Airway expression of the epithelial sodium channel α-subunit correlates with cortisol in term newborns

Regulation of Porcine Oviduct Epithelium Functions via Progesterone and Estradiol Is Influenced by Cortisol

Preimplantation maternal stress, characterized by elevated glucocorticoids (GCs), has been linked to reproductive failures caused by impaired oviduct functionality, which is known to be predominantly regulated by the sex steroids, progesterone (P4) and (17)estradiol (E2). Although steroid receptors share analogous structures and binding preferences, the interaction between GCs and E2/P4 in the oviduct has attracted little attention. Using an air-liquid interface culture model, porcine oviduct epithelial cells were stimulated with single (cortisol, E2, P4) or hormone mixtures (cortisol/E2, cortisol/P4) for 12 hours and 72 hours. Cultures were subsequently assessed for epithelial morphometry, bioelectrical properties, and gene expression responses (steroid hormone signaling, oviductal function, immune response, and apoptosis). Results confirmed the suppressive role of P4 in regulating oviduct epithelium characteristics, which was partially opposed by E2. Besides increasing the ratio of ciliated cells, cortisol antagonized the effect of P4 on epithelial polarity and modified sex steroid-induced changes in transepithelial electrical properties. Both sex steroids affected the glucocorticoid receptor expression, while cortisol downregulated the expression of progesterone receptor. The overall gene expression pattern suggests that sex steroid dominates the cotreatment, but cortisol contributes by altering the gene responses to sex steroids. We conclude that besides its individual action, maternal cortisol interplays with sex steroids at phenotypic and molecular levels in the oviduct epithelium, thereby influencing the microenvironment of gametes and early embryos.

Glucocorticoids, sodium transport mediators, and respiratory distress syndrome in preterm infants

BACKGROUND

Antenatal glucocorticoids (GCs) reduce respiratory distress syndrome (RDS) in preterm infants and are associated with reduced lung liquid content. Our aim was to assess whether airway gene expression of mediators of pulmonary epithelial sodium and liquid absorption, and further, respiratory morbidity, associate with cord blood GC concentrations.

METHODS

The study included 64 infants delivered <32 weeks gestation. Cortisol and betamethasone in umbilical cord blood were quantified with liquid chromatography-tandem mass spectrometry. The total GC concentration was calculated. Gene expression of the epithelial sodium channel (ENaC), Na,K-ATPase, and serum- and GC-inducible kinase 1 at <2 h and at 1 day postnatally in nasal epithelial cell samples was quantified with reverse transcription-polymerase chain reaction. The mean oxygen supplementation during the first 72 h was calculated.

RESULTS

Concentrations of cord blood betamethasone and total GC were significantly lower in infants with RDS and correlated with mean oxygen supplementation. Expression of αENaC and α1- and β1Na,K-ATPase at <2 h correlated with betamethasone and total GC concentrations. Expression of Na,K-ATPase was lower in infants with RDS.

CONCLUSION

Enhancement of lung liquid absorption via increased expression of sodium transporters may contribute to the beneficial pulmonary effects of antenatal GCs.

IMPACT

RDS is related to lower umbilical cord blood GC concentrations and lower airway expression of sodium transporters. In addition to the timing of antenatal GC treatment, resulting concentrations may be of importance in preventing RDS. Induction of sodium transport may be a factor contributing to the pulmonary response to antenatal GCs.

Lung development, regeneration and plasticity: From disease physiopathology to drug design using induced pluripotent stem cells

Lungs have a complex structure composed of different cell types that form approximately 17 million airway branches of gas-delivering bronchioles connected to 500 million gas-exchanging alveoli. Airways and alveoli are lined by epithelial cells that display a low rate of turnover at steady-state, but can regenerate the epithelium in response to injuries. Here, we review the key points of lung development, homeostasis and epithelial cell plasticity in response to injury and disease, because this knowledge is required to develop new lung disease treatments. Of note, canonical signaling pathways that are essential for proper lung development during embryogenesis are also involved in the pathophysiology of most chronic airway diseases. Moreover, the perfect control of these interconnected pathways is needed for the successful differentiation of induced pluripotent stem cells (iPSC) into lung cells. Indeed, differentiation of iPSC into airway epithelium and alveoli is based on the use of biomimetics of normal embryonic and fetal lung development. In vitro iPSC-based models of lung diseases can help us to better understand the impaired lung repair capacity and to identify new therapeutic targets and new approaches, such as lung cell therapy.

The effect of labour pain in caesarean delivery on neonatal and maternal outcomes in a term low-risk obstetric population

Planned caesarean delivery (CD) frequency is increasing in many countries, and elective CD accounts for 50% of preventable causes of neonatal respiratory morbidity. The clearing of fluid in the lungs is important for the establishment of normal gas exchange with inspired air. A defect in this clearance can result in respiratory problems in neonate, but on the other hand patients waiting for the onset of spontaneous labour pain, the increase in emergency CD, together with severe mortality and morbidity are causes of concern and cause anxiety and distrust of obstetricians. In the current study, it was observed that foetal respiratory morbidity was reduced in the group with labour pain. The caesarean applied after the onset of labour pain could be a reason for the significant increase in foetal cord cortisol values in term low-risk neonates. A major advantage of this study was the inclusion of a low-risk patient group, and the increase in foetal cortisol secondary to pain in term neonates was shown objectively. Impact statement What is already known on this subject: The timing of CD is reported to be critical for neonatal morbidity, and elective CD accounts for 50% of preventable causes of neonatal respiratory morbidity. The clearing of fluid in the lungs is important for the establishment of normal gas exchange with inspired air. Cortisol secretion from the foetal adrenal gland is stimulated by stress. What do the results of this study add: Labour pain-related stress in the foetus might be a cause for elevated physiological cortisol, and secondary to that, lower respiratory morbidity. Caesarean delivery commenced after the onset of labour pain could be a reason for the significant increase in foetal cord cortisol values in term neonates. A major advantage of this study was the inclusion of a low-risk patient group, and the increase in foetal cortisol secondary to pain in term neonates was shown objectively. What are the implications of these findings for clinical practice and/or further research: Although it would seem to be rational to perform a caesarean section after the onset of labour pain in cases with a planned caesarean and a history of C-section delivery, with respect to maternal complications, especially in those with a history of more than one caesarean or those who have started active labour; there is a need for further prospective studies.

The Successful Immediate Neonatal Transition to Extrauterine Life

Purpose:

To define and describe the processes underlying the successful neonatal transition to extrauterine life and methods to assess the transition.

Method:

Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Web of Science, and Google Scholar were searched using a combination of the key words neonate, neonatal, newborn, transition, respiratory OR pulmonary, cardiac, metabolic, pH, umbilical cord, and assessment. Articles in English and German were reviewed. The final sample of articles consisted of one randomized controlled trial, 30 observational studies using human neonates, one observational study using rabbit pups, one secondary analysis, three systematic reviews, and 23 review articles.

Major Findings:

The pertinent findings in regard to normal events in the respiratory, cardiovascular, and metabolic transitions are reviewed and summarized. We address the underlying factors necessary for the transition to extrauterine life, specify the consequences of a successful transition, and review common assessment approaches.

Conclusion:

Available evidence indicates that the successful immediate transition to extrauterine life should be completed within 1–3 hr after birth, though some adaptive processes can fail as late as 24–48 hr after birth. Further research is necessary to identify a feasible, easily used, noninvasive method to assess the status of a neonate’s transition to extrauterine life.

Duration of gestation and mode of delivery affect the genes of transepithelial sodium transport in pulmonary adaptation

BACKGROUND

Respiratory distress due to inadequate lung liquid clearance is a significant problem in infants delivered late preterm or early term, especially by elective cesarean delivery (CD). Lung liquid clearance depends on epithelial ion transport and in animals is induced by glucocorticoids.

OBJECTIVES

In newborn late preterm and term infants to study airway epithelial gene expressions of epithelial sodium channel (ENaC), and the serum and glucocorticoid-inducible kinase 1 (SGK1), and their association with cortisol, mode of delivery, and gestational age (GA).

METHODS

Infants were delivered at 35(0/7)-41(6/7) weeks. Cortisol in umbilical cord plasma was analyzed with liquid chromatography-tandem mass spectrometry. ENaC and SGK1 mRNAs in airway epithelial cells obtained within 3 h and at 1 day postnatally were quantified with real-time PCR.

RESULTS

ENaC and SGK1 mRNAs were significantly lower in late preterm and early term infants than in those ≥ 39(0/7) weeks. Significant correlations existed between both ENaC and SGK1 and cord cortisol and GA. In term infants, SGK1 mRNA at 1.5 h was higher after vaginal delivery than elective CD.

CONCLUSIONS

In late preterm and early term infants, low expression of ENaC and SGK1 may parallel insufficient lung liquid clearance predisposing to respiratory distress. Lower SGK1 expression after term CD could translate into insufficient sodium and lung liquid absorption. The findings demonstrate a central role for cortisol in regulation of ENaC and potentially perinatal sodium and lung liquid clearance.

The preterm lung and airway: past, present, and future

The tremendous advancement that has occurred in neonatal intensive care over the last 40-50 years can be largely attributed to greater understanding of developmental pathobiology in the newborn lung. Nonetheless, this improved survival from respiratory distress syndrome has been associated with continuing longer-term morbidity in the form of bronchopulmonary dysplasia (BPD). As a result, neonatal lung injury is a renewed focus of scientific interest. The onset of such an injury may begin in the delivery room, and this has generated interest in minimizing oxygen therapy and aggressive ventilatory support during the transition from fetal to neonatal lung. Fortunately, antenatal steroid therapy and selective use of surfactant therapy are now widely practiced, although fine tuning of this therapy for selected populations is ongoing. Newer therapeutic approaches address many aspects of BPD, including the pro-inflammatory component that characterizes this disorder. Finally, there is a greater need to understand the epidemiology and pathogenesis of the longer-term respiratory morbidity, most notably asthma, that persists in the preterm survivors of neonatal intensive care.

Delayed lung liquid absorption after cesarean section at term

BACKGROUND

Delayed postnatal removal of lung liquid may result in respiratory distress, which is more common in infants born by cesarean section. Vertical artefacts (B-lines) arising from the lung surface in lung ultrasound have been shown to correlate with the liquid content of the lungs.

OBJECTIVES

We studied whether lung ultrasound could be used for the assessment of postnatal lung liquid in healthy term infants born vaginally and by cesarean section.

METHODS

Lung ultrasound was performed 1, 3 and 24 h after birth to 22 vaginally born infants and 20 infants born by elective cesarean section. The abundance of B-lines was scored for each infant and time point by two independent observers blinded to the mode of delivery and time point on the examination on a five-step scale.

RESULTS

In both groups, a significant decrease in abundance of B-lines, indicative of lung liquid absorption, was observed during the first 24 h. 3 h after birth cesarean section was associated with significantly higher lung liquid content than vaginal delivery.

CONCLUSION

The noninvasive bedside ultrasound method for estimation of lung liquid is a promising tool for the early identification of infants at risk for pulmonary maladaptation.

Systemic steroid exposure is associated with differential methylation in chronic obstructive pulmonary disease

RATIONALE

Systemic glucocorticoids are used therapeutically to treat a variety of medical conditions. Epigenetic processes such as DNA methylation may reflect exposure to glucocorticoids and may be involved in mediating the responses and side effects associated with these medications.

OBJECTIVES

To test the hypothesis that differences in DNA methylation are associated with current systemic steroid use.

METHODS

We obtained DNA methylation data at 27,578 CpG sites in 14,475 genes throughout the genome in two large, independent cohorts: the International COPD Genetics Network (n(discovery) = 1,085) and the Boston Early Onset COPD study (n(replication) = 369). Sites were tested for association with current systemic steroid use using generalized linear mixed models.

MEASUREMENTS AND MAIN RESULTS

A total of 511 sites demonstrated significant differential methylation by systemic corticosteroid use in all three of our primary models. Pyrosequencing validation confirmed robust differential methylation at CpG sites annotated to genes such as SLC22A18, LRP3, HIPK3, SCNN1A, FXYD1, IRF7, AZU1, SIT1, GPR97, ABHD16B, and RABGEF1. Functional annotation clustering demonstrated significant enrichment in intrinsic membrane components, hemostasis and coagulation, cellular ion homeostasis, leukocyte and lymphocyte activation and chemotaxis, protein transport, and responses to nutrients.

CONCLUSIONS

Our analyses suggest that systemic steroid use is associated with site-specific differential methylation throughout the genome. Differentially methylated CpG sites were found in biologically plausible and previously unsuspected pathways; these genes and pathways may be relevant in the development of novel targeted therapies.