Neuroprotective properties of calretinin against the HIV-1 gp120 toxicity

The HIV-1 protein gp120 is toxic for neurons in cultures and this toxicity involves a calcium-mediated mechanism. In this study we have utilized immunocytochemical techniques to determine if cultured cortical neurons expressing calretinin or parvalbumin, two cytosolic calcium-buffering proteins are more resistant to gp120 toxicity after a 24 hour-exposure at different concentrations (1, 40, 100 pM). For calbindin there is a clear relation between the neuronal survival and the relative percentage of calbindin-expressing neurons in gp120 (100 pM) exposed cultures (63.0 +/- 3%) compared to control cultures (28.1 +/- 4.1%). No significant differences were observed for neurons in cultures expressing parvalbumin. In conclusion in this cell culture system neurons expressing calretinin are more resistant to gp120 toxicity compared to those not expressing calretinin.