University Of Iowa

NIH Research Projects · FY 2025 · 2021-09

Project Description The mitis group streptococci are ubiquitous microorganisms that colonize the human oropharynx. In susceptible hosts, these organisms are important opportunistic pathogens and they have shown to cause a wide range of infectious complications in humans, which includes bacteremia, orbital cellulitis, septic arthritis, and infective endocarditis. However, despite the clinical significances of these infections, the mechanisms of pathogenesis and the pathophysiology are poorly understood. Hydrogen peroxide (H2O2) produced by these microorganisms has been identified as an important virulence factor. Furthermore, H2O2 produced by members of this group such as Streptococcus oralis and Streptococcus mitis induced epithelial cell and macrophage death, while H2O2 produced by Streptococcus pneumoniae had a profound effect on the activation of cellular stress pathways in lung epithelial cells. The genetically tractable model organism Caenorhabditis elegans provides an opportunity to characterize the pathophysiology in context of the whole organism and to elucidate how non-immune cells facilitate innate immune and stress responses. In this study, we propose to elucidate mechanisms of activation of pathogen-induced immune and stress responses by the mitis group streptococci. Our central hypothesis is that immune and oxidative stress responses are mediated by the bZIP transcription factors ZIP-2 and ZIP-10 via pathogen-derived H2O2. To address our hypothesis the following aims will be tested; Specific Aim #1. To elucidate the mechanism how the bZIP transcription factor, ZIP-2 mediates the effector-triggered immune response in C. elegans against streptococcal-derived H2O2. Specific Aim #2. We will determine the mechanisms of activation of an immune and oxidative stress response via the bZIP transcription factor ZIP-10 in response to the pathogen-derived H2O2 in the worm. Specific Aim #3. To demonstrate the conservation of these mechanisms identified in aims 1 and 2 in human gingival fibroblasts. The proposed study is significant because we will identify how H2O2 produced by the mitis group streptococci causes pathogen-associated disruption of cellular processes and in turn the activation of protective mechanisms. Elucidating the protective mechanisms will help identify novel therapeutic strategies to combat these pathogens.

NIH Research Projects · FY 2025 · 2021-09

PROJECT SUMMARY Alopecia areata (AA) is a common autoimmune disease in which the hair follicle is the target of attack and results clinically in hair loss. Despite the associated high lifetime risk of approximately 2% and its substantive psychosocial impact, no FDA approved treatments exist for AA. The lack of effective options for the population that suffers from this disfiguring disease with significant psychosocial ramifications represents a significant unmet medical need. The absence of approved treatments is in part due to an incomplete understanding of the unbalanced equilibrium between pathogenic immune responses and immunoregulatory mechanisms that prevent autoimmunity in AA. Although many cytokines, pathways, and cell types have been hypothesized to prevent immune attack of the hair follicle, it is unknown what factors participate in regulating autoimmune responses in vivo. Identifying these critical immunoregulatory participants may not only deepen our understanding of AA pathogenesis, but may reveal anti-inflammatory pathways that may be exploited to develop novel approaches to treatment. IL-27 is a cytokine with immunoregulatory properties that has been studied in various autoimmune, infectious, and tumor models. The receptor for IL-27 is expressed by a wide array of immune cell types as well as epithelial and endothelial cells, supporting its potential to modulate the immune system and critical cell types that interact with the immune system. In particular, IL-27 has been shown to dampen conventional T cell responses, increase the number of regulatory T cells, and induce naïve and previously activated CD4 and CD8 T cells to produce IL-10, a well-known cytokine with anti-inflammatory effects in most contexts. Our preliminary data indicate that overexpression of IL-27 can substantially prevent the development of murine AA, and further analysis revealed regulatory T cells and IL-10 as potential downstream candidates participating in disease suppression. We propose to study the mechanisms of AA suppression of exogenous IL-27 and its downstream effects on regulating immune responses to the hair follicle and preventing the development of AA. We have adopted and further developed a spontaneous AA mouse model to robustly develop disease in an inducible, controlled, and well-characterized manner by adoptive transfer of activated pathogenic T cells. Combining our AA model with newly developed genetic tools will allow us to dissect the mechanisms by which IL-27 may be used to ablate AA pathogenesis and has the potential to reveal novel therapeutic strategies.

NIH Research Projects · FY 2024 · 2021-09

PROJECT SUMMARY Heart failure, measured at the subcellular level, is the result of impaired cardiomyocyte excitation-contraction (E-C) coupling. One key structural component of E–C coupling is the myocyte transverse (T)-tubule system. T- tubules play an essential role in coordinating membrane excitation with muscle contraction by facilitating the synchronized release of Ca2+ from the sarcoplasmic reticulum. Our group, as well as those of others, have provided strong evidence that failing myocytes from patients and animal models are characterized by a degenerated and disorganized T-tubule system resulting in impaired intracellular Ca2+ dynamics and myofilament contraction. The long-term goal of our research is to discern and take advantage of the fundamental mechanisms underlying T-tubule remodeling processes in heart disease toward restoring T-tubule integrity and slowing, if not reversing, heart failure progression. We have identified Mitsugumin 53 (MG53/TRIM72) as a potential T-tubule repair enzyme. We find MG53, known to be involved in injury-induced membrane vesicle trafficking and repair in striated muscle, localizes to T-tubules and is upregulated in human failing hearts and animal models of chronic heart failure. Our preliminary data indicate MG53 possesses apparent divergent functions in the heart, MG53 deletion of MG53 exacerbates T-tubule degeneration in stressed hearts while exogenous MG53 overexpression promotes progressive and severe T-tubule disruption. Interestingly, we have mapped overexpression effects to its little-studied E3-ligase domain. It is our hypothesis, therefore, that the membrane repair versus E3-ubiquitin ligase activities of MG53 determine cardiomyocyte T-tubule integrity and E-C coupling function during health and in disease. We have recently generated two novel knockin animals for separately examining endogenous MG53 E3-ligase and membrane repair functions during cardiac stress responses. We will test our hypothesis by first determining the physiological (Aim 1) and molecular (Aim 2) actions of the MG53 E3-ubiquitin ligase, as well as its membrane repair (Aim 3), domains in T-tubule structure and Ca2+ handling at baseline and in response to cardiac stress. We will attribute apparently discordant ubiquitin-dependent proteolysis and membrane healing functions of MG53 to overall T-tubule integrity, E-C coupling and cardiac remodeling processes. Understanding the mechanisms by which MG53 facilitates T-tubule remodeling versus repair will allow us design highly targeted and efficacious therapeutics for heart failure treatment.

NIH Research Projects · FY 2025 · 2021-09

PROJECT SUMMARY Bicycling is a leading cause of childhood injuries and, second to motor vehicles, bicycles contribute to more childhood injuries than any other consumer product. Approaches to increasing bicycling safety among youth include bicycle safety education programs and parents also play a vital role as influencers of their child's bicycle handling and traffic safety skills, perceptions, and self-efficacy. Bicycle safety education programs are abundant, but little is known about their effectiveness in terms of behavior change. This cluster randomized controlled trial will evaluate a community-based bicycle safety education program with and without an in- person parent training component. We will recruit 180 early adolescent bicyclists (ages 9 to 12) and a parent/guardian from local neighborhood centers after school and summer programs, where we have conducted preliminary studies. Randomization into the three study groups will occur at the site-level. Adolescent bicycles in all study group sites will be equipped with Pedal Portal, an innovative bicycle-mounted GPS/video system developed by our research team to objectively observe bicycling risk exposure and behaviors while bicycling. System data will be coded to measure bicycling exposure (hours, miles traveled, routes) and the types and rates of safety-relevant events (near crashes, crashes), and safety-relevant behaviors (e.g., following traffic rules, scanning for traffic at intersections). This will be the first randomized trial to use GPS and video technology to evaluate the effectiveness of a youth bicycle safety intervention in changing behavior. The control group will not receive any bicycle safety education programming. Participants in the first intervention group (Bike Club) will receive a 12-hour bicycle safety education program. Participants in the second intervention group (Bike Club Plus) will receive an enhanced version of the 12-hour bicycle safety education program which will include a parent training session on bicycling safety best practices, child development as it relates to bicycling, strategies for practice at home, and feedback on their adolescent's bicycling performance. Our main hypotheses are that adolescents who receive the bicycle safety intervention will have increased safety behaviors (e.g., helmet use, hazard recognition), reduced errors (e.g., riding against traffic, swerving/wobbling), and increased knowledge, perceptions, and self-efficacy compared to the control group; and adolescents whose parent receives the parent training will have even greater improvements in study outcomes than those whose parents do not receive the training. If successful, approaches from this study could be widely implemented to improve adolescent bicycling safety.

NIH Research Projects · FY 2024 · 2021-09

PROJECT SUMMARY Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is an inherited disease characterized by fibro-fatty infiltration of the heart, life-threatening ventricular arrhythmias and sudden cardiac death, particularly in response to sympathetic stress. ARVC is a leading cause of sudden cardiac death among young athletes with no prior symptoms or diagnosis of cardiovascular disease. Desmosome cell-adhesion gene mutations constitute the majority of familial ARVC cases, but it remains largely unknown how catecholamine-sensitive ventricular tachycardia and cardiac remodeling processes are facilitated by desmosome dysfunction. Patient management is therefore limited to improving quality of life by reducing arrhythmic symptoms or cardiac transplantation upon advanced heart failure. To begin to uncover mechanisms inherent to ARVC, we performed unbiased mass spectrometry analysis of ventricular samples from patients with different desmosomal gene mutations. Our preliminary data demonstrate that integrin β1D is significantly downregulated in ARVC resulting in de- stabilization of RyR2 ryanodine receptor Ca2+ channels that localize to cardiac dyad junctions. Mechanistically, we find that ERK1/2 activation in response to desmosome loss results in ubiquitin-dependent degradation of integrin β1D, RyR2 Ser-2030 phosphorylation, sarcoplasmic reticulum Ca2+ leak and arrhythmogenesis. Importantly, hearts of our integrin β1D knockout mice exhibit ARVC-like disease with increased RyR2 phosphorylation, catecholamine-induced ventricular arrhythmias and cardiac fibrosis. We hypothesize that communication between desmosome junctions and cardiac dyads is essential for maintaining Ca2+ homeostasis and that ERK1/2 activation-induced loss of integrin β1D impairs this “desmosome-dyad crosstalk” thereby promoting RyR2-dependent and catecholamine-sensitive arrhythmogenesis and fibrotic infiltration in ARVC. We further hypothesize that interventions targeting this pathway may offer a promising approach for treating ARVC. To test our hypothesis, we have generated three congenic knock-in mouse models using CRISPR-Cas9 that contain mutations equivalent to those we identified from human ARVC patients. In Aim 1, we will determine the pathogenicity of knock-in ARVC mutations in recapitulating cardiac remodeling, catecholamine-induced arrhythmogenesis and desmosome-dyad crosstalk in mutant ARVC mice. In Aims 2 and 3, we will test whether mutation-induced ARVC phenotypes can be effectively prevented through ERK1/2 (Aim 2) and RyR2 (Aim 3) inhibition. We expect our studies to show that life-threatening ventricular arrhythmias and heart failure from ARVC can be therapeutically managed by modulating desmosome-dyad crosstalk and attenuating Ca2+ handling dysfunction.

NIH Research Projects · FY 2025 · 2021-09

PROJECT SUMMARY/ABSTRACT Despite therapeutic advances, over 600,000 people in the US will die from cancer in 2019. Preventing cancer eliminates the risk of mortality and/or morbidity that may occur with the development of cancer. Thus, cancer prevention represents the most effective way for addressing cancer challenges. Healthy diet is considered be essential to reduce cancer risk by maintaining and improving immunity, but recent VITAL trials did not show beneficial effects of these supplements. The negative results reflect the mechanistic knowledge gap of how dietary factors modulate health. The objectives of this renewal application are to determine cellular and molecular mechanisms by which epithelial fatty acid binding protein (E-FABP) promotes n-3 fatty acid- mediated tumor prevention by enhancing immune cell differentiation and anti-tumor activity. Data collected in the last funding cycle have successfully established E-FABP as a new host-derived cancer prevention factor in non-obese subjects. During our studies, we observed that different types of high fat diets (HFD, 45% fat), including cocoa butter (rich in saturated fatty acids, FAs), safflower oil (rich in 18:2 linoleic acid), fish oil (rich in n-3 FAs), all induced similar degree of obesity in mouse models. However, tumor growth in these obese mice was dramatically different with the fastest growth in cocoa butter group and slowest in the fish oil group. In analyzing the immunophenotype of these obese mice, we found an atypical population of CD8+ γδ T cells that was specifically upregulated in the fish oil group. More interestingly, fish oil diet-induced CD8+ γδ T differentiation and anti-tumor effects were blunted in mice lacking E-FABP, suggesting a novel molecular mechanism mediated by E-FABP. Thus, we hypothesized that host expression of E-FABP plays a critical role in n-3 FA-induced immune cell differentiation and anti-tumor function. Three specific aims are proposed to address the central hypothesis in this renewal application. Specific Aim 1 will determine the mechanisms by which E-FABP promotes n-3 FA-induced immune cell differentiation. Experiments are designed to elucidate molecular mechanisms by which consumption of dietary n-3 FAs regulate CD8+ γδ T cell differentiation via E- FABP-dependent epigenetic reprogramming. Specific Aim 2 will delineate how E-FABP mediates n-3 FA- induced anti-tumor activity. Results of Aim 2 are expected to reveal that E-FABP promotes host anti-tumor activity through targeting both immune cells and tumor-derived epithelial cells. Specific Aim 3 will evaluate whether targeting E-FABP with optimized n-3 FA diets results in effective tumor prevention. In summary, successful completion of this proposal will offer E-FABP as a new cancer prevention target and have significant mechanistic and clinical implications for healthy diet-mediated cancer prevention.

NIH Research Projects · FY 2025 · 2021-09

Fuchs Endothelial Corneal Dystrophy (FECD) is a blinding disease that affects 4% over the age of 40 in the United States. There is no cure for this condition. Corneal tranplantation is the prevalent treatment. With the aging population, there is increasing scarcity of donor tissues. In addition, tranplant failures due to graft rejections occur in 10-25% of corneal transplantations. This proposal focuses on identifying previously understudied molecular signaling pathways in FECD. Successful completion of the specific aims in this proposal can lead to alternative therapies for FECD.

NIH Research Projects · FY 2025 · 2021-09

NIH Research Projects · FY 2025 · 2021-08

Abstract The US is facing a crisis of opioid overdoses and addiction. Current therapies consist largely of alternative opioids (i.e. maintenance with methadone or buprenorphine) and do not correct neurobiological factors that underlie drug craving and relapse. These factors include the long-lasting changes at glutamatergic synapses in the nucleus accumbens (NAc), which both resemble and differ from changes induced by other highly addictive drugs such as cocaine. Our recent studies suggest these synaptic effects of opioids are opposed by acid- sensing ion channels (ASICs). ASICs conduct inward Na+ and Ca2+ current at post-synaptic dendritic spines where they are activated during synaptic transmission by protons released into the synaptic cleft from neurotransmitter-containing vesicles. Because these protons are removed from the synaptic cleft via the actions of carbonic anhydrase 4 (CA4), genetically disrupting CA4 or pharmacologically inhibiting CA4 with acetazolamide (AZD) dramatically increases synaptic ASIC currents. These observations have led to our hypothesis that AZD will reverse synaptic changes following opioid withdrawal by inhibiting CA4 and increasing ASIC activity, and thereby reduce craving and relapse. In this proposal we plan to test this hypothesis by rigorously assessing effects of opioids on synaptic physiology and behavior. Together the experiments in this proposal will pave the way to a better understanding of the neurobiology underlying opioid addiction and to new molecular targets for treating opioid use disorder (OUD). Knowledge gained from these studies could suggest new ways to treat opioid addiction through non-opioidergic mechanisms, for example by manipulating ASICs, brain pH, or carbonic anhydrase, for which a number of inhibitors are already approved for human use, and might be efficiently repurposed.

NIH Research Projects · FY 2024 · 2021-08

Androgen receptor is a powerful sex-steroid hormone receptor that mediates homeostatic and pathological functions in hormone-responsive systems in humans. Over the past 30 years, since the original cloning of the androgen receptor cDNA, molecular insights into androgen receptor function, both normal and pathological, have been gleaned from the discovery of proteins that bind and regulate androgen receptor activity. These androgen receptor-interacting proteins, better known as the AR-interactome, constitute a functionally diverse spectrum of proteins that modulate androgen receptor function in space and time at the cellular level. Like other sex-steroid hormone receptor family members, androgen receptor is a very sticky receptor. It has more than 350 binding partners, which allows androgen receptor to serve as a hub to regulate cellular signaling at the molecular level through dynamic protein interactions with the AR-interactome. Unfortunately, the AR- interactome continues to grow over time with no clear end in sight. Our inability to define the AR-interactome in a single cellular model has made it nearly impossible to experimentally replicate the AR-interactome and understand how their coordinated actions regulate AR-dependent signaling in space and time. Thus, quantitative and predictive models of AR-dependent signaling remain speculative at best. Our scientific premise is that the careful annotation and discovery of the AR-interactome in cells will lay the foundation for understanding how this subproteome contributes to physiologic and pathologic androgen receptor functions in hormone-responsive systems. Thus, we have proposed an experimental plan to annotate the AR-interactome in androgen-sensitive cellular models using cutting-edge, quantitative proteomic techniques. Our proteomic approaches will define a spatiotemporal map of the AR-interactome in cells, and lay the foundation for probing genetic relationships within and between protein complexes comprising the AR-interactome. The proteomic findings will allow us to develop testable models of AR-dependent signaling in cellular systems. These models will provide a molecular framework to understand how androgen-mediated signaling operates under homeostatic and pathological states. More importantly, they will guide the discovery of novel druggable targets among the AR-interactome so that corrupted AR-dependent signaling can be attenuated in androgen receptor- related pathologies that afflict reproductive and non-reproductive systems in humans.

NIH Research Projects · FY 2025 · 2021-08

Abstract Sudden unexpected death in epilepsy (SUDEP) is the most common cause of death in patients with refractory epilepsy. Emerging data indicate that a substantial percentage of SUDEP is due to seizure-induced respiratory arrest. There is a gap in knowledge about how seizures cause apnea, who is at highest risk and what can be done to prevent it. We have found that postictal death is due to seizure-induced apnea in two genetic mouse models of human SUDEP (Scn1aR1407X and Scn8aN1768D mice). Our data indicate that seizures activate projections from the amygdala to the brainstem causing central apnea, and transient defects in CO2 homeostasis and serotonin (5-HT) neuron function. This is supported by data showing that 5-HT neurons, which are central CO2/pH chemoreceptors that stimulate breathing, are inhibited during seizures. The central hypothesis of the current proposal is that seizures impair CO2 chemoreception, in part by inhibiting 5-HT neurons, which increases the risk of a seizure becoming fatal. We have also found that a diet supplemented with milk whey causes a large reduction in the risk of SUDEP, and this may be due to an increase in 5-HT. This proposal will use Scn1aR1407X and Scn8aN1768D mice to carry out the following specific aims. 1) Determine the role of impaired CO2 chemoreception in fatal post-ictal apnea. Working hypothesis: Seizures inhibit CO2 chemoreception, which increases the risk of fatal apnea. Our preliminary data indicate that generalized seizures cause a large post-ictal decrease in ventilation, a decrease in the hypercapnic ventilatory response (HCVR), and a transient drop in body temperature. All three of these homeostatic brainstem functions are controlled by serotonin neurons. We will use 24-hour monitoring of EEG, EMG, EKG, plethysmography, body temperature and video in a mouse epilepsy monitoring unit (EMU) to study changes due to spontaneous seizures. 2) We will define the contribution of 5-HT system dysfunction to postictal hypoventilation and apnea. Working hypothesis: Impairment of the 5-HT system worsens ictal and post-ictal hypoventilation. A decrease in brain 5-HT has been shown to decrease the HCVR. We will increase or decrease brain 5-HT in mice and measure the frequency of spontaneous sudden death, and postictal changes in the HCVR. 3) Define the mechanisms by which whey prevents SUDEP. Working hypothesis: SUDEP risk is reduced by whey via an increase in brain 5-HT and/or CO2 chemoreception. We propose to examine whether whey is effective in preventing seizure-induced death in Scn8aN1768D, Kcna1-null and DBA/1 mice. We will examine whether whey prevents inhibition of the HCVR with seizures. We will examine which components have a protective effect on survival, and whether they act through changes in 5-HT. The expected outcome is that CO2 chemoreception will be established as central to the mechanisms of SUDEP and to how whey protects against it. The broader impact is that whey may be a new and safe approach to prevent SUDEP that targets mechanisms underlying postictal respiratory arrest.

NIH Research Projects · FY 2024 · 2021-08

The National Institutes of Health reports that > 23 million (~5-8%) of Americans suffer from chronic inflammatory conditions, many of which involve the pathogenic functions of autoreactive B lymphocytes and the autoantibodies they produce. Chronic inflammatory conditions also predispose to the subsequent development of malignancies, such as B cell lymphoma, in the affected cells and tissues. There is thus a critical window of opportunity in which alleviation of autoimmunity and chronic inflammation can also reduce future risk of malignancies. However, many of the current treatments for B cell-mediated autoimmunity globally deplete B cells, which can alleviate symptoms but result in immunosuppression. There is thus an ongoing need for development and refinement of therapies that target the pathogenic function of autoreactive B cells. The adapter protein TNF Receptor Associated Factor 3 (TRAF3) acts in a cell-type-specific manner to suppress B cell signaling pathways contributing to both autoimmunity and malignancy, and loss of TRAF3 protein in B cells by inflammation-induced degradation creates chronic B cell TRAF3 deficiency. This deficiency in turn predisposes to abnormally enhanced B cell survival and function, leading to autoimmunity in young adults in a preclinical mouse model, and development of B cell lymphoma in these mice as they age. This highlights a critical need to define how TRAF3 regulates B cell functions, the long-term goal of this work. The objective of this project is to address the knowledge gap of how TRAF3 regulates signals via the B cell antigen receptor (BCR) and the innate Toll-like Receptors (TLR) that are involved in autoimmunity, via the following Specific Aims: (1) Identify the molecular mechanisms by which TRAF3 restrains BCR signaling and BCR contributions to autoimmunity. (2) Define how TRAF3 inhibits B cell signals and functions of innate immune Toll-like receptors (TLRs). (3) Determine how inhibition of TRAF3-regulated BCR and TLR signaling pathways impacts development of autoimmunity in B cell-specific TRAF3-deficient mice (B-Traf3-/-). The expected outcome of these studies is a detailed knowledge of how a deficiency in TRAF3, which is associated with both aging and chronic B cell activation, contributes to B cell-mediated autoimmunity. This knowledge will be valuable in selection and development of pathway-targeted therapies for autoimmune conditions.

NIH Research Projects · FY 2025 · 2021-07

PROJECT SUMMARY: OVERALL This is a revised application to establish the University of Iowa “Hawkeye” Intellectual and Developmental Disabilities Research Center (Hawk-IDDRC), Our mission is to provide an organizational structure that fully integrates basic and clinical research across the lifespan—from conception to adulthood—that is focused on the prevention, diagnosis, treatment, and amelioration of intellectual developmental disabilities (IDDs), tailored to an underserved rural population. The Hawk-IDDRC includes four components: 1) the Hawk-IDDRC Research Project will examine the interaction of genetic and epigenetic/environmental risks in young children with developmental disabilities, including autism, and integrate services from all four research Cores; 2) Four Research Cores will facilitate interdisciplinary and translational research, including: an Administrative Core (AC) that provides leadership to ensure cost-effective and rigorous IDD research, while inspiring interdisciplinary collaboration and innovation; a Clinical Translational Core (CTC), which will apply basic science discoveries into clinical settings by streamlining patient recruitment and phenotyping, biobanking, and implementing clinical trials for the development of novel treatments that can be employed across the lifespan; a Developmental Genomic/Epigenetics Core (DGC), which will use RNA/exome/whole genome sequencing to uncover intrinsic genetic variation and the contributions of extrinsic (environmental and experiential) factors on epigenetic regulation, and the association of these with IDD; and a Neurocircuitry and Behavior Core (NBC), which will assess both animal and human neural circuit development and function, electrophysiology, and behavior; a 3) a Dissemination and Communication Plan that ensures Hawk-IDDRC research is effectively communicated to the scientific community, educators, policy makers, government officials, and the public, in an engaging and timely manner; and 4) an Educational Program, involving basic and clinical scientists, trainees, the public, and IDD-affected families, and will feature monthly seminars, mentoring of young and talented investigators focused on IDD research, and an educational program aimed at the lay public and IDD community. The Hawk-IDDRC will integrate and capitalize upon strong existing resources in the Hawkeye State: 1) the nationally renowned Center for Disabilities and Development; 2) the Iowa Neuroscience Institute; 3) Iowa’s University Center for Excellence in Developmental Disabilities (UCEDD), and 4) the Iowa Leadership Education in Neurodevelopmental Disabilities (LEND) program. The Center will foster strong existing collaborations between basic and clinical scientists, as well as the IDD community and their families, and support 73 federally funded projects ($28 million per year). The stable, non-transitory rural population in Iowa and an interconnected telehealth system uniquely position Hawk-IDDRC investigators to conduct longitudinal, multi-generational research, for which the University of Iowa is renowned. By providing the infrastructure to direct these outstanding resources, the Hawk-IDDRC will become a leading force in the study of IDD.

NIH Research Projects · FY 2025 · 2021-07

PROJECT SUMMARY Recently, we discovered that a small molecule inhibitor of acetyl CoA synthetase (ACS), AR-12, has broad spectrum fungicidal activity in vitro and promising activity in vivo. Consistent with this broad spectrum of activity, genetic studies indicate that ACS is essential for viability in multiple fungi (C. albicans, Fusarium, S. cerevisiae). In contrast, ACS is not essential in mammals. This is likely because, in mammals and plants, the vast majority of acetyl CoA is derived from ATP-citrate lyase (ACL) and not ACS. The most important exception to this rule is the cancer cell where ACS is the predominant source of acetyl CoA. Consequently, ACS has emerged as an anti-cancer target. Although the development of AR-12 stalled, we propose that its target, ACS, remains worthy of further exploration as the basis for a new class of antifungal drugs.To identify novel inhibitors of fungal ACSs, we have developed a multi-disciplinary approach based on: 1) two complementary small molecule screening strategies; 2) the structural characterization ACS-inhibitor complexes from multiple pathogenic fungi: 3) whole cell assays of ACS function and inhibition, and 4) medicinal chemistry strategies that have already yielded micromolar inhibitors of ACS. An STD-NMR screen with C. neoformans Acs1 and identified 492 ACS interacting molecular fragments, of which the vast majority also interacted with multiple fungal ACS enzymes. In Aim 1, we will further characterize these hits. As a parallel strategy, we adapted our ACS activity assay for high throughput screening (HTS) with the goal of directly identifying small molecule ACS inhibitors. Our chemistry plan (Aim 2) is guided, in part, by the hypothesis that molecules mimicking the acetyl adenosine-monophosphate ester (AcAMP) intermediate are likely to be effective inhibitors. In Aim 2A, we will characterize the acetyl-PO3 binding pocket by a structure-activity study of AcAMP mimics derived from molecules already crystallized in the active site of fungal ACSs. Biochemically stable, potent acetyl-PO3 isosteres emerging from this analysis will then be linked with putative ATP/AMP-binding pocket-targeted fragments to assemble candidate non-nucleoside, bi- substrate ACS inhibitors. To complement this hypothesis-based strategy, candidate inhibitors will also be assembled from other strongly interacting fragments and we will optimize inhibitors directly identified in the ACS activity-based HTS screen (Aims 2B&C). New molecules will be evaluated (Aim 3) with a testing funnel that includes biochemical characterization of ACS inhibition, antifungal activity against a range of pathogenic fungi, whole cell assays of on-target activity against ACS, and initial in vitro toxicity/ADME characterization. Our goal is to identify a lead ACS inhibitor scaffold along with a back-up series for further pre-clinical development as broad-spectrum antifungal drug candidates.

NIH Research Projects · FY 2025 · 2021-07

Many children who are hard of hearing (CHH) are identified and receive early intervention during infancy. Even with this early intervention, however, CHH are at risk for delays in language acquisition due to reduced auditory access. These challenges may have cascading effects on reading development because language plays a foundational role in reading. Much of the research on reading comprehension in children with hearing loss (HL) has focused on elementary-age children who are deaf or combined groups of CHH with children who are deaf. Because CHH have access to a qualitatively different auditory signal than children who are deaf, it is unclear if the significant delays we see with word reading and reading comprehension in children who are deaf apply to CHH in secondary grades. This lack of evidence hinders our understanding of the underlying processes that drive reading achievement in CHH, which in turn, limits the ability to develop scientifically based interventions and instruction. The current proposal is guided by the Simple View of Reading, which proposes that reading comprehension is the product of word reading and language comprehension. This proposal is also based on the Cumulative Auditory Experience model, which predicts that inconsistent auditory access in early childhood leads to reduced opportunities for language learning. Specifically, this proposal tests the hypothesis that auditory access (quantified by aided audibility and amount of hearing aid use) predicts reading comprehension growth rates in CHH, and this relationship is mediated by oral language. The current proposal will rectify some of the limitations of past research by leveraging our access to a large, well-characterized cohort of adolescents who are hard of hearing (AHH) and age-matched adolescents with normal hearing (ANH) who have been followed from preschool to 4th grade. We propose to prospectively test this cohort out to 12th grade. Our access to this cohort will allow us to conduct a rigorous longitudinal investigation of developmental trajectories in word-level decoding and text-level reading comprehension, as well as the underlying processes that drive these trajectories. We will also examine heterogeneity in sources of reading difficulty for AHH. Two aims are proposed: Aim 1. To establish developmental trajectories of reading in CHH and characterize the component reading skill profiles of AHH. We will evaluate these trajectories and profiles through a combination of retrospective (K-4th grade) and prospective (7th-12th grade) data. Aim 2. To specify the underlying processes that influence reading comprehension trajectories and outcomes in AHH and ANH. The data from this proposal will inform theoretical models of reading for children with HL, using robust and modern statistical approaches to examine reading comprehension. The proposed study will provide empirical evidence for the identification of unique component skills that support reading comprehension for young children and adolescents who are hard of hearing. This evidence will guide the development of differentiated instructional approaches and future intervention research designed to validate these scientifically based instructional approaches.

NIH Research Projects · FY 2025 · 2021-07

Project Summary The goal of this Mentored Patient-Oriented Research Career Development Award (K23) application is to support the additional training, mentorship and experience needed to develop a new methodology for analyzing the effects of repetitive brain stimulation using intracranial electroencephalography (iEEG) in humans. One form of repetitive brain stimulation is transcranial magnetic stimulation (TMS). TMS has revolutionized the field of therapeutics for neuropsychiatric disorders – it is a novel, noninvasive treatment option used most commonly for medication-refractory major depressive disorder. Despite this, remission rates from its use are suboptimal and ideal stimulation parameters are unknown. Suboptimal outcomes are due in large part to our poor understanding of TMS neurophysiology and antidepressant effects. TMS is thought to work by altering brain excitability within a network of targeted brain structures; for depression, this target is an emotional network including the dorsolateral prefrontal cortex. The ability of the brain to change excitability in response to repeated stimuli is referred to as plasticity. Noninvasive methods of measuring plasticity, such as scalp EEG and magnetic resonance imaging (MRI), are often imprecise and unreliable. This project proposes a novel method to invasively characterize brain plasticity induced by intracranial stimulation (Aim 1) or TMS (Aim 2) with exquisite spatiotemporal resolution. The method involves using iEEG single-pulse evoked potentials to probe and quantify excitability change (a correlate of plasticity) after repetitive stimulation in epilepsy patients. Network connectivity profiles will be analyzed with both iEEG and resting state MRI (Aim 3) to provide a unique bridge between invasive and noninvasive physiology measures. This project tests the hypothesis that repetitive brain stimulation (delivered via TMS and intracranial stimulation) will alter brain excitability in a parameter-dependent manner, and these effects will be most pronounced within the nodes of the stimulated brain network. A better understanding of how repetitive stimulation propagates through brain networks and alters brain excitability will revitalize the to-date fruitless search for reproducible biomarkers of target engagement and treatment response with these new technologies. Novel aspects of this study include the use of TMS in human subjects with iEEG, and the unique combination of both invasive and noninvasive connectivity measures (iEEG and MRI) to deeply characterize network effects of stimulation. Future directions will be 1) using this method to evaluate and refine novel brain stimulation protocols to optimize plasticity and therapeutic efficacy, and 2) applying learned principles about network effects of repetitive stimulation to inform clinical trial design and therapeutic use in other brain disorders, such as depression. The University of Iowa and this mentor team provide a rich research environment and world-class facilities for implementing this proposal. These K23 activities align with my long-term career goal of optimizing therapeutic brain stimulation to improve patient care.

NIH Research Projects · FY 2025 · 2021-07

PROJECT SUMMARY The University of Iowa Medical Scientist Training Program (MSTP) has successfully prepared students for careers as physician-scientists since its inception as an NIH-funded MSTP in 1977. The goal of the MSTP is to recruit, nurture, and graduate a well-rounded pool of well-trained physician-scientists with the technical, operational, and professional skills necessary to transition into successful careers in the biomedical research workforce. This goal is achieved through an integrated curriculum that assimilates scientific and clinical training, constantly emphasizing the intersections between science and medicine. Students complete 1.5 years of pre-clinical medical coursework, 4 to 5 years of graduate training, and approximately 1.5 years of clinical clerkships to fulfill the requirements for both the MD and PhD degrees. We have defined seven specific objectives for our graduating students, which are measured in our evidenced-based evaluation process. Upon completion of the MSTP, graduating students will be able to: 1) Combine the knowledge bases of science and medicine to establish a strong foundation; 2) Integrate critical thinking, reasoning and rigor in the conduct of research; 3) Demonstrate integrity in research and clinical practice; 4) Demonstrate skills in oral and written communication; 5) Acknowledge the value of a welcoming, fair, and inclusive environment.; Work effectively in a professional environment that includes people from various backgrounds, demonstrating respect for individual differences; 6) Demonstrate leadership in research and clinical care; and 7) Understand the wide range of career options available for physician scientists.. The U of Iowa MSTP is led by Co-PIs Steven Lentz, MD, PhD (Director) and Pamela Geyer, PhD (Co-Director) who share a long-standing passion for mentoring and training physician-scientists. The Program incorporates specific coursework and activities throughout the course of study to provide integration and enrichment of the curriculum and foster program identity, professionalism, teamwork, communication, career development skills, and mentorship of students during transitions. The Program has 87 talented and varied faculty members who provide exciting research training opportunities. Students are extensively involved in MSTP leadership, serving as members on the Executive, Admissions, MSTP Mondays, Seminar, Retreat, and Wellness committees. The Program enjoys strong institutional support from the Deans of the Carver College of Medicine and the Graduate College, who promote the MSTP as a driver for innovation in research, education and service at the university. The majority of our graduates have gone on to careers at major academic medical centers or research institutions. This application requests support for 18 trainees per year, reflecting the strength and outcomes of our training program.

NIH Research Projects · FY 2025 · 2021-07

Project Summary/Abstract Caries is a multifactorial disease that results from an imbalance between the microbiome and the host leading to demineralization of the dental hard tissues. After a lesion initiates in enamel, further tissue demineralization will lead to cavitation and involvement of the dentin. The etiology of caries attributes lesion progression to diet- and pH-dependent processes. However, enamel and dentin differ in terms of mineral content, structure and composition, and the degradation of the organic matrix of dentin seems to be a more complex mechanism than currently accepted. In vitro studies from the candidate’s research group and from others have shown in- creased presence and activity of endogenous proteases, such as matrix metalloproteases (MMPs), in caries dentin. Novel and important preliminary data suggest that while some MMPs may contribute for tissue degra- dation, specific MMPs might be important to favor reparative processes in dentin, even though tissue repair does not overcome degradation in advanced caries lesions. Fundamental questions remain concerning the regulatory mechanisms that drive MMPs expression and activation and how these mechanisms respond to bacterial infiltration as caries lesion advances. This proposal will address these issues by: (a) filling the gap in knowledge regarding the breadth of the contribution of specific MMPs to caries lesion progression; (b) defining the role of odontoblast-produced and dentin-released MMPs in caries; and (c) determining how the shift in the oral microbiome can modulate MMPs expression and/or activation as the lesion progresses. These studies will provide essential baseline information to facilitate the candidate’s long-term research goal, which is the devel- opment of new dental therapies based on modulation of MMPs activity in caries. The candidate aims to be- come an independent researcher to pursue the creation of novel therapeutic targets based on selective inhibi- tion of damaging endogenous mechanisms and promotion of repair mechanisms that would fundamentally change the way in which we manage and surgically treat dentin caries. This application for a K08 award will provide the candidate protected time and training to support her research goals and to ensure her career de- velopment. The candidate has assembled an outstanding group of mentor, co-mentors, collaborators, consult- ant, and advisors with expertise in microbiology, genomics, proteomics, and bioinformatics. This K08 award will facilitate the candidate’s career development by providing the structure and the guidance for expanding and acquiring: (1) advanced knowledge on dentin organic matrix composition and biochemical properties in health and caries disease, (2) experience with methodologies for the study of oral proteins and microorganisms in caries, including genomics and proteomics, (3) skills in leadership and scientific communication including writing, oral presentations and mentorship, and (4) the protected time and the resources to generate data and publications to support an R01 application by the end of the award period.

NIH Research Projects · FY 2025 · 2021-06

Project Summary/Abstract The diverse group Bacteroidales is a predominant component of human intestinal microbiota, linked to numerous disease processes. Manipulation of Bacteroidales at the genus and species level holds therapeutic potential, but requires a more detailed understanding of the intestinal ecosystem. Bacteroides spp. genomes encode polysaccharide utilization loci (PUL), allowing enzymatic breakdown, membrane transport, and utilization of complex carbohydrates. Bacteroides spp. antagonize one another within the intestinal environment by delivering toxic effectors via contact-dependent type VI secretion systems (T6SS), resulting in altered capacities for colonization and persistence. The central hypothesis of this proposal is that contact among Bacteroides spp. results in dynamic adaptive responses that alter cellular behavior and contribute to persistence in the intestinal environment. The proposed experiments will discover contact-dependent proteomic responses important for competition within Bacteroides communities using cutting-edge proteomics technology (Aim 1). Molecular mechanisms of two known contact-dependent responses, altered polysaccharide utilization (Aim 2) and T6SS- mediated delivery of hcp-effector fusions (Aim 3), will be elucidated and translated to competitive growth and intestinal colonization in a gnotobiotic mouse model. A long-term research goal is to understand mechanisms underlying interbacterial interactions among intestinal symbionts for the development of targeted therapeutics. The candidate for this career development award is an M.D./Ph.D. physician scientist with board certification in anatomic and clinical pathology. The research proposed in this grant application will be conducted under the mentorship of Dr. Joseph Mougous, Professor of Microbiology, and Dr. Matthew Yeh, Professor of Pathology. The candidate will join faculty in a department with ample clinical resources for development of specialized expertise in gastrointestinal pathology, established NIH-funded investigators and research infrastructure, and a track record of strong support for physician scientists. The candidate is committed to a career as a physician scientist and seeks further scientific training. Career development plans include participation in relevant local and national meetings, advanced didactics and workshops to gain expertise in commensal bacteriology, build research communication and grant writing skills, and develop leadership and management skills. This mentored clinical scientist development award will facilitate the candidate’s transition to become a competitive NIH-funded independent investigator.

NIH Research Projects · FY 2025 · 2021-06

Project Summary Clostridioides (Clostridium) difficile infections of the colon strike close to 500,000 people a year in the United States, leading to nearly 30,000 deaths. The CDC has declared this organism an “urgent” threat to public health, the highest threat category. C. difficile infections are difficult to treat in large part because the organism forms dormant spores that survive antibiotic therapy and seed recolonization of the gut when antibiotics are withdrawn. This problem is exacerbated by the fact that the antibiotics used against C. difficile also kill many of the healthy gut bacteria, clearing the way for C. difficile to recolonize when spores germinate. Thus, there is a tremendous need for new drugs that target C. difficile without disrupting the healthy microbiota. The premise of this proposal is that a deeper understanding of cell envelope biogenesis can pave the way towards developing better ways to treat C. difficile infections. The cell envelope is a well-validated target for antibiotics, and in C. difficile the envelope has some unusual features that suggest its assembly requires novel proteins that could be exploited as targets of C. difficile-selective antibiotics. In Aim 1 we will use genetics, biochemistry and microscopy to understand the roles and regulation of enzymes that crosslink the peptidoglycan cell wall. These enzymes captured our attention because in C. difficile the cell wall contains an unusually high percentage of “3-3” crosslinks as compared to the “4-3” crosslinks that predominate in most bacteria. Our experiments will address the following questions: Which enzymes are responsible for 3-3 and 4-3 crosslink formation and do they operate during division, elongation or both? How is the ratio of 3-3 to 4-3 crosslinking regulated? How does C. difficile benefit from using primarily 3-3 crosslinks? In Aim 2 we will leverage a powerful new gene-silencing tool called CRISPR interference (CRISPRi) to assign a set of ~50 putatively essential envelope biogenesis genes to more specific functional pathways. These genes are intrinsically interesting and constitute potential new antibiotic targets. We will also undertake a detailed analysis of a novel transcriptional regulatory system uncovered in a pilot version of our proposed screen. Collectively, the lines of investigation to be pursued here will greatly advance our understanding of C. difficile biology by identifying new proteins involved in assembly of the cell envelope and revealing how their activities are coordinated to accomplish the complex processes of growth and division.

NIH Research Projects · FY 2025 · 2021-06

Most spiral ganglion neurons (SGNs) make afferent synapses on the auditory sensory cells, the inner hair cells (IHCs), and convey auditory information to the brain. Noise damages cochlear afferent synapses even at sound levels too low to destroy hair cells. Noise-induced cochlear “synaptopathy” (NICS) is detectable by histological examination and counting of synapses and is also evident, noninvasively, as reduced auditory brainstem response (ABR) wave I amplitude. While synaptopathy does not detectably affect auditory thresholds, it may cause hearing impairments such as poorer speech-in-noise performance or tinnitus. In the course of investigating means to prevent NICS, we observed that female mice are significantly less susceptible than are males to NICS. Remarkably, female susceptibility varies with estrous cycle phase, with lowest susceptibility correlated with the estrous phase at which progesterone (P4) levels are highest (and estrogen lowest). In vitro experiments additionally show that a high level of P4 promotes rapid regeneration of synapses. These data showing sex differences in synaptopathy are the first to show that susceptibility varies through the estrous cycle and to show a protective role for P4. To follow up, our first aim is to determine whether a high level of steroid sex hormone does reduce NICS. To that end, we will experimentally manipulate levels of P4 and estrogen in male and female mice. We have further shown that, not only P4 but also the neurotrophic factor CNTF and agents that activate cyclic AMP (cAMP) signaling promote synaptic regeneration. The latter include compounds, such as rolipram, that can be administered systemically. P4, CNTF, and rolipram represent excellent reagents for investigating the role in vivo of cAMP in synapse regeneration and may also be candidate therapeutics for post-noise synapse regeneration therapy. However, cochlear synapses may lose their capacity for regeneration with time after damage and the timecourse may differ among the different agents promoting regeneration. Our second aim will determine how long after noise these agents, P4, CNTF, or cAMP, may be administered and still promote regeneration. Unlike the case for peptide neurotrophic factors, the molecular and cellular mechanism(s) by which progesterone or cAMP promote synapse regeneration remain obscure. Our third aim asks whether these factors function via genomic actions or via cytoplasmic targets or plasma membrane receptors – a necessary preliminary step for future detailed mechanistic studies of signaling pathways and possible transcriptome changes involved. For cAMP, the question is whether cAMP- dependent protein kinase enters the nucleus or remains a cytoplasmic signal, a question we successfully answered previously with respect to survival signaling. For progesterone, our preliminary studies suggest that a nuclear receptor is not involved so our focus will be on plasma membrane progesterone receptors.

NIH Research Projects · FY 2025 · 2021-06

NIH Research Projects · FY 2025 · 2021-05

Project Summary Pediatric chronic kidney disease (pCKD) is most commonly due to congenital anomalies of the kidney and urinary tract; thus, meaning a lifetime of disease. Children with even mild CKD are at risk for neurocognitive difficulties specific to attention regulation, academic underachievement, and executive function [1-3]. Neurocognitive deficits have broad implication on quality of life, as they contribute to poorer high school graduation rates and long-term underemployment in the adult CKD population [4]. The cognitive complications of pCKD are thought to represent sequelae of an aberrant “kidney-brain axis” whereby kidney impairment and associated disease sequelae may negatively impact the brain, leading to increased risk of cognitive impairment in the course of pCKD progression [5-7]. However, there is a critical gap in our understanding of the developing brain in the context of pCKD. Thus, the overarching goal of this proposal is to quantify structural and functional brain differences using MRI and cognitive/behavioral assessments in pCKD participants with mild to moderate (early) CKD compared to unaffected controls. To our knowledge, this proposal is the first in the world to quantitatively evaluate the brain in young children with early stage pCKD due to a focused disease etiology using magnetic resonance imaging (MRI). Preliminary data from our laboratory are striking and demonstrate robust structural brain differences (particularly within the cerebellum) in children with congenital, non-glomerular causes of CKD compared to healthy peers. There appears to be a direct relationship between decreased cerebellum volume and impaired kidney function. Furthermore, lower cerebellum gray matter volume appears to predict performance on neurocognitive tasks specific to executive function in children with CKD. Our pilot data demonstrate abnormal resting state connectivity in pCKD whereby children with CKD show hypo-connectivity between the cerebellum (dentate nucleus) and the frontal cortices. We will investigate a “dosage” effect of disease burden on neurodevelopment in children with mild/moderate CKD. Understanding the influence of pCKD progression and severity on the developing brain will allow enhanced awareness of the role of disease progression on neurodevelopmental outcomes in childhood and inform new approaches to patient care across the CKD lifespan.

NIH Research Projects · FY 2026 · 2021-05

Project Summary Under Cooperative Agreement UG4LM013729, the University of Iowa, Hardin Library for the Health Sciences serves as the Regional Medical Library (RML) for the National Library of Medicine. Region 6 covers Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin. It engages with more than 1,200 organizations comprised of health science, hospital, and public libraries, allied health providers, and community- and faith- based organizations in support of the National Library of Medicine (NLM) mission. 1

NIH Research Projects · FY 2025 · 2021-05

Project Summary / Abstract Neuroendocrine tumors (NETs) are incurable, clinically challenging malignancies that are rising in incidence. Although tumors grow slowly, they progress relentlessly and lack effective therapies once they become metastatic. Many patients with advanced NETs will die from their disease. Greater understanding of mechanisms driving NET progression and metastasis is needed to inform new therapies and improve patient outcomes. We discovered a RABL6A-PP2A pathway that promotes pancreatic NET (PNET) pathogenesis. RABL6A (RAB-like GTPase) is upregulated in patient PNETs and is required for PNET proliferation and survival. RABL6A acts through multiple mechanisms that are only partly defined, including inhibition of tumor suppressors (p27, RB1) and activation of oncogenic pathways (MYC, AKT-mTOR). A common regulator of all those factors is protein phosphatase 2A (PP2A), a powerful tumor suppressor whose role in NETs has not been explored. We found that RABL6A activates AKT-mTOR signaling in PNETs by inhibiting PP2A. In turn, RABL6A is down regulated by PP2A although the molecular mechanism by which these two proteins inhibit each other's function is unknown. Excitingly, specific `small molecule activators of PP2A' (called SMAPs) suppress PNET cell proliferation and survival in a RABL6A-dependent manner and abolish tumor growth in vivo. These findings support a novel strategy for PNET therapy involving PP2A reactivation. However, the role of RABL6A and PP2A in NET progression is only partly understood and their importance in NET metastasis is not known. This multi-PI study draws upon the collective knowledge of both PIs and their unique expertise / resources in NETs (Quelle) and PP2A (Narla) to test the central hypothesis that the RABL6A-PP2A pathway is a critical driver of NET progression and response to targeted therapies. Aim 1 will determine the mechanisms of RABL6A-PP2A reciprocal regulation. Aim 2 will define the roles and interdependence of RABL6A and PP2A in NET progression and metastasis. Aim 3 will establish the importance of the RABL6A- PP2A alterations in NET pathogenesis and the efficacy of pathway targeted combination therapies. This project will provide new insights into molecular events driving NET progression and metastasis while establishing the efficacy of promising NET therapeutics, thus addressing a critical gap in NET research that may ultimately improve patient outcomes. Moreover, this work builds upon an emerging strategy for anticancer therapy (i.e., pharmacological reactivation of PP2A), and may have broad cancer relevance beyond NETs given the importance of RABL6A overexpression and PP2A inactivation in other tumor types.