Washington University

NIH Research Projects · FY 2026 · 2025-06

PROJECT SUMMARY In Alzheimer Disease (AD), magnetic resonance imaging shows early atrophy and loss of functional connectivity in the medial temporal lobes, which then spreads to the posterior temporal lobe, parietal lobe, and finally the frontal lobe with relative sparing of the sensorimotor cortex. It is unclear what biological properties drive these different spatiotemporal patterns. At the other end of the lifespan, over the first few years of life the brain undergoes rapid cortical expansion and maturation. Whereas primary sensory regions are relatively stable from birth, there is tremendous cortical expansion in the temporal, parietal, and frontal regions. The networks that are most plastic mirror those regions most sensitive to AD pathology later in late. Further, adverse developmental conditions and structural and social determinants of health (SSDOH) such as low birthweight, poverty, and trauma can negatively impact the development of these networks, and increasing evidence indicates the repercussions persist throughout the lifespan. This raises the question whether degenerative processes in AD reflect downstream consequences of adverse developmental trajectories. The most frequent attempt to consider development and aging together has largely been qualitative in the recognition of the “first in last out” mirroring between regional changes in the brain. There has been minimal research testing hypotheses linking early development and degeneration together empirically. We posit two main theories. First, regions with high plasticity in early life have unique biological properties that inherently make them more susceptible to pathological changes later in life. Second, the detrimental impact of SSDOH on these regions during development are long-lasting and will contribute to adverse aging trajectories. Our goal is to determine the degree to which our understanding of healthy and pathological aging in the brain can be informed by early neurodevelopment. To accomplish this goal, the project will leverage multiple rich longitudinal datasets with advanced neuroimaging, deep clinical and cognitive phenotyping, and in-depth genotyping. In Aim1, we will quantify similarities and differences in the spatiotemporal progression of brain development and degeneration using neuroimaging to empirically test the spatiotemporal patterns predicted by the “first in last out” hypothesis. In Aim 2, we will determine the impact of deprivation and genetic risk on functional and structural brain development and degeneration. Finally, in Aim 3, we will elucidate early-life contributions to accelerated brain aging and susceptibility to degenerative diseases using genetic risk, neighborhood deprivation, birthweight, and early childhood trauma. Aims 1 and 2 will harmonize large, extant neuroimaging datasets including birth to three years of age (eLABE, BCP) and aging and degeneration (ADNI, SORTOUT-AB, HABS-HD) to directly test how normal and abnormal cortical expansion and brain connectivity development during childhood are reflected in healthy and pathological aging. In Aim 3, we will leverage lifespan, population level data from the UK Biobank. This proposal brings together an interdisciplinary team with expertise in both brain development, degeneration, and SSDOH.

NIH Research Projects · FY 2026 · 2025-06

Chemotherapy has extended survival for cancer patients across the cancer landscape. Unfortunately, chemotherapy is not benign as it induces a broad range of side effects that can significantly impact a cancer survivor’s quality of life. One such side effect is chemotherapy induced peripheral neuropathy (CIPN), affecting up to 90% of patients receiving taxanes, with 30% experiencing lifelong symptoms. Permanent symptoms can include tactile or thermal allodynia (pain), numbness, and dysesthesia (tingling) in the hands and feet, making everyday tasks a struggle. Current treatments, such as cryotherapy, offer only temporary and limited relief. Because chemotherapy induces robust senescence, we asked if senescence contributed to CIPN. Our genetic and pharmacologic studies revealed that senescence not only drives CIPN but also hinders axonal repair post-chemotherapy. Here we will ask how senescence drives CIPN by, 1) elucidating the impact of senescence on axonal loss in CIPN and 2) identifying senescent cells and determining how they contribute to CIPN. Preliminary data suggest that senescent nonneuronal cells in the peripheral nervous system (PNS) are key players in CIPN, likely through the secretion of p38MAPK-MK2 dependent senescence associated secretory phenotype (SASP) factors that activate neuronal SARM1 and impede the formation of reparative Schwann cells. We will use innovative genetic mouse models and in vitro assays to study the role senescent cells play and elucidate their mechanisms of action in CIPN. Our work promises not only a deeper understanding of CIPN’s molecular drivers but also potential new avenues for relieving the suffering of millions of cancer survivors.

NSF Awards · FY 2025 · 2025-06

This REU Site award to Washington University in St. Louis, located in St. Louis, MO, will support the training of 10 students for 10 weeks during the summers of 2025- 2027. It is anticipated that a total of 30 students, primarily from schools with limited research opportunities will be trained in the program. At the core of the program is a focus on understanding biological organization, rules, and interactions across scales in a variety of plants and microbes and how those insights can drive innovation in agriculture, biomedicine, and sustainability science. The REU will provide foundational training for undergraduates interested in translating basic science discoveries to real-world applications and for fostering the next generation of broadly prepared STEM professionals. Students will learn how research is conducted, and many will present the results of their work at scientific conferences. Students should apply to the REU site using NSF ETAP (Education and Training Application: https://etap.nsf.gov). Students in the program will work with mentors in the Departments of Biology and Chemistry to conduct research exploring plant and microbial bioscience from foundational discovery to real-world applications. Examples of student projects include structural biology of plant natural product biosynthesis, profiling plant-microbe interactions, investigating cellular structure in mycorrhizal fungi and plant root arbuscule formation, evaluation of sensor proteins that detect indoles as environmental signals, and comparative analysis of microbial eukaryotes in the gut. In addition to research, the program delivers personal and professional development in a tiered mentoring community. Three pathways - Research Competencies, Graduate Admissions, and Biotech Exploration - provide professional and career support for all interns, as well as training in the safe, ethical, and rigorous conduct of research. From pre-arrival and orientation to weekly activities and the final symposium, the REU brings faculty, bench/peer mentors, and summer interns together in a community that fosters student success. REU students will be science ambassadors to their home institutions, the St. Louis bioscience community, and engage with the private sector, while performing research and exploring career paths in plant and microbial bioscience. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2026 · 2025-06

Project Summary Mycobacterium tuberculosis (Mtb) is a major global health problem causing 1.6 million deaths a year worldwide. Options for tackling this scourge are limited as the only approved vaccine has little to no efficacy in adults and treatment involves a 4-6 month course of antibiotics. Host-directed therapies are an exciting alternative, but druggable pathways need to be identified for them to be a viable approach. Using a mouse model that recapitulates fundamental aspects of Mtb progression in humans, we demonstrated for the first time that plasmacytoid dendritic cells (pDCs) contribute to loss of Mtb control via their production of type I interferons. This proposal will build upon this finding to characterize pDC function during Mtb infection to identify pDC-specific therapeutic targets. Specific Aims: Aim 1) We identified that Mtb infection induces a 10- fold increase in lung pDCs at an early time point of infection. This aim will quantify pDC lung trafficking throughout the course of Mtb infection, identify the chemokine receptor required for the pDC lung honing, and define the contribution of pDCs at later time points of the infection. Aim 2) pDCs contribute to increased Mtb burden in a mouse model with a strong type I interferon response, but not in wild-type mice. We will test whether the difference in the effect of pDCs in these genotypes is due to differences in pDC localization within the lung or pDC activation state. Study Design: I will use our novel mouse model of Mtb infection that recapitulates the strong type I interferon response of human Mtb progressors to dissect pDC biology in response to a bacterial infection. This goal will be accomplished by leveraging flow cytometry, cutting-edge imaging approaches, single cell RNA-sequencing, and mouse genetics. Potential Impact: By characterizing pDC function during Mtb infection at the cellular level, we can identify pDC-specific targets that can serve as a basis for host-directed therapies to treat Mtb disease. Such therapeutics would constitute a major advance.

NIH Research Projects · FY 2025 · 2025-06

Our research focuses on understanding how long noncoding RNAs (lncRNAs) promote non-small cell lung cancer (NSCLC) to address the critical need for improved biomarkers and targeted therapies. Lung cancer is currently the leading cause of death worldwide, accounting for more than 150,000 deaths a year in just the United States. Approximately 85% of lung cancer patients have NSCLC and over 50% of these patients present with metastasis at their initial diagnosis. Historically, NSCLC research has primarily focused on the deregulation of protein-coding genes to identify oncogenes and tumor suppressors as potential diagnostic and therapeutic targets, thereby under-representing the emerging roles of long non-coding RNAs (lncRNAs). To address this critical knowledge gap, we focused on the discovery and functional characterization of novel lncRNAs that promote tumorigenesis and aggressive phenotypes in NSCLC patients. Through a pan-cancer computational analysis we discovered that the expression of our recently discovered oncogenic lncRNA, RNA associated with metastasis 11 (RAMS11), was elevated in NSCLC patients harboring mutations in the NRF2 signaling pathway (NRF2 activating mutations and KEAP1 inactivating mutations). Our preliminary data shows: (1) RAMS11 promotes aggressive phenotypes, (2) NRF2 transcriptionally activates RAMS11 by binding to its promoter region, (3) RNA-Seq analysis of models manipulating NRF2 and/or RAMS11 revealed overlapping downstream regulatory programs, (4) NRF2 and RAMS11 interact, and (5) NRF2 transcriptional regulation of canonical targets was dependent on RAMS11 expression. Notably, while NRF2 is dependent on RAMS11 to transcriptionally regulate canonical target genes activated in lung epithelial cells and NSCLC cells, we also demonstrated that RAMS11 may mediate a cancer specific NRF2 regulatory program. Collectively, this serves as a strong rationale for our hypothesis that RAMS11 is necessary to confer NRF2-dependent oncogenic phenotypes in NRF2/KEAP1 mutant NSCLC lung cancer patients. Here we will determine the role of RAMS11 dependent NRF2 transcriptional regulation of cancer-specific, non-canonical target genes and evaluate how RAMS11 interacts with NRF2. Our proposal will significantly advance the lncRNA tumor biology field by providing the first evidence of RAMS11-dependent NRF2 regulation to confer oncogenic phenotypes in vitro and in vivo.

NSF Awards · FY 2025 · 2025-06

Rainfall patterns in Central America and northern South America are changing as global climate warms, and are associated with disease outbreaks such as Dengue fever and agricultural losses from drought and flooding. The shifts in rainfall have previously been attributed to migration of the Intertropical Convergence Zone (ITCZ), a band of clouds and rain around the equator that tracks the Sun north and south through the seasons. However, it is becoming clear that the observed rainfall patterns can not be fully explained by ITCZ migration. Drivers of the change in rainfall are key uncertainties in future climate projections in this region and, consequently, the projected impacts on human livelihood and safety. This project will use sediments collected from lakes in Guatemala and Venezuela to reconstruct rainfall through the last 10,000 years by measuring the hydrogen isotope ratios of leaf wax molecules, which originate from the surrounding vegetation and reflect the local rainfall. These data will be synthesized with other climate datasets, and the spatial pattern in rainfall and isotopes will be used along with climate models to investigate the contributions of a variety of atmospheric phenomena. The foundation of this research project is investigation of the rainfall patterns in Earth's climate zones. These foundations map to many of the Missouri grade 6-8 learning standards, for which science curriculum resources are scarce. This project will partner with teachers to identify needs and co-develop, field test and improve curriculum, and disseminate materials across the Midwest. The goals of this project are to reconstruct Holocene hydroclimate and vegetation change in the Central America, northern South America (CANSA) region with leaf waxes from six previous collected and dated sediment cores; synthesize the multiple proxy records from these cores to identify spatiotemporal patterns in centennial, millennial and Holocene variability; analyze new and existing model simulations for the dynamics that drive rainfall changes; and compare the data and model simulations to identify mechanisms of rainfall change in the Holocene. The Broader Impacts are to develop grade 6-8 climate science lesson plans in partnership with teachers and disseminate the resources through the Midwest Climate Collaborative's educator network and design a lab for an undergraduate class. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2025 · 2025-06

PROJECT SUMMARY/ABSTRACT Alzheimer’s disease (AD) is a global public health priority as nearly 55 million of the world’s population live with dementia, with cases projected to triple to 150 million by 2050. Dementia prevalence varies across populations, and differences are due to complex relationships across demographic and social determinants of health (SDOH). Social isolation may lead to decreased cognitive stimulation, more stress and depression, higher physical inactivity, and increased neuroinflammation among older adults (OA). The overarching goal of this study is to examine and improve the validity and the generalizability of digital signals collected from everyday life, ranging from driving to other activities of daily living, in identifying biological AD using a large, diverse cohort. Our Specific Aims will (1) Determine the ability of digital markers of social isolation (smartwatch) and life space (datalogger) to cross-sectionally distinguish between OA with/without preclinical AD and cognitive impairment, (2) Model longitudinal trajectories as a function of driving behavior and physical activity to determine if OA with preclinical AD experiences greater life space constriction and social isolation over time, (3) Explore the effects of S/SDOH factors, including air pollution (PM2.5), neighborhood deprivation, green space, and cognitive stimulation on social isolation and life space. To accomplish this, a multidisciplinary team of experts will jointly assemble cohorts representing two geographically distinct and socio-cultural diverse sites (St. Louis, Greenville). We will capitalize on existing institutional infrastructure to longitudinally follow 350 cognitively normal older adults in St. Louis and 150 cognitively normal older adults in Greenville. This study will prospectively collect cross-sectional data on molecular plasma biomarkers, SDOH, and longitudinal digital markers, including naturalistic driving and physical activity/mobility for three to five years. This proposal is one of the first to examine preclinical AD, the natural environment, and longitudinal data on life space and social mobility. Once obtained, this knowledge can be used to map digital signals from daily life as a neurobehavioral biomarker that may be monitored and used for clinical trials and interventions throughout the disease progression of AD.

NSF Awards · FY 2025 · 2025-05

The project will advance a new approach to monitoring drinking water quality that will fill gaps in the current monitoring framework that leave millions of Americans at risk of exposure to harmful contaminants. The approach uses commercially available point-of-use (POU) filters as both treatment tools and monitoring devices. The new monitoring approach will be coupled with new communication tools that will be designed to increase understanding of water quality, communicate test results, and recommend next steps to a diverse cross-section of end-users. The new monitoring approach and communication tools will be evaluated under real-world conditions through pilot-testing for two end-use cases. The first is serving public water systems concerned about lead in customer taps. The second is serving the 23 million American households who receive their drinking water from private wells. The project will benefit urban and rural residents across the country to increase access to safe drinking water and restore trust in water supplies. The specific objectives of the project are to (1) refine and expand the POU filter monitoring approach for high priority contaminants, filter types, and water compositions; (2) develop communication tools to increase understanding of water quality, communicate test results, and recommend next steps to a diverse cross-section of end-users; (3) evaluate feasibility and cost when implementing Trusted Tap under real-world conditions; and (4) establish a sustainability plan to expand water quality monitoring and provide communication solutions beyond the period of NSF funding. In parallel efforts the project will refine the filter-based monitoring approach and develop the necessary communication tools. These efforts will feed into pilot-testing for two end-use cases. The sustainability plan will include the development of a business model architecture, design of a go-to-market strategy, and initiation of commercialization and funding processes. The convergent research will involve close partnerships among two universities, a major public water system, two rural community assistance programs, and a Tribal nation that will be guided by an advisory board with diverse perspectives. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2026 · 2025-05

PROJECT SUMMARY: OVERALL This Program Project Grant (PPG) aims to address important gaps in knowledge concerning the genetic, molecular and biologic control of von Willebrand factor (VWF) and pathogenesis of von Willebrand disease (VWD). The PPG consists of 4 projects and 3 cores that all focus on VWF and mechanisms influencing its genetic regulation, expression, dysfunction, increased clearance, interactions with FVIII and the role of carbohydrate modification in VWF biology. While this is a new PPG application, this program has access to tens of thousands of samples and extensive biodata from the pre-existing PPG, the Zimmerman Program. Project 1 will focus on resolving, by identifying common and rare variants, including complex loci, the condition called low von Willebrand factor; the 20-25% increase in VWF levels seen in individuals from African Ancestry; and the increase in VWF levels observed with aging. Cohorts of subjects with low VWF, with no sequence variants in VWF will undergo whole genome and long read sequencing. Whole genome sequencing of multiple multiethnic cohorts will allow for admixture studies that will leverage the power of trans-ethnic fine mapping and haplotype association. In active collaboration with Project 1, Project 2 will assemble and analyze one of the largest collections of phenotypic, genomic, and multi-tissue transcriptomic, proteomic and other -omics data to identify molecular signatures of low-VWF/VWD that will lead to novel insights into pathways associated with disease etiology. Project 2 will analyze human multi-omic data in large and well-characterized cohorts and shed additional light on the pathological events that lead to low-VWF/VWD and to age-dependent changes in VWF. With these discoveries, we will generate polygenic risk scores for low VWF and VWD. Project 3 will investigate distinct features of how and where VWF and FVIII are expressed; whether an intracellular chaperone effect of VWF can reduce the cellular stress associated with FVIII expression, and will characterize the influence of VWF on the clearance and subsequent immunogenic nature of FVIII. Project 4 will focus on the role of glycans in VWF biology and will investigate the roles that N and O glycans play in VWF biosynthesis characterize glycans involvement in VWF activation and define the impact of glycans in regulating VWF clearance pathways. Core A is the administrative core that will facilitate communication between the centers involved in this multi institutional PPG, and will provide all administrative oversight. Core B is the Bioinformatics Core and the site for all genome and mass spec -omics studies involved in this PPG. In addition, Core B will operate the Zimmerman Analytical Platform, our secure web-based interface, developed to oversee the exchange of MultiOmics data, patient samples and biodata on the Velos Database in Core C. Core C is the PPG Biorepository and Central Laboratory that will oversee the distribution of approximately 95,000 samples from 7,000 individuals to the different projects and will coordinate the recruitment of 7 Primary Clinical Centers that will be following our enrolled subjects. Together these studies will comprehensively study novel aspects of VWF biology and pathobiology, and will shed new light on the pathogenesis of VWD.

NIH Research Projects · FY 2026 · 2025-05

Postpartum hemorrhage (PPH) is defined as the loss of 1 L of blood or more within 24 hours after childbirth. In the United States, PPH is the leading cause of maternal morbidity and causes 11% of maternal deaths. Importantly, PPH is the most preventable cause of maternal mortality, and the leading factors causing preventable PPH are delays in diagnosis and treatment. Thus, there is an urgent need for an early and accurate PPH detection system that can facilitate prompt treatment to prevent PPH-related morbidity and mortality. During hemorrhage, several physiologic compensation mechanisms occur to help stabilize the patient, delaying the time until global vascular indicators such as blood pressure and heart rate are affected. These vital signs, as well as the visual estimate or quantitative measurement of blood loss, are the current methods used to detect PPH, but provide delayed measures of PPH. Additionally, vital signs can be affected by medications or intravenous fluid administration, making the interpretation of vital signs difficult. Non-invasive and continuous monitoring of cardiovascular parameters would enable rapid determination of blood loss, even in the presence of strong compensation or medical intervention, to reduce morbidity and mortality caused by PPH. Light-based technologies are well suited to noninvasively measure blood flow and blood content, which can provide accurate estimates of cardiovascular parameters. However, light-based tools can be impacted to skin pigmentation due to melanin absorption and must be carefully designed and tested to ensure they work accurately for all patients. The study team has specifically designed novel light-based sensors to minimize potential skin pigmentation errors and correct them if warranted, and capture important cardiovascular parameters. Preliminary experiments have demonstrated strong correlations between the wearable sensor data and hemorrhage severity. This proposal will use a novel multipigment swine hemorrhage model to test the wearable sensor performance on swine with differently pigmented forelegs to isolate skin pigmentation as a potential source of error and facilitate error correction if needed. The sensor will also be tested in human subjects with a broad range of skin pigmentation who are undergoing blood loss to assess wearable sensor accuracy. If successful, the wearable sensor will provide a continuous and accurate estimation of blood loss, facilitating early warning for improved PPH management and patient outcomes.

NIH Research Projects · FY 2025 · 2025-05

Abstract Despite effective antiretroviral therapy (ART), HIV-1 mainly persists in a small pool of latently infected, resting memory CD4+ T cells in people living with HIV-1 (PLWH). Virus eradication with ART alone will not be possible. The stability of the viral reservoir is a consequence of infection of cells that either have expanded or are destined to expand in response to cognate antigens or cytokines. CCR5 and CXCR4 are two co-receptors for HIV-1 entry. CCR5-tropic virus is critical for the establishment of infection and dominates the pool of viruses in blood and tissues early after infection. In PLWH, latent HIV-1 is predominantly CCR5-tropic, which is a reflection of selective transmission and dominant replication of CCR5-tropic virus before ART initiation. CCR5 is expressed predominantly by terminally differentiated CD4+ T cells which lose proliferation capacity and are prone to cell death. To seed the latent reservoir, CCR5-expressing CD4+ T cells are infected, carry integrated and transcriptionally silent HIV-1 provirus, and differentiate into long- lived memory cells. To maintain the latent reservoir, cells carry integrated HIV-1 proviruses proliferate despite potential viral cytopathic effects or immune clearance. Therefore, studies on the mechanisms suppressing terminal differentiation of CCR5+CD4+ T cells are significant. In this study, we plan to address the following three questions. 1) How does Bach2 inhibit terminal differentiation of CCR5+CD4+ T cells and how does it impact viral reservoir seeding in humanized mice? 2) Can Bach2-mediated differentiation of CCR5+CD4+ T cells results in long-lived memory cells with proliferation capacity? 3) Can we target Bach2 or its downstream molecules to prevent HIV reservoir seeding? Understanding this process can help us develop strategies to block seeding or expansion of the stable viral latent reservoirs in vivo.

NIH Research Projects · FY 2026 · 2025-05

Project Summary As we envision employing personalized approaches in medical practice, it is important to define the genomic, cellular, and molecular etiologies that underlie disease pathogenesis and determine how these determinants are modified by intrinsic and extrinsic influences (risk factors). This challenge is nicely illustrated by Neurofibromatosis type 1 (NF1), a rare neurogenetic condition caused by germline mutations in the NF1 gene. The hallmark of NF1 is extreme clinical heterogeneity, where children are prone to the development of a wide variety of neurological problems, including cognitive and behavioral problems (neurodevelopmental deficits; NDDs) and low-grade brain tumors (low-grade gliomas; LGGs). While making the diagnosis of NF1 in a child is usually straightforward, it is currently not possible to predict what medical problems will develop in any given child, how their disease will progress, and what therapies will be most effective. Moreover, our current therapies are effective for only a subset of patients, exhibit variable non-sustained responses, and sometimes result in accelerated growth following treatment cessation. We theorize that these disappointing outcomes reflect the use of a reductionist approach, in which a single cell type (e.g., neuron, cancer cell) or signaling pathway (e.g., MEK or mTOR activation) is targeted, largely ignoring the fact that these medical features result from the interactions of numerous distinct cell types (e.g., tumor cells, neurons, T cells, microglia) each with unique signaling pathway dependencies and tissue-level cellular and molecular interdependencies. Based on observations made possible by the flexibility of our prior R35 Research Program Award (RPA), we now hypothesize that these medical problems should be conceptualized as systems biology abnormalities in which risk factors (disease modifiers) converge on the specific multicellular circuits that drive and maintain these clinical phenotypes. For this new RPA, we propose to deploy a more holistic and integrated approach to elucidate the multicellular circuits that underlie the development and progression of NF1-associated LGG and NDD, the two most common nervous system problems in children with NF1. Leveraging patient-derived and CRISPR-engineered human iPSCs, patient-derived primary LGG cell lines, mice with patient-derived germline NF1 gene mutations, cell type-specific Nf1 conditional knockout strains, and multi-omic bioinformatic analysis approaches, we aim to (1) mechanistically define the cellular and molecular interdependences that underlie NF1 LGG and NDD pathobiology and (2) determine how these multicellular circuits are modified by risk factors to create the clinical heterogeneity that characterizes NF1. The overall mission of this project is to establish the etiologic bases for NF1 clinical variability and create a blueprint for other similar neurogenetic disorders affecting children and adults.

NIH Research Projects · FY 2026 · 2025-05

Project Summary Psychosis disorders are amongst the most debilitating and difficulty to treat forms of psychopathology, necessitating the development of early identification and prevention efforts. The development of early screening and prevention efforts requires first identifying reliable early risk indicators of worsening psychosis spectrum symptoms. The development of psychosis is preceded by the presence psychotic “like” experiences (PLEs) and then attenuated psychotic symptoms (APS). Ideally, prevention efforts would identify youth prior to the functional decline associated with clinical high-risk states (e.g., APS). Theoretical models posit that in order for PLEs to worsen and develop into psychotic disorders, additional environmental exposures are required (termed the persistence-proneness-impairment model). However, this theoretical model has not been directly tested and therefore it is not yet clear how PLEs evolve into APS or what risk factors predict which youth with PLEs will develop APS. Early prevention efforts have developed risk calculators for conversion to psychosis, but questions remained regarding whether these developed calculators will translate to the development of APS. The current application will address these pressing questions by capitalizing on a unique and time-limited opportunity provided by the Adolescent Brain Cognitive Development (ABCD) study. Aim 1 will examine the prevalence of APS among youth in the ABCD Study sample, expanding initial data collection efforts to provide robust estimates of APS amongst youth endorsing PD-PLEs and compare these rates to persistent internalizing or externalizing symptoms, as well as compare rates of APS to other forms of diagnosable psychopathology. The application will also identify predictors of transition from PLEs to APS (Aim 2), including whether, consistent with the persistence- proneness-impairment model, worsening environmental exposures over time predict transition to APS. The applicant will also examine whether psychosis risk calculators developed for conversion to psychosis also predict APS amongst youth endorsing PD-PLEs (Aim 3). The PI and her team have the unique necessary experience to conduct this research. Thus, consistent with NIMH Strategic Objective 3: Strive for Prevention and Cures, the present proposal will fill several gaps in the extant literature, improving our understanding of the nature of early worsening psychosis spectrum symptoms, including rates of APS and reliable risk factors in comparison to other forms of psychopathology, information that will provide the foundation for screening and prevention efforts.

NIH Research Projects · FY 2026 · 2025-05

Project Summary/Abstract Regulatory T cells (Tregs) are essential for maintaining immune tolerance, but the mechanisms governing their activation are not fully understood. Our preliminary data reveals a novel role for cDC1, a type of dendritic cell previously thought to primarily activate CD8 T cells, in Treg activation. We have found that cDC1s uniquely present self-antigens on MHCII molecules, a process crucial for Treg development and maintenance. Additionally, our CRISPR/Cas9 screen identified WDFY4, a BEACH domain protein, as essential for antigen presentation by cDC1s. This project will investigate the hypothesis that cDC1s utilize a WDFY4-dependent pathway to coordinate both MHC class I and II antigen processing from specific sources, particularly cell- associated antigens. This pathway is hypothesized to be critical for both effective immune responses against viruses and tumors, as well as for Treg selection and survival, thereby preventing autoimmunity. The proposed research aims to: 1) Determine the impact of WDFY4 on the T cell receptor (TCR) repertoire, particularly in Tregs, to identify self-reactive TCRs dependent on WDFY4 and assess their function in vivo; 2) Compare the MHC class I and II immunopeptidomes of cDC1s and cDC2s in the presence and absence of WDFY4 to identify the cellular source of self-peptides dependent on WDFY4 for presentation.; and 3) Identify and validate WDFY4 interacting proteins to elucidate the molecular mechanism by which WDFY4 controls MHCII antigen processing for self-antigens. This research has the potential to redefine our understanding of the immune mechanisms underlying coordinated antigen presentation and revolutionize current paradigms of immune response orchestration by cDC1s. Understanding these mechanisms could lead to novel therapeutic approaches for autoimmune diseases, cancer, and infectious diseases.

NSF Awards · FY 2025 · 2025-05

The functional cells in female ovaries are follicles, which are spherical aggregates of cells containing an immature egg. Follicles cannot be replenished, so the total number declines as some follicles are selected for growth every month. The remaining follicles remain dormant to preserve reproductive function over several decades. The mechanisms that determine which follicles are selected for growth and which remain dormant is poorly understood. A better understanding of these mechanisms could inform new treatments for infertility caused by polycystic ovary syndrome, cancer treatments, or aging. Studies suggest that changes in the stiffness of the follicle microenvironment may trigger follicle growth. The goal of this CAREER project is to investigate how dynamic stiffness influences follicle growth to interrogate this relationship. The project will use a new bioelectronic material that changes stiffness in response to an applied electric potential to modulate, study, and optimize mechanobiological functions of ovarian follicles. The project will support grade 6-12 outreach activities and curricula in biomaterials engineering as well as undergraduate learning modules, all to support increased participation in STEM fields. This CAREER project will investigate how dynamic stiffness of the microenvironment of ovarian follicles influences their growth characteristics. Extracellular matrix stiffness spatially varies in the ovaries and these different regions are associated with different follicle growth phenotypes. It is hypothesized that when follicles observe a decreased stiffness, cell signaling pathways are disrupted and dormant follicles are activated to a growing state. However, there are no material systems available that can present defined mechanical stimuli to follicles in a cytocompatible fashion. The goal of this proposal is to develop a biomaterial platform to investigate how microenvironment stiffness dynamics result in changes to follicle growth rates and the corresponding cell signaling pathways. Conducting polymers will be used to develop 3D bioelectronic scaffolds that change matrix stiffness in response to an applied electrical potential. The research objectives include (1) to define processing-property-function relationships of conducting polymers to optimize the stiffness range to match the ovarian microenvironment, (2) to determine cell signaling changes of ovarian cells in response to dynamic matrix stiffness in 2D culture, and (3) to determine if dynamic stiffness programs can control follicle growth rates using 3D printed microporous scaffolds. The outcome of this project will be a novel tool for the field of mechanobiology. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2026 · 2025-05

PROJECT SUMMARY In the United States, the continued rise in opioid overdose deaths is primarily driven by the synthetic opioid fentanyl, with opioid-induced respiratory depression (OIRD) being the main cause of death. Fentanyl exhibits both a faster onset of OIRD and higher potency for mu opioid receptor (MOR) binding compared to heroin and morphine, making successful intervention strategies more difficult to implement. The increasing availability of the competitive opioid receptor antagonist naloxone, including its widely distributed formulation Narcan, has made it possible for bystanders to readily administer it to someone that has overdosed. However, one major drawback of NLX is that it precipitates immediate withdrawal, which is highly aversive. This presents an additional challenge for someone caring for an individual that has overdosed. While many studies have evaluated central mechanisms underlying OIRD, less attention has been given to peripherally-located MOR. Our preliminary data demonstrate that the peripherally restricted MOR antagonist naloxone methiodide (NLXM) effectively reverses OIRD and is not aversive in rodents. Together, this highlights a substantial peripheral component of OIRD, and suggests that peripheral MOR antagonists may be a viable treatment strategy for managing overdoses without withdrawal or aversion seen with NLX. Many peripherally acting MOR antagonists (PAMORAs) are used for managing opioid induced constipation. Therefore, a primary goal of this grant is to evaluate PAMORAs in the context of fentanyl exposure to determine whether they can be used to prevent or reverse OIRD, and whether reversal of OIRD using these MOR antagonists minimizes withdrawal or aversion in rodents. A secondary goal of this proposal is to evaluate potential peripheral mechanisms underlying OIRD. The nucleus of the solitary tract (nTS) is the first central site that receives sensory afferent information from the periphery. This includes MOR-expressing vagal afferent inputs originating from the nodose ganglion. Our preliminary data demonstrate that fentanyl-induced nTS neuronal activity is mediated by peripheral MOR. Given the presynaptic location of MOR in the nTS, primarily on vagal afferent inputs, a major goal of this proposal is to evaluate a vagal-nTS pathway in the context of OIRD. The nTS is a heterogeneous nucleus containing catecholaminergic, GABAergic and MOR-expressing nTS neurons. These cells receive inputs from vagal afferents, but the role of these subtypes during OIRD is unclear. Overall, these studies aim to 1) repurpose the use PAMORAs to prevent and rescue fentanyl-induced overdoses devoid of unwanted side effects, which may lead to potential new therapeutic avenues; 2) assess the MOR mechanisms in a vagal-nTS pathway mediating OIRD and finally, 3) dissect cell-specific postsynaptic mechanisms within the nTS that contribute to OIRD. Generated studies will help develop novel, life-saving treatment for fentanyl overdoses.

NSF Awards · FY 2025 · 2025-05

Understanding how airway cells function is essential for studying lung diseases and developing improved treatments. The tiny hair-like structures on airway cells, known as cilia, play an important role clearing mucus and harmful particles from the lungs. When cilia do not function properly, conditions such as cystic fibrosis and chronic respiratory diseases can develop. Current imaging methods for studying cilia have limitations. These methods require artificial dyes that may interfere with the cells or lack the ability to capture the complex motion of cilia in three dimensions. This project aims to develop a new imaging technology which will allow scientists to image cilia movement in 3D without the need for labeling dyes. This advancement will provide a clearer picture of how airway cells function in health and disease. The proposed capabilities could aid in the development of better treatments for respiratory disorders. Through partnerships with the Colorado Photonics Industry Association (CPIA) and the Washington University Cardiovascular Research Summer (CardS) Program, undergraduate and graduate students will gain valuable experience in advanced imaging technologies. The project will also help prepare a skilled workforce for future biophotonics innovations, addressing industry needs and supporting economic growth in science and technology fields. This project will develop the first high-speed 3D Dynamic Contrast Microscopic Optical Coherence Tomography (3D DyC-μOCT) system, a label-free optical imaging technology designed to study human airway organoids with high temporal and spatial resolution. Traditional imaging methods either lack sufficient depth and speed for real-time volumetric studies or require fluorescent labels that introduce experimental complexity and phototoxicity. 3D DyC-μOCT overcomes these challenges by integrating a novel swept-source laser architecture with parallel imaging using space-division multiplexing and lithium niobate on insulator (LNOI) photonic integrated circuit technology. The project is structured around four key objectives: (1) engineering a broadband, high-coherence LNOI-based swept laser source to achieve superior axial resolution and imaging depth, (2) designing a scalable optical imaging platform to overcome current voxel rate limitations, (3) integrating 3D DyC-μOCT with widefield fluorescence microscopy to allow cross-validation of imaging data, and (4) applying 3D DyC-μOCT to study ciliary beating in airway organoids, demonstrating its potential for pulmonary research. The system will provide a new tool for studying airway physiology in disease models with applications in respiratory health research, drug screening, and personalized medicine. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2026 · 2025-05

Project Abstract Chimeric Antigen Receptor (CAR) T cells have revolutionized the treatment of hematologic malignancies, and recent clinical trials have also shown the potential of using CAR T cells against other pathologies, such as autoimmune diseases. Despite the common notion of brain-immune privilege, the presence of adaptive immune cells within the CNS has long been known to modulate cognition, suggesting that the immune system might be a viable target for improving cognition. We and others have implicated interactions between the CNS and the immune system in the development and progression of Alzheimer's disease (AD). T cells, specifically, have a complex role in AD pathology, with both protective and destructive functions. The exact mechanisms by which T cells convey pro-cognitive benefits remain poorly understood in many cases, although cytokine release remains the prevalent theory. For example, we recently showed a mechanistic link between IL- 4 secretion by meningeal T cells, improved memory, and rescued synapse function, and a pro-cognitive role of IL-4 has also been demonstrated in AD mouse models. While AD treatments using monoclonal antibodies have shown efficacy in reducing the level of amyloid beta (Aβ) plaques, their effects on cognition are limited and more powerful treatments are needed. Here, we propose an alternative approach in which amyloid beta (Aβ) plaques and other AD-related brain antigens are utilized as AD-specific signals to home neuroprotective T cells that will modulate the brain microenvironment to alter AD trajectories and improve cognition. In the Exploratory R61 phase, we will design and develop CARdinal (CAR Disease INterventions for ALzheimer's) T cells that are programmed to expand and persist at the site of AD pathology by utilizing cytokine signaling in our CAR constructs, rather than “classic” cytolytic CAR T cells. These T cells will release neuroprotective payloads that we propose will support neuronal function and improve cognition. Given that IL-4 can modulate memory and that BDNF can have protective effects in rodent and primate models of AD, we will engineer our CAR T cells to secrete IL-4 and/or BDNF as proof-of-concept therapeutic cargos. If defined milestones for the R61 phase are met, we will then pursue the Developmental R33 phase, in which we will test the hypothesis that repurposing our novel CARdinal T cells towards a proliferation and cargo secretion function, rather than a cytotoxic trajectory, will yield CAR T cells that are safe and effective for in vivo delivery of AD-therapeutic cargos to the brain with minimal cytotoxic effects. We will use single-cell multiomic technologies to determine the CARdinal T cells’ mechanism(s) of action by measuring cellular interactions, spatial organization, and temporal transcriptional changes in the CNS. We hypothesize that BDNF- and IL-4-secreting CAR T cells will significantly modify the CNS microenvironment, specifically by reprogramming microglial gene signatures and cellular programs, thus preventing cognitive decline. We expect that these studies will yield engineered neuroprotective CAR T cells that are safe and effective for in vivo use in AD.

NIH Research Projects · FY 2026 · 2025-05

PROJECT SUMMARY/ABSTRACT This proposal describes a four-year Career Development Plan (CDP) to prepare R. Alex Harbison, MD to become an independent physician-scientist focused on targeting polyamine (PA) metabolism to increase immune responses to head and neck squamous cell carcinoma (HNSC). There is an urgent need to identify less toxic, targeted therapy for HNSC. Leveraging the immune system to treat HNSC is a promising approach to decrease morbidity, although the response rate is limited due, in part, to immunosuppressive PA levels in the tumor microenvironment (TME). PAs are a family of small polycations important for immune cell homeostasis. T cells require PAs for activation (i.e., via RNA translation and chromatin regulation) and differentiation (T helper subsets). However, PAs are enriched in the TME which impairs 1) anti-tumor T cell function and antigen-presentation by dendritic cells, and 2) supports immunosuppressive myeloid cells. PAs are 15-fold higher than normal in HNSC. Inhibition of both PA synthesis and uptake, known as PA blockade therapy (PBT), has dual effects on immunity. It can promote anti-tumor immune responses while also decreasing inflammation in autoimmune mouse models. Thus, the overall objective of this proposal is to define the mechanisms through which PAs modulate anti-tumor immunity. The central hypothesis is that dysregulated PA metabolism in the TME diminishes anti-tumor T cell responses which can be therapeutically targeted. The specific aims of this proposal are 1) to test mechanisms through which extracellular PAs mediate T cell responses and antigen-presentation in the TME and 2) to evaluate the effect of PBT on cos+ T cell and immune responses in the TME. The proposed studies will utilize quantitative histology and spatially resolved mass spectrometry imaging, T cell culture and co-culture with tumor cells and dendritic cells, metabolomics and carbon tracing, PA transporter knockout, and in vivo murine HNSC models to evaluate the effect of PA metabolism on anti-tumor immune responses. The mentors, Ors. Peng, Patti, and Puram, will primarily oversee the CDP providing training on immune cell signaling and development, gene knockout in primary immune cells, animal models in immunology research, and metabolomic measurements. The Research Advisory Committee will add complementary expertise in systems immunology, innate immunity and nutrient utilization, and metabolic regulation of immune function. This group is the ideal forum to chaperone the candidate's progression as a physician-scientist. The training plan includes achievement of technical expertise, grant writing skills, responsible conduct of research, and mentorship though direct experience in the lab, seminars, workshops, coursework, and presentations at national/international meetings. Immersion in the research milieu of Washington University given its extensive track record, resources, and commitment to physician-scientists provides the ideal training environment. This K08 will provide the Pl necessary skills to obtain research independence.

NSF Awards · FY 2025 · 2025-05

Indoor air quality is affected by a variety of chemical and biological factors. For example, building materials and furniture surfaces inside homes are sources, sinks, and temporary reservoirs for chemicals. At the same time, microbes such as bacteria, viruses and fungi can grow on these surfaces. Usually, researchers study the chemical factors and biological factors affecting air quality separately. This project will investigate them in combination by exploring, for example, how chemical compositions on surfaces or in the surrounding air can trigger changes in the way microbes grow on various surfaces typically found in a home. By studying the chemical and biological factors together, the project will produce results that can inform air quality guidelines to improve indoor environmental quality. The project will also introduce local middle school students to air quality issues by helping them build environmental sensors that will be deployed on campus to monitor environmental conditions. This project will determine how perturbations to indoor surface chemical composition and indoor air pollutant distribution impact microbial gene expression and microbial volatile organic compound (mVOC) emissions, to better understand and mitigate the chemical and biological drivers of poor indoor air quality. Laboratory chamber experiments, volatile organic compound measurements, and microbial gene expression analysis will be performed to support the following research objectives: (1) Establish how building material surface composition influences microbial gene expression and emissions; and (2) Build networks to connect environmental pollutant exposures to microbial gene expression and emissions. This research will expand knowledge in indoor chemistry and microbiology by revealing how indoor surface and air composition influence indoor microbial communities, and vice-versa. The study will use RNA sequencing to connect microbial community metabolism with surface chemical composition and pollutant exposure in the built environment. Indoor environmental conditions, especially increased humidity in non-climate-controlled homes, could impact the chemical composition of indoor material surfaces and thus alter fluxes of chemicals between surfaces and air, as well as create favorable growth conditions for microbes. This study will advance our fundamental understanding of the connection between surface conditions and pollutant exposures, microbial gene expression, and mVOCs in the evolving indoor environment. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2026 · 2025-05

Project Summary: Defining a role and functional consequences of the disordered N-terminal domain from the Borna Disease Virus Phosphoprotein PI: Madison A. Stringer Borna Disease Virus causes fatal neurological diseases in mammals. Among a handful of proteins in the viral genome, phosphoprotein (P) is an essential component for genome replication. It required for bridging the genome to the polymerase, and this bridging requires an oligomeric form of P. P itself has three domains: the central helical domain is flanked by two intrinsically disordered regions (IDRs). The helical domain binds the polymerase, the C-terminal IDR is required to bind the nucleocapsid protein, and the N-terminal IDR is required for binding RNA and driving the formation of compartmentalized viral factories in the cell. Despite its essential role in genome replication, we know very little about P, and all biochemical studies to date have focused on the folded domain. I hypothesize that the physical properties encoded in the sequence of the IDRs are important to P’s functions. A major knowledge gap is understanding how the N-terminal IDR (NTD) specifically can modulate the functions of P: its self-association, RNA binding, and how oligomerization and RNA binding properties of P can influence the activity and localization of the viral polymerase. My central hypothesis is that the prolines and charged residues in P’s sequence modulate the activities of P by enhancing its self-association and affinity to RNA, ultimately altering L localization and activity in cells. To test this hypothesis, I will use a combination of biochemical and biophysical techniques to characterize the NTD and its interactions. Overall, this proposal aims to biophysically characterize P and use insights from these experiments to allow for mechanistic understanding of its function in cells. At the same time, it will offer a fundamental opportunity to develop skills in single-molecule spectroscopy, cell biology, and virology, fostering the multidisciplinary training needed for my future as an academic biomedical investigator.

NIH Research Projects · FY 2026 · 2025-05

ABSTRACT Metabolic diseases are a pressing public health issue in the United States. With the meteoric rise of insulin resistance, obesity, and atherosclerosis, mechanistic understanding of lipid metabolism could not be more imperative. Many of these metabolic disorders involve improper storage of lipids into cellular lipid storage organelles known as lipid droplets (LDs). These unique organelles, which contain a core of triglycerides (TAGs) and other neutral lipids, accumulate when dietary free fatty acids are abundant but are consumed when there is a high demand for energy. Although the metabolic roles of LDs are well appreciated, the mechanisms employed to regulate the growth and catabolism of individual LDs are poorly understood. It has emerged that protein networks that reside on the surface of LDs play critical roles in controlling the release of the lipids stored within. We have previously found that a protein that drives physical contacts between the ER and LDs, DFCP1, plays a key regulatory role in modulating the activity of adipose triacylglycerol lipase (ATGL) the rate limiting enzyme in LD catabolism. Specifically, we found that DFCP1 recruits and sequesters ATGL on the LD surface - even under conditions that promote the activation of ATGL - such as phosphorylation by energy sensing kinases, AMPK and PKA, or by interacting with cofactor CGI-58. Ablating DFCP1 from cells or forcing DFCP1 to disassemble from LDs leads to a dramatic increase in ATGL dynamics and lipolysis. Under these conditions, LD turnover is greatly accelerated leading to rapid breakdown of LDs and a surplus of free fatty acids in cells. Owing to the importance of this interaction, we found that ablation of DFCP1 from stem cells leads to changes in mitochondrial activity and lipid metabolism that ultimately leads to severe impairment of the ability of cells to differentiate. How DFCP1 specifically, and ER contact sites in general regulate lipid metabolism is not well understood, much less the roles these proteins serve in stem cell metabolism during differentiation. To address these gaps in our understanding of LD lipolysis, we are using bottom-up approaches to biophysically and structurally define how lipolytic complexes are assembled and regulated by protein networks on the LD surface. We will also employ novel optical biosensors to examine how organelle interactions correlate with metabolism and to define how LD contact site proteins regulate LD interactions with other organelles. Finally, we will examine how disruption of these LD contact site proteins and regulators of LD lipolytic complexes impairs the regenerative and differentiation capacity of stem cells. The mechanistic insight obtained by these studies will provide new understanding into how LD metabolism is regulated and helps to maintain cellular homeostasis, as well as how this process can be controlled to improve stem cell health and tissue regeneration.

NSF Awards · FY 2025 · 2025-05

2516787 (Yin). The Workshop on Urban Mining and Circular Economy in Construction aims to develop a roadmap leading to the advancement and widespread adoption of circular economy in the construction industry. The worshop is scheduled to be held during May 2025 at Washington University, St. Louis, MO. Transitioning to a circular economy is urgent and vital to achieving significant decarbonization, enhancing national economic resilience and fostering national prosperity. This transformation will replace traditional linear construction practices- take, make, consume, and dispose – with a sustainable, closed-loop system that minimizes waste, maximizes resource efficiency, and reintegrates materials into the supply chain. By promoting reuse, remanufacturing, and recycling, the circular approach enables locally available, high-value materials to be reclaimed through urban mining, driving sustainable innovation in the construction sector. Despite its potential, adoption is hindered by challenges such as the lack of advanced technologies, physical infrastructure, and digital systems, alongside entrenched reliance on new materials. Overcoming these barriers requires systemic changes to business models, policies, legislation, and workforce practices to unlock the economic and environmental benefits of building material reuse and recycling. This two-day workshop will convene a multidisciplinary group of stakeholders, including scientists, engineers, construction experts, policymakers, and social scientists, to identify barriers of urban mining and circular construction. Participants will collaboratively develop a roadmap for achieving a sustainable circular economy, while fostering innovation and knowledge-sharing through keynote presentations, panels, poster sessions, and networking opportunities. The workshop will also provide a platform for early-career researchers to share their work and receive feedback. Tangible outcomes include a comprehensive summary of key challenges and actionable near- and long-term solutions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2026 · 2025-04

Project Summary The KCNMA1-encoded BK Slo1 potassium channel plays a pivotal role in regulating neural activity and neurotransmitter release. KCNMA1 variants, or channelopathies, have been increasingly identified in patients with neurological disorders, representing a spectrum of clinical manifestations, ranging from epilepsy, neurodevelopmental anomalies to movement disorders. Given this heterogeneity, precision medicine emerges as a vital need for tailored diagnosis and treatment. To meet this challenge, our multidisciplinary team hypothesizes that different KCNMA1 variants influence distinct molecular gating mechanisms, leading to differential alterations of neuronal activities and varied clinical presentations. To test this hypothesis and to lay a solid foundation for future investigation of more KCNMA1 channelopathies, we aim to unravel the genotype- phenotype connections of three gain-of-function (GOF) KCNMA1 variants, D434G, A532V and N536H. Our previous publications and preliminary studies show that these GOF variants alter distinct BK channel gating mechanisms at the molecular level, and the patients show different clinical manifestations. In this proposal, we will closely compare the molecular gating mechanisms (Aim 1), neuronal activities and knock-in mouse behaviors (Aim 2) of these three GOF variants. In addition, we will strategically design and administer variant-specific modulators to either mimic or mitigate KCNMA1 channelopathies to further test the variant-specific alterations of neurological phenotypes. The variant-specific inhibitors may lead to the development of drugs with more specificity and thus with minimal effect on people with normal BK channels. Through molecular analysis, mouse model development, and innovative drug design, this research aspires to revolutionize our understanding of KCNMA1 channelopathies and accelerate the advancement of precision medicine solutions.

NIH Research Projects · FY 2026 · 2025-04

PROJECT SUMMARY Cells must maintain the integrity of their genome during mutagenic damage caused by endogenous or exogenous genotoxins. To do so, cells employ a multitude of genome-protective pathways. Cancer cells have a much higher mutation burden than non-malignant cells, and therefore are more genomically unstable. A common source of mutation in cancer is cytidine deamination caused by the endogenously encoded APOBEC3A enzyme. APOBEC3A normally functions as part of the innate immune system to restrict virus infection and retrotransposition, but when dysregulated can act on the cellular genome. Deamination events cause a spectrum of mutagenic outcomes which elicit DNA repair pathways and genome-protective responses. APOBEC3A deaminase activity is the cause of prevalent mutational patterns found in many human cancers, therefore it is imperative to understand the cellular factors that promote or mitigate mutagenesis. Our preliminary data identify the SMC5/6 (Structural Maintenance of Chromosomes 5/6) complex as essential to prevent genotoxicity from APOBEC3A activity. The SMC5/6 complex is highly conserved and has been studied mostly in budding yeast. From yeast models, SMC5/6 is known to play a role in support of both normal and stressed replication forks. APOBEC3A acts primarily on DNA at replication forks, and our data suggest that deaminase activity causes replication stress that is mitigated by the SMC5/6 complex. However, the mechanism by which SMC5/6 protects replication forks from APOBEC3A-mediated damage is unknown. The goals of this proposal are to define the impact of APOBEC3A activity on replication fork progression and the mechanism by which SMC5/6 protects forks from deaminase activity. Aim 1 will define the effect of APOBEC3A deaminase activity on replication fork progression and genome duplication. We will identify the cellular mechanisms that enable replication forks to tolerate obstacles presented by APOBEC3A activity, and how this influences overall mutational burden. Aim 2 will determine how SMC5/6 prevents replication-associated DNA breaks when APOBEC3A is active. Using proteomics, single-molecule imaging, and separation-of-function mutants, we will dissect the specific activities of SMC5/6 that confer replication fork protection. These studies will capitalize on our novel observation of synthetic lethality between APOBEC3A and loss of SMC5/6 to investigate mechanisms of genome protection by the SMC5/6 complex, which remain enigmatic especially in mammalian cells. The impact of the proposed studies will form a foundation for new targeted treatment options by defining mechanisms of DNA damage and genome protection in cancer.