Ut Southwestern Medical Center

NIH Research Projects · FY 2026 · 2026-06

Conventional chemotherapies remain the backbone of treatment for many cancers but often act through genotoxic mechanisms that damage DNA in both tumor and healthy cells, leading to serious side effects and dose-limiting toxicity. We have identified MM17, a small-molecule benzothiazepinone that inhibits NVL, an essential AAA+ ATPase required for large ribosomal (60S) subunit assembly. NVL functions as a remodeling enzyme that extracts ribosome biogenesis factors from pre-60S particles during nucleolar maturation. MM17 binding disrupts this activity, leading to stalled ribosome assembly, nucleolar stress, and potent cell cycle arrest in cancer cells. Notably, MM017 elicits both p53-dependent and p53-independent responses without inducing DNA damage, making it a promising prototype for a new class of nongenotoxic anticancer agents. This proposal aims to define the catalytic mechanism of NVL and characterize how benzothiazepinones modulate its structure and function. Using cryo-EM, we will determine high- resolution structures of wild-type and resistant NVL constructs bound to inhibitors, revealing how these compounds perturb ATPase activity and oligomer formation. Mass photometry experiments will quantify how these compounds affect NVL hexamerization, substrate recognition, and nucleotide engagement. Structural studies will also explore how full-length NVL captures its physiological substrate, the conserved C-terminal tail of MAK16, and how this process is disrupted by inhibitors. In parallel, we will test how NVL inhibition leads to the accumulation of free 5S ribonucleoprotein (5S rRNP) complexes that inhibit the E3 ligase MDM2 and activate p53. We will use heterochronic fluorescent labeling to determine whether free 5S rRNPs are newly synthesized or released from stalled pre-60S particles. Finally, we will investigate whether NVL serves a dual role by recruiting the TRAMP– exosome machinery to degrade stalled intermediates. Together, these studies will provide foundational insight into ribosome assembly inhibition as a cancer-selective strategy and establish MM017 as a mechanistically novel, nongenotoxic therapeutic candidate.

NIH Research Projects · FY 2026 · 2026-06

PROJECT SUMMARY Osteosarcoma (OS) is the most common bone sarcoma in children and the 8th most common childhood cancer. Currently, limited immunotherapies are available for OS due to two main obstacles: immunosuppressive tumor microenvironment and secondary immune toxicity. OS resistance mechanisms to immunotherapy can largely be categorized into tumor cell-intrinsic and extrinsic mechanisms. Tumor cell-intrinsic mechanisms include downregulation of major histocompatibility complex class I (MHC-I) molecules, which reduces tumor immunogenicity and enhances immune evasion. Although epigenetic dysregulation plays a crucial role in immune evasion by downregulating tumor antigen presentation in several other solid tumors, epigenetic modifiers, specifically implicated in OS immune evasion, remain largely to be determined. Tumor cell-extrinsic mechanisms involve the elevated expression of the innate immune checkpoint molecule, CD47, and PD-L1. In addition, tumor acidification within the OS TME, deactivates immunostimulatory cytokines, such as interleukin-2 (IL-2), thereby dampening CD8 T cell-mediated antitumor responses. We generated novel acid-resistant immunocytokines that blocked CD47 and PD-L1 activities and simultaneously activated IL-2 signaling in tumor- infiltrating CD8 T cells, leading to markedly enhanced antitumor efficacy and reduced systemic toxicity in the mouse model of OS. To target tumor cell-intrinsic mechanisms underlying immune evasion, we performed in vitro CRISPR epigenetic screening and identified evolutionarily conserved epigenetic modifiers involved in negative modulating tumor antigen presentation machinery. Here, we hypothesize that targeting these epigenetic modifiers in conjunction with acid-resistant immunocytokines will significantly enhance tumor antigen presentation, leading to more robust systemic antitumor responses for tumor eradication. In this study, we will investigate the function of these pMHC-I epigenetic regulators and assess the antitumor synergy of acid-resistant immunocytokine therapy with the inactivation of these epigenetic modifiers in clinically relevant mouse models of OS.

NIH Research Projects · FY 2026 · 2026-06

Summary: Chronic kidney disease (CKD) affects 10% of the world’s population and is characterized by progressive fibrosis and loss of kidney function, leading to end stage renal disease. Effective therapies to prevent or curtail the advancement of fibrosis remains a major clinical challenge. Kidney proximal tubule cells (PTC) have the remarkable ability to respond to injury by entering an earlier developmental state, termed dedifferentiation, and dividing to replace lost cells. PTCs then redifferentiate to resume normal function. For over 100 years, however, it has been known that a subset of PTCs never fully redifferentiate, and these chronically injured PTCs are a main driver of fibrosis and CDK progression. Although recent studies have better characterized these cells, it remains unclear why these chronically injured PTCs can’t recover from injury, while neighboring cells can. In studies funded by this award, we made a breakthrough by discovering key players that regulate G2/M arrest, dedifferentiation, senescence and fibrosis in CKD, the atypical cyclin, cyclin G1, and its cyclin dependent kinase (CDK5). Using cyclin G1 or CDK5 knockout kidneys as tools, we experimentally dissected G2/M arrest from dedifferentiation and fibrosis. Surprisingly, we found that while G2/M arrest was more common in maladaptively repaired cells, its functional role in CKD progression was limited. Instead, we discovered cyclin G1/CDK5 induced a state of profibrotic dedifferentiation that led to senescence and CKD we termed ‘maladaptive dedifferentiation.’ In the current proposal, we aim to test the therapeutic potential of redifferentiating maladaptively dedifferentiated cells. In our preliminary data we found that the cyclin G1/CDK5 pathway regulates dynamin related protein 1 (Drp1) mediated mitochondrial fission. In vitro, we discovered that maladaptive dedifferentiation could be reversed by targeting the cyclin G1/CDK5 pathway or mitochondrial dysfunction via Drp1. If the PTCs progressed to senescence, however, they became much harder to redifferentiate. Importantly, these findings translated in vivo. In animal models we found selective deletion of Drp1 after recovery from AKI induced redifferentiation and prevented senescence. These data indicate that redifferentiation of maladaptively repaired PTC is possible. Based on these data, cyclin G1/CDK5-induced mitochondrial dysfunction promotes and extends maladaptive dedifferentiation in PTCs, preventing redifferentiation and promoting irreversible senescence. To test this hypothesis, we will: 1. Determine the ‘point- of-no-return’ for PTC redifferentiation. We will test if and when targeting the cyclin G1/CDK5 pathway promotes redifferentiation and prevents AKI-to-CKD transition using Cre promotors to target dedifferentiated or senescent cells specifically. 2. Determine if restoration of mitochondrial morphology is necessary for PTC redifferentiation. Using conditional knockout mice, specific inhibitors, and metabolic flux assays we will examine whether restoration of FAO promotes redifferentiation. This proposal represents a new direction for the field of CKD research by directly targeting the maladaptive dedifferentiated PTCs with redifferentiation therapies.

NIH Research Projects · FY 2026 · 2026-06

ABSTRACT The cervical epithelium serves as the first line of defense to limit ascending infections into the upper reproductive tract. Previous animal studies have demonstrated the functional role of cervical epithelial cells in protecting against ascending infection-mediated PTB. However, there remains a gap in our understanding of the molecular mechanisms regulating cervical epithelial cell barrier function in human pregnancy due to ethical constraints and a lack of proper tools. To fill the knowledge gap, organoid models from nonpregnant human cervix have been established. However, there are currently no organoid models of human cervix that recapitulate the dynamic molecular states of epithelial cells during pregnancy. We reason that the primary obstacle that prevents the establishment of such a human in vitro cervix model is a scarcity of in vivo molecular information on the human cervical epithelium before and during pregnancy. To this end, we aim to build novel in vitro human cervical organoid-stromal cell co-culture models relevant to pregnancy and nonpregnancy through a two-pronged approach. First, we will apply single cell and spatial transcriptomics technologies to cervical tissue samples from nonpregnant and term pregnant women to molecularly characterize the human endocervix and ectocervix and to delineate the cervical epithelium-stroma interactions before and during pregnancy (Aim 1). Second, we will develop a co-culture model of human cervix epithelia and fibroblasts to better model the cervical epithelium-stroma interactions before and during pregnancy (Aim 2). The overall impact of this work is to lay a solid foundation for the identification of molecular mechanisms required for epithelial barrier function which is necessary to identify potential disruptors of epithelial barrier function that predispose women to ascending infection mediated preterm birth.

NIH Research Projects · FY 2026 · 2026-06

PROJECT SUMMARY Rachel Leon, MD, PhD is an Assistant Professor in the Division of Neonatal-Perinatal Medicine at UT Southwestern Medical Center (UTSW) with a PhD in neuroscience, and she is a current NHLBI K23 Awardee. Her goal is to become an independently funded investigator with expertise in neuroplacentology, a field that focuses on elucidating mechanisms of placental influence on fetal brain development. The long-term goal of her research program is to improve neurodevelopmental outcomes of children with complex congenital heart disease (CCHD) by restoring normal intrauterine brain development and increasing their neurologic reserve before they encounter postnatal physiologic stressors. Dr. Leon is in the 3rd year of her K23 award, which is focused on placental and cerebrovascular hemodynamics in fetuses with CCHD. Specifically, in pregnant patients with fetuses diagnosed with left or right ventricular outflow track obstruction CCHD, and healthy controls, she is using advanced MRI to evaluate placental perfusion longitudinally and determine associated differences in placental size and histopathology, determine the impact of placental perfusion on cerebral autoregulation from the fetal period to the early postnatal adaptation, and determine how placental perfusion affects the trajectory of regional brain growth. Dr. Leon has already made several novel discoveries about the fetal CCHD placenta through this work and successfully competed for both mentored and independent foundation funding. In this R03 proposal, Dr. Leon will branch out to a new study using her advanced MRI techniques to investigate the influence of placental hypoxia on inflammatory markers and mediators, which are known to have deleterious effects on fetal brain development. This study will leverage the robust research infrastructure that Dr. Leon has built to recruit pregnant patients from multiple clinical sites, apply custom advanced MRI protocols, collect placental tissue, and analyze complex multi-omic datasets. Given this research infrastructure and her developing expertise in translational methods of neuroplacentology, Dr. Leon is uniquely positioned to lead this cutting-edge team science investigation. In this proposal, she will test the central hypothesis that fetal CCHD pregnancies have decreased placental oxygenation, leading to a pro-inflammatory environment at the maternal-fetal interface, using the following specific aims: (1) Determine the effects of fetal CCHD on regional placental oxygenation using BOLD MRI; and (2) Define the relationship between placental oxygenation status and markers of inflammation in fetal CCHD placentas. Importantly, this project has been streamlined into the R03 timeframe and budget to create robust preliminary data for an R01 proposal that will be submitted by the end of the award period. The presence of hypoxia-induced inflammation in the placenta will be a paradigm shift in the fetal CCHD field and will provide novel information about the intrauterine environment of fetuses with CCHD. Moreover, by identifying placental hypoxia as a possible trigger for inflammation and inflammation-mediated disruption to fetal brain development, we will be poised to discover unique molecular targets for future interventional trials.

NIH Research Projects · FY 2026 · 2026-06

Project Summary In this proposal, a group of accomplished molecular scientists at the University of Texas Southwestern Medical Center requests funds for a surface plasmon resonance (SPR) device: the Biacore 1S+ model of SPR instrument manufactured by Cytiva. SPR is a well-established method to detect intermolecular interactions that is currently unavailable at UTSW. It utilizes as a sensor a thin metal surface near which a molecule (the “ligand”) is immobilized. A binding partner (the “analyte”) is flowed over this surface. As the analyte associates with the ligand, mass is added to the zone near to the metal. Concurrently, polarized light is reflected off of this surface, and the added mass can be detected by the angle at which the reflected light is effectively absorbed; this is the angle at which electron waves (surface plasmons) resonate with the energy of the incident light. Because the mass accumulation is detected in real time across several analyte concentrations, the resulting data can be analyzed to reveal the strength of the interaction and its kinetic aspects, both of which are important for the mechanistic characterization of such interactions. UTSW has a vigorous program of molecular research, and the Biacore 1S+ fills a need for many of our scientists. Specifically, our assembled group of investigators is mostly interested in the interactions of small, drug-like molecules binding to macromolecular drug targets, an application at which the Biacore 1S+ excels due to its extremely high sensitivity. Successful characterizations of such interactions is a critical step in the identification and optimization of new drug candidates. Other areas of research that would be enabled by the sensitivity of the Biacore 1S+ explore the signaling potential of small, cellular metabolites and the interactions associated with difficult-to-produce protein. Another key aspect of the Biacore 1S+, its six flow cells, will enhance the rigor and throughput of our experiments. The Biacore 1S+ will be overseen by the already existing Macromolecular Biophysics Resource, a successful core lab at UTSW with an excellent track record of incorporating and mastering new biophysical equipment. UTSW has pledged significant resources to the success of the instrument, and the scientific, innovation, and educational missions of the University will benefit from its presence at the institution. Our team of scientists will utilize the instrument with the aim of developing treatments for serious human health conditions, including Alzheimer’s disease, cancer, liver disease, neurological disorders, malaria, and schistosomiasis. Therefore, the successful placement of a Biacore 1S+ at UTSW has substantial potential to positively impact human health. Finally, access to this instrument will unleash the ability of our investigators to sensitively, accurately, and rigorously study intermolecular interactions, a field that is at the heart of biomedical research.

NIH Research Projects · FY 2026 · 2026-06

Type 1 diabetes (T1D) is viewed as a T cell-mediated autoimmune disease resulting in insulin deficiency due to the lack of functional pancreatic islet beta (β) cell mass. Despite significant advances in insulin replacement therapies, there continues to be an urgent need for treatments that can recapitulate physiologic insulin release. The most promising approach is allogeneic β cell replacement but immune reaction is a key challenge. Our group has developed a novel approach in which β cells are bioengineered to contain high levels of multiple types of immune checkpoint ligands. We found that engineered β cells can induce long term durable tolerance in allogeneic transplantation without the need for immune suppression. We have further identified that the most effective immune checkpoint combination for engineered β cells. The goal of this proposal is to optimize key steps of our engineering platform to enhance therapeutic efficacy, while defining immunological events that reestablish self-tolerance. Our application has 3 Specific Aims. The first Aim will to optimizing the tolerogenic formulation for allogeneic β cell transplantation. This involves examining PD-L1/HVEM ratio and ligand density in inducing transplant tolerance. The second Aim will study an approach where the decellularized pancreas matrix is engineered with immune checkpoint molecules. The success of this aim will improve translatability of this technology. Aim 3 will determine the mechanisms of tolerance induction and maintenance. Our application incorporates advances in chemistry, chemical biology, nanotechnology, and immunology to improve T1D treatment. Our findings can be rapidly translated and hold high potential for clinical impact.

NIH Research Projects · FY 2026 · 2026-06

PROJECT SUMMARY/ABSTRACT Mitochondria are multifunctional organelles with an endosymbiotic origin over 1.5 billion years ago. Beyond their classical role in bioenergetics, mitochondria are key regulators of calcium signaling, apoptosis, and epigenetic programming. Importantly, they retain their own genome (mtDNA), which is essential for cellular fitness, germline development, and species continuity. In oocytes, mitochondrial abundance—quantified by mtDNA copy number—correlates strongly with fertility and developmental potential, highlighting mitochondria as critical determinants of reproductive health. Despite this importance, conventional genetic approaches such as mtDNA depletion or gene knockouts often fail to capture the dynamic, tissue-specific, and temporally regulated roles of mitochondria, particularly in vivo. To overcome these limitations, we have developed a novel enforced mitophagy platform that enables controlled modulation of mitochondrial abundance and quality in vivo, across specific tissues and developmental windows. This proposal applies this innovative system to address key gaps in our understanding of mitochondrial dynamics in reproductive biology and aging. We propose: 1) To investigate how mitochondrial abundance influences primordial germ cell (PGC) specification and contributes to the mtDNA genetic bottleneck. 2) To establish an in vivo mitochondrial depletion model targeting developing germ cells, including spermatocytes, spermatozoa, and oocytes, which will clarify longstanding questions and controversies regarding the functional necessity of mitochondria across stages of gametogenesis. 3) To develop a periodic mitochondrial clearance system to enhance mitochondrial quality control in reproductive tissues. As a proof-of- concept, we will evaluate the system in ovarian stromal cells—an aging-sensitive population—with the goal of improving mitochondrial surveillance and extending reproductive lifespan. By establishing a tractable in vivo framework for manipulating mitochondrial abundance, this work will uncover foundational mechanisms underlying germ cell development, mtDNA inheritance, and age-related decline in reproductive function. The outcomes will have broad implications for reproductive biology, regenerative medicine, and the treatment of infertility and mitochondrial diseases.

NIH Research Projects · FY 2026 · 2026-06

Project Summary/Abstract The goal of this project is to use atomic structures of the activated human D2 dopamine receptor (DRD2) to develop potent small molecule positive allosteric modulators (PAMs) of this G protein-coupled receptor (GPCR) as biological tools and future therapeutic lead compounds. Dopamine activation of DRD2 regulates movement, reward and cognition among other physiological functions, and attenuation of dopamine signaling through this receptor is an important contributor to Parkinson’s disease (PD) which affects approximately 10 million people worldwide. Current therapeutics targeting DRD2 include orthosteric agonists that mimic dopamine for PD, however dopamine replacement therapy is unable to fully restore the natural spatiotemporal patterns of dopamine signaling in the brain, leading to loss of efficacy over time and other side effects. A complementary approach to targeting the orthosteric pocket of DRD2 is using a positive allosteric modulator (PAM) to act synergistically with endogenous dopamine to restore physiologically appropriate dopamine signaling. Despite the central importance of DRD2 signaling and the potential therapeutic benefits of positive allosteric modulation, no DRD2 PAMs have advanced to in-vivo preclinical studies or clinical evaluation. Harnessing our experience in structure determination of the activated signaling complex of DRD2 with Gi, we propose to use cryo-EM structures of this complex with dopamine and candidate PAM compounds in Aim 1 to guide the discovery of the first potent and drug-like small molecule PAMs that can potentiate dopamine signaling through this GPCR. In the second Aim, we will use our discovery of the presence of a binding pocket analogous to PAM sites in other GPCRs, along with the binding mode of the high-affinity agonist bromocriptine, to rationally design small molecules that can bind to this site in the active state and increase dopamine’s affinity. In the third Aim, we will use an unbiased synthon-based virtual screen of billions of drug-like small molecules to discover new compounds that can bind to this putative PAM site. Our combination of strengths in GPCR structural biology, computational drug discovery, and synthetic and medicinal chemistry places us in a unique position to pioneer development of DRD2 PAMs as tool compounds that occupy a unique and untapped pharmacological space with future therapeutic potential in PD.

NIH Research Projects · FY 2026 · 2026-06

Project Summary/Abstract Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a dismal 5-year survival rate of only 12%. A hallmark of PDAC is the extensive desmoplastic stroma, which can comprise up to 90% of the tumor mass, driven largely by the expansion of cancer-associated fibroblasts (CAFs). Through single-cell RNA sequencing (scRNA-seq), our group and others have identified distinct CAF subpopulations in PDAC. These include myofibroblastic CAFs (myCAFs), inflammatory CAFs (iCAFs), and a third, less understood population: antigen-presenting CAFs (apCAFs), which are defined by the expression of major histocompatibility complex (MHC) class II molecules. Using robust lineage-tracing techniques, we demonstrated that apCAFs originate from mesothelial cells. Importantly, apCAFs induce regulatory T cells (Tregs) through an antigen-dependent mechanism. Our spatial transcriptomics studies further revealed that apCAFs form specialized stromal niches that are enriched in chemoresistant cancer cells, myCAFs, and Tregs. These findings underscore the critical role of apCAFs in modulating the tumor microenvironment, with direct implications for immune regulation and therapy resistance. In this proposal, we aim to elucidate the interactions between apCAFs and other cell types within these unique stromal niches. Furthermore, we will examine the therapeutic potential of pharmacologically inhibiting apCAF formation and the key apCAF paracrine signal to overcome resistance to chemo- and immunotherapies. The insights gained from this study will significantly advance our understanding of stromal regulation by apCAFs and could lead to novel strategies for targeting CAFs specifically in PDAC and potentially other cancer types. The use of animal models is necessary for this project because the complex interactions among apCAFs, immune cells, and cancer cells within the tumor microenvironment cannot be adequately studied using in vitro systems alone. These models allow us to trace cell lineage, evaluate gene-specific functions in vivo, and test therapeutic strategies in physiologically relevant settings.

NIH Research Projects · FY 2026 · 2026-05

Project Summary/Abstract: Bloodstream infections (BSIs) caused by Staphylococcus aureus (S. aureus) represent a significant global health threat, accounting for over 1.2 million deaths annually worldwide. Despite advances in medical care, S. aureus BSIs remain challenging to treat due to the pathogen's ability to rapidly adapt to host environments and develop resistance to antibiotics. The mechanisms underlying S. aureus pathogenesis in BSIs are not fully understood, particularly the biological factors contributing to the sex bias in infection outcomes. Clinical data consistently show that males experience worse outcomes from S. aureus BSIs compared to females, yet the reasons for this disparity remain poorly defined. A major gap in current research is the role of sex hormones, particularly testosterone, which is present at significantly higher levels in males. Initial findings from my postdoctoral work have demonstrated that skin-secreted testosterone regulates the agr quorum-sensing system, promoting S. aureus skin infection and inflammation both in vitro and in vivo. However, the role of testosterone in the context of BSIs where testosterone concentrations are significantly higher in male serum remains unexplored. Understanding how testosterone shapes S. aureus behavior in the bloodstream could uncover mechanisms underlying sex-specific differences in disease severity and open new avenues for therapeutic intervention. This research aims to address this critical knowledge gap by investigating the molecular mechanisms through which testosterone influences S. aureus pathogenesis in BSIs. Ultimately, these insights could improve outcomes for male patients and inform the development of sex-specific treatment strategies. To achieve these goals, I will apply a multidisciplinary approach that integrates molecular biology, biochemistry, liquid chromatography–mass spectrometry (LC-MS), transcriptomics, and in vivo infection models. The project is structured around the following specific aims: Aim 1: Determine if testosterone promotes S. aureus virulence by modulating nitrogen metabolism, Aim 2: Determine if testosterone conjugation by S. aureus influences virulence regulation, and Aim 3: Determine if testosterone shapes S. aureus regulatory signaling during BSI. Collectively, these studies will provide critical insight into how testosterone influences S. aureus virulence and pathogenesis during BSI, advancing our understanding of sex-specific host-pathogen interactions. The long-term goal of this work is to improve outcomes for male patients and to address the critical need for targeted therapies. My ultimate objective is to establish an independent research program focused on host- pathogen interactions in BSIs. With a Ph.D. in Molecular Biology and Cellular Biotechnology from the University of Camerino, Italy, and postdoctoral training at UT Southwestern under Dr. Tamia Harris-Tryon, I have developed expertise in the role of sex steroids in bacterial pathogenesis. This award will support the final years of my training, allowing me to acquire new skills in bacterial genomics, metabolism, biochemistry, and advanced in vivo infection models. My mentorship team includes leading experts in microbial pathogenesis, genomics, and host- microbe interactions: Dr. Lora Hooper, Dr. Kim Orth, Dr. Thomas P. Mathews, and Dr. Alexander Horswill.

NIH Research Projects · FY 2026 · 2026-05

PROJECT SUMMARY BACKGROUND: Sepsis is the most common worldwide cause of death during hospitalization. One of the major complications contributing to death is sepsis-associated acute kidney injury (SA-AKI). Despite the rapid shutdown in kidney function, SA-AKI is associated with scant intrinsic cell death, suggesting the existence of mechanisms of physiological impairment that are at once non-lethal, but sufficiently robust to abrogate function. Vascular destabilization is one such target that we and many others have linked to SA-AKI and concomitant multi-organ dysfunction. How to measure and modulate the septic vasculature remain major gaps. We recently showed that the lysosomal cysteine protease cathepsin K (CTSK) is released by acutely inflamed macrophages and acts on key components of the vascular endothelial secretome. A newly reported CTSK target, Angiopoietin-2 (Angpt-2), is converted from a weak agonist to an antagonist of a receptor that signals vascular homeostasis, Tie2. When CTSK cleaves ANGPT2, the cleavage products of ANGPT2 strongly inhibit Tie2 signaling. Loss of Tie2 signaling switches the vascular endothelium to a hyperpermeable, pro-inflammatory, and pro-coagulant phenotype. In the setting of experimental systemic inflammation, CTSK activity rises a striking ~200-fold. Pharmacological cathepsin K inhibition ameliorates acute kidney injury (AKI), acute lung injury (ALI), and organismic survival during sterile inflammation and from polymicrobial sepsis. HYPOTHESIS: We will test the central hypothesis that macrophage-derived cathepsin K is an ANGPT- dependent mediator of SA-AKI. AIMS: Two parallel Aims are proposed. In Aim 1, we will study short and long-term kidney molecular, cellular, and physiological outcomes in murine models of sepsis examining gain of function variants of Angpt1 and Angpt2 and the role of the macrophage in suppling CTSK. In Aim 2, we will interrogate established cohorts to evaluate associations of peripheral CTSK and cleaved ANGPTs to short- and long-term outcomes following SA-AKI. CONCLUSIONS: No adjunctive therapy exists for SA-AKI, in part because current markers of sepsis are insufficiently mechanistic. Our preliminary results propose CTSK as a novel marker and mediator of SA-AKI acting through ANGPTs. Delineating a CTSK-ANGPT mechanistic pathway in septic organ failure offers powerful new translational opportunities for one of the world’s largest unmet medical needs.

NIH Research Projects · FY 2026 · 2026-05

PROJECT SUMMARY The scientific understanding of blood vessels has evolved significantly over the decades. They are now recognized as active gatekeepers that control organ function rather than passive conduits responding to external cues. Endothelial dysfunction is implicated in various pathologies, including atherosclerosis, which is a progressive disease linked to aging, hypertension, diabetes, and dyslipidemia. This condition involves subendothelial inflammation, arterial remodeling, lipid and cholesterol accumulation, arterial stiffness, and lumenal obstruction, which can lead to thrombosis, myocardial infarction, and stroke. Despite preventive therapies like statins, atherosclerosis remains a leading cause of death worldwide. The apolipoprotein E receptor-2 (ApoER2), encoded by the LRP8 gene, is expressed in endothelial cells and is a significant genetic modifier for premature atherosclerosis and acute myocardial infarction, identified across various human populations. Homozygous carriers of the ApoER2-R952Q variant have a twofold increased risk for cardiovascular disease, and those with the ApoE4 variant show a 3.9-fold increased susceptibility. This single-nucleotide polymorphism (SNP) R952Q is thought to confer a gain of function to ApoER2, although the mechanism remains unclear. In addition to ApoE, ApoER2 also binds to Reelin, an extracellular protein that is abundant in the blood. We have shown on endothelial cells that Reelin / ApoER2 interaction promotes vascular adhesion and leukocyte infiltration by elevating vascular immune surveillance. In the atherosclerosis-prone LDLR-deficient (Ldlr-/-) mouse model, Reelin depletion reduces leukocyte-endothelial adhesion and expression of pro-inflammatory adhesion molecules VCAM-1 and ICAM-1, slowing atherosclerosis progression and decreasing macrophage content in lesions. In human endothelial cells, Reelin / ApoER2 signaling enhances monocyte adhesion and upregulates ICAM1, VCAM1, and E-selectin by activating the nuclear factor κB (NF-κB). Based on these findings, we hypothesize that the ApoER2-R952Q mutation increases endothelial adhesion and leukocyte permeability, promoting endothelial dysfunction, inflammation, and plaque formation, which leads to atherosclerosis. To test this hypothesis, we have developed a mouse model with the equivalent Apoer2- R859Q mutation and propose here to dissect this mechanism leading to increased cardiovascular disease risk.

NIH Research Projects · FY 2026 · 2026-05

Abstract Cannabis use and cannabis use disorder (CUD) are increasing in prevalence. When present, CUD exhibits relapse rates similar to those of other substance use disorders, making it a significant and growing public health concern. Notably, CUD is highly comorbid with depression. People with CUD are up to four times more likely to experience depressive symptoms than non-users. This comorbidity is associated with more severe clinical profiles, including earlier onset, greater functional impairment and poorer treatment outcomes. Despite this clinical need, there are currently no FDA-approved pharmacotherapies for CUD, particularly for those with co-occurring depression. Preclinical research demonstrates that the neurosteroid pregnenolone acts as a negative allosteric modulator of the CB1 receptor and inhibits many of the adverse intoxicating effects of cannabis. Our preliminary human studies found that pregnenolone also attenuates cannabis effects in the brain. Given the involvement of the endocannabinoid system in both mood regulation and cannabis reinforcement, pregnenolone may hold dual therapeutic potential, reducing cannabis use while alleviating depressive symptoms. Intravenous allopregnanolone is FDA-approved for postpartum depression. Our previous work showed that pregnenolone reduced alcohol use and depressive symptoms compared to placebo, in individuals with bipolar disorder and alcohol use disorder. Additionally, we reported improvements in depression and anxiety in placebo-controlled trials of pregnenolone in individuals with bipolar disorder or major depressive disorder (MDD). We hypothesize that targeting CB1 signaling through pregnenolone may reduce cannabis use and mitigate adverse cannabis effects, while the GABAergic properties of allopregnanolone will improve mood and anxiety. We propose examining pregnenolone as a treatment for individuals with both CUD and MDD. As a negative allosteric modulator of CB1 receptors, pregnenolone may regulate CB1R activity more subtly than receptor antagonists, potentially resulting in fewer side effects or withdrawal symptoms. Moreover, allopregnanolone may alleviate depressive and anxiety symptoms. The dual actions of pregnenolone and allopregnanolone make them well-suited to treating CUD, particularly in individuals with comorbid MDD. We propose a milestone-driven effort using the UG3/UH3 mechanism to advance pregnenolone as a treatment in this population. The UG3 phase will focus on obtaining regulatory approvals, refining the protocol and harmonizing procedures across sites. To determine optimal dosing frequency, we will conduct a pharmacokinetic study to establish pregnenolone's half-life in this population. A pilot safety and feasibility study will evaluate 12 weeks of pregnenolone treatment. The UH3 phase will incorporate lessons learned during the UG3 phase to conduct a multisite efficacy trial in individuals with CUD and MDD.

NIH Research Projects · FY 2026 · 2026-05

PROJECT SUMMARY We are requesting a 120kV transmission electron microscope (TEM) for the Electron Microscopy Core Facility (EMCF) at UT Southwestern Medical School in Dallas, TX. The EMCF is a campus wide, institutionally supported, fee for service facility that provides electron microscopy services for basic and clinical science investigators at UT Southwestern. In the fiscal year 2025 (which ended August 31, 2025) the EMCF served 132 users from 67 UTSW laboratories. Over the past twenty years, the EMCF has supported nearly 300 publications. The EMCF has two TEMs that together are used more than 3200 hours per year. The instrument we are requesting is intended to replace our nineteen-year-old Tecnai G2 Spirit Biotwin TEM that is near the end of its lifetime. The two cameras on the microscope are failing and are no longer supported by the vendor. The instrument itself has begun to experience significant down time due to the difficulty of finding compatible parts and is often only partially functional because of recurring issues. If this heavily used instrument fails, demand for the remaining microscope will significantly exceed the time available. Timely replacement of the Tecnai G2 will enable the health-related research of the 16 major users listed in this application as well as many other laboratories who use the EMCF in support of their NIH funded research. Among other projects, the requested microscope will be used to study the structure and function of insulin receptors, ion channels, the virulence of bacterial pathogens, lipogenesis, cardiac and skeletal muscle development, and the mechanism of amyloid aggregation. These studies will have an impact on our understanding and treatment of diseases such as diabetes, obesity, muscular dystrophy, cardio myopathy, Alzheimer's and Parkinson's.

NIH Research Projects · FY 2026 · 2026-05

PROJECT SUMMARY Ribosomes are essential molecular machines that translate genetic information into proteins—a process especially critical in the immune system, where rapid cell proliferation, differentiation, and effector functions are necessary to maintain immune homeostasis and respond to pathogenic threats. Although ribosome biogenesis is central to immune cell function, the mechanisms regulating this process—and the consequences of their disruption—remain poorly defined. This gap in knowledge is clinically significant: enhanced ribosome production can drive malignancy and autoimmunity, while impaired biogenesis can lead to immune deficiency and cytopenia. Using unbiased germline mutagenesis and biochemical approaches, we have identified a novel nuclear complex composed of two previously uncharacterized zinc finger transcription factors, ZFP574 and THAP12. Loss of either factor destabilizes the other and leads to severe immune dysfunction, including pan-cytopenia and G1–S phase cell cycle arrest. Remarkably, neither ZFP574 nor THAP12 was previously known to regulate transcription. Our preliminary data reveal that this complex acts as a transcriptional activator of Polr1h, a core subunit of RNA Polymerase I (Pol I), which is predicted to contribute to the proofreading of rDNA–rRNA hybrids. Loss of either protein selectively downregulates Polr1h expression in lymphocytes—without affecting other Pol I subunits— suggesting a targeted mechanism that sustains rRNA synthesis and ribosome biogenesis. We hypothesize that ZFP574–THAP12–mediated regulation of Polr1h is essential for RNA Pol I function and immune cell competence. To test this, we will: (1) define the mechanisms by which the ZFP574–THAP12 complex supports immune development and function; and (2) evaluate the therapeutic potential of targeting this pathway in models of leukemia and autoimmunity. Relevance to public health: Signaling pathways that sustain lymphocyte survival are often hijacked in leukemia and autoimmune disease. There is a critical need for therapies that selectively disrupt these pro-survival programs. This project investigates a newly identified transcriptional complex essential for immune cell function and ribosome production, offering a novel therapeutic target in diseases marked by immune overactivation or malignant transformation.

NIH Research Projects · FY 2026 · 2026-05

PROJECT SUMMARY Despite advances in pre-operative diagnostic imaging and highly skilled surgeons, the positive margin rate (PMR) for HNC remains unacceptably high at 10-30%. Fluorescence-guided surgery (FGS) using cancer- targeted imaging agents highlights potential cancerous areas for immediate removal, reducing the risk of incomplete resections and subsequent rapid cancer recurrence. Previously, we’ve evolved the Cancer Vision Goggle (CVG) FGS technology into a user-friendly, lightweight, head-mounted system that’s untethered from cumbersome computers or displays, offering real-time monitoring of tissue and tumor locations and adjusting for positional changes during surgical manipulations. This innovation affords surgeons greater mobility and the convenience of hands-free operation with instantaneous fluorescence signal visualization, though weaknesses have been identified during our preclinical and clinical testing. The current CVG system, initially designed for breast cancer (BC) and head and neck cancer (HNC) surgeries, is now in use with aspirations to broaden its application across various cancer types and even non-cancerous procedures. Despite the system’s success, our collaborative surgeons have pinpointed critical areas for improvement to further advance this technology. These enhancements are essential for transforming the CVG into a versatile tool across a range of clinical settings. To address these shortcomings in this academic-industrial partnership, we will: 1) Transition from a monocular camera setup to a stereoscopic vision system. This will significantly improve the visualization of tissue contours and align the real and virtual worlds more accurately; 2) Integrate intraoperative ultrasound to address the limitations of pre-incision, subsurface tumor detection, that will work in tandem with optical methods of the existing system; and 3) augment the CVG with external exoscope microscopic imaging capabilities, enabling surgeons to more closely examine areas of concern that are highlighted during the video stream. These targeted enhancements are expected to elevate the CVG’s functionality, making it an indispensable asset in the operating room.

NIH Research Projects · FY 2026 · 2026-05

PROJECT SUMMARY (30 line limit) RAS mutations drive a substantial proportion (20~30%) of deadly tumors. Two KRASG12C inhibitors, sotorasib and adagrasib, are now approved, justifying the feasibility of direct targeting RAS. Despite this achievement, approved KRASG12C inhibitors do not address other oncogenic RAS alleles, such as the hotspot Q61 mutations (e.g. Q61H, Q61K, Q61L, and Q61R). Thus, a deeper understanding of fundamental RAS mechanisms and functions is essential for effectively tackling RAS-driven diseases. RAS transmits signals through protein-protein interactions controlled by nucleotide binding state. These interactions are thought to occur within multi- component "signalosomes" that form when RAS is bound to the cell membrane and various RAS effector proteins. We have published two structural models (Cell and Nat Struct Mol Biol) for membrane-bound KRAS protein complexes, validated in biological systems, while other models have been proposed without biological validation yet. The transient nature of these “complexes,” makes them difficult to isolate and study. This proposal aims to characterize the novel, covalent RAS dimer we have observed at the hotspot Q61, and to develop new therapeutic strategies specifically targeting RASQ61 mutants commonly found in human cancers, such as melanoma, leukemia, thyroid cancer, and lung cancer. Based on our preliminary data, we hypothesize that RASQ61 mutants form covalent dimer at differential propensity and are particularly responsive to specific classes of RAF and MEK inhibitors. Therefore, the specific aims of the current proposal are to 1) Determine the prevalence and determinants of the covalent dimer of RASQ61 mutants; 2) Evaluate the impact of RAFi’s and MEKi’s on covalent RAS dimer formation and signaling of RASQ61 mutants; 3) Elucidate the mechanism for RAFi’s and MEKi’s sensitivity in the context of RASQ61 mutants. The overarching goal of this proposal is to develop new therapeutic concepts specifically tailored to RASQ61 mutants (Q61H, Q61K, Q61L, and Q61R) found in cancer patients. Successful completion of this study will characterize Cys118-meidated covalent RAS dimer of Q61 mutants and pinpoint the best RAFi’s and MEKi’s for RASQ61 mutants-driven cancers. This research will set the stage for clinical development of the first RAS biomarker-driven, molecularly targeted RAFi and MEKi therapies, representing a significant and innovative advancement in clinical oncology given the current lack of targeted therapies for RASQ61 mutants-driven cancers. More broadly, this work will expand our fundamental knowledge of how RAS proteins function within larger signaling complexes at the cell membrane.

NIH Research Projects · FY 2026 · 2026-05

Project Summary To gain access to cells, most viruses attach to receptor molecules. While many virus receptors have been identified, the impact of post-translational modifications on receptor function remains understudied. Glycosylation is a major type of post-translational modification of cell surface proteins, and viruses often exploit cell surface glycans for entry. However, given the extreme heterogeneity of glycosylation, it is unlikely that all glycans play equivalent roles in host-virus interactions. This proposal posits that specific glycosylation patterns can disrupt virus-receptor interactions, serving as a host defense mechanism against viral entry. My preliminary studies identify β1,3-N-acetylglucosaminyltransferase 2 (B3GNT2) as an interferon-stimulated gene that strongly inhibits multiple alphaviruses, including Venezuelan equine encephalitis virus (VEEV). B3GNT2 catalyzes the biosynthesis of poly-N-acetyllactosamine (polyLacNAc) chains leading to heavy and bulky glycosylation of LDLRAD3, a host receptor for VEEV. Consistent with its role in receptor glycosylation, B3GNT2 reduces VEEV attachment to the cell surface. Based on these findings, I hypothesize that B3GNT2 inhibits VEEV entry by glycosylating the viral receptor and may protect against VEEV-induced pathogenesis in vivo. Given its broad antiviral effects against multiple alphaviruses, I further hypothesize that B3GNT2 inhibits other alphaviruses including Chikungunya virus (CHIKV), through a similar mechanism. In the K99 mentored phase, I will integrate biochemical, cell biological, and glycan-based approaches to define the antiviral mechanism of B3GNT2 against VEEV (Aim 1) and investigate its antiviral role in VEEV pathogenesis using mouse models (Aim 2). In the R00 phase, I will extend these studies to CHIKV infection in B3gnt2 knockout mice and define the role of polyLacNAc glycosylation in blocking receptor-mediated entry of multiple alphaviruses (Aim 3). These studies will provide key insight into how host cells prevent viral entry through glycosylation and establish experimental tools to explore the broader role of glycosylation in host-pathogen interactions.

NIH Research Projects · FY 2026 · 2026-05

PROJECT SUMMARY/ABSTRACT Interspecies blastocyst complementation (IBC) holds great potential to open new avenues for neuroscience, offering a unique perspective on brain development and evolution. This technique introduces donor pluripotent stem cells (PSCs) into host blastocysts lacking essential organ development genes, enabling the formation of interspecies chimeras. Such chimeras allow for the development of donor-cell-enriched organs in host organisms, a method previously applied to create various organs but not yet successful for brain tissue. Our preliminary studies have introduced a C-CRISPR-based blastocyst complementation method (CCBC), enabling the generation of rat forebrain tissue in mice for the first time. This allows us to study brain development and function from an evolutionary angle, potentially transforming brain research and providing a foundation for ethical considerations regarding the use of human PSCs in animal brains. Building on this, our proposal aims to dissect the xenogeneic barriers affecting brain development between mice and rats, explore non-cell autonomous mechanisms in rat-mouse forebrain chimeras, and attempt to create forebrain tissues from a wide rodent species, African pygmy mouse, in mice. Our objectives include: 1) Understanding Xenogeneic Barriers: Investigating the decline in rat cell contribution in chimeric mouse forebrains, potentially due to cell competition, proliferation differences, or cell adhesion incompatibility, and exploring strategies to overcome these barriers. 2) Exploring Non-Cell Autonomous Mechanisms: Examining how rat-mouse chimeras adapt brain size and developmental pace to the mouse host, using multi-omics analyses and interspecies mesenchymal blastocyst complementation to uncover the molecular and cellular basis of these effects. 3) Expanding to Wild Rodent Species: Venturing beyond common laboratory models to study the forebrains of wild rodents, such as the African pygmy mouse, to broaden our understanding of brain development. Our proposed study promises to illuminate fundamental aspects of brain organization, functionality, and evolutionary dynamics.

NIH Research Projects · FY 2026 · 2026-05

Summary We have identified a novel epigenetic susceptibility mediated by Jumonji enzymes that is acquired by ER+ breast cancers as they become resistant to CDK4/6 inhibitors. Preliminary data in multiple models indicates that as breast cancer cells and tumors become progressively more resistant to palbociclib, they become more dependent on enzymes that help them adapt, the targetable Jumonji histone demethylases. Cdk inhibitor- resistant breast cancers, especially those lacking functional pRB, are therefore hypersensitive to inhibitors of Jumonji histone demethylase enzymes. These enzymes are upregulated during the development of drug tolerance and therapeutic resistance and we think they are necessary for the transcriptional adaptability that allows cells to survive therapeutic stress. Resistant cells are exquisitely sensitized to Jumonji enzyme inhibitors in culture while they no longer respond to cdk inhibition. In the present application, our objective is to validate and translate these observations in three important ways: i) by testing the sensitivity of cdk inhibitor resistant cell lines, organoids and patient derived xenografts to our Jumonji inhibitors, ii) by identifying the epigenetic mechanisms underlying this response and iii) by evaluating if Jumonji genetic or pharmacological inhibition can prevent the emergence of drug tolerance and the development of resistance to CDK4/6 inhibitors in ER+ breast cancer. Our efforts can lead to immediate clinical translation since Jumonji inhibitors have just entered clinical trials.

NIH Research Projects · FY 2026 · 2026-05

PROJECT SUMMARY/ABSTRACT A common factor in the development of obesity involves maladaptive eating behaviors that lead to health- concerning increases in weight. In an effort to better understand feeding-regulating brain circuits, the hypothalamus has been a primary focus in studying satiety mechanisms, as it plays an important role in energy homeostasis and has a high expression of leptin receptors, a well-known satiety hormone. However, it has been shown that global deletion of leptin receptor (LEPR) in mice leads to more severe obesity phenotypes than hypothalamic-specific deletions. These data suggest that leptin signaling in other brain regions may play important roles in feeding regulation. Interestingly, several mRNA studies in rodents and humans have reported substantial expression of LEPR in the cerebellum. Yet, the specific contributions of cerebellar leptin signaling in feeding behavior remain unknown. Additionally, my preliminary data show that inhibition of Purkinje cells (PCs) in a cerebellar lobule, Crus I, might be sufficient to decrease feeding, and potentially body weight, in Lepr-null mice. This points to the potential roles for the cerebellum in feeding regulation, which could prove beneficial in activating satiation circuits in the context of hyperphagia and obesity. Based on these data, I hypothesize that important feeding behavior functions reside in the cerebellum, and that understanding the circuits and molecules critical for these functions could offer potential therapeutic opportunities in the treatment of obesity. To test these hypotheses, I propose the following specific aims. Aim 1: Delineate the efficacy of Crus I-mediated decreased feeding in models of obesity. Aim 2: Define the involvement of PC leptin signaling in feeding behavior. Understanding of the extra-hypothalamic contribution to feeding behavior remains limited despite mounting evidence for a role of brain regions beyond the hypothalamus. Successful completion of these aims can create a more complete understanding of satiety circuits by revealing the mechanisms of cerebellar-induced decreased food intake in obesity and the role of cerebellar leptin signaling. Therefore, this project can ultimately aid in identifying new targets to develop more effective treatments or prevention strategies for obesity.

NIH Research Projects · FY 2026 · 2026-05

Project Title: Targeting cell death pathways to prevent KRAS inhibitor resistance Abstract Pancreatic ductal adenocarcinoma (PDAC) remains one of the most lethal malignancies, with over 90% of cases driven by KRAS mutations. Although recently developed KRAS-G12C inhibitors have shown promise in other cancers, their applicability to PDAC is limited, as most patients harbor non-G12C KRAS mutations. New pan- KRAS inhibitors broaden therapeutic reach and often arrest tumor growth, but cancer cell subpopulations do not undergo adequate cell death, enabling the cells to survive and acquire resistance. Our preliminary studies indicate that KRAS inhibitor-resistant PDAC cells upregulate several death receptors, suggesting that cell death regulation plays a key role in KRAS inhibitor resistance. We found that combining TRAIL with pan-KRAS inhibitors synergistically promotes tumor cell death and disrupts proteostasis—a process essential for maintaining protein homeostasis and cell survival. While recombinant TRAIL effectively induces apoptosis, its efficacy is limited by its rapid clearance and by potential pro-survival signaling. To overcome these challenges, we will utilize two novel TRAIL-based approaches: a chimeric Fc-TRAIL fusion protein with enhanced stability, and natural killer (NK) cells engineered to secrete trimerized TRAIL, which will be combined with pan-KRAS inhibitors to enhance therapeutic efficacy. Our central hypothesis is that KRAS inhibition disrupts cell death signaling in PDAC, creating a therapeutic vulnerability that novel TRAIL-based strategies can exploit by disrupting proteostasis, restoring apoptotic pathways, and preventing resistance to KRAS inhibitors and TRAIL. In Aim 1, we will dissect how combining pan-KRAS inhibitors with Fc-TRAIL or TRAIL-secreting NK cells reactivate extrinsic apoptosis, disrupts proteostasis, and counters pro-survival signals. We will validate these findings in patient-derived PDAC primary cells. In Aim 2, we will assess the therapeutic efficacy of this combination in peritoneal metastasis models of PDAC, monitoring tumor progression, survival outcomes, and the tumor microenvironment using single-cell RNA sequencing and machine-learning analyses. Additionally, we will enhance NK cell specificity by engineering chimeric antigen receptors that recognize the immune checkpoint proteins PD-L1 or B7-H4, which are expressed on pancreatic cancer cells, while concurrently secreting TRAIL. By integrating pan-KRAS inhibition, targeted cell death pathways, and NK cell immunotherapy, this project aims to elucidate the response and resistance mechanisms to pan-KRAS inhibitors and develop a more effective, multifaceted strategy against KRAS-driven PDAC.

NIH Research Projects · FY 2026 · 2026-05

Project Summary/Abstract Protein phosphorylation is the most common post-translational modification in eukaryotic cells and impacts nearly every cellular process. Despite the ubiquity of phospho-regulation and its long history of study, there remain technical challenges to accurately detecting protein phosphorylation events, particularly in multi-site phosphorylation. For example, it remains impossible to predict how or if multi-site phosphorylation will shift a proteins migration on SDS-PAGE and, as a result, detecting phosphorylated proteins by western blot requires a priori knowledge to raise a phospho-specific antibody. As SDS-PAGE is arguably the most widely used, accessible, and cost-effective means of protein analysis, advancing this technology to enable the consistent and quantifiable detection of protein phosphorylation would benefit nearly all fields of cell biology. This exploratory project will exploit a novel mechanism for chemically modifying protein phospho-sites for the purpose of developing new methods to study protein phosphorylation. Specifically, we will take advantage of the newly characterized Legionella pneumophila effector protein LnaB, which installs adenosine monophosphate (AMP) specifically onto the phosphate group of phosphorylated serine, threonine, and tyrosine. These proof-of-principle studies will determine whether LnaB can accommodate ATP analogs with an alkyne adduct (ATP-alkyne), thus facilitating click-chemistry with azide-containing molecules for the modular modification of protein phospho-sites. Towards this end, we will first identify LnaB orthologs with optimal catalytic efficiency and broad specificity phosphoryl-AMPylase activity. Subsequently, we will test whether ATP analogs with alkyne adducts (on either the adenine base or ribose) are suitable substrates for LnaB. As a proof-of-principle application, we will use this method to quantify multi-site phosphorylation. Specifically, we will install “mass tags” – azide-containing peptides of defined molecular weight – on phosphorylated proteins to quantitatively shift their mass in a manner that is linearly dependent on the number of phosphates. By combining this with SDS-PAGE, we will determine whether we can quantify multi-site phosphorylation of recombinant proteins and detect both phosphorylated and non- phosphorylated proteins with a single antibody in complex samples by western blot analysis, thus directly quantifying fraction phosphorylated. Our long-term goal is to develop a modular set of reagents for modifying phospho-proteins for unique downstream applications, including counting multi-site phosphorylation by SDS- PAGE, fluorescent labeling, streamlined western blot detection, and, in the future, modulation of specific phospho-regulatory axes to alter signaling pathways for therapeutic purposes.

NIH Research Projects · FY 2026 · 2026-05

Abstract Clear cell renal cell carcinomas (ccRCC), the most common type of kidney cancer, rewire their metabolism to avidly take up circulating lipids carried by lipoproteins. However, the precise contributions of these lipids to cancer progression remain unclear. We recently demonstrated that ccRCC tumors bolster their antioxidant defenses by increasing their uptake of lipoproteins, which carry most circulating lipids. This enhanced lipoprotein uptake confers resistance to lipid peroxidation and subsequent ferroptotic cell death. Both major lipoprotein classes, low-density lipoproteins (LDL) and high-density lipoproteins (HDL), exhibit anti-ferroptotic properties; however, HDL has a much stronger antioxidant effect than LDL. Blocking the uptake of these antioxidant-rich lipoproteins induces oxidative stress and suppresses tumor growth. Despite these findings, the specific lipid functional nodes by which lipoproteins influence the redox state of ccRCC cells, and the distinct contributions of different lipoprotein classes to this phenomenon, remain uncertain. My research aims to investigate the antioxidant role of lipoprotein uptake in ccRCC by systematically examining their influence on tumor metabolism and progression. First, I will identify the antioxidant components of lipoproteins in ccRCC tumors. Using focused analytical and functional genetic approaches, I will pinpoint the lipid cargo acquired from lipoprotein uptake and assess its impact on the antioxidant response of ccRCCs in vitro and in vivo. Second, I will dissect the relative contribution of individual lipoprotein classes to ccRCC tumor growth. By employing genetic manipulation of class-specific uptake mechanisms, I will determine the unique effects of each lipoprotein class on the antioxidant response of ccRCC tumors in vivo. Finally, I aim to elucidate the mechanism underlying the strong antioxidant effect of HDL in cancer. Through a systematic analysis of lipidomic, proteomic, and genetic changes in response to HDL versus LDL uptake, I will clarify the differing anti-ferroptotic effects of these two lipoprotein classes. This research builds on our previous work by providing a mechanistic understanding of lipoprotein-mediated antioxidant protection and delineating the roles of different lipoprotein classes in this process. Tumors evade oxidative damage and other metabolic challenges by uptaking antioxidant-rich lipoproteins. This proposal seeks to explore this crucial antioxidant function in ccRCC. By systematically analyzing the contributions of lipoprotein classes to tumor redox homeostasis, we aim to identify targeted therapeutic strategies to improve outcomes for patients with aggressive ccRCC.