Scientists have found new evidence that may explain why men are more susceptible to severe infections of the SARS-CoV-2 virus, with increased death rates.
The research, published in the International Journal of Molecular Sciences, indicates males fare worse than females with the COVID-19 disease because the virus more readily attacks females’ fat tissue, in lieu of lung tissue.
“Our data suggested that in female mice adipose tissue may act as a sink/reservoir for SARS-CoV-2 and thus spares the lungs from a greater viral load, preventing pulmonary damage due to infiltrated immune cells and activated pro-inflammatory cytokines,” said Jyothi Nagajyothi, from the Hackensack Meridian Center for Discovery and Innovation (CDI), US.
The researchers evaluated the effect of SARS-CoV-2 infection on the function of adipose (fat) tissue and the impact of disease on fat loss in a COVID-19 model.
They examined hACE2 mice of both sexes and performed a comparative analysis. The hACE2 serves as an entry receptor for SARS-CoV-2 to infect people via binding to envelope spike proteins.
The Nagajyothi Lab’s mouse models, mimicking the human immune system, showed that females lost more fat compared to males when infected with COVID-19.
The study found that males had more virus in their lungs, while the females showed more virus in their fat tissue.
The theory is that the adipose (fat) tissue in females may act as a “sink” or “reservoir” of the virus, the researchers said.
The study follows a paper published last year in the journal Frontiers in Cardiovascular Medicine in which the team showed the virus infiltrated the lungs of males much more readily than it did in females.
The latest paper shows that an inverse relationship exists between the viral loads in the lungs and adipose tissue, and it differs between males and females, the researchers said.
They found that SARS-CoV-2 infection alters immune signalling and cell death signalling differently in COVID-19 infected male and female mice.
“These data may help explain the higher COVID-19 susceptibility in males compared to females,” the authors of the study added.
