Transporters (carriers, chaperones) for the endocannabinoid, anandamide (AEA) have recently been identified. One class of these transporters are the fatty acid binding proteins (FABPs). The FABPs are a family of small soluble carrier proteins for lipophilic substances. These FABPs have recently been shown to "solubilize" anandamide so it can move inside the cell for degradation by enzymes at the endoplasmic reticulum. The major goal of this proposal is to develop drugs that bind to these anandamide carriers. We hypothesize that targeting these FABPs with inhibitors will prevent anandamide being transported for breakdown inside the cell and subsequently raise the extracellular levels of anandamide, resulting in anti-nociceptive and anti-inflammatory effects. We will test this hypothesis by identifying and designing inhibitors of the anandamide transporters. This approach will involve a combination of interrelated techniques including in silico screening of commercial drug libraries using DOCK followed by re- ranking with a novel footprint-based scoring function. The most promising compounds will then be tested employing a fluorescent displacement assay for their ability to bind mainly to FABP5 and FABP7 that occur in the nervous system. From these binding data, chemical synthesis of lead compounds will be undertaken to authenticate their structure. The most promising compounds will be tested in cell culture uptake assays, engineered to contain specific FABPs. The best transport inhibitors will be tested for efficacy in mice using models of pain and inflammation. Finally, X-ray crystallographic structures of a select number of the aforementioned FABP-inhibitor complexes will be determined. This X-ray data will be employed for more accurate in silico screening and for the chemical synthesis of more potent and specific FABP inhibitors. Anandamide transport inhibitors found in this fashion may lead to novel approaches for treatment of pain and inflammation and eventually to medications for drug abuse and addiction. Our preliminary studies have identified a class of compounds, the "truxilloids", that are anti-nociceptive and anti inflammatory in mice.
Anandamide is a neurotransmitter that occurs naturally throughout the body for regulation of pain and stress. We have designed a way to raise anandamide levels, using newly identified compounds that binds to the recently discovered anandamide transporter. In this manner it will be possible to develop new drugs for pain, stress and issues with drug addiction and withdrawal.
|Sanson, Benoît; Wang, Tao; Sun, Jing et al. (2014) Crystallographic study of FABP5 as an intracellular endocannabinoid transporter. Acta Crystallogr D Biol Crystallogr 70:290-8|
|Kaczocha, Martin; Rebecchi, Mario J; Ralph, Brian P et al. (2014) Inhibition of fatty acid binding proteins elevates brain anandamide levels and produces analgesia. PLoS One 9:e94200|