Effect of Antioxidants in Cathepsin B Release by HIV Infected Macrophages

During HIV infection of macrophages, the lysosomal protein cathepsin B is released and induces neurotoxicity. Also, the levels of cathepsin B are increased in plasma and post-mortem brain tissue of patients with HIV-associated dementia. Oxidative damage is increased in HIV- infected patients, while antioxidants are decreased in HIV-associated dementia. Dimethyl fumarate (DMF), an antioxidant, has been reported to decrease HIV replication and neurotoxicity caused by HIV-infected macrophages. Since HIV also increases cathepsin B, we hypothesize that DMF will also reduce cathepsin B release from HIV-infected macrophages. Monocyte-derived macrophages (MDM) were isolated from healthy donors and inoculated with HIV-1ADA. After removal of infection, MDM were treated with DMF at different concentrations (15, 30, and 60 µM) until day 12 post-infection, changing and collecting media every three days. HIV-1p24 and cathepsin B levels were assessed from HIV-infected MDM supernatants at the end of cultures using ELISA. Results indicate that DMF reduced HIV-1 replication and cathepsin B secretion from HIV-infected macrophages, in a concentration-dependent manner, in comparison with vehicle (DMSO)-treated controls. However, cathepsin B secretion was not affected by HIV infection in vehicle-treated controls. In conclusion, DMSO may have had an unexpected effect in cathepsin B secretion in our experiments, and this could explain why cathepsin B secretion was not affected by HIV infection. Future experiments will include an untreated control group to determine if DMSO vehicle is having an effect in cathepsin B secretion. This will lead us to determine the role of DMF in cathepsin B secretion from HIV-infected macrophages

Quantitative Proteomics Reveal That CB2R Agonist JWH-133 Downregulates NF-κB Activation, Oxidative Stress, and Lysosomal Exocytosis from HIV-Infected Macrophages

HIV-associated neurocognitive disorders (HAND) affect 15–55% of HIV-positive patients and effective therapies are unavailable. HIV-infected monocyte-derived macrophages (MDM) invade the brain of these individuals, promoting neurotoxicity. We demonstrated an increased expression of cathepsin B (CATB), a lysosomal protease, in monocytes and post-mortem brain tissues of women with HAND. Increased CATB release from HIV-infected MDM leads to neurotoxicity, and their secretion is associated with NF-κB activation, oxidative stress, and lysosomal exocytosis. Cannabinoid receptor 2 (CB2R) agonist, JWH-133, decreases HIV-1 replication, CATB secretion, and neurotoxicity from HIV-infected MDM, but the mechanisms are not entirely understood. We hypothesized that HIV-1 infection upregulates the expression of proteins associated with oxidative stress and that a CB2R agonist could reverse these effects. MDM were isolated from healthy women donors (n = 3), infected with HIV-1ADA, and treated with JWH-133. After 13 days post-infection, cell lysates were labeled by Tandem Mass Tag (TMT) and analyzed by LC/MS/MS quantitative proteomics bioinformatics. While HIV-1 infection upregulated CATB, NF-κB signaling, Nrf2-mediated oxidative stress response, and lysosomal exocytosis, JWH-133 treatment downregulated the expression of the proteins involved in these pathways. Our results suggest that JWH-133 is a potential alternative therapy against HIV-induced neurotoxicity and warrant in vivo studies to test its potential against HAND