Newswise — Rockville, Md. (December 3, 2020)—New research suggests that levels of the sex hormones estrogen and testosterone could contribute to infection risk and severity of COVID-19. The study is published in the American Journal of Physiology-Lung Cellular and Molecular Physiology. It was chosen as an APSselect article for December.
SARS-CoV-2, the virus that causes COVID-19, enters the body by adhering to angiotensin converting enzyme-2 (ACE2). ACE2 is present in many organs, including the lungs. Higher ACE2 levels in the body—and how well the enzyme functions—can play a role in the progression and severity of COVID-19. Previous research has also found that men fare worse than women in both severity of and death from COVID-19. It’s not clear whether these sex differences are due to distinct physiological characteristics or the influence of estrogen and testosterone.
Researchers of a new study analyzed lung tissue and airway smooth muscle cells from men and women. They first confirmed that both types of samples expressed ACE2. Then they treated the airway cells from both sexes with estrogen and testosterone. “Female patients show downregulated baseline ACE2 expression compared with males, which may reflect elevated circulating [estrogen] concentrations in females,” the authors wrote. “Perhaps more interestingly, [testosterone] significantly upregulated ACE2 expression in human [airway smooth muscle] cells,” they added. Future studies that explore whether age and metabolism of sex hormones also play a role in ACE2 expression may be helpful, the researchers suggested.
Read the full article, “Sex steroids skew ACE2 expression in human airway: a contributing factor to sex differences in COVID-19?,” published in the American Journal of Physiology-Lung Cellular and Molecular Physiology. It is highlighted as one of this month’s “best of the best” as part of the American Physiological Society’s APSselect program. Read all of this month’s selected research articles.
Physiology is a broad area of scientific inquiry that focuses on how molecules, cells, tissues and organs function in health and disease. The American Physiological Society connects a global, multidisciplinary community of more than 10,000 biomedical scientists and educators as part of its mission to advance scientific discovery, understand life and improve health. The Society drives collaboration and spotlights scientific discoveries through its 16 scholarly journals and programming that support researchers and educators in their work.