Stress and the female reproductive system

The hypothalamic-pituitary-adrenal (HPA) axis, when activated by stress, exerts an inhibitory effect on the female reproductive system. Corticotropin-releasing hormone (CRH) inhibits hypothalamic gonadotropin- releasing hormone (GnRH) secretion, and glucocorticoids inhibit pituitary luteinizing hormone and ovarian estrogen and progesterone secretion. These effects are responsible for the "hypothalamic" amenorrhea of stress, which is observed in anxiety and depression, malnutrition, eating disorders and chronic excessive exercise, and the hypogonadism of the Cushing syndrome. In addition, corticotropin-releasing hormone and its receptors have been identified in most female reproductive tissues, including the ovary, uterus, and placenta. Furthermore, corticotropin-releasing hormone is secreted in peripheral inflammatory sites where it exerts inflammatory actions. Reproductive corticotropin-releasing hormone is regulating reproductive functions with an inflammatory component, such as ovulation, luteolysis, decidualization, implantation, and early maternal tolerance. Placental CRH participates in the physiology of pregnancy and the onset of labor. Circulating placental CRH is responsible for the physiologic hypercortisolism of the latter half of pregnancy. Postpartum, this hypercortisolism is followed by a transient adrenal suppression, which may explain the blues/depression and increased autoimmune phenomena observed during this period. © 2004 Elsevier Ireland Ltd. All rights reserved

Soy Isoflavones and Breast Cancer Risk: A Meta-analysis

BACKGROUND/AIM: Soy contains genistein and daidzein isoflavones. Isoflavones are phytoestrogens, with a similarity in structure to human 17-β estradiol hormone. They imitate the action of estrogen on organs by binding and activating estrogen receptors. Numerous studies have examined the relationship between soy consumption and breast cancer but not the amount of consumption itself. We performed a systematic review of the literature in order to determine whether the amount of soy and isoflavones consumed has a positive effect in pre- and post-menopausal women. MATERIALS AND METHODS: Data gathering was performed following PRISMA guidelines. Narrowing down the result set for all relevant data was performed via title, abstract, full-text evaluation and the snowball procedure. The selected articles had all relevant data extracted. Analysis of the data was performed using Cochrane's Review Manager statistical analysis tool in order to draw conclusions regarding the positive effect for the amount of soy and isoflavones consumed. RESULTS: Significant results were found when statistically analyzing data from prospective studies which compared soy isoflavones consumption, breast cancer risk and occurrence. The data were indicative of a clear inverse correlation between the amount of isoflavones consumed and breast cancer occurrence in pre- and post-menopausal women. CONCLUSION: The consumption of soy isoflavones can reduce the risk of breast cancer in pre-menopausal and post-menopausal women. Copyright © 2022, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved

Roles of reproductive corticotropin-releasing hormone

Corticotropin-releasing hormone (CRH), the principal regulator of the hypothalamic-pltuitary-adrenal axis, as well as its receptors, have been identified in most female reproductive tissues, including the uterus, placenta, and ovary. Endometrial CRH may participate in decidualization, implantation, and early maternal tolerance; placental CRH may participate in the physiology of pregnancy and the onset of parturition, and ovarian CRH may participate in follicular maturation, ovulation, and luteolysis. The hypercortisolism of the latter half of pregnancy can be explained by increased levels of placental CRH in plasma. This hypercortisolism is followed by a transient suppression of hypothalamic CRH secretion in the postpartum period, which may explain the blues or depression and autoimmune phenomena frequently observed during this period

"Reproductive" corticotropin-releasing hormone

Corticotropin-releasing hormone (CRH), a 41 amino acid peptide, is an important regulatory molecule synthesized by neurons of the parvocellular and magnocellular hypothalamic paraventricular nuclei. It acts as the major physiologic corticotropin (ACTH) secretagogue. The CRH gene is located in humans on chromosome 8. The CRH hormone family has at least four ligands, two receptors (CRH-R1 and CRHR2), and a binding protein (CRHbp). CRH is the principal regulator of the hypothalamic-pituitary-adrenal axis. Furthermore, CRH has been identified in most female reproductive tissues including the uterus, the placenta, and the ovary. CRH produced in the endometrium may participate in decidualization, implantation, and early maternal tolerance to semiallograft embryo. Placental CRH may participate in the physiology of pregnancy, in late pregnancy complications such as preterm labor and preeclampsia, and also in the onset of parturition. Ovarian CRH is involved in follicular maturation, ovulation, and luteolysis. Increased levels of unbound placental CRH may be responsible for the hypercortisolism of the second half of pregnancy. This hypercortisolism is followed by a transient suppression of hypothalamic CRH secretion in the postpartum period. This may explain the depressive states frequently observed in the postpartum period. © 2006 New York Academy of Sciences

The role of corticotropin-releasing hormone in blastocyst implantation and early fetal immunotolerance

During blastocyst implantation, the maternal endometrial response to the invading semi-allograft has characteristics of an acute, aseptic inflammatory response. However, once implanted, the embryo suppresses this response and prevents rejection. Simultaneously, the mother's immune system prevents a graft vs. host reaction deriving from the fetal immune system. We have shown that embryonic trophoblast and maternal decidua cells, i.e., cells located in the interface between the fetal placenta and the maternal endometrium, produce corticotropin-releasing hormone (CRH) and express Fas ligand. CRH may play a crucial role in the implantation and the anti-rejection process that protects the fetus from the maternal immune system, primarily by killing activated T cells through the Fas-FasL interaction. In experimental animals, type 1 CRH receptor (CRH-R1) blockade by antalarmin, a specific type 1 CRH receptor antagonist, decreased implantation sites by approximately 70%. CRH is also involved in controlled trophoblast invasion, by downregulating the synthesis of the carcinoembryonic antigen-related cell adhesion molecule 1 by extravillous trophoblast cells. In vitro findings showed that CRH-R1 blockade by antalarmin increased trophoblast invasion by approximately 60%. Defective uterine CRH/ CRH-R1 system during early pregnancy may be implicated in the pathophysiology of recurrent miscarriage, placenta accreta, and preeclampsia. © Georg Thieme Verlag KG Stuttgart

The role of HCG in implantation: A mini-review of molecular and clinical evidence

Embryo implantation is a complex process involving continuous molecular cross-talk between the embryo and the decidua. One of the key molecules during this process is human chorionic gonadotropin (HCG). HCG effectively modulates several metabolic pathways within the decidua contributing to endometrial receptivity. Herein, a brief overview of the molecular mechanisms regulated by HCG is presented. Furthermore, we summarize the existing evidence regarding the clinical impact on reproductive outcomes after endometrial priming with HCG prior to embryo transfer. Although promising, further evidence is needed to clarify the protocol that would lead to beneficial outcomes. © 2017 by the authors. Licensee MDPI, Basel, Switzerland

CRH receptors in human reproduction

Background: Corticotropin releasing hormone (CRH), the main peptide-mediator of stress, has been found in the female reproductive system. Objective: Herein, the role of CRH receptors in the female reproductive system is presented. Results: It is clear that CRH receptors are involved in the regulation of the hypothalamic-pituitary-ovarian axis, while locally are associated with decidualization, embryonic implantation, early fetal development and triggering of parturition. Conclusion: Abnormal CRH signaling may contribute to obstetrical pathophysiology, such as pre-eclampsia, abnormal placenta invasion, endometrial growth retardation and preterm delivery. © 2018 Bentham Science Publishers

Intrauterine CRH-treated PBMC in repeated implantation failure

Background: The intrauterine administration of activated autologous peripheral blood monocytes (PBMC) prior to embryo transfer seems to improve reproductive outcomes in women with repeated implantation failure (RIF). We have previously shown that the intrauterine administration of PBMC treated with corticotropin-releasing hormone (CRH) prior to blastocyst transfer (day 5) improves significantly the clinical pregnancy rate of women with RIF. In the present crossover pilot study, we have investigated whether CRH-PBMC treatment could be of benefit in case of fresh early cleavage stage embryo transfer (day 3) in women with RIF. Methods: Twenty-six (n = 26) women with at least three previous failed IVF attempts and no history of clinical pregnancy in the past were recruited in this study. Ovarian stimulation was performed following either the long or the short protocol. PBMC were collected during the oocyte retrieval, were treated with CRH, and transferred in the uterine cavity 2 days later. Good quality cleavage stage embryos were transferred at day 3, following oocyte retrieval. Results: Following the intrauterine administration of CRH-treated autologous PBMC, 15/26 clinical pregnancies occurred (57.69%). Compared to the null result of the same women prior to recruitment, this observation was considered significant (P < 10 −2 ). Conclusion: Our findings further support the role of the intrauterine administration of CRH-treated PBMC as an effective approach when transferring cleavage stage embryos in women with RIF. Prospective randomized studies are needed to clarify whether such intervention could be of benefit in clinical practice. © 2019 Stichting European Society for Clinical Investigation Journal Foundatio