University Of California Los Angeles

NIH Research Projects · FY 2026 · 2024-06

PROJECT SUMMARY We present an interdisciplinary target discovery and T-cell receptor (TCR) therapy development program focused on platinum-resistant high-grade serous ovarian carcinoma (HGSOC), a highly lethal disease with no effective long-term treatments or targeted therapies. Nearly all patients diagnosed with HGSOC will relapse after initial treatment. Disease recurrence within 6 months of platinum treatment is categorized as platinum-resistant HGSOC, which is highly fatal. Our strategy to develop TCR-based therapies for platinum-resistant ovarian cancer relies on unmasking the hidden diversity of cancer proteomes produced by RNA dysregulation and mRNA isoform variation. RNA dysregulation in cancer cells can produce new epitopes through the generation of novel mRNA and protein isoforms with increased cancer specificity. To identify sufficiently cancer-specific peptide targets for immunotherapy development, our proposed strategy expands beyond target discovery from somatic mutations alone. In particular, long-read RNA sequencing (RNA-seq) is a powerful approach for isoform analysis and tumor antigen discovery. We propose to exploit mRNA isoform variation as a source of shared tumor antigens for platinum-resistant ovarian cancer. We will first define the landscape of full-length mRNA isoforms in platinum-resistant ovarian cancer by generating and analyzing long-read nanopore RNA-seq datasets across a broad cohort of patients with this disease. We will couple this analysis with a big data examination of long- and short-read transcriptome profiles in a large panel of tumor and normal tissues to assess cancer specificity. Second, we will directly assay the peptides presented to the immune system by immunopeptidomics, and examine antigen heterogeneity by single-cell long-read nanopore RNA-seq. Integrating these multiple forms of - omics analyses with state-of-the-art computational epitope predictions, we will create a highly privileged set of potential TCR targets. Finally, we will utilize a novel in vitro human artificial thymic organoid (ATO) culture-based TCR discovery platform to rapidly create and select reactive TCRs from T cells generated through directed differentiation of pluripotent stem cells. Antigen-specific TCRs will be preclinically evaluated as therapeutically relevant reagents in vitro and by adoptive TCR-T cell therapy in patient-derived xenograft (PDX) models of platinum-resistant ovarian cancer. We have assembled a multi-disciplinary team of experts at UCLA and the Children’s Hospital of Philadelphia, with expertise in ovarian cancer biology and treatment (Memarzadeh), RNA genomics and computational immuno-oncology (Xing), tumor biology and immunology (Memarzadeh, Seet, Witte), and T-cell developmental biology (Seet). Our research seeks to discover a new class of antigens and their cognate TCRs for platinum-resistant ovarian cancer and establish their initial efficacy in preclinical models.

NIH Research Projects · FY 2026 · 2024-06

PROJECT SUMMARY/ABSTRACT T cell production declines with age and contributes to decreased immune function and increased susceptibility to infections and cancers in older adults. This decline in T cell output may be due to changes in the aged progenitor cells and/or changes in the thymic microenvironment. T cells develop from hematopoietic stem cells (HSCs) and progenitors that enter the thymus, an organ known to atrophy with age. Previous studies looking at T cell potential from aged HSCs have been limited by the assays available; determining T cell output in vivo has relied on hematopoietic transplantation models and is confounded by the long process of engraftment and thymic recruitment. While some in vitro models have looked at T cell output from aged HSCs and progenitors, these methods often start with a heterogenous population of cells and produce mixed conclusions about T cell potential. This proposal seeks to overcome these challenges by studying single, phenotypically-defined aged and young HSCs and progenitors to determine T cell output and development. Further, we will determine whether a pro-inflammatory signaling pathway enhanced in aging plays a role in driving reduced thymopoiesis with age. In this proposal, Specific Aim 1 will determine the role of HSC and progenitor age on T cell development using our in vitro Artificial Thymic Organoid (ATO) system. The ATO fully recapitulates all stages of T cell development from a single HSC or progenitor. Preliminary data from our lab suggests that aged stem cells exhibit differences at early stages of T cell development and removing aged stem cells from their inflamed microenvironment ultimately restores their ability to produce comparable T cell numbers, emphasizing the importance of inflammatory factors in the microenvironment. Specific Aim 2 will evaluate a specific signaling pathway enhanced in aging and its effects on T cell production using a novel mouse model. Levels of the inflammatory cytokine interleukin-6 (IL-6) increase in the aged bone marrow and thymus, and IL-6 may drive changes in the aged HSC pool (resulting in more myeloid- biased HSCs) and thymic atrophy. IL-6 requires signaling through glycoprotein 130 (gp130), and our collaborators identified a signaling modality within the gp130 receptor that produced regenerative effects in mouse models of wound healing and osteoarthritis when inactivated. In our preliminary data, we show that these mutant mice also have greater thymocyte numbers, prompting us to investigate whether signaling through this specific part of the IL-6 gp130 receptor mediates reduced thymopoiesis with age. Our results will improve our understanding of the aging immune system and inform potential therapies for regenerative medicine. Successful completion of these aims is a critical component of a comprehensive training plan, in which I will gain skills in experimental design, data analysis, scientific communication, and mentorship to grow as a future physician scientist. I will be supported by my sponsor, Dr. Gay Crooks, in a collaborative training environment at UCLA.

NIH Research Projects · FY 2025 · 2024-06

Project Summary / Abstract Primary visual cortex (V1) processes visual information along parallel pathways and distributes the results to high level cortical areas and subcortical targets. In mice, a species that lacks a strong, columnar organization, neurons carrying information from different streams are spatially intermixed, but nevertheless connect with specificity, both within and across areas. How are connections between neurons established on such a fine scale despite the spatial intermixing of neurons? We hypothesize that the visual properties of receptive fields of V1 neurons correlate with transcriptomic cell types, which further guide their projection patterns and orchestrate the wiring of local connections. We will establish if there is a correlation between cell type and visual function in V1. Our strategy consists of the following steps. Step 1) Express GCaMP8 in a sparse set of L2/3 neurons under the control of tamoxifen. Step 2) Use volumetric, in-vivo 2-photon calcium imaging to extensively characterize the visual properties of the labeled neurons. Step 3) Process the tissue using expansion-assisted iterative FISH (EASI-FISH) to yield the transcriptomic signatures of cells within the volume. Importantly, we will determine which cells express GCaMP8 that will provide the landmarks for alignment. Step 4) Alignment between in-vivo recordings and transcriptomic data using GCaMP6 expression. Step 5) Clustering of neurons according to visual properties and transcriptomic signature. The project addresses one of NEI’s priorities: to improve the understanding of neural activity and molecular events in the formation of central visual circuits. Success in this project will deliver the first database of excitatory cells in L2/3 of the mouse containing a characterization of their visual properties, cortical location, and transcriptomic signatures. We will test if basic properties of visual neurons, such as their receptive field linearity, correlate with cell types. The work will pave the way to study critical questions about how early visual experience interacts with genetic programs that lead to cell differentiation and their connectivity in a future R01.

NIH Research Projects · FY 2025 · 2024-06

ABSTRACT This is a K23 Patient-Oriented Mentored Career Development award for Dr. Matthew Durstenfeld. His proposed research focuses on cardiorespiratory fitness and chronotropic incompetence and their implications for cardiovascular disease among people with human immunodeficiency virus (HIV). Candidate: Dr. Durstenfeld is a board-certified internist and cardiologist and an Assistant Professor of Medicine at the University of California, San Francisco, in the UCSF Division of Cardiology at Zuckerberg San Francisco General. He seeks research training at the interface of cardiology and infectious diseases. Training: Through hands-on, mentored patient-oriented research, formal didactics and seminars, and other activities, Dr. Durstenfeld’s career development plan is designed to prepare him for a career as an independent investigator in the field of infection-associated cardiovascular disease. Dr. Durstenfeld’s goals are to: (1) Strengthen his ability to conduct and analyze longitudinal cohorts, (2) Gain content expertise in (a) HIV- associated immune activation and inflammation, (b) advanced cardiac imaging, and (c) exercise in HIV, and (3) Prepare to lead clinical trials to improve cardiovascular health for diverse populations. Mentors/Environment: Dr. Durstenfeld’s team of mentors at UCSF is led by Dr. Priscilla Hsue, a groundbreaking pioneer in HIV cardiology. Co-mentors include Dr. Steve Deeks (HIV, clinical research), Dr. John Kornak (biostatistics), and Dr. Alexis Beatty (methods, exercise, and cardiovascular monitoring), and Dr. Kristine Erlandson (Exercise in HIV). Advisors include Dr. Ahmed Tawakol (FDG PET/CT) and Dr. Michael Lu (Coronary CTA). UCSF is an exceptional environment for early-stage investigators and clinical research, especially at Dr. Durstenfeld’s focus interface of cardiology and HIV, with resources including the Clinical and Translational Science Institute, Center of Vascular Excellence, and UCSF Bay Area Center for AIDS Research. Research: Low cardiorespiratory fitness (CRF) and chronotropic incompetence (CI), the inability to increase heart rate adequately during exercise, may be underrecognized and treatable contributors to cardiovascular disease, especially among people with HIV. Leveraging three NIH-funded clinical trials, the first aim is to describe patterns and risk factors for low CRF and CI in HIV and longitudinal effects of CI on CRF. Leveraging measurements conducted in two NIH-funded clinical trials, the second aim is to identify associations of low CRF and CI with subclinical cardiovascular disease. The third aim is to conduct a proof-of-concept, randomized controlled trial of exercise training for HIV-associated chronotropic incompetence. Summary: These foundational studies will lead to a greater understanding of the role of CRF and CI in cardiovascular disease among people with HIV. Anchored by an experienced, multidisciplinary, collaborative mentoring team and formal career development activities, Dr. Durstenfeld’s career development plan will facilitate his development into an independent investigator and leader in infectious-disease cardiology.

NIH Research Projects · FY 2026 · 2024-06

Project Summary/Abstract The overall goal of the MARC program at UCLA is to increase the number of undergraduates from underrepresented backgrounds who successfully enroll into graduate programs at highly selective, research- intensive institutions and subsequently complete a PhD in biomedical fields. The program is designed to enhance the scientific and career knowledge, skills, and experience of MARC trainees to prepare them for graduate studies and enhance their persistence by building each trainee’s identity as a scientist. MARC trainees participate in a structured program that emphasizes research training with outstanding faculty, development of scientific writing and presentation skills, networking, and mentoring. Trainees will be recruited from life science majors throughout UCLA to start the program as rising juniors conducting full-time research in their first summer in the program. Trainees will work with research mentors that are active, well-funded, trained in evidence-based mentoring practices, and enthusiastic about their role in nurturing the next generation of scientific leaders. During the academic year, research will continue to be emphasized, and in weekly meetings throughout the academic year, trainees will receive instruction, opportunities to practice, and feedback on their presentations and writing. In the trainee’s second summer in the program, they will participate in a research experience at another institution. Each trainee will present their research in at least two conferences per year, where they can network with other scientists and build their scientific community. Throughout the program, the experienced MARC directors will provide both formal and informal mentoring to the students to build lasting, supportive, and responsive relationships with guidance that is individually tailored. Quarterly social events build community among the trainees and other scientists from backgrounds that are underrepresented in the sciences. Rigorous training in the responsible conduct of research and methods to enhance reproducibility, as well as informal discussions throughout the trainees’ participation in MARC, encourages reflection on the intersection of science and society and the roles that each individual plays in enhancing the human condition. The program emphasizes development of trainees as leaders in their scientific fields by encouraging participation in all aspects of the scientific endeavor. We propose to select 15 new junior level students per year to participate in this 2-year program, resulting in a total of 30 students in the program per year. The overall aim of the program is to have at least 80% of the trainees enter PhD or combined PhD programs within three years of their graduation and completion of the program. The cumulative effect of the proposed MARC program will increase the pool of strong candidates from underrepresented backgrounds for PhD or MD/PhD programs, and contribute to the biomedical workforce.

NIH Research Projects · FY 2026 · 2024-06

Project Summary/Abstractor In the retina, various neuronal types are confined to three somatic layers and connected in two plexiform layers. Defects in neuronal positioning or connections result in vision impairment or blindness. While migration of neurons to their destined layers is well studied, the influence of segregated nuclear layers on the formation of neuronal connections remains unclear. This project aims to delineate the transcriptional control of neuronal position and connection. We use starburst amacrine cells (SACs)—the cholinergic interneurons in the retina— as a model to address this question. SACs are crucial components of the direction-selective (DS) circuit and consist of two closely related subtypes. OFF SACs in the inner nuclear layer (INL) establish dendritic stratifications and connections in the OFF layer (S2) of the inner plexiform layer (IPL), whereas ON SACs in the ganglion cell layer (GCL) ramify their dendrites in the ON layer (S4) of the IPL. My previous research identified the transcription factor Fezf1 that is specifically expressed by ON SACs and determines their somatic positions in the GCL. In the Fezf1 constitutive knockout (Fezf1-/-), ON SACs are mislocalized to the INL alongside OFF SACs. To overcome the neonatal lethality associated with Fezf1-/-, we generated a new Fezf1 conditional allele to facilitate the study of postnatal development of SACs. We made three observations: (1) Similar to Fezf1-/-, early embryonic deletion of Fezf1 results in mislocalization of ON SACs to the GCL, but late deletion allows them to remain in the GCL (2) In both early and late Fezf1 deletions, SAC dendrites no longer separate into two distinct layers but remain intermingled. (3) Following altered SAC dendritic stratification, ON and OFF direction-selective ganglion cells (ooDSGCs) and ON DSGCs redirect their dendritic arbors from making contacts with SACs in S2 and S4 (ooDSGCs) or S4 (ON DSGCs) to contacting S2 alone. These findings collectively support the central hypothesis that Fezf1 sequentially controls the somatic position, dendritic stratification, and synaptic connections of SACs. We therefore propose two specific aims. Aim 1 aims to determine how Fezf1 mediates dendritic stratification of SACs. We will elucidate the morphological changes of developing SACs via image-tracing and assess the sufficiency of Fezf1 in rescuing the dendritic defects via in utero electroporation. We will determine the regulatory network of Fezf1 using combined ATAC-seq and RNA-seq assays. Lastly, we will test the role of repulsive molecules Slit2/Nell2/Robo2 in separating the dendritic arbors between ON and OFF SACs. Aim 2 aims to determine how the altered dendritic stratification of SACs redirects dendritic innervation of ooDSGCs and ON DSGCs. We will use genetic labeling and image-tracing to determine the specificity of targeting defects to DSGC types but not other RGC types. We will then use RNA-seq and AAV-mediated genetic manipulation to determine the molecular mechanism that mediates the dendritic mistargeting of DSGCs. This project will comprehensively dissect the transcriptional control of neuronal positioning and connection formation of SACs and generate a new molecular basis for the assembly of the direction-selective circuit.

NIH Research Projects · FY 2026 · 2024-06

Project Summary/Abstract Methamphetamine (MA), a potent addictive psychostimulant, is highly prevalent in HIV-infected individuals. Even for individuals with suppressive anti-retroviral therapy (ART), MA abuse has been linked to increased viral load, accelerated disease progression, and higher mortality rates in people living with HIV (PLWH). Despite well-documented evidence of MA's adverse effects on the central nervous system (CNS) and cognitive function, its effects on immunity remain unclear. Further research is needed to determine the molecular mechanisms of MA on the immune system, which could lead to targeted therapeutic interventions. Previous reports and our studies showed that MA could impair mitochondria function and exacerbate inflammasome activation and chronic inflammation during HIV infection. Autophagy, a homeostatic cellular mechanism involved in disposal of damaged organelles and intracellularly pathogens, has been reported to negatively regulate inflammasome activation. Our recent studies indicate that autophagy inducers such as rapamycin can induce autophagy, improve mitochondria function, reduce inflammasome activation and chronic inflammation in HIV infected humanized mice. We also observed improved anti-viral T cell immunity, reduced viral reservoir and lower viral rebound after ART withdrawal in rapamycin treated mice, suggesting its therapeutic potentials. In addition, we found that cannabis major components trans-Δ9-tetrahydrocannabinol (THC) and cannabidiol(CBD) can potently induce autophagy and reduce inflammasome activation in stimulated macrophages. Therefore, we hypothesize that inducing autophagy through rapamycin or THC/CBD may offer therapeutic benefits in reducing inflammasome-mediated inflammation in both the periphery and CNS in individuals with HIV infection and MA use. This, in turn, could enhance anti-viral immunity and decrease viral reservoirs. We will study the following aims: 1) Determine the effects of methamphetamine on inflammasome activation and T cell dysfunction during HIV infection with or without ART; 2) Examine the therapeutic potential of targeting autophagy to reduce excessive inflammasome activation and restore T cell function during HIV infection and methamphetamine abuse; 3) Investigate the effects of MA and autophagy induction on HIV- associated CNS inflammation.

NIH Research Projects · FY 2025 · 2024-05

PROJECT SUMMARY/ABSTRACT African trypanosomes (Trypanosoma brucei) and related trypanosomatid parasites are responsible for vector-borne diseases that cause great human suffering and economic burden in endemic countries. T. brucei is transmitted between humans and other mammalian hosts by the tsetse fly, which is not merely a vessel for moving parasites between hosts, but an integral part of the parasite's developmental life cycle necessary for sustained transmission. In the absence of a vaccine to prevent infection in the mammalian host, targeting parasite development within the insect vector is considered an option for reducing disease transmission, though little is known of parasite interactions in the vector necessary for transmission. To survive, develop, and be transmitted, T. brucei must sense and respond to changing environmental signals as it moves through tissues within the insect vector. Little is known about parasite signaling pathways and vector-derived factors that control parasite migration - this is a critical knowledge gap and potential target of new transmission-blocking agents. Trypanosome cAMP signaling, originally shown to be critical for parasite chemotaxis in vitro, has recently been connected to progression of parasites through the tsetse, in particular, migration from the midgut (MG) to the proventriculus (PV). Initiation of cAMP signaling is controlled by an expanded protein family of adenylate cyclases (ACs) that differ in their extracellular putative ligand-binding domains and exhibit tissue-specific expression profiles during parasite migration through the tsetse. Trypanosome cAMP signaling is therefore an attractive target for transmission-blocking agents, however, very little is known about regulation of AC activity and downstream targets of cAMP signaling. This proposal brings together a multidisciplinary team of investigators with collective expertise in trypanosome biology, cAMP signaling, transcriptomics, and genetic manipulation of parasites, as well as tsetse biology, fly infections, and interactions between parasite, vector, and microbiome. Our specific aims are to (1) identify endogenous, tsetse fly-derived modulators of T. brucei chemotaxis; (2) define parasite cAMP effector genes responsible for parasite migration from the tsetse midgut to proventriculus; and (3) define parasite receptors that perceive chemotactic signals in the fly. We will leverage our established chemotaxis assay to test tsetse-derived factors for impacts on parasite chemotaxis (Aim 1). To define genes required for MG ➔ PV migration in the tsetse, we will employ a MG ➔ PV defective trypanosome mutant to identify MG-induced, cAMP-dependent transcriptome changes associated with movement out of the MG (Aim 2). Finally, we will implement systems for genetic manipulation of fly-transmissible T. brucei to allow functional assessment of trypanosome receptors and additional cAMP signaling genes during tsetse infection (Aim 3). Completing these aims will increase understanding of parasite-vector interactions, provide new avenues for targeting the pathogen within the arthropod vector, and identify promising targets to consider for transmission-blocking vaccines or small molecule inhibition.

NIH Research Projects · FY 2025 · 2024-05

The period following release from incarceration is associated with increased risk for HIV and STI acquisition and transmission and fatal drug overdose. Implementation of effective programs for linkage to pre-exposure prophylaxis (PrEP) for HIV, screening for HIV/STIs/ hepatitis C virus (HCV), and rapid SUD treatment and harm-reduction services in reentry populations is needed to counteract these harms. Scale up of such programs may help to address racial/ethnic differences in these outcomes given the overrepresentation of Black and Latino people, men who have sex with men, and people who inject drugs in jails and prisons. The proposed research Hub will study the implementation of a demonstrated-effective, 6-month intervention designed to increase PrEP use and HIV/STI/HCV testing following reentry, in three high-priority California counties. The Mobile Enhanced Prevention Support or MEPS intervention combines evidence-based strategies, including Peer Mentors, cash incentives, and a mobile application for facilitating access, goal tracking, and receipt of incentives. In the first (R61) phase of the project, we will adapt the MEPS implementation to practical realities of new agencies in new areas. In the second (R33) phase, we will conduct a Type 3 Hybrid Implementation-Effectiveness study using a randomized controlled trial to evaluate the adapted MEPS intervention in Riverside and Alameda counties. Our academic-community partnership will also provide infrastructure for robust stakeholder engagement and support of pilot studies related to prevention during reentry. Our Study Aims are to: 1) Pilot the following aspects of the MEPS trial in one county: participant recruitment and enrollment; baseline needs assessment and client-centered planning sessions; retention and follow-up assessments; specimen collection for PrEP adherence monitoring; and peer mentor identification and training for the full intervention. 2a). Formalize partnerships with community agencies in each county and plans and adaptations for implementation of MEPS and the trial in their sites. 2b). Develop a set of common core measures with community and justice system partners and other components of the NIDA HIV/Justice Research Network. 3) Conduct a Type 3 Hybrid Effectiveness Trial, implementing the adapted MEPS intervention with the three agencies, with 300 participants. Use the RE-AIM framework and Proctor’s Implementation Science outcomes with a subset of participants, agency staff, and stakeholders to examine MEPS’ implementation and randomized design to assess intervention effectiveness for increasing PrEP uptake and adherence (via self-report and biomarkers), HIV testing, and SUD service utilization. 4) Create and deploy a website as a Community Commons, with integrated research and communications utilities designed to meet the study coordination, community engagement, and implementation needs of Hub partners in Aims 1-3; disseminate findings related to MEPS intervention scale-up and other Hub activities, (e.g., pilot studies); and support the sustainability and breadth of intervention adoption and knowledge production.

NIH Research Projects · FY 2025 · 2024-05

ABSTRACT Approximately 2 in 10 American adolescents have experienced major depression in their lifespan, and 3 in 10 have experienced an anxiety disorder. Despite the clear

NIH Research Projects · FY 2026 · 2024-05

PROJECT SUMMARY/ABSTRACT This U01-supported clinical trial will test a unique T follicular helper (Tfh)-targeting vaccine approach, “s3”, that we predict will generate exceptionally broad and long-lived antigen-specific antibody responses, characteristics likely to result in resilient vaccines that maintain protection over long periods. The “s3” adjuvant moiety is an anti- CD3 antibody fragment (scFv) that safely induces a potent Tfh and B-cell response to an immunogen to which it is fused. The combined immunogen simultaneously targets immunogen-specific B cells and local Tfh cells, thus accelerating and expanding B-cell development. Using the RBD immunogen in a low dose Ad35 vector, we showed in macaques that s3 safely stimulates high NAb titers that are stable for >10 months. The major deficiencies of current SARS-COV-2 and other vaccines (such as influenza) are limited durability and breadth of protection, even with booster vaccination. Over the course of 6 months, serum antibodies in COVID- naïve vaccine recipients decline by one order of magnitude. Booster vaccination confers greater durability but notable declines in serum NAb titers occur by 4-6 months. Limited mucosal IgA responses is another major deficit that may underlie failure of current vaccine options to prevent acquisition at the site of virus entry. Finally, the breadth of responses is limited, even with bivalent vaccines. These vaccine deficiencies have been linked repeatedly to inadequate T-cell help. Thus, new approaches that provide abundant T-cell help, such as the proposed s3 approach, are needed to deliver more effective SARS-CoV-2 as well as pancoronavirus, influenza, and other vaccines. We will test the safety and immunogenicity of the s3 adjuvant using Ad35 as the vector and the SARS-CoV-2 BA.5 receptor-binding domain (RBD) as the immunogen. We will compare a vaccine with s3 (CoTend-s3B) against one lacking s3 (CoTend-B). The vaccines will be given as a “booster” vaccine on the background of prior SARS-CoV-2 spike mRNA vaccination. This approach will allow us to evaluate the ability of CoTend-s3B to (i) boost pre-existing antibodies and (ii) recruit new naïve B cells with new specificity for BA.5 RBD. Aim 1. Test safety of s3-adjuvanted/Tfh-targeted (CoTend-s3B) and unadjuvanted (CoTend-B) SARS- CoV-2 RBD vaccines. The primary safety readouts are local and systemic reactions, grade 3+ adverse events (AEs), serious adverse events, AEs of special interest (including thrombotic events), and anti-PF4 antibodies. Aim 2. Evaluate intensity, breadth, and durability of adaptive immune responses to CoTend-s3B compared to CoTend-B in blood and saliva. We hypothesize that Tfh responses to CoTend-s3B will support NAb responses of sufficient breadth and potency for long-lived protection against SARS-CoV-2 variants. Aim 3. Examine the mechanisms of s3 adjuvant activity in germinal centers. Tfh targeting via s3 is predicted to generate robust germinal-center reactions that democratize recruitment of naïve B cells and spur development of long-lived plasma cells.

NIH Research Projects · FY 2026 · 2024-05

PROJECT SUMMARY/ABSTRACT Adolescents and young adults with mental, behavioral, or developmental disorders (MBDD) experience a peak in risk for poor access to care and adverse mental health outcomes, including suicidality, during the transition from pediatric- to adult-focused care. Despite the clear public health importance of this topic, little research exists regarding how health care transition is associated with high care quality and improved mental health outcomes, a deeper understanding of the scope of disparities in transition and downstream outcomes, and evidence toward the potential role of health policy for improving access to timely health care transition in the United States. This project proposes to provide new evidence using a novel dataset that links restricted use, national data on health care utilization and mental health outcomes, and will be unprecedented both in terms of its coverage and scope. Using this new dataset, we will examine the potential role for state and federal mental health policy in affecting access to health care transition in terms of occurrence, timing, and gaps (Aim 1) using quasi-experimental techniques that take advantage of the staggered implementation of mental health parity laws across states over time and the resulting variation in exposure to these policies. This will be the first evaluation of these policies' impact on health care transition. We will examine the impact of health care transition on receipt of high quality care for the treatment of specific MBDD (e.g., depression), and evaluate the extent to which socioeconomic factors moderate this association, potentially exacerbating disparities (Aim 2). Finally, we will use latent class analysis to ascertain mental health outcome patterns and subsequently identify if and to what extent health care transition is associated with these outcome patterns (e.g., whether later age at transition is associated with worsening mental health); further we also evaluate the extent to which socioeconomic factors moderate this association (Aim 3). For Aims 1 and 3, we will obtain estimates for the overall population with MBDD and for disease subtypes (e.g., depression). The scope and size of our dataset will allow us to generate precise estimates across these subgroups and will provide important new information on when and how to intervene to equitably improve mental health outcomes across this critical stage in the life-course. The analyses proposed under this study will generate new and actionable information for policymakers aiming to better understand and mitigate the impacts of inequalities across the transition from adolescence into adulthood.

NIH Research Projects · FY 2026 · 2024-05

Project Summary In biology, structure determines function. To understand the function of organs (i.e., physiology), we must obtain structural information on the organs’ structure (i.e., anatomy). Mapping organs’ structures must occur at (sub)cellular spatial resolution with sufficient details on cells’ molecular states. Spatial transcriptomics technologies have made significant advances in mapping thin tissue sections. However, all spatial transcriptomics approaches are restricted to sections thinner than 150 µm, with the vast majority needing to be less than 15 µm. While 2D sections are informative, sampling 3D organs with 2D sections loses information and provides a partial view of the organs’ full structure. Here we propose to develop whole organ spatial transcriptomics. Key to our approach is our recent invention (patent pending) of dimensionality reduced Fluorescent In Situ Hybridization (dredFISH). Single-molecule FISH approaches, such as smFISH, MERFISH, seqFISH+, and many other variants, label and count individual RNAs. dredFISH is not a single molecule FISH. Instead, it is designed to directly measure an approximation of cells’ transcriptional state by measuring multiple distinct weighted sums of thousands of genes. The transcriptional signatures represented by the distinct sums of genes are generated for the reference scRNAseq and compared to the ones directly measured by dredFISH. Integrating and harmonizing the directly measured FISH signatures and the reference data allows the inference of cell types (kNN classification) and gene expression reconstruction (kNN regression). By leapfrogging the need for individual gene measurements, dredFISH achieves multiple features that make it ideal for fast light-sheet microscopy of thick samples (500 µm). Specifically, i) dredFISH is performed using low magnification objectives (10x, 16x) instead of high magnification objectives (60x,100x) used for single-molecule FISH. ii) dredFISH utilizes the tissue clearing and hydrogel embedding technique used by CLARITY, making it compatible with existing light-sheet imaging protocols. iii) dredFISH signal comes from the weighted sums of fluorescence from tens of thousands of RNA molecules per cell, each stained by tens of probes, making it much brighter and easier to measure than all other FISH approaches. Our preliminary results demonstrate that dredFISH works well in thin 2D sections validating our approach. The goal of this proposal is to extend dredFISH from 2D to 3D to allow whole organ spatial transcriptomics. This goal will be accomplished by parallel development steps divided into two aims. Aim #1 will continue optimizing and validating dredFISH in 2D by changing a few aspects of the method that will ease the transition to 3D. Aim #2 will update the staining and imaging steps in the dredFISH protocol to make them compatible with thick samples. Aim #3 will demonstrate the power of dredFISH whole organ spatial transcriptomics by creating the entire mouse brain's cell type and gene expression atlases. By completing these aims, we will deliver new capabilities: whole organ spatial transcriptomics that will have transformative effects on numerous biomedical disciplines.

NIH Research Projects · FY 2025 · 2024-05

PROJECT SUMMARY/ABSTRACT Prostate cancer is the second-most diagnosed cancer and the second leading cause of cancer death in American men. Early detection of localized disease is common but is followed by the more challenging task of prognosing a highly variable clinical course. Localized tumors are often indolent, but not always. Current clinical risk- assessment schemes incorporating serum abundance of prostate specific antigen (PSA), tumor size & extent, and tumor grade based on biopsy are limited in accuracy; over a quarter of patients are over-treated. The goal of this proposal is to fill the urgent need for better markers discriminating indolent from aggressive localized prostate cancers. An improved method of risk stratification may lie in hereditary factors. Prostate cancer is one of the most strongly inherited (h2 = 57%), with accumulating evidence associating rare variants, common variants and genetic ancestry with clinical outcomes. The overall hypothesis of this proposal is that variant status of DNA damage repair (DDR) genes, prostate cancer polygenic risk and genetic ancestry will improve clinical risk stratification of prostate cancer. To address this hypothesis, the aims of this proposal focus on two clinical outcomes representing key decision points in the management of the disease. Specifically, the aims are to investigate the biomarker potential of the described germline factors to predict (1) progression from active surveillance of a patient, informing whether they should defer treatment, and (2) biochemical relapse after therapy of a patient, informing the most appropriate treatment course. For both aims, germline DNA samples from a cohort of patients diagnosed with localized prostate cancer and with extensive clinical follow-up data will be sequenced using a targeted sequencing approach. A bespoke bioinformatics workflow will be used to derive germline genomic endpoints: pathogenic and likely pathogenic DDR variants, genomic risk score and genetic ancestry. For each aim, exploratory univariate and multivariate analyses will validate associations between genomic and clinical endpoints, and control for clinical prognostic features. Multivariate Cox proportional-hazards regression models will be trained, validated, and evaluated for predictive performance to establish the utility of germline genomic biomarkers in prostate cancer clinical risk stratification. The results of this proposal have the potential to transform standard-of-care management for this disease and thus substantially contribute to enhancing human health and quality of life.

NIH Research Projects · FY 2025 · 2024-05

PROJECT SUMMARY/ABSTRACT Over 43M Americans (~13% of the population) will suffer from social anxiety disorder in their lifetime (Kessler et al., 2012) – 20M of which will have fear of public speaking (Kessler et al., 1998). Cognitive-behavioral therapy (a major component of which is exposure therapy) is a leading treatment for social anxiety disorder but is only fully effective in ~45% of individuals (Loerinc, et al., 2015). Exposure therapy is the clinical proxy of Pavlovian extinction in which the individual approaches their feared situation (e.g., social situation) without the expected aversive outcome (e.g., negative social judgment). Several basic research findings show that stronger reward processing is linked to better extinction of fear, suggesting that enhancing reward processing can improve exposure therapy. First, reward processing is involved in extinction learning at the time of omission of an expected aversive outcome, such that the omission is experienced as “relief-pleasantness” as measured by self- report and by neural mechanisms of reward processing (e.g., Lange, et al., 2020). Second, direct stimulation of the reward circuitry has been shown to enhance extinction of fear (Sierra, et al., 2023). Third, low self-reported reward processing is associated with low relief-pleasantness (Leng, et al., 2022). Fourth, social anxiety disorder is associated with poor reward processing (Cremers, et al., 2015). Lastly, anhedonia – a robust correlate of poor reward processing and social anxiety – is associated with poor extinction of fear (Young, et al., 2021). Thus, enhancing reward processing may be especially likely to improve exposure therapy outcomes in social anxiety disorder (Aim 1) by increasing relief-pleasantness when an expected aversive event does not occur (Aim 2). In this K23, we will conduct the first experimental therapeutics study investigating the effects of target engagement (reward processing) on subsequent exposure therapy outcome (social anxiety; specifically, fear of public speaking). To this end, socially anxious participants with a fear of public speaking and low reward processing will undergo the behavioral portion of Positive Affect Treatment (PAT-B) or Relaxation Treatment; both treatments are expected to decrease negative affect, but PAT-B is expected to improve reward processing more than Relaxation Treatment (Craske et al., 2023). Subsequently, all participants will undergo Exposure Therapy for fear of public speaking with the primary outcome being multi-modal assessment of public speaking anxiety. For experimental therapeutics, the target is reward processing, which we will measure primarily as relief- pleasantness in fMRI fear conditioning during extinction at the time of electric shock omission (measured neurally and with computational modeling of self-report relief-pleasantness). The training plan will help the Candidate gain expertise in experimental therapeutics, fMRI, and computational modeling in the service of his career goal: to improve our understanding and treatment of anxiety disorders. This K23 may improve the efficacy of exposure therapy, our understanding of its mechanisms, and help millions of people with social anxiety disorder.

NIH Research Projects · FY 2026 · 2024-05

Project Summary My lab develops and applies statistical models to make sense of genomic and biomedical data with the ultimate goal of understanding the biological basis of diseases and improving human health. The dramatic decrease in the cost of DNA sequencing has led to the emergence of datasets of genetic variation across large numbers of individuals (sample sizes upwards of hundreds of thousands). This genetic data is paired with deep phenotypic and disease information. While o ering the potential to answer important questions in biology and medicine, these complex and massive datasets present formidable challenges of statistical modeling and inference. Extracting meaningful insights from these datasets needs expressive and scalable statistical and computational methods. Our recent work has focused on understanding evolutionary processes that shape genetic variation within homogeneous and admixed populations and in understanding how genetic variation modulates variation in complex traits and disease risk. A major discovery from our work is our nding that west African populations derive substantial genetic ancestry from an unidenti ed ghost archaic population that was enabled, in turn, by new statistical methods that we developed to infer local ancestry in admixed populations in the challenging setting where reference genomes for ancestral populations are unavailable. Work from my lab has also led to statistical inference algorithms that are capable of analyzing millions of genomes to provide new insights into both evolutionary processes and genetic architecture of complex traits. We now propose to substantively expand our research applying statistical machine learning to population and quantitative genetics with the aim of understanding the interplay between evolution, genes and traits. We will develop algorithms to uncover complex evolutionary histories from genome sequence data in the presence of admixture, expressive and scalable models to infer the genetic architecture of complex traits within homogeneous and admixed populations, and methods for deep learning-based phenotype imputation that deal with the high- rates of missingness in biomedical datasets. Taken together, our e orts will provide powerful analytical tools to e ectively probe the structure and function of the human genome.

NIH Research Projects · FY 2026 · 2024-05

PROJECT SUMMARY Breast cancer is the most common cancer in younger women (≤ 50 years at time of diagnosis), who comprise approximately 19% of incident breast cancer cases. Improved survival after a breast cancer diagnosis has focused attention on the impact of the disease and its treatments on long-term outcomes in younger women. Studies have consistently shown that younger women have greater psychological and physical morbidity after breast cancer than older women and age-matched women with no cancer history, including elevated levels of depression. Depression has been linked to treatment non-adherence and predicts shorter recurrence-free and overall survival in women with breast cancer, highlighting its clinical relevance. Younger breast cancer survivors also report high levels of fatigue, insomnia, vasomotor symptoms, and cancer-related stress that may persist for years after diagnosis, causing significant impairment in quality of life. There is a critical need for effective, scalable interventions that can reduce depression and enhance long-term survivorship in this vulnerable group. To meet this need, we will conduct a phase III randomized clinical trial testing two new digital versions of a brief mindfulness intervention designed for younger breast cancer survivors. This study concept has been peer- reviewed and endorsed by the National Cancer Institute (NCI) and the NRG Oncology National Community Oncology Research Program (NCORP) which will implement the study protocol through its network of community and clinical sites, ensuring a broad and diverse group of participants. The Mindful Awareness Practices (MAPs) intervention has demonstrated efficacy in reducing depression and improving physical and psychological well- being in younger breast cancer survivors when delivered in person, in groups. We have developed and pilot tested two digital versions of the intervention, one delivered live online in groups over Zoom with an experienced instructor (MAPs live online), and the other delivered via a professionally-produced app (MAPs App). We hypothesize that both digital interventions will be effective in reducing depressive symptoms (primary outcome) and improving physical and psychological symptoms and work productivity (secondary outcomes) at post- intervention and over a 6-month follow-up relative to a meditation only control group. In addition to testing efficacy, we will evaluate the cost-effectiveness of these programs, which is critical for payors to make coverage decisions, healthcare providers and employers to make adoption decisions, and patients to make participation decisions. We will also collect implementation data from study sites to inform future dissemination efforts. Finally, we will explore potential mediators and moderators of intervention effects to determine how these approaches work and for whom, which will facilitate targeted intervention delivery and content to those most likely to benefit.

NIH Research Projects · FY 2025 · 2024-05

ABSTRACT Animal models are the backbone of many areas of biomedical and preclinical research and the mouse is the most used model organism in human disease research. Understanding and characterizing mouse models is considered key to improving the reproducibility of preclinical results in human subjects. To this end it is important to use preclinical techniques that are analogous to modern clinical techniques to increase the success of results that translate well to clinical implementation. Unfortunately, the standardization of preclinical radiation therapy (RT) studies using clinically analogous methodologies has not yet been achieved. In the last few decades clinical RT technology has developed dramatically, with intensity modulated RT (IMRT) representing one of the most significant developments. However, these advancements have not translated to preclinical small animal RT, which largely resembles the state of clinical RT in the 1970s in terms of its use of simple circular/rectangular beam geometries and uniform beam intensities, and lack of high-quality 3D target dose conformality. Consequently, small animal RT studies do not simulate the radiobiological, radioimmunological, hypoxic and toxicity environment of human therapies. To fully standardize preclinical irradiators to clinically analogous methodologies it is necessary to fully implement IMRT. However, reverse translation of IMRT from a clinical to preclinical scale (1-2 orders of magnitude smaller) has been challenging due to technical limitations in engineering appropriately small multi-leaf collimators (MLC). Our group has recently developed a 3D printed compensator (3DPC) approach that provides a simple, reliable, and cost-effective solution in implementing mouse based IMRT. In terms of simplicity and cost- effectiveness, 3DPC-IMRT requires no additional specialized equipment besides an inexpensive commercially available 3D printer and printing material. Unlike MLC systems, 3DPC-IMRT has no segments/steps during delivery leading to shorter treatment times and no mechanical/electrical parts leading to high reliability, lower maintenance, and reduced QA efforts. Our central hypothesis is that we can develop 3DPC-IMRT into a high- throughput preclinically useful small animal IMRT system using AI assisted contouring, novel high speed dose calculation and optimization algorithms, and a mechanism that will allow rapid switching of compensators for different fields. We propose the following specific aims: (1) Design and development of 3D printed compensator IMRT (3DPC-IMRT), (2) Development of VMAT like 3DPC-IMRT and AI mouse segmentation methods, and (3) Dosimetric accuracy evaluation and pancreatic ductal adenocarcinoma (PDAC) mouse model study. The success of the proposed project will help radiation biology research better simulate the clinical RT environment and enable future studies where accurate complex dose distributions are critical.

NIH Research Projects · FY 2026 · 2024-05

PROJECT SUMMARY Some of the most important unanswered questions in health and aging relate to the influence of early life and intergenerational factors. But documenting the role of these factors is limited by the dearth of longitudinal, intergenerational microdata containing health information. Our broad research objective is to build an unparalleled public resource to study the longitudinal and intergenerational determinants of health and aging, containing unprecedented sample sizes for understudied populations such as minorities and women. We propose to enhance and expand the Longitudinal Intergenerational Family Electronic Micro- dataset (LIFE-M), which integrates millions of birth, marriage, and death records with decennial censuses over four generations from the late 19th to the 20th century. Our specific aims are to: (1) Expand LIFE-M's geographic coverage by linking vital records for seven additional states, so that the covered states represent 28% of the U.S. population in 1940, including 28% of both the Black and White populations. (2) Enhance LIFE-M by adding non-vital records, including (a) the Social Security Death Index and Numerical Identification Files, (b) the 1930 and 1950 Censuses, and (c) World War I draft and World War II enlistment records. (3) Enhance LIFE-M's health information by digitizing millions of causes of death for LIFE-M individuals. (4) Publicly disseminate the new data through Inter-University Consortium for Political and Social Research (ICPSR), along with variable descriptions, documentation, user guides, and trained machine-learning models. Data releases will also include variables to integrate LIFE-M with other historical data infrastructure. Expanding and enhancing the LIFE-M infrastructure will facilitate path-breaking research on the role of early-life conditions on longevity, aging, causes of death, and life-course transitions for family networks across four generations. It will also allow research to understand heterogeneity in these relationships across geographic space and the role of moderating and mediating forces, such as rapid industrialization and urbanization, the expansion of public health and hospital infrastructure and policy, economic collapse, and war. The proposed work addresses a core mission of the Population and Social Processes branch of NIA: expanding and enhancing LIFE-M data will advance fundamental knowledge about the causes and consequences of changes in social, demographic, economic, and health characteristics of the older population and will support research on the effects of public policies, social institutions, and environmental conditions on the health, well-being, and functioning of individuals over their life-course.

NIH Research Projects · FY 2026 · 2024-05

PROJECT SUMMARY The Gram-negative oral anaerobe Fusobacterium nucleatum is associated with oral and extraoral diseases due to its remarkable ability to escape host immunity and spread to extraoral sites, including placenta and colon, promoting preterm birth and colorectal cancer. How this pathobiont adapts to various metabolically changing environments enabling its virulence potential is not well understood. To overcome the well-known genetic intractability of F. nucleatum, we employed multidisciplinary approaches, combining reverse and forward genetics, advanced electron microscopy, biochemical methods, and rodent models of infection to investigate the molecular assembly on the cell surface of F. nucleatum, since surface proteins and structures are important in many cellular processes, including host cell adherence/invasion, motility, and nutrient transport. Subsequently, we uncovered tubular structures produced by biofilm cells and planktonic cells under stress. Cryo-EM tomography revealed that these nanostructures are grown out from the outer membrane mainly at the cell pole, hence named outer membrane tubules or OMTs. Mass spectrometry analysis of isolated OMTs revealed a large number of proteins predicted to be involved in transport, metabolism, host cell interactions, and stress response, with many hypothetical outer membrane proteins/lipoproteins. Critically, genetic disruption of OMT-associated proteins identified two mutants defective in OMT formation, ∆omtA and ∆omtB. Informed by structural studies of OmtA and OmtB, we propose here to elucidate the mechanism of OmtA-mediated OMT biogenesis, examine the role of OmtB and its biochemically and genetically linked factors in OMT biogenesis and fusobacterial metabolism, and examine the role of OMT formation in the pathophysiology of F. nucleatum. The results generated from this study will not only provide insights into the pathophysiology of this oral pathobiont, as well as promising targets for therapeutic development, but also advance our knowledge of assembly mechanisms of membrane-derived appendages in other bacteria.

NIH Research Projects · FY 2026 · 2024-04

Project Summary/Abstract Abnormalities in feeding behaviors are a key symptom of several conditions, including binge-eating disorder, anorexia and obesity. In order to develop novel treatments, it is imperative to gain a deeper understanding of the circuits controlling adaptive feeding. Eating is affected by metabolic and hedonic features, and it consists of several actions, including exploratory food-seeking and consumption. Despite its central clinical and biological importance, networks controlling these behaviors are not well-understood. Prior data have indicated that activation of several GABAergic inputs to the midbrain lateral and ventrolateral periaqueductal gray (l/vlPAG) elicit hunting of insects in mice. However, the role of local l/vlPAG GABAergic cells in feeding is unknown. Intriguingly, our preliminary data show that these cells encode food-seeking actions, such as approach to food and consumption. Furthermore, activity in these ensembles, or of their projections to the subthalamic zona incerta (ZI) are required for foraging leading to consumption of both prey and non-prey food. Here, we propose to combine converging advances in neural activity recording, computational methods and molecular circuit dissection tools to: 1. Characterize how l/vlPAG VGAT cells encode food sources and food-seeking behaviors by recording the neural activity of large ensembles of cells with miniaturized microscopes. 2. Determine if activity in the l/vlPAG circuit and their projection to the ZI is necessary and sufficient to promote foraging leading to consumption, and 3. Dissect how the l/vlPAG input affects the ZI by combining ex vivo and in vivo recordings of neural activity. Since prior reports show ZI activation induces feeding, we hypothesize that activation of the inhibitory l/vlPAG input to ZI elicits feeding by disinhibiting the ZI. Importantly, feasibility for all proposed aims is demonstrated in preliminary data and our prior publications, and we have successfully collaborated with all participating key personnel. Taken together, execution of these aims will establish the function of a novel bottom- up midbrain-subthalamic pathway that is vital for food-seeking actions, having direct implications for understanding feeding mechanisms.

NIH Research Projects · FY 2025 · 2024-04

PROJECT SUMMARY/ ABSTRACT Type 2 diabetes mellitus (T2DM) patients make up 90-95% of all diagnosed diabetes mellitus and show serious cognitive and mood deficits that are associated with increased morbidity and mortality, poor self-care, and decreased life quality. These deficits are linked to brain tissue changes, potentially resulting from impaired blood brain barrier (BBB) function. However, it is unclear whether BBB function can be repaired in T2DM adults, reducing impaired cognition and mood functions and early risks of dementia and Alzheimer’s disease. The BBB restricts diffusion of microscopic objects (such as bacteria) and large (e.g., antibodies and many drugs) or hydrophilic molecules (e.g., salt) from crossing into brain tissue and protects from harmful substances. Although multiple methods, including positron emission tomography, single photon emission computed tomography, and contrast-based magnetic resonance imaging (MRI) can examine BBB function, they are either invasive or pose significant health risks on humans. Using non-invasive MRI based diffusion- weighted pseudo-continuous arterial spin labeling (DW-pCASL), BBB function status can be examined, which has been validated to examine BBB breakdown in pre-clinical and in pilot T2DM studies. Several pre-clinical studies suggest the possibility for BBB function repair, including low-cost thiamine intervention. Thiamine is an essential component for carbohydrate metabolism and adequate or higher levels promote aerobic metabolism. In addition, reduced thiamine levels are shown contributing to impaired endothelial cell functions, leading to BBB dysfunction, and higher doses improve endothelial functions. Although the majority of T2DM adults show thiamine deficiency that may contribute to impaired BBB function, but it is unclear if the thiamine treatment can improve BBB function. Therefore, using 52 T2DM adults with randomized clinical trial, the specific aims are to: 1) compare BBB function, using DW-pCASL, and blood serum BBB (S100β levels) biomarkers in T2DM adults with and without thiamine treatment and 2) examine cognition (Wide Range Assessment of Memory and Learning 2 and Montreal Cognitive Assessment) and mood (Beck Depression Inventory II and Beck Anxiety Inventory) between T2DM adults with thiamine treatment compared to T2DM adults without thiamine treatment. In summary, low-cost thiamine treatment will be performed to assess whether impaired BBB function and mood and cognition deficits are improved in T2DM adults. If successful, the information from this clinical trial might serve as a novel and innovative treatment strategy to repair BBB function, affecting less cognition and mood function, and hence better outcomes in T2DM adults. This R21 clinical trial study will provide required data regarding the benefits of a low-cost thiamine intervention that could be implemented on a large-scale clinical trial to repair BBB function, and thus, decrease early dementia and Alzheimer’s disease, reduce morbidity and mortality, and increase quality of life in T2DM adults.

NIH Research Projects · FY 2026 · 2024-04

Abstract In the last five years, we discovered a functional role for glycolytic metabolism in HFSC homeostasis. We found that lactate dehydrogenase (Ldh) activity is essential for HFSC activation, and that elevation of Ldh activity through blockade of pyruvate entry into mitochondria can promote HFSC activation. Left unknown from this work is why and how, specifically, HFSCs’ activation is subject to regulation by Ldh activity and/or pyruvate oxidation in the mitochondria. HFSCs are essential for new hair growth, contribute to wound healing, and are cancer cells of origin for squamous cell carcinoma. Therefore, understanding how metabolism can regulate cell fate in HFSCs has important implications. We have several hypotheses to explain how Ldh activity and/or mitochondrial pyruvate oxidation leads to HFSC activation. First, we have found that Ldh inhibition in tumors promotes glutamine anapleurosis, and it has been argued that glutaminolysis is important for HFSC maintenance, so perhaps elevated glutaminolysis prevents HFSC activation in Ldh-null stem cells. Second, lactate has been shown to act as a signaling molecule, sometimes referred to as a lactormone. Third, it is possible that instead of lactate, an alternate product of Ldh activity, L-2-hydroxyglutarate (L2HG), is the key metabolite promoting HFSC activation; L2HG can impact the activity of a diverse class of enzymes, some of which modulate epigenetic state and gene expression. Fourth, we have evidence to suggest that these same regulatory mechanisms are affecting the decision of HFSCs to initiate and drive tumorigenesis, so we will explore these hypotheses in an established cancer paradigm for squamous cell carcinoma.

NIH Research Projects · FY 2026 · 2024-04

PROJECT SUMMARY This proposal details a career training plan for Dr. Alexander Nguyen, a gastroenterologist and hepatologist at UCLA, to become an independent academic physician-scientist in the field of liver lipid metabolism. Dr. Nguyen received his M.D./Ph.D. degrees from the Weill Cornell/Rockefeller/Sloan-Kettering Tri-Institutional M.D.-Ph.D. program and completed Internal Medicine residency and Gastroenterology fellowship at UCLA. During his fellowship, Dr. Nguyen initiated mentored post-doctoral research advised by Dr. Peter Tontonoz at UCLA. Dr. Tontonoz is an internationally recognized expert in the control of gene expression by lipids and the role of nuclear hormone receptors in lipid metabolism. Dr. Tontonoz has served as mentor to numerous trainees, many of whom have become successful academic investigators. Under this award, Dr. Nguyen will be supported by Dr. Tontonoz as well as his co-mentor and advisory team whose scientific expertise and mentorship will facilitate his career development. Dr. Nguyen will have the resources and expertise available to allow for the development his own independent scientific career. Dr. Nguyen will have access to courses, seminars, and core facilities through UCLA School of Medicine and the UCLA Clinical and Translational Science Institute. The described research proposal seeks to reveal the role of a novel LXR target gene, a poorly characterized methyltransferase, in liver lipid homeostasis. Preliminary studies demonstrate that this gene functions to prevent lipid accumulation in the liver when mice are fed a lipid-rich diet. Aim 1 will focus on the molecular and physiologic transcription regulation of this gene. In Aim 2, the function of this gene in the liver and physiology will be determined. In Aim 3, the hypothesis that this gene suppresses the development of steatohepatitis will be tested. These studies will uncover a novel function of this gene in the regulation of cellular and systemic lipid homeostasis and implicate pathways through which non-alcoholic fatty liver disease (NAFLD) develops. Through this award, Dr. Nguyen will develop the training necessary to become an independent physician-scientist investigator.

NIH Research Projects · FY 2024 · 2024-04

Project Summary Cerebral microvascular disease (CMD) causes white matter injury and is a major contributor of the vascular contributions to cognitive impairment and dementia (VCID), including as the most common co-morbidity to clinical Alzheimer’s Disease. Chronic vascular risk factors such as obesity accelerate the progression of CMD by primarily damaging brain endothelial cells. Risk factor-induced changes in cerebral endothelial cells contribute to an increased risk of dementia. The molecular changes in cerebral endothelial cells caused by chronic cerebrovascular risk factors remain unknown yet are critical to designing therapies to prevent and repair ischemic white matter lesions thereby lessening the burden of VCID. We propose that a central mechanism of CMD progression is dysregulated signaling in brain endothelial cells damaged by chronic vascular risk factors. Using endothelial cell-specific transcriptional profiling, we show that chronic endothelial injury resulting from obesity results in abnormal vascular expression of an interleukin/chemokine signaling pathway. This molecular pathway results in dysregulated vascular-oligodendrocyte progenitor cell (OPC) signaling. OPCs are a critical progenitor cell population in brain white matter that respond to injury and are responsible for remyelination. Preliminary data demonstrate that chronically injured endothelial cells up-regulate IL-17 receptor b (IL-17Rb) and its effector chemokine CXCL5. Though many inflammatory pathways may play a role in brain ischemia, we show that this is the major inflammatory pathway that is active in endothelial cells injured by this chronic vascular risk factor. Critically, we further demonstrate that endothelial expression of CXCL5 results in the chemotaxis of OPCs to the vasculature, limiting their ability to remyelinate after a focal white matter ischemic lesion. Using gain and loss of function studies at the in vitro, in vivo, and functional levels after stroke, we will dissect the molecular pathways involved in dysregulated vascular-OPC signaling and identify a role for chemokine signaling in regulating white matter injury underlying VCID. Studies in Aim 1 will use an in vitro conditioned medium paradigm to identify the precise signaling mechanisms in endothelial cells that promote CXCL5 expression while identifying the necessary receptors on OPCs that regulate migration and differentiation. In Aim 2, we will broadly determine the role of chemokine receptor activation on the ability of OPCs to differentiate and remyelinate after stroke using CXCR2 knockout and small molecule antagonism. Finally, we will show in Aim 3 that blocking the expression of CXCL5 in white matter endothelia can reduce cognitive and motor impairment associated with focal white matter stroke by promoting remyelination within the peri-infarct tissue adjacent to stroke. Together, these studies establish new molecular mechanisms for the vascular regulation of remyelination as critical to the pathogenesis of CMD and establish a new therapeutic target for VCID.