bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 275: Quantification of the Mitochondrial Protein Interactome in Failing Hearts
Authors: Caudal Arianne , Chavez Juan D , Lee Chi Fung , Villet Outi , Bruce James E , Tian Rong
Published: February 2019

Mitochondrial dysfunction is a maladaptive mechanism in the progression of heart failure. However, the cause of mitochondrial dysfunction during cardiac stress remains elusive. To understand the pathogenic role of mitochondria in heart failure, a systems biology approach was used to quantify the protein interaction network by comparing mitochondria isolated from healthy and failing mouse heart. This is achieved by Protein Interaction Reporter (PIR) technology consisting of a cleavable, MS-identifiable, isotope labelled cross-linker, which allows identification and quantification of interacting peptide pairs. Heart failure was induced in three month old, wild-type C57Bl6/NCrl mice using chronic pressure overload by transverse aortic constriction (TAC, n=8) surgery. Age-matched Sham-operated (Sham, n=8) mice were used as controls. Four weeks post-surgery, cardiac function was measured by echocardiography. TAC hearts showed significantly lower contractile function than Sham (fractional shortening 49±2.1% vs 13±4.0%), and were dilated (LVID 2.7±0.34mm vs 3.4±0.46mm). Cardiac hypertrophy of TAC hearts (HW/TL 5.0±0.35 vs 9.1±0.58) was associated with greater lung edema (LW wet/dry 3.9±0.49 vs 4.9±0.24). Freshly isolated mitochondria from TAC and Sham hearts were cross-linked with heavy- or light-isotope labelled crosslinkers, digested, enriched, and analyzed by LC/MS
3
. Released peptide spectra were identified and categorized by known molecular functions using a MitoCarta 2.0 constructed database. We identified 3502 non-redundant cross-linked peptide pairs from 297 proteins, involving 1758 lysine residues linked in 2571 lysine-lysine interactions. From 3502 total links, we detected 2304 intra- and 1016 inter-protein links. Inter-protein changes between TAC/Sham were most prevalent in the electron transport chain and ATP synthasome networks. Intra-protein changes were evident in TCA cycle, fatty acid oxidation, and nucleotide transport, suggesting conformational remodeling. Interactome changes in amino acid metabolism, mitochondrial transcription and translation pathways were undetected. A complete picture of mitochondrial protein landscape in the failing heart will lead us to novel mechanisms and therapy.
Abstract 278: Dual Modulation of Microscale Tissue Engineering and Energy Metabolism for Maturation of Human Pluripotent Stem Cell-Derived Cardiomyocytes
Authors: Gentillon Cinsley , Duan Meixue , Yu Wen-Mei , Jha Rajneesh , Li Shuzhao , Liang Bill , Todor Andrei , Gibson Greg , Qu Cheng-Kui , Brown Lou Ann , Xu Chunhui
Published: February 2019

Background:
Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent a viable cell source for clinical application and other purposes, such as disease modeling and drug discovery for cardiovascular diseases. However, their immature phenotype limits their utility for these applications. It is widely known that the transition from fetal to adult heart during development is accompanied by an alteration in energy metabolism from glycolysis to fatty acid oxidation (FAO), respectively. Using this metabolic hallmark of cardiomyocyte maturation, we investigated a platform that combines three-dimensional (3D) cell cultivation and molecules that target key pathways involved in the energy metabolism of cardiomyocytes.

Methods:
Cardiac spheres of highly-enriched hPSC-CMs were generated from cardiac-differentiated cultures and treated with a combination of five molecules or control (DMSO) for one week. We used functional, morphological, transcriptome and metabolome analyses to assess the maturation status of hPSC-CMs.
RESULTS:
Treatment of 3D hPSC-CMs with a combination of five molecules elicited increased FAO along with mitochondrial respiratory capacity. These changes in oxidative capacity were associated with increased mitochondrial content and DNA. In addition, cardiac spheres treated with combined molecules displayed enhanced calcium transient kinetics when compared to control cells. RNA sequencing revealed upregulation of genes involved in many cellular metabolic processes, including FAO. Lastly, metabolic profiling of these cardiac spheres identified more than one hundred metabolites that were altered upon treatment.

Conclusions:
Our study showed that microscale tissue engineering along with treatment of hPSC-CMs with a combination of five molecules increase mitochondrial function, alter molecular and metabolic profiles, and potentially improve cardiomyocyte maturation.
Abstract 279: Effects of Acute Oxidative Stress on Cardiac Proteome Dynamics
Authors: Thomas Cody T , Lam Maggie Pui Yu
Published: February 2019

Introduction:
Acute reactive oxygen species exposure is thought to trigger endoplasmic reticulum (ER) stress and unfolded protein response (UPR) commonly observed in pathological hearts. The pathways and molecular features impacted by acute oxidative stress are incompletely understood. To understand how proteostatic stressors impact cardiac protein dynamics, we investigate the effect of low to high doses of acute oxidant on the cardiac proteome using a paraquat-induced oxidative stress model.

Methods:
C57BL/6J mice were exposed to low, mid, or high doses of paraquat for up to 48 hours. Cardiac proteins were extracted and digested on-filters into tryptic peptides. The peptides were then tagged with isobaric stable isotope tandem mass tags (TMT) followed by high-pH reversed-phase (RP) fractionation. Each fraction was further separated by low-pH RP liquid chromatography and analyzed on a Q-Exactive HF Plus high-resolution mass spectrometer to obtain proteome-wide abundance levels across treatment groups. We then focused on the differential expression in the mitochondrial and ER subproteomes as well as their respective protein quality control pathways.

Results:
We found prominent differential expression in specific quality control proteins in response across low and high doses of oxidative stresses. The data suggest that oxidative stress activates UPR pathways including notably mitochondrial UPR (UPRmt) components in a dose-specific manner. In particular, we observed the repression of mitochondrial protein import machinery components as a specific feature of low but not high oxidative stress response. In addition, the differential expression of pyruvate metabolism proteins may constitute a link between cardiac metabolism and UPRmt, and serve as a determinant between adaptive and maladaptive responses to reactive oxygen species.

Conclusion:
Our results indicate that the activation of the UPRmt pathways may be an overlooked feature of acute oxidative insults that underlies stress response in cardiac cells. Future work will interrogate the molecular crosstalks between mitochondria and ER stress response pathways.
Abstract 282: Increasing Cardiac Fatty Acid Oxidation Protects Against High Fat Diet Induced Mitochondria Dysfunction and Cardiomyopathy in Mice
Authors: Shao Dan , Kolwicz Stephen C. , Roe Nathan , Villet Outi , Tian Rong
Published: February 2019

In the obese and diabetic heart, an imbalance between fatty acid uptake and fatty acid oxidation (FAO) promotes the development of cardiac lipotoxicity. In this study, we tested the hypothesis that enhancing FAO via ACC2 deletion in an adult heart would prevent the cardiac lipotoxic phenotype in a mouse model of diet-induced obesity. ACC2 flox/flox (CON) and ACC2 flox/flox-MerCreMer+ (iKO) were injected with
tamoxifen
and subjected to a high fat diet (HFD) for 24 weeks. In isolated Langendorff-perfused heart experiments, HFD feeding increased FAO 1.6-fold in CON mice which was further increased to 1.9-fold in iKO mice compared with CON on chow diet. HFD induced systolic and diastolic dysfunction was abolished in iKO mice compared with CON mice (Fractional shortening 32.8±2.8% (CON) vs. 39.2±3.2% (iKO), E’/A’ ratio 0.91±0.09 (CON) vs. 1.11±0.08 (iKO), p< 0.05, n=5-6). Heart weight /Tibia length ratio was significantly higher in CON than iKO mice after HFD feeding (7.19±0.22 vs. 6.47±0.28, p<0.05, n=6). These data indicate that enhancing myocardial FAO via ACC2 deletion prevents HFD induced cardiac dysfunction and attenuates pathological hypertrophy in obese mice. We then examined the mitochondrial respiration activity under chow and HFD fed conditions. HFD feeding significantly reduced mitochondria oxygen consumption rate in Con hearts but not in iKO mice (332 vs. 418 pmoles/min, p<0.05, n=5), suggesting that enhancing FAO prevented HFD induced mitochondria dysfunction. In vitro, palmitate (PA) induced mitochondria fragmentation and increased reactive oxygen species production was partially attenuated in ACC2 knocked down cardiomyocyte. Knocking down of ACC2 also prevented PA induced cell death. Moreover, HFD treatment significantly reduced the expression of LC3 and p62 in mitochondria fraction, indicative of impaired mitophagy in obese mice, which was attenuated in iKO mice. Therefore, the beneficial effect for enhancing cardiac fatty oxidation in HFD induced obesity model is mediated, in part, by maintenance of mitochondrial function through regulating mitophagy activity. Taken together, our findings suggest that promoting cardiac FAO is an effective strategy to prevent the development of cardiac lipotoxicity during diet-induced obesity.
Abstract 283: Parkin Fails to Rescue Age-Dependent Cardiomyopathy in Mitochondrial DNA Mutator Mice
Authors: Woodall Benjamin P , Orogo Amabel M , Divakaruni Ajit S , Cortez Melissa Q , Wang Hongxia , Murphy Anne N , Gustafsson Åsa B
Published: February 2019

Temporal decline in mitochondrial function is widely considered to be a driver of cardiomyocyte aging, which in turn contributes to the prevalence of cardiovascular disease in the aging population. The accumulation of dysfunctional mitochondria appears to be a direct consequence of reduced autophagy and mitochondrial quality control in the aging heart. Parkin, an E3 ubiquitin ligase, plays a critical role in this process, marking dysfunctional mitochondria for degradation by autophagosomes; however, whether Parkin functions to prevent cardiac aging by maintaining a healthy population of mitochondria is still unclear. To examine the role of Parkin in the context of mtDNA damage and myocardial aging, we used a mouse model carrying a proofreading defective mitochondrial DNA polymerase gamma (POLG). We observed a significant decrease in Parkin protein levels in the hearts of aged (6 months) POLG mice, in spite of elevated Parkin mRNA. Seahorse analysis revealed a decrease in cardiac mitochondrial respiration in 6-month POLG mice. While cardiac structure and function were similar in both genotypes, POLG mice displayed modest but significant cardiac hypertrophy at this age. Next, we generated mice with concomitant Parkin deletion or cardiac specific Parkin overexpression with the mutant POLG. However, loss of Parkin did not exacerbate the accelerated cardiac aging phenotype observed in the POLG mice, and enhancing cardiac Parkin protein levels did not rescue the mitochondrial dysfunction or the cardiac hypertrophy observed in POLG mice up to 12 months of age. Surprisingly, we found that Parkin levels were reduced in POLG hearts, even with cardiac specific overexpression of Parkin. Translation of Parkin was unperturbed in 12-month POLGxParkin TG hearts, suggesting instead that Parkin protein stability is compromised in aged POLG hearts, a hypothesis we are currently testing. We also found both diminished protein ubiquitination and reduced degradation of Mfn1, a known Parkin substrate, in POLGxParkin TG hearts compared to Parkin TG hearts. These results provide new insights into mitophagy and aging, and suggest that Parkin plays a minor role in baseline mitochondrial maintenance and that overexpression of Parkin fails to prevent the cardiac aging process.
Abstract 284: Loss of Cardiomyocyte General Control of Amino-Acid Synthesis 5-like 1 Expression Impairs Mitochondrial Function and Exacerbates Heart Failure Progression
Authors: Zhang Manling , Thapa Dharendra , Manning Janet R , Stoner Michael W , Guimaraes Danielle , Corey Catherine , Shiva Sruti , St. Croix Claudette , Feng Ning , McTiernan Charles F , Sack Michael N , Scott Iain
Published: February 2019

Background:
Energy starvation resulting from impaired mitochondrial function is one of the key mechanisms of heart failure development. Emerging evidence shows that lysine acetylation is one of the critical post-translational modifications that modulates mitochondrial bioenergetic output. We have identified
General Control of Amino-Acid Synthesis 5-like 1 (GCN5L1)
as a key acetyltransferase protein responsible for dynamic mitochondrial protein acetylation, and that this mechanism plays an essential role in regulating fatty acid oxidation. However, the role of GCN5L1 regulation on mitochondrial function in heart failure development is unknown.

Methods and results:
We examined GCN5L1 expression in cultured neonatal cardiac myocytes (RNCM) challenged with hypertrophy inducer phenylepherine (PE), and in failing hearts. We found that GCN5L1 mRNA and protein expression is markedly decreased in RNCM treated with PE, and in heart failure induced by mouse transaortic constriction (TAC). In addition, total mitochondrial protein acetylation in failing hearts was significantly decreased, corresponding to the decreased levels of GCN5L1. Next, we investigated the impact of decreased level of GCN5L1 on mitochondrial function and cardiac function in response to pathological stress. We found that GCN5L1 knockdown by shRNA in RNCM results in a decrease in basal oxygen consumption rate and ATP-linked respiration upon PE stimulation. More importantly, knocking down GCN5L1 in the presence of PE exacerbates the RNCM hypertrophic response assessed by increased cellular area and elevated ANP and BNP. Consistent with these
in vitro
studies, cardiac specific GCN5L1 knockout mice subjected to TAC display accelerated cardiac hypertrophy and heart failure, compared to WT littermates (fractional shortening 15.7% vs 26.4%, n=6-7 in each group,
P
< 0.05).

Conclusion:
GCN5L1 plays a critical role in mitochondrial function and cardiac bioenergetics in response to stress. Impaired GCN5L1 function might be one of the key mechanisms of metabolic derangement in heart failure development, and could be a promising therapeutic target.
Abstract 316: Salusin-α Improved Atherosclerosis in High Cholesterol Diet Fed Rabbits by Inhibiting Smooth Muscle Cells Proliferation and Migration
Authors: Shoucui Gao , Xiaojing Wang , Sihai Zhao , Jianglin Fan , Enqi Liu
Published: February 2019

Aims:
To investigate the role of salusin-α in vascular smooth muscle cells (VSMCs) migration and proliferation during atherosclerosis development and its potential molecular mechanism.

Methods and results:
Salusin-α or saline (vehicle) was continuously infused through osmotic mini-pumps into high cholesterol diet fed male rabbits for 16 weeks. Salusin-α infusion significantly resulted in the reduction of aortic atherosclerosis by 59% (17% and 42%), including 39% (45% and 75%) in the aortic arch ,70% (13% and 44%) in the thoracic aorta, and 72%(7% and 25%) in the abdominal aorta without affecting plasma lipids level. Immunohistochemical staining showed that salusin-α decreased both the VSMCs and macrophage positive area in the atherosclerotic lesions by 69% (0.11 and 0.35) and 54% (0.31 and 0.68 ). In vitro, platelet-derived growth factor-BB induced proliferation and migration of VSMCs were also reduced by salusin-α. In these VSMCs, the phosphorylation of Akt and mTOR were also down-regulated, but not in ERK1/2 and p38MAPK.

Conclusions:
Our data indicated that Salusin-α might improve atherosclerosis by inhibiting smooth muscle cells proliferation and migration through the Akt/ mTOR pathway.
Abstract 330: Systemic Blocking Exosome Formation/Release Improves Ischemic Hindlimb Repair in Diabetic db/db Mice
Authors: Cheng Zhongjian , Garikipati Venkata Naga Srikanth , Cimini Maria , Tang Yan , Wang Chunlin , Trungcao May , Ye Yujia , Benedict Cindy , Mallaredy Vandana , Koch Walter , Verma Suresh K , Goukassian David , Kishore Raj
Published: February 2019

Background:
Recent studies demonstrated that plasma exosomes from diabetic patients and animals lose their ability to maintain physiological properties of cardiomyocytes. Exosome inhibitor GW 4869 (GW) tended to improve heart function in diabetic mice with myocardial infarction. We tested the hypotheses that systemic blocking exosome synthesis/formation improves ischemic hindlimb repair in diabetes.

Methods and Results:
Unilateral hindlimb ischemia (HLI) surgery was conducted by ligation of left femoral artery in 12-week male db/db and db/+ mice which were administrated with either GW (2 mg/kg body weight, i.p) or vehicle for 4 weeks starting from one week before HLI. Blood perfusion in ischemic hindlimbs was examined by Laser Doppler at pre-HLI, and 0, 3, 7, 14 and 21 days post-HLI. Plasma exosomes were isolated by standard ultracentrifugation method and counted by NanoSight. GW increased blood concentration of CD31
+
/Sca-1
+
cell 3-day post-HLI and decreased necrosis and loss of toe/toenail; improved blood flow; enhanced capillary/arterial density determined by CD31 and SMA-α staining and decreased fibrosis in the muscles of ischemic hindlimbs in db/db mice 21-day post-HLI. Plasma exosomes from db/db mice significantly impaired human cardiac microvascular endothelial cells (HCMVECs) tube formation and migration. Mechanistically, hepatocyte growth factor (HGF) expression was decreased in bone marrow-derived endothelial progenitor cells (EPCs) from db/db mice and HCMVECs treated with diabetic plasma exosomes. Administration of GW increased HGF level in diabetic EPCs. Furthermore, diabetic plasma exosomes decreased H3K4me3 (active maker of transcription) whereas increased H3K27me3 (suppressive marker of transcription) at HGF promoter. Finally, treatment of HCMEVs with exogenous HGF rescued diabetic exosomes impaired tube formation of HCMVEC.

Conclusions:
Systemic inhibition of exosome synthesis/formation by GW increased ischemic limb repair in diabetic db/db mice, at least partially, via histone methylation mediated suppression of HGF. Our findings suggest that therapeutic targeting of systemic dysfunctional exosomes could represent a new avenue for therapeutics of ischemic tissue injury in patients with diabetes.
Abstract 331: Conjugation of Graphene Oxide With Chitosan Improves Survival of Transplanted Allogeneic Stem Cells and Preserves Ventricular Function in the Infarcted Heart
Authors: Saravanan Sekaran , Sareen Niketa , Sequiera Glen Lester , Daesung Kim , Abu El Rub Ejlal , Moudgil Meenal , Dhingra Sanjiv
Published: February 2019

Allogeneic mesenchymal stem cells (MSCs) derived from bone marrow are considered to ideal candidate cell type for myocardial repair after a cardiac injury. However, recent reviews of allogeneic MSCs based clinical trials reported that transplanted cells were not able to survive for long term in the heart. Therefore, strategies to improve survival of transplanted cells would preserve the benefits of allogeneic MSCs therapy for heart repair. Recently, graphene oxide (GO) based biomaterials are being widely investigated for their ability to improve survival of transplanted MSCs in the heart. However, the presence of reactive oxygen functional groups (-OH, -COOH) in the structure of GO increases oxidative stress and activate cell death pathways, which impairs the benefits of GO based biomaterials. Therefore, to improve benefits of GO for stem cell delivery, we synthesized a thermosensitive hydrogel by conjugating GO with chitosan (CS). Our fourier transformed infrared spectrum (FTIR) analysis revealed an interaction between oxygen functional groups of GO and amino (-NH2) groups of chitosan. Our data demonstrate that CS masked the reactive functional groups of GO and prevented GO mediated ROS induction. This novel chitosan-graphene oxide (CS-GO) composite exhibited optimal porosity for cell conjugation and retention. Furthermore, CS-GO biomaterial was cyto-compatible as there was no cytotoxicity caused by CS-GO to MSCs. Furthermore, CS-GO also prevented hypoxia induced apoptosis of MSCs. We employed this novel biomaterial to deliver allogeneic MSCs to the infarcted heart in a rat model of myocardial infarction. After 5 weeks of cell transplantation, there was a significant improvement in the survival of implanted MSCs and cardiac function in CS-GO group. Therefore, conjugation of GO with chitosan prevented GO mediated ROS generation and cell death. Also, CS-GO mediated delivery of allogeneic MSCs to infarcted heart improved the survival of transplanted cells and preserved cardiac function.
Abstract 336: Human Bone Contains Primitive Cells With Angiogenic and Immunomodulatory Properties
Authors: Kubo Hajime , Feldsot Eric , Schena Giana , Hobby Alexander , Yang Yijun , Johnson Jaslyn , Gross Polina , Sharp Thomas , Mohsin Sadia , Berretta Remus , Choi Eric T , Donnelly Joanne , Christopher Hydel , Houser Steven R
Published: February 2019

Previously, we have shown that treatments of cortical bone derived stem cells (CBSCs) reduce ventricular remodeling and improve cardiac functions in both mouse and pig myocardial infarction (MI) models. The goals of the present study were to isolate and characterize human CBSCs (hCBSCs).

Using bone fragments obtained at the time surgeries, we isolated three morphologically distinctive hCBSC phenotypes; 1) sphere forming (SF); 2) epithelial like monolayer (ELM); and 3) larger and spindle shaped (LSS) phenotype. The hCBSC phenotypes grew without senescence in culture. Mean doubling time (hour) for SF, ELM, and LSS at the passage number 20 (P20) were 19.54, 21.21, and 20.3 respectively and at the P40 were 18.01, 17.13, and 20.56 respectively. All of the phenotypes were found to have surface expression of CD44; however, other markers detected (CD105, CD90, CD73, CD106, CD271, and CD133) on mouse CBSCs (mCBSCs) were not detected along with the markers not detected on the surface of mCBSCs (CD45, CD11b, CD31, CD34, CD117, and CD325). Erythrocytes (CD235a) and immune cell markers (CD2, CD3, CD14, CD16, CD19, and CD56) were also not detected. The hCBSCs were found without histocompatibility antigen Ia (MHC-Ia: HLA-A, HLA-B, and HLA-C) and MHC-II (HLA-DR); instead, they expressed soluble forms of MHC-Ib (HLA-G5, HLA-G6, and HLA-G7), potent inhibitor of natural killer cells and other immune cells. These features are commonly found in immune privileged cells. Further, the hCBSCs produced the immunomodulatory and anti-inflammatory factors (IL-4, IL-1RA, TGF-b and IL-10). Additionally, the hCBSCs secreted angiogenic factors that organize endothelial cells into tube like structures.

From these results, the hCBSCs we isolated have totally different surface marker characteristics compared to any other known cells including mCBSCs. In addition to their angiogenic effects, the hCBSCs have immunomodulatory properties that could make them suitable for cell therapy targeting inflammatory diseases such post myocardial infarction remodeling.
Abstract 339: A Novel Strategy to Harness Stem Cell-Intrinsic Mechanobiological Properties for Advanced Tissue Repair: Implication in Cardiac Tissue Injury
Authors: Paul Arghya , Chakravarti Aparna , Pacelli Settimio , Ahmed Rafeeq
Published: February 2019

Rationale:
Stem cells are constantly exposed to biomechanical and biochemical signals when transplanted in a continuously beating cardiac environment for treatment. Here, we postulated that an
in vitro
miniaturized beating cardiac microenvironment can induce unique biomechanical stimuli to co-cultured MSCs that can influence therapeutic potential of the later. This project aimed (i) to pre-condition mesenchymal stem cells (MSCs) with continuous mechanobiological stimuli using a 3D cardiac tissue environment (ii) to intramyocardially inject pre-conditioned MSCs into mice heart with myocardial infarction (MI) for tissue repair.

Methods:
We fabricated an
in vitro
cardiac platform as shown in
Fig 1
, using an electro-conductive hydrogel and human iPSC-derived cardiac cells. Adipose MSCs were then injected to the beating hydrogel platform. After 7 days, activated (MB+) and non-activated MSCs (MB-) were isolated for
in vitro
and
in vivo
analysis.

Results:
The force generated by the constant beating of cardiomyocytes induced profound effects in on MSC behavior in the MB+ group. Several mechano-transduction factors (YAP1, TAZ), actin polymerization genes involved in cardiac muscle contractions (
ACTA2
,
CDC42, TNNT2
) and angiogenic genes were upregulated in MB+. RNA-seq analysis further confirmed these findings. 3 week study in mice with MI demonstrated significant increase in capillary density and reduction in infarct sizes in MB+ (n=6) compared to MB- group. Furthermore, the MB+ group showed significantly higher cardiac performance in echocardiography.

We can conclude MB-activated MSCs can have significant impact in future treatment strategies for patients with MI.
Abstract 348: Epigenetic Regulation in Heart Regeneration
Authors: Tian Shuo , Lei Ienglam , Ma Peter X , Wang Zhong
Published: February 2019

Existing treatments for myocardial infarction (MI) include Medication, intervention, and surgical bypass. These strategies are mainly used to prevent disease progression, but do not address the fundamental problem of cardiomyocyte loss. Therefore, developing new effective therapeutic strategies to preserve the pumping function after MI is highly desired.

Acute injuries, such as MI, are companied with quick and massive loss of histone acetylation in injured cells, which lead to severe organ damage. Therefore, maintaining proper histone acetylation in a swift manner will likely protect the affected cell and organ function.

In this study, we showed that valproic acid (VPA), a pan HDAC inhibitor and a FDA approved drug for epilepsy and bipolar disorders, reduced ~50% of the infarct size and preserves the pumping function of heart after MI in rats. Moreover, 60 min after infarction, VPA administration still significantly decreased infarct size in MI rats. Mechanistically, we identified that that VPA treatment triggered a Foxm1 pathway, which in turn activated genes essential for cell survival and proliferation and inflammation suppression. Importantly, overexpression of Foxm1 provided similar heart protective effect after MI as VPA treatment. In contrast, inhibition of Foxm1 activity abolished the cardiac protective effect of VPA.

In parallel, we have applied novel biodegradable nanofibrous microspheres as cell carriers for cell transplantation. These microspheres dramatically improve engraftment of exogenously delivered cells and functional recovery of the infarcted hearts. Intriguingly, the efficacy of cell engraftment appears to correlate with the cell carrier’s ability to maintain the acetylation status of the cells.

We expect that the combined HDAC inhibitor treatment with cell carrier-mediated CM transplantation will work synergistically to regenerate infarcted heart functioning and lead to effective clinical applications in heart regeneration therapy.
Abstract 349: Sall4 Blocks Cardiac Trans-differentiation but Stimulates Cardiac Stem-like Cell (iPSC) Generation and Improve Post MI Function In Vivo
Authors: Yang Lina , Pinnamaneni Pratap , Gao Hong , Sanagasetti Deepthi , Singh Vivek , Mathison Megumi , Rosengart Todd , Yang Jianchang
Published: February 2019

Background:
Sall4 is an essential component in maintaining embryonic stem cell self-renewal and pluripotency. Given its functional and protein level interaction with cardiac trans-differentiation factors Tbx5/Gata4, as well as its critical role in modulating embryonic cardiac development, we hypothesized that Sall4 may play an important role in cardiac reprogramming.

Material/Method:
We conducted gain- and loss- of function studies on neonatal and adult cardiac fibroblast from both mouse and rat. We also evaluated Sall4 function on infarcted rat heart.

Results:
Gata4/Mef2c/Tbx5 (GMT) administration markedly upregulated mRNA expression levels of stem factors including
Sall4
,
Bmi1
, and
p63
, while inhibition of Sall4 largely enhanced GMT- mediated Cardiac troponin T (
cTNT
) induction. Conversely, overexpression of Sall4 plus Gata4/Mef2C in cardiac fibroblast for 7 days induces over 30-fold increase of
Oct4
and
Nanog
by real-time PCR; longer culture induced rapidly-dividing iPSC-like clusters in both neonatal mouse and adult rat cardiac fibroblasts. Further tests showed that these iPSC-like cells were partially positive in alkaline phosphatases staining, capable of forming cardiosphere and differentiating into various cell types. Sall4 delivery also improved post-infarct cardiac function to a level that is comparable with Gata4 in rat.

Conclusion:
These results suggested that Sall4 is a promising target for cardiac reprogramming even though further characterization in vitro as well as in vivo is needed.
Abstract 350: Human Cardiac Fibroblasts Have Angiogenic Inhibitory Phenotypes Through Their Expressing Lypd1 In Vitro
Authors: Matsuura Katsuhisa , Masuda Shinako , Shimizu Tatsuya
Published: February 2019

Bioengineered cardiac tissues are expected to use for regenerative medicine and tissue model, and tissue vascularization is necessary for fabricating three dimensional thickened cardiac tissues. Consistent with the evidence that fibroblasts are major component cells in heart, they are also imperative for fabricating bioengineered cardiac tissues. Although fibroblasts exist in many tissues and organs, tissue-specific phenotypes of fibroblasts remain unclear, which might make it difficult to fabricate bioengineered tissues close to the biological tissues. As bioengineered tissues provide the micromilieu for mutual communication among multilineage cells, we attempted to identify cardiac fibroblast-specific function against endothelial cells in comparison with dermal tissue-derived fibroblasts and the underlying mechanisms. When human atrial or ventricular cardiac fibroblasts (NHCFa or NHCFv) and dermal tissue-derived fibroblasts (NHDF) were co-cultured with various types of human endothelial cells including HUVEC for 3 days, NHCFa and NHCFv, but not NHDF, significantly inhibited CD31 positive endothelial cell network formation (NHCFa: 1.3±0.3, NHCFv: 2.3±0.1, NHDF: 4.6±0.7, n=3, p<0.05). Then we hypothesized that cardiac fibroblasts express angiogenesis inhibitory factors. We identified genes that were highly expressed in cardiac fibroblasts and encoded extracellular proteins through microarray analysis. After evaluating the effects of candidate genes on endothelial cell network formation by siRNA transfection to cardiac fibroblasts, Ly6/Plaur domain-containing 1 (LYPD1) was identified as the responsible factor. Next we generated recombinant LYPD1 (rLYPD1) and elucidated the effect of rLYPD1 on angiogenesis. Robust endothelial cell network formation in co-culture with NHDF was attenuated with the treatment with rLYPD1 and endothelial tube formation on Matrigel was also remarkably inhibited in the presence of rLYPD1, suggesting that LYPD1 has an angiogenesis inhibitory function. These findings indicate that human cardiac fibroblasts have angiogenesis inhibitory phenotypes through LYPD1 in vitro and inhibition of LYPD1 will be necessary for fabricating vascularized bioengineered cardiac tissues.
Abstract 351: Methylglyoxal Increases mTOR Activity Without Altering Autophagy in Animal Model of Acute Myocardial Infarction
Authors: Machado Alessandra , Fracasso Bianca , Rangel Juliana , Pinto Graziela , Medeiros Niara , Breidenbach Mariana , Caetano Daniel , Rohde Luiz , Biolo Andreia , Andrades Michael
Published: February 2019

Methylglyoxal (MG) is a highly reactive small carbonyl that generates Advanced Glycation End-products (AGEs) and both compounds are increased during diabetes, myocardial infarction (MI), and in inflammatory diseases. MI can trigger autophagy, a mechanism of cellular recycling that generates energy in situations of nutrient deprivation. However, the benefit of autophagy when stimulated in the presence of AGEs is still not clear. Therefore, the objective of this study was to evaluate the role of methylglyoxal in the activation of autophagy and on cardiac remodeling. To this, 90 male Wistar rats were randomized into Sham, MI, and MI pretreated with MG (7 days, 75 mg/kg/day, twice a day) or rapamycin (24 and 4 hours, 8 mg/kg). Echocardiography was performed by a blinded researcher 24 hours after the surgery and soon after the animals were killed and samples were prepared for western blot. MG treatment did not increase AGEs in the heart tissue or impair ejection fraction, fractional shortening, and chamber remodeling assessed 24 hours after the MI. However, it caused a 9-fold increase in mTOR activation (p=0.02) without changing the content of autophagy related proteins (LC3II/I ratio and p62). Curiously, Rapamycin, a known activator of autophagy, did not prevent heart remodeling. In conclusion, the glycating agent MG given before MI increases mTOR signaling without affecting autophagy and does not alter cardiac remodeling. Financial support: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Fundação de Incentivo à Pesquisa do Hospital de Clínicas de Porto Alegre (FIPE-HCPA), and Fundo de Amparo à Pesquisa do RS (Fapergs).
Abstract 355: A Systematic Review of Medication Adherence Interventions for Heart Failure Patients
Authors: de Tantillo Lila , Gonzalez Juan M , Ortega Johis
Published: February 2019

Background:
Heart failure (HF) is a leading cause of death in the United States and the world. Patients experience substantially reduced longevity and quality of life. Although treatments are available to slow disease progression, medication adherence is necessary. Previous research has explored interventions to increase adherence for HF patients, yet barriers to medication adherence remain.

Objective:
This systematic review examined articles describing adherence interventions among HF patients. The World Health Organization’s model of Adherence to Long-Term Therapies, developed with patients with chronic illnesses, was used as a conceptual framework. The model describes barriers to adherence as grouped into five factors:
patient factors
,
therapy-related factors
,
condition-related factors
,
social/economic factors
, and
health care/system factors
.

Methods:
A search was conducted in databases CINAHL, PubMed and Scopus to identify interventional studies comprised exclusively of patients diagnosed with HF and their families. Inclusion criteria for articles were evaluation and reporting of adherence as an outcome. Interventions were then considered in context of the WHO factor or factors addressed.

Results:
This review identified 24 articles meeting inclusion criteria. Of these, all 24 addressed
patient factors
, 17 discussed
therapy-related factors
, 11 addressed
condition-related factors
, 15 addressed
social/economic factors
, and 15 addressed
healthcare/system factors
.

Discussion:
Every intervention in the review examined
patient factors
of beliefs and behaviors. However, no intervention considered the
therapy-related
factor of the immediacy of benefit. Among
condition-related factors
, none of the interventions addressed the role of fatigue. The limited examination of the relationship of race and ethnicity (
social/economic factors
) on adherence was surprising, as previous research has linked these factors to adherence.

Conclusions:
Categorizing adherence interventions by WHO factors is useful to evaluate the scope of previous research. More work is needed to identify how
therapy-related
,
condition-related
and
social/economic
factors among HF patients can be incorporated into future adherence interventions.
Abstract 361: Analysis of Cardiotoxic Mechanisms Associated With Tyrosine Kinase Inhibitor Ponatinib
Authors: Singh Anand P , Glennon Michael S , Umbarkar Prachi P , Gupte Manisha , Galindo Cristi L , Zhang Qinkun , Force Thomas , Becker Jason R , Lal Hind
Published: February 2019

Background:
Ponatinib, a potent pan-BCR-ABL tyrosine kinase inhibitor (TKI) holds significant promise in the treatment of chronic myelogenous leukemia (CML), although the potential cardiotoxicity of this agent remains a concern. In order to overcome ponatinib associated cardiotoxicity, delineation of linked cardiotoxic mechanisms and potential rescue methods are urgently warranted.

Objectives:
The objectives of the present study were to delineate the signaling mechanisms responsible for ponatinib-induced cardiotoxicity and to identify the potential rescue strategies.

Methods:
In this study, we employed direct
in vivo
drug screening in zebrafish for the prediction of cardiotoxicity. We also exploited neonatal rat ventricular myocytes (NRVMs) to explore cardiotoxic mechanism associated with ponatinib.

Results:
We observed that ponatinib leads to cardiomyocyte apoptosis, elevation in BNP level, decrease in heart rate and fractional shortening leading to cardiac dysfunction in Zebrafish. Consistently, in cultured rat cardiomyocytes, ponatinib was found most cytotoxic drug among all the approved CML TKIs. Mechanistically, ponatinib inhibits the essential prosurvival AKT and ERK signaling pathway, resulting to cardiomyocyte apoptosis. Interestingly, we evaluated the cardioprotective effects of Neuregulin-1β to limit ponatinib toxicity. Neuregulin-1β treatment significantly protects ponatinib-induced cardiotoxicity by supplementing the essential cardiomyocyte prosurvival AKT/ERK signaling pathways. Additionally, the allosteric tyrosine kinase inhibitor asciminib depicts less pronounced cardiotoxic effects than ponatinib in similar settings.

Conclusions:
This study will advance our mechanistic understanding of ponatinib-induced cardiotoxicity, accelerate the discovery of cardioprotective strategies to prevent and rescue the ponatinib-induced cardiotoxicity. Furthermore, this study suggests asciminib as an alternate treatment option than ponatinib for patients suffering from CML with T315I “gatekeeper” mutation.
Abstract 363: The Brain - Pancreas Axis: An Alzheimer Nanoplaque Study
Authors: Siegel Guenter , Hammersen Stephanie , Becker Angela , Georgescu Dan , Lubitz Irit , Ermilov Eugeny , Malmsten Martin , Saunders Ramsey , Lindman Björn
Published: February 2019

Background:
The central-nervous regulation of blood glucose occurs purely neuroendocrine via the hypothalamus-hypophysis-adrenal cortex system. In this control loop, insulin is the adjustable and glucose the controlled variable.

Methods:
Ellipsometry, photometric methods and ELISAs were applied. Intracellular membrane potential and tension were recorded from human intracerebral arteries of consciousness areas.

Results and discussion:
Despite multiply feedback coupled and safeguarded control loops for maintenance of a constant blood glucose level, 4.7% of the world population suffered from diabetes mellitus (T2DM) in 1980 and already 8.5% in 2014. In parallel, the risk for cardiovascular (heart attack, stroke) and Alzheimer diseases (AD) has risen by a factor of four to eight. In ellipsometry measurements with polyanionic heparan sulfate proteoglycan (HS-PG), VLDLapoE4/E4 and IDLapoE4/E4, β-amyloid (1-42) and Ca
2+
-ions, we could show that non-enzymatic glycation of these substances leads to an Alzheimer nanoplaque formation increased by 20-30%. Since the viscoelastic polyelectrolyte HS-PG serves not only as lipoprotein receptor but also as blood flow sensor, we recorded with the same glycation a flow-dependent dilatation reduced by up to 80% in human brain arteries
ex vivo
(from neurosurgery) which express HS-PG in endothelial and smooth muscle cell membranes. The resulting O
2
-deficiency with certainty entails neuronal cell death. Postprandial, blood glucose levels can appear as were experimentally applied here.

Conclusion:
Also short-term distinctly increased blood glucose concentrations in apoE4 carriers can explain neuronal cell death like in AD.
Abstract 365: Potential Relationship Between Nitric Oxide Bioactivity And Kidney Function Following Cardio-pulmonary Bypass
Authors: Moyal Andrew J , Hausladen Alfred , Nazemian Ryan , Zhu Lin , Pacheco Colon Edwin , Reynolds James
Published: February 2019

Background:
Impaired kidney function is frequently observed in heart surgery patients following cardio-pulmonary bypass. Previous studies by our group have linked acute reductions in nitric oxide bioactivity, specifically declines in the main regulator of tissue blood flow S-nitrosohemoglobin (SNO-Hb), to reductions in kidney oxygenation and blood flow and subsequent renal impairment. For the current study, we hypothesized that components of the bypass procedure (viz. transfusion and red blood cell trauma) would reduce circulating SNO-Hb levels with the magnitude of this reduction correlating with markers of kidney function and patient outcome.

Methods:
After obtaining written informed consent, blood samples were obtained before and during bypass and on post-operative day (POD) 1. In addition to quantifying SNO-Hb samples were analyzed for change in kidney function (estimated glomerular filtration rate; eGFR), and plasma erythropoietin (EPO) concentration. Status and outcome data were secured from the patients’ medical record.

Results:
In the patients studied to date (n=30), there was a significant decline in SNO-Hb concentration by POD 1, the level of which inversely correlated with ICU stay (R=-0.32). In addition, there was a direct correlation between SNO-Hb and eGFR on PODs 1 & 2 (R=0.48 and 0.30, respectively), i.e. lower SNO-Hb tracked with reductions in kidney function. Consistent with a presumed reduction in kidney oxygenation, we observed a significant rise in plasma EPO levels when coming off pump that were sustained into POD 1. Furthermore, the rise in EPO was inversely correlated with both SNO-Hb (R=-0.53) and eGFR (R=-0.55).

Conclusion:
CPB decreases SNO-Hb and is associated with kidney dysfunction and worse patient outcome (e.g. increased ICU stay). While the mechanism for this decline remains to be determined, the results suggest that therapies directed at maintaining or increasing NO bioactivity could improve outcome in adult cardiac surgery patients.
Abstract 372: Master Transcriptional Regulators of Cardiac Gene Expression in Heart Failure
Authors: Rau Christoph D , Wang Jessica , Ohearn James , Avetisyan Rozeta , Lusis Aldons J , Wang Yibin
Published: February 2019

Background:
Heart failure (HF) is characterized by complex transcriptional networks that direct the heart from a healthy to diseased state. Although some contributing genes have been identified through molecular biology and GWAS, heritability studies suggest that many genes have resisted discovery through these approaches. Identifying connective regulatory loci, especially master transcriptional regulators that affect the expression of many genes, offers a promising means of discovering novel relevant genes that have not been detected with other methods.

Methods and Results:
Transcriptional regulators of HF were identified using nine-week-old female mice from 93 lines of the Hybrid Mouse Diversity Panel. Mice received 30 ug/g/day of isoproterenol (ISO) for 3 weeks to induce cardiac dysfunction. Transcriptomes were generated from left ventricles of these mice along with age-matched controls. Expression Quantitative Trait Loci (eQTLs) for 13,156 transcripts were identified using a mixed model in three conditions (control, treated, delta). Suggestive (P<1E-4) eQTLs were sorted into 500kb bins tiled across the genome to identify loci that regulate a significant number of transcripts. Ten hotspot loci that regulate over 5% (658 of 13156) of expressed genes were identified, several of which contain genes with known roles in HF, including
Drosha
,
Akap5
and
Dicer1
. Several novel regulators were also identified, including the Serine Proteinase Inhibitor,

Serpina3n
,

which resides in a locus that regulates the change in expression of 9.7% (1276 of 13156) of all genes and is strongly correlated with changes in heart weight after ISO treatment. In subsequent
in vitro
work,
Serpina3n
knockdown resulted in reduced cellular hypertrophy, changes to hypertrophy-related gene expression, and modulation of the expression of several genes linked to its locus.

Conclusion:
GWAS performed on over 20,000 transcripts in control and ISO-treated hearts identified 10 genomic loci that regulate over 5% of the expressed genes in the heart.
Serpina3n
is a novel master regulator of HF. Further analysis of other master regulatory loci will reveal additional genes and improve our understanding of the transcriptional networks that direct the progression towards heart failure.
Abstract 374: Gpr68 Senses Blood Flow and is Essential for Vascular Physiology
Authors: Xu Jie , Mathur Jayanti , Vessieres Emilie , Hammack Scott , Nonomura Keiko , Favre Julie , Grimaud Linda , Petrus Matt , Francisco Allain , Li Jingyuan , Lee Van , Xiang Fu-li , Mainquist James , Cahalan Stuart , Orth Anthony , Walker John , Ma Shang , Lukacs Viktor , Bordone Laura , Bandell Michael , Laffitte Bryan , Xu Yan , Chien Shu , Henrion Daniel , Patapoutian Ardem
Published: February 2019

Mechanotransduction plays a crucial role in vascular biology. One example of this is local regulation of vascular resistance via flow-mediated vasodilation (FMD). Impairment of this process is a hallmark of endothelial dysfunction, and a precursor to a wide array of vascular diseases such as hypertension and atherosclerosis. And yet, the molecules responsible for sensing flow (shear stress) within endothelial cells remain largely unknown. We designed a 384-well screening system that applies shear stress on cultured cells. We identified a mechanosensitive cell line that exhibits shear stress-activated calcium transients, screened a focused RNAi library, and identified GPR68 as necessary and sufficient for shear stress responses. GPR68 is expressed in endothelial cells of small diameter (resistance) arteries. Importantly, Gpr68-deficient mice display markedly impaired acute FMD and chronic flow-mediated outward remodeling in mesenteric arterioles. Therefore, GPR68 is an essential flow sensor in arteriolar endothelium, and is a critical signaling component in cardiovascular pathophysiology.