Distribution of lysine-specific demethylase 1 in the brain of rat and its response in transient global cerebral ischemia.

The lysine-specific histone demethylase 1 (LSD1) is a chromatin modifying enzyme that specifically removes methyl groups from lysine 4 of histone 3 (H3-K4) and induces transcriptional repression. However, limited knowledge exists, regarding the existence and significance of LSD1 in the brain. We identified the distribution of LSD1 and H3-K4 mono-, di-, and tri-methylation in the brain of rats, respectively. The temporal and spatial distribution of LSD1 during ischemic brain injury was also explored. LSD1 immunoreactive cells were nucleus positive and were concentrated in the neurons of the hippocampus, cerebral cortex, striatum and amagdala. The distributions of H3-K4 mono-, di-, and tri-methylation exhibited exactly the same pattern as LSD1. LSD1 expression was induced both region and cell specifically after ischemic/perfusion, and complied with the two-peak mode of expression. These studies revealed a tightly regulated distribution for LSD1 in the brain of rats under ischemic insult, suggesting a critical role in neuron function.