bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 810: Structural and Electrophysiological Maturation of Human iPSC-Derived Atrial Cardiomyocytes to Serve as a Platform to Model Atrial Fibrillation
Authors: Ly Olivia T , Youn Seock Won , Brown Grace , Hong Liang , Sridhar Arvind , Zhang Meihong , Lambers Erin , Khetani Salman , Darbar Dawood
Published: October 2019

Background:
Atrial fibrillation (AF), the most globally common arrhythmia requiring treatment, is associated with significant morbidity and mortality. Although antiarrhythmic drugs (AADs) are most commonly used to treat symptomatic AF, AADs are incompletely and unpredictably effective, and fail to target underlying cellular mechanisms of AF. Previously, pluripotent stem cell derived immature atrial cardiomyocytes (iPSC-aCMs) were shown to recapitulate the structural and electrophysiologic (EP) phenotype of AF-linked mutations. However, there are gaps in structural and EP phenotype between immature and mature iPSC-aCMs to successfully evaluate cellular mechanisms.

Objective:
The goal is to determine optimal condition(s) to enhance maturity of iPSC-aCMs, to establish iPSC-aCMs as a novel platform to model AF in a dish, elucidate cellular mechanisms and molecular pathogenesis, and identify and assess novel, personalized mechanism based therapies.

Methods:
Conditions used to enhance iPSC-aCMs maturity are 1) different ECMs to culture iPSC-aCMs, 2) patterned ECM to improve alignment and formation of intercellular gap junctions, and 3) treatment with postnatal factors (T3, IGF-1 and dexamethasone; TID). Maturity was assessed with immunofluorescence and EP measurement with patch-clamping and optical voltage analysis. Results were compared to equivalent parameters in adult atrial cardiomyocytes (aCM) and untreated atrial iPSC-CMs.

Results:
Fibronectin and laminin were ECMs found suitable for long time culture of iPSC-aCMs. Structural maturity (α-actinin and cardiac troponin T) and EP maturity (resting membrane potential [83 ± 3%], APD
90
[67 ± 2.5%], and conduction velocity [59.6 ±3%]) with patterned ECM and TID treatment were significantly improved compared to untreated iPSC-aCMs, and closer to those of adult aCMs.

Conclusion:
Structural and EP maturity of iPSC-aCMs are significantly enhanced by precise microenvironmental engineering of in-vivo relevant cell-cell, cell-ECM, and cell-soluble factor interactions. Thus, our findings will provide a platform to investigate cellular mechanisms of AF.
Abstract 824: Thromboxane/Prostanoid Receptor Activation Increases Calpain-Mediated Proteolysis and Alters Calcium Handling and Fibrosis Following Right Ventricular Pressure Overload
Authors: West James D , Kim Kyungsoo , Suzuki Toshio , Moore Christy , Knollmann Bjorn C , Carrier Erica J
Published: October 2019

In pulmonary arterial hypertension (PAH), the right ventricle undergoes remodeling and fibrosis as it struggles to adapt to the increased pressure overload. RV dysfunction and failure is the primary cause of death in PAH patients. The G protein-coupled thromboxane/prostanoid receptor (TPr) is expressed in vascular smooth muscle, myofibroblasts, and immune cells, and is upregulated in cardiomyocytes following PAH. Activation of the cardiomyocyte TPr increases intracellular calcium via G
αq
/IP
3
; activation of the receptor in other cells leads to fibrosis and vasoconstriction. The TPr is activated by isoprostane as well as thromboxane, which suggests that the receptor could contribute to deleterious remodeling during cardiac stress. Our previous studies demonstrate that TPr antagonism prevents RV fibrosis and dilatation in murine models of PAH, without affecting pressures. Because the TPr can signal through Gq, we hypothesized that its activation in PAH causes changes in cardiomyocyte calcium-handling proteins which contribute to remodeling and failure. In this study, we used pulmonary arterial banding (PAB) to induce fixed pressure overload of the RV. Mice were treated for 4 weeks past PAB with normal drinking water or water containing 25 mg/kg/day of the TPr antagonist ifetroban, and either underwent pressure-volume catheterization and whole RV evaluation, or cardiomyocytes were isolated for calcium handling and protein. PAB caused an increase in cardiomyocyte resting (end-diastolic) intracellular calcium, which was ameliorated in mice given TPr antagonist. The increased intracellular calcium following PAB was associated with increased activity of the calcium-activated protease calpain, also blocked with TPr antagonism. There was no decrease in caffeine-mediated release of calcium from the sarcoplasmic reticulum (SR) at 4 weeks past PAB, and phosphorylation of phospholamban was increased, suggesting compensation to drive calcium into the SR. Our findings suggest that TPr activation produces alterations in RV calcium handling, signaling, and calpain activity that contribute to deleterious remodeling and early failure in pressure overload. Therapeutic TPr antagonism may help preserve RV function in patients with PAH.
Abstract 837: Different Disease States in Heart Have Distinct Cardiac Interstitial Cells Contributing to Fibrosis
Authors: Khalil Hadi , Jones Shannon M , Alam Perwez , Aronow Bruce J , Molkentin Jeffery D , Kanisicak Onur
Published: October 2019

Cardiac fibrosis is a grim consequence for almost all myocardial injuries. In myocardial infarction (MI), what starts as a protective scarring process to prevent ventricular wall rupture becomes a pathological remodeling of the tissue with the accumulation of excess extracellular matrix (ECM) proteins. Eventually, this adaptation impedes the mechanical and electrical properties of the myocardium resulting in heart failure. Recently, we showed that periostin (Postn) expressing resident cardiac fibroblasts (CFs) are a potential therapeutic target since they differentiate into the scar associated, matrix-producing myofibroblasts (MFs) after injury. In fact, deletion of these cells after an acute injury eliminates interstitial fibrosis but results in ventricular rupture which is a hallmark outcome of impaired ECM deposition during the acute phase of MI. On the other hand, ablation of these cells during a chronic injury such as pressure overload-induced cardiac fibrosis model, we observe sustained perivascular fibrosis. Previous studies report heterogeneity of origin and function for ECM producing cells associated with different cardiac diseases. Here we utilized several novel mouse models that permit lineage tracing of all activated MFs as well as perivascular mural cells in the heart to elucidate the role and fate of these distinct cardiac interstitial cells during fibrogenesis. Cells were lineage traced with a tamoxifen-inducible cre recombinase cDNA knock-in alleles (PostnMCM and Gli1CreER) in combination with a Rosa26-eGFP cre-dependent reporter. Hearts subjected to MI, TAC or Angiotensin injury were processed for extensive histological and RNAseq analyses. Results show that interstitial fibrosis in acute MI injury is a result of Postn+ MFs activity, whereas a subset of Gli1+ mural cells are responsible for the perivascular fibrosis observed after pressure overload models. Therefore, we concluded that pathological ECM deposition resulting in fibrosis comes from disease-specific specialized sub-populations of interstitial cells of the heart with distinct gene expressions and require manipulation of alternative cell- and state-specific therapeutic targets.
Abstract 841: Loss of S-nitrosylation of G Protein-Coupled Receptor Kinase 2 Leads to Cardiovascular Dysfunction With Aging
Authors: Lieu Melissa , Traynham Christopher J , Petovic Jennifer , Landesberg Gavin P , Forrester Steven , Gao Erhe , Eguchi Satoru , Scalia Rosario , Koch Walter J
Published: October 2019

Nitric oxide (NO) and S-nitrosothiol (SNO) have cardiovascular-protective properties and we have shown that one mechanism is through SNO-modification of G protein-coupled receptor (GPCR) kinase 2 (GRK2). S-nitrosylation at Cys340 (C340S) of GRK2 inhibits its activity on GPCRs such as β-adrenergic receptors in the heart and other GRK2 dependent processes. S-nitrosylation is believed to act as a brake on this pathological kinase. We generated global knock-in (KI) mice that express endogenous levels of GRK2, but with C340 mutated to Ser (GRK2-C340S). The C340 site is the primary site of S-nitrosylation and is largely responsible for eNOS-mediated cardioprotection after acute ischemic injury of the heart. In this study we observed that the loss of SNO-mediated inhibition of GRK2 leads to cardiovascular dysfunction during normal aging. GRK2 has been shown to be up-regulated during several cardiovascular (CV) pathologies including hypertension and heart failure, and aging is a major risk factor of CV disease (CVD). GRK2-C340S KI mice compared to their wild-type (WT) controls showed significant pathology as early as 52 weeks of age and was maintained up to 82 weeks. Maladaptive cardiac hypertrophy was present in aged GRK2-C340S mice with significant perivascular myocardial fibrosis. Fibrosis was prevalent in the kidneys as well. These histological changes were accompanied by reduced systolic function and pulse pressure compared to WT mice. Within the vasculature, aged GRK2-C340S aortas had reduced medial thickness and had reduced contraction in response to PE, KCl, or L-NAME. Acetylcholine-induced relaxation responses remained intact. Consistent with enhanced GRK2 activity
in vivo
in the heart, we found increased circulating levels of serum catecholamines. Many of these phenotypes we observed in GRK2-C340S mice are also observed in human aging and CVD. These phenotypes predispose patients to developing other diseases. As the US population becomes increasingly older, understanding the dynamic between aging and CVD is important in disease management and therapy. The aged GRK2-C340S mouse model represents a model of higher CVD risk and provides insights into consequences of chronic GRK2 global over-activity when the regulation of this kinase by NO is lost.
Abstract 850: Metabolic Landscape of Human Heart Failure
Authors: Flam Emily , Jang Cholsoon , Bedi Kenneth , Margulies Kenneth , Arany Zoltan
Published: October 2019

Heart failure is characterized by insufficient pumping to match the needs of the body. Heart failure is thought to be associated with dysfunctional mitochondria and metabolic alterations, but there is little to no direct evidence in humans. The heart metabolizes a variety of substrates for energy production, including fatty acids, glucose, ketones, and branch chain amino acids (BCAAs). In the healthy heart, fatty acids are the main fuel source, and oxidation is balanced with energy need. In heart failure, it is asserted that fatty acid oxidation is suppressed, and glucose utilization is increased, but this has not been directly measured in humans. If true, this metabolic switch toward glucose may contribute to mechanical insufficiency by disrupting the balance between metabolism and energetic need, thus representing a potential area for therapeutic intervention in heart failure. Prior studies were largely performed in animal models, and results are often inconsistent across models and species. Challenges have constrained the use of human myocardium, including costly and cumbersome techniques for in vivo assessment; limited availability of high-quality human myocardial tissue; and low yields and short durability of isolated human cardiomyocytes. We addressed these challenges by taking advantage of human explanted hearts available via the Penn Heart Transplant program to investigate the metabolic differences between failing and healthy human hearts.

We performed metabolomics analysis using mass spectrometry on myocardium from 18 failing and 20 nonfailing human hearts. Of the 334 metabolites measured, 99 were significantly different between groups by Wilcoxon test and FDR correction. Metabolite set enrichment analysis revealed that the most enriched pathways included the glycerol phosphate shuttle, ammonia recycling, methylhistidine metabolism, and glutathione metabolism. The mitochondrial electron transport chain, BCAA catabolism, purine metabolism, the urea cycle, gluconeogenesis, glycolysis, ketone body metabolism, and the pentose phosphate pathway were also included in the top 50 most enriched pathways. These data will guide future targeted metabolic studies in human heart failure.
Abstract 875: Cardiomyocyte Derived DDT Protects Against Myocardial Infarction Induced Heart Failure
Authors: Ma Yina , Hu Xiaoyue , Wu Xiaohong , Pfau Daniel , Leng Lin , Bedi Kenneth , Margulies Kenneth , Bucala Richard , Young Lawrence
Published: October 2019

Background:
D-dopachrome tautomerase (DDT), the only homolog of macrophage migration inhibitory factor (MIF), is a cytokine highly expressed in cardiomyocytes and has autocrine-paracrine effects, signaling through the CD74 receptor. Endogenous DDT and MIF prevent ischemia-reperfusion injury in mice. In this study, we investigated whether endogenous cardiomyocyte DDT protects against myocardial remodeling and heart failure after myocardial infarction.

Methods:
Cardiomyocyte-specific DDT knockout (cKO) and littermate control (CON) mice underwent myocardial infarction (MI) or sham surgery. Serial echocardiography was performed at baseline, 1 day before permanent coronary ligation and 1 day, 1 week, and 4 weeks after MI or sham surgery. Hearts were analyzed at 3 days after MI or sham surgery for histology and molecular studies.

Results:
No baseline differences in left ventricular (LV) function were observed in cKO and CON mice at baseline or after sham surgery. The initial infarction sizes were comparable at 1 day after coronary ligation in cKO and CON. Compared to CON, cKO mice developed more rapid LV dilatation, and decreased LV ejection fraction (EF) and stroke volume (SV) as early as 1 week after MI. At 4 weeks after MI, LVEF was 33% lower and SV lower by 43% in cKO vs. CON (n=4-5/group, all P<0.01). Hemodynamic analysis showed that LV end diastolic pressure in the cKO mice was 38% higher in cKO vs. CON after 4 weeks MI (p=0.052). Immunoblots showed diminished phosphorylation of AMPK and downstream ACC in the cKO mice 3 days after MI. Immunohistochemistry staining with CD3 and F4/80 staining showed increased T cells and macrophage cells in the cKO mice 3 days after MI (p<0.05). We further assessed the regulation of cardiac DDT expression in chronic human heart failure. In hearts explanted from patients with advanced heart failure during transplantation for ischemic cardiomyopathy (n=8), DDT mRNA and protein expression were also reduced by 40% and 58% compared to controls (P<0.01).

Conclusion:
Cardiomyocyte-derived DDT prevents adverse cardiac remodeling after MI, potentially through AMPK signaling and anti-inflammatory effects. Down-regulation of cardiac DDT may contribute to pathogenesis of advanced heart failure.
Abstract 886: Mitochondrial Stress Response by Lonp1 in Cardiac Function and Protection
Authors: Sundararajan Venkatesh , Tong Mingming , Baljinnyam Erdene , Murari Anjaneyalu , Zhai Peiyong , Owusu-Ansah Edward , Fraidenraich Diego , Sadoshima Junichi , Suzuki Carolyn K
Published: October 2019

LonP1 is a mitochondrial protease that is crucial for maintaining cardiac mitochondrial homeostasis. We recently showed that LonP1 mediates cardioprotection during cardiac ischemia-reperfusion (I/R) by reducing oxidative stress and infarct size. We hypothesize that LonP1 promotes mitochondrial biogenesis during cardiac differentiation and development and protects the heart from oxidative injury by recalibrating bioenergetics. Here, we employ human induced pluripotent stem cells differentiated into cardiomyocytes (iPSC-CMs), rat neonatal ventricular myocytes (rNVMs), and mouse models with cardiac-specific LonP1 overexpression (LonTg) and heterozygous LonP1 knockout (

LONP1
+/-

). In iPSC-CMs, LonP1 is induced 4.8-fold at 39 vs. 12 days after differentiation. During the maturation of murine hearts, LonP1 is increased 4.6-fold at 3 months vs. during 1 day. Upregulation was also observed in rNVMs in which LonP1 is induced 5- fold after 5 days culturing, compared to 0 days. LonP1 induction in rNVMs is accompanied by substantial 2-fold upregulation of mitochondrial transcripts, MT-CYB and MT-COI. However, the levels of another mitochondrial matrix protease ClpP was not altered, suggesting that LonP1 specifically may play an important role during mitochondrial biogenesis and proteostasis in the heart. In vivo, LonTg protected the myocardium against ischemia-reperfusion (I/R) injury by preventing oxidative damage. In LonTg hearts, basal complex I activity was significantly (p<0.05) reduced (Ntg-0.01 ± 0.001 vs. LonTg-0.0078 ± 0.001 mOD/min), as well as during I/R (Ntg-0.0139 ± 0.0005 vs LonTg-0.0102 ± 0.001 mOD/min) (n=3 each). However, no difference was observed in the complex I activity in

LONP1
+/+

(0.0118 ± 0.0 mOD/min) and

LONP1
+/-

(0.0121 ± 0.0 mOD/min) mice (n=3 each). In addition, our preliminary native gel data of LonTg hearts shows a 40% reduction (n=1) in the levels of mitochondrial supercomplexes, compared to NTg hearts (n=4). Further studies are underway to explore the role of LonP1 during differentiation, and in response to mitochondrial cardiac stress. Together, our findings show a novel role of LonP1 in regulating cardiac function during mitochondrial biogenesis and in mitigating cardiac stress-induced injury.
Abstract 888: Exosomes Derived From Endothelial Progenitor Cells Modulate Flow-Induced Remodeling and Increase Angiogenesis/Arteriogenesis in Mesenteric Arteries of Mice
Authors: Dantas Ana Paula V , Bobi Joaquim , Grimaud Linda , Vessieres Emilie , Henrion Daniel
Published: October 2019

Exosomes are key regulators of cell-to-cell communication, becoming valuable tool as disease biomarker and in the development of new therapeutic strategies. We aimed to determine the role of endothelial progenitor cell (EPC)-derived exosomes (EXO) in vascular remodeling induced by flow. C57BL/6 mice underwent chronic changes in flow by mesenteric resistance arteries ligation. Arteries were thus submitted to high flow (HF), low flow (LF), or normal flow (NF). The day before surgery mice received I.P. injection with saline or exosomes (3x10
9
particle/kg), following the treatment every 3 days until sacrifice. After 14 days, arteries were studied in vitro in a pressure arteriograph. Increase in diameter and compliance by pressure found in HF arteries were not seen in EXO treated mice (Fig A). Decrease in diameter observed in saline treated LF arteries, was also abolished by EXO treatment. Network analysis of miRNA content in exosomes and arterial mRNA expression revealed an increased expression of components involved in angiogenesis/arteriogenesis (Fig B), which could contribute to flow maintenance in the tissue. Mesenteric arteries submitted to LF, HF and NF were isolated and placed in Matrigel matrix for angiogenesis analysis. We observed that change in flow is a trigger for vasculogenesis, which is enhanced by EXO treatment (Fig C). This study establishes the potential role of EPC-derived exosomes to regulate vascular remodeling during changes in flow. The mechanisms for these effects involve exosome-derived miRNA regulation of a network of mRNAs implicated in collateral angiogenesis/arteriogenesis, which in turn, may contribute to maintenance of tissue homeostasis.
Abstract 893: MicroRNA-448 Regulates the Cardiac Sodium Channel During Ischemia
Authors: Kang Gyeoung-Jin , Xie An , Dudley Samuel
Published: October 2019

Background:
The cardiac voltage-gated sodium channel (
SCN5A
; encoding Na
v
1.5) plays a key role in cardiac conduction. The sodium channel is downregulated in cardiomyopathy, contributing to arrhythmic risk. In part, this downregulation is because of abnormal mRNA splicing and reduced mRNA stability. The reason for decreased mRNA stability is unclear, however.

Objective:
Here, we examined whether microRNA-448 (miR-448)can contribute to SCN5A mRNA instability.

Methods:
Datasets from the Gene Expression Omnibus database were utilized to screen miR-448 in human and mouse heart tissues. The relationship between
SCN5A
and miR-448 was predicted by three independent prediction tools. The expressions of
SCN5A
and miR-448 were determined by quantitative real time polymerase chain reaction. Protein levels of Na
v
1.5 were determined by Western blot. The effect of miR-448 mimic on sodium current was determined in induced pluripotent stem cells-derived cardiomyocytes. Mouse myocardial infarction was created by left anterior descending coronary artery ligation.

Results:
The expression of miR-448 is increased in stressed heart after myocardial infarction. The binding sequence for miR-448 is well-conserved in 3’-UTR of
SCN5A
and miR-448 directly bound to a consensus cis element, suppressing
SCN5A
expression and sodium currents. miR-448 expression wass increased by hypoxia. Activated by hypoxia, HIF1α and NF-κB activated were major transcriptional regulator for
MIR448
.

Conclusion:
These results indicated that miR-448 contributed to post-transcriptional modification of
SCN5A
. miR-448 is likely one cause of sodium channel downregulation during ischemia and may represent a target for antagomir therapy to reduce arrhythmic risk associated with cardiomyopathy..

Keywords:
SCN5A, miR-448, Cardiomyocyte, Hypoxia, NF-κB, HIF1α
Abstract 896: Cardiomyocyte-derived Mir-200c-3p In Exosomes Affects Endothelial Angiogenic Capacity And Impairs Cardiac Function
Authors: Ottaviani Lara M , Juni Rio P , Sansonetti Marida , Sampaio-Pinto Vasco , Halkein Julie , el Azzouzi Hamid , Olieslagers Servé , Nascimento Diana S , de Windt Leon J , da Costa Martins Paula A
Published: October 2019

While cardiomyocytes (CMs) have been the main subject of extensive research, the role of other cardiac cell types, such as fibroblasts and endothelial cells (ECs), received considerable less attention in the pathogenesis of heart failure (HF). MiRNAs have recently emerged as mediators of paracrine signaling by being selectively incorporated in exosomes and exchanged between different cell types. The aim of our study is to investigate a potential paracrine miRNA crosstalk between CMs and cardiac ECs and assess the consequences of such miRNA transfer for cardiac vascular remodeling under pathological conditions. We isolated and characterized exosomes from CMs at baseline or after pathological stimulation with phenylephrine and isoproterenol. Although baseline and stressed CMs secrete miRNA-enriched exosomes at similar rates, comparative analysis of extracellular vesicles from both conditions revealed differential miRNA levels, with miR-200c-3p being highly enriched under stress conditions. Direct transfection of ECs with miR-200c-3p precursor molecules or indirect overexpression through transwell co-culture with stimulated CMs leads to diminished angiogenesis reflected by reduced capacity of ECs to proliferate, migrate, and form tubes. This effect was abrogated when we treated CMs with GW4869, an inhibitor of exosomal biogenesis and release. Next, we tested
in vivo
two doses of specific miR-200c-3p antagomir, Cy3 labelled, to assess specific target of ECs. FACS analysis on cardiac cells derived from the injected mice, confirmed that a low antagomir dose targets ECs whereas, the high dose of antagomir targets all different cardiac cell types. Moreover, when we treated mice subjected transverse aortic constriction (TAC)-induced cardiac pressure overload with miR-200c-3p antagomir, the animals developed a milder hypertrophic phenotype, smaller fibrotic areas, higher amount of capillaries and preserved cardiac ejection fraction, when compared to untreated pressure overloaded mice. Altogether, our results showing exosomal transfer of miR-200c-3p from CMs to ECs indicate the importance of cardiac intercellular communication in the pathophysiology of HF and identify a potential new therapeutic target for intervention strategies.
Abstract 910: Identification of Novel Cardiac Sarcomere Interactions Using BioID Proximity-labeling
Authors: PETTINATO Anthony M , Ladha Feria , Thakar Ketan , Hinson Travis
Published: October 2019

Mutations in components of the sarcomere, the contractile unit of cardiomyocytes, are a leading cause of genetic cardiomyopathies, such as dilated cardiomyopathy (DCM), which is an important contributor to heart failure burden. Using human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), our work has previously shown that DCM-causing mutations in titin, a major structural and functional component of the sarcomere, lead to diminished cardiac force production and impaired sarcomerogenesis. A classical model of sarcomerogenesis suggests that sarcomere assembly begins with pre-myofibrils containing beaded Z-disks composed of alpha-actinin, actin, and non-muscle myosin, with further assembly marked by addition of muscle myosin and titin. Once assembled, sarcomeres exhibit linear Z-disks and distinct protein markers. We are interested in understanding this stepwise process by probing sarcomere protein-protein interactions, with the objective of identifying novel developmental mediators and structural components of the sarcomere. More specifically, we would like to identify proteins that interact or localize near alpha-actinin at the Z-disk of the sarcomere. To do this, we have combined CRISPR/Cas9 genome-editing with BioID proximity-labeling to produce isogenic iPSC-CMs that express alpha-actinin fused with BirA, a promiscuous biotin ligase that biotinylates vicinal proteins. We have also generated a sarcomere-deficient iPSC-CM model that can readily reform sarcomeres on-demand, which we will use to further understand stage-specific interactions of sarcomere structure and development. Our results will not only provide novel insights into human sarcomere biology, but may also uncover novel targets for heart failure drug development.
Abstract 924: The Role of Protein Kinase C Isoforms in Cardiomyocyte Hypertrophy
Authors: Pohjolainen Lotta , Solanki Reesha , Ruskoaho Heikki , Talman Virpi
Published: October 2019

Background:
Protein kinase C (PKC) has been linked to cardiomyocyte hypertrophy. However, the exact role of different PKC isoforms in mediating the hypertrophic response remains controversial and both classical and novel isoforms have been suggested to play a critical role. The aim of this study was to characterize the role of PKC isoforms in cardiomyocyte hypertrophy using pharmacological tools and high content screening (HCS).

Methods:
Neonatal rat ventricular cardiomyocytes (NRVCs) isolated from 1-3 days old Wistar rats and human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) differentiated from iPS(IMR90)-4 line were exposed to endothelin-1 (ET-1) and PKC modulators for 48 h followed by fixing and immunofluorescence staining for nuclei, α-actinin and F-actin. Imaging and morphological analysis of thousands of cells were carried out using automated HCS platform.

Results:
NRVCs exposed to ET-1 (100 nM) or PKC agonists (HMI-1b11 at 10 μM or bryostatin-1 at 10 nM) or inhibitor of classical PKC isoforms, Gö6976 (1 μM), showed a hypertrophic phenotype measured by increased area and number of alpha-actinin and F-actin fibers in HCS. In contrast, inhibition of all PKC isoforms with Gö6983 (1 μM) attenuated ET-1 and PKC agonist-induced hypertrophy similarly to mitogen-activated protein kinase kinase 1/2 (MEK1/2) inhibitor U0126 (10 μM). In turn, these HCS parameters did not show ET-1 or PKC agonist -induced hypertrophy in hiPSC-CMs. However, qRT-PCR analysis of the expression of
NPPA
and
NPPB
genes showed hypertrophic responses to ET-1 and PKC agonists also in hiPSC-CMs.

Conclusions:
These results confirm the central role of PKC in cardiomyocyte hypertrophy and indicate that either classical PKC isoforms have a direct anti-hypertrophic role in cardiomyocytes or, when classical PKCs are inhibited, the balance is moved towards activation of novel isoforms, which mediate the hypertrophic response. Due to the morphological differences between NRVCs and hiPSC-CMs, similar phenotypic analysis readouts cannot be reliably applied to compare hypertrophic responses in these cell types. These findings may help in developing new drugs that target specific PKC isoforms to treat cardiac hypertrophy.
Abstract 940: Global Analysis of Histone Modifications and Long-range Chromatin Interactions Revealed the Differential Cistrome Changes and Novel Transcriptional Players in Dilated Cardiomyopathy
Authors: Liu Chia-Feng , Abnousi Armen , Bazeley Peter , Ni Ying , Morley Michael , Moravec Christine S , Hu Ming , Tang WH Wilson
Published: October 2019

Background:
Acetylation and methylation of histone alter the chromatin structure and accessibility that allows or prevents transcriptional regulators to bind to enhancers or promoters. The binding of transcriptional regulators enables the interaction between enhancers and promoters, thus affecting gene expression. However, our knowledge on the regulation of promoter and enhancer interactions and histone modifications in patients with heart failure remains limited.

Methods and Results:
We performed chromatin immunoprecipitation followed by sequencing (ChIP-seq) for major histone modifications and proximity ligation-assisted ChIP-seq (PLAC-seq) for long-range chromatin interaction for enhancer and promoter (E-P) using left ventricular tissues from dilated cardiomyopathy (DCM) patients and non-heart failure (NF) donors (n=2-3). We detected 37,531, and 8,587 differential H3K27ac and H3K4me3 regions between NF and DCM respectively (FDR <0.05). While the average read density (ARD) for H3K27ac, an active enhancer histone mark, is similar between NF and DCM, we observed the ARD of H3K4me3, which marks the active promoter region of the genes, is significantly lower in DCM samples than in NF ones (p<0.01). Super-enhancer (SE) analysis revealed that 481 and 119 genes are associated with NF- and DCM-specific SE respectively. Moreover, the differential E-P interactions were observed in the known heart failure gene loci, e.g.,
CTGF
and
NPPA-NPPB
and these alternation interactions are correlated with the gene expression levels. Motif analysis identified known cardiac factors, such as MEF 2D and A and possible novel players, such as SOX transcription factors, namely SOX4 and SOX8, are enriched within enhancers and prompter regions identified in DCM samples. Their expression levels were confirmed with the whole-transcriptome analysis and protein assays.

Conclusions:
We have established cistrome for major histone modifications and long-range chromatin interaction for enhancer and promoter in NF and DCM tissues. The differential histone modifications and E-P interactions were found in DCM and these differences were associated with the gene expression level of a subset of disease-associated genes in human heart failure.
Abstract 943: Circulating Mirnome in Obese and Lean Heart Failure Patients: A Case-control Study
Authors: Tobar Santiago Alonso L , Soares Douglas d , Bueno Rodrigo H , Calloni Raquel , Mendoza Mariana R , Andrades Michael , Rohde Luis Eduardo P , Biolo Andreia
Published: October 2019

Background:
Obesity is a risk factor for cardiovascular diseases; however, in obese heart failure (HF) patients live longer than lean HF patients, this observation is known as obesity paradox. MicroRNAs (miRs) regulate processes involved in both cardiac remodeling and obesity.

Objective:
We investigated whether the levels of circulating miRs in HF patients are influenced by obesity.

Methods:
In this case–control study, twenty HF patients (10 obese and 10 lean) and 10 healthy control individuals were analyzed using Affymetrix GeneChip miRNA 4.0 Array following manufacturer's instruction. Raw data was normalized using the Robust Multiarray Average method, batch effect was adjusted with Surrogate Variable Analysis, pairwise differential expression analysis was carry-out with Limma R package, and miRPath v3.0 was used to interrogate pathways enriched for the dysregulated miRNAs based on validated targets from Tarbase v7.0 and KEGG pathways annotation database. Bioinformatics and statistical analysis were performed using R and a p-value <0.01 was considered significant.

Results and conclusions:
We discovered a set of 36 and 48 miRNAs that were differentially expressed in obese HF and lean HF, respectively, in relation to controls. Thirteen miRNAs were commonly dysregulated in both HF groups. In addition, we found hsa-miR-451a to be up-regulated in obese HF in relation to controls, as well as to lean HF patients, suggesting that obesity may accentuate its dysregulation. On the other hand, hsa-miR-4738-5p, hsa-miR-1260a, and hsa-miR-98-5p were differentially expressed in lean HF in relation to both remaining groups. Pathways enrichment analysis suggested that hsa-miR-451a regulates genes from the mTOR signaling pathway (p=0.002), whereas hsa-miR-1260a modulates Hippo (p=0.02) and AMPK (p=0.03) signaling pathways, all of which have been previously related to cardiac hypertrophy. Further investigation and validation of their targets may contribute to a better understanding of the obesity paradox.
Abstract 944: Differential Dna Methylation Co-segregates With the Severity of Heart Failure
Authors: Wen Wilson Tan L , Wong Eleanor , Vondriska Thomas M , Yibin Wang , Rau Christoph D , Foo Roger
Published: October 2019

Heart failure (HF) is a leading cause of morbidity and mortality worldwide. As a potential epigenetic biomarker, DNA methylation differs between healthy and diseased hearts. However, its association according to disease severity has not yet been studied. Here, we sought to investigate how DNA methylation (DNAm) differs across HF disease severity, and study the use of a DNMT methyltransferase inhibitor RG108 on DNAm and its effect on heart function. A fixed dose of Isoprenaline (ISO), or saline control (SAL), administered to a hybrid mouse diversity panel (HMDP) consisting of 85 classical and recombinant inbred mouse strains produced a range of cardiac hypertrophy and/or LV dilatation. Left ventricles were harvested and subjected to genome-wide cardiac DNAm profiling by Reduced Representation Bisulfite Sequencing (RRBS). Unsupervised clustering of the top 1% most variable CpG methylation segregated strains to their genetic origin. Disregarding strain-specific methylation differences, differential methylation between ISO and SAL unexpectedly categorised mice into mild and severe disease responders. In the severe-responder strain BTBRT, the pharmacological DNMT methyltransferase inhibitor, RG108, rescued disease from ISO-response, with accompanying evidence of gene expression recovery. This work establishes the range of cardiac differential DNAm correlating according to disease severity. It displays the involvement of DNA methylation-dependent gene expression changes that turns out to be unique, despite different mouse strain backgrounds. This gives further proof of principle that cardiac DNAm changes represent novel biomarkers for disease stratification and consequent targeted therapy.
Abstract 946: Aberrant Activation of Nitric Oxide Synthase 1 in the Heart Accelerates Diastolic Dysfunction Though Protein S-nitrosylation
Authors: Yoon Somy , Kim Mira , Kim Yongsook , Ahn Youngkeun , Kook Hyun , Eom Gwang Hyeon
Published: October 2019

Heart failure refers to an inappropriate blood supply to the periphery. Among subtype of heart failure, pathophysiology and effective therapeutic strategy of systolic heart failure is well established. However, molecular mechanism and specific regimens for diastolic heart failure (DHF) still remains unclear. Here we propose nitric oxide synthase (NOS) 1 mediated exacerbation of DHF and therapeutic potential for novel therapeutics. We screened alteration of posttranslational modifications in DHF which were induced either by SAUNA (SAlty drinking water/Unilateral Nephrectomy/Aldosterone) model or transverse aortic constriction (TAC) model and observed that protein S-nitrosylation was dramatically increased. Total RNA sequencing revealed that transcription amount of NOS1 was aberrantly increased in DHF, whereas NOS2 or NOS3 was not changed. Either non-selective NOS inhibitor or specific NOS1 inhibitor effectively blocked diastolic dysfunction. To elucidate the molecular target of S-nitrosylation, we performed biotin switch assay and requested protein sequencing which were newly appeared in the presence of GSNO. Among novel signal, we identified and confirmed that Histone deacetylase (HDAC) 2 was target molecule of NOS1. HDAC2 cysteine 262 and cysteine 274 were responsible residue of NOS1-mediated S-nitrosylation. We generated knock-in mice carrying S-nitrosylation defect HDAC2 mutant, HDAC2 C262A/C274A (2CA). HDAC2 2CA knock-in mice underwent SAUNA surgery or TAC and diastolic function of those mice was measured by early diastole (E) and mitral valve annulus movement (E’). When compared to wild type littermates, the diastolic function assessed by E/E’ ratio in HDAC2 2CA knock-in mice were relatively well conserved both in SAUNA- and TAC-induced DHF model. Survival rate after TAC operation was also dramatically ameliorated in HDAC2 2CA knock-in mice. Taken together, we proposed novel molecular axis, NOS1/S-NO HDAC2, accelerating diastolic dysfunction and which implicated notable molecular target for treatment of DHF patients.
NON-STOP FLIGHTS AND EXPORTS: TURKISH EXPERIENCE
Authors: KAL Süleyman
Published: October 2019

The relationship between direct flights has attracted attention in the literature. Case in point Turkish Airlines opened many new routes between the years 1998 and 2015.  In this paper, we investigated impact of airline flight on export. To achieve this, using 51 first time destinations of Turkish Airlines, which opened 145 new destinations between 1998 and 2015, impact of direct flight on exports is analyzed by controlling bilateral real exchange rates and GDP with a panel data method accounting for endogeneity (using Arnello Bond method) between direct international flights and exports. Results suggest each additional first time direct flight increases the exports to those destinations by 12.7 %.
MOBİL ALIŞVERİŞ UYGULAMALARI KULLANAN BİREYLERİN, SATIN ALMA DAVRANIŞLARI
Authors: BİÇER Derya Fatma , YILDIZ Selçuk Yasin , SARITEPE Önder Kürşad
Published: October 2019

Akıllı telefonların ve tabletlerin kullanımlarının yaygınlaşmasıyla beraber hayatımıza giren mobil alışveriş uygulamaları, günden güne daha fazla kullanılmakta ve bireylerin internet alışverişlerinde öncelikli tercih ettikleri bir mecra haline gelmektedir. Bu çalışmanın amacı, mobil alışveriş uygulamaları kullanan bireylerin satın alma davranışlarını incelemek ve değerlendirmektir. Çalışmanın evrenini, Sivas ilinde yaşayan ve mobil alışveriş uygulamalarını kullanan bireyler oluşturmaktadır. Çalışma sonucunda; mobil uygulama kullanan bireylerin algıladığı kullanım kolaylığının ve yararın, genel satın alma niyetleri üzerinde pozitif etkisi belirlenmiştir. Bununla birlikte tüketicilerin yararlı gördükleri mobil uygulamaların, plansız satın alma davranışlarında da etkileri olduğu araştırma sonuçları ile ortaya konmuştur. Ayrıca mobil uygulama kullanan bireylerin plansız satın alma davranışlarının, genel satın alma niyeti üzerinde pozitif etkileri olduğu araştırma ile elde edilen diğer bulgulardır.
Ventriloquist Illusion Produced With Virtual Acoustic Spatial Cues and Asynchronous Audiovisual Stimuli in Both Young and Older Individuals
Authors: Stawicki Marnix , Majdak Piotr , Başkent Deniz
Published: October 2019

Ventriloquist illusion, the change in perceived location of an auditory stimulus when a synchronously presented but spatially discordant visual stimulus is added, has been previously shown in young healthy populations to be a robust paradigm that mainly relies on automatic processes. Here, we propose ventriloquist illusion as a potential simple test to assess audiovisual (AV) integration in young and older individuals. We used a modified version of the illusion paradigm that was adaptive, nearly bias-free, relied on binaural stimulus representation using generic head-related transfer functions (HRTFs) instead of multiple loudspeakers, and tested with synchronous and asynchronous presentation of AV stimuli (both tone and speech). The minimum audible angle (MAA), the smallest perceptible difference in angle between two sound sources, was compared with or without the visual stimuli in young and older adults with no or minimal sensory deficits. The illusion effect, measured by means of MAAs implemented with HRTFs, was observed with both synchronous and asynchronous visual stimulus, but only with tone and not speech stimulus. The patterns were similar between young and older individuals, indicating the versatility of the modified ventriloquist illusion paradigm.
Rotating One’s Head Modulates the Perceived Velocity of Motion Aftereffect
Authors: Bai Jianying , He Xin , Jiang Yi , Zhang Tao , Bao Min
Published: October 2019

As a prominent illusion, the motion aftereffect (MAE) has traditionally been considered a visual phenomenon. Recent neuroimaging work has revealed increased activities in MT+ and decreased activities in vestibular regions during the MAE, supporting the notion of visual–vestibular interaction on the MAE. Since the head had to remain stationary in fMRI experiments, vestibular self-motion signals were absent in those studies. Accordingly, more direct evidence is still lacking in terms of whether and how vestibular signals modulate the MAE. By developing a virtual reality approach, the present study for the first time demonstrates that horizontal head rotation affects the perceived velocity of the MAE. We found that the MAE was predominantly perceived as moving faster when its direction was opposite to the direction of head rotation than when its direction was the same as head rotation. The magnitude of this effect was positively correlated with the velocity of head rotation. Similar result patterns were not observed for the real motion stimuli. Our findings support a ‘cross-modal bias’ hypothesis that after living in a multisensory environment long-term the brain develops a strong association between signals from the visual and vestibular pathways. Consequently, weak biasing visual signals in the associated direction can spontaneously emerge with the input of vestibular signals in the multisensory brain areas, substantially modulating the illusory visual motion represented in those areas as well. The hypothesis can also be used to explain other multisensory integration phenomena.
Martial Identities in Colonial Nigeria (c. 1900–1960)
Authors: Stapleton Timothy J.
Published: October 2019

In British colonial Nigeria, the military was more heterogeneous than previously thought and British ideas about “martial races” changed depending on local reactions to recruiting. In the early twentieth century British officers saw the northern Hausa and southwestern Yoruba, who dominated the ranks, as civilized “martial races.” The Yoruba stopped enlisting given new prospects and protest, and southeasterners like the Igbo rejected recruiting given language difficulties and resistance. The British then perceived all southern Nigerians as lacking martial qualities. Although Hausa enlistment also declined with opportunities and religious objections, the inter-war army developed a northern ethos through Hausa language and the northern location of military institutions. The rank-and-file became increasingly diverse including northern and Middle Belt minorities, seen by the British as primitive warriors and as insurance against Muslim revolt, enlisting because of poverty. From 1930, military identities in Nigeria polarized with uneducated northern/Middle Belt infantry and literate southern technicians.
Descriptions of the larva and pupa of Mecynodera balyi Clark, 1864, with notes on its life history (Coleoptera: Chrysomelidae: Sagrinae)
Authors: REID CHRIS A.M. , BEATSON MAX
Published: October 2019

The larva and pupa of the sagrine chrysomelid Mecynodera balyi Clark, 1864 are described and life history notes provided for this species. The larva of Mecynodera balyi is spermophagous and feeds inside seed pods of Pandorea, a vine in the Bignoniaceae. This is the first record of larval spermophagy in any chrysomelid other than Bruchinae, the sister subfamily to Sagrinae. Several morphological features of the immature stages are newly recorded for the Sagrinae. The implications of these new data for systematic placement of Sagrinae are discussed.
Efficient Degradation of Atrazine by Magnetic CoFe2O4/g-C3N4 Catalyzed Peroxymonosulfate and Its Enhancement of Photocatalytic Ability Under Visible-Light
Authors: An Ji-Bin , Hu Dai-Peng , Li Yan-Lin , Chen Na-Li
Published: October 2019

The Magnetic photocatalytic cobalt ferrite/graphitic-carbon nitride (CoFe2O4/g-C3N4) composites with enhanced photocatalytic activity were successfully fabricated through a simple calcination method. Scanning electron microscopy, powder X-ray
diffraction, and infrared spectroscopy were applied to characterize the samples. The photocatalytic behavior of CoFe2O4/g-C3N4 was assessed by degradation of atrazine in photo Fenton-like system under visible light irradiation. The results showed
that CoFe2O4/g-C3N4 with 2.0 gL–1 catalyst loading in the presence of 1 mM peroxymonosulfate (PMS) exhibited the best catalytic performance, and more than 97% of atrazine was destructed in 12 min. This enhancement could be attributed
to the synergistic effect between CoFe2O4 and g-C3N4 promoting longer lifetime of separated electron–hole pairs derived from the formation of the heterojunction between CoFe2O4 and g-C3N4. This could
enhance the composite-mediated activation of PMS for the visible-light driven degradation of atrazine. Moreover, the quenching tests showed that sulfate radicals were responsible for the atrazine degradation. CoFe2O4/g-C3N4 composites have strong
magnetic ability, thus their recovery from water could be readily achieved by applying external magnetic field. This study demonstrates reasonable performance of the PMS/CoFe2O4/g-C3N4 system in water matrix as potentially important candidate for
environmental remediation.
Microtexture, Microstructure Evolution and Thermal Insulation Performance of Carbon Aerogels with High-Temperature Treatment
Authors: Yang Haixia , Huo Jianchun , Li Chunming , Ye Feng , Liu Jingxiao , Shi Fei
Published: October 2019

The microtexture, microstructure evolution and thermal insulation performance of carbon aerogels subjected to high-temperature treatment were investigated in detail. The results showed that carbon aerogels derived from resorcinol-formaldehyde (RF) resin were composed of fine particles
and cavities, which consisted of typical non-graphitized carbon according to X-ray diffraction analysis. The microcrystallite size (La) of the CAs increased from 4.49 nm to 6.92 nm, and the specific surface area (SBET) and the total pore volume (Vtal)
decreased from 727 to 290 m2/g and from 0.963 to 0.543 cm3/g, respectively, as the temperature increased from 900 °C to 1800 °C. The micropore-specific surface area and the micropore volume decreased with increasing treatment temperature, and a small amount of
macropores (>50 nm) appeared at a temperature of 1500 to 1800 °C. The carbon aerogels retained their porous structure at higher temperature, which indicated that they hold potential for application in the field of thermal insulation in high-temperature environments.