University Of Minnesota

NIH Research Projects · FY 2025 · 2023-09

Abstract The majority of Dementia with Lewy bodies (DLB) patients have a clinical syndrome of dream enactment that typically develops years before the onset of cognitive impairment. Under normal physiological conditions, rapid eye movement (REM) sleep is characterized by vivid dream mentation combined with skeletal muscle atonia. This REM paralysis is lost in REM sleep Behavior Disorder (RBD), resulting in patients who trash, punch and kick at night. RBD is a common condition affecting 80 million people worldwide and >5% of those older than 70. The presence of RBD is highly indicative of underlying neurodegeneration as nearly 75% will develop a neurodegenerative disorder in 12 years, most commonly DLB or other disorder of alpha-synuclein pathology such as Parkinson's disease (PD). Among patients with RBD approximately half have developed, or have had exacerbated, their dream enactment after starting a serotonergic antidepressant (usually a selective serotonin reuptake inhibitor-SSRI). This emergence of dream enactment after starting an SSRI, is termed serotonergic RBD (5-HT RBD) and was until recently assumed to be caused by a toxic effect on REM sleep circuitry. However, careful scrutiny of patients with 5-HT RBD reveals neurodegenerative findings suggestive of impending DLB, such as impaired color vision, mild cognitive impairment and subclinical motor deficits. These insights suggest that SSRI antidepressants do not induce RBD but instead unmask RBD in an individual who is already burdened by early alpha-synuclein pathology. However, this has not been proven, and it remains critical to understand whether 5-HT RBD is, as we suspect, an indicator of prodromal Lewy-body type pathology. This project will test the hypotheses that people with 5-HT RBD have systemic alpha-synuclein pathology, brainstem lesions in regions that control REM sleep, and prodromal DLB signs. AIM 1 will seek to detect abnormally phosphorylated alpha-synuclein aggregates on skin biopsy in a cohort of people with 5-HT RBD and matched controls (taking SSRIs but without RBD). Aim 2 will use ultra-high field MRI at 7T to examine the pontine region of the coeruleus/subcoeruleus complex for evidence of neurodegeneration as well as segment and parcellate REM sleep related neuronal structures. Aim 3 will test for prodromal deficits in speech consistent with Lewy body disease. While these Aims are independent we suspect that the severity of speech deficits will correlate with loss of neuromelanin signal on MRI and pathology on skin biopsy. These studies are important because confirming neurodegeneration in 5-HT RBD would be a breakthrough in understanding the natural history and progression of DLB pathology. Most importantly, by identifying an early prodromal syndrome and biomarkers of disease progression, this project will help speed up the development of therapies to impede or prevent the progression of Lewy body pathology.

NIH Research Projects · FY 2024 · 2023-09

Project Summary/Abstract: Despite global efforts to curtail emerging and reemerging pathogens, rationale vaccine design has failed to overcome devastating intractable diseases such as malaria, HIV, and tuberculosis. Memory T cells established after natural infection or vaccination contribute to protection against reinfection. Therefore, manipulating vaccine-elicited T cell immunosurveillance may provide protection against intracellular pathogens and might offer a strategy to bolster humoral-mediated vaccines. However, deep understanding of memory CD8 T cell migration will be critical to exploit T cells for next generation vaccine designs. For sixty years, we have understood that lymphocytes recirculate through blood and secondary lymphoid organs (SLO). However, memory T cells parked in the stromal and parenchymal compartments of barrier tissues, known as resident memory T cells (TRM), dominate nonlymphoid tissue (NLT) surveillance and contrast this paradigm. Although central memory T cells (TCM) migrate through blood and lymph, we and others have recently shown that SLO are also patrolled by nonrecirculating TRM ( SLO TRM), which may constitute a major reassessment of LN immunosurveillance. SLO TRM, are broadly distributed following systemic infections and may contribute a substantial fraction to the memory T cell pool in human LNs, but the roles of SLO TRM in immunity are unknown. Owing to their distinct migration properties, I hypothesize that SLO TRM play specialized roles in anamnestic immune responses compared to recirculating memory populations. Aim 1 will rigorously address the abundance and microanatomical localization of SLO TRM after diverse pathogen experiences and identify markers that reliably denote LN residence in ‘dirty’ mice. Aim 2 will test the hypothesis that SLO TRM are poised to migrate to their upstream NLT upon reactivation. And, Aim 3 will address the protective functions of SLO TRM upon reinfection. With implications for vaccine design and assessment, these studies will constitute some of the first investigations into SLO TRM biology. Most importantly, this proposal will serve as an ideal medium for predoctoral training. I will execute this fellowship at the University of Minnesota in the laboratory of David Masopust, Ph.D., a world-leader in the study of memory T cell immunosurveillance. With the combined support of the University’s Center for Immunology, the Microbiology, Immunology, and Cancer Biology Ph.D. program, and Dr. Masopust, I will receive personalized training to facilitate an efficient transition to the next stage of my research career. My long-term career goal is to obtain a faculty position at an academic research institution and direct innovative basic science with an emphasis in immunology.

NIH Research Projects · FY 2025 · 2023-09

Project Summary Sexual reproduction evolved more than one billion years ago, shortly after the appearance of eukaryotes. Sex is theorized to be an important aspect of creating genetic variation, adapting to new environments, and in removing disadvantageous traits from the gene pool. Despite this, many eukaryotes have reverted to asexual reproductive strategies. Importantly, such transitions to asexual reproduction have huge evolutionary impacts: we see regular examples of this in the rapid spread of invasive, pathogenic, and drug-resistant organisms. Unfortunately, such transitions are notoriously difficult to mechanistically interrogate due to their lack of experimental tractability and the fact that many reversions to asexuality are quite ancient. However, arthropods are rich in recently acquired vertically inherited microbes (e.g., Wolbachia, Rickettsia, and Cardinium) that convert their arthropod hosts to asexual reproduction. So-called “parthenogenesis induction” has been reinvented multiple times across these bacteria and relies on microbial mechanisms for impacting host meiosis or mitosis to alter ploidy. We can manipulate these recently asexual lineages in the lab to mechanistically define the cell biology of asexual reproduction. Furthermore, because there are numerous independent transitions to microbe-mediated asexuality, and lineages will slowly undergo a loss of sexual function, we can use this system to track the genomic and mechanistic consequences of lost sex. The long-term goal of my lab is to link mechanistic processes of mitosis, meiosis, and reproduction to long-term organismal and genomic consequences. This proposal describes my lab’s research goals across the next five years, which include: (1) mechanistically characterizing bacterial proteins mediating asexual reproduction, (2) identifying mitotic- and meiotic- effector proteins across diverse bacteria and reproductive biologies, and (3) using forward genetics to map the genomic consequences of lost sex. Specifically, our creative interdisciplinary research plan integrates genomic approaches (e.g., genome sequencing, comparative genomics, quantitative trait loci mapping), molecular approaches in non-model organisms, and genetics in tractable model systems (e.g., yeast, Drosophila). We will build on our recent discovery of the first putative asexuality inducing bacterial effector proteins to broadly define how microbes have evolved to manipulate mitosis and meiosis, and disentangle the causes of reproductive switches from the consequences. In addition to the broad significance of reproduction, these systems afford new opportunities to understand fundamental aspects of cell biology that underly many human-health relevant processes. For example, defects in mitosis are typical of certain degenerative conditions and cancers, and changes in ploidy significantly contribute to fungal pathogenesis and drug resistance. Our focus on novel mechanisms for altering reproduction and cell division will support the development of new therapeutic avenues across a range of systems.

NIH Research Projects · FY 2025 · 2023-09

Neuroscience research has the potential to impact wellness, learning, and mental health acceptance and care, as well as the treatment of neurological disorders for global populations. The application and impact of neuroscience innovation depends on multiple perspectives, diversity of thought, and cultural awareness. Specifically, recruiting, retaining, and training a diverse pool of highly skilled individuals in neuroscience is imperative for maximizing the impact of our research and education. However, the effort is compromised by existing race and ethnicity imbalances in the field. Despite many national efforts, underrepresented minorities (URM) experience barriers to participation in neuroscience research. In this proposed work, we will target middle school aged youth, as these years are a critical time in youth’s identity, self-concept, and accomplishment orientation formation processes, which will play a significant role in shaping their experience in community, school, work, and life. The primary goal of this proposal is to provide meaningful, reinforcing experiences and a supportive network for URM 6th-8th grade students as they explore potential opportunities in neuroscience. We will do this by integrating successful yet disparate single-organization practices into a unified and longitudinal statewide model. Our proposal incorporates and expands upon our team’s past success in (1) creating and delivering a novel neuroscience curriculum to be delivered statewide through Minnesota in a “Train-the-Trainer” model that will create a new generation of neuroscience educators, (2) creating and executing an immersive neuroscience summer camp for interested youth to help them begin to take steps toward aspiration achievement that include relying on supports, navigating barriers, and reimagining what is possible for them, and (3) developing a year-long mentorship program aimed at diversifying the field of neuroscience through underrepresented mentors connecting and forming long-term bonds with underrepresented students. For the first time, we will integrate three forms of engagement experiences into a single, cohesive ecosystem for participants to better understand potential synergistic benefits of multiple modes of engagement for students. We believe that these consistent and reinforcing experiences provide the next generation of underrepresented minorities, disadvantaged and/or disabled, and rural leaders a transformative opportunity for educational and research success in neuroscience fields.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY/ABSTRACT Hypertension (HTN) is one of the most important risk factors for cardiovascular disease. Nearly half of HTN patients are resistant or nonadherent to lifestyle modification and drug-based therapy, so novel therapies are desperately needed. While HTN is associated with increased global sympathetic nerve activity, renal efferent nerves have traditionally been the focus of research since they transmit sympathetic nerve impulses from the brain to regulate blood pressure. However, the kidneys are also innervated by renal afferent (sensory) nerves, which project to circuits in the brain that modulate sympathetic nerve output and cause HTN. Clinical trials using catheter-based total (efferent and afferent) renal nerve ablation (TRDN) have been shown to effectively lower arterial pressure in treatment-resistant HTN patients. Despite this intervention’s efficacy, it is unknown if ablation of the efferent or afferent renal nerves is more important in lowering arterial pressure. To elucidate the role that afferent renal nerves play in HTN, our laboratory developed a novel method of afferent renal nerve ablation (ARDN) and found that ARDN was as effective as TRDN in decreasing arterial pressure in the deoxycorticosterone acetate and high salt diet (DOCA-salt) induced HTN rodent model. Clinically, if ARDN can lower arterial pressure to the same degree as TRDN, efferent renal nerves could be preserved to maintain blood pressure and volume in response to hemorrhagic or septic shock. Furthermore, TRDN has shown variable efficacy in certain patients, and the lack of biomarkers to predict the arterial pressure response to TRDN is a major gap in the field. Recent studies from our lab suggest that the presence of specific inflammatory cytokines in the urine can identify renal inflammation. These cytokines can overstimulate afferent renal nerves and cause increased global sympathetic nerve output and HTN. I plan on translating our findings from DOCA-salt HTN rodents to the DOCA-salt HTN sheep model. The anatomic, physiologic, and hemodynamic properties of HTN sheep more closely resemble human pathophysiology and allows for the use of human TRDN catheters. Therefore, the overall goal of this proposal is to develop and validate a catheter-based ARDN method using the HTN sheep model to address current gaps in the field and move closer to a clinical therapeutic for hypertension. Our central hypothesis is that catheter-based ARDN will decrease arterial pressure to the same degree as TRDN, and the arterial pressure response to TRDN can be predicted by specific urinary markers of renal inflammation. I will test this hypothesis with the following aims: (1) Compare the efficacy of catheter-based ARDN versus TRDN in an established model of HTN in sheep. (2) Validate the utility of urinary biomarkers to measure renal inflammation associated with HTN to predict the anti-HTN efficacy of TRDN. If successful, the results of the proposed studies will provide a translational platform to subsequently move into clinical trials of catheter-based ARDN in humans. Furthermore, this catheter-based neuromodulation approach can also be applied to other organs (liver, spleen) in which chronic inflammation drives other neurogenically based diseases.

NIH Research Projects · FY 2024 · 2023-09

Project Abstract Postural instability and gait deficits are common causes of falls, decreased mobility, and increased morbidity in people with Parkinson's disease (PD). These axial motor signs are often resistant to current treatments, including dopamine replacement therapy (levodopa) and deep brain stimulation (DBS). Currently, the mechanisms contributing to the impaired control of the lower limbs are poorly understood. Extensor muscles of the lower limbs are critical for maintaining vertical support against gravity and generating power during gait. In people with PD, impairment in extensor muscle strength is greater than the flexors. Levodopa and subthalamic DBS (STN DBS) improve strength in both the flexors and extensors but have less of an effect in the extensors. Similarly, levodopa and STN DBS do not significantly improve plantar flexor torque generation during gait. Currently, the mechanisms contributing to greater defici ts in extensor compared to flexor muscle function in PD are unknown, but likely reflect differences in corticospinal, basal ganglia and brainstem contributions to the control of these muscles. This project aims to understand how flexors (tibialis anterior) and extensors (gastrocnemius, soleus) of the ankle contribute to leg rigidity and bradykinesia and gait in people with PD. Aim 1a will use transcranial magnetic stimulation of the leg region of the motor cortex to examine the excitability of corticomotoneuronal and intracortical pathways controlling the ankle flexors and extensors in PD, and controls. Aim 1b will examine the relationships between intracortical and corticomotoneuronal responses and quantitative measures of ankle bradykinesia and rigidity, and gait. Aim 2 will evaluate the response dynamics (60 minute wash-out, 60 minute wash-in) of globus pallidus DBS (GP DBS) on ankle rigidity, bradykinesia, and gait in PD to test the hypothesis that the acute and steady-state effects of GP DBS are different between the ankle flexors and extensors. Response dynamics across these behavioral measures will be examined in relation to the activation of neural pathways in and around the globus pallidus (estimated via patient-specific computational modeling of DBS) to determine which pathways are associated with which motor outcomes. The results of this project will provide an increased understanding of how PD and targeted TMS and GP DBS interventions impact the function of the ankle dorsi and plantar flexors. This knowledge will be important for the development and testing of novel interventions to treat postural and gait disorders and improve quality of life in people with PD.

NIH Research Projects · FY 2024 · 2023-09

Project Abstract: The highly complex OUD and overdose epidemic poses a huge public health and economic burden. Current FDA-approved pharmacotherapies against OUD and overdose use opioid receptor agonists and antagonists. These therapies show overall limited efficacy, due to their side effects, suboptimal patient access and compliance, and liability for abuse and diversion. Vaccines offer a new treatment option that is both alternative and complementary to existing measures. Preclinical testing demonstrated anti-opioids vaccines as a highly selective long-lasting treatment and prophylactic strategy that protects against opioid-induced antinociception, motor activity, respiratory depression, bradycardia, and self-administration in pre-clinical models. Previous clinical trials of addiction vaccines showed proof of efficacy in those subjects who achieved the highest antibody (Ab) titers, highlighting the need to design more effective vaccines and understanding the basis for variability in individual efficacy. Hence, this proposal focuses on developing next-generation nanoparticle-based anti-opioid vaccines and deciphering molecular and cellular mechanisms underlying their efficacy. Our team developed a novel lipid polymer hybrid nanoparticles (LPNP) platform, that enhanced the efficacy of conjugate vaccines against nicotine and oxycodone. Based on these preliminary data, we propose further dissecting the molecular basis of this increased efficacy and testing how nanovaccines composition, and adjuvant display determine innate and adaptive immune activation and whether specific cellular and molecular mechanisms underlie vaccine efficacy against OUD. AIM1 will test the effect of different polymers and adjuvant display methods on efficacy of nanovaccine against oxycodone. As well as how nanoformulation of conjugate vaccine affect the delivery and bioavailability of vaccine components. Studies will investigate vaccine efficacy in mice, IgG antibody titer and Ig subclass and vaccine kinetics in terms of biodistribution, accumulation and localization within spleen and lymph nodes. AIM2 will elucidate whether different nanovaccine formulations show distinctions in innate and adaptive immune responses. Studies will dissect innate immunity in vitro activation and in vivo dynamics in response to vaccination, addressing key cell subsets contributing to efficacy, as well as assess the magnitude of B cell responses. Results will provide a model vaccine that can be easily adapted to other abused substances. Such information will guide future vaccine design and the rational selection of the most appropriate formulation for a given antigen. The proposed mentored studies and this F31 fellowship are invaluable training and professional development opportunity as I strive to become an independent scientist. This hypothesis-driven multidisciplinary project encompasses various state-of-art approaches that are prerequisites to excel in translational research at the interface of immunology, pharmacology and substance abuse. The mentorship of NIDA-funded experts will ensure the successful completion of the proposed studies and the effective communication of research findings to the scientific community.

NIH Research Projects · FY 2025 · 2023-09

Abstract Leukemia is the most common childhood cancer and represents approximately one third of all cancer diagnoses among children age 0-14. There is strong evidence that acute lymphoblastic leukemia (ALL), the most common type of leukemia in children, is initiated in utero. The ETV6/RUNX1 gene fusion, which is considered an early initiating event in the development of ALL, is present at birth in some children who later develop ALL. Children born with these leukemia-specific translocation in blood cells have pre-leukemia, and there is a need to define the epidemiology of pre-leukemia and identify the factors that contribute to pre-leukemia persistence and progression to ALL. We have developed a robust new method for detection of ETV6/RUNX1 pre-leukemia which uses newborn blood spots. We propose to use this method to: 1) examine the newborn blood spots of 500 children who later developed leukemia and from 3000 healthy children who did not develop leukemia to identify the determinants of pre-leukemia at birth; 2) estimate the risk of childhood ALL given pre-leukemia at birth; and 3) evaluate how long pre-leukemia persists in childhood using both newborn blood spots and, from the same cohort of children, blood samples collected over time within early childhood. Together, these goals will allow us to determine how many children with ALL are born with the leukemia gene fusion; what factors predict pre- leukemia at birth; how many children who never develop leukemia are born with the gene fusion; and how long the gene fusion persists in childhood. Establishing the true population prevalence and determinants of ETV6/RUNX1 gene fusion at birth is an essential first step in reducing the burden of childhood ALL. Further, this project will be the first of its kind to monitor the persistence of pre-leukemia in early childhood. The proposal is an exceptional opportunity to understand childhood pre-leukemia, is robust in design using three independent studies, and leverages existing NIH investment in pediatric epidemiology. Successful completion of the project will foster epidemiologic innovation including cohort studies of infants at high risk for ALL, allowing us to fill significant gaps in our understanding of the most common childhood cancer. Importantly, the work has the potential to translate into clinical monitoring of ALL in high-risk populations.

NIH Research Projects · FY 2025 · 2023-09

Project Summary/Abstract Tobacco and alcohol are the most commonly used substances of abuse, resulting in heavy personal and public health costs. The ability to identify risk prior to substance initiation has important potential to inform prevention efforts and tailor more effective treatments through precision medicine approaches. Continuing technological progress and reduced costs of genotyping have resulted in very large sample sizes in genetic association studies, findings of which have allowed for the prediction of individual genetic risk, through polygenic risk scores. These results have ignited interest in the use of polygenic scores to inform personalized prevention efforts, population-level screening, and as statistical controls or genetic instruments within research. The incorporation of polygenic scores in clinical and research settings shows promise, however there are several limitations to their current use including modest predictive accuracy and limited portability across populations. The proposed research will leverage a trans-ancestry genome-wide association study of tobacco and alcohol use in 3.4 million individuals, combined with ~2.5 million additional participants with microarray, exome, or whole-genome sequencing data to improve polygenic prediction of substance use behaviors and to maximize predictive accuracy of such scores across individuals of diverse genetic ancestries. There are two major research aims: 1) to pool large cohorts of diverse ancestry genetic studies that include information on common and rare genetic variation, and gene expression, to improve genomic risk prediction for substance use, and 2) evaluate and correct for the sources of reduced cross-ancestry portability of polygenic scores in order to increase their utility with higher predictive accuracy across all genetic ancestries. To accomplish these research aims and to achieve the goal of an independent research career, this proposal includes new mentored training in 1) advanced and functional genomics, 2) advanced statistic and population genetics, 3) ethical, legal, and social implications (ELSI) of genetic research. This proposal directly aligns with NIDA’s goals to identify the genetic mechanisms that influence substance use and to use this research to address health disparities. The candidate will receive extensive mentorship and guidance with a team of leading experts in the fields of addiction, genetics, and bioethics. The training and support provided by this award will facilitate the candidate’s long-term career goal as an independent research scientist, building on her background in quantitative psychology, drug addiction, and behavioral genetics. The proposed research, coupled with the candidate’s research potential, has the ability to greatly expand the personal, clinical, and research utility of genomic prediction and to refine our understanding of the genetic architecture of substance use.

NIH Research Projects · FY 2025 · 2023-09

The Neurovascular unit (NVU) comprises of cells in the brain vasculature (endothelial cells and pericytes) working in coordination with parenchymal cells (neurons and astrocytes) to maintain brain homeostasis and cognitive function. Intricate functional interactions among NVU cells, referred to as neurovascular coupling, is progressively impaired and NVU composition is severely disrupted in Alzheimer’s disease. However, the underlying pathophysiological mechanisms are poorly understood due to paucity of molecular level information on the less abundant, yet functionally critical, cerebrovascular endothelial cells and pericytes. The fMRI imaging, widely used in the clinic to evaluate neurovascular coupling, may not inform molecular level changes. It is challenging to identify changes in NVU composition using standard histopathological methods, because they lack sensitivity and specificity to locate endothelial cells and pericytes in the brain tissue. Bulk RNA sequencing from postmortem Alzheimer's brain tissue can be used to investigate NVU components, but it measures gene expression averaged across all cells, thus making it difficult to define cell-specific pathways and NVU constituent interactions. Single-cell methods and linear deconvolution techniques are currently employed to analyze bulk RNA sequencing data to determine cell-type-specific gene expression patterns. However, these techniques struggle to capture the molecular signature of low-abundant cells like endothelial and pericytes. The objective of the current study is to develop deep-learning methods to accurately predict the composition and transcriptomic signature of NVU cells, and to map interactions among them. Our central hypothesis is that data-driven deep-learning models, which have the flexibility to capture underlying gene-gene and cell-cell interactions in the brain tissue, will predict the composition and transcriptomic signature of NVU cells more effectively than the conventional methods. In Aim 1, we will design NUGENT, a novel deep-learning framework, to identify cell-type composition and predict cell-type-specific gene expression patterns. In Aim 2, we will validate NUGENT using new scRNA-seq data of NVU constituent cells harvested from Alzheimer’s disease transgenic mice (APPswe/PSEN1dE9) and their non-transgenic littermates. Employing the data generated in Aim 2 and publicly available patient and mouse data on the NUGENT framework, in Aim 3 we will investigate molecular pathways regulating neurovascular coupling in cognitively normal and Alzheimer’s patients. It is highly likely that the proposed studies will help identify molecular determinants of neurovascular dysfunction underlying age-related cognitive decline and Alzheimer’s dementia and facilitate the discovery of novel biomarkers and therapeutic targets.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY Associating stimuli in the environment to biologically relevant outcomes, such as reward or threat, is necessary to survive and foundational to decision making. Given the prevalence of disordered decision making, there is a pressing need to understand the basic neurobiological mechanisms of associative learning underlying cue-guided motivation and behavior. The Ventral Tegmental Area (VTA) is essential to this behavioral process through its two main neuronal subtypes: dopamine (DA) and GABA. GABA neurons synapse directly onto local DA neurons and modulate DA transmission. DA neurons increase activity to cue-reward associations, modulating firing based on the extent to which reward predicted matches reward expected in a phenomenon known as reward prediction error (RPE). GABA neurons also increase activity in reward learning and their signaling contributes to RPE DA dynamics. In contrast, DA neurons are inhibited in aversive contexts while GABA neurons increase activity. Given VTA GABA’s role in both appetitive and aversive processing, these neurons may be uniquely engaged to integrate valence in decision making. Understanding the role of these neurons in multi-valent learning is important, because behavior often takes place in situations of motivational conflict, where opposing goals (i.e., consuming food and avoiding threats) occur simultaneously, requiring the appetitive and aversive elements to be weighed and integrated to guide choices. This proposal will make use of new tools to target, record, and manipulate VTA DA and GABA neurons, to investigate their functional connectivity (Aim 1) and their roles in valence integration (Aim 2). First, I will optogenetically inhibit GABA neurons while recording the activity of VTA DA neurons through in vivo fiber photometry. These experiments will test the hypothesis that the VTA GABA modulates local DA neurons and this relationship can change with experience. I will also manipulate and record DA and GABA dynamics during a motivational conflict task in which there are two opposing goals (consuming sucrose and avoiding shock) to dissect the roles these populations play in valence integration. These studies will test the hypothesis that VTA DA and GABA neurons produce value and salience signals, respectively, that are collectively necessary to integrate valence, for dynamic reward seeking.

NIH Research Projects · FY 2024 · 2023-09

Abstract The majority of Dementia with Lewy bodies (DLB) patients have a clinical syndrome of dream enactment that typically develops years before the onset of cognitive impairment. Under normal physiological conditions, rapid eye movement (REM) sleep is characterized by vivid dream mentation combined with skeletal muscle atonia. This REM paralysis is lost in REM sleep Behavior Disorder (RBD), resulting in patients who trash, punch and kick at night. RBD is a common condition affecting 80 million people worldwide and >5% of those older than 70. The presence of RBD is highly indicative of underlying neurodegeneration as nearly 75% will develop a neurodegenerative disorder in 12 years, most commonly DLB or other disorder of alpha-synuclein pathology such as Parkinson's disease (PD). Among patients with RBD approximately half have developed, or have had exacerbated, their dream enactment after starting a serotonergic antidepressant (usually a selective serotonin reuptake inhibitor-SSRI). This emergence of dream enactment after starting an SSRI, is termed serotonergic RBD (5-HT RBD) and was until recently assumed to be caused by a toxic effect on REM sleep circuitry. However, careful scrutiny of patients with 5-HT RBD reveals neurodegenerative findings suggestive of impending DLB, such as impaired color vision, mild cognitive impairment and subclinical motor deficits. These insights suggest that SSRI antidepressants do not induce RBD but instead unmask RBD in an individual who is already burdened by early alpha-synuclein pathology. However, this has not been proven, and it remains critical to understand whether 5-HT RBD is, as we suspect, an indicator of prodromal Lewy-body type pathology. This project will test the hypotheses that people with 5-HT RBD have systemic alpha-synuclein pathology, brainstem lesions in regions that control REM sleep, and prodromal DLB signs. AIM 1 will seek to detect abnormally phosphorylated alpha-synuclein aggregates on skin biopsy in a cohort of people with 5-HT RBD and matched controls (taking SSRIs but without RBD). Aim 2 will use ultra-high field MRI at 7T to examine the pontine region of the coeruleus/subcoeruleus complex for evidence of neurodegeneration as well as segment and parcellate REM sleep related neuronal structures. Aim 3 will test for prodromal deficits in speech consistent with Lewy body disease. While these Aims are independent we suspect that the severity of speech deficits will correlate with loss of neuromelanin signal on MRI and pathology on skin biopsy. These studies are important because confirming neurodegeneration in 5-HT RBD would be a breakthrough in understanding the natural history and progression of DLB pathology. Most importantly, by identifying an early prodromal syndrome and biomarkers of disease progression, this project will help speed up the development of therapies to impede or prevent the progression of Lewy body pathology.

NIH Research Projects · FY 2025 · 2023-09

ABSTRACT Stressful life events in childhood, including physical and sexual abuse, may have detrimental effects on adult health. Physical and sexual abuse is associated with a 40% increase in the risk of adult obesity; childhood abuse is also associated with pre-pregnancy weight though it is unclear whether abuse influences excessive weight gain during pregnancy. Phthalates, a group of environmental toxins commonly found in plastics and ultra-processed foods, have been associated with gestational weight gain. Phthalates are known to have obesogenic effects and could act through consumption of a poor diet (e.g., ultra-processed foods), which may also be associated with early-life abuse. In fact, those who had a history of physical violence in childhood were 44% more likely to have been exposed to ultra-processed foods. In our own previous work, we found that higher ultra-processed food diets were associated with 13.1% higher molar sum concentrations of di(2-ethylhexyl) phthalate metabolites. Despite the evidence that childhood abuse is associated with pre-pregnancy obesity, there have been mixed findings among the few studies that have examined whether childhood abuse is associated with excess gestational weight gain, and no data on whether phthalate levels are a modifying factor in the association. Therefore, our scientific aims are 1) to determine the association between childhood abuse and gestational weight gain and sequelae (i.e. large-for-gestational age newborns, childhood obesity, and cardiometabolic disorders in childhood); and 2) to assess whether high phthalate level measured during pregnancy shows effect modification in these associations. We hypothesize that phthalate exposure modifies the association so that pregnant women with both a history of childhood abuse and high phthalate exposure, possibly through unwholesome dietary patterns, have the highest risk of gaining too much weight during pregnancy thus conferring a harmful intergenerational effect on her child. Our operational aim will use the exceptional performance of our research team to enroll and retain a total of 780 pregnant women and their offspring into the ECHO Cohort, as well as enrolling their partners into the preconception cohort. We will employ a novel recruitment methodology that transcends healthcare systems across the Minneapolis/St. Paul metropolitan area. Upon enrollment into the ECHO Cohort, our study team will coordinate effortless biospecimen collection. This unprecedented collaboration of healthcare systems will leverage our previous success within the ECHO Cohort and provide valuable data to improve the health of American children.

NIH Research Projects · FY 2026 · 2023-09

PROJECT SUMMARY/ABSTRACT: This project will utilize stakeholder networks composed of members of the American public to co-create evidence-based solutions and ethical guidance to expand participation in human neuroimaging studies more broadly. AIM 1: A stakeholder network will co-develop a targeted, public-led and participant-centered set of deliverables to broaden participation in neuroimaging research. Utilizing a Theory of Change (ToC) process and a detailed roadmap and evaluation plan (Outcome Map) already established in pilot work, we will develop recruitment strategies for research with the BRAIN Initiative supported Connectome 2.0 project. AIM 2: In Aim 2 we will create consensus ethical guidance and proposed data elements for measuring and reporting demographics in neuroscience research, utilizing local public and WG input, systematic analysis of the literature, and comparison to closely related domains such as genetics. We will create applied tools: a) a decision-aid for neuroimaging researchers to recruit broadly from local communities and to solicit regular feedback from the public; b) an educational tool for local communities; and c) a template for neuroscience journal editors on publication guidelines for reporting of population descriptors that better reflects the United States.

NIH Research Projects · FY 2025 · 2023-09

PROJECT SUMMARY/ABSTRACT: Emergency general surgery (EGS) - accounting for 11% of US hospital admissions; over 50% of operative mortality; the highest risk, acuity, rate of complications, and cost in general surgery - particularly the subset of emergency laparotomy (EL) patients which suffer the worst EGS outcomes - is increasingly recognized as a public health crisis. While enhanced recovery programs (ERPs) have dramatically advanced pre-, intra-, and inpatient postoperative evidenced-based best practices (EBPs), ERPs have largely ignored subsequent postoperative home-based recovery. Despite certain postoperative complications occurring commonly after discharge (notably over 40% of surgical site infections [SSI]), recovery for surgical patients once discharged to home remains understudied and ripe for improvement and innovation, especially as surgical care models increasingly shift greater proportions of postoperative recovery into the home-based setting. Digital solutions for remote monitoring, patient engagement/education, and surgical prediction show promise but are used minimally for surgical recovery. We hypothesize that well-designed technology solutions for EL home- and transition-based workflows engaging diverse stakeholders will empower EL patients, their caregivers, and care teams to achieve optimal outcomes and safe recovery. The goal of REST-PSLL (Re-engineering Surgical Recovery and Transitions Using Technology Patient Safety Learning Laboratory) is to apply systems engineering approaches to co-produce innovative and scalable patient- and care team-centric solutions for EL home-based recovery. REST-PSLL has the following specific aims. Aim 1: Identify barriers and facilitators to ideal at-home recovery for patients following EL. We will engage stakeholders using the Systems Engineering for Patient Safety (SEIPS) model to identify and evaluate factors to understand barriers and facilitators of optimal care and postoperative complications with a focus on SSI. Aim 2: Iteratively design and develop new processes, tools, and technologies that help remove or reduce barriers to ideal at-home recovery. We will use swimlane diagrams to then analyze for areas of improvement to generate initial design requirements and prototypes for tools/technologies followed by iterative user-centered design to specify design requirements, develop solutions, and conduct end-user testing at our clinical sites. Aim 3: Implement and evaluate solutions in practice. Perform pilot testing and implementation, assess primary (addressing or avoiding trigger/potential issue, solution us) and secondary outcomes guided by RE-AIM framework; evaluate implementation phases guided by EPIS implementation framework to generate implementation learnings and solution revision plan(s). REST-PSLL is poised to be highly successful and impactful, highlighted by: a) anticipated learnings that can be extrapolated to other surgical populations; b) use of transdisciplinary complementary systems expertise and approaches; c) deep clinical expertise; d) patient- and caregiver- co-production; and e) expanding or optimizing existing solutions/platforms.

NIH Research Projects · FY 2024 · 2023-09

Project Summary Schizophrenia is a psychiatric disorder that affects approximately 24 million people worldwide and can lead to emotional distress, disability, and reduced lifespan. Cognitive dysfunction is the best predictor of patient outcome in schizophrenia, yet current pharmacological treatments often fail to treat cognitive symptoms such as working memory deficits. In addition, it is not yet understood how certain biological abnormalities associated with schizophrenia – for example, decreased cortical expression of N-methyl-D-aspartate (NMDA) receptors – lead to changes in brain circuit function, especially when these abnormalities progress over the course of the lifespan and may be affected by in vivo compensatory mechanisms in the brain. My proposed research seeks to investigate the effects of chronic NMDA receptor loss upon synaptic function and architecture in the prefrontal cortex, and its potential implications for neural network activity and working memory deficits. Specifically, this computational psychiatry project will focus on examining functional and structural abnormalities at excitatory-to- excitatory synapses, which produce the reverberant neural activity that allows information to be retained in working memory and are particularly vulnerable to disconnection in schizophrenia. I will measure functional changes in excitatory-to-excitatory synaptic strength using ex vivo slice electrophysiology in prefrontal cortex pyramidal neurons, and I will examine structural changes in dendritic spine morphology and density in the same neurons using confocal imaging. I will then leverage insights gained from these electrophysiology and imaging experiments to build and test predictions regarding stability and synchrony of brain activity in a spiking network model.

NIH Research Projects · FY 2026 · 2023-09

PROJECT SUMMARY/ABSTRACT The biological process heretofore implicated in MERTK loss-of-function-associated Retinitis Pigmentosa (RP) is defective phagocytosis of shed photoreceptor outer segments (POS) by retinal pigment epithelium (RPE) leading to photoreceptor (PR) degeneration. Here we propose a shift in this paradigm. We have demonstrated that the precise genetic ablation of Mertk in mice (Mertk -/- V2) results in deficient phagocytosis, but not PR degeneration. Furthermore, PR degeneration in the original Mertk knockout (Mertk -/- V1 that is hypomorphic from Tyro3) or Mertk -/- V2 Tyro3 -/- V2 mice is associated with RPE inflammation. Therefore, we hypothesize that loss of MERTK anti- inflammatory signaling in the RPE is a critical event leading to RP. To test this hypothesis, we propose to (i) conditionally ablate Mertk in Tyro3 -/- RPE to test if this recapitulates RPE inflammation seen in germline Mertk - /- V1 and Mertk -/- V2 Tyro3 -/- V2 mice. An alternate possibility, RPE inflammation when Mertk is conditionally ablated in Tyro3 -/- RPE notwithstanding, is that inflammation is a secondary consequence of loss of MERTK-mediated phagocytosis and the consequent build-up of POS debris. We do not see POS build up even at 6 months in Mertk -/- V2 or Mertk -/- V3 mice. We also detect RPE inflammation before eye opening (at p10) and thus inflammation in the absence of MERTK is likely primary. To directly test this, (ii) we have generated a unique set of mouse models wherein either the phagocytosis or anti-inflammatory signaling function of MERTK has been exclusively mutated, leaving the remaining function intact. These mouse models will allow us to definitively test the outcome of loss of MERTK-mediated phagocytosis alone in PR degeneration, as well as uncouple the effects of loss of MERTK anti-inflammatory signaling alone from that of loss of MERTK-mediated phagocytosis. Complementing these studies, we will test the orthologous mutations in differentiated human primary RPE in terms of their effect on inducing RPE inflammation in presence or absence of POS. If inflammation underlies the etiology of MERTK loss-of-function-associated RP, can it be therapeutically targeted to protect against vision loss? (iii) We have obtained promising preliminary data that the FDA-approved JAK1/2 inhibitor ruxolitinib reduces inflammatory gene expression in the Mertk -/- V1 RPE and the severity of PR degeneration in Mertk -/- V1 mice. Building on this proof-of-concept, we will optimize the ruxolitinib regimen (dose and duration of treatment) through dose- escalation studies to determine maximum protection against PR degeneration and vision loss. Taken together, these three independent, orthogonal approaches are expected to reveal mechanistic insight supporting a novel role of inflammation within the RPE itself as causally relevant to MERTK loss-of-function-associated RP, as well as, provide a therapeutic avenue using small molecule JAK1/2 inhibitors (“Jakinibs”) already in clinical use for this severe, early-onset form of RP.

NIH Research Projects · FY 2024 · 2023-08

Project Summary/Abstract Central to the development of medicine is organic chemistry and catalysis as it has permitted the discovery of new reactions and methods for the synthesis of key pharmaceutical components that will play a critical role in continuing the advancement of modern medicine. With the high presence of nitrogen atoms in drug candidates due to their high biological activity, it is crucial to develop new and innovative methods to synthesize and functionalize nitrogen-containing molecules. Recently, reactive titanium intermediates were used to explore second insertions of unsaturated species yielding useful nitrogen heterocycles. This proposal will focus on developing an efficient and one-step atom- economical Ti-catalyzed multicomponent, cascading hydroaminoalkylation reaction to produce β- cycloalkyl amines from dienes and amine/aniline substrates. This methodology has potential to be a valuable synthetic tool because β-cycloalkyl amines products are scaffolds present in pharmaceutical compounds such as cyclopentamine and propylhexedrine and in M3 muscarinic antagonist. Additionally, this method will provide a fundamental understanding of this new reaction class that can be extended into other cascading reactions to rapidly build molecule complexity.

NIH Research Projects · FY 2025 · 2023-08

Project Summary The human RNA-binding proteins, PUM1 and PUM2, are essential for mammalian development and their dysfunction is linked to multiple human diseases including developmental defects, neurological disorders, infertility, cancers, and mitochondrial dysfunction. These important functions compel our overall objective to discover how PUM1&2 control the flow of genetic information from gene to mRNA to protein and to identify the full repertoire of genes that they regulate. PUM1&2 bind to thousands of mRNAs in human cells by recognizing an RNA sequence called the Pumilio Response Element (PRE). Previous research showed that PUM1&2 promote degradation of hundreds of these PRE-containing mRNAs by recruiting RNA decay enzymes. It is now clear, however, that this mechanism represents only one type of PUM-mediated regulatory outcome. Thousands of mRNAs are bound by PUM1&2 but are not degraded. Therefore, it is now necessary to determine how PUM1&2 control the fate of all target mRNAs. The resulting data will provide a comprehensive view of their regulatory roles in biology and pathogenesis. We propose that human PUM1&2 repress many target mRNAs by inhibiting the process of translation. This hypothesis is supported by multiple examples of genes that are repressed by PUM1&2 at the level of protein abundance in the absence of mRNA degradation. The mechanism and prevalence of this translational inhibition is unknown. In addition, our data indicate that for some genes PUM-mediated translational inhibition can synergize with RNA degradation to regulate gene expression to a larger extent than either process alone. RNA molecules form structures that influence their function and fate. While biochemical evidence indicates that RNA structure can modulate PUM-PRE interactions, its effect in vivo remains unknown. In fact, there is an overall lack of RNA structural information of mRNAs in human cells that limits our understanding of how that structure influences gene regulation by RNA-binding proteins like PUM1&2. The proposed research seeks to determine how PUM1&2 inhibit translation and to identify the translational regulatory factors that are necessary for PUM1&2 activity. The structure of human mRNAs will be determined and its effect on PUM-mRNA interactions and regulatory network will be analyzed. By integrating this new data with existing knowledge of which mRNAs are bound and degraded by PUM1&2, we will develop a comprehensive understanding of this key genetic regulatory network. Discovery of the full regulatory network of PUM1&2 will provide new insights into how they control gene expression to regulate normal biological processes. Moreover, this knowledge will help elucidate how their dysfunction leads to diseases such as neurodegeneration and cancer.

NIH Research Projects · FY 2025 · 2023-08

Project Summary/Abstract Severe obesity in children is a highly prevalent, serious and chronic disease that directly leads to severe obesity in adults and the subsequent enormous social and financial burden on society. Lifestyle therapy is the cornerstone of pediatric obesity treatment, but this intervention when used alone is often insufficient for achieving clinically significant and durable BMI reduction. Adjunct anti-obesity medications may improve outcomes of this disease, but the pharmacological options used for obesity in children are extremely limited. Thus there is an urgency to identify anti-obesity medications for use in the pediatric population, which are safe, effective, easily administered and affordable. Psychostimulants, the second most commonly prescribed class of medications in children, have a long-standing safety profile and because of their favorable effect on weight, may serve as a useful adjunct to lifestyle therapy for the treatment of severe obesity in this population. Thus, the goal of this pilot and feasibility clinical trial is to estimate the treatment effect of a common psychostimulant, lisdexamfetamine, for the treatment of severe obesity in children. Specifically, 44 children ages 6 to <12 years with severe obesity (BMI ≥120% of the 95th percentile) will be randomized, 1:1, to lisdexamfetamine plus lifestyle therapy or placebo plus lifestyle therapy for 24 weeks of treatment. The primary outcome of the main aim will be change in BMI, and secondary outcomes will include changes in body composition, cardiometabolic health, and quality of life. The second aim will be to identify participant tolerability of the recommended starting dose of lisdexamfetamine and the emergence of clinically significant increases in blood pressure and heart rate. Potential mechanisms by which lisdexamfetamine reduces BMI will also be explored including changes in executive functioning, reward processing, appetite, resting energy expenditure, and health behaviors (diet, eating behaviors, and physical activity). The results of this pivotal pilot trial will directly inform the conduct of the larger, fully powered, definitive study, which ultimately, by identifying a safe, effective and scalable treatment, will improve the outcomes of the millions of children affected by this serious, chronic disease.

NIH Research Projects · FY 2026 · 2023-08

Project Summary Following weight loss, the new lower body weight is extremely difficult to maintain. Many studies have now shown this is because individuals who lose a significant amount of body weight typically have an “Energy Expenditure Gap” (EEgap) post-weight loss, defined operationally as total energy expenditure (TEE) in the pre-obese state, minus TEE in the post-weight loss state, when at the same body weight. Recent studies suggest that the EEgap may be caused in part by compensatory and enduring reductions in basal energy expenditure (BEE) resulting from increases in activity-induced energy expenditure (AEE). Therefore, someone who has lost significant weight has to consume less and expend more energy to stay weight-stable compared to weight-matched individuals who have never been overweight. Physical activity ranges from a subconscious drive to move (spontaneous physical activity, SPA) to voluntary, structured, goal-oriented and high-intensity physical activity (programmed exercise). Increasing EE through physical activity, in combination with caloric restriction is a common therapeutic approach for weight loss, but most individuals do not adhere to physical exercise programs or maintain sufficient intensity to compensate for reductions in TEE post weight-loss. Our lab is one of few to study CNS regulation of SPA and have focused on the hypothalamic neuropeptide orexin A (OXA), which plays a central role in promoting wakefulness and energy homeostasis. We found that OXA injection and/or orexin neuron activation reverses BEE reductions and increases NEAT and TEE in animal models, without compensatory increases in food intake. Our collaborator Dr. Zhang is on the forefront of developing new small molecular orexin agonists that activate both orexin 1(OX1R) and orexin 2 (OX2R) receptors, and one such OX agonist upon i.p. administration robustly enhances SPA without changing food intake in middle aged mice and 5-mo old obesity prone (OP) rats. In addition, chronic (5wk) administration of the agonist reduced adiposity and weight gain in the New Zealand Obese (NZO) mice, supporting orexin agonists as a potential therapy to prevent weight relapse post weight-loss. The goal of the current project is to test the effects of these orexin agonists in reducing the EEgap, following weight-loss in rodent models of obesity, and to understand if the underlying mechanism involves alterations in mitochondrial respiration. We will also test the effect of these agonists on sleep/wake patterns for side effects. To do this, we will use indirect calorimetry in conjunction with behavioral analyses and peripheral administration of orexin agonist(s), to determine if activation of the orexin system suppresses weight regain. The long-term goal of this project is to enable research and development in using orexin as a therapy for obesity, weight regain and associated comorbidities.

NIH Research Projects · FY 2025 · 2023-08

Project Summary/Abstract Bacterial expression of cell surface-associated adhesin proteins facilitates the formation of biofilms. Dental plaque is a polymicrobial biofilm of the human mouth that contributes to oral infectious diseases. Formation of this dental biofilm is initiated by pioneer colonization, whereby Streptococcus species use adhesin proteins to attach to the saliva-coated tooth surface. Among the many adhesins expressed by Streptococci, the antigen type I/II (AgI/II) adhesin family is widely conserved and has been shown to mediate interactions with several host molecules and other oral microbes. This proposal uses Streptococcus gordonii as a model to investigate the role of AgI/II adhesins in host surface attachment and biofilm development. S. gordonii is an oral commensal that expresses two AgI/II adhesins: SspA and SspB (SspA/B). Evidence shows that SspA/B is necessary for attachment to salivary mucin 5B (MUC5B)-coated surfaces. Proposed experiments will investigate binding between SspA/B proteins and MUC5B glycans. The variable (V) regions of SspA and SspB are expected to differentially bind the O-glycans decorating the MUC5B peptide backbone, contributing to initial attachment. SspA/B expression decreases, however, as the biofilm matures, suggesting that transcriptional regulation of sspA/B is complex. Data suggests that after initial surface attachment, protein acetylation regulates sspAB expression via the two-component system BfrAB. Therefore, genetic approaches are proposed to investigate the role of protein acetylation in sspA/B gene transcription. Overall, these studies will show that S. gordonii AgI/II adhesins mediate binding to MUC5B and are transcriptionally regulated by acetylation of the BfrB sensor kinase. Findings may be broadly applicable to streptococcal AgI/II adhesins and may suggest new mechanisms to control microbial community development in health and in streptococcal disease.

NIH Research Projects · FY 2025 · 2023-08

Screening tools for autism spectrum disorder (ASD) show poor predictive performance in practice, particularly for females, which may arise due to sex-related measurement bias of screening questionnaires, and lack of precision in capturing the variability in early symptom profiles of ASD. Computational approaches to characterize heterogeneity and assess and account for sex-related measurement bias in early ASD symptoms may identify ASD risk profiles that can be clinically actionable in practice. The candidate's long-term goals are to enhance goals quality of life for children with ASD and their families by lowering the age of diagnosis, especially in females missed by traditional screening methods. The research and training described in this K23 application will build on the candidate's existing expertise, adding conceptual and methodological skills needed to develop and implement a novel screening approach that will more precisely identify ASD risk in a community-based sample. Aim 1 evaluates the extent of sex-based measurement bias in measures shown to capture clinically-relevant variability in early ASD traits in a sample of 3,000 children between 17-25 months recruited from a community research registry. Aim 2 applies computational approaches to model dimensional variability in early ASD symptoms and identify subgroups of risk in the same sample that are hypothesized to vary on clinical outcomes at 36 months. Aim 3 takes a dissemination and implementation (D&I) science lens to assess parent and provider views on screening practices to identify facilitators and barriers to change via qualitative interviews (Pediatrician N=20; Parent N=40). This project is in line with NIMH Strategic Plan Goal 2 to “examining mental illness trajectories across the lifespan.” The candidate is a clinical psychologist and Assistant Professor at the University of Minnesota, with expertise in characterizing sex differences in early ASD trajectories. The proposed K23 application will provide the candidate with the training needed to develop new knowledge and skills in conducting community-based screening for ASD, computational modeling of heterogeneity, and dissemination and implementation science. Mentors Dr. Damien Fair, Jed Elison, and Timothy Beebe possess the expertise and mentoring skills to support these training and scientific aims. This will position the candidate to build an independent clinical-translational research program focused on improving the precision of early screening for ASD to enable precision medicine for early ASD concerns that are equitable by sex. Training will occur in an exceptional scientific environment in the Department of Pediatrics at the University of Minnesota and the newly established Masonic Institute of the Developing Brain.

NIH Research Projects · FY 2024 · 2023-08

Project Summary/Abstract Approximately 30% of all bacterial gene products are microbial “dark matter” and have no characterized function. Developing methods for describing gene function in commensal and pathogenic bacteria will advance the fields of fundamental bacteriology and microbial pathogenesis, driving new approaches to combat the rise of antibiotic resistance. The short-term training goal of this proposal is to provide the candidate with mentoring and training in computational biology and data science. The long-term objectives are to establish robust computational and genetic tools for functional analysis of uncharacterized bacterial genes. These will be applied to established, tractable experimental systems to make mechanistic discoveries about uncharacterized loci involved in biofilm formation and polymicrobial interactions. For career development, the candidate will undertake a comprehensive training plan with an outstanding mentor, co-mentor, and advisory committee. Aim 1 will use chemical genetics to identify hypothetical gene function in the commensal and pathogenic bacterium Enterococcus faecalis OG1RF. In Aim 2, the candidate will develop chemical genetics methodology to determine how pre-formed biofilms respond after treatment with bioactive compounds such as antibiotics. In Aim 3, these functional genomics approaches will be expanded to study interactions between OG1RF and the oral pathogen Streptococcus mutans, as the candidate determined that S. mutans kills OG1RF and a vancomycin-resistant isolate of E. faecalis through an unknown mechanism. Together, this research will generate genome-scale descriptions of gene function in medically relevant bacteria and define mechanisms by which novel factors contribute to biofilm formation and interactions between microbes. The University of Minnesota provides an ideal institutional environment for this work. This highly collaborative environment has diverse microbiology and computational biology research groups from biomedical, dental, veterinary, and basic science backgrounds. U Minnesota also offers exceptional career development opportunities, and the U Minnesota Genomics Center is a state-of-the-art facility with which the candidate has already established a productive collaboration. Together, the proposed training and research will be a platform from which the candidate will launch an independent research career combining functional genomics with in vitro model systems to study hypothetical gene function in diverse bacteria.

NIH Research Projects · FY 2025 · 2023-08

ABSTRACT: The recent FDA approval of 7T for clinical imaging of the knee, opens the possibility that this ultrahigh field MRI platform will become a more prominent tool in biomedical research and patient management. Musculoskeletal (MSK) research and diagnostic imaging have been traditionally performed at magnetic fields of 1.5 and 3T. While there is increasing availability of ultrahigh field (UHF) 7T instruments and FDA approval of 7T clinical use in the head and knee, only a fraction of the system’s true capability is being exploited. First, approval has only been given for operation in a single transmit mode configuration. As such, clinicians cannot take advantage of the available parallel transmit (pTx) functionality to integrate state-of-the-art solutions for tackling B1+ homogeneity and local SAR management. Even if available, the RF coils and optimization routines to use the pTx functionality do not exist. Second, traditional diagnostic imaging methods for evaluating the knee do not fully exploit the array of morphologic, compositional, and functional data available when performing MRI at UHF. Both the traditional and novel imaging approaches alike benefit from the increased signal-to-noise ratio at 7T. The increased sensitivity can be exploited to provide higher resolution images that are known to have a real and significant impact on diagnostic accuracy in the knee. Furthermore, certain methods are simply too compromised at lower field strengths to be obtained as part of routine imaging at 3T and below including techniques like quantitative sodium imaging and perfusion as measured through arterial spin labeling. In this proposal we focus on the engineering, methodological and protocol developments to realize the full potential of 7T knee imaging and provide a critical translational study focusing on the utility of the methods to impact clinical care. This work will be accomplished by completing four specific aims. Aim 1 will focus on the development, integration, and optimization of a pTx RF coil coil using ultrahigh dielectric constant (uHDC) material and RF management strategies to provide high-resolution morphological knee imaging methods including zero echo time imaging. Aim 2 will implement and optimizequantitative compositional and functional methods for evaluating the knee joint at 7T including T1rho andarterial spin labeling (ASL) perfusion methods. Aim 3 will involve the development and optimization of a sodium (23Na) knee coil using uHDC material and strategies for accurate quantification of 23Na concentration in the articular cartilage of the knee. Finally, the translational Aim 4, will involve a pilot study to explore the ability of the developed technologies and methods to impact patientcare. The technical developments in this proposal will advance knee imaging at 7T and likely accelerate its clinical adoption. The results of the pilot study are expected to have an immediate and important impact,by forming the basis of future longitudinal prospective studies evaluating the effects of medical treatmentson clinical outcome.