University Of California-Irvine

NIH Research Projects · FY 2026 · 2023-04

Project Summary Telomeres ensure genome integrity by facilitating chromosome end replication through telomerase, the activity of which enables cellular proliferation. Uncontrolled proliferation as may occur in cancer cells requires hyper-activation of telomere-extension activity. Conversely, lack of telomere extension results in degenerative disorders or premature aging. Critical to telomere structure and function, the conserved multifunctional shelterin complex associates with telomeres to coordinate multiple telomere activities. The long-term objective of our NIGMS MIRA research program is to determine, at the atomic resolution, molecular mechanisms of telomere length homeostasis through comprehensive biochemical, structural, and functional characterizations of the telomeric shelterin complex, shelterin-telomerase interactions, and telomerase biogenesis. Mutations in telomerase subunits or shelterin components have been increasingly linked to cancer and premature aging. Shelterin complex and shelterin-telomerase interactions play essential roles in regulating synthesis of telomeric DNA repeats and defining telomere lengths that support or restrict cell proliferation. Our recent efforts have achieved the conceptual advancement on the role of shelterin bridge, rather than individual shelterin component per se, in regulating telomere length and the landmark determination of the atomic views of shelterin bridge assembly process by x-ray crystallography. Our accumulated expertise and prior success position us to deepen our investigations. In the next five years, we aim to address the following three fundamental questions in the field: 1) Elucidate the biochemical and structural basis of the assembly of whole fission yeast shelterin complex and its role in telomere length control; 2) Determine the mechanistic basis of shelterin disassembly; 3) Determine the structural basis of telomerase RNA folding quality control mechanism by Pof8 complex. Accomplishment of the proposed studies will provide new and significant mechanistic insights into the maintenance of our chromosome ends and set up the foundation for the development of new therapeutic approaches against diseases caused by telomere dysfunction, such as premature aging.

NIH Research Projects · FY 2025 · 2023-04

Project Summary Approximately 10-25% of the population has degeneration of the temporomandibular joint (TMJ) condyle. Cartilage does not heal itself, and there are no mid-stage interventions to prevent condylar degeneration which can lead to life-threatening conditions such as changes to the airway. This proposal aims to improve translation of tissue engineering strategies for TMJ condylar regeneration toward human use in the clinic via characterization of the mandibular condyle of the Yucatan minipig, engineering neocartilage-bone implants with robust interfacial properties, and in vivo studies using neocartilage-bone implants to regenerate osteochondral defects of the TMJ condyle. Preliminary proteomics data show that spatial distributions of collagen types I and II can be achieved using matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS), indicators of fibrocartilage and hyaline articular cartilage, respectively. MALDI-IMS will serve as a powerful tool in a characterization of the Yucatan minipig mandibular condyle, including the spatial distributions of collagen types I, II, X, and XXVII. This characterization will provide gold standards for tissue-engineering approaches to treat condylar defects. Preliminary ex vivo experiments indicate a high feasibility of creating osteochondral defects on the TMJ condyle. Through these novel techniques, I will enhance tissue-engineering approaches for TMJ condyle regeneration in three specific aims. In Specific Aim 1, many techniques, including MALDI-IMS, will be used to characterize the TMJ condyle of the Yucatan minipig. This characterization will result in gold standard values for engineered tissues. In Specific Aim 2, a novel tissue-engineering technique involving seeding of mesenchymal stem cells into decellularized bone scaffolds, then combining with self-assembled neocartilage, will be interrogated. This will result in the formation of neocartilage-bone implants with robust interfacial properties for long term in vivo efficacy. Finally, in Specific Aim 3, neocartilage-bone implants will be used in a large animal study, where they will regenerate defects of the Yucatan minipig TMJ condyle. Successful completion of this proposal will enhance the translation of tissue engineering strategies for TMJ disorders toward the FDA paradigm of clinical trials and human use in the clinic.

NIH Research Projects · FY 2026 · 2023-04

PROJECT SUMMARY Continuous intracranial pressure (ICP) monitoring is an important surveillance tool for critically ill neurologic patients that provides critical insights on disease severity for guiding medical management . However, ICP monitoring requires a highly invasive procedures that incurs risks for intracranial hemorrhage and infection.24–28 Thus, the clinical indications for ICP monitoring are a topic of debate and up to 50% of traumatic brain injury patients who fulfill recommendation criteria for an ICP monitor never receive it.22 Moreover, nearly half of patients admitted to the Neuro-Intensive Care Unit (Neuro-ICU) without an ICP monitor go on to later develop elevated ICP.1 Unfortunately, even eligible patients are only provided ICP monitoring while in the Neuro-ICU. After adequate recovery, they are transferred to a step-down unit without a monitor even though they are still at high risk for developing elevated ICPs and potentially fatal brain herniation. Therefore, there is a clear unmet need for a non-invasive approach to continuous ICP monitoring. We propose to develop a non-invasive sensing system to continuously monitor ICP by correlating beat- to-beat carotid artery BP to ICP. Prior studies have demonstrated that central aortic waveforms detected at the extracranial portion of the carotid artery closely resemble ICP waveforms.3-10 In our previous work, we developed highly sensitivity conformal sensors capable of measuring carotid artery BP waveforms with minimal applanation pressure. 36,37 W e have also demonstrated a novel pressure estimation algorithm that can sustain high accuracy radial artery BP measurements in surgical and ICU patients. 13 By combining our highly sensitive sensors with our generalizable pressure estimation algorithm, we hypothesize that we can non-invasively and continuously monitor ICP by developing a parameter estimation model to correlate our sensor's carotid BP measurements with ICP waveforms using recordings from Neuro-ICU patients for training and validation . Studies have also demonstrated the clinical utility of other ICP waveform-derived indices for assessing intracranial compliance and prognosticating patient outcomes.14–18 Due to the morphological similarity between carotid BP and ICP waveforms, we hypothesize that these waveform features can also be applied to our carotid BP measurements and sensor-derived ICP estimations to gain unique insights on patient neurologic status that can aid medical decision-making. T he findings of this project have the potential to form the basis for future investigations on utilizing the waveform features of carotid BP as a proxy measure of ICP. Moreover, i f successful, our proposed non-invasive, continuous ICP monitor has the potential to not only enhance neurologic monitoring across a broader range of patients, but also create a paradigm shift in existing clinical protocols in favor of more proactive ICP surveillance.

NIH Research Projects · FY 2026 · 2023-04

Project Summary Addiction, and opioid use disorder (OUD) in particular, is a scourge on American life. Though we know much from animal models about how opioid drugs act on the brain, we have yet to develop new OUD treatments based on this knowledge. Why is this? Our lab, like others in recent years, have argued that in part it is due to a lack of translationally-relevant rodent models that capture the key behavioral features of addiction, such as the maladaptive, compulsive, and relapsing use that develops in a subset of individuals. In humans, OUD is characterized by continued use of opioids despite negative consequences, preoccupation with using these drugs, and relapse to drug use after quitting, and for long-lasting opioids like heroin, also escalation of use, tolerance, and withdrawal. Each of these translationally-relevant behavioral phenomena can now be modelled in rodents, but the neural networks underlying each of them are yet poorly understood. The ventral pallidum (VP), and especially its dense projections to the ventral tegmental area (VTA), have drawn increasing attention for their potent roles in motivation and addiction. We recently showed VP neurons are essential for translationally-relevant cocaine relapse-like behavior, and that GABAergic VP neurons (VPGABA) and their projections to VTA are specifically responsible for a range of strongly motivated behaviors—presumably via interactions with wider neural networks of motivation. We hope that by understanding how these neural networks function during behaviors that capture key aspects of OUD, we can leverage this information to develop new neuroscience-based treatment strategies. Here, we systematically dissect the involvement of VPGABA neurons, and the wider reward and aversion networks they modulate, in OUD-relevant behaviors. In well-validated GAD1:Cre transgenic rats, we use Cre and Flp-dependent chemogenetic manipulations to show how VPGABA neurons 1) modulate wider networks underlying opioid relapse, 2) participate via their functionally-segregated outputs in appetitive aspects of OUD, and 3) how these pathways mediate aversive aspects of OUD. We hypothesize that VPGABA neurons modulate wider neural networks to generate OUD behaviors, and that inhibiting this key pathway will reduce compulsive drug seeking.

NIH Research Projects · FY 2026 · 2023-04

PROJECT SUMMARY The vast majority of child tuberculosis (TB) deaths occur in children <5 years old, highlighting the importance of identifying young children at high risk of developing TB and initiating preventive treatment. However, current tests for Mycobacterium tuberculosis (Mtb) infection have poor predictive value for TB progression. To make progress toward biomarker-targeted TB preventive therapy in young children, there is an urgent need to identify novel host markers that reflect the unique pathogenesis of childhood TB, can be detected earlier in the course of disease progression and can be more easily translated to a point-of-care assay. The overall objective of the proposed project is to identify biomarker signatures among young children that meet the World Health Organization (WHO)-recommended minimum accuracy targets for a test of TB progression. We hypothesize that a subset of host biomarkers of childhood TB disease that reflect unsuccessful immune control of Mtb infection will have the best performance for early prediction of TB disease progression in young children. To examine our hypothesis, we propose to leverage 1) biorepositories that provide access to banked samples from children with presumptive TB and healthy children with and without TB exposure and Mtb infection (Uganda, South Africa, the Gambia); 2) biorepositories that provide serial samples from young children followed for 12 months or more for incident TB disease (Uganda, South Africa, Vietnam); and 3) state-of-the-art platforms and bioinformatic pipelines for multi-omics biomarker discovery. In Aim 1, we will measure and compare biomarker levels (host cell-free RNA, proteins, metabolites and antibodies to Mtb antigens) in symptomatic children with presumptive TB and healthy children to identify candidate host biomarkers that differentiate childhood TB disease, differentiate Mtb infection, overlap between TB disease and Mtb infection, and segregate Mtb infection into multiple sub-groups. In Aim 2, we will use pathway analysis, in vitro human models and in vivo mouse models to prioritize candidate host biomarkers that are functionally linked to immune control of Mtb infection. In Aim 3, we will derive biosignatures consisting of the prioritized candidate host biomarker(s) and evaluate their accuracy for predicting TB progression overall and among children living with HIV in independent training and test sets. Completion of these aims will result in identification of promising biosignatures that can be further validated in large-scale field studies and translated into point-of-care tests for predicting progression of childhood TB.

Fonds de recherche du Québec – Nature et technologies · FY 2023-2024 · 2023-04

Volet: Bourses de recherche postdoctorale; Domaine: Nature et interactions de la matière; Objet: Synthèse chimique et catalyse; Application: Science and Technologies; Mots-clés: ORGANIC CHEMISTRY, SYNTHESIS, TOTAL SYNTHESIS OF NATURAL PRODUCTS, POLYENE CYCLIZATION, TRANS-ANNULAR DIELS-ALDER, BRASILICARDIN A

NIH Research Projects · FY 2026 · 2023-03

PROJECT SUMMARY/ABSTRACT Alzheimer's disease (AD) is the most prevalent neurodegenerative disease with dementia among the elderly, yet exact causes of the disease and underlying pathogenic mechanisms that lead to development of effective therapeutic interventions have not been identified. Recently, a number of genetic and transcriptomic studies in humans and animal models highlight a critical, and possibly a disease-modifying role of microglia in AD. Once activated, microglia are capable of displaying a spectrum of phenotypes ranging from homeostatic to neurodegenerative phenotypes, with distinct transcriptomic signatures. However, it remains to be determined which subset(s) of microglia are neuroprotective or detrimental, and how such microglia activation is driven by what cellular mechanisms and disease conditions. We have strong evidence that microglia-enriched spleen tyrosine kinase (SYK) critically controls the activation pattern of microglia. The cellular SYK signaling in microglia is regulated by various cell-surface immunoreceptors including TREM2. The mechanistic details of SYK activation as well as how its frequency, duration and patterns of activation determine above-mentioned microglial phenotypes have not been elucidated. Here, we propose to test our novel hypothesis that SYK is the key molecular hub that regulates a spectrum of microglia activation depending on the expression levels of TREM2, age and the stage of Aβ pathology. We predict that activation of SYK, when its expression is physiological in microglia, is neuroprotective and promotes effective containment and removal of Aβ, whereas prolonged or chronic activation of SYK, especially when its expression is elevated in microglia, is detrimental and drives pro-inflammatory and degenerative activation. In this proposal, we will first carefully investigate the underlying mechanisms by which SYK controls several hallmark functions of microglia in various expression levels of SYK and wildtype TREM2, as well as in the presence of TREM2 risk variant. We will then use an animal model to determine if dichotomous activation of SYK depends on the Aβ plaque stages in two different mouse models of AD. To test our hypothesis, we propose a combination of in vitro and in vivo studies utilizing novel conditional transgenic mouse models and human iPSC-derived microglia (iMGL). The proposed research will provide insight into whether and how SYK activation and activated microglia contribute to the disease progression in AD. Furthermore, this proposal is feasible, highly-significant, and highly-relevant to the etiology and progression of AD and we believe that the outcomes could have large public health impact, while accelerating progress towards efficacious, therapeutic options for AD.

NIH Research Projects · FY 2026 · 2023-03

ABSTRACT Numerous clinical and preclinical studies have established the debilitating neurocognitive side effects of various chemotherapy regimens for the treatment of cancer, often referred as chemobrain. With substantial increases in the number of cancer survivors, over 16.9 million in the U.S. alone, cognitive function following cancer treatment is considered as one of the most critical criterion for evaluating therapeutic outcome and for determining long-term quality of life. The situation is confounded further by the conspicuous absence of satisfactory treatments for reducing the progressive neurocognitive sequelae associated with non-CNS cancer therapies. This application is in response to a specific RFA (PAR-21-329) to investigate interventions designed to prevent or reduce the adverse neurocognitive sequelae following cancer therapy. Our pre- clinical studies have shown long-term consequences of chronic chemotherapy (cyclophosphamide, CYP; Adriamycin, ADR monotherapy) including cognitive impairments, loss of neuronal architecture, spine integrity and neuroinflammation. We posit that neuroinflammation is one of the major contributory factors for long-term CNS dysfunction and that human neural stem cell (hNSC)-derived extracellular vesicle (EVs) treatment can ameliorate adverse neurocognitive and inflammatory sequelae associated with chemobrain. Our recent data show that hNSCs or hNSC-derived EV reverse cancer therapy (CYP or irradiation, IRR)-induced cognitive impairments, neuron and spine damage and, neuroinflammation. Intra-venous (retro- orbital vein, RO) injections of hNSC-EVs showed long-term neuroprotection in the IRR brain. We have also identified candidate miRNA within the EV cargo, with gene targets relevant to the molecular, structural and behavioral improvements observed in the cancer therapy-exposed animals following EV injection. Importantly, in vivo expression of miR-124-3p reversed IRR- induced cognitive deficits and neuroinflammation. Based on the foregoing, we propose a comprehensive series of studies designed to test the effectiveness hNSC-EV and determine an EV-derived candidate miRNA-based mechanism to ameliorate chemobrain and neuroinflammation in routinely used adjuvant chemotherapy regimens (Carboplatin-Taxol, ADR- CYP) to control the growth of ovarian and breast cancer. Our research design will delineate long- term neuroprotective effects of RO injections of hSNC-EV or in vivo expression of miR-124-3p following adjuvant chemotherapy regimens in disease-free or xenograft cancer mouse models. These studies will also elucidate the safety, toxicity and pharmacokinetics of hNSC-EVs therapy in the context of cancer. Thus, this project is based on a foundation of strong published and preliminary data supporting our rationale.

NIH Research Projects · FY 2026 · 2023-03

PROJECT SUMMARY Type II diabetes takes a large toll on both individuals and society through morbidity and financial burden. Patients with diabetes are at risk of developing diabetic foot ulcers that are nonhealing and can lead to infections and amputations. The pathophysiology that underlies this impaired wound healing can be due to damage to blood vessels, neurons, and immune function, all of which contribute to delayed wound healing. Normally, skin requires nutrients like nonessential amino acids for building material and energy to undergo repair and heal wounds. My preliminary metabolomics data in different wound regions in control and db/db mice indicate that four nonessential amino acids, including serine and glycine, are particularly depleted in diabetic wounds, suggesting their important biological roles in wound healing. Previous studies of diabetic mice and humans have also found a reduction of serine and glycine within wounds and systemic blood. However, it remains unknown why they are depleted, whether they are required for wound healing, and how they are used for healing. Thus, identification of the cause of their reduction and usage by different cell populations during wound healing in diabetic models will facilitate the future development of new therapeutics. To this end, I will 1) define the distribution and fates of the four nonessential amino acids in different wound regions in healthy and diabetic mice; and 2) determine whether serine and glycine supplementation can promote wound healing. My proposed study will utilize a broad spectrum of innovative tools including in vivo stable isotope tracing coupled with high-resolution mass spectrometry-based metabolomics, microscopy, and cell sorting. This study will expand our understanding of how efficient nutrient utilization facilitates wound healing in normal and diabetic wounds. The findings from this study will also generate important implications regarding potential targets for future pharmacological or genetic knockout experiments in the effort toward developing novel therapies for improving diabetic wound healing.

NIH Research Projects · FY 2026 · 2023-03

ABSTRACT: Visual pigments initiate the human visual experience, making them of great physiological interest, and also are affected in retinal diseases. Accordingly, numerous research efforts have been devoted to characterizing their structure-function relationships. Despite these efforts, critical gaps remain in our understanding of visual pigment photochemistry and signaling properties. Knowledge of this fundamental visual physiology is necessary to make accelerated progress in developing treatments for associated retinopathies. At the heart of all visual pigments is a retinaldehyde chromophore that undergoes a cis-trans isomerization upon absorption of a photon of a suitable wavelength. This complex reaction, which proceeds through several photointermediates, triggers the conformational changes necessary for the propagation of a light stimulus into a biochemical response. This photoactivation process ends with the hydrolysis and release of retinaldehyde, which is required for renewal of the receptor light-sensitive state and hence continuous visual function. Fundamental questions remain regarding receptor structure, mechanisms and modulators of hydrolysis of the retinaldehyde Schiff base, and the modes of interaction of small molecule therapeutic candidates. Here, we will pursue four specific aims that employ newly developed tools and approaches that we believe will overcome previously insurmountable experimental challenges. 1) Elucidate structures of rhodopsin photointermediates stabilized by nanobodies. Using a novel series of camelid antibodies that arrest the rhodopsin photocycle, we will perform a detailed structure-function characterization of metarhodopsin intermediates. 2) Define the kinetics of hydrolysis of the retinaldehyde chromophores of rhodopsin and cone opsin pigments in native membranes. We have developed a novel mass spectrometry-based method that can, for the first time, directly detect the retinal conjugation state of visual pigments in native membranes; we will use this method to determine key rate constants necessary to model the interplay between visual pigment bleaching cycles and the regenerative visual cycles. 3) Assess the influence of cytosolic effectors and visual cycle components on the rate of hydrolysis of rhodopsin chromophore in knockout mouse models. Using the methods described in Aim 2, we will characterize the rate of Schiff base hydrolysis in Arr1-/-, Grk1-/-, Abca4-/-, and Rdh8-/- mice, providing new insights into how light and dark adaptation are modulated by phototransduction and visual cycle proteins. 4) Characterize the molecular architecture of rhodopsin complexes with lipids and small molecules using native mass spectrometry. Using the native MS technique, we will quantify phospholipids that associate with rhodopsin in its various activation states. We will also validate the pharmacodynamics and pharmacokinetics of small molecule therapeutic candidates in vivo. We believe the information gleaned from these studies will enhance our understanding of retinal diseases at the molecular level and enable the development of novel strategies for their treatment.

NIH Research Projects · FY 2025 · 2023-03

SUMMARY Inherited retinal disorders are a genetically heterogeneous group of blinding diseases that have significant impact on quality of life. Therapeutic approaches have lagged significantly behind initial identification of the genetic bases for these diseases. However, there are some striking successes; e.g., RPE65 gene augmentation therapy was the first FDA-approved gene therapy for any genetically inherited disease. Clinical translation of current CRISPR-Cas9 technology has been impeded by its low editing efficiency, error-prone homology-directed repair (HDR), and substantial indel formation. Precision genome editing is an advanced, innovative CRISPR-Cas9- associated genome-editing tool that addresses the limitations of typical CRISPR-Cas9 implementation. Adenine base editors (ABEs) enable conversion of a point mutation independently of Cas9-induced double-stranded DNA breaks and HDR. When base editing is not applicable (e.g., due to transversion mutations, large deletions, or insertions), prime editing technology offers feasible alternatives. Genome editing is highly specific; however, prolonged expression of base editors could lead to undesired off-target alterations throughout the genome and transcriptome. We hypothesize that transient delivery of genome editors via RNPs and synthetic RNAs can achieve the same high editing rates as those for genome editors delivered via viral transduction with reduced off-target and bystander editing. Accordingly, we propose two thematically linked aims. Aim 1. Correct inherited retinal disease-causing mutations in the rhodopsin gene (RhoE150K/E150K) associated with autosomal recessive retinitis pigmentosa (RP) via adenine base editing. Delivery of ABEs will be optimized in the thoroughly characterized RhoE150K/E150K mouse model of RP. Proposed approaches will provide a platform for ABEs to be quickly adapted to any suitable RPE or retinal mutation. Aim 2. Repair the ABCA4 protein in Abca4PV/PV mice by prime editing. Using the PE3b prime editor and two concurrent stabilized engineered prime-editing guide RNAs (epegRNA), we will restore functional ABCA4 protein in Abca4PV/PV mice that carry double allelic mutations in photoreceptors and the RPE. Using immunoblotting and next-generation sequencing for detecting rescued Abca4, and two-photon imaging techniques to detect A2E, we will optimize genome editing efficiency in this animal model to improve prime-editing technology and its application to treat inherited retinal diseases. For both aims, we will test various means to deliver the editors transiently: (i) cell-penetrating peptides fused to editors in purified ribonucleoprotein (RNP)-editing complexes; (ii) Coomassie-lipid tags on purified RNP-editing complexes; (iii) viral-like particles containing RNP-editing complexes; or (iv) lipid nanoparticles containing stabilized mRNAs of genome-editing materials for intracellular expression. These delivery systems will be optimized first in engineered chromogenic cell lines. The efficacy of base and prime editing in mice will be benchmarked against the level of expression of RPE65 in the rd12 animal model of Leber congenital amaurosis.

NIH Research Projects · FY 2026 · 2023-03

PROJECT SUMMARY/ABSTRACT The Mobley laboratory focuses on developing and using computational tools to dramatically accelerate pharma- ceutical drug discovery. We focus on the interface between methods and applications, and invest in assessing and improving computational methods as well as applying methods directly in discovery. We take an open approach (open science, open source software, open data), making our work a community resource, including our FreeSolv database of solvation free energies, the Statistical Assessment of Modeling of Proteins and Ligands (SAMPL) series of blind challenges, our Lead Optimization Mapper (LOMAP) tool for automation of binding calculations, and the Open Force Field and Open Free Energy projects. Tools and methods we have contributed to are now broadly used in drug discovery research, including in pharma. Our overall vision is to make modeling a tool which plays a key role guiding drug discovery research, reducing costs, time and trial and error. In particular, we want researchers – ranging from medicinal chemists to structural biologists as well as experts in computation – to routinely input their latest results and ideas into their computer at the end of the work day, and return to work to find prioritized next steps for their research. For example, in the lead optimization process, one might input the latest assay results as well as ideas for new compounds which could be screened next, and on returning to work in the morning, find ideas ranked by affinity for the target, potential off- target effects and predicted solubility/oral availability. Results might also include additional synthetically accessible compounds not originally considered. If predictions were accurate, this pipeline would dramatically accelerate discovery; thus, we seek to make workflows like this a reality via our science and engineering efforts. In our next five years, we plan to develop an increasingly automated iterative pipeline for iterative library design, compound screening, and optimization. With an experimental partner, we use computation to design promising DNA-encoded compound libraries, computationally analyze screening results, then design models to recommend additional compound rounds for screening and further iterations of the cycle. When combinatorial screening leads to promising enough compounds, we shift to compound optimization, employing active learning in combination with free energy methods and machine learning to prioritize compounds for synthesis and, when possible, for purchase from compound libraries like Enamine, with assay results guiding additional cycles. Results from this work feed back into improving our models and guide early stage drug discovery projects. Our focus involves both pipeline development and actual discovery. While we are developing methods that can be applied to any therapeutic area or target when coupled with experimental work, we will also focus on antibacterial discovery, a particular interest for us and our partners in the Paegel lab. Their novel screening and discovery platform, coupled with our expertise in computational techniques to guide discovery, allow the development of a powerful new platform for pharmaceutical design, our focus for the next few years.

NIH Research Projects · FY 2026 · 2023-03

Project Summary This project pursues two research directions that build on two NIGMS funded research programs. Both projects are loosely connected and the pathways studied will help understand how metabolic and environmental cues are sensed and transmitted to the cell cycle machinery. Previous work in yeast models has established different ubiquitin-mediated signaling events that communicate metabolic and environmental states to the cell cycle machinery. Molecular understanding of the concepts that govern ubiquitin signaling are thus the topic of the first part of this application. Project-1 studies both yeast and mammalian cell line models to define general concepts of ubiquitin signaling. These experiments build on a plethora of tools we have developed to analyze biochemistry and physiology of ubiquitin signaling and will address the following questions: (1) How do readers of the ubiquitin signal distinguish different chain types? (2) How do F-box proteins sense metabolic and environmental states? (3) How do ubiquitin ligases recognize substrates in a context specific manner? (4) How is signaling achieved by phosphorylated ubiquitin. Proposed work in project 1 will define detailed molecular insight in aspects of ubiquitin signaling both proteolytic and non-proteolytic. Project-2 is focused on the mammalian system, were we discovered important connectors between methionine metabolism and cell proliferation. These include regulation of protein phosphatase 2A (PP2A) and RNA CAP methylation of selected transcripts. Work on PP2A in mammalian cells will focus on the role of methylation of the carboxy terminus of the catalytic subunit of PP2A as a sensor of methionine metabolism. Experiments will expand on proteomic profiling that identified several PP2A interaction partners with preference for the demethylated PP2A complex. We will dissect these interactions and define their role in communicating metabolic states to the cell cycle machinery. Studies related to mRNA CAP methylation will extend our recent findings that a small group of RNAs is highly sensitive to subtle fluctuations in the cellular methylation potential, which is controlled by methionine metabolism. These RNAs become hypomethylated on their mRNA CAPs, and thus are inefficiently translated when methionine is limiting. The goal is to understand mechanisms that make certain mRNAs hypersensitive to fluctuation in methionine metabolism, and to discover the mechanistic link to cell cycle control. Understanding the molecular concepts that integrate methionine metabolism with cell proliferation promise new therapeutic strategies, especially for the treatment of cancer and other age-related disorders. Thus, this proposal aims to development molecular insight into a fundamental, so far molecularly unexplored, biological process with great therapeutic potential.

NIH Research Projects · FY 2026 · 2023-02

PROJECT SUMMARY/ABSTRACT Pediatric and adult disorders of the urethra including hypospadias, trauma, and stricture disease represent significant health care burdens which require surgical intervention to replace developmentally absent or damaged tissue to preserve urinary tract function. Autologous tissue grafts derived from extragenital skin flaps or buccal mucosa are primarily utilized to restore urethral continuity in cases where end-to-end anastomosis is not feasible. However, these approaches have been associated with adverse side effects including stricture recurrence, diverticulae and fistula formation. Silk fibroin (SF) biomaterials provide an exceptional combination of physical characteristics including high tensile strength and elasticity, diverse processing flexibility, controllable degradability, and low immunogenicity to create “off-the-shelf” scaffolds for treatment of urethral stricture disease. Novel urethral reconstructive strategies employing bi-layer (BL) SF scaffolds impregnated with SF hydrogels capable of targeted urethral delivery of stem cell homing factors, MCP1/CCL2 or SDF1α/CXCL12, will be developed and investigated for their ability to restore normal micturition and promote superior constructive remodeling in newly developed, large animal models of long urethral strictures in males and females. In this proposal, we will challenge the overall hypothesis that: composite BLSF matrices loaded with SF hydrogels capable of controlled release of MCP1/CCL2 or SDF1α/CXCL12 will provide a superior approach for restoring function of long urethral strictures in comparison to buccal mucosal grafts. The specific aims of the proposal are: Specific Aim 1: Determine the impact of CXCR4-SDF1α/CXCL12 and CCR2-MCP1/CCL2 signaling axes on scaffold-mediated, urethral tissue regeneration in a rabbit model of urethral stricture repair. Specific Aim 2: Create MCP-1/CCL2 and SDF1α/CXCL12 releasing, composite BLSF grafts with the capacity to promote superior functional urethral regeneration in novel male and female porcine models of long urethral strictures.

NIH Research Projects · FY 2025 · 2023-02

This proposal describes a rigorous and comprehensive plan designed to obtain expert training in advanced MRI acquisition and analytical methods, developmental systems neuroscience, and fetal programming of health and disease risk. The proposed research relates to the public health problem of childhood obesity, with a specific focus on the characterization, role and determinants of energy homeostasis-related brain circuitry in the human newborn. Obesity is a multi-factorial phenotype. Among these factors, the critical importance of energy homeostasis (balance), and the hypothalamic-limbic-cortical brain circuitry that regulates it, is well established. However, it is unclear whether the observed difference in this brain circuitry between obese and normal-weight individuals is a cause or consequence of the obese state. Also, relatively little is known about the developmental origin (fetal and early postnatal) of variation in this brain circuitry and its prospective role in shaping propensity for childhood obesity. My proposal addresses this fundamental knowledge gap. I advance the overarching hypothesis that energy homeostasis brain circuitry a) already is established by the time of birth; b) exhibits developmental plasticity (fetal programming); and c) is functionally relevant (predicts postnatal adipose tissue accrual). The K99 mentored phase will be conducted under the mentorship of leading experts in fetal programming of health and disease (P. Wadhwa), brain imaging (P. Thompson), and developmental systems neuroscience (D. Fair). I will first develop novel MRI-based measures of the newborn brain circuitry underlying energy homeostasis, and then identify the prenatal determinants of variation in this circuitry. The importance of focusing efforts on the newborn brain derives from the logic that brain circuitry at this time is not yet influenced by postnatal factors. In the R00 phase, I will recruit a new cohort and use a repeated measures design to address the functional relevance of the initial (newborn) setting of this brain circuitry in the context of adipose tissue accrual over infancy (a key indicator of childhood obesity risk). K99/Aim 1. Develop measures of energy homeostasis brain circuitry using anatomical, diffusion and functional MRI. Because such measures have not yet been established in newborn homeostasis circuitry, this aim will fulfill an important and as yet unmet need in terms of not only scientific knowledge but also technical capability. K99/Aim 2. Identify the prenatal (gestational biology) determinants of variation in the measures of newborn brain energy homeostasis circuitry that are associated with infant adiposity. R00/Aim 3. Address the physiological relevance and clinical significance of these novel MRI-based newborn brain measures by testing the hypothesis that measures of the human newborn’s energy homeostasis brain circuitry are prospectively associated with infant adiposity and subsequent childhood obesity risk. R00/Aim 4. Consider the complimentary hypothesis that infant adiposity at birth is prospectively associated with changes in newborn energy homeostasis brain circuitry. Significance. By identifying the role and determinants of energy homeostasis-related brain circuitry in the human newborn, these findings will ultimately provide the basis for the subsequent development of strategies aimed at the primary prevention of childhood obesity.

NIH Research Projects · FY 2026 · 2023-01

PROJECT SUMMURY/ABSTRACT Valvular heart disease (VHD) is the third-most common cause of heart problems in the United States, with mitral valve disease as the second-most common VHD after aortic stenosis. Mitral valve disease can cause many complications if left untreated and is more common in younger patients, in whom bioprosthetic heart valves (BHVs) are prone to faster degeneration. An ultimate solution for younger patients with long life expectancy is a living tissue valve, although exploratory studies for tissue-engineered heart valve (TEHVs) have yet to satisfy the regulatory requirements for clinical use. In preclinical studies, current TEHVs have been unable to adjust their composition to withstand the hemodynamic loads to which they would be exposed, and their leaflets were found to shrink due to their degradable scaffolds, which led to poor leaflet coaptation, followed by progressive regurgitation and valvular insufficiency. The native mitral valve is bileaflet, with a saddle-shaped annulus that bounces dynamically during the cardiac cycle. It forms a diastolic transmitral vortex, which efficiently transfers momentum from the left atrium (LA) toward the aorta via the left ventricle (LV). The transmitral vortex ring is normally non-axisymmetric and helps maximize blood momentum transfer. Inspired by nature's optimizing of the swirling flow in the LV, we aim to gain new insights associated with LV vortex effects on heart valve tissue regeneration toward the development of improved TEHVs, and test those in preclinical studies to be conducted in an ovine model. More specifically, this project seeks to characterize transmitral vortex flow as a link to discovering novel approaches for heart valve tissue engineering to enhance tissue generation and cell viability of the engineered leaflets. We will test the overarching hypothesis that the reciprocal effects between non-axisymmetric vortex flow and mitral TEHVs' scaffold geometry and annulus dynamics enhance tissue generation and improve the valve's cell viability.

NIH Research Projects · FY 2026 · 2023-01

PROJECT SUMMARY High out-of-pocket costs (OOPC) of cancer treatment and lost income result in financial hardship. There is compelling evidence that OOPC communication complemented by financial navigation and counseling will decrease financial hardship by enabling cancer patients to anticipate and accommodate treatment costs and proactively seek financial assistance. Importantly, this intervention aligns with the Centers for Medicare and Medicaid Services (CMS) price transparency mandate. We will evaluate the effectiveness of an innovative personalized intervention designed to improve cost-related cancer care non-adherence by conducting a randomized controlled trial of OOP cost communication and financial navigation (CostCOM) vs. enhanced usual care (EUC) at NCI Community Oncology Research Program (NCORP) practices. Our multidisciplinary team has experience with all facets of the proposed intervention including conducting clinical trials at NCORP practices. CostCOM comprises four 1-hour counseling sessions to impart: (1) OOPC communication, individualized, patient-specific education of the anticipated OOPC using a price estimator tool; (2) Financial navigation, real-time professional guidance to identify financial assistance programs that will alleviate costs of care and discuss information to improve insurance coverage; and (3) Financial counseling to address the range of patients’ financial concerns and enroll patients in financial assistance programs. We will recruit 720 patients with newly diagnosed solid tumors (1:1 non-metastatic vs. metastatic) who plan to receive anticancer therapy at one of the participating NCORP practices. CostCOM arm patients will participate in four phone or video sessions with a remote financial counselor at baseline, 3, 6, and 12 months, with all three components of CostCOM delivered at each session. At enrollment, EUC arm patients will receive usual care enhanced by providing an educational brochure describing services and contact information of the Patient Advocate Foundation (PAF), a national non-profit financial navigation organization. Patients will complete surveys at baseline, 3, 6, and 12 months after enrollment. Our goals are to (1) compare the effectiveness of CostCOM vs. EUC at 12 months on patient-reported cost-related cancer care nonadherence, defined as any self-reported incident of delay, forgo, stop or change in cancer care due to cost concerns, as well as (2) patient-reported material financial hardship, financial worry, and quality of life; and (3) conduct a process evaluation to examine practice providers and CostCOM arm patients’ satisfaction with the intervention and their perceptions of barriers and facilitators to CostCOM delivery (for providers) or receipt (for patients). A successful CostCOM is a scalable and financially sustainable program that can be disseminated across systems, conditions, and populations and improve cancer care delivery, patients’ experience, and health outcomes.

NIH Research Projects · FY 2026 · 2023-01

PROJECT SUMMARY/ABSTRACT Limb malformations are the second most common congenital abnormality, occurring in 1 in every 500 live births. Mounting evidence implicates rare noncoding mutations to underlie non-syndromic (isolated) limb malformations. Many of these variants map to transcriptional enhancers, regions of regulatory DNA that tune gene expression. However, a fundamental gap remains in our understanding of the mechanisms by which these variants alter enhancer activity and their role in causing limb defects. The most frequently affected noncoding loci is the limb-specific enhancer of Sonic hedgehog (Shh). With over 30 independent rare variants linked to limb malformations, the Shh limb enhancer is particularly susceptible to so-called Gain-Of-Function (GOF) variants. GOF variants cause enhancer overactivity that leads to ectopic expression of their target genes. However, why GOF variants only cause ectopic gene expression in specific cell types and why only a small subset of enhancers are susceptible to GOF variants are both unknown. GOF variants are among the least understood enhancer mutations that cause human disease. Much of our lack of understanding of how GOF variants contribute to disease is owed to a lack of suitable model systems. In vitro cell culture and organoid-based systems fail to recapitulate ectopic expression from GOF variants nor model their phenotypic consequences. Thus, it is essential to use in vivo systems to determine the functional and clinical significance of GOF variants. To address this major need, our group recently developed a novel mouse enhancer reporter assay that enables highly-reproducible detection of ectopic gene expression in the cells of the anterior limb domain where Shh is normally not expressed. The overall goal of this proposal is to determine the genetic factors mediating the unique susceptibility of anterior limb bud cells and the Shh limb enhancer to GOF variants. I will test the hypothesis that susceptibility to GOF variants is dictated by the regulatory landscape of anterior limb bud cells and a unique, stable higher-order chromatin structure of the Shh locus. To identify the genetic factors that mediate ectopic Shh expression, I will characterize the regulatory landscapes and local chromatin architecture of anterior limb bud cells in which Shh is ectopically active at single-cell resolution. To determine genetic factors that predispose specific enhancers to pathogenesis, I will test the requirement of higher-order chromatin structure for limb malformations resulting from GOF variants. By identifying targetable genetic factors mediating ectopic gene expression, these studies will provide mechanistic insights into how GOF variants in the limb-specific Shh enhancer contribute to limb malformations. Findings resulting from this proposal can also be applied to predict the clinical significance of noncoding variants from patient sequencing data and will have implications for other developmental disorders linked to GOF variants.

NIH Research Projects · FY 2026 · 2023-01

PROJECT SUMMARY Anhedonia—the diminished capacity to experience pleasure from normally pleasurable stimuli—is a transdiagnostic symptom of multiple psychiatric disorders, including depression, schizophrenia and post- traumatic stress disorder. The recent and rapid growth of anhedonia research is fueled by its alarming clinical presentation: anhedonia is independently associated with increased risk of suicide, treatment resistance, and reduced quality of life. Major depressive disorder and schizophrenia—disorders of which anhedonia is a cardinal symptom—are linked with increasingly high levels of economic burden related to substantial health care costs and unemployment. There is currently no clear biological definition of anhedonia. As a result, clinicians rely on self-report measures with no clear established connection to its underlying neurobiology. While behavioral reward processing deficits and dysfunctional reward circuitry have been observed in anhedonia, in-the-moment reward responding is frequently preserved, suggesting that memory for the value of the experience may be compromised. This prompts the central question of this proposal: to what extent is anhedonia a memory problem? We propose to test a memory-based account for anhedonia as part of our goal to biologically define the construct. We note that while it is unlikely that memory is the only basis for anhedonia (certainly there are clear experiential aspects), it may be an understudied and underappreciated player. Critically, a well-defined memory contribution can help identify novel treatment targets and pave the path to improving clinical practice with biologically informed decision-making. We use a computational psychiatry approach, combining mathematical modeling of behavior in novel paradigms with advanced neuroimaging and AI tools to identify and validate biomarkers relevant to the prevention and treatment of anhedonia. We unite computational models of value, reinforcement learning, and episodic memory, bridging across the RDoC domains of Positive Valence and Cognitive Systems. Our aims are to: (1) Test the impact of anhedonia on value-modulated episodic memory and its neural mechanisms using high-resolution whole brain fMRI; (2) Test the impact of anhedonia on memory- guided decisions for reward and the associated neural mechanisms using high-resolution whole brain fMRI; and (3) Test the impact of anhedonia on structural and functional connectivity measures as well as autonomic regulation. We will also use AI/ML tools to create a multimodal library of predictive biomarkers for anhedonia. Our ultimate goal is to develop a comprehensive, mechanistic, and actionable memory-based account for anhedonia using new paradigms, computational models, high-resolution neuroimaging, as well as artificial intelligence approaches to develop novel interventions and improve clinical practice.

NIH Research Projects · FY 2026 · 2023-01

ABSTRACT Major advances have been made in mapping the genetic basis of epilepsy and other neurodevelopmental disorders (NDDs). In many cases, a candidate gene mutation has been identified, but there is no robust understanding of the neuronal causes for the particular disorder. Mutations in genes encoding chromatin regulators are commonly identified in human NDDs, with intellectual disability, autism and/or epilepsy often co- occurring in the same individual. Our recent work showed that mice with germline heterozygous mutations in Chd2 exhibit pathological changes across genomic, anatomical, electrophysiological and behavioral domains. Here, we propose studies to bidirectionally control Chd2 dosage in the developing or adult brain. Our approach involves a combination of sophisticated cellular, molecular, pharmacologic and electrophysiological approaches in conditional Chd2+/- mice and human-derived neurons. If successful, our results will provide important new information about the effects of chromatin regulators in driving NDD-associated pathologies in vivo and would provide critical proof-of-concept for the therapeutic potential of pharmacologically increasing Chd2 expression that could be rapidly translated into a new targeted therapy for Chd2 haploinsufficiency.

NIH Research Projects · FY 2025 · 2023-01

PROJECT SUMMARY/ABSTRACT Immune checkpoint inhibitors (ICIs) have significantly improved long-term survival across diverse cancer types including melanoma, non-small cell lung cancer, triple negative breast cancer, and others. However, ICI efficacy relies on multiple cancer, host, and environmental variables, and only a small fraction of patients will respond to these antibody drugs. Methods to improve ICI responsiveness are therefore a highly desirable, unmet clinical need. Human-associated microbes are critical regulators of host health and disease including cancer treatment. Clinical studies have shown that specific gut bacterial species correlate with improved patient outcomes of ICI therapy, and colonization by these active microbes can directly elicit antitumor activity in preclinical animal models. These observations raise a fundamental question: what are the microbial mechanisms that dictate ICI efficacy? My previous work has demonstrated that a secreted bacterial peptidoglycan hydrolase is sufficient to broadly improve ICI therapy in murine models of cancer. Moreover, this phenotype could be recapitulated simply by coadministration of a synthetic fragment that mimics the product of the peptidoglycan hydrolase. These findings raise the exciting hypothesis that the production of microbial metabolites can directly improve ICI efficacy. The main objective of my proposal is to examine enzymatic mobilization of bacterial PG metabolites as a general mechanism of immune modulation during cancer ICI therapy. Aim 1 will explore host enzymes as new factors that determine ICI efficacy. Aim 2 will produce chemical probes to discover ICI-activating bacterial enzymes. Aim 3 will examine PG mobilization as a broad-spectrum strategy to potentiate ICI response in new indications and against new checkpoint targets. To accomplish these goals, I have built a broad and interdisciplinary skill set from my graduate work in chemical tool development with Dr. Linda Hsieh-Wilson at Caltech and my postdoctoral work in host-microbial communication and cancer immunology with Dr. Howard Hang at Scripps Research. To complement these strengths, I have established collaborations with leaders in the fields of cancer immunotherapy and host-microbial interactions to provide training in new cancer model systems and access to critical human-derived isolates, which will greatly aid in my efforts to establish the generality and human relevance of PG mobilization during ICI treatment. In addition, I have proposed a comprehensive career development plan to address any residual gaps in my abilities to effectively manage a laboratory, disseminate our findings, and obtain independent funding. The acquisition of these skills during the K22 period will fuel progress towards the completion of my proposal, providing key preliminary data needed for my first NCI R01 grant application. My scientific and career development enabled by the K22 award will help me to achieve my long-term career goal to become a successful independent investigator at the intersection of host-microbial communication and cancer immunotherapy. Moreover, these efforts may yield mechanistic insights and translational avenues to understand and augment differential ICI responses in the clinic.

NIH Research Projects · FY 2026 · 2022-12

Stroke is the one of the leading causes for death and the leading cause of long-term disability in the USA, and most strokes originate from blood flow blockage known as ischemic stroke. Since the majority of cortical ischemic strokes originate from blockage in the middle cerebral artery (MCA), our lab has studied stroke protection in a rat model of permanent middle cerebral artery occlusion (pMCAo). Our findings have demonstrated that sensory stimulation in the early 2 hours following pMCAo is protective but later (3-4 hours) the same stimulation becomes damaging (known as infarct). It is assumed that the location and volume of either the damaged or protected territory depends on the spatial structure of the occluded artery (e.g., MCA), but research results in our lab point to an alternative hypothesis that the location and volume of an infarcted or protected territory depends on the spread of evoked neuronal activity in cortex. To address our hypothesis, we plan to apply state-of-the-art multi-modal battery of in vivo wide-field imaging techniques including blood flow imaging and functional imaging of cortical activity. These imaging techniques are complemented by optogentic stimulation, electrophysiological recordings using microelectrode arrays, histological, pharmacological treatment studies, and by the development of machine learning algorithms. These techniques will be employed to provide an unprecedented spatiotemporal, quantitative understanding on how the spread of evoked activity is pivotal for predicating the location and volume of the infarcted or protected cortical territory. Finally, to increase the translational potential of these studies, these techniques will be applied in old rats that represent the population most vulnerable to stroke, and in awake, head-fixed young and old rats to increase the translational potential of our research.

NIH Research Projects · FY 2026 · 2022-12

PROJECT SUMMARY The unpleasantness, or negative affective component, of pain perception is an emotional phenomenon distinct from the perceptive sensory qualities. This affective dimension of pain underlies the suffering and motivational deficits of chronic pain patients. However, similar cellular-resolution mechanisms within brain networks is lacking relative to the intricate nociceptive detail in the peripheral and spinal circuits. Thus, a key step toward accelerating the development of effective pain treatments must be the discovery of the specific neural circuits in the brain that are responsible for the aversive and unpleasant quality of pain perception. We recently reported the discovery and characterization of a basolateral amygdalar (BLA) neural ensemble, at single neuron resolution, that transforms nociceptive information in affective-motivational behavior in both acute and chronic pain conditions. While these studies provide a critical point of entry into the complex affective circuits of pain, it is not clear how the BLA nociceptive ensemble connects with other parts of the larger affective brain circuitry. Our goal here is to provide a systems-level understanding of the nociceptive cortical brain networks involved in the affective perception of pain by integrating multimodal data from pain-experience-dependent transcriptomics, activity based whole-brain circuit tracing, and precision chemogenetic control—anchored in motivational behavior-based classifications—throughout the transition from acute to chronic pain. Thus, to discover this nociceptive brain network, in AIM 1 we will use a rabies viral-genetic strategy combined with immediate early gene mapping in cleared, intact brain tissue to locate key neuronal populations whose activity is altered by chronic neuropathic pain. In AIM 2, we will employ single-nuclei RNA sequencing to link transcriptomic identity and change in cellular states during pain chronification in defined nociceptive input cells to the BLA noci- ensemble. In AIM 3, we will chemogenetically manipulate nociceptive cell-types projecting to the BLA to mitigate pain affective-motivational behaviors with locally infused microsphere drug-delivery. The cellular and functional identification of these fundamental nociceptive circuits should open new avenues for developing precision therapeutics to combat different dimensions of pain experiences, including the unpleasant affective component. Such circuit-targeted therapies could selectively diminish the suffering of pain patients, regardless of etiology and without influencing reward, while preserving necessary sensory discriminative processes for protective pain sensation.

NIH Research Projects · FY 2025 · 2022-12

Project Summary The R00 phase of this project will be conducted at the University of California, Irvine in the Department of Neurobiology and Behavior, School of Biological Sciences. Sleep is crucial for memory consolidation and its benefit is most commonly thought to occur via the reactivation of memories, thereby strengthening the neural infrastructure supporting them. Theoretical accounts of sleep-related consolidation focus on the process by which memories are independently strengthened, but in natural settings individual memories never exist in a vacuum. Importantly, the context in which memories are embedded during encoding governs retrieval and decision making behavior. However, context’s role in consolidation has not been directly explored. The goal of the proposed project is to improve our fundamental understanding of memory processes by developing an empirically-based framework unifying models of context’s effect on memory and models of sleep-related consolidation (Aim 1). Additionally, the framework will be used to support translational interventions to alter memories during sleep. Aim 2 will attempt to reinstate a suppression context during sleep to effectively weaken memories. This effort will inform future work on alleviating memory-related symptoms in clinical populations suffering from post-traumatic stress disorder. This project will combine novel techniques to selectively bias memory reactivation; machine-learning algorithms to decipher memory-related content from neural data; and neuroscientific methods for monitoring brain connectivity and rhythms in different regions and timescales. For Aim 1, functional MRI pattern analysis techniques will be used to reveal whether contexts, individual memories or both are reactivated during natural, undisturbed sleep. For Aim 2, the main behavioral manipulation used will be targeted memory reactivation, the unobtrusive presentation of learning-related stimuli during sleep, thereby enhancing memory. In one experiment included in Aim 2, individual memories will be embedded in a previously unrelated context during sleep: a reactivated “suppression” context (cued by an odor) will be presented with auditory cues linked to individual memories, hypothetically weakening them during sleep. An additional experiment will use a similar technique to try and alleviate distressful intrusive memories following a trauma manipulation in healthy participants. Taken together, these experiments should pave the way towards a richer understanding of the extent of memory reactivation during sleep, and toward content-specific interventions to selectively manipulate sleep, thereby improving mental health and wellbeing.

NIH Research Projects · FY 2026 · 2022-11

PROJECT SUMMARY Chronic pain affects nearly 1 in every 5 adults worldwide 1, posing a major public health concern and economic burden. Yet, despite the widespread prevalence of chronic pain, few effective strategies for long-term pain management exist. Historically, physicians have relied upon a cocktail of analgesics, including tricyclic antidepressants, serotonin norepinephrine reuptake inhibitors, and opiates, to treat persistent symptoms in chronic pain patients 54. However, this approach carries significant risks – reliance upon prescription opioids has fueled the opioid abuse epidemic that has crippled the United States for the past two decades, and long- term use of opioids has conversely been shown to increase pain sensitivity over time, necessitating larger and larger doses to achieve analgesic efficacy 53. Therefore, to successfully combat the opioid epidemic, we must investigate underlying mechanisms of pain chronification in pursuit of novel, non-addictive pain interventions. Until recently, much of the pain field has focused on peripheral nervous system and spinal cord circuit dysfunction, which primarily influence the somatosensory elements of chronic pain. Chronic pain, however, is more than purely a sensory phenomenon; patients also suffer from the “unpleasantness” or negative valence associated with pain 22. Recent work from our collaborators has identified a specific ensemble of neurons within the basolateral amygdala (BLA) that encodes for the negative valence of pain 22. However, it remains unknown how activity within these nociceptive BLA neurons and the circuits in which they are embedded are altered post-injury, and whether these changes contribute to pain chronification. Using an innovative activity-based rabies screen pioneered by our lab 28 in parallel with an unbiased whole-brain c-Fos activity mapping approach, we can generate a list of input regions to the BLA whose activity is elevated exclusively during chronic pain. To test the functional contribution of these input circuits in pain chronification, we will perform chemogenetic inhibition studies in tandem with classical pain assays. By identifying brain-wide, circuit-level changes that occur post-injury to promote chronic pain, we will elucidate key brain regions and circuit targets that will enable the development of non-opiate therapies for mitigating chronic pain.