Machine learning in cardiology: Clinical application and basic research

Machine learning is a subfield of artificial intelligence. The quality and versatility of machine learning have been rapidly improving and playing a critical role in many aspects of social life. This trend is also observed in the medical field. Generally, there are three main types of machine learning: supervised, unsupervised, and reinforcement learning. Each type of learning is adequately selected for the purpose and type of data. In the field of medicine, various types of information are collected and used, and research using machine learning is becoming increasingly relevant. Many clinical studies are conducted using electronic health and medical records, including in the cardiovascular area. Machine learning has also been applied in basic research. Machine learning has been widely used for several types of data analysis, such as clustering of microarray analysis and RNA sequence analysis. Machine learning is essential for genome and multi-omics analyses. This review summarizes the recent advancements in the use of machine learning in clinical applications and basic cardiovascular research.

MEF2C/p300-mediated epigenetic remodeling promotes the maturation of induced cardiomyocytes

Cardiac transcription factors (TFs) directly reprogram fibroblasts into induced cardiomyocytes (iCMs), where MEF2C acts as a pioneer factor with GATA4 and TBX5 (GT). However, the generation of functional and mature iCMs is inefficient, and the molecular mechanisms underlying this process remain largely unknown. Here, we found that the overexpression of transcriptionally activated MEF2C via fusion of the powerful MYOD transactivation domain combined with GT increased the generation of beating iCMs by 30-fold. Activated MEF2C with GT generated iCMs that were transcriptionally, structurally, and functionally more mature than those generated by native MEF2C with GT. Mechanistically, activated MEF2C recruited p300 and multiple cardiogenic TFs to cardiac loci to induce chromatin remodeling. In contrast, p300 inhibition suppressed cardiac gene expression, inhibited iCM maturation, and decreased the beating iCM numbers. Splicing isoforms of MEF2C with similar transcriptional activities did not promote functional iCM generation. Thus, MEF2C/p300-mediated epigenetic remodeling promotes iCM maturation.

Probing Superatomic Orbitals of Sc-Doped and Undoped Silver Cluster Anions via Photoelectron Angular Anisotropy

Valence s electrons in alkali- or coinage-metal clusters are conceived to delocalize over the metal frameworks. The electrons occupy so-called superatomic orbitals (SAOs, i.e., 1S, 1P, 1D, 2S, 1F, ...), which provide an essential picture for understanding the size-dependent, unique properties of these metal clusters. While such electronic shells are unambiguously identified in their photoelectron spectra and supported by electronic structure calculations, characterization of SAOs in heteroatom-doped metal clusters has remained elusive as the doping significantly affects its energy levels and even alters the ordering of SAOs. Here, we present a photoelectron imaging study to explore SAOs formed in Sc-doped and undoped silver cluster anions, Ag_NSc^- (N = 15, 16) and Ag_N^- (N = 18, 19). Photoelectron angular distributions from their outermost SAOs are clearly visualized, whose characters are analyzed with the aid of density functional theory calculations. The present methodology enables us to explore not only the quantized energy levels but also the spatial distributions of SAOs formed in various metal cluster anions.

Indirect impact of the COVID-19 pandemic on the incidence of non-COVID-19 infectious diseases: a region-wide, patient-based database study in Japan

OBJECTIVES

The COVID-19 pandemic has forced people to change many behaviours, including physical distancing, hygiene measures and lifestyles. This study aimed to evaluate the indirect impact of the COVID-19 pandemic on the incidence of non-COVID-19 infections and medical care costs/visits using health insurance claims.

STUDY DESIGN

This was an observational study using patient-based administrative claims covering approximately 800,000 insured persons and their dependents in the Mie Prefecture in Japan.

METHODS

This study identified non-COVID-19 infectious disease incidences, number of outpatient visits and healthcare costs between 2017 and 2021. Each year was divided into quarters. The adjusted incidence rate ratios (IRRs) during the pandemic (January 2020 to September 2021) and during the prepandemic period (January 2017 to December 2019) were determined using Poisson regression.

RESULTS

The adjusted influenza IRRs from April 2020 were close to zero. The incidence of upper respiratory tract infections and bacterial pneumonia was significantly reduced (IRRs range: 0.39-0.73 and 0.43-0.84, respectively). Gastrointestinal and urinary tract infection incidences decreased by approximately 30% and 10%, respectively. In contrast, sexually transmitted infections (STIs), including syphilis, gonococcal infection and Chlamydia trachomatis infection, did not decrease during the pandemic but increased significantly between April and June 2021 (adjusted IRR, 1.37; 95% confidence interval, 1.18-1.60). The adjusted IRRs for outpatient visits and healthcare costs were 0.86-0.93 and 0.91-0.97, respectively.

CONCLUSIONS

In contrast to other infections, STIs did not decrease during the COVID-19 pandemic. The IRR of STIs during the pandemic period is an area of public health concern. Appropriate screening and medical consultations are strongly recommended.

Abstract OEC101: Cardiac Reprogramming Inducer ZNF281 Is Indispensable For Heart Development By Interacting With Key Cardiac Transcriptional Factors

During direct cardiac reprogramming, cardiogenic transcription factors (TFs) cooperatively reshape the epigenomic landscape by activating cardiac enhancers, which describe a common epigenetic signature between in vitro cardiac reprogramming and in vivo heart development. We thus hypothesized that direct reprogramming could be a useful tool to study novel transcriptional regulators in heart development. To test this hypothesis, we focused on ZNF281/Zfp281(Zinc finger protein 281), a pluripotency regulator which showed up as an unexpected strong cardiac reprogramming inducer from our previous unbiased screen. Since Zfp281 is an essential factor for epiblast maturation, we established a Zfp281 floxed mouse line using CRISPR/Cas9 system to study the impact of Zfp281 after cardiac lineage commitment. We then generated multiple conditional Zfp281KO (cKO) mouse lines by crossing with different stage-specific Cre driver lines. Surprisingly, we found that mesodermal (Mesp1-Cre) Zfp281cKO mice were embryonic lethal as early as E9.5, associated with various cardiac anomalies. In contrast, cardiac progenitor (Nkx2-5-Cre) and cardiomyocyte (Myh6-Cre) Zfp281cKO mice survived to adulthood and appeared grossly normal, suggesting a crucial role of Zfp281 in mesodermal to cardiac differentiation. Next, we performed RNA-seq analysis to study the molecular mechanism of Zfp281 deficient cardiac anomalies. Interestingly, expression of cardiac TFs and sarcomeric genes were altered in Zfp281cKO embryos compared to control siblings. Consistently, co-immunoprecipitation analysis showed direct interaction of Zfp281 with Mesp1 and Gata4. These data indicate that Zfp281 directly interacts with cardiac TFs to cooperatively orchestrate the cardiogenic transcriptional network. In conclusion, by using multiple genetic mouse models, we discovered that cardiac reprogramming inducer Zfp281 plays a pivotal role in heart development. Although GWAS studies have identified various disease-causing mutations, the etiology for the majority of congenital heart disease remains largely unknown and there are still such missing pieces to be uncovered in the interdependent cardiogenic transcriptional network. Our study demonstrates and highlights the impact and possibility of direct reprogramming as a novel approach to study cardiovascular biology.

Abstract P493: Histone Reader PHF7 Cooperates With The SWI/SNF Complex At Cardiac Super Enhancers To Promote Direct Reprogramming

Ischemic heart disease is the leading cause of death worldwide. Direct reprogramming of resident cardiac fibroblasts (CFs) to induced cardiomyocytes (iCLMs) has emerged as a potential therapeutic approach to treat heart failure and ischemic disease. Cardiac reprogramming was first achieved through forced expression of the transcription factors Gata4, Mef2c, and Tbx5 (GMT); our laboratory found that Hand2 (GHMT) and Akt1 (AGHMT) markedly enhanced reprogramming efficiency in embryonic and postnatal cell types. However, adult mouse and human fibroblasts are resistant to reprogramming due to staunch epigenetic barriers. We undertook a screen of mammalian gene regulatory factors to discover novel regulators of cardiac reprogramming in adult fibroblasts and identified the epigenetic reader PHF7 as the most potent activating factor. We validated the findings of this screen and found that PHF7 augmented reprogramming of adult fibroblasts ten-fold. Mechanistically, PHF7 localized to cardiac super enhancers in fibroblasts by reading H3K4me2 marks, and through cooperation with the SWI/SNF complex, increased chromatin accessibility and transcription factor binding at these multivalent enhancers. Further, PHF7 recruited cardiac transcription factors to activate a positive transcriptional autoregulatory circuit in reprogramming. Importantly, PHF7 achieved efficient reprogramming through these mechanisms in the absence of Gata4. Collectively, these studies highlight the underexplored necessity of cardiac epigenetic readers, such as PHF7, in harnessing chromatin remodeling and transcriptional complexes to overcome critical barriers to direct cardiac reprogramming.

Exploring rare cellular activity in more than one million cells by a transscale scope

In many phenomena of biological systems, not a majority, but a minority of cells act on the entire multicellular system causing drastic changes in the system properties. To understand the mechanisms underlying such phenomena, it is essential to observe the spatiotemporal dynamics of a huge population of cells at sub-cellular resolution, which is difficult with conventional tools such as microscopy and flow cytometry. Here, we describe an imaging system named AMATERAS that enables optical imaging with an over-one-centimeter field-of-view and a-few-micrometer spatial resolution. This trans-scale-scope has a simple configuration, composed of a low-power lens for machine vision and a hundred-megapixel image sensor. We demonstrated its high cell-throughput, capable of simultaneously observing more than one million cells. We applied it to dynamic imaging of calcium ions in HeLa cells and cyclic-adenosine-monophosphate in Dictyostelium discoideum, and successfully detected less than 0.01% of rare cells and observed multicellular events induced by these cells.

The histone reader PHF7 cooperates with the SWI/SNF complex at cardiac super enhancers to promote direct reprogramming

Direct cardiac reprogramming of fibroblasts to cardiomyocytes presents an attractive therapeutic strategy to restore cardiac function following injury. Cardiac reprogramming was initially achieved through overexpression of the transcription factors Gata4, Mef2c and Tbx5; later, Hand2 and Akt1 were found to further enhance this process^1-5. Yet, staunch epigenetic barriers severely limit the ability of these cocktails to reprogramme adult fibroblasts^6,7. We undertook a screen of mammalian gene regulatory factors to discover novel regulators of cardiac reprogramming in adult fibroblasts and identified the histone reader PHF7 as the most potent activating factor⁸. Mechanistically, PHF7 localizes to cardiac super enhancers in fibroblasts, and through cooperation with the SWI/SNF complex, it increases chromatin accessibility and transcription factor binding at these sites. Furthermore, PHF7 recruits cardiac transcription factors to activate a positive transcriptional autoregulatory circuit in reprogramming. Importantly, PHF7 achieves efficient reprogramming in the absence of Gata4. Here, we highlight the underexplored necessity of cardiac epigenetic readers, such as PHF7, in harnessing chromatin remodelling and transcriptional complexes to overcome critical barriers to direct cardiac reprogramming.

Anti-senescent drug screening by deep learning-based morphology senescence scoring

Advances in deep learning technology have enabled complex task solutions. The accuracy of image classification tasks has improved owing to the establishment of convolutional neural networks (CNN). Cellular senescence is a hallmark of ageing and is important for the pathogenesis of ageing-related diseases. Furthermore, it is a potential therapeutic target. Specific molecular markers are used to identify senescent cells. Moreover senescent cells show unique morphology, which can be identified. We develop a successful morphology-based CNN system to identify senescent cells and a quantitative scoring system to evaluate the state of endothelial cells by senescence probability output from pre-trained CNN optimised for the classification of cellular senescence, Deep Learning-Based Senescence Scoring System by Morphology (Deep-SeSMo). Deep-SeSMo correctly evaluates the effects of well-known anti-senescent reagents. We screen for drugs that control cellular senescence using a kinase inhibitor library by Deep-SeSMo-based drug screening and identify four anti-senescent drugs. RNA sequence analysis reveals that these compounds commonly suppress senescent phenotypes through inhibition of the inflammatory response pathway. Thus, morphology-based CNN system can be a powerful tool for anti-senescent drug screening.

Cellular senescence is a hallmark of ageing and is important for the pathogenesis of ageing-related diseases. Here, the authors develop a morphology-based deep learning system to identify senescent cells and a quantitative scoring system to evaluate the state of endothelial cells to evaluate the effects of anti-senescent reagents.

Abstract 297: Development of Molecular Targeted Therapy Against Right Ventricular Failure: Involvement in a Network of Immunocompetent Cells

Backgrounds: Right ventricular (RV) failure plays a critical role in right heart failure and left heart failure. However, there is no specific therapy developed for RV failure. To elucidate a novel therapeutic target against RV failure, we focus on RV specific genes to develop novel therapeutics for RV failure.

Methods: Microarray analysis using several parts of adult murine heart was conducted and differentially expressed genes (DEGs) were applied to pathway analysis. Molecular mechanism was examined by using neonatal rat ventricular cardiomyocyte (NRVM) in vitro. To understand the function of target molecule in vivo, we induced RV failure by pulmonary artery constriction (PAC) in mice and inhibition experiments were performed using RV failure model.

Results: In microarray analysis for RV, left ventricle and ventricular septum, 995 genes were extracted as DEGs in RV. Pathway analysis showed that alternative complement pathway-related genes were significantly up-regulated in RV. Moreover, complement factor D (Cfd) and C3a was a potential upstream factor attributable to unique feature of RV. Administration of C3a recombinant protein to NRVM phosphorylated several MAP kinases. In vivo, in C3KO PAC mice, RV dysfunction was significantly suppressed, and histological study showed that RV fibrosis was significantly suppressed. In wild type mice with PAC, administration of C3a receptor antagonist dramatically improved RV dysfunction and reduced RV fibrosis. Additionally, in vivo electrophysiological study revealed that the inducibility of ventricular arrhythmia was increased in wild type PAC mice, but ventricular arrhythmia was significantly attenuated in C3KO PAC mice. Furthermore, the expression of chemokine Ccl5 was enhanced in RV of wild type PAC mice, while Ccl5 was significantly attenuated in C3KO PAC mice.

Conclusion: We revealed that complement C3a was highly produced in RV and chemical or genetical blockade of C3a ameliorates RV dysfunction and RV fibrosis in PAC mice. C3a was to be a potent bioactive protein for immunocompetent cells that played an important role in modulating cardiac function. Accordingly, we demonstrated that the blockade of C3a had a potential role for novel therapeutic target to RV failure.

P175 Prognostic value of 99mTc-ECD brain perfusion SPECT in patients with atrial fibrillation and dementia

Background

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and those afflicted have reduced quality of life, functional status, and cardiac performance. The patients with AF have a high risk of coronary heart disease and cardiovascular disease. Although the prevalence of AF is increasing, cognitive disorders are also on the rise in tandem with the aging of the population. The patients with dementia have also experienced lower the quality of life and have increased mortality. Technetium 99m ECD brain perfusion single photon emission computed tomography (99mTc-ECD brain perfusion SPECT) is a useful modality for diagnosing dementia and identifying high risk patients with mild cognitive impairment. However, there are few reports about the relationship between the value of Z score calculated by 99mTc-ECD brain perfusion SPECT and prognosis of patients with AF and dementia.

Purpose

The aim of this study was to evaluate the prognostic values of brain perfusion using 99mTc-ECD SPECT in patients with AF and dementia.

Methods

Among 405 consecutive patients who were diagnosed as AF in cardiac outpatients and subsequently diagnosed as dementia using Mini-Mental State Examination by neurologists or psychiatrists, we identified 170 patients (81 ± 10 years) who underwent 99mTc-ECD brain perfusion SPECT for the current study. Of those, 73, 73, and 24 were diagnosed as Alzheimer’s dementia (AD), vascular dementia (VD), and non-specified dementia respectively. Multivariate Cox model was used to assess if higher Z score by 99mTc-ECD brain perfusion SPECT and clinical parameters were associated with major adverse cardiovascular events (MACE) including cardiac death, myocardial infarction, hospitalization for heart failure, and stroke. Sub-analyses of multivariate Cox models by AD or VD were also assessed. The cut-off values of Z score were determined using area under the curve by a receiver operating characteristic analysis based on MACE occurrences.

Results

During a mean follow-up of 1258 ± 1044 days, 62 MACE occurred. There was not significant difference of MACE between AD and VD (33%, vs. 44%, p = 0.153). By multivariable Cox model, the higher Z score of temporal-occipital-pariental lobe was associated with increased MACE compared to the lower group (HR 2.521, 95% CI 1.465–4.337, p < 0.001). In a sub-analysis of patients with AD, Z score was the most significant prognostic factor for MACE (HR 3.969, 95% CI 1.374–11.468, p = 0.011). The similar trend was observed in those with VD (HR 2.247, 95% CI 1.028–4.913, p = 0.043). Conclusion: This study demonstrated that the Z score of temporal-occipital-pariental lobe by 99mTc-ECD brain perfusion SPECT could be a potential prognostic value among patients with AF and dementia, regardless of type of dementia.

P2570Synergistic activation of the cardiac enhancer landscape during reprogramming

Introduction

Cardiogenic transcription factors (TFs), Gata4, Mef2c, and Tbx5, can directly reprogram fibroblasts to a cardiac fate and their cardiogenic activity is enhanced by the Hand2 TF and the Akt1 kinase. Although these cardiac reprogramming factors are key regulators of heart development, their expression and biological functions are not limited to the heart, and the mechanism by which these cardiac factors orchestrate reprogramming remains unclear.

Purpose

We sought to study the molecular mechanisms by which cardiac reprogramming factors contribute to cell fate conversion using a genome-wide approach.

Methods

Here, we used chromatin immunoprecipitation followed by massively parallel DNA sequencing (ChIP-seq) to explore the genomic binding sites of reprogramming TFs and the landscape of active enhancers, annotated by H3K27ac histone modification, during cardiac reprogramming.

Results

We found that reprogramming TFs rapidly silence fibroblast enhancers and synergistically activate cardiac enhancers which were predominantly enriched with Mef2 motifs. Addition of Hand2 and Akt1 to GMT expands TF co-occupancy and thereby activates additional cardiac enhancers, which further augments cardiac gene expression. Moreover, additional cardiac enhancers were sequentially activated during the reprogramming process, in accordance with the temporal acquisition of functional phenotypes in induced cardiac-like myocytes. We discovered that subsets of reprogramming enhancers are conserved among other cardiogenic processes, and a collection of reprogramming enhancers displayed unique spatial expression patterns in the developing heart in transgenic mouse embryos.

Conclusion

Our study describes the epigenomic dynamics that underlie cardiac reprogramming which is cooperatively orchestrated by reprogramming factors to convert fibroblasts toward a cardiac lineage.

Acknowledgement/Funding

NIH (AR-067294, HL-130253, HL-138426, HD-087351), Fondation Leducq Transatlantic Networks of Excellence in Cardiovascular Research

P1608Inhibition of GATA4 dimerization suppress hypertrophic responses

Introduction

Hypertrophic signals eventually reach the nuclei of cardiomyocytes, change patterns of gene expression, and cause the development of heart failure. During the development of heart failure, intrinsic histone acetyltransferase called p300 induce GATA4 acetylation. Acetylated GATA4 increases its DNA binding, up-regulates cardiac hypertrophic response genes, and lead to heart failure. A zinc finger protein, GATA4 is the transcription factor that expression level is high in heart. It has been reported that GATA1, the same GATA family, regulates transcriptional activity through its homo-dimerization. However, GATA4 homo-dimerization and its relationship to hypertrophic responses are still unknown.

Purpose

To clarify the relationship between GATA4 homo-dimerization and transcriptional activity and investigate whether inhibition of this homo-dimerization become therapeutic target for cardiac hypertrophy.

Methods

GST pull-down and DNA pull-down assay were performed using GST fusion full length and deletion mutants of GATA4 and biotin-conjugated ET-1 promoter probe including a GATA element. Recombinant C-zinc finger domain (256–326), including C-zinc finger motif (256–295) and acetylation site (308–326) was cross-linked using glutaraldehyde and subjected to silver staining. An expression plasmid with three GATA4-acetylation site mutant-conjugated with nuclear localization sequence (3xG4D) was constructed. Immunoprecipitation and western blotting were performed using nuclear extract from HEK293T cells expressing p300, GATA4, and 3xG4D. Luciferase assay was using ANF and ET-1 promoter sequences. Neonatal rat cultured cardiomyocyte expressed 3xG4D and then stimulated with phenylephrine (PE) for 48 hours. Next cardiomyocytes stained with α-actinin antibody and measured the cell surface area.

Results

The acetylation site of GATA4 was required for the dimerization of GATA4. But, C-zinc finger motif (256–295) and the acetylation site were required for the DNA binding. Recombinant C-zinc finger domain formed not only a homo-dimer but also a multimer. Co-expression of p300 increased the formation of homo-dimer as well as the acetylation of GATA4 in HEK293T cells. The GATA4 homo-dimer was disrupted by acetyl-deficient GATA4 or HAT-deficient p300 mutant. Overexpression of 3xG4D prevented the dimerization of GATA4, but not acetylation of GATA4. The result of luciferase assay showed that overexpression of 3xG4D prevented p300/GATA-induced ANF and ET-1 promoter activities. Furthermore, overexpression of 3xG4D inhibited phenylephrine-induced cardiomyocyte hypertrophy.

Conclusions

These results suggest that GATA4 dimerization may play an important role in hypertrophy-response gene activation. Thus, it is likely that inhabitation of GATA4 dimerization become therapeutic target for cardiac hypertrophy.

Abstract 835: Development of Molecular Targeted Therapy Against Right Ventricular Failure: Evaluation by Transcriptome and i n vivo Analysis

Backgrounds: Right ventricular (RV) failure is a final common pathway in heart failure. But there is no specific therapy for RV failure. Moreover, it remains unclear how RV failure is developed. To develop a novel therapy for RV failure, we focused on the RV specific character and elucidate the function in RV failure.

Methods: Microarray analysis using several parts of adult murine heart was conducted and differentially expressed genes (DEGs) were applied to pathway analysis. Molecular mechanism was examined by using rat cardiomyocytes in vitro. To understand the function of target molecule in vivo, we induced RV failure by pulmonary artery constriction (PAC) in mice and the pathway was specifically blocked in the RV failure model.

Results: In microarray analysis for upper RV, RV free wall, LV and ventricular septum, 995 genes were statistically extracted as DEG in upper RV. An alternative complement pathway was significantly activated in upper RV and complement factor, and C3a was a potential upstream factor attributable to unique feature of upper RV. Because C3a plays a central role in alternative complement pathway, we examined the direct role of C3a in cardiomyocytes and RV function. Administration of C3a recombinant protein to primary-cultured cardiomyocytes activated the several MAP kinases including ERK, p38 and JNK, via C3a receptor. Mice developed severe RV failure around 14 days after PAC. Surprisingly, administration of C3a receptor antagonist dramatically improved right ventricular contractile dysfunction in PAC mice. C3 (substrate of C3a) deficient PAC mice also attenuated RV contractile dysfunction, fibrotic change and fetal gene expressions. There results indicated that complement factor C3a regulates the unique phenotypes in RV. Chemical or genetical blockade of C3a ameliorates RV dysfunction in PAC mice.

Conclusion: We revealed that alternative complement pathway was activated in RV and C3a had a crucial role in the pathogenesis of RV failure. Accordingly, the blockade of C3a pathway would be a potential therapeutic target for RV disorders.

Abstract 451: Pde1 Promotes Development of Pulmonary Arterial Hypertension and Could Be a Novel Treatment Target

Backgrounds: Pulmonary arterial hypertension (PAH) is a rare but fatal disease, with an estimated mean survival period in untreated patients of approximately 3 years. Pulmonary vascular remodeling is a hallmark of PAH. Pulmonary vasculature shows increased proliferation, irrelevant migration and apoptosis resistance of vascular cells such as pulmonary arterial smooth muscle cells (PASMCs) and endothelial cells. However, the molecular mechanism in the pathogenesis of PAH remains unclear. We previously performed genome-wide association study (GWAS) in Japanese patients with idiopathic / heritable PAH and healthy controls and identified novel disease related SNPs in PDE1A

Abstract 705: Synergistic Activation of the Cardiac Enhancer Landscape During Cardiac Reprogramming

Direct cardiac reprogramming of fibroblasts to cardiomyocytes is an attractive therapeutic strategy to restore cardiac function following injury. The cardiac transcription factors Gata4, Mef2c, and Tbx5 are sufficient to directly reprogram fibroblasts to a cardiac fate and their cardiogenic activity is enhanced by the addition of Hand2 and Akt1. However, the mechanisms by which these transcription factors orchestrate this cell fate conversion remains elusive. To understand the mechanistic basis of cardiac reprogramming, we performed a genome-wide analysis of cardiogenic transcription factor binding sites and enhancer activation throughout cardiac reprogramming. We found that cardiogenic transcription factors act cooperatively by co-occupying regulatory elements enriched with Mef2 binding sites during cardiac reprogramming. Importantly, these transcription factors when overexpressed in isolation are incapable of activating reprogramming enhancer elements. Further, we discovered that the early reprogramming enhancer landscape most closely resembles that of the neonatal heart. Acquisition of enhancers associated with cardiac maturation occurred at later stages in reprogramming, with addition of Hand2 and Akt1 augmenting activation of this more mature enhancer landscape. Additionally, we constructed a cardiac reprogramming gene regulatory network which demonstrated downregulation of the EGF receptor signaling pathway. We found that inhibition of EGF receptor signaling augments reprogramming toward the cardiac phenotype. Our findings demonstrate that cardiac reprogramming is coordinated by synergistic transcriptional activation across a broad landscape of cardiac enhancers and define the epigenetic landscape of the cardiac phenotype.

Contribution of pharmacists with expertise in infectious diseases to appropriate individualized vancomycin dosing

BACKGROUND/AIM

Dose adjustment of vancomycin (VCM) is important in improving clinical outcomes and avoiding adverse effects such as nephrotoxicity. Although pharmacist-managed VCM therapy has been reported to optimize treatment, there are no studies focused on pharmacist expertise to date. In this study, we compared the contribution of pharmacists trained for infectious diseases and general pharmacists to dose adjustment of VCM.

PATIENTS AND METHODS

We retrospectively investigated VCM trough concentration after dose adjustment by both trained (n = 67) and general (without special training for infectious diseases; n = 85) pharmacists. We also compared the incidence of nephrotoxicity during VCM treatment in both groups.

RESULTS

The rate of achieving therapeutic VCM trough concentration (10-20 μg/mL) was higher in the trained group than in the control group (80.6 vs. 54.1%, p < 0.001). No significant differences in incidence of nephrotoxicity were observed between the two groups (p = 0.744). Trained pharmacists could contribute more successfully to the achievement of therapeutic VCM concentration ranges without increasing the risk of nephrotoxicity.

Therapeutic approaches for cardiac regeneration and repair

Ischaemic heart disease is a leading cause of death worldwide. Injury to the heart is followed by loss of the damaged cardiomyocytes, which are replaced with fibrotic scar tissue. Depletion of cardiomyocytes results in decreased cardiac contraction, which leads to pathological cardiac dilatation, additional cardiomyocyte loss, and mechanical dysfunction, culminating in heart failure. This sequential reaction is defined as cardiac remodelling. Many therapies have focused on preventing the progressive process of cardiac remodelling to heart failure. However, after patients have developed end-stage heart failure, intervention is limited to heart transplantation. One of the main reasons for the dramatic injurious effect of cardiomyocyte loss is that the adult human heart has minimal regenerative capacity. In the past 2 decades, several strategies to repair the injured heart and improve heart function have been pursued, including cellular and noncellular therapies. In this Review, we discuss current therapeutic approaches for cardiac repair and regeneration, describing outcomes, limitations, and future prospects of preclinical and clinical trials of heart regeneration. Substantial progress has been made towards understanding the cellular and molecular mechanisms regulating heart regeneration, offering the potential to control cardiac remodelling and redirect the adult heart to a regenerative state.

Cuticle network and orientation preference of photonic crystals in the scales of the weevil Lamprocyphus augustus

This paper reports the structural and optical investigations of the structural colour of the weevil Lamprocyphusaugustus The photonic crystal structure within the weevil's scales was investigated using sequential focused ion-beam milling and scanning electron microscopy imaging. We carefully analysed the reconstructed three-dimensional structure to determine the unit cell of the photonic crystal. It was found that the cuticle network of the cubic unit cell perfectly matches the previously reported diamond-based network. However, different results were obtained for the crystal orientations of the small crystal domains that comprise the entire photonic crystal structure in the scales: <111> directions are highly preferred along the surface normal of the scale. This finding explains the fact that the scale is almost uniformly coloured despite the multi-domain structure. It is confirmed experimentally and theoretically that the wavelength range of the reflection band corresponds to the gap of the photonic band.

ZNF281 enhances cardiac reprogramming by modulating cardiac and inflammatory gene expression

Direct reprogramming of fibroblasts to cardiomyocytes represents a potential means of restoring cardiac function following myocardial injury. AKT1 in the presence of four cardiogenic transcription factors, GATA4, HAND2, MEF2C, and TBX5 (AGHMT), efficiently induces the cardiac gene program in mouse embryonic fibroblasts but not adult fibroblasts. To identify additional regulators of adult cardiac reprogramming, we performed an unbiased screen of transcription factors and cytokines for those that might enhance or suppress the cardiogenic activity of AGHMT in adult mouse fibroblasts. Among a collection of inducers and repressors of cardiac reprogramming, we discovered that the zinc finger transcription factor 281 (ZNF281) potently stimulates cardiac reprogramming by genome-wide association with GATA4 on cardiac enhancers. Concomitantly, ZNF281 suppresses expression of genes associated with inflammatory signaling, suggesting the antagonistic convergence of cardiac and inflammatory transcriptional programs. Consistent with an inhibitory influence of inflammatory pathways on cardiac reprogramming, blockade of these pathways with anti-inflammatory drugs or components of the nucleosome remodeling deacetylase (NuRD) complex, which associate with ZNF281, stimulates cardiac gene expression. We conclude that ZNF281 acts at a nexus of cardiac and inflammatory gene programs, which exert opposing influences on fibroblast to cardiac reprogramming.

Disturbed spermatogenic signaling in pituitary adenylate cyclase activating polypeptide-deficient mice

PACAP is a neuropeptide with diverse functions in various organs, including reproductive system. It is present in the testis in high concentrations, and in addition to the stage-specific expression within the seminiferous tubules, PACAP affects spermatogenesis and the functions of Leydig and Sertoli cells. Mice lacking endogenous PACAP show reduced fertility, but the possibility of abnormalities in spermatogenic signaling has not yet been investigated. Therefore, we performed a detailed morphological analysis of spermatozoa, sperm motility and investigated signaling pathways that play a role during spermatogenesis in knockout mice. No significant alterations were found in testicular morphology or motility of sperm in homozygous and heterozygous PACAP-deficient mice in spite of the moderately increased number of severely damaged sperms. However, we found robust changes in mRNA and/or protein expression of several factors that play an important role in spermatogenesis. Protein kinase A expression was markedly reduced, while downstream phospho-ERK and p38 were elevated in knockout animals. Expression of major transcription factors, such as Sox9 and phospho-Sox9, was decreased, while that of Sox10, as a redundant factor, was increased in PACAP-deficient mice. The reduced phospho-Sox9 expression was partly due to increased expression and activity of phosphatase PP2A in knockout mice. Targets of Sox transcription factors, such as collagen type IV, were reduced in knockout mice. In summary, our results show that lack of PACAP leads to disturbed signaling in spermatogenesis, which could be a factor responsible for reduced fertility in PACAP knockout mice, and further support the role of PACAP in reproduction.

Epigenetic barrier against the propagation of fluctuating gene expression in embryonic stem cells

The expression of pluripotency genes fluctuates in a population of embryonic stem (ES) cells and the fluctuations in the expression of some pluripotency genes correlate. However, no correlation in the fluctuation of Pou5f1, Zfp42, and Nanog expression was observed in ES cells. Correlation between Pou5f1 and Zfp42 fluctuations was demonstrated in ES cells containing a knockout in the NuRD component Mbd3. ES cells containing a triple knockout in the DNA methyltransferases Dnmt1, Dnmt3a, and Dnmt3b showed correlation between the fluctuation of Pou5f1, Zfp42, and Nanog gene expression. We suggest that an epigenetic barrier is key to preventing the propagation of fluctuating pluripotency gene expression in ES cells.

Clinical characteristics and outcome of human herpesvirus-6 encephalitis after allogeneic hematopoietic stem cell transplantation

In this retrospective analysis using the Transplant Registry Unified Management Program, we identified 145 patients with human herpesvirus (HHV)-6 encephalitis among 6593 recipients. The cumulative incidences of HHV-6 encephalitis at 100 days after transplantation in all patients, recipients of bone marrow or PBSCs and recipients of cord blood were 2.3%, 1.6% and 5.0%, respectively. Risk factors identified in multivariate analysis were male sex, type of transplanted cells (relative risk in cord blood transplantation, 11.09, P<0.001; relative risk in transplantation from HLA-mismatched unrelated donor, 9.48, P<0.001; vs transplantation from HLA-matched related donor) and GvHD prophylaxis by calcineurin inhibitor alone. At 100 days after transplantation, the overall survival rate was 58.3% and 80.5% among patients with and without HHV-6 encephalitis, respectively (P<0.001). Neuropsychological sequelae remained in 57% of 121 evaluated patients. With both foscarnet and ganciclovir, full-dose therapy (foscarnet ⩾180 mg/kg, ganciclovir ⩾10 mg/kg) was associated with better response rate (foscarnet, 93% vs 74%, P=0.044; ganciclovir, 84% vs 58%, P=0.047). HHV-6 encephalitis is not rare not only in cord blood transplant recipients but also in recipients of HLA-mismatched unrelated donors. In this study, development of HHV-6 encephalitis was associated with a poor survival rate, and neurological sequelae remained in many patients.

Impact of the presence of HLA 1-locus mismatch and the use of low-dose antithymocyte globulin in unrelated bone marrow transplantation

HLA 1-locus-mismatched unrelated donors (1MMUD) have been used in allogeneic hematopoietic stem cell transplantation (allo-HCT) for patients who lack an HLA-matched donor. We retrospectively analyzed 3313 patients with acute leukemia or myelodysplastic syndrome who underwent bone marrow transplantation from an HLA allele-matched unrelated donor (MUD) or 1MMUD between 2009 and 2014. We compared the outcomes of MUD (n=2089) and 1MMUD with antithymocyte globulin (ATG) (1MM-ATG(+); n=109) with those of 1MMUD without ATG (1MM-ATG(-); n=1115). The median total dose of ATG (thymoglobulin) was 2.5 mg/kg (range 1.0-11.0 mg/kg) in the 1MM-ATG(+) group. The rates of grade III-IV acute GvHD, non-relapse mortality (NRM) and overall mortality were significantly lower in the MUD group than in the 1MM-ATG(-) group (hazard ratio (HR) 0.77, P=0.016; HR 0.74; P<0.001; and HR 0.87, P=0.020, respectively). Likewise, the rates of grade III-IV acute GVHD, NRM and overall mortality were significantly lower in the 1MM-ATG(+) group than in the 1MM-ATG(-) group (HR 0.42, P=0.035; HR 0.35, P<0.001; and HR 0.71, P=0.042, respectively). The outcome of allo-HCT from 1MM-ATG(-) was inferior to that of allo-HCT from MUD even in the recent cohort. However, the negative impact of 1MMUD disappeared with the use of low-dose ATG without increasing the risk of relapse.

Notch Inhibition Enhances Cardiac Reprogramming by Increasing MEF2C Transcriptional Activity

Conversion of fibroblasts into functional cardiomyocytes represents a potential means of restoring cardiac function after myocardial infarction, but so far this process remains inefficient and little is known about its molecular mechanisms. Here we show that DAPT, a classical Notch inhibitor, enhances the conversion of mouse fibroblasts into induced cardiac-like myocytes by the transcription factors GATA4, HAND2, MEF2C, and TBX5. DAPT cooperates with AKT kinase to further augment this process, resulting in up to 70% conversion efficiency. Moreover, DAPT promotes the acquisition of specific cardiomyocyte features, substantially increasing calcium flux, sarcomere structure, and the number of spontaneously beating cells. Transcriptome analysis shows that DAPT induces genetic programs related to muscle development, differentiation, and excitation-contraction coupling. Mechanistically, DAPT increases binding of the transcription factor MEF2C to the promoter regions of cardiac structural genes. These findings provide mechanistic insights into the reprogramming process and may have important implications for cardiac regeneration therapies.

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Notch activation is a barrier for GHMT-induced cardiac cell reprogramming

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Notch blockade by DAPT improves GHMT-induced cardiac reprogramming

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DAPT increases sarcomere organization, calcium flux, and beating in GHMT reprogramming

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DAPT enhances transcriptional activity of MEF2C in GHMT reprogramming

Anti-anhedonic effect of selective serotonin reuptake inhibitors with affinity for sigma-1 receptors in picrotoxin-treated mice

BACKGROUND AND PURPOSE

Prefrontal dopamine release by the combined activation of 5-HT1A and sigma-1 (σ1 ) receptors is enhanced by the GABAA receptor antagonist picrotoxin in mice. Here, we examined whether this neurochemical event was accompanied by behavioural changes.

EXPERIMENTAL APPROACH

Male mice were treated with picrotoxin to decrease GABAA receptor function. Their anhedonic behaviour was measured using the female encounter test. The expression of c-Fos was determined immunohistochemically.

KEY RESULTS

Picrotoxin caused an anxiogenic effect on three behavioural tests, but it did not affect the immobility time in the forced swim test. Picrotoxin decreased female preference in the female encounter test and attenuated the female encounter-induced increase in c-Fos expression in the nucleus accumbens. Picrotoxin-induced anhedonia was ameliorated by fluvoxamine and S-(+)-fluoxetine, selective serotonin reuptake inhibitors with high affinity for the σ1 receptor. The effect of fluvoxamine was blocked by a 5-HT1A or a σ1 receptor antagonist, and co-administration of the σ1 receptor agonist (+)-SKF-10047 and the 5-HT1A receptor agonist osemozotan mimicked the effect of fluvoxamine. By contrast, desipramine, duloxetine and paroxetine, which have little affinity for the σ1 receptor, did not affect picrotoxin-induced anhedonia. The effect of fluvoxamine was blocked by a dopamine D2/3 receptor antagonist. Methylphenidate, an activator of the prefrontal dopamine system, ameliorated picrotoxin-induced anhedonia.

CONCLUSION AND IMPLICATIONS

Picrotoxin-treated mice show anhedonic behaviour that is ameliorated by simultaneous activation of 5-HT1A and σ1 receptors. These findings suggest that the increased prefrontal dopamine release is associated with the anti-anhedonic effect observed in picrotoxin-treated mice.