Losing an excessive amount of weight when infected with COVID-19 has been linked to worse outcomes. Now, researchers at Karolinska Institutet in Sweden have discovered that SARS-CoV-2 infection fuels blood vessel formation in fat tissues, thus revving up the body’s thermogenic metabolism. Blocking this process by utilizing an existing drug curbed weight reduction in mice and hamsters that were infected with the virus, based on the study published within the journal Nature Metabolism.

Our study proposes a totally recent concept for treating COVID-19 associated weight reduction by targeting the blood vessels within the fat tissues.”

Yihai Cao, Professor, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, and Study’s Corresponding Creator

The researchers examined how various kinds of fat, including brown fat and visceral and subcutaneous white fat, reacted when exposed to SARS-CoV-2 and the way it impacted weight in mice and hamsters. They found that the animals lost significant amounts of weight in 4 days and that this weight reduction was preceded by the activation of brown fat and the browning of each varieties of white fat. These fat tissues also contained more microvessels and high levels of a signaling protein called vascular endothelial growth factor (VEGF), which promotes the expansion of recent blood vessels.

The researchers observed the identical mechanisms in human tissue samples from 4 patients who died of COVID-19, suggesting the findings might be clinically relevant for humans.

When the researchers treated the animals with a substance that inhibits the formation of recent blood vessels, a so-called antiangiogenic drug, the animals recovered most of their lost weight and their fat tissues exhibited fewer microvessels.

“Antiangiogenic drugs are currently utilized in the clinic to treat various varieties of cancers,” Yihai Cao says. “It’s possible these drugs is also helpful in treating COVID-19-related problems resembling excessive weight reduction and metabolic changes, thus improving the standard of life and survival for these patients. After all, we are going to need more research to validate if our preclinical findings also delay in human trials.”

Source:

Journal reference:

Jing, X., et al. (2022) COVID-19 instigates adipose browning and atrophy through VEGF in small mammals. Nature Metabolism. doi.org/10.1038/s42255-022-00697-4.