Oxytocin Regulates Stress-Induced Crf Gene Transcription through CREB-Regulated Transcription Coactivator 3.
The major regulator of the neuroendocrine stress response in the brain is corticotropin releasing factor (CRF), whose transcription is controlled by CREB and its cofactors CRTC2/3 (TORC2/3). Phosphorylated CRTCs are sequestered in the cytoplasm, but rapidly dephosphorylated and translocated into the nucleus following a stressful stimulus. As the stress response is attenuated by oxytocin (OT), we tested whether OT interferes with CRTC translocation and, thereby, Crf expression. OT (1 nmol, i.c.v.) delayed the stress-induced increase of nuclear CRTC3 and Crf hnRNA levels in the paraventricular nucleus of male rats and mice, but did not affect either parameter in the absence of the stressor. The increase in Crf hnRNA levels at later time points was parallel to elevated nuclear CRTC2/3 levels. A direct effect of Thr(4) Gly(7)-OT (TGOT) on CRTC3 translocation and Crf expression was found in rat primary hypothalamic neurons, amygdaloid (Ar-5), hypothalamic (H32), and human neuroblastoma (Be(2)M17) cell lines. CRTC3, but not CRCT2, knockdown using siRNA in Be(2)M17 cells prevented the effect of TGOT on Crf hnRNA levels. Chromatin-immunoprecipitation demonstrated that TGOT reduced CRTC3, but not CRTC2, binding to the Crf promoter after 10 min of forskolin stimulation. Together, the results indicate that OT modulates CRTC3 translocation, the binding of CRTC3 to the Crf promoter and, ultimately, transcription of the Crf gene.


CONCLUSIONS
The neuropeptide oxytocin has been proposed to reduce hypothalamic-pituitary-adrenal (HPA) axis activation during stress. The underlying mechanisms are, however, elusive. In this study we show that activation of the oxytocin receptor in the paraventricular nucleus delays transcription of the gene encoding corticotropin releasing factor (Crf), the main regulator of the stress response. It does so by sequestering the coactivator of the transcription factor CREB, CRTC3, in the cytosol, resulting in reduced binding of CRTC3 to the Crf gene promoter and subsequent Crf gene expression. This novel oxytocin receptor-mediated intracellular mechanism might provide a basis for the treatment of exaggerated stress responses in the future.
Department of Behavioral and Molecular Neurobiology, University of Regensburg, Regensburg 93040, Germany.
Benjamin
B
Jurek
Department of Behavioral and Molecular Neurobiology, University of Regensburg, Regensburg 93040, Germany.
David A
http://orcid.org/0000-0001-8753-5005
DA
Slattery
Laboratory of Molecular Biology, Tohoku University Graduate School of Agricultural Science, Aoba-ku, Sendai-city 981-8555, Miyagi-pref, Japan, and.
Yuichi
Y
Hiraoka
Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver Institute of Child Health and Human Development, NIH, Bethesda, Maryland 20892.
Ying
Y
Liu
Laboratory of Molecular Biology, Tohoku University Graduate School of Agricultural Science, Aoba-ku, Sendai-city 981-8555, Miyagi-pref, Japan, and.
Katsuhiko
http://orcid.org/0000-0001-9921-2211
K
Nishimori
Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver Institute of Child Health and Human Development, NIH, Bethesda, Maryland 20892.
Greti
G
Aguilera
Department of Behavioral and Molecular Neurobiology, University of Regensburg, Regensburg 93040, Germany, inga.neumann@biologie.uni-regensburg.de.
Inga D
ID
Neumann
Department of Behavioral and Molecular Neurobiology, University of Regensburg, Regensburg 93040, Germany.
Erwin H
EH
van den Burg
D000818:Animals; D050882:CREB-Binding Protein / Q000378:metabolism*; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D003346:Corticotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism*; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D007031:Hypothalamus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D010120:Oxytocics / Q000494:pharmacology / Q000627:therapeutic use; D010121:Oxytocin / Q000031:analogs & derivatives / Q000494:pharmacology* / Q000627:therapeutic use; D021381:Protein Transport / Q000187:drug effects / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D018045:Receptors, Oxytocin / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013315:Stress, Psychological / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D013925:Thromboplastin / Q000378:metabolism*
D010120:Oxytocics; D018045:Receptors, Oxytocin; C033683:oxytocin, tri-Gly-; D005576:Colforsin; D010121:Oxytocin; D003346:Corticotropin-Releasing Hormone; D013925:Thromboplastin; D050882:CREB-Binding Protein
CRTC3/TORC3; Crf; intracellular signaling; oxytocin receptor; stress response