Neuroscience
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12503/21741
Browse
Browsing Neuroscience by Author "Ghorpade, Anuja"
Now showing 1 - 2 of 2
- Results Per Page
- Sort Options
Item Alcohol Regulates HIV-1-Mediated Astrocyte Inflammatory Responses Via cPLA2 Signaling Pathway(2015-03) Pandey, Richa; Ghorpade, AnujaAlcohol (EtOH) abuse and HIV-1 remain significant public health problems. Globally, drinkers have approximately 70-77% higher risk of HIV-infection than non-drinkers. The prevalence of alcohol abuse among HIV-positive individuals has been estimated to be between 29-60% in the United States. Many studies showed that neurodegeneration in alcohol abusers include exacerbated neuroinflammation and oxidative damage. However, how EtOH regulates HIV-1-induced astrocyte neuroinflammation is unknown. Thus, we explored mechanism(s) involved in alcohol-mediated activation of human astrocytes with HIV-1 and subsquent alterations in their inflammatory functions. Alcohol exposure altered the morphology of astrocytes, proinflammatory responses and induced cytotoxicity in a dose-dependent manner. Time-depended changes were also evaluated. Alcohol and HIV-1 co-treatment decreased cell viability and proliferation, while increasing apoptosis and mitochondrial depolarization. Alcohol and HIV-1 together increased the levels of proinflammatory molecules, IL-1b, TNF-a, CXCL8, TIMP-1 and more importantly, arachidonic acid, known to be downstream of cPLA2. Consistent with this observation, phospho-cPLA2 levels were augmented in HIV-1 and EtOH co-treatment as compared to HIV-1 or EtOH alone. COX2 was upregulated as measured by real time PCR and western blot, whereas co-treatment of HIV-1 and EtOH decreased CYP2E1 levels as compared to EtOH alone. In summary, our results demonstrate that EtOH-mediated astrocyte inflammation and cytotoxicity in context of HAND occurs via cPLA2 signaling.Item Astrocyte AEG-1 regulation of Wnt/β-catenin signaling in HAND(2015-03) Nooka, Shruthi; Ghorpade, AnujaPurpose: Glial induced chronic inflammation contributes to the pathogenesis of HIV-1-associated neurocognitive disorder (HAND), but the molecular mechanisms of inflammatory regulation have not yet been fully understood. Astrocyte elevated gene (AEG-1), an HIV-1 and tumor necrosis factor (TNF)-α inducible gene, is associated with multiple signaling cascades such as nuclear factor (NF)-κB, Wnt/β-catenin during tumor progression. Recently, upregulation of Wnt signaling proteins was observed in spinal cord dorsal horn of HIV-1 patients. In addition, Wnt signaling regulates pro-inflammatory cytokines expression in several inflammatory diseases including rheumatoid arthritis, psoriasis. However, the relationship between AEG-1 and Wnt signaling pathway in HIV-1-associated neuropathogenesis has not been studied. Hereby, we proposed that astrocyte AEG-1 induces inflammation via classical Wnt signaling in HAND. Methods: Cultured human astrocytes were treated with HIV-1DJV, interleukin (IL)-1β and TNF-α. Astrocytes were nucleofected with AEG-1 and β-catenin specific siRNA. Changes in AEG-1, β-catenin and lymphoid enhancing factor (LEF)-1 levels were determined by RT-PCR, western blot analysis and immunocytochemistry. Co-immunoprecipitation (Co-IP) studies were performed to examine AEG-1 interacting proteins and NF-κB dynamics. Pro-inflammatory molecules such as CCL2 and CXCL8 levels were measured by ELISA. Results: HIV-1DJV in combination with IL-1β and TNF-α significantly upregulated AEG-1, β-catenin and LEF-1 mRNA levels. Nuclear translocation of β-catenin decreased significantly in siAEG-1 transfected astrocytes. Further, Co-IP studies showed AEG-1 interacting with β-catenin and LEF-1, and upon activation with pro-inflammatory stimuli, interaction increased in both the cytoplasm and nucleus. Both AEG-1 and β-catenin also interacted with NF-κB, suggesting a common denominator in regulating inflammation. AEG-1 and β-catenin transient knockdown followed by IL-1β treatment altered NF-κB mediated pro-inflammatory cytokines production. Conclusion: In summary, HAND-relevant stimuli upregulated classical Wnt signaling and increased interactions between AEG-1, β-catenin and NF-κB, suggesting AEG-1 mediated Wnt signaling regulation of NF-κB activity in HAND neuropathogenesis.