The functional role of circRNA CHRC through miR-431-5p/KLF15 signaling axis in the progression of heart failure.

Pathological myocardial hypertrophy is a common early clinical manifestation of heart failure, with noncoding RNAs exerting regulatory influence. However, the molecular function of circular RNAs (circRNAs) in the progression from cardiac hypertrophy to heart failure remains unclear. To uncover functional circRNAs and identify the core circRNA signaling pathway in heart failure, we construct a global triple network (microRNA, circRNA, and mRNA) based on the competitive endogenous RNA (ceRNA) theory. We observe that cardiac hypertrophy related circRNA (circRNA CHRC), within the ceRNA network, is down-regulated in both transverse aortic constriction (TAC) mice and Ang-II--treated primary mouse cardiomyocytes. Silencing circRNA CHRC increases cross-sectional cell area, atrial natriuretic peptide, and ß-myosin heavy chain levels in primary mouse cardiomyocytes. Further screening reveals that circRNA CHRC targets the miR-431-5p/KLF15 axis implicated in heart failure progression in vivo and in vitro. Immunoprecipitation with anti-Ago2-RNA confirms the interaction between circRNA CHRC and miR-431-5p, while miR-431-5p mimics reverse Klf15 activation caused by circRNA CHRC overexpression. In summary, circRNA CHRC attenuates cardiac hypertrophy via sponging miR-431-5p to maintain the normal level of Klf15 expression.

Inhibition of a novel Dickkopf-1-LDL receptor-related proteins 5 and 6 axis prevents diabetic cardiomyopathy in mice.

BACKGROUND AND AIMS: Anti-hypertensive agents are one of the most frequently used drugs worldwide. However, no blood pressure-lowering strategy is superior to placebo with respect to survival in diabetic hypertensive patients. Previous findings show that Wnt co-receptors LDL receptor-related proteins 5 and 6 (LRP5/6) can directly bind to several G protein-coupled receptors (GPCRs). Because angiotensin II type 1 receptor (AT1R) is the most important GPCR in regulating hypertension, this study examines the possible mechanistic association between LRP5/6 and their binding protein Dickkopf-1 (DKK1) and activation of the AT1R and further hypothesizes that the LRP5/6-GPCR interaction may affect hypertension and potentiate cardiac impairment in the setting of diabetes. METHODS: The roles of serum DKK1 and DKK1-LRP5/6 signalling in diabetic injuries were investigated in human and diabetic mice. RESULTS: Blood pressure up-regulation positively correlated with serum DKK1 elevations in humans. Notably, LRP5/6 physically and functionally interacted with AT1R. The loss of membrane LRP5/6 caused by injection of a recombinant DKK1 protein or conditional LRP5/6 deletions resulted in AT1R activation and hypertension, as well as ß-arrestin1 activation and cardiac impairment, possibly because of multiple GPCR alterations. Importantly, unlike commonly used anti-hypertensive agents, administration of the anti-DKK1 neutralizing antibody effectively prevented diabetic cardiac impairment in mice. CONCLUSIONS: These findings establish a novel DKK1-LRP5/6-GPCR pathway in inducing diabetic injuries and may resolve the long-standing conundrum as to why elevated blood DKK1 has deleterious effects. Thus, monitoring and therapeutic elimination of blood DKK1 may be a promising strategy to attenuate diabetic injuries.

Kcnh2 deletion is associated with rat embryonic development defects via destruction of KCNH2­integrin ß1 complex.

The Kv11.1 potassium channel encoded by the Kcnh2 gene is crucial in conducting the rapid delayed rectifier K+ current in cardiomyocytes. Homozygous mutation in Kcnh2 is embryonically lethal in humans and mice. However, the molecular signaling pathway of intrauterine fetal loss is unclear. The present study generated a Kcnh2 knockout rat based on edited rat embryonic stem cells (rESCs). Kcnh2 knockout was embryonic lethal on day 11.5 of development due to a heart configuration defect. Experiments with human embryonic heart single cells (6.5­7 weeks post­conception) suggested that potassium voltage­gated channel subfamily H member 2 (KCNH2) plays a crucial role in the development of compact cardiomyocytes. By contrast, apoptosis was found to be triggered in the homozygous embryos, which could be attributed to the failure of KCNH2 to form a complex with integrin ß1 that was essential for preventing the process of apoptosis via inhibition of forkhead box O3A. Destruction of the KCNH2/integrin ß1 complex reduced the phosphorylation level of AKT and deactivated the glycogen synthase kinase 3 ß (GSK­3ß)/ß­catenin pathway, which caused early developmental abnormalities in rats. The present work reveals a basic mechanism by which KCNH2 maintains intact embryonic heart development.

Resveratrol prevents Ang II-induced cardiac hypertrophy by inhibition of NF-κB signaling.

BACKGROUND: Pathological cardiac hypertrophy is a hallmark of various cardiovascular diseases (CVD) including chronic heart failure (HF) and an important target for the treatment of these diseases. Aberrant activation of Angiotensin II (Ang II)/AT1R signaling pathway is one of the main triggers of cardiac hypertrophy, which further gives rise to excessive inflammation that is mediated by the key transcription factor NF-κB. Resveratrol (REV) is a natural polyphenol with multiple anti-inflammatory and anti-oxidative effects, however the ability of REV in preventing Ang II-induced cardiac hypertrophy in combination with NF-κB signaling activation remains unclear. METHODS: Murine models of cardiac hypertrophy was conducted via implantation of Ang II osmotic pumps. Primary neonatal rat cardiomyocyte and heart tissues were examined to determine the effect and underlying mechanism of REV in preventing Ang II-induced cardiac hypertrophy. RESULTS: Administrations of REV significantly prevented Ang II-induced cardiac hypertrophy, as well as robustly attenuated Ang II-induced cardiac fibrosis, and cardiac dysfunction. Furthermore, REV not only directly prevented Ang II/AT1R signal transductions, but also prevented Ang II-induced expressions of pro-inflammatory cytokines and activation of NF-κB signaling pathway. CONCLUSIONS: Our study provides important new mechanistic insight into the cardioprotective effects of REV in preventing Ang II-induced cardiac hypertrophy via inhibiting adverse NF-κB signaling activation. Our findings further suggest the therapeutic potential of REV as a promising drug for the treatment of cardiac hypertrophy and heart failure.

Transcriptome-based prediction of drugs, inhibiting cardiomyogenesis in human induced pluripotent stem cells.

Animal studies for embryotoxicity evaluation of potential therapeutics and environmental factors are complex, costly, and time-consuming. Often, studies are not of human relevance because of species differences. In the present study, we recapitulated the process of cardiomyogenesis in human induced pluripotent stem cells (hiPSCs) by modulation of the Wnt signaling pathway to identify a key cardiomyogenesis gene signature that can be applied to identify compounds and/or stress factors compromising the cardiomyogenesis process. Among the 23 tested teratogens and 16 non-teratogens, we identified three retinoids including 13-cis-retinoic acid that completely block the process of cardiomyogenesis in hiPSCs. Moreover, we have identified an early gene signature consisting of 31 genes and associated biological processes that are severely affected by the retinoids. To predict the inhibitory potential of teratogens and non-teratogens in the process of cardiomyogenesis we established the "Developmental Cardiotoxicity Index" (CDI31g) that accurately differentiates teratogens and non-teratogens to do or do not affect the differentiation of hiPSCs to functional cardiomyocytes.

Epigenetic mechanisms of Strip2 in differentiation of pluripotent stem cells.

Significant evidence points to Strip2 being a key regulator of the differentiation processes of pluripotent embryonic stem cells. However, Strip2 mediated epigenetic regulation of embryonic differentiation and development is quite unknown. Here, we identified several interaction partners of Strip2, importantly the co-repressor molecular protein complex nucleosome remodeling deacetylase/Tripartite motif-containing 28/Histone deacetylases/Histone-lysine N-methyltransferase SETDB1 (NuRD/TRIM28/HDACs/SETDB1) histone methyltransferase, which is primarily involved in regulation of the pluripotency of embryonic stem cells and its differentiation. The complex is normally activated by binding of Krueppel-associated box zinc-finger proteins (KRAB-ZFPs) to specific DNA motifs, causing methylation of H3 to Lysin-9 residues (H3K9). Our data showed that Strip2 binds to a DNA motif (20 base pairs), like the KRAB-ZFPs. We establish that Strip2 is an epigenetic regulator of pluripotency and differentiation by modulating DNA KRAB-ZFPs as well as the NuRD/TRIM28/HDACs/SETDB1 histone methyltransferase complex.

Concordant and Heterogeneity of Single-Cell Transcriptome in Cardiac Development of Human and Mouse.

Normal heart development is vital for maintaining its function, and the development process is involved in complex interactions between different cell lineages. How mammalian hearts develop differently is still not fully understood. In this study, we identified several major types of cardiac cells, including cardiomyocytes (CMs), fibroblasts (FBs), endothelial cells (ECs), ECs/FBs, epicardial cells (EPs), and immune cells (macrophage/monocyte cluster, MACs/MONOs), based on single-cell transcriptome data from embryonic hearts of both human and mouse. Then, species-shared and species-specific marker genes were determined in the same cell type between the two species, and the genes with consistent and different expression patterns were also selected by constructing the developmental trajectories. Through a comparison of the development stage similarity of CMs, FBs, and ECs/FBs between humans and mice, it is revealed that CMs at e9.5 and e10.5 of mice are most similar to those of humans at 7 W and 9 W, respectively. Mouse FBs at e10.5, e13.5, and e14.5 are correspondingly more like the same human cells at 6, 7, and 9 W. Moreover, the e9.5-ECs/FBs of mice are most similar to that of humans at 10W. These results provide a resource for understudying cardiac cell types and the crucial markers able to trace developmental trajectories among the species, which is beneficial for finding suitable mouse models to detect human cardiac physiology and related diseases.

An optimized proliferation system of embryonic stem cells for generating the rat model with large fragment modification.

Rats have long been an ideal model for disease research in the field of biomedicine, but the bottleneck of in vitro culture of rat embryonic stem (ES) cells hindered the wide application as genetic disease models. Here, we optimized a special medium which we named 5N-medium for rat embryonic stem cells, which improved the in vitro cells with better morphology and higher pluripotency. We then established a drug selection schedule harboring a prior selection of 12 h that achieved a higher positive selection ratio. These treatments induced at least 50% increase of homologous recombination efficiency compared with conventional 2i culture condition. Moreover, the ratio of euploid ES clones also increased by 50% with a higher germline transmission rate. Finally, we successfully knocked in a 175 kb human Bacterial Artificial Chromosome (BAC) fragment to rat ES genome through recombinase mediated cassette exchange (RMCE). Hence, we provide a promising system for generating sophisticated rat models which could be benefit for biomedical researches.

Epigenetic Mechanisms Involved in the Cardiovascular Toxicity of Anticancer Drugs.

The cardiovascular toxicity of anticancer drugs promotes the development of cardiovascular diseases. Therefore, cardiovascular toxicity is an important safety issue that must be considered when developing medications and therapeutic applications to treat cancer. Among anticancer drugs, members of the anthracycline family, such as doxorubicin, daunorubicin and mitoxantrone, are known to cause cardiotoxicity and even heart failure. Using human-induced pluripotent stem cell-derived cardiomyocytes in combination with "Omic" technologies, we identified several cardiotoxicity mechanisms and signal transduction pathways. Moreover, these drugs acted as cardiovascular toxicants through a syndrome of mechanisms, including epigenetic ones. Herein, we discuss the main cardiovascular toxicity mechanisms, with an emphasis on those associated with reactive oxygen species and mitochondria that contribute to cardiotoxic epigenetic modifications. We also discuss how to mitigate the cardiotoxic effects of anticancer drugs using available pharmaceutical "weapons."

Activation of Blood Vessel Development in Endometrial Stromal Cells In Vitro Cocultured with Human Peri-Implantation Embryos Revealed by Single-Cell RNA-Seq.

In humans, the maternal endometrium participates in the physical and physiological interaction with the blastocyst to begin implantation. A bidirectional crosstalk is critical for normal implantation and then a successful pregnancy. While several studies have used animal models or cell lines to study this step, little knowledge was acquired to address the role of endometrial cells in humans. Here, we analyzed single-cell sequencing data from a previous study including 24 non-coculture endometrial stromal cells (EmSCs) and 57 EmSCs after coculture with embryos. We further explored the transcriptomic changes in EmSCs and their interactions with trophoblast cells after coculture. Differentially expressed gene (DEG) analysis showed 1783 upregulated genes and 569 downregulated genes in the cocultured embryos. Weight gene coexpression network and gene ontology analysis of these DEGs showed a higher expression of RAMP1, LTBP1, and LRP1 in EmSCs after coculture, indicating the enrichment of biological processes in blood vessel development and female pregnancy. These data imply that EmSCs start blood vessel development at the implantation stage. Compared with endometrium data in vivo at the implantation window, key pathways including epithelial cell development and oxygen response were involved at this stage. Further analysis using CellphoneDB shed light on the interactions between EmSCs and embryonic trophoblasts, suggesting the important role of integrins and fibroblast growth factor pathways during implantation. Taken together, our work reveals the synchronization signaling and pathways happening at the implantation stage involving the acquisition of receptivity in EmSCs and the interaction between EmSCs and trophoblast cells.

Identification of an endogenous glutamatergic transmitter system controlling excitability and conductivity of atrial cardiomyocytes.

As an excitatory transmitter system, the glutamatergic transmitter system controls excitability and conductivity of neurons. Since both cardiomyocytes and neurons are excitable cells, we hypothesized that cardiomyocytes may also be regulated by a similar system. Here, we have demonstrated that atrial cardiomyocytes have an intrinsic glutamatergic transmitter system, which regulates the generation and propagation of action potentials. First, there are abundant vesicles containing glutamate beneath the plasma membrane of rat atrial cardiomyocytes. Second, rat atrial cardiomyocytes express key elements of the glutamatergic transmitter system, such as the glutamate metabolic enzyme, ionotropic glutamate receptors (iGluRs), and glutamate transporters. Third, iGluR agonists evoke iGluR-gated currents and decrease the threshold of electrical excitability in rat atrial cardiomyocytes. Fourth, iGluR antagonists strikingly attenuate the conduction velocity of electrical impulses in rat atrial myocardium both in vitro and in vivo. Knockdown of GRIA3 or GRIN1, two highly expressed iGluR subtypes in atria, drastically decreased the excitatory firing rate and slowed down the electrical conduction velocity in cultured human induced pluripotent stem cell (iPSC)-derived atrial cardiomyocyte monolayers. Finally, iGluR antagonists effectively prevent and terminate atrial fibrillation in a rat isolated heart model. In addition, the key elements of the glutamatergic transmitter system are also present and show electrophysiological functions in human atrial cardiomyocytes. In conclusion, our data reveal an intrinsic glutamatergic transmitter system directly modulating excitability and conductivity of atrial cardiomyocytes through controlling iGluR-gated currents. Manipulation of this system may open potential new avenues for therapeutic intervention of cardiac arrhythmias.

Autopsy and statistical evidence of disturbed hemostasis progress in COVID-19: medical records from 407 patients.

BACKGROUND: The progression of coagulation in COVID-19 patients with confirmed discharge status and the combination of autopsy with complete hemostasis parameters have not been well studied. OBJECTIVE: To clarify the thrombotic phenomena and hemostasis state in COVID-19 patients based on epidemiological statistics combining autopsy and statistical analysis. METHODS: Using autopsy results from 9 patients with COVID-19 pneumonia and the medical records of 407 patients, including 39 deceased patients whose discharge status was certain, time-sequential changes in 11 relevant indices within mild, severe and critical infection throughout hospitalization according to the Chinese National Health Commission (NHC) guidelines were evaluated. Statistical tools were applied to calculate the importance of 11 indices and the correlation between those indices and the severity of COVID-19. RESULTS: At the beginning of hospitalization, platelet (PLT) counts were significantly reduced in critically ill patients compared with severely or mildly ill patients. Blood glucose (GLU), prothrombin time (PT), activated partial thromboplastin time (APTT), and D-dimer levels in critical patients were increased compared with mild and severe patients during the entire admission period. The International Society on Thrombosis and Haemostasis (ISTH) disseminated intravascular coagulation (DIC) score was also high in critical patients. In the relatively late stage of nonsurvivors, the temporal changes in PLT count, PT, and D-dimer levels were significantly different from those in survivors. A random forest model indicated that the most important feature was PT followed by D-dimer, indicating their positive associations with disease severity. Autopsy of deceased patients fulfilling diagnostic criteria for DIC revealed microthromboses in multiple organs. CONCLUSIONS: Combining autopsy data, time-sequential changes and statistical methods to explore hemostasis-relevant indices among the different severities of the disease helps guide therapy and detect prognosis in COVID-19 infection.

Sinoatrial node pacemaker cells share dominant biological properties with glutamatergic neurons.

Activation of the heart normally begins in the sinoatrial node (SAN). Electrical impulses spontaneously released by SAN pacemaker cells (SANPCs) trigger the contraction of the heart. However, the cellular nature of SANPCs remains controversial. Here, we report that SANPCs exhibit glutamatergic neuron-like properties. By comparing the single-cell transcriptome of SANPCs with that of cells from primary visual cortex in mouse, we found that SANPCs co-clustered with cortical neurons. Tissue and cellular imaging confirmed that SANPCs contained key elements of glutamatergic neurotransmitter system, expressing genes encoding glutamate synthesis pathway (Gls), ionotropic and metabotropic glutamate receptors (Grina, Gria3, Grm1 and Grm5), and glutamate transporters (Slc17a7). SANPCs highly expressed cell markers of glutamatergic neurons (Snap25 and Slc17a7), whereas Gad1, a marker of GABAergic neurons, was negative. Functional studies revealed that inhibition of glutamate receptors or transporters reduced spontaneous pacing frequency of isolated SAN tissues and spontaneous Ca2+ transients frequency in single SANPC. Collectively, our work suggests that SANPCs share dominant biological properties with glutamatergic neurons, and the glutamatergic neurotransmitter system may act as an intrinsic regulation module of heart rhythm, which provides a potential intervention target for pacemaker cell-associated arrhythmias.

ERG1 plays an essential role in rat cardiomyocyte fate decision by mediating AKT signaling.

ERG1, a potassium ion channel, is essential for cardiac action potential repolarization phase. However, the role of ERG1 for normal development of the heart is poorly understood. Using the rat embryonic stem cells (rESCs) model, we show that ERG1 is crucial in cardiomyocyte lineage commitment via interactions with Integrin ß1. In the mesoderm phase of rESCs, the interaction of ERG1 with Integrin ß1 can activate the AKT pathway by recruiting and phosphorylating PI3K p85 and focal adhesion kinase (FAK) to further phosphorylate AKT. Activation of AKT pathway promotes cardiomyocyte differentiation through two different mechanisms, (a) through phosphorylation of GSK3ß to upregulate the expression levels of ß-catenin and Gata4; (b) through promotion of nuclear translocation of nuclear factor-κB by phosphorylating IKKß to inhibit cell apoptosis, which occurs due to increased Bcl2 expression. Our study provides solid evidence for a novel role of ERG1 on differentiation of rESCs into cardiomyocytes.

Literature-based learning and experimental design model in molecular biology teaching for medical students at Tongji University.

In 2018, to help undergraduate medical students strengthen their self-learning and scientific research skills, we introduced an instructional model that combined literature-based learning with experimental design. We tested this model on the molecular biology class at Tongji University. In the first step of the model, a topic is chosen, and students find, read, and evaluate scientific papers in groups and deliver presentations. In the second step, they design scientific experiments in groups and discuss their proposed experiments in class, which is to be followed by further experimental verification in the lab course. This entire activity was given 20% weightage in the final score. The model led to better student-centered teaching and self-directed learning according to quantitative and qualitative assessment. Students showed great interest in literature and research. They enjoyed group work and gained experience in organization and presentation. Apart from a significant increase in final score, assessment data from students indicated that they were satisfied with this teaching model and considered it a positive experience. Looking at the positive impact of the literature-based learning and experiment design model, we support its continued use for teaching molecular biology to undergraduate medical students.

Kcnh2 mediates FAK/AKT-FOXO3A pathway to attenuate sepsis-induced cardiac dysfunction.

OBJECTIVES: Myocardial dysfunction is a significant manifestation in sepsis, which results in high mortality. Even Kcnh2 has been hinted to associate with the pathological process, its involved signalling is still elusive. MATERIALS AND METHODS: The caecal ligation puncture (CLP) surgery or lipopolysaccharide (LPS) injection was performed to induce septic cardiac dysfunction. Western blotting was used to determine KCNH2 expression. Cardiac function was examined by echocardiography 6 hours after CLP and LPS injection in Kcnh2 knockout (Kcnh2+/- ) and NS1643 injection rats (n ≥ 6/group). Survival was monitored following CLP-induced sepsis (n ≥ 8/group). RESULTS: Sepsis could downregulate KCNH2 level in the rat heart, as well as in LPS-stimulated cardiomyocytes but not cardiac fibroblast. Defect of Kcnh2 (Kcnh2+/- ) significantly aggravated septic cardiac dysfunction, exacerbated tissue damage and increased apoptosis under LPS challenge. Fractional shortening and ejection fraction values were significantly decreased in Kcnh2+/- group than Kcnh2+/+ group. Survival outcome in Kcnh2+/- septic rats was markedly deteriorated, compared with Kcnh2+/+ rats. Activated Kcnh2 with NS1643, however, resulted in opposite effects. Lack of Kcnh2 caused inhibition of FAK/AKT signalling, reflecting in an upregulation for FOXO3A and its downstream targets, which eventually induced cardiomyocyte apoptosis and heart tissue damage. Either activation of AKT by activator or knockdown of FOXO3A with si-RNA remarkably attenuated the pathological manifestations that Kcnh2 defect mediated. CONCLUSION: Kcnh2 plays a protection role in sepsis-induced cardiac dysfunction (SCID) via regulating FAK/AKT-FOXO3A to block LPS-induced myocardium apoptosis, indicating a potential effect of the potassium channels in pathophysiology of SCID.

Molecular Signatures and Networks of Cardiomyocyte Differentiation in Humans and Mice.

Cardiomyocyte differentiation derived from embryonic stem cells (ESCs) is a complex process involving molecular regulation of multiple levels. In this study, we first identify and compare differentially expressed gene (DEG) signatures of ESC-derived cardiomyocyte differentiation (ESCDCD) in humans and mice. Then, the multiscale embedded gene co-expression network analysis (MEGENA) of the human ESCDCD dataset is performed to identify 212 significantly co-expressed gene modules, which capture well the regulatory information of cardiomyocyte differentiation. Three modules respectively involved in the regulation of stem cell pluripotency, Wnt, and calcium pathways are enriched in the DEG signatures of the differentiation phase transition in the two species. Three human-specific cardiomyocyte differentiation phase transition modules are identified. Moreover, the potential regulation mechanisms of transcription factors during cardiomyocyte differentiation are also illustrated. Finally, several novel key drivers of ESCDCD are identified with the evidence of their expression during mouse embryonic cardiomyocyte differentiation. Using an integrative network analysis, the core molecular signatures and gene subnetworks (modules) underlying cardiomyocyte lineage commitment are identified in both humans and mice. Our findings provide a global picture of gene-gene co-regulation and identify key regulators during ESCDCD.

miR-29b-3p protects cardiomyocytes against endotoxin-induced apoptosis and inflammatory response through targeting FOXO3A.

Cardiac dysfunction represents a main component of death induced by sepsis in critical care units. And microRNAs (miRNAs) have been reported as important modulators or biomarkers of sepsis. However, the molecular detail of miRNAs involved in septic cardiac dysfunction remains unclear. Here we showed that endotoxin (lipopolysaccharide, LPS) significantly down-regulated expression of miR-29b-3p in heart. Increased expression of miR-29b-3p by lentivirus improved cardiac function and attenuated damage of cardiac induced by LPS in mice. Furthermore, overexpression or knockdown of miR-29b-3p showed its crucial roles on regulation of apoptosis and production of pro-inflammatory cytokines in NRCMs through directly targeting FOXO3A. miR-29b-3p ameliorates inflammatory damage likely via reducing activation of MAPKs and nuclear-translocation of NF-κB to block LPS-activated NF-κB signaling. Notably, miR-29b is also down-regulated in septic patients' plasma compared with normal subjects, indicating a potential clinical relevance of miR-29b. Taken together, our findings demonstrate that upregulation of miR-29b-3p can attenuate myocardial injury induced by sepsis via regulating FOXO3A, which provide a potential therapy target for interference of septic cardiac dysfunction.

Risk Factors And Epigenetic Markers Of Left Ventricular Diastolic Dysfunction With Preserved Ejection Fraction In A Community-Based Elderly Chinese Population.

PURPOSE: Left ventricular diastolic dysfunction with preserved ejection fraction (LVDD-PEF) is an early-stage manifestation but poorly understood in the process of heart failure. This study was designed to investigate risk factors and epigenetic markers for predicting LVDD-PEF. PATIENTS AND METHODS: A community-based study in 1568 residents over 65 years was conducted in Shanghai, People's Republic of China, from June 2014 to August 2015. Echocardiography was performed to diagnose LVDD-PEF. DNA methylation by whole-genome bisulfite sequencing was used to determine those potential epigenetic markers contributing to LVDD-PEF. RESULTS: A total of 177 participants (11.3%) were diagnosed with LVDD-PEF, and higher prevalence in females than in males (15.0% vs 6.5%, P<0.001). Multivariate logistic regression analysis indicated that female sex (OR 2.46, 95% CI 1.47-4.13), body mass index (BMI) (OR 1.09, 95% CI 1.04-1.14), pulse pressure (PP) (OR 1.03, 95% CI 1.01-1.05) and carotid intima-media thickness (CIMT) (OR 4.20, 95% CI 1.40-12.55) showed a significant association with LVDD-PEF. Overall, 638 CpG sites were differentially methylated in LVDD-PEF group compared to non-LVDD-PEF group (P<0.001); 242 sites were significantly hypermethylated (covering 238 genes) and 396 sites were significantly hypomethylated (covering 265 genes). CONCLUSION: Our findings found female, BMI, PP, and CIMT were independent predictors for LVDD-PEF in the community-dwelling elderly population. Regulation of DNA methylation might play a crucial role for LVDD-PEF.

GSK-3ß inhibition protects the rat heart from the lipopolysaccharide-induced inflammation injury via suppressing FOXO3A activity.

Sepsis-induced cardiac dysfunction represents a main cause of death in intensive care units. Previous studies have indicated that GSK-3ß is involved in the modulation of sepsis. However, the signalling details of GSK-3ß regulation in endotoxin lipopolysaccharide (LPS)-induced septic myocardial dysfunction are still unclear. Here, based on the rat septic myocardial injury model, we found that LPS could induce GSK-3ß phosphorylation at its active site (Y216) and up-regulate FOXO3A level in primary cardiomyocytes. The FOXO3A expression was significantly reduced by GSK-3ß inhibitors and further reversed through ß-catenin knock-down. This pharmacological inhibition of GSK-3ß attenuated the LPS-induced cell injury via mediating ß-catenin signalling, which could be abolished by FOXO3A activation. In vivo, GSK-3ß suppression consistently improved cardiac function and relieved heart injury induced by LPS. In addition, the increase in inflammatory cytokines in LPS-induced model was also blocked by inhibition of GSK-3ß, which curbed both ERK and NF-κB pathways, and suppressed cardiomyocyte apoptosis via activating the AMP-activated protein kinase (AMPK). Our results demonstrate that GSK-3ß inhibition attenuates myocardial injury induced by endotoxin that mediates the activation of FOXO3A, which suggests a potential target for the therapy of septic cardiac dysfunction.