Morphine Exacerbates HIV-1 Tat-Induced Cytokine Production in Astrocytes through Convergent Effects on [Ca2+]i, NF-κB Trafficking and Transcription
Figure 2
Tat phosphorylates IκBα in astrocytes.
To verify that IκBα is phosphorylated in our cell culture system, astrocytes were treated with Tat alone or in combination with morphine for 30 min, 2 and 6 h (A). Increases in IκBα phosphorylation were noted in cell lysates treated with Tat±morphine at 30 min compared to treatment with vehicle or morphine alone (*P<0.05 vs. controls at 30 min). After 6 h, the amount of phosphorylated IκBα was equal in cell lysates treated with Tat alone or Tat plus morphine (A). Down regulation of NF-κB (p65), c-Rel and p50 by parthenolide. Nuclear extracts from cells treated with or without Tat±parthenolide for 24 h were subjected to electromobility shift assay (EMSA) with labeled NF-κB oligonucleotide (B). Nuclear extracts containing parthenolide showed a down regulation in NF-κB DNA binding activity as compared to the DNA binding activity of nuclear extract without parthenolide.