Regulation of gonadotropin-releasing hormone secretion by kisspeptin/dynorphin/neurokinin B neurons in the arcuate nucleus of the mouse.
Kisspeptin is encoded by the Kiss1 gene, and kisspeptin signaling plays a critical role in reproduction. In rodents, kisspeptin neurons in the arcuate nucleus (Arc) provide tonic drive to gonadotropin-releasing hormone (GnRH) neurons, which in turn supports basal luteinizing hormone (LH) secretion. Our objectives were to determine whether preprodynorphin (Dyn) and neurokinin B (NKB) are coexpressed in Kiss1 neurons in the mouse and to evaluate its physiological significance. Using in situ hybridization, we found that Kiss1 neurons in the Arc of female mice not only express the Dyn and NKB genes but also the NKB receptor gene (NK3) and the Dyn receptor [the kappa opioid receptor (KOR)] gene. We also found that expression of the Dyn, NKB, KOR, and NK3 in the Arc are inhibited by estradiol, as has been established for Kiss1, and confirmed that Dyn and NKB inhibit LH secretion. Moreover, using Dyn and KOR knock-out mice, we found that long-term disruption of Dyn/KOR signaling compromises the rise of LH after ovariectomy. We propose a model whereby NKB and dynorphin act autosynaptically on kisspeptin neurons in the Arc to synchronize and shape the pulsatile secretion of kisspeptin and drive the release of GnRH from fibers in the median eminence.
Navarro
Victor M
VM
Department of Physiology and Biophysics, University of Washington, Seattle, 98195, USA.
Gottsch
Michelle L
ML
Chavkin
Charles
C
Okamura
Hiroaki
H
Clifton
Donald K
DK
Steiner
Robert A
RA
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000378:metabolism*; D004399:Dynorphins / Q000235:genetics / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D017403:In Situ Hybridization; D059648:Kisspeptins; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008959:Models, Neurological; D015287:Neurokinin B / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D010052:Ovariectomy; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D018042:Receptors, Neurokinin-3 / Q000819:agonists / Q000378:metabolism; D011957:Receptors, Opioid / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
C491407:Kiss1 protein, mouse; D059648:Kisspeptins; D011498:Protein Precursors; D012333:RNA, Messenger; D018042:Receptors, Neurokinin-3; D011957:Receptors, Opioid; D025521:Tumor Suppressor Proteins; C030738:dynorphin receptor; C036448:pre-prodynorphin; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D004399:Dynorphins; D015287:Neurokinin B; D007986:Luteinizing Hormone