammation, development of airway hyperresponsiveness (AHR) and increase in mucus and airway wall thickening (hallmark features of allergic asthma). Allergic asthma features were significantly enhanced in offspring from eCig (+Nicotine)-exposed mothers and were mainly reliant upon Th2-dependent inflammation with complementary changes in mitochondrial homeostasis. Further, in vitro data demonstrated that eCig (±Nicotine)-exposure impaired airway cell homeostasis and perturbed mitochondrial function. Collectively, maternal eCig vaping enhanced and worsened features of allergic asthma and this could partly be attributed to aberrant mitochondrial function.

The rise of electronic nicotine delivery systems and the emergence of electronic-cigarette-driven disease.

In 2019, the United States experienced the emergence of the vaping-associated lung injury (VALI) epidemic. Vaping is now known to result in the development and progression of severe lung disease in the young and healthy. Lack of regulation on electronic cigarettes in the United States has resulted in over 2,000 patients and 68 deaths. We examine the clinical representation of VALI and the delve into the scientific evidence of how deadly exposure to electronic cigarettes can be. E-cigarette vapor is shown to affect numerous cellular processes, cellular metabolism, and cause DNA damage (which has implications for cancer). E-cigarette use is associated with a higher risk of developing crippling lung conditions such as chronic obstructive pulmonary disease (COPD), which would develop several years from now, increasing the already existent smoking-related burden. The role of vaping and virus susceptibility is yet to be determined; however, vaping can increase the virulence and inflammatory potential of several lung pathogens and is also linked to an increased risk of pneumonia. As it has emerged for cigarette smoking, great caution should also be given to vaping in relation to SARS-CoV-2 infection and the COVID-19 pandemic. Sadly, e-cigarettes are continually promoted and perceived as a safer alternative to cigarette smoking. E-cigarettes and their modifiable nature are harmful, as the lungs are not designed for the chronic inhalation of e-cigarette vapor. It is of interest that e-cigarettes have been shown to be of no help with smoking cessation. A true danger lies in vaping, which, if ignored, will lead to disastrous future costs.

Smoking Upregulates Angiotensin-Converting Enzyme-2 Receptor: A Potential Adhesion Site for Novel Coronavirus SARS-CoV-2 (Covid-19).

The epicenter of the original outbreak in China has high male smoking rates of around 50%, and early reported death rates have an emphasis on older males, therefore the likelihood of smokers being overrepresented in fatalities is high. In Iran, China, Italy, and South Korea, female smoking rates are much lower than males. Fewer females have contracted the virus. If this analysis is correct, then Indonesia would be expected to begin experiencing high rates of Covid-19 because its male smoking rate is over 60% (Tobacco Atlas). Smokers are vulnerable to respiratory viruses. Smoking can upregulate angiotensin-converting enzyme-2 (ACE2) receptor, the known receptor for both the severe acute respiratory syndrome (SARS)-coronavirus (SARS-CoV) and the human respiratory coronavirus NL638. This could also be true for new electronic smoking devices such as electronic cigarettes and "heat-not-burn" IQOS devices. ACE2 could be a novel adhesion molecule for SARS-CoV-2 causing Covid-19 and a potential therapeutic target for the prevention of fatal microbial infections, and therefore it should be fast tracked and prioritized for research and investigation. Data on smoking status should be collected on all identified cases of Covid-19.

microRNAs Are Key Regulators in Chronic Lung Disease: Exploring the Vital Link between Disease Progression and Lung Cancer.

microRNAs (miRNAs) bind to mRNAs and inhibit their expression through post-transcriptionally regulating gene expression. Here, we elaborate upon the concise summary of the role of miRNAs in carcinogenesis with specific attention to precursor respiratory pathogenesis caused by cigarette smoke modulation of these miRNAs. We review how miRNAs are implicated in cigarette-smoke-driven mechanisms, such as epithelial to mesenchymal transition, autophagy modulation, and lung ageing, which are important in the development of chronic obstructive pulmonary disease and potential progression to lung cancer. Extracellular vesicles are key to inter-cellular communication and sharing of miRNAs. A deeper understanding of the role of miRNAs in chronic respiratory disease and their use as clinical biomarkers has great potential. Therapeutic targeting of miRNAs may significantly benefit the prevention of cancer progression.

There can be smoke without fire: warranted caution in promoting electronic cigarettes and heat not burn devices as a safer alternative to cigarette smoking.

The tobacco industry is now shifting its focus from combustible cigarettes to promoting the "safer" electronic nicotine delivery alternatives. This editorial presents emerging challenges these devices pose to human health. http://bit.ly/2xdAjD0.