Human chorionic gonadotropin up-regulates expression of myeloid cell leukemia-1 protein in human granulosa-lutein cells: implication of corpus luteum rescue and ovarian hyperstimulation syndrome

A matter of new life and cell death: programmed cell death in the mammalian ovary

BACKGROUND

The mammalian ovary is a unique organ that displays a distinctive feature of cyclic changes throughout the entire reproductive period. The estrous/menstrual cycles are associated with drastic functional and morphological rearrangements of ovarian tissue, including follicular development and degeneration, and the formation and subsequent atrophy of the corpus luteum. The flawless execution of these reiterative processes is impossible without the involvement of programmed cell death (PCD).

MAIN TEXT

PCD is crucial for efficient and careful clearance of excessive, depleted, or obsolete ovarian structures for ovarian cycling. Moreover, PCD facilitates selection of high-quality oocytes and formation of the ovarian reserve during embryonic and juvenile development. Disruption of PCD regulation can heavily impact the ovarian functions and is associated with various pathologies, from a moderate decrease in fertility to severe hormonal disturbance, complete loss of reproductive function, and tumorigenesis. This comprehensive review aims to provide updated information on the role of PCD in various processes occurring in normal and pathologic ovaries. Three major events of PCD in the ovary-progenitor germ cell depletion, follicular atresia, and corpus luteum degradation-are described, alongside the detailed information on molecular regulation of these processes, highlighting the contribution of apoptosis, autophagy, necroptosis, and ferroptosis. Ultimately, the current knowledge of PCD aberrations associated with pathologies, such as polycystic ovarian syndrome, premature ovarian insufficiency, and tumors of ovarian origin, is outlined.

CONCLUSION

PCD is an essential element in ovarian development, functions and pathologies. A thorough understanding of molecular mechanisms regulating PCD events is required for future advances in the diagnosis and management of various disorders of the ovary and the female reproductive system in general.

Chemerin Impact on Alternative mRNA Transcription in the Porcine Luteal Cells

Chemerin participates in the regulation of processes related to physiological and disorder mechanisms in mammals, including metabolism, obesity, inflammation, and reproduction. In this study, we have investigated chemerin influence on alternative mRNA transcription within the porcine luteal cell transcriptome, such as differential expression of long non-coding RNAs (DELs) and their interactions with differentially expressed genes (DEGs), differences in alternative splicing of transcripts (DASs), and allele-specific expression (ASEs) related to the single nucleotide variants (SNVs) frequency. Luteal cells were collected from gilts during the mid-luteal phase of the oestrous cycle. After in vitro culture of cells un-/treated with chemerin, the total RNA was isolated and sequenced using the high-throughput method. The in silico analyses revealed 24 DELs cis interacting with 6 DEGs and trans-correlated with 300 DEGs, 137 DASs events, and 18 ASEs. The results enabled us to analyse metabolic and signalling pathways in detail, providing new insights into the effects of chemerin on the corpus luteum functions related to inflammatory response, leukocyte infiltration, the occurrence of luteotropic and luteolytic signals (leading to apoptosis and/or necroptosis). Validation of the results using qPCR confirmed the predicted expression changes. Chemerin at physiological concentrations significantly modifies the transcription processes in the porcine luteal cells.

Role of putrescine in ovary and embryo development in fruit bat Cynopterus sphinx during embryonic diapause

The aim of this study was to evaluate the effect of putrescine on ovarian activity and the rate of embryonic development in Cynopterus sphinx during delayed development. The result showed the presence of a rate-limiting enzyme, ornithine decarboxylase-1, in both ovary and utero-embryonic unit of C. sphinx suggests a synthesis of putrescine in these sites. The corpus luteum showed increased, whereas utero-embryonic unit showed decreased production of putrescine during delayed development as compared with the normal development. The bat treated in vivo with putrescine during delayed development showed increase in progesterone and estradiol synthesis, correlated with increased expression of luteinizing hormone receptor, steroidogenic acute receptor protein, and 3β-hydroxysteroid dehydrogenase through extracellular signal-regulated kinase (ERK1/2)-mediated pathway in the ovary; but showed increase in the weight and expression of progesterone receptor (PR), B-cell lymphoma 2, proliferating cell nucleus antigen, and vascular endothelial growth factor proteins in utero-embryonic unit. The in vitro treatment of putrescine showed stimulatory whereas treatment with an inhibitor of putrescine, 2-difluoromethylornithine caused an inhibitory effect on ovarian progesterone synthesis and cell proliferation, and cell survival in the utero-embryonic unit. In conclusion, the putrescine showed two separate roles during embryonic diapause, high concentration of putrescine in the ovary may support corpus luteum and basal synthesis of progesterone, whereas a low level of putrescine causes retarded embryonic development by inhibiting cell proliferation in the utero-embryonic unit. The bat treated with putrescine either directly promotes cell proliferation, cell survival, and angiogenic activities or acts indirectly increasing PR on utero-embryonic unit thereby activating development in delayed embryo in C. sphinx.

Neuroprotective Effects of Trolox, Human Chorionic Gonadotropin, and Carnosic Acid on Hippocampal Neurodegeneration After Ischemiareperfusion Injury

INTRODUCTION

One of the serious complications of stroke is memory impairment, which is considered as one of the complications of reperfusion of tissue. The present study was designed to compare the effect of administration of Trolox, carnosic acid and Human Chorionic Gonadotropin (HCG) immediately after reperfusion of the stroke tissue on the memory and hippocampal histology.

METHOD

Ischemia-Reperfusion Model (IRI) was created by bilateral occlusion of the common carotid artery for 15 minutes and the first dose was administered immediately after reperfusion. 10 days after ischemia, passive avoidance memory test and apoptotic protein levels were evaluated.

RESULTS

Cerebral Ischemia perfusion reduced the time of latency in entering the dark box in the ischemic group. Administration of Trolox and HCG increased this latency time, while treatment with carnosic acid had no effect. Also, IRI significantly reduced the number of healthy cells in the hippocampus. Administration of Trolox, carnosic acid and HCG increased the number of healthy cells and decreased the expression of Caspase-3 and Bax, but significantly increased the expression of Bcl-2 compared to the ischemic group.

CONCLUSION

Findings indicate the beneficial effects of HCG and Trolox on the improvement of memory and the number of healthy cells in the hippocampal region. It is worth noting that the amount of apoptosis in the hippocampus was significantly reduced by Trolox, HCG and Carnosic acid.

An optimized model for hCG stimulation of human mural granulosa cell culture

Ovarian follicular development and ovulation in mammals is a highly-regulated process. Most of the current knowledge of ovarian processes was obtained from the studies of non-human models. Molecular studies on human ovarian processes suffer from lack of material and appropriate research tools. Mural granulosa cells (MGCs) culture is a major tool for studying the effect of different substances but a major problem for using these primary MGCs is their unresponsiveness to hCG stimulation at the time of oocyte retrieval. It is acceptable that MGCs regain responsiveness during days in culture but when the best time is and how to accelerate the regenerative process are unknown. The aim of the current study was to establish an optimized protocol which will provide a practical and efficient tool to examine the effect of LH/hCG on different downstream targets in luteinized MGCs. hCG effects were examined according to days in culture and hCG stimulation time. As read-out, we analyzed the gene expression of known hCG targets, protein production, and progesterone secretion. Our results show that with a daily medium exchange, the strongest effect was achieved already 4 days after seeding. On day 4, hCG stimulation triggers two major patterns of gene expression. Early induced genes were highly expressed 6-8 h after hCG, while 24 h of hCG stimulation was needed for late induced genes. Based on our results, we suggest daily medium exchange for 4 days before adding hCG and examine its effect 6 and 24 h later.

Early stop of progesterone supplementation after confirmation of pregnancy in IVF/ICSI fresh embryo transfer cycles of poor responders does not affect pregnancy outcome

Previous studies indicated that progesterone can be withdrawn at the time of the first positive β-hCG test without compromising the clinical pregnancy outcome in normal ovarian responder. However, the effect of early stop of progesterone supplementation for patients with poor ovarian response (POR) has not been investigated. This study retrospectively collected data from patients with POR in 156 IVF/ICSI fresh embryo transfer (ET) cycles in single tertiary center from January 2010 to June 2016. All the patients met ESHRE consensus, the Bologna criteria, of POR and had hCG injection for luteal phase support (LPS) on day 2, 5 and 8 after ovum pick-up. The pregnant patients were divided into two groups: early stop group represented those who stopped LPS from day of positive pregnancy test; control group represented those who kept progesterone supplementation till gestational age of 9 weeks. There were no significant differences in age, BMI, parity, hormone data, number of follicles>10(mm), endometrial thickness and number of embryos transferred between the two groups. After adjustment for possible confounders with multivariate logistic regression analysis, the clinical pregnancy rates (55.0% vs. 57.1%, P = 0.35), ongoing pregnancy rates (47.0% vs. 46.4%, P = 0.66), miscarriage rates (34.0% vs. 26.7%, P = 0.66) and live-birth rates (44.0% vs. 46.4%, P = 0.41) were not statistically different between early stop group and the control group. Our study indicates that early stop of progesterone supplementation on the day of positive pregnancy test for patients of POR using hCG as LPS in fresh ET cycles does not affect pregnancy outcome.

Potential role of hCG in apoptosis of human luteinized granulosa cells

The corpus luteum (CL) forms after ovulation and acts as a temporary endocrine gland that produces progesterone (P4), a hormone that is essential for implantation and maintenance of pregnancy in mammals. In pregnant women, human chorionic gonadotropin (hCG) secreted by the conceptus prevents luteolysis. hCG also increases the survival of cultured human luteinized granulosa cells (hLGCs). To clarify the maintenance mechanism of the human CL, we investigated the effects of hCG and P4 receptor antagonists, onapristone (OP) and RU486, on the viability of hLGCs. With the patients’ consent, hLGCs were isolated from follicular aspirates for in vitro fertilization. The cells were cultured with hCG (0.1, 1, 10, 100 IU/ml), OP (10, 25, 50, 100 μM), RU486 (100 μM), P4 (1, 10, 25, 50 μM) or some combination of the four for 24 h. Cell viability was significantly increased by hCG (100 IU/ml) and significantly decreased by OP (100 μM) compared with the control. Cells treated with hCG and OP together were significantly less viable than the control and OP-treated cells. The combined treatment also significantly increased CASP3 activity and cleaved CASP3 protein expression. Furthermore, P4 addition reversed the reduction in cell viability caused by the combination of hCG and OP treatment. The overall findings suggest that hCG cooperates with P4 to increase survival of hLGCs and to induce apoptosis when P4 action supported by hCG is attenuated in the human CL.

Modulation of ovarian steroidogenesis by adiponectin during delayed embryonic development of Cynopterus sphinx

The aim of present study was to evaluate role of adiponectin in ovarian steroidogenesis during delayed embryonic development of Cynopterus sphinx. This study showed significantly low circulating adiponectin level and a decline in expression of adiponectin receptor 1 (AdipoR1) in the ovary during the period of delayed embryonic development as compared with the normal development. The adiponectin treatment in vivo during the period of delayed development caused significantly increased in circulating progesterone and estradiol levels together with increased expression of AdipoR1 in the ovary. The in vitro study confirmed the stimulatory effect of adiponectin on progesterone synthesis. Both in vivo and in vitro studies showed that the effects of adiponectin on ovarian steroidogenesis were mediated through increased expression of luteinizing hormone-receptor, steroidogenic acute regulatory protein and 3β-hydroxyl steroid dehydrogenase enzyme. The adiponectin treatment may also promote progesterone synthesis by modulating ovarian angiogenesis, cell survival and rate of apoptosis.

GnRH analogues in the prevention of ovarian hyperstimulation syndrome

The GnRH analogue (agonist and antagonist GnRH) changed ovarian stimulation. On the one hand, it improved chances of pregnancy to obtain more oocytes and better embryos. This leads to an ovarian hyper-response, which can be complicated by the ovarian hyperstimulation syndrome (OHSS). On the other hand, the GnRH analogue can prevent the incidence of OHSS: GnRH antagonist protocols, GnRH agonist for triggering final oocyte maturation, either together or separately, coasting, and the GnRH analogue may prove useful for avoiding OHSS in high-risk patients. We review these topics in this article.

Cyclic AMP is both a pro-apoptotic and anti-apoptotic second messenger

The second messenger cyclic AMP (cAMP) can either stimulate or inhibit programmed cell death (apoptosis). Here, we review examples of cell types that show pro-apoptotic or anti-apoptotic responses to increases in cAMP. We also show that cells can have both such responses, although predominantly having one or the other. Protein kinase A (PKA)-promoted changes in phosphorylation and gene expression can mediate pro-apoptotic responses, such as in murine S49 lymphoma cells, based on evidence that mutants lacking PKA fail to undergo cAMP-promoted, mitochondria-dependent apoptosis. Mechanisms for the anti-apoptotic response to cAMP likely involve Epac (Exchange protein activated by cAMP), a cAMP-regulated effector that is a guanine nucleotide exchange factor (GEF) for the low molecular weight G-protein, Rap1. Therapeutic approaches that activate PKA-mediated pro-apoptosis or block Epac-mediated anti-apoptotisis may provide a means to enhance cell killing, such as in certain cancers. In contrast, efforts to block PKA or stimulate Epac have the potential to be useful in diseases settings (such as heart failure) associated with cAMP-promoted apoptosis.

Circulating LH/hCG receptor (LHCGR) may identify pre-treatment IVF patients at risk of OHSS and poor implantation

BACKGROUND

Successful pregnancy via in vitro fertilization (IVF) depends on the recovery of an adequate number of healthy oocytes and on blastocyst implantation following uterine transfer. Two hormones, LH and hCG, utilize a common LH/hCG receptor (LHCGR), variations in which have profound implications in human reproduction. Soluble LHCGR (sLHCGR) is released from experimental cell lines and placental explants and it can be detected in the follicular fluid and serum.

METHODS

To evaluate the impact of circulating soluble LHCGR (sLHCGR) in fertility treatment, we measured sLHCGR and LH-sLHCGR complex in serum from women seeking IVF using specifically developed quantitative enzyme-linked immunosorbent assays (ELISA). Following an IVF cycle of treatment, patients were grouped according to oocyte yield into low (lower than or equal to 7 oocytes), intermediate (8-14 oocytes) and high (greater than or equal to 15 oocytes) responders and pregnancy outcome noted.

RESULTS

Pre-treatment sLHCGR identified many women at risk of ovarian hyperstimulation. Low levels of sLHCGR were associated with pregnancy in both high and low responders but sLHCGR did not significantly affect the treatment outcome of intermediate responders. Low responders who failed to become pregnant had high levels of circulating sLHCGR bound to LH (LH-sLHCGR).

CONCLUSIONS

Pre-treatment measurement of sLHCGR could be used to tailor individual fertility treatment programs and improve outcomes by avoiding ovarian hyperstimulation and poor embryo implantation.

Update on management of ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is a relatively common complication of ovarian stimulation and can be life threatening. The pathophysiology of OHSS is characterized by increased capillary permeability, leading to leakage of fluid from the vascular compartment, with third-space fluid accumulation and intravascular dehydration. The increased intra-abdominal pressure indicated that OHSS may be considered a compartment syndrome. Vascular endothelial growth factor, also known as vascular permeability factor, has emerged as one of the mediators intrinsic to the development of OHSS. Conventional management is focused on supportive care until the spontaneous resolution of the condition. The standard of care for treatment-monitoring of appropriate clinical parameters, fluid balance management, thrombosis prophylaxis, and ascites treatment-should prevent severe morbidity in most cases. This review will cover inpatient and outpatient management. The potential therapeutic approach targeting the vascular endothelial growth factor system will be discussed.