Funded Projects

The research team will develop stimulation control algorithms to treat chronic pain using a novel device that allows longitudinal intracranial signal recording in an ambulatory setting. Subjects with refractory chronic pain syndromes will undergo bilateral surgical implant of temporary electrodes in the thalamus, anterior cingulate, prefrontal cortex, insula, and amygdala to identify candidate biomarkers of pain and optimal stimulation parameters. Six patients will proceed to chronic implantation of “optimal” brain regions for long-term recording and stimulation. The team will first validate biomarkers of low- and high-pain states to define neural signals for pain prediction in individuals. They will then use these pain biomarkers to develop personalized closed-loop algorithms for deep-brain stimulation (DBS) and test the feasibility of closed-loop DBS for chronic pain in weekly blocks. Researchers will assess the efficacy of closed-loop DBS algorithms against traditional open-loop DBS or sham in a double-blinded cross-over trial and measure mechanisms of DBS tolerance.

The development of non-addictive pain therapeutics can help counter opioid addiction and benefit patients, including those who suffer from neuropathic pain, in particular diabetic neuropathic pain (DNP). This project’s goal is to develop a safe, efficacious, and non-addictive small-molecule drug that activates Kv7 voltage-gated potassium channels to address overactive neuronal activity in DNP. Researchers will discover Kv7 activators that favor Kv7 isoforms altered in DNP and found in dorsal root ganglia, decrease off-target side effects observed with the use of earlier non-biased Kv7 activators, and optimize the absorption, distribution, metabolism, excretion, and toxicity profiles of these activators. This screening paradigm is intended to establish a clinic-ready, well-tolerated, and widely effective product to treat neuropathic pain.

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.

The University of Pittsburgh Low Back Pain: Biological, Biomechanical, and Behavioral Phenotypes (LB3P) Mechanistic Research Center (MRC) will to perform in-depth phenotyping of patients with chronic low back pain (cLBP), using a multimodal approach to characterize patients and provide insight into the phenotypes associated with experience of cLBP to direct targeted and improved treatments. The LB3P MRC will be formed of three Research Cores, three support cores, and one research project. This approach will leverage and integrate distinctive resources at the University of Pittsburgh laboratories to deliver quantified biomechanical, biological, and behavioral characteristics; functional assessments; and patient-reported outcomes, coupled with advanced data analytics using a novel Network Phenotyping Strategy (NPS). By eliminating isolated and disconnected approaches to treatment and focusing on personalized patient-centric approaches, this approach will yield improved outcomes and patient satisfaction.

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.

Most of the 200k Americans who undergo thoracotomy each year receive opiates to reduce postoperative pain because clinicians have few non-addictive, cost-effective choices to control the severe pain patients often experience in the first two weeks after surgery. Managing pain post-thoracotomy is critical to enable patients to take deep breaths and remove (via coughing) lung secretions that otherwise significantly increase risk of pneumonia and collapsed lung, hospital re-admission and morbidity. The most severe pain associated with thoracotomy is transmitted along the intercostal nerves, but no long-term analgesic or nerve block device exists that can provide safe and effective long-term reduction of pain. A reversible, patient-controlled, non- addictive, intercostal nerve block device would reduce suffering due to thoracotomy, broken ribs and herpes zoster. In this Phase I project, the team will develop a minimally invasive thermal nerve block device that can control nerve conduction by gently warming and cooling a short nerve segment between room temperature and warm water temperature. This novel approach is based on the discovery that warm and cool temperature mechanisms of nerve block are different and additive, enabling moderate-temperature nerve block by cycling neural tissues slightly above and below body temperature. Reversible thermal nerve blocks represent a completely new approach to managing pain.  

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.

Chronic pain is common, costly, and debilitating. Opioid prescription in the treatment of chronic pain is frequent and carries a consequent risk of poor treatment outcome, as well as higher morbidity and mortality in a clinically significant number of patients, particularly those who meet criteria for opioid dependence. Despite the alarming increases in prescription opiate misuse and opioid use disorder (OUD) nationally in the United States, there are few treatment options available that target both pain-related interference and OUD among patients with chronic pain. In military veterans, this issue is of particular importance as numerous reports indicate frequent use of opioids in the treatment of chronic pain, as well as increasing opioid-related problems. To date, there are no evidence-based treatment options that aim to both reduce pain interference while simultaneously addressing problematic opioid use. The overall aim of this study will be to determine the efficacy of an integrated psychosocial treatment in veterans with chronic pain who are taking buprenorphine for the treatment of OUD. To achieve this aim, they will utilize a randomized design to assess the efficacy of two empirically supported interventions: Acceptance and Commitment Therapy for chronic pain and Mindfulness-Based Relapse Prevention for substance use and misuse.

 Non-Invasive Brain Stimulation (NIBS) has been successfully applied for the treatment of chronic pain (CP) in some disease states, where treatment induced changes in brain activity revert maladaptive plasticity associated with the perception/sensation of CP [25-28]. However, the most common NIBS methods, e.g., transcranial direct current stimulation, have shown limited, if any, efficacy in treating neuropathic pain. It has been postulated that limitations in conventional NIBS techniques’ focality, penetration, and targeting control limit their therapeutic efficacy . Electrosonic Stimulation (ESStim™) is an improved NIBS modality that overcomes the limitations of other technologies by combining independently controlled electromagnetic and ultrasonic fields to focus and boost stimulation currents via tuned electromechanical coupling in neural tissue . This proposal is focused on evaluating whether our noninvasive ESStim system can effectively treat CP in carpal tunnel syndrome (CTS), both as a lone treatment and in conjunction with physical therapy (PT). Investigators hypothesize ESStim can be provided synergistically with PT, as both can encourage plasticity-dependent changes which could maximally improve a CTS patient’s pain free mobility. In parallel with the CTS treatments, the team will build multivariate linear and generalized linear regression models to predict the CTS patient outcomes related to pain, physical function, and psychosocial assessments as a function of baseline disease characteristics. The computational work will be used to develop an optimized CTS ESStim dosing model. 

A primary factor contributing to acute or recurrent back injury is overexertion via excessive peak and cumulative forces on the back and the primary factors involved in the progression of acute low back injury to chronic low back pain (cLBP) include maladaptive motor control strategies, muscle hyperactivity, reduced movement variability, and the development of fear cognitions. This project will focus on the development of robotic apparel with integrated biofeedback components that can reduce exertion; encourage safe, varied movement strategies; and promote recovery. Robotic apparel will be capable of providing supportive forces to the back and hip joints through adaptive control algorithms that respond to dynamic movements and becoming fully transparent when assistance is no longer needed. This technology can be used to prevent cLBP caused by overexertion and provide a new tool to physical therapists and the clinical community to enhance rehabilitation programs.

For many years in the field of pain medicine it has been noted that many promising treatments emerging from animal studies fail to demonstrate efficacy in human trials. There are many reasons for these phenomena, and one of the key steps to improve this situation and establish more effective nonopioid treatments for pain is more rigorous conduct of multisite pain clinical trials from an experienced multidisciplinary team of investigators. The University of Pittsburgh Hub and Spoke Clinical Trials Network will establish an organizational structure to capitalize on institutional expertise at our Spokes to lead specific phase 2 clinical trials through EPPIC-Net.

Inhibitors of the epigenetic enzymes histone deacetylases (HDACs) produce analgesic responses and are therefore therapeutic targets for pain. The research team recently resolved a PET imaging agent, [11C]Martinostat, that selectively binds to a subset of HDAC enzymes. A series of initial proof-of-concept clinical validation studies will be conducted to evaluate whether [11C]Martinostat PET is a sensitive biomarker to detect the typical (axial) chronic low back pain (cLBP). The research team will validate [11C]Martinostat PET’s ability to differentiate subtypes of pain by comparing axial cLBP and other cLBP patients with radiculopathy and longitudinally study subacute LBP patients (sLBP) to investigate whether there is a unique imaging signature that differentiates patients who develop cLBP and those who recover from low back pain. Using [11C]Martinostat to understand HDAC expression changes in chronic pain patients will validate an epigenetic drug target, refine patient selection based on HDAC expression, and facilitate proof of mechanism in developing novel analgesics.

 Chronic persistent post-operative pain (CPOP) is a devastating outcome from any type of surgical procedure. Its incidence is anywhere between 20-85% depending on the type of surgery, with thoracotomies showing one of the highest annual incidences of 30-60%. Given that millions of patients (approximately 23 million yearly based on incidence) are affected by CPOP, the results are increased direct medical costs, increased indirect medical costs due to decreased productivity, and associated negative effects on an individual’s physical functioning, psychological state, and quality of life. Given these extensive public health and economic consequences there is a resurgence of research in the area of preventative analgesia.  The goal of this project is to evaluate a novel small molecule antagonist of MD2-TLR4, DT-001 in preclinical models of surgical pain representative of persistent post-operative pain. In collaboration with University of California, San Diego, DT-001 will be evaluated for its ability to block the development of neuropathic pain states. These studies will evaluate dose escalating efficacy of DT001 in rats in formalin and spinal nerve injury (SNI) models using both intrathecal and intravenous routes of administration. Tissues will be preserved to assess functional effects on relevant pain centers for analysis by Raft. With demonstration of efficacy, these studies will determine the optimal dose and route of administration of DT001 and guide a development path to IND and eventually clinical trials.