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BackgroundAstrocytes become activated with certain infections, and this might alter the brain to trigger or worsen depressed mood. Indeed, astrocytes are chronically activated in people with HIV infection (PWH), who are much more frequently depressed than people without HIV (PWoH). A particularly disabling component of depression in PWH is apathy, a loss of interest, motivation, emotion, and goal-directed behavior. We tested the hypothesis that depression and apathy in PWH would be associated with higher levels of a biomarker of astrocyte activation, glial fibrillary acidic protein (GFAP), in cerebrospinal fluid (CSF).MethodsWe evaluated PWH in a prospective observational study using the Beck Depression Inventory-II (BDI-II) and additional standardized assessments, including lumbar puncture. We measured GFAP in CSF with a customized direct sandwich ELISA method. Data were analyzed using ANOVA and multivariable regression.ResultsParticipants were 212 PWH, mean (SD) age 40.9±9.14 years, median (IQR) nadir and current CD4 199 (57, 326) and 411 (259, 579), 65.1% on ART, 67.3% virally suppressed. Higher CSF GFAP correlated with worse total BDI-II total scores (Pearson correlation r=0.158, p-value=0.0211), and with worse apathy scores (r=0.205, p=0.0027). The correlation between apathy/depression and GFAP was not in fluenced by other factors such as age or HIV suppression status.ConclusionsAstrocyte activation, reflected in higher levels of CSF GFAP, was associated with worse depression and apathy in PWH. Interventions to reduce astrocyte activation -- for example, using a peptide-1 receptor (GLP-1R) agonist -- might be studied to evaluate their impact on disabling depression in PWH.

Despite the success of antiretroviral therapies to control systemic HIV-1 infection, the prevalence of HIV-associated neurocognitive disorders (HANDs) has not decreased among aging patients with HIV. Autophagy pathway alterations, triggered by HIV-1 proteins including gp120, Tat, and Nef, might contribute to the neurodegenerative process in aging patients with HAND. Although no treatments are currently available to manage HAND, we have previously shown that sunitinib, an anticancer drug that blocks receptor tyrosine-kinase and cyclin kinase pathways, might be of interest. Studies in cancer models suggest that sunitinib might also modulate autophagy, which is dysregulated in our models of Tat-induced neurotoxicity. We evaluated the efficacy of sunitinib to promote autophagy in the CNS and ameliorate neurodegeneration using LC3-GFP-expressing neuronal cells challenged with low concentrations of Tat and using inducible Tat transgenic mice. In neuronal cultures challenged with low levels of Tat, sunitinib increased markers of autophagy such as LC3-II and reduced p62 accumulation in a dose-dependent manner. In vivo, sunitinib treatment restored LC3-II, p62, and endophilin B1 (EndoB1) levels in doxycycline-induced Tat transgenic mice. Moreover, in these animals, sunitinib reduced the hyperactivation of CDK5, tau hyperphosphorylation, and p35 cleavage to p25. Restoration of CDK5 and autophagy were associated with reduced neurodegeneration and behavioral alterations. Alterations in autophagy in the Tat tg mice were associated with reduced levels of a CDK5 substrate, EndoB1, and levels of total EndoB1 were normalized by sunitinib treatment. We conclude that sunitinib might ameliorate Tat-mediated autophagy alterations and may decrease neurodegeneration in aging patients with HAND.