Vanderbilt University Medical Center

NIH Research Projects · FY 2025 · 2022-06

Lowering TGs to reduce the risk of coronary heart disease (CHD) is an active area of drug development. New drugs under development target TG genes in the lipoprotein lipase (LPL). The status quo is that: (1) we know little about potential beneficial and detrimental effects of long-term inhibition (or activation) of these target TG genes; (2) most TG-lowering drugs in development focus on the LPL pathway--we need to identify new TG targets in other pathways; (3) TG drug development currently targets one gene at a time and neglects agents that affect many genes simultaneously. We propose to fill the knowledge gaps as follows. (1) TG levels are associated with many diseases and TG genes regulate many biological processes; thus, long-term targeting of TG genes may have pleiotropic effects other than reducing CHD. Traditional post- marketing approaches to identify such effects require a long time. The effects of long-term inhibition of TG genes can be defined rapidly by studying individuals with genetically determined variation in gene function--a Mendelian randomization approach. In Aim 1 we will define clinical phenotypes other than CHD associated with genetically determined variation of TG gene function by using (a) known functional variants, (b) imputed gene expression, and (c) a gene-specific genetic risk score (GRS) as proxies of long-term effect of drugs targeting TG genes (LPL, APOC2, APOC3, ANGPTL3, and ANGPTL4) and testing their association with ~1,600 clinical phenotypes extracted from EHRs in BioVU (~130,000) and eMERGE (~100,000). (2) Identifying novel genes associated with TG levels will facilitate the development of TG-lowering drugs. The high genetic diversity in people of African ancestry (AAs) enhances our ability to identify variants with large effect size. A strategy of combining sequencing and extreme-tail sampling (studying people at the extremes of a quantitative trait) led to the development of PCSK9 inhibitors to lower LDL-C. In Aim 2, we will apply extreme- tail sampling and exome sequencing in AAs to identify new therapeutic targets for lowering TGs. (3) In addition to targeting one gene at a time, there is increasing interest in using the transcriptome for drug development by searching for drugs that reverse the transcriptomic signature associated with a disease. However, the measured transcriptome is affected by the disease itself and associated diseases and therapies. In contrast, the genetic component of the transcriptome is not confounded in this way and is more likely to represent a causal signal. In Aim 3, we will impute the genetically determined component of the TG transcriptome (i.e., the virtual transcriptome). By searching drug perturbation databases, we will identify repurposing drug candidates that reverse the TG virtual transcriptomic signature. The candidates identified will be validated by characterizing their effects on measured TGs in large EHRs (BioVU and eMERGE). These studies will have potential high impact by identifying: 1) new uses and new adverse effects of TG-lowering drugs in development; 2) new genetic targets for TG lowering; 3) existing drugs that lower TGs.

NIH Research Projects · FY 2026 · 2022-05

ABSTRACT Pulmonary hypertension (PH) due to left heart failure is a common and highly morbid disease characterized by molecular, histophenotypic, and clinical heterogeneity that hampers progress in diagnosis and therapeutic target discovery. Biochemical markers and treatments for left heart failure-PH patients are lacking. Some patients with left heart disease develop combined pre- and post-capillary PH (CPH), characterized by severely elevated pulmonary vascular resistance, vascular remodeling, and early death. This vascular profile cannot be ascribed to pulmonary venous hypertension (PVH) alone. For example, we show that compared to PVH, patients with CPH are younger but have a similar duration and severity of left heart disease. We also reported that the genetic profile of CPH is divergent from patients with PVH but is also highly diverse among CPH patients. This observation is consistent with the complex patterns of vascular remodeling observed at autopsy in CPH, and, collectively, suggest that opportunity may exist to leverage the unique pathobiological profile of individual CPH patients for optimizing diagnosis and treatment. We present preliminary data innovating network medicine to exploit unique pathobiological features in patients with a complex left heart disease associated with PH. We developed patient-specific networks focusing on functional/physical protein-protein interactions (PPIs), generating a unique molecular ‘wiring map’ for each patient. Network topology predicted pulmonary hemodynamics and tissue histologic features (e.g. fibrosis) in individual patients despite phenotypic heterogeneity across the cohort. Therefore, we propose to use this approach to advance precision medicine in CPH, which sets the framework for our central hypothesis: In CPH, shared features across patient-specific PPI networks will identify next-generation biomarker(s) that are based on functional molecular pathways, disease-specific, and prognostic. We postulate also that targeting PPIs unique to individual patients using systems pharmacology will provide a novel avenue to individualize drug therapy. In Aim 1 we will profile the CPH, PVH, and pulmonary arterial hypertension (PAH) transcriptome (N= 50/group) to identify PPIs that are shared by all CPH patients, but distinct from PVH/PAH. We will use endophenotype enrichment, network topology, genetic context, and protein expression data as filters to identify next-generation CPH biomarker candidates in silico. Finally, we will validate the CPH biomarkers for associations with functional capacity and prognosis in two external cohorts and human lung samples. In Aim 2 we will integrate drug-protein interaction and PPI network data to identify patient-specific repurposed therapies and use functional genetics, drug effect-protein expression data, and drug availability and safety profiles to filter therapeutic candidates. Finally, we will perform five N-of-1 placebo-controlled cross-over trials using mechanistic endpoints to test the validity of our systems pharmacology pipeline for individualized drug selection. These innovative experiments advance precision medicine in CPH, a highly morbid disease that lacks treatment.

NIH Research Projects · FY 2026 · 2022-05

Project Summary / Abstract Osteoporosis is under diagnosed and under treated. It is essential that we develop novel tools for early detection and treatment strategies to reduce the number of fragility fractures that accompany aging. Systemic hypertension is another disease of aging that commonly co-exists with osteoporosis and likely predisposes individuals to the disease. In this multidisciplinary project, we will investigate a common molecular basis between hypertension and osteoporosis that weakens bone during aging. Our preliminary data indicate that experimental hypertension involving mice is associated with a striking loss in bone strength, which is mediated in part by the production of colony stimulating factor 1 (CSF1) in the bone marrow. The first goal of the project will be to test the hypothesis that enhanced endothelial cell deformation and elevated blood pressure promote the age-related decline in bone strength. We will employ cell culture experiments in which endothelial cells are dynamically stretched below human monocytes with and without exogenous recombinant proteins to determine if factors released by the activated endothelium promote osteoclast differentiation. In addition, we will lower blood pressure of aged mice and determine if this improves bone strength by reducing inflammatory cytokines that favor bone resorption. The second goal will be to test the hypothesis that enhanced sympathetic tone in aging and hypertension promotes immune activation and bone loss. We are experts at modulating sympathetic tone using a technique called Designer Receptor Exclusively Activated by Designer Drugs and by local denervation techniques. Thus, we will increase sympathetic tone to determine if this mimics the age-related decline in bone strength and decrease sympathetic tone to determine if this prevents hypertension and aging-induced loss in bone strength. The third goal will be to delete the endothelial CSF1 gene in adult mice to firmly establish the endothelium as a mediator of osteoporosis. Finally, our prior work has established a critical role of the cytokine interleukin (IL) 17A in hypertension, and others have shown that it plays a critical role in bone loss due estrogen withdrawal (menopause). We will therefore generate mutant mice that will allow deletion of IL17 receptor A in adult mice and determine if this prevents hypertension-related bone loss. As a translational goal, we will treat aged or hypertensive mice with a control antibody and vehicle, a neutralizing anti-CSF1 antibody, or an IL-17RA antagonist and determine if these strategies improve bone strength. In all aims we will 1) monitor blood pressure and bone mass, 2) assess immune cell profiles in the bone marrow, and 3) comprehensively characterize bone strength including toughness and other bone quality measurements. By understanding how hypertension affects bone marrow in the context of aging and by working as a collaborative research team comprised of different skill sets, new therapeutic strategies can be identified to prevent the age-related increase in fracture risk.

NIH Research Projects · FY 2024 · 2022-05

PROJECT SUMMARY Kidney stones can cause severe pain and are associated with kidney injury, infections, and reduced quality of life. The prevalence of kidney stone disease has risen across all demographic groups, especially among women, children, and minorities. All kidney stone patients are at risk for future symptomatic events. Therefore, determining the appropriate preventative strategies to prevent future symptomatic events will improve health and reduce the care-related costs for urinary stone disease. Diet and pharmacologic interventions for preventing future kidney stone episodes are effective, and these interventions are made over a lifetime due to kidney stone disease as a chronic condition. The interventions can be burdensome, have side effects, and have associated costs. Clinical guideline panels disagree on whether clinicians should perform selective therapy: performing 24-hour urine testing to guide choosing interventions to correct abnormal urinary parameters. The alternative strategy is empiric therapy: applying interventions without 24-hour urine testing. No trials have compared selective versus empiric pharmacologic intervention strategies to reduce kidney stone recurrence risk. In contrast, diet studies to date comparing these two strategies have had methodologic flaws limiting their interpretation. Our overall goal is to compare the effectiveness and safety of selective and empiric strategies for kidney stone prevention. The primary outcomes will be mean calculated supersaturations of calcium oxalate and calcium phosphate. Aim 1 will perform a randomized clinical trial of selective versus empiric diet and pharmacologic on therapy patients with presumed idiopathic calcium stones The empiric group will have pre-assigned diet recommendations and daily thiazide with potassium citrate, whereas the selective group will be prescribed an individualized diet and medication regimen as guided by 24-hour urine testing. Secondary outcomes will evaluate other urinary parameters and adverse events related to the interventions. Aim 2 will evaluate adverse effects from selective and empiric strategies and assess patient adherence. The contribution of the proposed research is expected to be identifying what preventative strategies work best among kidney stone patients, who are all at risk for kidney stone recurrence.

NIH Research Projects · FY 2025 · 2022-05

Prothrombin and plasminogen, two central hemostatic zymogens, are activated proteolytically by cleavage of an activation loop. The newly formed N-terminus inserts into a binding pocket and triggers formation of a functional active site. The activation products thrombin and plasmin respectively form and degrade fibrin, but physiological regulation prevents uncontrolled clotting and promiscuous plasmin-mediated tissue degradation. The bacterial virulence factors, staphylocoagulase (SC) and streptokinase (SK), hijack this mechanism by inserting their own N-termini into the host zymogen pockets, and conformationally activating the catalytic site. The SK-plasminogen complex proteolytically activates plasminogen to plasmin. Both the SC and SK complexes with the zymogens and the mature proteases cleave fibrin(ogen) but are impervious to host antithrombin and antiplasmin, and alternative methods are needed to zcontrol their unwanted activity. Our monoclonal antibodies (mAbs) against the SC and SK N-termini block complex formation and activity, counteracting infection-related thrombosis and bacterial spreading in vivo. This illustrates mechanism-based mAb feasibility in an environment of increasing antibiotic resistance. SC and SK have additional, incompletely defined binding sites for fibrin(ogen) independent of substrate recognition, that play a role in localization. Our proposal aims to identify unique SC and SK sequences, and conformational epitopes in their complexes with the zymogens, that promote binding of fibrin(ogen), both in substrate and anchoring modes. Our group has long-standing expertise with SC and SK- mediated zymogen activation, and we recently made good progress identifying fibrin(ogen) fragment D binding to the C-terminal repeats of SC. However, interactions of the SK-plasmin(ogen) complexes with host fibrin(ogen) are still not well understood. Our short-term goals are to define fibrin(ogen) binding, enhancement of cofactor- zymogen reactivity by fibrin(ogen), identify binding epitopes, and develop in vivo effective mAbs that will be added to our existing antibody arsenal. We combine our structure-function and mechanism expertise with that of experts in mAb development (Dr. Bill Church), and in application of mouse models of SC and SK action (Dr. Peter Panizzi). Aim 1 will define dual interaction mechanisms of the SC-prothrombin complex with fibrin(ogen), with the goal of identifying suitable linear and conformational epitopes for blocking fibrin(ogen) binding. Aim 2 will delineate fibrin(ogen)-dependent plasminogen activation mechanisms of S. pyogenes SK variants that to date are not well defined, with the same goal of identifying fibrin(ogen)-binding epitopes on the SK variants. Aim 3 will test our humanized mAbs targeting the N-termini of SC and SK in vivo, and select tight-binding anti- fibrin(ogen) binding site mAbs for in vivo studies. Long-term goals for future funding cycles are the development of mAbs that that cross-react with a wide range of serotypes and allelic variants, and may qualify for pre-clinical and clinical testing. Cocktails of these mAbs would support the patient's hemostatic system by minimizing plasmin-mediated bacterial spreading and unwanted prothrombin activation without causing bacterial resistance.

NIH Research Projects · FY 2025 · 2022-05

PROJECT SUMMARY High nursing workload is a threat to care quality, patient safety, and nurses’ well-being and job satisfaction. Workload – which lacks a universally accepted definition - is a complex multi-dimensional construct that is affected by external task demands and environmental, organizational, and psychological factors. The importance of managing high workload is nowhere more evident than in neonatal intensive care units (NICUs). Critically ill neonates are highly vulnerable to iatrogenic events due to their immaturity and fragility, and high workload has been directly associated with increased incidence of adverse neonatal safety outcomes. Despite the evidence and need, patient safety researchers have been slow to develop multi-level models, scalable workload measurement systems, or other health information technology interventions to improve workload management and patient safety. Conventional nursing workload management tools predominantly measure and predict workload using unit-level (e.g., staffing ratios) or patient-level (e.g., acuity) data rather than data collected across the four levels of workload recommended by human factors engineers (HFEs) - unit, job, patient, and situation. As a result, current tools under-measure the workload experienced by nurses and are not designed to identify mutable microsystem factors that contribute most to nursing workload. A promising development in nursing workload research is the increasing emphasis on measuring situational workload which best explains the workload experienced by nurses due to healthcare microsystem design. Situational workload is most affected by performance obstacles (i.e., delays, interruptions, etc.) in the local work environment and can be applied at the unit, job, or patient-levels. Most importantly, it is diagnostic of underlying contributory factors and therefore actionable for improvement. To date, situational workload has been measured using subjective surveys which are work-interrupting, thus difficult to integrate into practice. Vanderbilt University Medical Center (VUMC), in collaboration Johns Hopkins University (JHU), will employ a systems engineering human-centered design process to design, develop, and validate new multi-level models of NICU nursing workload derived from readily accessible electronic health record (EHR) data. The validated models will be the foundation for a future EHR-based clinical decision support (CDS) tool that will track the real-time workload of registered nurses, predict near- term future unit workload, and guide workload reduction and balancing interventions. The project’s three Specific Aims are: Aim 1. To conduct a comprehensive HFE-based analysis of NICU nursing workload; Aim 2. To design and develop real-time multivariable workload models and Aim 3. To validate the real-time workload models at VUMC (A) and to determine the generalizability of the models at an external hospital (B).

NIH Research Projects · FY 2025 · 2022-05

Summary Biliary tract cancer (BTC), which includes cancers of the gallbladder and bile ducts, is the second most common primary hepatobiliary cancer worldwide. BTC is highly fatal, with ~90% of its patients dying within five years after diagnosis. A better understanding of the etiology of BTC is critical for designing cost-effective prevention strategies to reduce the morbidity and mortality of this fatal cancer. The biliary tract plays a central role in the metabolism and absorption of fat-soluble endogenous and exogenous compounds and in the maintenance of normal liver functions. Many known risk factors for BTC are related to metabolic disturbance, suggesting a significant role of metabolic perturbance in BTC pathogenesis. Thus, a systematic investigation of circulating metabolites could provide valuable information regarding biomarkers for BTC risk and biological mechanisms of BTC pathogenesis. Herein, we propose a well-powered, multi-ancestry study, using resources from 17 large prospective cohort studies around the world and five large genetic consortia/studies of BTC, to identify and validate metabolomic biomarkers for BTC risk. In Aim 1, we propose to analyze blood samples collected prior to any cancer diagnosis from 750 incident cases and 750 matched controls to systematically search the blood metabolome to identify promising metabolite biomarkers for replication. In Aim 2, we will use genetic variants associated with circulating metabolites and data from large genome-wide association studies (GWAS) of BTC to search for additional promising metabolite biomarkers for replication. In Aim 3, we will quantify 50 promising metabolites selected from Aims 1 and 2 and evaluate their associations with risk of BTC overall, and by its subsites, in an independent sample of nearly 2000 cases and their matched controls. Finally, in Aim 4, we will build risk prediction models for BTC using metabolite biomarkers, genetic risk variants and traditional risk factors. This is the first large study ever conducted to systematically search the blood metabolome to identify risk biomarkers for BTC, and the first study to integrate metabolomic and genomic data in BTC biomarker research. Including multi-ancestry populations will allow us to cross-validate research findings and identify potential racial differences in biomarker associations. This study will provide substantial novel data to improve the understanding of BTC etiology and identify biomarkers for BTC risk assessment.

NIH Research Projects · FY 2025 · 2022-04

Clonal hematopoiesis of indeterminate potential (CHIP) is a newly recognized disorder characterized by the ontogenesis of a genetically distinct, proliferative clonal leukocyte population. The prevalence of CHIP increases with older age and is associated not only with risk of hematologic cancers, but with fibrosis, systemic inflammation, and atherosclerotic cardiovascular diseases. Recapitulation of CHIP in mice by transplantation of clonal leukocytes results in accelerated atherosclerosis, cardiac fibrosis and direct tissue infiltration of clonal macrophages and stimulation of interstitial fibrosis. Age is a dominant risk factor for chronic kidney disease (CKD), which is associated with accelerated cardiovascular disease, premature death, and progression to dialysis dependence. The biological mechanisms conferring this age-associated risk are incompletely understood. The final common pathologic process in progressive CKD is tubulointerstitial fibrosis, which is characterized by the accumulation of inflammatory infiltrates and fibroblasts within the kidney interstitium and permanent loss of tubular epithelial cells. Tubulointerstitial fibrosis also represents the central underlying lesion in the progression of acute kidney injury (AKI) to chronic disease. Based on mechanistic links between CHIP and atherogenesis, kidney interstitial inflammation, and fibrosis, we hypothesize that CHIP is a novel biological risk factor for CKD progression. To test this hypothesis, we propose to determine the associations of CHIP with kidney disease progression in established cohorts of CKD and AKI. In parallel, we propose to delineate potential causal mechanisms using recognized animal models of chronic and acute kidney disease. The identification of clonal leukocytes as a novel mechanism of CKD progression would represent a new disease pathway that could motivate future targeted interventions.

NIH Research Projects · FY 2025 · 2022-04

PROJECT SUMMARY The epidemic of cardiometabolic disease occurring throughout the world is taking a heavy toll on individuals’ quality of life, along with a huge economic impact Excess caloric intake leading to obesity is a major driver of the cardiometabolic syndrome. Brown adipose tissue (BAT) evolved in homeotherms as a mean to maintain body temperature by generating heat from stored calories. Brown adipocytes are highly enriched in mitochondria and express a unique protein called uncoupling protein-1 (UCP1). UCP1 ‘uncouples’ the mitochondrial proton gradient from ATP production, thus avidly consuming glucose and fatty acids with the result being net energy expenditure. Active brown fat is present in adult humans and its amount is significantly correlated with reduced body fat and circulating triglycerides, greater insulin sensitivity, and lowered incidence of Type II diabetes. Increasing brown adipocyte amount and activity could reduce the risk of cardiometabolic disease. The sympathetic nervous system (SNS)-derived catecholamine norepinephrine, which act through β-adrenergic receptors and cAMP, is a well-established activator of BAT and the recruitment of UCP1-positive cells in white adipose tissue (WAT) depots (a process termed ‘browning’ or ‘beiging’). We have shown in prior work that the cardiac hormones atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) also stimulate a similar ‘browning’ program in mouse and human adipocytes, and protect against obesity-associated insulin resistance, hepatic steatosis and inflammation. This suggests that increasing NP signaling in adipose tissues is metabolically beneficial. NP activation of NP receptor A (NPRA) leads to cGMP production, while the NP ‘clearance receptor’ NPRC removes NPs from circulation, and the ratio of NPRA to NPRC determines NP signaling capacity. Clinical studies show that compared to lean individuals, obese individuals have lower circulating NP level, increased NPRC level in adipose tissue, and blunted lipolytic responses to NPs. We observed similar patterns of receptor expression and physiological responses in mice. It has been postulated that higher adipose NPRC levels increases NP clearance, thus reducing NP availability in the circulation and efficacy in target tissues, resulting in a so-called ‘natriuretic handicap’. On the other hand, conditions such as fasting and cold temperature exposure reduce the level of NPRC expression, resulting in an increased NPRA/NPRC ratio and thus NP/cGMP signaling. Our studies with mouse models further support these observations. We also find that the expression of other components of the NP signaling system, such as phosphodiesterase-9 and the peptidase neprilysin are also decreased in response to cold and βAR agonists The overall objective of this project is to: define the transcriptional regulatory mechanisms of the Nprc, Pde9 and Mme genes in human and mouse adipocytes; determine whether increased levels of NPRC in obesity serves as a ‘sink’ to remove NPs from circulation, thus creating the ‘natriuretic handicap’, and test the effects of selective NP ligands to modulate insulin sensitivity.

NIH Research Projects · FY 2026 · 2022-04

PROJECT SUMMARY Traditionally, diabetes is defined as decreased insulin action resulting in impaired glucose homeostasis. However, inappropriate secretion of glucagon also contributes to the hyperglycemia in diabetes. Blocking glucagon action lowers blood glucose, but also leads to hyperglucagonemia with α cell proliferation and hyperplasia. We demonstrated that this is due to high blood levels of amino acids resulting from impaired amino acid catabolism in liver (gluconeogenesis). These studies demonstrated a classical endocrine feedback loop, the liver-islet α cell axis. As part of our K01 funded investigations, we discovered that high levels of arginine are required for the effects of high amino acid levels on α cell proliferation and function. We identified SLC7A2 (CAT2) is the major arginine transporter in pancreatic islet α cells. Using global CAT2 knockout mice, we found that loss of CAT2 results in protection from α cell hyperplasia and a complete loss of glucagon secretion even in response to strong depolarizing agents. This suggests that CAT2 is playing an important role in α cells beyond affecting membrane polarization as had been previously proposed as a mechanism for arginine-stimulated secretion. Our current objective is to define the mechanisms of arginine-stimulated α cell proliferation and secretion. Under the support of this R01 in Aim 1, we will characterize changes in the α cell when CAT2 expression is lost using α cell specific targeted deletion, including α cell proliferation and mass, glucagon secretion, Ca2+ dynamics, and gene and protein expression. We will also test if the heterodimeric amino acid exchanger LAT2 (SLC7A8/SLC3A2) is required for α cell proliferation and function. In Aim 2, we will examine a novel putative arginine cell surface binding protein called TM4SF4 that is selectively and robustly expressed on pancreatic α cells. We will fully characterize TM4SF4 arginine binding kinetics, protein binding partners in α cells, effects on arginine transport, and regulation of α cell proliferation and function. An important feature of our work is that we will translate our discoveries made in mouse islets using human islets. These studies will provide new insights into normal α cell function and how α cells could be targeted to repair dysregulated glucagon secretion in diabetes.

NIH Research Projects · FY 2025 · 2022-04

ABSTRACT The cancer burden in Zambia is increasing, making it one of the leading non-communicable causes of disability and premature death. This trend will continue and accelerate. However, cancer research in Zambia, particularly population-based research, is limited, primarily due to a lack of well-trained investigators, supportive research infrastructure, and adequate funding. Currently, Zambia has no cancer-specific research training programs to address the workforce gap. Vanderbilt University Medical Center (VUMC) and the University of Zambia (UNZA) are expanding their longstanding research training partnership to establish a new cancer epidemiology training program, the Vanderbilt-Zambia Cancer Research Training Program (VZCARE). The overall goal of VZCARE is to develop a cadre of researchers and educators equipped with modern knowledge and expertise to lead cancer epidemiology research and training in Zambia, to encourage US- based researchers to engage in cancer research in low- and middle-income countries, and to ensure long-term program impacts and sustainability. Specifically, VZCARE seeks to: 1. Train a cadre of researchers and educators (trainers) to conduct multidisciplinary cancer epidemiology research and build training capacity in Zambia, targeting faculty members and researchers from UNZA, University Teaching Hospital, Cancer Diseases Hospital, and the Zambia Ministry of Health. This will be accomplished via an intensive 3- month Visiting Faculty Scholars program at Vanderbilt, Zambia-based epidemiology workshops, and augmenting the UNZA PhD program with advanced cancer epidemiological curricula. 2. Train scientists and future leaders in cancer epidemiology research in Zambia. This will include US- and Zambia-based “sandwich” training and dual-mentored research for two Zambian PhD students and three Zambian postdoctoral trainees, and field research experience in Zambia for two US postdoctoral trainees. 3. Ensure and document VZCARE’s long-term impact. In addition to documenting the career development and research accomplishments of our trainees, we will provide continued support for their career development and foster collaborations beyond their supported training periods. With a very successful 23-year UNZA-Vanderbilt Training Partnership on HIV-related research and education, and Vanderbilt’s substantial global cancer epidemiology research and training programs, we are well positioned to launch this new training program with a focus on building world-class cancer epidemiology research and training in Zambia and promoting US investigators to engage in global cancer research.

NIH Research Projects · FY 2025 · 2022-04

PROJECT SUMMARY While cerebral oxygen delivery depends on the cerebral blood flow (CBF; ml blood/100g tissue/minute) and blood oxygen content, it is becoming increasingly recognized that blood capillary transit time itself can also influence tissue oxygen extraction, even in the presence of normal or elevated CBF. In individuals with anemia where accelerated capillary flow velocities may be present as a result of hyperemia and cerebral autoregulation, reduced capillary transit time can lead to reduced times for tissue oxygen offloading. Compelling evidence has been provided for heterogeneous capillary flow underlying abnormal oxygen delivery in multiple conditions including expansion of infarcts in acute ischemic stroke, traumatic brain injury, and Alzheimer's disease. In sickle cell anemia (SCA), we have observed that rapid capillary transit, visible on arterial spin labeling (ASL) CBF-weighted MRI, is present in more than 50% of adults and children. We have shown in published work and preliminary data from 154 adults and children with SCA that hyperintense ASL signal within cerebral dural venous sinuses is directly associated with elevated arterial velocities, elevated CBF, and reduced oxygen extraction fraction (OEF; ratio of oxygen consumed to oxygen delivered), and that this effect may reduce following transfusion therapies that improve oxygen delivery to tissue. These findings indicate that venous hyperintense signal on ASL images may represent a marker of capillary-level disturbances in oxygen exchange efficiency. One of the most impactful findings of our preliminary work is that we have observed that rapid capillary-level arterio-venous transit is associated with reduced oxygen metabolism, suggesting that these transit times may provide a biomarker of cerebral ischemia in individuals with SCA who have greater than a 50% risk of cerebral infarcts by age 30 years, yet often lack conventional stroke risk factors. Here, we propose to refine neuroimaging methods for evaluating arterio-venous transit to allow for robust, quantitative measures of capillary transit time non-invasively in vivo, and subsequently to test fundamental hypotheses regarding cerebral oxygen utilization in anemic individuals with vs. without infarcts. Aim (1): To apply innovative ASL MRI methods and time regression analyses over major intracranial arteries and dural sinuses in healthy control and SCA participants. Aim (2): To quantify cerebral capillary transit time in SCA participants before and after treatment with blood transfusion to understand how increases in hemoglobin parallel an improvement in brain oxygen extraction. Aim (3): To test the hypothesis that arterio-venous transit times are reduced in individuals with SCA with versus without infarcts. The short-term goal is to utilize non-invasive imaging approaches to understand mechanisms of oxygen utilization and neurovascular dysfunction in anemia. The long-term goal is to use this information to triage individuals with anemia for personalized stroke prevention therapies, as well as to objectively quantify the impact of these therapies on brain health.

NIH Research Projects · FY 2026 · 2022-04

PROJECT ABSTRACT It is critical to build biostatistics capacity in West Africa. Biomedical HIV research is growing in West Africa, but biostatistical support and expertise are lagging. In collaborative HIV studies between West Africa and U.S. institutions, the biostatistics leaders are almost always from the U.S. It is important to develop biostatistics leaders in West Africa – biostatisticians who will not be technicians, but co-investigators, principal investigators, and thought-leaders in funded HIV/AIDS research. There are several statistics PhD programs in West Africa, but they often have little or no connection with biomedical research. Funded training initiatives over the past ten years have been successful at building biostatistics in Southern Africa and East Africa, but no such programs currently exist in West Africa. The Vanderbilt-Nigeria Biostatistics Training Program (VN-BioStat) builds on long-standing collaborations between two leading research institutions in Nigeria and the United States, namely, Aminu Kano Teaching Hospital (AKTH) and Vanderbilt University Medical Center (Vanderbilt) to establish a research and training platform for biostatisticians doing HIV-related research in Nigeria. VN-BioStat will build upon the resources of AKTH and its parent institution, Bayero University in Kano (BUK), to create a cohort of highly skilled Nigerian biostatisticians with the capacity to lead and supervise biostatistical activities in West Africa. VN-BioStat leverages the highly successful, collaborative and rapidly expanding portfolio of U.S. National Institutes of Health (NIH) and other funded research at AKTH, with joint leadership from Vanderbilt investigators. To train biostatistician leaders in Nigeria, the VN-BioStat program proposes to bring two Nigerian data scientists per year (total of 10 over 5 years) to Vanderbilt to immerse them in biostatistics and to receive hands on training. During the one-year training period, trainees will lead the design, analysis, and publication of a collaborative research project using HIV data from AKTH. They will also lead a related, methodologically focused project that will culminate in a publication. While at Vanderbilt, they will interact with a team of HIV biostatisticians, take appropriate biostatistics courses (up to 8 credit hours per semester for 2 semesters), attend biostatistics and global health seminars, participate in a grant-writing workshop, attend biostatistics clinics, and collaborate with other Nigerian investigators. They will receive mentorship from Vanderbilt faculty (one biostatistician and one clinical investigator) and AKTH faculty. We will also conduct annual workshops in Nigeria to provide mid- level biostatistics training for up to 25 HIV researchers. Potential course topics include methods to address missing data, introduction to causal inference, regression modeling strategies, big data in biomedical research, and survival analysis.

NIH Research Projects · FY 2026 · 2022-04

PROJECT SUMMARY T cells have the potential to recognize and eliminate cancer cells. However, most often cancers progress in spite of the tumor-specific T cells present within tumors. While current immunotherapies such as immune checkpoint blockade can bring about long-lasting remissions in some patients with certain cancer types, most patients are not cured. Using a genetic liver cancer mouse model, we previously demonstrated that tumor-specific T cells, after entering malignant livers, rapidly differentiate to an early and then late dysfunctional state, encoded by distinct epigenetic programs. Late dysfunctional tumor-specific T cells failed to become functional again in response to immune checkpoint blockade, and we found that human tumor-infiltrating lymphocytes from patients with solid tumors shared key epigenetic hallmarks of late dysfunctional T cells from our mouse liver cancer model. Thus, a critical challenge for cancer immunotherapy is how to prevent or revert tumor-specific T cells from entering this epigenetically-enforced dysfunctional state. We now find that late TST fail to proliferate in response to T cell receptor stimulation, and we hypothesize that the barrier to functional rescue of late dysfunctional tumor-specific T cells is their inability to enter cell cycle in response to TCR stimulation. We will leverage our preclinical mouse cancer models and study TIL in liver and breast tumors from human patients to (i) understand how cell cycle kinetics and T cell receptor signaling defects change during dysfunctional differentiation, (ii) define how cell cycle and epigenetic changes determine functional rescue, and (iii) test strategies to overcome cell cycle and TCR signaling defects in late dysfunctional T cells. These studies will uncover critical insights into how cell cycle and T cell receptor signaling regulate the T cell epigenome and test therapeutically-applicable strategies to overcome barriers to tumor-specific T cell reprogramming, which may lead to improved cancer immunotherapies.

NIH Research Projects · FY 2026 · 2022-04

Project Summary Providers across multiple specialties face challenges in determining the clinical significance of a positive antinuclear antibody (ANA). While a positive ANA is highly sensitive for autoimmune disease, it is non-specific with up to 20% of the general population having a positive ANA without having autoimmune disease. Risk models to aide clinicians in stratifying positive ANA patients do not currently exist. By identifying high-risk patients, providers could properly triage patients for prompt treatment to reduce autoimmune disease-related morbidity and mortality. Our long-term goal is to build risk models in the electronic health record (EHR) for autoimmune diseases that improve outcomes. The overall objective of this proposal is to identify positive ANA patients who are at high risk for developing autoimmune disease to facilitate appropriate triage to rheumatology for earlier diagnosis and treatment. Our institution with expertise in biostatistics, biomedical informatics, and implementation science has demonstrated success in building and testing robust EHR risk models. Building upon this well-established infrastructure, we hypothesize that we can use available EHR data to identify positive ANA patients that are high risk for autoimmune disease. We hypothesize that using tailored risk assessments in real- time in the EHR can reduce time to autoimmune disease diagnosis and treatment. We will test these hypotheses with the following specific aims: (1) Refine and validate features available in the EHR to distinguish positive ANA patients who develop autoimmune disease from positive ANA patients who do not develop autoimmune disease and (2) Conduct an adaptive, randomized, pragmatic evaluation of an autoimmune disease risk model in the EHR to risk- stratify patients with a positive ANA. For Aim 1, we will validate a risk model for autoimmune disease in positive ANA patients using EHR data with logistic regression and machine learning methods. For Aim 2, we will deploy a risk model for autoimmune disease in real-time in the EHR. We will randomize positive ANA patients to either have a risk score from the model displayed and acted upon vs. not having a risk score displayed or usual care. We will assess if having this EHR system change with a risk score calculated and shared with the ordering provider compared to usual care affects time to autoimmune disease diagnosis and treatment. Our proposal is innovative in that it not only builds a predictive risk model for autoimmune disease but also deploys and assesses if the model impacts patient outcomes. For expected outcomes, we anticipate deploying an EHR risk model that identifies positive ANA patients at high risk for developing autoimmune disease and decreases time to diagnosis and treatment.

NIH Research Projects · FY 2025 · 2022-03

Project Summary and Abstract Hutchinson-Gilford Progeria Syndrome (HGPS) is an incurable, uniformly fatal disease involving a point mutation in a gene called Lamin A (LMNA). Children develop signs of HGPS typically within the two years after birth and die at a median age of 14, most commonly from progressive atherosclerotic cardiovascular disease. Although the causal mutation in HGPS was identified 18 years ago, no cures for this disease exist. Programmable base editing of DNA now enables the previously unprecedented ability to change single nucleotides in DNA and correct pathogenic mutations with DNA strand breaks. HGPS represents a tractable disease to test base editing, however it remains completely unknown whether this strategy will improve disease phenotypes associated with HGPS. As such, there is a critical need to study how DNA base editing alters the molecular defects driving HGPS in order to determine whether this genome therapy can fulfill its promise to cure disease. Our overall objective in this proposal is develop adenine base editing (ABE) as a treatment strategy for HGPS. Our central hypothesis is that ABE-treatment of adult mice can achieve sufficient editing in aortas to reverse vascular pathology through cell-autonomous effects on survival and clonal proliferation in VSMCs. Our hypothesis is formulated based on newly published and new preliminary data that demonstrate: 1) scarless correction of the pathogenic mutation by ABE in patient fibroblasts and in a humanized mouse model of HGPS; 2) prevention of vascular pathology and recovery of VSMCs at 6 months after ABE treatment of juvenile mice; 3) a significant increase in overall survival of ABE-treated juvenile animals. The rationale for this project is that validation of base editing therapies is needed to determine their potential in treating systemic human diseases. To attain our objectives, we will pursue the following two specific aims: 1) Test whether DNA editing improves vascular pathology in established disease by treating adult HGPS animals at different ages with a single injection of AAV-ABE; 2) Identify the mechanism(s) promoting VSMC recovery after ABE treatment. The overall contribution of this work will be to elucidate how adenine DNA base editing improves phenotypes in HGPS. The central innovation of this proposal is a conceptual shift in therapeutic treatment of HGPs by focusing on correcting the underlying pathogenic mutation in cells and tissues.

NIH Research Projects · FY 2026 · 2022-03

There has been extraordinary growth in new techniques to predict common, complex disease based on polygenic risk scores (PRS). Without an understanding grounded in evidence, it is unlikely that the clinical use of PRS will propagate from highly specialized applications and environments to become adopted more broadly and provide greater benefit to the US population. Critical challenges include: 1) understanding the impact of clinical PRS for multiple diseases on long-term patient outcomes, 2) identifying risk thresholds for return of results that optimize patient outcomes and provide cost-effective care, 3) understanding how PRS performance across varied populations may affect downstream patient outcomes. We propose to address these challenges using decision analytic modeling and by building on our extensive work in this area to create a novel framework capable of assessing PRSs in the context of monogenic and clinical risks. We have already created clinical-economic models to project lifetime clinical impact and cost-effectiveness for population-level genomic screening with return of monogenic disease risks associated with three CDC Tier 1 conditions: hereditary breast and ovarian cancer, Lynch syndrome, and familial hyperlipidemia. As part of this proposal, titled Rational Integration of Polygenic Risk Scores (RIPS), we will create models to assess the clinical outcomes and economic value of population screening using PRS in real-world settings and applied to large US populations. The Aims of the proposal include 1) to evaluate published and real-world evidence on the clinical value of adding PRS to inform comprehensive genomic risk assessment; 2) to understand the impact of PRS performance and return risk thresholds on incremental clinical benefit and cost effectiveness for breast cancer, atherosclerotic cardiovascular disease, and colorectal cancer, and 3) to develop research priorities for the development and implementation of PRS which account for their varied performance across populations of genetic ancestries.

NIH Research Projects · FY 2025 · 2022-03

PROJECT SUMMARY/ABSTRACT Oseltamivir (Tamiflu) is the only Food and Drug Administration (FDA) approved influenza medication for children < 12 years. Yet, oseltamivir is under prescribed, including in children at high risk for influenza complications. One key barrier is parental and provider concern about the safety of oseltamivir. Potential adverse drug events related to oseltamivir, especially neuropsychiatric adverse effects (NPAEs), are frequently reported in the medical liter- ature and in the media. Oslemativir may cause NPAEs through direct effects on NDMA/GABA signaling in the brain, which is known to cause neurospcyahitric symptoms in diseases such as schizophrenia. Oseltamivir passively diffuses into the brain and is then rapidly exported out of the brain by the P-gp transport system. There several mechanisms that might result in high concentrations in the brain, such as through alterations in this P- gp transport. However, there is no consensus on a causal relationship between oseltamivir and NPAEs. This is in part because of the background incidence of influenza associated neuropsychiatric symptoms is not known. There is a critical need to define the true risk of NPAE in children exposed to oseltamivir to best inform clinical practice and clarify the concerns of patients, their caregivers, and providers. The aims of this project are to: 1) to define the population-based incidence of influenza associated serious neuropsychiatric symptoms in children, 2) to test the hypothesis that oseltamivir is associated with serious NPAE and 3) to test the hypothesis that concurrent use of drugs modulating P-gp modifies the risk of oseltamivir associated serious NPAE. The pro- posed studies leverage data from the Tennessee Medicaid (TennCare) program comprising vital statistics, phar- macy claims data, and hospital administrative data from more than 750,000 children per year, representing 50% of Tennessee’s children. The TennCare database overrespresents vulnerable children, including those with chronic conditions and socioeconomic disadvantages. The large number of children in this database, and long history of successful, high-impact research conducted using these data are major strengths of the current pro- posal. The results of these studies will fill an important knowledge gap regarding serious adverse drug events in children and will inform treatment for influenza. The candidate’s career goal is to emerge as an independent clinical investigator with expertise in pharmacoepidemiology and drug safety. To accomplish this goal, in addition to completion of the proposed scientific aims, the candidate will augment his prior research training with ad- vanced coursework in pharmacoepidemiology methods, training in leadership and mentoring, and practical ex- periences with the FDA and Children's Hospital Association focused on observational studies to improve pedi- atric drug safety. Throughout this award, the candidate will work closely with a multidisciplinary team of mentors and advisors-including experts in pediatrics, pharmacoepidemiology, clinical pharmacology, infectious disease and epidemiology to carry out his stated career objectives and specific aims.

NIH Research Projects · FY 2026 · 2022-03

Despite the discovery of hundreds of genetic mutations associated with epilepsy and neurodevelopmental comorbidities – including autism and intellectual disability (ID) – no effective treatments are currently available. Our recent work has identified the primary common mechanisms across mutations at a large scale in astrocytes and inhibitory neurons that express the GABA transporter 1 (GAT-1) encoding SLC6A1. Preliminary findings suggest 4-phenylbutyrate (PBA), a previously FDA-approved chaperone inducer for pediatric use, displays a mechanism-based rescue in those mutations. Specifically, PBA appears to repair mildly misfolded proteins and increase membrane expression of the wildtype allele across all tested mutations. Moreover, our success has prompted a pilot trial with very promising results. This study aims to fully characterize the effect and detailed mechanisms of PBA rescue. Our central hypothesis states that protein misfolding and impaired trafficking are standard mechanisms for SLC6A1 mutations, which display rescue potential through pharmacological intervention by restoring effective protein activity. As a part of our research, our lab has developed highly relevant preclinical model systems, including a plasmid library of SLC6A1 mutations, mutation- bearing patient cell lines, and knockin mouse models. Future studies focused on these model systems will provide critical insights into disease mechanisms with high potential of translating the findings to treatment. Moving forward, our lab aims to (1) evaluate the effect of PBA on restoring GAT-1 function in vitro for 20 patient mutations, (2) gauge the effect of PBA on restoring GAT-1 function in vivo in Slc6a1 mutation knockin mice, and (3) elucidate the underlying mechanism of PBA rescue on GAT-1 functioning to establish a foundation for novel treatment approaches. Research design and methods. We will employ a plasmid library containing >50 SLC6A1 mutations identified from patients across a wide spectrum of disease phenotypes, two knockin mice, and two lines of patient induced pluripotent stem cells (iPSCs) derived neurons and astrocytes to determine the impact of PBA on the mutant GAT-1 trafficking and function. We will utilize a multidisciplinary approach, including in vivo microdialysis, to determine the dynamic interplay of GAT-1 inhibition, GABA levels, and seizures in knockin mice. All patients carrying SLC6A1 mutations are heterozygous, which suggests there is benefit in either boosting the remaining wildtype allele or rescuing the mutant copy or both. In either case, the overall GABA uptake activity should be improved in patients. The large-scale study will provide us a broad view of the impact of PBA. In contrast, the in-depth investigation of mice and patient-derived cells will provide critical insights into PBA's rescue mechanism in partial and complete loss-of-function mutations. We propose to test this hypothesis in vitro and in vivo with high-throughput assays and cutting-edge new techniques in iPSCs and mutation knockin mice. Our goal is to identify a novel treatment target for genetic epilepsy using SLC6A1 as example. We believe the impact of this study is broad as it can be scaled up for many genetic epilepsy syndromes and others.

NIH Research Projects · FY 2026 · 2022-02

PROJECT SUMMARY Influenza virus is a significant pathogen in solid organ transplant (SOT) recipients, including lung allograft recipients. Moreover, compared to other SOT, lung allograft recipients have more severe influenza disease. However, due to requisite immunosuppression, these individuals respond poorly to standard-dose (SD) inactivated influenza vaccine (IIV). Recent studies have investigated two strategies to overcome poor immune responses in SOT recipients: (1) administration of high-dose (HD)-IIV compared to SD-IIV and (2) two doses of SD-IIV compared to one dose of SD-IIV in the same influenza season. The first study, conducted in adult SOT recipients, reported that HD-IIV was safe and more immunogenic; however, the median post-transplant period was 38 months. The second study, another phase II trial in adult SOT recipients with a median post-transplant period of 18 months, reported that two doses of SD-IIV administered one month apart was more immunogenic than one-dose of SD-IIV. While promising, these studies lack evaluation in the early post-transplant period, when SOT patients are most vulnerable to influenza. Moreover, these studies had limited inclusion of lung transplant recipients, a population that is most at risk for influenza-related comorbidities, including respiratory failure, acute cellular rejection, and chronic lung allograft dysfunction. Finally, the administration of two doses of HD-IIV in the same influenza season has not previously been evaluated in SOT recipients. Thus, the optimal immunization strategy for lung allograft recipients in the early post-transplant period remains unknown. In addition, the immunologic predictors and correlates of influenza vaccine immunogenicity in lung allograft recipients have not been well-defined. The central hypothesis of our proposal is that lung allograft recipients who are 1-35 months post-transplant and receiving two doses of HD-quadrivalent inactivated influenza vaccine (QIV) will have higher HAI geometric mean titers (GMTs) to influenza antigens compared to those receiving two doses of SD-QIV. To test this hypothesis and address the critical knowledge gaps outlined above, we propose to conduct a phase II, multi-center, randomized-controlled immunogenicity and safety trial comparing two doses HD-QIV to two doses SD-QIV administered one month apart in lung allograft recipients who are ≥16 years and 1-35 months post-transplant. This study will be conducted at five lung transplant centers—Vanderbilt University Medical Center, Duke University, Northwestern University, University of Alabama in Birmingham, and University of Washington. The results of this study will illuminate immune responses in adult lung allograft recipients and help guide vaccine recommendations during the early post-transplant period. Moreover, our findings may help guide optimal vaccine strategies in other immunosuppressed populations.

NIH Research Projects · FY 2025 · 2022-02

PROJECT SUMMARY Sickle cell anemia (SCA) is a chronic hemolytic anemia that dramatically increases the risk of central nervous system complications including silent cerebral infarcts (SCI), overt strokes, and intracranial stenosis. Stroke risk screening procedures for adults with SCA are considerably underdeveloped compared to procedures for children with SCA and other populations of adults at risk for stroke. However, SCI and overt stroke risk persists across the lifespan, and SCIs occur in more than 50% of adults with SCA by age 30 years, representing a frequent cause of long-term disability. The absence of an approach to identify adults at risk for new or recurrent cerebral infarcts is a major limitation in adult SCA care, as treatments for SCA continue to improve and lifespan is increasing. The critical barrier to addressing stroke risk and prevention in adults rests with our inability to identify underlying brain tissue-level impairment as a part of routine medical care and our need to develop new screening tools to triage adults with SCA for appropriate stroke prevention therapies. The overall goal of this work is to utilize recently identified biomarkers of inadequate cerebral hemodynamic compensatory mechanisms to test fundamental hypotheses about stroke risk and treatment response in adults with SCA in a longitudinal study. Over the past seven years, we have established a multidisciplinary team to systematically evaluate adults with SCA, assessing known stroke risk factors in sequence with more novel pathophysiological indicators including: (i) oxygen extraction fraction (OEF; ratio of oxygen consumed to oxygen delivered), (ii) cerebral blood flow (CBF; rate of blood delivery to tissue), (iii) flow velocity, and (iv) cerebrovascular reactivity (CVR; ability of arterioles to respond to a vasoactive challenge). This work led to the findings that (i) OEF is elevated in adults with SCA and clinical impairment (prior stroke, intracranial stenosis, or monthly transfusions), (ii) OEF is elevated in adults with SCA and evidence of new or progressive infarcts (retrospective data), and (iii) CBF response to treatment with blood transfusion appears to be less robust in adults than children with SCA. We have developed methods to measure these hypothesized stroke risk biomarkers using MRI approaches that do not require exogenous contrast agents, making them a possible tool for SCI surveillance and for evaluating treatment response. Here, we propose to extend this work to (Aim 1) a longitudinal, prospective study, to evaluate how metabolic and hemodynamic stroke risk factors can be used to identify which adults with SCA will have new infarcts; (Aim 2) to quantify the impact of stem cell transplant, an emerging curative treatment, on brain tissue health; and (Aim 3) to compare OEF values obtained from the two most popular non-invasive MRI methods thereby informing their collective or individual use in future multi-site clinical trials. The long-term goal is to identify underlying brain tissue-level impairment that may provide evidence-based biomarkers to assess stroke risk, treatment response, and guide therapy decisions in adults with SCA, with the goal of reducing stroke and cognitive dysfunction in this high-risk population for which validated stroke screening tools do not exist.

NIH Research Projects · FY 2023 · 2022-02

Project Summary/Abstract: Mild cognitive impairment (MCI) reportedly affects up to 24% of older adults and involves an associated decline in functional mobility. Individuals with MCI experience decreased balance, decreased gait speed, altered gait parameters, and even a greater risk of falling. Currently, clinical measures of balance and mobility only moderately predict dysfunction associated with MCI. Recent studies using cognitive-motor dual-tasks were promising. This is done by attempting to increase the complexity brain processing demand by combining a movement task, such as gait, with a cognitive task, such as counting down from a random number by 3's. Current studies exploring dual-task assessments offer conflicting results in their ability to detect MCI, limiting their reliability. We hypothesize that current clinical testing paradigms lack ecological validity and functional task performance. This oversight limits the complexity of performing self- selected movements and the associated cognitive overlay required for instrumental activities of daily living (IADLs) engagement. It may be this additional real-world complexity that results in performance difficulty due to MCI and/or altered functional movement. The objective of this project is to combine the expertise of physical and occupational therapy and biomedical engineering to use advancing wearable technology of inertial measurement units (IMU) and advanced deep learning algorithms to develop a framework for recognizing and determining ability to perform naturalistic movements in an ecologically valid setting. To accomplish this, we will recruit individuals with MCI (n=15) and cognitively healthy (n=15) adults from 60-75 years old to perform a simulated IADL involving a series of tasks that include at least 10 repetitions of discrete activities that are involved in typical grocery shopping (e.g. carrying a basket, reaching up for an item, etc.). IMU data will be labeled using video ground truth, allowing files consisting of a full activity stream (the complete grocery shopping task) as well as files segregating discrete activities (retrieving a can of soup from a shelf). We will then develop and validate a deep learning framework in order to identify each discrete activity performed in the IADL task in both those with MCI and cognitively normal older adults (Aim 1). Additionally, we will use feature extraction methods to identify specific kinematic performance parameters of each gait and non-gait based activity (Aim 2). We then use this pilot kinematic data to identify sample sizes of future studies with adequate power and effect size to provide a robust framework to use naturalistic movements to detect movement dysfunction in those with MCI. By achieving these aims, we establish a state-of-the-art framework that may ultimately be used for detecting and measuring performance and safety of IADL engagement in older adults. Our long-term goal is to develop a naturalistic and highly reliable method that may provide early identification of cognitive and movement dysfunction in order to initiate treatment before the onset of dementia, as well as to provide a functional test to measure potential longitudinal functional changes.

NIH Research Projects · FY 2026 · 2022-02

Abstract Excess fat accumulation and deposition of ectopic lipid in visceral adipose tissue (VAT), the liver and skeletal muscles contribute substantially to the high risk for cardiometabolic disease in persons with HIV (PWH) on antiretroviral therapy (ART). While the potential for weight gain during the first year of ART is well-recognized, the amount of weight is highly variable, and more importantly, it is the accumulation of excess body fat and ectopic lipid that drives cardiometabolic comorbidities and complications. We hypothesize that during the first year of integrase strand transfer inhibitor (INSTI)-based therapy there is rapid onset of a state of positive energy balance, impaired fatty acid oxidation, and impaired ability of subcutaneous adipose tissue (SAT) to store lipids (driven in part by persistent T cell-mediated SAT inflammation), which leads to the deposition of excess lipids in VAT, the liver and skeletal muscle further inhibiting the ability of these organs and tissues to function normally. This multi-disciplinary study will be led by three established PIs with complementary expertise in the fields of HIV clinical research, adipocyte biology and physiology, nutrition, human metabolism, and imaging. We will leverage state-of-the-science procedures and technologies including comprehensive assessment of factors driving energy balance, adipose tissue micro-liposuction, adipose tissue single cell transcriptomics, SAT gene expression, and imaging of ectopic lipid depots during the first year of INSTI-based ART in 129 treatment-naïve PWH to meet the following specific aims: Aim 1: To determine precisely when and where excess fat accumulates, including ectopic depots (hallmarks for insulin resistance and development of diabetes) during the first year of INSTI- based ART (when viral suppression occurs), and whether the storage of excess fat in specific regions and depots is driven by excess energy intake, reduced energy expenditure, and/or reduced fatty acid oxidation; Aim 2: To determine the specific changes in the SAT architecture, cellular composition, and transcriptomic features that contribute to body region and depot-specific ectopic fat accumulation; Aim 3: To determine the specific changes that occur in the SAT immune environment and HIV reservoir that adversely modulate adipocyte cellular function and lipid storage. Our longitudinal study in treatment-naïve PWH during the first year of INSTI-based ART will be the first to identify mechanisms linking changes in energy balance, fatty acid oxidation, SAT architecture and function, and the impact of the SAT immune environment on adipocyte plasticity and adipocyte regulatory and lipid trafficking pathways involved in the accumulation of VAT and ectopic lipid in the liver and skeletal muscle. The first year of ART provides a critical opportunity to prevent increased adiposity and excessive fat deposition in the intra-abdominal, liver and skeletal muscle depots, and thus reduce the risk for cardiometabolic disease in PWH. These data will identify targets for future clinical and pharmaceutical intervention studies to prevent or re- direct body fat and ectopic lipid gain after ART initiation to prevent and/or reduce the growing burden of cardiometabolic diseases in PWH.

NIH Research Projects · FY 2026 · 2022-02

PROJECT SUMMARY/ABSTRACT Sequencing an individual’s genome now costs less than many routine medical procedures. A resulting vision is that everyone will have their genome sequenced early in life to enable individualized medical advice about disease prevention and drug selection. A major concern with this vision, however, is proper interpretation of the overwhelming volume of discovered novel and rare variants. In other contexts, a new diagnostic test can be benchmarked and validated in studies that compare large populations with and without a disorder to determine the predictive value of a positive result. In the genetic sequencing context, however, a positive test for most variants cannot be applied to enough heterozygous individuals for a definitive association with disease. Pathogenic variants in KCNH2 (a.k.a. hERG, a cardiac potassium channel gene critical for cardiomyocyte repolarization) can cause sudden cardiac death in the young and can predispose carriers to drug-induced arrhythmias. Genetic variants in KCNH2 are responsible for ~ 6% of autopsy-negative sudden unexplained death in the young and ~ 1% of sudden infant death syndrome cases. Additionally, among heterozygous carriers of variants in KCNH2, women are at greater overall risk of a severe event (including sudden cardiac death) which is increased in the postpartum period. Since most disease-associated variants in KCNH2 are rare, full exome sequencing has the potential to identify those individuals at greater risk early in life before any phenotype manifests. However, even among heterozygous carriers of KCNH2 variants definitively associated with disease, not all develop the same phenotype. To address the challenge of variant interpretation, the American College of Medical Genetics and Genomics suggests criteria to incorporate variant population, functional, computational, and segregation data using several described heuristics. Our foundational hypothesis is that clinically meaningful knowledge is lost in the compression of these variant-specific data to a dichotomous classification. To investigate this hypothesis, we will generate in vitro data for all missense variants in KCNH2 prospectively, build a prediction model of disease penetrance, and validate resulting predictions against the incidence of arrhythmias and cardiac events for variants observed in the Electronic Medical Records and Genomics Network (eMERGE), a Leducq Transatlantic Network, and the UK Biobank.

NIH Research Projects · FY 2025 · 2022-02

PROJECT SUMMARY The overarching goal of this K23 Mentored Patient-Oriented Research Career Development Award is to provide essential skills and mentored research experience to prepare Dr. Girish Hiremath as an independent investigator leading a multi-disciplinary team of researchers focused on eosinophilic esophagitis (EoE). EoE is a chronic, allergen-mediated, inflammatory condition of the esophagus. As one of the most common cause of upper gastrointestinal morbidity, it affects 1 out of 2000 individuals in the United States. Our understanding of the pathogenesis of EoE is incomplete and this has contributed towards burdensome approaches to treat EoE patients. There is a critical unmet need to understand all factors related with development of EoE, including determining the biochemical changes in the esophagus that leads to transformation of an unaffected esophagus to an inflamed esophagus in EoE. As a Pediatric Gastroenterologist with clinical and research focus on EoE for more than a decade, the candidate proposes to fill this important knowledge gap by building on his published work through: 1) Validating the esophageal biochemical changes in EoE using Raman spectroscopy (a uniquely suited, highly sensitive, laser-based technique) and machine learning, 2) Determining the correlation between the Raman peaks and the disease activity, and the operating characteristics of the key Raman peaks in distinguishing EoE activity states, and 3) Determining if a combination of the baseline Raman, histologic, endoscopic, and clinical features can predict response to EoE therapy. By defining the key esophageal biochemical alterations this study will offer novel insights into pathogenesis of EoE, and by identifying the baseline predictors of the treatment response it will lay a framework for personalized care of EoE patients. This cutting-edge and clinically relevant research will be conducted in an intellectually stimulating and supportive environment at the Vanderbilt University. Throughout the award period, the candidate will be mentored by Dr. Anita Mahadevan-Jansen (primary mentor, expert in Raman Spectroscopy), Dr. Evan Dellon (co-mentor, expert in EoE), and a team of exceptional mentors in pathology, allergic inflammation, biostatistics and bioinformatics, and data science who mirror the blend of researchers that the candidate will lead in the future Their distinguished career paths will serve as a template for the candidate's success. To achieve his long-term career goal, in conjunction with his mentoring team, the candidate has methodically carved out a 4- year career development program. This program will provide him essential skills in Raman spectroscopy, integration of multidimensional biomedical data, clinical translational research, EoE, grant writing, and leadership. The preeminent mentorship, rigorous career development plan, and clinical time under the auspices of this K23 award will lead to publications, data, and experience that will uniquely situate the candidate as an independent investigator at the intersection of EoE, biophotonics, and data science.