University Of Delaware

NIH Research Projects · FY 2025 · 2022-08

PROJECT SUMMARY Developmental language disorder (DLD) describes the idiopathic disorder(s) of language that occurs in approximately 7% of the population. Although DLD is understudied in adulthood, it is clear that the communication challenges in DLD extend beyond adolescence. The barriers to educational and vocational achievement for adults with DLD include persistent difficulties in learning and memory. Recent work suggests that these difficulties with learning and memory include deficits in overnight memory consolidation. Thus, an effective support for learning and memory function in adults with DLD must include strategies for both overcoming initial challenges in learning, as well as in mitigating a deficit in consolidation of learned information. In this project, we combine insights from the neurobiology of learning and memory, chronobiology, and speech perception, to determine the optimal training schedule for perceptual memory retention in adults with and without DLD. We have two Aims in this project: First, we will recruit 240 adults (120 with/120 without DLD) to participate in a speech-perceptual training to take place in one of six different training schedules over 24 hours. We predict that our manipulation of training schedules will interact with circadian preference and timing relative to overnight consolidation, such that we may discover the optimal practice schedule for speech sound retention for adult learners with & without DLD. Our focus on speech-sound information will allow us to track the learning and memory of linguistic form that is relatively independent from preexisting knowledge; moreover, speech perception is also a known difficulty for individuals with DLD. Under our second aim, we will recruit an additional 300 adults (150 with/150 without DLD) in order to determine how optimal training schedules interact with reflexive and reflective learning strategies in adults with and without DLD. We will achieve this aim by tracking the time course of learning and retention in adults participating in reflexive and reflective categorization training in one of six training schedules. This will provide us with generalizable insights into optimal training schedules for learning targets beyond the speech domain. The knowledge to be gained from this work will contribute to the basic science of learning and memory in adults with and without DLD. In addition, the factors that influence the successful retention of speech have substantial implications for intervention practices for other developmental disorders in which speech representations are implicated (speech sound disorder, dyslexia).

NIH Research Projects · FY 2025 · 2022-08

Project Summary Mating is essential for procreation, and it profoundly affects animals’ physiology, behavior, and wellbeing, particularly in females. Associating mating experience with a valence––either appetitive for a positive stimulus, or aversive for negative––allows females to adjust their mating strategy and exhibit appropriate behavioral responses in subsequent encounters. Yet, the molecular and cellular substrates that assign, store, retrieve, and update mating valence in females are largely unknown. I will interrogate how the valence of sexual stimuli is assigned and expressed using the fruit fly, Drosophila melanogaster, as a model system. I have identified a neural pathway (PLM pathway) that conveys the mechanosensation of copulation to the brain, where Myoinhibitory peptide is released upon copulation. Intriguingly, the PLM pathway is required for to develop wild-type valence for mating; thus, the PLM pathway provides a superb entry point to explore how mating valence is formed and maintained. We have generated and amassed an unparalleled collection of genetic tools to visualize and manipulate these neurons, and I have established novel behavioral paradigms to evaluate mating valence in female Drosophila. In the proposed study, I aim to delineate the molecular and cellular substrates that underlie the generation and expression of mating valence in female. I will also explore how an orthogonal experience––social experience––regulates females’ mating valence. To achieve these goals, I will carry out three complementary projects that exploit multidisciplinary approaches and cutting-edge tools in molecular genetics, anatomy, physiology, and behavior. First, we will determine the molecular and cellular pathways that link PLM neurons with the fly’s primary learning centers, where valence is assigned. Next, by exploiting candidate genes identified in transcriptome comparison in virgin and mated females, I will elucidate the molecular and cellular mechanisms that underlie the dramatic morphological changes of PLM pathway neurons that likely alter female mating latency. Finally, I will identify genes in the fly’s stress-response pathway that convey pathological social exposure to modulate females’ mating behavior. Together, these results will substantially advance our understanding of the molecular and neural pathways that underpin the generation and regulation of females’ mating valence.

NIH Research Projects · FY 2025 · 2022-07

Nitrogen-rich small molecules are critical to human health as they constitute the vast majority of all known pharmaceutical agents. As the requirements for new drugs become stricter, and as the diseases that are targeted become more complex, the chemical structures of those compounds are also becoming more complex. This is driving the need for more efficient means to prepare ever more complex nitrogen-containing small molecules. Typically, in synthetic chemistry, most chemical reactions of nitrogen centers involve low valent, nucleophilic nitrogen atoms. Over the past 100 years, countless synthetic transformations have been developed to prepare nitrogen-containing molecules using this paradigm. In contrast, this proposal seeks to leverage nitrogen compounds in higher oxidation states to seek new reactivity and chemical processes that can prepare complex nitrogen-containing molecules in new ways. Specifically, based upon a strong set of published preliminary results, we will develop new Heck-like reactions of electrophilic nitrogen centers as a means to construct highly substituted stereochemically and topologically complex nitrogen heterocycles. Our studies will discover new nitrogen electrophiles that can participate in these aza-Heck cyclizations, develop novel routes to important classes of biologically active heterocycles, design asymmetric entries into these compounds to control absolute stereochemistry, and dig deeper into the fundamental mechanisms of the reactions to enable further understanding of the processes. To demonstrate the importance of aza-Heck cyclizations, we will also prepare several highly complex natural products with interesting biological profiles in highly expedient ways. Each synthesis will feature aza-Heck technologies as the key enabling reaction. As reflected in our support letters, we are well positioned for follow-up studies at the completion of these synthetic efforts. We will also continue to develop new catalytic methods to prepare complex nitroalkanes and seek to use those compounds in novel transformation for preparing bioactive molecules. Overall, we expect that the development of this chemistry will positively impact human health by providing synthetic, medicinal, and process chemists valuable new tools for the construction of nitrogen-rich bioactive small molecules. At the same time, this study will provide fundamental advances in transition metal-catalyzed cross-coupling chemistry. Modified Specific Aims Nitrogen-rich small molecules are critical to human health as they constitute the vast majority of all known pharmaceutical agents. As targeted diseases are more complex and the requirements for new drugs become stricter to increase safety, the requirements and structures of the drug compounds have also become more complex. In particular, the need for increased selectivity and improved pharmacokinetics is driving a move away from traditional “flat” pharmaceuticals towards those that are chiral and rich in sp3 centers.1 In turn, this has driven the need to develop new methods that can efficiently prepare complex and highly substituted stereogenic nitrogen-containing small molecules. The proposed research will focus on new methods for preparing topologically complex, nitrogen-containing small molecules. We will focus on two strategies that are thematically related in the utilization of high-valent nitrogen precursors. These reactions are a departure from the vast majority of synthetic transformations that rely on low-valent nucleophilic nitrogen centers and will allow rapid access to compounds that traditional methods struggle to prepare. First, we will develop cyclizations of stable, readily prepared nitrogen electrophiles to prepare highly substituted stereogenic aza-heterocycles. These aza-Heck cyclizations will allow facile access to biologically and medicinally relevant heterocycles that other methods struggle to access. Second, we will develop new reactions of nitroalkanes to prepare complex amines. Specific Aims: Specific Aim 1: New Reactions of Electrophilic Nitrogen to Prepare Complex Heterocycles We will develop innovative Heck-type cyclizations of nitrogen electrophiles. This will include developing new routes to highly substituted nitrogen heterocycles of high biological importance, accessing larger heterocycles than are currently possible using aza-Heck reactions, developing asymmetric versions of these cyclizations, and studying the novel mechanisms of these transformations. This will allow rapid entry into heterocyclic systems and enable the synthesis of many bioactive compounds and natural products. Specific Aim 2: Synthesis of Complex, Biologically Active Molecules Using Aza-Heck Strategies We will apply aza-Heck cyclizations to the synthesis of complex natural products of direct interest to human disease. The proposed routes are extremely efficient and will demonstrate the power of aza-Heck technology over traditional synthetic methods. The synthetic efficiency, combined with the bioactivity of the chosen targets, will enable biological follow-up studies. Specific Aim 3: Nitroalkane Alkylation We will develop new reactions of nitroalkanes, including photodependent alkylations of highly substituted nitroalkanes, asymmetric nitroalkane alkylations, and asymmetric reductions of nitroalkanes, enabling innovative entries into biologically important alkyl amines. The unique and complex mechanisms of these transformations will also be elucidated. Overall, this research program will discover and seek to understand new methods for preparing complex, biomedically relevant compounds and enable the synthesis of target molecules of specific interest to the treatment of various human diseases.

NIH Research Projects · FY 2025 · 2022-07

Convergent advances in high-throughput experimental biology, digital transformation of biomedicine, and breakthroughs in high-performance computing, machine learning and data science have created critical needs– and an unprecedented opportunity–to train the next generation of multidisciplinary researchers at the interface of biomedical and computational sciences. This proposal would build an innovative and interdisciplinary Computational Biology, Bioinformatics, and Biomedical Data Science (CBB) T32 training program. The CBB program will feature: (i) multidisciplinary research training integrating biomedical and computational sciences; (ii) a cross-campus initiative integrating students across scientific disciplines, and leveraging research infrastructure at the Center for Bioinformatics and Computational Biology and the Data Science Institute; (iii) a collaborative team science environment with evidence-based, reproducible, and responsible research conduct to ensure scientific rigor; and (iv) workforce development for diverse career aspirations with societal impact. The CBB program brings together 30 program faculty with different career stages from ten departments at the University of Delaware, and affiliates from Delaware State University. The trainees will be co-mentored by faculty with vibrant research and complementary expertise in thematic research areas, employing mathematical, computational, and data science approaches for multi-scale systems-level understanding of biological networks, from molecular sequence and structure to cellular function, physiology, and interaction with environments. Six trainees will be recruited annually from eligible PhD students early in their course of study for T32 funding support, coupling with a recruitment strategy using university funds to support bringing the strongest predoctoral candidates to campus, thereby providing transformative training for up to 30 trainees during the 5-year period. The curriculum will encompass scientific training for technical competency and professional training to develop leadership and teamwork. Trainees will complete four core courses covering topics of quantitative/computational methods, technology, experimental design, and data interpretation, with individualized program of study and individual development plan. A three component CBB Development Core will cover responsible conduct, reproducibility, and ethics, and include a team-based experiential learning course emphasizing teamwork, communication, and innovation. Year 2 will culminate in a 10-week summer internship designed in collaboration with external academia, industry, government partners. All trainees, faculty mentors, and our partners will form the CBB community and engage in weekly seminars, workshops, annual symposia, hackathons, and other team-building events. An organizational structure with executive, program, and advisory committees will enhance oversight. Collectively, this T32 will form a collaborative team science infrastructure for transformative workforce development.

NIH Research Projects · FY 2026 · 2022-04

Project Summary/Abstract While the behavioral heterogeneity of stuttering has been long recognized, very little is known about mechanisms underlying the heterogeneity. Without this knowledge, the complex etiology of stuttering cannot be fully understood, and the development of individualized treatment approaches will continue to be severely hindered. Our long-term goal is to develop neuroscience-based treatment approaches for developmental stuttering. In pursuit of this goal, the objective of the present application is to identify subtypes of children who stutter (CWS) based on neuroanatomical anomalies and characterize each subtype’s behavioral profiles and brain activity during speech production. The central hypothesis is that each neural subtype is associated with behavioral and brain activity changes consistent with its primary neuroanatomical anomalies. The rationale of this proposed project is that elucidating the neural subtypes of stuttering will help us understand the heterogeneity and neurological etiologies of the disorder, which is an important basis for developing new treatment approaches that target individual neurological deficits. We will test our central hypothesis by pursuing three specific aims. i) Identify subtypes of CWS based upon patterns of neuroanatomical anomalies. To achieve this aim, we will use a clustering method to analyze gray matter volume patterns in CWS. We hypothesize that CWS comprise neural subtypes, characterized by primary structural anomalies in the prefrontal areas, the basal ganglia thalamocortical circuit and the cerebellum. ii) Characterize behavioral profiles associated with each neural subtype. Based on contemporary models of speech motor control, we hypothesize that each neural subtype will differ in both stuttering behaviors, language ability, and speech motor performance depending on the functions of its primary neuroanatomical anomaly loci. iii) Characterize brain activity associated with speech production in each neural subtype. To achieve this aim, we will identify differences in brain activity between neural subtypes during overt continuous speech using functional magnetic resonance imaging. Our working hypothesis is that compared to controls, each neural subtype of CWS will exhibit reduced activation associated with its primary anatomical anomalies as well as their common input region, the left premotor areas. Upon successful completion of the proposed research, we expect to gain an expanded understanding of anatomical neural subtypes of stuttering, and for the first time, link behaviors and brain activity differences during speech production among the different subtypes. Better characterizing neural subtypes of stuttering would substantially contribute to our understanding of the heterogeneity of stuttering, which is an important step in elucidating the disorder’s complex etiology.

NIH Research Projects · FY 2026 · 2022-02

PROJECT SUMMARY The majority of older adult patients who seek physical therapy have pain. Physical rehabilitation for many painful orthopedic and neurologic conditions often involves the use of motor learning strategies, in which new movement patterns are taught using repeated trial-and-error practice. However, preliminary data from our lab suggests that pain may negatively affect the retention of newly learned motor patterns. If correct, this would suggest that the presence of pain may limit rehabilitation outcomes sought through motor learning-based interventions. To date, the effects of acute or chronic pain on motor learning have not been thoroughly investigated in clinical populations. Further, it is not known how pain affects motor learning in older adults specifically, despite the fact that cognitive declines, which are well-documented in the elderly, could also negatively affect learning and motor memory. Broadly, the purpose of this research is to investigate the impact of both acute and chronic pain on locomotor learning and its retention in young and older adults as well as older adults with chronic low back pain. Our central hypothesis is that both acute and chronic pain impair retention of locomotor learning and that in older adults, these deficits are worsened and are related to the degree of cognitive decline. We will investigate this hypothesis with three aims: (1) using our experimental pain paradigm, to compare effects of acute pain on retention of locomotor learning in healthy young and healthy older adults; (2) to determine whether older adults with chronic low back pain have impaired retention of locomotor learning; and (3) to assess relationships between chronic pain, cognition, and motor learning retention capacity in older adults. Motor learning and its retention will be assessed using our novel visually- driven locomotor learning paradigm. Several aspects of cognition will be quantified with a cognitive battery, with special focus on attention and working memory. Finally, pain will be quantified with assessments of intensity, interference and sensitivity. Results from this work will provide much needed data concerning the relationship between pain and motor learning in older adult clinical populations. Given that many rehabilitation interventions utilize motor learning-based strategies to recover normal movement patterns, gaining this new knowledge is likely to fundamentally improve delivery of rehabilitation in multiple patient populations that experience pain.

NIH Research Projects · FY 2026 · 2022-02

PROJECT SUMMARY For blind people, visual aids like a graphic or a plot are not accessible. Instead, tactile aids are used help render abstract concepts through an arrangement of physical features, like bumps, lines, and textures. Although useful, static tactile aids cannot easily render many abstract concepts and still face difficulties when displaying large amounts of information. A key issue with displaying dense, complex information is that using too many lines or bumps in a small space creates “tactile clutter”, leading to confusion and misinterpretation by the user. In fact, the ability of tactile aids to render information by touch is practically at full capacity. While fabrication costs are lowering with emerging technologies, the core technology of using patterns of bumps and textures to render information by touch has largely remained the same. Most current research is not focused on addressing this fundamental limitation and instead sidesteps by using other senses instead, like audio. Therefore, there has been little progress in tactile stimuli generated by a tactile aid, which has limited their ability to make complex information accessible for blind people. To address the lack of methods to create tactile sensations in static tactile aids, this research will increase the variety and density of tactile sensations by using “designer materials”. Designer materials, unlike physical features like bumps and lines, are surface coatings which use phenomena from surface chemistry to control adhesion and friction and thereby generate new tactile sensations. By relying on surface chemistry, it is possible to exert a level of control and spatial resolution not currently possible. Designer materials will be combined with current physical features to build the next generation of easier-to-read and more information dense tactile aids. These tactile aids will be demonstrated in a series of everyday activities with blind subjects. This project combines our team’s expertise in material science, solid mechanics, human psychophysics, and tactile aid development. Our project is centered around the discovery of new designer materials, developing next generation tactile aids, and mechanistic studies into the optimal design of tactile aids. Together, these areas allow us to rapidly iterate new tactile aids, build rationale guidelines for designing traditional and next generation tactile aids, and provides a much-needed expansion in the toolkit for tactile aid developers. To maximize impact, all aspects of the project involve close collaboration with members of the blind community.

NIH Research Projects · FY 2026 · 2022-01

PROJECT SUMMARY/ABSTRACT Many emerging adults (aged 18-25) in the U.S. are living with unrecognized and/or untreated depression and anxiety. Emerging adults have the highest rates (26%) of mental illness (MI) and lowest rates of treatment seeking (38%), compared to all other age groups. Untreated depression and anxiety are particularly prevalent among emerging adults and are key risk factors for the development of substance use disorders, cardiovascular disease, and chronic health conditions later in adulthood, as well as premature death. Efficacious MI treatments are available, but MI stigma is a substantial barrier to recognizing and treating depression and anxiety. Emerging adults are particularly vulnerable to MI stigma given intense cognitive, biological, and social changes occurring during these years. Although scientists have begun to assemble and refine an evidence-based stigma-reduction toolbox, stigma interventions have fallen short of fully addressing MI stigma in part because they take a “one size fits all” approach. Stigma interventions may be more efficacious if they address stigma mechanisms when they are most pronounced, target the specific stigma mechanism(s) that are most harmful to treatment outcomes, and provide extra support for people who lack resilience to stigma. Our long-term goal is to tailor MI stigma interventions for emerging adults to promote positive treatment outcomes and lifetime wellbeing. In order to inform the tailoring of these interventions, we need greater understanding of how stigma evolves and impacts treatment outcomes during emerging adulthood. The objective of the current proposal is to examine longitudinal relationships between MI stigma and treatment outcomes among a large, national sample of emerging adults. Our specific aims are to: (1) Characterize trajectories of MI stigma mechanisms and identify moderators of trajectories among emerging adults experiencing depression and/or anxiety; (2) Examine associations between MI stigma mechanisms, MI recognition and MI treatment engagement over time; and (3) Identify latent profiles of MI stigma mechanisms, how individuals transition across profiles over time, and links between profiles and treatment engagement. We propose a national, longitudinal study of emerging adults (aged 18-25), surveying 4000 participants 4 times a year for 3 years regarding stigma mechanisms, moderating factors, mental health, and treatment engagement. Based on epidemiological estimates, we project that ~30% (n=1200) of participants will experience a new onset of depression or anxiety during the study. Data will be analyzed using multilevel modeling, moderation analyses, latent profile and latent transition analyses. Findings will enable researchers to better identify: (1) the ideal timing of stigma interventions to maximize impact among emerging adults, (2) who among emerging adults are most vulnerable to the effects of stigma, (3) which stigma mechanisms should be targeted for intervention to improve lifelong health and wellbeing, and (4) how to combine stigma-reduction tools for subgroups of emerging adults. This proposal responds to NIMH and NICHD’s strategic objectives to determine when, where, and how to intervene to improve healthcare during the transition to adulthood.

NIH Research Projects · FY 2025 · 2021-09

Project Summary Reactive oxygen species (ROS) are a family of small-molecules in living systems that serve vital roles in both signaling and stress. Hydrogen peroxide (H2O2), superoxide (O2•-), and hypochlorous acid (HOCl), among others, are all examples of ROS that have been traditionally viewed as sources of oxidative stress and damage. Aberrant ROS production contributes to a multitude of pathologies such as neurodegeneration, cancer, and cardiovascular disorders. However, ROS are also critical for maintaining metabolic homeostasis through activation of multiple classes of proteins. This signal-stress dichotomy, coupled with the small and transient nature of ROS, presents a challenge when attempting to decode the complex landscape of cellular redox homeostasis. Fluorescent probes are frequently employed to visualize ROS in living systems through fluorescence microscopy, however these probes are prone to diffusion after ROS detection. This leads to inaccurate determination of ROS localization and poor signal-to-noise responses. As such, there is a need to create probes amenable to the permanent recording of ROS via fluorescence imaging. We hypothesize that activity-based cell-trappable fluorescent probes can be used as a platform to gain further understanding of ROS-mediated inter- and intra- cellular signaling. We propose three specific aims to test this hypothesis. First, we will synthesize fluorophores caged with activity-based triggers and proximal fluoromethyl groups to serve as latent equivalents of quinone methide upon ROS sensing. ROS responsive uncaging will allow for the fluorescent labeling of adjacent biomolecules. Second, we will apply our probes across multiple model live cell lines to monitor ROS fluxes. We will also map cell-to-cell communication mediated by ROS using microglia-neuron co-culture as a biological model. This system will allow us to probe transcellular redox signaling as microglia can be selectively activated in the presence of neurons thereby dispatching H2O2 to nearby neurons. The third aim involves developing a fluorescent polymer amplification strategy to increase signal-to-noise responses of tandem activity-based sensing/labeling probes and will primarily be carried out in the R00 phase. Small- molecule polymer initiators will be caged in a similar manner to the previously described fluorescent probes. After ROS sensing and biomolecule labeling, polymerization will be performed to generate fluorescent polymers from biomolecule surfaces thus enabling signal amplification and visualization. This strategy will be carried over into live cell lines described above. This research fits into the applicant’s goal of establishing a program which uses polymer chemistry to probe fundamental questions in biological systems.

NIH Research Projects · FY 2025 · 2021-09

ABSTRACT/PROJECT SUMMARY Duchenne and Becker muscular dystrophinopathies (DMD/BMD) have a mutation in the dystrophin gene that, together, represent over 80% of all cases of muscular dystrophy. Historically, respiratory failure was the major cause of morbidity and mortality but recent treatment advances have changed the prognosis, with dilated cardiomyopathy and the resulting heart failure now being the leading cause of death. Currently, there is no consensus on predictors of cardiac disease trajectory, when to start treatment with cardiac medications, or the most appropriate outcome measures to evaluate the impact of therapies on the heart in patients with DMD and BMD. The long-term goal is to reduce the incidence and delay the progression of dilated cardiomyopathy/heart failure in children with DMD and BMD. The objective of this study is to determine the effects of DMD and BMD on peripheral vascular function and pulsatile load on the left ventricle (LV), and to determine if these variables can predict cardiac function. The central hypothesis is that both DMD and BMD patients will exhibit detrimental changes in their peripheral vascular health and pulsatile load on the LV which will relate to their cardiac function. This hypothesis is based on novel preliminary data showing an attenuation in peripheral vascular function and augmented central pressures and wave reflections, suggestive of increased pulsatile load, in both DMD and BMD patients. The central hypothesis will be tested by pursuing three specific aims: 1) Determine the effects of DMD and BMD on peripheral vascular function; 2) Determine the effects of DMD and BMD on pulsatile load on the LV; and 3) Determine if peripheral vascular function and pulsatile load on the LV can help predict cardiac function in patients with DMD and BMD. Under the first aim peripheral vascular function will be assessed using both a cross-sectional (baseline) and longitudinal design (12 & 24 months) in cohorts of DMD and BMD patients and typically-developing children. For the second aim, pulsatile load on the LV will be evaluated by assessing reflection magnitude, forward wave amplitude, aortic characteristic impedance, and arterial stiffness in the same design and participants as study aim 1. Finally, the third aim will use measures of peripheral vascular function and pulsatile load to evaluate predictors of cardiac function measured by echocardiography. The research proposed in this application is innovative because it represents the initial attempts at determining peripheral vascular function and pulsatile load on the LV in DMD and BMD patients which is the logical next step to previous animal studies. Additionally, the study uses novel, state-of-the-art non-invasive methodology that has the potential to be integrated into regular clinical practice to better diagnose and possibly predict cardiomyopathy development throughout DMD and BMD disease progression. The proposed research is significant because it will inform future interventional studies, including clinical trials that will ultimately alter the trajectory of care for the young patients struggling with DMD and BMD-related cardiomyopathy.

NIH Research Projects · FY 2025 · 2021-08

Protein Knowledge Networks and Semantic Computing for Disease Discovery The growing volume and breadth of information from the scientific literature and biomedical databases pose challenges to the research community to exploit the content for discovery. This MIRA grant application will advance our knowledge mining and semantic computing system to accelerate data-driven discovery for understanding of gene-disease-drug relationships. We have employed natural language processing and machine learning approaches in a generalizable framework for bioentity and relation extraction from large-scale text. Our Protein Ontology supports protein-centric semantic integration of biomedical data for both human understanding and computational reasoning. We have also developed a resource to support functional interpretation and analysis of protein post-translational modifications (PTMs) across modification types and organisms. Building on our computational algorithms, bioinformatics infrastructure and community interactions, we will further develop literature mining tools to support automated information extraction across the bibliome and open linked data models for semantic integration of biomedical data from heterogeneous resources. Our text mining tools will be trained for different use cases using deep learning methods. We will develop RDF (Resource Description Framework) semantic models in an increasingly computable, inferable and explainable knowledge system to assist in hypothesis generation. We will present evidence in the form of textual artifacts and semantic models to ensure unbiased analysis and interpretation of results to promote rigorous and reproducible research. We will develop scientific case studies to drive the system development. Examples include PTM disease variant and enrichment analyses for drug target identification, genotype- phenotype knowledge mining for Alzheimer's Disease understanding, and gene-disease-drug knowledge network construction for COVID-19 drug repurposing. To foster community engagement, we will host workshops and hackathons to address critical fundamental research questions and emerging disease scenarios. We have fully adopted the FAIR (Findable, Accessible, Interoperable, Reusable) principles for resource sharing. All data, tools and research results will be broadly disseminated from the project website, accessible programmatically via RESTful API, queryable via SPARQL endpoints, and dockerized for community code reuse. The successful completion of this research will thus support scalable, integrative and collaborative knowledge discovery to accelerate disease understanding and drug target discovery.

NIH Research Projects · FY 2025 · 2021-08

ABSTRACT Anxiety disorders remain one of the most common forms of mental illness and the 6th leading cause of disability worldwide. Anxiety pathology tends to emerge during early adolescence, and this process occurs differentially between the sexes, with rates becoming 2- to 3-fold higher in girls (vs. boys) post-puberty. Thus, identifying adolescence-specific factors that predispose towards anxiety disorders is crucial for identifying at-risk individuals early, before trajectories crystalize, and for providing novel intervention targets. Interestingly, the developmental course of anxiety is inversely related to the maturation of emotion-regulation capacity, with decrements in capacity appearing during the transition into adolescence. We and others have proposed that the development of adolescent anxiety is due, in part, to differences in the maturational trajectories of brain networks supporting emotion regulation (i.e., emotion dysregulation is a key endophenotype for anxiety development). However, the adolescent- and sex-specific neurobiological mechanisms that support the development of emotion regulation, and their implications for the manifestation of anxiety pathology, are not well understood. We will test a model incorporating two risk factors: pubertal testosterone and axonal myelination of prefrontal-subcortical circuits. We will collect longitudinal (3 waves, each 1 year apart) multi-modal (e.g., diffusion, ultra-fast fMRI) neuroimaging data from individuals at the transition into adolescence, half of whom are at high risk for developing an anxiety disorder. Aim 1: We recently proposed a model in which testosterone dampens the effectiveness of key emotion-regulation circuitry, whereas myelination of white matter in that circuit has the opposite effect. Aim 1 will evaluate this model by testing whether (i) increases over time in pubertal testosterone are linked to functional decoupling between orbitofrontal cortex (OFC) and amygdala and (ii) this decoupling predicts emotion dysregulation and consequent anxiety increases. This aim will also test whether sparser baseline myelination of uncinate fasciculus (connecting OFC-amygdala) is linked to weaker functional coupling, higher dysregulation, and anxiety. Aim 2: The biological mechanisms that confer greater risk for anxiety in females remain unknown. Our work in healthy adolescents suggests that females have a higher sensitivity to testosterone in the OFC- amygdala circuit, and there is some evidence of myelination differences in this circuit. Aim 2 will test whether testosterone and myelination have a greater impact on emotion-regulation circuitry/pathological anxiety in girls. Aim 3: It is critical to identify baseline biomarkers predictive of future anxiety development in order to detect at- risk individuals before trajectories crystalize. Aim 3 will test whether testosterone and myelination can be used to predict the emergence of future anxiety. In sum, this project aims to identify neural and hormonal mechanisms responsible for the development of adolescent anxiety. This work has the potential for tremendous public health impact by harnessing cutting-edge methods to uncover and validate novel risk trajectories for anxiety.

NIH Research Projects · FY 2025 · 2021-08

TITLE: Selectivity and regulation of mRNA demethylation by iron-dependent dioxygenases ABSTRACT: The long-term goals of this research program are to (1) define the structural and molecular mechanisms that control the selectivity and function of RNA demethylase enzymes, (2) develop new chemical tools to monitor RNA demethylation in cells, and (3) understand how the key cofactor ascorbic acid interacts with RNA demethylases and other iron-dependent dioxygenase family members to regulate their activity. Methyl modifications on mRNA tune transcript function, are essential for mammalian cell fate decisions, and play important roles in the progression of many human cancers. The iron-dependent dioxygenase enzymes FTO and AlkBH5 act as ‘erasers’ of highly abundant N6-methyladenosine (m6A) modifications found in the mRNA body and, in the case of FTO, N6,2’-O-dimethyladenosine (m6Am) modifications found on the 5’ mRNA cap. These RNA demethylases are overexpressed in cancers including glioblastoma and acute myeloid leukemia, where increased demethylation activity and reduced methyl modification levels promote tumorigenesis and cancer progression. Despite these clear links to human disease, we currently have a poor understanding of how FTO and AlkBH5 recognize their biological substrates, which mRNA transcripts are targeted for demethylation, and how demethylation influences mRNA function. Furthermore, FTO and AlkBH5 belong to the non-heme iron(II) and -ketoglutarate-dependent family of dioxygenases that require ascorbic acid (vitamin C) as a cofactor for efficient activity, but we have almost no structure-level insights into how ascorbic acid interacts with this diverse family of enzymes and how this physical interaction may potentiate dioxygenase activity in cells. This proposal combines approaches from biochemistry, structural biology, chemical biology, bioinorganic chemistry, and cell biology to determine the structural basis for RNA demethylase selectivity, develop novel probes to map demethylation targets across the transcriptome, and quantify and visualize the dioxygenase-ascorbic acid interaction to understand how this cofactor regulates enzymatic activity. The results from these proposed studies will significantly enhance our understanding of how cellular mRNA demethylation is regulated in cells and pave the way for therapeutics that target demethylation pathways in challenging cancers such as glioblastoma.

NIH Research Projects · FY 2025 · 2021-07

PROJECT SUMMARY – Diabetic foot ulcers (DFU) are an enormously costly worldwide health concern. They cause nearly 80,000 lower leg amputations annually in the U.S. alone and are associated with significantly increased likelihood of death. Strategies to improve their healing have been a subject of intense study for decades, yet myriad cellular and pathophysiological abnormalities continue to severely limit efficacy of standard therapies. Promising therapeutic alternatives include the application of cellular scaffolds, topical growth factors (especially platelet-derived growth factor), or combination wound dressings. However, the incidence of complete closure remains strikingly low and growth factor delivery strategies largely fail owing to their instability in the inflammatory, MMP-rich environment of the chronic wound. New strategies that can normalize this proteolytic and inflammatory environment, by stimulating local production of therapeutic proteins by fibroblasts and macrophages, would thus offer a provocative approach to improve clinical outcomes. We have recently demonstrated that protease activity in the wound bed can be harnessed to stimulate localized growth factor gene delivery and provide tailorable expression of growth factors over multiweek timeframes. We introduce collagen mimetic peptide (CMP) and therapeutic gene-modified collagens (COATs) as a platform for (i) robust retention of growth factor-encoding polyplexes in collagen- containing wound dressings and (ii) localized, cell-initiated gene delivery during collagen remodeling. Because COATs integrate DNA polyplexes directly into collagen fibrils, our approaches have been shown to significantly improve in vivo wound repair at concentrations of growth factors orders of magnitude lower than those in currently employed topical therapies. These outcomes, coupled with recent advances in the translation of other gene therapies, suggests the high potential for clinical impact of the COATs platform. In the proposed R01 program, we will apply COATs in experimental DFUs and cell-based assays to understand three important aspects of orchestrating wound repair, in the following three Aims. In Aim 1, we will probe variations in CMP modifications that optimize the extended delivery of genes (initially for platelet-derived growth factor (PDGF)) in a murine diabetic wound environment. In Aim 2, we will complement these studies with cell-based investigations that elucidate the role of MMPs (soluble and membrane-bound) in regulating PDGF gene delivery by COATs and PDGF protein lifetime. In Aim 3, we will test how COATs-mediated, sequential delivery of genes for immunomodulatory cytokines (IL4 and IL10) modulates MMP activity in DFUs. These approaches will provide both mechanistic insights for resolving the chronicity of DFUs, and also a new platform that could be integrated into existing wound-care strategies to dramatically improve clinical outcomes.

NIH Research Projects · FY 2025 · 2021-07

PROJECT SUMMARY/ABSTRACT Haploid gametes (i.e. eggs and sperm) are generated from diploid precursors through the cell division of meiosis. Eggs and sperm are highly specialized cells that differ in both their morphologies and in their contributions to fertilization and embryogenesis. To achieve these differences, eggs and sperm are generated from meiotic programs with sex-specific characteristics. However, surprisingly little is known about the molecular mechanisms that define sex-specificity. Previously, we identified a novel allele of C. elegans topoisomerase II that uniquely disrupts the segregation of homologous chromosomes during the meiotic divisions of spermatogenesis but not oogenesis. Topoisomerase II (Topo II) is an enzyme that plays a crucial role in chromosome fidelity by disentangling topological problems that arise in double stranded DNA. Topo II is a large ATP-dependent, homodimeric enzyme. Each subunit breaks one DNA strand, passes a second unbroken strand through the break, and then reseals the break. Thus, Topo II enzymes solve topological problems that arise during replication, transcription, chromosome segregation, and recombination. The identification of a sex-specific role for this key, ubiquitous enzyme highlights the differential regulation of the two meiotic programs. Our long-term goal is to understand the molecules and systems that ensure that each egg and sperm receive the correct number of chromosomes during meiosis. To understand this fundamental process, we will utilize the metazoan animal model C. elegans, which, in addition to sexually dimorphic meiotic programs, provides many experimental advantages such as a fast generation time, a transparent body for in vivo analysis of meiosis, and a single top-2 gene. The research in this proposal encompasses two main programs related to sex-specific regulation of meiotic chromosome structure and segregation. Program 1 will identify sex-specific differences in chromosomal axes components, synaptonemal complex (SC) disassembly, and chromosome compaction prior to the segregation of homologous chromosomes during the first meiotic division. Using a targeted candidate gene approach and mutational analysis, including our previously identified sex-specific top-2 allele, we will identify genes that differentially regulate SC disassembly and chromosome compaction in spermatogenesis and oogenesis. Then, in Program 2, we delve into the mechanisms that regulate TOP-2 localization and activity in spermatogenesis and oogenesis. This work builds on our findings that mutations within tyrosyl DNA phosphodiesterase 2 (TDPT-1) can suppress the top-2 mutant phenotypes. Using a combination of biochemical and genetic techniques we will identify the mechanism of suppression of top-2(it7) embryonic lethality for the tdpt-1 mutant suppressors and identify novel TOP-2 interacting proteins during mitosis vs. meiosis and in spermatogenesis vs. oogenesis.

NIH Research Projects · FY 2025 · 2021-07

Project Summary The long-term goal of the Fromen lab is to develop personalized immunomodulatory mucosal therapeutics using particle immune engineering. Mucosal surfaces line the respiratory, gastrointestinal, and urogenital tracts and serve as the first barrier to foreign invasions. These interfaces are home to the mucosal immune system, a specialized arm of the host immune protection that maintains balance at these critical barriers. Dedicated cells at the mucosa regulate commensal bacteria and maintain tolerance, while also mounting responses to combat pathogenic infections. In the past two decades, engineered particle platforms have emerged as a convenient way to interact with innate immune cells, providing precise chemical cues and pathogen mimicry capable of instructing immune response. Despite the overwhelming potential to directly regulate mucosal immune function at these essential interfaces, most advances to date in particle-inspired immune engineering have bypassed the mucosal interface altogether and instead focused on parenteral routes of administration. There is a critical need to develop particle immune engineering approaches that are designed specifically for the mucosal environment, that can overcome the unique multiscale obstacles faced in mucosal drug delivery. Broadly, there are two major challenges of particle-driven immune engineering at mucosal interfaces that must be addressed to generate needed translational advances: 1) overcoming the dynamic barrier function of the mucosal immune system and 2) tailoring effective stimulatory cues specifically to mucosal antigen presenting cells (APCs) for desirable responses. The Fromen lab has focused our short-term goals on generating fundamental advances in these two challenge areas, specifically using the respiratory tract as a model mucosal system. Major advances to date have included evaluation of novel nanoparticle platforms within the respiratory tract for lung APC modulation, discovery of particle-driven regulation over APC lifespan, and creation of full-size respiratory model systems. In this proposal, we will continue our efforts to engineer personalized immunomodulatory mucosal therapeutics. We will continue to develop tools at the chemical-biology interface that control cellular-APC interactions and subsequent cellular and microenvironment response. We will simultaneously advance macroscopic transport models to bridge the gap between organ-level and mucosal microenvironment motion that will advance multiple physiological applications. These future efforts are well suited to the research program, given the widely applicable multiscale experimental framework to address the broad challenges presented by the dynamic mucosal interfaces of the human body.

NIH Research Projects · FY 2025 · 2021-07

Project Summary Cytochromes c are highly conserved heme proteins that function in electron transport chains for cellular functions such as respiration, photosynthesis and detoxification. The ability of prokaryotes to survive and thrive in diverse, often hostile environments is a direct result of the plasticity of their electron transport chains, of which cytochrome c is an essential component. Much effort has been devoted to studying the roles of individual cytochromes c, but much less is understood about their biogenesis, which requires the covalent attachment of heme at a conserved CXXCH motif for proper folding and function. Despite their diversity, all cytochromes c are made by one of three pathways, System I (prokaryotes), System II (prokaryotes) and System III (eukaryotes), thus elucidation of the molecular mechanisms of these pathways is critical to our understanding of bioenergetics and cellular survival. While the three pathways have evolved different mechanisms to accomplish biogenesis, all must transport heme to a holocytochrome c synthetase. Heme is an essential co-factor in all organisms, functioning not only in electron transport chains for respiration, but also for catalysis, regulation and signaling. Yet our knowledge of heme transporters and heme trafficking is limited due to heme’s cytotoxicity, the transient nature of trafficking and the technical challenges of studying membrane proteins. Thus, we must also address the mechanisms of heme trafficking and here we describe our long-term vision to elucidate the general mechanisms of heme delivery, transport and attachment, beginning with the System I pathway. We propose to 1) identify the cytoplasmic heme receptor and mechanisms of heme delivery, 2) determine the path of heme trafficking by System I, and 3) identify the requirements for periplasmic heme attachment. The System I pathway consists of eight integral membrane proteins (CcmABCDEFGH) and provides a tractable model system to study these fundamental biological questions. CcmABCD are proposed to transport heme across the bacterial membrane and attach it to CcmE, the periplasmic heme chaperone, which trafficks heme to the holocytochrome c synthetase, CcmFH. Utilizing a functional, recombinant E. coli system, the System I proteins purify with endogenous heme, removing many of the technical barriers often associated with membrane proteins. Importantly, the heme attachment reaction occurs in the periplasm, is required for the survival of many pathogens, and likely differs in mechanisms of heme attachment from the eukaryotic synthetase, thus the CcmFH synthetase is a potential target for novel antimicrobials. Our proposed studies on System I will simultaneously provide insights into cytochrome c biogenesis and general mechanisms of heme trafficking, uniquely positioning us to study two fundamental biological processes. A natural extension of this work is to apply the general principles learned and approaches developed to the other cytochrome c biogenesis pathways, as well as to other prokaryotic and eukaryotic heme transporters.

NIH Research Projects · FY 2025 · 2021-07

PROJECT SUMMARY Engineering education must prepare trainees to meet the nation's workforce demands. Biomedical engineering students require early, practical experience to develop the technical skills, knowledge of regulatory pathways, and training in teamwork necessary to solve future unmet clinical needs. The undergraduate biomedical engineering capstone design course is often used as a “catchall” to develop these critical professional skills; however, in order to build competency, it is recommended that these skills be practiced throughout the curriculum, not just at the end. Our goal is to develop a core, sophomore-level, medical devices course in which students simulate the engineering teams found in industry in order to build workplace-ready skills. To accomplish this goal, we will implement innovative instructional methods. Sophomore-level students will work in teams, each with a defined engineering role. Teams will work through three medical device modules, and each module will consist of four main phases: needs identification, design requirements, regulatory, and ethics. Student teams will 1) evaluate how the engineering design process applies to the development of medical devices, with an emphasis on defining the unmet need, developing design requirements, and applying the voice of the customer; 2) create dimensioned models of medical devices by using computer-aided design; and 3) explain U.S. regulatory approval requirements to market different FDA classes of medical devices. We will leverage existing partnerships between the University of Delaware Biomedical Engineering Department and several local clinical sites to develop short videos of stakeholder perspectives of existing medical technologies, which will allow us to scale up some of the benefits of traditional clinical immersion courses and bring the voice of the customer to the students. Students will perform “device dissections” to take apart existing technology and learn how the medical devices work, benefiting from a hands-on experience that develops their engineering professional identities. Students will measure medical device components and recreate engineering drawings, building industry-valued computer-aided design skills. Embedded throughout the semester are professional proficiency lessons on high-performance teamwork and project management. Through this process, students will evaluate the broader context of medical devices, including regulatory, business, and ethical considerations. Overall, these approaches allow for explicit training in teamwork prior to capstone, scalable instructional methods, and early introduction to medical device design. Combined, we expect students to have increased biomedical engineering professional identity, industry-relevant skills, teamwork abilities, and identification of medical device career opportunities, leading to enhanced retention and representation in the biomedical engineering workforce.

NIH Research Projects · FY 2025 · 2021-05

Project Summary Despite advances in treatment strategies, xerostomia (or dry mouth) remains a permanent and devastating side effect of radiotherapy for head and neck cancers, reducing the quality of life for ~50,000 cancer patients each year in the U.S. We aim to develop tissue-engineering approaches to restore salivary function. We have isolated human salivary gland stem/progenitor cells (hS/PCs) from patients prior to radiotherapy. We have created tunable hydrogel matrices that maintain the progenitor status, induce lineage-specific differentiation and promote the development of organized multicellular spheroids from dispersed hS/PCs. Separately, we have engineered salivary gland microtissues that exhibit coordinated calcium activation between hS/PC-derived acini-like core and the surrounding myoepithelial cells. However, a functional gland with extensive branching, polarized acini, and interconnected ducts has not yet been realized. Here, we propose a bottom-up approach to establish functional salivary glands using multicellular assemblies of defined shape, geometry and composition. We will synthesize hydrogel scaffolds that recapitulate key features of the basement membrane and the interstitial matrix in the developing organ. We will reconstitute the vascular, neural and mesenchymal components in the engineered environment to foster tissue morphogenesis in vitro and to maintain tissue homeostasis in vivo. In Aim 1, we will exploit tetrazine ligation, the bioorthogonal and highly efficient cycloaddition reaction between s- tetrazine and strained alkenes, for the establishment of cell-instructive matrices. We will adapt our established methods to generate microgels containing sequestered acetylcholine analog, carbachol (CCh). In Aim 2, we will employ non-adhesive hydrogel microwells to produce multicellular epithelial assemblies consisting of hS/PCs and CCh depots. The resultant microtissue will be encased in a synthetic basement membrane with bioactive peptides to stimulate the development of proacrinar progenitor phenotype. We will generate endothelial microtissues consisting of a core of human salivary gland endothelial cells (hSECs) and a shell of human mesenchymal stem cells (hMSCs). We will co-culture the epithelial and endothelial microtissues in a synthetic extracellular matrix with defined cell-guidance cues to aid in the establishment of a hierarchically integrated tissue assembly. In Aim 3, the engineered gland with integrated microvasculature and conjugated neurotrophic factor, neurturin, will be implanted in the resected parotid bed of athymic rats. Enzymatically triggered release of neurturin will promote implant innervation. Tissue ultrastructure, biomarker expression, gland morphology, biointegration and function will be assessed under various construct configurations. We will interrogate how the engineered microenvironments stimulate differentiation, trigger polarization and promote branching. The overall hypothesis is that hS/PCs co-cultured with hSECs/hMSCs in 3D synthetic matrices displaying biochemical, geometrical and mechanical cues identified from the native organs will assemble into functional salivary tissues. Our investigations will help define bioengineering approaches toward the management of xerostomia.

NIH Research Projects · FY 2025 · 2021-02

ABSTRACT CANDIDATE: Alyssa Lanzi, Ph.D. is an academic speech-language pathologist and Research Assistant Professor at the University of Delaware. In this K23 application, Dr. Lanzi will build on her training and research studying cognitive rehabilitation approaches that preserve independence in adults with mild cognitive impairment (MCI) and early-stage dementia from Alzheimer’s disease (AD). The objective of this award is to acquire new knowledge, skills, and experiences needed to independently conduct clinical trials of these interventions, as well as future dissemination and implementation. Her long-term goal is to establish a productive research program that develops, evaluates, and disseminates cognitive rehabilitation interventions for adults with AD and MCI. CAREER DEVELOPMENT PLAN: Dr. Lanzi proposes to: 1) learn how to design and conduct randomized controlled trials of behavioral interventions for adults with MCI and dementia from AD; 2) receive training in the multidisciplinary assessment of the cognitive, psychological, and independent living skills of this population; 3) acquire knowledge and skills related to dissemination and implementation of behavioral interventions for rehabilitation clinicians. The training plan includes rich experiential learning activities such as multidisciplinary team-based cognitive assessment activities in diverse community settings. ENVIRONMENT: Dr. Lanzi will train with a multidisciplinary team of NIH-funded mentors with expertise in clinical trials research, MCI and dementia from AD, and dissemination/implementation research. Dr. Verdolini Abbott (U Delaware), co-primary mentor, is a senior academic speech-language pathologist and has extensive expertise in clinical trials of behavioral interventions. Dr. Cohen (U Delaware), co-primary mentor, is a rehabilitation-oriented neuropsychologist with a record of multi-disciplinary cognitive assessment research. Dr. Rodakowski (U Pittsburgh), co-mentor, is an academic occupational therapist with expertise in cognitive strategy training and independent living skills for adults with MCI. Dr. Smith (U Florida), co-mentor, is a senior neuropsychologist and renowned expert in MCI, AD, and behavioral intervention approaches. RESEARCH: Most treatment approaches for MCI and dementia from AD have focused on restoring cognitive weaknesses. Unfortunately, these are suboptimal for preserving or improving independent living skills. Aim 1 of the proposed research is to conduct a pilot trial to evaluate the efficacy of the Structured External Memory Aid Treatment, a compensation-based approach for adults with MCI that promotes independent living skills by teaching the use of strategies to compensate for cognitive weaknesses (e.g., note-taking systems). Aim 2 is to evaluate the demographic, clinical, and neuropsychological predictors of treatment adherence. Aim 3 is to refine treatment procedures and materials that will be used to train future interventionists. The completion of these training and research aims are critical for Dr. Lanzi’s career development and continued success in investigating the efficacy and effectiveness of compensatory cognitive interventions that enhance the independence and quality of life of adults with AD.

NIH Research Projects · FY 2025 · 2021-02

PROJECT SUMMARY/ABSTRACT The musculoskeletal system has both mechanical and biological functions—it generates, transmits, and supports forces, and it regulates organ-level homeostasis and whole-body metabolism. The mechanics and biology of the musculoskeletal system are inextricably intertwined and long-ranging, where mechanical cues, molecular signals, and cell interactions affect each other across multiple scales, from the body, to organ, tissue, cell, and molecule levels. Progress in musculoskeletal research depends on addressing the mechanics and biology of adjacent organs, and evaluating the effects of injury as well as aging. Identifying the mechanisms underlying musculoskeletal health and musculoskeletal disorders (e.g., osteoarthritis, osteoporosis, muscle wasting, post-traumatic repair, degeneration) therefore requires a research paradigm that addresses the synergies within the musculoskeletal system and combines both mechanical and biological approaches across multiple scales. The Delaware Center for Musculoskeletal Research (DCMR) will support basic and preclinical research on the central theme of musculoskeletal health—from the level of the entire body to the actions of key cells and molecules—with emphasis on understanding the mechanisms by which physical and biological cues influence tissue structure and normal function and dysfunction, and identifying potential therapeutic interventions. The proposed DCMR will: Aim 1: Accelerate fundamental musculoskeletal research by supporting synergistic and multidisciplinary Research Projects. Aim 2: Galvanize capabilities for musculoskeletal research by establishing a Multiscale Assessments Research Core. Aim 3: Amplify the impact of musculoskeletal research through faculty mentoring, expansion, and retention. Completion of this 5-year Phase I COBRE will build cross-cutting and synergistic research collaborations across multi-scale and multidisciplinary Research Projects and establish a state-of-the-art Research Core. The DCMR, which will focus on fundamental discovery and preclinical research, will complement the outstanding translational and clinical musculoskeletal research programs at Delaware, creating a comprehensive basic-to- clinical research pipeline at UD. Through fostering cross-cutting and convergent research partnerships, the DCMR aims to substantially reduce the burden of musculoskeletal disorders and improve musculoskeletal health.

NIH Research Projects · FY 2025 · 2020-09

Project Summary Developmental Language Disorder (DLD) is a disorder in language learning and use that affects 7% of the population. Grammatical difficulties are a hallmark characteristic of this disorder during childhood. Long-term academic and quality of life outcomes are poor. The development of broadly adoptable techniques to remediate comprehension and production of complex syntax prior to attainment of fluent reading would increase access to the academic curriculum earlier and improve long-term outcomes of individuals with DLD. It is unlikely that recast therapy, the current standard of care, is delivered effectively within the constraints of current service delivery approaches and reimbursement models. Thus, there is a need to either demonstrate that recasts are a superior intervention method worthy of the effort required for faithful implementation, or to identify and develop an alternative approach that is feasible for administration to children older than 3 who are not yet fluent readers. Illustrated syntax stories i.e., specially constructed stories loaded with the target grammatical form that can be read aloud by a caregiver, could be that more feasible approach. Literacy, while not universal, is more accessible than recast therapy to a broad range of adults and high rates of input can be rapidly and consistently provided. This approach has previously been shown to increase the production and comprehension of passives, reported speech, and conjoined clauses in typical preschoolers and school age children. Our own preliminary data suggests that illustrated syntax stories could also be effective for children with DLD. Here, we carry out a randomized controlled trial, enrolling 140 children with DLD between the ages of 4 and 7 who score below 40% correct on the use of passives and object relative clauses. Children receive one of four possible treatments (recasts at home, recasts in the lab, syntax stories at home, syntax stories in the lab) for one grammatical structure for 10 weeks and then outcomes are re-assessed for both the treated and untreated structures. Comparison of the two different treatment approaches in the lab under dose controlled conditions informs us as to the mechanism of action for language learning. Specifically in Aim 1, we contrast interactive, feedback-based learning (recast therapy) with concentrated systematic exposure (illustrated syntax stories). In Aim 2, we consider the influence of the delivery mechanism on the ultimate dose delivered when treatment is provided by caregivers. We ask whether there is sufficient difference between the two delivery methods in terms of the dose provided by caregivers such that it cascades down to affect child outcomes. Combining outcomes data with quantitative information about the degree of fidelity and adherence and qualitative information reasons for these behavior patterns (Aim 3) will provide critical information about the circumstances under which these treatments can be provided effectively. These data will be interpreted within the Theoretical Domains Framework to better understand barriers and enablers of treatment implementation and to inform future work to scale-up the most effective approach.

NIH Research Projects · FY 2025 · 2020-09

PROJECT SUMMARY Traumatic injuries in human joints can cause cartilage degeneration and lead to post-traumatic osteoarthritis. Few techniques are now available in practice to prevent the cartilage from degeneration after the joint injuries. Our research discovered that statins, a class of drugs used by 40 million US people to control the cholesterol levels, can effectively protect the cartilage from various OA-inducing factors. We found that statins can directly act on the cartilage cells and prevent them from degrading the cartilage matrix. In this project, we will determine the efficacy and mechanism of statins for the prevention of post-traumatic osteoarthritis. First, using a retrospective cohort study, we will determine the correlation between statin use and OA occurrence among the Delaware population. Second, using in vitro cell/tissue culture models, we will identify the cartilage- protective mechanisms of statin. Third, we will test the efficacy of statin for PTOA prevention using animal models. Outcome of this project can provide us justifications for the clinical trials of statin application on the patients with joint injuries. The long-term goal of this project is to pursuit an FDA approval for the repurpose of statins in joint treatment and PTOA prevention. If this project is successful, it will immediately increase the prescription adherence of 40 million current statin users, especially those at a high risk of osteoarthritis occurrence with a joint injury history.

NIH Research Projects · FY 2025 · 2020-08

PROJECT SUMMARY Bacterial cells surround themselves with a peptidoglycan (PG) cell wall, an essential structure that provides cell shape, and resists changes in osmotic pressure and other environmental insults. In addition, PG is highly inflammatory and an important trigger of innate immune responses across the animal kingdom. However, study of these important PG fragments has been hampered by the lack of reproducible, chemically defined, and high quality reagents. We hypothesize that the natural diversity of the generated PG fragments poses unique challenges to the innate immune system that utilizes specific uptake, transport, and receptor systems for sensing and responding to the presence of the bacterial cell wall derived molecules. The goal of this proposal is to develop a biologically relevant PG fragment library and PG synthesis strategies to facilitate a more precise understanding of PG mediated immune responses in the context of health (homeostasis) and inflammatory diseases. In the initial funding period, we used our PG library and genome wide transcriptome analysis to uncover that distinct PG fragments indeed induce specific immune responses, through related but distinct PG sensing receptors. We were successful in our aims to produce a fragment library, print a PG array, share the fragment library with multiple laboratories and to discover that specific immune receptors recognize discrete peptidoglycan fragments. Transporters responsible for the cellular internalization of specific PG fragments were defined and novel innate immune sensing complexes were identified. The project has now developed into a mechanistic phase with a keen focus on intestinal innate immunity and inflammation, where our team of chemical biologists and immunologists will work together to innovate PG production strategies and fine tune PG probes to better understand the specificity of their trafficking and signaling modalities. Ultimately, we aim to learn the molecular requirements for cellular uptake and innate immune recognition of a variety of PG fragments, especially in mucosal macrophages, by the characterizing the SLC transporters involved and the key innate immune receptors - PGLYRPs and the NOD proteins required. This renewal aims to enhance the PG library with additional modalities for partner capture (both in cellular, animal models and array format), synthesize and screen for inhibitors for bacterial cell wall uptake and recognition, and define the pathways driving specific gene expression outputs, all building upon the results from the previous funding cycle: Aim 1: Identification and fermentation of biologically relevant PG fragments, Aim 2: Defining requirements and mechanisms for PG fragments entering macrophages Aim 3. Define the role(s) of mammalian Peptidoglycan Recognition Proteins (PGLYRPs) in innate immunity and mucosal protection. Ultimately, this dynamic team will set the stage for the future development of small molecule modulators, PG based immunotherapies, adjuvants, and biomarkers while at the same time, sharing new tools with the microbial and immunological communities.

NIH Research Projects · FY 2024 · 2020-08

Project Summary Extracellular vesicles (EVs) are membrane-wrapped structures containing proteins, RNAs, lipids, and metabolites that are released from most if not all cell types to mediate intercellular communication. Roles for EVs in physiological processes as well as pathological conditions including neurodegenerative diseases and cancer have been established. Given the presence of EVs in diverse body fluids, there is also great interest in using these vesicles as biomarkers for disease detection and engineering EVs for therapeutics. Investigation of the release of EVs containing fluorescently-tagged cargo from identified cells in the model system C. elegans can provide insight into unresolved questions concerning conserved mechanisms of EV biogenesis and cargo selection in vivo. We discovered that the calcium homeostasis modulator ion channel CLHM-1 is cargo in EVs released from cilia of male-specific sensory neurons. Remarkably, when we coexpressed tdTomato- tagged CLHM-1 with GFP-tagged PKD-2, a known EV cargo protein expressed in the same neurons, we rarely observed colocalization of the fluorescent proteins in vesicles, suggesting that CLHM-1 and PKD-2 are in distinct EV subpopulations. We have found that the PKD-2 and CLHM-1 containing EVs do not utilize the same biogenesis and release mechanisms, are discharged in different quantities, and do not have the same physiological function. Our overarching goal is to draw upon the strengths of our genetic system and cutting edge imaging and mass spectrometry approaches to define mechanisms underlying formation of EV subpopulations and the physiological significance of EV heterogeneity. Our proposed research will utilize our unique transgenic animals that express fluorescently tagged EV cargoes at endogenous levels. Advanced imaging techniques including confocal microscopy with Airyscan detection and immunogold labeling for transmission electron microscopy will enable us to characterize the size, morphology, and ciliary release site(s) of EVs as well as the impact of lateral lipid asymmetry in the ciliary membrane on cargo sorting. Through a candidate approach, we will define the role of flippases, floppases and scramblases, which control transbilayer lipid asymmetry, in the biogenesis of the EV subsets. We will then explore how cellular stress conditions that disrupt plasma membrane phospholipid homeostasis impact EV cargo sorting and release. To identify other cargoes in the CLHM-1 EV subset, we will perform mass spectrometry on GFP-tagged CLHM-1 vesicles isolated by flow cytometry. Finally, we will identify the hermaphrodite-derived stimulus that induces an increase in formation of CLHM-1 containing EVs from male ciliated neurons as well as the importance of EV release for animal communication and ciliary function. This work will lead to an understanding of how an individual cell generates heterogeneous EV populations with different physiological functions, impacting broadly on our comprehension of basic biogenesis and cargo sorting mechanisms utilized in vivo.