Discovery of Mechanism that Processes 'THC' Type Brain Compound May Lead to New Medicines for Pain, Addiction

March 31, 2009

Science Daily/Stony Brook University Medical Center

Dale Deutsch, Ph.D., Professor of Biochemistry and Cell Biology at Stony Brook University and colleagues discovered a new molecular mechanism for the processing of endocannabinoids, brain compounds similar to THC, the active ingredient in marijuana, and essential in physiological processes such as pain, appetite, and memory.

Reported online this week in the Proceedings of the National Academy of Sciences (PNAS), the finding could pave the way for new medicines for pain, addiction, appetite control and other disorders.

Dr. Deutsch and colleagues in the Departments of Biochemistry and Cell Biology (Martin Kaczocha) and Neurobiology and Behavior (Sherrye Glaser, Ph.D.) are the first to successfully identify two known fatty acid binding proteins (FABPs) that carry the endocannabinoid anandamide (AEA), a neurotransmitter, from the cell membrane to interior of the cell where it is destroyed. This identification enabled the research team to inhibit FABPs in various laboratory experiments and thereby reduce AEA breakdown inside cells. In their study, “Identification of intracellular carriers for the endocannabinoid anandamide,” the researchers report that they decreased the breakdown of AEA in some instances by approximately 50 percent.

“Inhibiting FABPs could potentially raise the levels of AEA in the brain’s synapses,” says Dr. Deutsch. “Naturally occurring AEA levels have been shown to curb pain without the negative side effects, such as motor coordination problems, from molecules like THC. Therefore, it makes sense to target AEA for therapeutic purposes.”

He emphasizes that their groundbreaking discovery of the role of FABPs in transporting this class of neurotransmitters may prove to be a crucial step in developing novel drug targets for endocannabinoids by way of inhibiting FABPs. In support of the research, The State University of New York (SUNY) Stony Brook Office of Technology Licensing and Industry Relations (OTLIR) has filed U.S. Patent applications comprising the discovery.

The OTLIR manages all intellectual property matters for the SUNY Research Foundation. In actively marketing this unlicensed technology created by Dr. Deutsch, the Stony Brook OTLIR welcomes commercial entities interested in partnering with the University. The licensing agent for the project is Adam DeRosa of the OTLIR.

The breakdown of AEA requires two factors. First, there needs to be a mechanism for transporting AEA to the location where it is inactivated because AEA is a fatty compound and thus unable to move inside the watery cellular environment. Second, the cell must express an enzyme called FAAH, which controls the breakdown and inactivation of AEA. In the laboratory, the researchers coaxed a nonneuronal cell type (COS-7) to express FAAH. These FAAH-expressing COS-7 cells were able to break down AED efficiently, indicating that the intracellular AEA transport mechanism was already present and operation in these cells. The researchers identified these carriers as two separate FABPs.

Dr. Deutsch believes that because a transporter for the AEA class of neurotrasmitters had never been discovered until the Stony Brook findings, continued research may explain many unanswered questions about AEA. Future research may uncover more knowledge about AEA transport, as well as the entire role these neurotransmitters play in pain, inflammation, appetite control, addiction, and perhaps other physiological processes related to many human disorders.

The research was funded by the National Institute on Drug Abuse, part of the National Institutes of Health.

https://www.sciencedaily.com/releases/2009/03/090325190342.htm

Marijuana-inspired Painkiller? New Chemical Pathway Discovered

November 27, 2008

Science Daily/Scripps Research Institute

Marijuana can be an effective painkiller, but social issues and unhealthy smoke inhalation complicate its use. As a result, researchers have focused great attention on understanding the biochemical system involved so they might manipulate it by other means. Toward that end, scientists have definitively identified a chemical pathway that, in mice, imitates marijuana's painkilling effect. The work could enable the development of new pain treatments.

Marijuana kills pain by activating a set of proteins known as cannabinoid receptors, which can also regulate appetite, inflammation, and memory. The body also has chemicals known as endocannabinoids that naturally activate these same receptors, namely N-arachidonoyl ethanolamine (AEA) and 2-arachidonoylglycerol (2-AG).

These natural components of the cannabinoid system remain the focus of intense efforts to develop new treatments not only for chronic pain, but also for obesity, anxiety, and depression. However, until the new paper (citation below) specific methods to study 2-AG signaling have been lacking.

AEA's activity has been well understood for years. In past research, Cravatt and his team identified an enzyme called fatty acid amide hydrolase, or FAAH, that breaks down AEA, effectively reducing its pain killing activity. A number of compounds are now in clinical development that target and breakdown FAAH, allowing AEA to build up, reducing pain. However, FAAH does not control 2-AG metabolism in vivo, and therefore, the potential biological functions and therapeutic potential of this second endocannabinoid have remained largely unknown.

Teasing out 2-AG's specific impacts have proven challenging. Comparable to FAAH, an enzyme called monoacylglycerol lipase (MAGL) breaks down 2-AG. But, despite numerous attempts, no group had been able to develop a chemical that inhibits MAGL specifically.

"The tools—selective and efficacious MAGL inhibitors—just weren't there, " says Jonathan Long, a graduate student of the Scripps Research Kellogg School of Science and Technology who is a member of the Cravatt lab and a first author of the new paper.

But now, a MAGL-specific inhibitor is finally available, thanks to the lab's new work. Key to this success was Activity-Based Protein Profiling, a unique chemical technique the group devised and has used fruitfully in other inhibitor hunts. This system enables the rapid engineering and testing of chemical compounds against many members of enzyme families, in hope of finding effective and selective inhibitors.

For this project, the group developed about 200 compounds and found that one was a highly effective block for MAGL. The scientists dubbed the compound JZL184, named after Long's initials and the order in the series of potential inhibitors tested. JZL184 effectively blocks only MAGL among more than 40 related brain enzymes, which opened the door for the first definitive study of 2-AG's activity.

A New View of 2-AG

Unlike increased AEA, which causes only reduced pain sensation, the team found that MAGL inhibition using JZL184, and the resulting increase in 2-AG concentration, not only reduced pain in mice, but also induced other effects associated with the cannabinoid receptors, namely hypothermia and decreased movement.

"This really does suggest a sort of segregation of labor, if you will," says Cravatt of the differential effects of elevating AEA versus 2-AG as part of the overall function of the cannabinoid system. "That, I think, is a truly unique result."

While treatments based on inhibiting FAAH show great promise for controlling pain, manipulating MAGL levels could also be a boon for treatment development, especially if 2-AG's other effects, such as hypothermia, can be managed.

"There are so many different types of pain," Cravatt says, "that it's possible some types could be more effectively treated with one treatment than another."

This research was supported by the National Institutes of Health, the Helen L. Dorris Child and Adolescent Neuro-Psychiatric Disorder Institute, and the Skaggs Institute for Chemical Biology.

https://www.sciencedaily.com/releases/2008/11/081123150249.htm