Funded Projects

Opioid dependence is a leading cause of premature illness and death. Previous research suggests that a protein called G-protein coupled receptor (GPR88) controls many addiction-relevant behavioral and physiological actions of opioids. This research study will validate GPR88 as a drug target for opioid use disorder as well as develop novel, brain-penetrant GPR88-binding molecules with properties optimized for treating opioid dependence. This research is an initial step toward the goal of developing GPR88-binding molecules as novel therapeutics to facilitate abstinence in people dependent on opioids.

Chronic opioid use results in tolerance, a primary driver for opioid misuse and overdose that directly contribute to increased morbidity and mortality. Changes in neuronal connectivity known as synaptic plasticity are a key determinant of opioid tolerance, but the underlying molecular mechanisms remain unclear. Tiam1 is a protein known to control the development of nerve cells and their connections and is also involved in morphine-induced neuronal changes. This research will examine Tiam1-mediated synaptic plasticity underlying opioid tolerance and validate Tiam1 as a potential therapeutic target for prevention of tolerance development.

Currently available treatments for opioid use disorder (OUD) are insufficient for many patients. Novel compounds that can promote alterations in brain connections (i.e., neural plasticity) possess enormous potential for improving substance use disorder (SUD) treatments. Psychedelic compounds induce neural plasticity and can elicit long-lasting, beneficial impacts on a wide variety of SUDs. However, these compounds have significant side effects, including hallucinations and cardiotoxicity. Researchers have developed a novel, synthetic derivative of the psychedelic ibogaine, called tabernanthalog, that does not have these side effects. This compound has demonstrated both short- and long-term therapeutic effects in a preclinical model of OUD. This research study will determine the molecular and neural mechanisms through which tabernanthalog affects opioid seeking. It will also evaluate whether the effects are specific to opioids and do not alter response to natural rewards and will examine the efficacy of tabernanthalog in a preclinical model of comorbid opioid and alcohol use disorder.

Fentanyl and its analogs are synthetic opioids that are 100 to 10,000 times more potent than morphine. Overdose from these opioids is extremely dangerous due to their ultra-potency and longer half-life than naloxone, the front-line treatment for fentanyl overdose. This research study will develop novel mu opioid receptor antagonists that bind to the same receptor as the opioid drugs and specifically counteract fentanyl and its analogs, thereby reversing the drugs’ acute toxicity more effectively and with fewer side effects than current treatments. The researchers will characterize novel fentanyl derivatives, identify promising compounds, and pursue preclinical development of these compounds as novel reversal agents against the acute toxicity of fentanyl. The goal is to file an Investigational New Drug application with the U.S. Food and Drug Administration.

There is a need to improve access to treatments and address the stigma, bias, and mistrust that harm and isolate people with chronic pain, especially those from ethnic and racial minority populations. The Integrating Nonpharmacologic Strategies for Pain with Inclusion, Respect, and Equity (INSPIRE) Chronic Pain (CP) intervention blends cognitive-behavioral therapy, physical therapy, mindfulness, and pain education, and is delivered by a trilingual mobile app and supported by a telehealth pain coach who coordinates with doctors. The coach will collect and summarize patient reports on pain, depression, anxiety, substance use, and social factors, and share them with healthcare providers. In this project, researchers will create the digital tool and coaching protocol, develop educational and implementation strategies for healthcare providers, and conduct a pilot test. They will then perform a randomized clinical trial to compare INSPIRE to current treatment, analyze its effects, and evaluate outcomes.

Clinician bias causes inequities in healthcare, and interventions are needed to mitigate and eradicate this bias. This project aims to develop and test the impact of two interventions on overcoming clinician implicit bias in the management of pain for children from ethnic minorities treated in the emergency department. The study will include pediatric patients from under-represented minority groups with pain from long-bone fractures or acute appendicitis who are cared for by racially and ethnically diverse caregivers. Researchers will use stakeholder-informed approaches to establish quality of care metrics and then use clinician audit and feedback as well as data from electronic health records to quantify evidence of bias.      

This research project will include focus group interviews with clinicians, patients, medical interpreters, and healthcare administrators to identify barriers and facilitators to administering the GetActive+ intervention in a group visit at a clinic for older adults with chronic pain, to inform development of a therapy manual. The project will then test the GetActive+ intervention for changes in physical function immediately post-intervention and after 6 months, as well as for changes in pain, sleep, depression, and anxiety at both time points. This research will also assess feasibility, acceptability, fidelity, and adoption of the intervention with patients, providers, and healthcare staff. 

There are significant and persistent gaps in knowledge about effective pain management for acute and chronic sickle cell pain. This is an area of relevant interest for the NIH HEAL Initiative's Early Phase Pain Investigation Clinical Network (EPPIC-Net). In order to provide guidance for hospital-based administration of the medication ketamine, this project will conduct a cross-sectional survey study of healthcare professionals within EPPIC-Net who provide care for people with sickle cell disease. This information can be used to design a clinical protocol for a multisite, randomized clinical trial of sub-anesthetic (low) doses of ketamine for challenging vaso-occlusive episodes (“pain crises”) in people with sickle cell disease.

Spinal cord stimulators (SCS) and related devices are commonly used for hard-to-treat pain conditions, but how they work remains unclear. This knowledge is important for improving device design and stimulation patterns, as well as for determining which patients will benefit. Through a series of clinical studies in patients with SCS devices, this project will explore the hypothesis that SCS devices reduce pain by changing the excitability of peripheral sensory nerve fibers in the spinal cord. The results should guide development of biomarkers to advance research further.

Current treatments for chronic pain, including opioids, are not effective for many individuals. Much remains unknown about genes, circuits, and cells that contribute to chronic pain, including how chronic pain changes across the lifespan in certain populations, including infants, children, older people, and pregnant women. This project will develop technology to map the genes, circuits, and cells associated with pain across ages, sexes, and during pregnancy. The technologies will guide the search for new biomarkers for chronic pain diagnosis and treatments.

There is a continued need to discover and validate new targets for potential therapeutic strategies for effective and safe treatment of pain. This project focuses on the protein metadherin, also known as astrocyte elevated gene-1 protein (AEG-1), as a possible new target for pain treatment. Preliminary studies have shown that mice genetically engineered to lack metadherin had significantly lower inflammation and chronic pain-related behaviors. This project aims to further validate AEG-1 as a pain target and test whether reducing levels in white blood cells called macrophages might work as a therapeutic strategy to reduce chronic inflammatory and/or neuropathic pain using an innovative nanoparticle approach to target specific cells.

Chronic pain from tissue injury often stems from long-term changes in spinal cord circuits that change nerve sensation. Reversing these changes may provide better pain therapeutics. Previous work in animal models showed that activating G protein-coupled receptor 37 (GPR37) dampens nerve signal intensity after long-term stimulation and alleviates pain behavioral responses. This project aims to validate GPR37 in the spinal cord as a useful target for new treatments for neuropathic pain. The work will facilitate screening and identification of new molecules that activate GPR37, which can then be tested for efficacy and safety in further research in animal models of pain.

Pain is a common problem for people with end-stage renal disease that receive hemodialysis. Opioid use rates in this population are almost three times that of the general U.S. population over 65, putting them at significant risk for addiction. This research is testing treatments to manage chronic pain in this patient population. This project will develop educational materials to overcome barriers to telehealth toward enhancing research participation by American Indian/Alaska Native communities.