University Of South Florida

NIH Research Projects · FY 2025 · 2021-03

ABSTRACT Borrelia burgdorferi (Bb), the etiological agent of Lyme disease, maintains itself in nature via a complex life cycle involving an arthropod (tick) vector and small mammals. During its cycle between ticks and mammals, Bb undergoes dramatic adaptive changes in order to interact with and adapt to these two disparate niches. Previously, we found that BadR, a homologue of ROK repressors, binds to the rpoS promoter region and represses the expression of rpoS. Moreover, our preliminary findings have suggested that BadR has much broader biological relevance to the life cycle of Bb other than repressing rpoS expression. First, BadR is required for Bb's optimal growth. Second, BadR plays a vital role in the establishment of mammalian infection. Contrary to the wild-type strain, a badR deletion mutant is incapable of infecting mice, suggesting that BadR governs expression of key effector proteins associated with Bb's survival in the host. Phenotypic defects of the badR mutant in mice infection are NOT related to the well documented RpoN-RpoS regulatory pathway, because all of BosR, Rrp2, RpoN, and RpoS are still produced in the badR mutant. In fact, our preliminary global transcriptomic analyses using RNA-seq have identified numerous BosR/RpoS-independent genes regulated by BadR. In addition, we found that badR is expressed throughout Bb's tick-mammal infectious cycle. These combined data give rise to our hypothesis that BadR is a master regulator governing Bb's host adaption and virulence expression. This hypothesis will be addressed in two Specific Aims. In Aim 1 of this proposal, we will employ global transcriptome/proteome profiling to define the entire BadR regulon under various in vitro and in vivo conditions. In Aim 2, we will select BadR-regulated genes based on our global transcriptome/proteome analyses and characterize their contributions to Bb's infectious cycle. These combined studies will (i) refine our knowledge on BadR-mediated gene regulation; (ii) provide a transformative understanding of the in vivo importance of the regulon; and (iii) identify novel virulence determinants. Resultant findings could lead to the development of new strategies to prevent and/or treat Lyme disease.

NIH Research Projects · FY 2026 · 2021-03

Project Summary Malaria in the Greater Mekong Subregion (GMS) of Southeast Asia remains a major public health challenge and represents a critical threat to global malaria control and elimination efforts. Encouraged by recent reductions in malaria-related morbidity and mortality, the six GMS countries have endorsed a regional malaria elimination strategy with the goal of eliminating malaria by 2030. However, achieving this ambitious objective faces numerous urgent challenges. Malaria transmission in the GMS is highly heterogeneous, with Myanmar accounting for nearly half of the region’s confirmed malaria cases. The emergence and spread of artemisinin resistance in Plasmodium falciparum, together with declining efficacy of frontline therapies against Plasmodium vivax, pose serious threats to malaria elimination efforts worldwide. In addition, increasing insecticide resistance in major malaria vector mosquitoes undermines the effectiveness of core vector control interventions, including insecticide-treated bed nets and indoor residual spraying. The proposed program strongly aligns with the mission of the National Institutes of Health by addressing an urgent global infectious disease threat with direct relevance to American health. Drug-resistant malaria parasites that emerged in the GMS have historically spread to other regions, contributing to increased global morbidity and mortality and threatening U.S.-supported malaria control investments worldwide. In an era of extensive international travel and global interconnectedness, the emergence and spread of resistant malaria parasites and insecticide-resistant mosquito vectors abroad pose risks to U.S. travelers, military personnel, and global health security. Knowledge generated through this program will directly contribute to understanding the evolution and spread of antimalarial drug resistance, improving surveillance strategies, informing therapeutic policies, and advancing vector control approaches relevant to protecting Americans and supporting U.S. public health preparedness. In addition, training a cadre of scientists in Myanmar is critical for strengthening regional capacity to detect, study, and contain emerging vector-borne diseases before they spread to other parts of the world, including the United States. The scientific rationale for conducting this research and training program in Myanmar is compelling and cannot be replicated within the United States. Myanmar represents a unique epidemiological setting with high malaria burden, extensive parasite genetic diversity, ongoing emergence of antimalarial drug resistance, and widespread insecticide resistance in malaria vectors. These conditions provide exceptional opportunities to study evolving malaria epidemiology, resistance mechanisms, and intervention effectiveness in real-world elimination settings that are not readily available domestically. The program also leverages unique clinical populations, field sites, vector species, and longitudinal surveillance systems established through longstanding international collaborations. These partnerships provide access to scientific resources, endemic populations, and implementation environments that substantially augment existing U.S. research capabilities. Despite the urgent need for strengthened malaria research capacity, Myanmar faces a critical shortage of well-trained malaria researchers. To address this gap, the proposed training program will focus on three key scientific areas: (1) understanding the changing epidemiology of malaria in the region; (2) monitoring the clinical efficacy of antimalarial drugs and elucidating the molecular mechanisms underlying drug resistance; and (3) determining the extent, distribution, and mechanisms of pyrethroid resistance in major malaria vector mosquitoes. This multidisciplinary training program will bring together mentors with complementary expertise from the University of South Florida and Mahidol University to provide integrated training in innovative research approaches that address critical barriers to malaria elimination in the GMS. Based on a comprehensive training needs assessment, we propose a dual-track training mechanism consisting of: (1) long-term training for three junior faculty members, three postdoctoral fellows, and six PhD students; and (2) short-term training opportunities for endemic-country scientists through annual short courses and workshops. The overall training framework is designed to ensure that trainees acquire the technical skills, scientific knowledge, and intellectual independence necessary to conduct high-quality malaria research. In addition to strengthening scientific capacity in an endemic region of strategic global importance, this program will facilitate bidirectional transfer of knowledge, technologies, and surveillance approaches between Myanmar and the United States. By advancing the careers of these trainees and fostering sustainable international collaborations, the program will build a critical mass of investigators and a durable scientific network capable of addressing emerging vector-borne disease threats that have direct implications for global health and the protection of American health interests.

NIH Research Projects · FY 2025 · 2021-03

In the United States, fetal alcohol spectrum disorders (FASD) represent the leading preventable cause of birth defects and neurodevelopmental delay with life-long implications. FASD affects an estimated 40,000 infants in the US each year, with 2-5% of younger school-age children having FASD. Currently, prediction of FASD during pregnancy is not available, and there are no readily available cures against FASD. It is widely believed that early detection of FASD and its subsequent intervention strategies are critical to allow earliest and most effective therapeutic interventions. While fetal alcohol exposure targets multiple organs and systems, the brain constitutes the most severely affected organ, exhibiting both structural and functional abnormalities. As neuronal development critically depends on the oxygen delivery, nutritional supply and waste removal by cerebral circulation, recent studies have been paying increasing attention to the fetal cerebral circulation as a critical target of maternal alcohol consumption. However, the timing and mechanisms that govern fetal cerebrovascular response to alcohol remain elusive. One of the major obstacles that preclude rapid advancement of the studies on fetal cerebral circulation is lack of high-resolution imaging technique that would be suitable for imaging of small lab animal species. Current proposal is put forth by the collaborating teams of bioengineers and cerebrovascular physiologists with the overall goal of delivering a high-speed 3D photoacoustic tomography (PAT) that will allow non-invasive, simultaneous visualization of all the embryos in a mouse utero and track their development into adulthood longitudinally to study the association between alcohol exposure-induced changes in fetal hemodynamics and cerebrovascular outcome after birth. Another obstacle to developing effective treatments to alleviate symptoms and develop preventive measures against FASD is a relatively limited knowledge on relevant targets for alcohol, including targets within fetal cerebral arteries. In this regard, current proposal will focus on cerebral artery mitochondria. Critical role of mitochondria in regulating cerebral artery function is well documented, and there is no doubt that mitochondrial is one of the major sensors for alcohol as shown in liver and neurons. In our recent pioneered work we documented persistent up-regulation of fetal cerebral artery proteome in response to alcohol exposure during mid- pregnancy. However, systematic studies on cerebral artery mitochondria alterations in response to prenatal alcohol exposure remain to be performed and the role of alcohol targeting of fetal cerebral artery mitochondria remains to be established. To overcome these obstacles in the field, we propose to complete three related Aims: (1) We will optimize a high-speed PAT system for 3D high-resolution brain imaging of rodents; (2) We will develop advanced software for improved PAT 3D image reconstruction and analysis; (3) We will trace cerebrovascular morphological and functional changes following fetal alcohol exposure into adulthood, with the focus on fetal cerebral vessel density, artery diameter and mitochondrial function.

NIH Research Projects · FY 2026 · 2021-02

PROJECT SUMMARY Dementia is the most expensive medical condition in the US. There is an urgent need to intervene to curb the increasing prevalence of dementia in our population. Strong preliminary data from more than 18 ran- domized clinical trials demonstrate that computerized, cognitive speed of processing training (SPT) im- proves cognition and transfers to improved instrumental activities of daily living. Recent evidence further indicates that SPT may reduce dementia risk. Analyses of 10-year data from the ACTIVE trial revealed that older adults randomized to SPT were 29% less likely to develop dementia. Moreover, those who com- pleted additional training had a 48% reduced risk of dementia across 10 years. Two limitations of this study were a lack of clinical diagnosis of dementia and use of a no-contact control condition. Thus, an im- portant question is, “Can SPT be successfully implemented to reduce incidence of mild cognitive impair- ment (MCI) or dementia?”. Our primary goal is to test the effectiveness of SPT to reduce incidence of MCI or dementia. The Preventing Alzheimer's with Cognitive Training-PACT field trial advances prior research by rigorously implementing SPT in a large population of cognitively normal older adults and ex- amining the primary endpoint of MCI or dementia clinical diagnoses. Older adults are randomized to SPT or an active control arm of cognitive stimulation (i.e., computer games) and progression to MCI or demen- tia will be clinically assessed after 3 years. We further will explore if SPT effects are moderated by the de- gree of amyloid pathology or apolipoprotein E4 status. To demonstrate feasibility, our investigative team is implementing the study protocol in an R56 phase and successfully enrolled 744 older adults at the time of proposal submission. Three years after enrollment, we will re-assess study participants to identify those exhibiting cognitive decline. Such participants will be provided a thorough medical evaluation to clinically ascertain MCI or dementia diagnosis. Those classified as MCI or dementia will further complete an amy- loid PET scan and genetic testing. This non-pharmacological prevention trial is innovative with a highly efficient experimental design and optimized SPT training protocols including an active control group. The proposed research will determine if SPT successfully reduces incidence of MCI or dementia. This out- come will be significant in that if an intervention can delay the onset of dementia by only one year, there will be ~9.2 million fewer cases of the disease by 2050, substantially reducing cost. Positive results would support use of a relatively inexpensive and easy to apply intervention that could delay or prevent the on- set of Alzheimer’s disease and/or related dementias. Such an outcome would justify further research to identify mechanisms of action. Results will inform clinical practice of effective interventions to attenuate age-related cognitive and functional decline and thereby improve public health.

NIH Research Projects · FY 2025 · 2021-01

PROJECT SUMMARY Aging of skeletal muscle results in sarcopenia. It is believed that sarcopenia is in part due to a decreased capacity of stem cells, namely satellite cells, to repair the skeletal muscle after injury. Satellite cells are the major source of myogenic progenitors for adult muscle homeostasis and repair. A potential alternative for dysfunctional satellite cells is induced pluripotent stem cells (iPSC) which have the capacity to differentiate into skeletal muscle myocytes and blood vessels. Here, we have identified a highly efficient small molecule, givinostat (Givi), a histone deacetylase inhibitor (HDACi) which is capable of transforming human iPSC into myogenic progenitor cells (MPC) that are highly proliferative and generate large numbers of extracellular vesicles (EV). Our “pharmacological reprogramming” approach using small molecules to generate MPC in a limited period of time and without use of viral vectors is a very significant step forward in cell-based therapy. We are proposing that iPSC pharmacologically reprogrammed into MPC with Givi will be optimally effective to regenerate sarcopenic muscle. In specific aim 1, the hypothesis that induced myogenic progenitor cells (iMPC) from iPSC with novel small molecules are effective and safe for regeneration of aged muscle will be tested; In specific Aim 2, the hypothesis that accelerated mobilization and engraftment of iMPC in an aged muscle microenvironment stimulate muscle regeneration will be tested; In specific Aim 3, the hypothesis that EV derived from Givi-induced MPC rejuvenate aged muscle and augment muscle regeneration will be tested. If many of the regenerative properties of iMPC can be credited to EV, there will be a paradigm shift in regenerative medicine to enable endogenous self-repair in sarcopenia by cell to cell transfer of proteins, mRNAs, and miRNAs (miRs) by EV. EV from engineered or modified stem cells are highly enriched with bioactive molecules including myogenic miRs responsible for activation of signaling pathways important in muscle regeneration. These studies will involve multidisciplinary approaches which will employ state of the art molecular biology, biochemical, histochemical, immunohistochemical techniques and integrative physiology involving well established experimental animal model and muscle function. This proposal is conceptually innovative because it addresses the structural and molecular characterization of iMPC and their EV and tests their role as key biological messengers of iMPC action in the treatment of sarcopenia.

NIH Research Projects · FY 2025 · 2020-12

ABSTRACT In response to large numbers of senior center clients who suffer untreated depression and the dearth of geriatric mental health providers, we have partnered with senior center stakeholders to simplify Behavioral Activation (BA) to match the skill set of lay volunteers (“Do More, Feel Better”; DMFB). The lay delivery model: 1. makes use of existing volunteer resources that can address the insufficient workforce; and 2. has potential for being an acceptable and sustainable delivery model. However, the capacity of this model to engage the same target (increased activity) and to yield comparable clinical outcomes as professionally-delivered interventions is yet to be determined in a fully-powered trial. This Collaborative R01 proposes fully powered randomized effectiveness trial testing the effect of DMFB in comparison to professionally-delivered BA (MSW BA) on increased activity level (target) and decreased depressive symptoms. The specific aims are to: 1. Test the effectiveness of DMFB, in comparison to MSW BA, for depressed (PHQ- 9>10 and Ham-D>14) older adults (>60) on increasing overall activity level (target) and reducing depression symptoms; and 2. test whether increased activity level predicts greater reduction in depression severity and whether increased activity’s impact on depression is non-inferior across conditions. Client participants will be a total of 288 older (>60 years) non-psychotic, non-demented individuals with elevated depressive symptoms from 6 Seattle, 6 New York City, and 6 Tampa area senior centers serving economically and ethnically diverse communities. Eligible clients will be randomized within senior center to either DMFB (n=144) or MSW BA (n=144). Two lay volunteers and 2 MSWs per center will provide the intervention. Our proposal responds to the 2012 IOM report which highlighted the dearth of mental health providers for older adults and the need to develop a workforce of nontraditional providers. DMFB is a streamlined BA intervention that has high potential for sustainability by making use of an untapped volunteer resource and supervision infrastructure within senior centers. Our findings will identify effective interventions for an underserved and difficult to engage population, our partners in aging services would be pleased to implement either delivery format of BA to activate depressed older adults.

NIH Research Projects · FY 2025 · 2020-12

Project Summary/Abstract Plasmodium vivax is the second leading cause of malaria and the most prevalent cause of malaria outside of Africa. The estimated cost of the global burden of vivax malaria is $1.4 - $4 billion per year and more people live at risk worldwide from P. vivax than P. falciparum. It is endemic mostly in poor countries where access to affordable health care is lacking, which leads to lost adult productivity. Relapse infections from P. vivax poses a special challenge to malaria elimination and eradication because of its ability to repeatedly restart blood-stage infections from hypnozoites – the dormant parasite that can persist in human livers from weeks to years after the sporozoite infection. Exacerbating the problem, P. vivax transmission occurs prior to onset of clinical signs and treatment options to clear relapsing parasites in the dormant liver stage are limited. The goal of this U01 project is to accelerate vivax malaria vaccine development by validation of an optimal combination of P. vivax target antigens in pre-erythrocytic stages. Our vaccine strategy seeks to validate candidate antigens that together can effectively inhibit sporozoite infection and block liver stage development, including blood stage breakthrough infection. Our strategy exploits our new in vitro functional assay for experimental studies of liver stage development of P. vivax. We will pursue a structural vaccinology approach, using broadly neutralizing binding inhibitory antisera and monoclonal antibodies to identify and characterize the highest value immunogens and vaccine delivery method to design a multivalent vaccine to prevent and eliminate vivax malaria.

NIH Research Projects · FY 2025 · 2020-09

Project Summary Aging and age-related cardiometabolic diseases (CMDs) such as obesity, type 2 diabetes, hypertension, cardiovascular disease, and chronic kidney disease, along with their risk factors (e.g., insulin resistance, inflammation, dyslipidemia, etc.), result from the complex interplay between genetic, lifestyle, and environmental factors. American Indians (AIs) suffer disproportionately from these chronic cardiometabolic conditions. Gut microbiota (bacteria, viruses, fungi, multicellular parasites, and archaea in our intestine) has emerged as a novel, metabolically active “organ” that regulates many key biological processes and physiological functions. Gut dysbiosis (imbalance in gut microbial community, e.g., loss of microbial diversity or beneficial microbes, expansion of pathogenic microbes) has been associated with chronic metabolic disorders. However, several fundamental knowledge gaps exist, e.g., what are the key microbial signatures associated with aging and CMDs? What host factors shape the gut flora and how? What are the specific microbes or microbial species in human gut, and how does their composition and function differ across different populations/ethnic groups? Is the variation in human gut microbiota influenced by host genome, and if so, to what extent? Despite these unknowns, it is well accepted that the gut microbiome varies significantly among individuals and its composition heavily depends on an individual’s age, gender, geography, dietary preference, lifestyle, health status, etc. Since AIs suffer from high rates of obesity and diabetes, live on reservations or other tribal lands, eat traditional food and medicine, and practice other unique lifestyles, it is possible that they harbor different sets of disease- and health-associated gut microbiomes compared to other populations/ethnic groups. The objectives of this study are to address these fundamental questions by generating the first complete map of the human gut microbiome and identifying key microbial features associated with aging and CMDs in American Indians. To achieve this, we will leverage the parent SHS Phase VII (funded by NHLBI as a contract, 2019-2026) that will re-exam all living participants (N~=3,000) in 2020-2024 to collect stool samples from 1,500 well-phenotyped AI participants. We will conduct whole-genome shotgun metagenomic sequencing and perform innovative statistical analyses to: (1) identify key age-related gut microbiome features associated with biological aging (assessed by leukocyte telomere length) and CMDs (Aim 1); (2) identify host factors that shape the human gut microbiota in AIs (Aim 2); (3) explore the mechanistic links between gut dysbiosis, aging, and CMDs (Aim 3). Our long-term goal is to understand the mechanisms through which gut microbes interact with host factors in leading to accelerated aging and CMDs, with an ultimate goal to develop novel, precision therapeutic interventions (e.g., diet, drugs, live organisms, fecal microbiota transplantation) to promote healthy aging and improve cardiometabolic health.

NIH Research Projects · FY 2026 · 2020-09

Project Summary In the past decade, restoring the intrinsic axon growth ability of mature neurons has received promising results in promoting axon regeneration in the central nervous system (CNS). However, to date, axon regeneration that leads to successful functional recovery in the CNS is still practically impossible, primarily due to the inadequate distance of regeneration and the low number of regenerating axons. Previous studies and my preliminary data have shown that many genes mediating the intrinsic axon growth ability are differentially expressed at different developmental stages in neurons, indicating the altered gene expression level during neuronal maturation is an important factor underlying the diminished intrinsic axon growth capacity. However, how the altered gene expression program is regulated remains largely unknown. Transcription factors (TFs) play important roles during neuronal development, shaping the spatiotemporal gene expression landscape to control cellular activities including axon elongation. Thus, understanding the intricate transcriptional regulatory network orchestrating axon growth during development is critical for solving the challenge of mammalian CNS axon regeneration. In this proposed study, I will perform parallel RNA-seq and ATAC-seq of purified retinal ganglion cells (RGCs) at multiple developmental time points, and use advanced integrative bioinformatics analysis to obtain a comprehensive view of the transcriptional regulatory network controlling the axon elongation function during RGC development, and identify key TFs that function as core regulators of axon growth. The identified TFs will be functionally tested in mouse optic nerve regeneration model to verify if they play important roles in RGC axon regeneration and cell survival. RGCs are comprised of more than forty molecular distinct subtypes. Different RGC subtypes vary in vulnerability to axonal injury and have distinct responses toward gene modulations. I will conduct single-cell RNA-seq (scRNA-seq) in RGCs 2 weeks after optic nerve crush from control and TF- manipulated groups to acquire the frequency of each RGC subtype in the final population, and determine what specific RGC subtypes are protected by the manipulation of a specific TF by comparing the frequencies of RGC subtypes between control and TF-manipulated groups. TFs whose manipulations are found to improve survival in distinct RGC subtypes will be combined in the next step to determine if simultaneously manipulating these TFs could protect a wide variety of RGC subtypes from injury-induced cell death and induce synergistic promoting effect on RGC axon regeneration. In addition, I will also combine the manipulations of these TFs with non-muscle myosin IIA/B deletion in RGCs, which produces axon regeneration by modifying cytoskeletal dynamics in the growth cone of injured axons, to find out if this combinatory approach could lead to unprecedented long-distance axon regeneration.

NIH Research Projects · FY 2024 · 2020-09

CARDIAC TOXICITY OF FLAVORINGS IN ELECTRONIC NICOTINE DELIVERY SYSTEMS Tobacco cigarette smoking is on the decline, but the usage of electronic nicotine delivery systems (ENDS) is gaining popularity, specifically in the teen and young adult age groups. While the cardiac toxicity of tobacco cigarette smoking has been widely studied and is well established, the possible cardiac toxicity of ENDS products and their design characteristics, such as added flavorings, are largely underexplored. For instance, a form of electronic nicotine delivery known as vaping, uses “e-liquid” in order to generate “e-vapor”, an inhalable smoke-like aerosolized mixture containing nicotine and flavors. Here, we propose to investigate how e-liquids with different flavors affect cardiac in-vitro and in-vivo toxicity, in cell culture and in animal models. Our hypothesis is that inhalation exposure to e-liquid flavorings increases cardiac oxidative stress, leading to electrophysiological toxicity and arrhythmogenesis. We will conduct our studies in three aims: 1)- To investigate the in-vitro cardiac harm and toxicity of e-liquid flavorings, 2)- To investigate the in-vivo cardiac harm and toxicity of e-liquid flavorings, and 3)- To investigate the role of oxidative stress in mediating the cardiac toxicity of e-liquid flavorings. We believe that this proposal will produce new, useful and focused insights into the potential in-vivo and in-vitro adverse effects of e-liquid flavorings using functional and cellular indicators of cardiac harm. Our findings will hopefully be valuable in increasing our understanding of whether the flavoring aspect of ENDS products design could cause cardiac in- vivo and in- vitro toxicities.

NIH Research Projects · FY 2024 · 2020-08

PROJECT SUMMARY/ABSTRACT Alzheimer’s disease (AD) is a neurodegenerative disease that results in amyloid β plaque deposition, neurofibrillary tangle (NFT) formation, and life-altering cognitive defects. Many human genetic AD risk factors, including APOE, CLU, and TREM2, modulate neuroinflammation and/or the function of microglia, the central nervous system (CNS) resident innate immune cell. Deletion of all peripheral adaptive immune cells (i.e. CD4+ T cells, CD8+ T cells and B cells) or T cell depletion (i.e. CD4+T cells, CD8+T cells) increased cognitive abilities in amyloidosis and tauopathy models, respectively, and were associated with altered microglial function. Interestingly, aging, another major AD risk factor, is associated with inflammation and we have found that increases in CNS CD8+ T cells found with aging is further exacerbated by amyloidosis. Additionally, enhanced CNS CD8+ T cells numbers are also found during tauopathy. We hypothesize that CD8+ T cells impact cognition and CNS sequelae during tauopathy and age-associated amyloidosis. We predict that CD8+ T cells alter microglia function and transcriptomes as a mechanism for disease modulation. To address this hypothesis, we will utilize aged wild type (WT) control mice, aged APPNL-F/NL-F mice, which express human amyloid precursor protein (APP) or our AAV1 model of tauopathy, respectively, on a normal WT or CD8-/- background, to eliminate CD8+ T cells. We will also conduct similar studies on an OT-I background which contains CD8+ T cells that are not stimulated through their T cell receptor (TCR). We will assess multiple parameters including behavioral/ cognitive performance (using open field assay, elevated plus maze, contextual fear conditioning and morris water maze), immunofluorescence/immunohistology examining plaque deposition, tau phosphorylation, CD8+ T cell localization and microglial/ astrocyte reactivity, flow cytometric analysis of CNS CD8+ T cell function, western blot analysis for total and phosphorylated tau, ex vivo microglial cultures and RT-qPCR to examine cortical and hippocampal gene expression of proinflammatory and anti-inflammatory factors. Furthermore, we will be using single cell transcriptomics to examine the entire RNA transcriptome on a per cell basis to assess CNS CD8+T cell transcriptomes and the impact of CD8+T cells on microglial transcriptomes and subpopulations during normal aging, age-associated amyloidosis or tauopathy. Our proposed work will be the first to define the transcriptomes of CNS CD8+ T cells in the context of age-associated amyloidosis or tauopathy. Additionally, we will address for the first time how CD8+T cells impact behavior/cognition, neuroinflammation, gliosis, microglial transcriptomes and pathology during age-associated amyloidosis or tauopathy. This work will provide highly novel insights into how peripheral and central immunity interact during aging and disease, and could provide the impetus to examine new therapeutic measures for management/alleviation of AD associated CNS sequelae.

NIH Research Projects · FY 2024 · 2020-08

Project Summary/Abstract This proposal details a 5-year training plan to prepare the physician candidate, Thao (Tina) Ho, for a career as an independent, translational investigator who will become a leader in the field of iron deficiency and anemia of prematurity. The project will identify the effects of enteral iron supplementation, as prevention for anemia, on intestinal health of preterm infants through complementary clinical and basic science studies. All preterm infants are at risk for iron deficiency. Enteral iron supplementation is recommended to all preterm infants at 2-4 mg/kg/day; however, they are often given at higher doses, 6-10 mg/kg/day. Emerging evidence suggest that enteral iron can exacerbate the overgrowth of enteric pathogens and suppress beneficial bacteria. This imbalance, or intestinal dysbiosis, intestinal inflammation, and disrupted barrier are observed in necrotizing enterocolitis, a devastating intestinal disease of prematurity. Preterm infants are colonized with higher percentage of enteric pathogens at baseline compared to term infants. Dr. Ho’s preliminary data has led to the hypothesis that high enteral iron supplementation exacerbates intestinal dysbiosis, mucosal inflammation and permeability in preterm infants. Dr. Ho will test this hypothesis by conducting a randomized study to compare the fecal bacterial composition, mucosal inflammation and barrier function between premature infants given high vs. low iron regimens and investigating the cellular mechanisms with cytokine production and gene expression using human 3D enteroid models. At the completion of this project, Dr. Ho will be experienced in 1) designing and conducting clinical studies, 2) advanced biostatistical analyses and interpreting the results of large clinical datasets, and 3) performing experiments on 3D cell models. The candidate’s independent analytical thinking will grow with regular discussions among NIH-funded researchers and didactics provided by the University of South Florida. This award will allow her more protected time to develop necessary skills and collaboration to establish independence by the 4-5th year. Dr. Ho will work under the primary mentorship of Dr. Groer, an expert in translational microbiome and infant health research with many successful mentees. To complement her primary mentor, Dr. Ho’s mentoring team, Drs. Adams and Kim, will support her in cell culture techniques, microbiology, and genomics. Dr. Ho also has established a superb team of scientific advisors with the following expertise: Dr. Michael Georgieff (iron and neurodevelopment), Dr. Josef Neu (intestinal immunology), Dr. Sharon Donovan (childhood nutrition and intestinal microbiome), and Dr. Jason Spence (3D intestinal models). They have committed their time to her career development and research goals long before this application. Their mentorships, the fast-growing and supportive research environment at USF, the innovative research strategy, and a focused career development plan will provide a strong platform for Dr. Ho to secure an R01 to investigate the long-term health effects from different iron doses to optimize the prevention of iron deficiency and anemia of prematurity.

NIH Research Projects · FY 2026 · 2020-07

PROJECT SUMMARY Tens of thousands of replication forks duplicate both genetic and epigenetic information faithfully in each S-phase of cell cycle. Progression of replisomes, the macromolecular complexes that execute DNA synthesis, is often hindered by DNA lesions resulting in fork stalling events. Such perturbations activate the replication stress response that stabilize stalled forks to prevent irreversible collapse into double strand breaks. Replication stress response engages several proteins to remodel replication forks, activate DNA repair pathways and amplify replication checkpoint. Defective replication stress response engenders conditions associated with developmental abnormalities, accelerated aging, and tumorigenesis. Moreover, oncogene- induced replication stress is a key driver of chromosomal instability and cellular transformation. Thus, it is critical to elucidate the genome maintenance pathways that resolve replication stress to safeguard genome integrity. The primary goal of our research program is to understand genome maintenance pathways that promote accurate replication of the genome. Achieving this objective requires screening the composition of replication fork proteomes and mechanistic characterization of replisome proteins to elucidate their function in replication stress response. To this end, my lab has uncovered fork protection factors that block digestion of newly synthesized DNA by resection nucleases. Furthermore, we established that chromatin state is a critical determinant in replication fork protection and identified repair pathways that alter fork stability in BRCA-deficient cancers. We also characterized the contribution of nucleosome remodeling at replication forks, and identified proper chromatin assembly on daughter DNA molecules is necessary to prevent gap accumulation and break induction. These innovative contributions make us ideally poised to pursue detailed functional studies to uncover replication stress response pathways that function in promoting genome integrity. The research proposal will address three key goals – 1. Characterization of fork protection pathways, 2. Regulation of nascent ssDNA gap formation, and 3. Investigation of replication stress response during re-replication. Successful completion of these goals will provide critical insights into the fundamental mechanisms utilized by cells to deal with replication stress to promote genome stability. By exploring the scientific objectives using hypothesis-driven research, the proposed research will lead to significant breakthroughs and paradigm-shifting discoveries thereby enhancing our knowledge on mechanisms that control DNA replication and providing opportunities to target replication fork vulnerabilities for cancer treatment.

NIH Research Projects · FY 2026 · 2020-05

PROJECT SUMMARY/ABSTRACT Vascular barrier dysfunction causes aberrant transport of blood components into the vessel wall or surrounding tissues, a hallmark of inflammatory injury in response to trauma, sepsis, atherosclerosis, diabetes, and stroke. Currently, there are no effective therapies that directly target the leaky barrier, as drug development has been hampered by knowledge gaps and difficulties in translating cell/animal data to human pathophysiology. Our program addresses these challenges via comparative analyses of endothelial barrier structure and function in human and animal models of inflammatory injury. We conduct three series of studies in the blood, blood-vessel interface and endothelial barrier structure, aimed at 1) identifying key circulating factors that cause barrier leakage and their cell-specific mechanisms of production and action; 2) characterizing endothelial surface receptors and intracellular signals that transduce their effects; and 3) elucidating molecular events in cell-cell junctions, cytoskeleton, and glycocalyx that ultimately lead to barrier opening. Our work has continuously been supported by the NHLBI contributing to the development of novel techniques and transformative theories in vascular permeability. We were among the first to characterize the nmMLCK signaling in endothelial junction dynamics and paracellular permeability during leukocyte activation. Recently, we reported the discovery of a new post-translational modification pathway, dhhc21-mediated protein palmitoylation, in microvascular leakage and leukocyte-endothelium interactions following infection and sterile injury. Built on these exciting findings, our program continues to advance by exploring novel diagnostic/therapeutic targets with mechanistic insights that will transform the paradigm of inflammation. Current efforts are directed to the characterization of neutrophil extracellular traps, histones and microvesicles, focusing on their cell-specific mechanisms of generation and function in the microcirculation. Studies are on-going to test the roles of palmitoylation in vesicle biogenesis, cargo composition and interaction with endothelial cells. The barrier-disrupting effects of these factors will be uncovered with in-depth molecular details on endothelial glycocalyx receptors, intracellular signal transduction, and post-translational modification (palmitoylation) of junction structures. We use a multifaceted approach that incorporates innovative molecular biology and imaging techniques (many developed in our lab) into functional analyses of vascular permeability under clinically relevant conditions. Complementary in vitro, ex vivo, and in vivo experiments are designed testing pharmacological activators and inhibitors, molecular manipulations, and genetic/chimeric alterations at cell-tissue-body levels. A unique aspect of our program lies in the translational impact achieved through the studies with intact functionally viable human organs.

NIH Research Projects · FY 2024 · 2020-04

Kidney transplantation is a life-saving procedure for patients with end-stage kidney disease. Although the short-term organ survival post-transplantation has improved dramatically over the past decades, the long-term outcomes remain unsatisfied with the survival half-lives for transplanted renal grafts still about 10 years. In addition, organ shortage is a global crisis which has stimulated new approaches on expansion of the donor pool by using marginal organs. However, the employment of marginal organs has a significantly higher incidence of delayed graft function and lower graft survival rate compared with standard criteria donors. Therefore, there is an urgent need for new strategies to improve the long-term graft outcomes. In this proposal, a novel hypothesis that rescue macula densa NOS1 expression by renal alkalization with bicarbonate improves transplanted graft outcomes will be tested. The findings of the present proposal will provide a novel strategy with potential translational significance that could be applied to either donors or recipients during kidney transplantation. Additionally, the underlying mechanisms and potential targets will be examined. Renal alkalization to enhance the expression of macula densa NOS1 expression in donors or recipients is anticipated to be a simple and effective method that is used in the expansion of the donor pool and improvement of long-term graft survival.

NIH Research Projects · FY 2024 · 2020-04

PROJECT SUMMARY/ABSTRACT Pathogenic mutations in the tau gene (MAPT) are linked to the onset of tauopathy, but the A152T mutation is unique in acting as a risk factor for a range of disorders including Alzheimer’s disease (AD), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and dementia with Lewy bodies (DLB). As an unconventional approach to investigate the role of tau in neurodegeneration, we reasoned that understanding how the A152T variant modulates risk of AD and related disorders could reveal a common disease mechanism(s), uncovering novel strategies to increase resilience to tau toxicity and modify disease phenotypes in patients. Given the introduction of a new potential phosphoepitope, we questioned whether the A152T variant might impact disease risk through altered phosphorylation of tau on either T152 or the neighboring T153 residue. A series of novel antibodies were generated to test this idea, which revealed significant accumulation of soluble tau species hyperphosphorylated on T153 (pT153) in postmortem brain tissue from A152T carriers compared to noncarriers, as well as in mice expressing A152T-AAV. Therefore the current project will investigate the overall hypothesis that the A152T variant modulates disease risk through enhanced accumulation and increased solubility of pT153-positive tau, which subsequently primes tau for downstream pathological phosphorylation events and is critical for tau-mediated toxicity. Of note, phosphorylation on T153 and tau’s other serine/threonine-proline motifs has been shown to be required for tau toxicity, although the extent to which pT153 contributes to tau toxicity remains untested. In elucidating the pattern of pT153 deposition throughout the brain in A152T carriers and noncarriers, the proposed studies will determine if pT153-positivity coincides with neurodegeneration. Using site-directed mutagenesis and somatic brain transgenesis, we will determine whether pT153 is required for tau toxicity in vivo. Finally, incorporating rapidly evolving technology that is enabling acquisition of global gene expression profiles at the single cell level, we will assess whether expression of the A152T variant differentially impacts the transcriptome of individual cell populations. We anticipate that in uncovering the mechanisms by which A152T influences risk of tauopathy, and deciphering the involvement of pT153 in tau toxicity, the current project could identify novel approaches to block tau-mediated neurodegeneration in AD and related disorders.

NIH Research Projects · FY 2025 · 2019-12

Project Summary The overall aim of this application is to advance PfCDPK5 and PfGARP as vaccine candidates for falciparum malaria. P.falciparum malaria affects almost one-half of the world's population and causes more than 500,000 deaths annually. Young children in malaria endemic areas of Africa have the highest mortality rate because of their immature immune systems. Global efforts to control the disease have had limited success, and no vaccine has yet been approved for clinical use. Therefore, there is an urgent, unmet need to discover new vaccine candidates. A vaccine against childhood malaria is a priority because children below the age of 5 years are highly vulnerable to the disease. In recent studies, our laboratory discovered Schizont Egress Antigen-1 (PfSEA-1), a 244-kDa-parasite antigen that is crucial for parasite egress from an infected red blood cell (iRBC), which was published as a comprehensive, full-length Research Article in Science. In a parallel approach, we have screened phage display cDNA libraries constructed from parasites isolated at our Tanzanian field site with/without culture adaptation using positive selection with antibodies pooled from resistant two-year-olds and negative selection with antibodies pooled from susceptible children. We identified several independent cDNA clones encoding plasmodium falciparum glutamic acid reach protein (PfGARP) and plant-like calcium-dependent protein kinase (PfCDPK5) that were uniquely recognized by antibodies in resistant, but not susceptible sera. Our preliminary data demonstrate that PfGARP and PfCDPK5 is critical for parasite development in side RBC and egress respectively). PfGARP expresses on the surface of the trophozoite infected RBC and PfCDPK5 is expressed by merozoites as they rupture from erythrocytes. Antibodies against PfGARP and PfCDPK5 block parasite growth up to 99% in vitro, and ortholog vaccine of CDPK5 protect mice from parasitemia, and extend the survival of mice challenged with lethal P. berghei ANKA. Our vaccine discovery program has also identified several known invasion ligands (MSP-4 and MSP-7 collectively referred to as MSPs) In this application, we will evaluate these vaccine candidates with CDPK5 as single fusion protein (PfCDPK5-MSP4 & PfCDPK5-MSP7) in combination with PfGARP in in vitro assays and using multiple adjuvant systems in murine vaccine trials. The lead fusion antigen will be further evaluated for cell mediated immune response using TFRS depletion method in murine model. The deliverables from this study will be an adjuvant optimized tri-valent vaccine ready for Aotus/ P. falciparum challenge and Phase-1 clinical trial in human that targets the entry, intracellular development, and the exit of the parasite cycle in .

NIH Research Projects · FY 2025 · 2019-12

Project Summary There is an unmet need for interventions that address overweight/obesity in pediatric cancer survivors (PCS) after treatment. Rates of overweight and obesity for off-treatment pediatric cancer survivors (PCS) are higher than in the general pediatric population, ranging from 40% to 50%, significantly increasing their risk for concomitant negative health consequences. By the time survivors reach young adulthood they are 10.8 times more likely to have cardiovascular disease than healthy siblings. Reducing the risk of adult obesity in PCS who are overweight or obese by promoting healthy dietary and physical activity (PA) behaviors may serve an important preventive function for these survivors. We recently evaluated the feasibility of our intervention, NOURISH for Healthy Transitions (NOURISH-T), for PCS with obesity by targeting parents as agents for change. Results demonstrated that NOURISH-T was not only feasible, but showed promise of efficacy. We further refined our intervention, now referred to as NOURISH-T+, and implement these in this larger, multi-site RCT, with the aim of evaluating the efficacy of our intervention across diverse pediatric oncology clinics. We focus on parents to model healthy eating and PA behaviors to promote PCS behavior change. Topics relevant to parents of PCS (e.g., transitioning to survivorship and late effects) are discussed. Parents of PCS with overweight/obesity (BMI > 85th%ile), age 5-11, 1- <5 years off treatment will be randomly assigned to the NOURISH-T+ intervention or Enhanced Usual Care (EUC) comparison. Parents in NOURISH-T+ participate in a 6-session, manualized intervention, with an additional dietician session and 2 PCS sessions, as well as post- intervention booster sessions. Sessions are conducted via a videoconferencing platform. EUC consists of a one-time informational session, nationally available brochures and follow-up check-ins. Parents and PCS are assessed on anthropometric measures, PA and dietary behaviors at baseline, 3-, 6-, and 12-months post-intervention. We will enroll a highly diverse group of 260 parents/PCS dyads from Johns Hopkins Medical Center (JH), Nicklaus Children’s Hospital, Miami Children’s Health Care System (MC), Johns Hopkins/All Children’s Hospital (ACH), and Virginia Commonwealth University (VCU). University of South Florida (USF) serves as the coordinating center for intervention, data management and analyses. • Aim 1a: Evaluate NOURISH-T+ for its impact on the primary outcome of child BMI z-score. • Aim 1b: Evaluate NOURISH-T+ on secondary outcomes: PCS waist-to-hip-ratio (WHR), PA and eating behaviors. • Aim 2: Evaluate the impact of NOURISH-T+ on parents, including BMI, WHR, PA and eating behaviors, and perceptions of child-family eating and PA practices. • Exploratory Aim: Evaluate potential moderators of the intervention and examine the dyadic relations between parents and children.

NIH Research Projects · FY 2023 · 2019-09

Project Summary Alzheimer’s disease (AD) is the most common form of dementia among older people with no cure or effective treatment. A thorough understanding of its molecular mechanisms is required for discovering novel diagnostic and therapeutic strategies against AD. Chemical modifications of DNA such as methylation play critical roles in regulating gene expression and many other key biological processes, and altered DNA methylation pattern has been implicated in brain aging and AD. While much attention has focused on DNA methylation at the fifth position on cytosine (5mC), recent research identified a new form of DNA modification at the sixth position on adenine (6mA) in mammalian brains. However, little is known about its presence, genomic distribution, and possible functions in human brain and relevance to AD. Our preliminary data in mouse and human brain indicated that 6mA is dynamically responsive to environmental stress and accumulates in human AD brain. Our central hypothesis is that altered signature of 6mA modification is causally associated with AD neuropathology. The objectives of this project are to generate the first detailed map of brain 6mA methylome and identify causative genes harboring aberrant 6mA alterations associated with quantitative neuropathological measures for early features of AD pathology (e.g., amyloid plaques, neurofibrillary tangles). To achieve this, we propose three specific aims: (1) Genome-wide mapping of brain DNA 6mA methylome to identify differentially methylated genes/regions harboring altered 6mA sites (D6AMRs) associated with AD pathology in 1,200 postmortem brain tissue samples collected by two large, community-based population cohorts of aging and dementia. (2) Integrated multiomics analysis to elucidate the potential mechanistic role of 6mA alteration in AD pathology; and (3) Functionally validation of top-ranked candidate genes in 3D brain organoids derived from human iPSCs. This innovative project leverages the wealth of deep clinical and neuropathological phenotypes along with rich omics data including genetic (GWAS, WGS), epigenetic (5mC, 5hmC, 6mA, H3K9Ac), and transcriptome (RNA-seq) profiled on the same prefrontal cortex, and will provide unprecedented opportunities to uncover novel molecular mechanisms implicated in AD pathology. Our proposal brings together an exceptionally strong and unique multidisciplinary team with complementary expertise in genetic epidemiology, statistical genetics, bioinformatics, molecular and neuroepigenetics, and Alzheimer’s research. The work proposed represents the frontier in the interface between AD and omics research. Findings of this study will provide novel mechanistic insight into AD pathogenesis, and are likely to discover new molecular targets with important clinical and translational implications.

NIH Research Projects · FY 2024 · 2019-08

PROJECT SUMMARY What we know: There are 1.1 million persons living with HIV (PLH) in the US: at least 40% smoke and most want to quit. Almost none are currently accessing smoking cessation interventions designed to meet their specific needs and concerns. PLH who smoke have high rates of nicotine dependence, depression, and loneliness. Lung cancer due to tobacco use is a leading killer of people living with HIV (PLH), accounting for up to 61.5% of mortality. PLH who smoke reduce their life expectancy by 12.3 years on average. The lack of access to proven, effective, and HIV-tailored tobacco cessation services represents a health disparity of the first order. Eighty-one percent of PLH use the Internet and most do so on their own technology–making group-based video- conferencing–accessed through the Internet a promising avenue to deliver smoking cessation treatment. Although cessation programs are widely offered to the general public, there are no evidence-based programs available specifically for PLH and none found effective long-term for this population; no programs provide group- based video-conferencing (VG for video-groups); and no PLH-specific programs provide smoking cessation booster sessions. What we will do: In this rigorous trial, the efficacy of a PLH-specific cessation program (PSF- VG), guided by the Social Cognitive Theory, will be compared to an attention matched control condition (AMC; prevention with positives) in a randomized control trial. Participants will be N=482 PLH smokers recruited from Florida who are motivated to quit within the next 30 days. All participants will be offered nicotine replacement therapy and brief cessation counseling in addition to an 8-session intervention with booster sessions (PSF-VG or AMC). The primary outcome will be biochemically confirmed 7-day point prevalence abstinence at 12 months follow-up, although 30-day point prevalence abstinence and sustained abstinence (continuous abstinence post- quit day after a 2-week grace period) will be assessed, as well. We will also determine the cost per additional quit, an important cost-effectiveness measure for smoking cessation. We will examine model-driven hypotheses about the mediators of treatment outcome (e.g., knowledge, motivation to quit, self-efficacy), and explore effects on CD4 count and virologic suppression. Implications: 1) This trial will represent one of the most rigorous trials of tobacco cessation among PLH to date, given the AMC and 360-day follow-up period. 2) Establishing the long- term efficacy of a VG smoking cessation program for PLH, which reaches PLH “where they are,” will represent an enormous advance in the fight against tobacco use in PLH and provide a clearer understanding of the role of targeted, ehealth health interventions in comprehensive HIV care. 3) Determining the costs associated with this program will be critical for making real world implementation decisions. 4) Establishing effect mediators will help identify to what extent PSF-VG is working as intended and help build the mechanistic science of HIV smoking cessation. 5) Examining changes in CD4 and viral load will add to our understanding about how smoking cessation confers benefits for health in PLH. Thus, this study will likely have a high impact on the field.

NIH Research Projects · FY 2026 · 2018-09

Summary The long-term goal of the proposed project is to find a novel diagnostic and treatment approaches that address the corneal hypoesthesia, the hallmark of the neurotrophic keratitis (NK), a vision-threatening condition that results from injury or dysfunction of corneal nerves and subsequent corneal sensory nerve degeneration. The objective of this proposal is to determine the immune cell-type-specific ligand-receptor pairs that are involved in bidirectional cross talk between resident corneal immune cells and sensory afferent nerves originating from the neurons of trigeminal ganglia, and how these interactions impact the sensory afferents in the neurotrophic keratitis (NK). The central hypothesis is that subsets of immune as well as non-immune corneal cell populations play a crucial role in regulating survival and regenerative capacity of corneal sensory afferent neurons via direct neurotrophic support in healthy corneas and that the lack of these neurotrophic factors exacerbate degeneration of TG-derived sensory afferents resulting in progression of NK. The rationale underlying this proposal is that while corneal sensory nerves were shown to promote epithelial and stromal health through secretion of neurotrophic factors and neuropeptides, the target cells, including corneal parenchymal cells and resident and infiltrating leukocytes, also can produce biologically active neurotrophic factors that maintain corneal nerve survival, regeneration and importantly, can impact course of neurodegeneration. The central hypothesis will be tested by pursuing three specific aims: 1) To characterize the cell populations and molecular pathways involved in NK; 2) To identify corneal modulators of diseased nerve function/degeneration in TG-derived sensory afferents in vitro; 3) To assess the role of immune cells in the loss of corneal nerve function/degeneration in NK in vivo. We will pursue our goal using both recently-developed techniques specific to state-of-the art gene expression analysis, the next-generation protein expression analysis, intravital multiphoton microscopy, corneal electrophysiology and more-established techniques that have been uniquely and successfully applied in our laboratory. The expected outcome of this work is a deeper understanding of which neurotrophic molecules and corneal cell populations contribute the most to the positive clinical outcome in the NK. The results will have an important positive impact immediately because they will establish better understanding of complexity of the neuro-immune crosstalk, and long-term because they lay the groundwork to develop cellular-based therapies to promote corneal nerve regeneration for better treatment of NK.

NIH Research Projects · FY 2025 · 2018-09

Project Summary/Abstract To accurately compute free energies and reaction profiles of complex biomolecular systems and reactions there are two key prerequisites: the accurate description of inter- and intramolecular interactions, and adequate sampling of all relevant conformational degrees of freedom. Include the possibility that conformational dynamics may be coupled to complex electronic processes or chemical reactions, where quantum mechanical (QM) methods are needed, and this task becomes extremely daunting. Currently, whenever accurate computations of biomolecular systems are essential, the tool of choice is hybrid quantum mechanical/molecular mechanical (QM/MM) calculations, however, the application of these techniques to free energy simulations (FES) is still far from routine. Herein, we aim to develop a set of robust, efficient, and accurate new techniques that will make the application of QM/MM FES practical. These methods will be subsequently applied to study two classes of biomolecular applications that present extreme challenges to current techniques: (1) studying processes where conformational changes may be coupled to enzyme catalysis, as in 1-Deoxy- D-xylulose 5-phosphate synthase (DXPS), a key enzyme in the metabolic pathway of pathogenic bacteria, absent in humans and therefore a potential drug target; and (2) investigating the binding step in covalent inhibition of serine β- lactamases, one strategy to overcome antimicrobial resistance.

NIH Research Projects · FY 2024 · 2018-06

Project Summary/Abstract Plasmodium falciparum is the major global cause of malaria morbidity and mortality and is especially devastating in pregnant women and children in sub–Saharan Africa. Anopheline mosquitoes are essential for the spread of new infections, requiring ingestion of mature sexual stages from an infected person and then a second blood meal once infectious sporozoites are in the mosquito salivary glands. Development of sexual stages in an infected person’s blood cells requires a complex ~14-day development phase. Even with a lot of recent progress, many processes essential for sexual stage development remain poorly understood. Our group has developed a functional genomics approach using random piggyBac mutagenesis, which can be applied at genome scale to identify the P. falciparum genes essential for gametocyte development. We used this approach to complete the first saturation mutagenesis screen of P. falciparum to functionally annotate genes essential and dispensable for asexual blood-stage development. We estimate many genes in the cryopreserved saturation mutagenesis library are likely to be sexual-stage genes and this mutant library can be used for a forward phenotypic screen to identify most genes needed for sexual stage development. Advanced ‘omics analyses of selected mutants will be used to validate phenotypes and elucidate the broader cellular events that underlie the phenotypes during sexual stage development in infected human blood cells. The project combines expertise in gametocyte biology, advanced computational genomics, and phenotype comparisons with clinical isolates.

NIH Research Projects · FY 2026 · 2017-09

Alzheimer’s disease (AD) is the most devastating dementia causing severe global concern. Although the mechanism of AD pathogenesis is still under debate, it is widely accepted that aggregated fibrillar forms of Aβ peptides are prominent hallmarks and the major cause of AD due to their toxicity to neurons. Therefore, Aβ aggregates are the potential targets for the intervention of AD, as targeting and removal of Aβ fibrils or plaques is expected to eliminate the neuronal toxicity of Aβ aggregates. However, eradication of total Aβ peptides by antibodies such as the new drug aducanumab could lead to severe side effects, whereas anti-Aβ aggregation by β-sheet mimetics could only prevent or delay the process of aggregation process and could not disrupt the formed/existing Aβ aggregation. Therefore, development of more effective molecular probes that not only prevent but also disrupt Aβ fibril formation is still in an urgent need. In contrast to the use of β-sheet mimetics to block Aβ fibrillar growth, recently we designed a series of helical peptidomimetics that can tightly bind and stabilize monomeric helical Aβ and thereby shifting the equilibrium of Aβ conformation into off-pathway structure, leading to both potent prevention and disruption of Aβ aggregation, as well as significant enhancement of neuro cell growth and dendrite branching without virtually any cytotoxicity. Furthermore, this lead compound could remove Aβ plague deposited in the brain of the AD transgenic mouse and completely recover the memory of mice in the behavior test. As such, our long-term goal is to develop novel biomaterials that can prevent, halt and cure AD. The objective of this proposal, which is the first step to achieve the long-term goal, is to advance our preliminary work by rationally designing structurally related analogues of the current lead, so as to identify and develop more potent and effective compounds that can tightly bind and stabilize Aβ monomer and thus prevent and disrupt Aβ aggregation both in vitro and in vivo. We will first design helical peptidic foldamer bearing diverse functional groups and closely mimic the binding pattern of our lead compound. Then we will use our established in vitro assays such as 2D-NMR and kinetic binding assays to identify and optimize our designed compounds that target and inhibit the aggregation of Aβ peptides. The compounds with activity equivalent or better than the lead compound will be used to study their ability to inhibit Aβ aggregation both in vitro and in vivo in AD-transgenic mice. The proposed study is significant because there is no effective therapeutic strategy for AD diagnosis and prevention. Our research will provide molecules with novel mechanism to unravel AD pathogenies and to develop potential molecular probes and therapeutic agents for cure of AD. The proposed research is innovative because we not only provide a new strategy for the development of novel class of foldameric prevent and disrupt Aβ aggregation, in addition, this approach of rational design for the recognition of Aβ surface can be easily extended to identify new materials targeting other amyloid diseases such as Huntington’s disease and diabetes diseases.

NIH Research Projects · FY 2025 · 2017-08

PROJECT SUMMARY Post-traumatic stress disorder (PTSD) is a debilitating stress-related mental disorder that significantly impacts African Americans (AAs). Our earlier work identified key adversity factors, including cumulative trauma, emotional maltreatment and financial difficulties that, in combination with DNA methylation in glucocorticoid receptor regulatory network genes, prospectively predicted PTSD symptom severity. While studies examining the risk of PTSD among white and AA populations have shown that AAs are at a higher risk of PTSD following traumatic exposure, there are few studies that have specifically examined the contextual factors that lead to differential risk within AA populations. Within-population studies have the potential to uncover social and environmental factors that ultimately lead to differences in PTSD risk. Indeed, psychosocial and environmental mechanisms, such as living in unsafe environments and exposure to differing levels of social support, may contribute to differential PTSD risk in AAs. Our prior research confirms these findings. What remains unknown, however, are: (i) the potential buffering effects of positive psychosocial exposures, such as social support and cohesion, which have been shown to play an important role in mitigating risk of PTSD; and (ii) the extent to which peripheral epigenetic measures are relevant to the target organ of PTSD—the brain. Advances in the science of linking peripheral epigenomic variation to central nervous system (CNS) epigenomic variation (herein called brain-related epigenomic variation) are urgently needed in order to gain deeper mechanistic insight into PTSD-related health gaps among AAs affected by this mental health condition. Therefore, the overall goal of this renewal application is to provide mechanistic insight into how contextual factors, both positive and negative, affects brain-related epigenomic variation to impact risk of PTSD and traumatic stress in a prospective, community-based cohort of AAs. To achieve this goal, we will leverage publicly available, multi-tissue datasets to identify epigenomic markers that are highly correlated in brain and blood, and focus our proposed analyses on these correlated measures using existing and newly collected epigenomic and gene expression data from the Detroit Neighborhood Health Study (DNHS) cohort. The genomic data will be paired with DNHS survey data, which includes annual measures of adversity, psychopathology, and social support and cohesion. We will focus analyses on adversities previously implicated in our earlier work (e.g. cumulative trauma, financial difficulties, emotional mistreatment) and positive psychosocial exposures previously implicated in PTSD (social support and neighborhood social cohesion). Results from this study will provide a deeper characterization of how psychosocial exposures, both positive and negative, influence brain-related epigenomic processes to impact stress-related psychopathology among AAs, an under-studied U.S. population with substantial health gaps in traumatic-stress related psychopathology.