Despite the introduction of highly active antiretroviral therapy (HAART), the prevalence of human immunodeficiency virus associated dementia (HAD) has been steadily increasing. Neuronal injury and loss in HAD is initiated by HIV-infected, activated macrophage/microglia via soluble neurotoxic mediators including reactive oxygen species (ROS), excitotoxins, and other metabolites as well as viral proteins. These mediators, which induce oxidative stress, are known to injure neurons directly and alter astrocytic homeostatic functions such as glutamate homeostasis which can lead to excitotoxic neuronal injury. Importantly, several studies in vitro and in vivo have shown that oxidative stress and excitotoxicity are likely critical mechanisms of pathogenesis in HAD. How neurons and astrocytes respond to oxidative stress in HIV infection of the central nervous system (CNS) is largely undefined and underexplored. A major downstream response to oxidative stress is induction of the recently described integrated stress response (ISR) which may be the critical link between oxidative stress and excitotoxicity. Activation of the ISR results in translational attenuation, transactivation of ER chaperone gene promoters, activation of protein degradation pathways and activation of the endogenous antioxidant response. Induction of these responses is regulated by one or more of three distinct signaling pathways: pancreatic endoplasmic reticulum kinase (PERK), IRE1 alpha, and ATF6. Whether one or all of these pathways are induced in neuronal or astrocytic cells during HIV induced CNS injury is not known;however, we have demonstrated that supernatants from HIV infected monocyte derived macrophages (HIV-M/M) induce several components of the ISR including PERK in primary astrocytes in vitro. In addition, we have found that several antiretroviral drugs used in HAART also induce ISR in primary astrocytes. Thus, we hypothesize that that activation of the ISR in astrocytes by HIV M/M and/or HAART exposure is a major determinant of neuronal injury/survival in HAD. Our goal is to determine the role of ISR activation in astrocytes by HIV M/M and HAART therapeutics in mediating neuronal damage in vitro and in vivo in HAD. To do this we will: 1) Determine the mechanism by which ISR activation triggered by HIV-M/M supernatants impacts astrocyte neuroprotective functions and survival, 2) Define the role of HAART drugs in ISR activation in astrocytes, and 3) Define and validate the contribution of chronic activation of the ISR pathways in HAD. By investigating the role of ISR, we expect to uncover a novel mechanism for neuronal dysfunction and loss in HIVE and elucidate the impact of current HAART therapeutics on astrocytic mediated neuronal survival. Patients with HIV associated dementia have increased cellular stress in their brain due to inflammatory infiltration and oxidative stress. These stressors are known activate a protective pathway called the integrated stress response in non-neural cells. This proposal aims to assess the state of activation of the integrated stress response in astrocytes exposed to HIV-infected macrophage products and highly active antiretroviral therapeutic agents and determine the impact of such activation on neuronal survival.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS056885-04
Application #
7900322
Study Section
NeuroAIDS and other End-Organ Diseases Study Section (NAED)
Program Officer
Wong, May
Project Start
2007-09-30
Project End
2012-07-31
Budget Start
2010-08-01
Budget End
2011-07-31
Support Year
4
Fiscal Year
2010
Total Cost
$389,813
Indirect Cost
Name
University of Pennsylvania
Department
Pathology
Type
Schools of Dentistry
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Gannon, Patrick J; Akay-Espinoza, Cagla; Yee, Alan C et al. (2017) HIV Protease Inhibitors Alter Amyloid Precursor Protein Processing via ?-Site Amyloid Precursor Protein Cleaving Enzyme-1 Translational Up-Regulation. Am J Pathol 187:91-109
Ting, Jenhao H; Marks, David R; Schleidt, Stephanie S et al. (2014) Targeted gene mutation of E2F1 evokes age-dependent synaptic disruption and behavioral deficits. J Neurochem 129:850-63
Gill, Alexander J; Kovacsics, Colleen E; Cross, Stephanie A et al. (2014) Heme oxygenase-1 deficiency accompanies neuropathogenesis of HIV-associated neurocognitive disorders. J Clin Invest 124:4459-72
Akay, Cagla; Cooper, Michael; Odeleye, Akinleye et al. (2014) Antiretroviral drugs induce oxidative stress and neuronal damage in the central nervous system. J Neurovirol 20:39-53
Wang, Ying; Zyskind, Jacob W; Colacurcio, Daniel J et al. (2012) Differential roles for caspase-mediated and calpain-mediated cell death in 1- and 3-week-old rat cortical cultures. Neuroreport 23:1052-8
Akay, C; Lindl, K A; Shyam, N et al. (2012) Activation status of integrated stress response pathways in neurones and astrocytes of HIV-associated neurocognitive disorders (HAND) cortex. Neuropathol Appl Neurobiol 38:175-200
White, Michael G; Wang, Ying; Akay, Cagla et al. (2011) Parallel high throughput neuronal toxicity assays demonstrate uncoupling between loss of mitochondrial membrane potential and neuronal damage in a model of HIV-induced neurodegeneration. Neurosci Res 70:220-9
Lindl, Kathryn A; Marks, David R; Kolson, Dennis L et al. (2010) HIV-associated neurocognitive disorder: pathogenesis and therapeutic opportunities. J Neuroimmune Pharmacol 5:294-309
Dong, Ling; Odeleye, Akinleye O; Jordan-Sciutto, Kelly L et al. (2008) Painful facet joint injury induces neuronal stress activation in the DRG: implications for cellular mechanisms of pain. Neurosci Lett 443:90-4
Lindl, Kathryn A; Jordan-Sciutto, Kelly L (2008) Examining the endogenous antioxidant response through immunofluorescent analysis of Nrf2 in tissue. Methods Mol Biol 477:229-43

Showing the most recent 10 out of 11 publications