Objective: To investigate the mechanisms underlying HIV-1 envelope glycoprotein 120 (gp120)-associated neurotoxicity on rat cortical neuronal cultures.
Methods: Experiments were carried out on primary cortical neuronal cultures prepared from fetal Sprague-Dawley fetal rats. Immunocytochemistry and Western blot techniques were employed to examine the changes of the expressions of N-methyl-D-asparate receptors 2B(NR2B) and postsynaptic density 95 (PSD-95) in cultured neurons in the presence and absence of gp120 in the culture media. Gp120-induced neurotoxicity was determined by MTT assay.
Results: MTT assay showed gp120 produced dose-dependent neuronal injury when added to the culture media and the gp120-induced neuronal injury was blocked by memantine, a specific NR2B receptor antagonist. Further studies revealed that gp120 induced neuronal injury by up-regulation of NR2B and down-regulation of PSD-95 expressions in rat cortical neurons.
Conclusion: These results demonstrated that gp120 injures neurons via an increase of NR2B and a decrease of PSD-95 expressions. The gp120-induced neuronal injury can be blocked by a specific NR2B receptor antagonist, suggesting NR2B may function as a potential target for the development of therapeutic strategies.