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Journal of Neuroendocrinology Nov 2020The four genes coding for placental members of the human (h) growth hormone (GH) family include two that code independently for placental lactogen (PL), also known as... (Review)
Review
The four genes coding for placental members of the human (h) growth hormone (GH) family include two that code independently for placental lactogen (PL), also known as chorionic somatomammotrophin hormone, one that codes for placental growth hormone (PGH) and a pseudogene for which RNA but no protein product is reported. These genes are expressed preferentially in the villus syncytiotrophoblast of the placenta in pregnancy. In higher primates, the placental members, including hPL and PGH, are the result of multiple duplication events of the GH gene. This contrasts with rodents and ruminants, where PLs result from duplication of the prolactin (PRL) gene. Thus, unlike their mouse counterparts, the hPL and PGH hormones bind both lactogenic and somatogenic receptors with varying affinity. Roles influenced by nutrient availability in both metabolic control in pregnancy and maternal behaviour are supported. However, the effect maternal obesity has on the activation of placental members of the hGH gene family, particularly the expression and function of those genes, is poorly understood. Evidence from partially humanised hGH/PL transgenic mice indicates that both the remote upstream hPL locus control region (LCR) and more gene-related regulatory regions are required for placental expression in vivo. Furthermore, a specific pattern of interactions between the LCR and hPL gene promoter regions is detected in term placenta chromatin from women with a normal body mass index (BMI) in the range 18.5-25 kg m by chromosome conformation capture assay. This pattern is disrupted with maternal obesity (class II BMI > 35 kg m ) and associated with a > 40% decrease in term hPL RNA levels, as well as serum hPL but not PRL levels, during pregnancy. The relative importance of the chromosomal architecture and predicted properties for transcription factor participation in terms of hPL production and response to obesity are considered, based on comparison with components required for efficient human pituitary GH gene expression.
Topics: Animals; Female; Gene Expression Regulation; Humans; Obesity; Placenta; Placental Lactogen; Pregnancy
PubMed: 32500948
DOI: 10.1111/jne.12859 -
Reproductive Biomedicine Online Jan 2016During pregnancy, several tightly coordinated and regulated processes take place to enable proper fetal development and gestational success. The formation and... (Review)
Review
During pregnancy, several tightly coordinated and regulated processes take place to enable proper fetal development and gestational success. The formation and development of the placenta is one of these critical pregnancy events. This organ plays essential roles during gestation, including fetal nourishment, support and protection, gas exchange and production of several hormones and other mediators. Placental hormones are mainly secreted by the syncytiotrophoblast, in a highly and tightly regulated way. These hormones are important for pregnancy establishment and maintenance, exerting autocrine and paracrine effects that regulate decidualization, placental development, angiogenesis, endometrial receptivity, embryo implantation, immunotolerance and fetal development. In addition, because they are released into maternal circulation, the profile of their blood levels throughout pregnancy has been the target of intense research towards finding potential robust and reliable biomarkers to predict and diagnose pregnancy-associated complications. In fact, altered levels of these hormones have been associated with some pathologies, such as chromosomal anomalies or pre-eclampsia. This review proposes to revise and update the main pregnancy-related hormones, addressing their major characteristics, molecular targets, function throughout pregnancy, regulators of their expression and their potential clinical interest.
Topics: Animals; Chorionic Gonadotropin; Female; Fetal Development; Hormones; Humans; Placenta; Placentation; Pre-Eclampsia; Pregnancy; Progesterone
PubMed: 26615903
DOI: 10.1016/j.rbmo.2015.10.005 -
Obstetrical & Gynecological Survey Sep 2022The measurement of human chorionic gonadotropin (hCG) levels in different body fluids is a commonly utilized tool in obstetrics and gynecology, as well as other fields.... (Review)
Review
IMPORTANCE
The measurement of human chorionic gonadotropin (hCG) levels in different body fluids is a commonly utilized tool in obstetrics and gynecology, as well as other fields. It is often one of the first steps in the medical workup of female patients, and the results and interpretation of this test can have significant downstream ramifications. It is essential to understand the uses and limitations of hCG as a testing and therapeutic measure to appropriately evaluate, counsel, and treat patients.
OBJECTIVE
The purpose of this article is to review the current literature on hCG, including its origins, structure, pharmacokinetics, metabolism, and utility in testing and medical treatment.
EVIDENCE ACQUISITION
Original research articles, review articles, and guidelines on hCG use were reviewed.
CONCLUSIONS AND RELEVANCE
While the primary function of hCG is to maintain early pregnancy, testing for hCG demonstrates that this molecule is implicated in a multitude of different processes where results of testing may lead to incorrect conclusions regarding pregnancy status. This could affect patients in a myriad of settings and have profound emotional and financial consequences. In addition, hCG testing may be revealing of alternative pathology, such as malignancy. It is imperative to understand the nuances of the physiology of hCG and testing methods to effectively use and interpret this test for appropriate patient management.
Topics: Chorionic Gonadotropin; Female; Humans; Pregnancy
PubMed: 36136076
DOI: 10.1097/OGX.0000000000001053 -
American Journal of Reproductive... Mar 2016Human chorionic gonadotropin (hCG), as one of the first embryonic products, has been extensively investigated for its role in implantation and placental development.... (Review)
Review
Human chorionic gonadotropin (hCG), as one of the first embryonic products, has been extensively investigated for its role in implantation and placental development. Discovery of an over-glycosylated form of this hormone, hyperglycosylated hCG (hCG-H), has provided an additional level of complexity in our understanding of the implantation and placentation process; the structure, activity and functional implications of alterations in hCG isoforms throughout pregnancy are still being characterized. HCG-H comprises up to 90% of total hCG measurable in serum and urine during the first 2-3 weeks of pregnancy when invasive trophoblast activity is high, dropping to negligible proportions, less than 5%, of total hCG at the end of the first trimester. Functionally, hCG-H promotes trophoblast invasion during early pregnancy and has potential roles in immune cell modulation and endothelial function within the uterus at the time of pregnancy initiation. Altered levels of hCG-H are characteristics of pregnancy complications of altered trophoblast function and inadequate placentation, such as pre-eclampsia, and also over-abundance of invasive cytotrophoblasts, such as Down's syndrome. Improving our basic knowledge of the functional role-specific hCG isoforms plays in the complex cascade of events involved in implantation and placental development, and determining dynamic changes in the structure and activity of hCG isoforms throughout gestation will facilitate evidence-based decisions in assisted reproduction/in vitro fertilization based on the potential of embryos to implant, provide biomarkers for diagnosis of pregnancy complications associated with altered placental development and enhance understanding of how hCG isoforms may influence receptivity of the endometrium.
Topics: Biomarkers; Chorionic Gonadotropin; Embryo Implantation; Female; Fertilization in Vitro; Glycosylation; Humans; Pre-Eclampsia; Pregnancy; Protein Isoforms; Trophoblasts
PubMed: 26676718
DOI: 10.1111/aji.12459 -
Evolution, Medicine, and Public Health 2022We hypothesize that some placental hormones-specifically those that arise by tandem duplication of genes for maternal hormones-may behave as gestational drivers, selfish...
We hypothesize that some placental hormones-specifically those that arise by tandem duplication of genes for maternal hormones-may behave as gestational drivers, selfish genetic elements that encourage the spontaneous abortion of offspring that fail to inherit them. Such drivers are quite simple to evolve, requiring just three things: a decrease in expression or activity of some essential maternal hormone during pregnancy; a compensatory increase in expression or activity of the homologous hormone by the placenta; and genetic linkage between the two effects. Gestational drive may therefore be a common selection pressure experienced by any of the various hormones of mammalian pregnancy that have arisen by tandem gene duplication. We examine the evolution of chorionic gonadotropin in the human lineage in light of this hypothesis. Finally, we postulate that some of the difficulties of human pregnancy may be a consequence of the action of selfish genes.
PubMed: 36050940
DOI: 10.1093/emph/eoac031 -
International Journal of Molecular... May 2017Human chorionic gonadotropin (hCG) is no longer a single, omnipotent ovulation triggering option. Gonadotropin releasing hormone (GnRH) agonist, initially presented as a... (Review)
Review
Human chorionic gonadotropin (hCG) is no longer a single, omnipotent ovulation triggering option. Gonadotropin releasing hormone (GnRH) agonist, initially presented as a substitute for hCG, has led to a new era of administering GnRH agonist followed by hCG triggering. According to this new concept, GnRH agonist enables successful ovum maturation, while hCG supports the luteal phase and pregnancy until placental shift.
Topics: Biological Evolution; Chorionic Gonadotropin; Female; Fertilization in Vitro; Gene Expression Regulation; Humans; Recombinant Proteins; Reproductive Physiological Phenomena; Reproductive Techniques; Signal Transduction
PubMed: 28513550
DOI: 10.3390/ijms18051075 -
Endocrinology Jul 2020Successful pregnancies rely on sufficient energy and nutrient supply, which require the mother to metabolically adapt to support fetal needs. The placenta has a critical... (Review)
Review
Successful pregnancies rely on sufficient energy and nutrient supply, which require the mother to metabolically adapt to support fetal needs. The placenta has a critical role in this process, as this specialized organ produces hormones and peptides that regulate fetal and maternal metabolism. The ability for the mother to metabolically adapt to support the fetus depends on maternal prepregnancy health. Two-thirds of pregnancies in the United States involve obese or overweight women at the time of conception. This poses significant risks for the infant and mother by disrupting metabolic changes that would normally occur during pregnancy. Despite well characterized functions of placental hormones, there is scarce knowledge surrounding placental endocrine regulation of maternal metabolic trends in pathological pregnancies. In this review, we discuss current efforts to close this gap of knowledge and highlight areas where more research is needed. As the intrauterine environment predetermines the health and wellbeing of the offspring in later life, adequate metabolic control is essential for a successful pregnancy outcome. Understanding how placental hormones contribute to aberrant metabolic adaptations in pathological pregnancies may unveil disease mechanisms and provide methods for better identification and treatment. Studies discussed in this review were identified through PubMed searches between the years of 1966 to the present. We investigated studies of normal pregnancy and metabolic disorders in pregnancy that focused on energy requirements during pregnancy, endocrine regulation of glucose metabolism and insulin resistance, cholesterol and lipid metabolism, and placental hormone regulation.
Topics: Adaptation, Physiological; Diabetes, Gestational; Energy Metabolism; Female; Hormones; Humans; Placenta; Pregnancy
PubMed: 32417921
DOI: 10.1210/endocr/bqaa076 -
Animal Reproduction May 2020Bovids have enjoyed great evolutionary success as evidenced by the large number of extant species. Several important domestic animals are from this family. They derive...
Bovids have enjoyed great evolutionary success as evidenced by the large number of extant species. Several important domestic animals are from this family. They derive from both subfamilies: cattle and their kin belong to Bovinae and sheep and goats to Antilopinae. The premise of this review, therefore, is that evolution of reproduction and placentation is best understood in a context that includes antelope-like bovines and antelopes. Many key features of placentation, including hormone secretion, had evolved before bovids emerged as a distinct group. Variation nevertheless occurs. Most striking is the difference in fusion of the binucleate trophoblast cell with uterine epithelium that yields a transient trinucleate cell in bovines and many antelopes, but a more persistent syncytium in wildebeest, sheep and goat. There is considerable variation in placentome number and villus branching within the placentome. Many antelopes have right-sided implantation in a bicornuate uterus whilst others have a uterus duplex. Finally, there has been continued evolution of placental hormones with tandem duplication of genes in cattle, differences in glycosylation of placental lactogen and the emergence of placental growth hormone in sheep and goats. The selection pressures driving this evolution are unknown though maternal-fetal competition for nutrients is an attractive hypothesis.
PubMed: 33936288
DOI: 10.21451/1984-3143-AR2018-00145 -
Best Practice & Research. Clinical... Nov 2020Progesterone is the main hormone in the luteal phase. It plays a key role in preparing the uterus for a possible pregnancy, and in maintaining it after it has occurred.... (Review)
Review
Progesterone is the main hormone in the luteal phase. It plays a key role in preparing the uterus for a possible pregnancy, and in maintaining it after it has occurred. In assisted reproduction treatments, there is usually a luteal phase deficiency, so it is necessary to supplement this critical phase to obtain the best results, not only of implantation but also of ongoing pregnancy. Among all the available options, exogenously administered progestogens are the most used, as they have proven their efficacy and safety. This review will address the most relevant aspects of luteal phase support with progesterone in the different scenarios an embryo transfer can be performed, such as the stimulated cycle, the artificial cycle, or the natural cycle. Although there is no evidence of the perfect protocol for all patients, recent studies point to the need of individualizing luteal phase support according to the needs of each patient.
Topics: Chorionic Gonadotropin; Embryo Transfer; Female; Fertilization in Vitro; Humans; Luteal Phase; Pregnancy; Pregnancy Rate; Progesterone; Reproductive Techniques, Assisted
PubMed: 32616441
DOI: 10.1016/j.bpobgyn.2020.05.005 -
Advances in Experimental Medicine and... 2015New information concerning the effects of prolactin (PRL) on metabolic processes warrants reevaluation of its overall metabolic actions. PRL affects metabolic... (Review)
Review
New information concerning the effects of prolactin (PRL) on metabolic processes warrants reevaluation of its overall metabolic actions. PRL affects metabolic homeostasis by regulating key enzymes and transporters associated with glucose and lipid metabolism in several target organs. In the lactating mammary gland, PRL increases the production of milk proteins, lactose, and lipids. In adipose tissue, PRL generally suppresses lipid storage and adipokine release and affect adipogenesis. A specific case is made for PRL in the human breast and adipose tissues, where it acts as a circulating hormone and an autocrine/paracrine factor. Although its overall effects on body composition are both modest and species-specific, PRL may be involved in the manifestation of insulin resistance.
Topics: Adipogenesis; Adipose Tissue; Animals; Gene Expression Regulation; Growth Hormone; Humans; Lipid Metabolism; Placental Lactogen; Prolactin; Receptors, Prolactin
PubMed: 25472532
DOI: 10.1007/978-3-319-12114-7_1