Genomic regulation of Krüppel-like-factor family members by corticosteroid receptors in the rat brain.

Hippocampal mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs) mediate glucocorticoid hormone (GC) action in the hippocampus. These receptors bind to glucocorticoid responsive elements (GREs) within target genes, eliciting transcriptional effects in response to stress and circadian variation. Until recently, little was known about the genome-wide targets of hippocampal MRs and GRs under physiological conditions. Following on from our genome-wide MR and GR ChIP-seq and Ribo-Zero RNA-seq studies on rat hippocampus, we investigated the Krüppel-like factors (KLFs) as targets of MRs and GRs throughout the brain under circadian variation and after acute stress. In particular, Klf2, Klf9 and Klf15 are known to be stress and/or GC responsive and play a role in neurobiological processes including synaptic plasticity and neuronal differentiation. We found increased binding of MR and GR to GREs within Klf2, Klf9 and Klf15 in the hippocampus, amygdala, prefrontal cortex, and neocortex after acute stress and resulting from circadian variation, which was accompanied by upregulation of corresponding hnRNA and mRNA levels. Adrenalectomy abolished transcriptional upregulation of specific Klf genes. These results show that MRs and GRs regulate Klf gene expression throughout the brain following exposure to acute stress or in response to circadian variation, likely alongside other transcription factors.

Influence of Fetal Diagnosis on Management of Vascular Rings.

BACKGROUND: Fetal diagnoses of vascular rings have been increasing. We compared management strategies and outcomes of infants with fetal diagnosis with those with postnatal diagnosis to inform recommendations regarding optimal management. METHODS: A retrospective review was performed of vascular ring operations from January 2000 to June 2019. Standard demographic data (preoperative clinical status, timing of diagnosis, cross-sectional imaging, operative and perioperative details, and clinical outcomes) were collected. Statistical analysis was performed to compare characteristics and outcomes of fetal versus postnatal diagnosis. RESULTS: Of 190 patients, 15% (n = 29) were diagnosed prenatally. Anatomic variants were double aortic arch (n = 66, 14 fetal diagnoses), right aortic arch, aberrant left subclavian artery (n = 94, 12 fetal diagnoses), circumflex aorta (n = 7, 1 fetal diagnosis), and pulmonary artery sling (n = 19, 2 fetal diagnoses). An increasing frequency of fetal diagnoses has been noted in the past 10 years. In 2012 1 of 9 patients (11%) had a fetal diagnosis, whereas in 2018 8 of 11 (72%) had a fetal diagnosis (P < .001). Patients with a fetal diagnosis were significantly younger at the time of surgery (13.1 months [interquartile range (IQR), 20.6] vs 24.0 months [IQR, 87.0], P = .029). There was no difference in postoperative complications or length of stay (3 days [IQR, 1] for fetal diagnoses vs 4 days [IQR, 3] for postnatal diagnoses, P = .50). CONCLUSIONS: Fetal diagnosis leads to the potential for expectant management of vascular ring patients. This has resulted in earlier time of intervention with no increase in postoperative morbidity. This may lead to improved long-term outcomes and potentially alter the natural history for these children.

Distinct regulation of hippocampal neuroplasticity and ciliary genes by corticosteroid receptors.

Glucocorticoid hormones (GCs) - acting through hippocampal mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs) - are critical to physiological regulation and behavioural adaptation. We conducted genome-wide MR and GR ChIP-seq and Ribo-Zero RNA-seq studies on rat hippocampus to elucidate MR- and GR-regulated genes under circadian variation or acute stress. In a subset of genes, these physiological conditions resulted in enhanced MR and/or GR binding to DNA sequences and associated transcriptional changes. Binding of MR at a substantial number of sites however remained unchanged. MR and GR binding occur at overlapping as well as distinct loci. Moreover, although the GC response element (GRE) was the predominant motif, the transcription factor recognition site composition within MR and GR binding peaks show marked differences. Pathway analysis uncovered that MR and GR regulate a substantial number of genes involved in synaptic/neuro-plasticity, cell morphology and development, behavior, and neuropsychiatric disorders. We find that MR, not GR, is the predominant receptor binding to >50 ciliary genes; and that MR function is linked to neuronal differentiation and ciliogenesis in human fetal neuronal progenitor cells. These results show that hippocampal MRs and GRs constitutively and dynamically regulate genomic activities underpinning neuronal plasticity and behavioral adaptation to changing environments.

Evolution and Current Results of a Unified Strategy for Sinus Venosus Surgery.

BACKGROUND: Given recent reports of percutaneous closure of sinus venosus atrial septal defects, we reviewed our experience with surgical repair. Owing to the high incidence of arrhythmias with the two-patch technique, since 2001 we have used either one-patch repairs or the Warden procedure. METHODS: A retrospective review was performed of pediatric patients undergoing sinus venosus atrial septal defect repair at our institution from January 1, 1990, to July 1, 2018. Standard demographic data such as echocardiographic and cross-sectional imaging along with operative details and clinical echocardiographic outcomes were collected. RESULTS: The cohort included 144 patients with a median age of 4.3 years (interquartile range, 8.5). Inferior SVASD was present in 24 patients (17%). A single autologous untreated pericardial patch was used for 114 patients (79%), a two-patch technique for 20 patients (14%, last performed in 2000), and a Warden procedure in 10 patients (7%). Median length of stay was 4 days (interquartile range, 2). On echocardiogram follow-up, no patient had pulmonary vein stenosis. One patient who had the Warden procedure required a balloon dilation of the superior caval vein 2 years postoperatively and a stent 3 years later. Two-patch patients were substantially less likely to be in normal sinus rhythm (41%) on postoperative electrocardiograms compared with the other two techniques (81% one-patch and 89% Warden, P = .02). CONCLUSIONS: The great majority of patients with sinus venosus atrial septal defects can be successfully repaired with a single patch of autologous pericardium. We transitioned to using either a single pericardial patch or the Warden procedure, resulting in a higher frequency of normal sinus rhythm on postoperative electrocardiograms.

Unexpected effects of metyrapone on corticosteroid receptor interaction with the genome and subsequent gene transcription in the hippocampus of male rats.

Glucocorticoid hormones (GCs) play a pivotal role in many stress-related biological processes. In the hippocampus, GCs act through mineralocorticoid receptors (MRs) and glucocorticoid receptors (GRs) to modify gene transcription. The involvement of GCs in biological processes has been investigated using the corticosterone (CORT)-synthesis blocker metyrapone. How metyrapone affects the action of GC at the genomic level still remains unclear. Therefore, we investigated the effects of this enzyme blocker on plasma CORT levels and hippocampal MR and GR binding to GC responsive elements (GREs) within the GC target genes Fkbp5 (FK506-binding protein 5), Per1 (Period 1) and Sgk1 (Serum- and glucocorticoid-activated kinase 1), as well as the transcriptional responses of these genes under control and acute stress conditions in rats. For comparison, we also investigated these endpoints in rats that had undergone adrenalectomy (ADX). Although metyrapone had no effect on baseline levels of CORT, the drug increased MR and GR to GRE binding within the GC target genes and the transcriptional activity of these genes. As expected, acute forced swim (FS) stress strongly increased plasma CORT levels, hippocampal MR and GR to GRE binding within Fkbp5, Per1 and Sgk1, and the transcriptional activity (mainly hnRNA levels) of these genes. Metyrapone attenuated, but did not abolish, these effects of stress on plasma CORT and MR and GR to GRE binding. The drug effects on FS-induced transcriptional activity were gene-dependent with a reduction seen in Fkbp5 hnRNA (but not Fkbp5 mRNA), an enhancement in Per1 hnRNA (but not Per1 mRNA), and no effect on both Sgk1 hnRNA and mRNA levels. ADX however completely abrogated the effects of FS on plasma CORT, as well as hippocampal MR and GR to GRE binding and transcriptional responses. Thus, in contrast to ADX, metyrapone produced inconsistent effects on GC-sensitive genomic endpoints that question its suitability as a tool in neuroendocrine and other research.

Career choices: foundation year trainees' views on careers advice and information.

This article looks at careers information sources and advice for junior doctors in foundation training programmes and their specialty of choice. The need for targeted career planning is discussed.