Role of microglial ferritinophagy in HIV and cocaine-mediated neuroinflammation - Project Summary/Abstract: HIV/AIDS continues to affect nearly 39.9 million people worldwide. Although combination antiretroviral therapy (cART) effectively suppresses viral replication and reduces progression to AIDS, approximately 30–60% of people living with HIV (PLWH) still experience HIV-associated neurocognitive disorders (NeuroHIV), characterized by chronic neuroinflammation and progressive cognitive decline. This persistent inflammatory state is fueled by viral proteins such as Transactivator of transcription (Tat) that continue to be expressed in the brain, lifelong exposure to cART, and high rates of comorbid stimulant misuse, particularly cocaine, which exacerbates neuroinflammation and neuronal injury. Microglia, the resident immune cells of the brain, are central mediators of this process, as excessive activation drives inflammasome signaling, oxidative stress, and synaptic dysfunction. Mechanistically, these effects converge on dysregulated autophagy, lysosomal dysfunction, and impaired iron homeostasis. A critical yet underexplored pathway is ferritinophagy, the selective autophagic turnover of ferritin mediated by nuclear receptor coactivator 4 (NCOA4). When ferritinophagy is disrupted, ferritin accumulates, lysosomal acidification is impaired, and iron overload promotes oxidative stress, ferroptosis, and neuroinflammation. Our preliminary studies demonstrate that HIV Tat, cART, and cocaine cooperatively disrupt lysosomal integrity, impair ferritinophagy, and drive iron-mediated oxidative stress in microglia. Notably, we have identified C381, a novel brain-penetrant lysosomal activator in early clinical development, which restores lysosomal acidification, enhances autophagic flux, and protects against neuroinflammation. Our long-term goal is to develop translational strategies that alleviate neuroinflammation and cognitive decline in PLWH with stimulant use disorder. The short-term goal of this project is to define how HIV Tat, cART, and cocaine disrupt ferritinophagy in microglia and to test whether restoring lysosomal function with C381 can rescue ferritinophagy and mitigate neuroinflammation. Specific Aim 1 will dissect molecular mechanisms of ferritinophagy disruption in vitro and test whether C381 restores iron homeostasis and suppresses downstream inflammatory pathways. Specific Aim 2 will examine the efficacy of C381 in vivo using inducible Tat and EcoHIV mouse models with cocaine and cART exposure and validate ferritinophagy dysregulation in archival macaque and postmortem human brain tissues. Overall, this project will establish ferritinophagy as a mechanistic link between HIV, cART, and stimulant misuse, and neuroinflammation, while testing C381 as a therapeutic strategy. Because C381 is already advancing in clinical development, these studies have immediate translational potential for protecting brain health in PLWH with stimulant use disorder.
