title: Crebinostat: a novel cognitive enhancer that inhibits histone deacetylase activity and modulates chromatin-mediated neuroplasticity.
abstract: Long-term memory formation is known to be critically dependent upon de novo gene expression in the brain. As a consequence, pharmacological enhancement of the transcriptional processes mediating long-term memory formation provides a potential therapeutic strategy for cognitive disorders involving aberrant neuroplasticity. Here we focus on the identification and characterization of small molecule inhibitors of histone deacetylases (HDACs) as enhancers of CREB (cAMP response element-binding protein)-regulated transcription and modulators of chromatin-mediated neuroplasticity. Using a CREB reporter gene cell line, we screened a library of small molecules structurally related to known HDAC inhibitors leading to the identification of a probe we termed crebinostat that produced robust activation of CREB-mediated transcription. Further characterization of crebinostat revealed its potent inhibition of the deacetylase activity of recombinant class I HDACs 1, 2, 3, and class IIb HDAC6, with weaker inhibition of the class I HDAC8 and no significant inhibition of the class IIa HDACs 4, 5, 7, and 9. In cultured mouse primary neurons, crebinostat potently induced acetylation of both histone H3 and histone H4 as well as enhanced the expression of the CREB target gene Egr1 (early growth response 1). Using a hippocampus-dependent, contextual fear conditioning paradigm, mice systemically administered crebinostat for a ten day time period exhibited enhanced memory. To gain insight into the molecular mechanisms of memory enhancement by HDAC inhibitors, whole genome transcriptome profiling of cultured mouse primary neurons treated with crebinostat, combined with bioinformatic analyses of CREB-target genes, was performed revealing a highly connected protein-protein interaction network reflecting modules of genes important to synaptic structure and plasticity. Consistent with these findings, crebinostat treatment increased the density of synapsin-1 punctae along dendrites in cultured neurons. Finally, crebinostat treatment of cultured mouse primary neurons was found to upregulate Bdnf (brain-derived neurotrophic factor) and Grn (granulin) and downregulate Mapt (tau) gene expression-genes implicated in aging-related cognitive decline and cognitive disorders. Taken together, these results demonstrate that crebinostat provides a novel probe to modulate chromatin-mediated neuroplasticity and further suggests that pharmacological optimization of selective of HDAC inhibitors may provide an effective therapeutic approach for human cognitive disorders. This article is part of a Special Issue entitled 'Cognitive Enhancers'.
authors: Center for Human Genetic Research, Massachusetts General Hospital, Department of Neurology, Harvard Medical School, 185 Cambridge Street, Boston, MA 02114, USA.
authors: Daniel M
authors: DM
authors: Fass
authors: Surya A
authors: SA
authors: Reis
authors: Balaram
authors: B
authors: Ghosh
authors: Krista M
authors: KM
authors: Hennig
authors: Nadine F
authors: NF
authors: Joseph
authors: Wen-Ning
authors: WN
authors: Zhao
authors: Thomas J F
authors: TJ
authors: Nieland
authors: Ji-Song
authors: JS
authors: Guan
authors: Chelsea E Groves
authors: CE
authors: Kuhnle
authors: Weiping
authors: W
authors: Tang
authors: Douglas D
authors: DD
authors: Barker
authors: Ralph
authors: R
authors: Mazitschek
authors: Stuart L
authors: SL
authors: Schreiber
authors: Li-Huei
authors: LH
authors: Tsai
authors: Stephen J
authors: SJ
authors: Haggarty
mesh_terms: D000107:Acetylation / Q000187:drug effects; D000818:Animals; D000831:Animals, Newborn; D001713:Biphenyl Compounds / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D002478:Cells, Cultured; D003712:Dendrites / Q000187:drug effects / Q000378:metabolism; D055808:Drug Discovery / Q000379:methods*; D004622:Embryo, Mammalian / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D017930:Genes, Reporter / Q000187:drug effects; D056572:Histone Deacetylase Inhibitors / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D006655:Histone Deacetylases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006834:Hydrazines / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009473:Neuronal Plasticity / Q000187:drug effects*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D018697:Nootropic Agents / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D016548:Prosencephalon / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: C578174:(7-(2-((1,1'-biphenyl)-4-ylmethylene)hydrazinyl)-N-hydroxy-7-oxoheptanamide); D001713:Biphenyl Compounds; D056572:Histone Deacetylase Inhibitors; D006657:Histones; D006834:Hydrazines; D009419:Nerve Tissue Proteins; D018697:Nootropic Agents; D011994:Recombinant Proteins; D006655:Histone Deacetylases