Obesity & Gene Therapy

Researchers in Florida University have successfully used gene therapy to control weight gain and appetite in animal models. Though human studies are far away, still there is some hope  that some day a single injection may be a viable option for treating obesity.

Scientists injected mice and rats with genes that increased the production of two appetite-controlling compounds already existing in the body-leptin and ciliary neurotrophic factor, or CNTF. 

Leptin is a protein produced by fat cells that inhibits appetite and increases  energy expenditure. It signals the brain, affecting its secretion of appetite-regulating signals. Such signals include neuropeptide Y, a chemical that researchers found stimulates appetite. This process is thought to be faulty in most obese people so that even high levels of leptin fail to turn off the hunger signal. The concept is that if you can turn off the production of neuropeptide Y and other appetite-stimulating signals by increasing leptin levels, it is possible to control body weight.

Researchers injected leptin-producing genes into obese mice that did not produce the protein. Once inside the mice, the genes integrated into their cells and acted like small factories, producing increased levels of leptin. The result was weight loss in less than three weeks. Normal, lean rats given the leptin genes maintained their body weight for three months, the duration of the experiment. Research team also experimented with an alternative appetite-suppressing protein, CNTF. After six weeks, researchers observed a decrease in body weight similar to that in the mice treated with the leptin gene.

Clinical studies of CNTF and leptin gene therapy in humans will not be approved until researchers can prove that these gene treatments are safe.