Therapeutic potential of peroxisome proliferator-activated receptor agonists for neurological disease

Activation of peroxisome proliferator-activated receptors (PPARs) mediates the insulin-sensitizing effects of thiazolidinediones used for treatment of type 2 diabetes, owing to changes in the transcription and expression of genes influencing carbohydrate and lipid metabolism. However, PPAR activation can have additional effects upon cellular physiology, including anti-proliferative and anti-inflammatory. These effects are observed in many cell types, including brain glial cells and blood lymphocytes, cells whose activation contributes to the initiation and progression of damage occurring in neurological diseases such as Alzheimer's disease (AD) and multiple sclerosis (MS). In view of the need for development of additional therapeutic options, several recent studies have tested the possibility that PPAR agonists would be neuroprotective in these diseases. This paper will summarize data from cell culture experiments and from studies in animal models, demonstrating that PPARgamma agonists can exert neuroprotective effects, thereby providing the basis for the design of clinical trials to test the safety and efficacy of thiazolidinediones in neuroinflammatory conditions such as AD and MS.