Role Of Chorionic Gonadotropin Research Articles

Pregnancy-associated proteins and their role in the regulation of t-immune memory cell differentation

The role of chorionic gonadotropin (CG), alpha-fetoprotein (AFP) and pregnancy-specific β-1-glycoprotein (PSG) in the regulation of the processes determining the differentiation and maturation of naive T-cells into memory T-cells has been studied. It has been established that CG, AFP and PSG have a predominantly suppressing effect on the expression of CD28 and CD25 activation markers by naive T-cells (CD45RA+) and memory T-cells (CD45R0+), virtually without affecting the expression of CD71 proliferation marker. It has been established that the differentiation processes of naive T-cells and memory T-cells, under the influence of CG, AFP and PSG, are carried out with changing the expression of the - U2af1l4, Gfi1 and hTERT genes, which regulate the alternative splicing of the Ptprc gene (encoding CD45 molecule). At the same time, CG, AFP and PSG stimulated autocrine production of IL-2 with both naive and memory T-cells. Thus, for the first time, the modulating effects of the above-mentioned fetoplacental proteins in relation to the differentiation and functional activity of immune memory T-cells are shown.

The role of chorionic gonadotropin in the formation of immunological tolerance during pregnancy

We have studied the role of pregnancy hormone (chorionic gonadotropin, CG) in the control of expression of Foxp3 (a marker of T-regulatory lymphocytes, Treg), synthesis of interleukin-4 (IL-4) and interferon-gamma (IFH-γ) in lymphocytes, and secretion of indolamine-2,3-dioxygenase (IDO) by monocytes. Moreover, we evaluated the phagocytic and oxidative activities of these cells. It was shown that incubation of CG at a dose of 100 IU/ml with mononuclear cells from peripheral blood (MPC) resulted in a rise in the relative number of IL-4+CD3+CD4+T-lymphocytes whereas the number of IFN-γ+CD3+CD4+T-cells remained unaltered; the intracellular production of IFN-γ and IL-4 in the subpopulation of CD3+CD8+T-lymphocytes did not change either. In vitro, CG (10 and 100 IU/ml) significantly increased percentage of CD4+CD25 brightFoxp3+ cells and enhanced activity of indolamine-2,3-doxygenase in lipopolysaccharide-stimulated MPC. CG suppressed phagocitosis of E. coli lux+ by monocytes and simultaneously inhibited the production of active oxygen species in the reaction of spontaneous luminol-dependent chemiluminescence. Taken together, these properties of CG account for its role in the promotion of the formation of immunological tolerance during pregnancy.

The role of chorionic gonadotropin and Notch1 in implantation

Failed implantation is a major limiting factor in infertility and early pregnancy loss. In primates, human chorionic gonadotropin mediated inhibition of stromal cell apoptosis and their subsequent differentiation into decidual cells is critical for successful embryo implantation. A major regulator of cell survival and differentiation is the Notch receptor, which transduces extracellular signals responsible for cell fate determination during development. Proteolytic cleavage of full-length Notch1 releases an active intracellular peptide, which later translocates to the nucleus and activates gene transcription. Induction of Notch1 during the window of uterine receptivity in stromal fibroblasts in response to chorionic gonadotropin upregulates anti- apoptotic genes and induces alpha-smooth muscle actin, enabling stromal cells to proliferate and differentiate into a decidualized phenotype. As such, prior to implantation the embryonic signal, chorionic gonadotropin, rescues stromal fibroblasts from normal regression at the end of each ovarian cycle. We are suggesting that chorionic gonadotropin and Notch1 coordinately regulate decidualization by preventing apoptosis of endometrial stromal fibroblasts, averting uterine sloughing, and promoting cell survival and differentiation into the decidualized phenotype, which is critical for the maintenance of pregnancy.

Effect of chorionic gonadotropin on the activity of monocytes in relation to the phases of a menstrual cycle

The effect of physiological doses of chorionic gonadotropin (CG) on monocytic oxidative and phagocytic activities was studied in females having different phases of a menstrual cycle. CG (100 IU/ml) was found to suppress the baseline monocytic production of active oxygen forms and to lower (10 and 100 IU/ml) the generation of myeloperoxidase irrespective the phase of the cycle. In the follicular phase of the cycle, CG (10 and 100 IU/ml) was shown to Inhibit monocytic phagocytic activity, but when given in a dose of 100 IU/ml, it concurrently enhanced the latex-induced production of active oxygen forms. In the lutein phase of the cycle, CG exerted opposite effects: it suppressed the parameters of latex-induced luminescence-dependent chemiluminescence and stimulated monocytic phagocytic activity, moreover, a significant inverse correlation between these parameters. Thus, the role of CG in the regulation of oxidative and phagocytic functions of peripheral monocytes infertile women depends on the phase of a menstrual cycle and the degree of monocytic activation.

The role of chorionic gonadotropin in transient hyperthyroidism of hyperemesis gravidarum.

Biochemical evidence of hyperthyroidism is frequently encountered in hyperemesis gravidarum, but its relationship to the cause of hyperemesis is unknown. We studied the relationship of serum hCG, thyroid function, and severity of vomiting among 57 hyperemesis patients and 57 controls matched for gestational age. TSH was suppressed in 60% of hyperemesis patients and 9% of controls. hCG correlated directly with free T4(r = 0.45, P < 0.001) and inversely with TSH (r = -0.48, P < 0.001). Hyperemesis patients had significantly greater mean serum hCG, free T4, total T3, and estradiol, and lesser serum TSH compared to controls. Hyperemesis patients with suppressed TSH had significantly greater free T4 and hCG compared to those with TSH in the normal range. Control and hyperemesis subjects were divided into four groups based on the severity of vomiting. The degree of biochemical hyperthyroidism and hCG concentration varied directly with the severity of vomiting. Unextracted serum was tested for thyrotropic activity by measuring its effect on iodide uptake in cultured FRTL-5 rat thyroid cells. Thyrotropic activity correlated with serum hCG (r = 0.50, P < 0.001). These data show that biochemical hyperthyroidism is a common finding in patients with hyperemesis gravidarum and suggest that hCG is the thyroid stimulator in this state. The increased estradiol concentration in patients with hyperemesis gravidarum may be attributed to the effects of hCG on steroidogenesis.

The role of chorionic gonadotropin in transient hyperthyroidism of hyperemesis gravidarum

The role of chorionic gonadotropin in transient hyperthyroidism of hyperemesis gravidarum

Role of chorionic gonadotropin in the regulation of antigen-independent differentiation of immunocompetent spleen cells

Role of chorionic gonadotropin in the regulation of antigen-independent differentiation of immunocompetent spleen cells