Neonatal Heart Research Articles

Transitions from short to long-term outcomes in pediatric critical care: considerations for clinical practice.

Most children are surviving critical illness in highly resourced pediatric intensive care units (PICUs). However, in research studies, many of these children survive with multi-domain health sequelae that has the potential to affect development over many years, termed post-intensive care syndrome-pediatrics (PICS-p). Clinically, there are no recommendations for the assessment and follow-up of children with critical illness as exists for the premature neonatal and congenital heart disease populations. In research studies, primary and secondary outcomes are largely assessed at or prior to hospital discharge, disregarding post-hospital outcomes important to PICU stakeholders. Incorporating longer term outcomes into clinical and research programs, however, can no longer be overlooked. Barriers to outcomes assessments are varied and generalized vs. individualized, but some PICU centers are discovering how to overcome them and are providing this service to families—sometimes specific populations—in need. Research programs and funders are increasingly recognizing the value and need to assess long-term outcomes post-PICU. Finally, we should seek the strong backing of the PICU community and families to insist that long-term outcomes become our new clinical standard of care. PICUs should consider development of a multicenter, multinational collaborative to assess clinical outcomes and optimize care delivery and patient and family outcomes. The aim of this review is to present the potential considerations of implementing long-term clinical follow-up following pediatric critical illness.

Diallyl Trisulfide Suppresses High-Glucose-Induced Cardiomyocyte Apoptosis by Targeting Reactive Oxygen Species-Mediated Hypoxia-Inducible Factor-1α/Insulin-like Growth Factor Binding Protein 3 Activation.

It has been reported that 80% of diabetic patients die due to cardiovascular diseases. We previously demonstrated that activated hypoxia-inducible factor-1α (HIF-1 α)/insulin-like growth factor binding protein-3 (IGFBP-3) signaling by reactive oxygen species (ROS)-regulated prolyl hydroxylase domain-containing protein (PHD) is involved in high-glucose (HG)-induced cardiac apoptosis. Diallyl trisulfide (DATS), a garlic component, shows the strongest inhibitory effect on diabetic cardiomyopathy. In this study, we investigated whether HIF-1α/IGFBP-3 signaling governs the antiapoptotic effect by DATS on HG-exposed cardiomyocytes. It was observed that significantly increased levels of cell apoptosis and decreased Akt phosphorylation were reversed by DATS in HG-exposed cardiac cells. H2O2 and PHD small interfering RNA treatments increased HIF-1α and IGFBP-3 protein levels, which were decreased by DATS treatment. Overexpression of HIF-1α and IGFBP-3 increased HG-induced cell apoptosis, which was suppressed by DATS. The coimmunoprecipitation assay results showed that DATS not only increased the IGF-1 level and reduced IGFBP-3 level but also suppressed their extracellular association for cardiac cells exposed to HG. Experiments using neonatal cardiomyocytes and hearts showed similar results. These findings indicate that the effect of ROS-regulated PHD on the activation of HIF-1α/IGFBP-3 signaling governs the antiapoptotic effect by DATS on HG-exposed cardiomyocytes.

Third Trimester Fetal Heart Rates in Antibody-Mediated Complete Heart Block Predict Need for Neonatal Pacemaker Placement.

Congenital complete heart block (CCHB) affects 1 in 20,000 newborns. This study evaluates fetal and neonatal risk factors predictive of neonatal pacemaker placement in antibody-mediated complete heart block. The Children's Hospital Los Angeles institutional fetal, pacemaker, and medical record databases were queried for confirmed SSA/SSB cases of CCHB between January 2004 and July 2019. Cases excluded were those with a diagnosis beyond the neonatal period, diagnosis of a channelopathy, or if maternal antibody status was unknown. We recorded the gestational age (GA), birth weight (BW), fetal heart rates (FHRs) of the last echocardiogram before delivery, specific neonatal ECG and echocardiogram findings, age at pacemaker placement, and mortality. Of 43 neonates identified with CCHB, 27 had confirmed maternal antibody exposure. Variables associated with neonatal pacemaker implantation were FHRs < 50bpm (p = 0.005), neonatal heart rates < 52bpm (p = 0.015), and neonatal left ventricular fractional shortening (FS) percentages < 34% (p = 0.03). On multivariate analysis, FHR remained significant (p = 0.03) and demonstrated an increased risk of neonatal pacemaker placement by an odds ratio of 12.5 (95% CI 1.3-116, p = 0.05). The median GA at which the FHR was obtained was 34weeks (IQR 26-35weeks). Neonatal pacemaker placement was highly associated with a FHR < 50bpm, neonatal HR < 52bpm, and neonatal FS < 34%. FHRs at 34weeks GA (IQR 26-35weeks) correlated well with postnatal heart rates and were predictive of neonatal pacemaker placement.

Reconstruction of the Swine Pulmonary Artery Using a Graft Engineered With Syngeneic Cardiac Pericytes.

The neonatal heart represents an attractive source of regenerative cells. Here, we report the results of a randomized, controlled, investigator-blinded preclinical study, which assessed the safety and effectiveness of a matrix graft cellularized with cardiac pericytes (CPs) in a piglet model of pulmonary artery (PA) reconstruction. Within each of five trios formed by 4-week-old female littermate piglets, one element (the donor) was sacrificed to provide a source of CPs, while the other two elements (the graft recipients) were allowed to reach the age of 10 weeks. During this time interval, culture-expanded donor CPs were seeded onto swine small intestinal submucosa (SIS) grafts, which were then shaped into conduits and conditioned in a flow bioreactor. Control unseeded SIS conduits were subjected to the same procedure. Then, recipient piglets were randomized to surgical reconstruction of the left PA (LPA) with unseeded or CP-seeded SIS conduits. Doppler echocardiography and cardiac magnetic resonance imaging (CMRI) were performed at baseline and 4-months post-implantation. Vascular explants were examined using histology and immunohistochemistry. All animals completed the scheduled follow-up. No group difference was observed in baseline imaging data. The final Doppler assessment showed that the LPA’s blood flow velocity was similar in the treatment groups. CMRI revealed a mismatch in the average growth of the grafted LPA and contralateral branch in both treatment groups. Histology of explanted arteries demonstrated that the CP-seeded grafts had a thicker luminal cell layer, more intraparietal arterioles, and a higher expression of endothelial nitric oxide synthase (eNOS) compared with unseeded grafts. Moreover, the LPA stump adjacent to the seeded graft contained more elastin and less collagen than the unseeded control. Syngeneic CP engineering did not accomplish the primary goal of supporting the graft’s growth but was able to improve secondary outcomes, such as the luminal cellularization and intraparietal vascularization of the graft, and elastic remodeling of the recipient artery. The beneficial properties of neonatal CPs may be considered in future bioengineering applications aiming to reproduce the cellular composition of native arteries.

Surgical site infection after delayed sternal closure in neonates with congenital heart disease: retrospective case-control study

ObjectivesTo determine the prevalence of surgical site infections (SSIs) in neonatal congenital heart disease patients undergoing delayed sternal closure (DSC) and evaluate risk factors for SSI.MethodsHospital records of 483 consecutive neonates who underwent surgical intervention between January 2013 and December 2017 were reviewed, and perioperative variables were recorded.ResultsWe found that the prevalence of SSI was 87.5% when the body weight was less than 1500 g. When the operative age was between seven and 14 days, the probability of no SSI is about 93.9%. When the duration of the aortic cross-clamp was more than 60 min, the prevalence of SSI was 91.2%. The prevalence without SSI was 96.6% when the duration of DSC was less than 24 h. However, when the duration of DSC was more than 120 h, the prevalence of SSI was 88.9% (p = 0.000).ConclusionsWith the prolongation of aortic clamping duration, the probability of occurrence of SSI increased in neonatal CHD with DSC. The age at operation and body weight are closely related to the occurrence of SSI in neonatal CHD patients with DSC.

A neonatal dataset and benchmark for non-contact neonatal heart rate monitoring based on spatio-temporal neural networks

The digital revolution of noncontact physiological signal monitoring in clinical and home health care is underway, and deep learning techniques are incredibly popular. Camera-based physiological signal monitoring for adults has made considerable progress in recent years. However, most of existing methods and datasets are developed for adult subjects, and until now, there has been no neonatal public database that is collected for developing deep learning method. Thus, in this paper, we introduce a large-scale newborn baby database, named NBHR (newborn baby heart rate estimation database), to fill the abovementioned knowledge gap. A total of 9.6 h of clinical videos (1130 videos totaling 921 GB) and reference vital signs are recorded from 257 infants at 0–6 days old. The facial videos and corresponding synchronized physiological signals, including photoplethysmograph information, heart rate, and oxygen saturation level, are recorded in our database. This large-scale database could be used to develop deep learning methods to estimate heart rate or oxygen saturation levels. Furthermore, a multitask deep learning method, called NBHRnet, is proposed to estimate heart rate based on the NBHR database, and the model is succinct that it can be deployed on a computer without GPUs. The experimental results indicate that NBHRnet yields competitive performance in predicting infant heart rate, with a mean absolute error of 3.97 bpm and a mean absolute percentage error of 3.28%; additionally, it can estimate heart rate almost instantaneously (2 s/60 frames). Our datasets are freely publicly available by request.

Nrf1 promotes heart regeneration and repair by regulating proteostasis and redox balance

Following injury, cells in regenerative tissues have the ability to regrow. The mechanisms whereby regenerating cells adapt to injury-induced stress conditions and activate the regenerative program remain to be defined. Here, using the mammalian neonatal heart regeneration model, we show that Nrf1, a stress-responsive transcription factor encoded by the Nuclear Factor Erythroid 2 Like 1 (Nfe2l1) gene, is activated in regenerating cardiomyocytes. Genetic deletion of Nrf1 prevented regenerating cardiomyocytes from activating a transcriptional program required for heart regeneration. Conversely, Nrf1 overexpression protected the adult mouse heart from ischemia/reperfusion (I/R) injury. Nrf1 also protected human induced pluripotent stem cell-derived cardiomyocytes from doxorubicin-induced cardiotoxicity and other cardiotoxins. The protective function of Nrf1 is mediated by a dual stress response mechanism involving activation of the proteasome and redox balance. Our findings reveal that the adaptive stress response mechanism mediated by Nrf1 is required for neonatal heart regeneration and confers cardioprotection in the adult heart.

Abstract P446: Cyclophilin D Inhibition Rescues Cardiac Function And Electron Transport Chain Assembly And Activity In Hypoxia Exposed Neonatal Mice

Introduction: Mitochondria play a critical role in cardiac myocyte physiology and differentiation. Hypoxia decreases cardiac function. Changes in embryonic heart metabolism at the level of the electron transport chain (ETC) are regulated by a chaperone protein known as cyclophilin D (CypD). Inhibition of CypD with chemicals such as cyclosporin A (CsA) and N-methyl-4-isoleucine cyclosporin (NIM811) leads to more complex mitochondrial structure and effective oxidative phosphorylation. Hypothesis: Inhibition of CypD with CsA or NIM811 will rescue the detrimental effects of hypoxia on cardiac function and on ETC assembly and activity. Methods: Mice were exposed to continuous hypoxia (12% oxygen) immediately before birth (gestational age E19.5) to postnatal day 7 (P7). Hypoxic mice received no treatment (No Tx) or intraperitoneal injections 10mg/kg of vehicle (VEH), CsA, or NIM811 from P1 to P6. Litters of mice born into room air served as controls. On P7, mice were anesthetized and underwent echocardiography and/or hearts were harvested for mitochondrial isolation. Enzymatic activity of ETC complexes was quantified using spectrophotometry and normalized to total protein. To measure physical assembly of complex I &amp; V of the ETC, high resolution clear native polyacrylamide gel electrophoresis (HCRN PAGE) followed by in-gel assays were utilized using appropriate protein loading controls. Results: Cardiac ejection fraction was decreased in hypoxic No Tx (P&lt;0.0001) and VEH (P&lt;0.0001), but was rescued by CsA or NIM811 when compared to room air controls (P&gt;0.05). Heart weight to body weight ratio was increased in No Tx and VEH groups (P&lt; 0.0001) and rescued in the CsA and NIM811 groups when compared to room air controls (P&gt;0.05). Complex I enzymatic activity was rescued with treatment with CsA and NIM811. HCRN PAGE followed by in-gel ETC complex assay demonstrated assembly of complexes I and V into dimers and tetramer in the room air, CsA, and NIM811 groups that was not seen in the No Tx and VEH groups. Conclusion: Pharmacologic inhibition of CypD reversed the effects of hypoxia on cardiac function and ETC activity and assembly in the neonatal heart. Our studies may help develop therapies to treat neonatal cardiomyopathies and the effects of hypoxia on the neonatal heart.

Abstract P339: Examining Cardiac Phenotypes Of EF Hand Containing Domain 1 Protein (EFHD1) Knockout Mice

Mitochondrial dysfunction due to calcium overload is common in heart disease and results in heart failure. In a mouse model of mitochondrial cardiomyopathies we noted a substantial downregulation of the gene encoding for the EF hand containing domain 1 protein (EFHD1). EFHD1 is a mitochondrial protein which binds calcium and has been shown to stimulate both apoptosis and mitoflashes. These processes involve mitochondrial calcium overload. We therefore hypothesized that EFHD1 down regulation could represent a natural response by failing hearts to prevent mitochondrial calcium overload. We therefore studied the calcium handling properties of mice where Efhd1 had been knocked out (Efhd1-KO). These mice are viable and have no obvious adverse cardiac or metabolic phenotypes. We find that EFHD1 is expressed in the cytoplasm and mitochondrial outer membrane and intermembrane space. It associates strongly with endoplasmic reticulum (ER)-associated mitochondrial membranes. Moreover, mitochondria isolated from Efhd1-KO mice also exhibited 250±10 % improvement in calcium retention in liver but not heart, while neonatal mouse hearts were 3 times more resistant to hypoxia. These findings suggest that EFHD1 may modulate mitochondrial calcium uptake.

Abstract P325: The Role Of Runx1 In Cardiomyocyte Cell Cycle And Ploidy

Adult mammalian cardiomyocytes (CMs) are thought to be post-mitotic and therefore unable to regenerate the myocardium after injury. In recent years various studies have shown that the adult mammalian CM is capable of a small amount of proliferation, potentially restricted to a subset of CMs. One such study demonstrated that having greater percentages of the rare mononuclear diploid cardiomyocyte (MNDCM) is associated with improved outcomes after myocardial infarction (MI). An accompanying genome-wide association analysis identified genetic loci associated with the frequency of the MNDCM population. One candidate to come out of this screen was Runx1. Concurrently, RUNX1 captured the attention of cardiac regeneration researchers due to its increased presence in disease states, with some suggesting it may be a marker for dedifferentiation (fetal gene induction). One recent study demonstrated improved calcium handling and decreased eccentric hypertrophy following RUNX1 ablation after injury, perhaps corroborating the idea that RUNX1 is involved with CM dedifferentiation. We hypothesize that Runx1 influences dedifferentiation in CMs, impacting ploidy, as well as CM cell cycle activity and post-MI outcomes. We found that CM-specific overexpression (OE) of Runx1 results in a doubling of the MNDCM population, thereby validating its influence on the population. Via multiple contexts including postnatal development and adult injury, knocking out Runx1 decreases DNA synthesis while Runx1 OE increases DNA synthesis. Furthermore, an initial analysis of RNAseq data demonstrates that RUNX1 OE in a neonatal mouse hearts demonstrated differential expression in genes related to cardiac conduction, contraction, heart development, regeneration, and regulation of cell differentiation . After MI in the adult mouse heart, the effects of Runx1 OE resulted in transient benefits which included increased cell cycle activity and preservation of function. These data suggest that Runx1 is not simply a marker of CM dedifferentiation, but also a regulator of the process including cell cycle activation. Ongoing work will tease apart this role in more detail and could establish RUNX1 as a prominent therapeutic target for mitigating effects of cardiac injury.

Perinatal angiogenesis from pre-existing coronary vessels via DLL4-NOTCH1 signalling.

New coronary vessels are added to the heart around birth to support postnatal cardiac growth. Here we show that, in late fetal development, the embryonic coronary plexus at the inner myocardium of the ventricles expresses the angiogenic signalling factors VEGFR3 and DLL4 and generates new coronary vessels in neonates. Contrary to a previous model in which the formation of new coronary vessels in neonates from ventricular endocardial cells was proposed, we find that late fetal and neonatal ventricular endocardial cells lack angiogenic potential and do not contribute to new coronary vessels. Instead, we show using lineage-tracing as well as gain- and loss-of-function experiments that the pre-existing embryonic coronary plexus at the inner myocardium undergoes angiogenic expansion through the DLL4-NOTCH1 signalling pathway to vascularize the expanding myocardium. We also show that the pre-existing coronary plexus revascularizes the regenerating neonatal heart through a similar mechanism. These findings provide a different model of neonatal coronary angiogenesis and regeneration, potentially informing cardiovascular medicine.

Genetic Evaluation of Inpatient Neonatal and Infantile Congenital Heart Defects: New Findings and Review of the Literature.

The use of clinical genetics evaluations and testing for infants with congenital heart defects (CHDs) is subject to practice variation. This single-institution cross-sectional study of all inpatient infants with severe CHDs evaluated 440 patients using a cardiovascular genetics service (2014–2019). In total, 376 (85.5%) had chromosome microarray (CMA), of which 55 (14.6%) were diagnostic in syndromic (N = 35) or isolated (N = 20) presentations. Genetic diagnoses were made in all CHD classes. Diagnostic yield was higher in syndromic appearing infants, but geneticists’ dysmorphology exams lacked complete sensitivity and 6.5% of isolated CHD cases had diagnostic CMA. Interestingly, diagnostic results (15.8%) in left ventricular outflow tract obstruction (LVOTO) defects occurred most often in patients with isolated CHD. Geneticists’ evaluations were particularly important for second-tier molecular testing (10.5% test-specific yield), bringing the overall genetic testing yield to 17%. We assess these results in the context of previous studies. Cumulative evidence provides a rationale for comprehensive, standardized genetic evaluation in infants with severe CHDs regardless of lesion or extracardiac anomalies because genetic diagnoses that impact care are easily missed. These findings support routine CMA testing in infants with severe CHDs and underscore the importance of copy-number analysis with newer testing strategies such as exome and genome sequencing.

Overexpression of miR-1298 attenuates myocardial ischemia-reperfusion injury by targeting PP2A.

Previous studies reported that microRNA-1298 was abnormally expressed in the myocardium of rat hearts after hypoxia/normoxia injury. This study aims to investigate the function and specific mechanism of miR-1298 in myocardial ischemia/reperfusion (IR) injury. Neonatal rat cardiomyocytes (NRCMs) were isolated from neonatal rat hearts and subjected to oxygen/glucose deprivation/reperfusion (OGD/R) to induce I/R injury. The rat model with I/R injury was induced by ligating the proximal left anterior descending artery (LAD). MiR-1298 expression was detected by qRT-PCR. The levels of PP2A, Bcl-2, Bax, and AMPK signaling members (p-AMPK, p-GSK3β) was detected by Western blot. Cell apoptosis was evaluated by TUNEL staining assay and flow cytometry. The infarct size of rat hearts was assessed by TTC staining assay. Premature and mature MiR-1298 were significantly downregulated while PP2A was significantly upregulated during I/R injury both in vitro and in vivo. The prediction of Starbase suggested that PP2A was a potential target of miR-1298. MiR-1298 overexpression significantly reduced cardiomyocyte apoptosis in vitro, and its protective effect was obviously attenuated by PP2A overexpression. Luciferase reporter assay showed that miR-1298 targeted PP2A directly. In addition, miR-1298 overexpression significantly reduced infarct size and cardiomyocyte apoptosis in the hearts of rats received with I/R injury in vivo. Moreover, miR-1298 overexpression significantly elevated the levels of Bcl-2 and AMPK signaling members (p-AMPK, p-GSK3β) while decreased Bax level, and these effects were partially reversed by PP2A overexpression. MiR-1298 participated in myocardial I/R injury by targeting the PP2A/AMPK/GSK3β signaling pathway, suggesting that miR-1298 might be a potential therapeutic target for myocardial I/R injury.

San1 deficiency leads to cardiomyopathy due to excessive R-loop-associated DNA damage and cardiomyocyte hypoplasia

R-loops are naturally occurring transcriptional intermediates containing RNA/DNA hybrids. Excessive R-loops cause genomic instability, DNA damage, and replication stress. Senataxin-associated exonuclease (San1) is a protein that interacts with Senataxin (SETX), a helicase resolving R-loops. It remains unknown if R-loops-induced DNA damage plays a role in the heart, especially in the proliferative neonatal cardiomyocytes (CMs). San1−/− mice were generated using the CRISPR/Cas9 technique. The newborn San1−/− mice show no overt phenotype, but their hearts were smaller with larger, yet fewer CMs. CM proliferation was impaired with reduced cell cycle-related transcripts and proteins. S9.6 staining revealed that excessive R-loops accumulated in the nucleus of neonatal San1−/− CMs. Increased γH2AX staining on newborn and adult heart sections exhibited increased DNA damage. Similarly, San1−/− AC16-cardiomyocytes showed cumulative R-loops and DNA damage, leading to the activation of cell cycle checkpoint kinase ATR and PARP1 hyperactivity, arresting G2/M cell-cycle and CM proliferation. Together, the present study uncovers an essential role of San1 in resolving excessive R-loops that lead to DNA damage and repressing CM proliferation, providing new insights into a novel biological function of San1 in the neonatal heart. San1 may serve as a novel therapeutic target for the treatment of hypoplastic cardiac disorders.

IL4Rα signaling promotes neonatal cardiac regeneration and cardiomyocyte cell cycle activity

Neonatal heart regeneration depends on proliferation of pre-existing cardiomyocytes, yet the mechanisms driving regeneration and cardiomyocyte proliferation are not comprehensively understood. We recently reported that the anti-inflammatory cytokine, interleukin 13 (IL13), promotes neonatal cardiac regeneration; however, the signaling pathway and cell types mediating this regenerative response remain unknown. Here, we hypothesized that expression of the type II heterodimer receptor for IL13, comprised of IL4Rα and IL13Rα1, expressed directly on cardiomyocytes mediates cardiomyocyte cell cycle and heart regeneration in neonatal mice. Our data demonstrate that indeed global deletion of one critical subunit of the type II receptor, IL4Rα (IL4Rα−/−), decreases cardiomyocyte proliferation during early postnatal development and significantly impairs cardiac regeneration following injury in neonatal mice. While multiple myocardial cell types express IL4Rα, we demonstrate that IL4Rα deletion specifically in cardiomyocytes mediates cell cycle activity and neonatal cardiac regeneration. This demonstrates for the first time a functional role for IL4Rα signaling directly on cardiomyocytes in vivo. Reciprocally, we examined the therapeutic benefit of activating the IL4Rα receptor in non-regenerative hearts via IL13 administration. Following myocardial infarction, administration of IL13 reduced scar size and promoted cardiomyocyte DNA synthesis and karyokinesis, but not complete cytokinesis, in 6-day old non-regenerative mice. Our data demonstrate a novel role for IL4Rα signaling directly on cardiomyocytes during heart regeneration and suggest the potential for type II receptor activation as one potential therapeutic target for promoting myocardial repair.

Can polarization of macrophage metabolism enhance cardiac regeneration?

While largely appreciated for their antimicrobial and repair functions, macrophages have emerged as indispensable for the development, homeostasis, and regeneration of tissue, including regeneration of the neonatal heart. Upon activation, mammalian neonatal macrophages express and secrete factors that coordinate angiogenesis, resolution of inflammation, and ultimately cardiomyocyte proliferation. This is contrary to adult macrophages in the adult heart, which are incapable of inducing significant levels of cardiac regeneration. The underlying mechanisms by which pro-regenerative macrophages are activated and regulated remain vague. A timely hypothesis is that macrophage metabolism contributes to this proliferative and regenerative potential. This is because we now appreciate the significant contributions of metabolites to immune cell programming and function, beyond solely bioenergetics. After birth, the metabolic milieu of the neonate is subject to significant alterations in oxygenation and nutrient supply, which will affect how metabolic substrates are catabolized. In this context, we discuss potential roles for select macrophage metabolic pathways during cardiac regeneration.

Role of oxytocin and c-Myc pathway in cardiac remodeling in neonatal rats undergoing cardiac apical resection

Oxytocin (OT) is a nonapeptide hormone that can improve cardiomyocyte proliferation, suggesting a potential heart regeneration function. Here, we investigated the role of oxytocin and the c-Myc pathway in cardiac remodeling in neonatal rats undergoing cardiac apical resection. We have utilized a knockout of oxytocin receptor (OTR) with OTR-shRNA. A neonatal rat model of cardiac resection (≈10%–15%) was first established. The protein levels of OTR and c-Myc and the expression of cyclin d1 and c-Myc genes were then evaluated in the cardiac tissues at 1, 7, and 21 days after cardiac resection. We also analyzed the proliferation of cardiomyocytes through α-actinin, BrdU, and ki-67 markers. At last, the hemodynamic and electrophysiologic functions were evaluated eight weeks after cardiac resection. At 21 days, the regeneration of cardiomyocytes was repaired among rats in the control and resection groups, while OTR-shRNA groups were failed to improve. Inhibition of OTR failed cardiac regeneration and reduced the number of proliferating cardiomyocytes. The c-Myc protein was significantly reduced in the OTR-shRNA injection hearts. Moreover, we have severely found a depressed heart function in the OTR-shRNA injection animals. These observations revealed that the OT must improve cardiac remodeling in neonatal rat hearts by regulating the c-Myc pathway.

The Comparison of Left Ventricular Myocardial Performance Index (Tei index) in Term and Prema-ture Neonatal Calves

The neonatal heart is different from the adult heart in regard to both biochemical and structural features. Echocardiographic studies in human neonatology show that the myocardial function of left ventricle (LV) of premature infants differs from term infants. No study involving myocardial performance index (MPI) in neonatal animals has been performed until now. The objective of the present study was to evaluate LV MPI in premature calves and compare it to healthy newborn term calves. Ten healthy term and 20 premature calves were used. Echocardiographic evaluations were performed at days 1, 2, and 3 after birth and isovolumic contraction time (IVCT), isovolumic relaxation time (IVRT), ejection time (ET), and MPI calculated with PW tissue Doppler imaging (PW-TDI). Results of the study showed that the IVRT of the LV of premature calves was shorter than seen in healthy term calves. The LVMPI of healthy term calves was also higher than in premature calves. In conclusion, MPI measurement is feasible in neonatal calves. Significant decrements in MPI and shorter IVRT of preterm calves could be the result of the non-closure of the ductus arteriosus (DA), and along with the decreased afterload. Echocardiography and Doppler imaging technique are useful tools for exploring and follow up the cardiovascular system in neonatal calves.

Transcriptional Profiling of Cardiac Cells Links Age-Dependent Changes in Acetyl-CoA Signaling to Chromatin Modifications.

Metabolism has emerged as a regulator of core stem cell properties such as proliferation, survival, self-renewal, and multilineage potential. Metabolites serve as secondary messengers, fine-tuning signaling pathways in response to microenvironment alterations. Studies show a role for central metabolite acetyl-CoA in the regulation of chromatin state through changes in histone acetylation. Nevertheless, metabolic regulators of chromatin remodeling in cardiac cells in response to increasing biological age remains unknown. Previously, we identified novel cardiac-derived stem-like cells (CTSCs) that exhibit increased functional properties in the neonatal heart (nCTSC). These cells are linked to a unique metabolism which is altered with CTSC aging (aCTSC). Here, we present an in-depth, RNA-sequencing-based (RNA-Seq) bioinformatic with cluster analysis that details a distinct epigenome present in nCTSCs but not in aCTSCs. Gene Ontology (GO) and pathway enrichment reveal biological processes, including metabolism, gene regulation enriched in nCTSCs, and STRING analysis that identifies a network of genes related to acetyl-CoA that can potentially influence chromatin remodeling. Additional validation by Western blot and qRT-PCR shows increased acetyl-CoA signaling and histone acetylation in nCTSCs compared to aCTSCs. In conclusion, our data reveal that the link between metabolism and histone acetylation in cardiac cells is altered with the aging of the cardiac tissue.

Redefining the Relationship: Palliative Care in Critical Perinatal and Neonatal Cardiac Patients.

Patients with perinatal and neonatal congenital heart disease (CHD) represent a unique population with higher morbidity and mortality compared to other neonatal patient groups. Despite an overall improvement in long-term survival, they often require chronic care of complex medical illnesses after hospital discharge, placing a high burden of responsibility on their families. Emerging literature reflects high levels of depression and anxiety which plague parents, starting as early as the time of prenatal diagnosis. In the current era of the global COVID-19 pandemic, the additive nature of significant stressors for both medical providers and families can have catastrophic consequences on communication and coping. Due to the high prognostic uncertainty of CHD, data suggests that early pediatric palliative care (PC) consultation may improve shared decision-making, communication, and coping, while minimizing unnecessary medical interventions. However, barriers to pediatric PC persist largely due to the perception that PC consultation is indicative of “giving up.” This review serves to highlight the evolving landscape of perinatal and neonatal CHD and the need for earlier and longitudinal integration of pediatric PC in order to provide high-quality, interdisciplinary care to patients and families.