Funded Projects

Since 2002, persons with opioid use disorders who desire medication-assisted treatment can be treated with buprenorphine, which has been shown to be efficacious. Buprenorphine treatment can occur in any medical office-based setting, is prescribed by any physician who seeks to become waivered, and is taken by patients at home unsupervised. However, without visual confirmation of medication ingestion, providers remain unsure if patients divert part or all of their buprenorphine medication. This project will develop the technical and logistical workflow needed to implement a video-­based application, miDOT, for office-­based buprenorphine monitoring during the initial months of care, which will allow health care providers to monitor whether patients ingest the drug and adhere to treatment. The project will configure a video-based DOT platform, evaluate its effectiveness in securing medication ingestion and care retention for illicit opiate users, and solidify routes of sustainable commercial viability with commercial partners.

The ability to de-risk lead compounds during pre-clinical development with advanced “organoid-on-a-chip” technologies shows promise. Development of microphysiological models of the peripheral nervous system is lagging. The technology described herein allows for 3D growth of high-density axonal fiber tracts, resembling peripheral nerve anatomy. The use of structural and functional analyses should mean drug-induced neural toxicity will manifest in these measurements in ways that mimic clinical neuropathology. The goals of this proposal are to establish our human model using relevant physiological measurements in tissues fabricated from human iPS cells and to validate the model system with a library of compounds, comparing against conventional cell culture models. Validating the peripheral nerve model system with drugs known to induce toxicity via a range of mechanisms will demonstrate the ability of the system to predict various classifications of neuropathy, yielding a high-content assay far more informative than traditional in vitro systems.

This project will establish a rapid research pipeline for linking plant-derived compounds to nociception (pain) and to G Protein-Coupled Receptors (GPCRs) and ion channels in the druggable human genome. As more than 80% of these membrane proteins are conserved in the C. elegans nematodes, the study will screen for compounds and genes affecting nociception as well as to identify novel ligand-receptor pairs using this model organism. The study will test which understudied GPCRs and ion channels are involved in nociception as well as attraction or repulsion behaviors. This research has the potential to reveal novel ligand-receptor pairs that could serve as new entry points for improved or alternative pain treatments.

Effective medications for opioid use disorder (MOUD) are approved by the Food and Drug Administration for the treatment of people with opioid use disorder; however, only a small fraction of patients who would benefit from these medications actually use them. Several reasons contribute to low MOUD use, including lack of insurance; lack of knowledge about the medications, both among patients and providers; stigma associated with MOUD; and social norms. Innovative methods are needed to help increase MOUD use. One such option is peer-led interventions that might increase patients’ interest in MOUD. One existing peer-led intervention is the Harnessing Online Peer Education (HOPE) online community intervention that has been designed to reduce stigma and increase health behavior change among stigmatized populations, such as people living with HIV. This project will investigate whether and how HOPE can be adapted for people with opioid use disorder. It will assess whether HOPE can effectively increase MOUD requests, MOUD uptake, and sustained adherence to MOUD as well as reduce overdose rates.  

The science of recovery support services for individuals choosing to take medications for opioid use disorder as part of their recovery pathway is gaining momentum and will benefit from a dedicated, sustainable cross-project research infrastructure. This project enhances research in the existing Consortium on Addiction Recovery Research Science. This effort coordinates varied research and training efforts across recovery support research projects, amplifies communication and dissemination channels for their activities, and is organizing the first national meetings on addiction recovery support services science.

The opioid epidemic continues unabated in the United States, and despite the rapid expansion of this crisis, the nature of the risk factors that contribute to opioid misuse remain poorly understood compared with other substances of abuse. The goal of this project is to examine cannabis use and cannabis identification measures as risk factors for opioid misuse while also developing and evaluating novel implicit measures of opioid associations as risk factors for opioid misuse among an at-risk sample of adolescents. Findings from the proposed research are intended to improve the prediction of opioid misuse among adolescents and to potentially identify novel targets for prevention and intervention strategies that aim to combat the opioid epidemic.

Justice-involved veterans have lower access to opioid use disorder (OUD) pharmacotherapy and need an effective transition from the justice system to the Department of Veterans Affairs (VA) and community health care systems to improve drug addiction treatment and outcomes. We will quantitatively evaluate patient and facility characteristics associated with differences in receipt of OUD pharmacotherapy among justice-involved veterans compared with non-justice-involved veterans and within-facility changes over time; qualitatively identify drivers of higher or lower access to OUD pharmacotherapy among justice-involved veterans compared with other veterans with OUD at the same facility; evaluate stakeholders’ perceptions of factors that explain within-facility changes in access to OUD pharmacotherapy over time; and develop and conduct a formative evaluation of implementation strategies to improve access to OUD pharmacotherapy. Results will be used to design and select implementation strategies that address identified barriers to improve access to OUD pharmacotherapy for justice-involved veterans.

Neuropathic pain conditions are difficult to treat, and novel non-narcotic analgesics are desperately needed. The G protein-coupled receptor 160 (GPR160) has emerged as a novel target for analgesic development, as GPR160 in the spinal cord may play a role in the transition from acute to chronic pain. Cocaine- and Amphetamine-Regulated transcript peptide (CARTp) was identified as a ligand for GPR160. Blocking endogenous CARTp signaling in the spinal cord attenuates neuropathic pain, whereas intrathecal injection of CARTp evokes painful hypersensitivity in rodents through GPR160-dependent extracellular signal-regulated kinase (ERK) and cyclic AMP response element-binding pathways (CREB). This project will isolate and biochemically characterize GPR160 and establish methods for biochemical characterization of GPR160 interaction with CARTp activator. Researchers will miniaturize and optimize biochemical assay and scale up protein production for future high throughput biochemical screening to identify potent inhibitors of GPR160 activation. These studies are critical for defining the molecular mechanism of CARTp/GPR160 interactions and initiating large-scale screens for new inhibitors to develop novel therapeutics.

TWIK-related spinal cord K+ (TRESK) channel is abundantly expressed in all primary afferent neurons (PANs) in trigeminal ganglion (TG) and dorsal root ganglion (DRG), mediating background K+ currents and controlling the excitability of PANs. TRESK mutations cause migraine headache but not body pain in humans, suggesting that TG neurons are more vulnerable to TRESK dysfunctions. TRESK knock out (KO) mice exhibit more robust behavioral responses than wild-type controls in mouse models of trigeminal pain, especially headache. We will investigate the mechanisms through which TRESK dysfunction differentially affects TG and DRG neurons. Based on our preliminary finding that changes of endogenous TRESK activity correlate with changes of the excitability of TG neurons during estrous cycles in female mice, we will examine whether estrogen increases migraine susceptibility in women through inhibition of TRESK activity in TG neurons. We will test the hypothesis that frequent migraine attacks reduce TG TRESK currents.

Migraine is the most common neurological disorder. Currently available treatments fail to effectively manage migraine in most patients. Development of new therapeutics has been slow due in large part to a poor understanding of the underlying pathology of migraine. Endogenous proteases, released in the meninges by resident mast cells, have been proposed as a potential driver of migraine pain via an action on protease activated receptor type 2 (PAR2). The central hypothesis is that PAR2 expression in nociceptors that project to the meninges plays a key role in the pathogenesis of migraine pain. The aims are to: 1) use the established PAR2 development pipeline to design new PAR2 antagonists with improved drug-like properties; 2) use pharmacological tools in a novel mouse migraine model to further understand the potential role of PAR2 in migraine; and 3) use mouse genetics to study the cell type–specific role of PAR2 in migraine pain.

Multi-protein complexes have emerged as a mechanism for spatiotemporal specificity and efficiency in the function and regulation of myriad cellular signals. In particular, many ion channels are clustered either with the receptors that modulate them, or with other ion channels whose activities are linked. Often the clustering is mediated by scaffolding proteins, such as the AKAP79/150 protein that is a focus of this research. This research will focus on three different channels critical to nervous function. One is the"M-type" (KCNQ, Kv7) K+ channel that plays fundamental roles in the regulation of excitability in nerve and muscle. It is thought to associate with Gq/11- coupled receptors, protein kinases, calcineurin (CaN), calmodulin (CaM) and phosphoinositides via AKAP79/150. Another channel of focus is TRPV1, a nociceptive channel in sensory neurons that is also thought to be regulated by signaling proteins recruited by AKAP79/150. The third are L-type Ca2+ (CaV1.2) channels that are critical to synaptic plasticity, gene regulation and neuronal firing. This research will probe complexes containing AKAP79/150 and these three channels using"super-resolution" STORM imaging of primary sensory neurons and heterologously-expressed tissue-culture cells, in which individual complexes can be visualized at 10-20 nm resolution with visible light, breaking the diffraction barrier of physics. The researchers hypothesize that AKAP79/150 brings several of these channels together to enable functional coupling, which the researchers will examine by patch-clamp electrophysiology of the neurons. Förster resonance energy transfer (FRET) will also be performed under total internal reflection fluorescence (TIRF) or confocal microscopy, further testing for complexes containing KCNQ, TRPV1 and CaV1.2 channels. Since all three of these channels bind to AKAP79/150, the researchers hypothesize that they co-assemble into complexes in neurons, together with certain G protein-coupled receptors. Furthermore, the researchers hypothesize these complexes to not be static, but rather to be dynamically regulated by other cellular signals, which the researchers will examine using rapid activation of kinases or phosphatases. Several types of mouse colonies of genetically altered AKAP150 knock-out or knock-in mice will be utilized.

Many chronic pain conditions are dependent upon activity of the sympathetic nervous system. Sympathetic blockade is used clinically in chronic pain conditions, but the clinical and preclinical evidence for this practice is incomplete. We propose that certain pathological pain conditions require intact sympathetic innervation of the sensory nervous system at the level of the dorsal root ganglion (DRG) and that release of sympathetic transmitters enhances local inflammation and leads to pain. Our preliminary data show large, rapid, and long-lasting reduction of pain behaviors and inflammatory responses following a"microsympathectomy" (mSYMPX) in both neuropathic and inflammatory pain models. Our aims are to: 1) characterize the effects of mSYMPX on pain and on local inflammation in the DRG; 2) explore the molecular mechanisms for sympathetic regulation of inflammatory responses in the DRG; and 3) assess the functional role of sympathetic transmitters in the sympathetically mediated inflammatory responses in the DRG.