Altered circadian gene expression in primary human airway epithelial cells in asthma.

Primary human airway epithelial cells demonstrate altered rhythmic gene expression in cytokine-related pathways in asthma with intact core circadian gene expression https://bit.ly/3v9lOC6.

Temperature synchronisation of circadian rhythms in primary human airway epithelial cells from children.

INTRODUCTION: Cellular circadian rhythms regulate immune pathways and inflammatory responses that mediate human disease such as asthma. Circadian rhythms in the lung may also contribute to exacerbations of chronic diseases such as asthma by regulating observed rhythms in mucus production, bronchial reactivity, airway inflammation and airway resistance. Primary human airway epithelial cells (AECs) are commonly used to model human lung diseases, such as asthma, with circadian symptoms, but a method for synchronising circadian rhythms in AECs has not been developed, and the presence of circadian rhythms in human AECs remains uninvestigated. METHODS: We used temperature cycling to synchronise circadian rhythms in undifferentiated and differentiated primary human AECs. Reverse transcriptase-quantitative PCR was used to measure expression of the core circadian clock genes ARNTL, CLOCK, CRY1, CRY2, NR1D1, NR1D2, PER1 and PER2. RESULTS: Following temperature synchronisation, the core circadian genes ARNTL, CRY1, CRY2, NR1D1, NR1D2, PER1 and PER2 maintained endogenous 24-hour rhythms under constant conditions. Following serum shock, the core circadian genes ARNTL, NR1D1 and NR1D2 demonstrated rhythmic expression. Following temperature synchronisation, CXCL8 demonstrated rhythmic circadian expression. CONCLUSIONS: Temperature synchronised circadian rhythms in AECs differentiated at an air-liquid interface can serve as a model to investigate circadian rhythms in pulmonary diseases.

Trends in clinical presentation of children with COVID-19: a systematic review of individual participant data.

BACKGROUND: There are sparse patient-level data available for children with novel coronavirus disease (COVID-19). Therefore, there is an urgent need for an updated systematic literature review that analyzes individual children rather than aggregated data in broad age groups. METHODS: Six databases (MEDLINE, Scopus, Web of Science, CINAHL, Google Scholar, medRxiv) were searched for studies indexed from January 1 to May 15, 2020, with MeSH terms: children, pediatrics, COVID-19, SARS-CoV-2. 1241 records were identified, of which only unique papers in English with individual patient information and documented COVID-19 testing were included. This review of 22 eligible studies followed Preferred Reporting Items for Systematic Review and Meta-Analyses of individual participant data guidelines. RESULTS: A total of 123 patients from five countries were identified. 46% were females. The median age was 5 years (IQR = 8). At presentation, 62% had a fever, 32% had a cough, 58% had a single symptom, and 21% were asymptomatic. Abnormal chest imaging was seen in 62% (65/105) of imaged and 76.9% (20/26) of asymptomatic children. A minority of children had elevated platelets, CRP, lactate dehydrogenase, and D-dimer. CONCLUSION: Data from this independent participant data systematic review revealed that the majority of children with COVID-19 presented with either no symptoms or a single, non-respiratory symptom. IMPACT: This systematic review revealed that the majority of children with COVID-19 presented with either no symptoms or a single, non-respiratory symptom. By using an independent participant data approach, this analysis underscores the challenge of diagnosing COVID-19 in pediatric patients due to the wide variety of symptoms and seemingly poor correlation of imaging findings with symptomatic disease. The data presented from individual patients from case series or cohort studies add more granularity to the current description of pediatric COVID-19.

Parenthood, Parental Benefits, and Career Goals Among Pediatric Residents: 2008 and 2019.

OBJECTIVES: Examine reported availability of parental benefits for pediatric residents and impact of parenthood on reported importance of characteristics of post-training positions and career goals in 2008 and 2019. METHODS: We analyzed data from American Academy of Pediatrics surveys of graduating residents in 2008 and 2019 querying (1) parenthood, (2) benefits during residency, (3) importance of parental benefits and job characteristics in post-training position, and (4) subspecialty career goal. Logistic regression was used to estimate independent effects of gender, partner status, and parenthood via derived predicted values (PVs). RESULTS: Of 1021 respondents, three-fourths were women. Respondents in 2019 were less likely than in 2008 to have children (24.5% vs 33.8%, P < .01). In 2019, respondents were less likely to report availability of maternity (PV = 78.5% vs 89.5%, P < .001) or parental leave (PV = 42.5% vs 59.2%, P < .001) and more likely to report availability of lactation space (PV = 77.8% vs 56.1%, P < .001.). Most residents reported control over work hours, family considerations, and number of overnight calls per month as essential or very important characteristics in post-training positions. Controlling for resident characteristics, parenthood was associated with importance of family considerations and overnight calls in post-training position. Parenthood did not associate with subspecialty career goals, but gender did. CONCLUSIONS: Residents are less likely to report availability of parental benefits during residency training in 2019. Most residents, both those with children and those without, consider parent friendly characteristics important in post-training positions. Parenthood does not correlate with subspecialty career goals independent from gender.

Parenthood and Parental Leave Decisions in Pediatric Residency.

OBJECTIVES: The demands of residency training may impact trainees' decision to have children. We examined characteristics of pediatric residents' decisions regarding childbearing, determinants of resident parental leave, and associations with well-being. METHODS: A survey of 845 pediatric residents at 13 programs was conducted between October 2019 and May 2020. Survey items included demographics, desire for future children, and logistics of parental leave. Outcomes included parental leave length, burnout and depression screening results, satisfaction with duration of breastfeeding, and satisfaction with parental leave and parenthood decisions. RESULTS: Seventy-six percent (639 of 845) of residents responded to the survey. Fifty-two percent (330) of respondents reported delaying having children during residency, and 29% (97) of those were dissatisfied with their decision to do so. Busy work schedule (89.7%), finances (50.9%), and a desire not to extend residency (41.2%) were the most common reasons for delay. Of respondents, 16% were parents and 4% were pregnant or had pregnant partners. Sixty-one parental leaves were reported, and 67% of parents reported dissatisfaction with leave length. The most frequently self-reported determinant of leave duration was the desire not to extend residency training (74%). Program mean leave length was negatively associated with burnout, measured as a dichotomous outcome (odds ratio = 0.81 [95% confidence interval 0.68-0.98]; P = .02). CONCLUSIONS: Many pediatric trainees delay parenthood during residency and are not satisfied with their decision to do so. Pediatric resident parental leave remains short and variable in duration, despite the positive association between longer leaves and overall well-being.

Ambulatory blood pressure monitoring in children undergoing polysomnography.

Ambulatory blood pressure monitoring (ABPM) is recommended for the diagnosis of hypertension in children at high risk, such as children with obesity or obstructive sleep apnea (OSA). Nocturnal hypertension is highly predictive of cardiovascular outcomes. ABPM allows for early detection of nocturnal hypertension in children. Although OSA is the most common sleep disorder associated with hypertension, studies have also shown an increase in cardiovascular risk in adult patients with other sleep disorders; therefore, there is an imperative need to provide early diagnosis in children at high risk. In the present study, we evaluated the feasibility of using ABPM during polysomnography (PSG) in children referred for sleep disordered breathing to the Seattle Children's Hospital Sleep Disorders Center. A total of 41 children aged 7-18 years were included in this study. The ABPM monitor was worn for a mean (SD) of 10.2 (1.5) hr. No significant changes were seen in PSG parameters when ABPM was co-performed with PSG, including sleep efficiency and arousals. In total, 12 of the 41 patients were identified as having nocturnal hypertension. Our study is important in that it shows that concomitant use of ABPM during PSG can aid in the early identification of nocturnal hypertension in this population.

Acute ANCA Vasculitis and Asymptomatic COVID-19.

We describe the presentation and diagnosis of a child with newly diagnosed antineutrophil cytoplasmic antibody-associated vasculitis and associated diffuse alveolar hemorrhage who was positive for coronavirus disease 2019 immunoglobulin G antibodies, indicative of a previous asymptomatic infection. Results of multiple polymerase chain reaction tests coinciding with the start of symptoms were negative, indicating that acute infection was not the cause of the patient's symptoms. Coronavirus disease 2019-induced autoimmune diseases have been described in adults, but this case report represents the first case described in a pediatric patient.

Perspectives from the Society for Pediatric Research: advice on sustaining science and mentoring during COVID-19.

The COVID-19 pandemic will leave an indelible mark on the careers of current medical trainees. Given the disruptions to medical education, economic impact on institutions, and the uncertainties around future job prospects, trainees are facing unprecedented challenges. This situation is especially concerning for futures of pediatric physician-scientist trainees, where concerns regarding maintaining the pipeline were well documented prior to the emergence of COVID-19. In this Perspectives article, we leverage the unique expertise of our workgroup to address concerns of physician-scientist trainees and to provide suggestions on how to navigate career trajectories in the post-COVID-19 era. We identified and addressed four major areas of concern: lack of in-person conferences and the associated decrease access to mentors and networking activities, decreased academic productivity, diminished job prospects, and mental health challenges. We also suggest actions for trainees, mentors and educational leaders, and institutions to help support trainees during the pandemic, with a goal of maintaining the pediatric physician-scientist pipeline.

Sleep-disordered breathing in pediatric heart transplant recipients.

BACKGROUND: Sleep-disordered breathing is commonly found in adults with heart failure both before and after HTx. Untreated sleep-disordered breathing post-transplant has been linked to late graft dysfunction, reduced quality of life, and increased morbidity. Sleep-disordered breathing has not been investigated in pediatric HTx recipients. METHODS: We conducted retrospective review of patients <21yo who underwent primary HTx at our center from 2009 to 2019 to describe clinical characteristics, cardiac history, and PSG results. RESULTS: One hundred and fifty patients were included; 60% had congenital heart disease, and 40% had cardiomyopathy. Fifty patients had PSG performed at median age of 6.1 years. Forty-one were referred for symptoms of sleep-disordered breathing. Obstructive sleep apnea was diagnosed in 45 patients and central sleep apnea in 3 patients. Of those with first PSG post-transplant (n = 36), median AHI was 9.1/h, and 19 (53%) were diagnosed with moderate or severe sleep apnea. Patients diagnosed with obstructive sleep apnea on PSG had more post-transplant ventilator days (median 3 vs 2 days, P < .05) and longer post-transplant lengths of stay (median 28 vs 22 days, P < .05). CONCLUSIONS: In this single-center cohort of pediatric HTx recipients, sleep-disordered breathing was common and associated with longer peri-transplant respiratory support and length of stay. Given the high incidence of moderate and severe OSA detected in this population, clinicians should regularly screen for SDB and consider PSG testing more frequently in children who have undergone HTx. Further study into the long-term impact of sleep-disordered breathing in pediatric HTx recipients is needed.

Polysomnographic characteristics and sleep-disordered breathing in Schaaf-Yang syndrome.

INTRODUCTION: Schaaf-Yang syndrome (SYS) is a genetic disorder caused by truncating variants in the MAGEL2 gene located in the maternally imprinted Prader-Willi syndrome (PWS) region at 15q11-13. The SYS phenotype shares features with PWS, a syndrome with known high incidence of sleep disorders. However, the spectrum of sleep-disorders in SYS has not been described. METHODS: We performed a retrospective analysis of polysomnograms from 22 patients in an international SYS cohort. Sleep characteristics for individuals with the common c.1996dupC variant (n = 10) were compared to other truncating variants (n = 11). RESULTS: We collected 33 sleep study reports from 22 patients, ages 2 months - 18.5 years (mean 6.5 years). Mean sleep efficiency was 70.5% (range 45%-93%) with arousal index 14.1/h (1.2-45/h). The mean apnea-hypopnea index (AHI) was 19.1/h (0.9-49/h) with mean obstructive AHI (oAHI) of 16.3/h (0.6-49/h). Mean central apnea index was 2.8/h (0-14/h). Mean oxygen desaturation index was 20.8/h (range 0-85/hr). Obstructive sleep apnea (OSA) was diagnosed in 81%, and 62% had moderate or severe OSA. Elevated central apnea index occurred in 9.5%. Comparison by genotype groups and age did not reveal any difference in OSA findings. Periodic limb movement index (PLMI) was elevated in 4/15 (26%). CONCLUSION: OSA is frequently identified on polysomnography in patients with SYS. The mean PLMI is elevated compared to normative data. Patients with SYS should have routine polysomnography screening due to high risk of sleep disorders.

Prader-Willi locus Snord116 RNA processing requires an active endogenous allele and neuron-specific splicing by Rbfox3/NeuN.

Prader-Willi syndrome (PWS), an imprinted neurodevelopmental disorder characterized by metabolic, sleep and neuropsychiatric features, is caused by the loss of paternal SNORD116, containing only non-coding RNAs (ncRNAs). The primary SNORD116 transcript is processed into small nucleolar RNAs (snoRNAs), which localize to nucleoli, and their spliced host gene 116HG, which is retained at its site of transcription. While functional complementation of the SNORD116 ncRNAs is a desirable goal for treating PWS, the mechanistic requirements of SNORD116 RNA processing are poorly understood. Here we developed and tested a novel transgenic mouse which ubiquitously expresses Snord116 on both a wild-type and a Snord116 paternal deletion (Snord116+/-) background. Interestingly, while the Snord116 transgene was ubiquitously expressed in multiple tissues, splicing of the transgene and production of snoRNAs was limited to brain tissues. Knockdown of Rbfox3, encoding neuron-specific splicing factor neuronal nuclei (NeuN) in Snord116+/--derived neurons, reduced splicing of the transgene in neurons. RNA fluorescence in situ hybridization for 116HG revealed a single significantly larger signal in transgenic mice, demonstrating colocalization of transgenic and endogenous 116HG RNAs. Similarly, significantly increased snoRNA levels were detected in transgenic neuronal nucleoli, indicating that transgenic Snord116 snoRNAs were effectively processed and localized. In contrast, neither transgenic 116HG nor snoRNAs were detectable in either non-neuronal tissues or Snord116+/- neurons. Together, these results demonstrate that exogenous expression and neuron-specific splicing of the Snord116 locus are insufficient to rescue the genetic deficiency of Snord116 paternal deletion. Elucidating the mechanisms regulating Snord116 processing and localization is essential to develop effective gene replacement therapies for PWS.

Probiotic Administration in Infants With Gastroschisis: A Pilot Randomized Placebo-Controlled Trial.

OBJECTIVES: Infants with gastroschisis often require long periods of gastric suctioning and hospitalization. The impact of these interventions on the intestinal microbiota and attempts to alter the microbial community have not been studied. We sought to determine how the intestinal microbiota is influenced by the current treatment of gastroschisis and whether alteration of the intestinal microbiota with a probiotic microbe will influence length of hospitalization. METHODS: We performed a randomized, placebo-controlled pilot study of administration of probiotic Bifidobacterium longum subsp. infantis in 24 infants with gastroschisis. The primary outcome was changes in the fecal microbiota, and the secondary outcome was length of hospital stay. RESULTS: Administration of the probiotic or placebo was well tolerated, even during the period of gastric suctioning. The overall microbial communities were not significantly different between groups, although analysis of the final specimens by family demonstrated higher Bifidobacteriaceae, lower Clostridiaceae, and trends toward lower Enterobacteriaceae, Enterococcaceae, Staphylococcaceae, and Streptococcaceae in the probiotic group. Clinical outcomes, including length of hospital stay, did not differ between groups. CONCLUSIONS: In this pilot study, there was significant in infants with gastroschisis that was partially attenuated by the administration of B longum subsp. infantis.

Epigenetic mechanisms in diurnal cycles of metabolism and neurodevelopment.

The circadian cycle is a genetically encoded clock that drives cellular rhythms of transcription, translation and metabolism. The circadian clock interacts with the diurnal environment that also drives transcription and metabolism during light/dark, sleep/wake, hot/cold and feast/fast daily and seasonal cycles. Epigenetic regulation provides a mechanism for cells to integrate genetic programs with environmental signals in order produce an adaptive and consistent output. Recent studies have revealed that DNA methylation is one epigenetic mechanism that entrains the circadian clock to a diurnal environment. We also review recent circadian findings in the epigenetic neurodevelopmental disorders Prader-Willi, Angelman and Rett syndromes and hypothesize a link between optimal brain development and intact synchrony between circadian and diurnal rhythms.

R-loop formation at Snord116 mediates topotecan inhibition of Ube3a-antisense and allele-specific chromatin decondensation.

Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are oppositely imprinted autism-spectrum disorders with known genetic bases, but complex epigenetic mechanisms underlie their pathogenesis. The PWS/AS locus on 15q11-q13 is regulated by an imprinting control region that is maternally methylated and silenced. The PWS imprinting control region is the promoter for a one megabase paternal transcript encoding the ubiquitous protein-coding Snrpn gene and multiple neuron-specific noncoding RNAs, including the PWS-related Snord116 repetitive locus of small nucleolar RNAs and host genes, and the antisense transcript to AS-causing ubiquitin ligase encoding Ube3a (Ube3a-ATS). Neuron-specific transcriptional progression through Ube3a-ATS correlates with paternal Ube3a silencing and chromatin decondensation. Interestingly, topoisomerase inhibitors, including topotecan, were recently identified in an unbiased drug screen for compounds that could reverse the silent paternal allele of Ube3a in neurons, but the mechanism of topotecan action on the PWS/AS locus is unknown. Here, we demonstrate that topotecan treatment stabilizes the formation of RNA:DNA hybrids (R loops) at G-skewed repeat elements within paternal Snord116, corresponding to increased chromatin decondensation and inhibition of Ube3a-ATS expression. Neural precursor cells from paternal Snord116 deletion mice exhibit increased Ube3a-ATS levels in differentiated neurons and show a reduced effect of topotecan compared with wild-type neurons. These results demonstrate that the AS candidate drug topotecan acts predominantly through stabilizing R loops and chromatin decondensation at the paternally expressed PWS Snord116 locus. Our study holds promise for targeted therapies to the Snord116 locus for both AS and PWS.

A Prader-Willi locus lncRNA cloud modulates diurnal genes and energy expenditure.

Prader-Willi syndrome (PWS), a genetic disorder of obesity, intellectual disability and sleep abnormalities, is caused by loss of non-coding RNAs on paternal chromosome 15q11-q13. The imprinted minimal PWS locus encompasses a long non-coding RNA (lncRNA) transcript processed into multiple SNORD116 small nucleolar RNAs and the spliced exons of the host gene, 116HG. However, both the molecular function and the disease relevance of the spliced lncRNA 116HG are unknown. Here, we show that 116HG forms a subnuclear RNA cloud that co-purifies with the transcriptional activator RBBP5 and active metabolic genes, remains tethered to the site of its transcription and increases in size in post-natal neurons and during sleep. Snord116del mice lacking 116HG exhibited increased energy expenditure corresponding to the dysregulation of diurnally expressed Mtor and circadian genes Clock, Cry1 and Per2. These combined genomic and metabolic analyses demonstrate that 116HG regulates the diurnal energy expenditure of the brain. These novel molecular insights into the energy imbalance in PWS should lead to improved therapies and understanding of lncRNA roles in complex neurodevelopmental and metabolic disorders.

Epigenetic layers and players underlying neurodevelopment.

Epigenetic mechanisms convey information above and beyond the sequence of DNA, so it is predicted that they are critical in the complex regulation of brain development and explain the long-lived effects of environmental cues on pre- and early post-natal brain development. Neurons have a complex epigenetic landscape that changes dynamically with transcriptional activity in early life. Here, we summarize progress in our understanding of the discrete layers of the dynamic methylome, chromatin proteome, noncoding RNAs, chromatin loops, and long-range interactions in neuronal development and maturation. Many neurodevelopmental disorders have genetic alterations in these epigenetic modifications or regulators, and these human genetics lessons have demonstrated the importance of these epigenetic players and the epigenetic layers that transcriptional events lay down in the early brain.