Human Fetal Heart Research Articles

Methyltransferase METTL3 governs the modulation of SH3BGR expression through m6A methylation modification, imparting influence on apoptosis in the context of Down syndrome-associated cardiac development

Down syndrome (DS), caused by an additional chromosome 21, has a high risk of congenital heart defects (CHD), one of the primary causes of mortality in DS newborns. To elucidate the pathogenetic mechanisms underlying this condition, we explored the role of RNA m6A methylation, regulated by METTL3, in DS cardiac development and its impact on the expression of SH3BGR, a gene located at Down syndrome congenital heart disease (DS-CHD) minimal region. We analyzed DS fetal cardiac tissues to assess RNA m6A methylation levels and identify potential contributors. RNA sequencing was performed to detect differentially expressed genes in the same tissues. To further understand METTL3’s function in heart development, we inactivated Mettl3 in the developing mouse heart to mimic the significantly reduced METTL3 observed in DS cardiac development. Additionally, human cardiomyocyte AC16 cells were used to investigate the molecular mechanism by which METTL3 regulates SH3BGR expression. Apoptosis was analyzed to evaluate METTL3’s effect on heart development through SH3BGR regulation. Reduced m6A modification and decreased METTL3 expression were observed in human DS fetal hearts, along with a significant increase of SH3BGR expression. METTL3, through m6A modification, was found to regulate SH3BGR expression, by influencing mRNA stability. METTL3-deficient mouse embryos exhibited heart malformation with increased apoptosis, emphasizing its role in heart development. In DS hearts, METTL3 downregulation and SH3BGR upregulation, potentially orchestrated by abnormal m6A modification, contribute to gene dysregulation and apoptosis. This study reveals novel insights into DS cardiac pathology, highlighting the intricate role of METTL3 in DS congenital heart defects and presenting the m6A modification of SH3BGR as a potential therapeutic target.

Single-Cell RNA-Seq Analysis of Hearts in Patients with Fetal Tetralogy of Fallot.

To explore the cytological characteristics of tetralogy of Fallot (TOF), we collected samples and investigated the differences in the cytological classification between normal fetal hearts and fetal hearts with congenital defects. We then performed single-cell sequencing analysis to search for possible differential genes of disease markers. Here, the right ventricles of a heart sample with TOF and a healthy human fetal heart sample were analyzed through single-cell sequencing. Data quality control filtering, comparison, quantification, and identification of recovered cells on the raw data were performed using Cell Ranger, thereby ultimately obtaining gene expression matrices for each cell. Subsequently, Seurat was used for cell filtration, standardization, cell subgroup classification, differential expression gene analysis of each subgroup, and marker gene screening. Bioinformatic analysis identified 9,979 and 15,224 cells from the healthy and diseased samples, respectively, with an average read depth of 25,000/cell. The cardiomyocyte cell populations, derived from the abnormal samples identified through the first-level graph-based analysis, were separated into six distinct cell clusters. Our study provides some information on TOF in a fetus, which can offer a new reference for the early detection and treatment of TOF by comparing defective heart cells with normal heart cells.

Single-cell RNA sequencing reveals the gene expression profile and cellular communication in human fetal heart development

The heart is the central organ of the circulatory system, and its proper development is vital to maintain human life. As fetal heart development is complex and poorly understood, we use single-cell RNA sequencing to profile the gene expression landscapes of human fetal hearts from the four-time points: 8, 10, 11, 17 gestational weeks (GW8, GW10, GW11, GW17), and identified 11 major types of cells: erythroid cells, fibroblasts, heart endothelial cells, ventricular cardiomyocytes, atrial cardiomyocytes, macrophage, DCs, smooth muscle, pericytes, neural cells, schwann cells. In addition, we identified a series of differentially expressed genes and signaling pathways in each cell type between different gestational weeks. Notably, we found that ANNEXIN, MIF, PTN, GRN signalling pathways were simple and fewer intercellular connections in GW8, however, they were significantly more complex and had more intercellular communication in GW10, GW11, and GW17. Notably, the interaction strength of OSM signalling pathways was gradually decreased during this period of time (from GW8 to GW17). Together, in this study, we presented a comprehensive and clear description of the differentiation processes of all the main cell types in the human fetal hearts, which may provide information and reference data for heart regeneration and heart disease treatment.

Single-cell RNA sequencing analysis of the human fetal epicardium reveals several new genes involved in regulation of epicardial activation

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Dutch Heart Foundation Background The outside mesothelial layer of the heart, the epicardium, is essential for cardiac development. Cells from this layer undergo epithelial-to-mesenchymal transition (EMT), migrate into the tissue and partake in cardiogenesis by contributing cells and by secreting growth factors. In the adult heart, the epicardium is quiescent but upon ischemic injury it is activated and conveys a partial regenerative response. This activation step is important for repair, but suboptimal compared to the cardiogenic potential during development. Understanding the processes and cells that underlie developmental epicardial activation could contribute to enhancing the adult post-injury response, but little is known about the human developing epicardium. Purpose to determine the cellular composition of the human fetal epicardial layer and to identify the processes that regulate the activation of the epicardium. Methods An epicardial-cell enriched dataset was obtained by specifically dissecting the epicardial layers from 4 fetal human hearts (14-15 weeks gestation, obtained under informed consent and according to local ethical approval). Single live cells were sorted into 384-wells plates and sequenced. Data analysis was performed on 2073 cells using R-packages RaceID3 and StemID2. Findings were validated using qPCR and immunohistochemistry on tissue sections and cell culture models. Results Sequencing analysis revealed a distinct clustering of epicardial (epithelial, pre-EMT) and epicardial-derived mesenchymal (post-EMT) cell populations. Besides the identification of novel markers for epicardial cell states, the regulation of epicardial cell activation and EMT was investigated by applying pseudo-time analysis. We selected genes that were highly regulated (>2 fold change) in this trajectory for further analysis in vitro. We identified several genes including CRIP1, SULF1 and others that are expressed in epithelial cells in vitro and in vivo and are rapidly downregulated upon EMT. The expression profiles positively correlated with epithelial cell related genes and negatively with mesenchymal cell genes. Based on GO-terms, and protein expression within the epicardial layers in fetal and adult epicardium, we anticipated a role for these genes in maintaining the epithelial-state. Indeed, siRNA experiments in vitro with cultured primary human epicardial cells confirmed an essential role in EMT regulation. We continue to evaluate other genes identified in our sequencing dataset, resulting in several other potent and previously unknown pathways involved in regulation of epicardial activation. Conclusions We shed light on the composition of the human fetal epicardium using a highly enriched scRNA dataset. We identify specific markers for different cell-states, and reveal novel regulators of activation that in the future may be influenced to optimize the post-injury response.

Transcutaneous Discrimination of Fetal Heart Rate from Maternal Heart Rate: A Fetal Oximetry Proof-of-Concept.

Intrapartum care uses electronic fetal heart rate monitoring (EFHRM) for over 50years to indirectly assess fetal oxygenation. However, this approach has been associated with an increase in cesarean delivery rates and limited improvements in neonatal hypoxic outcome. To address these shortcomings, a novel transabdominal fetal pulse oximeter (TFO) is being developed to provide an objective measurement of fetal oxygenation. Previous studies have evaluated the performance of TFO on pregnant ewe. Building on the animal model, this study aims to determine whether TFO can successfully capture human fetal heart rate (FHR) signals during non-stress testing (NST) as a proof-of-concept. Eight ongoing pregnancies meeting specific inclusion criteria (18-40years old, singleton, and at least 36weeks' gestation) were enrolled with consent. Each study session was 15 to 20min long. Reference maternal heart rate (MHR) and FHR were obtained using finger pulse oximetry and cardiotocography for subsequent comparison. The overall root-mean-square error was 9.7BPM for FHR and 4.4 for MHR, while the overall mean-absolute error was 7.6BPM for FHR and 1.8 for MHR. Bland-Altman analysis displayed a mean bias ± standard deviation between TFO and reference of -3.9 ± 8.9BPM, with limits of agreement ranging from -21.4 to 13.6 BPM. Both maternal and fetal heart rate measurements obtained from TFO exhibited a p-value < 0.001, showing significant correlation with the reference. This proof-of-concept study successfully demonstrates that TFO can accurately differentiate maternal and fetal heart signals in human subjects. This achievement marks the initial step towards enabling fetal oxygen saturation measurement in humans using TFO.

Variations in the branching pattern of aortic arch in human fetal heart: A Morphological Study

Variations in the branching pattern of aortic arch in human fetal heart: A Morphological Study

STIGMA: Single-cell tissue-specific gene prioritization using machine learning

Clinical exome and genome sequencing have revolutionized the understanding of human disease genetics. Yet many genes remain functionally uncharacterized, complicating the establishment of causal disease links for genetic variants. While several scoring methods have been devised to prioritize these candidate genes, these methods fall short of capturing the expression heterogeneity across cell subpopulations within tissues. Here, we introduce single-cell tissue-specific gene prioritization using machine learning (STIGMA), an approach that leverages single-cell RNA-seq (scRNA-seq) data to prioritize candidate genes associated with rare congenital diseases. STIGMA prioritizes genes by learning the temporal dynamics of gene expression across cell types during healthy organogenesis. To assess the efficacy of our framework, we applied STIGMA to mouse limb and human fetal heart scRNA-seq datasets. In a cohort of individuals with congenital limb malformation, STIGMA prioritized 469 variants in 345 genes, with UBA2 as a notable example. For congenital heart defects, we detected 34 genes harboring nonsynonymous de novo variants (nsDNVs) in two or more individuals from a set of 7,958 individuals, including the ortholog of Prdm1, which is associated with hypoplastic left ventricle and hypoplastic aortic arch. Overall, our findings demonstrate that STIGMA effectively prioritizes tissue-specific candidate genes by utilizing single-cell transcriptome data. The ability to capture the heterogeneity of gene expression across cell populations makes STIGMA a powerful tool for the discovery of disease-associated genes and facilitates the identification of causal variants underlying human genetic disorders.

Hemodynamics During Development and Postnatal Life.

A well-developed heart is essential for embryonic survival. There are constant interactions between cardiac tissue motion and blood flow, which determine the heart shape itself. Hemodynamic forces are a powerful stimulus for cardiac growth and differentiation. Therefore, it is particularly interesting to investigate how the blood flows through the heart and how hemodynamics is linked to a particular species and its development, including human. The appropriate patterns and magnitude of hemodynamic stresses are necessary for the proper formation of cardiac structures, and hemodynamic perturbations have been found to cause malformations via identifiable mechanobiological molecular pathways. There are significant differences in cardiac hemodynamics among vertebrate species, which go hand in hand with the presence of specific anatomical structures. However, strong similarities during development suggest a common pattern for cardiac hemodynamics in human adults. In the human fetal heart, hemodynamic abnormalities during gestation are known to progress to congenital heart malformations by birth. In this chapter, we discuss the current state of the knowledge of the prenatal cardiac hemodynamics, as discovered through small and large animal models, as well as from clinical investigations, with parallels gathered from the poikilotherm vertebrates that emulate some hemodynamically significant human congenital heart diseases.

Integrated small RNA, mRNA and protein omics reveal a miRNA network orchestrating metabolic maturation of the developing human heart

BackgroundAs the fetal heart develops, cardiomyocyte proliferation potential decreases while fatty acid oxidative capacity increases in a highly regulated transition known as cardiac maturation. Small noncoding RNAs, such as microRNAs (miRNAs), contribute to the establishment and control of tissue-specific transcriptional programs. However, small RNA expression dynamics and genome-wide miRNA regulatory networks controlling maturation of the human fetal heart remain poorly understood.ResultsTranscriptome profiling of small RNAs revealed the temporal expression patterns of miRNA, piRNA, circRNA, snoRNA, snRNA and tRNA in the developing human heart between 8 and 19 weeks of gestation. Our analysis demonstrated that miRNAs were the most dynamically expressed small RNA species throughout mid-gestation. Cross-referencing differentially expressed miRNAs and mRNAs predicted 6200 mRNA targets, 2134 of which were upregulated and 4066 downregulated as gestation progressed. Moreover, we found that downregulated targets of upregulated miRNAs, including hsa-let-7b, miR-1-3p, miR-133a-3p, miR-143-3p, miR-499a-5p, and miR-30a-5p predominantly control cell cycle progression. In contrast, upregulated targets of downregulated miRNAs, including hsa-miR-1276, miR-183-5p, miR-1229-3p, miR-615-3p, miR-421, miR-200b-3p and miR-18a-3p, are linked to energy sensing and oxidative metabolism. Furthermore, integrating miRNA and mRNA profiles with proteomes and reporter metabolites revealed that proteins encoded in mRNA targets and their associated metabolites mediate fatty acid oxidation and are enriched as the heart develops.ConclusionsThis study presents the first comprehensive analysis of the small RNAome of the maturing human fetal heart. Our findings suggest that coordinated activation and repression of miRNA expression throughout mid-gestation is essential to establish a dynamic miRNA-mRNA-protein network that decreases cardiomyocyte proliferation potential while increasing the oxidative capacity of the maturing human fetal heart. Our results provide novel insights into the molecular control of metabolic maturation of the human fetal heart.

Single-cell RNA sequencing analysis of the human fetal epicardium results in novel epicardial-specific markers and reveals a role for CRIP1 in epicardial EMT

Abstract Background The outside mesothelial layer of the heart, the epicardium, is essential during cardiac development. Cells from this layer undergo epithelial-to-mesenchymal transition (EMT), migrate into the tissue and partake in cardiogenesis by contributing cells and by secretion of growth factors. In the adult heart, the epicardium is quiescent but upon ischemic injury it is activated and conveys a regenerative response. This activation is important for repair, but suboptimal compared to the cardiogenic potential during development. Understanding the processes and cells that underlie developmental epicardial activation could contribute to enhancing the adult post-injury response, but little is known about the human developing epicardium. The Purpose of this study is to unravel the cellular composition of the human fetal epicardial layer and to identify novel processes that regulate the activation of the epicardium. Methods An epicardial-cell enriched dataset was obtained by specifically dissecting the epicardial layers from 4 fetal human hearts (14-15 weeks gestation, obtained under informed consent and according to local ethical approval). Single live cells were sorted into 384-wells plates and sequenced. Data analysis was performed using R-packages RaceID3 and StemID2. Findings were validated using qPCR and immunohistochemistry on tissue sections and cell culture models. Results Analysis of 2073 cells revealed a clustering of epicardial (epithelial, pre-EMT) and epicardial-derived (mesenchymal, post-EMT) cell populations. Since classical markers for the epicardium such as Wilms’ Tumor 1 and T-box transcription factor 18 were unable to specifically demarcate the epithelial state, we identified and validated several new markers (e.g. C3, NRK) that allow robust classification of epicardium-associated populations. To establish the regulation of epicardial activation and EMT, we applied pseudo-time analysis. We selected genes that were highly regulated (&amp;gt;2 fold change) in this trajectory for further analysis in vitro. qPCR indicated that CRIP1 is expressed in epithelial cells and rapidly downregulated upon EMT (3x reduction, n=3, *p=0.0104). The expression profile of CRIP1 positively correlates with UPK3B (R2:0.98) and negatively with mesenchymal TCF21 (R2: 0.99), together with GO-terms a role for CRIP in maintaining the epithelial-state is likely. Indeed, siRNA experiments in vitro with cultured epicardial cells confirmed an essential role for CRIP1 in EMT regulation. Together with its confirmed protein expression within the epicardial layer in fetal and adult tissue, this protein is of interest for regulating activation of the epicardium. Conclusions We shed light on the composition of the human fetal epicardium using a highly enriched scRNA dataset. We identify specific markers for different cell-states, and reveal novel regulators of activation that in the future may be influenced to optimise the post-injury response.

A spatially-resolved multiomic cell atlas reveals gene regulatory networks underlying cell specification in the developing human heart

Abstract Introduction Cardiogenesis requires the differentiation and coordinated function of a large variety of cell types. Congenital heart disease (CHD), affecting 1% of live births[1], and several adult-onset heart diseases result when these processes go awry[2–4]. To understand the cellular and molecular mechanisms at play we must define the repertoire of cell types in the developing heart as well as the cellular niches within which they interact. Single-cell RNA sequencing is a powerful means of defining cell populations, however existing studies of the human foetal heart[5,6] have been hampered by low cell numbers which limits detection of rare but important cell types. To create an improved atlas we increased the number of cells, increased the age range of foetal hearts sampled, and generated spatial transcriptomic data to map the defined cells to multicellular niches of co-located and interacting cells. To better infer the transcription factors (TFs) governing cell identity using gene regulatory network (GRN) inference we also generated paired single-cell resolution RNA and chromatin accessibility profiles using Assay for Transposase-Accessible Chromatin (ATAC) sequencing. Methods We performed paired single-nuclei RNA and ATAC sequencing (10X Multiome) and single-cell RNAseq (10X 3’ RNAseq) on 23 human foetal hearts ranging from 4 to 20 post-conception weeks. In addition we generated spatial transcriptomic data (10X Visium) from these hearts. We validated cell types defined in single-cell data using protein-level immunofluorescence imaging. Results Our healthy reference atlas includes 300k cells and nuclei. Using their gene expression profile we resolved 46 fine-grained cell types (FIGURE 1). We used cell2location[7], a machine learning classifier trained on the atlas to map the defined cell types to the spatial data (FIGURE 2) and detected niches of co-locating cells, such as a macrophage population in the walls of the great vessels predicted to interact with mural cells. We were able to define location-specific transcriptional signatures such as cardiomyocytes of each chamber (as well as the compact and trabeculated myocardium) and smooth muscle cells specific to great vessels vs coronary arteries. Using a combination of RNA and ATAC data we inferred cell-specific GRNs, which implicated novel TFs such as MSX2 in sinoatrial node pacemaker cells and the enrichment of CHD genes amongst cardiomyocyte-specific GRNs. In the spatial data we showed that gene modules associated with different forms of CHD enrich in specific anatomical regions, such as the outflow tract. Discussion: Together these data constitute the most comprehensive cardiac developmental cell atlas to date. It sheds new light on the diversity of cell states, their niches, and their vulnerability to the genetic causes of CHD.Figure 1:UMAP showing atlasFigure 2:Spatial transcriptomic mapping

EP24.36: Normal anatomy of the human fetal heart, its chambers and septums as a morphological basis for its ultrasound examination

EP24.36: Normal anatomy of the human fetal heart, its chambers and septums as a morphological basis for its ultrasound examination

Single-nuclei multiomic analyses identify human cardiac lymphatic endothelial cells associated with coronary arteries in the epicardium

Cardiac lymphatic vessels play important roles in fluid homeostasis, inflammation, disease, and regeneration of the heart. The developing cardiac lymphatics in human fetal hearts are closely associated with coronary arteries, similar to those in zebrafish hearts. We identify a population of cardiac lymphatic endothelial cells (LECs) that reside in the epicardium. Single-nuclei multiomic analysis of the human fetal heart reveals the plasticity and heterogeneity of the cardiac endothelium. Furthermore, we find that VEGFC is highly expressed in arterial endothelial cells and epicardium-derived cells, providing a molecular basis for the arterial association of cardiac lymphatic development. Using a cell-type-specific integrative analysis, we identify a population of cardiac lymphatic endothelial cells marked by the PROX1 and the lymphangiocrine RELN and enriched in binding motifs of erythroblast transformation specific (ETS) variant (ETV) transcription factors. We report the invivo molecular characterization of human cardiac lymphatics and provide a valuable resource to understand fetal heart development.

Abstract P1005: Parallel Identification Of Gene-Environment Interactions In Cardiac Development Using Human Induced Pluripotent Stem Cells

Most human diseases are influenced by both genetic factors and environmental factors. However, it is not easy to identify causative combinations of genes and environmental factors that interplay in disease development. Congenital heart defects (CHDs), which is the most common birth defect occurring 1% of newborns in the US, are primarily caused by genetic mutations. On the other hand, phenotypes of CHDs are typically inconsistent among individuals with the same variants and the penetrance is often incomplete, which suggests the important role of environmental factors. Environmental factors known to be involved in the development of CHDs include maternal smoking, diabetes, inflammation, and use of certain medications. Here, we investigated gene-environmental interactions in cardiac development. First, we developed a CRISPR-screen system that screens essential genes in cardiac differentiation from human induced pluripotent stem cells (iPSCs). Our custom CRISPRi library targets ~ 700 genes, which are enriched in human adult or fetal hearts. Our screen system successfully identified positive control genes such as TNNT2, TNNC1, and TBX20 as well as genes that have not been intensively investigated in human cardiac development such as BAMBI and SMAD6. Second, to identify gene-environment interactions, we used the system under the exposure to various environmental stresses such as nicotine, ethanol, inflammatory cytokines, and multiple teratogenic drugs and identified stress-specific gene-environment interactions. This approach is applicable to any other screens of gene-environment interactions.

Abstract P1178: APOE-NOTCH Axis Governs Elastogenesis During Human Cardiac Valve Remodeling

Background: Valve remodeling is a complex process involving extracellular matrix organization, development of trilaminar structures, and physical elongation of valve leaflets. However, the cellular and molecular mechanisms regulating valve remodeling and their roles in congenital valve disorders remain poorly understood. Methods: Semilunar valves and atrioventricular valves from healthy and age-matched human fetal hearts with pulmonary stenosis (PS) were collected. Single-Cell RNA-sequencing (scRNA-seq) was performed to determine the transcriptomic landscape of multiple valvular cell subtypes in valve remodeling and disease. Results: scRNA-seq analysis of healthy human fetal valves identified a novel APOE+ elastin-producing valve interstitial cell (Elastin-VIC) subtype spatially located underneath VECs in the direction of unidirectional flow. Knockdown of APOE in fetal VICs resulted in significant elastogenesis defects. In pulmonary valve with PS, we observed decreased expression of APOE and other genes regulating elastogenesis such as EMILIN1 and LOXL1 , as well as elastin fragmentation. Cell-cell interaction analysis revealed that JAG1 from unidirectional VECs activates NOTCH signaling in Elastin-VICs through NOTCH3. In vitro Jag1 treatment in VICs increased the expression of elastogenesis-related genes and enhanced contractile functions with related gene expression. This was accompanied by activation of NOTCH signaling and elastogenesis observed in VICs co-cultured with VECs in the presence of unidirectional flow. Notably, we found that the JAG1-NOTCH3 signaling pair was drastically reduced in the PS valves. Lastly, we demonstrated that APOE is indispensable for JAG1-induced NOTCH activation in VICs, reinforcing the presence of a synergistic intrinsic and external regulatory network involving APOE and NOTCH signaling that is responsible for regulating elastogenesis during human valve remodeling. Conclusion: scRNA-seq analysis of human fetal valves identified a novel Elastin-VIC subpopulation, and revealed mechanism of APOE and NOTCH signaling mediated elastogenesis during valve remodeling, which provided opportunity to understand pathogenesis of elastic malformation within congenital valve disease.

Fetal metabolic adaptations to cardiovascular stress in twin-twin transfusion syndrome

Monochorionic-diamniotic twin pregnancies are susceptible to unique complications arising from a single placenta shared by two fetuses. Twin-twin transfusion syndrome (TTTS) is a constellation of disturbances caused by unequal blood flow within the shared placenta giving rise to a major hemodynamic imbalance between the twins. Here, we applied TTTS as a model to uncover fetal metabolic adaptations to cardiovascular stress. We compared untargeted metabolomic analyses of amniotic fluid samples from severe TTTS cases vs. singleton controls. Amniotic fluid metabolites demonstrated alterations in fatty acid, glucose, and steroid hormone metabolism in TTTS. Among TTTS cases, unsupervised principal component analysis revealed two distinct clusters of disease defined by levels of glucose metabolites, amino acids, urea, and redox status. Our results suggest that the human fetal heart can adapt to hemodynamic stress by modulating its glucose metabolism and identify potential differences in the ability of individual fetuses to respond to cardiovascular stress.

An Immunohistochemical Study of Proliferation of Human Fetal Heart Cardiomyocyte With Phospho-Histone H3 Antibody.

The rapid proliferation of cardiomyocytes in mammals occurs during fetal life. But in postnatal life, this capacity of proliferation is reduced or lost as they exit the cell cycle. However, the cardiomyocytes don't show the same activity for different species. In human fetuses orin adult life, the capacity of the proliferation of cardiomyocytes and their response to an injury arenot understood yet.In this study, we have done an immunohistochemical study using phospho-histone H3 (PHH3) to observe human fetal cardiomyocytes' proliferative activity. The heart specimens from the fetal autopsy of spontaneously aborted and stillborn human fetuses were subjected to immunohistochemical study using PHH3 antibody, and comparison between the PHH3 index (number of PHH3 positive cells per 1000 number of cardiomyocytes/high power field [HPF]) of myocardial regions was done using appropriate statistical tests. A total of 17 fetal hearts were included in our study. In the left ventricle, right ventricle, right atrium, and interventricular septum, the PHH3 index of myocardium was significantly higher over the pericardial region (p-value 0.002, p-value <0.001, <0.001, and 0.009 respectively) as compared to the region of over the endocardium and the middle part of the myocardium.The PHH3 index of the pericardial region of the left ventricle was significantly correlated with the maximum thickness of the left ventricle.

MYH3-associated non-syndromic palatoschisis (cleft palate,CP) in Limousine cattle.

MYH3-associated non-syndromic palatoschisis (cleft palate,CP) in Limousine cattle.

Postmortem Evaluation of First Trimester Fetal Heart.

Due to rapid technology advancement and increasing diagnostic expertise, fetal medicine is rapidly improving. Prenatal diagnostic advancements made it possible to identify structural abnormalities in fetuses as early as the first trimester of pregnancy. However, to validate the echocardiographic diagnosis that led to the pregnancy termination, the termination of pregnancy owing to severe fetal deformities should be audited in accordance with a correct anatomic diagnosis. Following the PRISMA declaration, a systematic literature search was done to find articles on post-mortem first trimester human fetal heart evaluation. Thirteen suitable studies were found using the search method. It is theoretically possible to examine the human fetal heart after death in early pregnancy however these methods are not widely available due the costs associated with the procedure and the equipment, the effects of tissue coloration and distortion brought on by the fixation and contrasting processes (for micro-CT), the current requirement for a skilled operator to acquire, reconstruct, and process the images, and data storage requirements greater than those of conventional clinical scans.

Genetics and Molecular Basis of Congenital Heart Defects in Down Syndrome: Role of Extracellular Matrix Regulation.

Down syndrome (DS), a complex disorder that is caused by the trisomy of chromosome 21 (Hsa21), is a major cause of congenital heart defects (CHD). Interestingly, only about 50% of individuals with Hsa21 trisomy manifest CHD. Here we review the genetic basis of CHD in DS, focusing on genes that regulate extracellular matrix (ECM) organization. The overexpression of Hsa21 genes likely underlies the molecular mechanisms that contribute to CHD, even though the genes responsible for CHD could only be located in a critical region of Hsa21. A role in causing CHD has been attributed not only to protein-coding Hsa21 genes, but also to genes on other chromosomes, as well as miRNAs and lncRNAs. It is likely that the contribution of more than one gene is required, and that the overexpression of Hsa21 genes acts in combination with other genetic events, such as specific mutations or polymorphisms, amplifying their effect. Moreover, a key function in determining alterations in cardiac morphogenesis might be played by ECM. A large number of genes encoding ECM proteins are overexpressed in trisomic human fetal hearts, and many of them appear to be under the control of a Hsa21 gene, the RUNX1 transcription factor.