Chromatin remodeling designates the restructuring of histone proteins and DNA through reversible covalent modifications (e.g. histone acetylation and methylation, methylation of CpG islands in DNA), which produces conformational changes in the chromatin (condensed vs relaxed) and thereby modulates the accessibility of DNA to transcription factors and RNA polymerases [80]. These epigenetic modifications therefore have the ability to regulate gene expression without altering the DNA primary sequence. The role of epigenetic mechanisms in alcoholism is becoming an intense area of investigation [81, 82]. Accordingly, recent gene expression profiling studies have pinpointed that markers of chromatin remodeling were regulated by chronic ethanol exposure, both in rodent models and in human alcoholics, as detailed below.
