Pain of any type is typically the underlying result of many disorders and diseases which compromises millions of Americans lives and lifestyles according to the American Pain Society. More specifically allodynia, which is a painful response to non-noxious stimuli is gaining more attention as it is commonly associated with disorders such as neuropathy, postherpetic neuralgia, fibromyalgia, and post operative surgeries. However, treatments for allodynia are not always effective due to the abundance of mediators contributing to its occurrence. Exogenously administered cannabinoids are capable of binding to the cannabinoid receptors, which then signals a downstream cascade to occur, and ultimately produce analgesia. Similarily, endocannabinoids (anandamide;AEA and 2-AG) also bind to the cannabinoid receptors;however, their activation at the receptor level is tremendously decreased due to degradative enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), which metabolizes AEA and 2-AG respectively. The goal of this project is to investigate the roles of FAAH and MAGL in modulating mechanical allodynia. Allodynia can be induced by intraplantar injections of low concentrations of lipopolysaccharide, sustainable up to 48 hrs and tested using calibrated von frey filaments. To elucidate FAAH and MAGL roles in vivo, we will combine the use of pharmacological tools (selective receptor and enzyme inhibitors) and genetically modified animals (receptor, enzyme, and conditional knockout mice). Additionally, we will quantify endogenous cannabinoid levels using LC/MS/MS technology for regional specific areas that are important in modulating mechanical allodynia. In addition to lipopolysaccharide directly inducing allodynia, a secondary response to the endotoxin results in the release of cytokines. Therefore, since a final goal of this project is to investigate the relevance of FAAH and MAGL in altering in vivo cytokine levels to determine if they also contribute to the allodynic response. We will use ELISA techniques to quantify actual protein levels of both pro-inflammatory and anti-inflammatory cytokines produced. These studies will correlate the importance of FAAH and MAGL in regulating pain and inflammation. Additionally, it will further the understanding of the endocannabinoid system and its potential implications in therapeutic treatments.
| Schlosburg, Joel E; Kinsey, Steven G; Ignatowska-Jankowska, Bogna et al. (2014) Prolonged monoacylglycerol lipase blockade causes equivalent cannabinoid receptor type 1 receptor-mediated adaptations in fatty acid amide hydrolase wild-type and knockout mice. J Pharmacol Exp Ther 350:196-204 |
| Booker, Lamont; Kinsey, Steven G; Abdullah, Rehab A et al. (2012) The fatty acid amide hydrolase (FAAH) inhibitor PF-3845 acts in the nervous system to reverse LPS-induced tactile allodynia in mice. Br J Pharmacol 165:2485-96 |
| Schlosburg, Joel E; Blankman, Jacqueline L; Long, Jonathan Z et al. (2010) Chronic monoacylglycerol lipase blockade causes functional antagonism of the endocannabinoid system. Nat Neurosci 13:1113-9 |
