HCG--A new kid on the block in prematurity prevention

Human Chorionic Gonadotropin Modulates the Transcriptome of the Myometrium and Cervix in Late Gestation

Human chorionic gonadotropin (hCG) is a critical hormone for the establishment and maintenance of pregnancy. hCG administration prevents the onset of preterm labor in mice; yet, the transcriptomic changes associated with this tocolytic effect that take place in the myometrium and cervix have not been elucidated. Herein, we implemented both discovery and targeted approaches to investigate the transcriptome of the myometrium and cervix after hCG administration. Pregnant mice were intraperitoneally injected with 10 IU of hCG on 13.0, 15.0, and 17.0 days post coitum, and the myometrium and cervix were collected. RNA sequencing was performed to determine differentially expressed genes, enriched biological processes, and impacted KEGG pathways. Multiplex qRT-PCR was performed to investigate the expression of targeted contractility- and inflammation-associated transcripts. hCG administration caused the differential expression of 720 genes in the myometrium. Among the downregulated genes, enriched biological processes were primarily associated with regulation of transcription. hCG administration downregulated key contractility genes, Gja1 and Oxtr, but upregulated the prostaglandin-related genes Ptgfr and Ptgs2 and altered the expression of inflammation-related genes in the myometrium. In the cervix, hCG administration caused differential expression of 3348 genes that were related to inflammation and host defense, among others. The downregulation of key contractility genes and upregulation of prostaglandin-related genes were also observed in the cervix. Thus, hCG exerts tocolytic and immunomodulatory effects in late gestation by altering biological processes in the myometrium and cervix, which should be taken into account when considering hCG as a potential treatment to prevent the premature onset of labor.

hCG and Its Disruption by Environmental Contaminants during Human Pregnancy

Human chorionic gonadotropin (hCG) is a hormone of considerable importance in the establishment, promotion and maintenance of human pregnancy. It has been clearly demonstrated that hCG exerts multiple endocrine, paracrine and autocrine actions on a variety of gestational and non-gestational cells and tissues. These actions are directed to promote trophoblast invasiveness and differentiation, placental growth, angiogenesis in uterine vasculature, hormone production, modulation of the immune system at the maternal-fetal interface, inhibition of myometrial contractility as well as fetal growth and differentiation. In recent years, considerable interest has been raised towards the biological effects of environmental contaminants, particularly endocrine disrupting chemicals (EDCs). Emerging evidence suggests that prenatal exposure to selected EDCs can have a deleterious impact on the fetus and long-lasting consequences also in adult life. The results of the in vitro effects of commonly found EDCs, particularly Bisphenol A (BPA) and para-Nonylphenol (p-NP), indicate that these substances can alter hCG production and through this action could exert their fetal damage, suggesting that hCG could represent and become a potentially useful clinical biomarker of an inappropriate prenatal exposure to these substances.

Advances in human chorionic gonadotropin detection technologies: a review

Human chorionic gonadotropin (HCG) is a glycoprotein secreted by placental trophoblast cells in pregnancy. HCG is a heterodimer composed of two different α- and β-subunits, with the latter being unique to HCG. As well as being the most important diagnostic markers for pregnancy, HCG is also a tumor marker, therefore, quantitative detection of HCG is of great value. Numerous advanced technologies have been developed for HCG concentration detection including electrochemical immunoassay, chemiluminescent immunoassay, fluorescence immunoassay, resonance scattering spectrometry, atomic emission spectrometry, radioimmunoassay, MS and so on. Some have pursued simple and easy operation, while others have emphasized on accuracy and applications in clinical medicine. This review provides a comprehensive summary of various methods of detecting HCG.

Human Chorionic Gonadotropin Has Anti-Inflammatory Effects at the Maternal-Fetal Interface and Prevents Endotoxin-Induced Preterm Birth, but Causes Dystocia and Fetal Compromise in Mice

Human chorionic gonadotropin (hCG) is implicated in the maintenance of uterine quiescence by down-regulating myometrial gap junctions during pregnancy, and it was considered as a strategy to prevent preterm birth after the occurrence of preterm labor. However, the effect of hCG on innate and adaptive immune cells implicated in parturition is poorly understood. Herein, we investigated the immune effects of hCG at the maternal-fetal interface during late gestation, and whether this hormone can safely prevent endotoxin-induced preterm birth. Using immunophenotyping, we demonstrated that hCG has immune effects at the maternal-fetal interface (decidual tissues) by: 1) increasing the proportion of regulatory T cells; 2) reducing the proportion of macrophages and neutrophils; 3) inducing an M1 → M2 macrophage polarization; and 4) increasing the proportion of T helper 17 cells. Next, ELISAs were used to determine whether the local immune changes were associated with systemic concentrations of progesterone, estradiol, and/or cytokines (IFNgamma, IL1beta, IL2, IL4, IL5, IL6, IL10, IL12p70, KC/GRO, and TNFalpha). Plasma concentrations of IL1beta, but not progesterone, estradiol, or any other cytokine, were increased following hCG administration. Pretreatment with hCG prevented endotoxin-induced preterm birth by 44%, proving the effectiveness of this hormone as an anti-inflammatory agent. However, hCG administration alone caused dystocia and fetal compromise, as proven by Doppler ultrasound. These results provide insight into the mechanisms whereby hCG induces an anti-inflammatory microenvironment at the maternal-fetal interface during late gestation, and demonstrate its effectiveness in preventing preterm labor/birth. However, the deleterious effects of this hormone on mothers and fetuses warrant caution.

Why are We Waiting to Start Large Scale Clinical Testing of Human Chorionic Gonadotropin for the Treatment of Preterm Births?

Preterm births are an expensive global health problem. Despite the basic science and clinical research advances to better understand and prevent preterm births, the rates are increasing. There are several therapeutic options. While some options such as progestins work for selected women, others such as magnesium sulfate can only be used for delaying births for 24 to 48 hours so that the patients can be treated with corticosteroids to promote fetal lung maturity. Based on the scientific and clinical evidence, we recommend testing human chorionic gonadotropin in a large multicenter, randomized, double-blind, and placebo-controlled clinical trials in women with active preterm labor and those with a previous history of preterm births. Human chorionic gonadotropin is not only inexpensive but also has not shown any side effects so far in the infants or in the mothers.

Potential Therapy for Rheumatoid Arthritis and Sjögren Syndrome With Human Chorionic Gonadotropin

Autoimmune diseases such as rheumatoid arthritis (RA) and Sjögren syndrome (SS) ameliorate during pregnancy, through dampening (immunotolerance) of the maternal immune system which protects the fetus from rejection. A large number of studies have shown that human chorionic gonadotropin (hCG) contributes to this tolerance. Studies on animal models have reaffirmed that hCG treatment mimics the benefits of pregnancy. Based on the scientific evidence, randomized clinical trials comparing hCG with current therapies and/or placebo are recommended for RA, SS, and for other autoimmune diseases such as, type 1 diabetes and ankylosing spondylitis, which also get better during pregnancy and hCG treatment seems to help.

Bisphenol A disrupts gene expression in human placental trophoblast cells

This study examined the effect of bisphenol A (BPA) on human placental gene expression using primary trophoblast cells as an in vitro model system. Trophoblast cells were isolated from human placentas at term, cultured and then exposed to environmentally relevant concentrations of BPA (0.1-2 μg/ml) for up to 24h, after which levels of 11β-HSD2 mRNA, protein and activity were determined by standard radiometric conversion assay, western blotting, and qRT-PCR, respectively. The mRNA levels of several other prominent placental hormones/factors were also assessed by qRT-PCR. BPA dramatically increased levels of 11β-HSD2 activity, protein and mRNA in a time- and concentration-dependent manner (> 4-fold). BPA also augmented aromatase, glucose transporter-1, CRH, and hCG mRNA levels while reducing the level of leptin mRNA. These findings demonstrate that BPA severely disrupts human placental gene expression in vitro, which suggests that exposure to BPA may contribute to altered placental function and consequent pregnancy complications.

Extragonadal actions of chorionic gonadotropin

The primary embryonic signal in primates is chorionic gonadotropin (CG, designated hCG in humans), that is classically associated with corpus luteum rescue and progesterone production. However, research over the past decade has revealed the presence of the hCG receptor in a variety of extragonadal tissues. Additionally, discoveries of the multiple variants of hCG, namely, native hCG, hyperglycosylated hCG (hyp-hCG) and the β- subunit of the hyperglycosylated hCG (hCG-free β) has established a role for extragonadal actions of hCG. For the initiation and maintenance of pregnancy, hCG mediates multiple placental, uterine and fetal functions. Some of these include development of syncytiotrophoblast cells, mitotic growth and differentiation of the endometrium, localized suppression of the maternal immune system, modulation of uterine morphology and gene expression and coordination of intricate signal transduction between the endometrium. Recurrent pregnancy loss, pre-eclampsia and endometriosis are associated with altered responses of hCG, all of which have a detrimental effect on pregnancy. A role for hyp-hCG in mediating the development of both trophoblastic and non-trophoblastic tumors has also been suggested. Other significant non-gonadal applications of hCG include predicting preeclampsia, determining the risk of Down's syndrome and gestational trophoblastic disease, along with relaxing myometrial contractility and preventing recurrent miscarriages. Presence of hCG free-β in serum of cancer patients enables its usage as a diagnostic tumor marker. Thus, the extragonadal functions of hCG encompasses a wide spectrum of applications and is an open area for continued investigation.