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Background The role of cellular senescence in human heart failure (HF) remains unclear. The senescence‐associated secretory phenotype (SASP) is composed of proteins released by senescent cells. We assessed the prognostic significance and biologic pathways associated with the SASP in human HF using a plasma proteomics approach. Methods and Results We measured 25 known SASP proteins among 2248 PHFS (Penn HF Study) participants using the SOMAScan V4 assay. We extracted the common variance in these proteins to generate SASP factor scores and assessed the relationship between these SASP factor scores and (1) all‐cause death and (2) the composite of death or HF hospital admission. We also assessed the relationship of each SASP factor to 4746 other proteins, correcting for multiple comparisons, followed by pathway analyses. Two SASP factors were identified. Both factors were associated with older age, lower estimated glomerular filtration rate, and more advanced New York Heart Association class, among other clinical variables. Both SASP factors exhibited a significant positive association with the risk of death independent of the Meta‐Analysis of Global‐Group in Chronic HF score and NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide) levels. The 2 identified SASP factors were associated with 1201 and 1554 proteins, respectively, belonging to various pathways including the coagulation system, complement system, acute phase response signaling, and retinoid X receptor–related pathways that regulate cell metabolism. Conclusions Increased SASP components are independently associated with adverse outcomes in HF. Biologic pathways associated with SASP are predominantly related to coagulation, inflammation, and cell metabolism.

Background: This study assesses the temporal responses of cardiovascular function, fibro-inflammation, and glucometabolic profiles in asymptomatic adults with type 2 diabetes, following a low-energy meal replacement plan (MRP) or exercise training. Methods: Secondary analysis of DIASTOLIC: a randomised, open-label, blinded-endpoint trial of 12 weeks MRP (~810 kcal/day) or exercise training. Cardiac magnetic resonance, plasma fibroinflammatory, and metabolic markers were undertaken at baseline, 4, and 12 weeks. Results: Out of 24 participants in the MRP group and 22 in exercise training, 18 and 11 completed all three visits. MRP resulted in early (0–4 weeks) improvement in insulin resistance (HOMA-IR: 10.82 to 4.32), decrease in FABP-4 (4.87 ± 0.19 to 5.15 ± 0.32 mg/L), and improvement in left ventricular remodelling LV mass: volume (0.86 ± 0.14 to 0.78 ± 0.11), all with large effect sizes. MMP8 levels increased moderately at 4–12 weeks. Peak early diastolic strain rate (cPEDSR) initially decreased, then improved. Exercise training led to minor improvements in insulin resistance and MMP-8 levels, with no significant changes in cPEDSR or LV remodelling. Conclusions: MRP resulted in early improvements in insulin resistance, cardiac remodelling, and inflammation, but with an initial decrease in diastolic function, improving by 12 weeks. Exercise training showed minor early benefits in insulin resistance and inflammation, but no significant cardiac changes.

Abstract Background Heart failure with preserved ejection fraction (HFpEF) and atrial fibrillation (AF) frequently co-exist. There is a limited understanding on whether this coexistence is associated with distinct alterations in myocardial remodelling and mechanics. We aimed to determine if patients with atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) represent a distinct phenotype. Methods In this secondary analysis of adults with HFpEF (NCT03050593), participants were comprehensively phenotyped with stress cardiac MRI, echocardiography and plasma fibroinflammatory biomarkers, and were followed for the composite endpoint (HF hospitalisation or death) at a median of 8.5 years. Those with AF were compared to sinus rhythm (SR) and unsupervised cluster analysis was performed to explore possible phenotypes. Results 136 subjects were included (SR = 75, AF = 61). The AF group was older (76 ± 8 vs. 70 ± 10 years) with less diabetes (36% vs. 61%) compared to the SR group and had higher left atrial (LA) volumes (61 ± 30 vs. 39 ± 15 mL/m2, p

Background Although several studies have addressed plasma proteomics in heart failure with preserved ejection fraction, limited data are available on the prognostic value of urinary proteomics. The objective of our study was to identify urinary proteins/peptides associated with death and heart failure admission in patients with heart failure with preserved ejection fraction. Methods and Results The study population included participants enrolled in TOPCAT (Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist Trial). The relationship between urine protein levels and the risk of death or heart failure admission was assessed using Cox regression, in both nonadjusted analyses and adjusting for urine creatinine levels, and the MAGGIC (Meta‐Analysis Global Group in Chronic Heart Failure) score. A total of 426 (12.4%) TOPCAT participants had urinary protein data and were included. There were 40 urinary proteins/peptides significantly associated with death or heart failure admission in nonadjusted analyses, 21 of which were also significant adjusted analyses. Top proteins in the adjusted analysis included ANGPTL2 (angiopoietin‐like protein 2) (hazard ratio [HR], 0.5731 [95% CI, 0.47–0.7]; P=3.13E‐05), AMY2A (α amylase 2A) (HR, 0.5496 [95% CI, 0.44–0.69]; P=0.0001), and DNASE1 (deoxyribonuclease‐1) (HR, 0.5704 [95% CI, 0.46–0.71]; P=0.0002). Higher urinary levels of proteins involved in fibrosis (collagen VI α‐1, collagen XV α‐1), metabolism (pancreatic α‐amylase 2A/B, mannosidase α class 1A member 1), and inflammation (heat shock protein family D member 1, inducible T cell costimulatory ligand) were associated with a lower risk of death or heart failure admission. Conclusions Our study identifies several novel associations between urinary proteins/peptides and outcomes in heart failure with preserved ejection fraction. Many of these associations are independent of clinical risk scores and may aid in risk stratification in this patient population.

Background Identifying novel molecular drivers of disease progression in heart failure (HF) is a high‐priority goal that may provide new therapeutic targets to improve patient outcomes. The authors investigated the relationship between plasma proteins and adverse outcomes in HF and their putative causal role using Mendelian randomization. Methods and Results The authors measured 4776 plasma proteins among 1964 participants with HF with a reduced left ventricular ejection fraction enrolled in PHFS (Penn Heart Failure Study). Assessed were the observational relationship between plasma proteins and (1) all‐cause death or (2) death or HF‐related hospital admission (DHFA). The authors replicated nominally significant associations in the Washington University HF registry (N=1080). Proteins significantly associated with outcomes were the subject of 2‐sample Mendelian randomization and colocalization analyses. After correction for multiple testing, 243 and 126 proteins were found to be significantly associated with death and DHFA, respectively. These included small ubiquitin–like modifier 2 (standardized hazard ratio [sHR], 1.56; P

Objective To characterise cardiac remodelling, exercise capacity and fibroinflammatory biomarkers in patients with aortic stenosis (AS) with and without diabetes, and assess the impact of diabetes on outcomes.Methods Patients with moderate or severe AS with and without diabetes underwent echocardiography, stress cardiovascular magnetic resonance (CMR), cardiopulmonary exercise testing and plasma biomarker analysis. Primary endpoint for survival analysis was a composite of cardiovascular mortality, myocardial infarction, hospitalisation with heart failure, syncope or arrhythmia. Secondary endpoint was all-cause death.Results Diabetes (n=56) and non-diabetes groups (n=198) were well matched for age, sex, ethnicity, blood pressure and severity of AS. The diabetes group had higher body mass index, lower estimated glomerular filtration rate and higher rates of hypertension, hyperlipidaemia and symptoms of AS. Biventricular volumes and systolic function were similar, but the diabetes group had higher extracellular volume fraction (25.9%±3.1% vs 24.8%±2.4%, p=0.020), lower myocardial perfusion reserve (2.02±0.75 vs 2.34±0.68, p=0.046) and lower percentage predicted peak oxygen consumption (68%±21% vs 77%±17%, p=0.002) compared with the non-diabetes group. Higher levels of renin (log10renin: 3.27±0.59 vs 2.82±0.69 pg/mL, p

Little is known about the developmental causes of aortic root defects. Here the authors show that the inactivation of Sox17 in aortic root endothelium results in aortic root defects affecting aortic valve and coronary ostium.

Abstract Despite the importance of cardiomyocyte proliferation in cardiac development and regeneration, the mechanisms that promote cardiomyocyte cell cycle remain incompletely understood. RE1 silencing transcription factor (REST) is a transcriptional repressor of neuronal genes. Here we show that REST also regulates the cardiomyocyte cell cycle. REST binds and represses the cell cycle inhibitor gene p21 and is required for mouse cardiac development and regeneration. Rest deletion de-represses p21 and inhibits the cardiomyocyte cell cycle and proliferation in embryonic or regenerating hearts. By contrast, REST overexpression in cultured cardiomyocytes represses p21 and increases proliferation. We further show that p21 knockout rescues cardiomyocyte cell cycle and proliferation defects resulting from Rest deletion. Our study reveals a REST-p21 regulatory axis as a mechanism for cell cycle progression in cardiomyocytes, which might be exploited therapeutically to enhance cardiac regeneration.

Lysyl oxidase-like 2 (LOXL2) is an enzyme that promotes scaffolding of extracellular matrix proteins. Here the authors show that LOXL2 is crucial for pressure-overload induced cardiac fibrosis, and that antibody-mediated inhibition or genetic disruption ofLoxl2in mice shows therapeutic potential for treatment of cardiac fibrosis.

The original version of this Article contained an error in the spelling of the author Jianyun Yan, which was incorrectly given as Jiangyun Yan. This has now been corrected in both the PDF and HTML versions of the Article.

Hearth valve morphogenesis in mice is studied and it is found that its initiation requires calcineurin/NFAT to repress VEGF expression in the myocardium underlying the site of prospective valve formation. This repression of VEGF is essential for the formation of mesenchymal cells through endocardial cell transformation.

Polymer photovoltaic devices are described based on poly(3-hexylthiophene) (P3HT) and Ti[O.sub.2] nanorod hybrid bulk heterojunctions and the interface modification of a Ti[O.sub.2] nanorod surface is conducted. The suppression of recombination at P3HT/Ti[O.sub.2] nanorod interfaces by attaching effective ligand molecules has improved the performance of the device.

Despite the importance of cardiomyocyte proliferation in cardiac development and regeneration, the mechanisms that promote cardiomyocyte cell cycle remain incompletely understood. RE1 silencing transcription factor (REST) is a transcriptional repressor of neuronal genes. Here we show that REST also regulates the cardiomyocyte cell cycle. REST binds and represses the cell cycle inhibitor gene p21 and is required for mouse cardiac development and regeneration. Rest deletion de-represses p21 and inhibits the cardiomyocyte cell cycle and proliferation in embryonic or regenerating hearts. By contrast, REST overexpression in cultured cardiomyocytes represses p21 and increases proliferation. We further show that p21 knockout rescues cardiomyocyte cell cycle and proliferation defects resulting from Rest deletion. Our study reveals a REST-p21 regulatory axis as a mechanism for cell cycle progression in cardiomyocytes, which might be exploited therapeutically to enhance cardiac regeneration. [ABSTRACT FROM AUTHOR]

Genes encoding angiotensin-converting enzymes (Ace and Ace2) are essential for heart function regulation. Cardiac stress enhances Ace, but suppresses Ace2, expression in the heart, leading to a net production of angiotensin II that promotes cardiac hypertrophy and fibrosis. The regulatory mechanism that underlies the Ace2- to-Ace pathological switch, however, is unknown. Here we report that the Brahma-related gene-1 (Brg1) chromatin remodeler and forkhead box M1 (FoxM1) transcription factor cooperate within cardiac (coronary) endothelial cells of pathologically stressed hearts to trigger the Ace2-to-Ace enzyme switch, angiotensin I-to-II conversion, and cardiac hypertrophy. In mice, cardiac stress activates the expression of Brg1 and FoxM1 in endothelial cells. Once activated, Brg1 and FoxM1 form a protein complex on Ace and Ace2 promoters to concurrently activate Ace and repress Ace2, tipping the balance to Ace2 expression with enhanced angiotensin II production, leading to cardiac hypertrophy and fibrosis. Disruption of endothelial Brg1 or FoxM1 or chemical inhibition of FoxM1 abolishes the stress-induced Ace2-to-Ace switch and protects the heart from pathological hypertrophy. In human hypertrophic hearts, BRG1 and FOXM1 expression is also activated in endothelial cells; their expression levels correlate strongly with the ACE/ACE2 ratio, suggesting a conserved mechanism. Our studies demonstrate a molecular interaction of Brg1 and FoxM1 and an endothelial mechanism of modulating Ace/Ace2 ratio for heart failure therapy. [ABSTRACT FROM AUTHOR]

Development of the cerebral vessels, pharyngeal arch arteries (PAAs). and cardiac outflow tract (OFT) requires multipotent neural crest cells (NCCs) that migrate from the neural tube to target tissue destinations. Little is known about how mammalian NCC development is orchestrated by gene programming at the chromatin level, however. Here we show that Brahma-related gene 1 (Brg1), an ATPase subunit of the Brg1/Brahma-associated factor (BAF) chromatin-remodeling complex, is required in NCCs to direct cardiovascular development. Mouse embryos lacking Brg1 in NCCs display immature cerebral vessels, aberrant PAA patterning, and shortened OFT. Brg1 suppresses an apoptosis factor, Apoptosis signal-regulating kinase 1 (Ask1), and a cell cycle inhibitor, p21cip1, to inhibit apoptosis and promote proliferation of NCCS, thereby maintaining a multipotent cell reservoir at the neural crest. Brgl also supports Myosin heavy chain 11 (Myh11) expression to allow NCCS to develop into mature vascular smooth muscle cells of cerebral vessels. Within NCCS, Brg1 partners with chromatin remodeler Chromodomain-helicase-DNA-binding protein 7 (Chd7) on the PlexinA2 promoter to activate PlexinA2, which encodes a receptor for semaphorin to guide NCCS into the OFT. Our findings reveal an important role for Brg1 and its downstream pathways in the survival, differentiation, and migration of the multipotent NCCs critical for mammalian cardiovascular development. [ABSTRACT FROM AUTHOR]

Heart malformations are common congenital defects in humans. Many congenital heart defects involve anomalies in cardiac septation or valve development, and understanding the developmental mechanisms that underlie the formation of cardiac septal and valvular tissues thus has important implications for the diagnosis, prevention and treatment of congenital heart disease. The development of heart septa and valves involves multiple types of progenitor cells that arise either within or outside the heart. Here, we review the morphogenetic events and genetic networks that regulate spatiotemporal interactions between the cells that give rise to septal and valvular tissues and hence partition the heart. INSET: Box 1. Glossary. [ABSTRACT FROM AUTHOR]

In this study, we investigated the interplay of three-dimensional morphologies and the photocarrier dynamics of polymer/inorganic nanocrystal hybrid photoactive layers consisting of TiO2 nanoparticles and nanorods. Electron tomography based on scanning transmission electron microscopy using high-angle annular dark-field imaging was performed to analyze the morphological organization of TiO2 nanocrystals in poly(3-hexylthiophene) (P3HT) in optimal solar cell devices. The Three-dimensional (3D) morphologies of these hybrid films were correlated with the photocarrier dynamics of charge separation, transport, and recombination, which were comprehensively probed by various transient techniques. Visualization of these 3D bulk heterojunction morphologies clearly reveals that elongated and anisotropic TiO2 nanorods in P3HT not only can significantly reduce the probability of the interparticle hopping transport of electrons by providing better connectivity with respect to the TiO2 nanoparticles, but also tend to form a large-scale donor-acceptor phase-separated morphology, which was found to enhance hole transport. The results support the establishment of a favorable morphology for polymer/inorganic hybrid solar cells due to the presence of the dimensionality of TiO2 nanocrystals as a result of more effective mobile carrier generation and more efficient and balanced transport of carriers. [ABSTRACT FROM AUTHOR]

The article talks about the importance of chromatin regulation in controlling cardiac gene expression under different physiological and pathological conditions. It discusses mechanisms that may provide a framework for the study of interactions among diverse chromatin remodelers or modifiers and transcription factors. The authors focused on the roles of adenosine triphosphate (ATP)-dependent chromatin-remodeling factors and chromatin-modifying enzymes that control gene expression during cardiovascular development and disease.

Cardiac hypertrophy and failure are characterized by transcriptional reprogramming of gene expression. Adult cardiomyocytes in mice primarily express α-myosin heavy chain (α-MHC, also known as Myh6), whereas embryonic cardiomyocytes express β-MHC (also known as Myh7). Cardiac stress triggers adult hearts to undergo hypertrophy and a shift from α-MHC to fetal β-MHC expression. Here we show that Brg1, a chromatin-remodelling protein, has a critical role in regulating cardiac growth, differentiation and gene expression. In embryos, Brg1 promotes myocyte proliferation by maintaining Bmp10 and suppressing p57kip2 expression. It preserves fetal cardiac differentiation by interacting with histone deacetylase (HDAC) and poly (ADP ribose) polymerase (PARP) to repress α-MHC and activate β-MHC. In adults, Brg1 (also known as Smarca4) is turned off in cardiomyocytes. It is reactivated by cardiac stresses and forms a complex with its embryonic partners, HDAC and PARP, to induce a pathological α-MHC to β-MHC shift. Preventing Brg1 re-expression decreases hypertrophy and reverses this MHC switch. BRG1 is activated in certain patients with hypertrophic cardiomyopathy, its level correlating with disease severity and MHC changes. Our studies show that Brg1 maintains cardiomyocytes in an embryonic state, and demonstrate an epigenetic mechanism by which three classes of chromatin-modifying factors—Brg1, HDAC and PARP—cooperate to control developmental and pathological gene expression. [ABSTRACT FROM AUTHOR]

Heterozygous mutations in the gene encoding the CHD (chromodomain helicase DNA-binding domain) member CHD7, an ATP-dependent chromatin remodeller homologous to the Drosophila trithorax-group protein Kismet, result in a complex constellation of congenital anomalies called CHARGE syndrome, which is a sporadic, autosomal dominant disorder characterized by malformations of the craniofacial structures, peripheral nervous system, ears, eyes and heart. Although it was postulated 25 years ago that CHARGE syndrome results from the abnormal development of the neural crest, this hypothesis remained untested. Here we show that, in both humans and Xenopus, CHD7 is essential for the formation of multipotent migratory neural crest (NC), a transient cell population that is ectodermal in origin but undergoes a major transcriptional reprogramming event to acquire a remarkably broad differentiation potential and ability to migrate throughout the body, giving rise to craniofacial bones and cartilages, the peripheral nervous system, pigmentation and cardiac structures. We demonstrate that CHD7 is essential for activation of the NC transcriptional circuitry, including Sox9, Twist and Slug. In Xenopus embryos, knockdown of Chd7 or overexpression of its catalytically inactive form recapitulates all major features of CHARGE syndrome. In human NC cells CHD7 associates with PBAF (polybromo- and BRG1-associated factor-containing complex) and both remodellers occupy a NC-specific distal SOX9 enhancer and a conserved genomic element located upstream of the TWIST1 gene. Consistently, during embryogenesis CHD7 and PBAF cooperate to promote NC gene expression and cell migration. Our work identifies an evolutionarily conserved role for CHD7 in orchestrating NC gene expression programs, provides insights into the synergistic control of distal elements by chromatin remodellers, illuminates the patho-embryology of CHARGE syndrome, and suggests a broader function for CHD7 in the regulation of cell motility. [ABSTRACT FROM AUTHOR]

The article discusses a study on the relation of deficiencies in Pbx and Meis with congenital heart disease. It was found that the reduction or absence of Pbx2 and Pbx3 result to the haploinsufficiency of Pbx1, which can lead to truncus arteriosus. Also, the disruption of Meis1, an encoder of a Pbx DNA-binding partner, is seen to be a cause of cardiac anomalies that are similar to those of Pbx mutations.

Bone marrow mononuclear cell (BMMC) therapy shows promise as a treatment for ischemic heart disease. However, the ability to monitor long-term cell fate remains limited. We hypothesized that molecular imaging could be used to track stem cell homing and survival after myocardial ischemia-reperfusion (I/R) injury. We first harvested donor BMMCs from adult male L2G85 transgenic mice constitutively expressing both firefly luciferase (Fluc) and enhanced green fluorescence protein reporter gene. Fluorescence-activated cell sorting analysis revealed ∼0.07% of the population to consist of classic hematopoietic stem cells (lin-,thy-int, c-kit+, Sca-1+). Afterward, adult female FVB recipients (n = 38) were randomized to sham surgery or acute I/R injury. Animals in the sham (n = 16) and I/R (n = 22) groups received 5 × 106 of the L2G85-derived BMMCs via tail vein injection. Bioluminescence imaging (BLI) was used to track cell migration and survival in vivo for 4 weeks. BLI showed preferential homing of BMMCs to hearts with I/R injury compared with sham hearts within the first week following cell injection. Ex vivo analysis of explanted hearts by histology confirmed BLI imaging results, and quantitative real-time polymerase chain reaction (for the male Sry gene) further demonstrated a greater number of BMMCs in hearts with I/R injury compared with the sham group. Functional evaluation by echocardiography demonstrated a trend toward improved left ventricular fractional shortening in animals receiving BMMCs. Taken together, these data demonstrate that molecular imaging can be used to successfully track BMMC therapy in murine models of heart disease. Specifically, we have demonstrated that systemically delivered BMMCs preferentially home to and are retained by injured myocardium. [ABSTRACT FROM AUTHOR]

Trisomy 21 results in Down's syndrome, but little is known about how a 1.5-fold increase in gene dosage produces the pleiotropic phenotypes of Down's syndrome. Here we report that two genes, DSCR1 and DYRK1A , lie within the critical region of human chromosome 21 and act synergistically to prevent nuclear occupancy of NFATc transcription factors, which are regulators of vertebrate development. We use mathematical modelling to predict that autoregulation within the pathway accentuates the effects of trisomy of DSCR1 and DYRK1A, leading to failure to activate NFATc target genes under specific conditions. Our observations of calcineurin-and Nfatc-deficient mice, Dscr1- and Dyrk1a–overexpressing mice, mouse models of Down's syndrome and human trisomy 21 are consistent with these predictions. We suggest that the 1.5-fold increase in dosage of DSCR1 and DYRK1A cooperatively destabilizes a regulatory circuit, leading to reduced NFATc activity and many of the features of Down's syndrome. More generally, these observations suggest that the destabilization of regulatory circuits can underlie human disease. [ABSTRACT FROM AUTHOR]

A correction to the article "Chromatin regulation by Brg1 underlies heart muscle development and disease," by Calvin T. Hang and colleagues that was published in the previous issue of the journal is presented.

Formation of the coronary vasculature requires reciprocal signaling between endothelial, epicardially derived smooth muscle and underlying myocardial cells. Our studies show that calcineurin-NFAT signaling functions in endothelial cells within specific time windows to regulate coronary vessel development. Mouse embryos exposed to cyclosporin A (CsA), which inhibits calcineurin phosphatase activity, failed to develop normal coronary vasculature. To determine the cellular site at which calcineurin functions for coronary angiogenesis, we deleted calcineurin in endothelial, epicardial and myocardial cells. Disruption of calcineurin-NFAT signaling in endothelial cells resulted in the failure of coronary angiogenesis, recapitulating the coronary phenotype observed in CsA-treated embryos. By contrast, deletion of calcineurin in either epicardial or myocardial cells had no effect on coronary vasculature during early embryogenesis. To define the temporal requirement for NFAT signaling, we treated developing embryos with CsA at overlapping windows from E9.5 to E12.5 and examined coronary development at E12.5. These experiments demonstrated that calcineurin-NFAT signaling functions between E10.5 and E11.5 to regulate coronary angiogenesis. Consistent with these in vivo observations, endothelial cells exposed to CsA within specific time windows in tissue culture were unable to form tubular structures and their cellular responses to VEGF-A were blunted. Thus, our studies demonstrate specific temporal and spatial requirements of NFAT signaling for coronary vessel angiogenesis. These requirements are distinct from the roles of NFAT signaling in the angiogenesis of peripheral somatic vessels, providing an example of the environmental influence of different vascular beds on the in vivo endothelial responses to angiogenic stimuli. [ABSTRACT FROM AUTHOR]

The patterning of the cardiovascular system into systemic and pulmonic circulations is a complex morphogenetic process, the failure of which results in clinically important congenital defects. This process involves extensive vascular remodeling and coordinated division of the cardiac outflow tract (OFT). We demonstrate that the homeodomain transcription factor Pbx1 orchestrates separate transcriptional pathways to control great-artery patterning and cardiac OFT septation in mice. Pbx1-null embryos display anomalous great arteries owing to a failure to establish the initial complement of branchial arch arteries in the caudal pharyngeal region. Pbx1 deficiency also results in the failure of cardiac OFT septation. Pbx1-null embryos lose a transient burst of Pax3 expression in premigratory cardiac neural crest cells (NCCs) that ultimately specifies cardiac NCC function for OFT development, but does not regulate NCC migration to the heart. We show that Pbx1 directly activates Pax3, leading to repression of its target gene Msx2 in NCCs. Compound Msx2/Pbx1-null embryos display significant rescue of cardiac septation, demonstrating that disruption of this Pbx1-Pax3-Msx2 regulatory pathway partially underlies the OFT defects in Pbx1-null mice. Conversely, the great-artery anomalies of compound Msx2/Pbx1-null embryos remain within the same spectrum as those of Pbx1-null embryos. Thus, Pbx1 makes a crucial contribution to distinct regulatory pathways in cardiovascular development. [ABSTRACT FROM AUTHOR]

Expression of bone morphogenetic protein receptor 1A (BMPR1A) is attenuated in the lung vessels of patients with pulmonary arterial hypertension, but the functional impact of this abnormality is unknown. We ablated Bmpr1a in cardiomyocytes and vascular smooth muscle cells (VSMCs) by breeding mice possessing a loxP allele of Bmpr1a (Bmpr1aflox) expressing R26R with SM22-Cre mice. SM22-Cre;R26R;Bmpr1aflox/flox mice died soon after embryonic day 11 (E11) with massive vascular and pericardial hemorrhage and impaired brain development. At E10.5, SM22-Cre;R26R;Bmpr1aflox/flox embryos showed thinning of the myocardium associated with reduced cell proliferation. These embryos also had severe dilatation of the aorta and large vessels with impaired investment of SMCs that was also related to reduced proliferation. SM22-Cre;R26R;Bmpr1aflox/flox mice showed collapsed telencephalon in association with impaired clearing of brain microvessels in areas where reduced apoptosis was observed. Transcript and protein levels of matrix metalloproteinase (MMP) 2 and 9 were reduced in E9.5 and E10.5 SM22-Cre;R26R;Bmpr1aflox/flox embryos, respectively. Knock-down of BMPR1A by RNA interference in human pulmonary artery SMCs reduced MMP2 and MMP9 activity, attenuated serum-induced proliferation, and impaired PDGF-BB-directed migration. RNA interference of MMP2 or MMP9 recapitulated these abnormalities, supporting a functional interaction between BMP signaling and MMP expression. In human brain microvascular pericytes, knock-down of BMPR1A reduced MMP2 activity and knock-down of either BMPR1A or MMP2 caused resistance to apoptosis. Thus, loss of Bmpr1a, by decreasing MMP2 and/or MMP9 activity, can account for vascular dilatation and persistence of brain microvessels, leading to the impaired organogenesis documented in the brain. [ABSTRACT FROM AUTHOR]

A large part of the mammalian genome is transcribed into noncoding RNAs. Long noncoding RNAs (IncRNAs) have emerged as critical epigenetic regulators of gene expression. Distinct molecular mechanisms allow IncRNAs either to activate or to repress gene expression, thereby participating in the regulation of cellular and tissue function. LncRNAs, therefore, have important roles in healthy and diseased hearts, and might be targets for therapeutic intervention. In this Review, we summarize the current knowledge of the roles of IncRNAs in cardiac development and ageing. After describing the definition and classification of IncRNAs, we present an overview of the mechanisms by which IncRNAs regulate gene expression. We discuss the multiple roles of IncRNAs in the heart, and focus on the regulation of embryonic stem cell differentiation, cardiac cell fate and development, and cardiac ageing. We emphasize the importance of chromatin remodelling in this regulation. Finally, we discuss the therapeutic and biomarker potential of IncRNAs. [ABSTRACT FROM AUTHOR]

This work presents polymer photovoltaic devices based on poly(3-hexylthiophene) (P3HT) and TiO2 nanorod hybrid bulk heterojunctions. Interface, modification of a TiO2 nanorod surface is conducted to yield a very promising device performance of 2.20% with a short circuit current density (Jsc) of 4.33 mA/cm², an open circuit voltage (V∞) of 0.78 V, and a fill factor (FF) of 0.65 under simulated A.M. 1.5 illumination (100 mW/cm²). The suppression of recombination at P3HT/TiO2 nanorod interfaces by the attachment of effective ligand molecules substantially improves device performance. The correlation between surface photovoltage and hybrid morphology is revealed by scanning Kelvin probe microscopy. The proposed method provides a new route for fabricating low-cost, environmentally friendly polymer/inorganic hybrid bulk heterojunction photovoltaic devices. [ABSTRACT FROM AUTHOR]

Patients with Down syndrome have characteristic heart valve lesions resulting from endocardial cushion defects. The Down syndrome critical region 1 (DSCR1) gene, identified at the conserved trisomic 21 region in those patients, encodes a calcineurin inhibitor that inactivates nuclear factor of activated T cells (NFATc) activity. Here, we identify a regulatory sequence in the promoter region of human DSCR1 that dictates specific expression of a reporter gene in the endocardium, defined by the temporal and spatial expression of Nfatcl during heart valve development. Activation of this evolutionally conserved DSCR1 regulatory sequence requires calcineurin and NFATcl signaling in the endocardium. NFATcl proteins bind to the regulatory sequence and trigger its enhancer activity. NFATcl is sufficient to induce the expression of Dscrl in cells that normally have undetectable or minimal NFATcl or DSCR1. Pharmacologic inhibition of calcineurin or genetic Nfatcl null mutation in mice abolishes the endocardial activity of this DSCR1 enhancer. Furthermore, in mice lacking endocardial NFATc1, the endogenous Dscrl expression is specifically inhibited in the endocardium but not in the myocardium. Thus, our studies indicate that the DSCR1 gene is a direct transcriptional target of NFATcl proteins within the endocardium during a critical window of heart valve formation. [ABSTRACT FROM AUTHOR]