Melatonin Pretreated Blastocysts along with Calcitonin Administration Improved Implantation by Upregulation of Heparin Binding-Epidermal Growth Factor Expression in Murine Endometrium

The Multiple Functions of HB-EGF in Female Reproduction and Related Cancer: Molecular Mechanisms and Targeting Strategies

Heparin-binding growth factor (HB-EGF) is a member of the epidermal growth factor (EGF) ligand family which has a crucial role in women's health. However, there is a lack of comprehensive review to summarize the significance of HB-EGF. Therefore, this work first described the expression patterns of HB-EGF in the endometrium and ovary of different species and gestational time. Then, the focus was on exploring how it promotes the successful implantation and regulates the process of decidualization and the function of ovarian granulosa cells as an intermediate molecule. Otherwise, we also focused on the clinical and prognostic significance of HB-EGF in female-related cancers (including ovarian cancer, cervical cancer, and endometrial cancer) and breast cancer. Lastly, the article also summarizes the current drugs targeting HB-EGF in the treatment of ovarian cancer and breast cancer. Overall, these studies found that the expression of HB-EGF in the endometrium is spatiotemporal and species-specific. And it mediates the dialogue between the blastocyst and endometrium, promoting synchronous development of the blastocyst and endometrium as an intermediate molecule. HB-EGF may serve as a potentially valuable prognostic clinical indicator in tumors. And the specific inhibitor of HB-EGF (CRM197) has a certain anti-tumor ability, which can exert synergistic anti-tumor effects with conventional chemotherapy drugs. However, it also suggests that more research is needed in the future to elucidate its specific mechanisms and to accommodate clinical studies with a larger sample size to clarify its clinical value.

Molecules and Prostaglandins Related to Embryo Tolerance

It is generally understood that the entry of semen into the female reproductive tract provokes molecular and cellular changes facilitating conception and pregnancy. We show a broader picture of the participation of prostaglandins in the fertilization, implantation and maintenance of the embryo. A large number of cells and molecules are related to signaling networks, which regulate tolerance to implantation and maintenance of the embryo and fetus. In this work, many of those cells and molecules are analyzed. We focus on platelets, polymorphonuclear leukocytes, and group 2 innate lymphoid cells involved in embryo tolerance in order to have a wider view of how prostaglandins participate. The combination of platelets and neutrophil extracellular traps (Nets), uterine innate lymphoid cells (uILC), Treg cells, NK cells, and sex hormones have an important function in immunological tolerance. In both animals and humans, the functions of these cells can be regulated by prostaglandins and soluble factors in seminal plasma to achieve an immunological balance, which maintains fetal-maternal tolerance. Prostaglandins, such as PGI2 and PGE2, play an important role in the suppression of the previously mentioned cells. PGI2 inhibits platelet aggregation, in addition to IL-5 and IL-13 expression in ILC2, and PGE2 inhibits some neutrophil functions, such as chemotaxis and migration processes, leukotriene B4 (LTB4) biosynthesis, ROS production, and the formation of extracellular traps, which could help prevent trophoblast injury and fetal loss. The implications are related to fertility in female when seminal fluid is deposited in the vagina or uterus.

Melatonin 1A and 1B Receptors' Expression Decreases in the Placenta of Women with Fetal Growth Restriction

Melatonin and its metabolites prevent oxidative stress and apoptosis, and it is actively produced by the placenta during pregnancy. Melatonin 1A and 1B receptors are present in human villous trophoblastic cells. We aimed to investigate the expression of melatonin 1A and 1B receptors in human placental tissue in the case of placental insufficiency manifested as the intrauterine growth restriction syndrome of the fetus (IUGR). Thirty-two pregnant women aged 18-36 with placental insufficiency manifested at the term 36 weeks of gestation as the IUGR syndrome (the estimated fetal weight less than the 3rd percentile) were included in the experimental group; all their babies had the diagnosis confirmed at birth, which occurred after 37 weeks of gestation. The control group consisted of 30 women with uncomplicated pregnancy of the same term. Pieces of the placental tissue were obtained after deliveries, and melatonin 1A and 1B receptors were immunoassayed; the richness of melatonin receptors in the placental tissue was estimated on the basis of immunohistochemical (IHC) staining of receptors, calculated in the IHC image score. The optical density of melatonin 1A receptors in the placentas obtained from women whose pregnancies were complicated with IUGR was significantly lower than that in the placentas from uncomplicated pregnancies: generally in the trophoblast, it was 0.095 ± 0.0009 IHC image score (in the control group, 0.194 ± 0.0015, p < 0.0001); in the apical parts of the syncytiotrophoblast, 0.108 ± 0.0016 IHC image score (in the control group, 0.221 ± 0.0013, p < 0.0001); and in the stromal cells of placental villi, 0.112 ± 0.0013 IHC image score (in the control group, 0.156 ± 0.0011, p < 0.0001). The optical density of melatonin 1B receptors in placentas obtained from women whose pregnancies were complicated with IUGR was also lower than that in the placentas from uncomplicated pregnancies: generally in the trophoblast, it was 0.165 ± 0.0019 IHC image score (in the control group, 0.231 ± 0.0013, p < 0.0001), and in the apical parts of the syncytiotrophoblast, 0.188 ± 0.0028 IHC image score (in the control group, 0.252 ± 0.0009, p < 0.0001). There was no difference found in the optical density of melatonin 1B receptors in the stromal cells of placental villi between the two groups: in the experimental group, 0.109 ± 0.006 IHC image score, and in the control group, 0.114 ± 0.0011 (p = 0.65). Melatonin receptors 1A and 1B are significantly less expressed in the placental tissue in the case that pregnancy is complicated with placental insufficiency, manifested as the intrauterine growth restriction syndrome of the fetus.

Melatonin Promotes Uterine and Placental Health: Potential Molecular Mechanisms

The development of the endometrium is a cyclic event tightly regulated by hormones and growth factors to coordinate the menstrual cycle while promoting a suitable microenvironment for embryo implantation during the “receptivity window”. Many women experience uterine failures that hamper the success of conception, such as endometrium thickness, endometriosis, luteal phase defects, endometrial polyps, adenomyosis, viral infection, and even endometrial cancer; most of these disturbances involve changes in endocrine components or cell damage. The emerging evidence has proven that circadian rhythm deregulation followed by low circulating melatonin is associated with low implantation rates and difficulties to maintain pregnancy. Given that melatonin is a circadian-regulating hormone also involved in the maintenance of uterine homeostasis through regulation of numerous pathways associated with uterine receptivity and gestation, the success of female reproduction may be dependent on the levels and activity of uterine and placental melatonin. Based on the fact that irregular production of maternal and placental melatonin is related to recurrent spontaneous abortion and maternal/fetal disturbances, melatonin replacement may offer an excellent opportunity to restore normal physiological function of the affected tissues. By alleviating oxidative damage in the placenta, melatonin favors nutrient transfer and improves vascular dynamics at the uterine–placental interface. This review focuses on the main in vivo and in vitro functions of melatonin on uterine physiological processes, such as decidualization and implantation, and also on the feto-maternal tissues, and reviews how exogenous melatonin functions from a mechanistic standpoint to preserve the organ health. New insights on the potential signaling pathways whereby melatonin resists preeclampsia and endometriosis are further emphasized in this review.

Effect of exosomal miRNA on cancer biology and clinical applications

Exosomes, extracellular vesicles with diameters ranging from 30 to 150 nm, are widely present in various body fluids. Recently, microRNAs (miRNAs) have been identified in exosomes, the biogenesis, release, and uptake of which may involve the endosomal sorting complex required for transport (ESCRT complex) and relevant proteins. After release, exosomes are taken up by neighboring or distant cells, and the miRNAs contained within modulate such processes as interfering with tumor immunity and the microenvironment, possibly facilitating tumor growth, invasion, metastasis, angiogenesis and drug resistance. Therefore, exosomal miRNAs have a significant function in regulating cancer progression. Here, we briefly review recent findings regarding tumor-derived exosomes, including RNA sorting and delivering mechanism. We then describe the intercommunication occurring between different cells via exosomal miRNAs in tumor microenvironmnt, with impacts on tumor proliferation, vascularization, metastasis and other biological characteristics. Finally, we highlight the potential role of these molecules as biomarkers in cancer diagnosis and prognosis and tumor resistance to therapeutics.

From Implantation to Birth: Insight into Molecular Melatonin Functions

Melatonin is a lipophilic hormone synthesized and secreted mainly in the pineal gland, acting as a neuroendocrine transducer of photoperiodic information during the night. In addition to this activity, melatonin has shown an antioxidant function and a key role as regulator of physiological processes related to human reproduction. Melatonin is involved in the normal outcome of pregnancy, beginning with the oocyte quality, continuing with embryo implantation, and finishing with fetal development and parturition. Melatonin has been shown to act directly on several reproductive events, including folliculogenesis, oocyte maturation, and corpus luteum (CL) formation. The molecular mechanism of action has been investigated through several studies which provide solid evidence on the connections between maternal melatonin secretion and embryonic and fetal development. Melatonin administration, reducing oxidative stress and directly acting on its membrane receptors, melatonin thyroid hormone receptors (MT1 and MT2), displays effects on the earliest phases of pregnancy and during the whole gestational period. In addition, considering the reported positive effects on the outcomes of compromised pregnancies, melatonin supplementation should be considered as an important tool for supporting fetal development, opening new opportunities for the management of several reproductive and gestational pathologies.