Mayo Clinic Rochester

NIH Research Projects · FY 2026 · 2017-09

PROJECT SUMMARY / ABSTRACT Cognitive Aging and risk of Alzheimer's disease, and Alzheimer's related dementias (AD/ADRD) is due to multiple aging and pathological processes that are driven by several upstream brain mechanisms and risk factors. The success of recent multi-domain interventions and our preliminary data suggests that multiple mechanisms need to be targeted for effective dementia prevention. In 2018, we proposed a simplistic conceptual framework that builds on existing concepts using the nomenclature of resistance in the context of avoiding AD pathology and resilience in the context of coping with AD pathology for investigating these distinct mechanisms. This proposal addresses an important barrier for developing effective therapeutic or preventive strategies for AD dementia - the poor understanding of how upstream risk factors and brain mechanisms (resistance and resilience) that could contribute to or protect from protein accumulation and neurodegeneration. Our central hypothesis is that identifying upstream brain mechanisms of resistance and resilience and modeling the complex inter-relationships between protective factors, brain mechanisms, and longitudinal changes in amyloid, tau, and cognition will aid in effective design of dementia prevention strategies. To test this hypothesis, our primary aim is to identify mechanisms of resistance and resilience using the existing infrastructure of the population-based Mayo Clinic Study of Aging (MCSA) (individuals aged ≥50 years) and Rochester Epidemiology Project (REP) which maintains a comprehensive medical records-linkage system. We will collect the following variables for this proposal: Genetics, Social Determinants of Health (SDoH), and systemic health (up to 20 years prior to scan from REP), longitudinal PiB and tau PET, baseline cutting edge MRI (high resolution T1/T2/FLAIR and multi-shell diffusion MRI to assess perivascular spaces, microstructural integrity, and cortical thickness), and cognitive decline. Our secondary aim is to develop and validate MRI- based resilience markers that can be used in the NIA-AA research framework alongside with AT(N) biomarkers to adjust for individual variability in cognition. Considering brain health measures (other than those included in the evaluation of N) as resilience markers will improve the prediction of cognitive decline across all aging and dementia studies. These measures will be able to capture biological variability due to SDoH and systemic health and facilitate better comparison of biomarkers across populations.

NIH Research Projects · FY 2025 · 2017-09

PROJECT SUMMARY/ABSTRACT Irritable bowel syndrome (IBS) is a globally prevalent disorder (~11%) characterized by an alteration in stool form/frequency in association with abdominal discomfort or pain. IBS is categorized into constipation, diarrhea or mixed (IBS-C, IBD-D, IBS-M) based on the predominant stool form/frequency. The pathophysiology of IBS is complex and therapeutic options targeting the underlying pathophysiology in IBS are limited. Recent studies support a role for gut microbial metabolites in maintaining normal gastrointestinal (GI) function, but how changes in different microbial metabolites and interactions among these metabolites affect molecular pathways involved in IBS pathophysiology remains a critical knowledge gap. Hence, it is not surprising that the current empirically designed microbial therapies (probiotics) have largely proven ineffective in IBS. To address this gap, in the previous grant cycle we focused on the bacterial metabolite tryptamine and found tryptamine increases secretion and mucus release in a 5- HT4R dependent manner, accelerates transit, and protects against inflammation in rodent models. The observations were supported by our finding of elevated levels of tryptamine in IBS-D in our human study. In the same longitudinal multi-omics human study, the most consistent finding in IBS-C across multiple -omics platforms were significant decreases in stool hypoxanthine and butyrate. The overall objective of this proposal is to determine the physiologic relevance of these metabolites by identifying the molecular pathways affected by each of these metabolites that are relevant to IBS-C. Our central hypothesis based on prior research and our preliminary data is that hypoxanthine is an effector metabolite that accelerates GI transit by increasing enterochromaffin (EC) cell serotonin release while butyrate is a regulatory metabolite that augments the biologic activity of effector metabolites. This will be tested in two Aims: In Aim 1, we will determine the mechanism by which hypoxanthine increases EC cell serotonin release and accelerates GI transit and in Aim 2, we will determine the mechanism by which butyrate regulates EC cell responses to effector metabolites and the resultant effects on GI function. We will use Ca2+ imaging in organoids/primary EC cell culture from novel transgenic mice, heterologous receptor expression with site- directed mutagenesis, and epigenomic and transcriptomics data, combined with ex vivo colon preparations, gnotobiotic- and EC cell-depleted mouse models, isogenic bacterial mutants, and novel encapsulation methods to address the above aims. Our findings will uncover specific pathways by which these microbial metabolites affect GI transit and allow development of novel mechanism-based microbial therapies for IBS-C.

NIH Research Projects · FY 2026 · 2017-08

PROJECT SUMMARY Progressive apraxia of speech (PAOS) is a devastating neurodegenerative syndrome that ultimately shortens lifespan and is most commonly due to an Alzheimer’s disease related disorders (ADRD) four-repeat tauopathy. Nine years ago, we described two distinct subtypes of PAOS: phonetic PAOS characterized predominantly by articulatory distortions and prosodic PAOS characterized predominantly by slow speech rate and abnormal prosody. In the 1st cycle we demonstrated that speech, language, and neurological features differ across PAOS subtypes which helped to validate these subtypes as being distinct. We performed cross-sectional analyses including voxel-based morphometry of structural MRI, diffusion tensor imaging and 18F- fluorodeoxyglucose PET (FDG-PET) and found evidence for greater cortical involvement in phonetic PAOS. Leveraging autopsy data, we also demonstrated that the PAOS subtypes are associated with specific 4-repeat tauopathies (phonetic with corticobasal degeneration and prosodic with PSP) and have neuronal loss in distinct cortico-striatal and pallido-nigro-luysial-cerebellar regions. However, there are still many gaps in knowledge. Little is known about progression, and whether longitudinal rates of clinical progression differ in PAOS subtypes, whether anatomic and metabolic rates differ and can be detected with advanced neuroimaging techniques, and whether genetic and histopathologic features of iron, Alzheimer disease neuropathologic changes or other co-pathologies play any role in PAOS subtypes. In the 2nd cycle we will proceed in new directions to address these knowledge gaps and limitations using data collected from 120 PAOS patients including 47 patients from the 1st cycle. In Aim 1, we will determine whether rates of decline in speech and other communication features, including acoustic characteristics derived from a novel rate modulation task, or time to the development of clinical outcomes, are associated with subtype. This aim will be critical to aid diagnosis and prognostication of disease progression. In Aim 2, we will determine whether advanced and novel neuroimaging techniques can detect regional longitudinal differences and whether imaging differences correlate with differences in clinical change over time, across PAOS subtypes. We will analyze structural MRI, FDG-PET and quantitative susceptibility mapping (QSM) to assess volume, metabolism, and iron deposition. This aim will improve understanding of how differential involvement of these regions relate to PAOS subtypes and provide specific neuroimaging biomarkers for diagnosis and disease tracking which is also important for clinical trials. In Aim 3, we will determine the relationship between tau- and Alzheimer disease related genetic risk alleles, regional iron burden, Alzheimer disease neuropathologic changes, and other co-pathologies, and PAOS subtype. Results from this aim will improve our understanding of the neurobiology of PAOS subtype. Achieving the aims of the 2nd cycle will have significant clinical relevance to every speech-language pathologist and neurologist who diagnose and care for patients with speech and language disorders.

NIH Research Projects · FY 2026 · 2017-07

ABSTRACT The most severe clinical complication of Plasmodium falciparum infection is cerebral malaria (CM) which has high morbidity despite treatment. Disruption of the blood-brain barrier (BBB), extensive edema, and brain swelling are associated with fatal human CM. Given the above observations in human CM, the mechanism of BBB disruption and vascular permeability needs to be defined. Plasmodium berghei ANKA (PbA) infection of mice is an established model of human CM. Considerable CNS pathology associated with PbA infection is driven by an acute CD8 T cell response which induces disruption of BBB tight junction proteins and CNS vascular permeability. Our laboratory developed an additional inducible model of CD8 T cell mediated BBB disruption which is initiated through administration of antigenic peptide. This Peptide Induced Fatal Syndrome (PIFS) model shares many similarities to lethal PbA infection in that CD8 T cells use perforin and engage brain vasculature to induce BBB disruption Importantly, we report that CD8 T resident memory (TRM) cells can induce BBB disruption, long after clearance of viral pathogen. We also demonstrate these CD8 TRM can be induced to mediate BBB disruption repeatedly, in multiple insults, at time points months apart. This discovery provides a unique opportunity to study the effects of CD8 TRM cells on brain vascular health and neuropathology in chronic phases of neurologic disease. Both PbA infection and the PIFS model employ a common pathway in which antigen-specific CD8 T cells engage endothelial cells of brain vasculature to promote BBB disruption. This was determined using our novel MHC class I conditional knockout mice generated by my research program. Our central hypothesis is CD8 T resident memory (TRM) cells directly engage brain vasculature in an MHC class I molecule restricted manner, initiating broad immune cell infiltration and BBB disruption. We will test this hypothesis through execution of the following aims: Specific Aim #1 – Identify the anatomical location of antigen-specific acute and memory CD8 T cell activation during onset of BBB disruption Specific Aim #2 – Determine the impact of T cell engagement of endothelial cell expressed MHC class I and MHC class II molecules on immune cell recruitment to brain parenchyma Specific Aim #3 – Define the neuropathological impact of repeated insult by CD8 TRM cell mediated BBB disruption The proposed work is innovative because it capitalizes on our unique transgenic mouse models, collaborations, novel imaging methodology, and core facilities available to our research program at Mayo Clinic. Our goal is to define mechanistically the contribution of inflammation to BBB disruption in neurologic disease using established models. Beyond the innovative methodology employed, the concept that antigen presentation by brain vasculature causes BBB disruption in acute and chronic phases of CNS disease has implications for the role of acute and memory CD8 T cells in complex human neurological conditions in general.

NIH Research Projects · FY 2025 · 2017-04

Alzheimer’s Disease (AD) has no effective treatments, and recent clinical trials focused on preventing of amy- loid beta (Aβ) production have consistently failed. Alternative approaches are urgently needed. We identified mitochondrial complex I (MCI) as a small molecule druggable target for AD. Partial inhibition of MCI induced multifaceted adaptive stress response activating neuroprotective mechanisms in multiple familial mouse mod- els of AD. Chronic treatment with MCI inhibitors was efficacious after the onset of cognitive dysfunction, reduc- ing inflammation, oxidative stress, Aβ and pTau, leading to improved synaptic function, brain energetics, and cognitive performance, ultimately blocking the ongoing neurodegeneration. Translational potential was sup- ported by cross-validation of the mouse data with the human transcriptomic data from the NIH AMP-AD data- base, demonstrating that pathways improved by the treatment in AD mice, including the immune system re- sponse and neurotransmission, represent mechanisms essential for therapeutic efficacy in AD patients. While mounting data suggest that the induction of mild energetic stress via MCI inhibition could promote longevity, increase health span, and delay the onset of age-related neurodegenerative disease, including AD, the mecha- nistic understanding of what makes targeting of MCI with small molecules safe is lacking. It is also remains to be determined whether this treatment could be beneficial in patients with late onset AD (LOAD), the most prev- alent form of the disease. The objective of this competitive renewal is to conduct structure-activity relationship studies using isolated mam- malian MCI, and array of biochemistry and cell biology techniques, reporter cells and human neurons, and a library of novel and established MCI inhibitors to determine what factors, including the site of MCI inhibition, binding affinity, levels and sites of ROS production, and the structure of small molecules ensure safety of MCI inhibition and the induction of a neuroprotective signaling. We will next validate efficacy of novel MCI inhibitor developed and patented in the lab in 3D co-cultures of neurons/astrocytes/microglia derived from the iPSCs of LOAD male and female patients. Finally, therapeutic efficacy and molecular mechanisms will be confirmed in APOE4 Knock In mouse model of LOAD. Cross-validation of multi-omics data with the existing human metabolic, epigenetic and transcriptomic databases will determine specific mechanisms reversed by the treatment in male and female LOAD patients, supporting translational value of this innovative therapeutic approach. Novel infor- mation delineating MCI as a small molecule druggable therapeutic target generated using isolated mammalian MCI, and advanced techniques, including cryo-EM, could significantly advance the field of drug discovery for AD and other diseases. Mechanistic studies using human and animal models of LOAD could provide novel evidence for the cell-specific role mitochondrial adaptive stress response plays in neuroprotection. Translational bi- omarkers of therapeutic efficacy could aid in the design of future clinical trials.

NIH Research Projects · FY 2025 · 2016-12

PROJECT SUMMARY Mayo Clinic Chemical Center (MCC) is funded to perform targeted metabolites and exosome cargo measurements in samples collected in the Clinical Centers of MoTrPAC. As advised by the steering committee, we have expended a substantial amount of time developing an innovative methodology to isolate plasma exosomes and demonstrated reproducibility in multiple experiments, at different time points and by different laboratories. We propose exosome-based proteome and miRNA analysis in a limited number of samples. Based on power calculations, we estimated that the proposed number of samples will detect significant changes in exosome proteome and miRNA responses to aerobic and resistance exercise training. We will also test a hypothesis that proteome and miRNA release after acute exercise will be different in people who are highly active in comparison with sedentary people, because the prior exercise training accretes specific exercise-induced proteins in tissues that will be released during and immediately after both modes of exercise. These measurements will be done in 140 sedentary people and 110 highly active people and will likely offer unique new information. In addition, 55 sedentary people will be evaluated at baseline and following 3 months each of aerobic and resistance training with 30 sedentary controls studied after a 3-month control period. Secondly, in alignment with metabolomic measurements done at other centers, we will perform measurement of two quantitative targeted metabolites-amino metabolites and organic acids in plasma and skeletal muscle. These targeted metabolites are chosen based on their biological relevance to exercise training, and the quantitative and reproducible data anticipated from our assays would complement large scale metabolites measured in other Chemical Centers. The targeted metabolome measurement will also offer an opportunity to potentially understand the biochemical pathways involved in exercise benefits. We chose muscle and plasma measurements of organic acids representing the substrates of the citric acid flux pathway and amino metabolites which, based on many preliminary studies, are shown to sensitively respond to exercise with distinct responses to aerobic and resistance exercise. Both targeted metabolites in muscle and plasma as well as exosome-based measurements of proteome and miRNA are anticipated to reveal novel information on how specific exercise programs may benefit physiological functions. We anticipate that the results from our study in combination with the ongoing multiple omic measurements in all chemical centers will likely unravel deeper insights on how exercise benefits multiple organs. Our objective is to advance the translational potential of exosome cargo by administering biological molecules offering exercise benefits via small vesicles like exosomes to multiple organs in the body. The metabolites, especially targeted metabolites, are likely biomarkers to monitor responses to the administered vesicles carrying potentially beneficial molecules.

NIH Research Projects · FY 2025 · 2016-09

PROJECT ABSTRACT. My long term career objective is to define the mechanisms of liver inflammation in nonalcoholic steatohepatitis (NASH), the most-prevalent chronic liver disease in the United States of America. NASH is characterized by endoplasmic reticulum (ER) stress, which results in release of proinflammatory extracellular vesicles (EVs) from lipid overloaded (lipotoxic) hepatocytes. The contribution of recruited monocyte-derived macrophages (MDMs) to the intrahepatic macrophage (IHM) pool increases in NASH and the recruited MDMs play a pivotal role in inflammation. The current proposal examines the mechanistic link between hepatocyte-derived EVs and specific MDM subsets. In preliminary studies we have identified that activation of the lipotoxic ER stress activated endoribonuclease, inositol requiring enzyme 1 alpha (IRE1α) and its target transcription factor X-box binding protein 1 (XBP1), upregulates the expression of S100A11. This upregulation of S100A11 is associated with activating, histone 3 lysine 27, acetylation in the enhancer region of S100A11. Lipotoxic hepatocytes release S100A11 containing EVs (S100A11-EVs). S100A11-EVs activate macrophage receptor for advanced glycation endproducts (RAGE) signaling. Hepatocellular expression of S100A11 and MDM expression of RAGE are upregulated in NASH. Silencing S100A11 decreases MDM- associated hepatic inflammation in NASH. Based on these original preliminary data, we have formulated the CENTRAL HYPOTHESIS that lipotoxic hepatocytes release S100A11-EVs which activate a subset of proinflammatory RAGE expressing IHMs promoting NASH pathogenesis. Therefore, the goals of this proposal are to understand: i) how S100A11-EVs are released by hepatocytes; ii) how RAGE is activated by lipotoxic EVs in a subset of macrophages; and iii) can hepatic inflammation be attenuated by inhibiting S100A11-EV-RAGE signaling? The proposed experiments will employ complementary in vitro and in vivo models of lipotoxicity and NASH, and pharmacological, molecular and genetic approaches to address three integrated hypotheses. First we will directly test the hypothesis that lipotoxic hepatocytes release S100A11- EVs a) by XBP1 driven transcriptional upregulation of S100A11 by binding to and recruiting histone acetylating factors to an enhancer region, and b) by selective cargo sorting of S100A11 into lipotoxic EVs. Second we will directly test the hypothesis that RAGE is activated in a subset of macrophages by lipotoxic EVs a) by generating multivalent signal competent RAGE oligomers, and b) leads to the accumulation of a subset of proinflammatory RAGE expressing macrophages in the liver. Third we will directly test the hypothesis that interrupting S100A11-EV induced RAGE activation attenuates murine NASH a) by reducing the release of S100A11-EVs, and b) when macrophage RAGE is deleted. This R01 grant application will yield mechanistic insights into hepatocyte-to-macrophage crosstalk in NASH, thus identifying potentially druggable targets, e.g., inhibitors of S100A11 or RAGE.

NIH Research Projects · FY 2025 · 2016-07

Pancreatic ductal adenocarcinoma (PDAC) is typically detected at late stage due to absence of a cancer screening strategy, with concomitant poor survival rates. Detection of PDAC at an early stage positively impacts survival, and currently screening in eligible high-risk individuals (HRIs) defined by family history and germline mutation status is considered best practice. The overall goal of this proposal is to use knowledge gained during the last grant period to considerably enhance our ability to develop and validate the diagnostic performance of new blood protein and methylated DNA (MDM) biomarkers for early detection of PDAC, using prospective specimen collection and retrospective blinded evaluation (PRoBE) compliant methods. We hypothesize that a combination of proteins, MDMs, and CA19-9 will accurately identify early stage PDAC in HRIs. We will assess the performance characteristics of our approaches in early stage and pre-diagnostic phase of PDAC and identify approaches that are optimized for clinical translation as an early detection tool using HRIs. For over two decades, Mayo Clinic’s prospective biospecimen resources have accrued, using standardized high-quality procedures, well-annotated biospecimens from thousands of PDAC patients including those with germline mutations in pancreas cancer susceptibility genes, high risk members in familial pancreatic cancer kindreds, patients with high-risk pancreatic conditions, and healthy controls. We have also launched the PCDC Signature Protocols at our center. Among those at risk with biospecimens who we have followed longitudinally over two decades, incident PDAC cases have developed, enabling us to utilize novel approaches to address the challenges and better design PRoBE phase 3 studies. Based on our findings in the last grant period, we now focus on tailoring samples for PRoBE phase 2 studies and characterizing performance to improve phase 3 studies. Our approach will allow us to assess, for example, variability in biomarker expression for intended use HRI settings, and temporality of biomarker expression to improve the ability to detect early onset PDAC. Our Specific Aims are to: 1) Accrue formal biospecimen sets from blood sample products and pancreatic cyst fluid suitable for PCDC biomarker studies; 2) Leverage our past knowledge and experience to develop new biomarker panels using tailored phase 2 designs and incorporating covariates to refine detection (age, sex, race, smoking, personal history of diabetes mellitus, symptoms at diagnosis) to optimize detection; and 3) Evaluate needed performance parameters that will inform the design of a successful phase 3 study for PDAC in a surveillance setting of HRIs. Our multidisciplinary team is committed to continue its leadership and contribution to the PCDC organization to advance the early detection of pancreatic cancer. Our project leverages existing infrastructures and biospecimen banks of pancreatic cancer and other pancreatic diseases at Mayo Clinic and University of Pennsylvania, and it will extend new prospective collections of blood and pancreatic cyst fluid from patients, contributing to PCDC Signature Protocol cohorts and a PCDC central biorepository.

NIH Research Projects · FY 2024 · 2016-06

Enter the text here that is the new abstract information for your application. This section must be no longer than 30 lines of text. The goal of the Precision Medicine Initiative (PMI) Cohort Program is to enroll one million volunteers into a national cohort that broadly represents the U.S. population and accelerate progress toward a new era of precision medicine on a larger scale than previously possible. The objective of this proposal is to utilize the full resources available through the Mayo Clinic Biorepositories Program and Mayo Medical Laboratories to efficiently and cost effectively support the activities of the PMI Cohort Program with respect to the Biobank, namely, biospecimen collection, kit assembly, biospecimen accessioning, tracking, processing, quality assurance, storage, and distribution. Mayo Medical Laboratories, the third largest reference laboratory in the United States, will enable efficient specimen transportation, routing, and information management between PMI collection sites and the Mayo Clinic Biobank. The aims of this proposal are to: (1) To provide collection kits and leverage existing sample shipment logistics to ensure specimens arrive at Mayo Clinic Rochester in the most expedient, efficient, and safe manner possible, in accordance with all federal and state regulations; (2) Scale up existing state-of-the-art laboratory automation and robotics to process, label, and store biospecimens, using established protocols compliant with laboratory best practices for all steps of specimen handling; (3) Use our high-quality, robust, and secure research laboratory information management system (RLIMS) for detailed tracking of sample receipt, processing, storage, retrieval, and distribution, while protecting participant confidentiality; (4) Apply our comprehensive Quality Management Program to ensure all work carried out is of the highest quality, and safeguard the collection with robust back-up systems and plans for disaster recovery; and (5) Work closely with the Coordinating Center, Collection Sites, and all other PMI Cohort Program Steering Committee Members to share biobanking expertise, infrastructure, and data to further the goals of the PMI. Overall, the Mayo Clinic Biorepositories Program laboratories combined with Mayo Medical Laboratories provide an unparalleled ability to collect, accession, process, distribute, store, and manage virtually any type of biospecimen on behalf of the Precision Medicine Initiative Cohort Program.

NIH Research Projects · FY 2025 · 2016-04

PROJECT SUMMARY Alzheimer’s disease (AD) is a major public health problem affecting over 5 million people in the US. Patients with AD have beta-amyloid (Aβ) and tau pathology and typically present with memory loss. However, approximately 25% of AD subjects do not present with early memory loss and instead present with other cognitive complaints, and are referred to as atypical AD. The most common atypical AD syndromes include logopenic aphasia (LPA), a syndrome affecting language syndrome, and posterior cortical atrophy (PCA), a syndrome affecting visuospatial/perceptual skills. In the 1st cycle of this R01 we used positron emission tomography (PET) to assess Aβ and tau deposition across atypical and typical variants of AD, and we found a large degree of heterogeneity both cross-sectionally and longitudinally that was associated with syndrome and age. The goal of the 2nd cycle of the R01 is to investigate the degree to which other biological mechanisms are related to the heterogeneity we observed in tau and Aβ. In aim 1, we will assess how both functional connectivity, measured using resting state fMRI, and iron deposition, measured using quantitative susceptibility mapping, are related to cross-sectional and longitudinal heterogeneity in tau and Aβ in AD. In aim 2, we will assess how genetic risk factors are related to heterogeneity in tau and Aβ. We will assess the relationship between apolipoprotein (APOE) ε4 and tau and Aβ, and we will also perform a whole genome sequencing analysis to identify genetic variants associated with heterogeneity in tau and Aβ in AD. In aim 3, we will model the system of genetic and multi-modal imaging mechanisms in order to determine inter- relationships and independent contributions of each of our disease mechanisms to the heterogeneity of tau and Aβ. We plan to recruit a cohort of 100 subjects (33 LPA, 33 PCA, 34 typical AD) into the 2nd cycle of the R01. Each subject will undergo two serial assessments 12 months apart that will include neurological and neuropsychological testing, 3T MRI that includes resting state fMRI and quantitative susceptibility mapping, Aβ PET using Pittsburgh Compound B and tau-PET using [18F]flortaucipir. All subjects will also undergo a blood draw for genetic analysis. These 100 subjects will be used to address aims 1 and 3. For aim 2, we will utilize the 100 subjects from the 2nd cycle plus the 70 subjects recruited into the 1st cycle that underwent Aβ and tau PET and provided a blood sample (total=170 subjects), and we will replicate our whole genome sequencing analyses in the AD Neuroimaging Initiative (ADNI) cohort. Our R01 will have a major impact on public health since atypical AD effects ~1,000,000 Americans. Our research will increase understanding of biological mechanisms underlying phenotypical and age differences in AD and mechanisms that may determine routes of protein spread through the brain. This knowledge will be useful to aid in the future development of mechanistically based treatments and interventions for AD.

NIH Research Projects · FY 2025 · 2015-09

PROJECT SUMMARY: Type 2 diabetes, chronic pancreatitis, and pancreatic cancer are common and inter-related diseases that require better approaches to diagnosis and treatment. N IDD K and NCI together formed a consortium of many centers called CPD PC (chronic pancreatitis, diabetes and pancreatic cancer). Under the leadership of Santhi Swaroop's Vege as the PI, the consortium is in the tenth year and now applying for the new 5 year cycle N IDD K Grant, CP CRC (chronic pancreatitis clinical research consortium). During these 9 years, for the 3 main studies PR OCE ED, DETECT and NOD, Mayo Clinic was at the top for recruitment of patients as well as for the ancillary studies like MINIMAP, PAIR, and IMPACT. We also could plan and complete ancillary studies which included salivary biomarker study, PAIR and IMPACT. We are now applying for the third 5 year cycle which will involve acute recurrent pancreatitis and chronic pancreatitis in adults at our center. We will try to full fill the goals and strategies of the C PCR C with regards to ongoing recruitment of participants, follow-up of the large number of participants already in the study during the first 2 cycles, continuing the collection of various bio specimens successfully as has been done for 9 years, and new ancillary studies understanding the pathogenesis of the disease as well as clinical trials (2 planned 1 in diabetes and 1 in smoking and chronic pancreatitis). In addition to the experienced PI and the co investigators who have all been involved in this consortium so far, the two experience study coordinators who have done exemplary work towards the goals of the second cycle of the consortium will form the team and work with the PI and co investigators. We have a well standardized mechanism to identify new patients with acute recurrent pancreatitis and chronic pancreatitis, request them for bio specimens, collection storage and shipment of those bio specimens to the central bio repository, frequent discussions with the monitoring team and other coordinating centers, and participation in face-to-face meetings by all the consortium centers when required. A detailed proposal for all the 3 aims of recruitment, collection of bio specimens and planning new studies to understand the pathogenesis including interventional trials is being submitted to N IDD K. .

NIH Research Projects · FY 2026 · 2015-09

PROJECT SUMMARY Progressive supranuclear palsy (PSP) is a devastating neurodegenerative disorder characterized by deposition of the protein 4-repeat (4R) tau in key brainstem and subcortical nuclei, including the substantia nigra, red nucleus, subthalamic nucleus, pallidum, thalamus and basal ganglia. Patients typically present with postural instability with falls, ocular motor impairments and parkinsonism, although there is a large degree of clinical heterogeneity in presenting syndrome and disease progression. In the 2nd cycle, we demonstrated volume loss and tau PET uptake in these key nuclei across different PSP clinical syndromes, albeit with some heterogeneity, although there are many gaps in knowledge regarding the role of these brainstem and subcortical nuclei in disease progression. The goal of the 3rd cycle is to determine the role of brainstem and subcortical nuclei in disease progression across the PSP clinical spectrum. To address this goal, we will investigate relationships between different pathophysiological abnormalities in these nuclei and disrupted brain connectivity, clinical decline and disease biomarkers measured in blood. In aim 1, we will use novel ultra-high field strength MRI (7T) to measure iron in these nuclei using quantitative susceptibility mapping (QSM) and dopaminergic depletion of the substantia nigra using neuromelanin-sensitive MRI. We will evaluate whether these pathophysiological abnormalities change over time, vary across the PSP clinical spectrum, and relate spatially and temporally to volume loss, tau uptake and disruptions in brain connectivity. We will measure breakdowns in structural connectivity using diffusion tractography with neurite orientation dispersion and density imaging (NODDI) and breakdowns in functional connectivity using resting-state fMRI. In aim 2, we will determine how pathophysiological abnormalities in these nuclei measured on neuroimaging and at autopsy are related to survival and progression in key clinical features (gait, parkinsonism, ocular motor impairment, dysphagia and cognition). In aim 3, we will assess plasma neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) that provide markers of neuroaxonal injury and astrogliosis, and plasma markers of tau, and determine whether these plasma metrics relate to pathophysiological abnormalities in the brainstem and subcortical nuclei and clinical progression across the PSP spectrum. To achieve our goals, we will recruit 100 PSP patients and utilize data from 95 autopsy-confirmed PSP cases. Each patient will undergo clinical and dysphagia evaluations, 3T MRI that includes structural MRI, diffusion MRI and resting-state MRI; 7T MRI that includes QSM and neuromelanin-sensitive MRI; and flortaucipir PET. All patients will undergo three serial assessments one year apart. The results of this grant will improve understanding of disease mechanisms, identify potential mechanistic treatment targets for the disease, and provide biomarkers for diagnosis, prognosis and tracking disease progression across the PSP clinical spectrum.

NIH Research Projects · FY 2024 · 2015-09

PROJECT SUMMARY Progressive supranuclear palsy (PSP) is a devastating neurodegenerative disorder that is characterized by deposition of the protein 4-repeat (4R) tau in the brain. Patients typically present with postural instability with falls, axial rigidity and vertical supranuclear gaze palsy, although other atypical clinical syndromes occur in which patients present with parkinsonism, freezing of gait, behavioral abnormalities, limb apraxia or speech and language difficulties. In the 1st cycle of the R01 we characterized the cross-sectional and longitudinal behavior of the tau-PET ligand [18F]AV-1451 in PSP and showed that it is related to other neuroimaging measures of neurodegeneration. The 1st cycle focused on the typical clinical presentation of PSP. Since the 1st cycle, a panel of leading experts published new criteria with a standard to diagnose the atypical clinical syndromes. We currently lack understanding of the neurobiology of the atypical PSP syndromes. The primary goal of the 2nd cycle is, therefore, to characterize the clinical, neuroimaging and neuropathological features across typical and atypical PSP syndromes. Specifically, we aim to characterize the cross- sectional and longitudinal multi-modal neuroimaging signatures of the PSP syndromes, determine the relationship between neuroimaging and clinical evolution, and evaluate the autopsy characteristics of the PSP syndromes. We will have data from 160 PSP patients to allow us to address our aims (84 recruited into the 1st cycle and 76 which will be recruited in the 2nd cycle). Each newly recruited patient will undergo the identical examinations as the 84 patients from the 1st cycle, including a neurological and dysphagia evaluation, a 3T magnetic resonance imaging (MRI) that includes structural MRI and diffusion tensor imaging (DTI), and tau- PET using the [18F]AV-1451 ligand. All patients will undergo two serial assessments one year apart. We will assess differences and commonalities in all three neuroimaging modalities across PSP syndromes primarily using a focused region-of-interest approach which will target key brainstem, subcortical and cortical regions that are involved in PSP. We will then ascertain whether the PSP syndromes exhibit unique multi-modal signatures using a classification model. Voxel-level analyses will also be performed to assess patterns across the whole brain. The relationship between clinical evolution, including the evolution of dysphagia, and the PSP syndromes and neuroimaging measures will be assessed. Autopsy examinations will be performed on all patients from both cycles that die and 4R tau burden will be compared across PSP syndromes. We will also determine the degree to which neuroimaging differences across syndromes are related to tau burden and investigate how additional pathologies are associated with the different syndromes. The results of this grant will increase our knowledge of the neural underpinnings of the clinical and anatomical heterogeneity in PSP and will also be essential for the development of optimum biomarkers for PSP that will aid diagnosis, track disease progression and allow patients with all PSP syndromes to be included in future treatment trials.

NIH Research Projects · FY 2025 · 2015-08

PROJECT SUMMARY/ABSTRACT Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA) comprise a group of neurodegenerative diseases that share the pathophysiological mechanism of abnormal aggregation of alpha-synuclein (αSyn). Promising attempts at disease modification in established synucleinopathies have failed, raising the important issue that patients who have clinically overt, established disease are too advanced for disease-modifying therapies to be efficacious. Therefore, strategies have evolved to allow for earlier disease detection and confirmation which was pursued in our current grant period with focus on pure autonomic failure (PAF). PAF has more recently been established as one of the synucleinopathies, and is characterized by isolated autonomic failure without motor or cognitive deficits, representing a pre-motor stage with high risk of conversion to MSA, PD, or DLB. The main goal of the current grant period was to identify and validate spinal fluid (CSF) and MRI biomarkers of conversion of PAF to motor synucleinopathies. We have accomplished that goal by identifying highly predictive mechanism-based CSF and MRI markers in established synucleinopathies, that when applied to the pre-motor stage can predict conversion and conversion phenotype. REM sleep behavior disorder (RBD) is a condition with close association with synucleinopathies and frequently presents as isolated RBD (iRBD) years before motor or cognitive symptoms develop. The relevance and implications of iRBD as prodromal synucleinopathy has been well recognized, but to date there are no reliable predictors of conversion, phenotype of conversion, or timing of conversion to an established synucleinopathy. We have expanded the biomarkers developed to predict PAF phenoconversion to iRBD patients and identified discrete CSF profiles akin to those seen in PAF and in manifest motor and cognitive synucleinopathies, so that we are now in a position to test the biomarker potential of these markers at the prodromal stage. In this renewal, we shall study sleep-study confirmed iRBD patients stratified by baseline CSF biomarker phenotype (MSA-, PD/DLB, or normal type) along with healthy control subjects with serial clinical evaluations combined with autonomic, CSF, and MRI biomarker studies. We will enhance the feasibility of reaching recruitment goals for each biomarker phenotype by enriching recruitment with participants in the North American Prodromal Synucleinopathy Consortium identified as biomarker phenotype required to reach our recruitment goals. Secondly, we will continue to follow PAF patients enrolled during the current grant period who have not yet phenoconverted to solidify the predictive value of developed biomarkers. The findings from this renewal proposal should result in establishing biomarkers for the pre-motor and prodromal stages of syncucleinopathies, which may translate to disease-modifying therapy trials standing a better chance at demonstrating efficacy, and which may eventually even allow for diagnosing selected neurodegenerative diseases at the preclinical stage.

NIH Research Projects · FY 2025 · 2015-06

PROJECT SUMMARY In 2020, an estimated 77,240 people in the US will be diagnosed with non-Hodgkin lymphoma (NHL), and 19,940 will die from this cancer. NHL incidence rates increased over the last half of the 20th century and only recently stabilized. In parallel, NHL survival rates began improving in the mid-1990s with the advent of improved treatment strategies, leading to the current 5-year survival rate of 74%. These trends have led to a growth in the number of NHL survivors, estimated at over 757,000 in 2019. To address the unmet health needs of this patient population, we established the Lymphoma Epidemiology of Outcomes (LEO) cohort study, which by June 2020 will have enrolled over 13,000 NHL patients and have <1% lost to follow-up. The LEO cohort supports multiple grants and has generated novel and high impact findings on NHL prognosis and survivorship. To continue and expand the key contributions of LEO, in this renewal we propose to: 1) Extend recruitment at all 8 LEO centers, with a goal of recruiting 3400 newly diagnosed NHL patients focused on Hispanic (N=900), African American (N=580), and Asian (N=200) participants (doubling the current sample size for these groups) and adolescent and young adult (AYA) participants age 18-39 years (N=870; 87% increase), and non-metro and rural patients of all ages and race/ethnicities (N=1,208, 72% increase), for a total cohort of 16,500 patients; 2) Review all pathology diagnoses and maintain a NHL tumor bank that includes an H&E slide, formalin-fixed, paraffin-embedded tissue samples in a tissue microarray, and extracted tumor DNA and RNA; 3) Collect a peripheral blood sample and maintain a central biorepository of DNA, serum, plasma and buffy coat; 4) Annotate and harmonize all cases with clinical, epidemiologic, pathology and treatment data, including development of new informatics enhancements to capture clinical data from electronic health records, digital pathology images and linkage to public databases to enhance data on environmental exposures and socioeconomic factors; 5) Prospectively follow patients in the cohort to ascertain disease progression/relapse, retreatment, transformation, second cancers, survival (including cause of death), updated exposures, patient- reported outcomes (PROs), and other long-term health outcomes; and 6) Facilitate research projects that use this infrastructure, promote interactions with NCI-supported clinical trials networks, patient advocacy groups, and other collaborators. We will achieve these aims through close coordination of each of the participating centers, supported by four cores (Administration; Clinical; Pathology & Biospecimens; and Biostatistics & Informatics). The LEO cohort is an exceptional resource that supports a broad research agenda aimed at identifying novel clinical, epidemiologic, germline genetic, tumor, and treatment factors that influence NHL prognosis and survivorship focusing on NCI research priorities in AYA, minority, and rural populations. LEO is led by international experts in clinical and epidemiologic research on NHL, thereby driving the translation of new findings to the clinic and the population.

NIH Research Projects · FY 2026 · 2014-08

Project Summary Primary cilia are microtubule-based sensory structures found on the surface of most eukaryotic cells. Dysfunctional cilia lead to numerous syndromic disorders, often characterized by renal abnormalities. Unlike other cellular organelles, the ciliary lumen is open to the cytoplasm, making it unclear how cilia-essential and renal-physiology-related proteins, such as Polycystin 1 and 2 from ADPKD, reach the cilia. There is growing evidence to support the existence of a selective gate at cilia base that regulates the import of ciliogenic proteins. Despite the poorly studied transition fibers (TFs) being implied to be a vital part of the ciliary gate, there is a lack of molecular insight into the establishment of TFs, either in terms of their structure or function. Investigating the connection between cilia and disease in mammalian models can be challenging due to the essential roles of cilia in mammalian embryonic development. Thus, alternative experimental systems are needed. Caenorhabditis elegans has proven to be an effective model for studying ciliary proteins in their natural cellular environment due to its highly conserved cilia composition and signaling. Our laboratory pioneered the application of C. elegans to study the ciliary gate in past funding periods and made important discoveries about its composition, establishment, and significance in human diseases. Our recent findings have shown that the ARPKD protein DZIP1L plays a crucial role in establishing functional cilia gates in both C. elegans and human renal epithelial cilia. Building on our expertise in cilia research and utilizing the resources of the Mayo Clinic PKD Translational Center, our main objective is to fundamentally advance the understanding of the physiological importance of cilia gating in ciliopathies beyond Polycystic Kidney Disease. This proposal is based on a novel discovery that DZIP1L and ANKRD26 forms a conserved protein module to recruit other essential TF proteins to build a functional cilia gate; a paradigm that the activity of a poorly defined phosphoinositide signaling, mediated by the ciliary PIPKg, determines the proper localization of DZIP1L; and an exciting hypothesis that the ARPKD variants of DZIP1L may specifically impact cilia import of polycystins. Emerging evidence from our laboratory and others shows that polycystin dosage closely correlate with the severity of various PKD conditions, highlighting the therapeutic potential of targeting cilia gating to enhance the import of PKD proteins. To comprehensively understand the regulatory pathways of DZIP1L- regulated cilia gating, especially for PKD proteins, we will use both C. elegans and mammalian renal cell models and employ an interdisciplinary approach. Our goal is to gain critical insights into this understudied area in cilia and ciliopathies, establish its physiological significance, and link fundamental discoveries to the molecular connections between aberrant cilia gating and the development of PKD disorders.

NIH Research Projects · FY 2025 · 2014-07

Project Summary The long-term goals of this project are to uncover molecular mechanisms of antibiotic resistance and to design inhibitors as therapeutics against disease-causing bacteria. Widespread antibiotic resistance among hospital and community associated bacteria, coupled with the lack of new antibiotics, poses an urgent threat to global public health. For these reasons, antibiotic resistance is the silent pandemic, which has been mounting since the introduction of antibiotics in the clinic. The situation is urgent for several pathogens and will become more acute for other pathogenic bacteria in the coming years. There is no magic bullet solution to solve the antibiotic resistance problem; rather, a concerted effort is required that includes new antibiotics, tackling resistance mechanisms head-on, and better stewardship of antibiotics and antiseptics. Bacteria possess several mechanisms to confer resistance to the host organism, including modification of the antibiotic, mutation to the target site, reduced uptake of antibiotics, and the presence of membrane protein efflux pumps. This proposal is aimed at understanding molecular mechanisms of efflux, which is a first-line resistance mechanism used by bacteria to lower the intracellular drug concentration, thereby facilitating pathogen survival. Inhibitors of efflux pumps have therapeutic potential as antibiotic adjuvants by directly targeting a central mechanism of resistance in pathogenic bacteria. However, the lack of clinically approved efflux pump inhibitors underscores a key challenge in the field: how to design specific inhibitors of a substrate binding pocket that promiscuously binds structurally diverse drugs? We recently uncovered a promising solution to this problem through the discovery of antibody inhibitors to B. subtilis Bmr and S. aureus NorA where a loop inserts into the substrate binding pocket. We hypothesize the substrate binding pockets of transporters can be systematically targeted for inhibition by peptide mimics of the antibody paratope. By using efflux pumps within the Bacillus genus, Bmr and Blt, this proposal will probe how efflux pumps recognize multiple substrates (Aim 1), will reveal cryptic pockets within the substrate binding pocket of efflux pumps by using antibodies as tools (Aim 2), and develop a systematic approach for creating conformationally defined mimics of the antibody b-hairpin paratope (Aim 3). Since Bmr and Blt share ~80% sequence homology yet display different substrate specificities, this system serves as a good comparative group for determining whether transporter-selective inhibitors can be designed. The approaches developed in this grant will establish the long-term viability of novel efflux pump inhibitors to the treatment of antibiotic resistant organisms.

NIH Research Projects · FY 2025 · 2014-05

PROJECT SUMMARY / ABSTRACT The growing prevalence of nonalcoholic fatty liver disease (NAFLD) creates an imperative to reliably distinguish between patients with simple steatosis and those with nonalcoholic steatohepatitis (NASH). However, hepatic inflammation and cellular injury diagnoses often require invasive liver biopsies for histopathologic staging. There is an urgent need for safe and reliable noninvasive imaging methods for diagnosing NASH and longitudinal assessing hepatic inflammation and hepatocellular injury to monitor treatment efficacy. The presence of and severity of steatosis and fiborosis are now well addressed with chemical shift imaging and magnetic resonance elastography (MRE). Our current cycle of research has confirmed that MRE-assessed loss modulus is a very promising biomarker for inflammation. In this renewal application, we propose to continue validation of this biomarker for inflammation and to add noninvasive assessment of cell injury (ballooning) by introducing a novel MR cytometry modification into the MRE protocol. The overall goal of this work is to develop and validate multiparametric MR-ICE imaging technologies for fully assessing disease states during NAFLD evolution, especially inflammation and hepatocellular injury. • In Aim 1, we will develop the MR-ICE imaging protocol. Fat fraction will be evaluated with a 6-point Dixon method. A dual-frequency, self-navigating, and hybrid radial-Cartesian 3D vector hepatic MRE technique will be optimized for characterizing multiple mechanical properties of viscoelasticity and nonlinearity. MRC sequence and reconstruction will be developed with gradient waveforms and diffusion signal fitting that are specifically designed for hepatocyte cytometry, with or without simultaneous MRE acquisition. • In Aim 2, we will perform longitudinal application of the MR-ICE in an in vivo rat model (N=96, diet-induced NASH). Technical integrity and diagnostic performance will be assessed by comparing multiple in vivo imaging biomarkers (fat fraction, hepatocyte size, viscoelasticity, nonlinearity) with ex vivo tissue composition (water and fat contents), dynamic mechanical analysis (DMA) testing and histologic features (steatosis, inflammation, ballooning, fibrosis), respectively. Statistical models will be trained to diagnose NASH. • Prior to pilot clinical evaluation, we will aseess the repeatability of MR-ICE biomarkers in 5 controls and 5 clinical patients using a test-retest strategy. Finally, a pilot clinical evaluation in 10 controls and 40 patients with biopsy-proven NAFLD/NASH will be performed to provide preliminary evidence of the diagnostic performance of the MR-ICE protocol for staging NAFLD/NASH. Emerging therapeutic interventions may require life-long treatment, creating the need for more precise non- invasive methods for identifying those patients who need such interventions. The development of MR-ICE will make it possible for us and other investigators to advance the precise noninvasive assessment of NASH.

NIH Research Projects · FY 2025 · 2014-04

Project Summary The Alliance for Clinical Trials in Oncology (Alliance) was founded on July 15, 2011, through the merger of 3 legacy groups: Cancer and Leukemia Group B, North Central Cancer Treatment Group, and American College of Surgeons Oncology Group. The Alliance Statistics and Data Management Center (SDMC) is responsible for all statistics, data management, and Information Technology functions for the Alliance and, as such, is an integral part of the Alliance’s mission. Despite being formed from 3 distinctive groups, all SDMC activities are now consolidated at a single location at the Mayo Clinic under the leadership of Dr. Sumithra Mandrekar as the Alliance Group Statistician, all while undergoing a leadership transition due to the untimely death of the previous group statistician, Dr. Daniel Sargent. Alliance faculty includes methodological leaders in biomarker- based clinical trial design, adaptive trials, surrogate endpoint evaluations, development of methodology and computing tools for identification of predictive genomic markers, and early-stage clinical trial design. From March 1, 2014 – August 31, 2017, the SDMC provided statistical, data management, and IT collaboration for 20 treatment trials currently in development, 21 treatment trials that opened to accrual and, 100 trials that opened prior to March 2014, for which patient follow-up or manuscript preparation is in progress. SDMC members were authors on 234 published manuscripts reporting on Alliance- led clinical trials and associated correlative or retrospective studies, authored an additional 149 reviews, editorials, or position papers on novel statistical and bioinformatics methods, analyses and software, and provided substantial statistical support and leadership on 44 publications which leverage individual patient data from multiple Alliance studies. SDMC systems are robust and scalable and support all needs of the Alliance. The SDMC has implemented Medidata Rave for all trials, consolidated to a single information systems infrastructure, met all NCI OEWG timelines, collaborated on international trials, partnered on prospective and retrospective registration trials, and is leading the ALCHEMIST trial, A151216 (part of the NCI precision medicine initiative). The SDMC has contributed to several national NCTN systems initiatives: piloting of the ePRO system, Source Data Verification, integrations between Rave and CTEP- AERs, implementing the Data Quality Portal and Central Monitoring Portal, and partnering on the NCTN Biospecimen Navigator. The Alliance SDMC has kept pace with, and in many cases led, innovation in scientific, administrative, and technological arenas of cancer research, and is ideally poised to meet the challenges of cancer clinical trials in 2018 and beyond.

NIH Research Projects · FY 2026 · 2014-04

Abstract: Mayo Clinic Nephrology & Urology Summer Undergraduate Research Fellowship (nuSURF) The Mayo Clinic has a rich history in both basic science and clinic science research in Nephrology & Urology, and has active PhD, MD and MD-PhD training programs. Annually, the Mayo Graduate School receives >1500 applications from Undergraduates to work with Mayo Clinic Investigators. The Mayo Clinic is home to both an Kidney Stone Research Center as well as a Mayo Translational Polycystic Kidney Disease (PKD) Center. Both Mayo Centers have been NIH funded. 2011-2013 both Centers have received supplemental funds to support summer undergraduate research related to kidney stones and PKD, respectively. This second renewal proposal, in response to RFA-DK-23-013 (R25) merged these successful summer undergraduate programs into a more generalized Mayo Clinic Nephrology & Urology Summer Undergraduate Research Fellowship (nuSURF; ~234 total students). Numerous students from Mayo's programs have entered or finished PhD, MD, MD-PhD, DO, DMD, VDM, MPH and MBA programs, or have co-authored Nephrology or Urology-oriented peer-reviewed papers. The “fruit” of the nuSURF program is that more than 25 federal / foundation grants were awarded, and at least 16 alumni (of 234) are in Nephrology or Urology-related research or clinical areas. Over the next 5 years, we proposed to fund 14 students/summer (70 students total) through nuSURF to work specifically with Mayo Investigators engaged in basic or translational research in Nephrology & Urology. This 5 year period will allow undergraduates in the program to perform innovative Nephrology & Urology research with leading Mayo Clinic research laboratories. Students will also participate in various educational programs (e.g., weekly seminars and mini-courses) to enhance their research experience. Their 10-week summer experience will culminate with (1) a 10-minute oral presentation of their work, (2) a Mayo-wide Summer Undergraduate poster presentation (> 180 student/yr) and (3) a NIDDK-KUH Summer Undergraduate Research Symposium held annually at the end of the Summer at one of the funded R25-centers. Following the Summer Program, students will be academically tracked to determine the effectiveness of the Mayo nuSURF experience in Nephrology & Urology, basic research and clinical medicine. Our goal is to continue increasing the number of basic and clinical Nephrology & Urology researchers through this nuSURF training experience. Thusfar, ~10% of our nuSURF alumni (those who have graduates college) are pursuing Nephrology or Urology-related careers.

NIH Research Projects · FY 2025 · 2014-01

Project Summary Giant Cell Arteritis (GCA) is an autoimmune and autoinflammatory disease which targets the aorta and its major branch vessels. GCA causes vaso-occlusive disease, leading to blindness and stroke. About half of the patients develop GCA aortitis, a potentially life-threatening complication due to aortic dissection and aneurysm formation. The underlying disease process is a granulomatous arteritis, with CD4 T cells, macrophages and multinucleated giant cells infiltrating into the vessel wall, eliciting maladaptive wall remodeling with neoangiogenesis and lumen- occlusive intimal hyperplasia. We have identified aberrant expression of the oncogene NOTCH1 in CD4 T cells as a key abnormality in the immune system of GCA patients. Here, we will examine the hypothesis that NOTCH signaling transforms protective immunity into pathogenic immunity by suppressing the mitochondrial enzyme succinate dehydrogenase (SDH) and truncating the tricarboxylic acid (TCA) cycle. Fragmentation of the TCA cycle then leads to the accumulation of the metabolic intermediate succinate, which is released into the tissue site and functions as a second messenger. We propose that succinate secreted by NOTCH1hi SDHlo CD4 T cells targets surrounding cells to redirect T effector cell differentiation, to induce multinucleated macrophages and to promote microvascular neoangiogenesis. We have assembled key enabling resources to mechanistically study how NOTCH-instructed succinate release enhances vascular inflammation; including a large cohort of clinically well phenotyped GCA patients and a chimeric mouse model in which vasculitis is induced in engrafted human arteries to corroborate in vitro data by in vivo studies. Aim 1 will define the molecular mechanisms leading to NOTCH-dependent SDH loss-of-function, building on preliminary studies that implicate RNA-binding proteins in regulating SDH mRNA stability through N6-methyladenosine modifications. Aim 2A examines mechanistically how succinate reprograms T effector cell differentiation. Experiments are designed to investigate how succinate paralyzes the NF-kappaB inhibitor A20/TNFAIP3 to unleash NF-kappaB signaling and induce polyfunctional effector T cells (Thpoly), including T cells that co-produce IFN-, IL-17, TNF-α, IL-21 and IL-22. Aim 2B will determine how NOTCH-instructed succinate alters macrophage function, specifically by driving formation of tissue-destructive multinucleated giant cells. We will delineate how succinate elicits a robust DNA damage response and how it promotes nuclear division and halts cytokinesis by interfering with the spindle assembly checkpoint. Aim 2C is focused on succinate’s role in inducing a pro-angiogenic endothelial cell (EC) phenotype and will explore how succinate-trained EC migrate, proliferate, and lose their barrier function. Aim 3 will bridge from the bench to the bedside and will test whether the suppression of succinate production by blocking the upstream enzyme a-ketoglutarate dehydrogenase can successfully treat vasculitis in vivo.

NIH Research Projects · FY 2025 · 2013-07

PROJECT SUMMARY/ABSTRACT Pancreatic β-cell failure in a distinctive feature of Type 2 diabetes mellitus (T2DM) and therefore preservation of β-cell health has been identified as a critical barrier for the development of successful preventative and treatment strategies in T2DM. Primary features of β-cell failure include insulin secretory dysfunction, loss of transcriptional identity/β-cell dedifferentiation, and β-cell loss, with growing evidence pointing to impaired endoplasmic reticulum (ER) proteostasis as a key driver of this process. Recent evidence suggests that environmental stress conditions that produce disruptions of daily fasting/feeding circadian cycles (i.e. circadian disruption, CD) lead to glucose intolerance, hyperglycemia, and promote β-cell failure in T2DM. However, the molecular mechanisms underlying circadian control of β-cell function and ER proteostasis remain unknown. In this regard, our preliminary studies determined that CD-mediated abrogation of normal fasting/feeding cycles is a potent physiological inducer of β- cell functional failure, and this process is molecularly mediated through loss of β-cell expression/activity of circadian transcription factor D-box binding PAR bZIP transcription factor (Dbp). Therefore, the key objective of the proposal is to test the hypothesis that Dbp is an important regulator of β-cell circadian function through rhythmic activation of transcripts regulating insulin secretion and ER proteostasis, whereas loss of Dbp expression, as occurs in β-cells in response to circadian disruption and diet-induced obesity, promotes β-cell functional decline in T2DM. To address this, Specific Aim 1 will utilize novel conditional genetic loss and gain-of- function Dbp mouse models to establish a causative relationship between circadian Dbp expression and the regulation of β-cell function, ER proteostasis, and transcriptional identity. In addition, we will also examine whether Dbp regulates β-cell function and transcription in human β-cells utilizing viral gain/loss of function techniques concurrent with transplantation of human stem cell-derived β-cells into immunodeficient mice. Specific Aim 2 will utilize β-cell-specific Dbp luciferase reporter mice and systems biology multiomics approaches (RNAseq + scATAC seq) to 1) identify molecular mechanisms by which obesity disrupts circadian regulation of Dbp expression and corresponding β-cell circadian clock function, and 2) test novel strategies designed to restore normal functionality of β-cell circadian clocks in obesity as means to prevent β-cell failure in T2DM. Taken together, successful completion of proposed studies will uncover novel molecular mechanisms through which β- cells integrate and respond to circadian changes in nutritional availability and will provide potential therapeutic targets for prevention and treatment of T2DM.

NIH Research Projects · FY 2025 · 2013-07

PROJECT SUMMARY The non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) is a neurodegenerative disorder defined by the presence of agrammatic aphasia and/or apraxia of speech that commonly results from a 4- repeat tauopathy. During the previous 2 cycles of the R01 we used neuroimaging to characterize the patterns of neurodegeneration and structural and functional breakdowns in connectivity associated with nfvPPA. However, little is known about how these brain changes are related to, or driven by, underlying biological processes. Two important biological mechanisms relevant to nfvPPA are deposition of the protein tau and neuroinflammation. In the 2nd cycle of the R01 we assessed tau deposition in vivo using PET. In the 3rd cycle we will focus on assessing the role of neuroinflammation and other biological processes. The first aim of the grant is to characterize the patterns of neuroinflammation in the brain using PET imaging with the 3rd generation ligand 11C-ER176 and determine whether neuroinflammation changes over time and is associated with clinical disease severity. The second aim is to determine whether biomarkers of pathological processes measured from blood plasma, including neurofilament light chain, plasma glial fibrillary acidic protein, tau, and inflammation biomarkers, are abnormal in nfvPPA. We will also assess whether these biomarkers change over time and are associated with clinical disease severity. These first two aims will determine whether neuroinflammation PET and blood plasma biomarkers are useful disease biomarkers in nfvPPA, and we will determine whether these measures could be useful prognostic markers of future clinical decline. Our third objective is to build upon knowledge gained from the first 2 cycles and determine how structural and functional abnormalities in the brain, measured using structural MRI, diffusion tractography and resting state fMRI, are related to neuroinflammation PET and blood plasma biomarkers. This aim will help model the degree to which these biological processes relate to other more established breakdowns in brain structure and function. To accomplish these aims we will recruit 50 patients with nfvPPA, and each participant will undergo three serial assessments one year apart. At each assessment, patients will have a neurological and speech-language assessment, 11C-ER176 neuroinflammation PET and a 3T magnetic resonance imaging scan that will include resting-state functional MRI and diffusion tensor imaging sequences. A blood sample will be collected from all patients at both visits. Blood samples were also collected in the 2nd cycle of the R01 and hence blood plasma biomarkers will be measured in 100 nfvPPA patients. We will also recruit 50 cognitively normal healthy controls who will undergo identical neuroimaging and provide a blood sample. This renewal is highly significant as results gained will be critical to understand the biology of nfvPPA and mechanisms of disease spread. Furthermore, this work may also help provide potential mechanistic treatment targets for nfvPPA and establish disease biomarkers for prognosis and for future research studies and clinical trials in patients with nfvPPA.

NIH Research Projects · FY 2025 · 2013-06

By 2030, ~70 million people in the USA will be >65 years old with ~10 million >85 years old. The studies proposed in this competitive renewal application are motivated by our previous finding that larger phrenic motor neurons (PhMNs) are selectively lost in old age and the work of others implicating mitochondrial disruption in motor neuron death. BDNF/TrkB signaling mediates CREB phosphorylation at serine 133 (pCREBs133), which promotes mitochondrial remodeling via gene targeting of PGC1a. Activity dependent pAMPK signaling also mediates pCREBs133 phosphorylation and PGC1a expression. It appears that BDNF/TrkB signaling in PhMNs is reduced in old age, but activity of smaller PhMNs persists to support breathing, which may underlie their sparing in old age. It is also well established that circulating TNFa is elevated with aging. In other cell types, we found that TNFa selectively activates the IRE1a/sXBP1 ER stress pathway, which induces mitochondrial fragmentation and mitophagy. Our experimental design involves a comprehensive array of novel techniques already established and validated in our lab. The results of the proposed studies will guide development of novel therapeutic approaches targeting BDNF/TrkB or pCREBs133 phosphorylation (e.g., quercetin) and/or TNFa induced IRE1a/sXBP1 ER stress (e.g., infliximab) to promote PhMN survival. Conceptual Framework: We hypothesize that mitochondrial volume density (MVD) and respiratory capacity (SDHmax) in PhMNs are affected by the balance between mitochondrial biogenesis and mitophagy. Mitochondrial biogenesis is regulated via pCREBs133 phosphorylation and PGC1a expression, which is triggered by both activity (via pAMPK – Aim 1) and BDNF/TrkB.FL signaling (Aim 2). In old age, the influence of BDNF/TrkB.FL signaling is diminished especially in larger PhMNs, while activity of smaller PhMNs persists. Furthermore, serum TNFa is elevated in old age, which induces pIRE1a/sXBP1 ER stress leading to mitophagy (Aim 3). Aim 1: Determine the role of pAMPK/pCREB/PGC1a signaling in maintaining mitochondrial volume density in smaller PhMNs.. Aim 2: Determine the impact of reduced BDNF/TrkB/pCREB signaling in age-related remodeling of mitochondria in PhMNs. Aim 3: Determine the impact of TNFa induced activation of the IRE1a/sXBP1 ER stress pathway in age-related remodeling of mitochondria in PhMNs.

NIH Research Projects · FY 2026 · 2012-09

PROJECT SUMMARY/ABSTRACT Half of the man-made radiation exposure to the U.S. population can be attributed to CT. Thus, stakeholders have invested heavily in the reduction of CT doses. Recently, CT Deep Learning Reconstruction or Denoising (DLRD) techniques have become available that claim to enable dose reduction in CT, just as CT iterative reconstruction (IR) claimed before it. Like DLRD, IR showed dramatic apparent increases in image quality by reducing image noise. Subsequent clinical studies found that true dose reductions capabilities for IR were only 20-25% in soft tissues and organs. Greater dose reductions resulted in compromised signal detectability for low-contrast lesions (e.g., liver metastases). Now, DLRD algorithms are being used in clinical practice and appear to yield image quality superior to IR. But again, we are finding that excessive radiation dose reduction can introduce new artifacts and compromise lesion detectability. Our overall objective is to develop and validate methods that can quantitatively determine CT protocols that deliver the needed diagnostic performance at the lowest patient dose for any scanner model or reconstruction algorithm. In our first two competitive award periods, we developed robust Channelized Hotelling model observers (MOs) to quantify diagnostic performance using low contrast objects within a uniform phantom and validated the work with large scale reader studies for both filtered back projection and IR images. We are deploying these tools under EB028936 to allow robust dose optimization by CT users. However, there remain challenges. First, low-contrast phantoms used with most MOs are too simple. Second, highly realistic lesion and noise insertion tools require use of proprietary projection data and access to manufacturer software tools. Third, MOs must be extended to work with DLRD methods and be generalizable to any scanner. The proposed work will use patient image data, obviating the need for projection data, use our developed deep learning (DL)-MOs to achieve a scalable solution for performance assessment, and be generalizable to any algorithm or scanner. The goal of this renewal application is to develop robust DL-MO tools to efficiently predict diagnostic performance for images created with DLRD methods. We will accomplish this through three specific aims: 1. Develop and validate disease-insertion and low-dose-simulation tools for CT DLRD techniques. 2. Develop and validate DL-MO tools to quantify mean diagnostic performance for DLRD methods. 3. Extend DL-MO methods to estimate performance variations across readers. This work is the first to develop and use DL-MOs as accurate and efficient surrogates of human readers to characterize task-specific performance of DLRD methods in CT using patient images. The resultant performance assessment engine will facilitate training / testing of DL-based noise reduction algorithms and optimizing CT protocols and doses. These significant capabilities will ensure that diagnostic performance and the lifesaving diagnostic information obtained from CT are not compromised in DLRD-processed images.