Catherine Cook Kaczorowski, PhD Neuroscience - US grants

DESCRIPTION (provided by applicant): Abeta has emerged as a key molecule in the pathogenesis of Alzheimer's Disease (AD). This proposal will exploit the dependence of Abeta formation on the availability of the beta-site amyloid cleaving enzyme (BACE1) in order to reduce or block production of Abeta. Transgenic mice that express mutated human amyloid precursor protein (APP) show dramatic elevations in Abeta that parallel those seen in sporadic AD cases. Additionally, these mice show learning deficits and alterations in neuronal biophysical properties that underlie learning. This proposal will test the hypothesis that the removal of BACE1 from the genome will rescue the learning abilities and altered biophysical properties from the overexpression of Abeta in the "Westaway" mouse. Eyeblink conditioning, one of the most well characterized neuro-behavioral systems for learning and memory, and alterations in the amplitude of the afterhyperpolarization (AHP) and spike frequency accommodation (Accom) will respectively be used as behavioral and biophysical assays. The progeny of the Westaway and BACE knockout mice will comprise the four geneotypes that are required to test this hypothesis: The results should indicate whether or not a beta-secretase inhibitor will be a viable therapeutic agent for the treatment of AD.

Project Summary Alzheimer's Disease (AD) dementia currently afflicts over 5 million people in the United States and is projected to rise to 11-16 million elderly by the year 2050. Although aging is the most important risk factor for AD, it remains unclear to what extent the molecular changes that underlie 'normal' age-associated memory deficits contribute to symptoms of dementia observed in patients with AD. Recently my colleagues and I demonstrated that spatial memory deficits in mouse models of aging and AD correspond to disruption of Ca2+-dependent plasticity in neurons of the hippocampus. Albeit similar, the magnitude of neuronal dysfunction and scope of memory deficits were exacerbated in AD mice. The present proposal seeks to address whether 'normal' aging and AD-related memory impairments in these mouse models result from disruption of common molecular pathways, or result from divergent molecular alterations that confer similar cellular phenotypes. In order to do this, the applicant requires additional supervised research training in proteomics and gene transduction systems under the direction of primary mentor Dr. Andrew Greene (Professor of Physiology and Director of a National Center for Proteomics Research and Development at MCW) and co-mentor Dr. Nashaat Gerges (Assistant Professor, Molecular, Cell Biology and Anatomy at MCW). The central goal of this proposal is to assist the Principal Investigator establish her independence and secure a tenure-track faculty position such that she can lead a major research program aimed at determining susceptibility and causal factors that underlie aging-related dementias. The Mentored Phase will provide the applicant with training in proteomics to identify and quantitate membrane proteins differentially expressed in the hippocampus of 'normal' aging and AD mice with memory deficits. She will also gain expertise using viral-based gene transduction techniques to validate the role of several de novo 'hits' in memory function, as well as determine their role in modulating intrinsic neuronal excitability and synaptic plasticity. During this phase, the candidate will gain further experience using viral-based gene transduction techniques to attempt the rescue of memory deficits in mouse models of 'normal' aging and AD by downregulating our a priori target TRPC3. The training agenda incorporates laboratory-based training at MCW, opportunities for specialty training in external laboratories, formal coursework, proteomics and AD journal clubs, seminars, and tutorials. Such multidisciplinary training will ensure her ability to design, perform, troubleshoot and interpret experiments at multiple, complementary levels of analysis. The training environment will provide numerous opportunities for career development through national research presentations, collaborations, mentoring students, and training on the responsible conduct of research. During the Independent phase, the applicant will apply her recent training to validate the role of several novel targets in memory function, determine the mechanism/s underlying targeted disruption of memory at the cellular/synaptic level, and attempt to rescue memory deficits in mouse models of 'normal' aging and AD. Because Ab42 levels are strongly correlated with AD-related memory deficits2, we expect that successful rescue of memory deficits may also reduce Ab42 levels that will be tested in collaboration with Alzheimer's Disease expert Dr. Robert Vassar at Northwestern University Medical School. Outcomes of the proposed research have the potential to make a major impact on the identification of new treatments for both aging and AD-related memory disorders.

DESCRIPTION (provided by applicant): Alzheimer's disease (AD) dementia currently afflicts over 5 million people in the United States and is projected to rise to 11-16 million elderly by the year 2050. Although aging is the most important risk factor for AD, it remains unclear to what extent the molecular changes that underlie 'normal' age-associated memory deficits contribute to symptoms of dementia observed in patients with AD. Recently my colleagues and I demonstrated that spatial memory deficits in mouse models of aging and AD correspond to disruption of Ca2+-dependent plasticity in neurons of the hippocampus. Albeit similar, the magnitude of neuronal dysfunction and scope of memory deficits were exacerbated in AD mice. The present proposal seeks to address whether 'normal' aging and AD-related memory impairments in these mouse models result from disruption of common molecular pathways, or result from divergent molecular alterations that confer similar cellular phenotypes. In order to do this, the applicant requires additional supervised research training in proteomics and gene transduction systems under the direction of primary mentor Dr. Andrew Greene (Professor of Physiology and Director of a National Center for Proteomics Research and Development at MCW) and co-mentor Dr. Nashaat Gerges (Assistant Professor, Molecular, Cell Biology and Anatomy at MCW). The central goal of this proposal is to assist the Principal Investigator establish her independence and secure a tenure-track faculty position such that she can lead a major research program aimed at determining susceptibility and causal factors that underlie aging-related dementias. The Mentored Phase will provide the applicant with training in proteomics to identify and quantitate membrane proteins differentially expressed in the hippocampus of 'normal' aging and AD mice with memory deficits. She will also gain expertise using viral-based gene transduction techniques to validate the role of several de novo 'hits' in memory function, as well as determine their role in modulating intrinsic neuronal excitability and synaptic plasticity. During this phase, the candidate will gain further experience using viral-based gene transduction techniques to attempt the rescue of memory deficits in mouse models of 'normal' aging and AD by downregulating our a priori target TRPC3. The training agenda incorporates laboratory-based training at MCW, opportunities for specialty training in external laboratories, formal coursework, proteomics and AD journal clubs, seminars, and tutorials. Such multidisciplinary training will ensure her ability to design, perform, troubleshoot and interpret experiments at multiple, complementary levels of analysis. The training environment will provide numerous opportunities for career development through national research presentations, collaborations, mentoring students, and training on the responsible conduct of research. During the Independent phase, the applicant will apply her recent training to validate the role of several novel targets in memory function, determine the mechanism/s underlying targeted disruption of memory at the cellular/synaptic level, and attempt to rescue memory deficits in mouse models of 'normal' aging and AD. Because Ab42 levels are strongly correlated with AD-related memory deficits2, we expect that successful rescue of memory deficits may also reduce Ab42 levels that will be tested in collaboration with Alzheimer's Disease expert Dr. Robert Vassar at Northwestern University Medical School. Outcomes of the proposed research have the potential to make a major impact on the identification of new treatments for both aging and AD-related memory disorders.

? DESCRIPTION (provided by applicant): Alzheimer's Disease (AD) dementia currently afflicts over 5 million people in the United States and is projected to rise to 11-16 million elderly by the year 2050. Recently my colleagues and I demonstrated that spatial memory deficits in mouse models of aging and AD correspond to a decrease in excitability of neurons of the hippocampus. However, the molecular mediators of these intrinsic changes and the consequence of excitability changes at the individual neuron level once they are embedded into an active neural network remains unknown. The present proposal is based on our new preliminary data showing that memory deficits in an AD mouse model correspond to changes in the expression of a specific subset of excitatory and inhibitory receptors. These changes in expression are indicative of a shift in the balance of excitatory and inhibitory influences on hippocampal neural networks. An appropriate balance has been shown to be crucial for the generation normal gamma band oscillatory network activity and for the long range synchronization of beta and gamma oscillations. We have new electrophysiological pilot data, showing that spatial memory deficits in our AD mouse model is correlated with a significantly reduced coherence of hippocampus (Hip) and prefrontal cortical (PFC) oscillatory network activity in the beta and gamma frequency ranges. Additional preliminary data on receptor expression provide a probable mechanistic explanation for the observed reduction in Hip-PFC coherence. It is posited that either misregulation of plasma membrane proteins normally required for memory (via de novo synthesis) and plasticity, or the dysfunction of Hip-PFC network coherence, or both, underlie spatial memory deficits in AD that will be tested in ensuing aims. Outcomes of the proposed research have the potential to make a major impact on the identification of new treatments for AD-related memory disorders. Our molecular and network level analysis may also discover biomarkers that could be used to detect potential onset of Alzheimer's disease well in advance, so that treatment could begin earlier with better success rates.

Alzheimer?s disease (AD), the most common form of dementia, affects over five million people in the United States. A vast majority of cases are the result of late-onset AD (LOAD), which has a wide variability in onset, progression, and severity across the population. We posit that normal aging and AD memory decline result from common molecular pathways; therefore, we expect that the identification of genetic factors and mechanisms underlying normal aging will provide feasible targets for intervention against AD. The identification of genetic risk factors and mechanisms in humans has been impeded largely by the known heterogeneity of degenerative changes, the numerous environmental confounds that can exist in human cohorts, and the difficulty in obtaining molecular and functional data from humans at the preclinical and/or early stages of disease. Genetic reference panels, such as the BXD panel of mice, model a portion of the genetic complexity of human populations while controlling for environmental factors. We will use the BXD panel in order to identify genetic factors and mechanisms that modify the onset and severity of memory decline. We will measure memory function in our BXD panel across their lifespan (6, 12, and 18 mo) and perform subsequent genetic linkage mapping in order to identify genomic areas that correlate to disease progression. We hypothesize that multiple gene variants modulating memory decline do so by altering expression of hippocampal proteins necessary for memory, so we will also quantitatively evaluate protein levels in the hippocampus across the lifespan in BXD strains that exhibit extreme variation in cognitive decline (i.e. susceptible and resilient strains; bottom and top 10%). Candidate risk and protective factors will be selected for functional validation in normal aging and AD mouse models using sequence data, existing hippocampal mRNA from age-matched strains, and numerous bioinformatics resources. Pilot studies suggest candidates involved in expression of hippocampus membrane proteins that modulate neuronal excitability (e.g. Hp1bp3, Trpc3) contribute to individual differences in cognitive aging, and may also impact the development and progression of AD. Thus, up to 5 novel candidate genes (alongside Hp1bp3, Trpc3) will be tested by manipulating gene sequence or expression using viral delivery of genome editing constructs or siRNA, respectively, and measuring the effect on cognitive decline, neurophysiological changes and neuropathological markers of AD using established AD- related mouse models and age-matched controls. The identification of novel genetic factors and mechanisms of memory decline will be a critical first step toward the development of both mechanistic-based treatments and personalized gene therapies that would maintain cognitive function in elderly humans. The identification of predictive genetic variants or neurophysiological biomarkers would also have the tremendous potential to provide biomarkers for earlier detection and more effective treatment in AD patients.

PROJECT SUMMARY Cognitive resilience to Alzheimer's Disease (AD) is a phenomenon whereby individuals are resistant to its most damaging effects on cognition, despite the presence of known familial AD (FAD) mutations or advanced neuropathology. Genetic factors promoting cognitive resilience may thus provide key targets for treatment and prevention of AD. Our overall objective is to identify drivers of cognitive resilience by using network approaches to integrate data collected from mouse FAD models with human AD data. To this end, we will in Aim 1 use a novel mouse panel that incorporates high-risk human FAD mutations on a segregated background of genetic diversity (BXD panel) to identify modifiers that contribute to AD resilience in a `humanized' mouse population. High-dimensional molecular, cognitive and pathologic data from these mice will be integrated to predict resilience factors and networks using causal inference analyses. In Aim 2, we will test two set of genes for association with resilience in humans with asymptomatic AD: 1) a previously validated list of genes identified by proteomics and behavioral analyses to be associated with exceptional cognitive longevity in mice and 2) novel genes and networks implicated by our analyses in Aim 1. In Aim 3, we will validate resilience factors and determine their effects on memory-relevant brain networks in powerful AD mouse models, testing both novel candidates identified in Aims 1 and 2 and a priori candidates (e.g., Trpc3, Adamts17 and Hp1bp3). This project will deliver novel, validated targets for promoting healthy brain aging and resilience to AD. Moreover, we will provide mechanistic insight into AD resilience, specifically supporting or refuting our hypothesis that modifiers of cognition in FAD similarly influence late-onset AD by preserving the functional connectivity of memory relevant networks. We will annotate, curate, and rapidly disseminate the data to the broad scientific community prior to publication via the NIA-supported AMP-AD Knowledge Portal to maximize the usability of these data for meta-analysis and systems biology research.

PROJECT SUMMARY/ABSTRACT Memory impairment and cognitive deficits are the most prominent feature of Alzheimer?s disease (AD); hence, current AD research has focused predominantly on CNS regions related to learning and memory, such as the hippocampus. However, one of the most consistently reported phenotypes in AD patients is weight loss, which may precede memory loss and cognitive decline by as much as 17 years, raising the question of whether hypothalamic dysfunction is an early cause of AD or merely coincident with disease onset? We propose that hypothalamic dysfunction during the preclinical stage of AD is an early causative step in a cascade of events culminating in dementia, which arises from complex interactions between genetic and environmental (GxE) risk factors that include diet and obesity. Our overall objective is to discover genetic variants and networks that modulate body weight across the lifespan, a clinically relevant biomarker of hypothalamic dysfunction that is predicative of cognitive status later in life. To this end, in Aim 1 we will use a novel mouse panel that incorporates high-risk human FAD mutations on a segregated background of genetic diversity (BXD panel) to identify modifiers that contribute to variation in body weight that is associated with cognitive decline. In Aim 2, we will identify genetic variants that modulate susceptibility to HFD, and derive directed networks and molecular pathways mediating the impact of diet and obesity on AD symptoms via causal inference analysis. In Aim 3, we will evaluate a priori candidates Igf1r, Esr2, and Apbb2 and up to 10 candidates from Aims 1 and 2, establishing the feasibility and independence of Aims. Successful completion of these aims will yield critical new insight into the pathogenesis of AD, including how modifiable environmental factors influence susceptibility and risk. Our deliverables include potential new biomarkers for early detection and new therapeutic strategies targeting the very earliest preclinical stages of the disease to delay or even prevent AD.

PROJECT SUMMARY/ABSTRACT Cognitive resilience to Alzheimer?s Disease (AD) is a phenomenon whereby individuals are resistant to its most damaging effects on cognition, despite the presence of known familial AD (FAD) mutations or advanced neuropathology. Genetic factors promoting cognitive resilience may thus provide key targets for treatment and prevention of AD. Our overall objective is to identify drivers of cognitive resilience by using network approaches to integrate data collected from mouse FAD models with human AD data. To this end, we will in Aim 1 use a novel mouse panel that incorporates high-risk human FAD mutations on a segregated background of genetic diversity (BXD panel) to identify modifiers that contribute to AD resilience in a ?humanized? mouse population. High-dimensional molecular, cognitive and pathologic data from these mice will be integrated to predict resilience factors and networks using causal inference analyses. In Aim 2, we will test two set of genes for association with resilience in humans with asymptomatic AD: 1) a previously validated list of genes identified by proteomics and behavioral analyses to be associated with exceptional cognitive longevity in mice and 2) novel genes and networks implicated by our analyses in Aim 1. Our recent analyses of bulk RNAseq data from the hippocampus and prefrontal cortex of the AD-BXDs suggest that there are changes in the cellular composition of these brain regions that are associated with resilience to AD, providing strong justification for the proposed supplement to add single-cell sequencing of these same brain regions. With the proposed supplement, we will be able to identify genes that are differentially expressed in specific cell-types that promote resilience to AD in mouse and human, but will be ?missed? by standard analyses of bulk sequencing data. In Aim 3, we will validate resilience factors using cell-type specific promotors and determine their effects on memory-relevant brain networks in powerful AD mouse models, testing both novel candidates identified in Aims 1 and 2 and a priori candidates (e.g., Trpc3, Adamts17 and Hp1bp3). This project will deliver novel, validated targets for promoting healthy brain aging and resilience to AD. Moreover, we will provide mechanistic insight into AD resilience, specifically supporting or refuting our hypothesis that modifiers of cognition in FAD similarly influence late-onset AD by preserving the functional connectivity of memory relevant networks. We will annotate, curate, and rapidly disseminate the data to the broad scientific community prior to publication via the NIA-supported AMP-AD Knowledge Portal to maximize the usability of these data for meta- analysis and systems biology research.

PROJECT SUMMARY Alzheimer?s disease is the most common cause of dementia in the elderly, but there are a number of other related dementias that exhibit substantial overlap in the behavioral, cognitive, and neuropathological manifestations of the disease. In fact, the majority of dementia cases likely arise from the co-occurrence of one or more of these AD and AD-related pathologies, with very few individuals exhibiting ?pure? Alzheimer?s pathology (e.g., only amyloid plaques). This complexity makes diagnosis and therapeutic development challenging, a problem exacerbated by a paucity of accurate animal models for ADRD that faithfully recapitulate the full spectrum of the molecular, cellular, cognitive, and behavioral pathologies of these dementias. In response to PAR-19-167, we will create a panel of genetically diverse knock-in mice harboring known mutations associated with AD and several related dementias using precise genomic editing to ensure biologically-relevant gene expression patterns and levels. In Aim 1, we will use CRISPR/Cas9 to create mice carrying combinations of disease-causing mutations in App, Psen1, Mapt, Tardbp, and Snca to produce a set of ?core? strains we expect to better capture the complexity of ADRD. To capture the role of genetic background in disease risk, we will then cross these ?core? mice to four genetic backgrounds known to promote susceptibility or resilience of ADRD (DBA/2J, FVB/NJ, WSB/EiJ, and C57Bl/6J). We will then leverage our expertise in high-throughput mouse neurobehavioral phenotyping to screen 16 new ADRD strains to identify the lines that best model ADRD. In Aim 2, we will use our deep phenotyping pipeline to fully characterize our top strains across the entire spectrum of ADRD-related symptoms, including both cognitive and non-cognitive domains. We will also use high-field MRI, histopathological measurements, and molecular phenotypes to assess effects on brain structure, extent of neuropathologies, and impact on gene networks and pathways associated with disease. Finally, in Aim 3, we will validate our new models for use in basic science and preclinical studies by determining concordance between mouse and human data and use network modeling approaches to identify early drivers of disease that predict late-stage outcomes in humans. This project will produce much-needed new models for AD and related dementias that will greatly enhance our understanding of the pathological mechanisms underlying these diseases. Finally, all of the models produced here will be distributed to the community via the JAX Repository. We will also make all of the phenotyping data publicly available using resources such as Mouse Phenome Database, GeneWeaver, and Synapse.

We propose to conduct the first comprehensive analysis of the determinants of normal human cognitive aging using a systems genetics resource?the Diversity Outbred panel of mice, DO?specifically designed to model the genetic and phenotypic variation of human populations. The goal of this project is to identify genetic factors and mechanisms underlying variation in normal cognitive aging, and that lead to pathologic brain aging. Large- scale human genetics studies have been central to understanding links between an individual?s genetic make- up and their risk for developing cognitive decline and Alzheimer?s Disease (AD). However, discovery of specific factors in humans has been impeded by the lack of longitudinal measures of cognitive function, heterogeneity of cognitive and neurophysiological changes, numerous environmental confounds, and difficulty obtaining molecular data at the early asymptomatic stages of disease. While mouse models offer significant experimental control for longitudinal and cross-sectional aging studies, conventional inbred strains do not recapitulate the genetic diversity necessary to identify human disease?relevant candidate genes. This proposal attempts to surmount these limitations by testing the translational relevance of gene candidates discovered using our DO panel against data from human cohorts. Since age and genetics are the leading risk factors for AD, we hypothesize that genetic factors underlying variation in normal cognitive aging (ranging from extreme risk to resilience) are involved in the development of cognitive symptoms in AD. We will take a systems genetic approach to identify genes and potential molecular and cellular mechanisms that modify the age at onset and severity of cognitive aging in a cohort of male and female DO mice (Aim 1). Candidate genes and networks will be tested for associations against normal aging and AD cohorts in humans to identify resilience factors conserved in humans (Aim 2). We will test the role of these candidate genes predicted to promote healthy brain aging (resilience), as well as those associated with a negative shift from normal cognitive aging toward AD pathophysiology (Aim 3). Specific innovations (in addition to the DO mice) include the use of multi-scale network methods to identify resilience proteins that are capable of distinguishing perturbations and networks that initiate cognitive resilience from those that merely correlate; our cross-species translational platform for testing candidates identified in mice in multiple human cohorts; the unmatched mouse resources and expertise of The Jackson Laboratory, which will be leveraged for gene validation and creation of precision AD models; and our team of experts in human and mouse genetics, bioinformatics, high-resolution microscopy and functional validation. IMPACT: We will discover and validate targets for promoting healthy brain aging and resilience to AD and will provide mechanistic insight into cognitive resilience. The identification of genetic factors and mechanisms underlying variation in normal cognitive aging, and that lead to pathologic brain aging, will likely point to novel therapeutic strategies, including ones that may be used before the onset of AD symptoms.

PROJECT SUMMARY Cognitive resilience to Alzheimer's Disease (AD) is a phenomenon whereby individuals are resistant to its most damaging effects on cognition, despite the presence of known familial AD (FAD) mutations or advanced neuropathology. Genetic factors promoting cognitive resilience may thus provide key targets for treatment and prevention of AD. Our overall objective is to identify drivers of cognitive resilience by using network approaches to integrate data collected from mouse FAD models with human AD data. To this end, we will in Aim 1 use a novel mouse panel that incorporates high-risk human FAD mutations on a segregated background of genetic diversity (BXD panel) to identify modifiers that contribute to AD resilience in a `humanized' mouse population. High-dimensional molecular, cognitive and pathologic data from these mice will be integrated to predict resilience factors and networks using causal inference analyses. In Aim 2, we will test two set of genes for association with resilience in humans with asymptomatic AD: 1) a previously validated list of genes identified by proteomics and behavioral analyses to be associated with exceptional cognitive longevity in mice and 2) novel genes and networks implicated by our analyses in Aim 1. In Aim 3, we will validate resilience factors and determine their effects on memory-relevant brain networks in powerful AD mouse models, testing both novel candidates identified in Aims 1 and 2 and a priori candidates (e.g., Trpc3, Adamts17 and Hp1bp3). This project will deliver novel, validated targets for promoting healthy brain aging and resilience to AD. Moreover, we will provide mechanistic insight into AD resilience, specifically supporting or refuting our hypothesis that modifiers of cognition in FAD similarly influence late-onset AD by preserving the functional connectivity of memory relevant networks. We will annotate, curate, and rapidly disseminate the data to the broad scientific community prior to publication via the NIA-supported AMP-AD Knowledge Portal to maximize the usability of these data for meta-analysis and systems biology research.

Resilience to brain aging and Alzheimer?s disease (AD) is a phenomenon whereby cognitive functioning is better than predicted based on chronological age, genetic risk and/or advanced neuropathology, likely because of the presence of as yet unidentified protective factors. These factors, once identified, are expected to provide key targets for treatment and prevention of AD. However, significant barriers limit discovery of the genetic mechanisms of resilience using human genetic methods alone, including: difficulties in identifying large numbers of individuals with asymptomatic AD, extracting age and interacting genetic effects from complex human genomes, controlling environmental factors, and obtaining brain tissue from asymptomatic AD cases. Moreover, it is well known that transcript abundance is not sufficient to infer protein abundance, as they differ spatially, temporally, and in response to learning tasks. Yet, our ability to discern how proteomes change across aging and AD progression is limited by the impossibility of longitudinal molecular analyses on human brain tissues, as well as the technology needed to profile cell type-specific proteomes associated with susceptibility versus resilience to AD. To fill these significant technological and knowledge gaps, here we will develop a robust pipeline using the most translationally relevant mouse models of human brain aging and AD (i.e., the AD-BXDs and their non-transgenic Ntg-BXDs controls) to obtain a longitudinal knowledge base of proteomes in specific cell types that we have found to exhibit robust changes in gene expression associated with highly susceptible and highly resilient phenotypes. We will focus on the hippocampus as it is required for spatial memory formation and recall in mice and humans, and hippocampus-dependent memory deficits are common in AD. Indeed, our work and preliminary data suggest that mouse strain differences in the age at onset and progression of cognitive deficits in the AD-BXDs (from extremely susceptible to resilient) result from cell type-specific differences in gene expression in the hippocampus. We will integrate these mouse data with clinical and omics data from NIA-sponsored AMP-AD and Resilience-AD Consortia to identify molecular drivers of cognitive resilience. In Aim 1, we will identify cell type-specific changes in neuron and microglia protein expression associated with resilience to AD using bioorthogonal non-canonical amino acid tagging (BONCAT) in AD-BXDs. In Aim 2, we will translate drivers and molecular networks underlying cognitive resilience to human AD cohorts. In Aim 3, we will leverage the unmatched genetic engineering resources at The Jackson Laboratory to functionally validate ?in-hand? resilience candidates by determining their effects on memory, hippocampal neuronal excitability, and synaptic plasticity in CRISPRed AD-BXDs. Using this pipeline, we will thereby discover novel and translationally relevant proteins and complexes for consideration under AMP-AD/TREAT-AD drug discovery pipelines to delay or prevent cognitive symptoms in susceptible AD mice, and ultimately AD patients.

PROJECT SUMMARY Our proposed research aims to identify sex-specific genetic drivers of neuropathologic, cognitive, and metabolic phenotypes of Alzheimer?s disease by integrating longitudinal behavioral and molecular data from AD mice with genetic, genomic and clinical data from human cohorts. We will leverage a newly generated mouse population that incorporates high-risk familial AD (FAD) mutations on a genetically diverse background (BXD panel) to identify modifiers that contribute to AD resilience in this ?humanized? mouse population. In parallel, we will incorporate cutting-edge single-cell omic approachs to generate a molecular atlas of human brains from carriers of FAD mutations (in APP, PSEN1 and PSEN2) and non-carriers with sporadic AD. By combining and validating analyses in both mouse and human datasets, we expect to find molecular candidates that robustly contribute to sex-specific variation in symptoms of AD. We will further validate these candidates using unparalleled in vivo mouse technology to not only empircally assess their role in sex-specific mechanisms of disease, but also to evaluate sex X genotype X treatment interactions in a subset of candidates (i.e., Apoe) to inform more personalized therapeutic approaches. The approach we propose benefits from the enhanced discovery power and value of existing human genetics resources and novel, precision AD mouse models across multiple institutions to investigate the mechanisms of sex differences in AD.