University Of Florida

NIH Research Projects · FY 2024 · 2023-07

Project Summary/Abstract Chronic respiratory tract diseases such as asthma are common and significantly affect the quality of patient lives. While effective and safe asthma medications are urgently needed, they pose a significant financial burden for patients. Moreover, the current regulatory pathway, the so-called “weight-of-evidence” approach, carries a considerable economic risk for generic drug developers. This presents an impediment for bringing cost-effective, safe and efficacious generic orally inhaled drug products (OIDPs) to the market. Therefore, systematically evaluating novel approaches that can reliably support the development and regulatory assessment of generic OIDPs is essential. This project will leverage innovative modeling and simulation strategies to evaluate whether population pharmacokinetic (PK) modeling and non-compartmental analysis (NCA) approaches based on plasma concentrations allow reliable conclusions on the bioequivalence of two OIDPS in the lung. Active pharmaceutical ingredients (APIs) with a range of physicochemical properties that are used in OIDPs will be studied through computer simulations. In Task 1, this project will develop lung physiologically-based PK (PBPK) models that can simulate both the local drug exposure profiles at different regions of the lung and plasma drug concentration profiles. These PBPK models will contain five or more lung compartments, reflecting the 23 physiological generations of the lung. Inhaled drug deposition in various lung regions will be implemented as a function of the particle size distribution. Further, the lung PBPK models will account for the total lung dose, dissolution kinetics, permeation, perfusion, as well as (for the upper airways) mucociliary clearance. These lung PBPK models will be used to simulate realistic plasma PK datasets for Test and Reference OIDPs with systematically varied properties, in the presence and absence of charcoal to block oral absorption. Simulated local drug exposure profiles at various regions of the lung will serve as the therapeutically relevant, true, pulmonary comparators. Studies in Task 2 will use the PBPK-simulated drug exposure profiles in plasma as relevant inputs. The main goal of this task is to probe whether, and with which level of granularity, population PK can detect differences in regional pulmonary exposure by modeling plasma concentration-time profiles of Test and Reference OIDPs. In addition to modeling pulmonary absorption via population PK, the less complex NCA with established and novel parameters (e.g. partial AUCs during the absorption phase) will be applied using the same data sets. This will allow one to compare the capabilities, strengths, weaknesses, and robustness of both approaches for detecting differences in regional pulmonary exposure. In Task 3, key findings across all simulated APIs, OIDPs, conditions, and study designs will be summarized to create robust and generalizable conclusions to support PK approaches and potential BE criteria for lung BE testing. In Task 4, the report, simulated datasets, PBPK, population PK and NCA models and results will be made available in an electronic database to the FDA.

NIH Research Projects · FY 2024 · 2023-07

PROJECT SUMMARY/ABSTRACT Evidence suggests quality of care has substantially improved in the in the US has over last 25 years. However, wide variability exists in the quality of care that some patient groups receive. Some suggest that structural barriers in within healthcare systems and in post-discharge community settings translate into racial-ethnic disparities in outcomes for conditions such as aphasia and dysphagia. To date, studies have not examined the role structural barriers play role in disparities in outcomes. In this study we propose to test the hypothesis that structural barriers at various stages of the post-stroke treatment condition for conditions like aphasia and dysphagia contribute to differences in quality of rehabilitation care and subsequently to racial-ethnic differences in aphasia and dysphagia outcomes. The objective of this study is to examine how healthcare institutions and healthcare provider practices impacts the receipt of quality rehabilitative care and whether it translates into racial disparities in post-stroke outcomes. The objective of this project will be achieved by the completion of the following specific aims: Aim 1: Determine how availability, accessibility, and quality of post-stroke acute inpatient care contribute to disparate outcomes of individuals with aphasia and dysphagia. We hypothesize that processes embedded in healthcare settings and communities where stroke survivors live will dictate: a) access to specific types of care, b) the path of care progression, and c) intensity of care. Aim 2: Determine how the timing and transition of care contribute to disparate outcomes of individuals with aphasia and dysphagia. We hypothesize that processes embedded in healthcare settings will lead to variations in the timing and transition from acute to post-acute care of stroke survivors with aphasia and dysphagia as they move across different facilities/systems of care. Aim 3: Determine how the post-discharge community environments contribute to disparate outcomes of individuals with aphasia and dysphagia. We hypothesize that personal, social, and community measures of prosperity and disadvantage will contribute to racial disparities in outcomes among individuals with aphasia and dysphagia. To complete this study we will use Medicare claims data which will enable us to track the care of stroke survivors with aphasia and dysphagia across the entire continuum of care.

NIH Research Projects · FY 2026 · 2023-07

PROJECT SUMMARY The aging process is associated with an increased risk of failure of therapeutic strategies to treat hematopoietic diseases, which often rely on myelosuppression and transplantation of hematopoietic stem cells (HSCs). There is a substantial need for the development of preventative and therapeutic options to delay the aging process, to rejuvenate tissues/organs, and to enhance regeneration and repair. However, the ability to truly rejuvenate aged HSCs or their supportive niches has eluded scientists. To date, published rejuvenation studies have shown marginal improvements in a few aspects of aged HSC function and have made exaggerated claims of `HSC rejuvenation' without employing assays to stringently evaluate aged stem cells. This research proposal reveals Netrin-1 (NTN1) as a niche-derived signal that can be utilized as a therapeutic that can restore the function of an aged HSC, including its self-renewal capabilities, by reactivating DNA Damage Response (DDR) pathways and resolving DNA damage, a hallmark feature of the aging hematopoietic system. We further define NTN1 as a critical regulator of HSC niche function, where deletion of NTN1 in critical bone marrow (BM) niche constituents leads to a decrease in vascular integrity and mesenchymal stem cell function. This proposal will elucidate the cellular and molecular mechanisms by which aging of the BM niche contributes to the decline of HSC function, as well as validate Netrin-1 as a new therapeutic target whose infusion can enhance, preserve, and rejuvenate an aging hematopoietic system. Specifically, we will: 1) determine which HSC-specific and BM niche-specific NTN1 receptors are critical for rejuvenating the aged hematopoietic system, 2) determine if NTN1 treatment can prevent or temporize the aging process to promote hematopoietic health span and longevity, 3) discover the cellular interactions and molecular mechanisms regulated by NTN1 signaling that are responsible for activating DDR pathways within HSCs and BM niche cells, and 4) test whether in vivo infusion of NTN1 can enhance the regeneration of an aged BM microenvironment following myelosuppression. Our research plan will utilize innovative in vivo animal models and imaging techniques to determine if we can alleviate aging-related pathological hematopoietic phenotypes observed in aged individuals by enhancing NTN1 signaling. Using sophisticated animal models, we will determine the critical cellular sources of NTN1 and its receptors in a cell- specific manner that are required to preserve HSC and niche function during the aging process. The success of this research proposal will open up new avenues for the development of a wide array of therapeutic strategies designed to effectively reverse age-related hematopoietic deficiencies.

NIH Research Projects · FY 2025 · 2023-07

PROJECT SUMMARY Fatigue is one of the most common and debilitating symptoms in neurological, psychiatric, and other chronic illnesses; however, it remains poorly understood and undertreated. Post-acute sequelae of SARS-CoV-2 infection (PASC) is a novel syndrome characterized by a range of symptoms present four or more weeks after the acute phase of COVID-19. Among these symptoms, severe fatigue is the most common and debilitating. Critical hurdles to understanding and treating fatigue include its multidimensional nature and the lack of quantitative methods to characterize it. In this MOSAIC K99/R00 application, I propose to use a novel `fatigue paradigm' that leverages neuromuscular, neuroeconomic, and computational methods to objectively investigate the neurobiological mechanisms of three features of fatigue in healthy individuals and individuals with PASC: feeling of weariness (how weary one feels), sense of effort (how one perceives a previously exerted force), and willingness to exert effort (an individual's decision to engage in effortful actions). My central hypothesis is that fatigue is comprised of at least three separable features, which represent distinct psychophysiological aspects, have unique neural correlates, and are differentially affected by PASC. The experiments proposed for the K99 Phase, which will be executed in Dr. Vikram Chib's Neuroeconomic Laboratory in the Kennedy Krieger Institute and Department of Biomedical Engineering at Johns Hopkins, will identify the brain network(s) encoding the features of fatigue in healthy individuals (Aim 1) and investigate how fatigue manifests in individuals with PASC (Aim 2). Through these projects, and the guidance of my mentoring team (Drs. Vikram Chib, Karen Quigley, Laura Malone, and Martin Lindquist), I will acquire complementary expertise in neuroimaging, psychophysiology, and computational and translational neuroscience. In the R00 Phase, I propose to merge my expertise in neuromuscular physiology and motor control with my newly acquired skills to identify the brain network(s) encoding fatigue in PASC (Aim 3). This Phase will be executed in my own laboratory upon securing an independent faculty position. The current epidemiological significance of fatigue and PASC makes this proposal especially timely and important, as it will significantly advance our understanding of fatigue and contribute to the NIH's RECOVER initiative. Further, the proposed research and training plans will allow me to accomplish my long-term career goal of becoming an independent investigator who will distinguish the neurobiological mechanisms of fatigue in different illnesses and develop targeted clinical interventions.

NIH Research Projects · FY 2025 · 2023-07

PROJECT SUMMARY/ABSTRACT A key feature of the COVID-19 infection is the vast inter-individual heterogeneity in the severity of the infection. The complex biological mechanisms that underlie this variability remain mostly obscure. We propose to provide a mechanistic understanding of this susceptibility by leveraging 3 key innovations: First, we have developed a 3-dimensional lung culture system that allows for detailed interrogation of the early events in SARS-CoV-2 infection. Second, we have established an animal model of COVID-19 in mice transgenic for the human ACE2 receptor in our facility. Third, we have built a multi-scale mathematical model of lung infection in COVID-19, that we now seek to expand and personalize to individual hosts. We have two Aims in this project: In Aim 1, we will validate, expand, and personalize our existing multi-scale model, using an unbiased approach to identify and test hypotheses relating to susceptibility to severe COVID-19, and in Aim 2 we will test a specific hypothesis regarding the mechanism of the observed inter-individual heterogeneity in COVID-19 severity, namely that it is, in part, mediated by divergent activation of the mTOR pathway in type I alveolar epithelial cells. If successful, this project will identify the biological basis of the immune pathways that result in heterogeneous outcome of COVID-19, paving the way for personalized, host-specific interventions to improve the outcome of the infection.

NIH Research Projects · FY 2024 · 2023-07

PROJECT SUMMARY Stress leads to the enhancement of memory in both humans and animals. This stress-enhanced memory has relevance to stress-related psychiatric disorders, such as posttraumatic stress disorder (PTSD), which is marked by heightened, perseverant memories of trauma. Interestingly, only approximately 10-20% of people develop the enduring symptoms of PTSD, despite nearly everyone experiencing at least one traumatic event in their lifetime. In addition, rates of PTSD are higher among women and military personnel. A protocol was developed by this group that results in differential susceptibility to stress enhancement of a remote (one month old) fear memory among male mice and a greater propensity for enhancement in females. Despite the clear importance of understanding the mechanisms supporting long-lasting, perseverant memory, the majority of basic memory research focuses on recent (~ 1 day old), not remote memory and does not incorporate a stress component. Additional research performed by the group with this protocol identified the basolateral amygdala (BLA) has a critical hub mediating stress-enhanced fear memory and the associated differential susceptibility. The primary goal of the current application is to delineate how stress engages and alters the function of the BLA to drive differential susceptibility to stress-enhanced fear memory. The work will place particular focus on sex as a biological variable and lateralized function of the BLA. Regarding the latter, the right hemisphere BLA is associated with negative valence, while the left is associated with positive valence. This is conserved from humans to rodents but is understudied in basic research. The central hypothesis of this proposal is that stress leads to lasting impacts on the BLA, resulting in differential susceptibility to remote stress-enhanced fear memory. The working hypothesis to be explored is that an intense acute stressor alters subsequent fear memory strength by influencing the recruitment of specific BLA cell populations to the memory trace. Work leading up to this proposal (F99 Aim 1A) details studies characterizing identity and laterality of neural ensembles supporting stress-induced memory enhancement. To examine how stress impacts experience coding to influence stress- enhanced fear memory (F99 Aim 1B), I will train in execution and data analysis of in vivo calcium imaging of the BLA. In transitioning to a postdoctoral fellowship, I will focus on research based on the high rate of co-morbidity between stress disorders and alcohol and substance sue disorders (K00). The research will incorporate neurophysiological and deep sequencing measures to further study how stress individually impacts function of the BLA and associated circuitry to influence alcohol or drug seeking. The proposed work will provide a much- needed, deep characterization of the impact of stress on the brain in the context of differential stress susceptibility. This information will then be used to guide cellular, molecular and circuit level mechanistic studies, with the goal of identifying therapeutic strategies.

NIH Research Projects · FY 2025 · 2023-07

PROJECT SUMMARY/ABSTRACT (30 lines of text): Alzheimer’s disease, the most common form of dementia, is characterized by cognitive decline and impairment of behavioral and functional abilities. Approximate 5.8 million people in the United States are affected by Alzheimer’s disease (AD) and this number is anticipated to triple by 2050. While mutations in amyloid precursor protein (APP) and presenillin (PSEN1 and PSEN2) are known to cause familial early onset AD and the APOE4 variant is a well-known disease risk factor, the genetic contributions to the majority of late onset AD cases are not clear. Additionally, while the accumulation of Aβ plaques and hyperphosphorylated tau are considered to be hallmark features of AD cases, Aβ plaques and tau tangles do not fully explain the clinical features and heterogeneity found in AD patients. The identification of the C9orf72 GGGGCC hexanucleotide repeat expansion as the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia raises an intriguing question whether unidentified repeat expansion mutations contribute to other form of dementia including AD. Additionally, similarities in disease pathology are observed between AD and patients with repeat expansion disorders. These similarities include the accumulation of abnormal proteins, neuronal loss in affected brain regions, and the involvement of stress in worsening disease. While repetitive elements account for a large portion of the human genome, the detection repeat-expansion mutations, especially GC-rich repeat expansions, is challenging. To overcome the difficulties in identifying repeat expansion mutations, I have developed a novel dCas9-based repeat pull-down method (dCas9READ) that allows the isolation of repeat expansion mutations directly from the genomic DNA of individual patients. The objective of this proposal is to test the hypothesis that novel repeat expansion mutations contribute to late onset AD and their repeat containing RNA and RAN products are toxic and contribute to AD pathology. I am excited to report that in an initial screen, 17.5% of human AD autopsy cases tested were positive for RAN protein aggregates and RNA foci. In this grant, I will follow-up on these exciting preliminary data and test this hypothesis that novel repeat expansion mutations contribute to AD in the following specific aims: Aim 1) Will develop a novel dCas9-based technique for rapidly identifying repeat expansions. Aim 2) Will test the hypothesis that novel repeat expansions mutations are present at higher frequencies in late onset AD vs. control samples. Aim 3) Will test the hypothesis that novel repeat expansion mutations are toxic and contribute to AD pathology.

NIH Research Projects · FY 2025 · 2023-07

PROJECT SUMMARY/ABSTRACT The 2014 Surgeon General’s report provided clear evidence that smoking by cancer survivors causes adverse health outcomes and the 2020 report concluded that smoking cessation after a cancer diagnosis improves survival. Though smoking cessation improves outcomes and is advocated as a standard of care in oncology, tobacco treatment is not consistently delivered as a part of cancer care. To address this challenge, the National Cancer Institute (NCI) launched the Cancer Center Cessation Initiative (C3I) in 2017. The C3I provides financial and technical assistance through a Coordinating Center to 52 NCI-designated cancer centers to implement evidence-based tobacco treatment programs and integrate smoking cessation into routine patient care in oncology settings. All funded centers were required to sustain their programs for a minimum of three years following the NCI-funded period. However, the trajectories and determinants of sustainability for tobacco treatment programs in these cancer centers are unknown. More broadly, achieving sustained delivery of evidence-based programs over time has been identified as one of the most crucial yet understudied challenges. Our long-term goal is to develop a generalizable model for sustaining evidence- based tobacco treatment programs in cancer care. The objective of this study is to investigate the trajectories and determinants of sustainability across evidence-based tobacco treatment programs in C3I and to identify appropriate strategies for promoting sustainability using an implementation mapping approach (i.e., “sustainability mapping”). We define sustainability as the extent to which programs maintain core components, implementation strategies, and program outcomes over time. We have demonstrated the feasibility of these assessments in collaboration with the C3I Coordinating Center and participating cancer centers. The proposed study will extend this collaboration and leverage the NCI’s substantial investment in the C3I to pursue the following specific aims: 1) Characterize the sustainment of tobacco treatment programs within cancer centers; 2) Specify the relationships between multilevel determinants, strategies, and outcomes of sustainability for tobacco treatment programs within cancer centers; and 3) Develop and test a toolkit to guide the selection of sustainment strategies for tobacco treatment programs in cancer care. The proposed research offers an unprecedented opportunity for identifying how investment in building evidence-based programs is converted into sustainable healthcare systems change.

NIH Research Projects · FY 2026 · 2023-07

Project Summary Over the past two decades significant effort has been directed to the identification of ligands that target the regulation of epigenetic marks. These post-translational modifications (PTMs) control all aspects of gene expression and are often deregulated in disease, providing attractive vectors for therapeutic intervention. Currently, despite significant investment, marketed drugs in this area have generally arisen from phenotypic screening as opposed to a priori design. One reason for this lack of success is the high degree of complexity within epigenetic regulation, where a protein target may perform multiple contradictory roles based upon cellular context. Additionally, the high homology between epigenetic proteins and their isoforms makes the design of selective inhibitors incredibly challenging. It is therefore critical that both the protein targets of a given ligand and the downstream epigenetic consequences are well characterized before clinical evaluation. This presents a singular challenge as epigenetic states (and therefore epigenetic consequences) differ dramatically between cell types and populations. In this proposal, we will develop proximity proteomics methods to understand how small molecule ligands remodel the chromatin microenvironment over time. We will achieve this through the targeted deployment of iridium catalysts to chromatin via ultrafast split intein splicing. Upon visible light irradiation, these catalysts activate biotin bearing diazirines within a short radius (through a process called Dexter energy transfer) which subsequently release molecular nitrogen and a highly reactive carbene. These carbenes insert into C-H and X-H bonds of biomolecules within ~10 nm, which can be enriched for downstream ‘omics analysis. This method will be used to monitor the biomolecules that associate to and dissociate from chromatin following ligand incubation. At short time points, this will provide target identification as ligand bound proteins no longer interact with chromatin. Following longer incubation, we will measure the functional effect of inhibition of epigenetic modulators as chromatin PTMs reach a new steady state. We will apply this method to two important areas of chromatin regulation that have been the target of intense drug development with limited success, lysine demethylation and c-myc based transcription. We hope to use this method to shed light on these important vectors for gene regulation, identifying new protein targets and off-targets of established inhibitor classes. Broadly, this project will provide a valuable tool to study ligands acting at chromatin that can be applied to many aspects of nuclear biology and drug development, paving the way for better drug candidates, and ultimately improving human health.

NIH Research Projects · FY 2025 · 2023-07

PROJECT SUMMARY This K99/R00 Pathway to Independence Award is designed to allow the candidate to achieve her long-term goal to establish an independent research career focused on how arousal circuits in the brain control breathing, and how these neural mechanisms are influenced by opioids. This proposal has been tailored to supplement the candidate’s background in neuroscience and respiratory neurophysiology with additional knowledge and technical skills to study respiratory control circuits in vivo and ex vivo, and will make her ideally suited to succeed on her career path. The primary cause of death from an opioid overdose is respiratory depression. The sedative effect of opioids further impairs respiratory drive through largely unexplored mechanisms. Although overdoses are routinely treated with the opioid antagonist, naloxone, naloxone reverses all opioid effects, causing pain and withdrawal. Our current understanding of opioid effects on the respiratory circuitry has not revealed an ideal therapeutic target to minimize respiratory depression without serious side effects. Therefore, it is essential to identify new strategies to alleviate respiratory depression and stimulate breathing. This proposal seeks to uncover important new insights whereby the locus coeruleus (LC), a brain structure widely known for its contributions to arousal, influences the Kӧlliker-Fuse (KF), a key respiratory region, which is highly sensitive to opioids and critical for opioid-induced respiratory depression. Preliminary data spanning cell-type specific neural tracing, ex vivo brain slice recordings, and in vivo optogenetics and fiber photometry, support a role for LC input to the KF in respiration, which has not been previously appreciated. Based on preliminary data, the overall hypothesis is that the LCKF circuit is a critical modulator of respiratory function, particularly during opioid-induced respiratory depression. The candidate’s prior training in brain slice recordings, in vivo electrophysiology in awake animals, and intersectional viral- genetic methods provides a solid foundation for the state-of-the-art ex vivo and in vivo optogenetics and fiber photometry techniques in the proposal. This multi-level approach will allow the candidate to test the hypothesis that KF neurons receive opioid-sensitive, monosynaptic excitatory input from LC neurons (Aim 1), that KF projecting LC neuron activity is coupled with respiration in vivo (Aim 2), and the LCKF circuit plays a key role in respiration and opioid-induced respiratory depression (Aim 3). Together, the aims of this proposal will yield novel information regarding the brain’s control of respiration and will also provide strong conceptual and methodological training, enabling development of an impactful and successful independent research program. Strong mentorship by Drs. Erica Levitt and David Fuller, as well as a Mentoring Committee comprised of established professors, who are experts in the proposed techniques and have extensive mentoring experience, will help the candidate achieve the research and career development goals of this proposal.

NIH Research Projects · FY 2025 · 2023-06

Project Abstract Opioid-alcohol polysubstance use (PSU) is a clinically-relevant problem, as it worsens the trajectories and outcomes of opioid use disorder (e.g., 14-16% of opioid overdoses also involve alcohol). Both alcohol and opioid use alone are associated with significant neurobehavioral consequences, such as impaired cognition, but it is not currently known if there are additive or synergistic impairments in such domains in opioid-alcohol PSU. In order to determine the mechanisms underlying the deleterious consequences of opioid-alcohol PSU (e.g. motivation to seek drug, relapse, cognition), rodent models are necessary. Here, we propose to develop novel rodent models based on back-translated data from human opioid-alcohol polysubstance users. Thus, in this 2- phase R61/R33 proposal, we will first assess human temporal patterns of opioid and alcohol use, in terms of hour-by-hour and day-by-day use, using our novel assessment, the PolySubstance Use – Temporal Pattern Section (PSU-TPS). We will also use the Substance Abuse Module-5 (SAM-5) to determine quantity, frequency, and duration (QFD) of use and the presence of use disorders. These data will be used to define clusters of PSU patterns, based on hours/day and days/month of use, and whether use is sequential, concurrent, or simultaneous. In the same participants, cognition will be assessed at baseline and one year later. The domains of interest include working and episodic memory, impulsivity, risky decision-making, and cognitive flexibility. We will determine associations between opioid/alcohol use and cognition at both baseline and at the one year follow- up. We will also compare the adverse consequences of use between PSU clusters, with a focus on QFD of use, percent meeting DSM-V criteria for use disorder, and cognitive impairments. We will then back-translate the most prevalent PSU patterns with deleterious consequences into rodents for the assessment of intravenous opioid self-administration, motivation to seek opioids using demand curve analyses, and relapse to opioid- seeking. We will also use rodent models to directly test the role of opioid and alcohol use and polysubstance use on such cognitive impairments, using rodent tasks that have been established to assess the same domains as in humans. We will also assess whether the two patterns of PSU alter the pharmacokinetics of alcohol and opioids. This proposed 2-phase study brings together a multidisciplinary team of experts in their fields to conduct novel assessments of the patterns and consequences of real-world opioid-alcohol polysubstance use for the establishment of translational animal models that can advance the field.

NIH Research Projects · FY 2026 · 2023-06

Certain regions in the Southern United States continue to experience elevated rates of new HIV diagnoses and challenges in achieving consistent treatment outcomes. Multiple overlapping personal and environmental factors – such as substance use, emotional strain, and limited access to services – have been linked to these outcomes. These combined influences, referred to here as co-occurring conditions, may interact in ways that complicate care and long-term health management. At the same time, support from personal networks has emerged as a potential factor that may influence clinical outcomes. To date, no study has identified specific socioeconomic and sociodemographic individuals living with HIV who may benefit from a shared behavioral approach designed to enhance support and improve treatment outcomes. The goal of this K01 award is to provide me with the resources, training, mentoring and knowledge needed to investigate the intersection of behavioral factors and HIV outcomes using a mixed methods approach. This study will use an explanatory sequential mixed method design to accomplish the specific aims which include: 1a) apply latent class analyses (LCA) to identify individuals based on co-occurring conditions; 1b) examine associations between class membership and demographic characteristics; 2) assess the relationship between socioeconomic individual membership and perceived support; 3) evaluate individual differences in baseline one-year change in treatment outcomes; and 4) conduct semi-structured interviews to validate and contextualize quantitative findings. This project will leverage existing data from an ongoing NIAAA-funded longitudinal study (U24AA022002) and interviewing a purposive sample of 20 participants. This K01 application will build on my expertise in HIV outreach, public health, qualitative research, and behavioral research related to substance use and HIV with advanced training in: using LCA to model co-occurring conditions among individuals living with HIV, recruiting participants into behavioral research, identifying effective behavioral interventions and strategies to improve support and treatment outcomes among these individuals, and responsible conduct of research. Training will be guided by a multidisciplinary team of mentors: Drs. Robert Cook and Eric Schrimshaw (co-primary mentors) and Drs. Typhanye Dyer, Mattia Prosperi, Michael Marsiske, Sheldon Fields, and Nicole Ennis (co-mentors). This K01 award will allow me to establish myself as an independent investigator focused on improving HIV-related outcomes through tailored behavioral strategies.

NIH Research Projects · FY 2026 · 2023-06

Abstract Neuroinflammation after stroke significantly contributes to neuronal damage and neurological impairment. Delayed cell death in the ischemic penumbra is associated with glial activation and recruitment and infiltration of peripheral immune cells to the brain. This is triggered by the production of pro-inflammatory cytokines and chemokines, contributing to cell death and blood-brain barrier (BBB) permeability after stroke. Dying cells in the penumbra also release pro-inflammatory signals and damage-associated molecular patterns (DAMPs) that activate resident microglia toward a pro-inflammatory phenotype, thus further contributing to brain injury. Our overall goal is to reduce the spread of stroke damage by limiting neuroinflammation. Receptor interacting serine/threonine protein kinase 2 (RIPK2) is a critical mediator of inflammation via its activation of multiple pro-inflammatory and cell death pathways. Inhibition of RIPK2’s kinase activity abolishes its signaling to alleviate inflammatory conditions in the periphery. The role of RIPK2 in ischemic stroke remains unexplored; however, our pilot data shows a substantial reduction in infarct size and improvement in post-stroke functional outcomes, both acutely and long-term, in Ripk2 knockout (Ripk2-/-) mice compared to wild-type (Ripk2+/+) mice. We propose that RIPK2 is an essential initiator and propagator of pro-inflammatory pathways in ischemic stroke. Our main objective is to attenuate its activity and assess the specific role of RIPK2 in vivo as it relates to stroke pathology. We hypothesize that RIPK2 signaling is detrimental in ischemic stroke, and RIPK2 degradation/inhibition or selective ablation in myeloid cells will improve outcomes. Aim 1 will determine the neuroprotective effect of RIPK2 blockade after ischemia using a highly selective RIPK2 inhibitor and a proteolysis-targeting chimera (PROTAC) that specifically degrades RIPK2 in vivo. We will utilize aged mice of both sexes subjected to ischemic stroke and investigate the effects of RIPK2 blockade on infarct size and long-term behavioral outcomes. In Aim 2, we will determine the impact of RIPK2 blockade on stroke-induced neuroinflammation and investigate neuroprotection mechanisms. In Aim 3, we will dissect the cell-specific role of RIPK2 in the neuroinflammatory process after stroke by using Ripk2 floxed mice crossed with lines producing Cre recombinase in specific cell types. We will study the contribution of RIPK2 from myeloid- lineage cells and brain-resident microglia to stroke injury. This project will leverage our expertise and unique tools (Ripk2 floxed mice, PROTAC, and selective inhibitors) to understand the mechanisms of RIPK2-driven inflammation in the context of ischemic stroke. This research may lead to identifying RIPK2 as a new therapeutic target to block neuroinflammation and promote neuronal survival in the aftermath of an ischemic stroke.

NIH Research Projects · FY 2025 · 2023-06

In recognition of achievements in fostering transdisciplinary research, workforce development, community engagement, and ability to enhance its impact on the catchment area (CA), the University of Florida Health Cancer Center (UFHCC) seeks NCI-Designation. UFHCC is a matrix center that supports cancer research and career enhancement across all 6 UF health sciences colleges (Dentistry, Medicine, Nursing, Pharmacy, Public Health & Health Professions, and Veterinary Med) and 5 other UF colleges (Agriculture, Engineering, Health & Human Performance, Journalism & Communications, and Liberal Arts & Sciences). Collaborative research is conducted by 147 members across 3 UFHCC scientific programs: Mechanisms of Oncogenesis, Cancer Therapeutics and Host Response, and Cancer Control and Population Sciences. The UFHCC provides access to state-of-the-art technologies and research expertise for its members through 3 shared resources: Biostatistics and Quantitative Sciences, Flow Cytometry and Confocal Microscopy, and Next Generation Sequencing. The UFHCC CA includes 23 contiguous counties in North Central Florida spanning ~17,500 mi2, about the size of Southern New England. Most of the counties (16) are rural and every county is classified as a Medically Underserved Area. The CA population is 2.2M and includes people who are Black (16%), Hispanic (10%), and has the highest fraction (23%) of residents ≥65 years in Florida. Through community outreach, UFHCC supports efforts to increase health literacy, prevention, screening, and research engagement. The UFHCC Clinical Research Office coordinates all cancer-relevant clinical research at UF, which includes a state-wide clinical trial network. IITs are facilitated through disease site groups with an IIT Think Tank that fosters clinician collaboration with basic and population scientists. UFHCC innovations translated to the clinic include targeted therapies, novel immunotherapies, therapeutic modulation of the microbiome, and new strategies to communicate with patients. UFHCC Developmental Funds seed early-stage research, support recruitment of new faculty, and build transdisciplinary teams. UFHCC offers research career enhancement programs across the learner spectrum. Since 2016, the UFHCC recruited 58 new members (45 external, 39 early-stage). Peer- reviewed funding increased from $21M in 2016 to $32.6M/yr in 2021 (up 55%); NCI $9.6M to $13.2M (up 37%). Accruals to all interventional trials rose from 515 in 2016 to 1,748 in 2021 (up 3.4-fold). Institutional support of a $32M/year budget over the next 5 years and 44,000ft2 of new research space will allow UFHCC to expand. The new UFHCC strategic plan, Momentum 2027, has 4 pillars: 1) conduct transdisciplinary research (RNA biology, microbiome); 2) translate UFHCC discoveries to trials (immunotherapy, small molecules, cancer communication); 3) address cancer burden (cancer and aging, cancer health disparities); and, 4) train a prepared cancer research workforce, including leadership development. UFHCC is poised to make a major impact on the cancer burden of the catchment area, Florida, and beyond.

NIH Research Projects · FY 2025 · 2023-06

Project Summary (30 lines) Project Summary/Abstract: This K01 career development award will provide Dr. Pratscher mentored training experiences that will accelerate his transition to independence as a productive researcher investigating complementary and integrative approaches for chronic pain, whole person health, and emotional well-being. Chronic pain is a major source of human suffering, and chronic low back pain (cLBP) is one of the most common, costly, and burdensome pain conditions. Pain is a sensory and affective experience, and psychosocial factors, such as emotional distress (e.g., depression), stressful life events (e.g., trauma), and unexpressed emotions (e.g., anger), contribute substantially to the persistence of pain. There is an urgent need for integrative treatments that address this complexity of chronic pain and provide significant and lasting pain relief. Breathwork interventions (i.e., therapeutic breathing practices) are promising treatments because they incorporate one of our most integrated physiological processes, respiration, to simultaneously address both physical and emotional causes and consequences of chronic pain. Therefore, the aims of the proposed research are to 1) develop and refine a multicomponent breathwork intervention (derived from Guided Respiration Mindfulness Therapy) and to 2) iteratively evaluate its feasibility and acceptability in people with cLBP. Specifically, we will modify a treatment manual to guide intervention sessions and adapt treatment fidelity evaluations to assess therapist competence and adherence to the manual. Then, we will conduct three single-arm iterations of the 8-week, individually delivered intervention, followed by a pilot randomized controlled trial comparing the most refined version of the intervention to usual care. Upon completion of each iteration, we will gather quantitative and qualitative data and meet with a panel of experts to discuss possible modifications to the intervention or protocol before proceeding with the next iteration. This work will result in a refined and reproducible multicomponent breathwork intervention that can be tested for efficacy in future research, which the candidate plans to pursue with an R-level application written during this award period. The University of Florida has a thriving clinical pain research environment that will support the candidate in completing the proposed research and career development plan. Guidance from an excellent mentoring team in addition to several training activities (e.g., seminars, conferences, independent study) will allow Dr. Pratscher to accomplish the following objectives: (1) build a foundation of knowledge in chronic pain research with emphases on biopsychosocial treatment factors; (2) obtain expertise in the processes of intervention development, refinement, and testing; and (3) enhance proficiency in the design and conduct of clinical trials to develop into a successful independent principal investigator. By completing the proposed project and training activities, Dr. Pratscher will become an independent scientist and leader in the field of breathwork interventions for chronic pain and whole person health.

NIH Research Projects · FY 2025 · 2023-06

Project Summary/Abstract Currently, in the United States, there are 5.8 million older adults with Alzheimer’s Disease and Alzheimer’s Disease-Related Dementias (AD/ADRD). Twenty-one percent of older adults with AD/ADRD have unplanned, and often preventable, hospital readmissions within 30-days, which are estimated to cost over $5.4 billion per year. The development of clinical data research networks (CDRN) and their large complex datasets including patient and clinical level data have led to the development of various models to predict readmissions. However, the existing models have not demonstrated adequate predictive capability. The opportunity to integrate nursing care plan (i.e., patient problems, goals, and interventions) to these large datasets can fill gaps and improve the accuracy of prediction models. The development of a research data infrastructure that supports the integration of nursing care plan data to CDRN datasets is therefore critical for understanding and improving interdisciplinary care aimed at reducing readmissions of older adults with AD/ADRD. In this project, we propose to expand the research infrastructure of the OneFlorida Clinical Research Consortium and Data Trust through the creation, for the first time, of a reusable and feasible data pipeline that will ultimately integrate key care plan data elements documented by nurses into the OneFlorida Data Trust. The long-term goal of our research program is to gain a deeper understanding of readmissions for the aging population with AD/ADRD through the availability of an expanded dataset with interdisciplinary data. We plan to carry out the following aims: Specific Aim 1 (R21 Phase): Develop and test a prototype pipeline for extracting, translating, and integrating problems and goals in nursing care plan data from the University of Florida (UF Health) into the statewide OneFlorida Data Trust. We will map the local vocabulary used to represent the two nursing data elements to nationally recognized terminology sets using natural language processing and have registered nurses validate the mapping results. We will then use automated scripts to replace the local vocabulary with the standardized terms and integrate the data into the Trust. Specific Aim 2 (R33 Phase): Convert and integrate into the Trust nursing interventions from UF Health. Specific Aim 3 (R33 Phase): Extract, convert, and integrate to the Trust nursing data from a second organization, using the pipeline from the R21 phase. Specific Aim 4 (R33 Phase): Construct and test readmissions prediction models for older adults (aged 65 and above) with AD/ADRD using pertinent variables from the Trust and environmental dataset linked to it. We will develop machine-learning models for predicting readmissions from the nursing care elements, other patient- level data in the Trust, and important environmental variables that influence post-discharge follow-up care. Our team will be among the first to develop sustainable data pipelines for transforming local nursing care plan data into standardized data for integration into a large dataset. Through this study, we will learn the improvements nurses, physicians, and other providers can make to prevent readmissions.

NIH Research Projects · FY 2024 · 2023-06

Project Summary Glioblastoma (GBM) is the most common and lethal form of brain cancer in adult, typically recurring after all therapies including surgery, chemotherapy, and radiation. A major part of the problem is that GBMs employ various mechanisms to suppress the host immune system, preventing the immune cells (e.g., cytotoxic effector T cells) from destroying and removing cancer cells. It is believed that tumor cells release or signal suppressive factors. Thus, a better understanding of the cellular and molecular crosstalk mechanisms between tumor and immune cell types are needed to advance immunotherapeutic approaches against brain tumors. Notably, we and others have reported that standard of care chemotherapy stimulates formation of primary cilia, an organelle that is likened to both a cellular ‘antenna’ and transmitter. The presence of cilia predicts more aggressive and treatment resistant GBM. We now show for the first time, in patient biopsies, that glioma- associated immune cells extend processes that contact the tumor cilia and cilia tip, thus positioned to send signals to or receive signals from GBM cells. Similar observations were made in intracranial GBM-bearing mice where we detected juxtaposition of cilia with recruited immune cells. Notably, cilia disproportionately and predominately associated with monocytic-MDSCs (M-MDSCs), a cell type with known T cell suppressive activity. In contrast, T cells rarely juxtaposed tumor cilia and maintained greater distances away from ciliated tumor cells compared to M-MDSCs. Our compelling data suggest potential mechanisms of crosstalk between ciliated tumor cells and specific immune-suppressive cell types that promote tumor progression and therapy resistance. Our working hypothesis is that GBM cilia are venues for mediating interactions with M-MDSCs, and this interaction supports their T cell suppressive activity. The aims of our studies will determine 1) how GBM cilia affect M-MDSC and T cell tumor infiltration and function, and 2) which immune cell types contact or avoid ciliated tumor cells in human GBM. We will tackle these aims by immunophenotyping syngeneic murine gliomas with or without cilia, and compare these findings to spatial profiling of the immune microenvironment around ciliated tumor cells in GBM patient specimens. Successful outcomes will shed light on a novel cell-cell interaction in the brain tumor microenvironment that may explain, in part, how tumor cells evade targeting by the immune system.

NIH Research Projects · FY 2026 · 2023-06

PROJECT SUMMARY/ABSTRACT Alcohol misuse is often associated with pathological aggression, a recurrent pattern of disruptive and violent behavior. Despite the significant socioeconomic burden imposed by the repercussions of this comorbidity, avail- able treatments are limited and inadequate. A critical problem in treating the association of alcohol misuse and pathological aggression lies in the complex links between these two entities: on the one hand, alcohol worsens violence propensity in predisposed individuals; on the other hand, anger and aggression increase the risk of alcohol use. Disentangling the links between these conditions is critical to developing better therapies. To study these neurobiological mechanisms, we focused on the best-characterized gene × environment (G×E) interaction underlying pathological aggression and alcohol use, occurring between low-activity alleles of the MAOA gene (encoding the enzyme monoamine oxidase A) and child maltreatment. We recently developed the first animal model of this G×E interaction by subjecting a line of mice with an MAOA hypomorphic mutation to early-life stress during the first week of life. The studies proposed in this application will test the hypothesis that the interaction of low-activity MAOA variants and child maltreatment leads to alterations of the prefrontal cortex and nucleus accumbens, which predispose to a vicious cycle of increased alcohol use and aggression. The three Aims of this proposal will focus on 1) the common neurodevelopmental mechanisms of these two problems; 2) the adverse effects of alcohol drinking on aggression; and 3) the impact of anger and social reactivity on the propensity to drink alcohol. Taken together, this research will help elucidate the mechanisms of the comorbidity of alcohol misuse and pathological aggres- sion and identify new potential targets for the prevention and treatment of alcohol-associated violence.

NIH Research Projects · FY 2026 · 2023-06

Project Summary BET proteins are directly involved in pathologies such as viral infection and different types of cancer. Although the different BET proteins satisfy different roles in the cell and are preferentially expressed in different tissues, current BET inhibition strategies are non-specific – resulting in toxicity. The ET domain of BET proteins has recently emerged as a protein interaction hub with promising selectivity of binders towards specific BET proteins – making the ET domain an interesting target towards the design of novel drug therapeutics. Yet, little is known about the ET interactome or its binding mechanism. This proposal aims to increase our understanding of the ET interactome (Aim 1) by using computational tools to: a) identify possible binders; b) select the strongest binders using machine learning and physics-based approaches; and c) characterize the most promising leads through NMR experiments. The challenge lies in addressing the polymorphic nature of ET: it can undergo conformational changes to bind different peptide sequences – which in turn bind along different binding modes. Such binding plasticity concomitantly leads to a wide range of binding affinities. Furthermore, a particular peptide sequence binds the ET domain of different BET proteins with different binding affinities, setting the foundation for the design of inhibitors specific to each BET protein. However, it is not clear where the origin of specificity lies, as the ET domains have high sequence and structural similarity across BET members. Thus, Aim 2 will unveil the binding mechanism for peptides to ET and elucidate the origin of specificity through the use of adaptive sampling molecular dynamics strategies and Markov State Models. The relationship between binding affinity and binding mode is currently unknown. It could be that virus are exploiting a binding mode that leads to higher binding affinity than those used by regulatory host proteins. Aim 3 of the proposal addresses this issue by designing novel peptide binders to identify the limits of binding affinity amongst the different binding modes. These computational designs will lead to the identification of hot-spot regions in the binding domain to exploit towards the long-term goal of therapeutic design strategies.

NIH Research Projects · FY 2024 · 2023-06

PROJECT SUMMARY Aging is a major risk factor for breast cancer and 80% of breast cancer cases are diagnosed after age 50. Currently in the US, there are more than 3.8 million breast cancer survivors, and this number is expected to increase dramatically due to the aging of the population. Chemotherapy is a highly effective treatment for breast cancer but is associated with acute and long-term cardiovascular toxicity that may accelerate cardiovascular aging, thus setting the stage for premature development of cardiovascular disease (CVD). Aerobic exercise is recommended for CVD prevention, however, evidence on the optimal exercise prescription in breast cancer survivors is limited. Breast cancer survivors often suffer from long-lasting cancer therapy-related side effects (e.g., physical dysfunction, severe fatigue, muscle weakness, peripheral neuropathy, and balance impairments) that may be compounded by age-related frailty and mobility issues (50% of breast cancer survivors are older than age 60). These unique challenges may limit exercise feasibility, adherence, and in turn efficacy. High- intensity interval training (HIIT) is attracting increasing attention as a time-efficient and potentially superior aerobic exercise strategy for CVD prevention compared to moderate-intensity continuous training (MICT) in clinical populations. We have recently adapted HIIT and MICT on an all-extremity non-weight-bearing exercise (ANE) ergometer that eliminates balance concerns and distributes work between the upper and lower extremities, compensating for weakness and fatigue. Our HIIT-ANE and MICT-ANE regimens are novel and innovative exercise interventions for breast cancer survivors. Our central hypothesis is that HIIT-ANE will result in greater and more durable improvements in endothelial and cardiac function compared with MICT-ANE and usual care (UC) in breast cancer survivors who have recently completed chemotherapy. The aims of this application are to conduct a randomized controlled trial to investigate: 1) the short-term and prolonged effects of HIIT-ANE, MICT-ANE and UC on endothelial and cardiac function; and 2) the durability of the endothelial and cardiac effects of HIIT-ANE vs. MICT-ANE. Women, 50 years of age and older, who have completed chemotherapy within the past 6 months for primary, invasive, non-metastatic, stage I-III breast cancer will be randomized to 1 of 3 groups: HIIT-ANE, MICT-ANE or UC. Exercise training will be performed 3 days/week over 12 weeks under supervision. The primary focus will be on endothelial and cardiac function assessed by flow- mediated dilation and global longitudinal strain, respectively. Assessments will be performed at baseline, after the 12-week exercise intervention and after a 12-week observation period. To gain mechanistic insight, we will investigate circulating blood biomarkers and key biomarkers in endothelial cells harvested using a state-of-the- art endovascular technique. This exploratory/developmental R21 will provide early evidence on whether our promising HIIT-ANE is more effective in mitigating CVD risk than MICT-ANE and UC following breast cancer chemotherapy. Our findings will lay the foundation for designing a rigorous full-scale clinical trial.

NIH Research Projects · FY 2026 · 2023-05

The estrogen receptor- (ER) represents one of the most successful molecular entities as both a biomarker and target for cancer therapy, but some 30-50% of patients show de novo or acquired resistance. ER is a ligand regulated transcription factor that acts as a scaffold for histone modifying enzymes to modulate gene expression and growth of ER+ breast cancers (BCs). Importantly, the different treatment modalities of SERMs, SERDs and aromatase inhibitors induce different conformational effects on ER that often allow resistance to one type of treatment to be effectively treated by another. There is currently a significant unmet clinical need for new therapies that are effective in de novo and acquired resistance models, such as overexpression of receptor tyrosine kinases or activation of their downstream signaling pathways. We recently showed that an EGFR overexpression model rendered breast cancer cells broadly resistant to SERMs, as seen in patients. We also developed a new chemical targeting strategy for ER, which we call dual mechanism ER inhibitors (DMERI). Importantly, we identified both SERM and SERD DMERI as efficacious in the EGFR overexpression model, and many of them showed efficacy greater than fulvestrant, and in fulvestrant resistance models. The SERM DMERI may be an effective treatment for patients with EGFR overexpression at initial presentation, comprising a significant subset of ER+ BCs associated with clinical resistance. The marked difference in efficacy between SERMs and SERM DMERI in this resistant model provide us with robust chemical biology tools to dissect mechanisms of action. Our first goal is to understand the mechanisms of ER/EGFR signaling crosstalk and its regulation by different classes of ER ligands. A second goal is to understand the molecular mechanisms of ligand efficacy more generally through identifying ligand-specific coregulator- gene networks that regulate ER-dependent growth inhibition. The delineation of the ligand-receptor-coregulator gene code will enable understanding ligand mechanism of action and basic principles of transcription regulation in control of cell growth.

NIH Research Projects · FY 2024 · 2023-05

PROJECT SUMMARY/ABSTRACT Parkinson’s disease (PD) is one of the fastest-growing neurodegenerative disorders in the United States, with cognitive decline being among its most debilitating non-motor symptoms. With disease progression, most individuals eventually develop dementia. However, the trajectory of cognitive decline varies between individuals—leading to a search for risk factors of impending decline. In 2019, Ryan and colleagues proposed a precision aging model and suggested that typical age-related cognitive decline was influenced by three broad categories of “brain drivers”: neuropathology (e.g., alpha-synuclein, tau), neuroinflammation (e.g., cytokines), and cerebrovascular dysfunction (e.g., white matter hyperintensities). Past research has consistently measured these brain driver factors in isolation, despite these factors all belonging to an interconnected, neurobiological system. Thus, the goal of the proposed study is to determine whether cognitive variation in PD is better explained by a combination of these neurobiological risk factors, relative to isolated factors. The central hypothesis is that each category of brain drivers (i.e., neuropathology, neuroinflammation, cerebrovascular dysfunction) will uniquely relate to cognitive performance (specifically executive function and memory), such that adding in each category will better explain changes in each cognitive domain. The proposed study will examine data from an existing, well-characterized cohort of individuals with idiopathic PD without dementia (N=112) to determine the association between brain driver factors and cognitive performance cross-sectionally and longitudinally (at a 2- year follow-up). To do so, brain driver relationships with cognition will be assessed in isolation (using correlations) and in combination (using hierarchical linear regressions, adding in factors from each brain driver category sequentially). Overall, this method shifts the focus towards a precision medicine approach—whereby examining multiple brain drivers may allow for greater understanding of individualized risk of cognitive decline in individuals with PD. Improving the assessment of cognitive risk could inform both clinical prognosis for patients with PD and allow for a more targeted selection of participants into experimental trials aiming to slow impending cognitive decline. The proposed training plan will provide the applicant with additional training experiences beyond that of her Ph.D. program. Specific training goals include (1) gaining expertise in the methodologies measuring neuroinflammatory and neuropathology biomarkers and their interpretation, (2) gaining proficiency with structural magnetic resonance imaging (acquisition, processing, and interpretation) to measure white matter hyperintensities (a metric of cerebrovascular dysfunction), (3) advancing statistical competencies and experimental rigor, and (4) professional and career skills development. The proposed project and training goals will be completed with the resources and support of a strong research environment, including a productive mentoring team with specific expertise in the proposed area of study. Taken together, the proposed research and other activities will help prepare the applicant as she transitions into a career as an independent investigator.

NIH Research Projects · FY 2025 · 2023-05

Project Summary/Abstract: Enteric synucleinopathy is characterized by the deposition of misfolded α- synuclein aggregates in enteric neurons and induces long-term gastrointestinal dysfunction. Enteric synucleinopathy is also thought to be a precursor to CNS synucleinopathies, such as Parkinson’s’ Disease (PD), PD-Dementia, and Lewy Body Dementia, a collective group of debilitating neurodegenerative disorders that cause motor, cognitive, and autonomic dysfunction. Notably, even after development of CNS synucleinopathy gastrointestinal symptoms remain as major causes of morbidity in these patients. However, a poor understanding of the cellular processes underlying development and progression has precluded any therapies aimed at preventing synucleinopathy progression into the brain or mitigating GI dysfunction. In the central nervous system resident macrophages, the microglia, can have pronounced impact on synucleinopathy. Enteric neuron- associated macrophages resemble microglia at rest in that they support nearby neurons. But unlike microglia, their phenotype and role in enteric synucleinopathy is undefined. Therefore, the Aims of this proposal seek to define how enteric neuron associated macrophages promote or palliate the neuropathological and neurophysiological aspects of enteric synucleinopathy. Aim 1: Explicate the macrophage subpopulations that influence spread of phosphorylated α-synuclein pathology in a mouse model of enteric synucleinopathy. Herein, I will characterize macrophage involvement in the development and spread of enteric, phosphorylated α-synuclein neuropathology and define the immune transcriptional landscape associated with this state. My working hypothesis for this aim is that a sub-population of macrophages initially take up α-synuclein to mitigate pathology and adopt an antigen-presentation phenotype to activate T-cells Aim 2: Determine how myenteric macrophages modulate enteric neuronal network functional and structural connectivity in a mouse model of enteric synucleinopathy. Alterations in myenteric macrophage phenotype and α-synuclein pathology have been shown to induce enteric neuronal network dysfunction and gut dysmotility independently, but how they work in concert in the setting of enteric synucleinopathy remains unknown. More specifically, whether myenteric macrophages mediate α-synuclein’s effects on network connectivity and network output has not been investigated. Thus, my working hypothesis for this aim is that α- synuclein pathology will prompt myenteric macrophages to engage in excessive, complement-dependent synaptic pruning leading to disrupted enteric neuronal network activity. Together, these experiments will reveal how neuro-immune interactions influence the early stages of synucleinopathies.

NIH Research Projects · FY 2026 · 2023-05

Project Summary/Abstract Norovirus is the leading cause of severe childhood diarrhea around the world and a major cause of acute gastroenteritis in all age groups. There are no currently approved vaccines or targeted therapeutics for norovirus infection and very little is known about the pathogenic mechanisms underlying gastroenteritis symptoms. To gain further understanding of this important virus, murine norovirus has been used as a model system for many years and has led to significant advances in understanding norovirus biology. However, the absence of symptoms in immunocompetent adult mice infected with murine norovirus limits the applicability of this model to delineation of viral mechanisms of disease. We recently discovered that genetically wild-type neonatal mice develop acute, self-resolving diarrhea when infected with murine norovirus, a disease course that mirrors human norovirus infection. This novel small animal model of norovirus disease represents a major advance in the norovirus field since it will enable a complete characterization of viral disease mechanisms and ultimately serve as a platform to test the efficacy of antiviral compounds in vivo. Using this model, we have observed that murine norovirus infects subepithelial immune cells in the intestine but not intestinal epithelial cells. The mechanisms by which murine norovirus transcytoses the epithelial barrier to reach its immune cell targets during symptomatic infection is unknown and is the focus on Specific Aim 1 of my proposal. Specifically, I will test the hypothesis that murine norovirus uses two well-established routes for macromolecular transport across the intestinal epithelium, microfold cells and CX3CR1+ antigen presenting cells that express transepithelial dendrites. Although we did not observe viral replication in intestinal epithelial cells, there was abundant virus in these cells at the peak of diarrhea. This finding was surprising given that these cells do not express the virus receptor, nor do they support viral replication. In Specific Aim 2 of my proposal, I will test the hypothesis that progeny virus complexed with bile acids are endocytosed by intestinal epithelial cells via engagement of the apical sodium-dependent bile acid transporter. Overall, my research focuses on understanding norovirus interactions with the intestinal epithelium because these are undoubtedly key to the induction of diarrhea.

NIH Research Projects · FY 2025 · 2023-05

PROJECT SUMMARY In the last 30 years, clinical outcomes for individuals with rotator cuff tears have not substantially improved, which is problematic for the 4.5 million Americans that seek medical care for rotator cuff tears each year. Our long-term goal is to maximize functional recovery following rotator cuff tears by identifying patients most likely to benefit from targeted pain interventions. This knowledge is necessary to optimize treatments of impaired pain processing. Our central hypothesis is that the nervous system plays a larger role in symptom severity and recovery than conventionally believed. The rationale for this hypothesis is based on the disconnect between the rotator cuff structural damage and pain severity and the poor relationship between the extent of structural damage (i.e., tear size, retraction, etc.) and functional recovery. Dr. Pozzi, a physical therapist with expertise in biomechanics and movement science, will take his research in a new direction by approaching rotator cuff tears from pain and neuroscience perspectives. Dr. Pozzi assembled a team with extensive clinical, pain, neuroimaging, and pain-neuroscience expertise to test his central hypothesis through three specific aims: 1) test the association between brain function during a shoulder motor-task, chronicity of injury, and clinical pain symptoms in individuals with rotator cuff tears; 2) test the relationship between pain phenotypes, chronicity of injury, and clinical pain symptoms in individuals with rotator cuff tears; and 3) test the utility of baseline dispositional traits, quantitative sensory testing, and brain function to predict recovery following rotator cuff repair. This application is innovative because we will recruit the three injury etiologies of rotator cuff tears (traumatic- symptomatic, chronic-symptomatic, and asymptomatic), which provide a key advantage in studying chronic pain. We are uniquely positioned to shed light on how the nervous system reacts to sudden and chronic loss of tendon structural integrity with and without pain symptoms. We have the potential to test specific central features of acute rotator cuff-induced pain that may become chronic. We designed a novel experiment in which we will acquire functional brain images during precisely controlled submaximal isometric shoulder contractions. We will elucidate factors influencing movement-evoked pain of body areas associated with the primary clinical symptoms, thus providing evidence of potential intervention targets. Our study will provide a significant contribution by identifying additional factors that may influence the variability in patient outcomes. Further, our findings will move us toward the long-term goals of this line of investigation: informing precision pain medicine with consideration for specific pain phenotypes in individuals with rotator cuff tears. The knowledge gained in this study will not be incremental; it will springboard a paradigm shift in treating patients with rotator cuff tears.