2001 — 2012 |
Dell'acqua, Mark L |
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. |
Regulation of Akap79 Postsynaptic Membrane Targeting @ University of Colorado Denver
DESCRIPTION (provided by applicant): At the postsynaptic density (PSD) of neuronal excitatory synapses, AMPA (AMPAR) and NMDA (NMDAR) glutamate receptors are linked to signaling proteins and the actin cytoskeleton in dendritic spines through a network of scaffolding proteins that play important roles during synaptic plasticity underlying learning and memory. AMPARs are recruited to dendritic spines through NMDAR activation during induction of long term potentiation (LTP) in hippocampal neurons through pathways that also increase spine size and actin polymerization. Phosphorylation of AMPAR-GluR1 subunits by the cAMP-dependent protein kinase (PKA) may promote surface expression of AMPARs recruited during LTP. In contrast, induction of long-term depression (LTD) leads to calcineurin-protein phosphatase 2B (CaN) mediated dephosphorylation of PKA phosphorylated GluR1, removal of AMPARs from synapses and depolymerization of spine actin followed by spine shrinkage. However, mechanisms for coordinately regulating AMPAR localization, phosphorylation, and spine structural plasticity are not well understood. A-kinase-anchoring protein (AKAP) 79/150 (human79/rodent150) is a PKA and CaN anchoring protein linked to NMDARs and AMPARs through PSD-95 and SAP97 membrane-associated guanylate kinase (MAGUK) scaffolds. AKAP79/150 is targeted to spines by an N-terminal basic region that binds phosphatidylinositol-4,5-bisphosphate (PIP2), F-actin, and cadherin adhesion molecules. Importantly, findings from the last funding period and recent preliminary studies indicate that AKAP79 is recruited to spines in LTP through palmitoylation of its targeting domain and that AKAP79 overexpression enhances dendritic spine size and AMPAR activity through MAGUK binding. In contrast, NMDAR-CaN signaling pathways implicated in AMPAR depression and spine shrinkage in LTD disrupt AKAP79/150 interactions with actin, MAGUKs and cadherins and lead to loss of the AKAP and anchored PKA from synapses. This AKAP79/150 translocation from spines depends on actin reorganization and phospholipase C (PLC) cleavage of PIP2, and preliminary studies suggest additional modulation by palmitoylation. Thus, AKAP79/150 is likely to play important structural and signaling roles in plasticity. Due to the complexity of PKA and CaN signaling in neurons and the multi-functionality of scaffold proteins such as AKAP79/150, it is a considerable challenge to understand the specific postsynaptic functions served by these proteins using simple pharmacologic, knock-out or RNAi approaches because these methods eliminate all functions at once. Thus, in this project we will pair RNAi knockdown with a mutant replacement approach in cultured rat neurons in addition to using a novel AKAP150 knock-in mutant mouse to probe the functions of specific AKAP79/150 membrane targeting motifs and protein-protein interactions in control of postsynaptic structure and function during induction of LTD and LTP. The hypotheses that we will be testing are that regulation of AKAP79/150 postsynaptic targeting and signaling by palmitoylation (Aim 1), MAGUK scaffolding interactions (Aim 1), and CaN anchoring (Aims 2 &3) coordinately regulate dendritic spine structure and AMPAR function in plasticity. PUBLIC HEALTH RELEVANCE: The AKAP79/150-organized neuronal excitatory postsynaptic signaling processes we are studying that control dendritic spine structure and glutamate receptor function are believed to be relevant for mechanisms of altered synaptic plasticity and cognition in neurological disorders such as Alzheimer's and epilepsy and mental health disorders such as Down syndrome and schizophrenia. These same pathways also have relevance for understanding how excessive glutamate receptor activation leads to excitotoxic neuronal death in neurodegenerative diseases, brain injury and stroke. In particular, regulation of glutamate receptor activity and dendritic spine structural changes have been implicated in both plasticity and excitoxicity, thus understanding the role of AKAP79/150 in controlling these events through both its structural interactions and signaling functions is important for understanding basic synaptic processes that are altered in human disease.
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0.936 |
2004 — 2006 |
Dell'acqua, Mark L |
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. |
Gene Targeting/Viral Vecto Core @ University of Colorado Denver |
0.936 |
2007 — 2008 |
Dell'acqua, Mark L |
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. |
Gene Targeting/Viral Vector Core - Neurological Disorders Core Center @ University of Colorado Denver |
0.936 |
2008 — 2012 |
Dell'acqua, Mark L |
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. |
Akap Anchored Pka and Calcineurin Regulation of Neuronal L-Type Calcium Channels @ University of Colorado Denver
DESCRIPTION (provided by applicant): Elucidating mechanisms regulating neuronal survival and plasticity is relevant for understanding normal learning and memory as well as cognitive impairments in mental retardation, aging and Alzheimer's. Influx of calcium ions (Ca2+) through L-type voltage-gated calcium channels (LTCCs) can influence long-term changes in synaptic plasticity and neuronal survival by turning on and off gene transcription in the nucleus. While it is known that signaling very near the site of Ca2+ influx is required for regulation of both LTCC activity and gene expression, molecular mechanisms that organize channel proximal signals and transduce them to the nucleus are largely unknown. One important pathway by which LTCC activity in neurons is regulated involves b-adrenergic receptor-mediated stimulation of cAMP production by adenylyl cyclase and activation of the kinase PKA. Previous studies in the heart suggest that efficient regulation of LTCC activity by PKA requires phosphorylation of the channel protein and localization of PKA near the channel through binding to A-kinase-anchoring proteins (AKAP). However, little is known about the roles of AKAPs or the opposing actions of protein phosphatases in neuronal LTCC regulation. In postsynaptic neurons one AKAP that may play a key role in regulating LTCC phosphorylation and signaling to transcription factors in the nucleus is AKAP79/150. Our overall hypothesis is that AKAP79/150 targets PKA and CaN to LTCCs to bi-directionally regulate channel activity and signaling to the nucleus. We will test this hypothesis in the context of a model in which anchored CaN strongly opposes cAMP-PKA regulation of the channel currents to function as a Ca2+ negative feedback mechanism. In addition, we will explore a novel role for dynamic anchoring of PKA and CaN to AKAP79/150 in these plasma membrane localized Ca2+ signaling events that also control downstream activation of NFAT and CREB transcription factors. Thus, our studies will characterize a novel molecular assembly that coordinates plasma membrane LTCC Ca2+ signaling to regulate both local and distal responses that are important in neuronal plasticity. We will use biochemical, cell biological and electrophysiological approaches in HEK-293 cells and hippocampal neurons to study AKAP79/150-LTCC regulation: (Aim 1) Molecular and functional characterization of a direct interaction between AKAP79/150 and the LTCC CaV1.2 in neuronal channel regulation;(Aim 2) Role of dynamic PKA and CaN anchoring to AKAP79/150 in neuronal LTCC regulation;(Aim 3) Role of the AKAP79/150 channel-associated signaling complex in regulating neuronal LTCC excitation-transcription coupling.
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0.936 |
2011 — 2015 |
Dell'acqua, Mark L |
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. |
Rocky Mountain Neurological Disorders Core @ University of Colorado Denver
C2 Core B;Gene-Targeting/Viral Vector Core C2.1 Rationale. Active genetic manipulation of mice and viral targeting of protein expression in neural tissue have resulted in a revolution in the study of the nervous system. Although interpretation of experiments involving genetic manipulation of mice must be performed with care, the ability to monitor changes in the CNS in vivo upon modification of a single gene makes this technique an indispensable tool for modern inquiry in neurobiology. The usefulness of genetically altered mice will grow even further with increased use of genetargeted mice expressing proteins deficient for specific protein-protein interactions, conditional knockouts, BAC-transgenics and animals expressing externally-triggered neuronal switches. Use of viral vectors to acutely alter protein expression is a powerful technique complementary to genetic manipulation. The group of NINDS researchers at the UCD AMC is using a variety of genetically altered mice and viral vectors to study fundamental questions in neurobiology. Although we have access to a the transgenic facility of the Charles C Gates Regenerative Medicine and Stem Cell Biology Program to produce gene targeted mice, the point of entry is a finished transgenic vector or transfected ES cells (see Appendix, letter from Dr. Peter Koch). Moreover, if Core B did not exist ES clone screening by PCR and/or Southern blotting - all labor intensive procedures - would have to be performed by the individual investigator. For transgenic mice, several lines are obtained for each construct injected. These lines then need to be tested initially to see if they have integrated the exogenous DNA. Subsequently, analysis of appropriate tissue-specific transgene expression is necessary, as well as the analysis of germ-line transmission. These ES and transgenic studies all require skills in molecular biology and mouse husbandry that are not the areas of expertise of the majority of investigators. Likewise, construction and production of viral vectors also requires specific expertise that is not easily established in most laboratories individually. Core B provides these specialized services to RMNDC users.
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0.936 |
2013 |
Dell'acqua, Mark L |
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. |
Akap Regulation of Neuronal L-Type Calcium Channel Signaling to the Nucleus @ University of Colorado Denver
DESCRIPTION (provided by applicant): In hippocampal neurons, somato-dendritic CaV1.2 L-type voltage-gated Ca2+ channels (LTCC) function in excitation-transcription (E-T) coupling. Depolarizing stimuli that open LTCCs activate the transcription factors cAMP-response element binding protein (CREB) and nuclear factor of activated T-cells (NFAT) through Ca2+-regulated kinase and phosphatases. Importantly, LTCC transcriptional regulation is required for long-lasting forms of excitatory synaptic plasticity that underlie learning and memory, such as late-phase long-term potentiation (L-LTP). Thus, it is crucial to understand how LTCC activity and signaling are controlled to promote efficient, specific synapse to nucleus communication. The primary question in synapse-to-nucleus signaling is how local Ca2+ signals generated in dendrites are relayed remotely to the nucleus in the soma. In the last funding period, we established the postsynaptic scaffold protein A-kinase anchoring protein (AKAP) 79/150, which binds to CaV1.2 through a modified leucine zipper (LZ) motif and anchors the cAMP-dependent protein kinase (PKA) and Ca2+-calmodulin (CaM)-activated protein phosphatase-2B (calcineurin; CaN), as an essential regulator of neuronal LTCC currents and NFAT activation. We found that AKAP-anchored PKA promoted LTCC current enhancement that was strongly opposed by a Ca2+ negative feedback loop activating AKAP-anchored CaN to favor rapid, calcium-dependent inactivation (CDI). In addition, we found that local LTCC activation of AKAP-anchored CaN was required for NFAT translocation to the nucleus and transcription in response to depolarization. However, key questions remain regarding whether AKAP79/150 regulates LTCC Ca2+ influx specifically in dendritic spines in response to glutamate receptor activation and whether postsynaptic Ca2+ signals restricted in dendrites can locally activate CaN-NFAT signaling to the nucleus. We will explore these questions using a combination of whole-cell LTCC current recordings, local glutamate uncaging, Ca2+ imaging (Aim 1), NFAT imaging (Aim 2), transcriptional analyses, and extracellular recordings of L-LTP (Aim 3). In all three aims, AKAP79/150 regulation of LTCC activity and NFAT signaling will be investigated by expressing PKA anchoring deficient (delta-PKA), CaN anchoring deficient (delta-PIX), and LZ domain (delta-LZ) AKAP79 mutants in in rat neurons or using neurons from AKAP150 delta-PIX and delta-PKA knock-in mice. Overall, this project will test a central hypothesis in synapse-to-nucleus communication that postsynaptic Ca2+ signals are locally decoded in dendrites and then efficiently relayed to the nucleus to control gene expression linked to synaptic plasticity.
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0.936 |
2013 — 2018 |
Dell'acqua, Mark L |
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. R56Activity Code Description: To provide limited interim research support based on the merit of a pending R01 application while applicant gathers additional data to revise a new or competing renewal application. This grant will underwrite highly meritorious applications that if given the opportunity to revise their application could meet IC recommended standards and would be missed opportunities if not funded. Interim funded ends when the applicant succeeds in obtaining an R01 or other competing award built on the R56 grant. These awards are not renewable. |
Regulation of Akap79 Postsynaptic Targeting and Signaling @ University of Colorado Denver
DESCRIPTION (provided by applicant): Regulation of AKAP79 Postsynaptic Targeting and Signaling Long-term potentiation (LTP) and depression (LTD) at hippocampal CA1 synapses are widely studied due to their involvement in spatial learning and memory processes that are altered in diseases including schizophrenia, Alzheimer's, and post-traumatic stress disorder. LTP and LTD are induced by postsynaptic NMDA glutamate receptor signaling and expressed by long-lasting increases or decreases, respectively, in AMPA glutamate receptor (AMPAR) function. AMPARs are tetrameric assemblies of GluA1-GluA4 subunits, and most synaptic AMPARs are composed of GluA1/2 or GluA2/3, with the GluA2 subunit preventing Ca2+ influx. However, a small number of Ca2+-permeable GluA1 homomers (CP-AMPARs) reside in extrasynaptic locations where they can be recruited to synapses during some forms of plasticity. One leading model proposes that phosphorylation of GluA1 S845 by the cAMP-dependent protein kinase (PKA) promotes GluA1 endosomal recycling leading to accumulation of CP-AMPARs in the extrasynaptic plasma membrane, where they are primed for synaptic insertion during LTP in response to additional signals from Ca2+-calmodulin- dependent protein kinase II (CaMKII). In contrast, during LTD, it is proposed that the Ca2+-activated protein phosphatase-2B/calcineurin (CaN) dephosphorylates extrasynaptic GluA1 and remove these CP-AMPARs via endocytosis. However, the importance of CP-AMPARs for plasticity at CA1 synapses is still controversial, and the mechanisms regulating AMPAR subunit composition are not well understood. This uncertainty has arisen in part because many studies only target AMPARs as the endpoint of plasticity regulation without elucidating how upstream signaling is controlled. Here we precisely target specific postsynaptic signaling pathways to overcome this limitation. PKA and CaN are both targeted to GluA1 through binding to the postsynaptic scaffold protein, A-kinase anchoring protein (AKAP) 79/150. During the last funding period we generated and characterized AKAP150 ¿PIX and ¿PKA mice knock-in mice that selectively disrupt CaN or PKA anchoring in vivo, respectively. Through characterization of these AKAP mutant mice we confirmed parts of this model by showing postsynaptic CaN anchoring is critical for LTD and constrains LTP, while PKA anchoring modulates both LTP and LTD. However, a number of our recent findings challenge current models by showing that CP- AMPARs may be transiently recruited to synapses and required for LTD, as in some forms of LTP. Also challenging conventional wisdom, we found that CaMKII activation is not only required for LTP but also for LTD induction. Thus, In Aim 1 we will test the novel hypothesis that LTD induction requires AKAP-PKA and CaMKII-dependent CP-AMPAR recruitment to synapses that is followed by AKAP-CaN mediated removal. In Aim 2 we further explore whether AKAP79/150 palmitoylation by DHHC2, which targets it to recycling endosomes, is required to coordinate this PKA/CaN regulation of GluA1 CP-AMPAR trafficking during LTP/LTD. Finally, In Aim 3 we will test the hypothesis that alterations in CP-AMPAR regulation of hippocampal synaptic plasticity in AKAP150 mutant mice result in changes in contextual fear learning and memory. We will test these hypotheses using a combination of biochemical, fluorescence imaging, electrophysiological, and behavioral approaches.
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0.936 |
2014 — 2019 |
Dell'acqua, Mark L |
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. |
Mechanisms of Neuronal Calcineurin-Nfat Synapse-to-Nucleus Signaling @ University of Colorado Denver
DESCRIPTION (provided by applicant): In hippocampal neurons, somato-dendritic CaV1.2 L-type voltage-gated Ca2+ channels (LTCC) function in excitation-transcription (E-T) coupling. Depolarizations that open LTCCs in postsynaptic neurons activate the transcription factors cAMP-response element binding protein (CREB) and nuclear factor of activated T-cells (NFAT) through Ca2+-regulated kinases and phosphatases. Because LTCC transcriptional regulation is required for long-lasting forms of excitatory synaptic plasticity that underlie learning and memory, it is crucial to understand how LTCC signaling leads to efficient, spatiotemporally specific synapse-to-nucleus communication. A question of fundamental importance in synapse-to-nucleus signaling is: how are early signals in E-T coupling Ca2+ signals in dendritic postsynaptic nanodomains transduced into signals that are reliably relayed over long distances to the nucleus? The postsynaptic scaffold protein A-kinase anchoring protein (AKAP) 79/150 binds to CaV1.2 through a modified leucine zipper (LZ) motif. This AKAP anchors both the cAMP- dependent protein kinase (PKA), via an amphipathic alpha-helical motif, and the Ca2+-calmodulin (CaM)-activated protein phosphatase-2B (calcineurin; CaN), via an atypical PxIxIT docking motif. Anchoring of PKA to AKAP79/150 supports enhancement of neuronal LTCC current amplitude that is potently opposed by Ca2+-dependent feedback through AKAP-anchored CaN. LTCC activation of AKAP-localized CaN is also required for K+ depolarization-triggered NFAT translocation to the nucleus and activation of transcription. However, key synapse-to-nucleus signaling questions remain for the LTCC-AKAP-CaN-NFAT pathway: (1) does the AKAP79/150 signaling complex regulate LTCC Ca2+ influx specifically in dendrites excited by postsynaptic glutamate receptor activation; (2) do these Ca2+ signals in dendrites locally activate CaN-NFAT signaling that ultimately acts in the nucleus; (3) what are the neuronal target genes regulated by this signaling pathway; and (4) is this process engaged during synaptic plasticity? We will explore these crucial questions in three aims that rely upon a combination of Ca2+ imaging (Aim 1), CaN and NFAT imaging (Aim 2), and gene transcription analyses (Aim 3). AKAP79/150 regulation of LTCC Ca2+ influx, CaN-NFAT signaling dynamics, and activity-dependent gene transcription will be investigated in neurons or brain slices expressing AKAP mutants that alter PKA anchoring, CaN anchoring, or LZ domain binding. The overall goal of this project is to test a central hypothesis in synapse-to-nucleus communication that postsynaptic Ca2+ signals are locally re-coded in dendrites as protein-based signals (e.g., NFAT), and relayed to the nucleus to control plasticity-associated gene expression.
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0.936 |
2016 — 2017 |
Dell'acqua, Mark L |
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.) |
Amyloid Beta Postsynaptic Signaling Through Akap-Anchored Calcineurin @ University of Colorado Denver
Project Summary Abstract Amyloid Beta Postsynaptic Signaling through AKAP-anchored Calcineurin A? overproduction from APP is believed to contribute to impaired synaptic plasticity and decreased cognitive function in Alzheimer?s disease (AD). Individuals with Down syndrome (DS; trisomy 21) have an extra copy of APP that predisposes them to early-onset AD. Thus, elucidating how A? inhibits plasticity is important for understanding cognitive impairments associated with the development of dementia in AD and DS and could identify novel drug targets, diagnostics, and therapies. Rodent model studies indicate that calcineurin (CaN) phosphatase signaling could contribute to altered LTP/LTD synaptic plasticity, dendritic spine loss, and learning and memory impairments in AD. A?-induced spine loss may be further linked to altered gene expression through CaN activation of the transcription factor NFAT. Here we propose to test the novel hypotheses that AKAP79/150-CaN anchoring is required for A? activation of CaN signaling that regulates the balance between LTP/LTD signaling and NFAT transcription associated with dendritic spine/synapse loss.
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0.936 |
2016 — 2019 |
Dell'acqua, Mark L |
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. |
Core B: Nanoscopy @ University of Colorado Denver
Project Summary/Abstract: Core B Nanoscopy Super-resolution light microscopy or nanoscopy (i.e. microscopy with nanometer-scale resolution) is defined as imaging with a resolution below the diffraction limit of conventional light microscopy, which is ~200 nm in the equatorial (xy) and ~500 nm in the axial (z) dimension. Recently developed super-resolution methods that allow light microscopy to image subcellular structure and molecular localization on the 10s of nm scale have revolutionized neurobiology by allowing neuroscientists to study the inner workings of glia, axons, dendrites, and synapses in unprecedented detail that had previously only been possible using electron microscopy (EM). In particular, super-resolution fluorescence imaging has many advantages over EM including much easier sample preparation and staining procedures as well as the ability to be applied to not only fixed, but also living cells and tissues. Several different super-resolution fluorescence imaging methods have been developed, such as STimulated-Emission Depletion (STED) microscopy and the related methods of Stochastic Optical Reconstruction Microscopy (STORM) and Photo-activation Localization Microscopy (PALM). Each of these nanoscopy methods has advantages and limitations depending on the properties of the biological sample and fluorophores to be imaged. Thus, it is advantageous and even necessary to employ more than one of these different methods when investigating any given scientific question. Accordingly, the RMNDC Nanoscopy Core B will provide access to recently acquired instrumentation and technical support for NINDS-funded and other neuroscience investigators at the University of Colorado-Anschutz Medical Campus (UC-AMC) to perform state-of-the-art STED and STORM/PALM super-resolution imaging (Aim 1) and complementary Forster-resonance energy transfer (FRET)-based imaging (Aim 2).
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0.936 |
2018 — 2021 |
Dell'acqua, Mark L |
T32Activity Code Description: To enable institutions to make National Research Service Awards to individuals selected by them for predoctoral and postdoctoral research training in specified shortage areas. |
Predoctoral Training Grant in Pharmacology @ University of Colorado Denver
The University of Colorado Denver | Anschutz Medical Campus (UCD|AMC) Pharmacology Graduate Training Program, currently in its 39th year of NIGMS funding, and requests annual support for 7 predoctoral students during the next five years. The Training Program distinguishes itself by providing a highly interactive environment in which students obtain a broadly based integrative perspective on science, training in the fundamental knowledge defining pharmacology. The Principle Investigator for the Training Grant is Dr. Mark Dell?Acqua, Vice Chair of the Department of Pharmacology. The Training Program Director is Dr. David Port, who Chairs the Graduate Training Committee (GTC), which provides the day-to-day oversight for this Training Program. The 47 members of the Training Program faculty are drawn numerous departments within the School of Medicine, and have been recruited to provide broad, multidisciplinary training opportunities in neuropharmacology, cell signaling, pharmacogenetics, cancer biology, biomolecular structure, and bioinformatics. Training Program faculty are all accomplished, committed researchers and mentors with significant extramural funding. The sources of students entering the Training Program include direct applicants to the Program, as well as students who transition from ?umbrella? programs (Biomedical Sciences and Medical Scientist Training Programs). Hallmarks of the Program are a comprehensive didactic component, 3 laboratory rotations, a strong emphasis on student presentations in seminar settings, and a wide choice of thesis research options. Career development in the pharmacological sciences and student initiative are also emphasized. During each of the past 4 years of this T32 funding cycle, 6 students have been supported by the Training Grant. As a composite, the last 4 classes (Fall 2014-17) of ?direct recruit? matriculated students include 5 URM?s This represents a 29% URM matriculation rate (5 of 17 students). During the same time period, an additional 5 students entered the Training Program, 3 MSTP?s, 1 BSP?s, and 1 transfer, for a total of 22 incoming students over 4 years, an average of 5.5/year. The Training Program currently has a total of 26 students, up from 16 at the last grant submission. Since 2013, 13 trainees have graduated with Ph.D. degrees in an average of 5.3 years. An additional 3 trainees graduated with M.S. Degrees. The competitiveness of the students for individual national fellowships, high quality publications in peer-reviewed journals and invitations to participate in national meetings are all measures by which the successful training of the students is gauged. Additionally, the retention of the graduates in academic, industry and government positions is another measure of the success of the Training Program. With renewal of funding, this Training Program will continue to thrive and meet the national demands for individuals, trained as pharmacologists, who are individually astute researchers, can be multidisciplinary research team members, and also have the breadth of knowledge to plan and communicate effectively across a spectrum of technologies.
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0.936 |
2019 — 2021 |
Bayer, K. Ulrich Dell'acqua, Mark L Kennedy, Matthew J (co-PI) [⬀] |
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. |
Postsynaptic Kinase/Phosphatase Networks in Amyloid Beta-Induced Synaptic Dysfunction @ University of Colorado Denver
Project Summary Abstract Postsynaptic kinase/phosphatase networks in amyloid ?-induced synaptic dysfunction Alzheimer's disease (AD) is characterized by impaired synaptic function and synapse loss in key forebrain areas required for learning and memory, including the hippocampus. While the pathologic agent that causes AD remains contentious (amyloid-beta; A? vs. tau) there is strong genetic, biochemical, anatomical and electrophysiological evidence supporting that A? is sufficient to initiate cellular processes leading to severe synaptic pathology. For example sub-micromolar doses of A? acutely (within minutes) inhibit long-term potentiation (LTP), a form of synaptic plasticity critical for learning and memory. In addition, longer A? exposure (days to weeks) leads to depression and elimination of excitatory synapses through a process that requires NMDA receptor signaling. However, the downstream signaling networks that drive acute and chronic A?-mediated synaptic pathologies are only beginning to emerge and need to be further investigated. Strong preliminary data from our labs implicate several postsynaptic ser/thr kinases (CaMKII, DAPK1, PKA) and a phosphatase (calcineurin (CaN)) as key molecular players responsible for acute A?- induced LTP disruption, possibly through impaired NMDA receptor Ca2+ entry. It remains unclear whether these same signaling mechanisms mediate chronic A?-induced synaptic depression and elimination, but published and preliminary data presented here indicate that CaN activity is required. Importantly, all of these kinases and phosphatases interact with one another in a postsynaptic signaling network that integrates NMDAR activity to promote either LTP or LTD. Indeed, synaptic anchoring of PKA and CaN by the scaffold protein AKAP79/150 appears to be critical for promoting signaling crosstalk between PKA, CaN, DAPK1 and CaMKII at synaptic sites to establish normal LTP/LTD balance. In this multi-PI project we will test the hypothesis that A? causes acute (Aims 1 & 2) and chronic (Aims 3 & 4) synaptic dysfunction by perturbing the balance of this signaling network and its downstream effectors to favor LTD, leading to impaired LTP and synapse elimination.
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0.936 |
2019 — 2021 |
Dell'acqua, Mark L |
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. |
Regulation of Calcium-Permeable Ampa Receptors by Akap79 Postsynaptic Signaling @ University of Colorado Denver
Learning and memory requires multiple forms of synaptic plasticity mediated by mGlu, NMDA, AMPA glutamate receptors (mGluR, NMDAR, AMPAR). These plasticity mechanisms include long-term potentiation (LTP) and depression (LTD), that rapidly increase or decrease synaptic strength of specific inputs, and homeostatic synaptic scaling, which scale-up or -down strength of all inputs. Importantly, alterations in LTP/LTD and homeostatic plasticity are associated with cognitive dysfunction in animal models of nervous system disorders. Until recently, the signaling mechanisms controlling AMPARs during LTP/LTD and homeostatic plasticity were envisioned as distinct. However, LTP/LTD and homeostatic plasticity can both result in synaptic incorporation of high-conductance, Ca2+-permeable AMPA receptors (CP-AMPAR) containing GluA1, but lacking GluA2, subunits that not only impact synaptic strength but also alter plasticity itself - i.e. metaplasticity. Nevertheless, the roles of CP-AMPARs in controlling plasticity in hippocampal neurons are controversial. A major barrier to moving the field forward has been that we do not have an adequate understanding of the signaling mechanisms that control CP-AMPARs. Importantly, recent studies from our laboratory employing knock-in mice demonstrated that the kinase PKA and phosphatase Calcineurin (CaN) anchored to A-kinase anchoring protein (AKAP) 79/150 play opposing roles regulating GluA1 phosphorylation to control both basal and plasticity-regulated CP-AMPAR synaptic incorporation at hippocampal synapses. In particular, we found that AKAP-PKA/CaN positive/negative regulation of CP-AMPAR synaptic incorporation controls LTP/LTD balance and determines whether synapses can undergo homeostatic potentiation. In addition, we found that palmitoylation/depalmitoylation of the AKAP N-terminal targeting domain controls AKAP delivery/removal from dendritic spines in coordination with cellular correlates of LTP/LTD. Furthermore, recent unpublished work indicates that knock-in disruption of AKAP palmitoylation in vivo increases basal CP-AMPAR activity to prevent subsequent LTP. Finally, both published and unpublished data indicate that these CP- AMPAR-mediated changes in plasticity are influenced by developmental age, induction stimulus, and crosstalk with CaMKII and mGlu1 signaling suggesting engagement of metaplasticity. Here we will use the unique knock-in mice we developed to test the overall hypothesis that regulation of AKAP postsynaptic targeting by palmitoylation (aim 1) and CaMKII signaling (aim 2), and interactions between AKAP-PKA/CaN and mGluR signaling (aim 3) control LTP/LTD balance at CA1 synapses through CP-AMPAR-mediated metaplasticity.
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0.936 |
2020 |
Dell'acqua, Mark L |
T32Activity Code Description: To enable institutions to make National Research Service Awards to individuals selected by them for predoctoral and postdoctoral research training in specified shortage areas. |
Predoctoral Training Grant in Pharmacology Include Down Syndrome Supplement @ University of Colorado Denver
Abstract: The University of Colorado Anschutz Medical Campus (UC/AMC) Pharmacology Graduate Training Program is currently in its 41st year of NIGMS funding. The Training Program distinguishes itself by providing a highly interactive environment in which students obtain a broadly-based integrative perspective on science and training in the fundamental knowledge defining pharmacology. The Principle Investigator for the Training Grant is Dr. Mark Dell'Acqua, Vice Chair of the Department of Pharmacology. The Training Program Director and co- PI of the Training Grant is Dr. David Port, who Chairs the Graduate Training Committee (GTC), which provides the day-to-day oversight for this Training Program. The ~50 members of the Training Program faculty are drawn from numerous departments within the School of Medicine and have been recruited to provide broad, multidisciplinary training opportunities in neuropharmacology, cell signaling, pharmacogenetics, cancer biology, cardiovascular/pulmonary biology, molecular structure, and bioinformatics. Training Program faculty are all accomplished, committed researchers and mentors with significant extramural funding. The sources of students entering the Training Program include direct applicants to the Program, as well as students who transition from `umbrella' programs (Biomedical Sciences and Medical Scientist Training Programs). Hallmarks of the Program are a comprehensive didactic component, 3 laboratory rotations, a strong emphasis on student presentations in seminar settings, and a wide choice of thesis research options. Career development in the pharmacological sciences and student initiative are also emphasized. The Training Program currently has a total of 33 students including 7 students from the MSTP track. The competitiveness of the students for individual national fellowships, high quality publications in peer-reviewed journals and invitations to participate in national meetings are all measures by which the successful training of the students is gauged. Retention of the graduates in academic, industry and government positions is another measure of the success of the Training Program. The Program continues to thrive and meet the national demands for individuals, trained as pharmacologists, who are individually astute researchers, can be multidisciplinary research team members, and also have the breadth of knowledge to plan and communicate effectively across a spectrum of technologies. The current proposal for a renewal of an INCLUDE Down syndrome supplement to the existing parent Program that will serve to continue to enhance the already robust environment for training graduate students in areas of scientific enquiry germane to Down syndrome and its co-occuring conditions. As articulated in the proposal, a number of faculty mentors in the training program are deeply invested in Down syndrome related research and are actively engaged in training mentees in this area.
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0.936 |