Ut Southwestern Medical Center

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY Atrial Fibrillation (AF) is an arrhythmia characterized by the aberrant, unorganized initiation and propagation of electrical impulses across the atria. The most common serious arrhythmia, AF affected an estimated 33.5 million globally in 2010, with a lifetime risk of 1 in 3 individuals older than 55 years old. A greater understanding of the mechanisms of AF is required to design more effective treatment strategies. Genome-wide association studies have linked AF with over 143 genomic loci, including the transcription factor (TF) TBX5. In our previous study, we integrated single-nucleus RNA- and ATACsequencing (multiomics) of control and Tbx5 KO aCMs with TBX5 chromatin occupancy in aCMs to identify direct TBX5 targets that might contribute to AF. In the process, we uncovered a novel function for TBX5 in maintaining genomic accessibility at enhancer elements, through genomic recruitment of CHD4. Inactivating CHD4 resulted in spontaneous AF and increased AF vulnerability in mice, and downregulated genes enhanced by TBX5. This finding is links genomic organization and a novel gene-activating function of CHD4 to rhythm maintenance, although the mechanism underpinnings of CHD4-mediated gene activation remain elusive. To better understand gene expression changes central to AF, we performed multiomics on a second AF mouse model caused by Liver Kinase B1 (LKB1) inactivation in aCMs, a gene decreased in human AF patient aCMs, revealing 632 core atrial rhythm (AR) genes that are commonly downregulated in aCMs from both models. 61% of AR genes were adjacent to regions co-occupied by CHD4-TBX5, and include the Na+ channel SCN5A, regulators FGF12/13 and the gap junction channels Connexin 43 (GJA1) and Connexin 40 (GJA5). These data lead to our central hypothesis that CHD4 maintains rhythm homeostasis in healthy atria through co-activating enhancers bound by TBX5, promoting the expression of genes critical for normal aCM electrical function. To determine the mechanisms by which the CHD4-TBX5 complex promotes the atrial enhancer network, we will identify CHD4 interacting proteins required for its activator function, by examining proteins bound at genes differentially regulated by CHD4 in aCMs and ventricular CMs. Our preliminary data suggests that FGF12 overexpression is protective against AF in the Tbx5 atrial KO AF model. We will examine how FGF12 alters atrial composition and electrical function in the established mouse AF models. This proposal is significant because it will mechanistically characterize genes required for atrial function, determine how they are regulated, and test their potential as therapies in multiple models, laying the groundwork for the development of more effective treatment strategies.

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY/ABSTRACT Life is dependent on the fundamental process of cellular migration for fertility, proper embryonic development, and wound healing/regeneration. Developmental transitions during embryonic, fetal, and post-natal maturation in metazoans are tightly controlled via a subset of conserved pathways characterized as heterochronic gene regulators, which regulate the rate and timing of development. Many of the same genes required for embryonic morphogenesis are also required for normal adult stem cell regeneration and wound healing. The long-term goal of our lab is to understand how positive and negative developmental regulatory loops between RNA processing proteins (RPP) and their downstream RNAs (microRNA and mRNA) control wound-healing/regeneration/cell migration. Previous investigations of developmental timing in worms, flies, and frogs have mainly focused on state transitions of stem cells from proliferative to differentiated states or during metamorphosis. Little is understood regarding the combined spatiotemporal regulation of normal adult wound repair and regeneration particularly, in mammals. Synchronization of cell fate and cell migration in the early embryo is an example of where heterochronic genes are key to proper mammalian development via spatiotemporal regulation. Our central hypothesis is developmental pathways that regulate proper morphogenesis are similarly engaged during normal adult wound- repair/regeneration. We propose certain injury conditions, may challenge normal wound repair and regeneration via spatial and/or temporal dysregulation of developmental feedback loops leading to incomplete repair or fibrosis. The objective of this grant is to investigate heterochronic pathways that participate in RNA-directed feedback loops during wound-healing and regeneration. Investigation into how these same heterochronic pathways is conserved or altered during wound-repair and regeneration of will be done using 1) primary and immortalized normal human epithelial cells and 2) established mouse models fibrosis.

NIH Research Projects · FY 2025 · 2025-09

Project Summary Lymphedema occurs when a part of the lymphatic system fails to remove lymph fluid resulting in edema and impaired immune function. Lymphedema impacts more than 10 million individuals in the United States (US) and is frequently reported as a complication in cancer-related surgery, affecting up to 30% of breast cancer survivors, as well as patients treated for prostate, ovarian, head and neck cancers, and melanoma. Nevertheless, lymphedema remains incurable. Despite conservative treatments like compression therapy and physiotherapy, disease progression occurs, which reduces patient quality of life and increases healthcare costs. The current standard imaging for lymphedema diagnosis is lymphoscintigraphy (LSG). LSG (2D planar imaging) shows the distribution of counts detected by gamma cameras at two fixed angles (anterior/posterior positions). LSG is widely available, easy to perform, and has long been considered the gold standard owing to its high sensitivity for lymphedema diagnosis. Since advanced surgical treatments such as lymphatic venous anastomosis are emerging, enhancing LSG is essential to guide lymphedema care and innovation. The primary limitation of 2D LSG is noise due to low photon counts. Lymphatic vessels are relatively small, lymph flow is generally much slower than blood flow, and gamma cameras capture only about 0.01% of emitted photons fromlymph fluid due to their low sensitivity. Consequently, LSG may require extended scan durations to collect sufficient photons, often resulting in noisy, low-quality images. In addition, attenuation correction (AC) is not available in 2D planar imaging, leaving LSG non- quantitative without calculating absolute activity concentrations (Bq/mL) at each voxel. Currently, visual assessment by physicians (qualitative analysis) remains the clinical standard for evaluating lymphedema. Therefore, to address the unmet needs of classical 2D LSG, we will develop a denoising solution (Aim 1) and quantitative imaging and analysis tools (Aim 2). In Aim 1, we will develop a deep learning (DL)-based denoising solution for LSG. A clinical dataset will be created by prospectively acquiring 150 studies as well as recruiting 10 subjects undergoing lymphatic venous anastomosis (Task 1.1). To address clinical data diversity, an anthropomorphic digital phantom dataset (1,000 subjects) will be created using the XCAT phantom that includes organs, muscles, bones, soft tissues, and a scalable lymphatic system (Task 1.2). Using these datasets, two state-of-the-art networks for PET denoising will be adapted for LSG denoising (Task 1.3). In Aim 2, we will develop DL-based attenuation correction (DL-AC) methods for quantitative LSG (qLSG) and establish quantitative analysis metrics for objective evaluation. For qLSG, a convolutional neural network (CNN) will be trained to translate CT scout images (2D topograms) to 2D μ-maps for AC in LSG (scout-2-μ-map translation). In addition, a direct DL-AC model will be developed to translate 2D anterior/posterior planar images (input) to 2D true activity maps (output) (NC-2-AC translation) (Task 2.1). We will develop quantitative imaging biomarkers using qLSG and evaluate their correlation with visual assessment by physicians (Task 2.2). The proposed project will enhance LSG by developing quantitative imaging and analysis tools readily translatable to clinical practice, which will improve care for patients with lymphedema in various clinics across the Plastic Surgery Department, the Lymphedema Center, and Children’s Medical Center.

NIH Research Projects · FY 2025 · 2025-09

Project Summary/Abstract Psoriasis is highly linked to cardiovascular disease (CVD), including myocardial infarction (MI), heart failure and CV mortality. An increased prevalence of CV risk factors in these patients only partially accounts for this enhanced clinical risk. Although systemic inflammation is thought to be a key mediator of the onset and progression of these cardiometabolic abnormalities, the excess CV risk conferred by psoriatic disease remains understudied. We will use novel multi-modality cardiac imaging to quantify abnormalities in vascular health, and cardiac structure and function and assess the association with cellular immunophenotype. The central hypothesis of this study is that reducing inflammation with tildrakizumab, an FDA approved therapy for psoriasis that inhibits the IL-23 and Th17 pathway of inflammation, will quantitatively improve myocardial blood flow and coronary flow reserve (CFR) as measured by positron emission tomography (PET) over 6 months in patients with moderate-severe psoriasis disease and enhanced CV risk. In so doing, improvement in coronary vasoreactivity, endothelial function, and tissue perfusion may have beneficial effects on myocardial mechanics, and ultimately, symptoms and prognosis. We propose to use two state-of-the-art techniques, quantitative perfusion PET imaging and cellular immunophenotyping by single cell analysis [single cell RNA-seq, cellular indexing of transcriptomes and epitopes (CITE)-seq] of peripheral blood mononuclear cells, combined with echocardiography. In Specific Aim 1, we will evaluate whether tildrakizumab therapy will (1) improve coronary vascular function based on CFR, (2) improve myocardial mechanics, and (3) whether this functional improvement will be correlated with the change in CFR after 6 months of treatment. In Specific Aim 2, we will evaluate the relationship between cellular immunophenotype and coronary vasomotor dysfunction and myocardial mechanics, at baseline and after therapy with tildrakizumab for 6 months. The overarching goal of this proposal is to use physiologic imaging techniques already available as part of routine clinical care, and novel cellular immunophenotyping to investigate mechanisms linking psoriatic disease and inflammation to coronary vascular health and cardiac structure and function. This study will address an unmet and needed clinical translation in psoriatic disease. This research will be accomplished in the setting of a comprehensive career development program designed to provide the candidate, an early career investigator with training in CV medicine and CV imaging, with the skills needed to become an independent physician-scientist in CV medicine. Her long-term career goal is to be an independent scientific investigator, integrating immunology with cardiovascular imaging to better define the role of systemic inflammation in cardiovascular pathophysiology, and ultimately inform future therapeutic trials. An outstanding mentoring team and advisory committee of established scientists in the fields of CV medicine, CV imaging, Rheumatology, Dermatology, Immunology, and cellular biology will guide the candidate in her transition to scientific independence over the course of the award period.

NIH Research Projects · FY 2025 · 2025-09

Project Summary Chronic liver diseases are common in the human population, including non-alcoholic fatty liver disease and liver failure. These conditions are inherited or acquired due to a number of potential etiologies and can progress to fibrosis, cirrhosis and hepatocellular carcinoma. Therapeutic strategies to limit the incidence and progression of liver disease would be broadly applicable to affected individuals. A common observance in humans and animal models with liver disease is accumulating mitochondrial electron transport chain (ETC) dysfunction, which contributes to disease progression and pathophysiology. Our long-term objective is to identify therapeutic opportunities which promote mitochondrial health in the mammalian liver. Our preliminary data indicate that there are selective processes in animals and humans in vivo which promote the expansion and proliferation of hepatocytes with functional mitochondria, centering around acetyl-CoA production and protection from hepatotoxic challenges. Understanding the biology underlying this processes may provide an opportunity to promote mitochondrial health in the liver. In Aim 1, we will examine the regulation of ETC health in the liver under homeostatic conditions, making use of a collection of conditional knockout alleles in mice which target each component of the mitochondrial ETC. In Aim 2, we will investigate how ETC health is regulated in non-alcoholic fatty liver disease. In Aim 3, we will examine regulation of ETC health following hepatotoxin challenges. In each aim, we will examine the underlying mechanisms as they relate to acetyl-CoA production, which we have found to be a key metabolite regulating proliferation and survival of hepatocytes. Together, these objectives will investigate mechanisms underlying the regulation of mitochondrial health in the mammalian liver in multiple physiologic scenarios, and inform on therapeutic strategies to augment these mechanisms and prevent progression of liver disease.

NIH Research Projects · FY 2025 · 2025-09

Abstract DNA can adopt different conformations besides the typical B-form. One such alternative DNA structure is Z-DNA which is characterized by unusual biophysical properties. Z-DNA is left handed, does not wrap the histone octamer efficiently, and has two minor grooves. The Z-alpha domain, first discovered in ADAR1, specially binds to the Z-DNA backbone in a sequence-independent manner. Although Z-DNA in the cytoplasm and Z-RNA have both described roles in innate immunity, it is unclear what the function of nuclear Z-DNA might be. To map Z-DNA in vivo, we used the Z-alpha ChIP-seq assay that captures regions of Z-DNA in vivo. We found that Z- DNA is highly enriched at sites of RNA polymerase III. We suspected that a subunit of RNA pol-III might recognize and induce Z-DNA formation. Indeed, POLR3F has cryptic structural homology to the Z-alpha domain and POLR3F binds to 79% of all Z-DNA sites. Depletion of POLR3F shows that POLR3F is required for Z-DNA formation at tRNA genes. POLR3F depletion also induces expression of nearby RNA polymerase II genes indicating that tRNA transcription can interfere with neighboring gene expression. In this proposal, we will test whether POLR3F has direct Z-DNA binding capacity using biochemical in vitro assays. Next, we will test through separation of function mutants whether Z-DNA affinity of POLR3F is required for Z-DNA formation and tRNA transcription by RNA pol-III. We will also evaluate the effect of RNA pol-III transcription on other genes genome wide, as well as its effect on herpes virus transcription. Since missense mutations in POLR3F are found in patients with innate immune defects, we will determine the impact of patient mutations on POLR3F Z-DNA binding ability and function. Our integrated proposal will define physiological roles for Z-DNA in transcriptional regulation using targeted studies of a previously unrecognized Z-DNA binding protein, POLR3F.

NIH Research Projects · FY 2025 · 2025-09

Project Summary Clubfoot deformity is the most common musculoskeletal birth defect (1-4 in every 1,000 live births) in which a baby's foot turns inward so severely that the bottom of the foot faces sideways or even upward, leading to lifelong pain and seriously limited activity. While clubfoot clinicians, including those on our team, have noted the increased force exerted by medial muscles likely due to aberrant neural development, little work has been done to elucidate this neural-tendon interaction. To offload the aberrant force caused by clubfoot deformity, 90% of kids require surgical cutting of the Achilles tendon shortly after birth followed by 2 years of splinting to further decrease mechanical strain on the foot. Despite these interventions, over 30% of kids develop recurrent clubfoot deformity leading to arthritis and pain requiring further surgical interventions. Post-tenotomy recurrence is the most common and most debilitating complication in kids with clubfoot deformity and no prevention or therapeutic strategies exist. Recent studies from our teams have uncovered an increase in PIEZO2 and TAZ signaling in clubfoot patients who suffer from recurrence. These observations have led to our central hypothesis that excessive PIEZO2 signaling activates aberrant TAZ signaling causing post-tenotomy recurrence seen in clubfoot patients and that FDA approved therapies and dietary modifications inhibiting PIEZO and TAZ signaling will mitigate post-tenotomy recurrence and enhance extremity function in kids treated for clubfoot deformity. Aim 1: Define the role of PIEZO2 as a critical upstream regulator of TAZ signaling in controlling post- tenotomy clubfoot recurrence in pediatric clubfoot patients and in a clinically relevant mouse model. We will map the neuro-tendon interactions in human pediatric clubfoot patients who developed post-tenotomy recurrence using scRNA seq and histologic analyses. Additionally, we will perform an Achilles tenotomy in our mouse clubfoot deformity model (PvalbCre;R26TdTom;Piezo2E2799del/wt) with a therapeutic TAZ inhibitor to mimic care of clubfoot patients. Our hypotheses are; 1) pathologic overexpression of PIEZO2 mediates TAZ signaling in clubfoot patients who suffer from post-tenotomy repair recurrence and that; 2) human and mouse nerve/tendon multi-tissue seq will map the neuro-tendon interactome and predict mechanisms for future study. Aim 2: Modulate mechanosensory signaling to mitigate post-tenotomy recurrence using FDA-approved therapies and dietary modifications in a clinically relevant mouse clubfoot model. Our Aim 2 hypothesis is that pharmacologic or dietary mechanosensory and PIEZO inhibition will prevent post-tenotomy recurrence in a mouse model of clubfoot deformity. To prevent post-tenotomy recurrence, we will target mechanosensory nerves (Botox) and PIEZO signaling pharmacologically (GsMTx4) as well as using a dietary supplement (w-3 poly-unsaturated fatty acid eicosapentaenoic acid; EPA).

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY Virtually exclusive to individuals of African ancestry, the valine-to-isoleucine substitution at position 122 (V122I) variant in the transthyretin (TTR) protein is the most common cause of hereditary cardiac amyloidosis (ATTR- CA) worldwide. ATTR-CA causes progressive heart failure (HF) and has no proven benefit from standard HF treatments. Fortunately, new therapies that stabilize TTR improve morbidity and mortality in ATTR-CA, especially when prescribed early in the disease. However, early diagnosis is uncommon and conventional diagnostic tools lack diagnostic specificity to detect early disease. As such, a screening technique that directly assesses amyloid infiltration, without the need for cardiac biopsy, in V122I TTR carriers is a major unmet need. Thus, the objectives of this proposal are to determine the presence of amyloid in the blood by measuring circulating TTR amyloid aggregates (TAAs) and the presence of early cardiac amyloid infiltration with iodine-124 evuzamitide (I-124E) positron emission tomography (PET) imaging. The central hypothesis of this proposal is that V122I TTR carriers will have detectable blood and imaging evidence of ATTR-CA prior to disease onset. Two specific aims will test this hypothesis: Aim 1) determine the association of V122I TTR carrier status with circulating TAAs; Sub-aim 1.1) determine the association of TTR stabilizing therapy with circulating TAAs over time in patients with ATTR- CA; Sub-aim 1.2) Determine the association of circulating TTR amyloid aggregates with structural and functional evidence of amyloid infiltration and cardiac reserve; Aim 2) determine the association of V122I TTR carrier status with direct evidence of cardiac amyloid infiltration by I-124E; and Sub-aim 2.1) determine the association of circulating evidence of TTR amyloidosis with the amount of cardiac amyloid infiltration. All aims will leverage active investigation of a large cohort of V122I TTR carriers who have undergone deep clinical, imaging, and biomarker phenotyping (NCT05489549). In Aim 1, TAA levels will be measured and compared in a cohort of V122I TTR carriers without HF, non-carrier controls, and subjects with symptomatic ATTR-CA. Sub-aims 1.1 and 1.2 are substudies that will determine the longitudinal stability of TAA levels as well as their association with TTR-stabilizing treatment and evaluate the association of TAA levels with early pathophysiological evidence of cardiac amyloidosis by CMRI, respectively. In Aim 2, I-124E PET imaging will be used to measure and compare early cardiac amyloid infiltration in V122I TTR carriers, race-matched controls, and subjects with symptomatic ATTR-CA. Sub-aim 2 will evaluate the association of TAA levels with cardiac amyloid infiltration by I-124E PET. The research proposed is innovative, because it will, for the first time, employ two highly sensitive and specific techniques to detect and quantify amyloidosis in V122I TTR carriers: 1) detection of circulating TAAs by structure- based probes and 2) PET imaging with I-124E, a novel amyloid-binding peptide. Identifying amyloidosis prior to ATTR-CA disease onset will allow us to track the natural history of the disease and justify age-based screening strategies leading to reduced HF morbidity and mortality through earlier ATTR-CA recognition and treatment.

NIH Research Projects · FY 2025 · 2025-09

Summary T cells play a prominent role in the immunity against malignancies. However, T cell immunity declines with aging. Immunosenescence of T cells leads to terminal differentiation and impaired expansion after stimulation. The age-driven decline in T cell immunity compromises immune control over tumor cells. Many types of cancers such as chronic lymphocytic leukemia (CLL) occur much more frequently in the elderly. T cells in CLL patients show signs of accelerated aging, including reduced proliferative capacity, terminal differentiation, and exhaustion. Most CAR T cells are generated from autologous T cells from cancer patients. As a result of aging and exhaustion of T cells, manufacture and expansion of chimeric antigen receptor (CAR) T cells are more likely to fail in CLL patients. Thus, understanding the molecular mechanism of T dysfunction in natural aging and cancer is critical for boosting immunity and improving cancer treatment in the elderly. Metabolism plays a critical role in regulating T cell proliferation, differentiation and function. We found that aging dysregulates metabolism in CD8 T cells both before and after activation. In addition, our preliminary data showed that rebalancing TCR and cytokine signaling rescued the age-associated defect in expansion of CD8 T cells. However, how natural aging and CLL compromise metabolic adaptation in T cells upon TCR and cytokine signaling is unclear. Strategies to correct defective activation and metabolic adaptation associated with T cell aging remain elusive. Here, we hypothesize that metabolic adaptation to T cell activation is impaired by aging and CLL and can be corrected by rebalancing cytokine and TCR stimulation. We will use cutting-edge metabolism assay to determine the effect of natural aging and CLL on the metabolism of CD8 T cells after TCR and cytokine stimulation. We will also evaluate strategies to improve the generation, expansion, and antitumor immunity of CAR T cells generated from the elderly and CLL patients.

NIH Research Projects · FY 2025 · 2025-09

Okur-Chung Neurodevelopmental Syndrome (OCNDS) is a recently described (2016) rare neurodevelopmental disorder. OCNDS results in a spectrum of intellectual disability, developmental delay, and epilepsy. There are over 130 patients reported in the literature/online databases, and ~340 within the CSNK2A1 Foundation registry. There is no cure for OCNDS patients with treatment limited to anti-convulsant, speech, and physical therapies. OCNDS is caused by mutations in the CSNK2A1 gene, which encodes the alpha subunit of the casein kinase 2 (CK2) protein complex. CK2 is a ubiquitous kinase that phosphorylates hundreds of substrates and has implications for human viral infections, cancer, neurodevelopmental disorders, autoimmune disorders, cardiovascular diseases, and diabetes. Currently, CK2 function in neurons remains poorly understood and little is known about how patient variants, particularly missense variants, affect CK2 function. As such, there is a need to assemble scientists and clinicians from the fields of genetics, neurology, epilepsy, movement disorders, model development, and drug discovery to accelerate OCNDS research and therapeutic development. The 2025 OCNDS Joint Scientific and Family Conference will be held in Denver, Colorado on July 17-20. This meeting will be hosted by the CSNK2A1 Foundation, which is the only OCNDS-focused patient advocacy group. Experts in their respective fields will be brought together with families with affected children to synergize research efforts. Speakers and attendees will present data, discuss progress and setbacks, set research priorities, and refine the current roadmap to better understand disease mechanism and to develop treatments for OCNDS and related disorders. Trainees and junior faculty will be targeted for attendance and will be encouraged to submit abstracts for presentation and travel award consideration. Following dissemination of the 2025 conference results, we plan to continue an annual virtual format and an in-person meeting every 2-3 years to maintain collaborations between investigators and continue momentum forward in realizing transformative treatments for OCNDS.

NIH Research Projects · FY 2025 · 2025-09

Project Summary Nuclear export of mRNAs through the nuclear pore complex (NPC) is an obligatory pathway for eukaryotic gene expression, which is regulated by various cellular stress conditions such as viral infections and immune responses. During gene expression, the TREX (TRanscription and EXport) complex is recruited co- transcriptionally and pre-mRNA processing further mediates TREX assembly on the transcript. Through the combined action of the TREX complex and other mRNA export factors, the major mRNA export receptor NXF1- NXT1 heterodimer is recruited to the mRNA. At the nuclear face of the NPC, NXF1-NXT1 bound to mRNA can either dock at the NPC or associate with an NPC-anchored complex termed TREX-2 (TRanscription and EXport 2) complex, enabling docking and translocation of mRNAs through the NPC. We and others have shown that the TREX-2 complex mediates nuclear export of a large subset of cellular mRNAs, among which are mRNAs that encode histone modifying enzymes and RNA processing factors, and influenza virus mRNAs. Additionally, we identified an RNA signal that can determine TREX-2 dependency. However, the molecular mechanisms involved in the functions of TREX-2 and the role of new constituents of the complex in the mRNA nuclear export pathway remain to be elucidated. Here, we will use interdisciplinary approaches including cell biology, biochemistry, and structural biology to pursue two extensive aims. In Aim 1, we will elucidate the differential role and interaction network employed by TREX-2 and a new form of the complex, TREX-2LENG8, to mediate nuclear export of cellular and influenza virus mRNAs. Additionally, we will investigate the RNA-protein interactions that determine TREX-2 or TREX-2LENG8 dependency. Thus, the findings from these studies will establish the molecular mechanisms by which TREX-2 or TREX-2LENG8 mediates recruitment and nuclear export of cellular and influenza virus mRNAs. In Aim 2, we will determine the structural and functional basis for the cellular NS1- BP protein in the TREX-2 mRNA export pathway. We have identified a network of interactions and potential mechanisms involving NS1-BP, NXF1-NXT1, and TREX-2 that mediate nuclear export of an important subset of cellular and influenza virus mRNAs. The latter also requires the viral NS1 protein. We will determine the structural basis for the established interactions and investigate their molecular mechanisms and functional significance within the TREX-2 mRNA export pathway. Moreover, we will systematically identify and characterize the cellular mRNAs that require NS1-BP for nuclear export and investigate the functional significance of NS1-BP interactions with NXF1-NXT1 and TREX-2 for nuclear export of these NS1-BP dependent mRNAs. Collectively, our studies will reveal fundamental knowledge on the role of the TREX-2 complex in mediating nuclear export of mRNAs, which impact a large subset of cellular mRNAs and influenza virus mRNAs. Additionally, the findings on the interaction between the influenza virus NS1 protein and the TREX-2 complex could be potentially used for designing antiviral strategies to inhibit influenza mRNA nuclear export and, consequently, viral replication.

NIH Research Projects · FY 2025 · 2025-09

ABSTRACT Urinary tract infections (UTIs) result in considerable morbidity and healthcare expenditures, especially for those who suffer from recurrent UTIs (rUTIs), defined as 3 or more symptomatic UTIs in a 12-month period or 2 or more in a 6-month period. Recent research has determined the considerable physical and psychological toll of UTIs and our work has demonstrated the frequency and impacts of antibiotic resistance and allergy in patients with rUTIs. Low-dose long-term antibiotic prophylaxis is one of the strategies typically considered for individuals who have frequent UTIs and have not durably responded to several 5-7-day courses of antibiotics. To investigate the source of reinfection in rUTI sufferers, our group examined the bladder wall during office cystoscopy and observed evidence of chronic inflammatory changes over the trigone and bladder base. Using a simple outpatient cystoscopic procedure, electrofulguration (EF), or cauterization of these areas of chronic inflammation within the bladder, we have shown symptomatic relief, endoscopic resolution of cystitis lesions, and clinical reduction in rUTIs. We recently reported long-term outcomes after EF (median follow-up 11 years) in women with stage 1 and 2 cystitis and a history of uncomplicated rUTI; 72% of women were cured, 22% were improved, and 6% did not benefit from the procedure. Work with collaborators using 16S rRNA fluorescence in situ hybridization (FISH) revealed resident intracellular/intratissue bacteria in inflamed regions of the bladder wallputative sources of reinfection. Despite our promising results, large gaps in knowledge on the management of women with rUTI indicate the need for definitive Level I evidence comparing the benefits of guideline-driven management relying on long-term (6 months) daily antibiotic prophylaxis versus EF of areas of chronic cystitis combined with long- term (6 months) daily antibiotic prophylaxis. Our central hypothesis is that those treated with EF will experience superior reduction in UTI episodes compared to those undergoing the standard antibiotic therapy alone. Here, we will perform a multicenter, randomized trial to determine whether EF with 6-month antibiotic prophylaxis will reduce UTI episodes in the 1-year (Aim 1) and 2-year (Aim 3) follow-up compared to 6-month antibiotic prophylaxis alone in women with a well-documented history of uncomplicated rUTI (Aim 1). We will determine changes in the urinary microbiomes due to EF with 6-month antibiotic prophylaxis compared to 6-month antibiotic prophylaxis alone (Aim 2). The multicenter, randomized clinical trial will enroll 104 women, aged 18 – 85, and consistent with current guidelines, use nitrofurantoin for antibiotic prophylaxis, a preferred antibiotic for rUTI treatment and prevention due to its concentration in the urine, low rates of resistance and allergy, and favorable safety profile to treat cystitis alone.

NIH Research Projects · FY 2025 · 2025-09

Project Summary/Abstract Primary hyperparathyroidism (PHPT) is a calcium metabolic disorder affecting nearly three million Americans, with a significant predominance in older adults. If left untreated, PHPT can lead to serious health complications, including fractures, neurocognitive decline, kidney stones, and kidney failure. While surgical parathyroidectomy (PTX) provides the only definitive cure, it remains underutilized, disproportionately so among the geriatric population. Various factors contribute to this underutilization of PTX in the geriatric population, including both perceived and actual risks of perioperative complications in older patients, competing medical priorities, under-recognition of the condition, and limited access to care. Current understanding of the risks associated with PTX in this demographic is superficial, lacking depth regarding the influence of frailty status and the unique priorities of older patients and their care teams in the decision-making process surrounding PTX. A critical barrier to enhancing surgical decision making for older patients with PHPT lies in the absence of detailed, personalized predictions of perioperative complications, as well as a lack of insight into the specific priorities of older patients and their healthcare providers. The overall objective of this proposed study is to improve surgical decision-making for older patients with PHPT through the development of personalized predictive models for PTX-related complications and by exploring the unique priorities and values that shape both patient and provider decision making. To achieve these objectives, two specific aims are outlined: 1) Develop predictive models for PTX-associated complications, leveraging age, frailty status, and relevant clinical characteristics within a large national cohort, and validate the models externally; and 2) Evaluate the unique priorities that influence older patients and their care teams when considering surgical management for PHPT. This research will yield validated models for predicting PTX-associated complications in older patients and will identify barriers and facilitators influencing surgical decision-making in this population, providing critical insights into the roles of patient and provider priorities and values. Ultimately, this work will enhance the alignment of care with the preferences and needs of older patients with PHPT, facilitating better health outcomes and more appropriate provision of care.

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY/ABSTRACT Rising rates of internalizing symptoms, including depression, anxiety, and suicidal ideation, in youth in the US represent a public health crisis. In 2024, 40% of youth experienced a past-year persistent sadness or hopelessness and 29% reported past-month poor mental health (i.e., depression, anxiety, or stress), while suicide has consistently ranked in the top three causes of death for youth aged 13-18. Coinciding with the increase in internalizing symptoms, social media use has rapidly grown, but the link between social media use and mental health is not well understood, especially in at-risk, clinical populations. Moreover, most research on the topic has been cross-sectional, lacking information about the impact of social media use on proximal and longer-term outcomes for internalizing symptoms. It also often fails to consider both ways in which social media use may be harmful and protective. There is a critical need for longitudinal research on social media’s relationship with internalizing symptoms in youth and risk and protective factors for individuals. Therefore, we propose a study in response to RFA-MH-25-206 (Bidirectional Influences Between Adolescent Social Media Use and Mental Health) that uses longitudinal and intensive monitoring on multiple timescales to identify how social media use and experiences are linked to internalizing symptoms in a sample of at-risk youth. The proposed study will enroll N=100 youth aged 13-18 years recruited from the University of Texas Southwestern Node of the ongoing Texas Youth Depression and Suicide Research Network (TX-YDSRN) Registry study. The Registry enrolls youth with depression and/or suicidal thoughts or behaviors, so participants have high rates of internalizing symptoms. At baseline, internalizing symptoms and social experiences (i.e., victimization) will be collected via clinical interview and self-report; subsequently, internalizing symptom self-report measures will be collected monthly for six months. Participants will complete ecological momentary assessments (EMA) twice daily during the first month, with questions on real-time positive and negative Emotional Responses to Social Media, internalizing symptoms (i.e., depression, anxiety, and suicidal ideation), and positive and negative in-person interactions. Objective social media use data (i.e., use duration), along with EMA, will be collected via a smartphone app (mHealth). Using these data, this proposal aims to: (1) Investigate how amount of social media use and positive/negative experiences impact internalizing symptom trajectories over six months and (2) Determine social context factors impacting the relationship between social media use amount and experiences and internalizing symptoms. Throughout the project, the established TX-YDSRN youth advisory board (N = 15) will be consulted to inform study approach, data interpretation, and dissemination of study findings. This proposed R21 will generate pilot data for a future R01 application aimed at state-wide investigation of social media use and mental health in Texas youth. Results of this project have the potential to inform clinical interventions and prevention programs to promote youth mental health in the context of social media.

NIH Research Projects · FY 2025 · 2025-09

PROJECT SUMMARY Cellular compartments are critical to controlling the biochemistry that is essential for organismal survival. Most compartments are membrane-bound, sequestering enzymatic reactions from the rest of the cellular milieu. Yet, many compartments lack membranes and exchange biomolecules freely with their surroundings. Such membraneless compartments were observed over a century ago, but attracted little attention until recently. Perhaps due to methodological advancements, a marriage of physics and cell biology sparked a revolution in our appreciation for membraneless compartments. Over the past 15-years, these compartments were shown to have liquid-like properties. Recent consensus states that biological phase transitions are fundamental to their (dis)assembly. Hence, they are now commonly referred to as biomolecular condensates. Such discoveries might have eluded the public curiosity if not for compelling human genetics and disease pathology, both of which implicate condensate dysfunction in diseases of aging including neuromuscular diseases (e.g., ALS) and cancers. Yet, a direct link between physiological condensation and disease pathobiology has evaded conclusive assessment. Such causal relationships have been difficult to infer, as entirely new technologies were required to rigorously and quantitatively illuminate this new biological frontier. With this unmet need in mind, my colleagues and I have invested heavily in creating the proper tools to link condensate biology to disease. My unique perspective is informed by my previous research on pathological protein aggregation. As an independent investigator, I now bridge my experience in cellular models of protein aggregation and physiological condensation to provide much needed insights into how cell biology and disease are connected. In this proposal, we will test a groundbreaking hypothesis for condensate function. Specifically, we propose that RNA-rich condensates, including cytoplasmic stress granules and nuclear speckles, coordinate RNA homeostasis to prevent RNAs from becoming hopelessly entangled. We surmise that such RNA entanglement mechanistically drives the pathological protein aggregates of neuromuscular diseases. We will rigorously test this hypothesis by taking a cross-disciplinary approach that scales from test tube biophysics to cellular and organismal biology then forward to the clinic. We will leverage our unprecedented tools to discover ligands that disassemble pathological aggregates. If successful, we will inform an entirely new way of thinking about RNA homeostasis that is independent of classic biochemical reactions. In doing so, we will provide a foundation for understanding the function of condensates in living cells and inform tractable targets for disease intervention.

NIH Research Projects · FY 2026 · 2025-08

Project Summary: The DNA methyltransferase DNMT3A is mutated in individuals with neurological disorders such as autism and intellectual disabilities. DNMT3A is highly expressed in the nervous system, primarily methylating atypical non- CG sequences, particularly at CA sites (mCA). The mCA mark is partially bound by MECP2, a protein mutated in Rett syndrome, which causes severe cognitive impairments. Deletions of either DNMT3A or MECP2 in the brain lead to significant gene expression defects and severe neurological and behavioral issues in mice. Despite the importance of mCA in brain function, its regulatory mechanisms and precise roles are largely unknown. Our lab has identified a novel phosphorylation site within the methyltransferase domain of DNMT3A that is responsible for adding methylation to the DNA. Preliminary data suggests that blocking this phosphorylation site in mice eliminates mCA in the brain without affecting DNMT3A protein stability. Unlike DNMT3A deletion mice, which die neonatally, the phospho-defective mice survive into adulthood but develop progressive behavioral issues. The exact mechanisms by which the phosphorylation site affects mCA, gene regulation, and animal behavior remain unclear. The proposed experiments aim to (1) elucidate the role of phosphorylation on DNMT3A function, (2) define the role of mCA in neural gene regulation, and (3) examine how neuronal activity influences DNMT3A phosphorylation and DNMT3A-mediated mCA. These insights could lead to new therapeutic strategies for neurological disorders such as autism spectrum disorders.

NIH Research Projects · FY 2026 · 2025-08

Project Summary/Abstract Atherosclerosis underlies life-threatening cardiovascular disorders such as myocardial infarction and stroke. We previously discovered that scavenger receptor class B type I (SR-BI, encoded by Scarb1) drives LDL transcytosis in endothelial cells, delivering LDL to the subendothelial space where its accumulation by macrophages promotes atherosclerosis. We recently determined by single cell RNAseq in human coronary arteries that SR-BI is upregulated in endothelial cells associated with atheromas versus in cells from segments lacking atheroma. Gene signatures for responses to varying blood flow revealed that disturbed flow may also upregulate SR-BI. We have revealed that endothelial SR-BI is upregulated in mice with either hypercholesterolemia or disturbed blood flow induced by carotid artery partial ligation. Using mass spectrometry and LDL transcytosis assays, we have determined that the E3 ligase c-Cbl and the Zn transporter ZIP10 interact with SR-BI and are required for LDL transcytosis via mechanisms likely shared with the receptor. Springboarding from these discoveries, the Overall Goal of the proposed research is to determine how endothelial SR-BI expression is regulated in vivo, and how SR-BI partners with other proteins to mediate LDL transcytosis. Aim 1 will determine how hypercholesterolemia and disturbed blood flow upregulate endothelial SR-BI. Transcription factor networks derived from the coronary endothelial cell RNAseq reveal parallel upregulation of HIF-1α and SR-BI and possible regulatory interaction in the setting of atheroma formation or disturbed flow. Using ChIP-seq, CHIP-qPCR and CRISPR, we have identified HIF-1α binding sites in intron 1 of human Scarb1 and 28kb 5’ of mouse Scarb1 that mediate HIF-1α upregulation of SR-BI. We will test the hypothesis in mouse models that there is a unifying mechanism in which HIF-1α mediates endothelial cell SR-BI upregulation by hypercholesterolemia and by disturbed blood flow to promote endothelial cell LDL uptake and atherosclerosis. Studies will include a test of the impact of CRISPR-based excision of the HIF-1α binding site 5’ to mouse Scarb1 in endothelium. Aim 2 will determine how the new partner proteins c-Cbl and ZIP10 modulate LDL transcytosis by SR-BI. In culture we will use mutagenesis to identify the specific functions of c-Cbl and ZIP10 and modes of SR-BI interaction required to govern LDL transcytosis. In vivo studies will determine how endothelial cell knockdown of c-Cbl or ZIP10 impacts artery LDL uptake and atherosclerosis. Guided by the findings in culture, using nanoparticles to reconstitute endothelial cell genes in mice, in vivo structure-function studies will be done of SR-BI interaction with c-Cbl or ZIP10 and their specific functions. Aim 2 will test the hypothesis that via discrete capacities and interactions with SR-BI, c-Cbl and ZIP10 partner with SR-BI to invoke artery wall LDL delivery and atherosclerosis. By accomplishing these Aims and unraveling how endothelial SR-BI expression is regulated and how SR-BI works with partner proteins to drive endothelial LDL transport, it is expected that novel therapies can then be developed to disrupt SR-BI-mediated artery entry of LDL for cardiovascular benefit.

NIH Research Projects · FY 2025 · 2025-08

Project summary One mechanism that is central to innate immunity against intracellular pathogens such as Mycobacterium tuberculosis (Mtb) is engagement and targeting of bacteria for degradation by the cellular ubiquitination machinery, a process that also directly impacts immune responses. Ubiquitin ligases expressed by host innate immune cells attach the protein ubiquitin to intracellular pathogens or the organelles containing them, and such ubiquitination events then trigger recruitment of the host autophagy-lysosomal degradation machinery to engulf and destroy the invading pathogen. Ubiquitin ligases such as SMURF1 and PARKIN tag Mtb-containing structures for autophagic degradation in a process termed xenophagy. Conversely, host deubiquitinating enzymes (DUBs) may remove these ubiquitin tags, potentially aiding the pathogen's survival. A major gap in our understanding of the cellular mechanisms of xenophagy is that we do not have a complete understanding of the mechanisms of ubiquitin attachment and removal from Mtb, and we hypothesize that the extent of Mtb ubiquitination, mediated by the relative balance between the activities of ubiquitin ligases and deubiquitinases, directly impacts the outcome of Mtb infection. Bridging the knowledge gap around the roles of individual ubiquitin ligases and DUBs may yield novel strategies for host-directed therapies, crucial in the current climate of growing antibiotic resistance. Here, we will apply genetic, biochemical, immunologic, transcriptomic and animal approaches to determine the functional role of specific ubiquitination and deubiquitination mechanisms in the context of Mtb infection. Thus, in the proposed research we will: (1) Elucidate the role of ubiquitin ligases SMURF1 and SMURF2 in targeting Mtb for autophagy and how they regulate interferon-β production during infection. (2) Delineate the roles of K63 and K48 deubiquitination during macrophage infection, focusing on the K63-specific DUB USP15 and the yet unidentified DUBs responsible for K48 deubiquitination, critical steps that negatively regulate autophagy. (3) Determine the function of linear M1-ubiquitination by the LUBAC system and its negative regulation by the DUB CYLD in cellular immunity to Mtb. The proposed work is expected to identify the molecular mechanisms that target Mtb for degradation and host proteins whose activities regulate protective immune responses.

NIH Research Projects · FY 2025 · 2025-08

Project Summary/Abstract Advanced stage hepatobiliary cancers, including hepatocellular carcinoma (HCC) and biliary tract cancers (BTC), are often rapidly fatal diseases due to a lack of effective systemic treatments for most patients. While anti-PD-1/L1 therapies have emerged as frontline treatments for hepatobiliary cancers, they only induce responses in a minority of patients. Identifying and thwarting resistance mechanisms to anti-PD-1/L1 therapies in hepatobiliary cancers is critical to expanding the effectiveness of immunotherapies in these diseases. T cell immunoglobulin and ITIM domain (TIGIT) is an inhibitory receptor expressed on lymphocytes and NK cells, and is a candidate compensatory immune checkpoint which may mediate anti-PD-1/L1 treatment resistance in hepatobiliary cancers. This proposal presents a five-year research career development program encompassing the study of an anti-TIGIT antibody as a novel treatment in refractory hepatobiliary cancers and training objectives that will enable the applicant to independently lead clinical trial investigations, learn new technologies and computational methods using spatial and single-cell data, and gain an expertise in tumor immunology. The central hypothesis is that concomitant blockade of TIGIT and PD-1 will induce robust anti-tumor immunity against HCCs and BTCs. This hypothesis will be tested in the following aims: Aim 1) Conduct a phase 2 trial of an anti- TIGIT plus anti-PD-1 antibody regimen in hepatobiliary cancers refractory to PD-1 blockade. Aim 2) Characterize immune and molecular features of anti-PD-1/L1 therapy refractory tumors and identify markers of resistance or response to TIGIT blockade. Aim 3) Assess dynamics in circulating tumor DNA (ctDNA) to define genetic markers of anti-PD-1 and/or anti-TIGIT therapy resistance and evaluate its use as a non-invasive pharmacodynamic marker. These studies have the potential to expand the treatment armamentarium against hepatobiliary cancers, and uncover mechanisms of anti-PD-1/L1 or anti-TIGIT therapy resistance through systematic investigations of longitudinally collected tissue and blood specimens. The long-term goal of the applicant is to become a leader in clinical investigations of novel immunotherapies in hepatobiliary cancers integrated with in-depth and systematic studies to elucidate mechanisms of response and resistance. The proposed study will be conducted under the mentorship of Dr. David Gerber, a clinical trialist and translational investigator, Dr. Tao Wang, a cancer immunologist and computational scientist, and Dr. Hao Zhu, a translational scientist in the fields of liver regeneration and tumorigenesis. In addition to the candidate’s passion for science, the enthusiastic support of his experienced mentors, and the breadth of resources and expertise at UT Southwestern, this award will enable the applicant to transition into an independent investigator and generate new hypotheses or treatment approaches to improve the lives of patients with hepatobiliary cancers.

NIH Research Projects · FY 2025 · 2025-08

Project Summary Placenta Accreta Spectrum (PAS) is a serious obstetric condition characterized by abnormal adherence of the placenta to the uterine wall, leading to significant maternal morbidity and mortality during delivery. The increasing incidence of PAS correlates with the rise in cesarean deliveries. Current imaging modalities, such as ultrasound and magnetic resonance imaging (MRI), rely heavily on subjective interpretation, lack quantitative measures, and require extensive training. There is an urgent need for improved diagnostic and quantitative predictive tools, particularly in assessing PAS that is severe enough to require hysterectomy. This project aims to develop a fully automated, open-source pipeline utilizing deep learning (DL) algorithms and regional radiomics analysis to objectively assess the risk of hysterectomy in patients with high- risk PAS. By focusing on the lower uterine segment (LUS), the most common site of prior cesarean uterine scars and PAS pathology, the proposed research seeks to enhance diagnostic accuracy, facilitate better surgical planning, and optimize delivery timing. In Aim 1, we will implement and test a novel DL-based segmentation algorithm to automatically isolate the 'at-risk' placental region within the LUS on sagittal T2W MRI images. Leveraging the anatomical marker of the pelvic inlet, the L5-S1 disc space, this will be the first approach to automatically segment presumed pathological areas of PAS. In Aim 2, we will extract and analyze regional radiomic features from the segmented LUS placental region to develop predictive models for assessing the risk of hysterectomy. By incorporating advanced radiomic features, including texture, shape, and location-based parameters, we aim to improve the predictive accuracy over existing methods. The proposed research is innovative in its application of automated DL segmentation and regional radiomics to a critical area of obstetric care. The development of an open-source pipeline will provide a valuable resource for clinicians and researchers, promoting widespread adoption and collaboration. Successful completion of this project has the potential to significantly impact patient outcomes by enabling earlier and more accurate identification of PAS cases that require advanced surgical intervention. The multidisciplinary team, comprising experts in radiology, biomedical engineering, and medical imaging analysis, is well- positioned to achieve these goals. The project leverages extensive institutional resources, including a large, well-characterized dataset of placental MRI scans and state-of-the-art computational facilities. In summary, this project addresses a critical gap in the management of PAS by introducing an objective, automated tool for risk assessment. The anticipated outcomes will advance the field of prenatal imaging and contribute to improved maternal and fetal health outcomes.

NIH Research Projects · FY 2025 · 2025-08

PROJECT SUMMARY Mitochondria regulate essential biological activities through their effects on cellular metabolism, particularly via oxidative phosphorylation (OXPHOS). Mitochondrial dysfunction leads to numerous human pathologies, including neurological disorders, autoimmune diseases, and cancer. However, while permanent impairment of the electron transport chain (ETC) in human tissues is detrimental, reversible suppression of OXPHOS is integral to some physiological processes, such as the activation of inflammatory responses in macrophages. Metabolic dysregulation in macrophages can either weaken their anti-microbial strength or drive inflammation to pathological levels. Therefore, defining the context-specific metabolic consequences of OXPHOS suppression is crucial for identifying the mechanistic basis of mitochondrial diseases and pathological inflammation. Previous studies, including mine, have shown that under conditions of suppressed OXPHOS, both ETC-deficient cancer cells and proinflammatory bone marrow-derived macrophages (BMDMs) exhibit suppressed de novo purine biosynthesis and increased purine salvage. Although enhanced purine salvage maintains nucleotide pools in response to ETC deficiency-induced DNPB suppression in vitro, it is unclear if this mechanism operates under in vivo conditions with more relevance to human health, including tumors and splenic macrophages. My recent work demonstrated that ETC deficiency potentiates purine salvage through increasing the levels of HPRT1 substrate, phosphoribosyl pyrophosphate (PRPP) via the pentose phosphate pathway (PPP) in cultured cancer cells. However, the molecular mechanisms promoting purine salvage and their impact on inflammatory signaling in macrophages are unknown. The overarching objective of this proposal is to elucidate molecular mechanisms underlying purine salvage regulation in response to suppressed OXPHOS under both pathological (e.g., ETC- deficient tumors) and physiological (e.g., inflammatory macrophages) conditions. Building upon my previous study, I will test the central hypothesis that ETC deficiency enhances purine salvage in tumors and inflammatory macrophages to support cell growth and function. In Aim1, I will test whether ETC-deficient tumors enhance purine salvage and utilize environmental nucleobases to maintain cellular purine nucleotide pools in vivo. In Aim2, I will characterize the role of purine salvage in inflammatory macrophages. Specifically, I will test if purine salvage is enhanced via the increased PPP to promote innate immune responses in BMDMs upon inflammatory stimulation. I will also characterize the role of purine salvage in splenic macrophages in vivo during systemic inflammation. Taken together, the proposed study will advance our understanding of purine nucleotide regulation in vivo under conditions of suppressed OXPHOS and facilitate the development of novel therapeutic strategies to treat patients with mitochondrial defects, purine abnormalities, or pathological inflammation.

NIH Research Projects · FY 2025 · 2025-08

Project Summary/Abstract: Stimulant use (cocaine/ methamphetamine) has a major impact on HIV transmission and acquisition. Justice- involved individuals are more likely to have stimulant use disorders and be at risk or living with HIV than the general population, face interruptions in HIV treatment (antiretroviral therapy (ART)) and have limited access to HIV pre-exposure prophylaxis (PrEP). There is thus a critical need for effective interventions that reduce stimulant use and potentially improve HIV viral suppression (VS) and PrEP initation and retention, particularly among justice-involved groups. The most successful treatment for stimulant use disorder to date is contingency management (CM), shown to reduce stimulant use and HIV risk behaviors, though implementation has been limited for justice-involved people due to competing priorities (transportation, housing, probation) and practical challenges of providing CM (frequent drug testing, trained staff, incentive management). DynamiCare is an FDA- approved mobile app that delivers patient-centered behavioral CM and has been shown to reduce biological and self-reported assessments of stimulant and other substance use, however it is unknown if it could improve PrEP/ART initiation for persons with stimulant use disorder at risk or living with HIV. Thus, in response to NIDA RFA-DA-23-008: Stimulants and HIV, we propose the RESTORE study: Recovery and Engagement for Stimulant Users on Re-entry. Guided by the Exploration Preparation Implementation Sustainment (EPIS) framework, we will assess if the addition of personalized CM via the DynamiCare app to a previously protocolized patient navigator (PN) (“DynamiCare-plus”) intervention improves initiation of PrEP/ART and reduces stimulant use. The Specific Aims are: Aim 1 (R61): To conduct a pilot assessment of DynamiCare-plus for persons at risk or living with HIV with DSM-5 stimulant use disorders (methamphetamine/cocaine) being released to the community from a closed justice setting (jail/ prison/ justice-mandated substance use program). N=40 adults in Dallas, TX and CT will be randomized 1:1 to DynamiCare-plus compared to enhanced treatment as usual (ETAU) (PN + smartphone) for 6 months to assess acceptability, feasibility and preliminary effectiveness: proportion who (1) initiate PrEP/ART; and (2) achieve/maintain VS (VL < 200 copies/mL) for those with HIV; Aim 2 (R33): The R61 pilot will inform a type 1 hybrid implementation effectiveness randomized controlled trial of DynamiCare- plus v. ETAU among 252 participants with the same eligiblity as the R61 to assess the primary outcome of initiation/reinitiation of PrEP/ART followed for 15 months, with a 12 month intervention period. Secondary outcomes include stimulant and other substance use, overdose, PrEP/ART/SUD retention, HIV risk behaviors, VS, Quality of life, and recidivism; Aim 2.1: Examine implementation of the intervention. Aim 2.2: Conduct cost analyses of the intervention compared to control. The Dynamicare app is mobile, adaptable and scalable, and combined with PN (DynamiCare-plus) has the potential to have a major impact on HIV treatment and prevention for justice-involved people with stimulant use disorder.

NIH Research Projects · FY 2025 · 2025-08

Developing vectors for potent and selective manipulation of cardiac rhythm PROJECT SUMMARY Within the cardiac conduction system (CCS), the atrioventricular node (AVN) optimizes the timing of heart contraction and is susceptible to varying degrees of AV block (AVB). The most recent Expert Consensus Statement from the Heart Rhythm Society lists 19 gene mutations that cause AVB, which often requires pacemaker (PM) implantation. Despite the clear efficacy of PMs, alternative treatments, such as targeted AAV gene therapies, could benefit patients that cannot tolerate or do not wish to undergo PM implantation. Recent studies suggest that the burden of genetic predisposition to arrhythmia is much more common than currently appreciated, and mechanistic overlap between genetic and acquired forms of AVB suggest that specific gene targets amenable to gene therapy are likely to exist. However, AAV delivery of therapeutic cargos to the CCS, including the AVN, requires further refinement of existing technology. To address this urgent need, we must accomplish two key objectives: 1) efficient cargo delivery to the AVN and 2) restriction of therapeutic gene expression to the AVN. Based on our preliminary data and the recent published literature, we have developed a feasible approach to address both objectives. The long-term goal of our research program is to devise new therapeutic approaches for cardiac dysrhythmias. The overall objective for this proposal is to develop AAV- based tools to deliver therapeutic cargos to the AVN. Our central hypothesis is that by optimizing AVN uptake of AAV and restricting gene expression to the AVN, we will enable efficient gene therapy for genetic and acquired AVB. The rationale for the proposed research is that once the tools for efficient AVN gene therapy are available, they can be more widely implemented for conduction abnormalities arising elsewhere in the CCS. To test our central hypothesis, we propose the following Specific Aims: 1) Optimize the potency of AAV vectors to efficiently transduce the AVN, 2) Enhance the selectivity of AAV vectors for AVN-specific targeting, and 3) Establish a platform for somatic manipulation of AVN gene expression. Successful completion of the proposed project will create critical gene therapy reagents to potentially cure specific cardiac dysrhythmias. We envision that these new capabilities will enable future extension to arrhythmias related to sinus node and distal conduction system dysfunction.

NIH Research Projects · FY 2025 · 2025-08

Project Summary The formation of intracellular inclusions containing fibrillar aggregates of alpha-synuclein (α-syn) is a hallmark of neurodegenerative diseases such as Lewy body dementia, Parkinson’s disease, and multiple systems atrophy. An intrinsically disordered monomer, α-syn, can assemble into various fibrillar forms influenced by its environment. Understanding the conformations that α-syn adopts in health and disease is crucial for developing diagnostic and therapeutic tools. Although advances in structural biology have accelerated the characterization of isolated amyloid fibrils, it is essential to know the α-syn structures in biological settings, as isolated fibrils may not represent in vivo conformations. Current methods, such as isolating fibrils from post-mortem tissues or using seeding to amplify fibrils in vitro, might not capture the prevalent in-cell conformations. This project aims to identify the amyloid conformations and their abundances inside cells, which will enhance our understanding of amyloid propagation and aid in identifying biologically relevant structures. We will investigate how different cellular environments affect seeded amyloid propagation by using biosensor cell lines and neurons. In biosensor cell lines expressing wild-type and mutant α-syn, we will introduce α-syn and assess its aggregation into amyloid fibrils upon exposure to seeds. This approach will allow us to compare amyloid propagation in vitro with that inside cells. In neurons, we will study the seeded amyloid propagation of well-characterized α-syn fibrils, considering the influence of the cellular environment on fibril formation and propagation. Understanding how specific cell types affect amyloid propagation is crucial, as different neurodegenerative diseases involve amyloid fibrils accumulating in distinct cell types. Additionally, we will analyze amyloid structures from tissue seeded Lewy body dementia patients. By comparing these structures with known α-syn fibril conformations, we aim to identify unique features and polymorphs relevant to disease pathology. We will use a multi-scale approach with two complementary, state-of-the-art in situ structural techniques: in-cell DNP sensitivity-enhanced NMR spectroscopy and cellular cryo- ET/subtomogram averaging to characterize the conformational ensembles and spatial organization of α-syn amyloids in situ. This comprehensive approach will provide insights into the structural diversity, molecular interactions and organization of α-syn amyloids, as well as their effects on cells, ultimately advancing our understanding of neurodegenerative disease mechanisms and pathology, and informing the development of targeted diagnostics and therapeutics.

NIH Research Projects · FY 2025 · 2025-08

The human gut is home to a complex ecosystem of microbes, including fungi. While bacterial contributions to gut health and disease have been extensively studied, the role of the fungal community (mycobiota), remains largely unexplored. Emerging evidence suggests that disruptions in the fungal community (fungal dysbiosis), play a significant role in inflammatory diseases such as inflammatory bowel disease (IBD). Despite this, little is known about how gut fungi interact with the host immune system during health and disease. Our recent research has identified a novel fungal RNA molecule, termed fungal stimulatory RNA (fsRNA), which activates the intestinal immune responses. Unlike other non-stimulatory eukaryotic RNAs, fsRNA triggers immune responses, suggesting an RNA-based communication mechanism between fungi and the host immune system. The goal of this proposal is to investigate the role of fsRNA in modulating intestinal innate immune responses and contributing to inflammation. By using interdisciplinary approaches such as fungal genetic engineering, long- read RNA sequencing, advanced imaging, and in vivo disease models, we aim to uncover the mechanisms of fsRNA-triggered immunity and its impact on gut inflammation. Understanding the interactions between fungal RNA and the immune system could reveal a novel mode of fungal-host communication and highlight new therapeutic targets for treating IBD. This research is expected to expand our knowledge of host-mycobiota interactions by shifting the focus from traditional protein-based virulence factors to RNA-based immune modulation. Ultimately, the findings could lead to innovative therapeutic approaches for managing inflammatory diseases and potentially open up new avenues for the development of RNA-based therapies.