In a new study, researchers have found why belly fat surrounding organs increases as people age.
This finding could offer new treatment possibilities for improving metabolic health, thereby reducing the likelihood of diseases like diabetes and atherosclerosis that stem from inflammation.
The research was conducted by a team at Yale University.
Previous work found that as people age, their body’s ability to generate energy by burning belly fat is reduced.
Consequently, the fat that surrounds the internal organs increases in the elderly.
The team had found that the immune cells necessary to the fat-burning process, called macrophages, were still active but their overall numbers declined as belly fat increased with aging.
This latest study found that something else is happening as well. Adipose B cells in belly fat unexpectedly proliferated as animals aged, contributing to increased inflammation and metabolic decline.
These adipose B cells are a unique source of inflammation. Normally the B cells produce antibodies and defend against infection.
But with aging, the increased adipose B cells become dysfunctional, contributing to metabolic disease.
According to the team, when they are working correctly, some B cells expand as needed to protect the body from infection, and then contract to baseline. But with aging, they don’t contract in belly fat.
The team theorizes that this ongoing expansion may be due to increased human life expectancy—a pushing of the body’s cells beyond their evolutionary limits.
They discovered that adipose B cells expand by receiving signals from nearby macrophages.
Relatedly, they found that by reducing the macrophage signal and by removing adipose B cells, they could reverse the expansion process, and protect against an age-induced decline in metabolic health.
The team says this could lead to exciting possibilities for repurposing drugs to target these dysfunctional adipose B cells for improved health outcomes and to protect against metabolic disease.
One drug, called cytokine IL-1B, reduces one of the small proteins driving this process and is currently used to protect against heart disease.
There are also immunotherapy drugs that neutralize B cells that are used in certain cancers.
These, too, could be tested for their effectiveness in reducing metabolic disease in elderly people.
The lead author of the study is Dr. Vishwa Deep Dixit, the Waldemar Von Zedtwitz Professor of Comparative Medicine and of Immunobiology.
The study is published in Cell Metabolism.
Copyright © 2019 Knowridge Science Report. All rights reserved.
