The long term goal is to elucidate the molecular basis by which activated glia (astrocytes and microglia) and glial derived molecules contribute to neuropathology, and to gain sufficient insight into molecular mechanisms for better treatment of neurodegenerrative diseases, such as Alzheimer's disease (AD). The focus of this AG13039 renewal application is on molecular mechanisms of glial activation induced by beta amyloid (Abeta)1-42 and inflammatory cytokine such as IL-1Beta and tumor necrosis factor (TNF). Key glial signal transduction pathways and gene expression changes mediated by AB and cytokines have been elucidated and novel mechanisms of modulation of these pathways have been defined. Abeta can stimulate astrocytes to express inducible nitric oxide synthase (iNOS), quantitatively the most important source of over expression of NO in the brain, and increased NO production can lead to neuronal death. Abeta stimulated iNOS expression is mediated through an induction of IL-1Beta and TNF alpha in microglia, which then activates astrocytes through an NFKbeta dependent mechanism to produce iNOS and NO. However, there remains a major gap in knowledge of the quantitative contribution of this cytokine induced NFKB-dependent, signaling pathways in relationship to other molecular pathways which mediates Abeta induced iNOS in astrocytes. Also, there is a lack of knowledge regarding the more upstream events by which Abeta induces the pro-inflammatory cytokines in miocroglia. In addition little is known about how modulation of specific molecular pathways are activated, affecting neuronal responses. The studies proposed here will fill these voids in knowledge and provide insight into how Abeta and cytokines are involved in progressive and chronic glial activation processes that compromise brain function.
The specific aims address the following questions: 1) What are the molecular mechanisms by which AB induces inflammatory cytokines and iNOS in activated glia? 2) What are the consequences to the neuron of modulation of glial signal transduction pathways leading to iNOS induction? Aim 1A will examine a recently discovered new pathway involving calmodulin -dependenmt kinase (CaMK) by determining if CaMKIV is involved in iNOS induction through activation of CREB-linked pathways.
Aim 1 B, will elucidate the mechanisms by which inflammatory cytokines are induced by ABeta by determining if p38 stress kinase are important for IL-1beta induction in activated microglia.
Aim2 will determine the contribution of specific signal transduction pathways leading to iNOS induction on neuronal dysfunction by utilizing a defined co-culture system of primary astrocytes and neurons where NO-dependent neuronal death occurs. Pathways will be modulated by selective pharmacological agents or molecular constructs and effects on neuronal viability will be determined. Astrocytes from genetically engineered mice with over expression of KO and specific components of glial signaling pathways will also be used to ascertain how an in vivo alteration in a specific pathway affects neuronal function. Elucidation of these molecular mechanisms and how they can be modulated as well as defining the effects on the neuron and how genotype affects the responses, will provide new insight into glial neuronal interactions and the knowledge base necessary for pursuit of novel strategies to block glial activation and its neurotoxic consequences.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
3R37AG013939-07S1
Application #
6596997
Study Section
Special Emphasis Panel (ZRG1 (01))
Program Officer
Snyder, Stephen D
Project Start
1996-09-19
Project End
2005-06-30
Budget Start
2002-07-01
Budget End
2003-06-30
Support Year
7
Fiscal Year
2002
Total Cost
$5,000
Indirect Cost
Name
Northwestern University at Chicago
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
005436803
City
Chicago
State
IL
Country
United States
Zip Code
60611
Barone, Eugenio; Di Domenico, Fabio; Sultana, Rukhsana et al. (2012) Heme oxygenase-1 posttranslational modifications in the brain of subjects with Alzheimer disease and mild cognitive impairment. Free Radic Biol Med 52:2292-301
Sultana, Rukhsana; Robinson, Renã A S; Di Domenico, Fabio et al. (2011) Proteomic identification of specifically carbonylated brain proteins in APP(NLh)/APP(NLh) × PS-1(P264L)/PS-1(P264L) human double mutant knock-in mice model of Alzheimer disease as a function of age. J Proteomics 74:2430-40
Thompson, Wendy L; Van Eldik, Linda J (2009) Inflammatory cytokines stimulate the chemokines CCL2/MCP-1 and CCL7/MCP-3 through NFkB and MAPK dependent pathways in rat astrocytes [corrected]. Brain Res 1287:47-57
Chico, Laura K; Van Eldik, Linda J; Watterson, D Martin (2009) Targeting protein kinases in central nervous system disorders. Nat Rev Drug Discov 8:892-909
Borders, Aaron S; de Almeida, Lucia; Van Eldik, Linda J et al. (2008) The p38alpha mitogen-activated protein kinase as a central nervous system drug discovery target. BMC Neurosci 9 Suppl 2:S12
Lloyd, Eric; Somera-Molina, Kathleen; Van Eldik, Linda J et al. (2008) Suppression of acute proinflammatory cytokine and chemokine upregulation by post-injury administration of a novel small molecule improves long-term neurologic outcome in a mouse model of traumatic brain injury. J Neuroinflammation 5:28
Thompson, Wendy L; Karpus, William J; Van Eldik, Linda J (2008) MCP-1-deficient mice show reduced neuroinflammatory responses and increased peripheral inflammatory responses to peripheral endotoxin insult. J Neuroinflammation 5:35
Fuller, Abby D; Van Eldik, Linda J (2008) MFG-E8 regulates microglial phagocytosis of apoptotic neurons. J Neuroimmune Pharmacol 3:246-56
Van Eldik, Linda J; Thompson, Wendy L; Ralay Ranaivo, Hantamalala et al. (2007) Glia proinflammatory cytokine upregulation as a therapeutic target for neurodegenerative diseases: function-based and target-based discovery approaches. Int Rev Neurobiol 82:277-96
Wing, Laura K; Behanna, Heather A; Van Eldik, Linda J et al. (2006) De novo and molecular target-independent discovery of orally bioavailable lead compounds for neurological disorders. Curr Alzheimer Res 3:205-14

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