1985 — 1988 |
Worley, Paul F |
K11Activity Code Description: Undocumented code - click on the grant title for more information. |
In Vivo Cns Muscarinic Receptor Assay/Alzheimer Disease @ Johns Hopkins University
The objective of this project is to develop and implement techniques for the in vivo assay of muscarinic cholinergic receptors in the central nervous system. This will be performed by the use of an intravenously administered iodinated radiopharmaceutical with very high affinity for the muscarinic receptor in conjunction with quantitative external imaging using Single Photon Emission Computerized Tomography (SPECT). The muscarinic receptor ligand we proposed to use [123I]3-quinuclidinyl-(3-iodo-4-hydroxybenzilate) (I-OH-QNB). This technique will ultimately be used to study muscarinic receptors in patients with Alzheimer's Disease. In a longitudinal fashion, we plan to study the alterations of the relative regional and absolute muscarinic receptor densities in patients with Alzheimer's Disease. This data will be obtained in parallel with careful cognitive and neurologic follow up. Additional correlation with neuropathologic examination of the muscarinic system may in some cases be possible.
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1991 — 1993 |
Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Regulatory Gene Induction by Activity in Visual Cortex @ Johns Hopkins University
stimulus /response; neural plasticity; developmental neurobiology; transcription factor; gene expression; visual cortex; regulatory gene; gene induction /repression; tetrodotoxin; retinal adaptation; retina; retinal ganglion; light adaptations; visual photosensitivity; protooncogene; genetic regulation; genetic transcription; afferent nerve; visual deprivation; photostimulus; antibody;
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1992 — 1994 |
Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Molecular Characterization of Visual Plasticity @ Johns Hopkins University
Classical studies have demonstrated a critical role for neuronal activity in normal cortical development and plasticity. Developmental plasticity appears similar in many respects to other forms of experimental neuroplasticity, however the molecular basis for the long- term adaptive response remains to be determined. Recent studies indicate that physiological activity can induce a rapid genomic response in neurons. Genes known to be activated in this response code for transcription factors, suggesting that the genomic response may play a regulatory role in neuronal plasticity. Similar regulatory gene responses are observed in a variety of cell types and are believed to underlie cellular growth and differentiation. In fact, insights into neuronal physiology have been achieved using molecular tools initially developed in studies of cultured fibroblasts and PC12 cells. Precedent from these culture systems indicate that the initial genomic response includes an array of molecules in addition to transcription factors including cytokines, transmembrane signalling molecules and cellular matrix proteins. It is notable, that of the set of rapid response genes clones from stimulated fibroblasts only transcription factors are induced in brain suggesting that these other molecules may define the cellular specificity of the response. The focus of this proposal is to identify novel neuronal genes involved in the initial response to activity. Based on precedent from culture systems, it is anticipated that these genes will code for proteins involved in regulating adaptive neuronal responses. I have used a differential cloning strategy to identify a set of six novel genes that are induced by physiological activity in the developing visual cortex. Preliminary data indicate that these genes may be neuron specific. As a first step in defining their function, full length cDNAs will be cloned, sequenced and analyzed for predicted structure and homology to previously identified genes (Aim 1) Unique regions of the predicted amino acid sequence will be expressed as bacterial fusion proteins for generation of specific antisera (Aim 2). With these tools, we will examine the regulation of the mRNA and presumed protein products during normal development and in the visual cortex in response to synaptic activity. These studies are likely to provide new tools and insights into the molecular basis of developmental plasticity.
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1994 — 2013 |
Worley, Paul F |
K02Activity Code Description: Undocumented code - click on the grant title for more information. R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Novel Cellular Mechanisms in Cortex Development @ Johns Hopkins University
DESCRIPTION (provided by applicant): This application is a competitive renewal of R01 MH 53608-09. The focus of the proposal is to examine the function of the immediate early gene (lEG) termed Arc, and its contribution to activity-dependent plasticity. Arc was cloned in our laboratory based on its rapid induction in response to neuronal activity (Lyford, 1995). Arc mRNA is strikingly induced during learning behaviors and its transcriptional response provides the basis for a novel imaging method that detects stable neural networks in brain (Guzowski, 1999). Arc protein appears to be essential for learning and memory as interruption of Arc induction blocks the maintenance phase of LTP and disrupts memory (Guzowski, 2000). These studies focus attention on the molecular basis of Arc protein function at the synapse. In preliminary studies for the present renewal, we find that Arc protein interacts with certain SH3 domain proteins and also interacts with CaMKII. Moreover, Arc expression induces a LTD-like down regulation of AMPAR responses in hippocampal neurons. Aim 1 will examine the hypothesis that Arc functions to recruit the SH3 domain protein termed endophilin 3, together with CaMKII, to form a unique endocytic vesicle that is involved in AMPAR trafficking. Biochemical studies will define the composition of the putative Arc endosome, and structural determinants of Arc essential for its action. Aim 2 will examine the mechanism of Arc function at the excitatory synapse. Preliminary studies indicate that the SH3 interaction site of Arc is required to evoke down regulate AMPAR, and proposed studies will test the hypothesis that the Arc-endosome selectively modifies trafficking of distinct AMPAR. We will also examine mechanisms that regulate localized expression of Arc protein. Aim 3 will generate mouse transgenic models to test the contribution of the SH3 and CaMKII interaction domains of Arc on synaptic and behavioral plasticity. These studies will identify novel mechanisms that underlie long-term, activity-dependent neuronal plasticity, and explore promising links with the biology of disease.
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1996 — 1999 |
Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Novel Cocaine-Induced Ieg @ Johns Hopkins University
Several lines of evidence suggest that aspects of drug abuse and addiction may be understood as drug-induced neural plasticity {Nestler, 1993 #3645}. Immediate early genes (IEGs) are believed to play a role in mediating stimulus-induced neural plasticity and several laboratories have examined the IEG response induced by cocaine to identify changes in gene expression that may underlie the long-term neurochemical and behavioral effects of cocaine. Our laboratory has been successful in implementing a differential screening strategy to identify novel, brain IEGs and we have focused on a subset of these genes that are dynamically regulated by cocaine. One of these novel IEGs, termed clone 62, is the focus of this proposal. Preliminary studies indicate that 62 protein is a cytosolic protein that modifies neuronal structure and growth properties. Unlike other IEGs which encode transcription factors, 62 is a member of a newly recognized class of "effector" IEGs that can directly modify cellular function. 62 mRNA is rapidly and transiently induced in neurons of the striatum by cocaine and by NMDA-dependent synaptic mechanisms in association with long-term potentiation in the hippocampus, suggesting a role in several forms of neural plasticity. Northern analyses indicate that 62 mRNA expression is restricted to brain where it is enriched in telencephalic structures. Our preliminary assays of 62 function indicate that 62 blocks growth factor-induced cytodifferentiation of PC12 cells and modifies growth properties of NIH3T3 fibroblasts. Using the yeast 2- hybrid system, we have identified proteins that physically interact with 62 and that are candidates to function with 62 in the cell. One of these is the metabotropic glutamate receptor, mGluR5. The major focus of this proposal is to continue our analysis of the cellular and biochemical functions of 62 and its regulation by acute and chronic administration of cocaine. Experiments in AIM 1 will focus on identifying proteins that interact with 62 and that are likely physiological partners. Candidate proteins include mGluR5 and a novel cytoskeletal protein. AIM 2 will develop cellular assays of 62 function and examine the hypothesis that 62 modifies neuronal cytodifferentiation. In AIM 3 will examine the dynamics and cellular localization of 62 expression in the forebrain and its regulation by acute and chronic administration of cocaine. These studies will provide basic information regarding the molecular mechanisms underlying neurochemical and cellular effects of cocaine.
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1998 — 2000 |
Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Ieg Homer and Drug Addiction Effector @ Johns Hopkins University
DESCRIPTION: (Applicant's Abstract) Recent evidence suggests that aspects of drug abuse and addiction may be mechanistically understood as drug-induced neural plasticity. Immediate early genes (IEGs) are believed to play a role in mediating stimulus-induced changes in gene expression that underlie the long-term neurochemical and behavioral effects of cocaine. Our laboratory has identified a novel brain IEG, termed Homer, which appears to function at excitatory synapses where it interacts with metabotropic glutamate receptors. Metabotropic receptors are enriched in neurons of the striatum and are known to play an important role in long-term neuronal plasticity and in reward behaviors. The rapid induction of Homer in the striatum by cocaine is therefore likely to be important in long-term adaptive responses. Our approach to understand the function of Homer utilizes recent advances in knockout and transgenic technologies. Aim 1 will generate and examine Homer "knockout" mice. Knockouts are anticipated to provide essential information regarding the role of Homer in forebrain development and test the hypothesis of a selective role for Homer in activity-dependent modification of excitatory synapses. Aim 2 will generate transgenic mice that express epitope-tagged, wild-type Homer in brain neurons and evaluate the consequences of constitutive over expression. We hypothesize that these mice will exhibit an alteration in their ability to modify excitatory synapses in responses to neuronal activity and this will consequently modify chronic responses to cocaine. Aim 3 will generate mice that conditionally express wild-type Homer. These studies will test the reversibility of findings from Aim 2 and confirm their dependence on Homer expression. Additionally, these mice will permit us to explore novel mechanisms involved in the targeting of Homer protein to excitatory synapses. Aim 4 will generate mice that express a mutant form of Homer that does not bind mGluR to test the hypothesis that phenotypic changes assayed in Aims 2 and 3 are due to the ability of Homer to interact with the mGluR. These studies may identify a specific protein-protein interaction that could ultimately be targeted as a therapeutic approach to modify cocaine-induced behaviors.
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1999 |
Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Neuronal Activity Regulated Pentraxin and Glutamate Rec @ Johns Hopkins University
DESCRIPTION (Verbatim from the Applicant's Abstract): Our research focuses on molecular mechanisms that underlie protein synthesis-dependent synaptic plasticity. In particular, we are examining an immediate early gene (IEG) termed Narp that was identified based on its rapid up-regulation in response to synaptic activity (Tsui et al., 1996). Narp (Neuronal activity-regulated Pentraxin) is a secreted, self-multimerizing protein that is expressed by neurons. In recent studies, we find that Narp is selectively enriched at axo-dendritic excitatory synapses. Moreover, Narp induces clusters of AMPA-type glutamate receptors on the surface of heterologous cells, and selectively co-immunoprecipitates with AMPA receptors from brain. Narp shows extensive co-localization with AMPA receptors, both before and after synaptogenesis, and transient up-regulation of Narp results in an increased number of excitatory synapses. Based on these observations, we hypothesize that Narp modulates synaptic clustering of AMPA receptors and plays a role in excitatory synaptogenesis. Studies described in Aims 1-3 will define the structure-function relationships for Narp membrane surface self-clustering and for its association with AMPA receptors. Conventional mutation analyses and genetic approaches will be used to define the critical sites of interaction for these molecules. Based on this information, peptide and antibody antagonists will be developed to perturb the clustering activity of Narp and test its role in natural synaptogenesis. Aims 4-5 will examine the cell biological properties of Narp in brain neurons. Studies will test the hypotheses that Narp is targeted to specific excitatory synapses and that it can modify their morphological and functional properties of excitatory synapses. Since Narp is an IEG, our research will provide new insights into the molecular and cellular mechanisms of activity dependent synaptic plasticity.
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2000 — 2019 |
Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. R37Activity Code Description: To provide long-term grant support to investigators whose research competence and productivity are distinctly superior and who are highly likely to continue to perform in an outstanding manner. Investigators may not apply for a MERIT award. Program staff and/or members of the cognizant National Advisory Council/Board will identify candidates for the MERIT award during the course of review of competing research grant applications prepared and submitted in accordance with regular PHS requirements. |
Analysis of a Novel Cocaine Induced Immediate Early Gene @ Johns Hopkins University
? DESCRIPTION (provided by applicant): Drug addiction arises from aberrant synaptic plasticity that is induced by cocaine or other drugs of abuse. Our studies examine the molecular and cellular basis of this plasticity, and focus on adaptations mediated by cellular immediate early genes (IEG). The IEG termed Homer1a functions at excitatory synapses, and controls a newly identified signaling pathway that integrates aspects of dopamine and glutamate receptor signaling, reward-dependent synaptic plasticity, and drug addiction (1). Studies to date reveal that cocaine induces dopamine receptor-dependent intracellular signaling events that result in the transcriptional induction of Homer1a, together with the phosphorylation of group 1 metabotropic glutamate receptor type 5 (mGluR5). These coordinated events result in the binding of a prolyl isomerase termed Pin1 to mGluR5, which mediates a conformational switch that enhances the ability of mGluR5 to activate the NMDA receptor. We term this the mGluR5-Pin1 signaling pathway. Using a combination of approaches, we find that this pathway mediates synaptic plasticity that underlies cocaine motor sensitization. We hypothesize this pathway contributes to several forms of neuromodulator-dependent synaptic plasticity, and is a fundamental mechanism to modulate NMDA receptor function. The renewal application will examine the molecular basis of mGluR5-Pin1 coupling to NMDA receptor. Studies will assess the role of mGluR directed scaffolding proteins and the role of intracellular Ca2+ stores. We will also define how the Pin1 mechanism regulates mGluR1 gating to TRPC ion channels, and assess the contribution of mGluR-Pin1 signaling to cocaine-induced plasticity.
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2000 — 2012 |
Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Narp and Glutamate Receptor Clustering @ Johns Hopkins University
DESCRIPTION (provided by applicant): This is a competitive renewal for RO1 NS39156, which supports our studies of Narp (Neuronal activity-regulated pentraxin) and related neural pentraxins including NP1 and NPR. Narp is an immediate early gene that is transcriptionally up-regulated in brain neurons in response to patterns of synaptic activity that evoke neuronal plasticity. Our broad goal is to understand how pentraxins contribute to neural plasticity, and thereby reveal new molecular and cellular mechanisms important for learning and memory, and diseases of cognition. Previously, we demonstrated that Narp is secreted at excitatory synapses where it binds AMPA-type glutamate receptors (AMPAR), and enhances synapse formation. Studies over the past 5 years have provided insights into the molecular basis of Narp's ability to enhance synapse formation, and support a model of diffusion-capture that depends on Narp-AMPAR binding. Remarkably, neural pentraxins also mediate rapid removal of AMPAR from synapses during the process of long-term depression that is induced upon activation of group 1 metabotropic glutamate receptors (mGluR-LTD). These studies revealed a novel coupling of mGluR to the extracellular protease TACE, which cleaves NPR and accelerates AMPAR endocytosis. The actions of neural pentraxins to both increase and decrease synaptic strength are dependent on their ability to form physical associations with AMPAR, and Aim 1 will extend our analysis of this physical interaction. Narp is particularly abundant at excitatory synapses on inhibitory interneurons, and we find that homeostatic changes in the strength of these synapses in response to changes in network activity are dependent on Narp. These observations support a new cellular model of Narp function as an activity-dependent regulator of inhibitory pathways that control network excitability. This hypothesis will be examined in Aim 2. Aim 3 also explores a new direction for the function of neural pentraxins. In ongoing studies, we have discovered a molecular complex that includes mGluR, neural pentraxins, TACE and BACE. Like TACE, BACE functions to cleave the extracellular (or luminal) domain of transmembrane proteins, and is the rate-limiting enzyme in the cleavage of amyloid precursor protein (APP) to generate A?. We find that neural pentraxins regulate the activity of TACE/BACE toward APP. A mouse KO model that deletes Narp, NP1 and NPR shows enhanced generation of A?40/42, and deposition of insoluble A? and plaque. Experiments in Aim 3 will define the molecular basis of pentraxin-dependent A??generation, and examine the hypothesis that this pathway is central for both normal synaptic plasticity and of activity-dependent generation of A? that contributes to Alzheimer's disease. PUBLIC HEALTH RELEVANCE: This proposal examines mechanisms that mediate long lasting changes to synapses that are important for learning and memory. The work focuses on a protein termed Narp (Neuronal activity-regulated pentraxin), which is rapidly up-regulated in neurons as they participate in information storage. Narp, and related pentraxins, bind AMPA type glutamate receptors at synapses and regulate their function. Proposed studies will define the molecular basis of the action of Narp, and its role in synaptic plasticity and diseases of cognition.
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2001 — 2010 |
Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Effector Ieg, Homer and Drug Addiction @ Johns Hopkins University
This application is for competitive renewal of NIDA RO1-11742, and will advance our understanding of the role of Homer in drug^-addiction using transgenic mouse models. During the previous funding period, we generated mouse knockout models for each of the three Homer genes, and in collaboration with Dr. Peter Kalivas of Univ. of South Carolina, determined that Homer 1 and Homer 2 knockout mice exhibit enhanced sensitivity to the acute psychomoter activating effects of cocaine, and self-administer cocaine at low doses that littermate wt mice do not.Furthermore, nai've HI and H2 knockout mice exhibit neurochemical parameters seen in wt mice that are sensitized to cocaine. Accordingly, genetic deletion of Homer 1 or 2 mimics critical aspects of cocaine addiction. This occurs in the absence of exposure to cocaine, and suggests that Homer is critical for adaptations that underlie addiction. Despite these important advances, it remains unknown how changes in Homer protein expression produce the phenotype. Here: Aim 1 will use newly developed transgenic Cre mice to delete Homer 1 and 2 in select populations of cells in the forebrain, and determine in which cells Homers' deletion evokes a cocaine-sensitized phenotype. One hypothesis that will be tested is that Homer's action is critically important in neurons of the striatum/accumbens that express dopamine Dl receptors (D1R). Aim 2 will examine the role of the immediate early gene form of Homer (termed HI a) in cocaine addiction using a newly generated selective genetic knockout model, and a proposed gain of function model. HI a is induced by both cocaine and spatial exploration, and is hypothesized to provide an important contribution to learning hi the cocaine place preference model. Aim 3 will examine the role of Homer interaction with mGluRS in responses to cocaine. mGluRS is known to be essential for behavioral responses to cocaine, and biochemical studies presented in the Preliminary Results reveal that Homer binding to mGluRS is regulated by D1R activity. We are generating mGluRS knock in mice with mutations that selectively disrupt Homer's regulated binding, and will examine the hypothesis that D1R- regulated Homer binding to mGluR is critical for cocaine addiction and Dl-dependent motor responses. Aim 4 will determine the cellular distribution of mGluRS expression that is sufficient to restore responses to cocaine in the mGluR5 knock out. Together, these studies will reveal the cellular bases of Homer's and mGluRS's contribution to cocaine addiction, and test the hypothesis that Homer's interaction with mGluRS is regulatory for Dl-dependent appetitive and motor behaviors.
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2003 — 2007 |
Worley, Paul F |
P50Activity Code Description: To support any part of the full range of research and development from very basic to clinical; may involve ancillary supportive activities such as protracted patient care necessary to the primary research or R&D effort. The spectrum of activities comprises a multidisciplinary attack on a specific disease entity or biomedical problem area. These grants differ from program project grants in that they are usually developed in response to an announcement of the programmatic needs of an Institute or Division and subsequently receive continuous attention from its staff. Centers may also serve as regional or national resources for special research purposes. |
Phosphoinositide Signaling At the Synapse @ Johns Hopkins University
Phosphoinositide signaling at the excitatory synapse generates Ca2+ signals that modify the function of the synapse, and propagate to the nucleus where they result in transcriptional responses. The Snyder/Worley project will examine three critical stages in signal transduction at the synapse. Group 1 metabotropic receptors (mGluR) stimulate phospholipase C to generate IP3, which evokes release of calcium from intracellular pools. Recent studies indicate that mGluR5 is essential for behavioral responses to cocaine. The Worley laboratory has studied mGluRs and their functional modulation by the immediate early gene Homer. In ongoing studies, they find that mice with a genetic deletion of Homer 2 exhibit enhanced responses to cocaine . These observations focus attention on the role of Homer in regulating mGluR function in models of drug addiction. Aim 1 will generate mouse genetic models with mutations of mGluR that disrupt specific interactions with Homer and Shank. Aim 2 will examine a novel signaling/scaffold protein for mGluR. A family of proteins, termed Hopi, was identified based on their coupling to mGluR by interacting with Homer. Preliminary studies indicate that Hopi couples group 1 mGluR to activation of p21-activated kinase (Pak) and perhaps CDK5. Studies will include generation and analysis of conditional Hopi knockout mice, and as well as molecular studies of signaling. Aim 3 will examine molecular mechanisms that target IP3 receptors to the excitatory synapse. The Snyder laboratory has a long-standing interest in the brain receptor for inositol trisphosphate (IP3R) and has defined important interactions involved in its signal transduction. The approach exploits a recent observation that Shank induces the formation of spines that include IP3R. In order to define regions of the IP3R that are essential for accumulation in spines, IP3R deletion mutants will be co-expressed with Shank in neurons. Critical finding will be confirmed in slice cultures. Parallel biochemical studies will identify proteins that interact with the domain of the IP3R that is essential in its spine localization and function. These studies will provide important new insights into how the mGluR5/IP3R signaling complex is assembled at the synapse, and how perturbations contribute to mental illness.
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2007 — 2011 |
Worley, Paul F |
P50Activity Code Description: To support any part of the full range of research and development from very basic to clinical; may involve ancillary supportive activities such as protracted patient care necessary to the primary research or R&D effort. The spectrum of activities comprises a multidisciplinary attack on a specific disease entity or biomedical problem area. These grants differ from program project grants in that they are usually developed in response to an announcement of the programmatic needs of an Institute or Division and subsequently receive continuous attention from its staff. Centers may also serve as regional or national resources for special research purposes. |
Molecular Mechanisms That Regulate Protein Synthesis in Neurons. @ Johns Hopkins University |
1 |
2009 — 2016 |
Savonenko, Alena Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Dynamic Regulation of Shank3 and Asd @ Johns Hopkins University
DESCRIPTION (provided by applicant): This is a competitive renewal of 5RO1NS070301-02, entitled Dynamic Regulation of Shank3 and Autism Spectrum Disorders, which was awarded as an ARRA grant beginning 09/30/2009. Shank3 is linked in human genetic studies to both autism spectrum disorders (ASD) and schizophrenia, and our broad goals are to define the molecular basis for behavioral diseases linked to mutations of Shank3, and to identify unifying concepts that are applicable to other genetic causes of ASD. We created a mouse model that mimics human subjects with mutations that delete the C-terminus of Shank3 [Shank3(+/ ¿exon21)], and have published findings that support a novel molecular model for ASD(1). We discovered that Shank3 (+/ ¿exon21) mice express Shank3 mutant protein lacking the C-terminus (Shank3¿C), and this acts in a gain-of-function manner to selectively increase the ubiquitination of WT Shank3 and the NR1 subunit of the NMDA receptor, and reduce their expression at synapses. Shank3(+/¿exon 21) mice show reduced NMDA receptor-dependent synaptic plasticity, as well as enhanced mGluR-dependent long-term depression. Shank3(+/¿exon21) mice have normal memory function but display prominent behavioral deficits in reciprocal social interaction, together with phenotypes classically associated with schizophrenia. These findings provide important validation that molecular mechanisms consequent to mutation of Shank3 can underlie behavioral dysfunction relevant to ASD in a mouse model. Aims of this competitive continuation are; Aim 1 will test our hypothesis that increased ubiquitination of Shank3 and NR1, and associated behavioral deficits, are dependent (inversely) on the degree of Shank3 cross-linking by Homer(1). We will use mouse genetic models that delete Homer2 (to reduce Homer crosslinking), or selectively delete the immediate early gene form Homer1a (to increase crosslinking), and determine how this modifies phenotypes in Shank3 (+/ ¿exon21) mice. Since Homer1a is dynamically regulated by behavioral experience, these studies will test a molecular mechanism linking behavioral experience and severity of phenotypes. Aim 2 will examine a candidate ubiquitin ligase for Shank3 and determine its contribution to phenotypes in Shank3 (+/ ¿exon21) mice.Aim 3 will evaluate the observation that mTORC1 (mammalian target of rapamycin complex 1) signaling is altered in Shank3 (+/¿exon21) mice, and examine a hypothesized general mechanism that links protein turnover with mTORC1 activity. Aim 4 will examine the link between Shank3¿C expression and enhanced mGluR5 signaling, and test if inhibition of mGluR5 can reduce the severity of phenotypes. Aim 5 will utilize the conditional property of the Shank3 mouse to examine the developmental, and cellular bases of phenotypes produced by Shank3 ¿C. These studies address important goals set by the NIH to establish animal models of behavioral disease, and to provide a scientific basis for development of rational therapies.
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2010 — 2014 |
Worley, Paul F |
P50Activity Code Description: To support any part of the full range of research and development from very basic to clinical; may involve ancillary supportive activities such as protracted patient care necessary to the primary research or R&D effort. The spectrum of activities comprises a multidisciplinary attack on a specific disease entity or biomedical problem area. These grants differ from program project grants in that they are usually developed in response to an announcement of the programmatic needs of an Institute or Division and subsequently receive continuous attention from its staff. Centers may also serve as regional or national resources for special research purposes. |
Neuronal Activity-Dependent Secretion of Ab and Immediate Early Genes @ Johns Hopkins University
Project 3 of the Johns Hopkins Alzheimer's Disease Research Center (ADRC) is titled Neuronal activity-dependent secretion of AB and immediate early genes. This project focuses on the activity-regulated gene termed Arc/Arg3.1, in order to identify mechanisms that are critical for secretion of the amyloid-beta peptide (AB) from neurons. Arc is an immediate early gene that is transcriptionally induced in response to forms of neuronal activity that underlie learning and memory. The overarching goal of the study is to examine the molecular mechanisms that underlie activity-dependent secretion of AB and to examine their potential impact on synaptic dysfunction in Alzheimer's disease (AD). There are four specific aims: (1) Aim 1: To examine the cellular basis of Arc-dependent AB secretion. We will test the hypothesis that Arc enhances the processing of amyloid precursor protein (APP) by gamma secretase in recycling endosomes. We will examine the model that Arc enhances AB generation by recruiting gamma secretase, either from the plasma membrane or intracellular endosomes, to endosomes that traffic APP from the plasma membrane. (2) Aim 2: To examine the hypothesis that Arc binding to presenilin 1 (PS-1) is essential for Arc-dependent AB generation. We will define regions of Arc and PS-1 that are necessary and sufficient for binding. As part of this analysis, we will identify peptides that can selectively block their interaction and we will test if these peptides can interrupt activity-dependent generation of AB in primary neuronal cultures. (3) Aim 3: To examine the hypothesis that Arc contributes to AB generation and plaque deposition in vivo. These studies will monitor the age and gender dependence of soluble and insoluble AB40/42 and plaque deposition in transgenic APPswe/PS1AE9/Arc+/+ mice versus APPswe/PS1AE9/Arc-/- mice. (4) Aim 4: To examine expression of Arc and associated proteins in the brains of cognitively normal and cognitively impaired subjects. Tissue samples will be obtained through the Neuropathology Core (Core D) of the ADRC. Preliminary studies indicate that Arc protein is up-regulated in brains of patients of AD. We will determine if this is consistent across a larger group of subjects and assess the association with plaques and with dementia severity.
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2011 — 2015 |
Worley, Paul F |
P30Activity Code Description: To support shared resources and facilities for categorical research by a number of investigators from different disciplines who provide a multidisciplinary approach to a joint research effort or from the same discipline who focus on a common research problem. The core grant is integrated with the center's component projects or program projects, though funded independently from them. This support, by providing more accessible resources, is expected to assure a greater productivity than from the separate projects and program projects. |
Jhu Center For Neuroscience Research @ Johns Hopkins University
EMBRYONIC STEM CELL CORE CI B1. Establishment of the ES Cell Core: The ES Cell Core was founded with the support of this award and began operations -four years ago. It is located on the 9th Floor of the Wood Basic Science Building in -500 sq. ft. of space that is contiguous with the JHU SOM Transgenic Animal Facility. Dr. Woriey serves as the Director of the ES Cell Core and works closely with Dr. Roger Reeves, Director of the Transgenic Animal Facility, to integrate the functions of these Cores (see letter of support from Dr. Reeves (consultant)). Ms. Holly Wellington serves as Core Manager for this facility. The ES Cell Core reviews the design of targeting constructs, electroporates targeting construct DNA into ES cells, and then selects and amplifies ES cell colonies in duplicate 96 well plates; one plate is cryogenically stored and the other provided to investigators to screen for homologous recombination. The Core then grows promising ES cell clones, checks karyotypes and provides the targeted ES cells to the Transgenic Facility for injection into blastocysts.
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2012 — 2017 |
Worley, Paul F |
P50Activity Code Description: To support any part of the full range of research and development from very basic to clinical; may involve ancillary supportive activities such as protracted patient care necessary to the primary research or R&D effort. The spectrum of activities comprises a multidisciplinary attack on a specific disease entity or biomedical problem area. These grants differ from program project grants in that they are usually developed in response to an announcement of the programmatic needs of an Institute or Division and subsequently receive continuous attention from its staff. Centers may also serve as regional or national resources for special research purposes. |
Research Project 2 @ Johns Hopkins University
The Woriey project examines molecular mechanisms of activity-dependent synaptic plasticity that contribute to drug addiction. Aim 1 will use newly developed mouse models that afford in vivo regulation of expression of the immediate eariy gene (IEG) Rhebl to examine how signaling of the mammalian target of rapamycin (mTOR) controls dynamic protein translation. In work supported by this grant, we have demonstrated that Rhebl is essential and sufficient to activate mTORCI in vivo, and have established viable mouse models that either conditionally delete Rhebl or express an activated Rhebl transgene (Zou et al., 2011). To explore the role of mTOR in protein translation, we will process brains of Rhebl transgenic mice to isolate mRNAs that are associated with polyribosomes or ribosomes in the process of translation initiation, and identify those RNA sequences that are protected from RNase digestion using RNA seq (Ingolia et al., 2009). Studies will test the hypothesis that mTOR controls translation of a specific set of brain mRNAs, and will test the scanning hypothesis for translation initiation. Aim 2 will focus on mTOR-dependent proteins that are generated in neurons, and that regulate myelination in the CNS. Myelination is known to be dependent on neural activity and is disrupted in patients with drug addiction, however the molecular basis ofthis process is unknown. Rhebl transgenic mice show prominent changes in myelination (Zou et al., 2011) and preliminary studies indicate a role for neuron-generated proteins that control the differentiation of oligodendrites and their generation of myelin proteins. Information from Aim 1 mRNA analysis and direct assays of protein expression will generate candidate proteins, and these will be tested using in vivo assays for effects on myelination. Aim 3 will explore the role of a novel protein family termed LanCLI in regulation of activity- dependent reactive oxygen species (ROS). LanCLI is regulated as an lEG and is highly expressed in normal brain. We have developed models that conditionally delete LanCLI gene or express LanCLI transgene in brain and we will use these models to test the hypothesis that dynamic expression of LanCLI is essential for normal synaptic plasticity and cocaine-evoked plasticity.
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2014 — 2017 |
Worley, Paul F |
P50Activity Code Description: To support any part of the full range of research and development from very basic to clinical; may involve ancillary supportive activities such as protracted patient care necessary to the primary research or R&D effort. The spectrum of activities comprises a multidisciplinary attack on a specific disease entity or biomedical problem area. These grants differ from program project grants in that they are usually developed in response to an announcement of the programmatic needs of an Institute or Division and subsequently receive continuous attention from its staff. Centers may also serve as regional or national resources for special research purposes. |
Intracellular Stores of Calcium and Plasticity At the Excitatory Synapse @ Johns Hopkins University
Neurons possess prominent intracellular stores of Ca2+ in specialized endoplasmic reticulum. These stores release Ca2+ that acts as a second messenger. Upon depletion, stores must then refill, and recent studies have identified a molecular pathway required for Ca2+ store refilling in the process termed capacitive Ca2+ entry (CCE). The ER resident protein Stimi senses depletion of Ca2+ stores, whereupon it forms clusters within the ER membrane and its C-terminus spans the cytosol to activate membrane ion channels of the Oral family. Orai-Stim1 and CCE play a critical role in the physiology of many cell types. Here, we will examine the role of Stimi and Orai in neural physiology using newly developed conditional genetic deletion models. Aim 1 will examine the role of Stimi and Orai in NMDA-dependent receptor function. Preliminary studies indicate Stimi is required for NMDA receptor dependent long-term depression, and suggest a role for Stimi in activation of calcineurin. Experiments will image Ca2+ dynamics in acute tissue slices using the genetic GCaMPS reporter line developed by Dr. Bergles. 2-photon microscopy will reveal how the absence of Stimi or Orai results in changes of Ca2+ in cell compartments including spines, dendrites and nuclear envelope. Mechanistic studies will link Ca2+ dynamics with changes in synaptic function and plasticity. These studies are directly relevant to the goals of NIMH since NMDA and calcineurin pathways are important targets for understanding schizophrenia. Aim 2 will explore the role of STIMI-Orai in diseases linked to Ali amyloid. Preliminary studies indicate that deletion of Stimi or Orai results in increased AU-amyloid generation in vivo. This finding, together with previous reports that mutations of presenilini or presenilin2 linked to familial Alzheimer's disease inhibit CCE. suggest that inhibition of CCE may be central to mechanisms of increased AB generation. Studies will define the role of STIMI. Orail and Orai2 in Ali generation, and determine how presenilin inhibits STIMI-Orai coupling to mediate CCE. Since Ali acts to influence synaptic plasticity, an integrated understanding ofthe role of STIMI and Orai in Ali generation and NMDA plasticity will define novel pathways important for synaptic function and diseases of cognition.
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2014 — 2015 |
Sockanathan, Shanthini [⬀] Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Gde and Neurodegenerative Diseases @ Johns Hopkins University
? DESCRIPTION (provided by applicant): This proposal imagines a paradigm shift for understanding human Alzheimer's disease that is based on a newly discovered, druggable enzyme. Our current understanding of AD proposes a central role for the accumulation of amyloid A? (1), but there is great need for advances in understanding mechanisms that cause increases of A? in sporadic AD. Moreover, there are many aspects of the pathology of AD that cannot be simply understood as a consequence of A? accumulation, and suggest other molecular mechanisms contribute to pathogenesis. There is also a great need for diagnostics that can be rationally linked to pathogenesis. Most of all there is a need for effective therapeutics. These challenges are well known to the field. We see a unique opportunity to advance AD research that builds on the discovery of a novel enzyme family that controls several of the most important signalling pathways in brain development. GDEs catalyze cleavage of the phosphodiester bond that links a class of extracellular proteins to the cell surface (2). These GPI-linked proteins act as activators or inhibitors of Notch, sonic hedgehog, fibroblast growth factor, Wnt, ephrin (EphA5), ciliary neurotrophic factor receptor (CNTF), glial derived neurotrophic factor, and contactins. The role of GDEs in neurodegeneration was made serendipitously with the discovery that conditional deletion of GDE in adult brain results in profound, age-dependent neurodegenerative changes that include many of the hallmarks of human neurodegenerative disease. We hypothesize that loss of GDE function contributes to human neurodegenerative disease. The approach exploits the fortunate consequence of GDE activity, which is to shed substrate proteins into the extracellular compartment and CSF. This creates biomarkers of GDE activity. As proof of concept, we have determined that prion protein is a substrate of GDE. Prion protein is present in the CSF at levels that are reduced in human AD subjects in parallel with cognitive decline(3), and recent studies implicate prion protein in pathological reduction of synaptic strength and enhanced A? generation in AD(4, 5). We will expand this precedent using non-biased methods to identify GDE substrates in CSF and brain of normal and diseased humans. These biomarkers will identify specific signalling pathways consequent to GDE function that are consistently disrupted in AD. Where successful, this approach will provide mechanism-linked biomarkers of disease that can be combined with modulators of the GDE pathway as new mechanism-based diagnostics and therapeutics for AD.
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2014 — 2015 |
Wang, Tao Worley, Paul F |
R21Activity Code Description: To encourage the development of new research activities in categorical program areas. (Support generally is restricted in level of support and in time.) |
Functional Characterization of a Frmpd4 Mutation in a Udp Family @ Johns Hopkins University
DESCRIPTION (provided by applicant): Abstract The NIH-undiagnosed disease program (UDP) focuses on defining the molecular basis and mechanisms of rare genetic disorders. A large fraction of patients applying for the UPD program suffer from unknown neurological disorders (43%), which underscores the importance to develop novel diagnostic workup and therapies through close collaborations between clinical and basic investigators. A missense mutation in an X-linked gene, FRMPD4 (also termed Preso1), was recently identified in two male sibs who exhibited global developmental delays, cognitive regression, seizure disorders, and a constellation of other clinical findings. Here, we will examine the hypothesis that human Preso1-K195E is causal for these symptoms. In our previous work, we have identified Preso1 as a co-functional protein with the group 1 metabotropic glutamate receptors (mGluR). Genetic modifications of group 1 mGluR signaling are known to result in various developmental and degenerative phenotypes in mouse models (Niswender and Conn, 2010). Preso1 encodes a multi-domain protein that binds mGluR5 and controls its phosphorylation state, and thereby provides important regulation of mGluR5 function. We propose to utilize in vitro and neuron- based assays, and to generate transgenic mouse models to examine the hypothesis that the K187E mouse mutation of Preso1 results in altered mGluR5 functions that are crucial for synapse formation, synaptic plasticity, and behavioral responses in social interaction and to rewarding stimuli that are important for learning and memory. We will examine convergent mechanisms with other genetic causes of developmental brain disease that impact mGluR5 function including Fragile X Mental Retardation Syndrome. We will also screen for mutations in the Preso gene family members in additional patients with X-linked intellectual disability and/or epilepsy. These studies will determine if Preso1 (K195E) is causal for the neurological defects in the UDP family and if the Preso gene family represents a novel cause for developmental brain disorders. The results will provide mechanistic insights into pathogenesis that will be important for the establishment of rational therapies.
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2015 — 2021 |
Worley, Paul F |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Arc and Synaptic Plasticity @ Johns Hopkins University
? DESCRIPTION (provided by applicant): This is a proposal to renew RO1 MH053608, which supports our studies of the immediate early gene Arc. Arc is a synaptic protein that is required for animals to learn and store information1. Arc associates with endocytic proteins to regulate glutamate receptor trafficking and thereby control the strength of excitatory synapses2,3. Arc-dependent mechanisms play an important role in synaptic plasticity of learning, but are also implicated in diseases of cognition including fragile X mental retardation syndrome4-6, Angelman syndrome7, Alzheimer's disease8,9 and schizophrenia 10,11. The association of Arc with synaptic pathophysiology drives a need for deep understanding of Arc's function. This has been challenging because Arc is a single copy gene without discernable family members or recognizable functional domains. To address this challenge, we have focused recent efforts on defining the structure of Arc, and have made break through discoveries that reveal the basis of Arc association with synaptic proteins important for trafficking and synaptic turnover. We have also identified protein interactions that support a role for Arc in control of PI3 Kinase, AKT and mTORC. Studies will evaluate hypotheses of Arc functions that derive from new structural information and that are central to its action in synaptic plasticity and disease.
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2017 |
Savonenko, Alena Worley, Paul F |
RF1Activity Code Description: To support a discrete, specific, circumscribed project to be performed by the named investigator(s) in an area representing specific interest and competencies based on the mission of the agency, using standard peer review criteria. This is the multi-year funded equivalent of the R01 but can be used also for multi-year funding of other research project grants such as R03, R21 as appropriate. |
Mechanisms of Synaptic Aging Mediating Cognitive and Behavioral Symptoms of Ad @ Johns Hopkins University
SUMMARY Alzheimer's disease (AD) is a complex cascade of neurodegenerative processes that expressed as gradual accumulation of A? peptides and hyperphosphorylated tau (ptau). The single most important factor is aging. However, mechanisms that mediate aging-associated risks are not well understood. Loss of synaptic structure and function marks early stages of AD that may precede clinical symptoms by decades. This implies that mechanisms of aging-related risks might be at work already by middle age. Explicit testing of such mechanisms in AD mouse models has been problematic, since in conventional models the effects of aging cannot be separated from the effects of advanced pathology. To address this challenge, we have employed inducible models that can conditionally delay expression of tau and/or APP until early adulthood, middle, or old age. We find that middle-age onset APP mice, which model initiation of amyloidosis in humans in the 4th decade of life develop more severe cognitive deficits and at earlier stages of A? accumulation than mice with an early-adulthood onset. Here, we will further employ these conditional models to search for molecular mechanisms that underlie age vulnerability. As part of this analysis we will explore the contribution of a candidate gene pathway, NPTX2, which was first implicated in our studies of human AD. Preliminary studies in mouse models demonstrate Aß dependent down-regulation of NPTX2 in middle and old age but not young adult mice. Accordingly, we hypothesize that NPTX2 represents an aging-sensitive pathway that is relevant to the pathophysiology of human AD. In Aim 1, we will use inducible transgenic mice with different ages of onset of APP and/or tau expression (young-adult, middle- or old-age) to test whether tau alone or in combination with Aß causes a reduction of NPTX2 expression. In Aim 2, we will screen for aging and Aß/tau associated changes in synaptic protein expression by quantitative mass spectrometry. Verified changes in NPTX2 and other synaptic proteins will be used to confirm sensitivity of MS analyses. In Aim 3, we will test whether age- associated downregulation of NPTX2 contributes to cognitive phenotypes. Aim 4 will assess the role of aging, Aß/tau and NPTX2 in depression phenotypes. Aim 5 will address possible sex-related differences in the aging- associated cognitive and depressive phenotypes. The studies planned in this proposal are designed to delineate the function and regulation of NPTX2-dependent pathways in a setting of progressive aging and AD pathologies and will help to reveal the molecular basis and therapeutic directions for cognitive and behavioral symptoms of AD.
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2017 — 2021 |
Worley, Paul F |
R35Activity Code Description: To provide long term support to an experienced investigator with an outstanding record of research productivity. This support is intended to encourage investigators to embark on long-term projects of unusual potential. |
De Novo Synthesis and Memory @ Johns Hopkins University
Project Summary Memory is our most precious possession, yet we remain unable to prevent its loss in neurological diseases. Here we examine a fundamental property of memory, which is its dependence on rapid de novo protein synthesis, and identify pathways that contribute to normal memory and that underlie human memory loss. Dr. Worley's laboratory pioneered the discovery and analysis of cellular immediate early genes (IEGs) as effectors of protein synthesis-dependent memory, and has described mechanisms mediated by IEGs Arc, Homer 1a and NPTX2 at excitatory synapses that strengthen active synapses and weaken inactive synapses. Emerging concepts integrate their individual molecular and synaptic functions into a temporal program of sequential cellular and circuit adaptations that encode information. The process begins with Arc and Homer1a, which act cell-autonomously to control the synaptic expression of AMPA type glutamate receptors. A later process mediated by secreted NPTX2 acts non cell-autonomously to strengthen excitatory synapses on a specific class of inhibitory neurons that express parvalbumin. Studies from mouse models indicate that down regulation of NPTX2 results in increased neural activity that may occlude the ability of networks to encode information, as well as a propensity for activity-dependent pathology including seizures and Aß amyloid generation. Remarkably, aspects of this inhibitory network phase of information storage can be monitored in living human subjects. Secreted NPTX2 is detected in human CSF and is prominently down-regulated in neurological diseases in association with cognitive deterioration. We hypothesize that NPTX2 down-regulation provides a rational biomarker of cognitive status in human neurological disease and may be is causal for certain memory deficits. Basic studies will examine the unusual regulatory mechanisms that control NPTX2 expression and function, and identify processes that result in its down-regulation in human brain. We will also gain deeper insight into how IEGs, and NPTX2 in particular, contribute to memory using gain and loss of function approaches in in vivo models of activity-dependent network plasticity including hippocampal replay. Stable, long-term support will allow us to establish a multidisciplinary research program that leverages the strengths of the Neuroscience community at Johns Hopkins for basic studies, and the Clinical Departments of Neuropathology and Psychiatry at Johns Hopkins and Neurology at UC San Diego for translational aspects of disease research. These studies will establish a novel, rational, and translatable concept for why humans lose memory function in disease.
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2018 — 2021 |
Worley, Paul F |
P50Activity Code Description: To support any part of the full range of research and development from very basic to clinical; may involve ancillary supportive activities such as protracted patient care necessary to the primary research or R&D effort. The spectrum of activities comprises a multidisciplinary attack on a specific disease entity or biomedical problem area. These grants differ from program project grants in that they are usually developed in response to an announcement of the programmatic needs of an Institute or Division and subsequently receive continuous attention from its staff. Centers may also serve as regional or national resources for special research purposes. |
Rheb 1 and Mtorc1 Signaling @ Johns Hopkins University
Project Summary mTORC1 as an essential signaling pathway for drug addiction. In its canonical role, mTORC1 responds to the energy and nutrient status of cells to control fundamental processes that control cell growth and reestablish homeostasis. mTORC1 is also dynamically activated by cocaine in neurons that express D1 dopamine receptors (D1R) and inhibition of mTORC1 prevents behavioral effects of cocaine including cocaine self- administration. Accordingly, it is important to understand how mTORC1 is activated in neurons and how mTORC1 signaling contributes to effects of cocaine. Aim 1 tests the hypothesis that mTORC1 signaling is induced as part of the homeostatic scaling process that controls the strength of excitatory synapses. Preliminary studies indicate that Rheb1, which is essential for mTORC1 activation, associates with group 1 metabotropic glutamate receptors and endosomes that move synaptic proteins from the postsynaptic spine to sites of protein degradation in the dendrite. Studies will examine trafficking of Rheb1 and test the role of adaptor proteins that may couple Rheb1 to glutamate receptors and play a role in mTORC1 activation. The role of the amino acid sensor GATOR2 will also be examined in mTORC1 activation in neurons. Aim 2 examines the hypothesis that mTORC1 functions as a co-stimulatory pathway for D1R signaling. This hypothesis builds upon use state of the art mass spectroscopic analysis of phosphoproteins to identify signaling crosstalk between mTORC1 and D1R. Studies will also test the hypothesis that persistent activation of mTORC1 can block D1R behaviors by ?occluding? D1R signaling. Aim 3 tests the relevance of biochemical signaling pathways in behaviors relevant to cocaine addiction including self-administration and reinstatement after extinction. These studies will define essential mechanisms of mTORC1-D1R signaling important for drug addiction.
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2019 — 2021 |
Worley, Paul F |
U19Activity Code Description: To support a research program of multiple projects directed toward a specific major objective, basic theme or program goal, requiring a broadly based, multidisciplinary and often long-term approach. A cooperative agreement research program generally involves the organized efforts of large groups, members of which are conducting research projects designed to elucidate the various aspects of a specific objective. Substantial Federal programmatic staff involvement is intended to assist investigators during performance of the research activities, as defined in the terms and conditions of award. The investigators have primary authorities and responsibilities to define research objectives and approaches, and to plan, conduct, analyze, and publish results, interpretations and conclusions of their studies. Each research project is usually under the leadership of an established investigator in an area representing his/her special interest and competencies. Each project supported through this mechanism should contribute to or be directly related to the common theme of the total research effort. The award can provide support for certain basic shared resources, including clinical components, which facilitate the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence. |
Project 1 Biomarkers @ Johns Hopkins University
PROJECT 1: SUMMARY/ABSTRACT The goal of Project 1, entitled ?Synaptic and Inflammatory Markers for Preclinical AD? is to examine several new measures related to synaptic function and systemic inflammation to determine their value as biomarkers for preclinical AD. These analyses will use longitudinally collected CSF and blood specimens from BIOCARD participants to evaluate these measures. For the synaptic markers, there are two primary aims: (1) to measure NPTX2, a synaptic protein, and related markers NPTX1 and NPTXR in CSF, and examine their relationship with the clinical, cognitive and biomarker data previously collected in the BIOCARD participants; and (2) to examine a blood-based assay that measures NPTX2 and related proteins in neural exosomes isolated from blood and determine if it has a similar association with comparable measures obtained from CSF. For the inflammatory markers, there are two primary aims: (1) to measure 3 key inflammatory biomarkers in blood (IL-6, TNFR1, and CRP) and examine their relationship with the clinical, cognitive and biomarker data previously collected in the BIOCARD participants; and (2) to conduct targeted exploratory metabolomic analyses in both blood and CSF samples, in order to identify inflammatory pathways that may be involved in preclinical AD. Overall, these studies will determine if the changes in these synaptic and inflammatory markers during preclinical AD can provide insights into measures that might be useful for a clinical trial in preclinical AD (i.e., for either selecting subjects to include in a clinical trial or for tracking response to treatment in a clinical trial), and/or provide insights into the underlying neurobiological processes that are evolving during the preclinical phase of AD.
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2020 — 2021 |
Worley, Paul F |
P30Activity Code Description: To support shared resources and facilities for categorical research by a number of investigators from different disciplines who provide a multidisciplinary approach to a joint research effort or from the same discipline who focus on a common research problem. The core grant is integrated with the center's component projects or program projects, though funded independently from them. This support, by providing more accessible resources, is expected to assure a greater productivity than from the separate projects and program projects. |
Research Education Component @ Johns Hopkins University
REEARCH EDUCATION COMPONENT - REC: PROJECT SUMMARY/ABSTRACT The Research Education Component (REC) will expand the rich training enviroment of the Johns Hopkins Alzheimer's Disease Research Center (JHADRC) by providing additional training opportunities for young investigators. It will: (1) provide mentoring and financial support for talented Research Associates and Junior Faculty, with the goal of enabling them to become independent investigators working in the field of ADRD; (2) organize a new course, in collaboration with the Department of Neuroscience, entitled `Brain Circuits and Diseases' that will provide training opportunities for investigators supported through the REC as well as for the broader student community at the Johns Hopkins School of Medicine; (3) organize seminars and conferences aimed at researchers throughout the University interested in aging and ADRD; and (4) participate in an innovative exchange program with the Emory ADRC in which REC trainees will visit the respective institutions to meet with faculty and other REC trainees and give a research seminar. The REC will be led by a three-person leadership team that exemplifies the diverse expertise and strong interdisciplinary mentoring experience that this training program aims to provide. The goals of the REC will be supported by training faculty with a broad range of expertise in the field, and a commitment to fostering the development of the next generation of researchers.
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2021 |
Worley, Paul F |
P01Activity Code Description: For the support of a broadly based, multidisciplinary, often long-term research program which has a specific major objective or a basic theme. A program project generally involves the organized efforts of relatively large groups, members of which are conducting research projects designed to elucidate the various aspects or components of this objective. Each research project is usually under the leadership of an established investigator. The grant can provide support for certain basic resources used by these groups in the program, including clinical components, the sharing of which facilitates the total research effort. A program project is directed toward a range of problems having a central research focus, in contrast to the usually narrower thrust of the traditional research project. Each project supported through this mechanism should contribute or be directly related to the common theme of the total research effort. These scientifically meritorious projects should demonstrate an essential element of unity and interdependence, i.e., a system of research activities and projects directed toward a well-defined research program goal. |
Project 4-Nptx2 and Adaptation to Cognitive Aging @ Johns Hopkins University
Project 4 examines the role of NPTX2 and homeostatic scaling in age-related cognitive decline. NPTX2 is an immediate early gene expressed by pyramidal neurons and mediates activity-dependent homeostatic strengthening of inhibitory circuits by adaptively strengthening excitatory drive of parvalbumin interneurons (PV-IN). This PPG has examined the effect of aging on cognition using outbred Long-Evans rats and has documented increased pyramidal neuron excitability and reduced PV-IN circuit inhibition that are associated with cognitive decline. Preliminary studies further reveal reduced NPTX2 expression in Aged-Impaired rats and rescue of circuit deficits by NPTX2 transgene expression. Here, we build on these observations and examine the hypothesis that failure of NPTX2 homeostatic mechanisms contribute to age-related cognitive decline. Aim 1 will test the hypotheses that NPTX2 loss-of-function (LOF) accelerates age-related cognitive decline while NPTX2 gain-of-function (GOF) delays or prevents age-related cognitive decline. A conditional NPTX2 LOF model uses a newly developed NPTX2f/f rat together with virus-mediated delivery of Cre to delete NPTX2 at 11 m and together with Core B details the impact on cognitive behavior. In a reciprocal set of experiments, we create NPTX2 GOF models using two distinct approaches that include virus mediated NPTX2 transgene and oligonucleotide mediated NPTX2 mRNA stabilization. The impact of GOF on cognitive behavior is evaluated in collaboration with Core B. Aim 2 examines molecular and cellular mechanisms mediating dynamic targeting of NPTX2 to excitatory synapses. Studies use state-of-the-art proximity labeling methods to identify proteins involved in synaptic NPTX2 exocytosis and shedding. Aim 3 uses in vivo 2-photon imaging to examine the hypothesis that age-related cognitive deficits are associated with disruption of a critical phase of homeostatic scaling that mediates activity-dependent NPTX2 exocytosis and shedding. Analyses examine diurnal changes in synaptic NPTX2 in association with waking behaviors and sleep comparing Young, Aged-Impaired and Aged-Unimpaired rats. We also test the effect of levetiracetam in Aged-Impaired rats. Studies in Aims 1 and 3 include both male and female rats. The Aims are highly synergistic with other Projects and together will reveal fundamental mechanisms of aging, cognitive resilience and cognitive decline.
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