Abstract: Objective　To explore the effect of trichostatin A (TSA) on the apoptosis of mouse hippocampal neuron cell line HT-22 cells under different sugar concentrations. Methods　The mouse hippocampal neuron HT-22 cells in high glucose medium (glucose concentration 55 mmol/L) and normal medium (grape concentration 25 mmol/L) were cultured. The cells in high glucose medium and normal medium were divided into control group (NC group) and inhibitor group (TSA group). Cells were treated with 1 mmol/L TSA for 1, 4 and 8 h, or 0.4 mmol/L TSA for 1, 4, 8, 12, 14, 16, 20 and 24 h. The cell viability was detected by the CCK8 method after treatment. Histone deacetylase (HDAC) and histone acetyltransferase (HAT) enzyme activities were detected by ELISA. Cell apoptosis was detected by flow cytometry. The expression levels of B lymphoma-2 (Bcl-2), Bcl-2 related X protein (Bax) and cysteine protease 3 (Caspase-3) were detected by Western blot assay. Results　The 0.4 mmol/L of TSA and 20 hours were the optimal condition for culturing HT-22 cells after testing. ELISA results showed that after treatment with TSA, HDAC significantly decreased and HAT increased significantly (P＜0.05). Flow cytometry results showed that after TSA inhibiting for 20 h, the apoptosis rate increased significantly. While TSA was added to cells under high glucose conditions, the apoptosis rate increased more. After 20 hours of TSA treatment, Bcl-2 expression was significantly down-regulated, while Caspase-3 was significantly up-regulated (P＜0.05). Conclusion　TSA may increase the level of histone acetylation by inhibiting HDAC, which could lead to the apoptosis of mouse neuronal cells HT-22.

Key words: glucose, diabetes mellitus, brain diseases, hippocampus, apoptosis, histone deacetylases, trichostatin A