JunB is a repressor of MMP-9 transcription in depolarized rat brain neurons

摘要

Matrix Metalloproteinase-9 (MMP-9) is an extracellularly operating enzyme involved in the synapticplasticity, hippocampal-dependent long term memory and neurodegeneration. Previous studies have shownits upregulation following seizure-evoking stimuli. Herein, we show that in the rat brain, MMP-9 mRNAexpression in response to pentylenetetrazole-evoked neuronal depolarization is transient. Furthermore, wedemonstrate that in the rat hippocampus neuronal activation strongly induces JunB expression,simultaneously leading to an accumulation of JunB/FosB complexes onto the -88/-80 bp site of the ratMMP-9 gene promoter in vivo. Surprisingly, manipulations with JunB expression levels in activated neuronsrevealed its moderate repressive action onto MMP-9 gene expression. Therefore, our study documents theactive repressive influence of AP-1 onto MMP-9 transcriptional regulation by the engagement of JunB.