Smoking increases the ACE2 receptors available for coronavirus infection

Vapers, smokers, and non-smokers with chronic conditions such as high blood pressure or diabetes are all at higher risk for COVID-19. While the common thread is not entirely clear, researchers suspect that it can be explained by the number of ACE2 receptors that are available for the coronavirus to enter.

Evidence shows that people with chronic inflammatory illnesses, older adults, and individuals who smoke or vape have an abundance of ACE2 receptor proteins, according to researchers at the University of Rochester Medical Center. 

Led by Dr. Irfan Rahman, the research team has published a series of studies during the pandemic focusing on the vital role of ACE2 receptors. Dr. Rahman has taken a special interest in the growing problem of young people who test positive and may be spreading COVID-19 at alarming rates. Despite their age, children and teens who have higher levels of the ACE2 receptor seem to be more vulnerable to the virus.

“Our next step is to investigate whether ACE2 is normally low in young people, hence their relatively low infection and mortality rates from COVID-19, but to find out if ACE2 is increased by smoking or vaping rendering them more susceptible to the virus,” said Dr. Rahman. “This would be in contrast to older people with lung diseases such as COPD and pulmonary fibrosis, who we already know are at higher risk for severe viral illnesses and death.”

Dr. Gangandeep Kaur, a postdoctoral scientist in Dr. Rahman’s lab, previously investigated tuberculosis. His experience led the experts to examine the ties between vaping and the coronavirus. 

According to one of the team’s studies, the combination of smoking and aging alters more than 20 genes involved in lung cell function. This results in a spike in ACE2 receptors and three other proteins associated with the coronavirus.

The findings confirm the observations of other experts that smokers and people with chronic lung diseases such as COPD are more prone to coronavirus infection.

Using a mouse model, the scientists investigated the chronic effects of nicotine exposure on lung tissue while looking for links to known COVID-19 proteins. The team discovered other receptors with a direct relationship to ACE2 that have a significant role in regulating the inflammatory response in the lungs and cause a higher expression of ACE2. 

The researchers also found that COVID-19 patients in Wuhan, China had worse outcomes if they smoked or had more ACE2 receptors, and that ACE2 is linked to known nicotine receptors

Currently, the Rahman lab is examining blood and saliva samples of young people who have been infected with COVID-19 to evaluate ACE2 levels and see if the ACE2 protein can be a biomarker for a rapid coronavirus test.

The study is published in the journal Frontiers in Pharmacology.

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By Chrissy Sexton, Earth.com Staff Writer