James J. Lah - US grants

The recent identification of genes associated with early -onset familial Alzheimer's disease (FAD) opens new and exciting avenues of investigation into the pathogenesis of this devastating and incurable cause of dementia. The first gene to be identified, S182, may be responsible for many of the chromosome 14 associated cases of FAD. Subsequent reports identifying a homologous gene, STM2, implicated in chromosome 1 associated FAD are perhaps most remarkable for the fact that these two genes have begun to define a new gene family which is important in the pathogenesis of Alzheimer's disease. There are two other known members of this family which have been identified in Caenorhabditis elegans. The amino acid sequences and the putative structure of the four proteins are closely related and suggest that they may share functional similarities. In this proposal, we outline a series of experiments and hypotheses which will begin to critically analyze the function of these proteins. In Specific Aim 1, we propose the production of a series of isoform- and domain-specific antibodies to S182 and STM2. These antibodies are being designed to allow their use in addressing several specific hypotheses in subsequent Specific Aims. We present the results of some Preliminary Studies which demonstrate the successful production of the antibody to S182. In Specific Aims 2 and 3, we will exploit these antibodies to pursue questions regarding the distribution and structure of these proteins. In the final Specific Aim, we will investigate the possible functional relationship between S182 and STM2 and the C. elegans protein SPE-4. These experiments will attempt to phenotypically rescue loss of function spe-4 mutants through the introduction of human S182 and STM2 sequences. In addition to these research activities, this proposal is being submitted as part of an overall plan of training and career development. Activities are outlined over a five year period which will provide the Principal Investigator with a unique opportunity to development as a research scientist and help to insure his success in academic neurology.

DESCRIPTION (provided by applicant): Converging lines of evidence have highlighted the involvement of lipoprotein receptors in common, sporadic cases of Alzheimer's disease (AD). The apolipoprotein E (apoE) e4 allelic variant increases AD risk, and the apoE receptors have been linked to the metabolism of the B-amyloid precursor protein (APP) and beta-amyloid peptide (AB), which are believed to play a central role in AD. Using cDNA microarrays to screen changes in gene expression in AD patients, we discovered altered expression of LR11, a multifunctional apoE receptor that is expressed predominantly in brain. LR11 has not previously been linked to AD, but our exciting preliminary findings reveal marked loss of LR11 among vulnerable neurons in AD. In addition, LR11 appears to interact with APP, and we have found important links between LR11 expression and levels of AB These observations provide a strong foundation for the central hypothesis of this proposal: The multifunctional apoE receptor LR11 participates in Alzheimer's disease pathogenesis through its interactions with B-amyloid precursor protein and AB peptide. In Aim 1, we will characterize the molecular interactions of LR11 with APP and generate modified LR11 constructs that will be used in subsequent Aims. In Aim 2, we will examine the ability of LR11 to influence the subcellular distribution of APP and assess the effects on proteolytic processing of APP. In Aim 3, complementary studies will test the ability of LR11 to modulate AB production and mediate AB clearance. In Aim 4, we will generate and characterize cell culture and mouse model systems with reduced LR11 levels to mimic the loss of expression observed in AD brains. These Aims will test our central hypothesis and the findings will generate insights into the biology of apoE receptors, and the results may identify LR11 as an important new target for AD therapeutics.

With the maturation of our understanding of disease mechanisms in Alzheimer's disease (AD) and other neurodegenerative disorders, there is an urgent need to relate basic neurobiological advances to patientbased research. To capitalize on scientific advances during the past two decades, the community of basic, translational, and clinical investigators must coordinate our efforts to maximize opportunities to accelerate improvements in clinical care. The Emory ADRC maintains an intense focus on integrative research efforts, and the Clinical Core serves the vital functions of providing clinical infrastructure and facilitating access to research participants to support research on AD and related neurodegenerative disorders. Key themes for the Clinical Core in this competing renewal are to continue to support and strengthen our center's focus on integrative science and expand the participation of African-American elders in these activities. During our initial funding period, the Emory ADRC Clinical Core has worked closely with other elements of our center to establish a strong foundation and demonstrable effectiveness in supporting productive basic and clinical research studies. The Specific Aims forthe current proposal are 1) to recruit participants for ADRC Research Projects and support translational neurodegenerative disease research at Emory, 2) to maintain a cohort of research participants and contribute top-quality clinical data and biological samples to national coordinating centers, and 3) to maximize participation of African-American elders in ADRCsponsored research and related projects. Through these Aims, we will continue building our capacity to support cutting edge research with a specific emphasis on developing methods to identify and recruit individuals at early stages of cognitive decline to participate in basic research and clinical research on early detection and disease-modifying therapies. We will also continue to explore unique opportunities to ameliorate the existing racial disparities in biomedical research through a unique partnership between the Emory ADRC and leaders in the Atlanta African American community. The themes and goals that are proposed for the Clinical Core are consistent with the overall focus of the Emory ADRC, and it will serve as a powerful proponent for basic and clinical research efforts to advance our abilities to diagnose and treat patients suffering from AD and other neurodegenerative dementing diseases.

Understanding the onset of Alzheimer's disease (AD) requires the development of new research methods, which can be applied to preclinical disease and for the generation of new as well as the improvement of currently available drugs such as those which augment cholinergic neurotransmission early in the progression of AD. During the current five years of the PPG, subproject 2 has pioneered methods for using liquid chromatography coupled with tandem mass spectrometry for proteomic examination of brain tissue to study the proteome of AD during disease progression. These efforts led to the discovery of pathological accumulations of components of the Ul small nuclear ribonucleoprotein (Ul snRNP) and global disruption of RNA processing in Alzheimer's disease (AD). We will apply these innovative proteomics approaches along with well-established biochemical and immuohistochemical methods to 1) define pathological accumulations of Ul snRNP within the cortical regions which compose the memory default network which receive extensive cholinergic innervation from the long cortical cholinergic projection neurons located within the subfields of the nucleus basalis of Meynert during progression of AD, 2) Identify changes in Ul snRNP components, posttranslational modifications of tau, and novel proteins that define cholinergic basal forebrain neuron subfield dysfunction that follows a caudal to rostral progression the during progression of AD, and 3) examine changes In RNA processing linked to Ul snRNP pathology within the cholinergic basal forebrain neurons during the progression of AD. The proposed studies will improve our understanding ofthe role of Ul snRNP in the development and progression of AD, and likely to identify novel mediators of disease. Such advances are critical to advancing our understanding of AD and the development of more effective therapeutics.

SUMMARY/ABSTRACT: CLINICAL CORE (CORE B) The primary goals of the Emory ADRC Clinical Core are to support and enhance research efforts to understand the causes of Alzheimer's disease and related neurodegenerative disorders in order to develop effective treatments. To accomplish these goals, the Clinical Core maintains a cohort of volunteers who allow investigators to examine the process of normal and pathological cognitive aging, provide essential biological specimens and neuroimaging data, and serve as participants in promising clinical trials. The Clinical Core contributes to local, national, and international studies and reflects NIA-defined network-wide priorities. In the current funding period, the Core has provided top-quality clinical data and biological samples to national coordinating centers, and has maximized community engagement and participation of African-American older adults in ADRC-sponsored research and related projects. Specific Aims for this renewal are to 1) continue to maintain a cohort of well-characterized participants to support efforts to understand normal cognitive aging and decline due to AD and related disorders; 2) develop innovative approaches to increase the participation of African Americans in AD research; and 3) establish a Longitudinal Biomarker Collection to support research and improve understanding of the early stages of pathological cognitive aging. We will focus our efforts on preclinical disease and mild cognitive impairment since treatments are more likely to be successful if implemented at an early stage. We also plan to double the current cohort to include 50% African Americans to address stark racial imbalances in understanding clinical, pathological, and genetic features of AD and to make data available for multicenter studies. As part of this effort, we will collect data to define elements that improve success in recruiting and engaging African-American research volunteers. Longitudinal biomarker sampling of blood, CSF, and neuroimaging will provide a powerful resource since cross-sectional studies limit our ability to identify predictors of AD onset and progression. The themes and goals that are proposed for the Clinical Core are consistent with the overall focus of the Emory ADRC, and it will serve as a powerful proponent for basic and clinical research efforts to advance our abilities to diagnose and treat patients suffering from AD and other neurodegenerative dementing diseases.

Project Summary ? Biomarker Core Alzheimer's disease (AD) is a chronic disease that progresses through a lengthy asymptomatic period before entering a period of mild cognitive impairment (MCI) and dementia. Using current biomarker tools, we can determine with a fair degree of confidence whether or not AD-related pathology is present in a living individual. However, there remain major limitations in the capabilities of AD biomarkers, and there is a critical need for new biomarkers to overcome remaining barriers. The proposed Biomarker Core will support research activities in the Emory ADRC by pursuing four Specific Aims: 1) Establish an ethnoracially diverse biomarker collection in the Emory ADRC UDS cohort; 2) Perform assays for established CSF AD biomarkers and explore promising candidates; 3) Support network-wide neuroimaging initiatives and evaluate promising exploratory sequences; and 4) Establish standard genetic profiles for the UDS cohort and explore potential gene expression and epigenomic changes relevant to AD. The proposed Biomarker Core will provide a number of important enhancements to the research environment. Longitudinal collection of common datasets, including clinical information, CSF AD biomarkers, core genetic information, and standard brain MRI sequences, will provide foundations upon which new AD biomarkers can be tested, evaluated, and confirmed. Exploratory research in each of these areas should provide significant advances in CSF proteomics, new MR sequences, and genomic and epigenomic data. Lastly, the current proposal engages a group of talented investigators who will bring their expertise to the ADRC and the larger research community. Each of these elements advance the overall goals of the ADRC and will be fully integrated into existing Cores and local research environment.

SUMMARY/ABSTRACT: CLINICAL CORE The primary goals of the Clinical Core are to support and enhance research efforts of the Goizueta Alzheimer?s Disease Research Center (ADRC) at Emory to advance cutting-edge research to identify novel biomarkers and therapeutic targets while reducing racial disparities in AD research. The Clinical Core plays a central role in the Goizueta ADRC by engaging diverse research participants and driving activities that reflect the Center?s overall themes. To accomplish these goals, the Clinical Core has well-established processes to recruit, track, characterize, and retain a cohort of longitudinal research participants and to effectively coordinate activities and share data with other components of the ADRC and external partners. In the current funding period, the Clinical Core established a Longitudinal Biomarker Collection to support high-priority multicenter research projects, including the Accelerating Medicine Partnership for AD (AMP-AD) and Molecular Mechanisms of the Vascular Etiology of AD (M2OVE-AD). Successful development of the LBC led to a competitive supplement to establish a Biomarker Core which will continue as a Core component in the ADRC renewal. Also, during the current cycle, we succeeded in our ambitious goal for increasing the diversity of our UDS cohort by enrolling an equal number of new African-American and Caucasian participants. This success supported the establishment of a Minority Engagement Core (MEC). Specific Aims for this renewal are to 1) Establish and maintain a diverse cohort of well-characterized research participants to support priorities in current ADRD research; 2) Advance biomarker discovery efforts by harmonizing procedures for sample collection and clinical phenotyping across multiple related projects and cohorts; and 3) Expand and integrate activities in ADRD, including vascular cognitive impairment and Lewy body diseases. Achieving these Specific Aims will advance the priorities identified in the National Alzheimer?s Project Act (NAPA) and recommendations from the NIH ADRD Research Summits, and will ultimately lead to effective diagnostic tools and treatments for individuals suffering from AD and related disorders.

Abstract/Summary Progress in understanding Alzheimer?s disease and related disorders (ADRD) is close to producing more effective treatments, creating an urgent need for disease-predictive biomarkers to guide their use. Using cerebrospinal fluid (CSF) measurements of beta-amyloid and Tau and positron-emission tomography tracers, we can detect AD pathology in cognitively normal individuals. However, current tools do not allow us to predict when or even if an individual with asymptomatic pathology will develop symptoms. To address this need, we propose to longitudinally study ?3000 cognitively normal individuals (50-75 years at enrollment) in the Emory Healthy Brain Study to define the frequency of asymptomatic AD and rates of cognitive decline in a racially diverse cohort of healthy individuals (Specific Aim 1). An important goal of Aim 1 is to achieve ?33% African- American participants to provide sufficient power to address questions regarding race- and sex-dependent differences in biomarkers and risk of cognitive decline. Participants will be phenotyped biennially with cognitive testing, cardiovascular physiology, brain MRI, and blood and CSF collection. Cross-sectional (Specific Aim 2) and longitudinal analyses (Specific Aim 3) will test the hypothesis that biomarkers of synaptic, vascular, myelination, glial immunity, and metabolic functions will identify subgroups who are at greatest risk of progressing to symptomatic AD. Candidate biomarkers will be identified through state-of-the-art proteomics, MR imaging, and statistical methods. A highly collaborative data and biospecimen sharing plan will allow other investigators to leverage these resources to advance a broad spectrum of ADRD research.