Multiple novel roles of luteinizing hormone

Development of a reporter gene-based assay for the bioactivity determination of rhLH pharmaceutical products

To establish an in vitro biological activity detection method for luteinizing hormone (LH), the hLHCGR-CREB-HEK293 cell line was constructed to stably express human luteinizing hormone/chorionic gonadotropin receptor (hLHCGR). After optimization, the rhLH starting working concentration was 800 mIU/mL with 4-fold serial dilutions, 10 concentrations and an incubation time of 5 h. The method was confirmed to be highly specific, with good accuracy, precision and linearity, meeting the needs of process research and release testing, and can be used as a routine detection method for LH biological activity. With the increasing demand for research and development of rhLH biologically similar drugs, establishing a stable and simple activity assay method to evaluate the biological activity of rhLH can provide technical support for quality control of rhLH products and powerful tools for comparability research of similar products.

Association between serum LH levels on hCG trigger day and live birth rate after fresh embryo transfer with GnRH antagonist regimen in different populations

Objective

To investigate whether serum LH levels on hCG trigger day are associated with live birth rate (LBR) after fresh embryo transfer with GnRH antagonist regimen in different populations.

Methods

This study was a retrospective study. A total of 3059 fresh embryo transfers were divided into three populations: predicted normal ovarian responders (NOR) (n=2049), patients with PCOS (n=533), and predicted poor ovarian responders (POR) (n=477). Each population was stratified into three groups based on LH levels: < 25th percentile, 25-75th percentile, and > 75th percentile. The primary outcome of the study was LBR, and secondary outcomes included implantation, clinical pregnancy, and early pregnancy loss rates. Univariable and multivariable regression analyses were performed to adjust for potential confounders.

Results

In NOR, compared to the reference group (>75th percentile), LBR was significantly lower in the < 25th percentile group (adjusted OR=0.662; 95%CI, 0.508-0.863) and 25-75th percentile group (adjusted OR=0.791; 95%CI, 0.633-0.988). In PCOS patients, LBR decreased significantly in the < 25th percentile group (41.4%) compared to the 25-75th percentile group (53.7%) and > 75th percentile group (56.1%). In addition, the LBR was lower in the < 25th percentile group (33.6%) compared with the 25-75th percentile group (43.4%) and the>75th percentile group (42.0%) in POR, but this was not statistically significant.

Conclusions

High serum LH levels are associated with increased LBR after fresh embryo transfer in GnRH antagonist cycles, which may be attributable to higher implantation rate. LH may be a predictor of whether to schedule fresh embryo transfer in IVF cycles for better clinical outcomes.

Association between endogenous LH level prior to progesterone administration and live birth rate in artificial frozen-thawed blastocyst transfer cycles of ovulatory women

STUDY QUESTION

Is there an association between serum LH levels prior to progesterone administration and live birth rate (LBR) in artificial frozen-thawed embryo transfer (FET) cycles?

SUMMARY ANSWER

: Low serum LH levels on the day before progesterone initiation in artificial frozen-thawed blastocyst transfer cycles of ovulatory women are associated with a lower LBR.

WHAT IS KNOWN ALREADY

In artificial FET cycles, exogenous oestrogen and progesterone are administered sequentially to mimic the serum hormone pattern similar to the natural cycle. In oestrogen-only phase, the supplemental oestrogen causes thickening of the endometrium and is sometimes accompanied by a rise in serum LH. However, whether the endogenous LH level in artificial FET cycles is related to clinical outcomes remains unclear.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study including 3469 artificial frozen-thawed blastocyst transfer cycles was conducted at a tertiary-care academic medical centre between February 2014 and January 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 3469 frozen blastocyst transfer cycles were stratified into four groups based on the quartiles of serum LH level before progesterone initiation: <25th percentile (LH < 8.79 mIU/ml), 25-50th percentile (8.79 ≤ LH ≤ 13.91 mIU/ml), 51-75th percentile (13.91 < LH ≤ 20.75 mIU/ml) and >75th percentile (LH > 20.75 mIU/ml). The serum LH level >75th percentile group was considered as the reference group. Patients with polycystic ovarian syndrome or other ovulatory disorders were excluded from the study. We also excluded cycles with an endometrial thickness <7 mm before progesterone initiation and patients with intrauterine adhesions and uterine abnormalities. In order to avoid the interference of BMI, all patients were divided into two categories based on the overweight threshold: BMI <25 kg/m2 and ≥25 kg/m2, and the impacts of serum LH levels on LBR were investigated separately. Univariable and multivariable logistic regression analysis were performed to adjust for potential confounders. EmpowerStats software and R-project were used to build smooth curve fitting models.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared with the reference group, the implantation rate significantly decreased with low LH levels (<25th percentile) on the day before progesterone initiation (odds ratio [OR] = 0.74; 95% CI, 0.64-0.86; P = 0.001). Accounting for major covariates, low LH levels were associated with a relatively lower LBR (adjusted OR = 0.649; 95% CI, 0.531-0.794; P < 0.001), mainly due to a lower implantation rate, lower clinical pregnancy rate and higher pregnancy loss rate. Moreover, in the patients with BMI <25 kg/m2, low LH was associated with a lower LBR (P < 0.001); while in the overweight subgroup, LBR and LH were not correlated (P = 0.823).

LIMITATIONS, REASONS FOR CAUTION

The main limitation of this study is its retrospective design. Owing to the relatively small number in the overweight group, the results of the overweight subgroup should be interpreted with caution.

WIDER IMPLICATIONS OF THE FINDINGS

The evidence provided in this study shows the importance of serum LH levels on the day before progesterone initiation in patients undergoing artificial FET cycles. Hypothalamic dysfunction may be one of the important causes of a relatively low LH, which is related to impaired pregnancy outcomes. Serum LH levels may be used as one of the clinical indicators to predict pregnancy outcomes.

STUDY FUNDING/COMPETING INTEREST(S)

No funding and no competing interest were involved in this study.

TRIAL REGISTRATION NUMBER

NA.

In Vitro Study on the Regulation of Annexin IV and VEGF by hCG in the Human Endometrium

Objective

Whether changes in vascular endothelial growth factor (VEGF) and annexin IV during implantation are regulated through the LH/hCG-R needs further research. To investigate the mechanism of hCG on the expression of annexin IV and VEGF in human endometrial cells.

Methods

Endometrial cells were isolated and identified from human specimens. The proportion of glandular and epithelial cells was analyzed. Annexin IV and VEGF were analyzed by qRT-PCR (mRNA), western blot (proteins), and immunohistochemistry (proteins). Protein location was identified by immunohistochemistry. The cells were cultured with hCG, hCG/PD98059 (a MAPK inhibitor), or no treatment (control).

Results

The proportions between the glandular epithelial cells and stromal cells at inoculation and when adding hCG were 25.8 ± 0.2% and 27.8 ± 0.04%, respectively (P > 0.05). LH/hCG-R, annexin IV, and VEGF were found in the cytoplasm of endometrial cells. After 2, 6, 12, and 24 h of hCG treatment, compared with 1 h, VEGF mRNA was increased by 1.25-fold, 3.19-fold, 4.21-fold, and 4.86-fold and annexin IV by 2.23-fold, 3.37-fold, 5.14-fold, and 5.02-fold. Compared with the control group, annexin IV mRNA and protein were increased in the hCG and hCG/PD98059 groups (mRNA/protein: 1.99-fold/1.80-fold and 2.33-fold/1.93-fold, P < 0.05). Compared with the control group, VEGF mRNA and protein were increased in the hCG group (mRNA/protein: 2.30-fold/1.86-fold), but not in the hCG/PD98059 group.

Conclusion

hCG could upregulate the mRNA and protein expression of annexin IV and VEGF. The upregulation of annexin IV by hCG could not be inhibited by PD98059, but the upregulation of VEGF by hCG could.

Towards an optimal luteal support modality in agonist triggered cycles: a randomized clinical trial

STUDY QUESTION

In ICSI patients with high risk of ovarian hyperstimulation syndrome (OHSS), are antagonist cycles triggered by gonadotropin releasing hormone (GNRH) agonist with a specialized luteal support regimen associated with comparable ongoing pregnancy rate (OPR) and less OHSS than those triggered by hCG?

SUMMARY ANSWER

In antagonist ICSI cycles, GnRH agonist triggering with a specialized luteal support regimen is associated with comparable OPR to those triggered by hCG but may be less likely to be associated with OHSS.

WHAT IS KNOWN ALREADY

In IVF/ICSI protocols, exogenous hCG was used for years as a substitute of the endogenous LH surge. However, because of its longer half life, hCG is associated with more risk of OHSS, especially in high risk women. For this reason, GnRH agonist triggering was introduced. There is, however, no consensus on the best protocol for luteal support on agonist triggered cycles.

STUDY DESIGN, SIZE, DURATION

Randomized controlled open label trial including 190 participants recruited from June 2015 to March 2016 in a private fertility center. Participants were divided into 2 equal groups; GnRH agonist trigger and hCG trigger. Randomization was done using identical sealed envelope technique.

PARTICIPANTS/MATERIALS, SETTING, METHODS

One hundred ninety women, predicted to have high response, were randomized on the day of final oocyte maturation into two equal groups: group (A), GnRH agonist trigger followed by specialized regimen (1500 IU hCG) at time of oocyte retrieval plus oral estradiol and intramuscular progesterone during luteal phase; and group (B), 5000 IU of hCG with luteal support (oral estradiol and vaginal progesterone).

MAIN RESULTS AND THE ROLE OF CHANCE

The 2 groups were comparable in baseline characteristics. OPR per randomized patient was comparable in the 2 groups {49/95 (51.6%) in group A, and 50/95 (52.6%) in group B ((P = 0.88); RR = 0.980, 95% CI: 0.75-1.29)}. Considerable (moderate + severe) OHSS was higher in group B (13/95 [14%] versus 5/95 [5%] P = 0.047; uncorrected Chi-square test). Upon performing multivariate regression analysis for predicting OHSS, number of follicles ≥11 mm on trigger day was the only independent predictor (P = 0.0004).

LIMITATIONS, REASONS FOR CAUTION

Strict selection criteria limit generalization of results. The study was powered for pregnancy rate not OHSS, so that the strength of evidence on OHSS prediction is weak.

WIDER IMPLICATIONS OF THE FINDINGS

We recommend the use of GnRH agonist plus the specialized luteal phase support in high responders with high risk of OHSS undergoing IVF/ICSI cycles. This protocol achieved a similar ongoing pregnancy to hCG triggering and may be less likely to result in moderate to severe OHSS.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

PACTR 201506001132105.

TRIAL REGISTRATION DATE

24/6/2015.

DATE OF FIRST PATIENT’S ENROLLMENT

26/6/2015.

Human Chorionic Gonadotropin: The Pregnancy Hormone and More

To thoroughly review the uses of human chorionic gonadotropin (hCG) related to the process of reproduction and also assess new, non-traditional theories. Review of the international literature and research studies. hCG and its receptor, LH/CGR, are expressed in numerous sites of the reproductive tract, both in gonadal and extra-goanadal tissues, promoting oocyte maturation, fertilization, implantation and early embryo development. Moreover, hCG seems to have a potential role as an anti-rejection agent in solid organ transplantation. Future research needs to focus extensively on the functions of hCG and its receptor LH/CGR, in an effort to reveal known, as well as unknown clinical potentials.

Alpha or beta human chorionic gonadotropin knockdown decrease BeWo cell fusion by down-regulating PKA and CREB activation

The aim of the present study is to delineate the role of human chorionic gonadotropin (hCG) in trophoblast fusion. In this direction, using shRNA lentiviral particles, α- and β-hCG silenced ‘BeWo’ cell lines were generated. Treatment of both α- and β-hCG silenced BeWo cells with either forskolin or exogenous hCG showed a significant reduction in cell fusion as compared with control shRNA treated cells. Studies by qRT-PCR, Western blotting and immunofluorescence revealed down-regulation of fusion-associated proteins such as syncytin-1 and syndecan-1 in the α- and β-hCG silenced cells. Delineation of downstream signaling pathways revealed that phosphorylation of PKA and CREB were compromised in the silenced cells whereas, no significant changes in p38MAPK and ERK1/2 phosphorylation were observed. Moreover, β-catenin activation was unaffected by either α- or β-hCG silencing. Further, inhibition of PKA by H89 inhibitor led to a significant decrease in BeWo cell fusion but had no effect on β-catenin activation suggesting the absence of non-canonical β-catenin stabilization via PKA. Interestingly, canonical activation of β-catenin was associated with the up-regulation of Wnt 10b expression. In summary, this study establishes the significance of hCG in the fusion of trophoblastic BeWo cells, but there may be additional factors involved in this process.

hCG stimulates angiogenic signals in lymphatic endothelial and circulating angiogenic cells

Human chorionic gonadotropin (hCG) has long been associated with the initiation and maintenance of pregnancy, where angiogenesis plays an important role. However, the function of hCG in angiogenesis and the recruitment of vascular active cells are not fully understood. In this study, the role of hCG and its receptor in circulating angiogenic and human endothelial cells, including lymphatic, uterine microvascular, and umbilical vein endothelial cells, was examined. Immunohistochemistry and immunoblot analysis were used to detect LH/hCG receptor expression and the expression of hCG-induced angiogenic molecules. HIF-1α was determined via ELISA and downstream molecules, such as CXCL12 and CXCR4, via real-time PCR. Chemotaxis was analyzed using Boyden chambers. Our results show that the LH/hCG receptor was present in all tested cells. Furthermore, hCG was able to stimulate LH/hCG-receptor-specific migration in a dose-dependent fashion and induce key angiogenic molecules, including HIF-1α, CXCL12, and CXCR4. In conclusion, our findings underscore the importance of hCG as one of the first angiogenic molecules produced by the conceptus. hCG itself alters endothelial motility, recruitment, and expression of pro-angiogenic molecules and may therefore play an important role in vascular adaption during implantation and early placental formation.

Mini-dose GnRH-a long versus short protocol in patients ≥ 35 years old undergoing in vitro fertilization

PURPOSE

To compare the clinical result of mini-dose GnRH-a long protocol with short protocol in older patients undergoing IVF.

MATERIALS AND METHODS

This was a retrospective study. Four hundred and sixty-one women aged above 35-year-old in first cycle were assigned to two groups: GnRH-a short protocol (n=359); and mini-dose GnRH-a long protocol (n=102). Both groups were divided based on their age, into groups over and under 38 years old. Primary outcome include live birth rate per started cycle. Other clinical outcomes were good-quality embryo rate, clinical pregnancy rate.

RESULTS

Patients treated with mini-dose GnRH-a protocol and those treated with short protocol showed similar live birth rate. In the mini-dose long protocol group aged 35-38 years old, patients showed significantly thicker endometrium at the day of hCG administration, higher number of good embryos obtained and higher good-quality embryo rate (56.3% versus 46.5%) compared with short protocol. The implantation rate and clinical pregnancy rate were higher versus short protocol group, but this result was not statistically significant.

CONCLUSION(S)

Mini-dose GnRH-a long protocol for older women is at least as effective as short protocol, especially in patients aged 35-38 years, with a better good-quality embryo rate and higher number of good embryos obtained, therefore mini-dose GnRH-a long protocol can be considered as an alternative protocol for patients above 35 years age.

Effects of sub-chronic aluminum chloride exposure on rat ovaries

AIMS

This experiment investigated the effects of sub-chronic aluminum chloride (AlCl3) exposure on rat ovaries.

MAIN METHODS

Eighty female Wistar (5weeks old) rats, weighed 110-120g, were randomly divided into four treatment groups: control group (CG), low-dose group (LG, 64mg/kg BW AlCl3), mid-dose group (MG, 128mg/kg BW AlCl3) and high-dose group (HG, 256mg/kg BW AlCl3). The AlCl3 was administered in drinking water for 120days. The ovarian ultrastructure was observed. The activities of acid phosphatase (ACP), alkaline phosphatase (ALP), succinate dehydrogenase (SDH), Na(+)-K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPase, the contents of Fe, Cu and Zn, and the protein expression of follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in the ovary were determined.

KEY FINDINGS

The results showed that the structure of the ovary was disrupted, the activities of ALP, ACP, SDH, Na(+)-K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPase, the contents of Zn, Fe and the protein expression of FSHR and LHR were lowered, and the content of Cu was increased in AlCl3-treated rats than those in control.

SIGNIFICANCE

The results indicate that sub-chronic AlCl3 exposure caused the damage of the ovarian structure, the disturbed metabolism of Fe, Zn and Cu and the decreased activities of Na(+)-K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPase in the ovary, which could result in suppressed energy supply in the ovary. A combination of suppression of energy supply and reduction of expression of FSHR and LHR could inhibit ovulation and corpus luteum development, leading to infertility in female rats.

Exposure to the endocrine disruptor di(2-ethylhexyl)phthalate affects female reproductive features by altering pulsatile LH secretion

The patterns of growth of preovulatory follicles and corpora lutea, as well as plasma concentrations of estradiol, progesterone and LH were evaluated in sheep exposed to DEHP. There were not found effects on the preovulatory follicular dynamics nor on the ovulatory efficiency between DEHP-exposed and control sheep. However, plasma estradiol concentration was significantly higher in the ewes exposed to DEHP than in the control females (P<0.001). Afterwards, DEHP-exposed ewes had significantly higher plasma progesterone concentration from Day 2 of the luteal phase (P<0.05), although there were no differences between groups in the macro- and microscopic features of the corpora lutea. Analysis of mean basal concentrations of LH showed lower values in DEHP-exposed than in control sheep (0.3 ± 01 ng/mL vs. 0.7 ± 0.1; P<0.05). Moreover, the frequency of LH pulses was 0.3 pulses/4 h, with amplitude of 0.6 ng/mL, in the control group; on the other hand, the pulsatile secretion of LH in the DEHP-exposed group was undetectable during the period of sampling.

Improved pregnancy rates with luteinizing hormone supplementation in patients undergoing ovarian stimulation for IVF

INTRODUCTION

Luteinizing hormone (LH) is believed to play a role in follicle maturation during the natural cycle. However, the need for co-treatment with recombinant LH (rLH) for controlled ovarian stimulation is controversial.

PURPOSE

The primary objective of our study was to determine if pregnancy rates are improved when rLH is used in addition to rFSH for ovarian stimulation. Secondary outcomes were fertilization rate, implantation rate and live birth rate.

METHODS

A retrospective cohort study was performed of 1565 IVF or ICSI cycles. Outcomes were compared between ovarian stimulation cycles from 2007 when rLH and rFSH was used (n = 765) to 2006 when rFSH only was used (n-800).

RESULTS

Improved outcomes were found for rLH + rFSH versus rFSH alone for; pregnancy rate (61% and 54% respectively, p = 0.006), live birth rate (49% and 42% respectively, P = 0.01), fertilization rate (74% versus 72% respectively, p = 0.04 and implantation rate (41% versus 37% respectively, p = 0.03).

CONCLUSIONS

Our large retrospective cohort study showed an improved pregnancy rate and live birth rate with rLH supplementation. This was associated with an improved fertilization and implantation rate and therefore may reflect an improvement in oocyte quality and/or uterine receptivity.

Effects of subchronic aluminum exposure on the reproductive function in female rats

The aim of this study was to investigate the effects of aluminum (Al) exposure on the reproductive function in female rats. Forty female Wistar (5 weeks old) rats, weighing 110-120 g, were divided randomly into four groups. They were orally administrated with 0, 64.18, 128.36, and 256.72 mg aluminum chloride (AlCl(3)) per kilogram body weight in drinking water for 120 days. Levels of Al, estrogen (E(2)), progestogen (P), testosterone (T), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) in serum were measured at the end of experiment. The results showed that levels of E(2), P, FSH, and LH were significantly lower and Al concentration was significantly higher in all three Al-treated groups than those in the control group (GC). The level of T was significantly higher in the low- and medium-dose groups (GL and GM) (P < 0.05) but not in high-dose group (GH) compared with GC. The results suggest that the reproductive function of female rats is inhibited under long-term Al exposure in an Al dose-dependent manner.

GnRH agonist for triggering of final oocyte maturation: time for a change of practice?

BACKGROUND

GnRH agonist (GnRHa) triggering has been shown to significantly reduce the occurrence of ovarian hyperstimulation syndrome (OHSS) compared with hCG triggering; however, initially a poor reproductive outcome was reported after GnRHa triggering, due to an apparently uncorrectable luteal phase deficiency. Therefore, the challenge has been to rescue the luteal phase. Studies now report a luteal phase rescue, with a reproductive outcome comparable to that seen after hCG triggering.

METHODS

This narrative review is based on expert presentations and subsequent group discussions supplemented with publications from literature searches and the authors' knowledge. Moreover, randomized controlled trials (RCTs) were identified and analysed either in fresh IVF cycles with embryo transfer (ET), oocyte donation cycles or cycles without ET; risk differences were calculated regarding pregnancy rate and OHSS rate.

RESULTS

In fresh IVF cycles with ET (9 RCTs) no OHSS was reported after GnRHa triggering [0% incidence in the GnRHa group: risk difference 5% (with 95% CI: -0.07 to 0.02)]. Importantly, the delivery rate improved significantly after modified luteal support [6% risk difference in favour of the HCG group (95% CI: -0.14 to 0.2)] when compared with initial studies with conventional luteal support [18% risk difference (95% CI: -0.36 to 0.01)]. In oocyte donation cycles (4 RCTs) the OHSS incidence is 0% [10% risk difference (95% CI: 0.02-0.40)].

CONCLUSIONS

GnRHa triggering is a valid alternative to hCG triggering, resulting in an elimination of OHSS. After modified luteal support there is now a non-significant difference of 6% in delivery rate in favour of hCG triggering.

Participation of signaling pathways in the derepression of luteinizing hormone receptor transcription

The luteinizing hormone receptor (LHR) transcription is subject to an epigenetic regulatory mode whereby the proximal Sp1 site acts as an anchor to recruit histone deacetylases (HDAC)1/2 and the Sin3A co-repressor complex. This results in promoter-localized histone hypo-acetylation that contributes to the silencing of LHR transcriptional expression. Chromatin changes resulting from site-specific acetylation and methylation of histones regulate LHR gene expression. The HDAC inhibitor TSA-induced cell-specific phosphatase release from the promoter, which serves as an 'on' mechanism for Sp1 phosphorylation by phosphatidylinositol 3-kinase/protein kinase Czeta (PI3K/PKCzeta) at Ser641, leading to p107 repressor derecruitment and LHR transcriptional activation. The methylation status of the promoter provides another layer of modulation in a cell-specific manner. Maximal derepression of the LHR gene is dependent on complete DNA demethylation of the promoter in conjunction with histone hyperacetylation and release of repressors (p107 and HDAC/Sin3A). Independently, the PKC-alpha/Erk pathway, participates in LHR gene expression through induction of Sp1 phosphorylation at Ser site(s) other than Ser641. This causes dissociation of the HDAC1/mSin3A from the promoter, recruitment of TFIIB and Pol II, and transcriptional activation. Collectively, these findings demonstrate that LHR gene expression at the transcriptional level is regulated by complex and diverse networks, in which coordination and interactions between these regulatory effectors are crucial for silencing/activation of LHR expression.

Early hCG addition to rFSH for ovarian stimulation in IVF provides better results and the cDNA copies of the hCG receptor may be an indicator of successful stimulation

A simple, safe and cost-effective treatment protocol in ovarian stimulation is of great importance in IVF practice, especially in the case of previous unsuccessful attempts. hCG has been used as a substitute of LH because of the degree of homology between the two hormones. The main aim of this prospective randomized study was to determine, for the first time, whether low dose hCG added to rFSH for ovarian stimulation could produce better results compared to the addition of rLH in women entering IVF-ET, especially in those women that had previous IVF failures. An additional aim was to find an indicator that would allow us to follow-up ovarian stimulation and, possibly, modify it in order to achieve a better IVF outcome; and that indicator may be the cDNA copies of the LH/hCG receptor. Group A patients (n = 58) were administered hCG and Group B rLH (n = 56) in addition to rFSH in the first days of ovarian stimulation. The number of follicles and oocytes and, most importantly, implantation and pregnancy rates were shown to be statistically significantly higher in the hCG group. This study has also determined, for the first time to our best knowledge, m-RNA for LH/hCG receptors in the lymphocytes of peripheral blood 40 h before ovum pick-up. cDNA levels of the hCG receptor after ovarian stimulation were significantly higher among women receiving hCG compared to those receiving LH. In addition, higher levels were encountered among women with pregnancy compared to those without, although this was not statistically significant due to the small number of pregnancies. It seems that hCG permits a highly effective and more stable occupancy of rLH/hCG receptors and gives more follicles and more oocytes. The determination of cDNA copies could be, in the future, a marker during ovulation induction protocols and of course a predictor for the outcome of ART in the special subgroup of patients with previous failures.

Effects of recombinant LH supplementation to recombinant FSH during induced ovarian stimulation in the GnRH-agonist protocol: a matched case-control study

BACKGROUND

Some studies have suggested that the suppression of endogenous LH secretion does not seem to affect the majority of patients who are undergoing assisted reproduction and stimulation with recombinant FSH (r-FSH). Other studies have indicated that a group of normogonadotrophic women down-regulated and stimulated with pure FSH preparations may experience low LH concentrations that compromise the IVF parameters. The present study aimed to compare the efficacy of recombinant LH (r-LH) supplementation for controlled ovarian stimulation in r-FSH and GnRH-agonist (GnRH-a) protocol in ICSI cycles.

METHODS

A total of 244 patients without ovulatory dysfunction, aged <40 years and at the first ICSI cycle were divided into two groups matched by age according to an ovarian stimulation scheme: Group I (n = 122): Down-regulation with GnRH-a + r-FSH and Group II (n = 122): Down-regulation with GnRH-a + r-FSH and r-LH (beginning simultaneously).

RESULT(S)

The number of oocytes collected, the number of oocytes in metaphase II and fertilization rate were significantly lower in the Group I than in Group II (P = 0.036, P = 0.0014 and P = 0.017, respectively). In addition, the mean number of embryos produced per cycle and the mean number of frozen embryos per cycle were statistically lower (P = 0.0092 and P = 0.0008, respectively) in Group I than in Group II. Finally the cumulative implantation rate (fresh+thaw ed embryos) was significantly lower (P = 0.04) in Group I than in Group II. The other clinical and laboratory results analyzed did not show difference between groups.

CONCLUSION

These data support r-LH supplementation in ovarian stimulation protocols with r-FSH and GnRH-a for assisted reproduction treatment.

1,500 IU human chorionic gonadotropin administered at oocyte retrieval rescues the luteal phase when gonadotropin-releasing hormone agonist is used for ovulation induction: a prospective, randomized, controlled study

OBJECTIVE

To prospectively assess the reproductive outcome with a small bolus of hCG administered on the day of oocyte retrieval after ovulation induction with a GnRH agonist (GnRHa).

DESIGN

Prospective, randomized trial.

SETTING

Three hospital-based IVF clinics.

PATIENT(S)

Three hundred five IVF/intracytoplasmic sperm injection patients after a GnRH antagonist protocol.

INTERVENTION(S)

Ovulation induction was performed with either 10,000 IU hCG or 0.5 mg GnRHa (buserelin) supplemented with 1,500 IU hCG on the day of oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Reproductive outcome in the two groups.

RESULT(S)

No significant differences were seen regarding positive hCG/ET rate (48% and 48%), ongoing pregnancy rate (26% and 33%), delivery rate (24% and 31%), and rate of early pregnancy loss (21% and 17%) between the GnRHa and 10,000 IU hCG groups, respectively.

CONCLUSION(S)

A small bolus of hCG in the GnRHa group secured the luteal phase, resulting in a comparable reproductive outcome in the two groups. However, a nonsignificant difference of 7% in delivery rates justifies further studies to refine the use of GnRHa for ovulation induction.

Extragonadal LH/hCG action--not yet time to rewrite textbooks

Gonadotropins are indispensable in both sexes in the regulation of gonadal sex steroid production and gametogenesis. In addition to their well-established classical actions, numerous recent publications have indicated the presence and function of luteinizing hormone/chorionic gonadotropin receptors (LH/hCG-R) in a variety of extragonadal tissues. However, the physiological significance of such effects has remained unclear. We have generated two genetically modified mouse models, one with excessive production of hCG and the other with targeted disruption of LH/hCG-R gene, and used them to address the functions of LH and hCG. Numerous gonadal and extragonadal phenotypes were found in the models with the two extremes of LH/hCG action. However, when the extragonadal effects were scrutinized in greater detail, they all appeared to arise through modification of gonadal function, either through enhanced or inhibited response to LH/hCG stimulation. Hence, further evidence is needed before the extragonadal LH/hCG-R expression can be considered functionally significant.

Phenotypic characterisation of mice with exaggerated and missing LH/hCG action

In order to study the physiology and pathophysiology of gonadotrophin action, we have produced transgenic (TG) mice overexpressing human chorionic gonadotrophin (hCG) alpha and beta subunits (hCG+ mice) and knockout (KO) mice for the luteinising hormone receptor (LHR; LuRKO mice). The two extremes in LH function, i.e. strong LH/hCG stimulation and total blockade of this action, confirm numerous earlier concepts about LH function, but they also reveal new aspects about gonadal function during excessive LH production and in the absence of this trophic stimulus. The purpose of this review is to summarise the key findings on these two genetically modified mouse models.

Recombinant luteinizing hormone supplementation to recombinant follicle-stimulation hormone during induced ovarian stimulation in the GnRH-agonist protocol: a meta-analysis

PURPOSE

to compare the efficacy of recombinant LH supplementation for controlled ovarian stimulation in recombinant FSH and GnRH-agonist protocol.

METHODS

Search strategies included on-line surveys of databases. The fixed effects model was used for odds ratio and effect size (weighted mean difference). Four trials fulfilled the inclusion criteria.

RESULTS

a fewer days of stimulation (p<0.0001), a fewer total amount of r-FSH administered (p<0.0001) and a higher serum estradiol levels on the day of hCG administration (p<0.0001) were observed for the r-LH supplementation protocol. However, differences were not observed in number of oocyte retrieved, number of mature oocytes, clinical pregnancy per oocyte retrieval, implantation and miscarriage rates.

CONCLUSIONS

more randomized controlled trials are necessary before evidence-based recommendations regarding exogenous LH supplementation in ovarian stimulation protocols with FSH and GnRH-agonist for assisted reproduction treatment can be provided.

Production of recombinant orange-spotted grouper (Epinephelus coioides) luteinizing hormone in insect cells by the baculovirus expression system and its biological effect

The cDNA sequence encoding orange-spotted grouper lhb (LHbeta) and cga (GTHalpha) subunits were cocloned into baculovirus transfer vectors and expressed in insect Sf9 cells. The results showed that two bands of 15.6 kDa and 11.4 kDa could be detected by SDS-PAGE and a band of 30 kDa could be detected by native PAGE. The recombinant grouper Lh (rgLh) could stimulate the secretion of testosterone (T) and estradiol-17beta (E2) from the gonad in a static incubation system in a time-dependent, but not a dose-dependent, manner. Using in vivo bioassay, the mRNA levels of two aromatases (cyp19a1a [P450aromA] and cyp19a1b [P450aromB]), gnrh (GnRH), lhb, and cga in the pituitary, gonad, and hypothalamus were determined in different groups of orange-spotted groupers treated respectively with rgLh, human chorionic gonadotropin (hCG), and a culture medium of insect cells transformed with an expression vector without lhb and cga subunits. The mRNA levels of cyp19a1a and cyp19a1b rose dramatically after injecting rgLh intraperitoneally, which was consistent with the secretion of sex steroid hormones. Interestingly, the mRNA levels of gnrh dropped in the pituitary, hypothalamus, and gonad, and the mRNA levels of lhb and cga in the pituitary of the experimental group expressed at a higher level than that of the hCG group. These results are in accord with the long positive feedback loop of Lh on gonad sex steroid hormones and the short negative feedback loop of Lh on gnrh mRNA levels. These results indicate that the rgLh is successfully expressed by the baculovirus-insect expression system and that the rgLh has biological activity.

Genetically modified mouse models in studies of luteinising hormone action

Numerous genetically modified mouse models have recently been developed for the study of the pituitary-gonadal interactions. They include spontaneous or engineered knockouts (KO) of the gonadotrophin-releasing hormone (GnRH) and its receptor, the gonadotrophin common-alpha(Calpha), luteinising hormone (LH) beta and follicle-stimulating hormone (FSH) beta subunits, and the two gonadotrophin receptors (R), LHR and FSHR. In addition, there are also transgenic (TG) mice overexpressing gonadotrophin subunits and producing supraphysiological levels of these hormones. These models have offered relevant phenocopies for similar mutations in humans and to a great extent expanded our knowledge on normal and pathological functions of the hypothalamic-pituitary-gonadal (HPG) axis. The purpose of this article is to review some of our recent findings on two such mouse models, the LHR KO mouse (LuRKO), and the hCG overexpressing TG mouse (hCG+).

Efficacy of low-dose human chorionic gonadotropin (hCG) in a GnRH antagonist protocol

PURPOSE

To examine the efficacy of low-dose hCG using a GnRH antagonist protocol.

METHODS

Prospective randomized study was performed at the Kyono Ladies Clinic. One hundred ninety-two women (<40 -years old, <3 previous cycles) were randomly assigned to GnRH agonist (buserelin) long protocol (LP, n = 66), GnRH antagonist (cetrorelix) with no low-dose hCG protocol (NhCGP, n = 63), or GnRH antagonist with low-dose hCG protocol (hCGP, n = 63).

RESULTS

The hCGP was associated with reduced total amounts of FSH, increased oocyte maturation rate, high-quality day 3 embryos rate, and number of frozen embryos. Ovarian hyperstimulation syndrome (OHSS) tended to be lower in the GnRH antagonist protocol. Pregnancy and implantation rates did not differ significantly between study groups.

CONCLUSIONS

Daily low-dose hCG supplementation in the late follicular phase could improve the outcome in FSH based-GnRH antagonist protocol. This protocol, however, does require further modifications, including determination of the optimal doses for hCG and gonadotropin pretreatment.

Precycle administration of GnRH antagonist and microdose HCG decreases clinical pregnancy rates without affecting embryo quality and blastulation

The outcome of a novel protocol utilizing precycle gonadotrophin-releasing hormone (GnRH) antagonist administration and LH activity support with microdose recombinant human chorionic gonadotrophin (HCG) was compared to GnRH agonist long protocol used in patients undergoing their first ICSI (n=707) or IVF (n=571) cycles, which had resulted in one or two blastocyst transfers. In GnRH antagonist cycles, cetrorelix acetate (3 mg) was administered s.c. 4 days before FSH stimulation and a repeat dose was given when the lead follicular diameter was 13-14 mm. LH support was provided by recombinant HCG (2.5 microg). Embryo progression and blastulation were evaluated using embryo progression indices and blastocyst quality scores. The tested protocol demonstrated reduced implantation and clinical pregnancy rates as compared with GnRH agonist long protocol, although the embryo progression and blastulation parameters and blastocyst quality were comparable among the groups. Logistic regression models further supported the significant negative impact of GnRH antagonist/microdose HCG protocol on clinical pregnancy rates in both ICSI and IVF patients. Assisted reproduction cycles with fresh blastocyst transfers utilizing precycle GnRH antagonist administration and microdose HCG support resulted in lower implantation and clinical pregnancy rates as compared with GnRH agonist cycles, although the embryo progression and blastulation parameters were comparable.

What have we learned about gonadotropin function from gonadotropin subunit and receptor knockout mice?

A number of biochemical and physiological studies elucidated the roles of pituitary and placental glycoprotein hormones. Advances in the past two decades in manipulating the mouse genome by random or site-specific mutagenesis have heralded a new dimension to our understanding of the biology of gonadotropins. It is now possible to model many human reproductive disorders involving gonadotropins/gonadotropin-signaling in the mouse. Mutant mice selectively lacking either FSH or LH or their cognate receptors have been generated. The gonadotropin ligand and the corresponding receptor knockout mice mostly phenocopy each other. Analyses with these genetic models confirmed earlier physiological studies; in addition they also revealed novel roles for gonadotropins previously unrecognized. While FSH action seems dispensable for male but not female fertility, absence of LH causes infertility in both the sexes. While Sertoli cell number and germ cell carrying capacity of the Sertoli cells in compromised in FSH mutants, both somatic and germ cell lineages are affected in the LH mutants resulting in complete male infertility. FSH mutant females demonstrate a preantral stage block in folliculogenesis and FSH alone is not sufficient to promote full folliculogenesis in the absence of LH. Pre-ovulatory stage follicles do not form and most of the follicles undergo apoptosis in the absence of LH. Many extra-gonadal phenotypes have been described for the receptor knockout mice and whether these bear any resemblances to those in patients with similar inactivating mutations in the receptors for FSH and LH remains an open question. Thus the in vivo models will continue to have a significant impact in understanding gonadotropin physiology and pathophysiology and serve as novel genetic tools to study signaling mechanisms in the gonads.

Orthotopic transplantation of LH receptor knockout and wild-type ovaries

Luteinizing hormone (LH) receptor knockout animals have an ovarian failure due to an arrest in folliculogenesis at the antral stage. As a result, the animals have an infertility phenotype. The present study was undertaken to determine whether this phenotype could be reversed by orthotopic transplantation of wild-type ovaries. The results revealed that transplanting wild-type ovaries into null animals did not result in resumption of estrus cycles. Although the number of different types of follicles increased, none progressed to ovulation. The serum hormone profiles improved, reflecting the ovarian changes. The wild-type animals with null ovaries also failed to cycle and their ovaries and serum hormone levels were more like null animals with their own ovaries. Although the lack of rescue of null ovaries placed into wild-type animals was predicted, the failure of wild-type ovaries placed in null animals was not, which could be due to chronic exposure of transplanted tissue to high circulating LH levels and also possibly due to altered internal milieu in null animals. These findings may have implications for potential future considerations of grafting normal donor ovaries into women who have an ovarian failure resulting from inactivating LH receptor mutations.

Novel concepts of human chorionic gonadotropin: reproductive system interactions and potential in the management of infertility

OBJECTIVE

To extensively review the scientific literature on the potential sites of hCG action and the role of this hormone on reproductive processes not necessarily related to the classic hCG functions of supporting early pregnancy.

DESIGN

Review of the international scientific literature and the authors' personal research experience in this area.

RESULT(S)

The LH/hCG receptor has an almost ubiquitous distribution in reproductive organs, thus suggesting that the actions of hCG might be more extensive than previously thought. Independently of FSH, low-dose hCG can support development and maturation of larger ovarian follicles that have acquired granulosa cells LH/hCG receptors, potentially providing effective and safer ovulation induction regimens. Human chorionic gonadotropin seems to be capable of improving uterine receptivity by enhancing endometrial quality and stromal fibroblast function. Furthermore, through its actions on insulin-like growth factor binding protein-1 and vascular endothelial growth factor, hCG might stimulate endometrial angiogenesis and growth and extend the implantation window, thus making pregnancy more likely.

CONCLUSION(S)

Mounting evidence indicates that hCG could be mediating relevant actions enhancing fertility and the efficacy of therapeutic procedures used in the management of infertility. Greater understanding of the physiologic roles that hCG plays in human reproduction might suggest novel clinical applications for this traditional hormone of pregnancy.

Fertility in luteinizing hormone receptor-knockout mice after wild-type ovary transplantation demonstrates redundancy of extragonadal luteinizing hormone action

The luteinizing hormone receptor (LHR), mainly expressed in gonads, is essential for normal reproduction. However, numerous recent studies have also demonstrated LHR expression in multiple extragonadal reproductive and nonreproductive tissues. Although some effects of luteinizing hormone (LH) or its agonist, human chorionic gonadotropin, have been shown in extragonadal sites, their physiological significance remains open. In the present study, we have addressed the function of the extragonadal LHR using LHR-KO mice (LuRKO mice), in which the ovaries of prepubertal mice were orthotopically replaced with pieces of WT ovary using similarly transplanted WT mice as controls. Most ovarian transplants attained normal endocrine function in both groups of mice, as demonstrated by normal age at vaginal opening, estrous cycles, and sexual behavior. Both the LuRKO and WT mice repeatedly became pregnant (9/16 vs. 16/20 after first mating; difference not significant) and delivered similarly sized litters, which grew normally after birth, indicating normal lactation. In conclusion, fertility is restored in LuRKO mice by transplantation of WT ovarian tissue. This is achieved in the absence of extragonadal LHR expression, which indicates physiological redundancy for such receptor sites.

GnRH agonist (buserelin) or hCG for ovulation induction in GnRH antagonist IVF/ICSI cycles: a prospective randomized study

BACKGROUND

We aimed to determine the efficacy of ovarian hyperstimulation protocols employing a GnRH antagonist to prevent a premature LH rise allowing final oocyte maturation and ovulation to be induced by a single bolus of either a GnRH agonist or hCG.

METHODS

A total of 122 normogonadotrophic patients following a flexible antagonist protocol was stimulated with recombinant human FSH and prospectively randomized (sealed envelopes) to ovulation induction with a single bolus of either 0.5 mg buserelin s.c. (n = 55) or 10,000 IU of hCG (n = 67). A maximum of two embryos was transferred. Luteal support consisted of micronized progesterone vaginally, 90 mg a day, and estradiol, 4 mg a day per os.

RESULTS

Ovulation was induced with GnRH agonist in 55 patients and hCG in 67 patients. Significantly more metaphase II (MII) oocytes were retrieved in the GnRH agonist group (P < 0.02). Significantly higher levels of LH and FSH (P < 0.001) and significantly lower levels of progesterone and estradiol (P < 0.001) were seen in the GnRH agonist group during the luteal phase. The implantation rate, 33/97 versus 3/89 (P < 0.001), clinical pregnancy rate, 36 versus 6% (P = 0.002), and rate of early pregnancy loss, 4% versus 79% (P = 0.005), were significantly in favour of hCG.

CONCLUSIONS

Ovulation induction with a GnRH agonist resulted in significantly more MII oocytes. However, a significantly lower implantation rate and clinical pregnancy rate in addition to a significantly higher rate of early pregnancy loss was seen in the GnRH agonist group, most probably due to a luteal phase deficiency.

The human cytotrophoblastic cell, a mononuclear chameleon

The human placenta represents an abundant; easily accessible and unlimited study material (at birth a human placenta provides about 500 g of trophoblast). Cytotrophoblastic cells (CTB) are one constituent of the human placenta and represent epithelial cells with fascinating properties: They are able to fuse to form syncytia, can behave like immotile polarized epithelial cells, can phenocopy stromal fibroblasts or endothelial cells or undergo a mesenchymal-like transformation that converts them into non proliferative and highly invasive cells. Like a chameleon, CTB are thus able to adapt to their immediate environment by phenocopying their neighbor cells. This review describes the different routes that CTB follow during their differentiation pathways, the regulation of these at the molecular level, it gives also an overview of the pathologies associated with faulty pathways and describes the usual phenotypic markers used to identify the different CTB subsets. This review is intended to stimulate investigators not acquainted with the field of placental biology to use CTB as a model to study important biological functions in vitro, such as cell fusion, cell invasion and cell transformation.