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Journal ArticleDOI

New Gatekeepers of Reproduction: GPR54 and Its Cognate Ligand, KiSS-1

01 Apr 2005-Endocrinology (Endocrine Society)-Vol. 146, Iss: 4, pp 1686-1688
About: This article is published in Endocrinology.The article was published on 2005-04-01 and is currently open access. It has received 60 citations till now.

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Citations
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Journal ArticleDOI
TL;DR: It is demonstrated that kisspeptin exerts a potent depolarizing effect on the excitability of almost all adult GnRH neurons and that the responsiveness of Gn RH neurons tokisspeptin increases over postnatal development.
Abstract: We examined the role of kisspeptin and its receptor, the G-protein-coupled receptor GPR54, in governing the onset of puberty in the mouse. In the adult male and female mouse, kisspeptin (10-100 nM) evoked a remarkably potent, long-lasting depolarization of >90% of gonadotropin-releasing hormone (GnRH)-green fluorescent protein neurons in situ. In contrast, in juvenile [postnatal day 8 (P8) to P19] and prepubertal (P26-P33) male mice, kisspeptin activated only 27 and 44% of GnRH neurons, respectively. This developmental recruitment of GnRH neurons into a kisspeptin-responsive pool was paralleled by an increase in the ability of centrally administered kisspeptin to evoke luteinizing hormone secretion in vivo. To learn more about the mechanisms through which kisspeptin-GPR54 signaling at the GnRH neuron may change over postnatal development, we performed quantitative in situ hybridization for kisspeptin and GPR54 transcripts. Approximately 90% of GnRH neurons were found to express GPR54 mRNA in both juvenile and adult mice, without a detectable difference in the mRNA content between the age groups. In contrast, the expression of KiSS-1 mRNA increased dramatically across the transition from juvenile to adult life in the anteroventral periventricular nucleus (AVPV; p < 0.001). These results demonstrate that kisspeptin exerts a potent depolarizing effect on the excitability of almost all adult GnRH neurons and that the responsiveness of GnRH neurons to kisspeptin increases over postnatal development. Together, these observations suggest that activation of GnRH neurons by kisspeptin at puberty reflects a dual process involving an increase in kisspeptin input from the AVPV and a post-transcriptional change in GPR54 signaling within the GnRH neuron.

940 citations


Cites background or result from "New Gatekeepers of Reproduction: GP..."

  • ...These findings suggest that kisspeptin–GPR54 signaling is critical for sexual maturation in humans and mice, but precisely how and where this signaling occurs and its relationship to puberty remain a mystery (Seminara and Kaiser, 2005)....

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  • ...Thus, it seems plausible that kisspeptin–GPR54 signaling within the GnRH neuronal network is critical for the pubertal activation of GnRH neurons (Popa et al., 2005; Seminara and Kaiser, 2005), and the results of recent studies support this concept....

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  • ...Hence, as a whole, these investigations have laid the foundation for the concept that kisspeptin-GPR54 signaling within the GnRH neuronal network may be a “gatekeeper” for puberty onset (Seminara and Kaiser, 2005)....

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Journal ArticleDOI
TL;DR: The data are the first to provide conclusive evidence for the existence of a second KiSS gene, KiSS-2, in non-placental vertebrates, whose product is likely to play a dominant stimulatory role in the regulation of the gonadotropic axis at least in teleosts.

224 citations


Cites background from "New Gatekeepers of Reproduction: GP..."

  • ...Identification and characterization of the physiological roles of the so-called KiSS-1 system is a major breakthrough in modern Neuroendocrinology that has revolutionized the area of vertebrate reproduction (de Roux et al., 2003; Seminara et al., 2003; Matsui et al., 2004; Kaiser and Kuohung, 2005; Seminara, 2005; Seminara and Kaiser, 2005; Gottsch et al., 2006; Roa and Tena-Sempere, 2007; Roa et al., 2008)....

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  • ...…in modern Neuroendocrinology that has revolutionized the area of vertebrate reproduction (de Roux et al., 2003; Seminara et al., 2003; Matsui et al., 2004; Kaiser and Kuohung, 2005; Seminara, 2005; Seminara and Kaiser, 2005; Gottsch et al., 2006; Roa and Tena-Sempere, 2007; Roa et al., 2008)....

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Journal ArticleDOI
TL;DR: The present data document the ontogeny, sensitivity and intracellular signals for the stimulatory action of kisspeptin on the GnRH/LH axis in the rat and stress the essential role ofkisspeptin in normal, and eventually pathological, timing of puberty.

173 citations

Journal ArticleDOI
TL;DR: It is shown that glucagon stimulates via cAMP-PKA-CREB signaling hepatic production of the neuropeptide kisspeptin1, which acts on β cells to suppress GSIS, and this indicates a hormonal circuit between the liver and the endocrine pancreas in glycemia regulation and suggests in T2DM a sequential link between hyperglucagonemia via hepatic kisspe leptin1 to impaired insulin secretion.

172 citations


Cites background from "New Gatekeepers of Reproduction: GP..."

  • ...…including kisspeptin 54 (K54), K14, K13, and K10, of which the latter exerts ell Metabolism 19, 667–681, April 1, 2014 ª2014 Elsevier Inc. 667 (legend continued on next page) 668 Cell Metabolism 19, 667–681, April 1, 2014 ª2014 Elsevier Inc. full biological effects (Seminara and Kaiser, 2005)....

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Journal ArticleDOI
TL;DR: This work evaluated maximal LH and FSH secretory responses to kisspeptin-10, as well as changes in sensitivity and hypothalamic expression of KiSS-1 and GPR54 genes, in different physiological and experimental models in the adult female rat to document for the first time the changes in leptin expression and the gonadotropic effects in different functional states of the female reproductive axis.
Abstract: Kisspeptins, products of the KiSS-1 gene with ability to bind G protein-coupled receptor 54 (GPR54), have been recently identified as major gatekeepers of reproductive function with ability to potently activate the GnRH/LH axis. Yet, despite the diversity of functional states of the female gonadotropic axis, pharmacological characterization of this effect has been mostly conducted in pubertal animals or adult male rodents, whereas similar studies have not been thoroughly conducted in the adult female. In this work, we evaluated maximal LH and FSH secretory responses to kisspeptin-10, as well as changes in sensitivity and hypothalamic expression of KiSS-1 and GPR54 genes, in different physiological and experimental models in the adult female rat. Kisspeptin-10 (1 nmol, intracerebroventricular) was able to elicit robust LH bursts at all phases of the estrous cycle, with maximal responses at estrus; yet, in diestrus LH, responses to kisspeptin were detected at doses as low as 0.1 pmol. In contrast, high doses of kisspeptin only stimulated FSH secretion at diestrus. Removal of ovarian sex steroids did not blunt the ability of kisspeptin to further elicit stimulated LH and FSH secretion, but restoration of maximal responses required replacement with estradiol and progesterone. Finally, despite suppressed basal levels, LH and FSH secretory responses to kisspeptin were preserved in pregnant and lactating females, although the magnitude of LH bursts and the sensitivity to kisspeptin were much higher in pregnant dams. Interestingly, hypothalamic KiSS-1 gene expression significantly increased during pregnancy, whereas GPR54 mRNA levels remained unaltered. In summary, our current data document for the first time the changes in hypothalamic expression of KiSS-1 system and the gonadotropic effects (maximal responses and sensitivity) of kisspeptin in different functional states of the female reproductive axis. The present data may pose interesting implications in light of the potential therapeutic use of kisspeptin analogs in the pharmacological manipulation of the gonadotropic axis in the female.

170 citations

References
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Journal Article
TL;DR: The results show that KiSS-1 also functions as a metastasis suppressor gene in at least some human breast cancers, implying a mechanism whereby Ki SS-1 regulates events downstream of cell-matrix adhesion, perhaps involving cytoskeletal reorganization.
Abstract: Based on the observation that chromosome 1q deletions are not infrequent in late-stage human breast carcinomas, we tested whether the recently discovered human melanoma metastasis suppressor gene, KiSS-1, which maps to chromosome 1q32–q41, could suppress metastasis of the human breast carcinoma cell line MDA-MB-435. Parental, vector-only transfectants and KiSS-1 transfectant clones were injected into the mammary fat pads of athymic nude mice and assessed for tumor growth and spontaneous metastasis to regional lymph nodes and lungs. Expression of KiSS-1 reduced metastatic potential by 95% compared to control cells but did not suppress tumorigenicity. Metastasis suppression correlated with a decreased clonogenicity in soft (0.3%) and hard (0.9%) agar. Although the overall rate of cell adhesion to extracellular matrix components was unaffected, KiSS-1 transfectants spread on immobilized type-IV collagen more rapidly than did control populations. Invasion and motility were unaffected by KiSS-1. Based on the predicted structure of the KiSS-1 protein, our results imply a mechanism whereby KiSS-1 regulates events downstream of cell-matrix adhesion, perhaps involving cytoskeletal reorganization. In addition to its already described role in melanoma, our results show that KiSS-1 also functions as a metastasis suppressor gene in at least some human breast cancers.

356 citations

Journal ArticleDOI
TL;DR: It is proposed that the KiSS-1/GPR54 system is a novel, pivotal downstream element in the neuroendocrine network governing gonadotropin secretion and provides solid evidence for a stimulatory effect of Ki SS1 on FSH release, acting at central level.
Abstract: KiSS-1 was originally identified as a metastasis suppressor gene encoding an array of structurally related peptides, namely kisspeptins, which acting through the G protein-coupled receptor GPR54 are able to inhibit tumor progression. Unexpectedly, a reproductive facet of this newly discovered system has recently arisen, and characterization of the role of the KiSS-1/GPR54 system in the neuroendocrine control of gonadotropin secretion has been initiated. However, such studies have been so far mostly restricted to LH, and very little is known about the actual contribution of this system in the regulation of FSH release. To address this issue, the effects of KiSS-1 peptide on FSH secretion were monitored in vivo and in vitro under different experimental conditions. Intracerebroventricular administration of KiSS-1 peptide significantly stimulated FSH secretion in prepubertal and adult rats. Yet, dose-response analyses in vivo demonstrated an ED50 value for the FSH-releasing effects of KiSS-1 of 400 pmol, i.e....

312 citations

Journal ArticleDOI
TL;DR: Evidence is provided for metastin as a novel placenta-derived hormone in humans and the major portion of the circulating metastin, as determined by the two-site enzyme immunoassay, represents endogenous metastin.
Abstract: Metastin is a novel peptide that was recently isolated from human placenta as the endogenous ligand of an orphan heptahelical receptor, hOT7T175. Metastin has been shown to suppress the motility of hOT7T175-transfected melanoma cells; however, studies of the physiological function of metastin have begun only recently. To investigate the possibility that metastin is an endocrine peptide, we determined the immunoreactive (ir-) metastin concentration in human plasma using our newly developed, sensitive, and specific two-site enzyme immunoassay. The plasma concentrations of ir-metastin in males and females were 1.30 +/- 0.14 (n = 12) and 1.31 +/- 0.37 fmol/ml (n = 10), respectively. As metastin is known to be abundant in human placenta, the ir-metastin concentration in the maternal plasma was then determined. The ir-metastin concentrations were 1230 +/- 346 fmol/ml (n = 11) in the first trimester, 4590 +/- 555 (n = 16) in the second trimester, and 9590 +/- 1640 (n = 12) in the third trimester. On d 5 after delivery, the ir-metastin concentration returned to nearly the nonpregnant level (7.63 +/- 1.33 fmol/ml; n = 10), suggesting that ir-metastin increases in pregnancy and is derived mainly from the placenta. The plasma from both nonpregnant and pregnant women showed a single ir-metastin peak at the same retention time as authentic metastin on reverse phase HPLC analysis, indicating that the major portion of the circulating metastin, as determined by our two-site enzyme immunoassay, represents endogenous metastin. Histochemical studies of human placenta localized metastin mRNA and immunoreactivity to the syncytiotrophoblasts. The present study provides evidence for metastin as a novel placenta-derived hormone in humans.

302 citations

Journal ArticleDOI
TL;DR: The data show that the frequency of GnRH stimulation can differentially regulate gonadotropin subunit mRNA expression and may be a mechanism that enables a single GnRH peptide to selectively regulate gonadic subunit gene expression and hormone secretion.
Abstract: The hypothalamic decapeptide GnRH is known to regulate the synthesis and secretion of LH and FSH by pituitary gonadotrope cells. The frequency of pulsatile GnRH secretion changes and LH and FSH are differentially secreted in various physiological situations. To investigate the potential role of altered frequency of GnRH stimulation in regulating differential secretion of LH and FSH, we examined the effects of GnRH frequency on expression of the alpha, LH beta, and FSH beta genes. GnRH pulses (25 ng/pulse) were administered to castrate testosterone-replaced rats at intervals of 8-480 min to cover the range of physiological pulsatile GnRH secretion. Fast frequency GnRH pulses (8-min pulse intervals) increased alpha-subunit mRNA concentrations 3-fold above those in saline-pulsed controls (controls, 1.01 fmol cDNA bound/100 micrograms pituitary DNA) and LH beta mRNA by 50% (controls, 0.18 fmol cDNA bound), but FSH beta mRNA was unchanged (controls, 0.38 fmol cDNA bound). GnRH pulses given every 30 min increased all three subunit mRNAs (alpha, 3-fold, LHbeta, 2-fold; FSH beta, 2-fold), and acute LH release and serum FSH concentrations were maximal after this frequency. Slower frequency GnRH stimuli (120- to 480-min pulse intervals) did not change alpha and LH beta mRNA levels, but increased FSH beta mRNA 2- to 2.5-fold, and FSH secretion was maintained. Equalization of the total dose of GnRH given at different intervals over 24 h confirmed the frequency dependence of subunit mRNA expression. Fast frequency GnRH stimuli (8 min) increased alpha mRNA 1.5- to 2.5-fold, while the same total GnRH doses were ineffective when given at slow frequency (480 min). Similarly, LH beta mRNA was only increased by GnRH pulses given at 8-min intervals. In contrast, FSH beta mRNA increased 2-fold after pulses given every 480 min, and the 8-min pulse interval was ineffective. The data show that the frequency of GnRH stimulation can differentially regulate gonadotropin subunit mRNA expression and may be a mechanism that enables a single GnRH peptide to selectively regulate gonadotropin subunit gene expression and hormone secretion.

288 citations

Journal ArticleDOI
TL;DR: The results demonstrate that L beta T2 cells represent a suitable model for the study of the differential regulation of gonadotropin subunit gene expression by pulsatile GnRH, and indicate that cell-surface GnRHR density is a critical mediator of this differential regulation.
Abstract: The pulsatile release of GnRH by the hypothalamus is required to stimulate the pituitary-gonadal axis, and variations in GnRH pulse frequency are associated with differential synthesis and release of LH and FSH by pituitary gonadotropes. How gonadotropes differentiate between GnRH pulse frequencies and subsequently differentially regulate the expression of the LH beta and FSH beta genes remains to be determined. In the present study, using a perifusion system that allows us to replicate the GnRH pulsatility occurring in vivo, we have systematically characterized the effects of varying GnRH pulse frequencies on LH beta, FSH beta, alpha, and GnRH receptor (GnRHR) gene promoter stimulation in L beta T2 cells. We demonstrate that LH beta gene promoter activity is stimulated to the greatest extent at higher GnRH pulse frequencies, whereas the FSH beta gene promoter is preferentially stimulated at lower GnRH pulse frequencies, reflecting previous observations in primary rat pituitary cells in vivo and in vitro. By measuring GnRH binding, we demonstrate that cell-surface GnRHR number is increased at higher frequencies of pulsatile GnRH and that this increase precedes the differential regulation of LH beta and FSH beta gene promoter activity. To test the role of GnRHR number in mediating the differential effects of pulsatile GnRH, the rat GnRHR was overexpressed in L beta T2 cells, and the response to pulsatile GnRH was again assessed. Interestingly, although overexpression of GnRHR had no effect on the frequency-dependent regulation of LH beta, the induction of FSH beta gene promoter activity by pulsatile GnRH was reduced, and frequency dependence was abrogated. Our results demonstrate that L beta T2 cells represent a suitable model for the study of the differential regulation of gonadotropin subunit gene expression by pulsatile GnRH. Furthermore, our studies indicate that cell-surface GnRHR density is a critical mediator of this differential regulation.

142 citations

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