E-cigarette-Induced Pulmonary Inflammation and Dysregulated Repair are Mediated by nAChR α7 Receptor: Role of nAChR α7 in ACE2 Covid-19 receptor regulation

Cardiorespiratory and Immunologic Effects of Electronic Cigarettes

PURPOSE OF REVIEW

Although e-cigarettes have become popular, especially among youth, the health effects associated with e-cigarette use remain unclear. This review discusses current evidence relating to the cardiovascular, pulmonary, and immunological effects of e-cigarettes.

RECENT FINDINGS

The use of e-cigarettes by healthy adults has been shown to increase blood pressure, heart rate, and arterial stiffness, as well as resistance to air flow in lungs. Inhalation of e-cigarette aerosol has been shown to elicit immune responses and increase the production of immunomodulatory cytokines in young tobacco-naïve individuals. In animal models, long-term exposure to e-cigarettes leads to marked changes in lung architecture, dysregulation of immune genes, and low-grade inflammation. Exposure to e-cigarette aerosols in mice has been shown to induce DNA damage, inhibit DNA repair, and promote carcinogenesis. Chronic exposure to e-cigarettes has also been reported to result in the accumulation of lipid-laden macrophages in the lung and dysregulation of lipid metabolism and transport in mice. Although, the genotoxic and inflammatory effects of e-cigarettes are milder than those of combustible cigarettes, some of the cardiorespiratory effects of the two insults are comparable. The toxicity of e-cigarettes has been variably linked to nicotine, as well as other e-cigarette constituents, operating conditions, and use patterns.

SUMMARY

The use of e-cigarettes in humans is associated with significant adverse cardiorespiratory and immunological changes. Data from animal models and in vitro studies support the notion that long-term use of e-cigarettes may pose significant health risks.

Significant Unresolved Questions and Opportunities for Bioengineering in Understanding and Treating COVID-19 Disease Progression

COVID-19 is a disease that manifests itself in a multitude of ways across a wide range of tissues. Many factors are involved, and though impressive strides have been made in studying this novel disease in a very short time, there is still a great deal that is unknown about how the virus functions. Clinical data has been crucial for providing information on COVID-19 progression and determining risk factors. However, the mechanisms leading to the multi-tissue pathology are yet to be fully established. Although insights from SARS-CoV-1 and MERS-CoV have been valuable, it is clear that SARS-CoV-2 is different and merits its own extensive studies. In this review, we highlight unresolved questions surrounding this virus including the temporal immune dynamics, infection of non-pulmonary tissue, early life exposure, and the role of circadian rhythms. Risk factors such as sex and exposure to pollutants are also explored followed by a discussion of ways in which bioengineering approaches can be employed to help understand COVID-19. The use of sophisticated in vitro models can be employed to interrogate intercellular interactions and also to tease apart effects of the virus itself from the resulting immune response. Additionally, spatiotemporal information can be gleaned from these models to learn more about the dynamics of the virus and COVID-19 progression. Application of advanced tissue and organ system models into COVID-19 research can result in more nuanced insight into the mechanisms underlying this condition and elucidate strategies to combat its effects.

SARS-CoV-2 COVID-19 susceptibility and lung inflammatory storm by smoking and vaping

The current pandemic of COVID-19 has caused severe morbidity and mortality across the globe. People with a smoking history have severe disease outcomes by COVID-19 infection. Epidemiological studies show that old age and pre-existing disease conditions (hypertension and diabetes) result in severe disease outcome and mortality amongst COVID-19 patients. Evidences suggest that the S1 domain of the SARS-CoV-2 (causative agent of COVID-19) membrane spike has a high affinity towards the angiotensin-converting enzyme 2 (ACE2) receptor found on the host’s lung epithelium. Likewise, TMPRSS2 protease has been shown to be crucial for viral activation thus facilitating the viral engulfment. The viral entry has been shown to cause ‘cytokine storm’ involving excessive production of pro-inflammatory cytokines/chemokines including IL-6, TNF-α, IFN-γ, IL-2, IL-7, IP-10, MCP-3 or GM-CSF, which is augmented by smoking. Future research could target these inflammatory-immunological responses to develop effective therapy for COVID-19. This mini-review provides a consolidated account on the role of inflammation and immune responses, proteases, and epithelial permeability by smoking and vaping during SARS-CoV2 infection with future directions of research, and provides a list of the potential targets for therapies particularly controlling cytokine storms in the lung.