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Clinical and epidemiological evidence supports that pregnancies carrying a male fetus are more vulnerable to infections and preterm birth, probably due to testosterone immunosuppressive properties. In human placentas, testosterone lowers the expression of CYP27B1, the vitamin D (VD)-activating enzyme, diminishing cathelicidin synthesis, a potent VD-dependent antimicrobial peptide (AMP). VD also stimulates other AMPs, including defensins. To get insights into the increased male vulnerability mechanisms, we investigated the relationship between fetal sex and the immunoendocrine milieu at the fetoplacental unit. For this, umbilical vein serum and placental samples were collected from healthy newborns. In males' serum, testosterone levels were significantly higher and negatively associated with TNF-α, a cytokine that strengthens the immune response. Males showed lower serum TNF-α and increased levels and gene expression of the immunosuppressive cytokine IL-10. Only in female samples there was a positive association (P 0.05) between AMPs and both TNF-α and CYP27B1 and between 25-hydroxyvitamin D

Male fetus and neonates show increased immune vulnerability compared to females, which results in a higher risk of perinatal infections. These differences could partially be due to sex steroids differential modulation of vitamin D metabolism; since calcitriol, the most active vitamin D metabolite, regulates immune responses and transcriptionally induces the antimicrobial peptide cathelicidin in the human placenta. Calcitriol availability depends on CYP27B1 and CYP24A1 expression, the cytochromes involved in its synthesis and degradation, respectively. However, the effects of testosterone upon these enzymes and the final biological outcome upon the calcitriol-dependent immune-target cathelicidin in the placenta have not been studied. In this study we show that testosterone significantly inhibited CYP27B1 while stimulated CYP24A1 gene expression in cultured trophoblasts. These effects were accompanied by CREB activation through cAMP-independent and androgen receptor-dependent mechanisms. Male placental cotyledons showed reduced basal CYP27B1 and cathelicidin gene expression compared to females (P

IL-10 and calcitriol help to achieve a successful pregnancy by suppressing active maternal immunity; however, these factors exert opposite effects upon microbial infections. In the skin and immune cells, IL-10 downregulates β-defensins while calcitriol induces cathelicidin gene expression in various tissues including placenta. Though, the regulation of human placental β-defensins by IL-10 and calcitriol has not been studied. Therefore, we explored the regulation of these antimicrobial peptides expression in cultured placental cells by calcitriol and IL-10 alone and combined. Real time PCR showed that calcitriol stimulated, while IL-10 inhibited, β-defensins and cathelicidin gene expression (P

1,25-dihydroxivitamin D3 (calcitriol), is a secoesteroid involved in several placental functions. In particular, we and others showed that calcitriol regulates peptides, proteins, cytokines and hormones production in human trophoblastic cells. On the other hand, calcitriol modifies the activity and expression of some steroidogenic enzymes, a process that is considered tissue-specific. However, the effects of calcitriol on the expression of enzymes involved in the synthesis of sex steroids in placental tissue have not yet been entirely studied. The aim of the present study was to investigate the effects of calcitriol upon gene expression of several steroid enzymes such as cytochrome P450scc (CYP11A1), type 1 3β-hydroxysteroid dehydrogenase(3β-HSDI), 17β-HSD3, 17α-hydroxylase/17,20 lyase (CYP17A1) and aromatase (CYP19A1) in primary cultures of human placental cells. Cell cultures were performed using placentas obtained immediately after delivery by caesarean section from normotensive healthy women and calcitriol effects were evaluated, at level of transcription, by qPCR. The results showed that: 1) from basal expression values of the five genes studied, 3β-HSDI was the most expressed gene (P

Factors affecting vitamin D metabolism may preclude anti-carcinogenic effects of its active metabolite calcitriol. Chronic ethanol consumption is an etiological factor for breast cancer that affects vitamin D metabolism; however, the mechanisms underlying this causal association have not been fully clarified. Using a murine model, we examined the effects of chronic moderate ethanol intake on tumoral and renal CYP27B1 and CYP24A1 gene expression, the enzymes involved in calcitriol synthesis and inactivation, respectively. Ethanol (5% w/v) was administered to 25-hydroxyvitamin D3-treated or control mice during one month. Afterwards, human breast cancer cells were xenografted and treatments continued another month. Ethanol intake decreased renal Cyp27b1 while increased tumoral CYP24A1 gene expression.Treatment with 25-hydroxyvitamin D3 significantly stimulated CYP27B1 in tumors of non-alcohol-drinking mice, while increased both renal and tumoral CYP24A1. Coadministration of ethanol and 25-hydroxyvitamin D3 reduced in 60% renal 25-hydroxyvitamin D3-dependent Cyp24a1 upregulation (P