During pregnancy, trophoblasts grow to adapt the feto-maternal unit to fetal requirements. Aldosterone and cortisol levels increase, the latter being inactivated by a healthy placenta. By contrast, preeclamptic placental growth is reduced while aldosterone levels are low and placental cortisol tissue levels are high due to improper deactivation. Aldosterone acts as a growth factor in many tissues, whereas cortisol inhibits growth. We hypothesized that in preeclampsia low aldosterone and enhanced cortisol availability might mutually affect placental growth and function. Proliferation of cultured human trophoblasts was time-and dose-dependently increased with aldosterone (P Ͻ 0.04 to P Ͻ 0.0001) and inhibited by spironolactone and glucocorticoids (P Ͻ 0.01). Mineralo-and glucocorticoid receptor expression and activation upon agonist stimulation was verified by visualization of nuclear translocation of the receptors. Functional aldosterone deficiency simulated in pregnant mice by spironolactone treatment (15 g/g body weight/day) led to a reduced fetal umbilical blood flow (P Ͻ 0.05). In rat (P Ͻ 0.05; R 2 ϭ 0.2055) and human (X 2 ϭ 3.85; P ϭ 0.0249) pregnancy, placental size was positively related to plasma aldosterone. Autocrine production of these steroid hormones was excluded functionally and via the absence of specific enzymatic transcripts for CYP11B2 and CYP11B1. In conclusion, activation of mineralocorticoid receptors by maternal aldosterone appears to be required for trophoblast growth and a normal feto-placental function. Thus, low aldosterone levels and enhanced cortisol availability may be one explanation for the reduced placental size in preeclampsia and related disorders. (Endocrinology 152: 263-271, 2011)
Despite continued advances in neonatal medicine, sepsis remains a leading cause of death worldwide in neonatal intensive care units. The clinical presentation of sepsis in neonates varies markedly from that in older children and adults, and distinct acute inflammatory responses results in age-specific inflammatory and protective immune response to infection. This review first provides an overview of the neonatal immune system, then covers current mainstream, and experimental preventive and adjuvant therapies in neonatal sepsis. We also discuss how the distinct physiology of the perinatal period shapes early life immune responses and review strategies to reduce neonatal sepsis-related morbidity and mortality. A summary of studies that characterize immune ontogeny and neonatal sepsis is presented, followed by discussion of clinical trials assessing interventions such as breast milk, lactoferrin, probiotics, and pentoxifylline. Finally, we critically appraise future treatment options such as stem cell therapy, other antimicrobial protein and peptides, and targeting of pattern recognition receptors in an effort to prevent and/or treat sepsis in this highly vulnerable neonatal population.
Bacterial and viral infections cause high rates of morbidity and mortality in premature newborns. In the setting of viral infection, pDCs play a key role as strong producers of IFN-α upon TLR9 activation. We analyzed pDC frequency, phenotype, morphology, and function in CB of preterm and term newborns in comparison with adults. Whereas all age groups show similar pDC numbers, BDCA-2, CD123, and TLR9 levels, the expression of BDCA-4 and capacity to produce IFN-α upon TLR9 challenge were decreased significantly in preterm neonates. Furthermore, we show by means of electron microscopy that pDCs from preterm newborns exhibit a distinct, "immature" morphology. Taken together, these findings suggest decreased functionality of pDCs in the premature newborn. The reduced capacity to produce IFN-α is likely to render such infants more susceptible to viral infections.
Considering that the final protection of the DNA against major assaults in terms of chromatin condensation is finalized in the epididymis, it is not known how sperm production of reactive oxygen species (ROS) and inflammatory processes can contribute to protamine deficiency that is predetermined in the testes. Therefore, this study aimed at investigating relationships between poor chromatin condensation, morphology, ROS production, DNA damage and the impact of the presence of leucocytes. In 70 patients, sperm DNA status was determined using TUNEL and chromomycin A(3) (CMA(3)) assays, and ROS-production by means of dihydroethidine. Morphology was evaluated according to strict criteria. The percentage of CMA(3)-positive spermatozoa and leucocyte concentration (r = 0.178, P = 0.0377) as well as percentage of ROS-positive spermatozoa (r = 0.3010; P = 0.012) correlated significantly. Particularly, patients with leucocyte counts >0.5 x 10(6) ml(-1) exhibited higher CMA(3) positivity. No association was found between CMA(3) positivity, TUNEL positivity and sperm morphology. While P- (poor prognosis: 0-4% normal morphology) and G-pattern (good prognosis: 5-14% normal morphology) morphology did not differ regarding chromatin condensation, P-pattern patients had a significantly higher percentage of DNA fragmentation (P = 0.0323). As oxidative stress is associated with disturbed chromatin condensation, results suggest that the idea that under-protamination of sperm DNA will automatically lead to DNA fragmentation might have to be revisited.
BackgroundIn the last decades, human full-term cord blood was extensively investigated as a potential source of hematopoietic stem and progenitor cells (HSPCs). Despite the growing interest of regenerative therapies in preterm neonates, only little is known about the biological function of HSPCs from early preterm neonates under different perinatal conditions. Therefore, we investigated the concentration, the clonogenic capacity and the influence of obstetric/perinatal complications and maternal history on HSPC subsets in preterm and term cord blood.MethodsCD34+ HSPC subsets in UCB of 30 preterm and 30 term infants were evaluated by flow cytometry. Clonogenic assays suitable for detection of the proliferative potential of HSPCs were conducted. Furthermore, we analyzed the clonogenic potential of isolated HSPCs according to the stem cell marker CD133 and aldehyde dehydrogenase (ALDH) activity.ResultsPreterm cord blood contained a significantly higher concentration of circulating CD34+ HSPCs, especially primitive progenitors, than term cord blood. The clonogenic capacity of HSPCs was enhanced in preterm cord blood. Using univariate analysis, the number and clonogenic potential of circulating UCB HSPCs was influenced by gestational age, birth weight and maternal age. Multivariate analysis showed that main factors that significantly influenced the HSPC count were maternal age, gestational age and white blood cell count. Further, only gestational age significantly influenced the clonogenic potential of UCB HSPCs. Finally, isolated CD34+/CD133+, CD34+/CD133– and ALDHhigh HSPC obtained from preterm cord blood showed a significantly higher clonogenic potential compared to term cord blood.ConclusionWe demonstrate that preterm cord blood exhibits a higher HSPC concentration and increased clonogenic capacity compared to term neonates. These data may imply an emerging use of HSPCs in autologous stem cell therapy in preterm neonates.
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