Funded Projects

Approximately 20% of patients who undergo surgery develop chronic pain, or Chronic Postsurgical Pain (CPSP). CPSP is highly associated with impaired functional recovery and persistent opioid use and dependence, and current standard postoperative multimodal analgesia is only moderately effective for its prevention. This study aims to determine whether the use of ketamine during and/or after surgery prevents Post-Mastectomy Pain Syndrome (PMPS), one of the most common CPSP conditions. Ketamine is a low-risk treatment option that is easy to implement in a wide range of clinical settings. If successful, this treatment could improve postoperative pain management in individuals undergoing mastectomy and help combat the opioid epidemic.

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.

Multiple factors, including inflammation contribute to chronic low back pain. Inflammation is mediated by numerous genes. The study aims to determine how variations in the genes encoding key inflammatory mediators impact the response of patients with chronic low back pain to physical therapy treatment. Gene variations that are known to be linked to inflammation and pain will be tested against their possible association on physical therapy treatment outcomes, to inform clinical decisions on optimal care. This study will support training in clinical research on pain within the context of the HEAL BACPAC Mechanistic Research Center. It will provide resources for a research project relevant to the parent grant and the career development of an individual in the field of pain research. The ability to identify a set of genetic variations and classify patients according to treatment response might enable use of DNA testing as a screening tool for targeted treatments for patients with CLBP.

Back pain is the most common chronic pain diagnosis and the most common diagnosis for which opioids are prescribed. Clinical practice guidelines make it clear that nonpharmacologic treatments are preferable to opioids for patients with back pain. Despite clear evidence, over-prescribing of opioids to individuals with back pain continues. Providers of nonpharmacologic care are often absent or unreachable from rural and low-income communities and patients with limited financial resources. Many rural and low-income communities are served by Federally Qualified Health Centers (FQHCs) that are at the forefront of the opioid crisis, but often lack adequate options to provide accessible nonpharmacologic treatments. This pragmatic clinical trial will compare the effectiveness of different telehealth strategies to provide effective nonpharmacologic interventions to overcome the barriers specific to serving rural and low-income communities. The trial will evaluate two strategies, one providing both a brief pain teleconsult with phone-based physical therapy, the other uses an adaptive strategy ? providing the brief pain teleconsult first, followed by phone-based physical therapy to those who need additional treatment. The study will also evaluate outcomes related to the efforts to implement strategies in FQHC clinics. This research will provide a toolkit for future efforts to make nonpharmacological interventions for back pain available in other low resource health care settings.

Peripheral nerve injury-induced upregulation of three axonal guidance phosphoproteins correlates with the development of neuropathic pain through an unidentified mechanism: 1) collapsin response mediator protein 2 (CRMP2); 2) the N-type voltage-gated calcium (CaV2.2); 3) the NaV1.7 voltage-gated sodium channel. Injury induced phosphorylated-CRMP2/CaV2.2 and phosphorylated-CRMP2/NaV1.7 upregulation in the sensory pathway may promote abnormal excitatory synaptic transmission in spinal cord that leads to neuropathic pain states. This project will validate CRMP2 phosphorylation as a novel target in neuropathic pain using innovative tools. Examples include a genetic approach (crmp2S522A) in mice as well as a non-opioid pharmacological approach (a novel CRMP2-phsphorylation targeting compound). Demonstrating that inhibition of CRMP2 phosphorylation reverses or prevents neuropathic pain will promote the discovery and validation of a novel therapeutic target (CRMP2-phosphorylation) to facilitate the development of novel pain therapeutics.

Chronic low back pain is difficult to diagnose and treat effectively in part, because of the interplay of biophysical and psychosocial influences that complicate the relationship between impairment, disability, and pain. Psychological factors such as fear of movement and catastrophyzing can lead to compensatory movement patterns that affect movement biomechanics and paraspinal structure and function, driving further impairment, disrupting the balance between passive and active spine stabilizers, and reinforcing the patient?s perceived disability status. This study will support research to determine how psychological factors, spinal pathology, and perception of pain severity and disability status influence compensatory movement strategies, how movement biomechanics, psychological factors, and pain mechanisms relate to paraspinal muscle quality, and their relative changes during treatment. The supplement will provide training opportunities for skills in clinical pain management research.

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.

G protein-coupled receptors (GPCRs) are the largest family of transmembrane signaling proteins and play important roles in inflammation and pain. GPCR signaling is fast and temporary, making it hard to measure in clinical studies of potential drugs to interfere with the signaling. This research is using selectively designed nanoparticles to stimulate or block GPCRs toward identifying new treatments for oral cancer pain. This award will use a new nanoformulation approach to understand how nanoparticles affect nerve function by i) testing the effects of continuous release of a GPCR inhibitor in an oral cancer microenvironment and ii) investigating the influence of various physicochemical characteristics of nanoparticles on nerve function in an oral cancer microenvironment.

Approximately 3.6 million Americans live with an amputated extremity, and the majority of these individuals are likely to suffer from chronic post-amputation pain. There is no consensus as to a recommended therapy for such pain, and many treatments do not provide sufficient pain control. Some studies have shown effective pain suppression from delivering an anesthetic agent directly to an injured nerve. This research aims to develop a device that can be implanted near the injured nerves of an amputated limb to deliver an anesthetic. Findings from this preclinical study will optimize design and delivery features to maximize its effect on pain control for as long as possible without needing a drug refill. The research is expected to advance eligibility for further testing in large animals and humans.

The emergency department is an ideal venue to reach and intervene with adolescents and young adults at risk for opioid misuse, particularly as young adults may disconnect from primary care when transitioning out of care in pediatric settings. This study will evaluate the efficacy of interventions of varying type and intensity to prevent or reduce opioid misuse or opioid use disorder. The research leverages technology that is appealing to youth to facilitate intervention delivery by health coaches. In this study, adolescents and young adults in the emergency department screening positive for opioid use or misuse will be randomly assigned to one of four intervention conditions with outcomes measured at 4, 8, and 12 months. Technology-driven, scalable interventions delivered via health coaches allow for real-time tailoring to the rapidly changing opioid epidemic, with the potential to prevent an increase in opioid misuse among adolescents and young adults.  Black/African American youth are at increased risk for opioid and other substance use, but they often do not participate in research studies. As a result, it is not known how well prevention interventions work with Black/African American people. This supplement will focus on increasing participant diversity and inclusion by recruiting additional Black/African American participants for this ongoing randomized controlled study of technology-driven prevention interventions.

This award funds EPPIC-NET’s first phase 2 clinical trial, testing the novel oral drug CNTX-6970 in patients with moderate to severe knee osteoarthritis pain. It will include 150 participants at EPPIC-Net sites across the United States. Preclinical studies of CNTX-6970, which binds effectively and dose-proportionally to C-C chemokine type 2 (CCR2) receptors, have demonstrated potent analgesia in multiple pain models, with no emergent safety issues. CNTX-6970 has effects both at an affected joint, as well as on neural signaling. Participants will be randomized to receive CNTX-6970, placebo, or a third pain medication and will be followed for 24 weeks.

Knee osteoarthritis is one of the leading causes of disability worldwide, particularly among older adults. Despite multiple guidelines for care, most patients do not receive adequate treatment, and about 30% are prescribed long-term opioids. This award will be used to recruit and support an early career faculty member from a group underrepresented in biomedicine. This research, part of the Pain Management Effectiveness Research Network will evaluate conservative and more aggressive treatments for knee osteoarthritis and determine which individual-level factors contribute to treatment outcomes.

The University of California, San Francisco, as part of the Back Pain Consortium (BACPAC) Research Program, has established a Core Center for Patient-centric Mechanistic Phenotyping in Chronic Low Back Pain (REACH). The main goal of REACH is to define different subtypes (phenotypes) of chronic low back pain as well as to identify underlying pain mechanisms that can lead to effective, personalized treatments for patients across all population subgroups. To achieve this goal, REACH is, or will be, participating in several clinical trials, and it is imperative that the patients participating in these trials reflect the diversity of the U.S. population. Therefore, this project seeks to adapt methods that have successfully improved minority participation in other settings as well as to develop and deploy digital strategies that can promote recruitment and engagement of patients from marginalized populations.