February 12, 2014

Obesity sends immune cells to the brain

Obesity causes peripheral immune cells to move to the brain, where they may contribute to inflammation and the pathophysiology of obesity.

A characteristic of obesity is chronic low-grade inflammation, which is caused by the recruitment of immune cells into fatty tissue and contributes to co-morbidities such as type 2 diabetes and cardiovascular disease. Recent studies have also shown increased inflammation in the central nervous system (CNS), which could contribute to an increased susceptibility to neurologic disease.

To determine whether obesity is associated with the recruitment of peripheral immune cells into the CNS, Kate Ellacott, Ph.D., and colleagues used a mouse model that enabled the tracking of fluorescently labeled immune cells. They report in the January issue of Brain, Behavior, and Immunity that mice fed a high-fat diet became obese and had a 30 percent increase in the number of fluorescent immune cells in the CNS compared to mice fed a control diet. The glowing cells had characteristics of macrophages.

The findings indicate that peripheral immune cells can be recruited to the CNS and may contribute to the inflammatory response and the pathophysiology in obesity.

This research was supported by pilot and feasibility grants from the National Institutes of Health-supported Vanderbilt Digestive Disease Research Center (DK058404) and Vanderbilt Diabetes Research and Training Center (DK020593).

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