Gene therapy has been used in mice to successfully reverse obesity and insulin resistance, as well as other markers of type 2 diabetes.
Researchers introduced the gene FGF21 into obese mice via an adeno-associated virus. They found that this had a long-term impact, leading to weight loss and reduced insulin resistance in the animals for over a year, noting no side effects.
'This is the first time that long-term reversion of obesity and insulin resistance have been achieved upon a one-time administration of a gene therapy, in an animal model that resembles obesity and type 2 diabetes in humans,' said the first author of the study Dr Veronica Jimenez at Universitat Autònoma de Barcelona in Spain. The research was published in EMBO Molecular Medicine.
The therapy worked on two different mouse models of obesity, in which the mice were obese either through their diet or through genetic modification. The scientists also found similar results when introducing the gene into one of several different tissues - liver, skeletal tissue or adipose tissue.
'This gives a great flexibility to the therapy since it allows [us] to select each time the most appropriate tissue, and in case some complication prevents manipulating any of the tissues, it can be applied to any of the others,' said Professor Fatima Bosch, who led the study. 'When a tissue produces FGF21 protein and secretes it into the bloodstream, it will be distributed throughout the body.'
As well as the effects in obese mice, the researchers found that introducing FGF21 in the same way in healthy mice reduced age-related weight gain and promoted healthy ageing.
'The results demonstrate that it is a safe and effective therapy,' said Dr Jimenez.
The next steps will be to 'test this therapy in larger animals before moving to clinical trials with patients', said Professor Bosch.