Funded Projects

Pain is a major problem for spinal cord injury (SCI) patients that tends to persist and even worsen with time. No treatments are currently available to consistently relieve pain in SCI patients. This study will investigate the feasibility of Epidural Electrical Stimulation (EES) using the Abbott Proclaim? SCS system with two electrodes to treat neuropathic pain in patients with thoracic spinal cord injury. In this double-blind, prospective, randomized clinical trial, patients with subacute, traumatic, complete thoracic SCIs with American Spinal Injury Association (ASIA) Impairment Scale A will be randomized to receive either ?EES on? (treatment intervention) or ?EES off? (control intervention) of the target regions for pain control (lead overlying the spinal cord anatomy corresponding with their pain distribution) and neurorestoration (lead overlying the conus medullaris) as an adjunct to physical therapy. This study will help determine whether EES can help patients with SCI neuropathic pain and have more widespread clinical applicability.

The clinical utility of opioids for pain treatment is limited by its risk for developing opioid usage disorders (OUD). These untoward effects impose a severe burden on society and present difficult therapeutic challenges for clinicians. We propose to extend our cerebral organoid MPS to facilitate the investigation of neuronal response to opioids and identify cellular and molecular signatures in patients vulnerable to OUD. We have assembled a team with complementary expertise in clinical characterization of OUD, cerebral organoid MPS modeling, single cell RNA-seq technology, and functional characterization of neurons in a mesolimbic reward system to test the hypothesis that midbrain MPS is a clinically relevant pre-clinical model for study of opioid usage disorder.

Efforts to identify non-opioid analgesics for treatment of chronic pain have identified a protein, carbonic anhydrase-8 (CA8), in pain-sensing nerve cells in the spinal cord (dorsal root ganglion cells) whose expression regulates analgesic responses. Gene therapy delivering CA8 to dorsal root ganglion cells through clinically relevant routes of administration functions as a “local anesthetic” that induces long-lasting pain relief in animal models of chronic pain. This project will further develop CA8 gene therapy with the goal of treating chronic knee osteoarthritis pain. It will assess several gene therapy constructs to determine the doses needed, safety, efficacy, and specificity to nerve cells for each construct. It will then select the safest and most effective construct that can be administered via the least invasive route for further development. The project will include all steps necessary to identify one candidate gene therapy construct that will be suitable to begin clinical trials in patients with chronic knee osteoarthritis pain.

Overreliance on opioids to treat chronic pain has been a contributor to the increase in individuals experiencing opioid addiction. This project aims to develop an innovative treatment approach for chronic pain that targets the cannabinoid receptor 1 (CB1R) to block the sensation of pain. The approach seeks to identify molecules that interact with a different part of the CBR1 receptor than do endocannabinoids and the primary active component of cannabis, tetrahydrocannabinol. Molecules that bind to and activate CBR1 in this different way (at an “allosteric” site) may produce nerve signaling that might differ from the effects of cannabis and endocannabinoids. This redirection of signaling pathways could help eliminate the risk of adverse effects observed with natural cannabinoids and other CBR1-binding molecules. The goal of this project is to identify a CB1R allosteric molecule, conduct studies toward obtaining federal permission to develop it as a medication, and to test it in a Phase I clinical study.

Migraine is one of the most common primary headache disorders and affects one in four U.S. households; however, there are few effective treatments. Migraine is a complex neurological disorder mediated in part by alterations in the way the brain processes sensations like touch and pain (somatosensation) in the head. These sensations are transmitted by the trigeminal nerve and a cell cluster called the trigeminal ganglion. To better understand the function of the human trigeminal system and its role in migraine, this project will conduct multiple types of molecular analyses of human trigeminal ganglia from people with and without migraine. The project will also perform sensory evaluations and measure the signals sent from the trigeminal ganglion to the brain in individuals with and without migraine.

Multidisciplinary chronic pain treatments show incomplete recovery at the population level because of significant heterogeneity on the individual level in the high impact chronic pain population. Subgroups of individuals either completely respond, do not change, or even worsen following pain management. Therefore, diagnostic biomarker signatures are needed to differentiate high impact chronic pain from low impact chronic pain. This study aims to develop prognostic biomarkers to predict the disease trajectory for individuals with musculoskeletal high-impact chronic pain. These biomarker signatures will integrate central nervous system (CNS), multi-?omic?, sensory, functional, psychosocial, and demographic domains into detection algorithms. Biomarker signatures from the proposed research are intended to facilitate risk and treatment stratification for clinical trial design and to facilitate treatment decisions in clinical practice for patients with musculoskeletal chronic pain.

Current medications for chronic pain are largely ineffective and rely heavily on opioids, one contributor to the nation’s opioid crisis. The endocannabinoid system that consists of cannabinoid receptors (CB1R and CB2R) and their endogenous ligands is a natural pathway in the human body and has emerged as an alternative target for developing new pain medications with few side effects. Current molecules that bind to CB1R in the brain and spinal cord have psychoactive side effects, limiting their therapeutic use for treating chronic pain. This study aims to develop new molecules to bind to CB1R tightly and selectively, are metabolically stable, and are also unable to enter the brain.

This project will use a variety of technologies to create a comprehensive, 3D map of how sensory neurons activate knee joints in both mice and humans. The research will use imaging techniques and molecular approaches that measure gene expression. The findings will help create a comprehensive gene expression profile map of individual cells in the nerve fibers leading to the knee, as well as describe how nerve cells and joint cells interact at the most fundamental level. This research will generate a rich anatomical and molecular resource to understand the molecular basis of joint pain and guide the development of novel pain-relieving strategies.

The research team will develop an implantable neural stimulation system to provide natural and intuitive sensation for prosthesis users. The nerve cuff technology meets the requirements for a sensory feedback system capable of providing consistent and controlled electrical stimulation. Coupled with a multichannel implantable stimulator, this electrode array will offer substantial improvement over existing options to treat phantom limb pain (PLP). In Phase I, researchers will finalize array architectures for evaluation in cadaver studies, complete integration of electrodes with our stimulator, conduct benchtop verification of electrical and mechanical performance, send implants for third-party evaluation of system biocompatibility, and complete a Good Laboratory Practice animal study to validate safety and efficacy. In Phase II, researchers will conduct a 5-subject clinical study to test the implantable stimulation system. Each unilateral prosthesis user will be implanted for one year as researchers evaluate the safety and efficacy of this implantable device to treat PLP.

This research seeks to develop a high-resolution spinal cord stimulation therapy for treating chronic neuropathic pain of the lower extremities, groin, and lower back. Systems that use wireless communication methods require robust strategies to prevent various forms of cyberattacks on implantable devices. The focus of this project's research will be to develop a new cybersecurity risk-reduced architecture for Bluetooth low-energy implant communication.

The goal of this project is to generate data and reagents that help uncover critical functions of the poorly characterized members of ion channels. It focuses on co-perturbation of ion channel genes and their interacting genetic components as opposed to singly altering ion channel genes in mouse models. This approach will validate our proteomics approaches in the most definitive manner: in vivo. We see in vivo exploration as an essential step to evaluate ion channel function. Our major aims include mapping ion channel interactions and complexes using a high-throughput proteomics platform at UCSF. These data will be interrogated using integrative approaches established by the Monarch Initiative, where biochemical interactions will be validated and prioritized for further study. Another major aim is function-centric: We use mouse models for elucidation of human disease mechanisms, where we embrace a genetic interaction scheme to uncover ion channel redundancy and polygenic effects.

Pain associated with surgery is experienced by millions of patients every year. Although post-surgical pain usually resolves as the surgical site heals, up to half of the patients develop chronic pain after surgery. Opioids remain the mainstay treatment for post-surgical pain which are fraught with serious side-effects and abuse liabilities. The endogenous mechanism that leads to the resolution of post-surgical pain remain unclear, specifically the effects of surgery on the metabolism of sensory neurons and how those changes influence the resolution of post-surgical pain are not known. Preliminary findings suggest that surgical trauma suppresses pyruvate oxidation while increased glutamine catabolism was associated with the resolution of post-surgical pain. This project will test the hypothesis that tissue incision and surgery disrupt the expression of the glutamine transporter ASCT2, which then prevents the resolution of post-incisional pain and aims to validate ASCT2 as a therapeutic target. This project will also employ pharmacological, genetic and animal pain model studies test a novel RNA expression-based strategy to enhance ASCT2 expression in DRG sensory neurons and alleviate postoperative pain in animal model systems. Successful completion of this project would validate ASCT2 as a novel endogenous non-opioid and non-addictive mechanism-based target for the resolution of postoperative pain.

Persistent pain states arising from inflammatory conditions, such as in arthritis, diabetes, HIV, and chemotherapy, exhibit a common feature in the release of damage-associated molecular pattern molecules, which can activate toll-like receptor-4 (TLR4). Previous studies suggest that TLR4 is critical in mediating the transition from acute to persistent pain. TLR4 as well as other inflammatory receptors localize to lipid raft microdomains on the plasma membrane. We have found that the secreted apoA-I binding protein (AIBP) accelerates cholesterol removal, disrupts lipid rafts, prevents TLR4 dimerization, and inhibits microglia inflammatory responses. We propose that AIBP targets cholesterol removal to lipid rafts harboring activated TLR4. The aims of this proposal are to: 1) determine whether AIBP targets lipid rafts harboring activated TLR4; 2) test whether AIBP reduces glial activation and neuroinflammation in mouse models of neuropathic pain; and 3) identify the origin and function of endogenous AIBP in the spinal cord.