Expression of mRNAs encoding receptors that mediate stress signals in gonadotropin-releasing hormone neurons of the mouse.
Neurons that synthesize and secrete gonadotropin-releasing hormone (GnRH) represent the neural control point for fertility modulation in vertebrates. As such GnRH neurons are ideally situated to integrate stress responses on reproduction. By isolating individual GnRH neurons from acute brain slices of adult female GnRH-EGFP transgenic mice and using microarray analyses, we have identified a range of transcripts encoding receptors known to be involved in stress responses in GnRH neurons. Prominent among these were receptors for corticotropin-releasing hormone (CRH), vasopressin, interleukins, prostaglandins, tumor necrosis factor alpha and other inflammatory mediators. We selected 4 of these targets [interleukin 1 receptor accessory protein (IL-1Racc), prostaglandin E(2) receptor subtype EP2 (PGER2), CRH receptor type 1 (CRH-R1), and arginine-vasopressin receptor type 1b (AVP-R1b)] for validation using single-cell RT-PCR from individual GnRH neurons. In total, 54% of GnRH neurons (n = 26) were found to express at least 1 of these transcripts. The IL-1Racc, PGER2 and CRH-R1 mRNAs were each detected in approximately 25% of the GnRH neurons tested, but no evidence was found for AVP-R1b transcripts. Overlap was found between the expression of CRH-R1 and PGER2, and IL-1Racc and PGER2 in individual GnRH neurons. Dual immunofluorescence experiments confirmed the expression of CRH-R1/2 in a subpopulation ( approximately 30%) of GnRH neurons. These observations indicate that a variety of different stressors and stress pathways have the capacity to have an impact directly upon a subpopulation of GnRH neurons to influence the reproductive axis.
Jasoni
Christine L
CL
Centre for Neuroendocrinology, Department of Physiology, University of Otago School of Medical Sciences, Dunedin, New Zealand.
Todman
Martin G
MG
Han
Seong-Kyu
SK
Herbison
Allan E
AE
D000818:Animals; D005260:Female; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D007987:Gonadotropin-Releasing Hormone / Q000032:analysis*; D007150:Immunohistochemistry; D053577:Interleukin-1 Receptor Accessory Protein; D051379:Mice; D008822:Mice, Transgenic; D009474:Neurons / Q000737:chemistry* / Q000166:cytology / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics*; D011956:Receptors, Cell Surface / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D018019:Receptors, Corticotropin-Releasing Hormone / Q000032:analysis / Q000235:genetics / Q000502:physiology; D017472:Receptors, Interleukin-1 / Q000032:analysis / Q000235:genetics / Q000502:physiology; D018078:Receptors, Prostaglandin E / Q000032:analysis / Q000235:genetics / Q000502:physiology; D058307:Receptors, Prostaglandin E, EP2 Subtype; D017483:Receptors, Vasopressin / Q000032:analysis / Q000235:genetics / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D013312:Stress, Physiological / Q000235:genetics / Q000503:physiopathology*
C507767:Il1rap protein, mouse; D053577:Interleukin-1 Receptor Accessory Protein; C545645:Ptger2 protein, mouse; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D018019:Receptors, Corticotropin-Releasing Hormone; D017472:Receptors, Interleukin-1; D018078:Receptors, Prostaglandin E; D058307:Receptors, Prostaglandin E, EP2 Subtype; D017483:Receptors, Vasopressin; D007987:Gonadotropin-Releasing Hormone