Funded Projects

MNK-eIF4E signaling is activated in nociceptors upon exposure to pain or peripheral nerve injury, promoting cytokines and growth factors and increasing nociceptor excitability, which leads to neuropathic pain. Genetic or pharmacological inhibition of MNK signaling blocks and reverses nociceptor hyperexcitability as well as behavioral signs of neuropathic pain. A clinical phase drug for cancer shows strong specificity as an MNK inhibitor but requires optimization because MNK inhibition in the central nervous system (CNS) may lead to depression, an unacceptable side effect for a neuropathic pain drug. The research team plans a targeted medicinal chemistry and screening campaign directed at generating a MNK-inhibitor-based neuropathic pain treatment with the goal of restricting its CNS penetration while retaining potency, specificity, and in vivo bioavailability and efficacy.

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. 

Endometriosis is an often-painful disorder in which uterine tissue grows outside the uterus. Treatment of endometriosis-associated pain involves use of opioids in many women. This project aims to study a culprit gene thought to be involved with the disorder (capillary morphogenesis gene or CMG2) as a target for new, nonopioid pain medications. The research will also clarify how CMG2 s affects endometriosis-associated pain to test the effects of new medications for endometriosis pain.

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. 

Patients with severe, intractable chronic pain primarily receive treatment with opioids, and non-opioid treatment options are urgently needed. These patients may be candidates for treatment using other types of pain medications administered via intrathecal injection—that is, injection directly into the fluid-filled space between the membranes surrounding the brain and spinal cord. Intrathecal injection requires much lower medication doses than systemic administration. Centrexion Therapeutics Corporation seeks to develop CNTX-3100, a highly selective and highly potent novel small molecule that activates the nociception receptor (NOPr), for intrathecal administration using a pump approved by the U.S. Food and Drug Administration. In animal studies, such NOPr agonists had powerful analgesic effects when delivered directly to the spinal cord by intrathecal administration. CNTX-3100 has ideal properties for intrathecal delivery and in animal studies provided pain relief and a safety profile that was superior to intrathecally administered morphine. This project will scale up the drug, develop a formulation that ensures a stable product for intrathecal delivery, and conduct preclinical toxicity studies to prepare for a Phase 1 clinical trial.

Complex regional pain syndrome is one of the most disabling and difficult-to-treat chronic pain conditions. This project seeks to develop a novel, biological treatment for the condition using injected human bone marrow cells. that can form and repair skeletal tissues and control nervous and immune system activity. The research will determine the dose and source of clinical-grade bone marrow cells needed, toward the goal of submitting an Investigational New Drug Application to the U.S. Food and Drug Administration that will enable further clinical study.

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.

There is an urgent need to find new ways to treat chronic pain through better targeting of underlying biological processes. Research shows that flexible synapses within the amygdala brain region play a role in the progression of pain from acute to chronic, but the details are not fully understood. The receptor glutamate delta 1 helps to form and maintain synapses in the amygdala in inflammatory and neuropathic pain. This project will study how the shape and characteristics of glutamate delta 1 affect pain conditions that involve the amygdala, toward informing future development of pain medications. 

Spinal cord injury (SCI) impairs sensory transmission leading to chronic, debilitating neuropathic pain. While our understanding of the molecular basis underlying the development of chronic pain has improved, the available therapeutics provide limited relief. In the lab, we have shown the timing of exercise is critical to meaningful sensory recovery. Early administration of a sustained locomotor exercise program in spinal cord–injured rats prevents the development of neuropathic pain, while delaying similar locomotor training until pain was established was ineffective at ameliorating it. The time elapsed since the injury occurred also indicates the degree of inflammation in the dorsal horn. We have previously shown that chronic SCI and the development of neuropathic pain correspond with robust increases in microglial activation and the levels of pro-inflammatory cytokines. This proposal seeks to lengthen the therapeutic window where rehabilitative exercise can successfully suppress neuropathic pain by pharmacologically reducing inflammation in dorsal root ganglia.

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.

Common chronic pain syndromes such as fibromyalgia, temporomandibular disorder, and low back pain, are significant health conditions for which safe and effective treatments are needed. Previous studies have identified the adrenergic receptor beta-3 (Adrb3) as a novel target for chronic pain, but past attempts to block this receptor have not worked. This project aims to identify and develop new molecules to attach selectively and block Adrb3 without entering the brain and spinal cord. The research will test these molecules in rodent animal models to determine their ability to block pain without significant side effects.

This project will design and test optimized temporal patterns of stimulation to improve the efficacy of commercially available spinal cord stimulation (SCS) systems to treat chronic neuropathic pain. Researchers will build upon a validated biophysical model of the effects of SCS on sensory signal processing in neurons within the dorsal horn of the spinal cord to better understand how to improve the electrical stimulus patterns applied to the spinal cord. They will use sensitivity analyses to determine the robustness of stimulation patterns to variations in electrode positioning, selectivity of stimulation, and biophysical properties of the dorsal horn neural network. Researchers will demonstrate improvements from these new stimulus patterns by 1) measuring their effects on pain-related behavioral outcomes in a rat model of chronic neuropathic pain and by 2) quantifying the effects of optimized temporal patterns on spinal cord neuron activity. The outcome will be mechanistically derived and validated stimulus patterns that are significantly more efficacious than the phenomenologically derived standard of care patterns; these patterns could be implemented with either a software update or minor hardware modifications to existing SCS products.

Masticatory and spontaneous pain associated with temporomandibular joint disorders (TMJD) is a significant contributor to orofacial pain, and current treatments for TMJD pain are unsatisfactory. Pain-related transient receptor potential (TRP) channels, expressed by trigeminal ganglion (TG) sensory neurons, have been implicated in both acute and chronic pain and represent possible targets for anti-pain strategies. Using bite force metrics, we found TMJ inflammation-induced masticatory pain to be significantly, but not fully, reversed in Trpv4 knockout mice, suggesting the residual pain might be mediated by other pain-TRPs. Our gene expression studies demonstrated that TRPV1 and TRPA1 were up-regulated in the TG in response to TMJ inflammation in a Trpv4-dependent manner. We hypothesize that TRPV1 and TRPA1, like TRPV4, contribute to TMJ pain. Our specific aims will examine the contribution of TRPV1, TRPV4, and TRPA1 to pathogenesis of TMJD pathologic pain including assessment of the role of neurogenic inflammation.