Sex-specific modulation of renal epigenetic and injury markers in aging kidney.

Sex differences in renal physiology and pathophysiology are well established in rodent models and humans. While renal epigenetics play a crucial role in injury, the impact of biological sex on aging kidney epigenome is less known, as most of the studies are from male rodents. We sought to determine the influence of sex and age on kidney epigenetic and injury markers, using male and female mice at 4-month (4M; young), 12-month (12M), and 24-month (24M; aged) of age. Females exhibited a significant increase in kidney and body weight and serum creatinine and decreased serum albumin levels from ages 4M to 24M, whereas minor changes were observed in male mice. Males exhibited higher levels of circulating histone 3 (H3; damage-associated molecular pattern molecules) compared with age-matched females. Kidney injury molecule-1 levels increased in serum and renal tissues from 12M to 24M in both sexes. Overall, females had markedly high histone acetyltransferase activity than age-matched males. Aged females had substantially decreased H3 methylation at lysine 9 and 27 and histone methyltransferase activity compared to aged males. Klotho levels were significantly higher in young males than females and decreased with age in males, whereas epigenetic repressor of Klotho, H3K27me3 and its enzyme, EZH2 augmented with age in both sexes. Proinflammatory NF-κB (p65) signaling increased with age in both sexes. Taken together, our data suggest that renal aging may lie in a range between normal and diseased kidneys, but differ between female and male mice, highlighting sex-specific regulation of renal epigenome in aging.

Aurora Kinase A inhibition enhances DNA damage and tumor cell death with 131I-MIBG therapy in high-risk neuroblastoma.

BACKGROUND: Neuroblastoma is the most common extra-cranial pediatric solid tumor. 131I-metaiodobenzylguanidine (MIBG) is a targeted radiopharmaceutical highly specific for neuroblastoma tumors, providing potent radiotherapy to widely metastatic disease. Aurora kinase A (AURKA) plays a role in mitosis and stabilization of the MYCN protein in neuroblastoma. We aimed to study the impact of AURKA inhibitors on DNA damage and tumor cell death in combination with 131I-MIBG therapy in a pre-clinical model of high-risk neuroblastoma. RESULTS: Using an in vivo model of high-risk neuroblastoma, we demonstrated a marked combinatorial effect of 131I-MIBG and alisertib on tumor growth. In MYCN amplified cell lines, the combination of radiation and an AURKA A inhibitor increased DNA damage and apoptosis and decreased MYCN protein levels. CONCLUSION: The combination of AURKA inhibition with 131I-MIBG treatment is active in resistant neuroblastoma models.

Late cognitive and adaptive outcomes of patients with neuroblastoma-associated opsoclonus-myoclonus-ataxia-syndrome: A report from the Children's Oncology Group.

BACKGROUND: Opsoclonus-myoclonus-ataxia syndrome (OMAS) is a rare autoimmune disorder of the nervous system presenting with abnormal eye and limb movements, altered gait, and increased irritability. Two to four percent of children diagnosed with neuroblastoma have neuroblastoma-associated OMAS (NA-OMAS). These children typically present with non-high-risk neuroblastoma that is cured with surgery, with or without chemotherapy. Despite excellent overall survival, patients with NA-OMAS can have significant persistent neurological and developmental issues. OBJECTIVE: This study aimed to describe long-term neurocognitive and adaptive functioning of patients with NA-OMAS treated with multimodal therapy, including intravenous immunoglobulin (IVIG) on Children's Oncology Group (COG) protocol ANBL00P3. METHODS: Of 53 children enrolled on ANBL00P3, 25 submitted evaluable neurocognitive data at diagnosis and at least one additional time point within 2 years and were included in the analyses. Adaptive development was assessed via the Vineland Adaptive Behavior Scale, and validated, age-appropriate measures of intellectual function were also administered. RESULTS: Twenty-one of the 25 patients in this cohort ultimately received IVIG. Descriptive spaghetti plots suggest that this cohort demonstrated stable long-term cognitive functioning and adaptive development over time. This cohort also demonstrated decreased OMAS scores over time consistent with improved OMAS symptoms. CONCLUSIONS: While statistical significance is limited by small sample size and loss to follow-up over 10 years, findings suggest stable long-term cognitive and adaptive functioning over time in this treated cohort.

Aurora Kinase A inhibition enhances DNA damage and tumor cell death with 131I-MIBG therapy in high-risk neuroblastoma.

Background: Neuroblastoma is the most common extra-cranial pediatric solid tumor. 131I-metaiodobenzylguanidine (MIBG) is a targeted radiopharmaceutical highly specific for neuroblastoma tumors, providing potent radiotherapy to widely metastatic disease. Aurora kinase A (AURKA) plays a role in mitosis and stabilization of the MYCN protein in neuroblastoma. Here we explore whether AURKA inhibition potentiates a response to MIBG therapy. Results: Using an in vivo model of high-risk neuroblastoma, we demonstrated a marked combinatorial effect of 131I-MIBG and alisertib on tumor growth. In MYCN amplified cell lines, the combination of radiation and an AURKA A inhibitor increased DNA damage and apoptosis and decreased MYCN protein levels. Conclusion: The combination of AURKA inhibition with 131I-MIBG treatment is active in resistant neuroblastoma models and is a promising clinical approach in high-risk neuroblastoma.

Sex-specific epigenetic programming in renal fibrosis and inflammation.

The growing prevalence of hypertension, heart disease, diabetes, and obesity along with an aging population is leading to a higher incidence of renal diseases in society. Chronic kidney disease (CKD) is characterized mainly by persistent inflammation, fibrosis, and gradual loss of renal function leading to renal failure. Sex is a known contributor to the differences in incidence and progression of CKD. Epigenetic programming is an essential regulator of renal physiology and is critically involved in the pathophysiology of renal injury and fibrosis. Epigenetic signaling integrates intrinsic and extrinsic signals onto the genome, and various environmental and hormonal stimuli, including sex hormones, which regulate gene expression and downstream cellular responses. The most extensively studied epigenetic alterations that play a critical role in renal damage include histone modifications and DNA methylation. Notably, these epigenetic alterations are reversible, making them candidates for potential therapeutic targets for the treatment of renal diseases. Here, we will summarize the current knowledge on sex differences in epigenetic modulation of renal fibrosis and inflammation and highlight some possible epigenetic therapeutic strategies for CKD treatment.

Ligand-Dependent Downregulation of Guanylyl Cyclase/Natriuretic Peptide Receptor-A: Role of miR-128 and miR-195.

Cardiac hormones act on the regulation of blood pressure (BP) and cardiovascular homeostasis. These hormones include atrial and brain natriuretic peptides (ANP, BNP) and activate natriuretic peptide receptor-A (NPRA), which enhance natriuresis, diuresis, and vasorelaxation. In this study, we established the ANP-dependent homologous downregulation of NPRA using human embryonic kidney-293 (HEK-293) cells expressing recombinant receptor and MA-10 cells harboring native endogenous NPRA. The prolonged pretreatment of cells with ANP caused a time- and dose-dependent decrease in 125I-ANP binding, Guanylyl cyclase (GC) activity of receptor, and intracellular accumulation of cGMP leading to downregulation of NPRA. Treatment with ANP (100 nM) for 12 h led to an 80% decrease in 125I-ANP binding to its receptor, and BNP decreased it by 62%. Neither 100 nM c-ANF (truncated ANF) nor C-type natriuretic peptide (CNP) had any effect. ANP (100 nM) treatment also decreased GC activity by 68% and intracellular accumulation cGMP levels by 45%, while the NPRA antagonist A71915 (1 µM) almost completely blocked ANP-dependent downregulation of NPRA. Treatment with the protein kinase G (PKG) stimulator 8-(4-chlorophenylthio)-cGMP (CPT-cGMP) (1 µM) caused a significant increase in 125I-ANP binding, whereas the PKG inhibitor KT 5823 (1 µM) potentiated the effect of ANP on the downregulation of NPRA. The transfection of miR-128 significantly reduced NPRA protein levels by threefold compared to control cells. These results suggest that ligand-dependent mechanisms play important roles in the downregulation of NPRA in target cells.

Medulloblastoma Presenting As Isolated Leptomeningeal Enhancement With No Primary Mass.

Medulloblastoma presenting with diffuse leptomeningeal enhancement and no identified intra-parenchymal primary mass is extremely rare. A 14-year-old previously healthy boy presented with a three-week history of symptoms consistent with increased intracranial pressure (ICP). Magnetic resonance imaging (MRI) revealed diffuse leptomeningeal enhancement which prompted consideration of infectious, inflammatory, and neoplastic etiologies. The patient became rapidly unstable requiring the placement of an external ventricular drain (EVD) and induction of a phenobarbital coma for refractory seizures. The "sugar-coated" appearance of the abnormal enhancement and thickened tissues raised concern specifically for malignancy. The patient remained extremely unstable and ultimately required surgical decompression for increased ICP at which time a biopsy was obtained. Despite attempting bridging intra-ventricular chemotherapy, the patient, unfortunately, passed away, just 14 days from the initial presentation. Final pathology later confirmed the diagnosis of medulloblastoma. Awareness of medulloblastoma in the differential of diffuse leptomeningeal enhancement is crucial for early identification and treatment of this rare presentation. This case is the first pediatric report of primary leptomeningeal medulloblastoma without a primary mass involving the large cell/anaplastic variant.

Manuscript Review at the Journal of Pediatric Gastroenterology and Nutrition: The Impact of Reviewers on Editor Decisions.

OBJECTIVE: Given the importance of scholarly work in academic medicine, better understanding of the manuscript review process (MRP) is useful for authors, reviewers, and editorial boards. We aim to describe the MRP at the Journal of Pediatric Gastroenterology and Nutrition (JPGN), assess the correlation between editor decisions and reviewer recommendations, and provide transparency to this process. METHODS: All manuscripts submitted in 2018 to JPGN were included in this analysis. Data included reviewers' manuscript scores and recommendations, time spent on each review by reviewers, the editor's rating of the reviewers' reviews, the editor's first decision, and final outcome. Data were collated using the JPGN manuscript submission website, Editorial Manager. RESULTS: 1023 manuscripts were submitted to JPGN in 2018 and included in this analysis. Of these, 486 manuscripts had at least two peer reviewers. The recommendations of the two reviewers were in agreement 43% of the time. Intra-class correlation (ICC) between the two reviewers suggests moderate agreement (ICC = 0.40). When both reviewers agreed to Not Reject (289/486), the editor agreed in 93% of cases (269/289). When both reviewers agreed to Reject (55/486), the editor agreed 100% of the time (55/55). The reviewers disagreed in about one-third of submissions (142/486), and the editor recommended to Reject in two-thirds of these cases (95/142). Overall, inter-reviewer agreement strongly correlated with the editor's initial decision (P < 0.001). CONCLUSIONS: The editor most often agreed with reviewers' assessments when there was concordance between the two reviewers' recommendations. About a third of peer reviews result in discordant recommendations between the two reviewers.

Angiotensin II represses Npr1 expression and receptor function by recruitment of transcription factors CREB and HSF-4a and activation of HDACs.

The two vasoactive hormones, angiotensin II (ANG II; vasoconstrictive) and atrial natriuretic peptide (ANP; vasodilatory) antagonize the biological actions of each other. ANP acting through natriuretic peptide receptor-A (NPRA) lowers blood pressure and blood volume. We tested hypothesis that ANG II plays critical roles in the transcriptional repression of Npr1 (encoding NPRA) and receptor function. ANG II significantly decreased NPRA mRNA and protein levels and cGMP accumulation in cultured mesangial cells and attenuated ANP-mediated relaxation of aortic rings ex vivo. The transcription factors, cAMP-response element-binding protein (CREB) and heat-shock factor-4a (HSF-4a) facilitated the ANG II-mediated repressive effects on Npr1 transcription. Tyrosine kinase (TK) inhibitor, genistein and phosphatidylinositol 3-kinase (PI-3K) inhibitor, wortmannin reversed the ANG II-dependent repression of Npr1 transcription and receptor function. ANG II enhanced the activities of Class I histone deacetylases (HDACs 1/2), thereby decreased histone acetylation of H3K9/14ac and H4K8ac. The repressive effect of ANG II on Npr1 transcription and receptor signaling seems to be transduced by TK and PI-3K pathways and modulated by CREB, HSF-4a, HDACs, and modified histones. The current findings suggest that ANG II-mediated repressive mechanisms of Npr1 transcription and receptor function may provide new molecular targets for treatment and prevention of hypertension and cardiovascular diseases.

The General Pediatrician's Guide to Isolated Thrombocytopenia.

Platelets are an essential component of the hemostatic pathway; therefore, it is important to identify and diagnose patients with low platelet counts. This can be challenging, however, because thrombocytopenia can be relatively common and the differential diagnosis can be broad. Furthermore, because platelets can be affected both in form and function in a variety of medical conditions, platelet abnormalities can be the principal driver in some disorders but only a consequence in others. Critical factors in identifying the etiology of the thrombocytopenia include the severity and acuity of the patient's initial presentation along with the history, physical examination, and laboratory findings, all of which can provide important clues. The accurate diagnosis of thrombocytopenia is crucial for determining the appropriate management. This review highlights the key diagnostic considerations and recommended treatment when isolated thrombocytopenia is encountered in clinical practice. [Pediatr Ann. 2020;49(1):e27-e35.].

Surveillance Screening in Li-Fraumeni Syndrome: Raising Awareness of False Positives.

Li-Fraumeni syndrome (LFS) is a rare cancer predisposition syndrome inherited in an autosomal dominant fashion that involves a germline mutation of tumor protein 53 (TP53). With the advent of more accessible and accurate genetic testing methods, along with more widespread knowledge of LFS, asymptomatic carriers can now be more easily identified. No general surveillance protocols were previously recommended other than routine physical exams and breast and colon cancer screening at younger ages, primarily due to questions involving efficacy, cost, and clinical benefits. With more data now available to support the implementation of a surveillance protocol for cancer predisposition syndromes such as LFS, preventative screening has become a national standard of care. However, as surveillance becomes more integrated into patient care, the benefits and risks must be further evaluated. We briefly describe our institutional experience with surveillance screening in LFS and describe two patients in depth where surveillance imaging brought to light false positives that led to increased utilization of resources and concern for new malignancy. Though the benefits of surveillance are clear, it is important to understand the potential for false positives involved with instituting this practice. Continued research of this topic is thus warranted, perhaps with larger prospective studies, to better capture the survival benefits of patients undergoing surveillance screening and more comprehensively understand the incidence of false positives.

Inhibition of HDAC enhances STAT acetylation, blocks NF-κB, and suppresses the renal inflammation and fibrosis in Npr1 haplotype male mice.

Guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) plays a critical role in the regulation of blood pressure and fluid volume homeostasis. Mice lacking functional Npr1 (coding for GC-A/NPRA) exhibit hypertension and congestive heart failure. However, the underlying mechanisms remain largely less clear. The objective of the present study was to determine the physiological efficacy and impact of all-trans-retinoic acid (ATRA) and sodium butyrate (NaBu) in ameliorating the renal fibrosis, inflammation, and hypertension in Npr1 gene-disrupted haplotype (1-copy; +/-) mice (50% expression levels of NPRA). Both ATRA and NaBu, either alone or in combination, decreased the elevated levels of renal proinflammatory and profibrotic cytokines and lowered blood pressure in Npr1+/- mice compared with untreated controls. The treatment with ATRA-NaBu facilitated the dissociation of histone deacetylase (HDAC) 1 and 2 from signal transducer and activator of transcription 1 (STAT1) and enhanced its acetylation in the kidneys of Npr1+/- mice. The acetylated STAT1 formed a complex with nuclear factor-κB (NF-κB) p65, thereby inhibiting its DNA-binding activity and downstream proinflammatory and profibrotic signaling cascades. The present results demonstrate that the treatment of the haplotype Npr1+/- mice with ATRA-NaBu significantly lowered blood pressure and reduced the renal inflammation and fibrosis involving the interactive roles of HDAC, NF-κB (p65), and STAT1. The current findings will help in developing the molecular therapeutic targets and new treatment strategies for hypertension and renal dysfunction in humans.

Public Views on Pulse Oximetry Screening for Critical Congenital Heart Disease.

OBJECTIVES: To understand public views on pulse oximetry screening for critical congenital heart disease. METHODS: Two hundred thirteen adults read a brief vignette describing the importance of early detection of critical congenital heart disease and then answered five questions on a five-point scale of how likely or unlikely they were to support pulse oximetry screening. Responses were tabulated and analyzed using a Fisher exact test, and logistic regression was used to estimate odds ratios for adjusted associations using generalized estimating equations. RESULTS: Almost 90% of all participants expressed support for routine pulse oximetry screening. The possibility of false positives leading to a delay in discharge, and the potential need for transfer to another facility lowered support but did not reach a statistical significance. The overall support for pulse oximetry screening was strong and consistent between different participant demographics. CONCLUSION: A large majority of participants in this study support pulse oximetry screening for the early detection of critical congenital heart disease.

Retinoic acid and sodium butyrate suppress the cardiac expression of hypertrophic markers and proinflammatory mediators in Npr1 gene-disrupted haplotype mice.

The objective of the present study was to examine the genetically determined differences in the natriuretic peptide receptor-A (NPRA) gene (Npr1) copies affecting the expression of cardiac hypertrophic markers, proinflammatory mediators, and matrix metalloproteinases (MMPs) in a gene-dose-dependent manner. We determined whether stimulation of Npr1 by all-trans retinoic acid (RA) and histone deacetylase (HDAC) inhibitor sodium butyric acid (SB) suppress the expression of cardiac disease markers. In the present study, we utilized Npr1 gene-disrupted heterozygous (Npr1(+/-), 1-copy), wild-type (Npr1(+/+), 2-copy), gene-duplicated (Npr1(++/+), 3-copy) mice, which were treated intraperitoneally with RA, SB, and a combination of RA/SB, a hybrid drug (HB) for 2 wk. Untreated 1-copy mice showed significantly increased heart weight-body weight (HW/BW) ratio, blood pressure, hypertrophic markers, including beta-myosin heavy chain (ß-MHC) and proto-oncogenes (c-fos and c-jun), proinflammatory mediator nuclear factor kappa B (NF-κB), and MMPs (MMP-2, MMP-9) compared with 2-copy and 3-copy mice. The heterozygous (haplotype) 1-copy mice treated with RA, SB, or HB, exhibited significant reduction in the expression of ß-MHC, c-fos, c-jun, NF-κB, MMP-2, and MMP-9. In drug-treated animals, the activity and expression levels of HDAC were significantly reduced and histone acetyltransferase activity and expression levels were increased. The drug treatments significantly increased the fractional shortening and reduced the systolic and diastolic parameters of the Npr1(+/-) mice hearts. Together, the present results demonstrate that a decreased Npr1 copy number enhanced the expression of hypertrophic markers, proinflammatory mediators, and MMPs, whereas an increased Npr1 repressed the cardiac disease markers in a gene-dose-dependent manner.

Transforming growth factor ß1 antagonizes the transcription, expression and vascular signaling of guanylyl cyclase/natriuretic peptide receptor A - role of δEF1.

The objective of this study was to determine the role of transforming growth factor ß1 (TGF-ß1) in transcriptional regulation and function of the guanylyl cyclase A/natriuretic peptide receptor A gene (Npr1) and whether cross-talk exists between these two hormonal systems in target cells. After treatment of primary cultured rat thoracic aortic vascular smooth muscle cells and mouse mesangial cells with TGF-ß1, the Npr1 promoter construct containing a δ-crystallin enhancer binding factor 1 (δEF1) site showed 85% reduction in luciferase activity in a time- and dose-dependent manner. TGF-ß1 also significantly attenuated luciferase activity of the Npr1 promoter by 62%, and decreased atrial natriuretic peptide-mediated relaxation of mouse denuded aortic rings ex vivo. Treatment of cells with TGF-ß1 increased the protein levels of δEF1 by 2.4-2.8-fold, and also significantly enhanced the phosphorylation of Smad 2/3, but markedly reduced Npr1 mRNA and receptor protein levels. Over-expression of δEF1 showed a reduction in Npr1 promoter activity by 75%, while deletion or site-directed mutagenesis of δEF1 sites in the Npr1 promoter eliminated the TGF-ß1-mediated repression of Npr1 transcription. TGF-ß1 significantly increased the expression of α-smooth muscle actin and collagen type I α2 in rat thoracic aortic vascular smooth muscle cells, which was markedly attenuated by atrial natriuretic peptide in cells over-expressing natriuretic peptide receptor A. Together, the present results suggest that an antagonistic cascade exists between the TGF-ß1/Smad/δEF1 pathways and Npr1 expression and receptor signaling that is relevant to renal and vascular remodeling, and may be critical in the regulation of blood pressure and cardiovascular homeostasis.

Information gaps in newborn care and their potential for harm.

BACKGROUND: Access to complete and correct patient information is vital for physicians to make appropriate patient care decisions and to avoid medical errors. However, the perinatal period represents a unique situation in which care of the fetus is initiated by an obstetrician and then assumed by either a pediatrician or a family practice physician after birth. This often abrupt handoff of care has the potential to result in an inadequate transfer of information and significant gaps in care. A study was conducted to determine the presence and extent of information gaps in newborn care. METHODS: Maternal demographics and history, and results of all prenatal laboratory tests, were obtained from maternal interviews and medical records. The collected data were compared with information in infant medical records. A positive maternal history not documented in the infant medical record was counted as an information gap. RESULTS: Of 72 enrolled mother-infant dyads, nearly all (71 [99%]) of mothers had at least one positive history in the areas reviewed, and 59 (82%) newborn charts had one or more information gaps. Thirty-eight (53%) newborn charts had one of two or fewer information gaps, and 17 (24%) had four or more information gaps. None of the infants with a maternal history of depression, positive family history of an infectious disease, potentially inheritable genetic disorder, or family history of phototherapy or exchange transfusion had these documented in their medical records. CONCLUSIONS: The results of this study suggest that significant information gaps are common in newborn care at birth and may have the potential for an adverse impact on the care and outcomes of the newborn. Obtaining a history directly from the parents rather than relying on maternal medical records may minimize or eliminate these information gaps and thus improve newborn care.

All-trans retinoic acid and sodium butyrate enhance natriuretic peptide receptor a gene transcription: role of histone modification.

The objective of the present study was to delineate the mechanisms of GC-A/natriuretic peptide receptor-A (GC-A/NPRA) gene (Npr1) expression in vivo. We used all-trans retinoic acid (ATRA) and histone deacetylase (HDAC) inhibitor, sodium butyrate (NaBu) to examine the expression and function of Npr1 using gene-disrupted heterozygous (1-copy; +/-), wild-type (2-copy; +/+), and gene-duplicated heterozygous (3-copy; ++/+) mice. Npr1(+/-) mice exhibited increased renal HDAC and reduced histone acetyltransferase (HAT) activity; on the contrary, Npr1(++/+) mice showed decreased HDAC and enhanced HAT activity compared with Npr1(+)(/+) mice. ATRA and NaBu promoted global acetylation of histones H3-K9/14 and H4-K12, reduced methylation of H3-K9 and H3-K27, and enriched accumulation of active chromatin marks at the Npr1 promoter. A combination of ATRA-NaBu promoted recruitment of activator-complex containing E26 transformation-specific 1, retinoic acid receptor α, and HATs (p300 and p300/cAMP response element-binding protein-binding protein-associated factor) at the Npr1 promoter, and significantly increased renal NPRA expression, GC activity, and cGMP levels. Untreated 1-copy mice showed significantly increased systolic blood pressure and renal expression of α-smooth muscle actin (α-SMA) and proliferating cell nuclear antigen (PCNA) compared with 2- and 3-copy mice. Treatment with ATRA and NaBu synergistically attenuated the expression of α-SMA and PCNA and reduced systolic blood pressure in Npr1(+/-) mice. Our findings demonstrate that epigenetic upregulation of Npr1 gene transcription by ATRA and NaBu leads to attenuation of renal fibrotic markers and systolic blood pressure in mice with reduced Npr1 gene copy number, which will have important implications in prevention and treatment of hypertension-related renal pathophysiological conditions.

Histone deacetylase inhibitors modulate the transcriptional regulation of guanylyl cyclase/natriuretic peptide receptor-a gene: interactive roles of modified histones, histone acetyltransferase, p300, AND Sp1.

Atrial natriuretic peptide (ANP) binds guanylyl cyclase-A/natriuretic peptide receptor-A (GC-A/NPRA) and produces the intracellular second messenger, cGMP, which regulates cardiovascular homeostasis. We sought to determine the function of histone deacetylases (HDACs) in regulating Npr1 (coding for GC-A/NPRA) gene transcription, using primary mouse mesangial cells treated with class-specific HDAC inhibitors (HDACi). Trichostatin A, a pan inhibitor, and mocetinostat (MGCD0103), a class I HDAC inhibitor, significantly enhanced Npr1 promoter activity (by 8- and 10-fold, respectively), mRNA levels (4- and 5.3-fold, respectively), and NPRA protein (2.7- and 3.5-fold, respectively). However, MC1568 (class II HDAC inhibitor) had no discernible effect. Overexpression of HDAC1 and HDAC2 significantly attenuated Npr1 promoter activity, whereas HDAC3 and HDAC8 had no effect. HDACi-treated cultured cells in vitro and intact animals in vivo showed significantly reduced binding of HDAC1 and -2 and increased accumulation of acetylated H3-K9/14 and H4-K12 at the Npr1 promoter. Deletional analyses of the Npr1 promoter along with ectopic overexpression and inhibition of Sp1 confirmed that HDACi-induced Npr1 gene transcription is accomplished by Sp1 activation. Furthermore, HDACi attenuated the interaction of Sp1 with HDAC1/2 and promoted Sp1 association with p300 and p300/cAMP-binding protein-associated factor; it also promoted the recruitment of p300 and p300/cAMP-binding protein-associated factor to the Npr1 promoter. Our results demonstrate that trichostatin A and MGCD0103 enhanced Npr1 gene expression through inhibition of HDAC1/2 and increased both acetylation of histones (H3-K9/14, H4-K12) and Sp1 by p300, and their recruitment to Npr1 promoter. Our findings define a novel epigenetic regulatory mechanism that governs Npr1 gene transcription.

Pulse-oximetry screening to detect critical congenital heart disease in the neonatal intensive care unit.

The current pulse-oximetry screening (POS) protocol for detection of critical congenital heart defects (CCHDs) is recommended only for newborns in well-infant and intermediate care nurseries, and there is no evidence-based protocol for infants discharged from the neonatal intensive care unit (NICU). The objectives of this study were to examine the efficacy of the current screening protocol in a NICU setting and to determine the impact of a unit protocol on the use of POS. Charts of 250 infants previous (group 1) and 250 infants after (group 2) the protocol implementation were reviewed. The results of screening test and preductal and postductal SpO2 were recorded for screened infants. A predischarge SpO2 value was recorded if screening was not performed. No infant in group 1 had POS. All eligible infants in group 2 received screening and passed. Preductal and postductal oxygen saturations in preterm infants at discharge were similar to saturations in late preterm and term infants. These results show that oxygen saturations at discharge in late preterm and term infants requiring admission to the NICU are similar to infants with no morbidities and that the current POS protocol can be safely used for these infants at discharge from the NICU. This study also confirms that preductal and postductal oxygen saturations at discharge in preterm infants are not different from those in late preterm and term infants. A unit protocol is likely to be more effective than relying on individual providers to ensure that all infants undergo POS for detection of CCHD.

Interactive roles of Ets-1, Sp1, and acetylated histones in the retinoic acid-dependent activation of guanylyl cyclase/atrial natriuretic peptide receptor-A gene transcription.

Cardiac hormones atrial and brain natriuretic peptides activate guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA), which plays a critical role in reduction of blood pressure and blood volume. Currently, the mechanisms responsible for regulating the Npr1 gene (coding for GC-A/NPRA) transcription are not well understood. The present study was conducted to examine the interactive roles of all-trans retinoic acid (ATRA), Ets-1, Sp1, and histone acetylation on the transcriptional regulation and function of the Npr1 gene. Deletion analysis of the Npr1 promoter and luciferase assays showed that ATRA enhanced a 16-fold Npr1 promoter activity and greatly stimulated guanylyl cyclase (GC) activity of the receptor protein in both atrial natriuretic peptide (ANP)-dependent and -independent manner. As confirmed by gel shift and chromatin immunoprecipitation assays, ATRA enhanced the binding of both Ets-1 and Sp1 to the Npr1 promoter. The retinoic acid receptor α (RARα) was recruited by Ets-1 and Sp1 to form a transcriptional activator complex with their binding sites in the Npr1 promoter. Interestingly, ATRA also increased the acetylation of histones H3 and H4 and enhanced their recruitment to Ets-1 and Sp1 binding sites within the Npr1 promoter. Collectively, the present results demonstrate that ATRA regulates Npr1 gene transcription and GC activity of the receptor by involving the interactive actions of Ets-1, Sp1, and histone acetylation.