Funded Projects

For patients with neuropathic pain refractory to therapy using small molecules, modulation of specific neural structures in the central or peripheral nervous system can provide effective alternative treatments. While current Food and Drug Administration–approved devices for dorsal root ganglion (DRG) stimulation are safe and effective, there have been an unfortunate number of adverse events associated with pulse generator infections and lead migration. The research team will develop a wireless, millimeter-sized nerve stimulator that can be delivered through the vasculature and stimulate the DRG to alleviate symptoms of neuropathic pain and the associated minimally invasive delivery method. This endovascular nerve stimulation (EVNS) system depends on development and integration of key novel technologies into an endovascular stent. The magnetoelectric transducers and electronic circuits will convert wireless power and data into stimulus patterns that can trigger neural activity in the DRG via miniature electrodes. After chronic demonstration of safety and functionality in large animal models, the team will prepare for regulatory discussions with the FDA. If successful, the EVNS will provide a technology platform for treating other neuropathic pain syndromes. 

Postoperative pain is a major contributor to the current opioid epidemic. Novel objective measures capable of personalizing pain care will enhance medical precision in prevention and treatment of postoperative pain. This project seeks to discover and validate a novel biosignature of the human pain experience, based on underlying IL-1 family cytokine activity and associated brain endogenous opioid function, that is readily quantifiable and clinically translatable to prevention and treatment of postoperative pain states. Specific aims will assess whether the novel biosignature will predict 1) experimentally induced pain during an experimental nociceptive pain challenge; 2) postoperative pain states with accuracy >75%, accounting for a wide range of variance in the human pain experience; and 3) postoperative pain states in an expanded clinically enriched sample.

This project focuses on identifying and validating a new central analgesic circuit in the brain, based on a highly innovative hypothesis that the strong analgesic effects of general anesthesia (GA) are in part carried out by GA-mediated activation of the endogenous analgesic circuits. Preliminary discovery studies found that a subset of GABAergic neurons located in the central amygdala (CeA) become strongly activated and express high levels of the immediate early gene Fos under GA (hereafter referred to as CeAGA neurons). Furthermore, activation of these neurons exert profound pain-suppressing effects in an acute pain model and a chronic orofacial neuropathic pain model in mice. Based on these exciting preliminary findings, this project will identify and validate CeAGA neurons’ analgesic functions utilizing multiple mouse pain models. Identification of these shared common pathways that need to be suppressed by specific subtypes of CeAGA analgesic neurons will be highly critical for developing precise CeAGA-targeted therapies to treat chronic pain.

There is currently no recognized way of accurately predicting who will recover from post-traumatic headache (PTH) during the acute phase following concussion and who will go on to develop persistent post-traumatic headache (PPTH), a condition that is difficult to treat effectively. Clinical experience suggests that early treatment is most effective, before headache patterns become persistent, but treating all patients with PTH would expose some patients to unnecessary treatment. Clinicians lack the information needed to make informed treatment decisions. Therefore, the study goals are to develop a prognostic biomarker signature for PPTH using clinical data and structural and functional brain neuroimaging and to assess the predictive accuracy of an ensemble biomarker signature for the early identification of patients at high risk for PPTH. This study can be translated into clinical practice and integrated into PTH clinical trials for early identification of those individuals who are at high risk for PPTH.

Researchers will develop a novel transcranial focused ultrasound (tFUS) device for pain treatment and establish its effectiveness for treating sickle cell disease (SCD) pain in humanized mice. The tFUS will target the specific cortical regions involved in SCD pain using a novel non-invasive electrophysiological source imaging technique. The project’s goals have several aims. Aim 1: Develop tFUS devices for pain treatment. The mouse-scale system will be designed to validate the therapeutic effect of stimulating the anticipated cortical targets. This will inform development of the simpler human-scale system, which will use models of the skull to select cost-effective transducers to reach the targets. Aim 2: Evaluate tFUS effectiveness and optimize stimulation parameters in an SCD mice model. Researchers will determine effective tFUS parameters to chronically reduce SCD pain in mice and validate this using behavioral measures. Aim 3: Use electrophysiological source imaging to target and trigger closed-loop tFUS in animal models. This aim also includes performing safety studies to prepare for human trials. The project will develop a transformative, noninvasive tFUS device to effectively and safely treat pain in SCD. 

This project will develop a human cell-based model of the afferent pain pathway in the dorsal horn of the spinal cord. The research team’s approach utilizes novel human pluripotent stem cell (hPSC)-derived phenotypes in a model that combines 3D organoid culture with microfabricated systems on an integrated, three-dimensional (3D) microelectrode array. Researchers will establish the feasibility of a physiologically relevant, human 3D model of the afferent pain pathway that will be useful for evaluation of candidate analgesic drugs. They will then improve the physiological relevance of the system by promoting neural network maturation before demonstrating the system’s utility in modeling adverse effects of opioids and screening compounds to validate the model. Completion of the study objective will establish novel protocols for deriving dorsal horn neurons from hPSCs and create the first human microphysiological model of the spinal cord dorsal horn afferent sensory pathway.

Chronic pain diminishes the quality of life for millions of patients, and new drugs that have better efficacy and/or fewer side effects are needed. A promising target is the sphingosine-1-phosphate (S1P) receptor system, which mediates central nervous system (CNS) neuromodulatory functions. FTY720-phosphate, the active metabolite of FTY720 (FTY), acts as an agonist at four of the five S1P receptors (S1P1, 3, 4, 5). We propose that the S1P1 receptor is a target for treatment of neuropathic pain. We will test whether S1P1 receptors mediate anti-hyperalgesic effects in a mouse neuropathic pain model. The specific aims are to: 1) determine the role of S1P1Rs in alleviation of neuropathic pain by S1PR ligands; 2) determine the role of FTY-induced S1PR adaptation in FTY-mediated reversal of neuropathic pain; and 3) determine the role of S1P and S1P1 receptors in spinal glia in CCI-induced neuropathic pain and its reversal by FTY.

Initial studies using positron emission tomography (PET) with [11C] carfentanil, a selective radiotracer for ?-opioid receptor (?OR), have demonstrated that there is a decrease in thalamic µOR availability (non-displaceable binding potential BPND) in the brains of TMD patients during masseteric pain compared to healthy controls. ?-opioid neurotransmission is arguably one of the mechanisms most centrally involved in pain regulation and experience. The main goals of our study are: first, to exploit the ?-opioidergic dysfunction in vivo in TMD patients compared to healthy controls; second, to determine whether 10 daily sessions of non-invasive and precise M1 HD-tDCS have a modulatory effect on clinical and experimental pain measures in TMD patients; and third, to investigate whether repetitive active M1 HD-tDCS induces/reverts ?OR BPND changes in the thalamus and other pain-related regions and whether those changes are correlated with TMD pain measures.

Postoperative ileus (POI) following gastrointestinal (GI) surgery leads to significant patient morbidity and prolonged hospitalizations. Recent studies have demonstrated that intestinal manipulation and surgical trauma activate inflammatory macrophages (M?) and release inflammatory mediators such as nitric oxide (NO) to inhibit intestinal smooth muscle cells in POI. Intestinal M? are a highly heterogeneous and dynamic population in the innate immune system. Preliminary studies show that transient receptor potential vanilloid 4 (TRPV4) channel, a molecular sensor of tissue damage and inflammation, is exclusively expressed by the F4/80+/CD206+ intestinal anti-inflammatory M2 M?. Activation of TRPV4 produces an intestinal contractile response and improves GI transit in a mouse model of POI. The current proposal aims to elucidate the cellular and molecular mechanisms underlying the activation of TRPV4 in the intestinal M2 M?.

Chronic pancreatitis (CP) and the debilitating pain associated with it remains a common and challenging clinical syndrome that is difficult to treat effectively. Using rodent models of CP, preliminary studies have found that nerve growth factor (NGF) and transforming growth factor beta (TGFb) appear to be acting by the common effector, calcitonin-gene related peptide (CGRP), to induce pain in CP. CGRP is known to mediate pain as a neurotransmitter in the central nervous system, specifically as a potent vasodilator involved in migraine. This project will test the hypothesis that peripheral CGRP is a major mediator of peripheral nociceptive sensitization in CP, and that peripherally restricted anti-CGRP treatment could provide an efficient and sufficient approach for the treatment of pain in pancreatitis

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.

This project aims to develop a next-generation noninvasive neuromodulation system for non-addictive pain treatments. The research team will build an integrated system that uses magnetic resonance image-guided focused ultrasound (MRgFUS) stimulation to target pain regions and circuits in the brain with high precision. The system will use MR imaging to locate three pain targets commonly used in clinical pain treatments, to stimulate those targets with ultrasound, and to monitor responses of nociceptive pain circuits using a functional MRI readout. Three collaborating laboratories will tackle the goals of this project: (Aim 1) Develop focused ultrasound technology for neuromodulation in humans, compatible with the high magnetic fields in an MRI scanner. (Aim 2) Develop MRI technology to find neuromodulation targets, compatible with focused ultrasound transducers. (Aim 3) Validate the complete MRgFUS neuromodulation system in brain pain regions in nonhuman primates. By the end of the project, the research team will have a fully developed and validated MRgFUS system that is ready for pilot clinical trials in pain management.

This International Cooperative Biodiversity Group application aims to discover and develop small molecule drug leads from cultured marine microbes and diverse coral reef organisms collected from Fiji and the Solomon Islands. Drug discovery efforts will focus on four major disease areas of relevance to the United States and low- and middle-income countries: infectious disease, including tuberculosis and drug-resistant pathogens; neglected tropical diseases, including hookworms and roundworms; cancer; and neurodegenerative and central nervous system disorders. Screening in these therapeutic areas will be performed in collaboration with two major pharmaceutical companies, two highly respected academic groups, and various testing centers and government resources that are available to facilitate drug discovery and development. The acquisition of source material for this program will be linked to biotic surveys, informed by ecological investigations addressing the chemical mediation of biotic interactions, and enriched using ecology-based strategies designed to maximize secondary metabolite production and detection.