The chemical identity of the immunoreactive LHRH-like peptide biosynthesized in the human placenta

Tan, Liat; Rousseau, Patrick

doi:10.1016/0006-291x(82)92047-2

Cited by 75 publications

(9 citation statements)

References 22 publications

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“…The evidence that the placenta produces these hypophysiotropic peptides, which modulate the secretion of various hormones related to those in the pituitary [human chorionic gonadotropin (hCG), human placental lactogen (hPL), and corticotropin], supports the hypothesis that placental hormonogenesis may be regulated in part by locally produced peptides (13)(14)(15)(16)(17)(18)(19)(20)(21)(22).…”

Section: Introductionmentioning

confidence: 88%

Inhibin and activin modulate the release of gonadotropin-releasing hormone, human chorionic gonadotropin, and progesterone from cultured human placental cells.

Petraglia

Vaughan

Vale

1989

Proc. Natl. Acad. Sci. U.S.A.

172

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Although it is clear that human chorionic gonadotropin (hCG) and progesterone play fundamental roles in pregnancy, the regulation of placental production of these hormones remains to be defined. Recent evidence suggests that the human placenta expresses proteins related to inhibin (afi subunits) or activin (8P subunits). Inhibin and activin (folliclestimulating hormone-releasing protein) possess opposing activities in several biological systems including pituitary folliclestimulating hormone (follitropin) secretion, erythroid differentiation, and gonadal sex-steroid production. The actions of purified inhibin and activin on hormonogenesis by primary cultures of human placental cells were studied. The addition of activin increased gonadotropin-releasing hormone (GnRH) and progesterone production and potentiated the GnRHinduced release of hCG. Inhibin by itself did not modify placental immunoreactive GnRH, hCG, and progesterone secretion but reversed the activin-induced changes. Neither inhibin nor activin influenced the release of human placental lactogen. Furthermore, transforming growth factor (3, structurally related to inhibin/activin, did not signifcantly influence hormone release from cultured placental cells. These results support the hypothesis that inhibin and activin may play a role in regulating the release of GnRH, hCG, and progesterone from placenta and implicate inhibin-related proteins in the endocrine physiology of human pregnancy.Inhibins are heterodimeric proteins, consisting of an a subunit and one of two ,8 subunits (13A or PB), that were originally identified based upon their abilities to selectively suppress follicle-stimulating hormone (FSH) secretion (1-6). FSHreleasing proteins or activins were subsequently isolated and characterized as dimers comprised of inhibin (3 subunits APA or AJB) (7,8). Although inhibin and activin were first isolated from the gonads, various tissues including the placenta contain inhibin subunit mRNAs (9-12). Whereas the gonads contain a large excess of a-over (B-chain mRNAs, the placenta has an excess of p-subunit mRNAs; such observations raise the possibility that the placenta might have a preponderance of,,8 dimers (12). However, there is not yet conclusive evidence that intact activin is synthesized by human placenta.Placental inhibin a-subunit immunoreactivity is localized in the cytotrophoblast layer of the villi (11), a region shown earlier to contain other regulatory peptides including gonadotropin-releasing hormone (GnRH;, somatostatin (21), and corticotropin-releasing factor (22). The evidence that the placenta produces these hypophysiotropic peptides, which modulate the secretion of various hormones related to those in the pituitary [human chorionic gonadotropin (hCG), human placental lactogen (hPL), and corticotropin], supports the hypothesis that placental hormonogenesis may be regulated in part by locally produced peptides (13)(14)(15)(16)(17)(18)(19)(20)(21)(22).A recent report (11) showed that the addition of inhibin antiserum increased hC...

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Section: Introductionmentioning

confidence: 88%

Inhibin and activin modulate the release of gonadotropin-releasing hormone, human chorionic gonadotropin, and progesterone from cultured human placental cells.

Petraglia

Vaughan

Vale

1989

Proc. Natl. Acad. Sci. U.S.A.

172

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“…However, the impact of this, if any, on regulation is not clear. GnRH is expressed early in development in fish (25) and in the human placenta (26) and mouse embryo (27), suggesting that a function for GnRH in early development is conserved in tunicates and vertebrates.…”

Section: Tgnrh Genes Are Expressed Early In Developmentmentioning

confidence: 97%

Six Novel Gonadotropin-Releasing Hormones Are Encoded as Triplets on Each of Two Genes in the Protochordate,Ciona intestinalis

et al. 2003

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GnRH is the key regulator of the reproductive axis in vertebrates, but little is known about GnRH before the origin of vertebrates. We have identified two genes encoding GnRH in a protochordate, Ciona intestinalis, thought to be related to the ancestral animal that gave rise to vertebrates. Each gene, Ci-gnrh1 and Ci-gnrh2, encodes in tandem three GnRH peptides, each of which is unique compared with known forms. Ci-gnrh1 encodes three peptides and contains no introns, whereas Ci-gnrh2 encodes three more peptides but has two introns. This is the first report in which more than one GnRH peptide is encoded on a single gene. The Ciona genes reveal consensus promoter elements that are conserved compared with human GNRH1. Both tunicate genes are expressed as mRNA early and throughout development, measured at the stages of four-cell, gastrulation, tail release, and tail resorption. In a closely related tunicate species, Ciona savignyi, we used in silico analysis to identify two similar genes encoding six peptides, only one of which is unique compared with C. intestinalis. Immunohistochemistry showed that at least one GnRH peptide was in the nerve net that surrounds the dorsal strand. Synthetic forms of the seven novel tunicate peptides induced release of gametes in adult tunicates. In contrast, the peptides did not activate the human GnRH-I receptor or cause release of LH in a rat pituitary cell assay. These data provide insight into the structural evolution of the GnRH peptides and their genes and show a functional role for GnRH in tunicate spawning.

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“…Its sequence was originally isolated and identified using a cDNA library derived from human placenta, one of several extrahypothalamic tissues known to synthesize GnRH (Khodr and Siler-Khodr, 1980;Tan and Rousseau, 1982). In subsequent studies, a cDNA probe generated from human placenta was used to characterize further the gene in human hypothalamus (Adelman et al, 1986).…”

Section: The Gnrh Genementioning

confidence: 99%

Hormonal and neurotransmitter regulation of GnRH gene expression and related reproductive behaviors

et al. 1996

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Gonadotropin-releasing hormone (GnRH), having a highly conserved structure across mammalian species, plays a pivotal role in the control of the neuroendocrine events and the inherent sexual behaviors essential for reproductive function. Recent advances in molecular genetic technology have contributed greatly to the investigation of several aspects of GnRH physiology, particularly steroid hormone and neurotransmitter regulation of GnRH gene expression. Behavioral studies have focused on the actions of GnRH in steroid-sensitive brain regions to understand better its role in the facilitation of mating behavior. To date, however, there are no published reports which directly correlate GnRH gene expression and reproductive behavior. The intent of this article is to review the current understanding of the way in which changes in GnRH gene expression, and modifications of GnRH neuronal activity, may ultimately influence reproductive behavior.

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The chemical identity of the immunoreactive LHRH-like peptide biosynthesized in the human placenta

Cited by 75 publications

References 22 publications

Inhibin and activin modulate the release of gonadotropin-releasing hormone, human chorionic gonadotropin, and progesterone from cultured human placental cells.

Inhibin and activin modulate the release of gonadotropin-releasing hormone, human chorionic gonadotropin, and progesterone from cultured human placental cells.

Six Novel Gonadotropin-Releasing Hormones Are Encoded as Triplets on Each of Two Genes in the Protochordate,Ciona intestinalis

Hormonal and neurotransmitter regulation of GnRH gene expression and related reproductive behaviors

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