Why do we get colder with age? Researchers may finally have an answer from a study that came to a surprising conclusion, SciTechDaily reports.
Human evolution has given us a level of protection against the existential threat of cold temperatures through the ability to produce heat from the fat stored by the body.
But with age, people become more sensitive to low temperatures, as well as inflammation or other metabolic problems that can lead to a number of chronic diseases.
Researchers at Yale University and the University of San Francisco in California (UCSF) have found a culprit for this process: the same cells in the fat immune system that are created by the body to protect us from the cold.
A new study published by them shows that the adipose tissue of older mice loses its group of ILC2 lymphocytes that restore body temperature in the presence of cold.
But research also warns of the dangers of easy treatments for aging, finding that stimulating the production of ILC2 cells in older laboratory mice makes them more vulnerable to death from hypothermia.
“What is good for you when you are young can be harmful to you as you get older,” says Vishwa Deep Dixit, a professor of immunology and comparative medicine and a co-author of the study.
Dixit and her former colleague Emily Goldberg, now an assistant professor at UCSF, were intrigued as to why lipids, the body’s fat cells, contain cells in the immune system that are usually concentrated in areas of the body that are often exposed. of pathogens (lacrimal duct, lungs, skin, etc.).
The two genetically sequenced cells from young and old mice, finding that older animals had a deficiency of ILC2 cells that led to a limited ability to burn fat to raise body temperature in cold conditions.
When scientists introduced a molecule that stimulates the production of ILC2 cells in older mice, their immune system cells returned to previous values but, surprisingly, the mice became even less tolerant of low temperatures.
“The simple assumption is that if we regain something that was lost then life will return to normal. But that didn’t happen. Instead of expanding healthy young cells, the growth factor has led to a multiplication of harmful ILC2 cells, ”explains Dixit.
But researchers have found that this problem can be overcome by transplanting cells from young to old mice, a process that leads to the restoration of tolerance to cold.
“Immune cells have a different role than the defense against pathogens and help maintain the metabolic processes necessary for life,” the study points out.
The research was published in September in the journal Cell Metabolism.
– .
