The researchers took the gene that produces leptin – a hormone that has been linked to appetite control – and put it into the brains of mice that are obese and have lower bone mass than normal mice because they cannot make leptin.
This gene therapy not only lowered the mice’s body weight, but also increased bone growth, said Urszula Iwaniec, an assistant professor in the Department of Nutrition and Exercise Sciences at OSU. Iwaniec is the lead author on the paper, which was published in the most recent issue of Peptides.
Iwaniec worked on the study with Satya Kalra, a distinguished professor emeritus in the Department of Neuroscience at the McKnight Brain Institute at the University of Florida.
Iwaniec said that these findings tell us that leptin is not only a major factor in obesity, but that leptin is essential for normal bone growth. The research is critical for understanding how the bones grow and remain healthy during aging. This study gives new insights into bone diseases, including osteoporosis, which contributes to more than 2 million fractures annually in the United States alone.
“We’re really just starting to scratch the surface on how powerful leptin is in the body, and what gene therapy can do,” she said.
Because the “blood-brain barrier” reduces entry of leptin into the brain, the researchers found that the treatment was most effective when the leptin was injected directly into the hypothalamus of the brain.
The research is critical to understanding how the bones grow and remain healthy during aging.
Iwaniec said the next step is to look at the effects of extra leptin in animals that already are able to produce leptin.