Effects of estradiol on the expression of immunophilin in cultured hippocampal neurons

Abstract

Objective To evaluate the effects of estradiol and estradiol receptor inhibitor ICI 182,780 on the expression of immunophilin FKBP12 in the primary culture of rat hippocampal neurons.Methods New-born SD rats were sacrificed and the hippocampi were dissected into small pieces and cultured in 24-well plates and 60 mm petri dishes. MAP-2 immunocytochemical methods were used to identify hippocampal neurons. Neurons were divided into four groups: control, estrogen, estrogen + ICI 182,780, and ICl 182,780. The final concentration of estradiol and ICI 182,780 was 10-8 mol/L. Western blotwas used to examine the expression of FKBP12 protein and RT-PCR was used to examine the mRNA of FKBP12. Results At the ninth day of culture, there were over 95% of the cells that were verified as hippocampal neurons. There was positive immunoreactivity of FKBP12 protein in cultured rat hippocampal neurons and the immunoreactivity of FKBP12 was up-regulated by estradiol treatment. This up-regulation could be blocked by ICI 182,780. The parallel results were found in the expression of the mRNA of FKBP12 in RT-PCR reaction. Conclusion Immunophilin FKBP12 expresses in the primary culture of rat hippocampal neurons. The protein and mRNA of FKBP12 could be up-regulated by estradiol treatment; this promotion could be blocked by estradiol receptor inhibitor ICI 182,780. Key words: Hippocampus; Estradiol; Immunophilin