Serum and follicular fluid levels of serotonin, kisspeptin, and brain-derived neurotrophic factor in patients undergoing in vitro fertilization: an observational study : Neurohormones in patients receiving IVF

Yueliang Yin Ameliorates Endometrial Receptivity in Mice with Embryo Implantation Failure by Reducing Pyroptosis and Activating BDNF/TrkB Pathway

SCOPE

Endometrial receptivity plays a vital role in embryonic implantation. Yueliang Yin is a marketed solid drink in China, also known as Bushen Cuyun Recipe (BCR), that is, assumed to have a therapeutic effect on infertility by improving endometrial receptivity. This study investigates the effects and mechanisms of BCR in protecting the endometrium.

METHODS AND RESULTS

Mice with mifepristone-induced embryo implantation failure that exhibited a decreased implantation sites number, thinner endometrium, reduced endometrial glands number, and poor pinopode expression levels are treated with BCR, and these mentioned conditions significantly improves afterward. Molecular docking shows that the main active components kaempferol, quercetin, and hesperetin of BCR stably bound to gasdermin D (GSDMD). Experimental results demonstrate that levels of GSDMD, cleaved caspase-1 and leucine-rich repeat, and pyrin domain-containing 3 and IL-1β levels in model mice are significantly decreased and expressions of brain-derived neurotrophic factor (BDNF) and tyrosine protein kinase B (TrkB) expression levels are significantly elevated after BCR treatments, and that the DNA damage is significantly reversed in BCR-treated mice.

CONCLUSIONS

BCR is potent and effective in ameliorating endometrial receptivity. The potential mechanisms of BCR on endometrial receptivity may mediate by activating BDNF/TrkB pathway activation and protecting endometrial cells' protection against pyroptosis.

Kisspeptin: a potential therapeutic target in patients with unexplained infertility?

BACKGROUND

Kisspeptin has recently emerged as a key regulator of the reproductive axis in women. Kisspeptin, acting centrally via the kisspeptin receptor, stimulates the secretion of the gonadotrophin-releasing hormone (GnRH).

AIMS

To investigate serum kisspeptin levels in infertility patients for its clinical utilisation in management and understanding of the pathophysiology of infertility in a wide array of patients.

METHODS

This prospective case-control study analysis involved 92 primary infertile women with PCOS, diminished ovarian reserve (DOR), unexplained infertility (UEI), and male factor infertility between 20 and 42 years of age. Serum samples were collected between the second and fifth day of the menstrual cycle. The kisspeptin level was determined using a human kisspeptin ELISA kit according to the manufacturer's procedure.

RESULTS

The median value of serum kisspeptin in the PCOS infertility group was significantly higher than that in the UEI group (p = 0.011). There was a statistically significant (p = 0.015, r =  -0.182) negative weak correlation found between serum kisspeptin levels and age. The optimal cutoff value obtained to differentiate the UEI from others (PCOS infertility + DOR + male factor infertility) according to the serum kisspeptin level was 214.3 ng/L with a sensitivity of 55% and specificity of 80.9%.

CONCLUSIONS

Understanding the role of kisspeptin may lead to its use as a biomarker in infertility diagnosis in UEI patients and might guide the use of kisspeptin analogues in selected patients for infertility management.

Sexual Dimorphism in Kisspeptin Signaling

Kisspeptin (KP) and kisspeptin receptor (KPR) are essential for the onset of puberty, development of gonads, and maintenance of gonadal function in both males and females. Hypothalamic KPs and KPR display a high degree of sexual dimorphism in expression and function. KPs act on KPR in gonadotropin releasing hormone (GnRH) neurons and induce distinct patterns of GnRH secretion in males and females. GnRH acts on the anterior pituitary to secrete gonadotropins, which are required for steroidogenesis and gametogenesis in testes and ovaries. Gonadal steroid hormones in turn regulate the KP neurons. Gonadal hormones inhibit the KP neurons within the arcuate nucleus and generate pulsatile GnRH mediated gonadotropin (GPN) secretion in both sexes. However, the numbers of KP neurons in the anteroventral periventricular nucleus and preoptic area are greater in females, which release a large amount of KPs in response to a high estrogen level and induce the preovulatory GPN surge. In addition to the hypothalamus, KPs and KPR are also expressed in various extrahypothalamic tissues including the liver, pancreas, fat, and gonads. There is a remarkable difference in circulating KP levels between males and females. An increased level of KPs in females can be linked to increased numbers of KP neurons in female hypothalamus and more KP production in the ovaries and adipose tissues. Although the sexually dimorphic features are well characterized for hypothalamic KPs, very little is known about the extrahypothalamic KPs. This review article summarizes current knowledge regarding the sexual dimorphism in hypothalamic as well as extrahypothalamic KP and KPR system in primates and rodents.

Hypoxia: Role of SIRT1 and the protective effect of resveratrol in ovarian function

Background

Ovarian function is closely related to the degree of vascular network development surrounding the ovary. Maternal aging‐related construction defects in this vascular network can cause ovarian hypoxia, which impedes oocyte nutrient supply, leading to physiological changes in the ovaries and oocytes. The anti‐aging gene Sirtuin 1 (SIRT1) senses and adapts to ambient stress and is associated with hypoxic environments and mitochondrial biogenesis.

Methods

The present study is a literature review focusing on investigations involving the changes in SIRT1 and mitochondrial expression during hypoxia and the cytoprotective effects of the SIRT1 activator, resveratrol.

Main findings

Hypoxia suppresses SIRT1 and mitochondrial expression. Resveratrol can reverse the hypoxia‐induced decrease in mitochondrial and SIRT1 activity. Resveratrol suppresses the production of hypoxia‐inducible factor‐1α and vascular endothelial growth factor proteins.

Conclusion

Resveratrol exhibits protective activity against hypoxic stress and may prevent hypoxia‐ or aging‐related mitochondrial dysfunction. Resveratrol treatment may be a potential option for infertility therapy.

Impact of serum and follicular fluid kisspeptin and estradiol on oocyte maturity and endometrial thickness among unexplained infertile females during ICSI

Objective

To relate serum and follicular fluid (FF) kisspeptin and estradiol levels in different stages of stimulation during Intracytoplasmic Sperm Injection (ICSI) with oocyte maturity and endometrial thickness among unexplained infertile females.

Methods

This cross-sectional study was carried out at the Australian Concept Infertility Medical Centre from March 2017 till March 2018. Fifty unexplained infertile females, booked for ICSI, were included in the study. Serum kisspeptin and estradiol were estimated by Enzyme-Linked Immunosorbent Assay in all four stages; 1: follicular stimulation, 2: ovulation induction, 3: oocyte pickup, and 4: embryo transfer. FF was aspirated during oocyte retrieval (stage 3) for the analysis of KP and estradiol. Pregnancy outcomes were categorized as non-pregnant, preclinical abortion, and clinical pregnancy.

Results

The age of the study subjects was 32.04 ± 2.29 (Mean±SD) years, with mean BMI of 28.51 ± 4.15 (Mean±SD) kg/m². Mean serum kisspeptin and estradiol levels increased in all subjects as the stimulation proceeded stages 1–3; however, the mean dropped after retrieval of the oocytes (stage 4). Out of 27 female subjects who completed the cycle, 17 remained non-pregnant, 4 had preclinical abortion, and 6 acquired clinical pregnancy. The FF kisspeptin concentration was significantly higher than serum concentrations and positively correlated with serum and FF estradiol concentrations. FF-kisspeptin correlated with serum kisspeptin in Stage 3 (r = 0.930, p<0.001), maturity of oocyte (r = 0.511, p = 0.006) and endometrial thickness (r = 0.522, p = 0.005). Kisspeptin in stage 3 was also found to correlate with endometrial thickness (r = 0.527, p = 0.005) and with estradiol (r = 0.624, p = 0.001) independently.

Conclusion

Increase in serum and FF-kisspeptin and estradiol levels from stages 1 to 3, resulted in an optimum endometrial thickness, probability of fertilization of oocytes and chances of clinical pregnancy in Assisted Reproductive Techniques /ICSI cycles of unexplained infertile females.