Altered decidual and placental catabolism of vitamin D may contribute to the aetiology of spontaneous miscarriage

Association of serum vitamin D concentration and miscarriage rate in women with first-trimester threatened miscarriage

RESEARCH QUESTION

Is low serum 25-hydroxyvitamin D (25(OH)D) associated with an increased risk of miscarriage in women who presented with threatened miscarriage to the Early Pregnancy Assessment Clinic (EPAC)?

DESIGN

This was a secondary retrospective analysis using archived serum samples from a randomized, double-blind, placebo-controlled trial. Stored serum samples from 371 women presenting to the EPAC with threatened miscarriage during the first trimester were assayed for 25(OH)D by liquid chromatography-mass spectrometry.

RESULTS

The overall miscarriage rate was 45/371 (12.1%) in the whole cohort. After grouping vitamin D insufficiency and vitamin D sufficiency together into a 'non-deficient' group and excluding participants who underwent termination of pregnancy, there was no difference in the miscarriage rate between those who were vitamin D deficient compared with those who were not (25/205, 12.2% versus 20/157, 12.7%, P= 0.877, odds ratio 0.951, 95% CI 0.507-1.784). When analysed according to the number of gestational weeks, the miscarriage rate was significantly higher in the vitamin D non-deficient group than the vitamin D-deficient group in women who presented at 6 gestational weeks or earlier (13/33 [39.4%] versus 10/58 [17.2%], P= 0.019), but there were no statistically significant differences between the two groups presenting at later gestations. There was no difference in the vitamin D level in women who had a miscarriage compared with those who had a live birth (48 [37-57] versus 47 [37-58] nmol/l, P= 0.725 median [25th-75th percentile]).

CONCLUSIONS

A low serum vitamin D concentration was not associated with an increased risk of miscarriage in women with threatened miscarriage presenting to the EPAC.

Maternal Circulating Vitamin D Level, Targeted Supplementation, and Perinatal Outcomes in Twin Pregnancy

BACKGROUND

Vitamin D deficiency is associated with several obstetric complications in singleton pregnancy. The aim of this study was to assess whether vitamin D levels affect the outcomes of twin pregnancy and if targeted supplementation can improve perinatal outcomes.

METHODS

The serum vitamin D levels of 143 women with twin pregnancies were measured during their first trimester. Those with insufficient (10-30 ng/mL; IL group) or severely deficient (<10 ng/mL, DL group) vitamin D levels were supplemented. In the third trimester, vitamin D levels were reassessed. Perinatal outcomes of the IL and DL groups were compared with those of patients with sufficient levels (>30 ng/mL, SL group) since the beginning of pregnancy.

RESULTS

Women in the IL and DL groups had a higher incidence of hypertensive disorders of pregnancy (HDP) compared to the SL group (24.8% and 27.8% vs. 12.5%, p = 0.045): OR = 1.58 for the IL group and 1.94 for the DL group compared to the SL group. In patients whose vitamin D levels were restored after supplementation, HDP incidence was lower than in patients who remained in the IL or DL groups (23.4% vs. 27.3%) but higher than those who were always in the SL group (12.5%).

CONCLUSIONS

Insufficient or severely deficient levels of vitamin D in the first trimester are associated with an increased risk of HDP in twin pregnancy. The beneficial effect of targeted vitamin D supplementation in reducing HDP seems limited.

The therapeutic effects of vitamin D3 administration on the embryo implantation

Various adjuvants have been tested clinically for patients with problems with embryo implantation during in vitro fertilization (IVF)-embryo transfer (ET). Vitamin D3, an essential modulator of various physiological processes, has received attention as an important adjuvant for successful pregnancy, as many studies have shown a strong association between vitamin D deficiency and implantation failure and fetal growth restriction. However, vitamin D has been widely utilized in different protocols, resulting in non-reproducible and debatable outcomes. In the present study, we demonstrated that cyclic intrauterine administration of vitamin D3 increased endometrial receptivity and angiogenesis, which could be attributed to increased recruitment of uterus-resident natural killer cells. In particular, cyclic treatment of vitamin D3 promoted stable attachment of the embryo onto endometrial cells in vitro, suggesting its merit during the early stage of embryo implantation to support the initial maternal-fetal interactions. Our findings suggest that women with repeated implantation failure may benefit from the use of vitamin D3 as a risk-free adjuvant prior to IVF-ET procedures to improve the uterine environment, and make it favorable for embryo implantation.

Association of vitamin D receptor genetic polymorphisms with the risk of infertility: a systematic review and meta-analysis

BACKGROUND

The causes of infertility have remained an important challenge. The relationship between VDR gene polymorphisms and infertility has been reported, with controversial findings.

OBJECTIVE AND RATIONALE

We aimed to determine this relationship by conducting a systematic review and meta-analysis.

SEARCH METHODS

The study was started with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) declaration and the final draft was registered as a protocol in PROSPERO (ID: CRD42023416535). The international electronic databases including PubMed (Medline), Scopus, Web of Sciences, and Cumulative Index to Nursing and Allied Health Literature (CINHAL) were searched until January 30, 2023, by using appropriate keywords. The quality of the final studies was assessed using the NOS Checklist for case-control studies. The odds ratios (ORs) for each of the genetic models were pooled, and a subgroup analysis based on geographical region and types of infertility was carried out by the MetaGenyo online tool.

OUTCOMES

Case-control studies including 18 and 2 studies about infertility in women and men, respectively, and 4 miscarriage studies were entered into the meta-analysis. The VDR gene TaqI polymorphism was associated with infertility susceptibility in women in the allele contrast [OR = 1.2065, 95% CI (1.0846-1.3421); P = 0.0005], Recessive model [OR = 1.3836, 95% CI (1.1197-1.7096); P = 0.002], Dominant model [OR = 1.2146, 95% CI (0.0484-1.4072); P = 0.009], Homozygote [OR = 1.4596, 95% CI (1.1627-1.8325); P = 0.001], and TT vs. Tt [OR = 1.2853, 95% CI (1.0249-1.6117); P = 0.029. ApaI and FokI gene polymorphisms were found to be significantly protective SNPs against women and men infertility in the Dominant model [OR = 0.8379, 95% CI (0.7039- 0.9975); P = 0.046] and Recessive model [OR = 0.421, 95% CI (0.1821-0.9767); P = 0.043], respectively. Sub-group meta-analysis showed a protection association of ApaI in dominant [OR = 0.7738, 95% CI = 0.6249-0.9580; P = 0.018] and AA vs. aa [OR = 0.7404, 95 CI% (0.5860-0.9353) P = 0.011725] models in PCOS subgroup, however, a negative association with idiopathic infertility was found in AA vs. Aa [OR = 1.7063, 95% CI (1.1039-2.6375); P = 0.016187] and Aa vs. aa [OR = 0.6069, 95% CI (0.3761-0.9792); P = 0.040754]. TaqI SNP was significantly associated with infertility in the African population and BsmI was associated with the disease mostly in the Asian population.

CONCLUSION

This meta-analysis showed that the TaqI polymorphism may be linked to women's infertility susceptibility. However, ApaI and FokI might be the protective SNPs against infertility in Women and men, respectively.

Vitamin D binding protein correlate with estrogen increase after administration of human chorionic gonadotropin but do not affect ovulation, embryo, or pregnancy outcomes

Background

Vitamin D binding protein (DBP) might increase substantially after ovarian stimulation and hence could be associated with IVF/ICSI outcomes because it determines the fraction of free bioavailable 25(OH) vitamin D. In this study, we aim to determine whether DBP is associated with E2 level after ovarian stimulation and IVF/ICSI outcomes.

Design

Post-hoc analysis of a prospective observational cohort.

Setting

Single-center study.

Participants

2569 women receiving embryo transfer.

Intervention

None.

Main outcome measures

The main outcomes were oocyte and embryo quality as well as pregnancy outcomes.

Results

DBP concentration correlates with E2 on hCG day (=day of inducing ovulation with hCG; correlation coefficient r = 0.118, P<0.001) and E2 x-fold change to baseline level (r = 0.108, P<0.001). DBP is also positively correlated with total 25(OH)D (r = 0.689, R2 = 0.475, P<0.001) and inversely with free 25(OH)D (r=-0.424, R2=0.179, P<0.001), meaning that E2-stimulated DBP synthesis results in a decrease of free 25(OH)D during ovarian stimulation. However, such alteration does not affect IVF/ICSI outcomes when considering confounding factors, such as the number and quality of oocytes nor embryo quality as well as pregnancy outcomes.

Conclusion

DBP concentration correlates with the degree of E2 increase after ovarian stimulation. DBP is also positively correlated with total 25(OH)D and inversely with free 25(OH)D, suggesting that the proportion of free 25(OH)D decreases during ovarian stimulation caused by E2-stimulated DBP synthesis. However, such alteration does not affect clinical IVF/ICSI outcomes.

Discovery of Pathogenic Variants Associated with Idiopathic Recurrent Pregnancy Loss Using Whole-Exome Sequencing

Idiopathic recurrent pregnancy loss (RPL) is defined as at least two pregnancy losses before 20 weeks of gestation. Approximately 5% of pregnant couples experience idiopathic RPL, which is a heterogeneous disease with various causes including hormonal, chromosomal, and intrauterine abnormalities. Although how pregnancy loss occurs is still unknown, numerous biological factors are associated with the incidence of pregnancy loss, including genetic variants. Whole-exome sequencing (WES) was conducted on blood samples from 56 Korean patients with RPL and 40 healthy controls. The WES data were aligned by means of bioinformatic analysis, and the detected variants were annotated using machine learning tools to predict the pathogenicity of protein alterations. Each indicated variant was confirmed using Sanger sequencing. A replication study was also conducted in 112 patients and 114 controls. The Variant Effect Scoring Tool, Combined Annotation Dependent Depletion tool, Sorting Intolerant from Tolerant annotation tool, and various databases detected 10 potential variants previously associated with spontaneous abortion genes in patients by means of a bioinformatic analysis of WES data. Several variants were detected in more than one patient. Interestingly, several of the detected genes were functionally clustered, including some with a secretory function (mucin 4; MUC4; rs200737893 G>A and hyaluronan-binding protein 2; HABP2; rs542838125 G>T), in which growth arrest-specific 2 Like 2 (GAS2L2; rs140842796 C>T) and dynamin 2 (DNM2; rs763894364 G>A) are functionally associated with cell protrusion and the cytoskeleton. ATP Binding Cassette Subfamily C Member 6 (ABCC6) was the only gene with two variants. HABP2 (rs542838125 G>T), MUC4 (rs200737893 G>A), and GAS2L2 (rs140842796 C>T) were detected in only the patient group in the replication study. The combination of WES and machine learning tools is a useful method to detect potential variants associated with RPL. Using bioinformatic tools, we found 10 potential variants in 9 genes. WES data from patients are needed to better understand the causes of RPL.

CPY27B1-related vitamin D deficiency contributes to the impaired function of CD4+T cells in Recurrent spontaneous miscarriage

The study aimed to explore the relationship between the expression of cytochrome P450 family 27 subfamily B member 1 (CYP27B1), vitamin D, and impaired T cell subsets in recurrent spontaneous miscarriage (RSM). A Total of 779 healthy women of childbearing age and 1031 women with a history of RSM were involved in this study. The results of flow cytometry showed that the proportion of Tregs was higher in healthy women than in the women with RSM. For cytokines, the levels of interleukin-17 (IL-17) and interferon-gamma (IFN-γ) were significantly higher in RSM patients than in healthy women, while IL-10 was notably lower in RSM patients. Furthermore, compared to healthy individuals, RSM patients had lower levels of serum 25(OH)D detected by chemiluminescence. The frequency of Tregs was negatively correlated with 25(OH)D. Specifically, for every 10 ng/ml increase in 25(OH)D, the percentage of Tregs increased by 0.58 as calculated. IL-17 and IFN-γ were inversely correlated with 25(OH)D, while the serum interleukin-10 (IL-10) level was positively correlated with 25(OH)D. CYP27B1 was found to be expressed in both cytotrophoblast and extracellular villi trophoblast cells. However, reduced expression of CYP27B1 was observed in the placenta with RSM. Notably, the level of 25(OH)D increased in the supernatant of CYP27B1 knockdown BeWo compared to normal cells, while human chorionic gonadotropin (hCG) was significantly reduced. The hCG secretion of CYP27B1 KO BeWo cells was partially restored after 1,25(OH)2D3 supplementation. In addition, 1,25(OH)2D3 treatment could induce more CD4+ T cells to convert to Foxp3+iTreg, which in turn inhibited the secretion of IL-17, IFN-γ. In summary, this research unveiled a connection between reduced CYP27B1 and vitamin D deficiency in RSM. Our study underscores the potential benefits of vitamin D treatment supplementation in the context of RSM. However, it is important to note that further research is imperative to validate these observations.

Transcriptome analysis of adenomyosis eutopic endometrium reveals molecular mechanisms involved in adenomyosis-related implantation failure and pregnancy disorders

BACKGROUND

Women with adenomyosis are characterized by having defective decidualization, impaired endometrial receptivity and/or embryo-maternal communication, and implantation failure. However, the molecular mechanisms underlying adenomyosis-related infertility remain unknown, mainly because of the restricted accessibility and the difficult preservation of endometrial tissue in vitro. We have recently shown that adenomyosis patient-derived endometrial organoids, maintain disease-specific features while differentiated into mid-secretory and gestational endometrial phase, overcoming these research barriers and providing a robust platform to study adenomyosis pathogenesis and the associated molecular dysregulation related to implantation and pregnancy disorders. For this reason, we aim to characterize the dysregulated mechanisms in the mid-secretory and gestational endometrium of patients with adenomyosis by RNA-sequencing.

METHODS

Endometrial organoids were derived from endometrial biopsies collected in the proliferative phase of women with adenomyosis (ADENO) or healthy oocyte donors (CONTROL) (n = 15/group) and differentiated into mid-secretory (-SECorg) and gestational (-GESTorg) phases in vitro. Following RNA-sequencing, the significantly differentially expressed genes (DEGs) (FDR < 0.05) were identified and selected for subsequent functional enrichment analysis and QIAGEN Ingenuity Pathway Analysis (IPA). Statistical differences in gene expression were evaluated with the Student's t-test or Wilcoxon test.

RESULTS

We identified 1,430 DEGs in ADENO-SECorg and 1,999 DEGs in ADENO-GESTorg. In ADENO-SECorg, upregulated genes included OLFM1, FXYD5, and RUNX2, which are involved in impaired endometrial receptivity and implantation failure, while downregulated genes included RRM2, SOSTDC1, and CHAC2 implicated in recurrent implantation failure. In ADENO-GESTorg, upregulated CXCL14 and CYP24A1 and downregulated PGR were related to pregnancy loss. IPA predicted a significant inhibition of ID1 signaling, histamine degradation, and activation of HMGB1 and Senescence pathways, which are related to implantation failure. Alternatively, IPA predicted an inhibition of D-myo-inositol biosynthesis and VEGF signaling, and upregulation of Rho pathway, which are related to pregnancy loss and preeclampsia.

CONCLUSIONS

Identifying dysregulated molecular mechanisms in mid-secretory and gestational endometrium of adenomyosis women contributes to the understanding of adenomyosis-related implantation failure and/or pregnancy disorders revealing potential therapeutic targets. Following experimental validation of our transcriptomic and in silico findings, our differentiated adenomyosis patient-derived organoids have the potential to provide a reliable platform for drug discovery, development, and personalized drug screening for affected patients.

Ectopic pregnancy: search for biomarker in salivary proteome

Ectopic pregnancy (EP) is associated with high maternal morbidity and mortality. Ultrasonography is the only dependable diagnostic tool for confirming an ectopic pregnancy. In view of inadequate early detection methods, women suffer from a high-life risk due to the severity of EP. Early detection of EP using pathological/molecular markers will possibly improve clinical diagnosis and patient management. Salivary proteins contain potential biomarkers for diagnosing and detecting various physiological and/or pathological conditions. Therefore, the present investigation was designed to explore the salivary proteome with special reference to EP. Gel-based protein separation was performed on saliva, followed by identification of proteins using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS). Totally, 326 proteins were identified in the salivary samples, among which 101 were found to be specific for ruptured ectopic pregnancy (EPR). Reactome analysis revealed innate immune system, neutrophil degranulation, cell surface interactions at the vascular wall, and FCERI-mediated NF-kB activation as the major pathways to which the salivary proteins identified during EPR are associated. Glutathione-S-transferase omega-1 (GSTO1) is specific for EPR and has been reported as a candidate biomarker in the serum of EPR patients. Therefore, saliva would be a potential source of diagnostic non-invasive protein biomarker(s) for EP. Intensive investigation on the salivary proteins specific to EP can potentially lead to setting up of a panel of candidate biomarkers and developing a non-invasive protein-based diagnostic kit.

Maternal vitamin D deficiency in early pregnancy and perinatal and long-term outcomes

Background

Vitamin D deficiency is common in pregnant women. Some studies have linked vitamin D deficiency to obstetric complications such as gestational hypertension, gestational diabetes, and preterm birth. Therefore, the objective of this study is to investigate the potential impact of vitamin D deficiency during pregnancy on both perinatal and long-term outcomes.

Methods

In this retrospective study, conducted between 2017 and 2021, we analyzed the data of 1079 singleton pregnant women with no medical or surgical complications prior to pregnancy. We evaluated obstetric and perinatal outcomes, as well as neurodevelopmental outcomes using Bayley-III tests, Gross Motor Function Measure, or chart review.

Results

The maternal serum vitamin D level in the first trimester was 18.2 ± 9.0 ng/mL. Vitamin D deficiency (<20 ng/mL) was found in 308 (62.0%) women in the first trimester, of which 288 women (26.7%) were in the very deficient group (<10 ng/mL). There were no differences in maternal age, body mass index, and previous preterm birth between the group with vitamin D < 10 ng/mL and ≥10 ng/mL group. There were also no differences in the rates of gestational hypertension, gestational diabetes, and preterm birth between the two groups, except for the rate of preterm birth before 37 weeks of gestation, which was significantly higher in the very deficient group (adjusted odds ratios [aOR] = 7.78, 95%CI [2.23-27.12], p = 0.001). In the very deficient group, the risk of developmental delay was also higher (aOR = 4.28, 95%CI [1.40-13.05], p = 0.011).

Conclusions

This is the first study to analyze the effects of maternal vitamin D deficiency during pregnancy on both long-term developmental outcomes and perinatal prognosis. Vitamin D deficiency, defined as a level lower than 10 ng/mL in the first trimester, may increase the risk of preterm birth and developmental delay in children.

Association between female circulating heavy metal concentration and abortion: a systematic review and meta-analysis

Objective

This study aimed to evaluate the association between blood heavy metal (zinc (Zn), copper (Cu), lead (Pb), and cadmium (Cd)) concentrations and spontaneous abortion (SA) and recurrent pregnancy loss (RPL) and explore the possible endocrine dysfunction associated with it.

Methods

A literature search was performed in the PubMed, Embase, Cochrane Library, and Web of Science databases up to April 2023. The overall effects were expressed as the standard mean difference (SMD). Subgroup analysis was performed according to the type of abortion (SA or RPL). Stata 16.0 was utilized for data analysis.

Results

Based on the integrated findings, abortion women showed significantly lower Zn (SMD = -1.05, 95% CI: -1.74 to -0.36, p = 0.003) and Cu concentrations (SMD = -1.42, 95% CI: -1.97 to -0.87, p <0.001) and higher Pb (SMD = 1.47, 95% CI: 0.89-2.05, p <0.001) and Cd concentrations (SMD = 1.15, 95% CI: 0.45-1.85, p = 0.001) than normal pregnant women. Subgroup analysis showed that Zn and Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with RPL, whereas Cu deficiency and Cd and Pb exposure were significantly (p <0.05) associated with SA.

Conclusion

Zn and Cu deficiencies and Pb and Cd exposure were associated with abortion. Endocrine dysfunction, such as insulin resistance, vitamin D insufficiency, and abnormal thyroid and sex hormone concentrations, is thought to be involved in heavy metal-related abortion.

Exploration of fetal growth restriction induced by vitamin D deficiency in rats via Hippo-YAP signaling pathway

INTRODUCTION

Maternal vitamin D deficiency (VDD) is associated with intrauterine growth restriction (IUGR), but the exact mechanism remains unclear. Here we explored the mechanism through which VDD induced IUGR.

METHODS

Female SD rats were fed a control normal diet (VD > 800 IU/Kg) or VDD diet (VD: 0 IU/Kg) for 8 weeks. Then, females were mated with 12-week-old male SD rats, and fetal and placental tissue were collected on the gestational day 13 (GD13) or 18 (GD18) to analyze the effects of VDD on pregnancy outcome and embryonic development. In vitro, the VDR gene of HTR-8/SVneo cells was knocked down to establish VDD model. Then, HTR-8/SVneo cells were treated with the MST1/2 inhibitor XMU-MP-1 or 0.1 μM/L calcitriol for 24 h (h). The mechanism of Hippo-YAP signaling pathway in VDD-induced placental dysplasia was further investigated by western blot, invasion assay, wound healing assay and Hoechst/PI staining.

RESULTS

The IUGR of the pregnant rats in the VDD group was significant, the placental structure and function were damaged, and there was an obvious inflammatory response, accompanied by a significant increase in the level of the transcription co-activator YAP phosphorylation. In vitro, VDD significantly inhibited the migratory and invasive abilities of HTR-8/SVneo cells, accompanied by decreased EMT capacity and increased apoptosis. When intervening with XMU-MP-1 in advance, we found that the effects of VDD were neutralized by Hippo-YAP signaling blocker.

DISCUSSION

Maternal VDD causes placental dysplasia and IUGR, and these abnormal changes may be associated with the activation of Hippo-YAP signaling pathway.

The role of vitamin D-synthesizing enzyme CYP27B1 in systemic lupus erythematosus

BACKGROUND

To measure the expression of 1α-hydroxylase (CYP27B1) and serum 25(OH)D concentration in systemic lupus erythematosus (SLE) and to investigate the role of CYP27B1 in SLE.

METHODS

Seventy-seven SLE patients and 35 healthy controls (HCs) were enrolled from September 2017 to January 2020. The study design is cross-sectional. mRNA expression of CYP27B1 in peripheral blood mononuclear cells (PBMCs) was measured by reverse-transcription quantitative PCR, the protein level of CYP27B1 was quantified by western blotting, and the serum level of 25(OH) D was determined by an enzyme-linked immunosorbent assay.

RESULTS

The mRNA expression of CYP27B1 in PBMCs was significantly lower in SLE patients than in HCs (p < 0.001), and the protein quantification confirmed that CYP27B1 expression was lower in SLE patients than in HCs (p = 0.001). Among SLE patients, the prevalence of lupus nephritis was higher in a subgroup with lower CYP27B1 mRNA expression than in a subgroup with normal CYP27B1 mRNA expression (41.07% vs. 14.28%, p = 0.028). The mRNA expression of CYP27B1 negatively correlated with the Systemic Lupus Erythematosus Disease Activity Index (r = -0.331, p = 0.003). Serum 25(OH)D concentration was lower in SLE patients than in HCs (37.64 ± 19.89 vs. 50.58 ± 12.74 ng/mL, mean ± SD, p = 0.003).

DISCUSSION

The expression of CYP27B1 in PBMCs may be related to SLE pathogenesis, disease activity, and nephritis.

Altered vitamin D metabolism is involved in the dysregulation of γδT cell function and their crosstalk with trophoblasts in recurrent pregnancy loss

BACKGROUND

Recurrent pregnancy loss (RPL) is a common disease characterized by immune dysfunction and vitamin D deficiency. This study aimed to investigate vitamin D metabolism and γδT cell phenotypes at the maternal-fetal interface in women with early normal pregnancy (NP) and RPL and to determine the effects of vitamin D on the functions of γδT cells and their crosstalk with trophoblasts.

METHODS

The levels of 25-(OH)VD₃ , the expression of vitamin D metabolic enzymes in the villi, and the proportion of γδT cells in the decidua were detected in women with NP and RPL. After treatment with different concentrations of vitamin D, the mRNA expression of the vitamin D receptor (VDR), cytokines, and transcription factors was detected in Vδ2⁺ γδT cells. In addition, the proliferation, migration, and invasion of HTR-8/SVneo trophoblasts were determined by co-culturing them with vitamin D-treated Vδ2⁺ γδT cells and their supernatants.

RESULTS

In women with RPL, the level of 25-(OH)VD₃ in the villi was increased; however, that of CYP27B1 (enzyme converting 25-(OH)VD₃ into 1,25-(OH)₂ VD₃ ) was decreased. In addition, the proportion of Vδ2⁺ γδT cells increased, whereas that of Foxp3⁺ Vδ2⁺ γδT cells decreased in the decidua of women with RPL. An in vitro study showed that vitamin D increased the expression of VDR mRNA and Foxp3, but decreased the expression of IFN-γ mRNA, in Vδ2⁺ γδT cells. Finally, vitamin D-treated Vδ2⁺ γδT cells promoted trophoblast migration and invasion.

CONCLUSIONS

Abnormal vitamin D metabolism and γδT cell proportions were present at the maternal-fetal interface in women with RPL. Under normal pregnancy conditions, vitamin D can induce the differentiation of decidual Vδ2⁺ γδT cells toward an anti-inflammatory phenotype (Treg-like γδT cells) and modulate the crosstalk between Vδ2⁺ γδT cells and trophoblasts. This article is protected by copyright. All rights reserved.

Effects of Vitamin D on Fertility, Pregnancy and Polycystic Ovary Syndrome-A Review

Polycystic ovary syndrome (PCOS) is one of the most common endocrine reproductive disorders in women. Vitamin D deficiency is also quite common in this condition. The degree of vitamin D deficiency correlates with the severity of PCOS. Both male and female vitamin D levels play a role in fertility and affect the outcomes of in vitro fertilization (IVF). Moreover, fertility and IVF indicators are improved by vitamin D not only in healthy women but in those diagnosed with PCOS. Both vitamin D deficiency and PCOS increase pregnancy-related complications. Vitamin D supplementation and optimal vitamin D levels decrease both maternal and fetal risk for complications and adverse events. Furthermore, vitamin D supplementation may ameliorate or even prevent pregnancy-related reversible bone loss in mothers. This review emphasizes the roles of vitamin D deficiency and vitamin D supplementation and their correlation with PCOS regarding reproductive health.

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.

HMGB1 regulates lipopolysaccharide-induced cellular dysfunction in HTR8/SVneo cells: Implications for the role of HMGB1 in unexplained spontaneous miscarriage

INTRODUCTION

Approximately half of miscarriages are of an unknown aetiology and are likely characterized by aberrant inflammation at the uteroplacental interface. High mobility group box 1 (HMGB1) is a ubiquitous nuclear protein that participates in the pathological inflammatory response. The present study investigated the role of HMGB1 in inflammation-induced damage in trophoblasts and elucidated the underlying mechanism.

METHODS

Immunohistochemistry, qRT-PCR and Western blotting were used to detect the expression of HMGB1 in early unexplained miscarriage and normal placentas. Lipopolysaccharide (LPS)-induced HTR8/SVneo cells were used as an in vitro model to mimic the aberrant inflammation at the uteroplacental interface of miscarriage. The expression of HMGB1 and the autophagy-related proteins LC3 and Beclin1 was detected using Western blotting. Autophagy was studied in villous tissues using immunofluorescence and Western blotting. Cell proliferation and migration were analysed.

RESULTS

The expression level of HMGB1 in villous tissues with early unexplained miscarriage was significantly higher than the normal pregnancy group. The inhibition of HMGB1 in LPS-treated HTR8/SVneo cells decreased the expression of Beclin 1 and LC3, which promoted cell proliferation and migration. We found a high level of autophagy in miscarriage placentas. HMGB1 and autophagy inhibition reversed the proliferation and migration of LPS-induced HTR-8/SVneo cells.

DISCUSSION

Our results demonstrated that HMGB1 participated in LPS-induced inflammation via autophagy and regulated trophoblast functions, such as cell proliferation and migration, to potentially participate in the pathogenesis of miscarriage.

Complementary and Alternative Medicine for Threatened Miscarriage: Advantages and Risks

Threatened miscarriage is one of the most common complications causing pregnancy loss, and it affects approximately 20% of confirmed pregnancies. More and more women are seeking treatment with complementary and alternative medicine (CAM) for this common complication, and it has been reported that women have had successful pregnancies after threatened miscarriage when being treated with CAM, which mainly includes Chinese herbal medicines, acupuncture, and nutritional supplements as well as psychological interventions and other approaches. However, many experts are concerned about the safety and adverse events of certain CAM approaches in women with threatened miscarriage. Therefore, this review focuses on the status of CAM for threatened miscarriage and presents the potential therapeutic efficacy and safety of CAM based on some clinical and experimental studies. We thus hope to provide some instructive suggestions for the application of CAM for treating threatened miscarriage in the future.

Vitamin D receptor gene polymorphisms and haplotypes in the etiology of recurrent miscarriages

A few years ago it was shown that disturbed metabolism of the vitamin D/receptor (VD/VDR) complex may be important in the etiology of spontaneous abortion, as well as in the etiology of recurrent miscarriages (RM). The goal of this study was to investigate the association between four maternal VDR polymorphisms as well as haplotypes settings and RM occurrence in a Polish population of women in reproductive age. A total of 230 women were recruited to this study (110 with RM, 120 consecutively recruited age-matched healthy women with at least two full-term pregnancies and with no history of miscarriages). DNA samples were genotyped for VDR polymorphisms: FokI (rs2228570), BsmI (rs1544410), ApaI (rs7975232) and TaqI (rs731236). Significant differences in genotype distributions and allele frequencies between case and control groups were observed in VDR BsmI polymorphism (GG vs. GA and AA, OR = 0.56, p = 0.036 and OR = 1.49, p = 0.035, respectively). The best evidence of an association with RM prevention was observed for the TTGT haplotype, which was more frequent among controls than cases even after permutation test (0.09 vs. 0.017, p = 0.0024). Other haplotypes were also significantly more frequent in the control group: TGT (rs7975232, rs1544410, rs2228570), TG (rs7975232, rs1544410), TTG (rs731236, rs7975232, rs1544410), TT (rs731236, rs7975232). Our research indicated the possible role of VDR BsmI genetic polymorphism in RM etiology, suggesting at the same time the active role of maternal VD metabolism and its influence on pregnancy outcome. The significant influence of several maternal haplotypes was shown to prevent RM occurrence.

Vitamin D insufficiency as a risk factor for reproductive losses in miscarriage

OBJECTIVE

To study the relationship between vitamin D deficiency, VDR gene polymorphism rs10735810 (A > G), and a missed abortion in the first trimester of gestation; to determine the predictors of its risk.

RESEARCH METHODS

178 women aged between 18 and 41 were surveyed. The main group consisted of patients with miscarriage (n = 101), verified at the hospital stage (O02.0; O02.1), which were stratified by I group (n = 58, patients with the first miscarriage) and II groups (n = 43, patients with repeated miscarriage). The control group (n = 77) consisted of women with a successful pregnancy (Z34.0), which subsequently ended in delivery at term with a live fetus. Patients were surveyed and data was extracted from primary medical records. The level of 25(OH)D in the blood serum was investigated by mass spectrometry (n = 99). Genotyping for the vitamin D receptor gene polymorphism rs10735810 (VDR A > G) was performed for 177 patients. Statistical data analysis was performed via Statistica 10 and SAS JMP 11 application packages, using single-factor prediction for quantitative and binary factors, ROC analysis, and CHAID decision tree construction.

RESULTS OF THE STUDY

WE found that patients with miscarriage in the first trimester of gestation (n = 60) more frequently than those in the control group (n = 39) had vitamin D insufficiency (93.3% versus 76.9%, p = .0183) including its deficiency, occurring at 25(OH)D of blood <20 ng/ml (71.7% versus 51.3%, p = .0392). This pattern was found in patients with the first miscarriage, where significant differences in the frequency of vitamin D deficiency were also detected in comparison with the control group (80.0% versus 51.3%, p = .0026). No direct correlation was found between the frequency of miscarriages in the first trimester and the variant of the polymorphism of the vitamin D receptor gene (VDR A > G [rs10735810]); the GG genotype in patients with repeated miscarriages was even less frequent compared to the control group (14.0% versus 23.7%, p = .3344). However, the decision tree has identified four risk classes and has determined that the highest risk of missed abortion in the cohort studied is formed by three predicates: smoking, serum level 25(OH)D < 6.5 ng/ml and VDR AA and GG genotypes.

CONCLUSION

The data obtained show that vitamin D insufficiency plays a pathogenetically significant role in early reproductive losses associated with miscarriages, both first and recurrent.

Features of the 1st trimester of pregnancy course with severe deficiency of 25(OH)D

INTRODUCTION

The course of physiological pregnancy is provided by many complementary factors. Thus, a deficiency in one of the links of the metabolic network contributes to the development of an imbalance in the work of the whole organism, which ensures the growth and development of the embryo from the first days of gestation. It has been demonstrated that vitamin D can act as an immune regulator during implantation, providing a protective effect in the entire period of pregnancy.

OBJECTIVE

The aim of this study is to assess the features of the course of pregnancy in patients with different levels of vitamin D in the blood in the first trimester.

MATERIALS AND METHODS

A prospective multicenter randomized study was conducted in the North-West region of the Russian Federation among 88 pregnant women in the first trimester of gestation (up to 13 weeks). All patients were divided into 3 groups depending on the initial level of vitamin D (group 1-14 women with a 25(OH)D < 10 ng/ml, group 2-62 pregnant women from 10 to 30 ng/ml, group 3-12 pregnant women with a vitamin D content >30 ng/ml).

INTERVENTIONS

Criteria of inclusion: pregnant women from 20 to 44 years of the first trimester of gestation (up to 13 weeks) with the studied level of vitamin D in the blood serum; singleton pregnancy; BMI ≤30 kg/m2; signing by the patient of informed consent for inclusion in the study group.

MAIN OUTCOME MEASURES AND RESULTS

In group 1, 86% of patients with severe vitamin D deficiency were diagnosed with threatened miscarriage, which is significantly higher than in group 3 (85.7% and 33.3%, χ² = 7.490, p = .007). At the same time, retrochorial hematoma in group 1 occurred 3.5 times more often than in group 3 (57.1% and 16.67%, respectively, χ² = 4.473, p = .035). Subsequently, every 4^th woman from the group with vitamin D deficiency gave birth earlier than expected, which was not observed among patients from group 3 (25%, 0%, χ² = 1.231, p = .268).

CONCLUSION

Prescribing cholecalciferol vitamin replacement therapy as part of complex preserving therapy for threatening miscarriage, followed by monitoring its blood level and deviating from normal parameters, contributing to a favorable course of pregnancy and improving perinatal outcomes.

Vitamin D Promotes Trophoblast Cell Induced Separation of Vascular Smooth Muscle Cells in Vascular Remodeling via Induction of G-CSF

Vitamin D deficiency is associated with complications of pregnancy such as pre-eclampsia, fetal growth restriction, and miscarriage, all of which are also associated with incomplete spiral artery (SpA) remodeling. We have previously shown that both uterine natural killer (uNK) cells and extravillous trophoblast cells (EVT) are required for successful SpA remodeling, but whether their activity in this process is modulated by vitamin D is not known. In the current study, we use a previously described chorionic plate artery (CPA) ex vivo model of vascular remodeling to determine the effects of 1,25(OH)₂D treated uNK cell, placental explant (PEx), and uNK/PEx conditioned medium (CM) on vascular smooth muscle cell (VSMC) disorganization and phenotypic switching. Significant results were followed up in VSMCs in vitro. We demonstrate that 1,25(OH)₂D can enhance the ability of PEx to induce SpA remodeling, via a mechanism associated with increased secretion of granulocyte-colony stimulating factor (G-CSF). G-CSF appears able to increase VSMC disorganization and phenotypic switching in both an ex vivo vascular model and in vitro VSMC cultures. The clinical relevance of these findings are still to be determined. G-CSF may have differential effects depending on dose and vascular bed, and vitamin D may play a role in potentiating these actions. G-CSF may be an interesting potential therapeutic target for facilitating physiological vascular remodeling for the prevention of adverse obstetric outcomes.

Role of Slit2 upregulation in recurrent miscarriage through regulation of stromal decidualization

INTRODUCTION

Knockout mouse model has shown a relationship between Slit2/Robo1 signalling and altered fertility. Altered expression by endometrial epithelium and trophoblast and is associated with the pathogenesis of pregnancy complications but few studies have investigated the expression of decidual Slit2 in miscarriage.

METHODS

Expression profiles of Slit2 and Robo1 were measured in human endometrial tissues during the menstrual cycle phases (n = 30), in decidua tissues from recurrent miscarriage (n = 20) and healthy control (n = 20) at 6-8 weeks of gestation. The hormonal regulation of Slit2/Robo1 expression and the role of Slit2/Robo1 signalling in decidualization was investigated in vitro, along with its effects on β-catenin and MET expression.

RESULTS

In human endometrium, Slit2 and Robo1 protein expression in stromal cells were decreased between the late-proliferative and early-secretory phase. In recurrent miscarriage patients, decidual expression Slit2 was increased and associated with lower expression of E-cadherin and higher level vimentin compared to controls. In vitro, the expression of Slit2 was downregulated by cAMP and progesterone in hESCs. Upregulation of Slit2 resulted in inhibition of cell decidualization and β-catenin translocation to nucleus.

DISCUSSION

This study indicates a functional role for Slit2 in endometrial stromal cell decidualization and the pathogenesis of recurrent miscarriage. Aberrant Increase in Slit2 expression may impairs decidualization of endometrial stromal cells leading to recurrent in recurrent miscarriage.

Vitamin D-Binding Protein in Pregnancy and Reproductive Health

Vitamin D-binding protein (VDBP), the main carrier of vitamin D, has recently been implicated in reproductive health and pregnancy outcomes including endometriosis, polycystic ovary syndrome (PCOS), pre-eclampsia, and gestational diabetes mellitus (GDM). Improved methods for measuring VDBP and an increased understanding of its role in biological processes have led to a number of newly published studies exploring VDBP in the context of pregnancy. Here, we synthesize the available evidence regarding the role of VDBP in reproductive health and pregnancy, and we highlight areas requiring further study. Overall, low levels of maternal serum VDBP concentrations have been associated with infertility, endometriosis, PCOS and spontaneous miscarriage, as well as adverse pregnancy outcomes including GDM, pre-eclampsia, preterm birth and fetal growth restriction. However, increased VDBP concentration in cervicovaginal fluid has been linked to unexplained recurrent pregnancy loss and premature rupture of membranes. Some genetic variants of VDBP have also been associated with these adverse outcomes. Further studies using more accurate VDBP assays and accounting for ethnic variation and potential confounders are needed to clarify whether VDBP is associated with reproductive health and pregnancy outcomes, and the mechanisms underlying these relationships.