University Of South Florida

NIH Research Projects · FY 2026 · 2017-06

Abstract Clostridioides difficile is a spore-forming and toxin-producing anaerobic bacterium. It is the most common cause of nosocomial antibiotic-associated diarrhea and the etiologic agent of life-threatening pseudomembranous colitis. Current treatment options of C. difficile infection (CDI) with very few antibiotics are plagued by high recurrence rates (15-35%). CDI symptoms are mainly caused by toxins TcdA and TcdB. In addition, 5-30% of C. difficile isolates produce binary toxin (CDT), which is associated with increased morbidity and mortality rates. Active vaccination provides the attractive opportunity to prevent CDI and recurrence, but no vaccine against CDI is licensed. Vaccines should target all three toxins and C. difficile cells/spores that transmit the disease and cause recurrence. The goal of this project is to develop multivalent parenteral/mucosal vaccines that target three C. difficile toxins and colonization. Specifically: 1) We have demonstrated effective protection of animals from CDI with a potent immunogen Tcd169FI, which includes immunodominant regions of both TcdA and TcdB. 2) We found that parenteral immunizations with FliCD (a fusion containing C. difficile flagellins FliC and FliD) effectively protected mice against CDI and significantly decreased C. difficile spores and toxin levels in the feces after infection. 3) CDT consists of CDTa and CDTb. CDTa is the enzymatic component, and CDTb is the binding component. The receptor-binding domain 2 (RBD2) of CDTb is critical for host cell toxicity. We found that parenteral immunizations with RBD2 induced potent immune responses to CDTb and provided mice full protection against a lethal challenge of CDT. In this R01 project, we will investigate immune responses to immunizations with combined protein antigens (Tcd169Fl, FliCD, and RBD2) via intramuscular, sublingual, and intranasal routes or “Protective Immunity Enhanced Salmonella Vaccine (PIESV)” platform expressing these protein antigens via oral route. We will evaluate protection efficacy of these vaccine candidates in animal models of CDI and recurrence to select 2 best vaccine candidates for further clinical trial in the next funding period.

NIH Research Projects · FY 2025 · 2016-08

Project Summary/Abstract Down syndrome (DS), the condition caused by trisomy of human chromosome 21, affects approximately 1 in 700 newborns in the United States. Congenital heart defects (CHDs) are very frequent in children with DS with a prevalence of 50% compared to a risk of < 1 % in typical children. Although remarkable advances in health care and cardiac correction surgery have improved the survival rate of children born with DS, CH Ds are still a primary and significant risk factor for mortality in people with DS through age twenty. Using a combination of the human induced pluripotent stem cell (iPSC)-based model and Dp(16)1Yey/+ (Dp16), a mouse model for DS, we identified increased dosage of interferon (IFN) receptor encoded by genes, IFNAR1, IFNAR2, IFNG2, and IL10RB on chromosome 21 (chr21) as a causative factor of CHDs in DS. The canonical Wnt signaling pathway was down-regulated during DS cardiogenesis in vitro and in vivo. Normalization of I FN signaling restored the canonical Wnt pathway and ameliorated cardiogenesis in DS. In this project, we propose to (1) determine molecular mechanisms by which increased IFN signaling down-regulates the Wnt/β-Catenin pathway during heart development in DS and (2) examine cell populations associated with response to increased IFN signaling during heart development in DS. The results from this project have the potential to facilitate the development of novel therapeutic strategies to benefiting both people with DS and typical children born with CHDs.

NIH Research Projects · FY 2025 · 2016-08

PROJECT SUMMARY Understanding the regulation of intraocular pressure (IOP) is crucial in diagnosing and managing glaucoma, a leading cause of irreversible blindness characterized by preferential loss of retinal ganglion cell (RGC). One of the most potent regulators is the autonomic nervous system, which most glaucoma medicines target to achieve therapeutic IOP-lowering effects. Autonomic signals can modulate IOP rapidly by altering ocular blood flow and slowly by adjusting aqueous humor production and outflow. As a result, IOP fluctuates over a wide range of time scales. The importance of these fluctuations to glaucoma etiology and pathophysiology remains largely uncertain. Of interest to this project are circadian fluctuations in IOP that are controlled by the suprachiasmatic nucleus (SCN) in the brain. IOP telemetry studies in rats and other animals find that these rhythmic fluctuations can attain levels at night that would be glaucomatous if sustained throughout the day, and yet the eye continues to stay healthy. How can this be? More research is needed on the influence of the circadian system and environmental factors, such as light exposure, on the IOP dynamics of healthy and glaucomatous eyes. The proposed work utilizes one-of-a-kind technologies for measuring and manipulating IOP round-the-clock in awake free-moving animals as small as rats to investigate the hypothesis that daily IOP elevation is crucial for eye function. So important that recurrent disruption of circadian signals to the eye at night by light, and possibly other factors, pushes homeostatic mechanisms to raise IOP at unnatural times of day and that this abnormal activation may contribute to glaucoma onset or accelerate disease progression. The specific aims are to characterize light-driven changes in IOP rhythmicity and variability, the processes that mediate these changes, and their impact on eye health in rats. Insights gained from the work could inform the development of personalized treatment strategies or lighting regimens that optimize IOP control according to individual circadian profiles and uncover novel pathways for glaucoma intervention and vision preservation to explore in larger animals and humans.

NIH Research Projects · FY 2025 · 2016-03

PROJECT SUMMARY Corneal epithelium (CE) is a self-regenerating stratified squamous tissue that protects the rest of the eye by serving as the anterior-most barrier.1, 2 Our long-term goal is to identify the regulatory networks that govern the CE stratification and homeostasis, facilitating better understanding of the molecular basis for sight-threatening corneal disorders. Previously, we demonstrated that the Krüppel-like factors Klf4 and Klf5 play crucial non- redundant roles in maturation and maintenance of the ocular surface.2-17 In this proposal we seek to determine their role in regulating distinct cellular and molecular pathways of CE stratification and homeostasis, and elucidate how defects in these pathways affect CE plane of division and genetic stability, causing ocular surface diseases. We will employ complementary and innovative cell culture and imaging systems, transgenic mouse models and Next-Gen sequencing approaches to test the novel central hypothesis that `Klf4 and Klf5 orchestrate CE cell stratification and homeostasis by coordinating the CE cell plane of division and genetic stability in a TGF-, BMP6-, and Pard3-dependent manner'. This hypothesis was formulated based on our published work, 2-16 and exciting preliminary results. We will test this hypothesis by pursuing three Specific Aims. In Aim 1, we will test if KLF4 and KLF5 play key roles in regulating CE cell shape, apical-basal polarity (ABP) and plane of division, thereby elucidating the link between these transcription factors and the cellular processes that regulate CE stratification. In Aim 2, we will test if CE stratification is driven by a crosstalk between transcription factors Klf4 and Klf5, and signaling network involving TGF and BMP6 pathways, thereby elucidating the molecular mechanisms that regulate CE stratification and homeostasis. In Aim 3, we will test if Klf4 is a key regulator of genome stability that protects the CE from radiation-induced DNA damage and tumor development by upregulating the ABP gene Pard3 (also called Par3) expression. By delineating the regulatory pathways of corneal epithelial differentiation, stratification and carcinogenesis, and elucidating the molecular underpinnings of ocular surface disorders such as pterygium and ocular surface squamous neoplasia (OSSN), this proposal directly addresses the NIH mission of `seeking fundamental knowledge about the nature and behavior of living systems' and offers the potential for translation to ocular surface disorders which account for considerable healthcare burden in the world. The proposed research is significant as its anticipated outcomes will identify the molecular factors and pathways important for normal growth and function of CE cells, and their deficiencies that lead to sight-threatening corneal disorders.

NIH Research Projects · FY 2025 · 2015-09

This application requests support for the continuing operations of the TrialNet Coordinating Center (TNCC) at the University of South Florida. The University of South Florida has served as the Coordinating Center for TrialNet since October 2008. The primary objective of TrialNet is to prevent or delay initial onset and/or progression of type 1 diabetes (T1D) by preserving insulin-producing beta cells in individuals at elevated risk and those who have been newly diagnosed with T1DM. To achieve this goal, TrialNet designs and implements prevention and interventional clinical trials intended to test treatments that may preserve remaining insulin secretion in recently diagnosed individuals. The TNCC provides epidemiological, biostatistical, operational and administrative expertise and advice to the clinical centers, reference laboratories and the NIDDK which include the following tasks: 1) study-wide communications, procurement and dissemination of study materials, and related activities 2) data management and records maintenance; 3) clinical site and central laboratories monitoring; 4) data analyses; 5) preparation of study reports and papers for publication; 6) implementation of procedures to evaluate management, methodology, and cost-effectiveness of procedures utilized by the TNCC; and 7) periodic meetings. This application provides support for enhancing perspectives, managing current trials and studies and developing new interventions to delay or prevent T1D. It builds upon innovative successes in trial design, applications of artificial intelligence and machine learning and deep experience and expertise in study designs, conduct and analysis.

NIH Research Projects · FY 2026 · 2015-09

Project Summary Glaucoma is a leading cause of irreversible blindness throughout the world and the second leading cause of blindness overall in the USA. Elevated intraocular pressure (IOP) and aging are the most important risk factors for most forms of glaucoma. IOP level is highly dependent on the rate at which the aqueous humor is filtered through the conventional outflow pathway containing the trabecular meshwork (TM). Reduced cellularity within the TM and abnormal extracellular matrix (ECM) turnover occur in glaucomatous conditions and correlate with increased outflow resistance, elevated IOP, and subsequent vision loss. The goal of this project is to define the mechanisms of stem cell homing and engrafting to the TM tissue, activating regeneration of the TM tissue, and hence restoring outflow facility, reducing IOP, and preventing vision loss. In our previous funding period, we have identified the mechanisms of stem cell homing and integration are partially associated with CXCR4/SDF1 chemokine pair and α5β1 integrin. We have also confirmed that TM stem cells (TMSCs), after intracamerally injection, can regenerate the TM tissue, reduce IOP, and preserve the retinal ganglion cell function in a mouse glaucoma model. This project is designed to test specific hypotheses about the mechanisms by which human TMSCs remodel the pathological TM tissue and restore the TM function. Specific Aim 1 tests the hypothesis that TMSCs and differentiated TM cells remodel the abnormal TM ECM via the COX2/PGE2/MMP pathway. We will utilize myocilin mutant TM cells and dexamethasone-treated TM cells as well as a mouse glaucoma model with myocilin mutation to test how TMSCs promote the ECM turnover and modify the TM segmental outflow pattern. Specific Aim 2 tests the hypothesis that transplanted TMSCs can promote endogenous TMSC activation, migration, and function via the SOX21/WNT signaling. We will unveil if the endogenous TMSCs are viable with a reduced number in aged and glaucomatous TM tissue in human and in mice and uncover how TMSCs awake endogenous TMSCs via SOX21/WNT signaling. The scientific impact of this study will be the elucidation of the cellular and molecular mechanisms of TM regeneration potential by stem cells. The results may also directly lead to the design of stem cell-based therapies or adjunctive treatments that prevent blindness from glaucoma clinically.

NIH Research Projects · FY 2025 · 2015-07

Atherosclerotic cardiovascular disease (CVD) represents a serious affliction affecting millions globally. Despite recent advances in pharmacological and percutaneous interventions, CVD remains the leading cause of death and disability in the world. One of the main therapeutic challenges facing atherosclerotic CVD is the delivery of therapies to the atherosclerotic plaque that target the specific cells which contribute to its formation, while protecting the endothelium. Vascular endothelial cells provide crucial protection against lipid uptake, inflammation and thrombosis. We hypothesize that cell-selective therapy that inhibits infiltration of inflammatory cells and proliferation of vascular smooth muscle cells, while protecting endothelia cell function will be effective in combating CVD and thrombosis. To achieve this goal, we will develop a novel miRNA switch that combines synthetically modified mRNA with miRNA target site. As a delivery platform we will utilize the cationic amphipathic cell-penetrating peptide that forms a self-assembled, compacted, nanoparticle when mixed with synthetic mRNA. Moreover, to increase the targeting of inflammation in the atherosclerotic plaque, we will combine the miRNA switch together with siRNA targeting IL1-β to generate nanoparticles using the same cationic amphipathic cell- penetrating peptide. In two specific aims, we will test 1) the efficacy of this cell-selective nanotherapy to inhibit atherosclerosis and restenosis after percutaneous intervention, while protecting EC to reduce thrombosis; and 2) the translational potential of the miRNA switch nanotherapy in viable, isolated human coronary arteries. Completion of the aims will provide the foundation for the development of a novel category of biological drugs that can accommodate the advent of personalized medicine and will advance the treatment of cardiovascular disease.

NIH Research Projects · FY 2025 · 2015-02

Project Summary/Abstract Malaria is a leading cause of human death and illness, causing over 200 million cases of clinical malaria and 400,000 deaths each year. Traditional measures to control and cure malaria are threatened by emergence of artemisinin resistance (ART-R). Research into ART-R has focused mostly on mechanisms allowing parasite to tolerate the oxidative stress and protein damage resulting from ART’s mechanism of action. However, recent discoveries indicate that resistance- associated mutations in the K13 slows cytostome function to diminish the available hemoglobin in the food vacuole. Our preliminary results revealed that the parasite’s sensitivity and tolerance to ART significantly overlaps with innate stress response pathways that enable P. falciparum survival of malaria fever. Our experimental approach is to elucidate drug-gene associations and decipher mechanisms of action and resistance to ART and other antimalarial drugs, using forward genetic screens of P. falciparum mutants created by random piggyBac mutagenesis. This approach has determined that genetic mutations in the major parasite processes critical for P. falciparum malarial fever survival response significantly correlate with altered sensitivity to ART (DHA, AS), indicating the parasite hijacked the heat-shock stress response pathways to cope with ART toxicity. We will use small libraries of piggyBac clones and GO-focused libraries for iterative screens of different phenotypes to functionally annotate interacting partners, pathways, and regulatory processes linked to ART mechanism of action and resistance. We will use genome-level screens to identify factors linked to ART mechanism of action. We will extend our analysis to P. knowlesi to characterize the conserved high-value antimalarial drug targets by adapting and applying chemogenomic profiling analysis to this vivax-like malaria parasite.

NIH Research Projects · FY 2026 · 2012-04

Abstract The applicant proposes the continued development and expansion of a successful research education program for graduate level students and professionals to acquire innovative research skills to address drug use and related behavioral health concerns of children and adolescents with an emphasis in implementation science. We continue our effort of addressing research education that target groups of researchers with interests in working with child and adolescent populations and their families who use substances and other co-morbid behavioral health conditions. We continue to innovate through the utilization of Peer Mentors who are provided advanced research education opportunities in research project leadership. Implementation Science continues to be at the forefront of innovative research education; the Institute for Translational Research and Education in Adolescent Drug use (ITRE) is unique in focusing on training in implementation research methods, with practical applications in programs at the community level. We emphasize translation of implementation research into community practice and the practical skills of participatory research. A cross-disciplinary approach, involving multiple colleges at the University of South Florida and Northern Arizona University, as well as local community service agencies, has been developed with special attention to evidence-based practices, translational research, and the critical need for services for children and adolescents.

NIH Research Projects · FY 2026 · 2011-06

Project Summary We propose to develop new kappa opioid receptor (KOR) agonists that have diverse signaling profiles with the goal of correlating cellular signaling properties to favorable properties (antipruritic, anxiolytic and non-sedating) in mice. The KOR is an attractive drug target because drugs that activate KOR do not lead to overdose or addiction. However, drugs that act at KOR have had their own side effects that have hampered their use clinically. These include diuresis, dysphoria and sedation. Our prior work has introduced new probe compounds that raise the possibility that the therapeutic effects may be separated from the side effects. Compound triazole 1.1 is a potent KOR agonist that activates GTPγS binding in cells and in mouse striatum with the same potency and efficacy as a standard KOR agonist, U50,488H. U50,488 is potent and efficacious at inducing KOR activation across several signaling platforms, including βarrestin2 recruitment. However, triazole 1.1 is far less potent in recruiting βarrestin2 recruitment, and has been shown to be a biased agonist at KOR (bias factor >20). We and others have shown that triazole 1.1 produces antinociception and suppresses pruritis in rodents, yet is devoid of sedating and dysphoria-like properties. Others have shown that triazole 1.1 suppresses oxycodone- induced itch in nonhuman primates and decreases oxycodone self-administration in rats. Therefore, we propose that selective, G protein signaling biased KOR agonists may be a means to preserve desirable effects and avoid side effects. This proposal seeks 5 years of support to generate diverse chemical probes in order to test the extent of this correlation (does biased agonism = less side effects). We introduce two new chemical scaffolds to build upon our already extensive structure-activity relationship collection. We will fully characterize the pharmacological properties of the compounds across functionally diverse cell-based assays with of a goal of identifying compounds capable of fine-tuning KOR responsiveness. Cell-based responses will be validated in mouse models assessing locomotor responses, suppressing pruritis (itch response), diuresis, and measures of anxiolytic-like behaviors to determine that compound maintains the pharmacological profiles in vivo. Compounds will also be tested in combination with morphine. Probe compounds that show favorable behavioral profiles will be used to explore differential KOR signaling in mouse striatum and striatal neurons. Our enthusiastic team consists of established medicinal and synthetic chemists, a structural biologist, and an opioid neuropharmacologist (with both molecular and behavioral pharmacology expertise). The development of pharmacological tools across diverse pharmacophores and correlating their properties with in vivo response profiles will provide guiding evidence of the optimal chemical and pharmacological properties required to refine KOR-targeting therapeutics.

NIH Research Projects · FY 2026 · 2011-04

Project Summary/Abstract Neuropsychiatric symptoms (NPS), like depression, are common early in Alzheimer’s disease (AD) and correlate with a faster decline in patients. NPS and cognitive deficits in AD have been linked with the accumulation of tau protein. Two independent studies associated an allelic variant in the 51kDa FK506-binding protein (FKBP51) with increased risk for depression in AD. FKBP51 also regulates tau accumulation and toxicity to nerve cells. We will use transgenic mouse models to determine if either removing or inhibiting FKBP51 in mice will be protective against tau accumulation. We will also study whether mice that have this risk variant in combination with tau accumulation are more vulnerable to NPS. The critical knowledge gained through this work will add to our understanding of the role of FKBP51 in regulating tau pathogenesis especially during disease progression. This work will have a positive impact in AD research as we will further validate FKBP51 as a target and characterize the molecular landscape associated with vulnerability to NPS in tauopathies.

NIH Research Projects · FY 2026 · 2007-06

Project Summary: A hallmark of developing neural systems is the guidance by spontaneous and experience-driven neural activity for strengthening of some synaptic inputs and pruning of others to define topography of mature neural circuits. We and others have established formation of the calyx of Held (CH) and its innervation of principal neurons (PN) in the medial nucleus of the trapezoid body as a model system to study neural circuit development. We showed that that the CH:PN system, relative to other model systems, has precise onset and short duration of strengthening and pruning to a topographically mature circuit by postnatal day 9, prior to ear canal opening. Preliminary data demonstrates that suppression of spontaneous activity (SA) targeted to the CH:PN synapse prevents key aspects of PN functional maturation. In this proposal we capitalize on this observation to define the functional and structural elements of circuit construction so that we can identify those maturational events that depend on SA. Our research team brings extensive experience with biophysical and physiological properties of this system, which we examine at high (daily) temporal resolution. We leverage our experience with imaging and reconstruction of large electron microscopy volumes to specify global aspects of initial circuit topography along with subcellular detail as a precise structural framework to anchor our observations. We next explore cellular and molecular mechanisms that transmit information about neural activity to maturational programs at high temporal resolution, focused upon activity-dependent Ca2+ entry and phosphorylation of the constitutive transcription factor CREB. These accumulated data can be correlated with better temporal precision than in other model systems to provide deeper insight into causal relationships between SA and maturational events. Errors in early neural circuit specification can result in generalized intellectual and social disabilities, which can have auditory specific phenotypes as in autism spectrum disorders.