Funded Projects

More than 100 million adults in the U.S. suffer from intermittent or constant chronic pain, and chronic pain affects at least 10 percent of the world’s population. The primary pharmaceuticals for treatment of chronic pain have been natural or synthetic opioids, and the use of opioids for pain treatment has resulted in what has been called an “epidemic” of opioid abuse, addiction, and lethal overdoses. Through a process of rational drug design, the research team has generated a new chemical entity (NCE) and have given it the name Kindolor, a non-opiate, non-addicting molecule that was shown to reduce or eliminate chronic pain in five animal models at doses compatible with use of Kindolor in humans. This project intends to complete the pre-clinical studies required for an IND application, which, if approved, would allow for proceeding onto the Phase 1 and 2 studies to assess safety and efficacy of the compound against osteoarthritic pain.

Identification of new targets and mechanisms underlying chronic neuropathic pain is essential for the discovery of novel treatments and preventative tactics for better neuropathic pain management. A recent exploration of next-generation RNA sequencing identified a large, native, full-length long noncoding RNA (lncRNA) in mouse and human dorsal root ganglion (DRG). It was named as nerve injury-specific lncRNA (NIS-lncRNA), since its expression was found increased in injured DRGs, in response to peripheral nerve injury, but not in response to inflammation. Preliminary findings revealed that blocking the nerve injury-induced increases in DRG NIS-lncRNA levels ameliorated neuropathic pain. This project will validate NIS-lncRNA as a therapeutic target in animal models of neuropathic pain and in cell-based functional assays utilizing human DRG neurons. Completion of this proposal will advance neuropathic pain management and might provide a novel, non-opioid pain therapeutic target.

Many individuals with opioid use disorder (OUD) pass through the criminal justice system over the course of their life. Improved access to high-quality, evidence-based addiction treatment in justice settings will be critical to addressing the opioid crisis. Through the Justice Community Opioid Innovation Network (JCOIN), the National Institutes of Health will study approaches to increase high-quality care for people with opioid misuse and OUD in justice populations. The Mason Coordination and Translation Center (MCTC) will manage logistics, stakeholder engagement, and dissemination of findings and products from the JCOIN network. This will include establishing infrastructure to support research education and rapid response and pilot research.

Severe tissue injury generates central sensitization. Latent sensitization (LS) is a silent form of central sensitization that persists after tissue has healed and overt signs of hyperalgesia have resolved. Pain remission during LS is likely maintained by tonic opioid receptor activity. The opioid receptor inverse agonist, naloxone, can reinstate experimental pain when delivered one week after the resolution of secondary hyperalgesia following first degree thermal injury. Our aims are to test: 1) the hypothesis that burn or surgery triggers LS and long-term opioid analgesia in humans; 2) the hypothesis that mu-opioid receptor (MOR) constitutive activity (MORCA) receptors by opioid peptides maintains endogenous analgesia and restricts LS to a state of pain remission; 3) the extent to which MORs inhibit neural activity in the DH and synaptic strength in presynaptic terminals of primary afferent nociceptors during LS; and 4) whether MORs inhibit spinal NMDA receptor subunits to block pain during LS.

Rates of neonatal abstinence syndrome have reached a staggering 6.5 per 1,000 births nationwide, creating an urgent need to identify how in-utero exposure to opioids and associated risk factors influence the developing brain. A multidisciplinary team will address these challenges in Oregon, a state particularly hard hit by the opioid epidemic. Through linking sites, the impact of the Phase I project is enhanced and will provide critical information to support a national-level effort for Phase II of the HEALthy Brain and Child Development Study. Aim 1 will develop, implement, and evaluate innovative recruitment and retention strategies for high-risk populations. Aim 2 will address anticipated challenges of the planned Phase II study by implementing and evaluating a multi-site, standardized research protocol including multimodal MRI of placenta, fetus, neonate, and 24-month-old brain; biospecimen collection; and assessment of substance use and other key domains. Aim 3 will evaluate data acquisition, processing, and statistical considerations to maximize data quality, usability, and integration across sites.

Natural products, which are substances found in nature and made by living organisms, have been used in the past as good sources for developing new medications. Natural products isolated from marine bacteria that attach to the pain-signaling protein sigma-2 receptor (also known as transmembrane protein 97 [TMEM97]), may serve as a starting point to create new, non-opioid pain medications. This project will use chemistry and biology approaches to refine such natural products as a treatment for neuropathic pain.

Structural and functional neuroimaging measures are prone to errors induced by subject motion. Many comorbid features of opioid exposure are likely to increase children’s in-scanner motion. In total, this raises substantial concern that existing neuroimaging methods are not sufficiently motion-robust to be used in studies of children ages 3–5. Researchers will address these concerns with a feasibility study, comparing the existing methods developed for the Adolescent Brain Cognitive Development (ABCD) study with novel methods we will develop and optimize for young children. They will evaluate research methods in a sample of 100 children and test whether novel technologies improve the quality of the raw imaging data and reduce motion biases in the derived measures. Researchers will determine predictors of successful imaging to inform sampling strategies in future studies. The primary outcomes will be novel, validated structural and functional neuroimaging imaging methods for young children and feasibility data to inform the design of future studies addressing developmental questions, particularly those related to opioid exposure.

Currently no medications are approved by the U.S. Food and Drug Administration for psychostimulant (cocaine and methamphetamine) use disorder. This project will develop a novel opioid molecule (PPL-138) that blocks cocaine and methamphetamine self-administration in animal models and that lacks rewarding properties that could lead to addiction. This research will conduct manufacturing and safety studies to prepare for Phase 1 clinical trials to determine safety in human patients.

As many as 64% of patients with Temporomandibular Joint Disorders (TMJDs) report symptoms consistent with Irritable Bowel Syndrome (IBS). However the underlying connection between these comorbid conditions is unclear and treatment options are poor. As such, pain management for these Chronic Overlapping Pain Conditions (COPCs) is a challenge for physicians and patients. This project will determine whether the convergence of pain from different peripheral tissues and perceived stress occurs in the brain and elicits a change in central neural processing of painful stimuli. This project will identify and validate specific lipids, enzymes and metabolic pathways that change expression in the brain during the transition from acute to chronic overlapping pain that can be therapeutically targeted to treat COPCs. Multi-disciplinary approaches will be used to combine brain imaging, visualization of spatial distribution of molecules, genetics, pharmacological and behavioral research techniques.

This project is focused on identifying the clinical, genetic, and neural characteristics that convey risk for prescription opioid addiction. We will leverage the central biorepository and electronic health record (EHR) database of the Geisinger Health System to conduct large-scale genomics research and phenotype development. Through a collaboration with Regeneron Pharmaceuticals, the Geisinger biobank currently contains DNA samples on about 110,000 participants and includes both Illumina OmniExpressExome genotyping and whole exome sequence data, including common and rare variants, from over 60,000 of these subjects. This discovery cohort contains thousands of chronic musculoskeletal pain patients who have been taking greater than 120 mg equivalents of morphine for more than three months. Using EHR and self-report tools to develop a case definition and quantitative scoring, we will derive a clinical/genetic profile of prescription opioid addiction. This profile will be enhanced via integration of neuroimaging data.

The Early Phase Pain Investigation Clinical Network (EPPIC-Net) conducts comprehensive analyses of observable traits (deep phenotyping) and aims to identify molecular and physiological signatures to help characterize specific pain conditions. To achieve these goals, researchers collect complex data using technologies such as magnetic resonance imaging of the brain, actigraphy, and electroencephalography. There is a need to train researchers to be able to extract key information from high-powered computing resources now widely available.  This research will complement the goals of EPPIC-Net by enhancing development of novel statistical methods to analyze complex data generated by EPPIC-Net pain studies.

Although opioid-based analgesics have been proven effective in reducing the intensity of pain for many neuropathic pain conditions, their clinical utility is grossly limited due to the substantial risks involved in such therapy, including nausea, constipation, physical dependence, tolerance, and respiratory depression. Cumulative evidence suggests that human Mas-related G protein-coupled receptor X1 (MRGPRX1) is a promising target for pain with limited side effects due to its restricted expression in nociceptors within the peripheral nervous system; however, direct activation of MRGPRX1 at peripheral terminals is expected to induce itch side effects, limiting the therapeutic utility of orthosteric MRGPRX1 agonists. This finding led to the exploration of positive allosteric modulators (PAMs) of MRGPRX1 to potentiate the effects of the endogenous agonists at the central terminals of sensory neurons without activating peripheral MRGPRX1. An intrathecal injection of a prototype MRGPRX1 PAM, ML382, effectively attenuated evoked, persistent, and spontaneous pain without causing itch side effects. The goal of this study is to develop a CNS-penetrant small-molecule MRGPRX1 PAM that can be given orally to treat neuropathic pain conditions.

There are no FDA-approved medications for stimulant use disorders, and therapies for opioid use disorders remain suboptimal in ways that are now a focus of national attention. Thus, there is a clear need to identify new targets and explore new approaches for addiction medication development. Several lines of evidence suggest that PTPRD (receptor type protein tyrosine phosphatase D) may be a promising target for development of pharmacotherapeutics to treat not only stimulant use disorders but opioid use disorders as well. This research will focus on improving existing PTPRD ligands, identifying their effects on the dopamine and opioid systems, and moving the best novel, patentable PTPRD ligands toward human studies. If successful, this project will generate novel, well-tolerated, and bioavailable PTPRD ligands that display in vitro potency, selectivity and stability, and in vivo modulation of both cocaine and opioid-mediated reward at doses that present no significant toxicity.