Ut Southwestern Medical Center

NIH Research Projects · FY 2026 · 2026-02

Project Summary Alzheimer’s disease (AD) is the most common type of dementia and causes progressive memory loss. AD is a major challenge for our society since increasing numbers of individuals are affected. Currently, there are no treatments that can stop or reverse the disease. AD leads to buildup of toxic clumps of two proteins in the brain: Amyloid-beta (Aβ), which forms plaques, and tau, which forms tangles. Prior research shows that tau tangles are more directly responsible for worsening symptoms and disease progression than Aβ. Tau spreads by being released from one cell and taken up (“tau uptake”) by a neighboring cell. Blocking tau uptake could potentially stop the disease from progressing. One key player of tau uptake is a group of molecules on the surface of cells called heparan sulfate proteoglycans (HSPGs). HSPGs consist of core proteins and side chains of sugars called heparan sulfate (HS). Our prior research showed that a specific HS length and pattern of sulfate groups (“size and sulfation code”) is required for binding to tau. However, there are still major gaps in our understanding of how HSPGs drive tau uptake: 1.) We do not know if the HS size and sulfation code applies to neurons and microglia, two cell types in the brain that are mainly affected in AD. 2.) We do not know which specific HSPG core proteins are involved in tau uptake. 3.) We have not tested the role of HSPGs in mouse models. Our work also showed that an enzyme called NDST1, which is involved in making HSPGs, plays a crucial role in tau uptake. Reducing the activity of NDST1 in cells changes the sulfation pattern of HSPGs and substantially lowers tau uptake. Studies in mice show that reducing NDST1 activity is non-toxic. This makes NDST1 a potential target for new treatments to block tau spread. In this study, we propose two main goals: Goal 1: Identify the specific HS size and sulfation code and the HSPG core proteins involved in tau uptake in human neurons and microglia. We will use advanced tools (pharmacological tools, CRISPR interference, sugar photocrosslinking, mass spectrometry) to determine which components of HSPGs are key for tau binding and how they differ between neurons and microglia. Goal 2: Test how HSPGs contribute to tau uptake and spread in a mouse model. We will use genetically modified mice to reduce NDST1 activity specifically in neurons or microglia and measure how this affects tau buildup and disease progression. This research will enhance our understanding how HSPGs control cellular tau uptake and spread in the brain. The results could lead to new treatments that block tau spread, thereby slowing or stopping the progression of AD and related conditions.

NIH Research Projects · FY 2026 · 2026-01

Abstract Hepatic phosphatidylcholine (PC) metabolism is essential for maintaining lipid homeostasis, as PCs are required for very-low-density lipoprotein (VLDL) secretion and protection against hepatic fat accumulation. Disruptions in PC synthesis are linked to metabolic dysfunction-associated fatty liver disease (MAFLD), a condition affecting over 25% of the U.S. population. However, the genetic regulation of PC metabolism in response to metabolic stress, and its relevance to MAFLD prevention and progression, remain poorly understood. Our preliminary data reveal that the transmembrane oxidoreductase VKORC1L1 regulates hepatic PC levels through a function independent of its enzymatic activity. Furthermore, loss of hepatic Vkorc1l1 in mice decreases PC levels, reduces VLDL secretion, and promotes hepatic fat accumulation. Lastly, human genetic data indicate a potential link between VKORC1L1 variants and liver steatosis, suggesting a role in MAFLD progression. Hepatic PC levels are regulated through three primary pathways: de novo synthesis from choline via the Kennedy pathway, methylation of phosphatidylethanolamine (PE), and the salvage of exogenous lipids. We aim to define the role of VKORC1L1 in hepatic PC metabolism and MAFLD by addressing three key questions. First, we will determine whether VKORC1L1 is necessary and sufficient to regulate PC levels and mitigate MAFLD progression in mouse models under varying dietary conditions, focusing on two MAFLD-relevant nutrients: fat and choline—a precursor for PC synthesis. Using liver-specific Vkorc1l1 knockout and overexpression mice, we will assess its impact on VLDL secretion, hepatic lipid accumulation, and whole-body metabolic health. Second, we will delineate the broader impact of VKORC1L1 on hepatic PC homeostasis by assessing its influence on the three major pathways that maintain PC levels—the Kennedy pathway, PE methylation, and lipid salvage—using isotope-labeled metabolic precursors and phospholipid analytical approaches. Finally, we will investigate the molecular mechanism by which VKORC1L1 influences de novo PC synthesis, building on our preliminary data showing that VKORC1L1 binds to and activates CCTα, the rate-limiting enzyme of the Kennedy pathway. By combining biochemical and structural approaches, including cryo-electron microscopy, we will test whether this interaction is influenced by membrane PC content in cells and mouse liver. By uncovering how VKORC1L1 regulates PC metabolism and VLDL secretion, our study will reveal key molecular mechanisms linking choline and PC deficiency to MAFLD. This is particularly relevant, as low-choline and high-fat diets are prevalent in segments of the U.S. population. Our findings could inform therapeutic strategies targeting VKORC1L1 to restore PC homeostasis and mitigate MAFLD progression—an urgent priority given the widespread prevalence of MAFLD and its considerable variability in severity and treatment response.

NIH Research Projects · FY 2025 · 2025-12

Project Summary Duchenne muscular dystrophy is a severe X-linked genetic disorder characterized by progressive muscle degeneration and weakness caused by the loss of dystrophin protein. There are no curative therapies for DMD, and recently approved micro-dystrophin gene therapies have shown modest clinical benefit. Adeno-associated virus (AAV) delivered CRISPR gene editing strategies have achieved high rates of corrective gene editing in mouse and canine models of DMD but rely on dangerously high doses of AAV and result in constitutive expression of immunogenic gene editors. Lipid nanoparticles (LNPs) have emerged as a promising non-viral delivery strategy for gene editing but have lower delivery efficiency in skeletal muscle than AAV. Significant effort has been put towards improving delivery efficiency of LNPs, however, the factors that limit gene editing in skeletal muscle after delivery have not been addressed. Gene editing efficiency is not only determined by the entry of the delivery vehicle into the cell but also by the ability of the gene editor protein to populate all the myonuclei of the myofiber. Myofibers have hundreds or thousands of myonuclei that must be edited to achieve therapeutic benefit, but our preliminary data show that gene editor proteins cannot propagate to myonuclei distant from the site of transfection/transduction. In addition to the issue of low myonuclear propagation, low mRNA stability prevents the accumulation of sufficient levels of gene editor protein to edit most myonuclei. The objective of this project is to develop a muscle-optimized gene editor that can increase gene editing efficiency after non-viral delivery. This objective will be achieved by developing an in-vitro myotube based screening platform to identify modifications to the ABE8e adenine base editor that improve myonuclear propagation. An in-vivo pooled LNP screen will be performed to identify UTRs and codon optimization strategies that improve base editor mRNA stability in skeletal muscle. Modifications identified in these screens will be combined into a muscle-optimized base editor that will be used in LNP-delivered editing of a humanized mouse model of DMD. Completion of these studies will contribute to the development of a non-viral curative therapy for DMD. The insight gained from these studies will provide a basis for developing other muscle-optimized gene therapy cargos. These studies will be carried out in the laboratory of Dr. Eric Olson, PhD at University of Texas Southwestern Medical Center. All studies and career development will be performed under the mentorship of Dr. Olson and Dr. Ning Liu, PhD, pioneers in the field of skeletal muscle gene editing.

NIH Research Projects · FY 2025 · 2025-12

PROJECT SUMMARY/ABSTRACT Non-small cell lung cancer (NSCLC) is a leading cause of cancer-related mortality worldwide. The development of targeted molecular therapies that inhibit mutant oncogenic proteins and immunotherapies that inhibit the PD- 1/PD-L1 pathway have improved outcomes for subsets of patients with NSCLC. However, targeted therapies are only effective against NSCLCs that harbor actionable genetic alterations. In addition, anti-PD-1/PD-L1 immune checkpoint inhibitors are most effective against NSCLCs that express high levels of PD-L1 or have a high tumor mutation burden. Thus, patients with NSCLCs that lack these features do not benefit from targeted therapies and are less likely to benefit from immunotherapies, emphasizing the need to identify novel therapeutic targets in this disease. This project seeks to characterize the XRN1 exoribonuclease, which functions in cellular RNA degradation, as a target that may have broad therapeutic potential in NSCLC. My preliminary data show that XRN1 inactivation induces cell lethality in a subset of human NSCLC cell lines. In an implantable mouse tumor model, XRN1 deletion can synergize with anti-PD-1 immunotherapy to enhance tumor eradication. Aim 1 will define the molecular signaling pathways that mediate cell lethality after XRN1 deletion in a subset of human NSCLC cell lines. Aim 2 will assess the impact of XRN1 deletion in mouse NSCLC models of anti-PD-1 immunotherapy. Aim 3 will determine whether XRN1 gene expression in human NSCLC tumors may serve as a predictive biomarker for treatment response to anti-PD-1 immunotherapy. The long-term goals of the proposed research are to gain fundamental insights into how RNA metabolism regulates cancer cell survival and anti- tumor immunity and to establish RNA metabolism pathways as potential therapeutic targets in NSCLC. The applicant, Dr. Tao Zou, is an oncologist at Dana-Farber Cancer Institute (DFCI). He spends 80% of his time engaged in research and career development activities and 20% of his time in clinical practice caring for patients with lung cancer. Dr. Zou has outlined a five-year career development plan that will enable him to achieve his goal of leading an independent laboratory that conducts basic and translational research at the intersection of RNA biology and lung cancer immunotherapy. Dr. Zou will perform the proposed research under the mentorship of Dr. Matthew Meyerson, an expert in lung cancer biology with a strong record of training independent investigators in academic cancer research. Together with expert members of Dr. Zou’s Scientific Advisory Committee, Dr. Meyerson will ensure that Dr. Zou will obtain additional training in innate immune RNA sensing, tumor immunology, translational studies using human biospecimens, and computational biology. Dr. Zou will conduct the proposed research primarily at DFCI and will leverage additional resources available to him at the Broad Institute and Harvard Medical School. DFCI is a rich research community with a distinguished track record of training successful physician-scientists. DFCI provides the ideal environment for Dr. Zou to build his research expertise and engage in career development activities prior to transitioning to an independent academic position.

NIH Research Projects · FY 2025 · 2025-09

Project Abstract/Summary: The Earned Income Tax Credit (EITC) plays a critical part in the social safety net by increasing financial security for low to moderate income working families, particularly the 5.4 million households headed by single female parents with low education. The EITC has been identified as a promising primary prevention strategy for preventing child injury and risk factors for youth violence. However, program design fails vulnerable first-time mothers. EITC payments are so limited for first-time mothers that researchers have used less educated, single first-time mothers as the “control” group to establish the positive impacts of the EITC. Our central hypothesis is that current EITC design contributes to higher child abuse and neglect and youth violence and exacerbates health inequities for groups already experiencing disproportionate burdens of violence. The EITC gap exists as women pregnant with their first child receive little to no EITC benefit until 2-14 months following birth despite strong evidence that stress, nutrition, and economic well-being during pregnancy and early infancy impact a lifetime of outcomes including experiences with violence. Our long-term goal is to support the health and well- being of families by equitably reducing experiences with violence. The overall objective of this application is to estimate how EITC policy design impacts outcomes for first children and how this contributes to the disproportionate burden of violence. We update the existing literature on EITC effects with a combination of data sources and causal design and provide the first estimates of the child abuse and neglect and youth violence improvements possible by closing the EITC gap for first-time mothers. Specific Aim 1: To quantify child abuse and neglect and youth violence effects that would be achieved by closing the EITC gap for first births. Specific Aim 2: To understand community member perspectives on risk factors for child abuse and neglect and youth violence including EITC eligibility. Specific Aim 3: To estimate a simulation model of the costs and benefits of closing the EITC coverage gaps for first-time mothers. 3.1: Assess the CAN and youth violence effects of closing the EITC gap at the federal level. 3.2: Separately estimate impacts of the EITC gap for people disproportionately impacted by violence based on disability status and race and ethnicity and assess the role of the EITC gap in perpetuating disproportionate burdens of violence.

NIH Research Projects · FY 2025 · 2025-09

Project Summary Heterotopic ossification (HO) is a debilitating condition characterized by aberrant bone formation in soft tissues following trauma or surgery, often leading to chronic pain, severe functional impairment, and reduced quality of life. Notably, obesity increases the risk of developing HO, complicating recovery outcomes. Current treatment options for HO are limited or invasive, underscoring the urgent need for innovative, non-invasive strategies to prevent HO onset and progression. Recent studies suggest that dietary interventions, specifically calorie restriction (CR) and intermittent fasting (IF), may hold therapeutic potential by modulating inflammation and promoting tissue regeneration in other disease contexts. However, no dietary interventions currently exist to prevent or reverse HO. This proposal aims to investigate dietary therapies, specifically CR and IF, as potential interventions to target the key inflammatory and cellular pathways central to HO. The central hypothesis guiding this research is that dietary modifications regulate HO formation and progression through CCL2-mediated monocyte recruitment, with the timing of these modifications being crucial to their therapeutic efficacy. Aim 1 will define the optimal therapeutic window for CR and IF, examining pre-injury and post-injury regimens to establish the timing and duration of the diet that maximally suppresses HO formation in clinically relevant mouse models of trauma and surgery. High resolution micro-computed tomography (µCT), histology, and functional assessments will be used to evaluate treatment efficacy. Aim 2 will delineate the mechanistic effects of CR and high-fat diet on mesenchymal progenitor cell (MPC)-monocyte interactions, focusing on the CCL2-CCR2 signaling axis. Lineage specific and global gene deletion mice with impaired CCL2-CCR2 signaling will be used to investigate how dietary modifications impact monocyte recruitment, inflammation, and HO progression. Advanced molecular techniques, including single-cell RNA sequencing (scRNA-seq), spatial transcriptomics, and multiplexed ion beam imaging (MIBI), will be employed to evaluate how dietary interventions affect inflammatory signaling and immune cell dynamics in HO. This research addresses a critical public health challenge by aiming to develop novel, non-invasive dietary strategies that could prevent HO and transform recovery and long-term outcomes for high-risk patients, particularly those with obesity. The applicant will conduct this work under the mentorship of clinician scientist Dr. Benjamin Levi at UT Southwestern Medical Center, who is a previous F32 recipient and who has mentored several F32 awardees who now run independent laboratories. The training plan that includes advanced coursework and hands-on experience in scRNA-seq and spatial transcriptomics, high-resolution imaging, immunology, bioinformatics, and metabolomic techniques, preparing the applicant for a career as a physician-scientist specializing in tissue regeneration and wound healing.

NIH Research Projects · FY 2025 · 2025-09

Abstract Heart failure (HF) is a common and morbid consequence of metabolic dysfunction (excess/ectopic adipose, insulin resistance). Social determinants of health (SDOH) contribute to excess metabolic and HF risk, and disproportionately impact the health of Black and Hispanic adults, although many survive to late-life free of CV disease. Critical barriers to the development of interventions to prevent HF include the limited knowledge of molecular pathways (a) that link excess and ectopic adiposity to cardiac dysfunction and (b) by which SDOH and resilience to such adversity influence susceptibility to CV disease. Our overall objective is to use metabolomics and genomics to identify biologic pathways linking metabolic dysfunction – and ectopic adiposity specifically - to the development of subclinical and clinical cardiac dysfunction; mediating the impact of adverse SDOH on HF risk; and characterizing biologic resilience to these outcomes in the presence of adverse SDOH. The central hypothesis is that large-scale metabolomic and genomic data in a multiethnic population will enable discovery of novel metabolic signatures of specific ectopic fat depots that are relevant to HF pathobiology and underlie SDOH-related risk for and resilience to cardiac dysfunction. The rationale is that identifying metabolites with causal effects on cardiac dysfunction and defining molecular mediators of CV resilience to adverse SDOH may yield new prevention targets especially relevant to diverse populations. This project will measure metabolomics (~1,000 serum metabolites), and leverages existing WES, rich CV phenotyping (serial cardiac MRI, rest-exercise echo), MRI-based quantification of total and regional adipose, and prospectively adjudicated HF in the multiethnic Dallas Heart Study to address the following aims: (1) Identify metabolites reflecting metabolic dysfunction that associate with progressive subclinical cardiac dysfunction and development of HF; (2) Define genetic determinants of HF- and cardiac function-related metabolites, and identify metabolites with possible causal effects on HF development; (3) Discover molecular pathways linking SDOH, and resilience to social adversity, to cardiac dysfunction. The unique contribution will be to identify metabolic pathways linking ectopic fat to cardiac impairment and HF, and underlying SDOH- related risk of and resilience to cardiac dysfunction in diverse populations. This contribution will be significant in helping to identify novel therapeutic targets to prevent of cardiac dysfunction that are tailored to disease mechanisms impacting these communities. These studies may therefore help to reduce the morbidity, mortality, and racial/ethnic disparities associated with HF. Innovative features include: (a) linking ectopic adipose to impaired cardiac reserve, longitudinal changes in cardiac function, and HFpEF not feasible in other cohorts; (b) focus on understudied populations to interrogate mechanisms by which SDOH influence disease susceptibility; and (c) integration of SDOH and psychosocial assessments to identify protective metabolites underlying cardiac resilience in the face of social adversity.

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY In spite of the benefits of antiretroviral therapy, the burden of central nervous system complications remains high among virally-suppressed people with human immunodeficiency virus (VS+PWH). Study of cognitive impairment across cohorts of VS+PWH often reveals subsets of VS+PWH with relatively marked, low performance in executive function (EF) that is now referred to as cognitive control (CC). This project aims to study regional proliferation of microglia, and the relationship to EF/CC in VS+PWH. Our focus on positron emission tomography (PET) imaging of microglia stems from our previous efforts. Our group validated use of [11C]DPA-713 (DPA) PET to localize a microglial marker of brain injury and repair, the translocator protein 18 kDa (TSPO) in human health and VS+PWH. Among 23 VS+PWH, high TSPO in prefrontal cortex or frontal cortex associated with low performance across select cognitive domains of memory, motor function, and EF/CC. Our subsequent study of VS+PWH (n=25) focused on the relationship between TSPO and EF/CC. Using DPA PET and a priori-defined regions relevant to EF/CC function, higher levels of TSPO in EF/CC regions were found in VS+PWH compared to HIV-CON. Higher TSPO in each EF/CC region showed association with higher self-reported burden of cognitive problems. Further, higher TSPO in the two EF/CC regions that subserve the EF/CC subdomain of response inhibition (lateral PFC, inferior parietal lobe) associated with lower performance in EF/CC response inhibition. Since TSPO is not microglia-specific in its expression, [11C]CPPC (CPPC) was developed to image the colony stimulating factor 1 receptor (CSF1R), which is chiefly expressed by microglia and myeloid cells. Using pilot design, CPPC brain PET demonstrated a trend of higher CSF1R in 16 VS+PWH relative to 15 HIV- uninfected controls (HIV-CON) including in EF/CC regions of PFC and parietal cortex. In VS+PWH, higher CSF1R in each EF/CC region (PFC, parietal cortex) associated with poorer performance on the Stroop test of EF/CC response inhibition and higher CSF1R in parietal cortex associated with higher peripheral blood signature of myeloid cell activation and proliferation. Building on prior findings, we will use CPPC PET cross-sectionally in VS+PWH and HIV-CON to study further the CSF1R that marks microglial proliferation, as well as its regional relationship to EF/CC (self-report and performance metrics) or other immune markers in circulating blood. Our team at University of Texas Southwestern Medical Center is positioned well to use CPPC PET in an ethnically diverse population of VS+PWH and HIV-CON. The proposed approach (clinical, biofluid and imaging) will complement our prior body of work using TSPO PET in VS+PWH. Further, we use the NIMH Research Domain Criteria framework to study EF/CC in VS+PWH. These data will characterize further the cross-sectional relationship between microglial proliferation, EF/CC, and peripheral myeloid immune markers in VS+PWH – toward strategies for longitudinal tracking of the hypothesized, detrimental microglial contribution to EF/CC and deployment of immune modulating and/or EF/CC-targeted therapies to improve cognitive health in VS+PWH.

NIH Research Projects · FY 2025 · 2025-09

There is a growing and pressing need to train the next generation of clinical oncology researchers. The overall objective and long-term goal of the UT Southwestern Harold C. Simmons Comprehensive Cancer Center (SCCC) Clinical Oncology Research Career Development Award (K12) is to meet our regional and national needs in the rapidly changing clinical and translational cancer research landscape by training a nimble and effective clinical and translational cancer research workforce. Our near-term goal is to support the transition from mentored to independent investigators. This Scholar-focused program will leverage world-class laboratory-based research, a rapidly growing and varied patient population, expanding clinical research infrastructure, and exceptional faculty to provide career development and mentorship to the next generation of clinical and translational cancer researchers through the following Specific Aims: (Aim 1) Ensure personalized research career development; (Aim 2) Support collaboration and innovation; (Aim 3) Promote the successful transition of trainees to independent research careers; (Aim 4) Contribute to a productive and effective clinical and translational cancer research workforce. To support these Aims, the SCCC K12 Program has five components: (a) selection of applicant and mentor (b) participation in a Scholar-driven research project with training potential, (c) gaining critical knowledge, (d) development of essential translational and clinical research skills, and (e) monitoring of career development. To provide mentorship and career development across the spectrum of cancer clinical trials and translational studies, Program Faculty span three categories: (1) Basic Science Mentors, (2) Translational/Clinical Science Mentors, and (3) Clinical Trial Experts. Additional faculty, Technical Advisors, will provide project-specific support in biostatistics, bioinformatics, biomarker development, imaging, molecular diagnostics, biospecimen acquisition and processing, pharmacology, and protocol implementation. The interdisciplinary approaches of these faculty will support personalized and relevant mentorship in all aspects of the Scholar’s research and career development, including hypothesis generation, experimental design and conduct, data analysis and presentation, clinical trial design and implementation, correlative study development and performance, grant and manuscript preparation, project management, and team leadership. In Year 1, we will develop curriculum and evaluation materials. We will also initiate recruitment among institutional junior faculty, trainees, and external faculty candidates. Faculty from different scientific perspectives will provide Scholars with truly interdisciplinary training. Scholars will (a) develop clinical research skills; (b) receive instruction and experience in interacting and communicating with basic scientists and training in hypothesis-driven approaches; and (c) obtain laboratory experience while moving their research toward a translational and therapeutic endpoint.

NIH Research Projects · FY 2025 · 2025-09

Children with cancer live in poverty have worse quality of life and are more likely to relapse and die. Unmet social needs – housing, food, utility, or transportation insecurity – are highly prevalent during pediatric cancer care and associated with poor outcomes. Despite the fact that social needs are modifiable drivers of health outcomes, pediatric oncology lacks interventions to systematically address unmet social needs. The overall objective of this application is to refine and pilot test a novel benefits navigator intervention, ASSIST, to address unmet social needs in pediatric oncology. Iterative parent input informed the ASSIST intervention prototype and logical next steps include intervention refinement and pilot testing. Following a stepwise approach for rigorous intervention development, Aim 1 will refine the ASSIST intervention prototype based on parent and community advisory board input, with a focus on optimizing intervention components and delivery to address identified barriers to uptake. Aim 2 will pilot test the refined ASSIST intervention among children with newly diagnosed cancer to examine feasibility, acceptability, and proof-of-concept of preliminary efficacy among endpoints including benefits receipt, decreased food insecurity, and decreased parent distress. Aim 3 will leverage a national dataset of children with acute lymphoblastic leukemia treated on Children’s Oncology Group trial AALL1731 to identify patterns and predictors of Supplemental Nutrition Assistance Program (SNAP) non-participation among eligible families as an exemplar means-tested benefit that reduces unmet social needs. Results will inform the approach for a subsequent multicenter efficacy evaluation of the ASSIST intervention. Dr. Umaretiya has foundational methodologic training and a strong academic track record that make her an excellent K08 candidate. This proposal will facilitate her transition to an independent physician-scientist focused on supportive care intervention development and evaluation through training in 1) community-engaged methodology, 2) supportive care clinical trial design, 3) measurement of parent- and patient-reported outcomes, and 4) longitudinal data analysis. Dr. Umaretiya’s proposal is supported by a highly skilled and successful mentorship team with expertise in these areas. She will complete this proposal in the unparalleled environment at UT Southwestern Medical Center, with strong institutional support, robust research infrastructure, and a large patient population. At the conclusion of this award, Dr. Umaretiya will have a feasible, pilot-tested intervention, pilot data, and essential training to support an R01 for a multicenter randomized efficacy trial to test the hypothesis that the ASSIST intervention will improve parent- and child-outcomes during cancer care. This application is highly significant in its aim to improve pediatric oncology outcomes by addressing unmet social needs. This program of research will innovatively shift the paradigm of pediatric oncology outcomes research from description to intervention, aligned with national calls from the National Cancer Institute, American Society for Clinical Oncology, and American Cancer Society.

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY Bariatric surgeries, such as Vertical Sleeve Gastrectomy (VSG) and Roux-en-Y Gastric Bypass (RYGB), are highly effective interventions for obesity and related metabolic disorders. While they lead to weight loss and improved glucose metabolism, the neural mechanisms underlying these effects are not fully understood. These data suggest disparate and spatially distinct activity profiles of arcuate Neuropeptide Y/Agouti-related Peptide (NPY/AgRP), Proopiomelanocortin (POMC), and leptin receptor (LepR) expressing neurons that may contribute to the metabolic benefits of RYGB and/or VSG. A critical question is whether the changes in arcuate neuron activity precede or are required for the observed metabolic benefits of bariatric surgery. To address this, we will employ electrophysiological techniques to study alterations in neuronal excitability and synaptic physiology, providing insights into the activity patterns of these neurons before the weight loss effects are observed post- bariatric surgery. Additionally, we will measure metabolic parameters while silencing or inhibiting the activity of arcuate POMC, NPY/AgRP, and LepR to investigate if these neurons contribute to the RYGB and/or VSG- induced metabolic benefits. Furthermore, we aim to explore molecular alterations in the differential responses of POMC, NPY/AgRP, and LepR based on the type of bariatric surgery. In pursuing these research objectives, our study seeks to understand the intricate mechanisms and cell populations involved in the metabolic benefits induced by bariatric surgery. Together these data have the potential to inform the development of targeted therapeutic interventions for obesity and associated metabolic disorders.

NIH Research Projects · FY 2025 · 2025-09

Project Summary/Abstract Hyperlipidemia, characterized by elevated levels of lipids in the blood, causes significant abnormal metabolism such as lipid accumulation, insulin resistance, mitochondrial dysfunction, and inflammation. These alterations contribute to or are associated with various metabolic disorders, obesity, and diabetes, and become a leading cause of atherosclerotic cardiovascular diseases (ASCVD). However, there is no compelling alternative to replace conventional lipid-lowering therapies, which are still risky to many patients due to their associated adverse effects. Therefore, developing more specific and efficient lipid-lowering therapies is essential. Fibroblast growth factor 1 (FGF1) exhibits unexpected and potent glucose-lowering and insulin-sensitizing effects in diabetic mice, leading to increasing attention to FGF1 in metabolic diseases. Nevertheless, the pathophysiological roles of FGF1 in lipid homeostasis and atherogenesis remain unclear. Moreover, there is a significant gap in the field regarding the underlying mechanism of FGF1 action on systemic metabolism. My preliminary studies showed chronic administration of FGF1 and a non-mitogenic FGF1 variant (FGF1ΔHBS). ameliorated atherosclerotic phenotypes associated with rectified hyperlipidemia, promoted insulin sensitivity, and enhanced brown adipose tissue (BAT) activation in ApoEKO mice. Notably, FGF1 treatment accelerated the plasma lipid clearance and distinctively enhanced lipid uptake in BAT, accompanied by significant increases in lipoprotein lipase (LPL) activity and expression in BAT. My data further indicated brown adipocyte LPL-specific deletion (LPLBAT-KO) abolishes FGF1’s benefits in lipid-lowering and glucose intolerance in ApoEKO mice. Currently, activating BAT in adult humans has fueled substantial interest in exploring its potential as a ‘metabolic sink’ in mice. The FGFR1 in adipose tissue is essential for FGF1’s anti-diabetic effects. These findings lead me to central hypothesize that the FGF1/FGFR1 axis promotes LPL-mediated signaling in BAT to modulate systemic metabolism and prevent atherosclerosis. Aim 1 will define BAT as a mediator for FGF1 effects on systemic lipid homeostasis. Systematic assessment of the effects of FGF1 on lipid clearance and BAT activation in ApoEKO, LDLRKO, and ApoEKO/LPLBAT-KO mice. FGF1 treated-BAT suppression and BAT ablation mouse models will be subject to metabolic characterization. Aim 2 aims to determine whether brown adipocyte FGF1/FGFR1-LPL plays a critical role in regulating metabolic homeostasis and preventing the progression of atherosclerosis. The gain and/or loss of function of FGF1 will be investigated through BAT-specific FGF1 overexpression using the AAV/Rec2-mADIPOQP-Fgf1 vector in ApoEKO/FGF1KO and brown adipocyte-specific FGFR1 knockout (ApoEKO/Fgfr1BAT-KO) mice. These studies aim to uncover the mechanistic role of FGF1 in BAT in systemic homeostasis. Additionally, brown adipocyte-specific knockout mice will be used to assess the clinical translatability of FGF1ΔHBS in protecting against atherosclerosis. This proposed study will reveal that FGF1/FGFR1-LPL signaling in BAT plays critical roles in modulating systemic metabolism, paving the way for novel therapeutic strategies to address dyslipidemia-related metabolic diseases.

NIH Research Projects · FY 2025 · 2025-09

Project Summary/Abstract Introduction: Out-of-hospital cardiac arrest (OHCA) is a major public health problem that affects over 350,000 adults in the US each year. Survival from OHCA remains unacceptably low despite promising advances over the last decade. During cardiac arrest, all circulation stops. Cardiopulmonary resuscitation (CPR) combines chest compressions (circulation) with lung inflation (ventilation) to restore perfusion and oxygenation to the body. During the past decade, research focused on measuring chest compressions during CPR has led to improvements in performance of chest compressions and improved clinical outcomes. However, ventilation has long been a “neglected parameter” in CPR research, in part, because measuring ventilation during OHCA and CPR is difficult. To address this problem, we developed a novel method for measuring ventilation during CPR using thoracic bioimpedance (electrical resistance), which can be monitored through defibrillator pads placed during CPR. Our studies showed that lung inflation does not occur in most ventilation attempts with use of a bag-mask (BM) device during standard 30:2 CPR. We now have developed and validated a machine-learning automated program that can measure ventilation during continuous chest compression (CCC) CPR. Objectives: The objectives of this study are to facilitate trial design development through measurement and analysis of ventilation metrics using data from a large, comprehensive OHCA trial. Methods: The study will use data from one of the largest, comprehensive OHCA multi-center clinical trial in the world. The ROC CCC Trial database includes CPR resuscitation metrics, patient outcomes, and access to defibrillator bioimpedance recordings. A validated method to identify bioimpedance ventilation waveforms has been programmed into an automated computer algorithm, which will extract ventilation data from defibrillator- monitor bioimpedance recordings from approximately 7,600 patients from seven ROC sites that participated in the CCC Trial. Ventilation data will be matched with clinical data. Specific Aims: 1) To determine ventilation frequency, incidence, bioimpedance waveform amplitude, and inspiratory and expiratory times from the CCC CPR defibrillator and clinical files and 2) determine association of variable with types of airway devices 3) To determine the association of BVM ventilation frequency, incidence, and fraction with survival outcomes in the CCC CPR group and association with airway devices and compare it with the 30:2 CPR group. Significance: The results may provide evidence for a paradigm shift of our view regarding the importance of ventilation during CPR and impact CPR training and guidelines. It will provide support for developing trial design to test ways to improve ventilation during CCC and 30:2 CPR.

NIH Research Projects · FY 2025 · 2025-09

Project Summary/Abstract Pleuropulmonary blastoma (PPB) is the most common pediatric lung cancer in children and one of the sentinel manifestations of DICER1-related tumor predisposition. While some patients with PPB may be treated with surgery alone, children with advanced PPB require an intense combination of surgery, chemotherapy and often radiation. Unresectable or recurrent disease is associated with a poor prognosis. Currently, there are no molecular factors sufficiently predictive to allow risk stratification in advanced PPB and no ways to rationally target oncogenic DICER1 variants. The DICER1 enzyme normally produces mature microRNAs by cleaving the two arms of a pre-microRNA hairpin, and PPBs typically exhibit a loss-of-function variant on one DICER1 allele and a missense variant on the second allele, predominantly affecting one of five specific “hotspot” positions. These hotspot variants in DICER1 impair cleavage of microRNAs derived from the 5p arms of pre-microRNA hairpins (“5p microRNAs”) but allow cleavage of 3p microRNAs. Although these hotspots have previously been thought of as interchangeable, our analysis suggests that hotspot variants differ in clinical prognosis, ability to engraft as patient-derived xenografts (PDXs), and expression of 5p microRNAs. More severe impairment of 5p microRNAs leads to higher levels of genes targeted by 5p microRNAs, including MYC. Thus, here we will examine the clinical and functional impact of DICER1 variants in PPB with the following specific aims: AIM 1. To validate the prognostic significance of DICER1 variants in PPB, we will correlate hotspot with clinical outcome and PDX engraftment in a larger set of tumors. AIM 2. To test whether DICER1 variants have different effects on 5p microRNA production, we will analyze more tumors, and we will model hotspot variants in cell-free assays and in cell lines. AIM 3. To evaluate therapeutic strategies for targeting MYC in PPB, we will test silencing and inhibition of MYC cofactors in PPB cell lines and xenografts. The overall goal of our research program is to improve outcomes for patients with PPB and other DICER1-related cancers. If successful, this project could advance molecular risk stratification in PPB and identify novel therapeutic approaches to target these tumors.

NIH Research Projects · FY 2025 · 2025-09

Project Abstract The global tuberculosis (TB) epidemic is fueled by the airborne transmission of Mycobacterium tuberculosis (Mtb), yet the mechanisms underlying cough-mediated aerosolization and the impact of antibiotic treatment and drug resistance on transmission remain poorly understood. We propose to address these gaps using ex vivo cultured nociceptive neurons and a guinea pig model of human cough to investigate the role of host and bacterial factors in TB transmission and evaluate strategies to disrupt this process. Preliminary data show that Mtb glycolipids, sulfolipid-1 (SL-1) and phenolic glycolipid (PGL), activate nociceptive neurons and drive the cough reflex, a critical driver of Mtb aerosolization and person-to-person transmission. Leveraging our innovative nociceptive neuron activation model and Mtb cough measurement and particle capture systems we developed specifically to study Mtb aerobiology, this project will uncover the drivers of Mtb transmission and explore interventions to mitigate it. In the first aim, we will analyze how biological sex, antibiotic treatment, and drug resistance influence Mtb-induced cough and Mtb aerosol production. By comparing male and female guinea pigs, we will determine the impact of host sex on cough frequency and Mtb aerosol generation. We will also evaluate how standard (rifampin-isoniazide-pyrazinamide; RIP) and newer (bedaquiline-pretomanid-linezolid; BPaL) antibiotic regimens reduce cough and Mtb aerosol production and test whether drug-resistant Mtb strains alter these processes, potentially enhancing transmissibility. The second aim will focus on cough suppression as a host-directed intervention. Using inhibitors of nociceptive neuron pathways, we will evaluate their ability to reduce Mtb-induced neuronal activation, cough and infectious particle production. These studies will test whether blocking the cough reflex has potential to mitigate Mtb transmission.

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY Alpha-ketoglutarate (aKG, also known as 2-oxoglutarate) is a key metabolic regulator of chromatin structure and, by extension, cell fate and function. aKG is imbued with this regulatory capacity based on its role as a requisite substrate for a broad class of epigenetic ‘eraser’ enzymes that catalyze the removal of methyl marks from DNA and histones. The importance of aKG in establishing and maintaining cellular identity is underscored by a series of recent discoveries that cut across normal and diseased biological states. For example, elevated aKG levels in naïve embryonic stem cells are critical for maintaining a genomic architecture that facilitates pluripotency. Conversely, many cells display aKG antagonism phenotypes that promote malignancy or alter immune cell function, which is achieved through elevated aKG catabolism or by production of metabolites that competitively inhibit aKG binding to proteins. Despite the fundamental role for aKG in establishing cellular identity, we have limited understanding of the molecular mechanisms that control the pool of aKG that is available in the nucleus to support DNA and histone demethylation. This limitation is tied to one central roadblock: a paucity of biomedical research tools that can be used to quantify changes in nuclear aKG pool size with high sensitivity and specificity. To address this issue, we have designed and collected feasibility data supporting a new biomedical research tool to measure nuclear aKG. This tool, which we term the aKG-ON biosensor system, is similar to the classical TET-ON system. Rather than responding to exogenous tetracyclines, however, the aKG-ON biosensor system responds to changes in nuclear aKG. The aKG-ON biosensor system has two components: 1) a chimeric transcription factor based on a cyanobacterial protein, NtcA, whose DNA binding activity is allosterically regulated by aKG, and 2) a synthetic reporter gene comprising a promoter with NtcA DNA binding sites and a GFP cDNA. The output of this system, GFP expression, can be used to assess levels of aKG in nuclei of live mammalian cells. Our central hypothesis is that the transcription factor NtcA presents an attractive starting point for biosensor engineering and synthetic biology given its evolutionarily conserved role in aKG sensing in cyanobacteria. We seek to develop and validate an optimized prototype of the aKG-ON biosensor system via three Aims. In Specific Aim #1, we seek to improve the dynamic range of this system through signal amplification and directed evolution approaches to produce a prototype of the aKG-ON biosensor system. In Specific Aim #2, we seek to validate utility of the aKG-ON biosensor system prototype in unbiased forward genetic studies. In Specific Aim #3, we seek to engineer the aKG-ON biosensor system into mice and validate its utility for measuring nuclear aKG levels in vivo. If successful, our work will create a new biomedical research tool that permits direct assessment of the aKG pool that is available to chromatin-modifying enzymes, thereby enabling studies of mechanisms of metabolic-epigenetic crosstalk that drive cell state transitions in development and disease.

NIH Research Projects · FY 2025 · 2025-09

Immune checkpoints play a key role in regulating hemostasis and maintaining self-tolerance, including in the human autoimmune disease of the central nervous system: multiple sclerosis (MS). We previously employed metabolic glycoengineering and biorthogonal click chemistry to bioengineer immune checkpoint functionalized mouse glial cells. We demonstrated that these immune-checkpoint engineered cells are highly effective in preventing and treating EAE in mice. Based on this exciting preliminary data, we aim to further develop this technology to improve MS treatment. Our overarching hypothesis immune checkpoint engineered oligodendrocytes (OLG) can engage autoreactive immune cells and lead to T cell exhaustion and immune tolerance. We further theorize that we can identify a highly effective combination of immune checkpoints that can provide additive or synergistic effects that regulates CNS autoimmunity. To demonstrate the feasibility of this approach, we developed two specific aims. The first aim will formulate checkpoint engineered OLGs using stem cells and iPSCs. This aim will demonstrate the feasibility of generating autologous oligodendrocytes for checkpoint engineering. Second aim will examine engineered OLGs using MOG and PLP MS models. Our application has high potential impact on the treatment of MS. Our approach of using biomedical engineering and glycochemistry to engineer cell-based treatment is highly innovative and novel. Our work can reveal new mechanistic insights in MS and potential new treatments for MS. In the long term, our work can lead to a new class of therapeutics for MS treatment. Our proposed treatment is highly translatable. Our work can also bring new interest in the application of biomedical engineering approaches to MS.

NIH Research Projects · FY 2025 · 2025-09

Nocturnin (NOCT) is a NADP(H) phosphatase with highly rhythmic expression peaking in the early dark phase (ZT12). Notably, Noct-/- (Noct-KO) mice are resistant to obesity and hepatic steatosis on a high-fat diet. Given the widespread role of NADP(H) as an essential cofactor in numerous metabolic reactions, it is likely that NOCT has distinct tissue-specific effects, making it difficult to understand NOCT’s role in metabolism using a global KO model. In fact, previous studies have observed contradictory changes in lipid and lipoprotein metabolism across different tissues in Noct-KO mice. Specifically, while previous studies have found that Noct- KOs have delayed chylomicron transit into circulation following olive oil gavage, other studies have found significantly higher circulating VLDL, triglycerides, and cholesterol at certain times of day in the plasma of chow- fed Noct-KO mice as compared to controls. In further contradiction to the lean phenotype seen under high-fat diets, chow-fed Noct-KOs have significantly higher expression of hepatic enzymes involved in fatty acid synthesis during their active phase. Given these seemingly paradoxical phenotypes, this proposal will use novel adipose- , liver-, muscle-, and intestine-specific conditional Noct-KO (cKO) mice, generated via the Cre-loxP system, to better understand NOCT’s role in metabolism. Both male and female cKO and control mice will be subject to a high-fat diet for twenty weeks, with body weight and food intake recorded on a weekly basis, to determine if loss of NOCT in one tissue is sufficient to confer resistance to diet-induced obesity. A separate cohort of cKO mice will be placed in metabolic cages for one week to discern any differences in energy expenditure. At the end of the high-fat diet challenge, body composition measurements will be taken to determine differences in fat and lean mass. Plasma, adipose, liver, muscle, and intestinal tissues will be collected from each cKO line and their respective controls at two circadian phases for further analyses. Plasma lipoprotein classes will be fractionated and characterized to determine how tissue-specific loss of NOCT impacts lipid mobilization and trafficking. Plasma adipokine levels will also be measured to identify any differences in adipocyte metabolism and health. To confirm the mechanism by which any observed phenotype originates, NAD(H) and NADP(H) levels will be measured in each cKO tissue. Further, RNA-seq will be performed on all collected tissues to investigate how tissue-specific loss of NOCT impacts transcriptional networks. Tissues will also be stained with hematoxylin and eosin to define any gross morphological changes. Lastly, lipogenic flux will be measured in both liver-cKO and global KO mice to determine the direct impact on de novo lipogenesis. The experiments outlined in this proposal will define how tissue-specific loss of NOCT, and thus how tissue-specific increases in NADP(H) levels, impact metabolism. More specifically, this proposal will aid in understanding how loss of NOCT protects against diet- induced obesity and hepatic steatosis, which, in turn, can aid in the development of treatments for obesity and obesity-related diseases.

NIH Research Projects · FY 2025 · 2025-09

Abstract Celiac disease (CeD) affects approximately 1% of the U.S. population. It is associated with several co- morbidities, including osteoporosis, type 1 diabetes (T1DM), anemia, reduced quality of life, and increased cancer risk. Currently, there is no approved drug to treat CeD, and the primary management strategy—strict adherence to a gluten-free diet—is not always fully effective. Human genetics play a critical role in CeD, as the presence of HLA-DQ2 or DQ8 is necessary for disease development, but not sufficient on its own to cause it. Our aim is to identify additional genetic factors that influence the clinical penetrance of HLA-DQ2 or DQ8. We recruited 51 families with multiple affected individuals and conducted exome sequencing to create a familial CeD cohort. In addition, we utilized whole genome sequencing data from 1,930 CeD patients enrolled in the All of Us research program (AoU-CeD cohort). Our analysis of genomic data from these two cohorts has led to important discoveries and unexpected insights. In this R03 grant, we propose to further explore the genetic risks for CeD using three innovative approaches based on next-generation sequencing data. Our first aim is to identify functional variants in linkage disequilibrium with the AH8.1 (A1:B8:C7:DR3:DQ2) haplotype, which includes the high-risk HLA-DQ2.5 allele. The second aim focuses on gene burden testing and pathway analysis to identify rare variants and evaluate their impacts on CeD. The third aim seeks to identify genetic risk factors for CeD in patients with admixed African and American ancestry. Through this research, we hope to uncover novel genetic factors that can enhance risk stratification and identify potential therapeutic targets for patients from diverse ethnic and genetic backgrounds. These findings could significantly improve genetic diagnosis and guide future therapeutic strategies for CeD.

NIH Research Projects · FY 2025 · 2025-09

Diabetes mellitus has been rapidly increasing and is approaching pandemic levels worldwide. Pancreatic b-cell function and mass are found to be reduced in the clinical onset of type 1 and 2 diabetes causing deterioration of glycemic control. In type 1 diabetes (T1D), the loss of b-cell function is more severe and mainly due to a T-cell mediated autoimmune destruction of b-cells in genetically predisposed individuals. In type 2 diabetes (T2D), the pathogenesis is complex, and in many cases, the reduction of b-cell function and mass is associated with different degrees of insulin resistance and b-cell stress. As such, there has been great interest in devising new therapeutic strategies to maintain or restore b-cell function, and to prevent b-cell loss for treating both forms of diabetes. Based on extensive human genetic and physiological data, ZnT8 protein (encoded by the SLC30A8 gene) has emerged as a therapeutic target for b-cell protection and diabetes prevention/treatment. ZnT8 mutants including loss of function mutant p.Arg138* and point mutant p.Trp325 have been found to be protective against diabetes, yet the underlying precise molecular mechanisms remain uncertain. To gain mechanistic insights and to understand the physiological roles of ZnT8 in islet biology and in diabetes, this project takes an integrated approach by combining diverse approaches including islet biology, protein biochemistry, differential metabolomics, chemical biology and high throughput screening. ZnT8 has been known as a zinc transporter responsible for importing Zn2+ into the dense core granules of islet endocrine cells. Our recent studies suggest that, besides Zn2+, ZnT8 may also transport small organic molecules into the dense core granules. The central aim of this proposal is to characterize this novel transporter activity of ZnT8 in islet b-cell; to identify endogenous substrates/metabolites of ZnT8; and to exploit this small organic molecule (SOM) transport activity to develop ZnT8 inhibitors for b-cell protection. If successful, we anticipate that concepts and approaches developed in this proposal will have important and far-reaching implications for studying islet cell biology, and uncovering new mechanisms for b-cell protection and functional enhancement.

NIH Research Projects · FY 2025 · 2025-09

The UT Southwestern (UTSW) Liver Cancer SPORE assembles a multidisciplinary team of basic, clinical, and translational scientists to tackle one of the major health problems in the U.S., liver cancer. The overarching goal of this SPORE is to leverage innovative, groundbreaking basic science discoveries from UTSW investigators to develop personalized medical interventions that can significantly reduce liver cancer mortality. We will particularly focus on hepatocellular carcinoma (HCC), the most common form (>85%) of liver cancer in Texas and the U.S. To accomplish this goal, we take a multi-pronged approach, including prevention of incident HCC and improving efficacy of treatment options for patients with HCC. Given that HCC arises almost exclusively in patients with cirrhosis from viral hepatitis, alcohol abuse, or metabolic dysfunction associated steatotic liver disease (MASLD), HCC prevention in cirrhosis patients is rational and feasible. We will clinically evaluate two complementary approaches of HCC prevention in patients with cirrhosis, and a novel approach to overcome resistance to immune checkpoint blockade to substantially improve HCC mortality. Project 1. Cirrhosis stroma-directed HCC chemoprevention with EGFR inhibition. In this phase II clinical trial, we will test 24-week low-dose epidermal growth factor receptor (EGFR) inhibitor, erlotinib, for safety and efficacy in reducing HCC risk in high-risk patients with cirrhosis. We will explore clinical and molecular variables that affect erlotinib response to guide subsequent phase III clinical trial design. Project 2. Hepatocyte-targeted HCC chemoprevention with Anillin knockdown. Based on our discovery that hepatocyte polyploidy prevents HCC development in cirrhosis, we will perform a phase Ia adjuvant clinical trial in patients with HCC undergoing locoregional therapy to assess an alternative chemoprevention strategy to therapeutically induce polyploidy using a hepatocyte-targeted siRNA for a cytokinesis regulator, Anillin (ANLN-siRNA). We will also develop biomarkers to measure Anillin levels and software to quantify hepatocyte polyploidy to monitor treatment response. Project 3. Targeting telomerase to induce anti-tumor immunity in HCC. Leveraging our basic science discovery that 6-thio-dG shows anti-tumor effect by inducing anti-tumor immunity in telomerase-active cancer, including HCC, we will test the agent in combination with cemiplimab (anti-PD1) as neoadjuvant therapy in a phase Ib clinical trial for patients with early-stage HCC undergoing surgical resection. By analyzing samples from enrolled patients, we will evaluate molecular factors that affect 6-thio-dG response to guide patient selection, improve efficacy, and resolve resistance to 6-thio-dG-based therapy. These Projects are supported by the Administrative and Outreach Core (Core A), Biospecimen and Pathology Core (Core B), and Data Science Core (Core C). The Developmental Research Program (DRP) and Career Enhancement Program (CEP) will contribute to sustainable translational research in liver cancer to impact the disease burden and mortality in Texas and the U.S.

NIH Research Projects · FY 2025 · 2025-09

Modulation of Insulin Signaling in Adipocytes Adipose tissue is essential for normal energy homeostasis. It exerts important anti-lipotoxic effects by neutralizing free fatty acids after nutrient absorption and by releasing them through lipolysis upon systemic demand. It has been established that a dysfunctional adipocyte is tightly linked to metabolic challenges in other tissues. Aberrant insulin signaling, as observed in insulin resistance at the level of the adipocyte, is a key driver of systemic metabolic dysfunction. Our key hypothesis is that any intervention that aims to alleviate aspects of systemic metabolic dysfunction critically relies on an improvement in the insulin sensitivity of the adipocyte. How does improved adipocyte insulin sensitivity contribute to positive metabolic outcomes? We identified a number of gaps in our knowledge regarding insulin signaling in the adipocyte. We will take advantage of a multipronged approach to finetune the insulin response selectively in the adipocyte. We will deploy diverse tools to investigate the contribution of adipocyte insulin signaling to a new paradigm of insulinopenic insulin sensitization and to the effects of modern incretin and glucagon receptor agonists. We will address these questions at the cellular, tissue, and systemic level with the following Specific Aims: In Aim 1, we propose to carefully titrate insulin signaling within the adipocyte by i) inducible reduction of insulin receptor expression, ii) selective activation of an artificial insulin receptor, or iii) manipulation of the insulin signaling modulator PTEN. Many of these approaches will take advantage of recently developed models that were not previously available to the field. In Aim 2, we plan to define the consequences of a targeted reduction in β-cell insulin release on the adipocyte by i) controlled suppression of membrane depolarization or ii) induction of progressive mitochondrial dysfunction. Our new β-KIR6.2V59M and β-mitoKiller mouse models use a mouse insulin 1 promoter-based driver to achieve β- cell-specific and inducible transgene expression. In β-KIR6.2V59M mice, an activating mutant KATP channel subunit is used to suppress membrane depolarization, which, upon mild induction, results in reduced glucose- stimulated insulin secretion (GSIS) without hyperglycemia. These mice retain insulin sensitivity upon exposure to a high-fat diet. In β-mitoKiller mice, a viral protein is employed that specifically degrades mitochondrial DNA, causing mitochondrial dysfunction. This results in a lack of GSIS, progressive hyperglycemia, and deteriorated glucose tolerance while basal insulin levels are maintained. We will specifically examine the role of altered adipocyte insulin signaling in these two unique models. In Aim 3, we will determine the contribution of adipocyte insulin signaling to the beneficial effects of GLP1-R+GIP-R and GLP-1R+GIP-R+GCG-R agonists. Does increased adipocyte insulin responsiveness contribute to the effects of these drugs on weight loss and systemic metabolism? Does an insulin-resistant adipocyte prevent such improvements? Combined, our studies should provide new insights into the physiological contributions of the insulin-sensitive adipocyte.

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY/ABSTRACT Despite being healed from their burn injuries, burn survivors have impaired thermoregulation, decreased pulmonary function with accompanying dyspnea at rest and during exercise, a greater incidence of cardiovascular disease, and higher mortality rates. Regarding the former, grafted skin does not appropriately dissipate heat, resulting in exaggerated increases in core temperature during physical activity in this population. Skin wetting of just the grafted sites blunts the exaggerated increases in core temperature, and perhaps the accompanying increased cardiac and pulmonary stress, though the latter has not been experimentally verified. Therefore, we aim to investigate the efficacy of whole-body skin wetting to mitigate otherwise heightened indices of cardiac and pulmonary stress during physical activity in the heat in well-healed burn survivors. As a secondary exploratory aim to continue to explore the consequences of a severe burn injury on long term health, we aim to investigate the possible effects of an inhalation injury, time on a ventilator, and/or significant torso burns and associated skin scarring on detailed respiratory function and mechanics at rest and during physical activity in well-healed burn survivors. The overarching goal of the proposed work is to identify physiological barriers, and assess a potential mitigation strategy, that likely dissuade burn survivors from achieving the recommended levels of physical activity necessary for their cardio-metabolic health, thereby predisposing burn survivors to the aforementioned greater mortality risk. The expected outcomes from this work will have a direct impact on burn survivors and their caretakers by evaluating the efficacy of a practical cooling strategy that has the potential to decrease cardiac stress and reduce the severity of dyspnea thereby improving exercise “comfortability” in burn survivors. Secondly, establishing a foundation of the effects of a severe burn injury on detailed respiratory mechanics is necessary to develop future studies where interventions (i.e., inspiratory muscle training) can be tested to improve the mechanics of breathing in this population. This research directly supports the mission of the NIH in that we will uncover mechanistic physiological findings from human participants with the goal of translating those findings to guide individuals and caregivers on how to increase exercise tolerance in burn survivors thereby improving their quality of life. To ensure that this study is designed to maximize clinical relevance and my scientific training, I assembled a strong interdisciplinary clinical research/mentoring team consisting of expert integrative physiologists, physician- scientists, and a biostatistician. My primary goals during this fellowship are to complete the proposed project, master several technical skills (i.e., echocardiography), improve my ability to obtain future extramural research funding, and publish research findings in peer-reviewed medical and physiology journals.

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY More than 30 million Americans have pre- or existing diabetes. An innovative approach to treat diabetes is to generate functional insulin-producing -cells for transplantation in vitro. This approach is currently in clinical trials, but a recognized problem is suboptimal progenitor generation. -cells originate from a multipotent progenitor population in the early pancreatic epithelium. Elucidating mechanisms that regulate progenitor specification and maturation in vivo using mouse models will instruct in vitro differentiation efforts. The Hippo pathway is emerging as a key mechanotransducive pathway involved in regulating organ development, however, mechanisms that regulate Hippo signaling in the context of pancreatic development remain unclear. This proposal will examine Merlin, a key regulator of Hippo signaling, to determine if it relays biomechanical signals during tissue morphogenesis. We have found that deleting Merlin leads to severely aberrant pancreatic morphogenesis and cell differentiation. Currently, we aim to elucidate both how Merlin is regulated and what its molecular function is in pancreatic development. The central hypothesis of this proposal is that Merlin enables pancreatic lumenogenesis by interpreting cues from cytoskeletal contractility to organize the apical membrane. In Aim 1, I will examine if Merlin directs pancreas formation non- cell autonomously in vivo by using mouse genetics and in vitro by using a 3-D spheroid model. Using a mosaic deletion system, I will assess if Merlin is required for propagation of tension-based cues. In Aim 2, I will determine the cellular function of Merlin; specifically, I will determine if Merlin facilities vesicular trafficking events required for lumenogenesis by using a novel live imaging system that our lab developed. In Aim 3, I will examine if mechanical cues regulate Merlin phosphorylation status and function in a 2D cell culture, through direct application of tension using cell stretching system. I will further determine if Merlin phosphorylation is required for YAP1/TAZ inhibition. Together, this data will provide us with insight into how mechanical cues guide pancreatic morphogenesis and cell fate. More broadly, our results will shed light on how progenitor specification and maturation occur and will guide regenerative medicine efforts.

NIH Research Projects · FY 2025 · 2025-09

Catalytic Mechanism, Regulation and Drug-Target Potential of Alarmone Hydrolases The research program in our laboratory focuses on understanding bacterial signaling mechanisms through the molecule (p)ppGpp, a key mediator in bacterial stress responses. Often called the "alarmone," (p)ppGpp helps bacteria survive adverse conditions such as nutrient starvation and antibiotic exposure. By halting cell growth and shifting bacteria into a persistent state, (p)ppGpp enables tolerance to chemotherapies without requiring genetic resistance, contributing to recurring infections. (p)ppGpp level is controlled by both its synthesis and degradation. The current paradigm of alarmone signaling, however, primarily focuses on the sensory role of alarmone synthetases, while hydrolases have been largely overlooked. Our goal over the next five years is to elucidate the catalytic mechanisms and regulatory roles of (p)ppGpp hydrolases. X-ray crystallography will be used to determine a hydrolase structure bound to a transition-state analog, revealing how the enzyme organizes its active site for catalysis. Literature and our preliminary data both suggest that alarmone hydrolases may also sense transition metals like manganese and iron. During infections, host defenses cause metal starvation or expose pathogens to toxic levels of zinc or reactive oxygen/nitrogen species. We hypothesize these stresses inactivates (p)ppGpp hydrolases, promoting alarmone accumulation and bacterial persistence. To investigate how metal stress impacts alarmone degradation, we will use structural biology, biochemistry and bacterial genetics to study these enzymes in vitro and in vivo. Additionally, we will explore the potential of hydrolases as antibiotic targets. While most antibiotics target essential genes, (p)ppGpp hydrolases have been overlooked due to the assumption that alarmone accumulation caused by inhibiting them would be pro-survival and bacteriostatic. However, our previous work with a related alarmone, (p)ppApp, suggests that unchecked alarmone accumulation without hydrolase activity can be lethal. We will assess the viability of a “synthetase+/hydrolase-” state for (p)ppGpp in Gram-negative pathogens to evaluate the therapeutic potential of hydrolase inhibition. Our research will significantly expand the understanding of bacterial persistence and provide new insights into how bacteria sense metal stress via alarmone signaling. The knowledge gained from this work could open new avenues for therapeutic developments by targeting alarmone hydrolases. Our long-term vision is to identify bacterial vulnerabilities that can be exploited to combat antibiotic persistence, improving clinical outcomes in the treatment of chronic infections. This research is poised to make foundational insights to bacterial stress response and resilience and advance our understanding of the communication between human hosts and bacterial symbionts.