In a new paper published in Nature Metabolism, researchers found that cold temperature exposure resolved obesity-induced inflammation while improving insulin sensitivity and glucose tolerance in diet-induced obese mice. The process depended on brown adipose tissue producing a molecule called Maresin 2 when stimulated by cold.
Brown adipose tissue is known to be an active endocrine orgain which helps dissipate stored energy and might promote weight loss and metabolic health.
“Extensive evidence indicates that obesity and metabolic syndrome are linked with chronic inflammation that leads to systemic insulin resistance, so interrupting inflammation in obesity could offer promising therapies for obesity-related disease,” said co-corresponding author Yu-Hua Tseng, PhD, professor of medicine at Harvard Medical School. “We discovered that cold exposure reduced inflammation and improved metabolism in obesity, mediated at least in part by the activation of brown adipose tissue. These findings suggest a previously unrecognized function of brown adipose tissue in promoting the resolution of inflammation in obesity.”
In two previous studies, Tseng and colleagues discovered that cold exposure could activate brown fat to produce specific lipid mediators that regulate nutrient metabolism. In the current study, the researchers identified a novel role for a lipid mediator produced from brown fat to resolve inflammation.
In the present study, the scientists created a mouse model that becomes obese when fed a typical high-fat, Western diet. When the animals were exposed to a cold environment (around 4°C), the researchers observed that the animals’ insulin sensitivity and glucose metabolism improved and their body weight decreased, compared to control animals maintained at a thermoneutral zone – the environmental temperature where the body does not need to produce heat for maintaining its core body temperature. What’s more, the scientists also noticed a profound improvement in inflammation, as measured by reduced levels of a major inflammatory marker.
“We found that brown fat produces Maresin 2, which resolves inflammation systemically and in the liver,” said co-corresponding author Matthew Spite, PhD, a lead investigator at Brigham and Women’s Hospital and Associate Professor of Anesthesia at Harvard Medical School. “These findings suggest a previously unrecognized function of brown adipose tissue in promoting the resolution of inflammation in obesity via the production of this important lipid mediator.”
Moreover, these findings also suggest that Maresin 2 could have clinical applications as a therapy for patients with obesity, metabolic disease, or other diseases linked to chronic inflammation; however, the molecule itself breaks down quickly in the body. Tseng and colleagues seek a more stable chemical analog for clinical use.
The team notes a shortcut to improved metabolic health may already exist. Multiple human studies show that exposure to mild cold temperatures (10 to 13°C) have been shown to be sufficient to activate brown adipose tissue and improve metabolism, though the mechanisms are not well understood.
Source: EurekaAlert
