Reduced ACTC1 expression might play a role in the onset of congenital heart disease by inducing cardiomyocyte apoptosis

Comparative transcriptome analysis between long- and short-term survival after pig-to-monkey cardiac xenotransplantation reveals differential heart failure development

Cardiac xenotransplantation is the potential treatment for end-stage heart failure, but the allogenic organ supply needs to catch up to clinical demand. Therefore, genetically-modified porcine heart xenotransplantation could be a potential alternative. So far, pig-to-monkey heart xenografts have been studied using multi-transgenic pigs, indicating various survival periods. However, functional mechanisms based on survival period-related gene expression are unclear. This study aimed to identify the differential mechanisms between pig-to-monkey post-xenotransplantation long- and short-term survivals. Heterotopic abdominal transplantation was performed using a donor CD46-expressing GTKO pig and a recipient cynomolgus monkey. RNA-seq was performed using samples from POD60 XH from monkey and NH from age-matched pigs, D35 and D95. Gene-annotated DEGs for POD60 XH were compared with those for POD9 XH (Park et al. 2021). DEGs were identified by comparing gene expression levels in POD60 XH versus either D35 or D95 NH. 1,804 and 1,655 DEGs were identified in POD60 XH versus D35 NH and POD60 XH versus D95 NH, respectively. Overlapped 1,148 DEGs were annotated and compared with 1,348 DEGs for POD9 XH. Transcriptomic features for heart failure and inhibition of T cell activation were observed in both long (POD60)- and short (POD9)-term survived monkeys. Only short-term survived monkey showed heart remodeling and regeneration features, while long-term survived monkey indicated multi-organ failure by neural and hormonal signaling as well as suppression of B cell activation. Our results reveal differential heart failure development and survival at the transcriptome level and suggest candidate genes for specific signals to control adverse cardiac xenotransplantation effects.

Pyroptosis in cardiovascular diseases: Pumping gasdermin on the fire

Pyroptosis is a form of programmed cell death associated with activation of inflammasomes and inflammatory caspases, proteolytic cleavage of gasdermin proteins (forming pores in the plasma membrane), and selective release of proinflammatory mediators. Induction of pyroptosis results in amplification of inflammation, contributing to the pathogenesis of chronic cardiovascular diseases such as atherosclerosis and diabetic cardiomyopathy, and acute cardiovascular events, such as thrombosis and myocardial infarction. While engagement of pyroptosis during sepsis-induced cardiomyopathy and septic shock is expected and well documented, we are just beginning to understand pyroptosis involvement in the pathogenesis of cardiovascular diseases with less defined inflammatory components, such as atrial fibrillation. Due to the danger that pyroptosis represents to cells within the cardiovascular system and the whole organism, multiple levels of pyroptosis regulation have evolved. Those include regulation of inflammasome priming, post-translational modifications of gasdermins, and cellular mechanisms for pore removal. While pyroptosis in macrophages is well characterized as a dramatic pro-inflammatory process, pyroptosis in other cell types within the cardiovascular system displays variable pathways and consequences. Furthermore, different cells and organs engage in local and distant crosstalk and exchange of pyroptosis triggers (oxidized mitochondrial DNA), mediators (IL-1β, S100A8/A9) and antagonists (IL-9). Development of genetic tools, such as Gasdermin D knockout animals, and small molecule inhibitors of pyroptosis will not only help us fully understand the role of pyroptosis in cardiovascular diseases but may result in novel therapeutic approaches inhibiting inflammation and progression of chronic cardiovascular diseases to reduce morbidity and mortality from acute cardiovascular events.

Alpha-cardiac Actin Serum Expression Levels Detect Acute Cellular Rejection in Heart Transplant Patients

BACKGROUND

Given the central role of sarcomeric dysfunction in cardiomyocyte biology and sarcomere alterations described in endomyocardial biopsies of transplant patients with rejection, we hypothesized that the serum expression levels of genes encoding sarcomeric proteins were altered in acute cellular rejection (ACR). The aim of this study is to identify altered sarcomere-related molecules in serum and to evaluate their diagnostic accuracy for detecting rejection episodes.

METHODS

Serum samples from transplant recipients undergoing routine endomyocardial biopsies were included in an RNA sequencing analysis (n = 40). Protein concentrations of alpha-cardiac actin were determined using a specific enzyme-linked immunoassay (n = 80).

RESULTS

We identified 17 sarcomeric genes differentially expressed in patients with clinically relevant rejection (grade ≥2R ACR). A receiver operating characteristic curve was done to assess their accuracy for ACR detection and found that 6 relevant actins, myosins, and other sarcomere-related genes showed great diagnostic capacity with an area under the curve (AUC) > 0.800. Specifically, the gene encoding alpha-cardiac actin ( ACTC1 ) showed the best results (AUC = 1.000, P < 0.0001). We determine ACTC1 protein levels in a larger patient cohort, corroborating its overexpression and obtaining a significant diagnostic capacity for clinically relevant rejection (AUC = 0.702, P < 0.05).

CONCLUSIONS

Sarcomeric alterations are reflected in peripheral blood of patients with allograft rejection. Because of their precision to detect ACR, we propose sarcomere ACTC1 serum expression levels as potential candidate for to be included in the development of molecular panel testing for noninvasive ACR detection.

A Comprehensive Analysis of the Myocardial Transcriptome in ZBED6-Knockout Bama Xiang Pigs

The ZBED6 gene is a transcription factor that regulates the expression of IGF2 and affects muscle growth and development. However, its effect on the growth and development of the heart is still unknown. Emerging evidence suggests that long noncoding RNAs (lncRNAs) can regulate genes at the epigenetic, transcriptional, and posttranscriptional levels and play an important role in the development of eukaryotes. To investigate the function of ZBED6 in the cardiac development of pigs, we constructed the expression profiles of mRNAs and lncRNAs in myocardial tissue obtained from Bama Xiang pigs in the ZBED6 knockout group (ZBED6-KO) and the wild-type group (ZBED6-WT). A total of 248 differentially expressed genes (DEGs) and 209 differentially expressed lncRNAs (DELs) were detected, and 105 potential cis target genes of DELs were identified. The functional annotation analysis based on the Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) databases revealed two GO items related to muscle development by the cis target genes of DELs. Moreover, IGF2 was the direct target gene of ZBED6 by ChIP-PCR experiment. Our results explored the mechanism and expression profile of mRNAs and lncRNAs of ZBED6 gene knockout on myocardium tissue development, mining the key candidate genes in that process like IGF2.

Dynamic Observation of Autophagy and Transcriptome Profiles in a Mouse Model of Bleomycin-Induced Pulmonary Fibrosis

Pulmonary fibrosis is a group of progressive, fibrotic, and fatal lung diseases, and the role of autophagy in pulmonary fibrosis is controversial. In the current research, we dynamically observed a bleomycin-induced pulmonary fibrosis mouse model after 3, 7, 14, 21, and 28 days and investigated the expression of autophagy markers. We found that autophagy markers were not significantly changed on the indicated days in the mouse lung tissue. Then, RNA-Seq was used to analyze the gene expression and associated functions and pathways in fibrotic lung tissue on different days post-bleomycin. In addition, short time series expression miner (STEM) analysis was performed to explore the temporal post-bleomycin gene expression. Through STEM, continually up- or downregulated profiles did not demonstrate the critical role of autophagy in the development of fibrosis. Furthermore, gene ontology (GO) annotations showed that continually upregulated profiles were mainly related to fibrosis synthesis, extracellular space, and inflammation, while enriched pathways were mainly related to the PI3K-Akt signaling pathway, ECM-receptor interactions, and focal adhesion signaling pathway. For continually downregulated profiles, GO annotations mainly involved sarcomere organization, muscle contraction, and muscle fiber development. The enriched KEGG signaling pathways were the cAMP signaling pathway, cGMP-PKG signaling pathway, calcium signaling pathway, and cardiac muscle contraction. Moreover, we analyzed autophagy-related genes' expression in specific cells from a publicly available database of three human and one animal study of pulmonary fibrosis using single-cell sequencing technology. All results consistently demonstrated no critical role of autophagy in the pathogenesis of pulmonary fibrosis. In summary, autophagy may not critically and consistently change during the development of pulmonary fibrosis at different stages post-bleomycin in a mouse model. These continually up- or downregulated profiles, including gene profiles, and the corresponding functions and pathways may provide mechanistic insights into IPF therapy.

Short-term high fat diet alters genes associated with metabolic and vascular dysfunction during adolescence in rats: a pilot study

Background

Diet-induced metabolic dysfunction precedes multiple disease states including diabetes, heart disease, and vascular dysfunction. The critical role of the vasculature in disease progression is established, yet the details of how gene expression changes in early cardiovascular disease remain an enigma. The objective of the current pilot project was to evaluate whether a quantitative assessment of gene expression within the aorta of six-week old healthy male Sprague-Dawley rats compared to those exhibiting symptoms of metabolic dysfunction could reveal potential mediators of vascular dysfunction.

Methods

RNA was extracted from the aorta of eight rats from a larger experiment; four animals fed a high-fat diet (HFD) known to induce symptoms of metabolic dysfunction (hypertension, increased adiposity, fasting hyperglycemia) and four age-matched healthy animals fed a standard chow diet (CHOW). The bioinformatic workflow included Gene Ontology (GO) biological process enrichment and network analyses.

Results

The resulting network contained genes relevant to physiological processes including fat and protein metabolism, oxygen transport, hormone regulation, vascular regulation, thermoregulation, and circadian rhythm. The majority of differentially regulated genes were downregulated, including several associated with circadian clock function. In contrast, leptin and 3-hydroxy-3-methylglutaryl-CoA synthase 2 (Hmgcs2) were notably upregulated. Leptin is involved in several major energy balance signaling pathways and Hmgcs2 is a mitochondrial enzyme that catalyzes the first reaction of ketogenesis.

Conclusion

Together, these data describe changes in gene expression within the aortic wall of HFD rats with early metabolic dysfunction and highlight potential pathways and signaling intermediates that may impact the development of early vascular dysfunction.

Polar Gini Curve: A Technique to Discover Gene Expression Spatial Patterns from Single-cell RNA-seq Data

In this work, we describe the development of Polar Gini Curve, a method for characterizing cluster markers by analyzing single-cell RNA sequencing (scRNA-seq) data. Polar Gini Curve combines the gene expression and the 2D coordinates ("spatial") information to detect patterns of uniformity in any clustered cells from scRNA-seq data. We demonstrate that Polar Gini Curve can help users characterize the shape and density distribution of cells in a particular cluster, which can be generated during routine scRNA-seq data analysis. To quantify the extent to which a gene is uniformly distributed in a cell cluster space, we combine two polar Gini curves (PGCs)-one drawn upon the cell-points expressing the gene (the "foreground curve") and the other drawn upon all cell-points in the cluster (the "background curve"). We show that genes with highly dissimilar foreground and background curves tend not to uniformly distributed in the cell cluster-thus having spatially divergent gene expression patterns within the cluster. Genes with similar foreground and background curves tend to uniformly distributed in the cell cluster-thus having uniform gene expression patterns within the cluster. Such quantitative attributes of PGCs can be applied to sensitively discover biomarkers across clusters from scRNA-seq data. We demonstrate the performance of the Polar Gini Curve framework in several simulation case studies. Using this framework to analyze a real-world neonatal mouse heart cell dataset, the detected biomarkers may characterize novel subtypes of cardiac muscle cells. The source code and data for Polar Gini Curve could be found at http://discovery.informatics.uab.edu/PGC/ or https://figshare.com/projects/Polar_Gini_Curve/76749.

Peptidomics Analysis Reveals Peptide PDCryab1 Inhibits Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX) is limited due to dose-dependent cardiotoxicity. Peptidomics is an emerging field of proteomics that has attracted much attention because it can be used to study the composition and content of endogenous peptides in various organisms. Endogenous peptides participate in various biological processes and are important sources of candidates for drug development. To explore peptide changes related to DOX-induced cardiotoxicity and to find peptides with cardioprotective function, we compared the expression profiles of peptides in the hearts of DOX-treated and control mice by mass spectrometry. The results showed that 236 differential peptides were identified upon DOX treatment, of which 22 were upregulated and 214 were downregulated. Next, we predicted that 31 peptides may have cardioprotective function by conducting bioinformatics analysis on the domains of each precursor protein, the predicted score of peptide biological activity, and the correlation of each peptide with cardiac events. Finally, we verified that a peptide (SPFYLRPPSF) from Cryab can inhibit cardiomyocyte apoptosis, reduce the production of reactive oxygen species, improve cardiac function, and ameliorate myocardial fibrosis in vitro and vivo. In conclusion, our results showed that the expression profiles of peptides in cardiac tissue change significantly upon DOX treatment and that these differentially expressed peptides have potential cardioprotective functions. Our study suggests a new direction for the treatment of DOX-induced cardiotoxicity.

Identification of Potential Hub Genes of Atherosclerosis Through Bioinformatic Analysis

Cardiovascular and cerebrovascular diseases, which mainly consist of atherosclerosis (AS), are major causes of death. A great deal of research has been carried out to clarify the molecular mechanisms of AS. However, the etiology of AS remains poorly understood. To screen the potential genes of AS occurrence and development, GSE43292 and GSE57691 were obtained from the Gene Expression Omnibus (GEO) database in this study for bioinformatic analysis. First, GEO2R was used to identify differentially expressed genes (DEGs) and the functional annotation of DEGs was performed by gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The Search Tool for the Retrieval of Interacting Genes (STRING) tool was used to construct the protein-protein interaction network and the most important modules and core genes were mined. The results show that a total of 211 DEGs are identified. The functional changes of DEGs are mainly associated with the cellular process, catalytic activity, and protein binding. Eighteen genes were identified as core genes. Bioinformatic analysis showed that the core genes are mainly enriched in numerous processes related to actin. In conclusion, the DEGs and hub genes identified in this study may help us understand the potential etiology of the occurrence and development of AS.

Genetics of Congenital Heart Disease

Congenital heart disease (CHD) is one of the most common birth defects. Studies in animal models and humans have indicated a genetic etiology for CHD. About 400 genes have been implicated in CHD, encompassing transcription factors, cell signaling molecules, and structural proteins that are important for heart development. Recent studies have shown genes encoding chromatin modifiers, cilia related proteins, and cilia-transduced cell signaling pathways play important roles in CHD pathogenesis. Elucidating the genetic etiology of CHD will help improve diagnosis and the development of new therapies to improve patient outcomes.

TBX3 deficiency accelerates apoptosis in cardiomyoblasts through regulation of P21 expression

Congenital heart disease (CHD) is the most common birth defect in newborns. There is increasing evidence that apoptosis and remodeling of the cardiomyoblasts are the major pathology of CHD. Previous research found that T-box transcription factor 3 (TBX3) was compulsory for the regulation of proliferation, cell cycle arrest and apoptosis in various cells. Hence, TBX3 might be involved in the treatment of CHD. The primary aim of this study was to study the effects of TBX3 on apoptosis in aged cardiomyoblasts and investigate the latent mechanism. In the present study, we found TBX3 knockdown induced proliferation inhibition, cell cycle arrest and apoptosis accompanied by mitochondrial dysfunction in cardiomyoblasts at passage 10 to 15. Apoptosis-inducing effects of TBX3 silence could be neutralized by silencing P21 using specific siRNA. In addition, the mRNA and protein expression levels of TBX3 in the heart tissues of sporadic type CHD donors were obviously down-regulated. In conclusion, we demonstrated that TBX3 deficiency accelerated apoptosis via directly regulating P21 expression in senescent cardiomyoblasts.

Novel phenotype-genotype correlations of hypertrophic cardiomyopathy caused by mutation in α-actin and myosin-binding protein genes in three unrelated Chinese families

BACKGROUND

The correlations between genotype and phenotype in hypertrophic cardiomyopathy (HCM) have not been established. Mutation of α-actin gene (ACTC1) is a rare cause of HCM. This study aimed to explore novel genotype-phenotype correlations in HCM patients with the variants in ACTC1 and myosin-binding protein (MYBPC3) genes in three unrelated Chinese families.

METHODS

Clinical, electrocardiographic, and echocardiographic examinations were performed in three Han pedigrees. Exon and boarding intron analysis of 96 cardio-disease-related genes was performed using second-generation sequencing on three probands. The candidate variants were validated in 14 available family members and 300 unrelated healthy controls by bi-directional Sanger sequencing. The pathogenicity and conservation were calculated using MutationTaster, PolyPhen-2, SIFT, and Clustal X. Pathogenicity classification of the variants was based on American College of Medical Genetics and Genomics (ACMG) guidelines.

RESULTS

Nine members fulfilled diagnostic criteria for HCM with clinical characteristics, electrocardiographic, and echocardiographic findings. Two candidate variants in ACTC1 p.Asp26Asn (ACTC1-D26N) and MYBPC3 p.Arg215Cys (MYBPC3-R215C) were identified in patients. Only ACTC1-D26N strongly co-segregated with the HCM phenotype. Seven patients who harbored variant ACTC-D26N only were diagnosed with non-obstructive HCM, and four of these patients exhibited a triphasic left ventricular (LV) filling pattern. Two patients carrying both ACTC1-D26N and MYBPC3-R215C variants showed a higher LV outflow tract pressure gradient. Bioinformatics analysis revealed that the two variants were deleterious and highly conserved across species. According to ACMG guidelines, ACTC1-D26N is classified as a likely pathogenic mutation. The second variation MYBPC3-R215C may function as a genetic modifier, which remains uncertain here.

CONCLUSIONS

Novel p.(Asp26Asn) mutation of ACTC1 was associated with HCM phenotype, and the penetrance is extremely high (∼81.8%) in adults. The second variation, MYBPC3-R215C may function as a genetic modifier, which remains uncertain here.

Comparative Bioinformatics Characteristic of Bladder Cancer Stage 2 from Stage 4 Expression Profile: A Network-Based Study

BACKGROUND

Bladder cancer (BC) has remained as one of the most challenging issues in medicine. The aim of this study was to investigate the differential network analysis of stages 2 and 4 of BC to better understand the molecular pathology of these states.

MATERIALS AND METHODS

We chose gene expression data of GSE52519 from Gene Expression Omnibus (GEO) database analyzed by the GEO2R online tool. Cytoscape version 3.6.1 and its algorithms are the methods applied for the network construction and investigation of differentially expressed genes (DEG) in these states.

RESULT

Our result revealed that the analysis DEGs provides useful information about a common molecular feature of stages 2 and 4 of BC.

CONCLUSION

Consequently, the network finding revealed that more investigation about stage 2 is required to achieve an effective therapeutic protocol to block the transition from stage 2 to stage 4.

Transcriptome and DNA Methylome Dynamics during Triclosan-Induced Cardiomyocyte Differentiation Toxicity

Cardiac development is a dynamic process and sensitive to environmental chemicals. Triclosan is widely used as an antibacterial agent and reported to transport across the placenta and affect embryonic development. Here, we used human embryonic stem cell- (hESC-) derived cardiomyocytes (CMs) to determine the effects of TCS exposure on cardiac development. After TCS treatment, the differentiation process was significantly blocked and spontaneous beating rates of CMs were also decreased. Transcriptome analysis showed the dysregulation of genes involved in cardiogenesis, including GATA4 and TNNT2. Additionally, DNA methylation was also altered by TCS exposure, especially in those regions with GATA motif enrichment. These alterations of transcriptome and DNA methylation were all associated with signaling pathways integral to heart development. Our findings indicate that TCS exposure might cause cardiomyocyte differentiation toxicity and provide the new insights into how environmental factors regulate DNA methylation and gene expressions during heart development.

Biomimetic engineering of the cardiac tissue through processing, functionalization, and biological characterization of polyester urethanes

Three-dimensional (3D) tissue models offer new tools in the study of diseases. In the case of the engineering of cardiac muscle, a realistic goal would be the design of a scaffold able to replicate the tissue-specific architecture, mechanical properties, and chemical composition, so that it recapitulates the main functions of the tissue. This work is focused on the design and preliminary biological validation of an innovative polyester urethane (PUR) scaffold mimicking cardiac tissue properties. The porous scaffold was fabricated by thermally induced phase separation (TIPS) from poly(ε-caprolactone) diol, 1,4-butanediisocyanate, and l-lysine ethyl ester. Morphological and mechanical scaffolds characterization was accomplished by confocal microscopy, and micro-tensile and compression techniques. Scaffolds were then functionalized with fibronectin by plasma treatment, and the surface treatment was studied by x-ray photoelectron spectroscopy, attenuated total reflectance Fourier transform infrared spectra, and contact angle measurements. Primary rat neonatal cardiomyocytes were seeded on scaffolds, and their colonization, survival, and beating activity were analyzed for 14 days. Signal transduction pathways and apoptosis involved in cells, the structural development of the heart, and its metabolism were analyzed. PUR scaffolds showed a porous-aligned structure and mechanical properties consistent with that of the myocardial tissue. Cardiomyocytes plated on the scaffolds showed a high survival rate and a stable beating activity. Serine/threonine kinase (AKT) and extracellular signal-regulated kinases (ERK) phosphorylation was higher in cardiomyocytes cultured on the PUR scaffold compared to those on tissue culture plates. Real-time polymerase chain reaction analysis showed a significant modulation at 14 days of cardiac muscle (MYH7, prepro-ET-1), hypertrophy-specific (CTGF), and metabolism-related (SLC2a1, PFKL) genes in PUR scaffolds.

A MicroRNA93-Interferon Regulatory Factor-9-Immunoresponsive Gene-1-Itaconic Acid Pathway Modulates M2-Like Macrophage Polarization to Revascularize Ischemic Muscle

BACKGROUND

Currently, no therapies exist for treating and improving outcomes in patients with severe peripheral artery disease (PAD). MicroRNA93 (miR93) has been shown to favorably modulate angiogenesis and to reduce tissue loss in genetic PAD models. However, the cell-specific function, downstream mechanisms, or signaling involved in miR93-mediated ischemic muscle neovascularization is not clear. Macrophages were best known to modulate arteriogenic response in PAD, and the extent of arteriogenic response induced by macrophages is dependent on greater M2 to M1 activation/polarization state. In the present study, we identified a novel mechanism by which miR93 regulates macrophage polarization to promote angiogenesis and arteriogenesis to revascularize ischemic muscle in experimental PAD.

METHODS

In vitro (macrophages, endothelial cells, skeletal muscle cells under normal and hypoxia serum starvation conditions) and in vivo experiments in preclinical PAD models (unilateral femoral artery ligation and resection) were conducted to examine the role of miR93-interferon regulatory factor-9-immunoresponsive gene-1 (IRG1)-itaconic acid pathway in macrophage polarization, angiogenesis, arteriogenesis, and perfusion recovery.

RESULTS

In vivo, compared with wild-type controls, miR106b-93-25 cluster-deficient mice (miR106b-93-25-/-) showed decreased angiogenesis and arteriogenesis correlating with increased M1-like macrophages after experimental PAD. Intramuscular delivery of miR93 in miR106b-93-25-/- PAD mice increased angiogenesis, arteriogenesis, and the extent of perfusion, which correlated with more M2-like macrophages in the proximal and distal hind-limb muscles. In vitro, miR93 promotes and sustains M2-like polarization even under M1-like polarizing conditions (hypoxia serum starvation). Delivery of bone marrow-derived macrophages from miR106b-93-25-/- to wild-type ischemic muscle decreased angiogenesis, arteriogenesis, and perfusion, whereas transfer of wild-type macrophages to miR106b-93-25-/- had the opposite effect. Systematic analysis of top differentially upregulated genes from RNA sequencing between miR106b-93-25-/- and wild-type ischemic muscle showed that miR93 regulates IRG1 function to modulate itaconic acid production and macrophage polarization. The 3' untranslated region luciferase assays performed to determine whether IRG1 is a direct target of miR93 revealed that IRG1 is not an miR93 target but that interferon regulatory factor-9, which can regulate IRG1 expression, is an miR93 target. In vitro, increased expression of interferon regulatory factor-9 and IRG1 and itaconic acid treatment significantly decreased endothelial angiogenic potential.

CONCLUSIONS

miR93 inhibits interferon regulatory factor-9 to decrease IRG1-itaconic acid production to induce M2-like polarization in ischemic muscle to enhance angiogenesis, arteriogenesis, and perfusion recovery in experimental PAD.

A gain-of-function ACTC1 3'UTR mutation that introduces a miR-139-5p target site may be associated with a dominant familial atrial septal defect

The ostium secundum atrial septal defect (ASDII) is the most common type of congenital heart disease and is characterized by a left to right shunting of oxygenated blood caused by incomplete closure of the septum secundum. We identified a familial form of isolated ASDII that affects four individuals in a family of five and shows autosomal dominant inheritance. By whole genome sequencing, we discovered a new mutation (c.*1784T > C) in the 3′-untranslated region (3′UTR) of ACTC1, which encodes the predominant actin in the embryonic heart. Further analysis demonstrated that the c.*1784T > C mutation results in a new target site for miRNA-139-5p, a microRNA that is involved in cell migration, invasion, and proliferation. Functional analysis demonstrated that the c.*1784T > C mutation specifically downregulates gene expression in a luciferase assay. Additionally, miR-139-5p mimic causes further decrease, whereas miR-139-5p inhibitor can dramatically rescue the decline in gene expression caused by this mutation. These findings suggest that the familial ASDII may be a result of an ACTC1 3′UTR gain-of-function mutation caused by the introduction of a new miR-139-5p target site. Our results provide the first evidence of a pathogenic mutation in the ACTC1 3′UTR that may be associated with familial isolated ASDII.

Identification of Region-Specific Myocardial Gene Expression Patterns in a Chronic Swine Model of Repaired Tetralogy of Fallot

Surgical repair of Tetralogy of Fallot (TOF) is highly successful but may be complicated in adulthood by arrhythmias, sudden death, and right ventricular or biventricular dysfunction. To better understand the molecular and cellular mechanisms of these delayed cardiac events, a chronic animal model of postoperative TOF was studied using microarrays to perform cardiac transcriptomic studies. The experimental study included 12 piglets (7 rTOF and 5 controls) that underwent surgery at age 2 months and were further studied after 23 (+/- 1) weeks of postoperative recovery. Two distinct regions (endocardium and epicardium) from both ventricles were analyzed. Expression levels from each localization were compared in order to decipher mechanisms and signaling pathways leading to ventricular dysfunction and arrhythmias in surgically repaired TOF. Several genes were confirmed to participate in ventricular remodeling and cardiac failure and some new candidate genes were described. In particular, these data pointed out FRZB as a heart failure marker. Moreover, calcium handling and contractile function genes (SLN, ACTC1, PLCD4, PLCZ), potential arrhythmia-related genes (MYO5B, KCNA5), and cytoskeleton and cellular organization-related genes (XIRP2, COL8A1, KCNA6) were among the most deregulated genes in rTOF ventricles. To our knowledge, this is the first comprehensive report on global gene expression profiling in the heart of a long-term swine model of repaired TOF.

Changes in renal tissue proteome induced by mesenteric lymph drainage in rats after hemorrhagic shock with resuscitation

Kidney injury commonly occurs after hemorrhagic shock. Previous studies have shown that post-hemorrhagic shock mesenteric lymph (PHSML) return negatively affects the kidneys and may induce injury. This study investigates the effect of PHSML drainage on the proteome in renal tissue. A controlled hemorrhagic shock model was established in the shock and shock+drainage groups. After 1 h of hypotension, fluid resuscitation was implemented within 30 min. Meanwhile, PHSML was drained in the shock+drainage group. After 3 h of resuscitation, renal tissue was extracted for proteome analysis using two-dimensional fluorescence difference gel electrophoresis. Differential proteins with intensities that either increased or decreased by 1.5-fold or greater were selected for trypsin digestion and analyzed by matrix-assisted laser desorption/ionization time-of-flight (TOF) mass spectrometry and tandem TOF/TOF mass spectrometry. Enzyme-linked immunosorbent assay was used to validate the identified partial proteins. Compared with the sham group, hnRNPC and Starp decreased in the shock group, whereas Hadha, Slc25a13, Atp5b, hnRNPC, Starp, Rps3, and actin were downregulated in the shock+drainage group. Meanwhile, Atp5b and actin decreased in the shock+drainage group relative to the shock group. The identified proteins can be classified into different categories, such as cell proliferation (hnRNPC, Strap, and Rps3), energy metabolism (Hadha, Atp5b, and Slc25a13), cell motility, and cytoskeleton (actin). Moreover, enzyme-linked immunosorbent assay measurement validated the changed levels of Atp5b and Actg2. Our findings provide a starting point for investigating the functions of differentially expressed proteins in acute kidney injury induced by hemorrhagic shock. These findings hold great potential for the development of therapeutic interventions.

Transcriptome responses to heat stress in hypothalamus of a meat-type chicken

Background

Heat stress has resulted in great losses in poultry production. To address this issue, we systematically analyzed chicken hypothalamus transcriptome responses to thermal stress using a 44 k chicken Agilent microarray,

Methods

Hypothalamus samples were collected from a control group reared at 25°C, a heat-stress group treated at 34°C for 24 h, and a temperature-recovery group reared at 25°C for 24 h following a heat-stress treatment. We compared the expression profiles between each pair of the three groups using microarray data.

Results

A total of 1,967 probe sets were found to be differentially expressed in the three comparisons with P < 0.05 and a fold change (FC) higher than 1.5, and the genes were mainly involved in self-regulation and compensation required to maintain homeostasis. Consistent expression results were found for 11 selected genes by quantitative real-time PCR. Thirty-eight interesting differential expression genes were found from GO term annotation and those genes were related to meat quality, growth, and crucial enzymes. Using these genes for genetic network analysis, we obtained three genetic networks. Moreover, the transcripts of heat-shock protein, including Hsp 40 and Hsp 90, were significantly altered in response to thermal stress.

Conclusions

This study provides a broader understanding of molecular mechanisms underlying stress response in chickens and discovery of novel genes that are regulated in a specific thermal-stress manner.

Electronic supplementary material

The online version of this article (doi:10.1186/s40104-015-0003-6) contains supplementary material, which is available to authorized users.

Chagas disease cardiomyopathy: immunopathology and genetics

Chagas disease, caused by the protozoan Trypanosoma cruzi, is endemic in Latin America and affects ca. 10 million people worldwide. About 30% of Chagas disease patients develop chronic Chagas disease cardiomyopathy (CCC), a particularly lethal inflammatory cardiomyopathy that occurs decades after the initial infection, while most patients remain asymptomatic. Mortality rate is higher than that of noninflammatory cardiomyopathy. CCC heart lesions present a Th1 T-cell-rich myocarditis, with cardiomyocyte hypertrophy and prominent fibrosis. Data suggest that the myocarditis plays a major pathogenetic role in disease progression. Major unmet goals include the thorough understanding of disease pathogenesis and therapeutic targets and identification of prognostic genetic factors. Chagas disease thus remains a neglected disease, with no vaccines or antiparasitic drugs proven efficient in chronically infected adults, when most patients are diagnosed. Both familial aggregation of CCC cases and the fact that only 30% of infected patients develop CCC suggest there might be a genetic component to disease susceptibility. Moreover, previous case-control studies have identified some genes associated to human susceptibility to CCC. In this paper, we will review the immunopathogenesis and genetics of Chagas disease, highlighting studies that shed light on the differential progression of Chagas disease patients to CCC.

Myocardial gene expression of T-bet, GATA-3, Ror-γt, FoxP3, and hallmark cytokines in chronic Chagas disease cardiomyopathy: an essentially unopposed TH1-type response

Background. Chronic Chagas disease cardiomyopathy (CCC), a late consequence of Trypanosoma cruzi infection, is an inflammatory cardiomyopathy with prognosis worse than those of noninflammatory etiology (NIC). Although the T cell-rich myocarditis is known to play a pathogenetic role, the relative contribution of each of the functional T cell subsets has never been thoroughly investigated. We therefore assessed gene expression of cytokines and transcription factors involved in differentiation and effector function of each functional T cell subset (T_H1/T_H2/T_H17/Treg) in CCC, NIC, and heart donor myocardial samples. Methods and Results. Quantitative PCR showed markedly upregulated expression of IFN-γ and transcription factor T-bet, and minor increases of GATA-3; FoxP3 and CTLA-4; IL-17 and IL-18 in CCC as compared with NIC samples. Conversely, cytokines expressed by T_H2 cells (IL-4, IL-5, and IL-13) or associated with Treg (TGF-β and IL-10) were not upregulated in CCC myocardium. Expression of T_H1-related genes such as T-bet, IFN-γ, and IL-18 correlated with ventricular dilation, FoxP3, and CTLA-4. Conclusions. Results are consistent with a strong local T_H1-mediated response in most samples, possibly associated with pathological myocardial remodeling, and a proportionally smaller FoxP3⁺CTLA4⁺ Treg cell population, which is unable to completely curb IFN-γ production in CCC myocardium, therefore fueling inflammation.

Polymorphism in the alpha cardiac muscle actin 1 gene is associated to susceptibility to chronic inflammatory cardiomyopathy

Aims

Chagas disease, caused by the protozoan Trypanosoma cruzi is endemic in Latin America, and may lead to a life-threatening inflammatory dilated, chronic Chagas cardiomyopathy (CCC). One third of T. cruzi-infected individuals progress to CCC while the others remain asymptomatic (ASY). A possible genetic component to disease progression was suggested by familial aggregation of cases and the association of markers of innate and adaptive immunity genes with CCC development. Since mutations in multiple sarcomeric genes, including alpha-cardiac actin (ACTC1) have been involved in hereditary dilated cardiomyopathy, we investigated the involvement of the ACTC1 gene in CCC pathogenesis.

Methods and Results

We conducted a proteomic and genetic study on a Brazilian study population. The genetic study was done on a main cohort including 118 seropositive asymptomatic subjects and 315 cases and the replication was done on 36 asymptomatic and 102 CCC cases. ACTC1 protein and mRNA levels were lower in myocardial tissue from patients with end-stage CCC than those found in hearts from organ donors. Genotyping a case-control cohort of CCC and ASY subjects for all informative single nucleotide polymorphism (SNP) in the ACTC1 gene identified rs640249 SNP, located at the 5’ region, as associated to CCC. Associations are borderline after correction for multiple testing. Correlation and haplotype analysis led to the identification of a susceptibility haplotype. Functional assays have shown that the rs640249A/C polymorphism affects the binding of transcriptional factors in the promoter regions of the ACTC1 gene. Confirmation of the detected association on a larger independent replication cohort will be useful.

Conclusions

Genetic variations at the ACTC1 gene may contribute to progression to chronic Chagas Cardiomyopathy among T. cruzi-infected patients, possibly by modulating transcription factor binding to ACTC1 promoter regions.

Effects of low-level hexabromocyclododecane (HBCD) exposure on cardiac development in zebrafish embryos

Hexabromocyclododecane (HBCD) is one of the most widely used brominated flame retardants. In the present study, zebrafish embryos were exposed to HBCD at the low concentrations of 0, 2, 20 and 200 nM. The results showed HBCD exposure resulted in an increase in heart rate and cardiac arrhythmia after exposure for 72 h, though the survival rate and the whole malformation rate were not significantly affected. These results demonstrated that the heart might be a target of HBCD. Low-level HBCD exposure may not share the same mechanisms as exposure to high concentrations, since no obvious increase of apoptotic cells around the heart was observed in the HBCD-treated groups. It was observed that the expression of Tbx5 and Nkx2.5 was significantly elevated by HBCD treatment in a dose-dependent manner using real-time quantitative PCR, which may be mainly responsible for the alteration of heart rate, given that Tbx5 and Nkx2.5 are two factors regulating ventricle conduction. The mRNA expression of RyR2 and Atp2a2b (SERCA2a) was up-regulated in the exposure group, which may be one of reasons to affect the normal heart rate, since SERCA2a and RyR2 play an important role in calcium ion transport of cadiomyocytes. However, HBCD exposure did not significantly change the expression of Actc1l, Tnnt2, and Myh6, which are mainly muscle contractile genes that play key roles in the formation of cardiac structure. These results were consistent with the lack of effect seen on the other measurements of cardiac function, end diastolic volume, end-systolic volume, stroke volume, and cardiac output.

Ca²+-regulatory proteins in cardiomyocytes from the right ventricle in children with congenital heart disease

BACKGROUND

Hypoxia and hypertrophy are the most frequent pathophysiological consequence of congenital heart disease (CHD) which can induce the alteration of Ca2+-regulatory proteins and inhibit cardiac contractility. Few studies have been performed to examine Ca2+-regulatory proteins in human cardiomyocytes from the hypertrophic right ventricle with or without hypoxia.

METHODS

Right ventricle tissues were collected from children with tetralogy of Fallot [n = 25, hypoxia and hypertrophy group (HH group)], pulmonary stenosis [n = 25, hypertrophy group (H group)], or small isolated ventricular septal defect [n = 25, control group (C group)] during open-heart surgery. Paraffin sections of tissues were stained with 3,3'-dioctadecyloxacarbocyanine perchlorate to measure cardiomyocyte size. Expression levels of Ca2+-regulatory proteins [sarcoplasmic reticulum Ca2+-ATPase (SERCA2a), ryanodine receptor (RyR2), sodiumcalcium exchanger (NCX), sarcolipin (SLN) and phospholamban (PLN)] were analysed by means of real-time PCR, western blot, or immunofluorescence. Additionally, phosphorylation level of RyR and PLN and activity of protein phosphatase (PP1) were evaluated using western blot.

RESULTS

Mild cardiomyocyte hypertrophy of the right ventricle in H and HH groups was confirmed by comparing cardiomyocyte size. A significant reduction of SERCA2a in mRNA (P<0.01) was observed in the HH group compared with the C group. The level of Ser16-phosphorylated PLN was down-regulated (P<0.01) and PP1 was increased (P<0.01) in the HH group compared to that in the C group.

CONCLUSIONS

The decreased SERCA2a mRNA may be a biomarker of the pathological process in the early stage of cyanotic CHD with the hypertrophic right ventricle. A combination of hypoxia and hypertrophy can induce the adverse effect of PLN-Ser16 dephosphorylation. Increased PP1 could result in the decreased PLN-Ser16 and inhibition of PP1 is a potential therapeutic target for heart dysfunction in pediatrics.

Epidemiology, genetics and treatments for myopia

Myopia is a significant public health problem and its prevalence is increasing over time and genetic factors in disease development are important. The prevalence and incidence of myopia within sampled population often varies with age, country, sex, race, ethnicity, occupation, environment, and other factors. Myopia growth is under a combination of genes and their products in time and space to complete the coordination role of the guidance. Myopia-related genes include about 70 genetic loci to which primary myopias have been mapped, although the number is constantly increasing and depends to some extent on definition. Of these, several are associated with additional abnormalities, mostly as part of developmental syndromes. These tend to result from mutations in genes encoding transcriptional activators, and most of these have been identified by sequencing candidate genes in patients with developmental anomalies. Currently, COL1A1 (collagen alpha-1 chain of type I), COL2A1 (collagen alpha-1 chain of type II), ACTC1 (actin, alpha, cardiac muscle 1), PAX6 (paired box gene 6) and NIPBL (nipped-B homolog), and so on have been mapped. Myopia is most commonly treated with spectacles or glasses. The most common surgical procedure performed to correct myopia is laser in situ keratomileusis (LASIK). This review of the recent advances on epidemiology, genetic locations and treatments of myopia are summarized.