Children’s National Health System researchers have uncovered evidence that obesity may have a broader impact than previously thought on inflammatory and other diseases, with belly fat more responsible than other areas of the body.
In an extensive and far-reaching study, the Children’s National team found that cell particles known as exosomes, which often play an important role in regulating body functions, are more uncontrolled in obese individuals, leading to toxicity in other organs. Exosomes are present in virtually all bodily fluids, including blood and urine.
Researchers are excited about the findings and can take steps to uncover more of the secrets underlying cell structure and the role of obesity, says Robert J. Freishtat, MD, MPH, Associate Chief for Academic Affairs, Division of Emergency Medicine at Children’s National. Dr. Freishtat was lead investigator in a Children’s National team that published its findings in Pediatric Research.
“We’ve known for a long time that belly fat is bad, and now we’re learning why it’s so bad,” Dr. Freishtat says. “The belly fat expands, and it becomes inflammatory. More fat is worse, in that it becomes even more inflammatory, and theoretically, it releases more of the bad exosomes.”
Obesity prompts “significant changes in the function of fat cells. By releasing abnormal exosomes, they are behaving in a way that otherwise they would not be behaving,” says Dr. Freishtat. “In this way, we are taking a major step toward understanding how obesity changes the whole body function.”
Scientists have always believed that obesity would cause a “dysfunction in cells, but the degree of dysfunction is surprising,” Dr. Freishtat says. The impact of obesity on exosomes is “a major reason why and how obesity changes the whole body function,” he says.
The researchers’ report noted, “Obesity is a systemic inflammatory state associated with chronic inflammatory and metabolic diseases, impacting nearly every organ system within the body. Obesity is frequently complicated by comorbid conditions,” the researchers stated, “yet how excess adipose (body fat) contributes is poorly understood.” Exosome cells in body fluids may “carry pro-inflammatory factors” as a result of obesity.
The Children’s National researchers used software to evaluate the exosomes and their link to body fat. Obesity “causes all these problems in individuals as they get older,” Dr. Freishtat says. “It’s not the fat underlying the skin that’s the big problem; it’s really the fat in the belly.”
Adipocyte-derived Exosomal miRNAs: A Novel Mechanism for Obesity-Related Disease, Sarah C Ferrante, Evan P Nadler, Dinesh K Pillai, Monica J Hubal, Zuyi Wang, Justin M Wang, Heather Gordish-Dressman, Emily Koeck, Samantha Sevilla, Andrew A Wiles & Robert J Freishtat, Pediatric Research, doi:10.1038/pr.2014.202, published online 17 December 2014.
Source: Children’s National Health System