Yale University

NSF Awards · FY 2025 · 2025-05

Natural selection can be a powerful agent of adaptation in species. Yet, organisms are not exclusively at the environment’s whim and mercy. Through their behavior, organisms can dictate their environmental conditions and guide the selective pressures they experience. Consider, for example, a lizard darting into the shade, a mouse digging a burrow, and humans building houses and engineering indoor heating or cooling. This project will test the idea that behavior can shield organisms from natural selection, modify adaptive response, and enhance the exchange of genetic material. The project will focus on anole lizards, a system that provides the variation and replication necessary to isolate the role of behavior in adaptation. The results of this study will provide a new lens on natural selection by illustrating the role that organisms exert over their own adaptive trajectories; all animals - including humans - can use behavior to negotiate their environments. This project contributes to a better prepared STEM workforce through student training. Educational modules will be developed for the undergraduate classroom, providing experiential learning in experimentation, bioinformatics, and statistics. The results from this project will be infused into a museum exhibit in the Yale Peabody Museum, which is free to all visitors and is the most visited landmark by Connecticut schoolchildren. Local educators and scientists will work together in summer workshops to develop educational modules for the museum exhibit that align with state curricula, providing experiential learning opportunities for K-12 students. Natural selection is a powerful agent of evolution; shifts in temperature across environmental gradients, for example, should favor local adaptation and limit gene flow among populations. Yet, homeostatic behaviors like behavioral thermoregulation (e.g., basking) may buffer organisms from selection, and potentially create corridors for gene flow across environmental gradients. This project will investigate the genetic signatures of thermoregulatory behavior, and test whether homeostatic behaviors circumvent climatic obstacles to dispersal and enhance gene flow across environmental gradients. To do so, this project will leverage the replicated behavioral, physiological, and ecological diversity of anole lizards as an ideal study system. Thermal modification behavior will be quantified through detailed field studies, with preliminary results indicating that lizard species from canopied forests are poor thermoregulators while those from forest edges thermoregulate effectively. The connection between thermal behavior and the phenotype will be quantified by laboratory-based investigation of thermal and hydric physiology, and functional morphology. Preliminary results indicate that thermoregulating lizards exhibit physiological stasis across elevation, while thermoconformers exhibit the expected clinal pattern of local adaptation. Lastly, 3RAD sequencing will be used to infer patterns of gene flow across elevation, and those patterns will be compared among thermoregulators and thermoconformers. Preliminary results indicate that thermoregulating lizards exhibit high rates of gene flow across elevation, suggesting that buffering behaviors shield these animals from selection and facilitate gene connectivity among populations from environmentally dissimilar habitats. The results of this study will provide a new lens on natural selection by illustrating the role that organisms exert over their own evolutionary trajectories. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2025 · 2025-05

PROJECT SUMMARY Methylenedioxy-methamphetamine (MDMA) enhances the extinction of learned threat associations in mice and humans and has recently demonstrated efficacy in augmenting psychotherapy in posttraumatic stress disorder (PTSD). However, the mechanism of this effect is unknown. Understanding the neural circuits responsible for MDMA-enhanced threat extinction may facilitate the development of new treatments of anxiety and trauma- related disorders. In this application, we utilize longitudinal two-photon imaging of dendritic spines to characterize the structural changes in frontal cortex occurring with MDMA and how they relate to the 5HT2A receptor which is both directly and indirectly activated by MDMA. We use microendoscope calcium imaging and to understand how neural populations in the infralimbic cortex represents innate and learned fear differently after MDMA treatment. Subsequently, we directly manipulate plasticity optogenetic suppression of CaMKII signaling affects subsequent innate and learned fear behaviors. Finally, we utilize engram mapping and optogenetics to stimulate behaviorally specific ensembles of neurons in infralimbic cortex during MDMA exposure. We hypothesize that activation of distinct ensembles will differentially affect the subsequent lasting effects of MDMA on behavior. Thus, this study applies cutting edge optical neurophysiology approaches to a critical mechanistic question: delineating the frontal cortical circuit- and subcellular adaptations to MDMA that underlie its diverse effects on innate and learned fear.

NIH Research Projects · FY 2026 · 2025-05

PROJECT SUMMARY Significance: Intestinal dysfunction leads to diseases of enormous morbidity. Maintenance of intestinal stem cell self-renewal and differentiation is dependent on extrinsic signals from the supporting niche. Despite their abundance in the intestinal stem cell niche, the role of endothelial cells in supporting intestinal regeneration and facilitating repair after injury, remain largely understudied. Recently, Dr. Brisa Palikuqi reported that lymphatic endothelial cells, through the expression of the WNT modulator Rspo3, are essential for intestinal repair after cytotoxic injury. Yet, the role of blood vessel endothelial cells in intestinal regeneration and their dysfunction in inflammatory bowel disease, remains undetermined. By utilizing mouse models, immune profiling, single cell RNA sequencing and spatial transcriptomics, this Mentored Career Development Award proposal seeks to gain a comprehensive understanding of the role of blood endothelial cells in intestinal repair after injury and investigate changes in the blood endothelial cell niche in models of inflammatory bowel disease. Candidate and environment: The candidate for this Mentored Career Development Award, Dr. Brisa Palikuqi, is committed to leading an independent research group at the intersection of the fields of intestinal biology, endothelial cell biology and regenerative medicine. Dr. Palikuqi was trained in the laboratory of Dr. Shahin Rafii, at Weill Cornell Medicine, where she developed a three-dimensional platform for the vascularization of organoids and islet explants. During her postdoctoral studies at UCSF, in the laboratory of stem cell and developmental biologist Dr. Ophir Klein, Dr. Palikuqi has studied the role of lymphatic endothelial cells in intestinal regeneration. As described in her proposal, during the rest of the postdoctoral training and as she transitions to an independent position, Dr. Brisa Palikuqi plans to examine the role of blood endothelial cells in intestinal regeneration and inflammatory bowel disease. At UCSF, Dr. Palikuqi has assembled a team of mentors, advisors and collaborators that will support the successful completion of her proposed research and training. Career development: During the mentored period, the candidate will train in new techniques such as human and mouse intestinal models of regeneration and disease, single cell RNA sequencing analysis, spatial transcriptomics and immunology. The candidate will work closely with her mentoring team and enroll in complementary coursework to acquire the necessary expertise to accomplish the research and career goals proposed in her application. She will also undertake a program of training to support her professional development as a mentor and supervisor. A central goal of the mentored period is for the candidate to obtain a Principal Investigator position. The execution of the training in this proposal will equip the candidate with the necessary skillset and robust research platform to launch her independent research career.

NIH Research Projects · FY 2026 · 2025-05

Abstract Bacteria use a conserved signaling pathway to direct their behavior in chemical gradients. This directed motion, called chemotaxis, is essential for clinically relevant phenomena like biofilm formation and host invasion. Extensive work has characterized the dynamics of chemical sensing, adaptation, and behavior in Escherichia coli. However, a fully integrated picture of chemotaxis is currently lacking in other bacteria. Given the diversity of sensing and behavioral strategies across bacteria, to fully understand the role of chemotaxis in pathogenicity, it is essential to characterize the interaction between signal transduction and behavior in other species. In this application, the PI proposes to extend two experimental lines of inquiry first explored in E. coli, to pathogenic bacteria. One direction of the lab is to use single-cell fluorescence resonance energy transfer to characterize the dynamics of chemotactic signal processing to Vibrio cholerae. While E. coli navigate with ‘run- and-tumble’ cycles, alternating between straight ‘runs’, and stationary reorienting ‘tumbles’, V. cholerae and other singly-flagellated bacteria navigate with ‘run-reverse-flick’ cycles, where after a run, cells backtrack along their run trajectory, and then ‘flick’ at a 90o angle. In a chemical gradient, different swimming behaviors will generate inputs to the chemosensory system with different statistics. Characterizing chemosensory responses in V. cholerae will reveal how a common signaling architecture can be repurposed to process diverse signals and control diverse chemotaxis strategies. Another direction of the lab is to study the role of cell-to-cell variability in chemotactic behavior and its effect on the collective migration of populations. By consuming environmental attractants, groups of bacteria can establish moving attractant gradients to follow, which results into waves or bands of migrating bacteria that can travel over long distances. For E. coli, our lab previously demonstrated that during collective migration individual phenotypes spontaneously sort themselves along the traveling gradient according to their chemotactic performance. Importantly, we found that the leader-follower organization that emerges enables traveling populations to, over time, adapt their phenotypic composition to the environments they traverse by culling the weakest phenotypes that end up at the back of the traveling group. Moving forward, we want to understand the dynamics of how new spatial configurations of chemotaxis phenotypes emerge when populations encounter new environments, and the consequences of spatial sorting in migrating populations on pathogenicity. As such, we will examine phenotypic diversity in traveling waves of E. coli migrating through interfaces between liquid and agar, and of Pseudomonas aeruginosa were virulence traits and chemotaxis are often coregulated.

NIH Research Projects · FY 2026 · 2025-05

Preterm birth is commonly associated with chorioamnionitis; infection/inflammation of the fetal membranes (FM). Pathogens contributing to this do not typically cross the placenta. However, abnormal maternal and/or placental immune responses can cause inflammation in the fetus, contributing to Fetal Inflammatory Response Syndrome (FIRS). FIRS is a systemic activation of the fetal immune system associated with fetal injury and lifelong health issues. The mechanisms by which maternal/placental immune responses induce fetal inflammation, the method of communication between mother and fetus, and the breadth of fetal developmental consequences are not fully understood. FMs generate inflammatory responses to infections through activation of Toll-like receptors (TLRs). A novel family of microRNAs (miRs) can induce sterile inflammation through the ssRNA sensors, TLR7 and TLR8. We found an intermediate role for TLR7/8-activating miR-146a-3p in driving FM inflammation via TLR8, downstream of TLR4 activation by bacterial LPS. In preliminary studies, we found TLR7/8-activating miR-21a and miR-29a are elevated in exosomes released from bacterial LPS- and viral Poly(I:C)-stimulated human FMs, and in amniotic fluid exosomes of pregnant mice exposed to LPS. Preliminary data also show maternal exposure to LPS increases fetal brain, tail, and gut inflammatory IL-1b and KC (IL-8) in wildtype (WT) mice but not in TLR7- /-/TLR8-/- mice. Thus, our central hypothesis is that maternal infection induces FMs to release exosomes containing TLR7/8-activating miRNAs into the amniotic fluid which drive sterile fetal inflammation via TLR7/8 signaling. This leads to FIRS and subsequent developmental consequences. We will determine if: FM/amniotic fluid-derived exosomes containing TLR7/8-activating miRs mediate sterile fetal inflammation (Aim 1); Fetal inflammation, injury and altered development after a maternal infection is dependent on exosomes causing fetal TLR7/8 signaling (Aim 2); and Exosomes carrying TLR7/8-activating miRs traffic via the amniotic fluid to cause fetal inflammation and injury through initial contact with the fetal skin and gut (Aim 3). During the first two aims, the PI will gain valuable training and experience in various in vitro, ex vivo and in vivo models along with mouse fetal manipulations, exosome biology, and fetal immune and organ development (K99 Phase). Under the guidance of her primary mentor, Dr Vikki Abrahams, her expert mentorship and advisory teams, and exceptional training resources at Yale University, the PI is well positioned to establish herself as an independent investigator in Reproductive Immunology following her K99 training phase. After securing a faculty position and transitioning to the R00, the PI will use her newly acquired skills and expertise to study maternal/fetal exosome trafficking and TLR7/8-activating miR function and signaling in vivo at her new institution. The proposed studies are significant because they will establish a role for exosomes and TLR7/8 signaling in the initiation of sterile fetal inflammation and its subsequent impact on fetal/neonatal development, providing critical insight into the mechanisms underlying FIRS for future work in prevention, treatment, and advancement of maternal/fetal medicine.

NIH Research Projects · FY 2026 · 2025-04

PROJECT SUMMARY: The HIV-1 life cycle critically depends on a maturation process that transforms the viral core from a spherical to a conical shape, a crucial step for productive infection of host cells. This process is driven by the proteolytic cleavage of Gag and Gag-Pol polyproteins, resulting in the formation of the mature capsid. Although significant progress has been made in understanding Gag assembly and capsid structures, the dynamic transitions and molecular mechanisms underlying HIV-1 maturation remain inadequately understood, particularly within native cellular environments. To address these gaps, the Xiong laboratory has developed an advanced in situ cryo- electron microscopy (cryo-EM) approach, enabling high-resolution visualization of these processes in their native context. The research is structured around two specific aims: Aim 1 focuses on determining the high- resolution structural pathway of HIV-1 Gag assemblies and capsid during maturation within their native environment. This will involve using in situ cryo-EM and cryo-electron tomography (cryo-ET) to visualize the complex structural transitions of HIV-1 Gag and capsid during maturation. These studies will be conducted on both purified virus-like particles (VLPs) and budding viruses from infected cells, including clinically derived HIV- 1 isolates and primary CD4+ T cells. Preliminary data identify a novel hybrid capsid structure that may represent a transitional state in HIV-1 maturation, supporting the hypothesis of a replacive maturation pathway. This will be further tested through biochemical, structural, and functional experiments. Aim 2 will define the mechanisms by which HIV-1 capsid cofactors and maturation inhibitors influence virus maturation during budding. This will involve investigating how capsid inhibitors impact the maturation process using a comprehensive experimental system, including in vitro assembled Gag constructs, purified VLPs, and budding viruses on the cell surface. Preliminary findings have revealed new binding sites for Lenacapavir and a novel cellular cofactor within the immature Gag lattice. The cellular cofactor will be thoroughly investigated to determine its identity and function. The insights gained from this research will advance the understanding of HIV-1 maturation, guide the development of new therapeutic strategies targeting the immature Gag structures and the capsid, and provide valuable tools for studying host-virus interactions within their native cellular environments.

NSF Awards · FY 2025 · 2025-04

With the support of the CLP program in the Division of Chemistry, Professor Crawford from Yale University is investigating the role of nucleotide inhibitors of protein translation that are encoded in microbiomes across diverse body sites. The microbiome of humans and other animals is now considered to be an organ-like system, digesting our food, regulating host behaviors, training the immune system, and producing diverse nutrients, signaling molecules, and/or toxins to effectively compete and survive in their local environment. However, the molecular mechanisms and fundamental chemical understanding of how key members of the microbiome compete for effective colonization remain unknown. Colonization mechanisms underlie whether microbiomes across diverse animals are in balance. The proposed experiments will characterize the structures and functions of nucleotide translational inhibitors produced by microbiome members, how they are produced, and how they regulate community dynamics. These efforts will allow graduate students to acquire training in specialized metabolism in the context of animal-microbe chemical interactions. This research is also integrated with an outreach program “Microbial Magic: Harnessing the Power of Bacteria” to introduce high school students to the science of the microbiome and microbial metabolism. The Crawford laboratory discovered a wide family of mis-annotated tRNA synthetases in microbiomes that are dedicated to the synthesis of a new class of specialized nucleotides featuring a remarkable orthoester functionality. These metabolites, which very likely evolved from translational machinery, do not contribute to cellular growth, but rather were found to inhibit translation. While nucleoside natural products are well known, the phosphate group on these functionalized nucleotides prevents passive cellular diffusion. This limitation demands specialized uptake mechanisms in recipient organisms and potentially allows for selective taxonomic targeting across diverse microbiomes. The proposed studies combine chemistry, biochemistry, and microbiology interdisciplinary approaches to provide new insights into this family of mis-annotated tRNA synthetases that have remained “hidden in plain sight” in genome databases until now. Project goals include structural characterization of nucleotides from “orphan” pathways, biochemical characterization of the enzymes involved in nucleotide biosynthesis, and functional characterization of the molecules in in vitro translation inhibition and their regulatory effects on microbiome community structure. The information gained from this work will provide new molecular insights on how microbiome members employ specialized metabolism to regulate microbiome structure and function across diverse environments. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NSF Awards · FY 2025 · 2025-04

This CAREER award funds four projects on agricultural markets. Each examines the effects of market frictions on whether or not farmers are able to sell in high value-added, export-oriented markets. The frictions include limited competition, lack of information, and financial market imperfections. Economic theory predicts that certain specific policies may reduce the impact of these market frictions and improve economic outcomes. Each research project tests whether or not these predictions are supported by real-world evidence in a specific agricultural market. Because farmers earn higher incomes when they are successful in producing these high-value products, the broader impacts of this award could include economic growth in regions dependent on agriculture as a main economic sector. The award also funds an education plan to mentor students and support international scientific collaboration. This CAREER award funds a research plan including four field experiments to study how market frictions at each step of agricultural supply chains impede structural economic transformation. Project 1 uses a randomized control trial (RCT) design to study the limited pass-through of quality incentives from world markets to upstream coffee producers to identify whether intermediary market power constrain quality upgrading by farmers. Projects 2 and 3 explore the role of search costs and information constraints in preventing agricultural small and medium enterprises (SMEs) from connecting with exporters and multinational buyers. Project 4 uses an RCT of an export loan facility to test whether agricultural exporters are constrained by limited availability of financing. In all projects, original data collection and administrative data access allow measurement of causal effects on directly impacted firms, on competitors, and on upstream suppliers. The results of this research project will help to identify ways to improve agricultural markets, increase agricultural incomes and accelerate structural transformation. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2026 · 2025-04

SUMMARY STATEMENT on which Merit has been based The major goal of this Merit Award was to elucidate the mechanisms of development of the primate cerebral cortex that are most relevant to humans but cannot be adequately studied experimentally in non-primate species. We proposed to perform unique research on molecular and cellular mechanisms of cortical development with focus on association areas and particularly the prefrontal cortex (PFC) that are linked to major cognitive disorders and addiction susceptibility but cannot be studied adequately in human. Thus, in the original application we proposed to perform multidisciplinary experimental research in non-human primate (NHP) Macaques Rhesus within the scope of 3 Specific Aims that were approved with high rate by the Study Section: Aim 1: deals with genetic determinants of early cortical expansion and functional analysis of proliferation/differentiation of radial glial cells (RGCs) in NHPs. Aim 2 deals with commitment of RGCs leading to laminar specificity of neuro- and gliogenesis and region-specific contributions of Hopx+ bRGC to neuro- and glio-genesis analysis in fetal macaque. Aim 3: deals with the role of neuropil and white matter growth in cortical expansion and gyrification and genetic basis of the cortical neuropil explosion and role of incoming/outgrowing axon tracts and emerging sulci/gyri in NHP.

NIH Research Projects · FY 2026 · 2025-04

SUMMARY The adult spinal cord is incapable of self-repair after injury or disease, thus leading to lifelong sensory, autonomic, and motor functional deficits. Rehabilitation remains the only effective treatment after CNS trauma, however the anatomical and molecular substrates that support rehab-induced functional re-enforcement and recovery are known. Central to the recovery of voluntary motor function is the capacity for supraspinal circuits to regain access to spinal motor centers. The raphespinal tract (RpST) innervates all spinal lamina and has been shown to be remarkably plastic after spinal cord injury (SCI). Here, we propose to use anatomy, spatial transcriptomics and intersectional in vivo chemogenetics to define the capacity and necessity of intact and lesioned supraspinal RpST terminals to support rehab-induced functional recovery after SCI.

NIH Research Projects · FY 2026 · 2025-04

Abstract: Cocaine use disorder (CUD) is a growing public health concern, with over 2.2 million individuals in the US regularly using cocaine, and cocaine-related overdoses accounting for 1 in 5 drug-related deaths in 2017. Relapse rates for CUD are approximately 50% within the first 12 weeks of rehabilitative therapy, and stress is a trigger for drug craving during abstinence. There's a pressing need to understand the mechanisms underlying stress-induced relapse. Recent studies have pointed to corticotrophin releasing factor type 1 receptor (CRF1R) and the L-type calcium channel (LTCC), Cav1.2, as players in stress-induced relapse. A risk allele in the Cav1.2 gene, CACNA1C, has been associated with altered fear and reward processing within stress-sensitive brain regions such as the nucleus accumbens (NAc) and prefrontal cortex (PFC). Additionally, variants in the CRF1R gene have been linked to higher rates of mood disorders, suicidality, and addiction. Decades of preclinical research demonstrated that CRF1 antagonists produced anxiolytic and antidepressant like effects, and reduced stress-induced relapse. However, clinical trials with LTCC and CRF1 blockers have seen mixed results in its efficacy for addiction treatment, suggesting deeper understanding of these compounds in stress-induced relapse is needed. Most studies have focused on Cav1.2 and CRF1R actions in various regions of the mesolimbic circuits, but very few have focused on the prelimbic cortex pyramidal neurons that project to the nucleus accumbens core (PrL-NAcc), a circuit known to be involved in stress and cocaine cue reactivity. My proposal will investigate the role of Cav1.2 and CRF1R during abstinence in the PrL-NAcc and its role in stress-induced relapse. The major goals of this proposal are to determine the regulation of Cav1.2 and CRF1R in the PrL-NAcc circuit, as well as to determine the role these channels and receptors play in mediating stress-induced relapse at different times in abstinence. I will investigate this question through two aims: In Aim 1 I will use retrograde tracing to isolate PrL-NAcc neurons and perform immunofluorescence experiments to examine the expression pattern of Cav1.2 and CRF1R within the prelimbic to see if they are co-localized on PrL-NAcc neurons or if they are on distinct cell populations (Aim 1.1). I will also use flow cytometry and cell sorting to isolate the specific population of PrL-NAcc cells and perform immunoblotting to investigate the dynamic regulation of Cav1.2 and CRF1R during cocaine abstinence (Aim 1.2). In Aim 2 I will determine the functional role of Cav1.2 or CRF1R activity during abstinence. During early and extended abstinence, I will perform stress-induced relapse tests in cocaine-abstinent rats and infuse an LTCC blocker (Aim 2.1) or CRF1R antagonist (Aim 2.2) in the PrL and measure the effect on stress-induced relapse in cocaine-seeking behavior. The proposed research will advance our understanding of LTCC and CRF1R mechanisms that support stress-induced relapse and guide clinicians on the most effective therapy to use at various points in cocaine addiction.

NSF Awards · FY 2025 · 2025-04

Computer simulations are an essential part of modern scientific inquiry. They allow detailed investigations of phenomena at time and length scales difficult to observe directly. In particular for complex systems such as the human brain, they have become indispensable for testing hypotheses and making predictions for experiments. Cognitive phenomena such as learning and memory evolve on timescales from minutes to years, while the underlying processes on the level of individual nerve cells involve milliseconds timing. Bridging these timescales in computer simulations requires significant computational resources. This project develops a new hardware system specifically designed to meet the increasing computational demands arising for increasingly sophisticated multi-scale brain models. This new tool will both support fundamental neuroscience research and accelerate the translation of insights into biological computation into novel computing devices for commercially relevant applications. While the project focuses on computational neuroscience models, the implementation challenges and proposed solutions are applicable to the simulation of a broad class of dynamical systems such as power grids, financial markets, and epidemics. Finally, this project will support the continuous development of open-source workflows for the design of asynchronous digital hardware. Despite tremendous progress in recent decades, the biophysical mechanisms and computational principles underlying memory and learning in the brain remain poorly understood. Due to the complexity of biological systems and the difficulty in reproducibility (in the engineering sense) of results, researchers rely on computational models to test hypotheses and to make experimental predictions. Modern models of neuronal computation and learning are formulated in continuous-time with continuous interactions, i.e., as systems of ordinary differential equations. Yet, these are a poor fit for existing accelerators which are optimized for either continuous time with discrete (spiking) interactions or discrete time with continuous interactions. A significant implementation challenge on the path to a scalable accelerator lies in efficient parallelization of the spatially discrete, non-locally and non-uniformly coupled systems of equations, in particular due to the communication requirements arising from continuous interactions in continuous time. To overcome these challenges, we propose a convergent simulator architecture that can accelerate continuous-time models of learning using neuromorphic hardware principles. On the algorithmic end, we exploit the insight that continuously interacting systems do not necessarily require dense communication, i.e., that communication in implementations of these dynamics can be both sparse and adaptive to computational demand. The resulting algorithms are ideally suited for implementation in asynchronous digital hardware with fine-grained parallelism and share similarities with existing neuromorphic computing approaches. To validate our approach and ensure its usefulness to the scientific community, we create both an FPGA implementation and silicon prototype for a recently proposed cortical learning model and develop novel model variants for processing and learning across long time scales. This collaborative U.S.-Swiss project is supported by the U.S. National Science Foundation (NSF) and the Swiss National Science Foundation (SNSF), where NSF funds the U.S. investigator and SNSF funds the partners in Switzerland. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2025 · 2025-04

PROJECT SUMMARY Irritable bowel syndrome (IBS) is a functional gastrointestinal condition caused by a disruption in the brain-gut interaction and psychological factors such as stress and anxiety contribute to the onset and severity of the symptoms of IBS that typically manifests in the early adult years and detrimentally impacts mood, quality of life (QOL), and employment. Pain is the most distressing symptom reported by individuals with IBS, and it greatly impacts their overall health. While non-pharmacological pain management strategies have shown promise in diverse populations and regions, their feasibility and practicality in the context of young adults (YAs) with IBS remain underexplored. Home-based transcutaneous auricular vagus nerve stimulation (taVNS) targets the auricular branch of the vagus nerve, aiming to modulate nervous system activities and restore normal vagal tone. This mind and body intervention offers a nonpharmacologic, noninvasive, and portable approach, demonstrating promising therapeutic effects in alleviating IBS-related pain and symptoms in YAs. This pilot randomized controlled study aims to evaluate the feasibility, acceptability, adherence, safety, and potential implementation barriers of home-based taVNS intervention in YAs (18-29 years old) diagnosed with IBS. A two-site, two-arm, parallel, proof-of-concept randomized trial will be conducted to assess the feasibility of using the Active taVNS intervention compared with Sham taVNS in managing IBS-related pain and symptoms. Eighty YAs meeting the Rome IV diagnostic criteria of IBS will be recruited and receive either Active or Sham taVNS for pain and symptom management, along with self-management education and their usual treatment and care. After enrollment and a 2-week baseline run-in period, participants will be randomized to the Active or Sham taVNS with a 6-week treatment (30 minutes per session, twice daily for 6 weeks) and be followed up for another 6 weeks of post-treatment. We will assess feasibility through recruitment rates, adherence, factors influencing adherence, safety, satisfaction, and collection of patient-reported outcomes. This innovative home-based taVNS intervention aligns with the National Center for Complementary and Integrative Health's (NCCIH) mission to improve pain management through mind and body interventions. The data from this trial will inform the development of large-scale studies, ultimately enhancing pain management strategies, quality of life, and overall health for YAs with IBS.

NIH Research Projects · FY 2026 · 2025-04

Isocitrate dehydrogenase (IDH) mutations are found in many malignancies including gliomas, cholangiocarcinomas, and acute myeloid leukemia. Mutations in the IDH gene lead to the neomorphic production of 2-hydroxyglurate (2HG), a competitive inhibitor of -ketoglutarate. A series of clinical studies showed enhanced sensitivity to chemotherapy and radiation therapy, and further characterization by several groups revealed DNA repair defects in IDH-mutant cancers. Our lab discovered this defect arises from 2HG-mediated inhibition of the -ketoglutarate dependent dioxygenase KDM4B, which leads to aberrant H3K9 trimethylation at the site of DNA damage, resulting in chromatin condensation and impairing recruitment of homology-directed repair proteins to the site of damage. This DNA repair defect yields IDH-mutant cancers sensitive not only to chemotherapy and radiation therapy, but also to poly (ADP-ribose) polymerase (PARP) inhibitors. This defect is currently being evaluated in clinical trials using PARP inhibitor monotherapy or in combination with other agents. Nonetheless, some patients do not respond to treatment, suggesting resistance to PARP inhibitors. Thus, a critical opportunity to uncover and to describe mechanisms of PARP inhibitor resistance in IDH-mutant cancers will be addressed here. Several studies have described mechanisms of PARP inhibitor resistance in patients with mutations in the breast cancer genes 1/2 (BRCA1/2). These studies have employed the use of PARP inhibitor resistant clonal lines, as well as a genome scale CRISPR-Cas9 knockout (GeCKO) screen and have identified restoration of homology directed repair and replication fork stabilization as mechanisms of resistance. This study will employ similar techniques to study PARP inhibitor resistance in IDH-mutant cancers. Aim 1 will determine mechanisms of PARP inhibitor resistance in IDH-mutant cancers using clonal cell lines previously established by our group. RNA sequencing data from these PARP inhibitor resistant clones exhibit differences in transcriptomic profiles, specifically downregulation of 53BP1, RIF1, and the HP1 isoforms. To deconvolute the RNA sequencing data, generating constitutive CRISPR-Cas9 knockout cell lines of these genes of interest will allow us to test sensitivity to PARP inhibition and to evaluate the effects in homology directed repair and chromatin remodeling. Aim 2, on the other hand, will identify novel genes conferring PARP inhibitor resistance in IDH1-mutant cells using an unbiased GeCKO screen. Specifically, a publicly available human GeCKO lentiviral pooled library will be transduced into IDH1-mutant cells, and further challenged with a PARP inhibitor. Two genes involved in DNA repair and two genes involved in chromatin remodeling will be selected to create constitutive CRISPR-Cas9 knockout cell lines and characterization will be conducted as in Aim 1. Together, this work will reveal undescribed mechanisms of PARP inhibitor resistance in IDH-mutant cancers, and it will provide insight into combinatorial therapy with other DNA damaging agents that may synergize to overcome this resistance.

NIH Research Projects · FY 2026 · 2025-04

Project Summary/Abstract This research proposes a new image analysis technology for PET/SPECT neuroimaging. Analysis of PET/SPECT neuroimages often requires an image reference region where the radiotracer has non-specific binding. Unfortunately, many old as well as emerging radiotracers do not have a useful reference region, and this can limit their use. In this research, we propose the development of a new computational technology for processing such images using ideas from projective geometry. This methodology will enable reference-region- free analysis of PET/SPECT images, thereby enabling a more widespread use of tracers that do not have an optimal reference region. There are three specific aims to this exploratory research: The first is to fully develop the mathematics and algorithms of the projective approach. The second is to evaluate the proposed methods using a large image dataset of a SPECT tracer (Ioflupane) with a known reference region. This tracer is used in imaging Parkinson's Disease. This dataset will enable the comparison of the new methods (with the reference region ignored) with classical methods which use the reference region. Finally, we will evaluate the performance of this method with a new PET tracer for synaptic vesicle protein SV2A. This tracer has a suboptimal reference region; no non-specific binding region is known. The results of the reference region free method will be compared with classic compartmental modeling.

NIH Research Projects · FY 2024 · 2025-03

Adipose tissue has important implications for metabolism and general health. It is now well established that, rather than being a passive tissue for energy storage, as it was once perceived, adipose is a dynamic tissue that responds to changing physiological needs and systemic signals as well as secretes a variety of potent hormones with metabolic implications. The primary cell type within adipose tissue is the adipocyte and more recent advances have elucidated that there is heterogeneity in types of adipocytes, including divergent functional properties. Using cellular energetics to classify types of adipocytes defines two broad categories: adipocytes that store energy (‘white’ adipocytes) and adipocytes that disperse energy (‘brown’ adipocytes). Perhaps most intriguingly, more than one type of adipocyte can reside within a single adipose depot; in particular, within subcutaneous adipose depots in rodents, which are primarily white, there are also adipocytes that have properties of brown adipocytes, referred to as brown-in-white (‘brite’) or ‘beige’ adipocytes. Furthermore, the number of these adipocytes is dynamic, responding to changes in the systemic signals and environments. As the number of individuals with obesity continues to rise, the potential implications of adipocytes that disperse energy has generated enthusiasm for elucidating this biology in detail with the expectation that this knowledge will provide a foundation for the development of novel therapeutic approaches, in addition to advancing our understanding of cell and molecular biology in general. Yet, there is a knowledge gap in our understanding of the molecular mechanisms that direct this important process. There is an additional knowledge gap in our understanding of how physiological systemic signals converge on these mechanistic pathways. Using a conditional deletion mouse model, we identified Klf15 as a potent regulator of the generation of beige adipocytes. We will use state-of-the-art molecular and cell biology approaches to expose the mechanisms by which Klf15 regulates this process

NIH Research Projects · FY 2026 · 2025-03

PROJECT SUMMARY Over 1 million people have type 1 diabetes in the United States and greatly affects their quality of life. In vivo measurement of insulin vesicle functional capacity (IVFC) and beta cell mass (BCM) would allow tracking and monitoring of recent advances in therapies designed to preserve IVFC and BCM and/or monitor transplanted beta cells. Beta cell loss occurs in the endocrine pancreas resulting in loss of insulin secretion and subsequent onset of diabetes. Current clinical measurements of beta cell function (e.g., C-peptide release in response to oral glucose tolerance test (OGTT)) may underrepresent total IFVC or BCM due to variability in beta cell function in response to glucose. The aim of this study is to utilize PET and MR techniques to study insulin vesicle functional capacity, beta cell mass and pancreas volume in non-diabetic individuals, and stage 2 T1D with high and low PI:C ratio as they progress to stage 3 T1D. The opportunities afforded by this award would enable us to provide a comprehensive picture of multiple longitudinal measures of beta cell function and mass in vivo and increase our knowledge of the relationship of proposed imaging markers to greater pancreas architecture and function.

NSF Awards · FY 2025 · 2025-03

This I-Corps project is focused on the development of artificial intelligence (AI)-driven strategies to accelerate early-stage drug discovery in broad therapeutic areas. Drug discovery and development is time consuming and costly with high failure rates. Success often depends on reliable identification of potential drug candidates in the early stage of the pipeline. Virtual screening of large numbers of compounds has been very useful in identifying additional drug candidates for experimental validation and subsequent optimization. However, there still exists an unmet need for improved virtual screening due to the billions of chemical compounds and unknown target molecules or biomarkers. AI technologies have had considerable impact in drug discovery. Improved predictions by AI-based technologies can significantly accelerate virtual screening or early-stage drug discovery and hence subsequent drug development in many disease areas, providing broad economic advantages in terms of time and cost in both biomedicine and healthcare. This I-Corps project utilizes experiential learning coupled with a first-hand investigation of the industry ecosystem to assess the translation potential of the technology. This solution is based on the development of a general meta-modeling framework of ligand-protein binding affinity prediction by integrating traditional physical docking tools and sequence-based artificial intelligence (AI) models. The technology has more than 1,000 pre-trained, sequence-based, deep learning models using 10 different architectures and more than 200 pre-trained machine-learning meta-models. The combined models have shown superior performance in three different benchmarks compared to exclusively structure-based AI models, suggesting that scalable virtual screening is possible without structural data for accurate prediction of binding affinities. A key advantage of the technology is to leverage the ensembling power of multiple tools and datasets in multi-dimensional ways, reducing model-specific bias and enhancing model-specific strengths. The technology expands the scope of diverse drug targets, providing new avenues for different diseases. In particular, the innovation may help discover and optimize small molecule ligands for challenging target proteins. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NSF Awards · FY 2025 · 2025-03

The endoplasmic reticulum (ER) is found in all eukaryotic cells and functions in many essential processes. The project will provide a better understanding of how various ER structures, such as tubules and sheets, determine where proteins of the ER accumulate and interact. These studies will ultimately reveal how the ER can serve multiple roles in cells and will assist in generating a more complete picture of the entire ER system. The project will focus on the role of the ER in immune recognition (i.e., how cells recognize what is “self” and what is “non-self”). The Broader Impact of the work includes its intrinsic merit as the ER as a ubiquitous organelle. It also could provide understanding of how some viruses escape notice by the immune system. Other activities include the training of graduate students and postdoctoral researchers in interdisciplinary research that bridges physics, biophysics, cell biology and biochemistry, preparing them for a career in research at universities or in industry. The project will also provide local high school students an opportunity to participate in hands-on learning experiences and benefit other students with optics demonstrations. These outreach activities are designed to inspire students to pursue STEM careers. Through these outreach and training initiatives, this project will contribute to the development of a well-equipped STEM workforce in the United States, fostering the next generation of scientists and engineers. This research examines the nanoscale organization of the peptide loading complex (PLC) within the ER, focusing on its structural relationship with the transporter associated with antigen processing (TAP1/2). The complex plays a critical role in assembling major histocompatibility complex class I molecules, which are essential for immune recognition. The project aims to determine how ER morphology influences the function of the complex, thereby providing insight into the broader role of ER architecture in cellular processes. By employing advanced super-resolution microscopy techniques such as DNA-PAINT and 4Pi-SMS, the study will map the spatial distribution of PLC clusters and quantify their size and stoichiometry. Additionally, the research will explore how modulating the PLC’s supramolecular organization affects its function, shedding light on the structural determinants of its activity. This investigation will combine expertise in biochemistry, structural biology, and high-resolution imaging, drawing on the collaborative strengths of the Tampé lab (Frankfurt) and the Bewersdorf lab (Yale). By systematically integrating these methodologies, the project aims to build a comprehensive model of how ER nanomorphology supports cellular processes essential to immune function. The insights gained from this study will not only deepen our understanding of antigen presentation but also contribute to the broader field of ER research by elucidating how macromolecular assemblies are spatially regulated within cellular compartments. This collaborative US/Germany project is supported by the US National Science Foundation and the German Deutsche Forschung Gemeinschaft (DFG) where NSF funds the US investigator and DFG funds the German partner. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NSF Awards · FY 2025 · 2025-03

In nature, bacteria either swim freely to search for food or attach to surfaces, forming biofilms. Biofilms are groups of bacteria that stick together via secreted polymers and can be found on many surfaces—from rocks in streams to medical devices. While sometimes beneficial, biofilms often cause problems in industrial and medical settings because they are hard to remove and resist antibiotics. Understanding how bacteria interact with biofilms and switch between swimming/non-swimming states is crucial for controlling harmful biofilms. However, studying these interactions has been challenging due to the lack of tools that can observe both types of bacteria simultaneously. This project aims to develop HoloCon, a new imaging tool that combines three-dimensional holographic imaging and fluorescent microscopy, allowing scientists to see both free-swimming bacteria and biofilms in three dimensions and observe their interactions in real time at the single-cell level. HoloCon will visualize and quantify both bacterial populations in one setup, explaining how resident biofilms repel free-swimming cells attempting to colonize and invade them—a common scenario in natural environments like the ocean. HoloCon will be widely useful to researchers observing cell dynamics at high spatial and temporal resolutions, and to others imaging cell or particle trajectories in complex three-dimensional environments such as tissues. The Broader Impacts of the project include its intrinsic merit as the project could impact the work of microbiologists, cell biologists, and developmental biologists. Research tasks will be integrated with educational missions to train future scientists and engineers and inspire public interest through classes, research, and outreach activities in high schools. The major goal of the proposal includes both the development of a new tool for cell biology studies and the scientific discoveries enabled by the new tool. Specifically, in Aim 1, an innovative imaging tool named HoloCon will be developed, which represents the first system capable of simultaneously capturing 3D images of rapidly swimming bacteria and monitoring the dynamic evolution of biofilm architecture at single-cell level. HoloCon is composed of three integrated modules: a real-time 3D particle tracking module based on digital in-line holography (DIH) integrated with machine learning, a customized spinning disk confocal microscope module that receives information from DIH, and a fully integrated data analysis module ready for the research community to use. Aim 2 centers on addressing the key scientific questions of how resident biofilms repel free-swimming cells attempting to colonize and invade the biofilm. New information revealed by HoloCon with be combined with bacterial genetics, biochemistry, and surface engineering tools to paint a comprehensive picture about the interactions between the sessile and planktonic bacterial populations at sub-micron spatial resolution and <10 ms temporal resolution. The central hypothesis is that the interaction between a swimming cell and an established biofilm depends on the swimming behavior of the invading cell, the topography of the resident biofilm, and the biochemical interactions between cells and the extracellular matrix. Revealing the resistance mechanism to biofilm will add significantly to our understanding on the competition between bacterial populations in nature, and on how ecological functions are tightly coupled with the cell biology of individual bacterium. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

NIH Research Projects · FY 2026 · 2025-02

In Malaysia, there is a concentrated HIV epidemic among men who have sex with men (MSM) and the incidence and mortality rates are increasing, which is not the case globally. Stigma towards MSM is widespread and impedes HIV prevention and treatment efforts. Rapid Start ART (RS-ART) is an evidence-based practice that WHO, IAS, and Malaysia's Ministry of Health endorse, but it has not been studied in MSM. This grant proposal is a comprehensive fellowship training program focused on HIV prevention and stigma reduction, particularly among MSM. The fellowship, underpinned by the applicant's background in public health and biostatistics, aims to develop and implement RS-ART as an innovative Behavioral Design Interventions (BDIs) for effective stigma reduction. Central to this are three specific aims: Firstly, the identification of facilitators and barriers to the implementation of BDIs targeting HIV prevention among MSM using asynchronous online focus groups. The findings of this aim will be used to tailor an existing RS-ART protocol to MSM in particular. Secondly, the project with facilitate the introduction of RS-ART, an approach informed through training in NIATx implementation facilitation. Lastly, the program focuses on advancing dyadic analysis techniques to better understand the relational dynamics between healthcare providers and patients, aiming to reduce stigma and improve health outcomes. The fellowship's training component is multidisciplinary, encompassing stigma, implementation science including NIATx, and dyadic analysis. Planned activities include coursework, mentorship, and hands-on research, with a substantial component conducted in Malaysia, providing a unique international perspective and practical experience in diverse healthcare settings. This fellowship represents a critical step in the applicant's career trajectory towards becoming an independent researcher, with long-term goals centered on the development and implementation of high- impact stigma-reduction interventions for marginalized groups. The training and research conducted during this fellowship will contribute significantly to the fields of HIV prevention, stigma reduction, and public health implementation science, with a focus on addressing health disparities in low-income and marginalized communities.

NIH Research Projects · FY 2026 · 2025-02

Project Summary/Abstract Individuals with autism and intellectual disability (ASD+ID) comprise a significant portion of the autism spectrum but have historically been excluded from most neuroscience research. As a result, little is understood about differences in brain function among those with the most significant need, and neuroscientific understanding in autism represents only a subset of the autistic community. The current project aims to bridge this knowledge gap by applying innovative technological and clinical approaches to include 70 6-11-year-old children with ASD+ID and a matched sample of 70 children with ID without ASD (ID) in a rigorous neuroscience study. We apply novel hardware and software solutions according to a behavioral protocol designed by a Board Certified Behavior Analyst. Automated quantification of visual attention and bodily movements, along with individualized reinforcers, supports participant behavior conducive to data collection. Electroencephalography (EEG) and eye-tracking (ET) data streams are co-registered for simultaneous, multimodal collection of neural and visual attentional data. This approach is applied to collect assays that are well-evidenced in ASD without ID (ASD-ID), appropriate for those with ASD+ID, and associated with key facets of social-communication relevant to autism: the N170 event-related potential (ERP), which quantifies neural response to faces, and proportion of looking to faces, measured by ET. These assays are collected using experimental paradigms validated in the Autism Biomarkers Consortium for Clinical Trials (ABC-CT), a multisite study collecting highly reliable EEG and ET data in ASD-ID and typical- developing children (TD). By using these assays, we can compare the data collected here to the large ABC-CT samples to understand differences specifically informative about ASD+ID and ID. Strong preliminary data demonstrate this approach is feasible and yields robust psychometric information that is uniquely relevant to ASD+ID and associated with clinical characteristics. This innovative project uses a suite of contingent technologies to acclimate participants to the testing environment and apparatus, attenuate motion, permit real- time feedback on data quality, and support post-processing of artifact using computer vision derived motion estimates. High impact stems from application of promising indices of social-communication to an understudied population with great potential to benefit from novel neurobehavioral insights. By optimizing an innovative clinical and technological approach to data collection in ASD+ID and disseminating it to other researchers, this research will also yield indirect impact beyond the specific findings of this study. The long term goal of this line of research is to develop sensitive and objective indices of social-communicative function to improve clinical research in ASD by informing stratification of autistic individuals into more homogenous subgroups for intervention selection or clinical trial enrichment and to measure treatment response effectively and efficiently.

NIH Research Projects · FY 2026 · 2025-02

Project Summary Anxiety disorders are the most common mental illnesses in the world. One in 14 people worldwide currently suffer from dysregulated anxiety. People with dysregulated anxiety report poor quality of life, loss of independence and are at an increased risk of suicide attempts. A key component of anxiety disorder is a persistent and disruptive state of aversion, high arousal, and negatively valenced perception even in the absence of threat. Remarkably, up to 30 percent of those who suffer from anxiety disorders do not respond to currently available pharmacologic and behavioral therapies. Part of the reason for this treatment gap is because we do not have a mechanistic understanding of anxiety related brain circuits in humans. Noninvasive neuroimaging techniques, mainly fMRI, have been used to study anxiety related brain circuits. However, fMRI may not capture dynamics and other aspects of the neural mechanisms of anxiety that require greater temporal and spatial resolution. Extensive work in rodent models has identified brain circuits associated with anxiety, in the context of simple experiences. Causal manipulations at the level of specific brain regions and individual neurons have defined their contributions to anxiety-like behavior with potential implications for the treatment of dysregulated anxiety. However, studies in rodent systems may not capture the relationship of anxiety to human subjectivity or the complexities of higher-order human cognition. Circuit-level work in humans is required. The goal of this proposal is to mechanistically uncover neuroanatomical substrates of anxiety related brain circuits that will be candidates for neural circuit reprogramming in future studies. Two reciprocally connected brain regions that have been implicated in top down and bottom-up control of anxiety are the dorsal Anterior Cingulate (Area 24) and the anterior insula. Here we propose a theoretical model where safety assessment and aversive outcomes are dissociably represented in the dorsal Anterior Cingulate Cortex and anterior Insula, respectively. To determine how this circuit operates in humans requires causal manipulations which are difficult due to their deep location. We will take a two-level approach in dissecting these anxiety related brain circuits in epilepsy patients implanted with intracranial depth electrodes, for the sole purpose of seizure onset localization and functional brain mapping. First, using multiregional invasive neurophysiology, we will outline the individual and complementary roles these brain regions play in safety assessment and outcomes response as subjects engage in a spatial avoidance of threat task. This will be done at single neuron, population activity, and network oscillation levels. Next, transient disruption of key nodes of this network, using direct electrical brain stimulation, will provide a mechanistic understanding and causal relationships across these brain regions. This scientific approach—linking single neuron activity to behavior through large scale brain oscillations will set the stage for outlining the fundamental circuit level organization of anxiety in humans.

NIH Research Projects · FY 2026 · 2025-02

SUMMARY The ability of an animal to successfully navigate the world and carry out goal-directed behavior is dependent on the hippocampus and entorhinal cortex but is also strongly shaped by visual information derived from external cues. Indeed, manipulation or elimination of visual input can significantly disrupt ongoing activity in these regions and impair tasks that require accurate internal representations of the local environment. Considerable anatomical data indicate that the occipital cortex, including primary and higher-order visual areas, sends projections to the medial entorhinal cortex (MEC). However, the ability of MEC neurons to encode visual cues and the specific circuits mediating this function are largely unknown. Whether the MEC can respond to low-level visual features or primarily represents complex, behaviorally salient relationships between stimuli has not been examined. Furthermore, how visual inputs interact with ongoing network activity within the MEC is unclear. In the present study, we propose a combination of electrophysiology, anatomical tracing, optogenetic manipulation, and ex vivo synaptic physiology to (1) determine the capacity for visual stimulus representation by MEC neurons, (2) identify the afferent pathways and specific subpopulations of MEC neurons that encode visual input, (3) determine the microcircuit organization of connections within the MEC that shape visual responses, and (4) link visually-evoked MEC activity to virtual navigation for reward. Our overall goal is to understand the pathways by which visual information guides complex behaviors such as navigation through the environment. We expect that our results will generate new avenues for exploring both the cellular and circuit foundations of visual behavior and the mechanisms underlying coordination of activity between different brain regions.

NIH Research Projects · FY 2026 · 2025-02

PROJECT SUMMARY/ABSTRACT Incretin mimetics, such as glucagon-like peptide-1 receptor agonists (GLP-1RAs), have revolutionized obesity and diabetes treatment, become first-line anti-obesity medications, and may soon be more widely used for other indications including cardiovascular and renal disease prevention, neurodegeneration, and addiction. Like bariatric surgery, GLP-1RAs may decrease the incidence of obesity-driven cancers, including pancreatic ductal adenocarcinoma (PDAC), a highly lethal disease with few effective therapies. However, several clinical trials and real-world studies based on the FDA Adverse Event Reporting System (FAERS) have raised the question of whether GLP-1RAs enhance PDAC risk. As persons with obesity and diabetes are the typical population treated with GLP-1RAs, it has been challenging to disentangle the effects of the medications themselves versus these established risk factors on possibly increasing PDAC risk. Similarly, studies in preclinical models have shown inconsistent results and largely lacked the right genetic and physiologic context to faithfully study the impact of GLP-1RAs on pancreatic tumorigenesis. Therefore, whether and how incretin mimetics modulate PDAC risk remains unknown. GLP-1R, the target receptor for GLP-1RAs, is highly expressed in endocrine beta (β) cells and to a lesser degree in exocrine acinar cells. Although PDAC is primarily thought to arise from acinar cells, our lab has established a critical role for dysfunctional β cell expression of the hormone cholecystokinin (CCK) in driving obesity-associated PDAC progression through a previously unappreciated endocrine-exocrine signaling axis. In both humans and mice, GLP-1RAs improve β cell health through direct β cell GLP-1R signaling and weight reduction. Conversely, GLP-1RAs stimulate acinar cell proliferation and digestive enzyme production and secretion, mechanisms linked to CCK-induced tumorigenesis. Therefore, we hypothesize that GLP-1RAs act directly on acinar and β cells to promote or suppress PDAC tumorigenesis, respectively, and that the balance of these opposing effects in different physiologic contexts determines PDAC risk. The studies in Aim 1 utilize powerful genetically engineered mouse models that closely recapitulate human PDAC progression, multiple obesity paradigms, modern FDA-approved GLP-1RAs used in obesity treatment, single-cell sequencing and multimodal computational analyses, and islet functional studies to define whether and how GLP-1RAs alter β cell state and function to modulate obesity-driven exocrine tumorigenesis. The proposed work in Aim 2 leverages sophisticated genetic methods, molecular studies, and state-of-the-art primary cultures to determine how GLP1- RAs perturb acinar cell fate and function to regulate pancreatic tumorigenesis in the lean context. Together, these experiments will transform our understanding of how GLP-1RAs alter pancreatic endocrine and exocrine cell function to govern PDAC development in different physiologic contexts, enabling targeted deployment of incretin mimetics to decrease the risk of this highly lethal and recalcitrant cancer.