Effects of a Novel, Non-Toxic Histone Deacetylase Inhibitor on Histone Acetylation Levels in Mice

Grace Geiger, “Effects of a Novel, Non-Toxic Histone Deacetylase Inhibitor on Histone Acetylation Levels in Mice”
Mentors: Karyn Frick and Sarah Beamish, Psychology

The molecular mechanisms that contribute to long-term memory formation remain a point of inquiry for many neuroscientists today. Chromatin remodeling through epigenetic modifications, such as histone acetylation, promotes successful formation of long-term memories by increasing levels gene expression. Research demonstrates that histone deacetylase inhibitors (HDACi) improve memory by preventing the deacetylation of core histone proteins and allowing transcriptional machinery increased access to open chromatin. HDACi are a promising therapeutic target for memory decline, however, the memory enhancing effects of existing HDACi are precluded by their poor toxicity and unwanted solubility. In collaboration with the Chemistry and Biology Departments at UWM, we have developed a novel brain-penetrant HDACi compound, MJM-1, that shows no evidence of toxicity. Data collected from our lab indicates that MJM-1 is capable of enhancing spatial memory in mice. However, it remains unclear the extent to which MJM-1 modifies levels of histone acetylation in the brain. The goal of this work is to determine whether MJM-1 modifies histone acetylation levels in the dorsal hippocampus (DH), a brain region critical for spatial memory formation. Mice received an intraperitoneal injection of negative control (100% DMSO), positive HDACi control sodium butyrate (0.6 g/kg NaBu), or one of three doses of MJM-1 (20, 30, or 40 mg/kg), and the DH was dissected 60 min later. DH tissue was then homogenized so that histones were extracted and posttranslational modifications were kept intact. Here, we demonstrate that i.p. administration of MJM-1 does not increase levels of histone acetylation at one hour. Future steps include assaying DH tissue at shorter timepoints and possibly different brain regions to detect any changes in histone acetylation.

Comments

  1. Hi everyone, my name is Grace Geiger. I’m a sophomore here at UWM majoring in Biochemistry and minoring in Psychology. I was first introduced to undergraduate research through the UR@UWM program and was matched in Karyn Frick’s memory lab. I was fortunate enough to be invited back into the lab as a freshman, and have been helping out ever since. I’ve worked on a variety of projects, but this semester I was paired with Sarah Beamish to study the memory effects of a novel HDACi compound. If you have any questions, please leave a comment!

  2. Excellent presentation of a complex and interesting topic. I appreciated the effort to explain why the findings were not exactly what was expected.

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