Low vibrations greatly reduce fat production in mice

Date: October 22, 2007

The elusive dream of keeping fat cells from developing while doing nothing is one step closer to reality. Researchers at Stony Brook University and Cold Spring Harbor Laboratory in New York, and The Jackson Laboratory in Bar Harbor, Maine, have demonstrated that mice receiving 15 weeks of high-frequency, low-magnitude mechanical signals (i.e., virtually imperceptible vibrations) developed far fewer fat cells than genetically identical mice not receiving the treatment. The procedure also substantially reduced triglicerides in the liver and other key risk factors in type 2 diabetes.

According to lead researcher Clinton Rubin, Ph.D., SUNY Distinguished Professor and Chair of the Department of Biomedical Engineering at Stony Brook University, the study results are striking and the method used may someday lead to a non-strenuous, drug-free method for control of obesity. The study is published in this weekÍs online edition of the Proceedings of the National Academy of Sciences (PNAS).

One of the authors of the study, Clifford Rosen, M.D., is an osteoporosis researcher at The Jackson Laboratory. "Obesity and type 2 diabetes are a real threat to public health in the United States and the rest of the developed world," Rosen says. "People know they're supposed to eat less and exercise more, but aren't always successful. We're now looking at a possible treatment for humans at risk for these diseases, especially elderly people with limited mobility."

Dr. Rubin and colleagues investigated what effect vibration would have on fat cells. They subjected mice to virtually imperceptible vibrations for 15 minutes a day for 15 weeks, and reported the results in a paper titled "Adipogenesis is inhibited by brief, daily exposure to high-frequency, extremely low-magnitude mechanical signals."

By the end of the 15-week period, the vibrating mice had nearly 28 percent less fat in the torso than control animals. In addition, levels of fatty compounds linked to type 2 diabetes, such as triglycerides and free fatty acids, were reduced by 43 percent and 39 percent, respectively, in the livers of vibrating mice.

"These low-magnitude mechanical signals appear to do something remarkable, and that is inhibit the differentiation of mesenchymal stem cells into fat cells," says Dr. Rubin, indicating that stem cells turn into either fat, bone, or muscle cells. "Theoretically, a mechanical signal that controls the differentiation of stem cells could prevent obesity and perhaps osteoporosis by inducing the cells to develop into bone or muscle cells rather than fat cells."

Two different strains of mouse from The Jackson Laboratory were used in the study: the famous "Black 6" or C57BL/6J, the world's most widely used genetically defined strain, and a hybrid variety that early in life develops the kind of age-related body composition changes we humans dread: losing lean muscle mass and gaining fat.

Dr. Rubin emphasizes that that many steps are ahead of the research team before they can demonstrate that low-magnitude vibration may reduce the production of fat in humans let alone develop a targeted therapy. The results, however, bring a new view on the etiology of obesity, from both a developmental and metabolic perspective.

"The results are somewhat contrary to a 'metabolic' perspective of fat reduction because they illustrate that the inhibition of fat production can be achieved by developmental pathways other than an exercise-mediated increase in metabolic activity," adds Dr. Rubin, who cautions, however, that the role of exercise in reducing existing adipose (fat) tissue remains critical to weight control and weight loss.

The researchers took into account associations that persist between vibration and adverse health conditions, such as low-back pain, cartilage erosion, and circulatory disorders. Such associations have led the International Safety Organization to advise limiting human exposure to mechanical signals. The mechanical signals used on the mice produce a vibration barely perceptible to the human eye and are at a magnitude of the human equivalent well below that which would arise during walking.

Dr. Rubin's and Rosen's colleagues include: Stefan Judex, Ph.D, B. Busa, and Y.K. Lu of the Department of Biomedical Engineering at Stony Brook University; E. Capilla, Ph.D., Howard Crawford, Ph.D., and Jeffery Pessin, Ph.D., of the Department of Pharmacology at Stony Brook University; and D.J. Nolan and V. Mittal, Ph.D., of the Graduate Program in Genetics, Stony Brook University.

The study and continued research is supported by the National Institutes of Health, the National Aeronautics and Space Administration, and the W.H. Coulter Translational Research Award.

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Contact(s):

Greg Filiano, Stony Brook University
gfiliano@notes.sunysb.edu, 631-444-9343

Joyce Peterson, The Jackson Laboratory
joyce.peterson@jax.org, 207-288-6058

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