Does the 2nd and 4th digit ratio reflect prenatal androgen exposure?

OBJECTIVES:  The aim of our study was to describe the effect of prenatal testosterone exposure on 2D:4D in both sexes, and to determine whether this effect is mediated via the androgen receptor. In addition, the sex differences in lengths of 2D, 4D, and 2D:4D ratio were analyzed. BACKGROUND:  Clinical studies suggest a negative correlation between prenatal testosterone exposure and ratio of the lengths of the second and fourth digits (2D:4D). However, less is known about the underlying molecular mechanisms. METHODS:  Pregnant rats were treated with olive oil, testosterone, flutamide or testosterone with flutamide daily from the fourteenth day of pregnancy until delivery. The finger lengths of adult offspring were measured using both, digital scanning of the paws and µCT analysis of the phalanges. RESULTS:  None of the aforementioned methods revealed any effect of testosterone on 2D:4D. µCT measurements showed that prenatal hyperandrogenism in both sexes leads to shorter 2D compared to controls. Moreover, the testosterone treatment in males resulted in the shortening of 4D when compared to controls. CONCLUSION:  Prenatal hyperandrogenism leads to shorter lengths of 2D and 4D; however, it does not affect 2D:4D ratio. Whether other steroid hormones and/or testosterone metabolites affect the 2D:4D ratio requires further investigation (Tab. 5, Fig. 3, Ref. 32).

Immune activation by nucleic acids: A role in pregnancy complications.

Cell-free self-DNA or RNA may induce an immune response by activating specific sensing receptors. During pregnancy, placental nucleic acids present in the maternal circulation further activate these receptors due to the presence of unmethylated CpG islands. A higher concentration of cell-free foetal DNA is associated with pregnancy complications and a higher risk for foetal rejection. Cell-free foetal DNA originates from placental trophoblasts. It appears in different forms: free, bound to histones in nucleosomes, in neutrophil extracellular traps (NETs) and in extracellular vesicles (EVs). In several pregnancy complications, cell-free foetal DNA triggers the production of proinflammatory cytokines, and this production results in a cellular and humoral immune response. This review discusses preeclampsia, systemic lupus erythematosus, foetal growth restriction, gestational diabetes, rheumatoid arthritis and obesity in pregnancy from an immunological point of view and closely examines the different pathways that result in maternal inflammation. Understanding the role of cell-free nucleic acids, as well as the biogenesis of NETs and EVs, will help us to specify their functions or targets, which seem to be important in pregnancy complications. It is still not clear whether higher concentrations of cell-free nucleic acids in the maternal circulation are the cause or consequence of various complications. Therefore, further clinical studies and, even more importantly, animal experiments that focus on the involved immunological pathways are needed.

Does rat fetal DNA induce preeclampsia in pregnant rats?

Cell-free fetal DNA in maternal circulation is higher during preeclampsia. It is unclear whether it is the cause or the consequence of the disease. The aim of this study was to prove whether injected rat fetal DNA induces preeclampsia-like symptoms in pregnant Wistar rats. They received daily i.p. injections of water or rat fetal DNA (400 µg) from gestation day 14 to 18. Blood pressure, proteinuria, placental and fetal weight were measured at gestation day 19. Plasma DNase activity, proteinuria and creatinine clearance were assessed. There was no significant difference in any of the measured parameters. The results of this study do not confirm the hypothesis that fetal DNA might induce preeclampsia. This is in contrast to others using human fetal DNA in mice. Further studies should be focused on the effects of fetal DNA from the same species protected from DNase activity.

Short-term effects of continuous positive airway pressure on sex hormones in men and women with sleep apnoea syndrome.

Patients with sleep apnoea syndrome (SAS) suffer from symptoms of hypogonadism. Besides surgical interventions, in some cases, the standard care of SAS for most patients is continuous positive airway pressure (CPAP). Studies focusing on the long-term effects of CPAP on testosterone levels revealed conflicting results. None of the studies included female patients with SAS. The aim of our study was to analyse and compare sex hormone levels in saliva before and after a night without and with CPAP in women and men with SAS. The results were negative. One night with CPAP did not affect the dynamics of sex hormones, neither in men nor in women. Future studies should focus on long-term effects of CPAP in both genders.

Association of biochemical parameters and RAGE gene polymorphisms in healthy infants and their mothers.

BACKGROUND: The receptor for advanced glycation end-products (RAGEs) and its gene polymorphisms are implicated in the pathogenesis of different chronic diseases including diabetes and its complications. Infant formulas contain high amounts of advanced glycation end-products (AGEs) - the ligands of RAGE. METHODS: In this cross-sectional study, we examined the impact of G82S and -374 A/T polymorphisms in the gene encoding RAGE on standard blood chemistry, soluble (s)RAGE and inflammatory markers in 244 healthy infants (3-16months of age) and in 119 healthy mothers. Children were subdivided according to age (younger and older than 8months) and for the -374 A/T polymorphism according to the feeding regimen (breast-fed vs. infant formula-fed). RESULTS: Minor allele of the RAGE gene polymorphism G82S was associated with reduced plasma sRAGE in all age groups and with increased sICAM-1 in older children and mothers. Minor allele carrying mothers had decreased insulin sensitivity and HDL. The A allele of the RAGE gene promoter polymorphism -374 A/T was associated with higher indices of insulin resistance in young infant formula-fed, but not breast-fed children. In older, formerly infant formula-fed children signs of insulin resistance diminished, while formerly breast-fed children with A allele were more insulin sensitive. CONCLUSIONS: The phenotype of minor allele carriers in G82S is associated with reduced levels of protective sRAGE in healthy infants. With increasing age sICAM-1 levels increased and insulin resistance developed. In early childhood the phenotype of the -374 A/T polymorphism was diet-dependently associated with changes in glucose metabolism, which diminished with increasing age.