University Of Florida

NIH Research Projects · FY 2026 · 2023-05

Declines in cognitive function and walking function are highly intertwined in older adults. For instance, lower executive function exacerbates conversion to Alzheimer’s disease and is also associated with slow walking speed, instability, and falling. In turn, low levels of walking activity are a risk factor for age-related cognitive decline including Alzheimer’s disease. Combinatorial interventions that target both cognition and walking function may break this vicious cycle. Prefrontal networks are a crucial intervention target due to their role in executive function, which underlies performance of both complex cognitive tasks and complex walking tasks. Our research targets prefrontal neuroplasticity using a potent behavioral intervention of complex (cognitively engaging) aerobic walking exercise combined with frontal lobe transcranial direct current stimulation (tDCS). tDCS is a mild form of electrical brain stimulation which may be an effective adjuvant for enhancing the effects of behavioral interventions on cognitive and motor function. The overarching hypothesis of our research is that tDCS delivered over prefrontal regions during complex walking exercise can improve both executive function and walking function. We have previously conducted a successful Phase 1 study that demonstrated feasibility, safety, and positive behavioral outcomes from this intervention in older adults. Now we are proposing a Phase 2 study that is designed to establish initial efficacy, investigate mechanisms of intervention response, and to develop a multi-site research infrastructure. We will enroll 104 older adult participants who have age-related cognitive decline. All participants will undergo the same 18-session high intensity aerobic walking program, which will emphasize the use of complex walking tasks that engage prefrontal cortex, such as obstacle negotiation and walking on compliant surfaces. Participants will be randomly assigned to a tDCS treatment group or sham control group. The treatment group will receive 20 minutes of 2mA tDCS over prefrontal regions F3/F4. The sham control group will receive just 30 seconds of 2mA tDCS at F3/F4 at the beginning of the session, which is known to be an effective sham procedure. A wearable stimulator will be used, so participants can receive stimulation while simultaneously performing the complex walking exercise. Specific Aim 1 will establish efficacy of prefrontal tDCS as an adjuvant to complex walking exercise for enhancing executive function and walking function. Specific Aim 2 will investigate mechanisms of response, including task-based prefrontal activity (with functional near infrared spectroscopy), MRI modeling of person-specific tDCS dosage, and their association with behavioral outcomes. The deliverable for this line of research will be a clinically- feasible multi-modal intervention for preserving function and independence in older adults.

NIH Research Projects · FY 2026 · 2023-05

Project Summary/Abstract: This K23 Clinical Trial project will provide Dr. Gullett, an Assistant Professor at the University of Florida, the direct mentored-training needed to address important questions related to intervention response in an amnestic mild cognitive impairment (aMCI) diagnosed population at risk for Alzheimer’s disease. As a neuropsychologist, Dr. Gullett has gained clinical experience in the assessment of neurodegenerative diseases including Alzheimer’s disease and its precursor, MCI, as well as research experience using structural neuroimaging to investigate various clinical disorders. The support provided by the K23 mechanism through the NIA will provide Dr. Gullett with the protected mentored-training needed to build on his current skills and become an expert in clinical neuroscience, machine learning, and behavioral interventions for mild cognitive impairment and Alzheimer’s disease. Career development and training plan: Dr. Gullett’s training plan consists of foundational formal coursework in 1) clinical trials, 2) MCI and Alzheimer’s disease effects, and 3) biostatistics and machine learning investigative techniques. These foundations will be directly applied through mentorship by experts in the fields of behavioral cognitive interventions, neuroimaging, and machine learning, as well as a proposed in-person workshop in functional neuroimaging analysis. This mentored-training plan will provide Dr. Gullett with the expertise to not only carry out the proposed project, but to become a unique and invaluable resource for future collaborative efforts applying neuroscience-based machine learning tools to investigate personalized interventions for Alzheimer’s disease. Research plan: The proposed project will provide the clinical trials training needed for Dr. Gullett to establish the effectiveness of a planned take-home, 12-week cognitive training program in patients with amnestic mild cognitive impairment (N=75; Aim 1). The expert mentorship team proposed has decades of experience in behavioral clinical trials interventions, which will provide the applicant with design and methodology guidance, as well as the recruitment infrastructure and resources needed to successfully carry out the proposed project. Further, this project will provide training in multi-modal neuroimaging-based machine learning to determine the baseline neural, cognitive, and functional factors that distinguish aMCI patients who respond to treatment from those who do not (Aim 2). This innovative approach will ultimately allow the applicant to investigate which of a myriad of features aMCI patients possess at a baseline assessment are the most salient predictors of their ability to improve from a well-validated cognitive training intervention. A project such as this will enable Dr. Gullett to develop a unique skillset to facilitate an R01-level academic career tasked with providing individual aMCI patients personalized interventions based on their own unique neurobiological and cognitive features.

NIH Research Projects · FY 2026 · 2023-05

Project Summary/Abstract Heterocycles are ubiquitous components of pharmaceutical drugs essential for human health. A particularly attractive approach to nitrogen containing heterocycles is the modification of cheap and readily available amines via C–H bond functionalization. However, methods that efficiently accomplish this task typically require the use of expensive transition metal catalysts and/or oxidants. This proposal is focused on the design and development of efficient and practical methods for amine functionalization, including the development of asymmetric variants. The main goal is the alpha- functionalization of amines through conceptually new and underdeveloped methods of substrate activation. Unique methods for the synthesis of heterocycles will also be explored in the context of asymmetric Lewis and BrØnsted acid catalysis. In addition to targeting the rapid preparation of compounds related to structures with known biological activities, efforts will center on the development of particularly powerful reactions that rapidly produce new polycyclic heterocycles. A priority is the generation of new structural frameworks that are absent from current drug discovery screening libraries.

NIH Research Projects · FY 2026 · 2023-05

Amyotrophic lateral sclerosis (ALS) is a fatal, adult-onset neurodegenerative disease characterized by progressive motor neuron (MN) loss, muscle denervation, and eventually, paralysis. Currently, no effective treatments are available to stop or reverse ALS disease progression and the precise molecular mechanisms underlie ALS pathogenesis remain elusive. Prior studies revealed decreased mitochondrial respiratory chain activity, altered mitochondrial ultrastructure, and mitochondrial dysfunction in both MN and skeletal muscle (SM) in ALS patients and mouse models. The first sign of ALS pathology occurs at the neuromuscular junction (NMJ), where presynaptic MN axons connect with postsynaptic SM end plates. To date, whether signals resulting in the initial NMJ damage are from MN or SM remain unclear. In this project, we aim to determine the tissue-specific causative role of mitochondrial Ca2+ uptake in SM and MN in disease onset and progression, and the therapeutic efficacy of reducing mitochondrial Ca2+ uptake on NMJ and SM function in ALS mice. We hypothesize that mitochondrial Ca2+ mishandling in both SM and MN actively contribute to ALS disease pathogenesis and that attenuating mitochondrial Ca2+ uptake mitigates mitochondrial damage and preserves NMJ/muscle function. To test this hypothesis, we will use transgenic mice with inducible, SM or MN-specific expression of a dominant negative form of the mitochondrial Ca2+ uniporter to specifically and selectively reduce mitochondrial Ca2+ uptake in SM and MN in hSOD1G93A mice and C9-500 (C9orf72) mice, two mouse models associated with the most prevalent genetic causes for ALS. The central hypothesis will be tested in two Specific Aims. Aim 1 will determine the role of mitochondrial Ca2+ uptake in SM or MN in survival, motor function, NMJ function and in vivo muscle performance in hSOD1G93A and C9-500 mice. Aim 2 will assess the impact of tissue-specific inhibition of mitochondrial Ca2+ uptake in SM or MN on NMJ and muscle structure, MN survival, muscle intrinsic contractile properties, mitochondrial structure and mitochondrial bioenergetics in SM of hSOD1G93A and C9-500 mice. This project will: 1) provide a systematic, longitudinal characterization of SM and NMJ function from a cellular level to whole animal level at different stages of disease progression in hSOD1G93A and C9-500 mice; 2) determine the degrees to which defects in mitochondrial Ca2+ uptake in SM or MN contribute to altered NMJ structure/function, disease onset and progression in hSOD1G93A and C9-500 mice; 3) provide the first detailed dissection on the relative role of mitochondrial Ca2+ uptake in SM and MN in ALS phenotype using the same genetic models and determine the origin of the signals that result in NMJ destruction (from SM or MN or both); 4) provide mechanistic evidence for whether mitochondrial Ca2+ mishandling is a trigger or a target for disease progression in ALS mice, regardless of the causing mutations (mitochondrial related or non-mitochondrial related); and most importantly, 5) test the validity of a potential new therapeutic target (mitochondrial Ca2+ uptake, or the mitochondrial Ca2+ uniporter) for the treatment of ALS.

NIH Research Projects · FY 2026 · 2023-04

ABSTRACT This work responds to the current federal and the NIH Office of AIDS Research priority areas, diagnose–treatprevent–respond, to Ending the Human Immunodeficiency Virus (HIV) Epidemic, focusing on Florida, which has the highest incidence of HIV infections in the US. About 40% of people with HIV in Florida do not reach undetectable viral load, and certain population clusters—such as residents of rural areas, all facing barriers to timely care—experience higher risk of unfavorable outcomes. Besides well-known risk factors contributing to drops in care retention and ART success, part of such remains unexplained and cannot be actioned upon. Advances in artificial intelligence (AI) and increasing availability of large real-world data (RWD), e.g., electronic health records (EHRs) and claims data, are ideal for developing models for precision health. However, the full capabilities of AI are still hampered by the fact that EHRs are not well integrated with other relevant data sources, containing information on behavioral and contextual factors, key drivers of HIV care continuum progression. Notably, circumstances such as alcohol or substance use and domestic violence are infrequently represented in structured EHRs, but can be systematically identified from clinical narratives using natural language processing (NLP). Another critical problem with AI built on RWD is that, due to inherent systematic errors due to confounding or selection in observational data like EHRs, the models might identify wrong effects for interventions. Thus, alternative predictions (i.e., counterfactuals) of naïve AI systems can be mistaken, potentially leading to harm. Causal inference methods can be coupled with AI to address RWD data issues. The overarching goal of this project is to develop “AI-CARE-HIV,” an actionable counterfactual AI framework to improve HIV outcomes in Florida, through multimodal model augmentation that includes patient circumstances and ecological measurements. This framework can be used to develop a causally-sound (under certain assumptions), actionable model usable for planning and implementing clinical, public health interventions. We will develop the project through the OneFlorida+ Clinical Research Consortium, which collates RWD data from >16.8M Floridians, and specifically the OneFlorida+ HIV cohort (N=71,363). Our project aims to: (1) Enhance the cohort by incorporating large-scale socioeconomic, ecological factors (9,000+) and prospectively validate new ones using NLP, including stigma and behavioral circumstances; (2) Create multimodal risk scores from clinical, behavioral, socioeconomic and ecological factors, identify population-level causal effects for candidate interventions apt to improve care retention, develop individualized counterfactual AI models for HIV outcomes; (3) Plan–with healthcare providers, State officials, citizen scientists–actual clinical, public health interventions anchored on counterfactual AI, using implementation science and standardized protocols. Our team includes multidisciplinary expertise supported by OneFlorida+, the Fl Dept of Health, and community entities. We expect impact at multiple levels, from infrastructure enhancement to public health benefit.

NIH Research Projects · FY 2026 · 2023-04

Project Summary/Abstract Accumulation of α-synuclein (α-syn) into Lewy Bodies and Lewy Neurites is a hallmark of the Lewy Body Dementias (LBD), Dementia with Lewy Bodies and Parkinson’s Disease-Dementia. Additionally, some brain regions in Alzheimer’s Disease have pathological α-syn. Therefore, α-syn is likely a major cause of cognitive decline across several dementias. One possible mechanism underlying the core cognitive impairments centered around impaired executive function in LBD may be loss or dysfunction of projection neurons from the basal forebrain that produce acetylcholine (ACh). Across LBD, there is profound loss of cholinergic cells of the basal forebrain, which project to the prelimbic medial prefrontal cortex (PL-mPFC), a known key brain nucleus for executive function. Basal forebrain ACh acts through nicotinic and muscarinic ACh receptors (mAChR) to modulate PL-mPFC glutamatergic projection neurons critical for normal executive function. Recent evidence has further refined the mechanisms by which ACh regulates the PL-mPFC, and has suggested a key role for the M1 mAChR in regulating executive function. Despite this critical neuromodulatory role of ACh and M1 in the PL-mPFC in executive function, there are few studies that examine this important relationship in the context of α-syn related dementias. This has led to our overall hypothesis that cognitive decline in the context of α-syn linked dementias results from disrupted ACh signaling in the mPFC. We have used the pre-formed fibril (PFF) model of α-synucleinopathies to show that inputs into the PL-mPFC show enhanced ACh dependent long term depression in PFF injected mice. Additionally, layer 5 pyramidal cells of the PL-mPFC show decreased excitability in PFF injected mice compared to controls that may be attributable to ACh dependent changes in intrinsic properties of these cells. This suggests that α-syn dysregulates multiples aspects of the PL-mPFC through alterations in ACh release or signaling. To rigorously test this, we will perform a series of electrophysiology and behavioral experiments to determine, define, and dissect how α-ayn dysregulates the PL-mPFC through loss of ACh signaling or release. In Aim 1, we will test the hypothesis that α-syn dysregulates PL-mPFC inputs through altering ACh signaling. In Aim 2, we will test the hypothesis that α-syn alters intrinsic properties and output of PL- mPFC projection neurons through loss of ACh signaling. In aim 3, we will test the hypothesis that boosting cholinergic signaling will rescue deficits in executive function. Completion of these aims will provide fundamental understanding of how α-syn dysregulates ACh signaling to impair executive function in LBD.

NIH Research Projects · FY 2026 · 2023-04

PROJECT SUMMARY (See instructions): Double-negative T cells (DNTs), characterized by the absence of CD4 and CDB expression but the presence of aBeta T cell receptors (TCRs), play a pivotal role in regulating immune homeostasis within the ovary and uterus. However, how the origin and function of DNTs in the ovary and reproductive tract remains poorly understood, representing a critical gap in our knowledge of ovarian immune regulation. My recent investigations have demonstrated that these DNTs arise from peripheral CD8+ T cells that downregulate the CD8 coreceptor, adopting a unique transcriptional profile and acquiring suppressive functions. In models of autoimmune ovarian failure (AOF), DNTs are markedly reduced, correlating with ovarian dysfunction and infertility, while adoptive transfer of DNTs restores ovarian function and fertility by restraining pathogenic CD8+ T cell responses. Intriguingly, emerging observations indicate that DNTs also accumulate within ovarian tumors, suggesting a complex role in reproductive health by simultaneously modulating autoimmunity and potentially promoting local immune tolerance that could be co-opted by tumors. The central hypothesis of this project is that the reprogramming of peripheral CD8+ T cells into DNTs constitutes a critical immune checkpoint in the ovary, which can be harnessed to treat AOF and strategically modulated to enhance anti-tumor immunity. Specifically, this project will: (1) elucidate the molecular and transcriptional mechanisms driving the conversion of CD8+ T cells into regulatory DNTs within the ovarian microenvironment; (2) determine how DNTs suppress autoreactive T cells to maintain fertility in AOF models; (3) investigate how ovarian tumors exploit this pathway to establish local immune tolerance; (4) develop targeted strategies to enhance ONT-mediated tolerance in autoimmune conditions; and (5) explore engineering DNTs to restore CD8-associated cytotoxic programs as a novel approach to overcome ovarian tumor immune barriers. These studies will reveal a previously unrecognized pathway of peripheral T cell reprogramming with important implications for reproductive immunology. They will also lay the groundwork for innovative immunotherapeutic strategies that leverage or redirect DNT functions to restore ovarian health and improve outcomes in ovarian cancer, addressing critical unmet needs in women's health.

NIH Research Projects · FY 2026 · 2023-04

In the United States, older adults are more likely to experience chronic pain and related decline in physical functioning. Evidence suggests that exposure to both interpersonal and residential stressors may contribute to the development and progression of chronic pain. The psychological and neurobiological mechanisms through which these stressors influence pain outcomes—and to what extent they overlap-- remain insufficiently understood. Clarifying these mechanisms is critical to identifying modifiable factors that could improve pain management strategies for older adults. We hypothesize that residential stressors (e.g., limited neighborhood resources) and interpersonal stressors (e.g., negative social interactions) affect chronic pain outcomes through at least partially distinct psychosocial and neurobiological pathways. Our rationale is that such stressors influence interconnected biological and psychological systems, potentially accelerating the progression of musculoskeletal pain and related decreased physical function. We will test this central hypothesis through three specific aims: (1) Evaluate the independent and combined effects of residential and interpersonal stressors on chronic pain outcomes; (2) Identify psychosocial and biological mediators linking these stressors to pain outcomes; and (3) Examine individual-level protective factors that may buffer the psychological and biological effects of these stressors. Residential stress will be assessed using objective measures of neighborhood resource availability (e.g., Area Deprivation Index). Interpersonal stress will include perceived and observed experiences of negative social interactions. This research is innovative in its integration of multiple stress domains, mechanistic pathways, and protective factors. It is expected to improve our understanding of how different forms of stress contribute to chronic pain in older adults, ultimately informing strategies to improve outcomes in aging populations.

NIH Research Projects · FY 2026 · 2023-04

PROJECT SUMMARY/ABSTRACT Lupus nephritis is one of the most severe end-organ manifestations of systemic lupus erythematosus. Immunosuppression, the cornerstone for treating this disease, is complicated by many adverse effects. Although traditionally considered as a glomerular disease, up to 80% of lupus nephritis patients present with tubular injury, and tubular injury is a better predictor of progression to end stage kidney disease than glomerular injury. This identifies the renal tubules as a therapeutic target in lupus nephritis. The complex biological mechanisms that underlie tubular epithelial cell injury in lupus nephritis remain, for the most part, obscure. We propose to provide such a mechanistic understanding by leveraging our key novel findings. We have shown that iron accumulates in the tubular compartment of the lupus nephritis kidneys but not in the glomeruli. Most of the iron recycling in the kidney is performed by proximal tubular epithelial cells, and excess iron induces ferroptosis -- an inflammatory form of cell death characterized by high levels of lipid peroxidation. Ferroptosis is mostly observed in the tubular segments of human and murine lupus nephritis kidneys. We have found that the enzyme Acyl-CoA synthetase long-chain family member 4 (ACSL4), a ferroptosis promoter, was increased whereas SLC7A11, a ferroptosis inhibitor, was decreased in lupus nephritis. Additionally, human lupus nephritis serum induced ferroptosis in proximal tubular epithelial cells and this was associated with inflammation and injury. Liproxstain-2, a novel ferroptosis inhibitor, blocked these outcomes. These data led us to hypothesize that iron accumulation in proximal tubular epithelial cells promotes ferroptosis, propagates tubulointerstitial inflammation and worsens outcomes of lupus nephritis. We aim to test this hypothesis using congenic mice deficient for ACSL4 (Acsl4PTEC-/-) and SCL7A11 (Slc7a11PTEC-/-) only in their proximal tubular epithelial cells (PTEC). We will first investigate the resistance of Acsl4PTEC-/- and susceptibility of Slc7a11PTEC-/- mice to ferroptosis using an inducible and a spontaneous mouse model of immune complex glomerulonephritis, identify the downstream molecular pathways that block or lead to ferroptosis and follow the outcomes of kidney injury. Using lupus nephritis patients and healthy controls, we will dissect the ferroptosis inducing ability of whole and immunoglobin depleted serum on proximal tubular epithelial cells as well as test novel ACSL4 inhibitors. Using purified cells from the same cohort of patients and controls we will block known repressors of SLC7A11 and evaluate outcomes of ferroptosis and tubular pathology. Finally, we will evaluate the in vivo therapeutic efficacy of Liproxstain-2 in two spontaneous murine models of lupus nephritis with existing renal injury. These studies will identify novel mechanisms of proximal tubular epithelial cell injury in lupus nephritis and support use of ferroptosis inhibitors as a novel adjunct therapy to reduce dependency on traditional immunosuppressants.

NIH Research Projects · FY 2026 · 2023-04

Summary/Abstract More than 75,000 drug overdose deaths this past year were associated with opioids. To address this epidemic, NIH has prioritized the development of more effective opioid use disorder (OUD) treatments, as current interventions are helpful but inadequate. OUD is common among people living with Human Immunodeficiency Virus (HIV) and comorbid OUD/HIV increases risk for mental and physical health impairments of greater severities. Thus, comorbid OUD/HIV patients constitute a vulnerable group and basic research must study factors relevant to this group. We and others have data indicating that when combined, opioids and HIV proteins induce convergent deleterious effects that likely engender problematic opioid use behaviors and impair general health. This basic science R01 program aims to fill knowledge gaps in the individual and combined effects of the prototypical opioid, morphine, and HIV transactivator of transcription (Tat) protein, on mitochondrial function, brain derived neurotrophic factor (BDNF) expression, and on animal behavior, including those analogous to human behaviors that moderate health outcomes in patients with OUD and comorbid OUD/HIV. Improving our understanding of Tat protein’s effects is critical to better understanding effects of HIV because despite nearly complete viral suppression during antiretroviral therapy for HIV (ART), Tat is detectible with repeat testing in 40% of ART-treated patients at least once over the course of a year. This is important because Tat expression in animals induces phenotypes analogous to those observed in people living with HIV, including impairments in anxiety, inhibitory control, and brain structural and functional deficits. Tat’s relevance to comorbid OUD/HIV is illustrated in our pilot behavioral data indicating that Tat amplifies morphine taking, seeking, and post-extinction reinstatement. We also test effects of dimethylfumarate (DMF), which we have shown moderates morphine withdrawal symptoms. Studies in SIV-infected macaques report that DMF protects mitochondria and other studies show that DMF stimulates BDNF signaling. We focus on mitochondria because they supply most of the energy needed for neuronal and higher order brain function and they are impaired by morphine, Tat, and in human brain in vivo in people with OUD or HIV. Our working hypothesis is that morphine, Tat, and their combination will increase morphine self-administration, impair learning, memory, and cognitive flexibility, impair in vivo brain mitochondrial function assessed with phosphorus (31P) magnetic resonance spectroscopy, and will lower levels of mitochondrial biogenesis factors including Nuclear Respiratory Factor 1 and 2 expression, as determined postmortem. DMF, by protecting mitochondria and by increasing BDNF levels, will limit morphine’s and Tat’s deleterious effects. This basic science program aims to fill important knowledge gaps on the individual and combined effects of opioids, Tat, and DMF, and could yield data that support applied studies of novel treatments for OUD and HIV studied by us and by others, including DMF.

NIH Research Projects · FY 2026 · 2023-04

Project Summary The broad, long-term objective of this application is to generate an efficient, effective decision-support system to augment postoperative triage, transfer, and discharge decisions that affect more than 15 million patients in the United States annually. Evidence from single-institution studies suggests that postoperative overtriage of low acuity patients to intensive care units (ICUs) is associated with low value of care (outcomes/costs) compared with general ward admission, and that undertriage of high acuity patients to general wards is associated with increased mortality. These associations require validation externally and prospectively. In addition, further investigation is needed to determine whether there are similar, identifiable misalignments between patient acuity and resource intensity occurring throughout postoperative hospital admission and at the time of hospital discharge. Our central hypothesis is that aligning automated, data-driven patient acuity assessments with postoperative resource intensity using explainable, fair, uncertainty-aware deep learning models will be associated with decreased mortality and increased value of care. We will test our central hypothesis by performing three sets of related but independent experiments. First, we will externally validate an interoperable version of our postoperative triage classification system, initially using retrospective data at 42 hospitals across four institutions, then performing similar analyses with retrospective data on a federated learning platform, and finally using prospective data from 15 hospitals at two institutions. Second, we will generate continuous postoperative patient acuity assessments with novel DL architectures using multicenter, multimodal (including clinical notes), retrospective EHR data at three hospitals within a single institution. Third, we will critically evaluate and optimize model certainty and fairness using retrospective data at 43 hospitals across four institutions, generate an EHR-embedded decision-support system, and perform prospective decision support usability testing and optimization at two institutions. The proposed research is intended to produce a validated, interoperable postoperative triage classification system, foundational evidence for generating continuous streams of postoperative transfer and discharge recommendations, a postoperative triage decision support system ready for clinical implementation, and open-source software for optimizing deep learning certainty and fairness. Achieving these outcomes would increase the probability of success for automated, real-time postoperative triage decision-support in subsequent clinical trials, and the ultimate goal of augmenting personalized, patient-centered decision making in surgery.

NIH Research Projects · FY 2026 · 2023-04

PROJECT SUMMARY Despite recent emphasis on the microbiome, there are few skin microbiome studies in infants; even fewer have been performed in preterm infants. Currently, there is a significant gap in our knowledge of the normal evolution of the preterm infant skin microbiome from birth to an independent, site-specific cutaneous microbiome. Preliminary studies show that preterm infants have limited microbial diversity and different predominant cutaneous microbes compared to full-term infants. This lack of a robust, diverse skin microbiome may render preterm infants susceptible to pathogenic skin bacteria that cause disease, particularly neonatal sepsis. The research goals of this mentored career-development award are to: 1) characterize the establishment of the neonatal skin microbiome in a cohort of preterm infants from birth to 4 weeks and compare to demographic and clinical variables, 2) recruit a cohort of term infants to determine if the preterm infant skin microbiome is significantly different than term infants, and 3) analyze cultured pathogens with the skin microbiome in late-onset neonatal sepsis (LOS). Our methods represent a departure from the currently available studies, which provide opportunistic sampling of the neonatal skin microbiome rather than sampling at defined timepoints. This study will vertically-advance the field by sampling the preterm skin microbiome systematically after birth. The role of the skin microbiome in neonatal sepsis has also not been described, and the design of this study will provide a better understanding of changes in the skin microbiome before late onset sepsis. Together, these aims will provide insight into the normal and abnormal development of the preterm infant skin microbiome. Future studies will then leverage the neonatal skin microbiome via therapeutic and preventative strategies to lower the incidence of LOS. This K23 is the next logical step in the training program started under my KL2 award, and the final step in my transition to an independent physician scientist. This proposal describes mentored research and training activities designed to launch a novel neonatal skin microbiome research program, the first in the field of pediatric dermatology. Five training and career development goals, facilitated by my mentoring team, are required to accomplish this. These include: extend my understanding of research design, deepen my knowledge of microbiome and relevant laboratory science, gain working knowledge of statistics/bioinformatics (including advanced metagenomic analyses), learn to lead an independent laboratory, and expand my professional network within microbiome science. The University of Florida provides a rich environment with expertise in the neonatal microbiome and metagenomics, ideal to extend my previous work as I develop a novel neonatal skin microbiome research program. The resources at UF will be augmented by additional skin microbiome expertise and laboratory resources from Dr. Pammi at Baylor College of Medicine and Diversigen Inc.

NIH Research Projects · FY 2026 · 2023-04

PROJECT SUMMARY/ABSTRACT Dynamic regulation of mitochondrial localization is vital for the various energy demands and homeostasis maintenance of subcellular regions. Key components governing mitochondrial motility, dynamics, anchoring, and quality control have been identified. However, little is known about the signaling mechanisms by which neurons coordinate mitochondrial localization in the short and long term in response to environmental and physiological stimuli. This proper regulation of mitochondrial localization is particularly important in neurons with unique and elongated structures that lead to a fundamental problem of a mismatch between the mitochondrial biosynthesis site (cell body) and the high-demanding site for mitochondrial function (axon and synapse). Growing evidence indicates that an irregular mitochondrial localization to the axon and synapse is closely associated with many neurological disorders, including Alzheimer's disease, nerve degeneration, and regeneration failure. This proposal aims to elucidate how neurons regulate mitochondrial localization in two fundamental conditions including age and injury. In addition, we propose to determine how the regulation of mitochondrial localization affects the maintenance of neuronal function against injury and aging. This proposal is built based on recent in vivo studies that adult neurons undergo progressively reduced mitochondrial movement. Our lab and others have also revealed that injured neurons acutely change mitochondrial movement and localization, determining axon regeneration ability. The underlying mechanisms by which neurons regulate mitochondrial localization in aging and injury conditions remain poorly understood. Lack of this knowledge hinders the development of therapeutic strategies for neurological diseases such as Alzheimer's disease and nerve injury that have been associated with abnormal mitochondrial localization. We combine Caenorhabditis elegans genetics, mitochondrial biology, innovative in vivo imaging, and laser axotomy to address these unmet needs. Our preliminary data suggest that the DLK-1 MAPK signaling, a conserved pathway associated with synapse development, axon regeneration, and progressive neurodegeneration in Alzheimer's disease model, could be a novel regulator of mitochondrial localization in neurons. This proposal consists of three specific aims to answer how neurons regulate mitochondrial localization in aging and injury conditions (Aim 1), what the role of mitochondria in the recovery of the adult neurons after injury (Aim 2), and how the communication between mitochondria and nucleus controls the DLK-1 signaling, thereby mitochondria function and axon regeneration (Aim 3). We expect that our proposed experiments will achieve a new understanding of the mechanisms that maintain the optimal function of the nervous system by regulating mitochondrial function in aging and injured neurons. Also, our findings will provide better insight into novel therapeutic approaches to restoring neuronal function after nerve injury.

NIH Research Projects · FY 2025 · 2023-03

Research Abstract Mother own milk (MOM) provides personalized risk reduction for neonatal intensive care unit (NICU) infants, but little is known about insufficient MOM in 84% of NICU mothers with non-very low birthweight infants, leaving a major research gap that disproportionately impacts Black NICU mother-infant dyads. Insufficient MOM volume has its origins in late pregnancy and postpartum days 1-14. The goal of this research is to determine the effect of GA on lactation outcomes among pump-dependent mothers of critically ill infants admitted to the NICU. A major lack of knowledge exists about the effect of mammary gland maturation on MOM volume, secretory activation (SA), and if/how it is mediated by MOM removal (e.g., breast pump use) during the critical window (postpartum days 1-14) of transition from secretory differentiation (epithelial cell preparation) to SA (onset of copious MOM volume) and autocrine control of lactation (permanence of SA) to ensure continued production of adequate MOM volume. To fill this gap, this revised mentored patient-oriented research career development award (K23) proposed study will follow 188 racially and economically diverse mothers of infants admitted to the NICU for postpartum days 1-14 and assigned to 1 of 4 groups based on the infant's GA at delivery. Aim 1 will compare measures of MOM volume between the GA groups over postpartum days 1-14. Aim 2 will compare measures of onset and permanence of SA using MOM biomarkers between the GA groups. Aim 3 is exploratory to gain evidence to characterize the relationship between biomarkers and MOM volume for the 4 GA groups. Understanding of these mechanisms and the impact of GA is critical to translate findings into early identification and personalized interventions for this vulnerable population. To this end, I have assembled an interdisciplinary team of senior scientists with complementary expertise in nutritional support for critically ill infants, clinical and translational research, biostatistics, and lactation biology who will provide mentorship to achieve the proposed training goals and facilitate my transition to an independent research career. Essential primary training goals include: 1) Advance understanding of the biology of lactation, maternal, and infant factors; 2) Develop and apply knowledge of the application of clinical and experimental designs, data acquisition, data analysis, and interpretation of findings; and 3) Develop leadership, research management, academic faculty, and grant writing skills essential for a productive research faculty member. University of Florida (UF), Shands Children's Hospital, and UF Diary Science are ideal environments to provide unparalleled resources to support and extend the PI's emerging translational clinical research to become a productive faculty member and independent researcher in patient-oriented research. The revised research plan is directly responsive to the reviewer comments and to the National Institute of Nursing Research's priorities focused on research using multilevel approaches bridging biology to society reducing risk, improving health, and advancing health equity, as well as aligns with NIH initiatives to prioritize human milk research.

NIH Research Projects · FY 2026 · 2023-03

Abstract HIV-1 transcriptional inhibitors have immense potential in functional cure approaches and could transform the way we treat HIV infections. Unlike current antiretroviral therapy (ART), transcriptional inhibitors offer the prospect of reducing residual viremia derived from reservoir of long-lived cells containing integrated proviruses, likely reducing ongoing the chronic immune activation, inflammation and HIV-associated co-morbidities still experienced by ART-adherent individuals living with HIV. Furthermore, we believe transcriptional inhibitors are amenable to block-and-lock functional cure approaches, aimed at the durable suppression of HIV in the absence of daily therapy, through permanent epigenetic silencing of integrated proviruses. This hypothesis was founded on the activity of the potent Tat inhibitor didehydro-Cortistatin A (dCA). In in vitro and in vivo models of HIV latency, dCA inhibition of HIV transcription over time prompts the viral promoter into deep transcriptional inhibition, limiting viral reactivation upon treatment interruption or with latency reactivating agents (LRAs). Despite their great potential, there are still no HIV transcriptional inhibitors in the clinic, and challenges with the cost of large-scale production of dCA are slowing its progression towards clinical studies. Here we propose to investigate the repurposing the FDA approved aldosterone antagonist Spironolactone (SP) for HIV transcriptional inhibition. An off-target activity of SP is the degradation of the XPB subunit of the general transcription factor TFIIH, a key player in RNAPII initiation at the transcriptional start site (TSS) of genes. We demonstrated in vitro that SP treatment or shRNA knockdown of XPB selectively inhibits HIV transcription and blocks viral reactivation from latency without global transcriptomic defects. This study highlighted the host factor XPB as a novel drug target and SP as a potential block-and-lock agent. Here we propose to explore the potential of SP, alone or in combination with dCA, as a block-and-lock agent in the humanized bone-marrow, thymus liver (BLT) mouse model of HIV infection by: 1) Determine the relationship between SP treatment length with residual viremia levels in tissues and correlates of chronic immune activation/inflammation in HIV infected ART- suppressed BLT mice.; 2) Assess the ability of SP to maintain deep latency as a single drug in the absence of ART and study viral resistance evolution; 3) Impact of dCA and SP in combination as front-line therapy on the size of the established viral reservoir and time to viral rebound. We predict that longer treatment lengths of HIV infected BLT mice with SP will correlate with improved reduction of low-grade HIV persistent transcription from the viral reservoir and likely chronic immune activation. Importantly, we seek to demonstrate that once deep transcriptional suppression is established, SP alone blocks viral rebound. In addition, when used as front-line therapy we expect a reduction in the size of the established viral reservoir and the combination with dCA will improve the outcome. This study will provide an important proof-of-concept for the use of transcriptional inhibitors to treat people living with HIV and explore optimal experimental settings to be tested in future clinical trials

NIH Research Projects · FY 2026 · 2023-03

ABSTRACT Enterococci are the 3rd most common cause of hospital-acquired infections and a major public health threat due to the continuous rise of multidrug-resistant (MDR) isolates. Because the pathogenic potential of enterococci is closely linked to their ubiquitous stress resilience, work in our lab aims to identify and dissect the mechanisms that allow Enterococcus faecalis, the most prevalent enterococcal species of human infections, to survive in the hostile host environment. Second messenger nucleotides such as (p)ppGpp (the effector molecule of the stringent response) and c-di-AMP are produced by bacteria in response to internal or external stimuli, playing major roles in the regulation of processes associated with cell homeostasis and virulence. In addition, cyclic nucleotides such as c-di-AMP act as agonists of the innate immune response of mammalians by stimulating a potent STING-dependent type I interferon response. Of interest, previous investigations have shown that the c-di-AMP and (p)ppGpp signaling networks are interconnected in other bacteria, but a clear understanding of the mechanics and physiological significance of this interaction are still lacking. In previous studies, we discovered that E. faecalis depends on small amounts of (p)ppGpp to maintain a balanced metabolism and to respond to external cues in an accurate and timely manner. We also found that lack of (p)ppGpp greatly increases antibiotic sensitivity and attenuates the virulence of E. faecalis. More recently, we showed that c-di-AMP is also critical to E. faecalis pathophysiology and that either accumulation or lack of c- di-AMP can drastically impair the virulence potential of E. faecalis. The goals of this application are: (i) to probe the multifaceted roles played by c-di-AMP during infection using a catheter-associated urinary tract infection (CAUTI) mouse model that recapitulates many of the clinical characteristics of the disease in humans, (ii) to identify and characterize the c-di-AMP binding/effector proteins in E. faecalis, and (iii) to investigate how integration of the c-di-AMP and (p)ppGpp regulatory networks controls specific processes that promote bacterial fitness and then determine how this association contributes to E. faecalis pathophysiology. This conceptually innovative application builds on our extensive preliminary data and the complementary expertise and solid track record of our research team in each specific area of this application. Significance of the proposed studies lies in unravelling the multifaceted role of c-di-AMP in host-pathogen interactions, uncovering the scope of c-di-AMP regulation in a major MDR pathogen, and shedding new light onto the intricate relationship between c-di-AMP and (p)ppGpp. Given the central role of regulatory nucleotides in bacterial pathogenesis, a better understanding of how they modulate cell physiology based on identification and characterization of their mechanisms of action and effectors can facilitate the rational design of new antimicrobial therapies.

NIH Research Projects · FY 2026 · 2023-03

To date there is no disease-modifying therapy for cognitive impairment and dementia. Understanding mechanisms that strengthen cognitive resilience and delay vascular dementia is a complimentary approach to protect cognitive health in aging. Survivors of stroke and vascular disorders are rapidly growing in the U.S. and can rapidly progress to vascular dementia. Cognitive trajectories assessed over long durations of follow-up, allow monitoring of cognitive resilience and timing of dementia onset. Tau and Beta-amyloid pathologies, infarction and stroke-related factors leave ~ 59% of the variance in cognitive trajectory unexplained. Mechanisms that elicit differences in cognitive resilience and timing of vascular dementia onset, remain unclear. Biological aging is the decline in system integrity with advancing chronological age and has been associated with age-related diseases. Biological aging can be measured by composite algorithms of biomarkers’ combinations in routine blood-tests to assess the underlying body integrity at the physiological level. However, it remains poorly understood if biological aging explains variabilities in post-stroke cognitive resilience and timing of vascular dementia onset. At the molecular level, among aging biology mechanisms, the proteome is hypothesized to play a central role in cognitive resilience and brain health. Proteins control cell functions, can help identify novel therapeutic targets and have been associated with cognitive trajectories in postmortem assessments. Aging-related proteomic changes are best detected in the systemic circulation. Proteomic technologies allow measuring protein changes in aging with high levels of specificity and precision. Establishing molecular proteomic pathways of cognitive resilience in survivors of stroke and vascular disorders, is a critical step to translate biomarker discoveries to dementia treatment and therapeutics. The immediate objective of this application is to assess the role of biological aging and molecular proteomic mechanisms in cognitive resilience and onset of dementia in the context of stroke and vascular disorders for prevention and to identify new therapeutics. I will measure vascular and biological aging phenotypes in population-based studies such as the Baltimore Longitudinal Study of Aging, the Cardiovascular Health Study, the Health and Retirement Study and the Rotterdam Study. I will integrate these phenotypes with state-of-the art clinical ascertainment of vascular disorders and dementia over long durations of follow-up. I will leverage proteomic platforms (e.g. aptamer-based, antibody-based) to identify molecular cellular pathways of biological aging and cognitive resilience in survivors of stroke, vascular disorders and healthy controls. I will lastly evaluate algorithms of combined molecular, proteomic and clinical data to monitor cognitive and vascular health using semi-supervised machine learning approaches. This project will enable actionable findings on molecular mechanisms of cognitive resilience to uncover novel therapeutic targets and biomarkers for dementia prevention in aging.

NIH Research Projects · FY 2026 · 2023-03

Severe headache is ubiquitous in subarachnoid hemorrhage (SAH), present in 90% of patients after ictus bleed. Despite steady consumption of analgesics, the degree of pain control in SAH patients is remarkably poor. In spite of this high prevalence, a dearth of data guides optimal management of post-SAH headache. Opioids are the most prescribed pain medication for severe post-SAH headache. However, opioid-based analgesia presents considerable risks: depressed level of consciousness and respiratory drive, hypotension, slow gastrointestinal transit, and high frequency of tolerance and addiction. Furthermore, it is urgent and critical to identify novel strategies to alleviate the excruciating and nearly universal headache post-SAH, while mitigating consequences of opioid use. This unmet therapeutic need reflects a key knowledge gap in a condition afflicting nearly 30,000 individuals each year in the US. We present an inexpensive, opioid-sparing strategy for post-SAH headache, using a nerve-block into the pterygopalatine fossa (PPF) to improve pain control and lessen opioid needs. A growing body of literature on the use of nerve-blocks in acute and chronic headache disorders supports our overarching hypothesis that PPF-block provides rapid, opioid-sparing analgesia, is safe and well-tolerated, and holds promise to adequately treat post-SAH headache. The pathophysiology of these headaches is complex and involves meningeal irritation from blood products, release of inflammatory cytokines, vasomotor instability, and central pain sensitization. Through selective modulation, PPF-blocks address pain mechanisms at their origin, targeting the maxillary nerve and sphenopalatine ganglion, including their branches. We propose a multicenter phase II, randomized, double-blinded, placebo-controlled study with sequential parallel comparison design of bilateral PPF-injections over 4 days at 12 centers. Following aneurysm treatment, 195 adults hospitalized with aneurysmal SAH, who are experiencing severe headaches and can verbalize pain scores, will be randomized to once daily active (ropivacaine + dexamethasone) or sham (saline) or PPF-injections during the first 2 consecutive days of the intervention period (Day 1/Stage 1, Day 2/Stage 2). The open-label phase spans the subsequent 2 days (Days 3-4), during which subjects may opt to receive an active PPF-block. This two-stage design leverages increased efficiency in data generation from the pooled sequential blinded stages (i.e., Stages 1 & 2) and reduced impact of sham responses, and thus, allows for smaller sample size without compromising statistical power. Our primary objective is to demonstrate the opioid-sparing analgesic effect of PPF-blocks vs sham. Our secondary objective is to assess the tolerability of PPF-injections as measured by rates of acceptance of second injection on Day 2, and their safety as measured by vasospasm rates at the end of the open-label period in patients with SAH. We will also explore the potential interplay of sex and racial disparities in pain experiences and both PPF- block tolerability and efficacy. This initiative merges our expertise in neurosurgery, neurocritical care, and acute- pain-anesthesiology to tackle a historically neglected aspect of the critical care management of SAH.

NIH Research Projects · FY 2026 · 2023-03

Project summary Obesity is a major risk factor for NAFLD/NASH. In obesity, energy accumulation causes metabolic dysfunction and endoplasmic reticulum (ER) and oxidative stress, leading to tissue inflammation and injury, which are hallmarks of NASH. The DNA damage response and unfolded protein response are vital to maintain the integrity of cellular genome and proteome. The ER maintains proteostasis via ER-associated protein degradation and unfolded protein response. Metabolic dysfunction alters ER-associated protein degradation and unfolded protein response, leading to ER stress, caspase activation and cell death. Moreover, increased oxidative stress enhances DNA damage-induced cell death. Defining how these pathways integrate to dictate cell metabolism and survival is the long-term goal of The Chakraborty lab. The objective of this proposal is to decipher the role of the E3 ubiquitin ligase Ube4A in the obesogenic IP6K1 protein-mediated hepatocyte metabolic dysfunction and DNA damage response and unfolded protein response mediated hepatocyte survival and NAFLD/NASH. The overarching hypothesis is that Ube4A maintains metabolic homeostasis and protects hepatocytes from stress-induced death, delaying the development and progression of obesity and NAFLD/NASH. The rationale is that determining the role of Ube4A in NAFLD/NASH and the mechanisms by which it regulates hepatocyte metabolism and survival will provide new therapeutic opportunities. Our specific Aims will test the following hypotheses: (Aim 1) Test the impact of whole-body- and hepatocyte-Ube4A deletion on metabolic dysfunction, liver injury, and NAFLD/NASH in mice; (Aim 2) Determine mechanisms of Ube4A-mediated IP6K1 inhibition and its impact on metabolic dysfunction and NAFLD/NASH in mice; (Aim 3) Decipher the mechanisms by which Ube4A regulates hepatocyte survival. The contribution is significant and transformative because it is expected to unravel the role of a novel pathway that regulates obesity, insulin resistance and hepatic steatosis and distinguish the hepatocyte-specific impact of this pathway on NAFLD/NASH. Moreover, it is the first step to defining the mechanisms of how Ube4A regulates hepatocyte metabolism and survival and how the obesogenic protein IP6K1 is modulated in vivo. These exciting findings could lead to development of new therapeutic approaches to treat obesity and NAFLD/NASH. The proposed research is innovative as it will utilize exciting new tools to unravel a novel pathway that regulates cell metabolism and survival, which is therapeutically relevant and has broad implications for many diseases.

NIH Research Projects · FY 2026 · 2023-03

Role of cortical catecholamines in regulating motivated behavior and striatal dopamine Abstract Cognitive flexibility and goal-directed behavior are critical for normal functioning, and their dysfunction is central to multiple neuropsychiatric conditions, including dementias associated with neurodegenerative disease. Cortical catecholamines and prefrontal cortical (PFC) dopamine receptors are potent regulators of cognitive flexibility and goal-directed behavior. In addition to these cortical mechanisms, striatal dopamine is necessary for motivated behavior (Yin et al., 2005); however, the cellular, molecular, and projection-specific heterogeneity of PFC projections to the basal ganglia, the impact of individual PFC catecholamines, and how they regulate striatal dopamine and motivated behavior, are not clear. A better understanding of the mechanisms by which PFC and PFC catecholamine signaling regulate cortico-basal ganglia circuitry could lead to novel therapeutic approaches for addressing cognitive dysfunction in neurological and psychiatric disorders. Our central hypothesis is that cortical norepinephrine and dopamine play distinct roles in regulating striatal dopamine dynamics and motivated behavior through PFC D2R+ and D1R+ sub-circuits. Our goal is to use intersectional chemogenetics, fiber photometry and behavior to decipher the roles of NET and cortical catecholamines in the regulation of motivated behavior and striatal dopamine dynamics. We will test our hypothesis using the following three aims: 1) Determine the contributions of the norepinephrine transporter to cognitive flexibility and striatal dopamine dynamics.2) Determine the contributions of norepinephrine vs. dopamine to cognitive flexibility and striatal dopamine dynamics. 3) Determine the contributions of PFC D1+ and D2R+ pyramidal neuron subpopulations to striatal dopamine and cognitive flexibility. The outcomes of this R01 proposal will provide a refined molecular and anatomical framework describing the functional roles of individual PFC catecholamines in regulating PFC D1/D2R+ circuits, striatal dopamine dynamics and motivated behavior. Given that catecholamine dysfunction is central to cognitive pathology of dementias, neurological and neuropsychiatric diseases, our results may reveal novel mechanistic strategies for developing molecular- and circuit-based therapeutics for these disorders.

NIH Research Projects · FY 2026 · 2023-03

Project Summary This proposal will develop Bayesian machine learning approaches via Bayesian nonparametrics (BNP) to handle nonignorable missingness (in outcomes and covariates) and conduct causal inference for electronic health records (EHRs), to address missingness in multivariate longitudinal data, and for causal mediation problems. Missing data remains a problem in clinical studies and in particular, for studies using EHRs. In clinical studies, more effort is spent to try to minimize the amount of missingness, but it still remains a problem and missingness is a constant issue (and less controllable) in studies based on EHRs. In addition, there has been limited work on the use of auxiliary information in EHRs that can enhance the ability to deal with missing data. Approaches for missingness in multivariate longitudinal data is underdeveloped and relevant across many clinical trials settings from cost effectiveness analysis to incomplete time-varying auxiliary covariates (or confounders) to causal mediation to multiple outcomes of interest. The mechanisms of treatment effectiveness are of particular interest in behavioral trials. Specifically, how do different processes mediate the effect of an intervention? This can facilitate constructing future interventions. However, determining the causal effect of such 'mediators' on outcomes is difficult. We will develop new approaches to identify these effects in the complex setting of cluster randomized trials for which little work has been done. For all these settings, a Bayesian approach is ideal as it allows one to appropriately characterize uncertainty about unverifiable assumptions (which are present in all these problems) and allows the flexibility of Bayesian nonparametric models. MCMC algorithms for BNP can sometimes converge slowly and can be untenable for large n. We will extend existing approaches to address both these complications which will be important for all the applications considered and in general, given the increasing size and complexity of data. The methods are motivated by several NHLBI funded studies, whose PJ's are co-investigators on this proposal, and will be developed to help answer numerous important clinical questions including the mechanisms of behavior change in weight management and the impact of linkage ( and engagement) to care on treatment effectiveness for blood pressure outcomes. The methods will also help us evaluate potentially synergistic effects when drugs with potential diabetogenic effects are used concomitantly and whether the impact on cancer outcomes varies by different bariatric surgeries. The history of the the collaborations among the entire study team will help produce the best science and facilitate dissemination of our methodological and clinical findings. We will disseminate code for these methods (via the PJ's github page and software papers) to ensure the methods will be readily usable by investigators involved in cardiovascular, obesity, diabetes, and cancer studies.

NIH Research Projects · FY 2026 · 2023-03

SUMMARY As ligand-regulated transcription factors, nuclear receptors (NRs) evolved to respond to natural small molecules, such as vitamins and lipids, translating endocrine and metabolic signals into changes in gene expression. Our data, that ligand-dependent REV-ERB activity may regulate TH17 cell inflammatory responses, suggests that the REV-ERBs natural endogenous ligand, heme, may function as a REV-ERB-dependent signaling molecule in TH17 cells. Given the evidence that both intracellular and extracellular ligands regulate NR activity in TH17 cells, defining ligand mechanisms of action and/or understanding the source and effects of heme- dependent REV-ERB activity in TH17 cells may reveal signaling pathways underlying homeostasis vs. pathogenesis. Our preliminary data suggests that REV-ERBa/heme dependent signaling may be required for protection from inflammation in the gut (colitis). This coincides with recent evidence demonstrating that dietary heme induces gut dysbiosis and aggravates colitis. Therefore, understanding how ligands, like heme, regulate the REV-ERBs would be particularly valuable for understanding how environmental signals influence TH17 cells and inflammation. Our overarching goals are to define the role of heme as an endocrine signaling molecule and elucidate the ligand-mediated mechanisms that regulate REV-ERBa’s transcriptional activity and interacting partners, thus driving repressive functions in TH17 cells during inflammatory processes. We will accomplish this goal by identify heme’s role as a REV-ERBa-dependent signaling molecule in TH17 cells; establishing whether heme-dependent REV-ERBa activity affects TH17-mediated inflammation in vivo; and defining how ligands affect the REV-ERBa’s transcriptional partners and repressive function in TH17 cells. The proposed studies will address fundamental questions regarding ligand-dependent REV-ERBa activity. Importantly, these insights will be particularly valuable in understanding TH17-mediated disease development and may inform on future pharmaceutical approaches.

NIH Research Projects · FY 2025 · 2023-02

PROJECT SUMMARY Oxidative stress plays a key role in the pathogenesis of osteoarthritis (OA) and is an important therapeutic target. While antioxidants or agents that target the reactive oxygen species (ROS) have been investigated for treating OA, many have demonstrated common disadvantages such as poor bioavailability and stability, as well as rapid joint clearance or release profiles from delivery vehicles following intra-articular injections. Therefore, there exists a critical need to localize and retain therapeutic levels of antioxidants within joint tissues for protection against the deleterious effects of oxidative stress. This proposal explores the application of manganese dioxide nanoparticles (MnO2 NPs) with antioxidant enzyme-like activity to reduce oxidative stress in OA joints while addressing limitations of small molecule antioxidants and natural enzymes, such as cost and stability. In addition, the properties of these nanomaterials can be tailored for tissue retention and cell targeting, which is important for addressing critical barriers to therapeutic localization and uptake in joint tissues. Recently, we reported engineering MnO2 NPs for uptake into cartilage and prolonged joint retention in vivo, as well as reduction of inflammation-induced oxidative stress in cartilage in vitro. Given its limited capacity to regenerate, cartilage is particularly vulnerable to oxidative stress and represents a crucial yet challenging tissue target. As such, this proposal focuses on interrogating the mechanisms of MnO2 NP-mediated chondroprotection while testing the efficacy of MnO2 NPs in an in vivo disease model. The central hypothesis is that MnO2 NPs will alleviate oxidative stress after joint injury and prevent or delay the onset of OA. In Aim 1, we will examine how uptake mechanisms and intracellular localization of MnO2 NPs affect compartment-specific ROS scavenging and the ability to rescue specific antioxidant pathways in chondrocytes. Furthermore, the effects of intracellular targeting versus extracellular retention on redox signaling, chondroprotective, and anti-inflammatory effects will be determined. In Aim 2, we will evaluate the effects of MnO2 NP treatment on oxidative stress and OA progression in vivo in a rat model of post-traumatic OA (PTOA). We will comprehensively evaluate the efficacy of the particles in modulating ROS in vivo, mitigating OA-related histological and biochemical (synovial fluid) changes, and alleviating OA-related pain and disability via behavioral assays. The proposed work will advance a new ROS scavenging strategy for the treatment of PTOA that overcomes persistent challenges with the delivery of antioxidants. The proposed work will also reveal key mechanisms involved in intracellular delivery to chondrocytes and how location and timing of antioxidant delivery impacts disease mechanisms. The mechanistic and comprehensive approach we propose here to characterize the effects of ROS scavenging by MnO2 NPs may facilitate successful translation long-term of this and/or other antioxidant strategies for joint injuries and disease.

NIH Research Projects · FY 2026 · 2023-02

Abstract: Alzheimer’s disease (AD) is a devastating diagnosis and there is a critical need to understand the fundamental molecular pathogenesis of AD to design effective therapies. In addition to the well-known AD pathologies, perturbed glucose metabolism is also a clinical feature of AD. Glycogen and N-linked glycans are two critically important but understudied facets of glucose metabolism. Both glycogen and N-linked glycans are complex carbohydrates that play vital roles in brain physiology such as cognition, memory formation, and life span. Despite the importance of these pathways in normal brain function, whether complex carbohydrate metabolism are perturbed during AD disease progression remains a critical knowledge gap in neurobiology. In exciting preliminary data, we discovered profound glycogen accumulation and protein hyperglycosylation in the prefrontal cortex of both mouse models of AD and human AD specimens. Further, we found a positive correlation between increased glycogen and Braak staging in an analysis of a 97-patient cohort. Finally, oral glucosamine supplement, a precursor to UDP-N-acetylglucosamine biosynthesis, building block of N-linked glycans further exacerbated hyperglycosylation and led to poorer cognitive performance in the 5xFAD mouse model of AD. Based on these preliminary data, we hypothesize that aberrant complex carbohydrate metabolism are pathogenic processes during AD disease progression. The major objective of this study is to systematically resolve cellular and extracellular origins of perturbed complex carbohydrate metabolism using state-of-the-art single cell technologies. We will achieve this through synergistic integration of multi-parameter single-cell mass spectrometry imaging methodologies. First, we will define complex carbohydrates with clinical course and disease progression in patient samples (Aim 1). Then, we will interrogate cellular and extra-cellular architecture in normal and AD patient samples (Aim 2). Finally, we will apply multimodal integration to track cellular and extracellular origins of complex carbohydrate perturbation in AD (Aim 3). This study will provide critical new information regarding ideal cell-, region- and temporally-specific opportunities for therapeutic modulation of AD. Collectively, we believe the resultant findings from this proposal will be highly salient for multiple related fields of Alzheimer’s disease and other neurodegenerative disorders.

NIH Research Projects · FY 2026 · 2023-02

Sexual Minority (SM) individuals face unique health issues, but studies on SM health are scarce. In particular, limited data are available among SM individuals on age-related conditions such as Alzheimer’s disease (AD) and related dementias. AD is a fatal degenerative disease with a diverse range of risk factors, ranging from clinical characteristics to social determinants of health (SDoH). AD patients often progress from cognitively unimpaired to (possible) mild cognitive impairment (MCI), followed by increasing severity of dementia with AD clinical syndrome. Nevertheless, evidence suggests there exists heterogeneity in the progression to AD through multiple intermediate stages. Characterizing the different AD progression pathways and the associated risk factors is crucial for risk stratification and prevention. On the other hand, the proliferation of large clinical research networks (CRNs) with real-world data (RWD), including electronic health records (EHRs), claims, and billing data among others, offers opportunities for generating real-world evidence (RWE) that will have direct translational impacts on AD prevention and care in the SM populations. Nevertheless, there are a number of key research and methodological gaps in using RWD for studying AD in SM, including the lack of (1) validated computable phenotypes (CP) and natural language processing (NLP) tools that can accurately define the SM populations and extract key patient characteristics and outcomes (e.g., MoCA scores to determine severity), (2) consideration of the heterogeneity in AD and its progression pathways, and (3) consideration of AD disparities in SM populations, especially structured on both individual- and contextual-level SDoH. In this project, we propose to analyze large collections of RWD in the OneFlorida+ and INSIGHT networks, two CRNs contributing to the national Patient-Centered Clinical Research Network (PCORnet), to: (1) create real-world longitudinal SM and AD cohorts that can be followed by virtue of routine clinical care, (2) model the heterogeneity in AD progression with novel federated machine learning methods, and (3) examine SM disparities in AD outcomes (i.e., onset and progression pathways) and in the causal paths via which AD clinical risk factors and SDoH impact these AD outcomes. Our project is novel and will have direct translational impact as it provides concrete RWE to fill the knowledge gaps by examining whether AD disparities exist between SM (and SM subgroups) and non-SM individuals, and identifies potentially actionable AD risk factors and SDoH significant to SM and their disparities. The success of this project will fill important gaps in our knowledge of AD risk and progression pathways in the SM populations, and establish a framework for creating RWD-based virtual cohort, which can inform national pragmatic trials across PCORnet for future SM aging clinical studies.