New research on mice with the flu found that males produce more of a growth factor protein called amphiregulin, which promotes lung healing. The study, which came out of Johns Hopkins University Bloomberg School of Public Health, may point to similar results in humans.
Understanding the flu in humans
The scientists also injected the flu into cells from human males and found that they, too, produced more amphiregulin.
In the mouse study, the researchers noticed that although males and females had similar levels of the virus and cleared it in nearly the same length of time, the females suffered significantly more from their infections, including greater loss of body mass, greater lung inflammation and later, a longer recovery in order to return to normal lung function.
They also found that male mice that were genetically engineered to keep them from producing amphiregulin responded similarly to female mice. They had more severe infections and slower recoveries.
The research may explain why women tend to have more severe flu symptoms with slower recoveries than men even when the virus levels are the same. It was previously thought that this was due to women’s greater levels of lung inflammation while experiencing the flu.
“The novel finding here is that females also have slower tissue-repair during recovery, due to a relatively low production of amphiregulin,” explains the Bloomberg School’s Sabra Klein, PhD, an associate professor in the Department of Molecular Microbiology and Immunology.
How amphiregulin fights the flu
Amphiregulin promotes the proliferation of epithelial cells in the skin, lungs and other surfaces in the body. This means that there may be therapeutic strategies in the future that use amphiregulin to fight the flu.
In fact, a 2016 study found that the sex hormone progesterone stimulates amphiregulin production in female mice. When the progesterone stimulated amphiregulin production in the female, the recovery was expedited.
