Effect of 1,25(OH)2-vitamin D3 on expression and phosphorylation of progesterone receptor in cultured endometrial stromal cells of patients with repeated implantation failure

Comparing the effect of sequential embryo transfer versus double blastocyst embryo transfer on pregnancy outcomes in intracytoplasmic sperm injection (ICSI) cycles in patients with repeated implantation failure: A randomized controlled trial

OBJECTIVE

Recurrent implantation failure (RIF) is the main challenge in assisted reproductive technology (ART) practice. Sequential embryo transfer, in which both, cleavage-stage embryo on day 3 and blastocyst on day 5, are sequentially transferred in the same cycle, has been suggested for increasing embryo implantation in RIF patients. The aim of the present study was to compare the effect of sequential embryo transfer versus double blastocyst embryo transfer on pregnancy outcomes in intracytoplasmic sperm injection (ICSI)/frozen embryo transfer (FET) cycles in RIF patients.

MATERIALS AND METHODS

This prospective study was enrolled 224 RIF patients undergoing ICSI/FET cycles and randomly divided to sequential and control groups. In sequential group, embryo transfer was conducted on day 3 (cleavage stage) and day 5 (blastocyst stage). In control group, two top-quality blastocysts were transferred on day 5.

RESULTS

Two hundred and two couples accomplished the trial, and their data were analyzed. Results demonstrated that sequential embryo transfer on day 3 and day 5 compared to double blastocyst transfer on day 5 significantly increased implantation rate, clinical pregnancy rate and ongoing pregnancy rate in RIF patients (p-value = 0.0142, p-value = 0.0154, p-value = 0.0201, respectively). However, there were no significant differences in terms of chemical pregnancy rate, multiple pregnancy rate, miscarriage rate and ectopic pregnancy rate in the studied groups.

CONCLUSION

Sequential embryo transfer is associated with improved pregnancy outcomes in RIF patients. Further prospective studies with larger sample sizes are required to validate these results.

A bibliometric analysis of global research on vitamin D and reproductive health between 2012 and 2021: Learning from the past, planning for the future

Background

Vitamin D plays an invaluable role in reproductive health, but vitamin D insufficiency and deficiency are generally common among couples of childbearing age and pregnant women. This study aimed to evaluate the evolution, development trend, and research hotspot of publications on vitamin D and reproductive health.

Methods

The literature on vitamin D and reproductive health between 2012 and 2021 was retrieved from the Web of Science Core Collection (WoSCC). We used VOSviewer and CiteSpace to analyze publication years, countries, institutions, journals, highly cited authors and publications, and co-occurrence and citation bursts of keywords.

Results

A total of 1,828 articles and reviews on vitamin D and reproductive health published between 2012 and 2021 were identified. The annual publication outputs showed steady growth, with the most publications (272) and citations (7,097) in 2021. The United States contributed the most publications (458) and had the highest h-index (58). In terms of the number of publications and h-index, the journal named Nutrients ranked first. Nutrition dietetics, obstetrics gynecology, and endocrinology metabolism were three well-represented disciplines in research on vitamin D and reproductive health. Hollis BW, Wagner CL, and Litonjua AA were the top three most productive authors in this field during the last decade. Apart from vitamin D, the five keywords with the most frequent occurrence were vitamin D deficiency, pregnancy, risk, vitamin D supplementation, and 25-hydroxyvitamin D. Keyword citation burst analysis revealed that low birth weight, adipose tissue, marker, and embryo had a citation burst lasting until 2021.

Conclusion

In conclusion, vitamin D has received continuous attention in the field of reproductive health, and there appears to have a higher level of research in North America. Multidisciplinary intersection contributed to the in-depth exploration in this field. And the effect of maternal vitamin D levels on fetal lipid metabolism and the prediction of fertility by vitamin D-related markers might be hotspots for the research.

Effect of 1,25(OH)2-vitamin D3 on decidualization of human endometrial stromal cells

Decidualization is the differentiation of endometrial stromal cells (eSC) to rounded, epithelioid-like cells during menstrual cycle and pregnancy. The impairment of this process leads to infertility and a variety of pregnancy disorders, including recurrent miscarriages and uteroplacental disorders. The aim of this study was to evaluate the effect of 1,25(OH)2-vitamin D3 (VD) on transformation of primary eSC into decidual cells. After isolation of eSC from biopsy samples of healthy fertile women and their characterization, the cells were cultured and propagated, and confluent cultures were decidualized for 12 days with progesterone (P4) and estradiol (E2) in presence or absence of VD. Prolactin (PRL) concentration was measured every 48 h in culture medium of eSCs, and ultrastructural changes were evaluated at the end of treatment. The results showed that PRL concentration in culture medium of eSCs was significantly increased in VD-treated decidual cells compared to control groups in a time-dependent manner. Ultrastructural analysis demonstrated that VD enhances many of the ultrastructural changes of decidualized cells including expansion of rough endoplasmic reticulum (rER), increased lipid droplets and high number of euchromatin round nuclei. These results suggest that VD may play an important role during early pregnancy by promoting cellular transformation associated with decidualization.

Vitamin D Supplementation Improves Uterine Receptivity in a Rat Model of Vitamin D Deficiency: A Possible Role of HOXA-10/FKBP52 Axis

Synchronized uterine receptivity with the time of implantation is crucial for pregnancy continuity. Vitamin D (VD) deficiency has been linked to the failure of implantation. Therefore, we tested the link between the Homeobox transcription factor-10/immunophilin FK506-binding protein 52 (HOXA-10/FKBP52) axis and the uterine receptivity in VD-deficient rats. The effect of VD supplementation at different doses was also investigated. Forty-eight pregnant rats were divided into six groups (eight/group); normal control rats fed with standard chow (control), control rats supplemented with VD (equivalent dose of 400 IU/day) (control-D400). VD-deficient group (DEF) and the three VD deficiency groups with VD supplementation were equivalent to 400, 4,000, and 10,000 IU/day (DEF-D400, DEF-D4000, and DEF-D10000, respectively). The expression levels of HOXA-10/FKBP52, progesterone level, and histological evaluation of decidualization using osteopontin (OSN) and progesterone receptor (PGR) were estimated. An assessment of the uterine contractility was conducted for all rats. This study showed the downregulation of HOXA-10/FKBP52 together with increased amplitude and frequency of the uterine contractility in the DEF group compared to control. VD dose-dependent supplementation restored progesterone/receptor competency, upregulated the expressional response of HOXA-10 and its downstream FKBP52, and improved uterine receptivity and endometrial decidualization at the time of implantation that was documented by increased area% of OSN and the number of implantation beads.

The Effects of Autologous Platelet-Rich Plasma on Pregnancy Outcomes in Repeated Implantation Failure Patients Undergoing Frozen Embryo Transfer: A Randomized Controlled Trial

Repeated implantation failure (RIF) is a disorder in which good-quality embryos fail to implant in the endometrium following several in vitro fertilization (IVF) cycles. This study aimed to evaluate the efficiency and safety of intrauterine infusion of platelet-rich plasma (PRP) in improvement of pregnancy outcomes in RIF patients undergoing frozen embryo transfer (FET). A total of 438 women with a history of RIF undergoing FET were assessed for eligibility to enter the study. Patients were randomly assigned to the intervention (PRP) and control groups. The intervention group received an intrauterine infusion of 0.5 ml PRP 48 h before embryo transfer while the control group received standard treatment. The rates of chemical and clinical pregnancy were defined as the primary outcome values. All women were followed up until the study endpoints that included the number of neonates born and pregnancy-related complications. Three hundred and ninety-three participants accomplished the study and their data were analyzed. The chemical pregnancy, clinical pregnancy, and live birth rates were higher in the PRP group than control group (p value: <0.0001; p value: <0.0001; p value: <0.0001 respectively). However, there were no significant differences between the two groups in terms of multiple pregnancies and pregnancy complications except for spontaneous abortion. The spontaneous abortion rate was significantly higher in the control group compared to the PRP group (p value = 0.0262). These results suggest that intrauterine infusion of PRP is an effective and safe route to improve pregnancy outcomes in RIF patients undergoing FET.

Vitamin D3 protects against lead-induced testicular toxicity by modulating Nrf2 and NF-κB genes expression in rat

Lead (Pb) is an environmental toxin that has the ability to alter biological processes by inducing oxidative stress (OS) and inflammation. Nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappa B (NF-κB) are two transcriptional factors that participate in the regulation of cellular responses against OS and inflammation. This study was conducted to evaluate the effects of vitamin D3 (VD) on the prevention of testicular damages of Pb and its association with Nrf2 and NF-κB gene expression levels and their downstream molecules. Forty male Wistar rats were divided into four groups and treatments were performed as following for four weeks: control group received no treatment, VD group were injected intramuscularly with 1000 IU of VD/Kg every other day, Pb group received 1000 mg of Pb/L of drinking water, and Pb + VD group were exposed to Pb and VD simultaneously. The results demonstrated significant decrease in the levels of tissue antioxidants, and increase in inflammatory cytokines in the Pb-intoxicated group, with increased Nrf2 and NF-κB mRNA levels. A remarkable reduction in sperm criteria and a significant disruption in serum hormones were also observed. Anyhow, VD supplementation during exposure to Pb showed a significant protective effect against all pathophysiologic alterations caused by Pb. Furthermore, VD affected the expression of Nrf2 and NF-κB and mitigated the harsh effects of Pb. In conclusion, our findings indicate that VD attenuated the toxic impacts of Pb on testis through modulation of Nrf2 and NF-κB gene expression levels which further regulated the OS and inflammatory responses.

Protective Effect of Vitamin D3 Against Pb-Induced Neurotoxicity by Regulating the Nrf2 and NF-κB Pathways

Lead (Pb) is a known toxic heavy metal which accumulates in different tissues and causes oxidative stress (OS) and inflammation. The brain tissue is considered as one of the most vulnerable organs to the Pb-induced toxicity. The aim of this study was to investigate the therapeutic effects of vitamin D3 (VD) supplementation against the damages caused by chronic Pb toxicity in the cerebral cortex. Forty Wistar rats were divided into four equal groups and were treated as follows: control group received no treatment, VD group received 1000 IU/kg of VD by intramuscular injection every other day, Pb group received 1000 mg/L of Pb in drinking water, and Pb + VD group received VD and Pb simultaneously. The experiment lasted for 4 weeks and the analyses were conducted 24 h after the last administrations. The obtained results demonstrated that Pb significantly increased cortical lipid peroxidation and reactive oxygen species (ROS) levels. At the same time, there was a significant reduction in glutathione (GSH) content, catalase (CAT), and superoxide dismutase (SOD) activities, as well as a significant increase in the tissue level of inflammatory cytokines. Furthermore, Pb increased the messenger RNA (mRNA) expression level of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-kappa B (NF-κB). Anyhow, VD administration during the period of Pb exposure suppressed the OS and inflammation by increasing the antioxidant molecules and decreasing the inflammatory cytokines and consequently repaired Pb-induced cortical tissue damages. Remarkably, these responses were concomitant with the alterations in Nrf2 and NF-κB gene expressions. In conclusion, the present study discloses the potential protective effects for VD against Pb-induced neurotoxicity via anti-inflammatory and antioxidative mechanisms.