Worldwide, there are more than 40 million people infected with human immunodeficiency virus (HIV-1). Approximately 10-15% of HIV-1 infected individuals suffer from CNS pathologies including HIV-associated encephalitis and HIV dementia (HAD), collectively termed neuroAIDS. Increasing evidence suggests that neuronal damage associated with neuroAIDS results in part from microglial and astroglial mediated inflammation. Astrocyte-derived chemokines, including CCL2 and CXCL10, have been implicated as inflammatory molecules involved in neuroAIDS. We recently characterized 2-funaltrexamine (2-FNA) inhibition of astroglial chemokine expression; however, the mechanism by which 2 FNA inhibits chemokine expression remains unclear. A critical need exists, therefore, to identify the mechanism whereby 2-FNA inhibits HIV-1-induced astroglial chemokine expression. The long-term goal is to identify the molecular mechanism responsible for the anti-inflammatory actions of 2-FNA. The overall objective of this application is to identify the mechanism by which 2-FNA attenuates astroglial expression of CCL2 and CXCL10. The central hypothesis is that 2-FNA inhibits astroglial expression of CCL2 and CXCL10 in part through a pre-transcriptional mechanism. This hypothesis will be tested through experiments included in three separate aims:
SPECIFIC AIM 1 : Determine the effects of 2-funaltrexamine on proinflammatory-induced CCL2 and CXCL10 expression in human astroglia.
SPECIFIC AIM 2 : Determine the role of opioid receptors in 2-funaltrexamine mediated effects on proinflammatory induced CCL2 and CXCL10 expression in human astroglia.
SPECIFIC AIM 3 : Determine the effects of 2-funaltrexamine on NFkB activation in human astroglia. To model a key aspect of CNS inflammation associated with HIV-1 infection, we will expose human astroglial cells to TNF1 and HIV-1 Tat1-72 resulting in the induction CCL2 and CXCL10. We will then characterize the effects of 2-FNA on CCL2 and CXCL10 expression in astroglia. Also, selective opioid receptor antagonists will be utilized in order to characterize the involvement of specific opioid receptor types in the anti inflammatory actions of 2-FNA. Oxidative stress and the transcription factor NFkB are instrumental in the proinflammatory induced expression of both CCL2 and CXCL10. Thus, the effects of 2-FNA on the generation of reactive oxygen species and NFkB activation will also be characterized. This project will fill basic gaps in our knowledge base by identifying and characterizing novel actions of the opioid antagonist 2-FNA, particularly the anti-inflammatory actions of this molecule. This information is expected to be instrumental in the development of therapeutic strategies to prevent and treat neuroinflammatory conditions including, HIV-1 neuropathogenesis.
TO PUBLIC HEALTH The information obtained through this AREA Award is expected to be instrumental in the development of therapeutic strategies to prevent and treat numerous neuroinflammatory conditions and in particular, HIV-1 neuropathogenesis. Additionally, this award will support the research training of multiple undergraduate, graduate and medical students at OSU-CHS. This training will lend to the success of these students in their future careers in health related professions. ? ? ?
