Evaluation of 1,25(OH)2D3 Effects on FOXP3, ROR-γt, GITR, and CTLA-4 Gene Expression in the PBMCs of Vitamin D-Deficient Women with Unexplained Recurrent Pregnancy Loss (URPL)

Associations between 25 hydroxyvitamin D concentration and spontaneous abortion

BACKGROUND

Spontaneous abortion is a common complication of pregnancy that can lead to adverse physical and psychological outcomes for women. Vitamin D is reported to be associated with reproductive functions, whereas its casual effects on abortion remains unclear.

MATERIALS AND METHODS

In this study, a two-sample Mendelian randomization (MR) analysis was performed to systematically assess the causal relationships between serum 25 hydroxyvitamin D [25(OH)D] concentration and the risk of spontaneous abortion. GWAS summary data of 25(OH)D were used as exposure, and data of spontaneous abortion was considered as outcome. A retrospective study was additionally conducted to verify the MR results.

RESULTS

MR estimates showed that a higher 25(OH)D level was potentially associated with decreased risk of spontaneous abortion (IVW, OR = 0.98, 95%CI = 0.90-1.06; MR Egger, OR = 0.94, 95%CI = 0.84-1.05; Weighted median, OR = 0.93, 95%CI = 0.82-1.06; Weighted mode, OR = 0.93, 95%CI = 0.84-1.03), though the P-value was not statistically significant. The retrospective study also produced consistent result of Vitamin D's protective role to spontaneous abortion. The P-value was very close to statistical significance (P = 0.053).

CONCLUSIONS

This study reports the potential protective role of serum 25(OH)D concentration to spontaneous abortion, suggesting that increased vitamin D levels may decrease the risk of abortion. Further larger prospective studies and/or even randomized controlled trials are needed to confirm causal relationship between vitamin D and abortion.

Vitamin D, Th17 Lymphocytes, and Breast Cancer

Simple Summary

The effect of vitamin D₃ on the development of breast cancer (favorable, ineffective, or even unfavorable) depends on many factors, such as age, menopausal status, or obesity. The immunomodulatory effect of vitamin D may be unfavorable in case of breast cancer progression. The effect of vitamin D on Th17 cells may depend on disease type and patients’ age. Our goal was to summarize the data available and to find indications of vitamin D treatment failure or success. Therefore, in this review, we present data describing the effects of vitamin D₃ on Th17 cells, mainly in breast cancer.

Abstract

Vitamin D₃, which is well known to maintain calcium homeostasis, plays an important role in various cellular processes. It regulates the proliferation and differentiation of several normal cells, including immune and neoplastic cells, influences the cell cycle, and stimulates cell maturation and apoptosis through a mechanism dependent on the vitamin D receptor. The involvement of vitamin D₃ in breast cancer development has been observed in numerous clinical studies. However, not all studies support the protective effect of vitamin D₃ against the development of this condition. Furthermore, animal studies have revealed that calcitriol or its analogs may stimulate tumor growth or metastasis in some breast cancer models. It has been postulated that the effect of vitamin D₃ on T helper (Th) 17 lymphocytes is one of the mechanisms promoting metastasis in these murine models. Herein we present a literature review on the existing data according to the interplay between vitamin D, Th17 cell and breast cancer. We also discuss the effects of this vitamin on Th17 lymphocytes in various disease entities known to date, due to the scarcity of scientific data on Th17 lymphocytes and breast cancer. The presented data indicate that the effect of vitamin D₃ on breast cancer development depends on many factors, such as age, menopausal status, or obesity. According to that, more extensive clinical trials and studies are needed to assess the importance of vitamin D in breast cancer, especially when no correlations seem to be obvious.

Evaluation of Th17 and Treg cytokines in patients with unexplained recurrent pregnancy loss

Background and Aim

The Th17/Treg balance in peripheral blood and reproductive tissues may have a role in the etiology of unexplained recurrent pregnancy loss (URPL). In this study, we evaluated the major cytokine of Treg cells transforming growth factor-beta (TGF-β), and their specific transcription factor Forkhead box P3 (FOXP3), as well as the most highlighted cytokine of Th17 cells (interleukin [IL]-17A) in both URPL patients and healthy women.

Methods

Samples were extracted from the peripheral blood, endocervix, endometrium, and vagina of 14 patients with URPL and 12 normal non-pregnant women as a control (normal) group. Quantitative reverse transcription polymerase chain reaction was used to determine gene expression. Enzyme-linked immunosorbent assay was used to determine the levels of cytokines in the serum and cervicovaginal fluid.

Results

We found that in the URPL group, FOXP3 gene expression was considerably higher in peripheral blood than in the normal group (P=0.043). TGF-β levels in the cervicovaginal fluid were different in the URPL and normal groups (P=0.015). In comparison to the control group, women with URPL had significantly greater IL-17 gene expression in the peripheral blood (P=0.01).

Conclusion

Lower TGF-β levels in the cervicovaginal fluid of patients compared to controls may be related with increased IL-17 and FOXP3 mRNA levels in patients with URPL. Dysregulation of local immune responses in reproductive tissues may represent dysregulation of systemic regulatory immunological responses in the pathogenesis of URPL.

Relevance for Patients

Dysregulation of immune responses may play a role in the pathogenesis of URPL at least in some patients with URPL. We conclude that the breakdown of tolerance in the local immune responses is more critical than the breakdown of tolerance in systemic tolerance in the pathogenesis of URPL. Therefore, modulating immune responses in the endometrium and decidua may be the focus of future therapeutic approaches in URPL. The impact of seminal plasma on the expansion of Tregs may provide a novel therapeutic intervention that has already been used in assisted reproductive technologies. Therefore, we suggest that transvaginal TGF-β in women with URPL may induce maternal tolerance which leads to the successful pregnancy.

Evaluating Vitamin D and foxp3 mRNA levels in women with recurrent spontaneous abortion

OBJECTIVE

This current survey investigated the role of the Forkhead 3 box protein (foxp3) gene and serum vitamin D levels in women with recurrent spontaneous abortion (RSA).

METHODS

The mRNA level of the foxp3 gene in peripheral blood was evaluated in women with a history of RSA (N=40) and in controls (N=40) via quantitative polymerase chain reaction. We employed the enzyme-linked immunosorbent assay to assess the serum levels of 1,25-dihydroxyvitamin D3 (1,25(OH)2 D) in both groups. The Mann-Whitney U test and Pearson's correlation coefficient were used to statistically compare study groups between and within themselves, respectively.

RESULTS

Although mRNA levels of foxp3 were higher in women with RSA than in controls, we observed no significant change in mRNA levels of foxp3 between the two groups (p=0.16). An important positive correlation was observed between foxp3 mRNA levels and 1,25(OH)2 D in controls (p=0.003). In contrast, the correlation between foxp3 expression and 1,25(OH)2 D was not significant in the case group (p=0.14). Serum vitamin D levels were lower in women with RSA than in controls (p<0.001).

CONCLUSIONS

Our findings demonstrated that 1,25Vitamin D3 along with other molecules might help prevent RSA by providing for an anti-inflammatory state not necessarily through foxp3 expression or T cell differentiation.

The therapeutic potential of regulatory T cells in reducing cardiovascular complications in patients with severe COVID-19

The SARS coronavirus 2 (SARS CoV-2) causes Coronavirus Disease (COVID-19), is an emerging viral infection. SARS CoV-2 infects target cells by attaching to Angiotensin-Converting Enzyme (ACE2). SARS CoV-2 could cause cardiac damage in patients with severe COVID-19, as ACE2 is expressed in cardiac cells, including cardiomyocytes, pericytes, and fibroblasts, and coronavirus could directly infect these cells. Cardiovascular disorders are the most frequent comorbidity found in COVID-19 patients. Immune cells such as monocytes, macrophages, and T cells may produce inflammatory cytokines and chemokines that contribute to COVID-19 pathogenesis if their functions are uncontrolled. This causes a cytokine storm in COVID-19 patients, which has been associated with cardiac damage. Tregs are a subset of immune cells that regulate immune and inflammatory responses. Tregs suppress inflammation and improve cardiovascular function through a variety of mechanisms. This is an exciting research area to explore the cellular, molecular, and immunological mechanisms related to reducing risks of cardiovascular complications in severe COVID-19. This review evaluated whether Tregs can affect COVID-19-related cardiovascular complications, as well as the mechanisms through which Tregs act.

Evaluation of the Effects of 1,25VitD3 on Inflammatory Responses and IL-25 Expression

VitD3 may contribute to a successful pregnancy through modulation of immune responses, so VitD3 deficiency may have a role in the immunopathogenesis of unexplained recurrent spontaneous abortion (URSA). However, the mechanisms of immunomodulatory actions of VitD3 in decreasing the risk of recurrent spontaneous abortion have not been understood well.

Objective: The purpose of this research was to investigate the influence of 1,25VitD3 on IL-25 and related cytokines of Th17 cells including IL-17A, IL-6, and IL-23 in peripheral blood mononuclear cells of healthy women as a control group and women with unexplained recurrent spontaneous abortion.

Method: Isolation of peripheral blood mononuclear cells (PBMCs) was performed from peripheral blood of the subjects of the studied groups (20 women with URSA as a case group, and 20 control women). The effects of 1,25VitD3 (50 nM, for 24 h) on the studied parameters were evaluated and were compared to the positive and negative controls in vitro. Flow cytometry analysis was used to determine the percentages of regulatory T cells and Th17 cells. For gene expression measurement and cytokines assay, real-time PCR and ELISA were carried out.

Results: The proportion of Th17 cells in women with URSA was considerably higher than in the control group. IL-25 mRNA and protein levels in cultured PBMCs from women with URSA were lower than the controls. 1,25VitD3 increased IL-25 expressions at both the protein and mRNA levels in PBMCs from women with URSA relative to the control group. Additionally, 1,25VitD3 treatment not only significantly decreased the percentage of Th17 cells frequency but also reduced expressions of IL-6, IL-17A, and IL-23 in PBMCs from women with URSA.

Conclusion: 1,25VitD3 may diminish inflammatory responses cells via downregulation of IL-25 expression. It could be an interesting subject for future researches in the field of the immunopathology of URSA to identify molecular pathways in URSA treatment.

A novel update on vitamin D in recurrent pregnancy loss (Review)

Recurrent pregnancy loss (RPL) is usually characterized as ≥3 miscarriages before 20 weeks of gestation. Patients with RPL may have autoimmune abnormalities or alloimmune problems. Vitamin D has a major function on the mechanism of immunomodulation at the maternal-fetal interface. However, whether vitamin D can be used as an effective method to treat patients with RPL requires investigation. It has been reported that vitamin D could prevent the occurrence of antiphospholipid syndrome (APS) by reducing the expression levels of anti-β2 glycoprotein and tissue factor in RPL cases with APS. In addition, there is an opposite relationship between vitamin D and thyroid peroxidase antibody levels in autoimmune thyroid disease cases with RPL. Vitamin D changes the ratio of T helper (Th) 1/Th2 and regulatory T cell/Th17 to a certain extent, as well as affects the activity of natural killer cells and the production of cytokines to reduce the incidence of RPL. The objective of the current review was to address the research progress of vitamin D in RPL in recent years, which could facilitate the use of vitamin D treatment to enhance the pregnancy outcome of RPL. Collectively, it was suggested that vitamin D may be used as an important and effective immunotherapeutic agent for patients with RPL.

Cytokine imbalance at materno-embryonic interface as a potential immune mechanism for recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a prominent reproductive disease that distresses about 2%-5% of couples. RPL is the loss of two or more successive spontaneous pregnancies prior to the 20th week of embryo development. The commencement of pregnancy necessitates implantation of the embryo into responsive maternal decidua synchronized with the process of placentation, decidual and myometrial trophoblast incursion as well as refashioning of spiral blood arteries of uterus. The collapse of any of the processes fundamental for pregnancy success may result into an array of pregnancy problems including spontaneous pregnancy loss. Endometrium of human female manufactures an extensive range of cytokines during the proliferative and secretory stage of the menstrual cycle. These endometrial cytokines are thought as major players for making the uterus ready for embryo implantation and placental development during pregnancy. Decidual cytokines regulate the invasion of trophoblast and remodeling of spiral arteries as well as take part in immune suppression to accomplish the pregnancy. Deterrence of maternal rejection of embryo needs a regulated milieu, which takes place essentially at the embryo-maternal interface and the tissues of the uterus. The reasons of RPL remain anonymous in a large number of cases that lead to difficulties in management and severe trauma in couples. Cytokine modulatory therapies have been shown promising for preventing RPL. Further study of novel factors is wanted to establish more effective RPL treatment protocols. The present study aims to review the outcome of cytokine breach at materno-embryonic interface and the efficacy of cytokine modulatory therapies in RPL.