Endocytic Trafficking of HIV gp120 is Mediated by Dynamin and Plays a Role in gp120 Neurotoxicity.
Erin D WenzelAlessia BachisValeria AvdoshinaFrancesca TaraballiEnnio TasciottiItalo MocchettiPublished in: Journal of neuroimmune pharmacology : the official journal of the Society on NeuroImmune Pharmacology (2017)
Neurons that endocytose the human immunodeficiency virus-1 (HIV) protein gp120 exhibit neurite retraction and activation of caspase-3, suggesting that the endocytic process may be crucial for gp120-mediated neuronal injury. The goal of this study is to demonstrate that internalization and accumulation of gp120 play a role in its neurotoxic effects. In mammalian cells, endocytosis is primarily a dynamin-dependent process. To establish whether gp120 is endocytosed in a dynamin-dependent manner, we used fibroblasts in which deletion of dynamins was induced by tamoxifen. We observed a robust reduction of intracellular gp120 immunoreactivity in tamoxifen-treated cells. To examine whether endocytosis of gp120 is crucial for its neurotoxic effect, we blocked gp120 internalization into primary rat cortical neurons by dynasore, an inhibitor of the dynamin GTP-ase activity. We found that dynasore blocks both gp120 internalization and neurotoxicity. We then utilized gp120-loaded mesoporous silica nanoparticles to deliver gp120 intracellularly. We established that once internalized, gp120 is neurotoxic regardless of chemokine receptor activation. Our data suggest that dynamin-dependent endocytosis of gp120 is critical for its neurotoxicity.
Keyphrases
- human immunodeficiency virus
- antiretroviral therapy
- hepatitis c virus
- hiv infected
- hiv positive
- spinal cord
- induced apoptosis
- drug delivery
- hiv aids
- oxidative stress
- spinal cord injury
- machine learning
- brain injury
- signaling pathway
- men who have sex with men
- breast cancer cells
- binding protein
- extracellular matrix
- pi k akt
- amino acid