Histones are modified by MGO. (A) Western blotting demonstrates complete knockout of GLO1. (B) GLO1-/- cells lack any measurable GLO1 activity. (C) Western blotting of chromatin fractions using isoform-specific MG-H antibodies (courtesy of Dr. David Spiegel) reveals histones as targets for modification with markedly increased levels observed in GLO1-/- cells treated with MGO. Due to a lack of measurable MG-H2 protein adduction, chromatin was treated with 5 mM MGO for 6 h (‘Control’) to serve as a positive control for MGO modification. (D,E) RNA-Seq reveals transcripts altered by MGO. Venn diagrams displaying significantly decreased or increased protein coding transcripts in GLO1-/- cells treated with either vehicle, 50 µM MGO, or 500 µM MGO compared with WT vehicle control. WT cells were also analyzed, revealing minimal alterations in gene expression, likely a result of the rapid metabolism of MGO by GLO1. We are actively investigating the role of MGO-derived histone PTMs in the regulation of gene expression.