HIV-1 Vpu induces neurotoxicity by promoting Caspase 3-dependent cleavage of TDP-43.

ABSTRACT

Despite the efficacy of highly active antiretroviral therapy in controlling the incidence and mortality of AIDS, effective interventions for HIV-1-induced neurological damage and cognitive impairment remain elusive. In this study, we found that HIV-1 infection can induce proteolytic cleavage and aberrant aggregation of TAR DNA-binding protein 43 (TDP-43), a pathological protein associated with various severe neurological disorders. The HIV-1 accessory protein Vpu was found to be responsible for the cleavage of TDP-43, as ectopic expression of Vpu alone was sufficient to induce TDP-43 cleavage, whereas HIV-1 lacking Vpu failed to cleave TDP-43. Mechanistically, the cleavage of TDP-43 at Asp89 by HIV-1 relies on Vpu-mediated activation of Caspase 3, and pharmacological inhibition of Caspase 3 activity effectively suppressed the HIV-1-induced aggregation and neurotoxicity of TDP-43. Overall, these results suggest that TDP-43 is a conserved host target of HIV-1 Vpu and provide evidence for the involvement of TDP-43 dysregulation in the neural pathogenesis of HIV-1.