Tescalcin is a potential target of class I histone deacetylase inhibitors in neurons

Class I histone deacetylase (HDAC) inhibitors are believed to have positive effects on neurite outgrowth, synaptic plasticity, and neurogenesis in adult brain. However, the downstream molecular targets of class I HDAC inhibitors in neurons are not clear. Although class I HDAC inhibitors are thought to broadly promote transcription of many neuronal genes through enhancement of histone acetylation, the affected gene set may include unidentified genes that are essential for neuronal survival and function. To identify novel genes that are targets of class I HDAC inhibitors, we used a microarray to screen transcripts from neuronal cultures and evaluated changes in protein and mRNA expression following treatment with four HDAC inhibitors. We identified tescalcin (Tesc) as the most strongly up-regulated gene following treatment with class I HDAC inhibitors in neurons. Moreover, hippocampal neurons overexpressing TESC showed a greater than 5-fold increase in the total length of neurites and number of branch points compared with controls. These findings highlight a potentially important role for TESC in mediating the neuroprotective effect of class I HDAC inhibitors. TESC may also be involved in the development of brain and neurodegenerative diseases through epigenetic mechanisms.