Funded Projects

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

The Pain Reduction and Opioid Medication Safety in ESRD (PROMISE) study aims to improve the safety of opioid use and pain management in end-stage renal disease (ESRD) patients on hemodialysis (HD) using a Type I effectiveness-implementation hybrid design. A multisite randomized controlled trial of HD patients from the Hemodialysis Opioid Prescription Effort (HOPE) Consortium will examine the effectiveness of two separate nine-month evidence-based interventions: 1) Opioid Tapering Management (OTM) and 2) Behavioral Pain Management (BPM). We will examine the effectiveness of OTM (versus no OTM, Aim 1) and BPM (versus no BPM) over nine months for reducing opioid use (primary outcome) and improving pain severity (secondary outcome) in HD patients on chronic opioids. The implementation goal will take advantage of the diverse patient, provider, and organizational settings in the HOPE Consortium to evaluate process outcomes.

Chronic visceral pain disorders, such as interstitial cystitis/bladder pain syndrome, are among the most difficult types of pain to treat. This project will conduct a detailed analysis of an enzyme thought to be involved with the disorder (purine nucleoside phosphorylase, or PNPase) as a target for new nonopioid pain medications to treat interstitial cystitis/bladder pain syndrome. The research will lay the groundwork for developing targeted treatments for visceral pain disorders.

Sickle cell disease is an inherited blood disorder affecting about 100,000 Americans and more than 20 million people worldwide. It is caused by a mutation in the gene for beta-globin that results in the characteristic sickled shape of red blood cells, life-long severe pain, and shortened lifespan. Sickle cell disease pain episodes are usually unanticipated, making it hard for people with the condition to manage their pain and putting them at risk for increased use of opioids and poor health outcomes. This project will use existing real-time health data to identify factors that can predict onset, severity, and worsening of daily pain in children with sickle cell disease.

The primary objective of this project is to de-implement the use of opioid analgesics for the management of postoperative pain following dental extractions and to implement effective alternative pain management. We propose a cluster-randomized trial designin which dental practitioners are randomly assigned to one of three conditions: 1) standard practice as a control condition; 2) a clinical decision support (CDS) tool that will extract patient history and interface with the state prescription drug monitoring program to provide personalized recommendations for analgesic prescribing and offer language for discussing non-opioid pain management; 3) an enhanced version of the CDS (CDS-E) that will also include information regarding optimal, evidence-based non-opioid pain management delivered to the patient both before and following the dental extraction visit. We will examine opioid and non-opioid prescribing data from the electronic health record across study arms as well as other provider- and patient-focused outcomes using mixed methods.

Validation of novel pain targets is a critical step toward the development of new non-addictive therapeutic agents for chronic pain management. Recent findings suggest that nerve injury-induced concurrent upregulation of the calcium channel alpha-2delta-1 subunit (CaValpha-2-delta-1) and thrombospondin-4 (TSP4) proteins in sensory and spinal cord neurons contributes to neuropathic pain development. Specifically, induction of aberrant excitatory synapse formation and sensitization of neurotransmission in spinal cord underlies this process; accordingly, a target site has been identified in the TSP4 that plays a critical role in mediating these pathological changes upon interaction with the CaValpha-2-delta-1 protein. This project will validate this novel target site in TSP4 for development of non-addictive pain medications, utilizing multidisciplinary approaches to investigate if blocking and genetic deletion of the target site can block or prevent the development of chronic pain state, aberrant excitatory synapse formation, and spinal cord neuron sensitization after injury in multiple rodent neuropathic pain models.

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.

Cerebral palsy is the most common physical disability in children. Those who have this condition experience pain throughout their lives. Although opioids are generally not recommended, many adults with cerebral palsy are prescribed them for pain. This project will assess the incidence of chronic pain conditions in adults with and without cerebral palsy as well as measure opioid treatment-related health outcomes in adults with cerebral palsy. This research will also evaluate pain treatment disparities related to race/ethnicity and insurance coverage using national medical claims databases.

Mismanagement of orofacial chronic pain, such as temporomandibular joint and muscle disorders (TMJD) and oral cancer, substantially contributes to opioid overuse; overdose-related deaths; and cardiovascular, renal, and neurological complications at epidemic proportions. The current paradigm implies that orofacial conditions could trigger maladaptation of the immune system and plasticity supporting persistent inflammation, which influences the development and maintenance of orofacial chronic pain. LIGHT (TNFSF14) and Lymphotoxin-beta (LT?), members of the tumor necrosis factor superfamily, provide a balance between protective immunity and immunopathology during chronic inflammatory diseases. This project will test the hypothesis that targeting LIGHT and LT? signaling could prevent the development and inhibit the maintenance of chronic pain produced by TMJD and oral cancer, via peripheral mechanisms involving plasticity of immune, stromal, and tumor cells, as well as sensory neurons. The proposed research is significant as it advances our understanding of mechanisms regulating the development and maintenance of orofacial pain and offers new therapeutic targets and an immunotherapeutic approach for preventing and blocking chronic pain during TMJD and oral cancer.

Buprenorphine is commonly used in medication-assisted treatment of opioid use disorders. The U.S. Food and Drug Administration recently issued a warning that the drug may lead to serious tooth damage in some patients. It is thought that high concentrations of the drug in saliva may contribute to tooth damage and decay. This project will use a mouse model of dental caries to explore the mechanism leading to high buprenorphine concentrations in saliva and examine ways to reduce concentrations in the mouth but not the rest of the body; it will also examine buprenorphine’s effects on the bacteria that lead to caries development.

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.

Oral cancers are painful and often require use of opioid medications to manage pain. However, the effectiveness of opioids often wanes quickly, and many patients require higher doses because they develop tolerance to these medications. This project will study the potential value of blocking epidermal growth-factor receptors interacting with peripheral nerves to treat oral cancer pain. The findings will advance understanding of the molecular mechanisms underlying oral cancer pain and provide a rationale for repurposing epidermal growth-factor receptor blockers, which is already approved for head and neck cancer treatment for treating oral cancer and associated pain.

Human oral cancer is associated with significant chronic pain, and a comprehensive understanding of the biology and mechanisms underlying this chronic pain is critical for developing better pain management strategies. This project will determine molecular characteristics, including a specific signaling system (endosomal GPCR kinase), associated with chronic oral cancer pain, using tissue samples obtained from patients with this condition. The findings will then be used to inform studies in animal models of human oral cancer pain to enhance understanding how endosomal GPCR kinase contributes to human oral cancer pain.