Published May 2, 2016
Jun-Xu Li, MD, PhD, assistant professor of pharmacology and toxicology, has received the Joseph Cochin Young Investigator Award from the College of Problems of Drug Dependence (CPDD) for his research on pharmacotherapy for stimulant abuse.
“Jun-Xu Li is a very creative experimentalist who has conceived of new approaches for examining a wide variety of topics in neuropharmacology, in general, and addiction research, in particular,” says Li’s former mentor Charles France, PhD, from the University of Texas Health Science Center at San Antonio, who nominated Li for the award.
Li and his research team study new drug targets and evaluate potential pharmacotherapeutic treatments for stimulant abuse. They use behavioral pharmacological approaches in animal models that are predictive of human stimulant abuse conditions.
“Stimulant abuse and addiction are difficult conditions to treat because they lack FDA-approved pharmacotherapies, and the biggest challenge is the high relapse rate, which currently has no effective treatment,” says Li.
Li’s laboratory has found novel data showing that TAAR1 agonists might be effective for treating cocaine abuse. His research in this area has been the basis of lectures and symposia in China and the United States — and in summer 2016 he will present his work at a symposium in Hungary.
Li has also found that drugs acting on imidazoline I2 receptors may produce analgesic effects that are devoid of the abuse liability, tolerance, dependence and other adverse effects of opioid analgesic drugs.
His research aims to further delineate the pharmacological properties of these drugs as a novel class of analgesics.
“It is particularly noteworthy that such a junior investigator has been so innovative in identifying and exploring new targets for treating addiction,” emphasizes France.
Training the next generation of addiction researchers is a high priority for Li, says France, describing Li as a mentor who is “patient yet demanding, engaging while entertaining and unanimously liked and respected by all.”
He mentors “very effectively as an independent investigator, having graduated his first doctoral student, who himself was very productive as a graduate student — and who immediately got a full-time position conducting research,” France notes.
Li is currently training two doctoral students, one master’s student and a postdoctoral fellow.
Lakeisha Lewter, a second-year student in the biomedical sciences doctoral program and an Institute for Strategic Enhancement of Educational Diversity graduate scholar, says, “Dr. Li gives me and my work personalized feedback and attention.”
“When I first joined Dr. Li’s lab, I didn't have a pharmacology background, so I was unaware of some of the pharmacological terms, methods and concepts. Dr. Li took the time to introduce certain pharmacological concepts to me,” she explains.
Lewter is studying the behavioral effects of novel positive allosteric modulators (PAMS) for alpha-2 and alpha-3 containing GABA A receptors and the potential utility of these PAMs as analgesics.
“Li has made a number of important discoveries on a variety of topics in pharmacology,” says France.
He demonstrated that rats’ feeding conditions significantly modify the behavioral effects of direct- and indirect-acting serotonin (5-HT) receptor agonists. His experiments suggested that different dietary conditions might impact individuals’ vulnerability to abuse drugs that have actions on 5-HT systems and the therapeutic effects of drugs acting on 5-HT systems.
He also discovered that agonists acting at 5-HT2A receptors significantly enhance the antinociceptive effects of opioid receptor agonists without enhancing the drugs’ abuse-related effects. The discovery provided a potential mechanism to account for the widespread use of indirect-acting 5-HT receptor agonists — such as selective serotonin re-uptake inhibitors — in combination with opioids for treating pain.
Li has shown that cannabinoids enhance the potency of opioids for antinociception, but not their potency for discriminative stimulus or positive reinforcing effects. His finding is being pursued by several laboratories in the hope of developing an opioid and cannabinoid mixture that is safe, effective for treating pain and with reduced abuse liability, compared with larger doses of opioids administered alone.
The Joseph Cochin Young Investigator Award, which was established in 1986, is named for a respected leader in drug abuse research and a former chair and executive secretary of the CPDD.
“This means a lot to me because it is a major award to independent investigators under the age of 40 and because it is judged on overall research achievements — instead of one significant paper or finding,” says Li.
“This is recognition of scientific excellence from the oldest and most prestigious scientific organization on drug abuse research, and only one award is given each year,” he adds.
Li will accept the award at the 78th annual CPDD meeting in June.