NEUROPROTECTIVE PROPERTIES OF CALRETININ AGAINST THE HIV-1 GP120 TOXICITY

The HIV-1 protein gp120 is toxic for neurons in cultures and this toxi city involves a calcium-mediated mechanism. In this study we have util ized immunocytochemical techniques to determine if cultured cortical n eurons expressing calretinin or parvalbumin, two cytosolic calcium-buf fering proteins are more resistant to gp120 toxicity after a 24 hour-e xposure at different concentrations (1, 40, 100 pM). For calbindin the re is a clear relation between the neuronal survival and the relative percentage of calbindin-expressing neurons in gp120 (100 pM) exposed c ultures (63.0 +/- 3%) compared to control cultures (28.1 +/- 4.1%). No significant differences were observed for neurons in cultures express ing parvalbumin. In conclusion in this cell culture system neurons exp ressing calretinin are more resistant to gp120 toxicity compared to th ose not expressing calretinin.