Funded Projects

Epidural/spinal administration of analgesics such as opioids, ziconotide and local anesthetics have profound efficacy in some of the most intractable pain conditions such as severe neuropathic pain after failed back surgery, cancer pain and post-operative pain after major abdominal/thoracic surgeries. Contulakin G (CGX) is a snail venom derived peptide that has homology with mammalian neurotensin and was shown to be safe in humans in preliminary studies. A small pilot study demonstrated CGX?s analgesic effect in some patients with spinal cord injury-associated pain. Preliminary findings from mechanistic studies in rodents identified neurotensin receptor 2 (NTSR2) as the mediator for analgesic effects of CGX. This project aims to validate spinal NTSR2 as an analgesic target utilizing three species (rat, mice and human), and two pain models (neuropathic pain and post-surgical pain). The project will utilize pharmacological and gene editing tools such as CRISPR-Cas9 and will include assessment of both sensory and affective measures of pain. A two-site parallel confirmation study is designed based on multisite clinical trials to further authenticate spinal NTSR2 as an analgesic target. Successful completion of this project could lead to the development of a non-opioid spinal analgesic that has high translational potential.

Using neural tissues from pain patients, this project will investigate mechanisms of neuronal and/or immune dysfunction driving chronic pain. The researchers will use spatial transcriptomics on human dorsal root ganglion (DRG) and spinal cord tissues to examine the cellular expression profile for these targets using the 10X Genomics Visium technology. The use of tissues from control surgical patients and organ donors as well as surgical patients with neuropathic pain will enable validation of expression of these targets in human tissue as well as indication of their potential involvement in neuropathic pain. This collaborative effort will use DRGs removed from pain-phenotyped patients during neurological surgery, as well as lumbar DRGs and spinal cord from organ donors. This study will map the spatial transcriptomes at approximately single cell resolution in the human DRG and spinal cord.

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 aims to develop and clinically validate a 64-channel spinal cord stimulation therapy for treating chronic neuropathic pain of the lower extremities, groin, and lower back. With an increased channel count and the ability to precisely target medial and lateral structures of the spinal cord, the system will treat chronic pain with greater efficacy and reduced side effects. This project will pursue a safe, effective, and non-addictive treatment for neuropathic pain through the testing of enhanced HD64 active leads to be manufactured under GMP regulations. The leads will then undergo electrical, mechanical, biocompatibility, and sterilization testing before being tested in a 10-subject early feasibility study.

Neck pain is the fourth leading cause of disability and also a significant cause of cervicogenic headaches. Many of the currently available neck pain treatments are invasive with associated risks and complications, particularly because of the complex anatomy. Magnetic resonance guided focused ultrasound, a novel, completely noninvasive technique, can precisely target spinal facet joints to help ameliorate neck pain, potentially transforming the current practices. The goal of this study is to develop a cervical spine-specific device and demonstrate its safety and efficacy on targeting cervical sensory fibers and the third occipital nerve. The results of these studies will provide an understanding on how to best use this technology for chronic neck pain as well as a basis for translation into human use.

Many non-opioid drugs target G Protein-Coupled Receptors (GPCRs), a family of proteins involved in many pathophysiological processes including pain, fail during clinical trials for unknown reasons. A recent study found GPCRs not only function at the surface of nerve cells but also within a cell compartment called the endosome, where their sustained activity drives pain. This study will build upon this finding and test whether the clinical failure of drugs targeting plasma membrane GPCRs is related to their inability to target and engage endomsomal GPCRs (eGPCRs). This study will use stimulus-responsive nanoparticles (NP) to encapsulate non-opioid drugs and selectively target eGPCR dyads to investigate how eGCPRs generate and regulate sustained pain signals in neuronal subcellular compartments. This study will also validate eGCPRs as therapeutic targets for treatment of chronic inflammatory, neuropathic and cancer pain. Using NPs to deliver non-opioid drugs, individually or in combinations, directly into specific compartments in nerve cells could be a potential strategy for new pain therapies.

This project will establish a rapid research pipeline for linking plant-derived compounds to nociception (pain) and to G Protein-Coupled Receptors (GPCRs) and ion channels in the druggable human genome. As more than 80% of these membrane proteins are conserved in the C. elegans nematodes, the study will screen for compounds and genes affecting nociception as well as to identify novel ligand-receptor pairs using this model organism. The study will test which understudied GPCRs and ion channels are involved in nociception as well as attraction or repulsion behaviors. This research has the potential to reveal novel ligand-receptor pairs that could serve as new entry points for improved or alternative pain treatments.

A substantial proportion of Americans seeking emergency care after traumatic stress exposure (TSE) are at a high risk of chronic pain and opioid use/misuse. Physiologic systems involved in the stress response could possibly play a critical role in the development of chronic pain after TSE. FK506-binding protein 51 (FKBP51) is an intracellular protein known to affect glucocorticoid negative feedback inhibition and component of stress response, provides an important non-opioid therapeutic target for such chronic pain. This project will test the hypothesis that functional inhibition of FKBP51 prevents or reduces enduring stress-induced hyperalgesia in a timing, dose, and duration-dependent manner in animal models of single prolonged stress alone and in combination with surgery. This project will also test if FKBP51 inhibition enhances recovery following TSE via reduction in pro-inflammatory responses in peripheral and central tissues. It will also test whether FKBP51 inhibition effects cardiotoxicity or addiction. Completion of these studies will increase understanding of FKBP51 as a novel therapeutic target for the prevention of chronic pain and opioid use/misuse resulting from TSE.

There is an urgent need for new non-opioid therapeutic agents that treat the pain associated with Osteoarthritis (OA) ? a chronic, progressive disease that leads to pain in weightbearing joints, pain during movement, and pain at rest. This project will refine techniques for targeting several proteins expressed in sensory neurons associated with OA pain, with the goal of testing the potential of these proteins to serve as targets for development of effective, non-opioid painkillers.

There is a distinct neural ensemble in the brain that encodes the negative affective valence of pain. This project will identify novel targets to treat pain by determining the molecular identity of these BLA nociceptive cells via in situ hybridization and single cell RNAsequencing (scRNA-seq). Resolving the molecular identity of these ACC nociceptive cells will also reveal new targets to treat pain affect. To achieve these results the project will catalog candidate Gi/o-GPCR targets in BLA and ACC, test their utility to treat pain, and verify these new targets have no effect in the brain?s reward and breathing circuitry. The experiments in this project will also evaluate each target for abuse potential and effects on breathing by using behavioral assays for reward processing and whole-body plethysmography, respectively. To evaluate whether our results in rodents are likely to translate clinically, there will be an analysis of expression patterns of these drug targets in human tissue using in situ hybridization.

G-protein coupled receptor 3 (GPR3) is an orphan receptor present in the central nervous system (CNS) that plays important role in many normal physiological functions and is involved in a variety of pathological conditions. Although the brain chemical that activates this receptor has not been identified, work with GPR3 knockout mice has identified GPR3 as a novel drug target for several Central Nervous System (CNS) mediated diseases including neuropathic pain. However, despite the emerging behavioral implications of the GPR3 system, little is known about how GPR3 affects behavior due to the lack of potent and selective chemical probes that allow scientists to examine functioning of the receptor. Recently, two cannabinoid chemicals present in the cannabis plant were discovered as affecting GPR3. This study will modify the chemical structure of these compounds to increase their potency and selectivity so that they may be used as pharmacological tools to investigate the role of GPR3 in modulating pain. In addition, this project focuses on identifying new compounds that show promise for development into therapeutics for the treatment of pain.

Functional selectivity is a term used to describe the ability of drugs to differentially regulate the activity of multiple signaling cascades coupled to the receptor. The underlying mechanism for functional selectivity is based upon the formation of ligand-specific receptor conformations that are dependent upon ligand structure. Functional selectivity has the potential to revitalize the drug discovery/development process. Ligands with high efficacy for specific signaling pathways (or specific patterns of signaling) that mediate beneficial effects, and with minimal activity at pathways that lead to adverse effects, are expected to have improved therapeutic efficacy. We propose to demonstrate that ligand efficacy for specific signaling pathways associated with antinociception can be finely tuned by structural modifications to a ligand. We propose to use U50,488 and Salvinorin-A (Sal-A) as scaffolds to develop functionally selective analogs that maintain high efficacy for signaling pathways that lead to antinociception and minimize activity toward anti-antinociceptive signaling pathways.

This project will build overdose models for fentanyl, methadone, codeine, and morphine in a multi-organ system and evaluate the acute and repeat dose, or chronic effects, of overdose treatments as well as off-target toxicity. Researchers developed a system using human cells in a pumpless multi-organ platform that allows continuous recirculation of a blood surrogate for up to 28 days. They will develop two overdose models for male and female phenotypes based on pre-B?tzinger Complex neurons and will integrate functional immune components that enable organ-specific or systemic monocyte actuation. Models for cardiomyopathy and infection will be utilized. Researchers will establish a pharmacokinetic/pharmacodynamic model of overdose and treatment to enable prediction for a range of variables. We will use a serum-free medium with microelectrode arrays and cantilever systems integrated on chip that allow noninvasive electronic and mechanical readouts of organ function.