“In a bid to explore the ACE2 link to COVID-19 in more detail, Lane, Mengfei Chen, Ph.D., a research associate in Lane’s lab at the Johns Hopkins University School of Medicine, and others on his team took a close look at ACE2 levels in nasal tissue specimens from 19 adult men and women with chronic rhinosinusitis (inflammation of nasal tissue) and in tissues from a control group of four people who had nasal surgeries for issues other than sinusitis,” the scientists wrote.
The researchers also studied tissue samples of the trachea from seven people who underwent surgery for abnormal narrowing of the trachea.
None of the participants had been diagnosed with COVID-19.
The Johns Hopkins team used fluorescent stains to identify ACE2 receptors and found high levels among nasal cells that give structural support. These are called sustentacular cells. These cells are in an area called the olfactory neuroepithelium, where odor-sensing neurons are found.
Scientists found 200-700 times more ACE2 proteins in the olfactory neuroepithelium than in samples from the nose and trachea.
“Because the cells with high levels of ACE2 are associated with odor sensing, the researchers suggest that infection of these cells may be the reason some people with COVID-19 experience loss of smell,” they wrote.
It’s also why they urge everyone to wear a face covering correctly — making sure to cover both your mouth and nose.