bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 838: High Molecular Weight FGF2 Contributes to Pressure Overload Induced Systolic Dysfunction by a Mechanism Associated With Modulation of the NR1D1 Orphan Nuclear Receptor Expression
Authors: Koleini Navid , Nickel Barbara E , Nagalingam Raghu S , Landry Natalie M , Fandrich Robert R , Dixon Ian M , Czubryt Michael , Cattini Peter A , Kardami Elissavet
Published: October 2019

Fibroblast growth factor 2 (FGF2) is implicated in normal cardiac development as well as cardiac pathophysiology; however, FGF2 exist as multiple high and low molecular weight isoforms. While endogenous low molecular weight FGF2 (Lo-FGF2) is cardioprotective during chronic stress, the more prevalent endogenous high molecular weight FGF2 (Hi-FGF2) is proposed to promote maladaptive cardiac remodeling. We have investigated the hypothesis that genetic elimination of Hi-FGF attenuates cardiac dysfunction in mice that have been subjected to pressure overload by transverse aortic constriction (TAC).

Two groups of male C57BL/6mice were compared: (1) Wild type (WT) mice, expressing Hi- and Lo-FGF2 (FGF[WT] mice); and (2) Hi-FGF2 knock-out mice, expressing only Lo-FGF2 (FGF[Lo] mice). Echocardiographic assessment of heart function and dimensions was done at baseline and then 4 and 8 weeks after TAC or sham surgery. FGF[WT] mice displayed a decline in systolic function compared to their corresponding sham animals at 4- and 8-weeks post-TAC, which was absent in the FGF[Lo] mice. Relative levels of B-type natriuretic peptide, a marker of cardiac pathology severity, were elevated in FGF[WT] but not FGF[Lo] mice compared to shams. Increased accumulation of the pro-cell death protein BCL2/adenovirus E1B 19 kDa protein-interacting protein-3 was more pronounced in the FGF(WT) compared to FGF(Lo) mice, post TAC. Microarray analysis of the whole transcriptome of hearts in FGF2[WT] and FGF2[Lo] mice indicated the pathway linked to circadian rhythm as a candidate for the most significant differentially regulated. Specifically, upregulation of the circadian rhythm master regulator, Nuclear Receptor Subfamily 1 Group D Member 1 (NR1D1), was validated by qPCR and protein immunoblotting in FGF[Lo] mice versus downregulation of NR1D1in FGF[WT] mice post-TAC, when compared to their sham operated littermates.

Taken together these studies suggest that expression of Hi-FGF2 contributes to cardiac systolic dysfunction in left ventricular pressure overloaded WT mice by downregulation of Nr1D1, post-TAC.
Abstract 842: Protein kinase G - Regulator of G protein Signaling 2 Axis of Cardiac Myocytes Critically Determines Cardiac Performance in Early Cardiac Remodeling
Authors: Numata Genri , Takimoto Eiki , Kariya Taro , Ueda Kazutaka , Blanton Robert M , Karas Richard H , Mendelsohn Michael E , Komuro Issei
Published: October 2019

Introduction:
Regulator of G protein signaling 2 (RGS2) is a negative regulator of G protein-coupled signaling, and is potentiated by cGMP-PKG. Our prior work using a global deletion model demonstrated the protective role for RGS2 against mal-adaptive cardiac remodeling, which is essential to the cGMP-PDE5 inhibitor efficacy; however, cell type-specific contribution remains to be determined, given the expression of RGS2 in myocytes, fibroblasts and vascular smooth muscle cells. We hypothesized that myocyte RGS2 might serve as a primary contributor to the cardio-protection and mediates cGMP-PKG benefits.

Method:
We generated cardiomyocyte-specific RGS2 knockout mice (cKO) on a C57BL/6 background. Pressure overload was produced by transverse aortic constriction (TAC) in male RGS2-cKO mice (RGS2cKO) and their littermate controls (WT). To investigate cGMP-PKG enhancing effects, a soluble guanylyl cyclase stimulator (riociguat) was orally administrated daily (3mg/kg/day). Invasive hemodynamics, anatomy, histology and molecular signaling were assessed at 1wk after TAC.

Results:
RGS2-cKO revealed exacerbated dilative cardiac remodeling (LVDD: cKO 3.57±0.36 vs WT 2.90±0.16) and severely impaired cardiac function (dPdt/IP: cKO 166±3.49 vs WT 195±7.40), while their basal phenotype was undistinguishable from WT. cKO-TAC hearts showed larger cardiomyocyte size and more fibrosis than WT-TAC hearts, associated with aberrant gene expression induction including
Myh6, Myh7, Col1a2, and TGFβ
. Intriguingly, concomitant riociguat treatment reduced LV chamber size and fibrosis but failed to improve cardiac performance in cKO-TAC hearts, while riociguat ameliorated all these in WT-TAC hearts.

Conlusion:
These results suggest that RGS2-PKG axis in cardiac myocytes critically contributes to cardiac functional performance and that cGMP-PKG exerts anti-fibrotic effects independently of myocyte conditions.
Abstract 843: Non-oxidized Protein Kinase G 1 Alpha Antagonizes mTORC1 Signaling in a Tuberin-dependent Manner to Ameliorate Cardiac Disease
Authors: Oeing Christian U , Ranek Mark J , Dunkerly-Eyring Brittany L , Kass David A
Published: October 2019

Rationale:
Protein kinase G 1α (PKG1α) confers anti-hypertrophic effects in hearts subjected to mechanical and neurohumoral stress. Human heart failure with a reduced ejection fraction (HFrEF) and mouse pressure overloaded hearts present with increased mechanistic target of rapamycin complex 1 (mTORC1) activity, protein aggregation, oxidative stress, and, as we previously described, increased PKG1α disulfide dimer formation indicative of PKG1α oxidation. Recently we demonstrated that stimulation of PKG1α phosphorylates tuberin (TSC2) at one specific serine, S1365, to inhibit mTORC1 signaling and attenuate pathological hypertrophy.

Objective:
To determine if the redox state of PKG1α impacts its ability to target TSC2 signaling in a chronic pressure-overload mouse model exhibiting pathologic hypertrophy. We hypothesize non-oxidized PKG1α will increase TSC2 S1365 phosphorylation to antagonize mTORC1 signaling, thereby enhancing autophagic flux to clear protein aggregates, culminating in ameliorated cardiac disease.

Methods and Results:
Mice expressing a non-oxidizable (redox-dead) PKG1α (cysteine 42 serine, CS) knock-in mutation and wild type (WT) littermate controls were subjected cardiac pressure overload stress via transaortic constriction (TAC) or sham surgeries. Following TAC, PKG1α CS mice exhibited reduced mTORC1 activation leading to increased autophagic flux and preventing protein aggregation, compared to WT mice. PKG1α CS TAC mice had decreased expression of the hypertrophic genes, attenuated cardiac hypertrophy (p<0.0001), and improve fractional shortening compared to WT TAC mice (28.14%±10.82 in WT vs. 47.42%±15.62 in CS; p<0.01). Treating WT TAC mice with an mTORC1 inhibitor (everolimus) abrogated mTORC1 hyperactivation, which lead to enhanced autophagic flux, attenuated hypertrophy, and improved cardiac function. Crossing PKG1α CS mice with TSC2 S1365 phospho-null mice resulted in increased cardiac hypertrophy and reduced lifespan (p<0.05).

Conclusions:
Preventing PKG1α oxidation attenuates mTORC1 activation to enhance autophagic flux, prevent protein aggregation, and ameliorate pathological hypertrophy in following cardiac pressure overload, dependent onTSC2 S1365 phosphorylation.
Abstract 846: The Effects and Mechanisms of Pyridostigmine on Cell Proliferation and Fibrosis of Human Cardiac Fibroblasts
Authors: Shen Li-Shui
Published: October 2019

Background:
Heart failure (HF) is a common, costly, and potentially fatal condition. Cardiac fibrosis plays a key role in the process of HF. Pyridostigmine (PYR) could improve the cardiac function by inhibiting collagen deposition in cardiac tissue, but the molecular mechanisms are unknown.

Objective:
To investigate the effects and mechanisms of Pyridostigmine on cell proliferation and fibrosis in human cardiac fibroblasts (HCFs).

Methods:
The model of fibrosis in HCFs was induced by transforming growth factor beta. After the intervention of PYR, the content of collagen I(COL1) was observed by measuring the hydroxyproline concentration. The cell cycle of HCFs was screened by Flow cytometry. The mRNA levels of Connective tissue growth factor (CTGF) and Smad3 were examined by real-time qPCR analysis. The expressions of CTGF, Smad3, pSmad3 were examined by Western blot.

Results:
Compared with the TGF-β group, the TGF-β+PYR group had significantly lower proportion of S/G2 phased cells[(30.8±1.4) % vs (48.6±3.5)%], less synthesis of COL1 [(0.95±0.15) vs (1.25±0.18)]and fewer expressions of CTGF mRNA [(1.73±0.10) vs (2.92±0.12)]and CTGF protein[(1.23±0.42) vs (2.36±0.62)]. However, the expressions of Smad3 mRNA [(1.50±0.06) vs (1.55±0.08)], Smad3 protein [(2.85±0.45) vs (2.98±0.47)] and pSmad3 protein [(2.39±0.32) vs (2.51±0.52)] between these two groups showed no difference (P>0.05).

Conclusion:
Pyridostigmine significantly alleviated cell proliferation and collagen synthesis in HCFs induced by TGF-β, and its mechanism was related to the inhibition of CTGF expression rather than blocking the TGF-β/Smads signaling pathway.
Abstract 851: NCLX Expression Attenuates Pathological Remodeling in Experimental Cardiac Hypertrophy and Non-ischemic Heart Failure
Authors: Garbincius Joanne F , Luongo Timothy S , Kolmetzky Devin W , Hildebrand Alycia N , Elrod John W
Published: October 2019

Mitochondrial calcium (
m
Ca
2+
) uptake couples acute changes in cardiomyocyte bioenergetic demand to ATP production, but in excess triggers mitochondrial permeability transition and cardiomyocyte necrosis, as occurs during cardiac injury. Despite established roles for
m
Ca
2+
flux in response to acute stress, the role of
m
Ca
2+
signaling in chronic stress is poorly defined. As
m
Ca
2+
regulates the TCA cycle with the potential to affect mitochondrial signaling and/or metabolite pools required for biosynthesis, we reasoned that altered
m
Ca
2+
homeostasis may be an essential mechanism underlying hypertrophic growth and remodeling of the myocardium. Here, we used mice with cardiac-specific overexpression (OE) of the mitochondrial Na
+
/Ca
2+
exchanger (NCLX), the primary mediator of
m
Ca
2+
efflux in the heart, to test the hypothesis that
m
Ca
2+
signaling contributes to cardiac remodeling during sustained hemodynamic stress. We subjected NCLX OE (TRE-NCLX x α-MHC-tTA) and control (αMHC-tTA) mice to 12-wk transverse aortic constriction (TAC) or 4-wk infusion with angiotensin II + phenylephrine (AngII/PE) as experimental models of cardiac hypertrophy and non-ischemic heart failure. Cardiac function of NCLX OE and control mice was monitored throughout these studies via echocardiography and remodeling was assessed via tissue gravimetrics, histology, and qPCR gene expression analysis. Cardiac NCLX OE preserved ejection fraction, prevented afterload-induced hypertrophy and fibrosis, and attenuated the induction of both hypertrophic (
Nppa
,
Nppb
,
Acta1
) and fibrotic (
Postn1
,
Spp1
) gene programs in mice subjected to 12-wk TAC. Examination at 2-wk post-TAC revealed attenuated hypertrophy and blunted hypertrophic and fibrotic gene expression in NCLX OE mice. These data indicate that increased capacity for
m
Ca
2+
efflux mitigates TAC-induced remodeling, prior to the development of contractile dysfunction. NCLX OE similarly attenuated atrial hypertrophy and the induction of hypertrophic and fibrotic gene programs in mice infused with AngII/PE. Together, these findings support a critical role for
m
Ca
2+
in driving pathological remodeling in non-ischemic heart disease and point to NCLX as a potent therapeutic target for cardiovascular disease.
Abstract 864: Mitochondrial Morphology During Stress is Regulated by GJA1-20k Interaction With Actin
Authors: Shimura Daisuke , Baum Rachel , Xiao Shaohua , Hong TingTing , Shaw Robin M
Published: October 2019

Connexin (Cx) 43 is encoded by the GJA1 gene and GJA1-20k has been identified as an N-terminal truncation of Cx43 generated endogenously by internal translation. Previously we have found GJA1-20k increases with ischemic stress and induces actin organization and, in mice, mitochondrial biogenesis. In this study we explored the acute effect of GJA1-20k on mitochondria. We transfected GFP-tagged GJA1-20k plasmid into HEK293T cells and analyzed mitochondrial morphology by fluorescent microscopy. We found GJA1-20k results in mitochondria that are associated with actin and also are smaller and more circular than in GST-transfected control cells. In addition, quantitative analysis indicated preservation of mitochondrial area and thus enhanced mitochondrial fission in the presence of GJA1-20k. Disruption of actin polymerization inhibited the effect of GJA1-20k on mitochondrial fission as did use of the actin stabilizer phalloidin, indicating the need for robust actin dynamics for GJA1-20k to be effective. These data suggest that the interaction between GJA1-20k and actin cytoskeleton is necessary for stress related mitochondrial fission. The results indicate that, during stress, upregulated GJA1-20k recruits the actin cytoskeleton to directly affect mitochondrial dynamics and cellular metabolic function.
Abstract 865: The E3 Ubiquitin Ligase Parkin Regulates Metabolism From the Nucleus
Authors: Shires Sarah E , Najor Rita H , Leon Leonardo J , Cortez Melissa Q , Gustafsson Åsa B
Published: October 2019

Parkin facilitates mitophagy by ubiquitinating depolarized mitochondria to label them for degradation. We have previously shown that Parkin is important for adaptation to myocardial infarction (MI) and that loss of Parkin leads to accumulation of dysfunctional mitochondria. Although Parkin is mainly studied for its role at the mitochondria, it is unclear whether Parkin also functions in other subcellular compartments. Here, we used immunofluorescence and subcellular fractionation to find that a portion of Parkin localizes to the nucleus under basal conditions
in vitro
and
in vivo
. Pathogenic Parkin mutants, however, are selectively excluded from the nucleus. To further examine conditions that induce Parkin nuclear enrichment, we subjected HeLa cells stably expressing YFP-Parkin to starvation or hypoxia. During nutrient-deprivation, Parkin rapidly exits the nucleus and accumulates in the cytosol. Conversely, exposure to hypoxia causes Parkin enrichment in the nucleus and depletion from the cytosol. To separate the roles of nuclear versus mitochondrial Parkin, we generated nuclear- and mitochondrial- targeted constructs: NLS-Parkin and Mito-Parkin. RNA-sequencing analysis revealed widespread transcriptional changes in response to targeting Parkin to the nucleus, particularly in metabolic processes. Through a non-biased proteomics screen, we identified the transcription factor estrogen related receptor α (ERRα) as a potential Parkin target. ERRα is highly expressed in the heart and promotes transcription of genes involved in mitochondrial biogenesis and metabolism. We therefore used co-immunoprecipitation and qPCR to determine whether Parkin regulates cellular energetics through ERRα. Indeed, we found that NLS-Parkin interacts with and ubiquitinates ERRα. Additionally, expressing NLS-Parkin increases protein levels of both endogenous and overexpressed ERRα and promotes transcription of ERRα-targets. These data indicate that Parkin-mediated ubiquitination of ERRα leads to its increased stability and activity resulting in increased transcription of genes involved in mitochondrial biogenesis and metabolism. This study provides insight into new ways Parkin may be targeted to enhance energetic function in the heart.
Abstract 869: Cysteine-based Redox Regulation of Soluble Guanylyl Cyclase
Authors: Cui Chuanlong , Alapa Maryam , Shu Ping , Kholodovych Vlad , Li Hong , Beuve Annie V
Published: October 2019

Soluble guanylyl cyclase (GC1) is the major receptor of nitric oxide (NO) and a key regulator for cardiovascular physiology. NO binding to the heme of GC1 catalyzes conversion of GTP to cGMP, which in turn activates protein kinase G pathway, thus leading to vasodilation. However, the mechanism by which NO signaling is propagated within the GC1 molecule for its stimulation is still poorly understood. The high frequency of solvent-exposed cysteines (Cys) of GC1 suggests a potential role of Cys posttranslational modifications (PTMs) in regulating GC1 activity. Our previous studies show that the disulfide reductase Thioredoxin 1 (Trx1) can interact with GC1 and affect its activity in cells. Together with studies showing that GC1 activity is modulated by thiol redox, we hypothesize that thiol/disulfide switch might be a mechanism that regulates the activity of GC1. Here we show that dithiol oxidant diamide can dose-dependently affect the activity of GC1. PEG-switch assay, LC/MS/MS and mutational analysis identified Cys involved in redox regulation of GC1. In addition, we show that Trx1 modulates Cys-based redox PTMs of GC1 in cells and blocking the interaction between Trx1 and GC1 affects GC1 activity in a purified system. Taken together, these results suggest that the thiol/disulfide switch of GC1 and its interaction with Trx1 could be an underlying mechanism for NO stimulation of GC1.
Abstract 873: Acetate Protects the Heart Against Ischemic Injury by Alternating TCA Cycle-related Metabolites and AMP-activated Protein Kinase
Authors: Ichihara Genki , Katsumata Yoshinori , Goto Shinichi , Ko Seien , Hiraide Takahiro , Kitakata Hiroki , Moriyama Hidenori , Shirakawa Kohsuke , Anzai Atsushi , Endo Jin , Kataoka Masaharu , Keiichi Fukuda , Sano Motoaki
Published: October 2019

Introduction:
Acetate is preferentially taken up in the heart, and converted into acetyl-CoA by acetyl-CoA synthetase2 (AceCS2), which is abundant in the mitochondria of cardiomyocytes, resulting in activation of AMPK through an elevation of AMP/ATP ratio. In this context, we investigated the effects of acetate on myocardial ischemic injury in isolated cardiomyocytes and
in vivo
mouse hearts.

Methods and Results:
In isolated cardiomyocytes,
13
C-labelled metabolites were analyzed using capillary electrophoresis-electrospray ionization mass spectroscopy (CE-ESI-MS) in order to determine the fate of exogenously administered
13
C-acetate. The oxygen consumption rate (OCR) was evaluated using a flux analyzer. A variety of
13
C-labelled intermediates in the TCA cycle increased 10 minutes after administration of
13
C-acetate followed by a subsequent increase in OCR. The OCR elevation was sustained more than 2 hours after acetate injection. The acetate-induced OCR elevation was partially blocked by the glycolysis inhibitor 2-Deoxyglucose (2-DG), carnitine palmitoyl transferase1A (CPT-1A) inhibitor (etomoxir), and mitochondrial pyruvate carrier (MPC) inhibitor (UK5099). The acetate-induced OCR elevation was also blocked by AMP-activated protein kinase (AMPK) inhibitor (compound C). These findings indicated that acetate caused an elevation in mitochondrial function through activation of various metabolic pathways, which may be related to activation of the AMPK pathway. Next, left anterior descending artery-ligated hearts were processed with focused microwave and analyzed by CE-MS and matrix-assisted laser desorption/ionization imaging mass spectrometry in order to examine the region-specific metabolite changes at the early phase of ischemia. Nicotinamide adenine dinucleotide (NADH) elevation in the ischemic core region was suppressed by acetate administration. Furthermore, acetate inhibited cardiac remodeling in a protective manner several weeks after myocardial ischemia when viewed by cardiac ultrasound.

Conclusion:
Acetate caused an increase in OCR via both a significant elevation in TCA cycle metabolites and activation of AMPK pathway, and may have a protective effect on myocardial ischemic injury.
Abstract 892: Ablation of MiR-144 Increases Vimentin Expression and Atherosclerotic Plaque Formation
Authors: He Quan , Wang Fangfei , Honda Takashi , Greis Kenneth D , Redington Andrew N
Published: October 2019

Objective:
It has been suggested that miR-144 is pro-atherosclerotic via effects on reverse cholesterol transportation targeting the ATP binding cassette protein 1 (ABCA1). This study used proteomic analysis to identify additional cardiovascular targets of miR-144, and subsequently examined the role of a newly identified regulator of atherosclerotic burden in miR-144 KO mice receiving a high fat diet (HFD).

Approach and Results:
To identify affected secretory proteins, miR-144 treated endothelial cell culture medium was subjected to proteomic analysis including two-dimensional gel separation and nanospray liquid chromatography coupled to tandem mass spectrometry. We identified 5 gel spots representing 19 proteins that changed consistently across the biological replicates. One of these spots, was identified as vimentin. Atherosclerosis was induced in miR-144 KO mice by HFD and vascular lesions were quantified by Oil Red-O staining of the serial sectioned aortic root and from en-face views of the aortic tree. Unexpectedly, HFD induced extensive atherosclerosis in miR-144 KO mice in aortic root (WT 100% ± 22.71 vs miR-144 KO 256.88% ± 58.19, p < 0.05, n = 10) and arch areas (WT 100% ± 29.67 vs miR-144 KO 371.74% ± 73.48, p < 0.01, n = 10), and was accompanied by severe fatty liver disease compared with wild type littermates (WT). Vimentin levels were reduced by miR-144 and increased by antagomiR-144 in cultured cardiac endothelial cells without affecting vimentin mRNA levels. Compared with WT, ablation of the miR-144/451 cluster significantly increased plasma vimentin, while vimentin levels were decreased in control mice injected with synthetic miR-144 as double confirmed with Western blot and ELISA assays. Furthermore, increased vimentin expression was seen in the commissural regions of the aortic root (WT 100% ± 10.02 vs 164.19 ± 13.90, p < 0.01, n = 10) and collocated with other areas of aortic atherosclerosis. In contrast, neither liver ABCA1 nor circulating cholesterol levels were different between WT and miR-144/451 KO mice.

Conclusion:
We conclude that miR-144 is a potential regulator of the development of atherosclerosis via changes in vimentin signaling and both miR-144 and vimentin are potential therapeutic targets for atherosclerosis.
Abstract 894: Inhibition of Long Noncoding RNA lncExACT1 Induces Physiological Cardiac Hypertrophy and Protects Against Pathological Hypertrophy
Authors: LI Haobo , Liu Xiaojun , Xiao Chunyang , Li Guoping , Yeri Ashish , Rosenzweig Anthony
Published: October 2019

Long noncoding-RNAs (lncRNAs) are critical regulators of cardiac development as well as pathological hypertrophy and heart failure (HF). However, their roles in exercise-induced physiological hypertrophy are unclear. Here, we used RNAseq to identify a novel class of cardiac lncRNAs that are dynamically regulated by exercise. We call these
l
ong
n
on
c
oding
Ex
ercise
A
ssociated
C
ardiac
T
ranscripts (lncExACTs). Among them, lncExACT1, a highly conserved lncRNA, is down-regulated in exercised hearts but upregulated in transverse aortic constriction (TAC)-induced pathological hypertrophy and HF. In primary neonatal cardiomyocytes (CMs), transfection of LNA antisense oligonucleotide complementary to lncExACT1 (GapmeR) was sufficient to inhibit lncExACT1 expression and increase CM size with a gene expression pattern consistent with physiological hypertrophy (increased PCG1α and α/βMHC ratio, all
p
<0.05
vs
. control). In contrast, lentiviral overexpression of lncExACT1 in primary CMs induced a pathological gene expression pattern (decreased PCG1α and β/αMHC ratio, with increased ANP and BNP, all
p
<0.05
vs
. control). In vivo, GapmeR treatment for two weeks reduced cardiac lncExACT1 expression (0.5-fold at 2 weeks), increased ventricular wall thickness and fractional shortening (FS,
p
=0.034
vs
. control), increased heart weight to tibial length ratio (HW/TL) and α/βMHC. In contrast, injection of AAV9-lncExACT1 increased cardiac lncExACT1 (6-fold at 5 weeks) increased HW/TL as well as βMHC and ANP. Further, lncExACT1 acted as a sponge for microRNA-222 (a microRNA we previously reported is necessary for physiological cardiac growth) thereby increasing expression of microRNA-222 targets, including p27, a cell cycle inhibitor protein. Moreover, GapmeR injection reduced TAC-induced increase of interventricular septal end diastole (IVSd) and left Ventricular Posterior Wall Dimensions (LVPWd) without affecting FS. We conclude that inhibition of lncExACT1 is sufficient to induce physiological hypertrophy and protect against pathological hypertrophy, while induction of lncExACT1 promotes pathological hypertrophy. lncExACT1 appears to mediate these effects, at least in part, by acting as competing endogenous RNA for microRNA-222.
Abstract 900: Troponin I Tyrosine 26 Phosphorylation Accelerates i
n vivo
Myocardial Relaxation
Authors: Brundage Elizabeth A , Shettigar Vikram , Lin Ying H , Agatisa-Boyle Brendan , Jeong Mark Y , Ziolo Mark T , Biesiadecki Brandon J
Published: October 2019

Heart failure results in depressed cardiac systolic contraction and diastolic relaxation, both of which limit the heart’s ability to pump blood. Currently there is no therapy to accelerate the detrimental slowed relaxation in heart failure. A fundamental mechanism of the heart to modulate cardiac relaxation is through serine/threonine kinase-mediated phosphorylation of the contractile regulatory protein troponin I (TnI). Non-receptor tyrosine-specific kinases are expressed in the heart and their activity is altered in disease; yet, the role of tyrosine kinase-mediated phosphorylation to directly modulate cardiac relaxation has not been described. TnI is phosphorylated at tyrosine 26 (Tyr26) in the heart and we previously demonstrated TnI Tyr26 phosphorylation accelerates myofilament deactivation. TnI Tyr26 phosphorylation is therefore the first tyrosine phosphorylation identified to directly modulate cardiac myofilament function, however the effects of tyrosine phosphorylation on in vivo function of the heart are unknown. To determine the effect of tyrosine phosphorylation on heart function, we generated a TnI Tyr26 phosphorylation (Tg Y26E) mouse. At the muscle level, myofibrils from Tg Y26E mice exhibit accelerated myofibril relaxation. Echocardiography and pressure-volume hemodynamic measurements demonstrate Tg Y26E mice have enhanced diastolic function evident in accelerated myocardial relaxation, without depressed systolic function or altered morphology. As a whole these data support the phosphorylation of TnI at Tyr26 as a novel tyrosine signaling mechanism to accelerate in vivo diastolic function without depressing systolic contraction.
Abstract 906: Age-Dependent Modifications in Cardiac Myofilament Proteins are Graded by Overall Health, Measured as Frailty, in Aging Male and Female C57BL/6 Mice
Authors: Kane Alice , Bisset Elise S , Keller Kaitlyn , Pyle W G , Howlett Susan E
Published: October 2019

Previously, we showed that the age-dependent decline in ventricular function in male mice is proportional to overall health, as quantified with a frailty index (FI) tool. This tool is based on the accumulation of deficits in health across many systems, but not the cardiovascular system
per se
. Here we investigated whether frailty grades age-dependent modifications in myofilaments in young and aged mice of both sexes. Myofilaments were isolated from ventricles of adult (12-13 mos; n=5 males, 5 females) and aged (22-23 mos; n=6 males, 5 females) mice. FI scores were obtained from all mice. Actomyosin Mg-ATPase activity as a function of increasing calcium concentration and phosphorylation of major myofilament proteins were quantified and compared between groups. Results showed that myofilament calcium sensitivity (EC
50
values) was similar regardless of age or sex and was not affected by FI score. Maximal actomyosin Mg-ATPase activity increased with age in females, but this was not linked to frailty. Hill coefficients declined with age in males only and were lower than females in the older group (p<0.05). However when all mice were examined, Hill coefficients declined as frailty increased (r=0.68, p=0.001). Total phosphorylation levels of myosin-binding protein C (MyBP-C), desmin, tropomyosin and essential myosin light chain (ELC) increased with age, but only in males. Interestingly, phosphorylation of MyBP-C (r=0.49; p=0.03), desmin (r=0.65; p=0.003), tropomyosin (r=0.62; p=0.004) and ELC (r=0.71; p=0.001) were highly correlated with overall health (FI scores). By contrast there was no link between frailty and phosphorylation of actin, troponin T and troponin I. These findings suggest that poor overall health, quantified in an FI, predicts changes in the myofilaments across the life course in both sexes. This may contribute to changes in cardiac contractile function in frail older adults.
Abstract 911: New Promoters to Improve the Efficiency of Cardiac Gene Therapies Using 2 Deoxy-ATP
Authors: Robeson Kalen Z , Moussavi-Harami Farid , Davis Jennifer , Regnier Michal
Published: October 2019

Traditional inotropes work by altering intracellular calcium levels but have many off-target effects. Myosin activators have shown promise for treating the increasing number of heart failure patients today, with one drug in phase three clinical trials. These drugs work by increasing the affinity of myosin for actin. Our lab has demonstrated that the small molecule 2 deoxy-ATP (dATP) can improve both myosin binding to and myosin release from actin. We have also demonstrated the efficacy of a cardiac targeted gene therapy to improve heart function via increasing intracellular dATP levels. This was done by overexpressing ribonucleotide reductase (RNR)—the rate-limiting enzyme in de novo dNTP synthesis. This cardiac therapy, using the cardiac troponin T (cTnT) promoter, was effective in a mouse model but provided variable results in a large animal model due to delivery challenges. Therefore, we are now investigating alternative promoters to deliver dATP to cardiomyocytes and/or other striated muscles. Here we present our investigation of the CK8 promoter for striated muscle specific delivery of RNR. We report that the CK8 promoter was able to produce a greater than fourfold increase in mouse ventricular tissue dATP levels above that seen with the cTnT promoter (2.0 to 8.4 pmol/mg; P<0.01). RNR was also delivered to skeletal muscle with a twofold increase in gastrocnemius dATP levels (0.62 to 1.31 pmol/mg; P<0.01). We have also been investigating cardiac fibroblasts as a route to deliver dATP to cardiomyocytes. We have shown that
in vitro
fibroblasts can transmit dATP to coupled cardiomyocytes through gap junctions, indicating that overexpressing RNR in cardiac fibroblasts could increase dATP levels in both cell types. Previous research has shown that proliferating fibroblasts have increased levels of dATP, and preliminary results in our lab show that differentiated myofibroblasts have decreased levels of dATP. We therefore hypothesize that increased dATP in cardiac fibroblasts will not only improve contraction in coupled cardiomyocytes but may also inhibit fibroblast transdifferentiation into collagen producing myofibroblasts.
Abstract 917: Actively Blocking Nuclear Localization of G Protein-Couple Receptor 5 Blunts Hypertrophy and Heart Failure After TAC
Authors: Coleman Ryan , Barr Eric W , Chuprun Kurt , Koch Walter J
Published: October 2019

Introduction:
The induction of heart failure (HF) after aortic banding (TAC) in mice encompasses aberrations in gene regulation, leading to maladaptive cardiac hypertrophy and contractile dysfunction. Previously, our lab has shown that the nuclear targeting of GRK5, which is required for maladaptive hypertrophy, is controlled by its N-terminal (NT) calmodulin-binding domain.

Hypothesis:
We hypothesize that expression of a peptide encoding the NT of GRK5 will act as a GRK5-calmodulin inhibitor preventing the nuclear accumulation of GRK5 and inhibit its pathological activities.

Methods:
Neonatal rat ventricular cardiomyocytes (NRCM) overexpressing GRK5-NT or control virus were subjected to α-adrenergic stress with 50μM phenylephrine (PE) or vehicle for 30 minutes. Subcellular fractionation and western blotting were used to detect nuclear GRK5. Novel cardiac-specific transgenic mice were generated expressing HA-tagged GRK5-NT and these mice along with their control mice were characterized 8 weeks after TAC or sham surgery. Echocardiography, fibrosis, and lung and heart weight to tibia length metrics were used to evaluate hypertrophy and heart failure response post-TAC. Other cohorts were subjected to TAC for 1 week followed by Western blotting to assess acute signaling and nuclear accumulation of GRK5.

Results:
In vitro, expression of the GRK5-NT peptide reduced PE-induced nuclear accumulation of GRK5. In both NRCM and tissue, the GRK5-NT peptide was found to bind to calmodulin, which disrupts the endogenous calmodulin-GRK5 interaction. GRK5-NT expression abrogates nuclear GRK5 accumulation following hypertrophic stress in vitro and in vivo. Following 8 weeks of TAC, cardiac function, hypertrophy, and pulmonary congestion were significantly attenuated in GRK5-NT mice compared to NLC mice.

Conclusion:
We show that the GRK5-NT peptide binds to calmodulin and prevents nuclear accumulation of GRK5 following hypertrophic stress. Our in vivo data show that cardiac-restricted expression of GRK5-NT prevents HF by partially restoring cardiac dysfunction, hypertrophy, and pulmonary congestion following 8 weeks of TAC. Further in vitro work will reveal the calmodulin-dependence of GRK5-NT and the peptide’s effects on G-protein signaling.
Abstract 930: Aerobic Dose Intensity and the Human Exercise Plasma Proteome
Authors: Guseh James S , Churchill Timothy W , Yeri Ashish , Lo Claire , Brown Marcel , Rosenzweig Anthony , Baggish Aaron
Published: October 2019

Aerobic exercise confers myriad benefits to human health but the mechanism by which it does so remain incompletely understood. We hypothesize that exercise works in part through circulating protein signaling. Healthy adult men (n, 12) participated in treadmill running sessions at both low (6 mph) and high intensity (maximal effort). We used pre- and post-exercise plasma and a high-throughput aptamer-based assay (SomaScan) to examine the acute impact of exercise on the plasma proteome.

Acute aerobic exercise consistently alters the resting plasma proteome in an intensity-dependent fashion. Of 1,305 proteins assayed 184 (14%) and 598 (46%) change at low and high intensity respectively (FDR p < 0.05). 159 protein species (12%) are common to both intensities. Gene ontology analysis revealed enrichment of pathways associated with leukocyte chemotaxis and chylomicron metabolism at low intensity and Wnt signaling, neuronal axonogenesis, and nitric oxide metabolism pathways at high intensity. We used human sequencing data from the GTEX Consortium (Broad, Cambridge MA) to computationally infer the sources of increasing proteins and found major contributions from the cardiovascular, gastrointestinal, and nervous systems. We identified 43 cis-SNPs that approximate the upregulated proteomic response to acute exercise and used Mendelian randomization to infer a causal relationship between the exercise proteome and decreased muscle wasting in a UK Biobank cohort.

Although guidelines present low and high intensity exercise as equivalent alternatives for health, these data suggest that distinct exercise intensities might offer common and distinct exercise benefits.
Abstract 933: Integrated Omics Analysis of Diabetic Heart Failure in Human Myocardium
Authors: Page Stephani , Kwee Lydia , Kraus William , White Phillip , Devore Adam , Mentz Robert , Bristow Michael , Milano Carmelo , Bowles Dawn , Ilkayeva Olga , Felker G. Michael , Christopher Bridgette , Holley Christopher , McGarrah Robert , Shah Svati
Published: October 2019

Background:
Patients with diabetes mellitus (DM) have a higher risk of heart failure (HF). While metabolic dysregulation has been well-established in HF and DM separately, molecular mechanisms associated with diabetic HF are incompletely understood. Thus, we sought to test the overarching hypothesis that cardiac metabolic programming is distinct in diabetic HF compared to DM and HF individually.

Methods:
RNA-sequencing and targeted metabolomics profiles were completed on human myocardial tissue from 54 unique individuals received from the Duke Human Heart Biorepository and the University of Colorado. Multi-omics profiles of cardiac tissue from 4 groups were compared: a) controls with no clinical evidence of DM or HF (n = 12), b) DM-only (n = 15), c) HF-only (n = 10), and d) HF+DM (n = 17).

Results:
After using statistical criteria to prioritize genes, we looked for genes that function together or modulate the same activity. Genes encoding producers of reactive oxygen species (ROS), DUOX2, DUOXA2, and DUOXA1, were differentially upregulated in diabetic-HF, compared to DM or HF alone (FDR HF+DM vs DM-only/HF-only = 6.6 x 10
-7
/2.2 x 10
-4
, 7.7 x 10
-3
/6.7 x 10
-3
, and 3.6 x 10
-6
/0.013, respectively). Modulators of mTOR signaling, ERBB3, ERBB4, and PIK3R3, were also differentially regulated in diabetic-HF (FDR HF+DM vs DM-only/HF-only = 1.4 x 10
-3
/0.010, 0.012/7.4 x 10
-3
, and 0.011/9.3 x 10
-3
, respectively). Gene set enrichment analysis supported our focus on these genes; top enriched gene sets included mTOR signaling and processes related to oxidative stress response. In our metabolomics data, long chain acylcarnitines (AC) and ceramides (Cer) are decreased in diabetic-HF. For example, C20:1 AC can be converted to C20:1 Cer and accumulation of both is diminished in diabetic-HF (FDR = 0.0032 and 0.035, respectively).

Conclusions:
We found that diabetic-HF was characterized by a distinct omics profile consistent with increased ROS production, diminished AC and Cer accumulation, and modulation of mTOR signaling. The fact that ceramide accumulation has been previously associated with oxidative stress and also linked to ERBB and PI3K pathways suggests that these data may reveal a unique regulation of these pathways in diabetic-HF.
İSLAMİ FİNANSIN TÜRKİYE, ABD, İNGİLTERE VE MALEZYA’DA GELİŞİMİ
Authors: GÜÇLÜ Fatih , KILIÇ Metin
Published: October 2019

İslami finans, finansal faaliyetlerin İslami kurallara uygun olarak
gerçekleştirildiği bir finansal sistemdir. Bu çalışmanın amacı da, Türkiye,
A.B.D., İngiltere ve Malezya’da İslami finansın gelişiminin incelenmesidir. Söz
konusu ülkelerdeki katılım bankacılığı, İslami sermaye piyasaları ve katılım
sigortacılığı alanlarında yaşanan gelişmeler hem rakamsal veriler hem de bu
konudaki yasal düzenlemeler ışığında irdelenmiştir. Türkiye’nin son 10-15
yıllık süreçte hem siyasi hem de ekonomik yapısında yaşanan değişim ve
gelişimin etkisiyle, İslami finansın var olan potansiyelini yakalayacak
adımlara attığı görülmektedir. A.B.D.’de özellikle büyük yatırımcıların etkin
olduğu sermaye piyasaları alanında İslami finansın yüksek bir potansiyele sahip
olduğu söylenebilir. İngiltere, Avrupa ülkeleri içerisinde İslami finans
endüstrisinde en önde gelen ülkelerden biridir. İngiltere, özellikle katılım
bankacılığı ve İslami sermaye piyasaları alanında önemli bir tecrübeye
sahiptir. 1960’lı yıllardan bu yana İslami finans çalışmalarının sürdüğü
Malezya ise hem katılım bankacılığı hem de İslami sermaye piyasaları
alanlarında İslami finans endüstrisinin gelişiminde tüm dünyada öncü ülkelerin
başında gelmektedir.
VERGİ GELİRLERİNİN EKONOMİK BELİRLEYİCİLERİ ÜZERİNE AMPİRİK BİR ANALİZ: YÜKSEK GELİRLİ OECD ÜLKELERİ ÖRNEĞİ
Authors: YILDIZ Barış
Published: October 2019

Çalışmanın
amacı 19 yüksek gelirli OECD ülkesine ilişkin vergi gelirlerinin ekonomik
belirleyicilerini analiz etmektir. Çalışma 1995-2017 dönemini kapsamaktadır.
Ampirik analizde vergi gelirleri (% GSYH) bağımlı değişken olarak
kullanılmıştır. Bağımsız değişken olarak kullanılan ekonomik belirleyiciler ise
kişi başına Gayri Safi Yurtiçi Hasıla (GSYH), ticari açıklık, enflasyon, kamu
harcamaları ve tarımsal katma değer verileridir. Sabit etkiler Genelleştirilmiş
Momentler Metodu (GMM) tahmincisi kullanılarak yapılan analiz sonucuna göre,
kişi başına GSYH vergi gelirlerini istatistiksel olarak anlamlı ve pozitif
etkilemektedir. Kamu harcamaları ve tarımsal katma değer vergi gelirlerini
istatistiksel olarak anlamlı ve fakat negatif etkilemektedir. Ticari açıklık ve
enflasyonun ise vergi gelirleri üzerinde istatistiksel olarak anlamlı bir
etkisi bulunamamıştır.
Neural Correlates of Causal Confounding
Authors: Liljeholm Mimi
Published: October 2019

As scientists, we are keenly aware that if putative causes perfectly covary, the independent influence of neither can be discerned—a “no confounding” constraint on inference, fundamental to philosophical and statistical perspectives on causation. Intriguingly, a substantial behavioral literature suggests that naïve human reasoners, adults and children, are tacitly sensitive to causal confounding. Here, a combination of fMRI and computational cognitive modeling was used to investigate neural substrates mediating such sensitivity. While being scanned, participants observed and judged the influences of various putative causes with confounded or nonconfounded, deterministic or stochastic, influences. During judgments requiring generalization of causal knowledge from a feedback-based learning context to a transfer probe, activity in the dorsomedial pFC was better accounted for by a Bayesian causal model, sensitive to both confounding and stochasticity, than a purely error-driven algorithm, sensitive only to stochasticity. Implications for the detection and estimation of distinct forms of uncertainty, and for a neural mediation of domain-general constraints on causal induction, are discussed.
Ablative Properties of Calcium Carbonate-Filled Phenolic Matrix Composite Coatings Irradiated by High Energy Continuous-Wave Laser
Authors: Ma Chen , Ma Zhuang , Gao Lihong , Liu Yanbo , Wu Taotao , Wang Lijun , Li Hezhang , Wang Fuchi
Published: October 2019

Laser, especially high energy continuous-wave (CW) laser, can destroy traditional structure material of aircrafts or vehicles easily. Therefore, anti-laser damage is gradually becoming a major concern. In this case, calcium carbonate (CaCO3)-filled phenolic matrix composite
coatings have been designed and prepared to prevent from high energy CW laser damage. Laser ablation behavior of the coating is deeply studied by varying the laser parameters including laser power density and irradiation time. The results show that the phenolic resin keeps decomposing into
residual char caused by the high temperature during laser irradiation. The porous structure of phenolic resin of residual char provides an excellent thermal insulation property for the coating. In addition, the decomposition reaction of CaCO3 consumes a large amount of laser energy,
which has a cooling effect on the residual char. CaO that is produced during the decomposition of CaCO3 has a high melting temperature and can lead to the thermal stability improvement of the residual char. Due to the introduction of CaCO3, the back-surface temperature
of sample is decreased from 94 °C to 64 °C when irradiated at 500 W/cm2 for 10 s and the anti-laser property of the coating is improved. All the analysis indicate that the designed coating can perform as a shield to prevent from high energy CW laser.
Photocatalytic Oxidation of Alcohols Over Magnetically Recoverable Gold Supported Iron Oxide Nanoparticles
Authors: Hui Ma , Juzhen Wu , Li Zhao , Zheng Zhou , Jiahu Guo
Published: October 2019

A one-pot simple and efficient synthetic route for the synthesis of Au-loaded Fe2O3 nanoparticles was developed, and this material's photocatalytic activity for visible light assisted oxidation of alcohols and degradation of organic dye were studied. As-synthesized
nanostructured catalyst was characterised by powder X-ray diffraction (XRD), transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), SEM-mapping, X-ray photoelectron spectroscopy (XPS), N2 adsorption–desorption isotherm (BET), and inductively coupled
plasma-atomic emission spectroscopy (ICP-AES). It was observed that 5–10 nm Au-nanoparticles supported on 10–80 nm Fe2O3 shows boomerang-shaped nanoparticle. Gold loading of 1 wt% shows high conversion and selectivity towards the target product aldehyde. The
synthesized nanomaterial also proved to be an excellent photocatalyst for degradation of organic dyes such as methylene blue (MB) and rhodamine B (RhB). The catalyst proved to be noteworthy as it does not loss in its catalytic activity even after five cycles of reuse.
Microstructure and Property of In-Situ TiC Reinforced Co-Based Composite Coatings by Laser Cladding
Authors: Quan Xiumin , Ding Lin
Published: October 2019

In order to improve the wear resistance of Co-based alloy coatings, in-situ TiC reinforced Co-based composite coatings were prepared on 45 steel surface by laser cladding Co-based alloy, Ti and C powders. The effect of (Ti + C) addition on the microstructure and wear resistance
of in-situ TiC reinforced Co-based composite coatings was investigated systematically. The results showed that TiC and Co3Ti phases were detected in the in-situ TiC reinforced Co-based composite coatings, besides γ-Co and Cr23C6.
The in-situ TiC reinforced Co-based composite coatings was mainly composed of planar crystals in the binding zone, dendrites in the bottom and equiaxed crystals in the upper. With the increase of (Ti + C) addition, the number of short rod-like dendrites and equiaxed crystals was gradually
increased, the microstructure was more fine and uniform. The microhardness of the composite coatings was improved gradually, and the maximum improvement in the microhardness was 35.7%, for 30.0 wt.% (Ti + C) addition. The mass loss of the composite coatings was firstly reduced and then increased,
the lowest value was 10.5 mg for 20.0 wt.% (Ti + C) addition, which was 59.7% of that of Co-based alloy coatings, and the wear mechanism of the composite coatings after adding (Ti + C) was the abrasive wear. These results indicated that adding (Ti + C) had a significant influence on the properties
of the composite coatings, and were consistent with the calculated results of applied multivariate statistical analysis.
Durability of Concrete Under the Combined Action of Carbonization and Fatigue Loading of Vehicles
Authors: Miao Yuan-Yao , Niu Di-Tao , Cheng Ning
Published: October 2019

Natural factors such as environments gradually cause the aging of structural materials of concrete bridges and mechanical properties of the components are constantly degraded. When highway bridge structures are under the combined with vehicle loading and environmental diversities, the
degradation of structural performance is further aggravated. In this study, according to the deterioration trend of concrete durability in atmospheric environment, durability tests for concrete under the combined action of fatigue loading of vehicles and carbonization were performed by artificial
climate simulation. A bending fatigue test for concrete under vehicle loading was carried out, and the trend of fatigue life change with vehicle loading level and the trend of fatigue strain development were obtained. The results show that the fatigue life increases with the decrease in fatigue
loading level of vehicles, and the logarithmic value of fatigue life Nf is linear with the fatigue stress level S. Fast carbonization tests for concrete were performed with respect to the fatigue damage degree D of 0, 0.2, 0.4, 0.6, and 0.8. It was found that
the carbonization trend of fatigue damaged concrete under vehicle loading follows the Fick first law. The carbonization depth increases with the increase in carbonization time, relatively fast at the initial stage and then slowly at the later stage. When the fatigue damage degree D
is less than 0.4, the effects of fatigue damage on carbonization is relatively small. When D is more than 0.4, the effect of fatigue damage on carbonization is relatively significant. The extension of interior micro-cracks and micropores caused by fatigue damage is a significant factor
affecting the carbonization performance of fatigue damaged concrete. The change trend of carbonization depth of damaged concrete with time was fitted and analyzed. An influencing factor of fatigue damage was introduced, and a durability prediction model for concrete under the combined action
of carbonization and fatigue loading of vehicles was established.