HIV Protease Inhibitors Alter Amyloid Precursor Protein Processing via β-Site Amyloid Precursor Protein Cleaving Enzyme-1 Translational Up-Regulation

Am J Pathol. 2017 Jan;187(1):91-109. doi: 10.1016/j.ajpath.2016.09.006.

Abstract

Mounting evidence implicates antiretroviral (ARV) drugs as potential contributors to the persistence and evolution of clinical and pathological presentation of HIV-associated neurocognitive disorders in the post-ARV era. Based on their ability to induce endoplasmic reticulum (ER) stress in various cell types, we hypothesized that ARV-mediated ER stress in the central nervous system resulted in chronic dysregulation of the unfolded protein response and altered amyloid precursor protein (APP) processing. We used in vitro and in vivo models to show that HIV protease inhibitor (PI) class ARVs induced neuronal damage and ER stress, leading to PKR-like ER kinase-dependent phosphorylation of the eukaryotic translation initiation factor 2α and enhanced translation of β-site APP cleaving enzyme-1 (BACE1). In addition, PIs induced β-amyloid production, indicative of increased BACE1-mediated APP processing, in rodent neuroglial cultures and human APP-expressing Chinese hamster ovary cells. Inhibition of BACE1 activity protected against neuronal damage. Finally, ARVs administered to mice and SIV-infected macaques resulted in neuronal damage and BACE1 up-regulation in the central nervous system. These findings implicate a subset of PIs as potential mediators of neurodegeneration in HIV-associated neurocognitive disorders.

MeSH terms

  • Amyloid Precursor Protein Secretases / metabolism*
  • Amyloid beta-Protein Precursor / metabolism*
  • Animals
  • Axons / drug effects
  • Axons / metabolism
  • Axons / pathology
  • Cells, Cultured
  • HIV Protease Inhibitors / pharmacology*
  • Macaca
  • Male
  • Mice, Inbred C57BL
  • Microtubule-Associated Proteins / metabolism
  • Neuroglia / drug effects
  • Neuroglia / metabolism
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology
  • Protein Biosynthesis / drug effects*
  • Protein Processing, Post-Translational / drug effects*
  • Protein Stability / drug effects
  • Rats
  • Ritonavir / pharmacology
  • Unfolded Protein Response / drug effects
  • Up-Regulation / drug effects*
  • eIF-2 Kinase / metabolism

Substances

  • Amyloid beta-Protein Precursor
  • HIV Protease Inhibitors
  • Microtubule-Associated Proteins
  • PERK kinase
  • eIF-2 Kinase
  • Amyloid Precursor Protein Secretases
  • Ritonavir