Stress and the dynamic genome: Steroids, epigenetics, and the transposome.
Stress plays a substantial role in shaping behavior and brain function, often with lasting effects. How these lasting effects occur in the context of a fixed postmitotic neuronal genome has been an enduring question for the field. Synaptic plasticity and neurogenesis have provided some of the answers to this question, and more recently epigenetic mechanisms have come to the fore. The exploration of epigenetic mechanisms recently led us to discover that a single acute stress can regulate the expression of retrotransposons in the rat hippocampus via an epigenetic mechanism. We propose that this response may represent a genomic stress response aimed at maintaining genomic and transcriptional stability in vulnerable brain regions such as the hippocampus. This finding and those of other researchers have made clear that retrotransposons and the genomic plasticity they permit play a significant role in brain function during stress and disease. These observations also raise the possibility that the transposome might have adaptive functions at the level of both evolution and the individual organism.
Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY; Developmental and Brain Sciences Program, Department of Psychology, University of Massachusetts, Boston, MA 02125; and pfaff@rockefeller.edu richard.hunter@umb.edu.
Richard G
RG
Hunter
Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY;
Khatuna
K
Gagnidze
Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY;
Bruce S
BS
McEwen
Laboratory of Neurobiology and Behavior, The Rockefeller University, New York, NY 10065 pfaff@rockefeller.edu richard.hunter@umb.edu.
Donald W
DW
Pfaff
D000818:Animals; D044127:Epigenesis, Genetic / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology*; D006624:Hippocampus / Q000378:metabolism*; D008954:Models, Biological; D009473:Neuronal Plasticity / Q000502:physiology; D051381:Rats; D018626:Retroelements / Q000502:physiology*; D013256:Steroids / Q000378:metabolism*; D013312:Stress, Physiological / Q000502:physiology*
D018626:Retroelements; D013256:Steroids
brain; genomic stress response; hippocampus; histone marks; retrotransposon