Duke University

NIH Research Projects · FY 2026 · 2024-02

Abstract Salmonella enterica serovar Typhimurium is the causative agent of salmonellosis, leading to ~150 million cases of gastroenteritis annually around the world, making it one of the most common foodborne diseases. Salmonella enterica serovars are especially reliant on secreted protein effectors for virulence. These effectors can mimic and reprogram host cellular functions to create a beneficial environment for the invading bacteria, such as formation of the intracellular salmonella containing vacuole (SCV) and antagonization of the immune response. My lab previously found that increased intracellular replication of S. Typhimurium and production of anti-inflammatory cytokine interleukin-10 (IL-10) by host cells is associated with the secreted protein effector SarA. SarA acts through host STAT3 (signal transducer and activator of transcription) signaling by mimicking the function of host cytokine receptor gp130. However, despite homology between SarA and gp130, I have shown that SarA leads to greater STAT3 phosphorylation over a longer period of time than gp130. Previous research in the field of STAT3 signaling suggests that the kinetics of STAT3 activation have a dramatic effect on whether the downstream transcriptional targets are pro- or anti-inflammatory. I hypothesize that S. Typhimurium effector SarA evolved molecular characteristics to hijack and prolong host STAT3 signaling to promote important anti-inflammatory responses during acute infection in the gut. I propose mutagenizing SarA and measuring how these manipulations alter 1) SarA binding to STAT3 and negative regulators, 2) SarA-directed phosphorylation of STAT3, 3) expression of downstream transcriptional targets and 4) SarA-associated burden and IL-10 phenotypes in cells and mice. My lab has previously shown that SarA leads to increased STAT3 phosphorylation and fitness in systemic sites (spleen, liver) during intraperitoneal (I.P.) and chronic murine infection models. However, neither of these models represent the natural oral infection route of S. Typhimurium in humans. I have shown that wild-type and complemented Salmonella Typhimurium have ~100x greater burden in the small intestine compared to ∆sarA during infection in an oral murine model. I will further elucidate the mechanism by which SarA signaling acts on the mucosal immune responses to benefit S. Typhimurium during oral infection. This proposal aims to understand the molecular basis for robust STAT3 activation by SarA, and how S. Typhimurium hijacking of the host STAT3 signaling pathway impacts infection outcome during intestinal infection in vivo.

NIH Research Projects · FY 2026 · 2024-02

PROJECT SUMMARY When patients present with urinary urgency, frequency and nocturia, with or without urgency incontinence, we consider this the clinical phenotype of overactive bladder (OAB). Clinical observations and data suggest that clinical OAB may be comprised of several underlying subtypes. Discerning between subtypes has been challenging but is imperative to precisely guide targeted treatments. Within the last decade, several large observational cohort studies have been developed with the goal of improving our understanding of the pathophysiology underlying benign urologic symptom disorders. The NIDDK-sponsored Multidisciplinary Approach to the Study of Pelvic Pain (MAPP) network and Lower Urinary Tract Dysfunction Research Network (LURN) have collected data on urologic pain syndromes and non-painful lower urinary tract symptoms (LUTS), respectively. Both cohorts included patients with OAB. To identify clinically meaningful subtypes, MAPP and LURN used clustering methods to mathematically classify patients into probable subtypes using clinical characteristics. Though biospecimens were collected in both cohorts, biologic data from these specimens were not included in clustering. If OAB subtypes have different pathophysiology, biologic data are likely to add important distinguishing information, and possibly be predictive of differential treatment responses. Based on clinical observations and prior clustering work, we hypothesize that the syndrome of idiopathic OAB is comprised of 5 phenotypic subtypes, including dysbiotic and metabolic subtypes that will have distinct microbiome profiles from the others. To test our hypotheses, we propose an innovative approach combining MAPP and LURN clinical datasets and already collected biospecimens. Since sex-specific factors may affect subtypes, analyses will be performed on females and males separately. Our current “one-size fits all” algorithm of OAB treatments results in repeated medical visits, high health-care costs, and marginal long-term effectiveness. There is a major gap in knowledge of OAB subtypes, which in turn hampers our ability to target treatments to subgroups where they would be most effective. The proposed analyses by experienced data scientists present a unique opportunity to leverage existing resources from well-defined prospective clinical cohorts to substantially enhance our understanding of OAB.

NIH Research Projects · FY 2026 · 2024-01

Abstract Cells undergo several types of regulated cell death, often initiated by proteases in the caspase family. Once initiated, regulated cell death activates multiple processes in the cell in order to accomplish the demise of the cell in a regulated fashion. For example, intestinal epithelial cells undergo the process of extrusion, whereby the cell is detached from the epithelial monolayer and ejected into the lumen of the intestine. The process of extrusion takes about 10 minutes, and requires that the extruding cell actively participate in the process by disassembling its cytoskeleton, reassembling a contractile actomyosin ring, and then constricting and disassembling adhesions to neighboring cells. Thus, the cell must remain alive for about 10 minutes, and during that short time it must complete what we term a “bucket list” of tasks that accomplish the extrusion process. Similarly, cells undergoing apoptosis activate multiple cellular processes to disassemble cellular structures and package them into apoptotic blebs. This takes perhaps 30-60 minutes, the time in which the cell must complete a bucket list of apoptotic tasks. Failure to complete these bucket lists will result in a defective form of cell death that can be pathological. We recently discovered that caspase-7, once thought to be a cell death executioner, is actually a death delaying caspase that buys the cell time to complete these bucket lists. Caspase-7 hyperactivates the acid sphingomyelinase membrane repair pathway, allowing dying cells to more efficiently repair damage to their membranes. Here we study the molecular mechanisms that enable caspase-7 to accomplish this unique function.

NIH Research Projects · FY 2025 · 2024-01

ABSTRACT The demand for pediatric clinical pharmacologists continues to grow, necessitating investment in career development programs to train the next generation of pediatric clinical pharmacologists. This new K12 application seeks to establish the “National Career Development Program for Researchers in Pediatric Clinical Pharmacology.” This program will combine faculty expertise, pediatric clinical pharmacology research programs, and clinical research resources from a nationally dispersed group of leading academic institutions. The goal for this national career development program is to enhance the existing training opportunities through the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Pediatric Clinical and Developmental Pharmacology Training Network (PCDPTN). Program faculty are grouped into three areas of subject matter expertise: 1) Pharmacokinetics/Pharmacodynamics and Clinical Trials, 2) Pharmacoepidemiology and Data Science, and 3) Translational Research. The program faculty are selected based on their outstanding research accomplishments and track record mentoring junior investigators. In addition, the proposed career development program will leverage resources provided by the Pediatric Trials Network (PTN), the Maternal and Pediatric Precision in Therapeutics (MPRINT) Hub, and other NICHD-sponsored programs. The participating institutions have outstanding research environments and a reputation for successful mentorship of junior faculty pursuing academic careers in pediatric clinical pharmacology. Each scholar will complete a research project within one of the theme areas for the career development program, and they will be matched with a primary research mentor and a faculty mentoring committee. Scholars will be able to leverage faculty expertise across the participating institutions for research and mentoring. In addition to the research project, scholars will complete professional development opportunities, including training and mentorship in pediatric clinical pharmacology, written and oral communication, methods for enhancing research reproducibility, and research ethics. An Internal Advisory Board comprised of experts in pediatric clinical pharmacology will help with scholar selection, developing strategic partnerships, and advising on program enhancements. In addition, an External Advisory Board composed of experts in pediatric and maternal pharmacology and with extensive experience mentoring junior faculty will meet annually with scholars and the Executive Committee and provide advice on the structure and future directions for the program. The program will be evaluated by the External Advisory Board and through scholar and mentor evaluations. This career development program will enable scholars to generate the publication record, preliminary data, and skill set that is necessary to be competitive for independent research grants. Following completion of the program, all scholars will be exceptionally well-positioned to pursue impactful careers focused on promoting the safe and effective use of medications in children.

NIH Research Projects · FY 2026 · 2024-01

ABSTRACT The vertebral column or spine is the main structural element of the vertebrate body axis. It is assembled around the notochord, a conserved axial structure that provides developmental cues for the development of other organs and serves as a structural scaffold for the embryo in all chordates. Importantly, in vertebrates, the notochord also attracts osteoblast precursors that give rise to the vertebral bodies of the spine. The vertebrate notochord is composed of a core of highly conserved vacuolated cells that is surrounded by a thick extracellular matrix that acts as a corset for the notochord rod. Importantly, loss of notochord vacuole function has been shown to cause defects in vertebral formation and spine morphology that resemble congenital scoliosis (CS) in humans. While genetic and embryological evidence clearly showed that the structural role of the notochord is conserved, whether vacuolated cells function in vertebral patterning in mice as shown in zebrafish is not known. Moreover, following vertebral patterning, notochord vacuolated cells form the nucleus pulposus (NP) at the center of the intervertebral disc (IVD), where they remain until adulthood. However, little is known about the function of vacuolated cells within the IVD. Also not known are the mechanisms that regulate notochord vacuole biogenesis and integrity and how these are linked to IVD degeneration during aging. The proposed studies will investigate mechanisms regulating notochord vacuole biogenesis and function in zebrafish and mice and will investigate the role of notochord vacuoles in spine formation in mice. Altogether, these studies will bring important new insights into spine morphogenesis and the origin of pathologies such as CS and disc disease.

NIH Research Projects · FY 2025 · 2024-01

Our focus is on translation of a novel microscopy approach, femtosecond pump-probe microscopy, which our preliminary data shows can determine which (nominally) early-stage primary melanomas are instead metastatic cancer. This is important because the current clinical “gold standard” of staging (histopathology and sentinel lymph node biopsy (SLNB)) can assign early (non-metastatic) stages to tumors which are in reality metastatic cancers, which delays treatment and costs lives. In fact, more people die from melanoma after initial Stage I tumor diagnosis than after diagnosis of any higher grade. Today adjuvant therapies have made great strides (on late-stage tumors) but all FDA-approved therapies are restricted to metastatic (stage III or IV) melanomas because significant treatment-related adverse events are common. We believe adjuvant therapies could be more effective, and less toxic, if applied to supposedly early stage tumors which have already generated undetected metastases. Such “early adjuvant therapy” could have great benefits for disease control, reduced toxicity, and reduced health costs, but this requires a good marker for deciding which early-stage patients should go into such therapy, and existing markers have limited value. Our preliminary results show that we can identify such patients with pump-probe microscopy. The ultimate goal is routine identification of incorrectly classified early-stage lesions, at least from stages IIB/C and preferably from earlier stages as well, so the patient can be treated to interrupt disease progression. Specific Aim 1 focuses on optimizing multi-parameter pump-probe imaging to concentrate the clinically relevant contrast. The apparatus redesign features modulation schemes that keep the applied power constant while retaining complete control over pulse polarization and delays, plus detection schemes with angular resolution. Demonstrations start with melanin in model systems and melanoma cells and move on to biopsies, characterizing directional and polarization components of the pump-probe decay to maximize signal correlation with chemical or cellular melanin degradation. Specific Aim 2 focuses on maximizing diagnostic utility using patient biopsies from the Duke Biorepository to retrospectively diagnose metastatic melanoma and test the performance of the improved clinically relevant contrast. This work is closely connected to pathology, as we view the technology as complementing existing diagnostic protocols. Based on our very encouraging preliminary results, machine learning algorithms will pay a large role in our assessment of diagnostic utility. We expect to demonstrate that for at least Stage IIB/IIC tumors (7000 cases a year) pump-probe imaging can reliably segment this population and identify the patients who almost certainly need treatment beyond excision.

NIH Research Projects · FY 2026 · 2024-01

SUMMARY The inner blood-retina barrier (iBRB), formed by retinal endothelial cells (RECs) and pericytes, and supported by astrocytes, is the critical pathological location mediating the manifestation and sequelae of retinal vascular diseases. Although the vascular system in the retina is one of the most studied vascular beds, there remain significant knowledge gaps in our understanding of the processes that lead to retinal vascular dysfunction. Due to the lack of in vitro models, we propose establishing 3D human iBRB models with physiological characteristics as functioning healthy tissue. In Aim 1, we will develop a tissue-engineered post-capillary venule model of the healthy iBRB. In Aim 2, we will develop a tissue-engineered capillary model of the healthy iBRB. In Aim 3, we will increase the complexity of iBRB models’ extracellular mimicry environment. In vitro microphysiological models capable of recapitulating the healthy iBRB can be applied to examine tissue perturbations towards addressing the knowledge gaps in our understanding of the processes that lead to retinal vascular dysfunction. Challenges in developing such in vitro model include a need for necessary cellular components, physiological and pathological environment mimetics, and controlled perfusion conditions. Moreover, there are significant differences along the arterio-venous axis, from arterioles to capillaries to venules, in physical dimensions, flow rates, and supporting cell organization. Therefore, the significance of this work lies in developing mimicry iBRB models that further capture different zonations in the retina’s vascular system. No model has been developed that uses human retina vascular cells and astrocytes in a 3D setting with controllable perfusion at the post-capillary venule and capillary size scales, and no study further introduced changes in oxygen concentration and matrix mechanics that allows an understanding of the impact on the retinal barrier function, underscoring the innovation herein. We use cutting-edge tissue-engineered microvessel models, stem cells, and biomaterials to develop iBRB in vitro models. Successful completion of the Aims is ensured by the interdisciplinary environment at Duke University and Johns Hopkins University, as well as the collaborative track record among Drs. Sharon Gerecht and Peter Searson, and newly joined Drs. Jeremy Kay and Xi Chen, with relevant neuroscience and clinical research expertise. The proposed work will engineer the next generation of human iBRB microphysiological systems that will enable future mechanistic studies of tissue development, function, and aging in health and disease states.

NIH Research Projects · FY 2025 · 2024-01

Project Abstract Parkinson's disease is the leading cause of movement disorders and currently there are no disease‐ modifying therapies available. Parkinson's disease is associated with progressive and selective degeneration of dopamine neurons in the substantia nigra pars compacta, however the exact biological mechanisms underlying dopamine neuron susceptibility remains unknown. Current working models for many neurodegenerative diseases, including Parkinson's disease, is that runaway activation of cell stress response pathways in response to disease‐relevant pathology exacerbate and drive neuronal death. However, stress response pathways are also required for cell survival and restoring homeostasis. One such pathway is the integrated stress response (ISR), which is a biochemical pathway that responds to various forms of internal and external cellular stress to regulate protein translation. Activation of the ISR results in a global reduction of protein synthesis, and also a selective increase in cell survival genes that are regulated by the transcription factor ATF4. While triggering the ISR is a key mechanism to protect a cell from a stressor, prolonged and excessive activation of the ISR can lead to cell death through apoptosis. In advanced disease stages of Parkinson's, both human pathological studies and mouse models show evidence of high ISR activation. This has led to the idea that dysregulation of the ISR could be one driver of PD pathophysiology, and that inhibiting the ISR would be beneficial. However, no studies have investigated the role of the ISR in pre‐disease states or the role of the ISR specifically in brain dopaminergic neurons. It was recently discovered by our lab that the ISR is not just used as a stress response pathway in a class of neuromodulatory cells (cholinergic interneurons), but rather, these cells basally constitutively engage this pathway to maintain proper biological and electrophysiological function. This work unveiled a novel role for the ISR in some neurons in a normal, non‐disease or exogenous cell stress state. When looking at other high firing neuromodulatory cells, we found that dopaminergic neurons showed a broad range of ISR activity states, from low/off to high. I hypothesize that subclasses of dopamine neurons share the cholinergic neuron phenotype of having an activated ISR state normally. I further hypothesize that, in contrast to the idea that a high ISR accelerates disease pathogenesis, a higher ISR state basally, pre‐insult protects neurons better from future cell stressors. This hypothesis is based on the concept of hormesis. In this proposal, I will examine ISR states in dopamine neuron subclasses in health and PD mouse models and bidirectionally test how dopamine neuron ISR state modifies cell death and disease progression.

NIH Research Projects · FY 2026 · 2024-01

Project Summary/Abstract Prostate cancer is a leading cause of cancer death in American men. The National Cancer Institute estimated that there would be ~268,490 new cases of prostate cancer and ~34,500 deaths from prostate cancer within the United States for 2022. Despite the development of second-generation hormonal therapies (e.g., enzalutamide) and targeted poly(ADP-ribose) polymerase (PARP) inhibitors (e.g., olaparib), the mortality of prostate cancer remains high as intrinsic and acquired drug resistance is common to all these agents, and many patients develop incurable metastatic castration-resistant prostate cancer (mCRPC) within 2–3 years. Accumulating evidence and our preliminary data show that mCRPC cells deficient in homologous recombination repair (HRR) activities due to genetic mutations of DNA repair genes, such as BRCA1/2, or due to the enzalutamide treatment-induced BRCAness state are particularly vulnerable to disruption of DNA-damage tolerance pathways, such as the mutagenic translesion DNA synthesis (TLS). TLS is a fundamental cellular defense mechanism that enables DNA replication across lesion sites under replication stress in order to promote cell survival at the cost of replication fidelity. The eukaryotic Y-family polymerase Rev1 is an essential scaffolding protein in TLS, and the interaction between its C-terminal domain (CTD) with translesion polymerase z is absolutely required for function. Aided by our structural elucidation of the Rev1-bridged translesionsome complex in TLS, we have identified the first-in- class in vivo active small molecule inhibitor, JH-RE-06, that disrupts TLS by directly binding to the Rev1 CTD to block the Rev1 interaction with the Rev7 component of polymerase z. JH-RE-06 suppresses spontaneous and treatment-induced mutagenesis in cells and sensitizes cancer cells to a variety of DNA-damaging agents both in vitro and in a murine xenograft tumor model. Recently, we have shown that mCRPC cells in the BRCAness state are particularly vulnerable to JH-RE-06 inhibition. The goal of this proposal is to further characterize JH- RE-06 and derivatives in prostate cancer cells, optimize their potency, safety, and other pharmacological properties, and demonstrate their effectiveness in treating mCRPC and suppressing acquired drug resistance in murine tumor models. The successful execution of the proposal will profoundly alter the existing paradigm of lethal prostate cancer treatment by providing effective means to overcome intrinsic and acquired drug resistance, thus improving the outcomes for patients with lethal prostate cancer.

NIH Research Projects · FY 2025 · 2024-01

PROJECT SUMMARY This proposal seeks to advance the state of the art in ophthalmic imaging to improve diagnosis and treatment of diabetic retinopathy (DR). DR is a leading cause of blindness in adults, and prevention of irreversible vision loss requires prompt identification and treatment. Prior work has shown that neurodegenerative findings in the retina, such as a decrease in thickness of the outer nuclear layer (ONL), occur alongside and may predate microvascular changes. Measurements of ONL thickness may therefore provide non-invasive metrics to monitor the progression of DR. Injectable agents like anti-VEGF therapy have revolutionized DR treatment, but they often require repeat and invasive procedures for patients. There has been great interest in novel in-office treatments that can be delivered into the suprachoroidal space; however clinicians performing these injections are limited to 2D surface visualization that offers no depth information. Optical coherence tomography (OCT) is a low-coherence interferometry technique that allows for high- resolution, volumetric imaging of the anterior and posterior eye. While OCT is currently the only clinical technology that can visualize individual layers of the retina in vivo, conventional OCT systems are not able to distinguish Henle’s Fiber Layer (HFL) from the ONL. Previous research has shown that HFL and the ONL can be correctly visualized in a single cross-sectional scan by offsetting the pupil entry position of the sample beam. Our research group has pioneered the invention of robotically-aligned OCT (RAOCT) that is capable of imaging freestanding individuals and has precise, automatic control of beam position at the pupil plane. We therefore propose to develop this technology for fully automated volumetric imaging of the complete HFL and the ONL, in order to investigate these measurements as potential clinical biomarkers to monitor DR progression. OCT similarly provides excellent in vivo visualization of distinct features in the anterior segment. We also propose to develop a custom anterior segment handheld OCT probe that can be used for in vivo, real- time visualization and quantification of suprachoroidal injections with novel therapeutics agents for DR. The expected outcome of the proposed research is a series of technologies that will provide automated measurement of a novel retinal biomarker as well as real-time 3D image guidance for a novel, less invasive clinical procedure. Our adapted RAOCT system will be capable of volumetric imaging and measurement of the corrected ONL when accounting for HFL, without the need for operator guidance or input; in addition, our custom handheld anterior segment OCT system will be able to provide real-time, 3D feedback to clinicians for guidance and evaluation of suprachoroidal injections. We believe our proposed developments have the potential to advance the state of the art in image guidance for diagnostics and therapeutics in DR.

NIH Research Projects · FY 2026 · 2024-01

We propose here a five-year R01 project to fully develop an integrated RF/shim/WiFi coil array and high- resolution diffusion MRI (dMRI) methodology for the detailed mapping of spine-brain pathways and their connections to the brain. This project is motivated by the exponential growth in spinal cord stimulation (SCS) in the recent decade to treat various brain disorders. Unlike other targeted neural stimulation approaches, such as deep brain stimulations or DBS, SCS has the advantage of being less invasive, and has the potential to achieve targeted precision in the brain if appropriate imaging methods can be developed to characterize the underlying spine-brain pathways. While dMRI is the current method of choice to map neural connectivities, it is not yet ready to image in the spinal cord due to the pronounced dynamic magnetic field fluctuations arising from breathing-induced chest wall motions, in addition to the severe static field inhomogeneities at air/tissue/bone interfaces. While static inhomogeneities would lead to geometric distortions that can be largely corrected by improved shimming methods and post-processing strategies, dynamic field fluctuations result in imbalance of the diffusion-weighting gradients and significant signal losses that cannot be corrected at the present time. It is thus the goal of our project to develop the much-needed imaging hardware and software solutions to address these challenges, and reliably acquire high-resolution dMRI images to map the brain-spine pathways and their connections to the brain. Specifically, we will develop an integrated RF/shim/WiFi coil array with automatic real-time shimming to synchronously compensate for the dynamic field fluctuations, we will also develop innovative dMRI acquisition strategies to achieve high spatial resolution with both high temporal throughput and high signal-to-noise ratio (SNR), and we will map in detail the spine-brain pathways and associated connections to the deep brain and to the relevant cortical areas, and make these maps publicly accessible. We anticipate that this project will deliver critical imaging technologies to enable high-resolution dMRI in the brain and spinal cord, which can provide detailed and standardized maps of the spine-brain connectivities in vivo. It is hoped that these maps will improve the current practice of SCS by allowing precise planning of the simulation sites in the spinal cord, thereby leading to increased efficiency and effectiveness in treating patients with various movement and sensory brain disorders.

NIH Research Projects · FY 2026 · 2023-12

Treatment of cancer is an ongoing process during which clinicians make a series of decisions at critical points in a patient's disease by synthesizing baseline and evolving patient information with the goal of optimizing expected long-term patient benefit. We use the term “treatment” to refer broadly to therapeutic agents and supportive behavioral interventions to mitigate adverse effects of therapies or symptoms, as well as to inter- ventions focused on prevention and screening. An evidence-based approach to optimizing decision making is to study entire sequential treatment strategies, which can be formalized as treatment regimes. A treatment regime is a sequence of decision rules, each of which is associated with a key decision and uses accrued information on a patient to select a treatment option from among the feasible options for the patient. An optimal regime is one that maximizes expected patient benefit in the population. Sequential multiple assign- ment randomized trials (SMARTs), in which subjects are randomized at each of several key decision points to feasible treatment options based on their accrued information, are ideally suited to discovery and evaluation of treatment regimes, and a number of SMARTs in cancer have been conducted. At the same time, great innovations have been made in cancer clinical trials; platform and response-adaptive trials that seek to op- timize treatment for both participants and future patients and that allow for incorporation of new options and elimination of ineffective options are increasingly being conducted. The potential for SMARTs to advance op- timal sequential decision making in cancer treatment thus requires a next generation of design and analysis methods for SMARTs that incorporate similar innovations in the more complex setting of multiple decisions and repeated randomization of subjects and that address current cancer research priorities. The goal of this project is to develop a comprehensive statistical framework for next-generation SMARTs in cancer research, the first steps toward which we will undertake through four specific aims. Our first aim is to develop methods for design and analysis of platform SMARTs that use response-adaptive randomization to favor optimal treatment assignments and allow introduction of new treatments and discontinuation of ineffective treatments at any de- cision point. Aim 2 is to develop methods for design and analysis of SMARTs involving multi-component and multi-modal treatments at each decision point. Our third aim proposes a novel trial framework that merges a SMART with a micro-randomized trial to allow joint optimization of sequential therapeutic decisions and selec- tion of supportive mHealth interventions that address the adverse consequences of cancer therapy, where the supportive interventions are chosen to maximize the success of therapy. In Aim 4, we develop a framework for interim analysis of SMARTs, for which little methodology is available. The methods handle binary, continuous, and censored time-to-event outcomes of interest in cancer research. A software package will be developed to assist users in the design and analysis of next-generation SMARTs.

NIH Research Projects · FY 2026 · 2023-12

ABSTRACT Stroke remains a leading cause of death and disability in the US, with the situation in the southeastern states of North Carolina and Virginia being particularly severe. To address the critical need for promising interventions for stroke prevention, treatment, and recovery, and to improve stroke outcomes in this region, we propose a newly formed Duke-University of North Carolina (UNC) Eastern North Carolina and Southern Virginia RegIonal Stroke TrIal CONsortium (ENVISION) Regional Coordinating Center. The ENVISION RCC will consist of two major academic institutions, Duke and UNC, with 22 regional/community hospitals in eastern North Carolina and southern Virginia (including hospitals with various stroke center designations, pediatric hospital/services, and rehabilitation facilities). In this catchment area, we will draw stroke patients from a population of 4.9 million, predominantly in suburban and rural areas, with a large proportion from groups that traditionally are lacking in clinical trials. Both institutions have successful track records in stroke research study recruitment, retention, and follow-up, and are supported by Clinical and Translational Science Awards (CTSAs). Our Center’s success will build upon strong, existing stroke clinical and research infrastructures and foundations: 1) strong, stroke educational, clinical, and research programs within the Duke-UNC hub; 2) robust patient volumes, pre-existing referring hospital networks, and prior close collaboration; 3) a dedicated, collaborative, multi-disciplinary leadership team [MPIs Drs. Wayne Feng (Duke, Vascular Neurology),Alexander Limkakeng (Duke, Emergency Medicine), and David Hwang (UNC, Neurocritical Care)]; 4) supportive junior faculty training and career development environments; and 5) strong institutional and departmental resource commitments. Through the following aims, we will contribute to the overall success of the NIH StrokeNet clinical trials network: Aim 1. Effectively enroll and retain a diverse population of stroke participants with high protocol adherence and high-quality data integrity with a balanced portfolio of stroke trials; Aim 2. Successfully identify, engage, and train the next generation of stroke scientists; and Aim 3. Actively contribute to the overall success of NIH StrokeNet leadership. As a new RCC, Duke-UNC ENVISION will optimize trial operations and provide high quality studies by leveraging its resources, expertise, experience, productivity, and commitment to inclusivity, thus contributing to StrokeNet goals to reduce stroke burden, and improve stroke and other health related outcomes. .

NIH Research Projects · FY 2025 · 2023-12

Project Summary. The dynamic restructuring and precise positioning the actin cytoskeleton is essential for complex cell morphologies, cell motility, and cell signaling among other processes. While there is a large inventory of actin regulatory proteins and their biochemical activities, the spatial regulation of these biochemical activities throughout the cell still represents a key gap in understanding intracellular organization. Biomolecular condensates have emerged as a central mechanism for controlling diverse areas of biochemistry. Several studies from evolutionarily divergent systems point to the possibility that actin assembly may be controlled by condensates. Specifically, some actin regulators have hallmark features of intrinsically disordered regions (IDRs), and some sites where F-actin forms have biophysical properties ascribed to condensates. In some cases, these assemblies likely form by phase separation, but in others the condensates appear to emerge by different mechanisms. What isn’t clear is how biomolecular condensates specifically contribute to the localized assembly of the actin cytoskeleton and how this mode of regulation controls cell morphogenesis. In this proposal, I will identify the mechanisms by which ribonucleoprotein (RNP) condensates, containing both RNA and protein, pattern the assembly of the actin cytoskeleton in time and space. I will use the mycelial branching seen in the syncytial fungus Ashbya gossypii (“Ashbya”) as a model system for deciphering the links between condensates and actin regulation. It is known that focused enrichment of actin- interacting proteins leads to a local polarized cytoskeletal network at hyphal tips, and incipient branch sites in Ashbya. studies in the Gladfelter lab have shown the RNA-binding protein, Whi3, is required to promote formation of new polarity sites in Ashbya. Notably, Whi3 condenses with mRNA transcripts for the formin Bni1 and polarity protein Spa2 at existing and incipient branch sites. Ashbya provides a powerful system to study the role of condensates in actin regulation because the essential and physiological role of condensates can be genetically dissected in live cells. My preliminary data show Whi3-coated beads are capable of nucleating polarized actin networks in Ashbya cell-free extracts, opening up the ability to combine the power of genetics with cell-free extracts, a workhorse of cytoskeletal discovery. With this new assay, I will distinguish between two models for how condensates may regulate actin assembly through either (i) the local translation of or (ii) by changing the activity of condensate-controlled actin regulators in Aim 1. I will then identify how multiple Whi3 condensates in a common cytoplasm contribute to the complex morphology of Ashbya in Aim 2. This work will reveal mechanisms for how biomolecular condensates control spatial organization of the actin cytoskeleton, and how these assemblies drive complex cell morphology, an essential feature of many cells.

NIH Research Projects · FY 2025 · 2023-11

ABSTRACT About 51.5 million people (1 in 5 US adults) lives with a mental illness (MI) and it is estimated that serious MI costs Americans about $193 billion in lost earnings, yearly. Given the high prevalence and social cost of MI, there has been a growing push for translating advances in neuroscience research into improvements in MI prevention and psychiatry care delivery. In this context, it has become increasingly evident that psychiatric diseases emerge as result of abnormalities in brain spatiotemporal dynamics and network connectivity. Furthermore, neuropsychiatric diseases typically have a high degree of individual variability in presentation, symptom severity, and treatment response. In this proposal, we aim to design new fMRI analysis methods capable of tackling the abovementioned challenges – i.e., capable of directly modeling brain spatiotemporal dynamics, while also capturing individual variability. More specifically, the main goal of this proposal is to extend a previously developed deep-generative fMRI analysis model (VAE-GAM) that produces interpretable spatial effect maps for each covariate (as in standard methods) while capturing nonlinear effects and correlations across voxels. To accomplish this goal, I propose to: 1) Model temporal dynamics directly by fitting a Recurrent Neural Network (RNN) to the VAE-GAM latent space; and 2) Capture individual differences by using a deep Mixed Effects Modeling framework to model individual subject maps as being the sum of a group-level baseline map and a subject-unique map, generated using a learned, subject-unique embedding vector. The expected outcome of this proposal is a flexible fMRI analysis toolset that will allow researchers and clinicians to identify new brain activity patterns linking high-level behavior in health and disease states. We believe such a model could be a step towards fulfilling the goal of delivering biologically-sound, computationally driven, and personalized health care for millions of patients afflicted by mental illness.

NIH Research Projects · FY 2026 · 2023-10

Despite remarkable advances in biomedical HIV prevention and treatment, gaps remain in viral suppression and PrEP engagement among populations disproportionately impacted by HIV. Intervenable barriers to engagement in HIV services may include facility-based stigma and limited access to prioritized primary care. Differentiated service delivery models have recently been implemented as demonstration projects in South Africa, providing a unique opportunity to assess feasible and acceptable implementation strategies as well as analyze the effectiveness and cost of integrating prioritized primary care services as well as and stigma-reduction strategies into HIV care. This observational, multi-site, mixed methods prospective implementation study will be guided by the RE-AIM (Reach, Effectiveness, Adoption, Implementation, Maintenance) implementation science evaluation framework to meet the following aims: (1) assess barriers, facilitators, acceptability, and feasibility of differentiated service delivery using site observation checklists, key informant interviews with facility staff, and longitudinal in-depth interviews with clients; (2) evaluate the effect of differentiated service delivery on viral suppression and PrEP adherence - testing for mediators, using a longitudinal cohort of clients, which compares participants enrolled at differentiated service delivery sites with participants enrolled in standard service delivery sites (200/arm on ART and 100/arm on PrEP for a total N = 600); and (3) estimate the cost associated with differentiated service delivery versus standard service delivery sites using a micro-costing approach to estimate the cost per service user served and per service user successfully treated at differentiated service delivery sites relative to standard service delivery sites, as well as the budget needed for successful country-wide implementation.

NIH Research Projects · FY 2026 · 2023-09

ABSTRACT Bone fractures occur in 50% of the population causing significant morbidity and mortality and costing more than $20 billion annually. Advanced age diminishes bone repair capacity and is associated with increased surgical intervention at the time of the injury and subsequently with the need for revisions. The development of therapies aimed at enhancing bone repair would significantly reduce the burden on the geriatric population. We recently identified Apolipoprotein E (ApoE) to be an age-associated inhibitor of fracture repair. ApoE is a circulatory protein and increases in abundance with age in mice and in humans. In our published work, circulating ApoE inhibited osteoblast differentiation and activity decreasing the amount of bone deposited within the fracture callus. The liver produces >90% of the ApoE found in circulation, as such, we delivered siRNA against ApoE using an AAV targeting hepatocytes in aged mice. Circulating levels of ApoE were dramatically decreased and subsequent aged bone healing was greatly improved. This finding serves as a ‘proof of concept’ that ApoE is a viable target to improve aged fracture repair. Within this proposal we will build on these findings identifying interventions that can be translated to clinic to improve aged bone healing. In Aim 1 we will determine whether neutralizing circulating ApoE improves aged fracture healing. We have developed an ApoE-neutralizing antibody. A small cohort of aged male mice underwent fracture injury and were later treated with this antibody IP. Versus IgG-treated mice, the calluses of anti-ApoE treated mice contained higher amounts of bone tissue. In this aim we will identify the optimal regimen and dose of antibody to use and determine how this treatment changes the stages of fracture repair. Furthermore, we have identified ApoE-based inhibition to propagate through osteoblastic muscle-specific kinase (MuSK), a cell-surface tyrosine kinase receptor whose osteogenic expression and function has yet to be reported in the literature. In Aim 2 we will we will use MuSK floxed mice crossed with inducible Cre-recombinase mice to identify the role of osteogenic progenitor and osteoblastic MuSK in bone repair. In Aim 3 we will identify the mechanism by which ApoE decreases osteoblast differentiation. Using in vitro cell culture techniques, we have identified the Yap/Taz pathway to be modulated with ApoE treatment. An osteoblastic cell-surface receptor for this pathway has yet to be identified. We have determined MuSK to potentially serve as such a receptor. Using transgenic mouse models, we will determine functionality of MuSK in osteoblast biology and investigate the role of MuSK in ApoE-based osteoblast inhibition/signal transduction.

NIH Research Projects · FY 2026 · 2023-09

This proposal addresses one of the most fundamental unsolved problems in vision: the molecular and cellular mechanism responsible for building and maintaining the light-sensitive organelle of vertebrate photoreceptor cells, the outer segment. The outer segment is a ciliary structure filled with a stack of disc membranes, which provide vast surfaces for light capture and harbor proteins comprising the phototransduction machinery. Discs are renewed on a daily basis in order to counteract the adverse effects of light exposure, and the fidelity of disc renewal is critical for maintaining photoreceptor health and normal vision. It is now well-established that the formation of each new disc begins with an evagination of the ciliary plasma membrane driven by an expansion of branched actin network in a mechanism akin the formation of lamellipodia in motile cells. What remain entirely unknown are the molecular mechanism that initiate the formation of each new disc with the striking periodicity of approximately 80 times per day in mammals. Pinpointing this mechanism is the overall goal of this application. Our recent work shows that this actin network is nucleated by the WAVE protein complex whose unique subunit composition is specifically fitted to perform this function. Because WAVE complexes mediate between the upstream signaling pathways and downstream actin networks, this opens doors to elucidating the entire mechanism responsible for the periodic assembly and disassembly of actin at the disc morphogenesis site. To accomplish this goal, we will combine the efforts of two laboratories, which will contribute unique expertise and two complementary models of genetically modified animals: mice and Xenopus frogs. Our proposed experiments will investigate the regulation of the actin cytoskeleton dynamics, including that in living photoreceptors, by two classes of regulatory molecules: small GTPases and phosphoinositides. Elucidating these mechanisms is critical for advancing our understanding of basic photoreceptor cell biology and pathobiological mechanisms underlying photoreceptor degeneration frequently associated with defects in outer segment morphogenesis.

NIH Research Projects · FY 2025 · 2023-09

ABSTRACT This research proposal from a multi-disciplinary team including urgent and emergent care physicians, ophthalmologists, and biomedical engineers seeks to improve the ability of non-specialty providers to provide ocular exams at the point of care. Urgent and emergent care settings are frequently the access point of patients seeking eye care. Standard of care instruments to examine the eye in these non-specialty settings are notoriously difficult to use, and patients frequently are referred out for later specialty care at added expense in time and delayed care. To improve the likelihood of diagnostically useful eye examinations in these non- specialty settings, we will introduce a remote, semi-autonomous eye imaging system capable of retinal optical coherence tomography (OCT), retinal scanning laser ophthalmoscope (SLO), and anterior segment slit illuminated imaging that can be used without need for on-site staffing for operation. These developments have both direct immediate clinical and research applicability by providing the potential to readily examine patient eyes where the patients already are. In addition, there are future implications as a platform for remote diagnostic capabilities in other settings where specialty eye care may be limited.

NIH Research Projects · FY 2024 · 2023-09

PROJECT SUMMARY/ABSTRACT Staphylococcus epidermidis is found across human skin as a common commensal but is also a hospital-acquired pathogen. This duality makes this microbe a considerable pathogen and is likely due to the immense genetic diversity that exists across its many strains. However, our understanding of the functional consequences of this genetic diversity is limited in part due to significant gaps in gene functional characterization (over 25% of genes have no known functions) and in part due to dynamic environmental effects of complex polymicrobial settings, in which S. epidermidis is nearly always found, that can influence gene expression, function and virulence. However, a comprehensive analysis of all gene functions in all S. epidermidis strains across multiple pathogenicity-relevant environmental conditions would present a massive and intractable search space. Systematic assessments of gene function can be generated by multiple `omics approaches: e.g., transcriptional data and gene essentiality screen data can be readily generated for all genes irrespective of their annotation status and can be interpreted within the context of genetic background and environmental conditions, is a powerful tool for large-scale gene characterization. Currently, a limited set of transcriptional and gene fitness data exists for a few strains of S. epidermidis, but extensive analogous data has been generated for its more deeply studied cousin, skin pathogen S. aureus. New algorithms that could use existing data to transfer knowledge from characterized genes, including those present in S. aureus, to lesser explored genes, including strain-specific genes, would rapidly predict relevant gene functions that could then be tested experimentally. Thus, my goal in this proposal is to develop computational tools that leverage existing transcriptomic and gene essentiality data from S. aureus and S. epidermidis to identify functions for uncharacterized genes in S. epidermidis that could determine a pathogenic vs. commensal lifestyle. In Aim 1 I will use transfer learning to derive putative gene functions, benchmark the limits of this method with RNA-seq data collected from multiple strains of S. epidermidis grown in polymicrobial communities on reconstructed human epidermis, and assess the functional characterizations produced by this tool by testing the contributions to growth in a phenotypic array with stressors and epistatic interactions with stress responsive transcription factor SrrA of genes suggested to be important in multiple stress responses, as a case study. In Aim 2 I will use similar algorithms as in Aim 2 but include gene essentiality data to derive condition-specific gene essentiality cliques then validate gene characterization cliques using gene knock-downs and phenotype arrays. The work proposed here presents a framework for the development of tools for rapid hypothesis generation paired with focused, experimental hypothesis testing to identify functional consequences of genetic diversity across strains of the perplexing pathogen S. epidermidis.

NIH Research Projects · FY 2026 · 2023-09

Systemic lupus erythematosus (SLE) is a multi-organ autoimmune disease that is 2-4x more common among Black persons. Black patients with SLE are 6-7x more likely to suffer from kidney failure and die 13 years younger. Exacerbating these disparities, Black patients with SLE also have worse medication adherence, which is partially explained by mistrust about medicines and the medical system. Trust can be built through effective patient-clinician communication, but unfortunately, effective adherence communication occurs sporadically, and Black patients experience poorer communication quality with clinicians and participate less in decision making in clinic visits. Adherence interventions in SLE to date have only had limited success with patient reminders and education and have not attended to the quality of patient-clinician communication nor focused on ameliorating racial disparities in SLE medication adherence. The long-term goal is to reduce racial disparities and improve health outcomes among patients with SLE. The overall objective of this proposal is to optimize the delivery and test the effect of CO-LEADER (COmmunication for Lupus Engagement in Adherence with DOSE-Nonadherence-SLE and Refill data), a simple and flexible intervention that combines clinician training in communication skills centered around the needs of Black patients to effectively utilized pharmacy refill data with patient-reported adherence barriers. Pilot data for CO-LEADER suggest that 1) it is feasible, 2) it can be performed with high fidelity, 3) it enables consistent adherence discussions with excellent patient-clinician communication, and 4) it improves medication adherence while reducing racial disparities. A Hybrid Type I design will be used to conduct a cluster randomized trial of CO-LEADER at 2 heterogeneous rheumatology clinics. Informed by the Ecological Model of Patient-Centered Communication, the central hypothesis is that CO-LEADER enables clinicians to consistently discover and collaboratively address patients’ adherence barriers. More effective adherence discussions will then enhance shared understanding, therapeutic alliance, and trust, thereby improving medication adherence, particularly for Black patients. The aims of the study will compare important outcomes between clinicians randomized to CO-LEADER and usual care to test the effect of the intervention on 1) patient-clinician communication via clinic visit audio recordings and patient surveys, and 2) SLE medication adherence via pharmacy refill data. The study will also simultaneously evaluate relevant implementation outcomes to identify areas for improvement in the intervention’s delivery. This innovative proposal is the first to test a communication-based SLE medication adherence intervention. The proposal is significant because successful completion of the award will provide robust data on an intervention that has high potential for implementation across many health systems to fill a critical gap in the care of patients with SLE.

NIH Research Projects · FY 2025 · 2023-09

ABSTRACT: Each year, low- and middle-income countries (LMICs) account for over 85% of the 400,000 newly diagnosed pediatric cancer cases. Survival rates in LMICs are 5-25% compared to 80% in high-income countries (HICs). The largest single contributor to this disparity is treatment abandonment. Many societal, health system, and individual level barriers impact treatment abandonment, including low caregiver knowledge about cancer and its treatment, social norms, low perceived behavioral self-control to obtain cancer care, cost and limited supportive infrastructure. At Bugando Medical Centre (BMC), one of three childhood cancer referral hospitals in Tanzania, treatment abandonment rates were 40% with a 20% 2-year overall survival rate. In 2014, BMC and Duke formed a collaborative capacity development and research partnership and developed several interventions targeting low supportive care infrastructure and cost, providing free patient housing, a patient navigation program, and chemotherapy at no cost to the families, which reduced treatment abandonment from 40 to 23%. However, while caregiver education is standard in HIC, implementation of previously designed interventions targeting caregiver knowledge, attitudes and perceived self-control have been challenging due to human resource limitations and community literacy rates of <50%. There is an urgent need for innovative education strategies to address this barrier to treatment completion. Digital health strategies such as videos or voice-overs can provide an important alternative modality to provider-led education but have not been evaluated for use in LMIC settings or for their impact on treatment. This multidisciplinary international team previously developed mNavigator, a tablet-based digital case management system that records demographic and outcome data and provides tailored treatment guidance based on provider entered clinical information. This R21/R33 proposal seeks to leverage this established technology to evaluate two digital education strategies to improve caregiver knowledge about their child’s cancer diagnosis and its treatment: 1) multimedia education modules accessed on clinic tablets and (2) targeted education text messages sent directly to the caregiver’s phone. In the R21 phase, we seek to digitally and culturally adapt education media and evaluate caregiver acceptance of developed content. In the R33 phase, we will use a factorial study design to evaluate their impact as compared to standard education on treatment abandonment. Intervention development will be guided by our strong parent and stakeholder advisory board and the use of implementation science principles for end user engagement, to contribute to our understanding of not only what works in the context of digital health education for pediatric cancer but how it works. The proposed Tanzanian led digital media adaptation and annual Tanzanian childhood cancer advisor board meetings will provide opportunities for training on the use of mHealth applications, discussion of future collaborative research, and provide guidance on scale up and dissemination within the country to ensure continued mHealth research opportunities extending well beyond this current proposal.

NIH Research Projects · FY 2024 · 2023-09

PROJECT SUMMARY. Introduction: Biomolecular condensates, composed of a concentrated network of proteins and nucleic acids, compartmentalize cellular biochemistry. The establishment of a precise molecular composition is critical for the biological functions of condensates. In particular, cells must assemble either (a) coexisting condensates of distinct composition within a shared environment or (b) coexisting sub-layers of distinct composition within the same condensate. In both cases, the mechanisms by which cells specify compositional identity are poorly understood. In this proposal, I will examine how two types of biological “surfaces,” (a) two-dimensional lipid membranes and (b) one-dimensional long noncoding RNA polymers, establish condensate identity and dictate the formation of distinct layers. I hypothesize that each type of surface regulates condensate composition and function by modifying RNA structure in distinct ways. Research: In Aim 1, I will examine how membrane surfaces modify RNA structure to control condensate identity and regulate mRNA translation in the cytoplasm. In Aim 2, I will examine how the structural features of a long noncoding RNA control the formation of condensates with discrete layers and regulate mRNA retention in the nucleus. The overall outcome will be an enhanced, mechanistic understanding of how cells assemble key compartments of mRNA function. Training: I will complete my training with Prof. Amy Gladfelter at UNC Chapel Hill. During the training period, I will work with innovative collaborators to acquire new skills that will enable me to probe and manipulate RNA structure and dissect the molecular driving forces of biomolecular condensation. These skillsets will accelerate discovery during the remainder of my training and form the foundation for my independent lab. Specifically, I will learn powerful strategies to (1) map RNA structure with Kevin Weeks at UNC; (2) study long noncoding RNAs with Mauro Calabrese at UNC; (3) examine the spatial regulation of mRNA translation with Chris Nicchitta at Duke University; and (4) develop mathematical models of biological self-assembly with Krishna Shrinivas at Harvard University. Environment: Prof. Gladfelter is a supportive and inspiring mentor who fosters creativity and collaboration. UNC Chapel Hill is a hub for world-class RNA biology and will provide valuable opportunities to learn from experienced scientists. This K99/R00 award will enable me to pursue exciting new research directions beyond my core skillsets, form strong collaborations with leading labs, and immerse myself in new disciplines through a variety of courses, seminars, workshops, and conferences. Impact on Public Health: The process of biomolecular condensation has generated intense interest in recent years, in part due to its role in the formation of pathological aggregates that cause neurodegenerative diseases such as amyotrophic lateral sclerosis. My work will uncover fundamental mechanisms by which cells control the composition and emergent functions of biomolecular condensates. Through these discoveries, I hope to aid in the development of clinical interventions to treat diseases caused by disruptions to this important cellular phenomenon.

NIH Research Projects · FY 2023 · 2023-09

PROJECT SUMMARY / ABSTRACT The goal of this proposal is to develop a platform to model host-microbe interactions in skin, featuring a 3D bioprinted follicular skin model and spatial transcriptomics of host and microbial cells to retain physiologically relevant interactions. In human skin, a majority of microbial interactions with the host epithelium and cutaneous immunity is thought to occur in deeper, protective adnexal structures, e.g., hair follicles and glands. For example, recent work in mice has suggested a homeostatic interaction between different tissue resident cells, sebaceous glands, and the microbiome. Given the substantial diversity of the microbiome – encompassing hundreds of different bacterial and fungal species, it would be highly impactful to model such potential interactions systematically. In addition, examining interactions with human cells would best provide translational data on cellular response to microbial colonization. However, there are major limitations in the 3D skin models that are available – they lack complex structures where skin microbes reside, and second, current approaches to investigate host-microbiome interactions lack resolution on spatial activity. Here, our two aims address these key limitations. In Aim 1, we will develop a 3D bioprinted skin tissue model containing follicular structures. In Aim 2, we will develop in situ microbial sequencing technology for spatial profiling of microbial colonization of these tissues and other available human 3D skin models. These aims taken together will allow us to address fundamental questions on the underlying biology of the skin microbiome, which we will pilot in this R21. Our success would result in two new technologies that would enable construction of a high-resolution spatial map of the microbiome and host interactions, enabling foundational investigations into mechanisms of interstrain interactions and regulation of virulence to promote skin homeostasis.

NIH Research Projects · FY 2026 · 2023-09

Abstract To enable the expression of ideas in everyday conversation, our brain must hold on to speech information for short periods of time in verbal working memory (vWM). This is particularly important for everyday conversation that takes place in chaotic environments: Plans for speaking change quickly, and the brain has to adapt to these changes. Previous models of vWM, have suggested that vWM is anatomically and functionally discrete, with only indirect interactions with speech production. Evidence from lesions following strokes however, have shown a wide range of speech production deficits that are also associated with problems with vWM, arguing against a strong dissociation between speech production and vWM. We propose instead that vWM is integrated in the speech production planning system, sharing an anatomical and functional substrate. To study this overlap, we propose to examine neural responses associated with this functional overlap through a population of neurosurgical patients who as part of their clinical care have electrodes implanted directly in their brain, giving us a unique opportunity to study the human brain at a greater resolution that has been done in the past. We will leverage this access to address the following questions: 1) Does speech production and vWM overlap in the brain? 2) What kind of information is held when planning for speech production? 3) What motor features are shared between speech production and vWM? We will use a series of tasks that are designed to separate out the role of vWM for different speech production components and measure human brain responses using direct brain recordings, including high density electrodes that have unprecedented spatial resolution (<1 mm, up to 1024 electrodes for a 10 x increase in sampling). Understanding this basic cognitive process and their role in everyday language use will lead to more targeted approaches to help the over 1 million Americans who suffer from stroke-induced aphasia.