The prefrontal cortex as a target of HIV-1 neurotoxicity: molecular mechanisms of viral protein-mediated neurodegeneration and executive dysfunction

Despite the success of combined antiretroviral therapy (cART) in achieving peripheral viral suppression, HIV-associated neurocognitive disorder (HAND) remains a persistent challenge, affecting approximately 50% of people living with HIV. This review identifies the prefrontal cortex (PFC) as a primary target of HIV-1 neurotoxicity, as HIV-1 can directly infect the brain, and cART fails to eliminate the production of viral proteins from latent HIV-microglial reservoirs. The blood-brain barrier receives several hits from HIV-1 proteins, leading to a leaky and highly permeable barrier. Several proteins drive chronic neuroinflammation through inflammasome activation and pyroptosis, and ferroptosis in microglia. Glutamatergic dysregulation in the CNS results in increased neuron excitability and neurotoxicity. Also, overactive complement-mediated synaptic pruning and microglial senescence disrupt the intricate neural networks required for higher-order signaling. Neuroimaging and PFC dysfunction can be linked to specific HIV-1 proteins and their effects on the brain. Clinical symptoms of HAND directly reflect specialized PFC dysfunction. Deficits include impaired executive processes, which can present as lacking foresight for goal-directed actions, poor planning, and difficulty switching between tasks. Significant behavioral changes, including disinhibition, impaired moral reasoning, and increased risk-taking, can also be seen. Patients experience apathy, emotional blunting, and rapid mood shifts. Cognitive impairments include working memory loss, distractibility, and inappropriate memory linking. PFC disruptions can escalate into neuropsychiatric sequelae, driven by damaged dopamine and serotonin pathways. Defining these viral-mediated mechanisms will facilitate the development of pharmacological strategies that target several HIV-mediated neurotoxic pathways to prevent the debilitating characteristics of HAND.