bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 423: Cardiomyocyte-Specific Epidermal Growth Factor Receptor Deletion Differentially Alters Cardiac Contractility and Remodeling During Physiologic versus Pathologic Development
Authors: Guo Shuchi , Lambert Jonathan , Song Jianliang , Carter Rhonda , Lucchese Ana Maria , Gao Erhe , Cheung Joseph , Elrod John , Tilley Douglas
Published: February 2019

Epidermal Growth Factor Receptor (EGFR), a member of the Erbb receptor tyrosine kinase family, is essential to the development of multiple tissue and organs. Due to the embryonic lethality of global EGFR deletion, the impact of EGFR signaling in the adult heart, normally or in response to pathological stimuli, has not been well-explored. Using recently attained mice with floxed EGFR alleles crossed with αMHC-Cre mice, we have generated a cardiomyocyte-specific constitutive EGFR knockout mouse model (CM-EGFR KO) to address its role in the heart. Compared to their wild-type (WT) littermate controls, CM-EGFR-KO mice displayed age-related development of cardiac dysfunction and remodeling, occurring between 7 and 9 weeks of age, as monitored via echocardiography and immunohistochemistry analyses. Although contractile responsiveness to β-adrenergic receptor stimulation was unaffected by EGFR deletion, RNASeq analysis of CM-EGFR-KO hearts within this timeframe revealed alterations in myofilament protein expression profiles. Additionally, there was enhanced cardiomyocyte death in the 7-9 week window of development, which persisted to 10 months of age, at which time the CM-EGFR KO mice had progressively worsened cardiac function, dilation and cardiomyocyte loss. To investigate the impact of cardiomyocyte-specific EGFR deletion on the response to pathologic stress, we challenged 12-14 week old WT and CM-EGFR KO mice with chronic isoproterenol infusion. Notably, while chronic isoproterenol treatment diminished cardiac function and induced hypertrophic remodeling in WT mouse hearts, CM-EGFR-KO mouse hearts displayed progressively improved contractility and ablated hypertrophy over time, suggesting that EGFR differentially regulates cardiac function and remodeling processes during physiological versus pathological development.
Abstract 440: The Cardiomyocyte Diastolic Stiffness and Contractility are Inversely Related to the Size of Titin: A Cellular Work Loop Study of Single Intact Cardiomyocytes
Authors: Methawasin Mei , Strom Joshua , Helmes Michiel , Granzier Henk
Published: February 2019

Studying cardiac titin under physiological conditions can be at the level of the left ventricular (LV) chamber and the multicellular muscle level. However, those preparations are influenced by neurohormonal reflex, preload-afterload status and extracellular matrix. In this study, cellular work loop force measurement of the single intact cardiomyocyte was conducted under physiological conditions. Intact cell experiments were performed at 37°C under field-stimulation at 2 Hz frequency. The cell was attached to the force transducer and the piezo length controller which modulates the cell length by the feedback control system based on developed force. The force length relation (cellular work loop) of the single cell was generated. The end diastolic force length relation (EDFLR), the end systolic force length relation (ESFLR) and the preload recruitable stroke work (PRSW) were obtained. The

Ttn
ΔIAjxn

-/-
(
IA
-/-
) mice, in which the I-band/A-band region of titin’s spring has been deleted were studied in comparison to
α-MHC-Cre
;

cRbm20
ΔRRM +/-

(

cRbm20
+/-

) mice which are deficient in titin splicing and express large titin isoforms in the heart. The cellular diastolic stiffness (slope of EDFLR) was increased in
IA
-/-
and was reduced in

cRbm20
+/-

(151.3, 104.0 and 91.5 μN/mm
2
in
IA
-/-
, WT and

cRbm20
+/-

respectively). The contractility (slopes of ESFLR and PRSW) were 233.5 and 1215.6 uN/mm
2
in WT, and were increased in
IA
-/-
(371.2 and 2076 μN/mm
2
) but attenuated in

cRbm20
+/-

(202.9 and 907.7 μN/mm
2
). Cellular work loop studies were also conducted in intact cells isolated from the mice that underwent transverse aortic constriction (TAC) surgery with deoxycorticosterone acetate (DOCA) implantation. TAC DOCA mice developed diastolic dysfunction at the LV chamber level. The result showed that the cells from TAC DOCA hearts had increased slopes of EDFLR, ESFLR and PRSW ( 157.9, 378.9 and 1699.0 μN/mm
2
) compared to the cells from sham mice (98.6, 230.3, and 1203.9 μN/mm
2
).

Conclusions:
Cellular work loops recapitulated the cardiac physiology at the LV chamber level. The result showed that the cellular diastolic stiffness and contractility were inversely related to the size of titin and that titin stiffness plays an important roles in both diastolic and systolic function.
Abstract 465: Short Term Hypoxia Can Induce Adult Feline Cardiomyocytes to Re-enter the Cell Cycle and Divide
Authors: Johnson Jaslyn , Gross Polina , Berretta Remus , Kubo Hajime , Mohsin Sadia , Houser Steven R
Published: February 2019

Rationale:
The mammalian adult heart has a very limited capacity to regenerate cardiomyocytes that die from pathological damage. Most recent studies suggest that those few new myocytes found after injury are derived from pre-existing cardiomyocytes. A recent study in mice suggest that systemic hypoxemia in adult animals can induce cardiac myocyte cell cycle reentry and myocyte proliferation. In the present experiments we evaluate the ability of adult feline cardiomyocytes to reenter the cell cycle and proliferate in hypoxic environments.

Hypothesis:
To determine if hypoxia induces adult feline cardiomyocytes to regenerate.

Methods and results:
Adult ventricular cardiomyocytes were isolated from adult felines and maintained in culture. For acute hypoxia, cultures were placed in a hypoxic chamber on day 1, 3, 5, 7, 10, or 14 following isolation and subjected to 1% O
2
, 5% CO
2
, and the balance was N
2
for 24 hours. For chronic hypoxia, adult cardiomyocytes were subjected to 1% O
2
, 5% CO
2
with the balance of N
2
at day 1 after isolation and kept at continuous hypoxia for 3, 5, 7, 10, or 14 days. Prior to hypoxia, cells were treated with 10uM EdU to identify new DNA in cardiomyocytes. Acute hypoxia was shown to promote cell division in cardiac myocytes at all time points except at day 1 post isolation when compared to control cultures. However, chronic hypoxia caused cardiomyocyte damage and increased cell death in all time points as compared to control and acute hypoxia cultures.

Conclusion:
Short term hypoxia can induce adult feline cardiomyocytes to proliferate, while long term exposure leads to injury and apoptosis.
Abstract 468: Mitochondrial Dysfunction and Senescence of Human Cardiac Progenitor Cells Are Prevented by Hypoxic Culture
Authors: Kubli Dieter A , Korski Kelli I , Sussman Mark A
Published: February 2019

Rationale:
Therapeutic potential of c-Kit
+
cardiac progenitor cells (CPCs) is modest in autologous cell therapy clinical trials and could benefit from optimization to maximize functional activity. Early proliferation arrest limits expansion potential of human CPCs
in vitro
. In contrast, self-renewal is preserved and mitochondrial reactive oxidative species (mtROS) minimized within the CPC hypoxic niche
in vivo
. Expansion under oxygen tension comparable to the hypoxic niche may therefore improve CPC reparative function.

Hypothesis:
Senescence of CPCs derived from heart failure patients is suppressed by dampening mtROS through long-term hypoxic culture.

Methods and Results:
Environmental oxygen was maintained with constant hypoxia (1% O
2
; H-CPCs) or atmospheric oxygen tension (20 - 21% O
2
; N-CPCs) for isolation and expansion of CPCs from patients undergoing left ventricular assist device implantation. A 4-fold increase in clonogenesis and 73% fewer senescence-associated β-Gal-positive cells were found in H-CPCs. Oxidative stress and DNA damage were also reduced with 80% lower malondialdehyde content and significantly fewer nuclear γ-H2AX foci in H-CPCs. Accumulation of dysfunctional mitochondria was revealed in N-CPCs through functional metabolic analyses. Basal (-59%), maximal (-50%), and ATP production-coupled (-62%) oxygen consumption rates were significantly lower in N-CPCs, despite upregulation of electron transport chain subunits and 72% greater mitochondrial DNA content than H-CPCs. MtROS was elevated, and large mitochondria with swollen morphology were found by TEM in N-CPCs, confirming mitochondrial damage. Key indicators of mitochondrial function including NAD
+
/NADH ratio and autophagic flux were preserved in H-CPCs.

Conclusions:
Development of mitochondrial dysfunction and senescence are consequences of normoxic CPC expansion. CPC senescence is delayed by preserving mitochondrial health and limiting oxidative damage through hypoxic culture.
Abstract 470: Gata4, Mef2c and Tbx5 More Efficiently Transdifferentiate Endothelial Cells into Cardiomyocyte-like Cells Through Endothelial-Mesenchymal Transition Process
Authors: Sanagasetti Deepthi , Singh Vivek P , Pinnamaneni Jaya Pratap , Pugazenthi Aarthi , Jang Anna , So Davis , Kim Mary , Yang Lina , Wang Kai , Yang Jianchang , Mathison Megumi , Rosengart Todd K
Published: February 2019

Background:
The cardiac transcription factors Gata4, Mef2c, and Tbx5 (GMT) have been used to successfully reprogram cardiac fibroblasts into induced cardiomyocyte-like cells (iCMs). However their effects on other cell types remain largely unknown. Endothelial cells are an important population of the heart by Pinto et al. (2016). Given the more profound iCM induction effects observed in vivo, we have speculated that reprogramming of endogenous endothelial cells may also play an important role.

Purpose:
To investigate the cellular reprograming effects and mechanisms of GMT factors on cardiac endothelial cells and compare the outcomes with that from cardiac fibroblasts.

Methods:
Adult rat cardiac endothelial cells (REC) and cardiac fibroblasts (RCF) were purchased commercially. The cells were cultured in appropriate media and infected with GMT-expressing lentivirus and maintained with iCM media. Fourteen days later Immunofluorescence staining, FACS, and qRT-PCR were performed.

Results:
Both GMT treated RCFs and RECs showed positive staining of cardiac marker cTnT and αActinin-positive cells via immunofluorescence staining. FACS analysis showed GMT treated RECs had 16.7% of cTnT positive cells versus 3.3% in GMT treated RCF’s. qRT-PCR results demonstrated significant up-regulation of cTnT in GMT infected RECs (74.4±23.3 times, p<0.05) as compared to the control group. Similar upregulation of cTnT was observed in RCFs but to a lesser degree (16.1±7.2 times, p=NS). Moreover, RECs presented a significant change in cell morphology from rounded cells in a cobblestone arrangement to elongated spindle-shaped cells during 14 days culture. In addition, qRT-PCR analysis demonstrated that endothelial-mesenchymal transition (EndoMT) markers such as Slug, Snail, Oct4, and αSMA were upregulated in the cells with GFP encoded virus infection and those markers were downregulated in the GMT-treated RECs (p<0.01 for Snail, p<0.05 for Slug, and αSMA).

Conclusion:
This report suggests that RECs are susceptive to GMT induced cardiac reprogramming than in RCFs. Our study also indicate that EMT and MET sequential process are involved in the reprogramming of RECs toward iCM cells. RECs could be targeted towards iCM generation for a higher reprogramming rate.
Abstract 487: Arginine Methylation Through PRMT5 Mediates Energy Stress-Induced Autophagy in the Heart
Authors: Mukai Risa , Saito Toshiro , Zhai Peiyong , Sadoshima Junichi
Published: February 2019

Autophagy is a mechanism of bulk degradation of organelles and proteins that protects cells against stress by maintaining cellular homeostasis. Although autophagy is known to be an adaptive mechanism against stress, how autophagy is activated in cardiomyocytes (CMs) during stress is not fully understood. The ATG proteins, which are required for autophagy, are modulated by post-translational modifications (PTMs) such as phosphorylation, ubiquitination, and acetylation. The level of arginine methylation, another form of PTM, is altered in the heart in response to stress. However, the role of arginine methylation in regulating autophagy is poorly understood in CMs. We postulated that arginine methylation may play an important role in the regulation of autophagy. The level of arginine methylation was significantly increased (1.52-fold, p<0.05) in CMs subjected to glucose deprivation (GD) for 6 hours compared to those without GD. Expression of protein arginine methyltransferases (PRMTs), including PRMT5, was also increased at both the mRNA and protein levels (1.6- and 1.72-fold, p<0.05) in the mouse heart in response to 48 hours of starvation. Energy stress-induced autophagy, as evaluated with LC3-II and p62, was inhibited when PRMT5 function was downregulated. Increased arginine methylation was also observed in the mouse heart in response to 1 hour of myocardial ischemia (1.87-fold, p<0.01), which was accompanied by upregulation of PRMT5 (1.54-fold, p<0.05). These results suggest that arginine methylation mediated through PRMT5 may play an important role in mediating autophagy during energy stress, such as starvation and ischemia, in the heart.
Abstract 489: Ex vivo Porcine Coronary Artery Remodeling With Seeded Endothelial Cells
Authors: Kural Mehmet H , Li Guangxin , Wang Juan , Dai Guohao , Niklason Laura E , Gui Liqiong
Published: February 2019

Coronary heart disease is the most common cardiovascular problem that causes 370,000 deaths in America annually. Replacing the diseased coronary artery with a conduit obtained from another part of the patients’ body is the gold standard for the current surgical interventions. The great saphenous veins are widely preferred as coronary bypass grafts since they are easy to harvest and can replace multiple arteries due to their abundance. However, the endothelial cells in saphenous vein lose their venous characteristics and cannot function properly, which causes frequent graft failure. Conversely, arterial grafts have higher patency rate due to better function of endothelium. Yet, arterial grafts are not abundantly available as saphenous veins. Tissue engineered blood vessels can potentially serve as an ample source for bypass conduits. However, small-diameter engineered vessels are also tending to fail without a healthy endothelium. Here we propose to investigate the potential of Sox17-overexpressing endothelial cells in the vessel lumens to prevent intimal hyperplasia. Sox17 expression leads to upregulation of arterial, anti-thrombotic and anti-inflammatory markers in endothelial cells. We used an ex-vivo porcine coronary artery model where we cultured the vessels in perfusion bioreactors to mimic arterial flow conditions. Our preliminary results show that the vessel wall injury, seeded endothelial cells and arterial shear acted synergistically on smooth muscle cell death in the media layer (Fig. 1). The present ex vivo vessel culture platform is a promising tool to study remodeling by isolating factors like endothelial cells, soluble and mechanical factors.
Abstract 490: Enhanced Therapeutic Effects of MSC-derived Exosomes with an Injectable Hydrogel for Hindlimb Ischemia Treatment
Authors: Li Zongjin , Zhang Kaiyue , Zhao Xiangnan , Kong Deling , Zhao Qiang , Liu Na , Ma Fengxia
Published: February 2019

Mesenchymal stem cell (MSC)-derived exosomes have been recognized as new candidates for cell-free treatment of various diseases. However, maintaining the retention and stability of exosomes over time
in vivo
after transplantation is a major challenge in clinical application of MSC-derived exosomes. Here, we investigated if human placenta-derived MSCs (hP-MSCs) derived exosomes incorporated with chitosan hydrogel could boost the retention and stability of exosomes and further enhance their therapeutic effect. Our results demonstrated that chitosan hydrogel notably increased the stability of proteins and microRNAs in exosomes, as well as augmented the retention of exosomes
in vivo
as confirmed by
Gaussia
luciferase imaging. In addition, we evaluated the therapeutic function of hP-MSCs derived exosomes incorporated with chitosan hydrogel in a murine model of hindlimb ischemia. Our data demonstrated that chitosan hydrogel could enhance the retention of exosomes and further augment the therapeutic effects for hindlimb ischemia as revealed by firefly luciferase imaging of angiogenesis. The strategy used in this study may facilitate the development of easy and effective approaches for assessing and enhancing the therapeutic effects of stem cell-derived exosomes.
Abstract 491: Cardiomyocyte Braf Promotes Hypertrophy and is Required for Hypertrophic Adaptation to Hypertension in Mice In Vivo, but Raf Inhibitors Have Differential Effects
Authors: Meijles Daniel N , Rostron Kerry A , Fuller Stephen J , Sugden Peter H , Clerk Angela
Published: February 2019

Introduction:
Raf kinases lie upstream of ERK1/2 with BRaf having the highest activity. ERK1/2 promote hypertrophy/cardioprotection, but the role of BRaf in the adult heart is unclear. BRaf mutations cause cancer and Raf inhibitors (Rafi) are used but, paradoxically, they can activate ERK1/2 and the cardiac consequences remain to be established.

Hypothesis:
We hypothesise that BRaf is critical in regulating ERK1/2 signaling in cardiomyocytes and Rafi affect cardiac function.

Methods:
We studied 8 wk wild-type male C57Bl/6 mice, or mice with cardiomyocyte-specific tamoxifen-inducible knock-in of activating BRaf(V600E) or BRaf knockout (BRafKO). V600E and BRafKO mice received vehicle or tamoxifen (40mg/kg; 6-12 mice per group). Mice were also treated with 0.8 mg/kg/d AngII, 0.5 mg/kg/d SB590885 (SB), 3 mg/kg/d dabrafenib (Dab) or vehicle delivered by osmotic minipumps. Echocardiography was performed and data for each mouse were normalized to the mean of 2 baseline control scans. Kinase activities and mRNA expression were assessed by immunoblotting and qPCR.

Results:
Knockin of BRaf(V600E) activated ERK1/2 and increased expression of ERK1/2 dependent genes (24h). By 7 d, there was increased ejection fraction (24%) and cardiac output (17%) with increased systolic left ventricular (LV) posterior wall (PW) thickness (13%). Cardiac function normalised by 10 d, but there was significant hypertrophy with increased LVPW in systole/diastole (11-19%) and decreased LV internal diameter. BRafKO alone did not affect cardiac function/dimensions or changes in function induced by AngII, but loss of BRaf inhibited the increase in systolic/diastolic LVPW (30% increase with AngII alone vs 9% with AngII/BRafKO). SB (type I Rafi), but not Dab (type 1.5 Rafi) activated cardiomyocyte ERK1/2 and induced hypertrophy in cultured neonatal rat ventricular myocytes. Consistent with this, SB (not Dab) promoted cardiac hypertrophy in vivo with increased LVPW (3d), but Dab (not SB) inhibited AngII-induced hypertrophy (7 d).

Conclusions:
Activation of cardiomyocyte BRaf promotes cardiac hypertrophy and cardiomyocyte BRaf is required for AngII-induced hypertrophy. However, Rafi developed for cancer have differential effects on the heart according to their mode of action.
Abstract 515: Bariatric Surgery Reverses Vascular Pathology in Mice With Morbid Obesity and Type 2 Diabetes
Authors: Park Yoonjung , Wang1 Yong , Zhang Hanrui , Dellsperger Kevin D , Potter Barry J , Cao Ji-min , Zhang Cuihua
Published: February 2019

Objective:
The mechanism of improved insulin sensitivity and vascular function following bariatric surgery remains unclear. We assessed the role of bariatric surgery in coronary arteriolar function in murine type 2 diabetic mice.

Approach and Results:
The animals were randomly allocated into normal control (Lean) sham, Lean surgery, db/db sham, and db/db surgery (at 5, 10, 20 and 30 days post-operatively). Impaired vasodilation to acetylcholine (ACh) in db/db mice was partially restored by bariatric surgery. Ghrelin administration restored endothelium-dependent dilation in db/db mice, but surgery-induced restoration was disappeared by ghrelin antagonist. Additionally, the incubation of coronary arterioles with IL-6 prevented the restoration of ACh-induced vasodilation. Bariatric surgery attenuated plasma concentration and protein expression of IL-6 in db/db. Bariatric surgery increased protein expression of eNOS and SOD2 in db/db mice.

Conclusions:
Decreased IL-6 expression after bariatric surgery induce up-regulation of eNOS and SOD2, and down-regulation of iNOS and O
2
.−
, leading to restoration of endothelial function in coronary arterioles in type 2 diabetes.
Abstract 525: Recapitulating
in vivo
Fibroblast Differentiation Using a Hydrogel Cell Culture System
Authors: Fischesser Demetria
Published: February 2019

Acute
activation of cardiac fibroblasts as a result of heart failure characterized by cardiomyocyte loss is essential to maintaining proper cardiac structure and function.
Chronic
fibroblast activation, however, causes excessive fibrotic response leading to fibrosis and organ failure. The role of fibroblasts in this disease process has yet to be fully understood. Many previous
in vitro
studies have cultured fibroblasts on plastic, which can create an artificial tensile environment causing fibroblasts to behave differently than they do
in vivo.
To better understand fibroblast behavior, we used a hydrogel cell culture system wherein soft hydrogels mimic healthy heart tissue and stiff hydrogels mimic injured heart tissue. Another critical aspect of this system is an ability to change hydrogel stiffness for existing cultured fibroblasts. The activation of the smooth muscle α-actin (αSMA)-encoding gene (Acta2) and subsequent upregulation of its protein product correlate with fibroblast activation. Therefore, we looked at the induction of the αSMA promoter as well as the expression of αSMA protein. Here we show that stiffer hydrogels cause fibroblast activation more quickly when compared to fibroblasts plated on softer hydrogels. We also observed that on soft hydrogels, fibroblasts have smaller area with fewer branches that are longer compared to fibroblasts on stiff hydrogels. The increase in branch length along with a proclivity to migrate correlates with an increase in contact between fibroblasts on soft hydrogels not seen on stiff hydrogels. Additionally, RNA expression at various stages of differentiation will be compared to the RNA expression profile of injured and uninjured hearts previously collected in our lab. Collectively, these data will be used to classify fibroblasts into specific stages of activation and differentiation, as well as to generate a reliable
in vitro
model system to study fibroblast dynamics that more closely reflects their properties
in vivo
.
Abstract 539: MCUB Regulates the Macromolecular Composition of the Mitochondrial Calcium Uniporter Channel to Limit Mitochondrial Calcium Overload During Ischemic Cardiac Injury
Authors: Lambert Jonathan P , Luongo Timothy S , Jadiya Pooja , Gao Erhe , Lucchesee Anna M , Zhang Xueqian , Kolmetzky Devin W , Shah Neil , Elrod John W
Published: February 2019

The mitochondrial calcium uniporter channel (mtCU) resides in the inner mitochondrial membrane and is a multi-subunit complex required for mitochondrial Ca
2+
(
m
Ca
2+
) uptake. RNA-seq and PCR analysis of mtCU component expression revealed that
MCUB
expression increases after myocardial infarction. To investigate how
MCUB
, a paralog of the
MCU
gene, contributes to mtCU regulation we created a
MCUB
-/-
cell line (HeLa) using CRISPR-Cas9n.
MCUB
deletion increased histamine-mediated
m
[Ca
2+
] transient amplitude by ~50% vs. WT controls (mito-R-GECO). Biophysical characterization found
MCUB
deletion increased mtCU capacitance and rate of
m
[Ca
2+
] uptake. FPLC fractionation of mtCU revealed loss of MCUB increased MCU incorporation into the supercomplex, suggesting MCUB replacement of MCU and overall increase in functional mtCU supercomplexes. Next, we generated a cardiac-specific, tamoxifen-inducible MCUB overexpression mouse model (CAG-CAT-MCUB x MCM; MCUB-Tg) to examine how the MCUB/MCU ratio regulates mtCU function and cardiac physiology. MCUB-Tg mice were infected with AAV9-mitycam (mito genetic calcium reporter) and adult cardiomyocytes were isolated to record [
m
Ca
2+
] transients during pacing. Increasing the MCUB/MCU ratio decreased [
m
Ca
2+
] peak amplitude by ~30% and significantly reduced the [
m
Ca
2+
] uptake rate. FPLC assessment of the mtCU revealed
MCUB
was undetectable in the supercomplex fraction (~700kD) of Cre controls, but enriched in
MCUB
-Tg hearts. Examining the oxygen consumption rate of cardiomyocytes isolated from
MCUB-
Tg hearts found decreased maximal respiration and spare reserve capacity, which correlated with severe impairment in isoproterenol-induced contractile reserve. Mitochondria from
MCUB
-Tg mouse hearts were resistant to Ca
2+
induced mitochondrial swelling suggesting
MCUB
protects against permeability transition.
MCUB
-Tg mice subjected to myocardial ischemia reperfusion injury had a ~50% decrease in infarct size suggesting increased MCUB expression prevents
m
Ca
2+
overload and limits cell death. These data suggest that
MCUB
regulation of the mtCU is an endogenous compensatory mechanism to decrease
m
Ca
2+
overload during ischemic injury, but maladaptive in mitochondrial energetic responsiveness.
Abstract 540: Magnesium Improves Cardiac Diastolic Function by Modulating Mitochondria
Authors: Liu Man , Jeong Euy-Myoung , Xie An , So Eui Yong , Shi Guangbin , Jeong Go Eun , Zhou Anyu , Dudley Samuel C
Published: February 2019

Rationale:
A diet rich in saturated fat has been found to induce diabetes mellitus (DM) accompanied by myocardial mitochondrial dysfunction, insulin resistance, and magnesium (Mg) deficiency. The most prominent characteristic of diabetic cardiomyopathy is cardiac diastolic dysfunction (DD). Mg supplementation improves the heart rate variability and arterial elasticity in chronic heart failure. Recently, we have reported that mitochondrial reactive oxygen species (mitoROS) play a critical role in the progress of DD and diastolic heart failure. Therefore, we hypothesized that Mg supplementation would benefit diastolic function by improving mitochondrial function.

Methods and Results:
High fat diet (HFD)-induced diabetic mouse hearts showed cardiac DD with increased E/e’ (45±2 in DM mice vs. 32±2 in control mice), increased left ventricular diastolic volume (LVDV, 80±1 μL in DM vs. 61±4 μL in control), and increased incidence of DD (9 of 10 mice in DM vs 1 of 10 mice in control; P<0.05 for all). DM mice also showed decreased plasma Mg concentration (0.80±0.04 mmol/L in DM vs. 0.98±0.03 mmol/L in control, P<0.05). Ventricular cardiomyocytes isolated from DM mice exhibited decreased mitochondrial ATP production (75±11% of control), a 1.7±0.2-fold increase in mitoROS, significantly depolarized mitochondrial membrane potential, and mitochondrial Ca
2+
overload (3.7±1.3-fold; P<0.05 vs. control for all). Dietary Mg administration (50 mg/mL, ≈6-8 g/kg/day) for 6 weeks corrected all these parameters with increased plasma Mg concentration (1.5±0.1 mmol/L), improved cardiac diastolic function (E/e’ 37±1; LVDV 54±5 μL; LVPWT 0.77±0.02 mm; the incidence of DD, 2 of 10 mice; P<0.05 vs. DM for all). Mitochondrial function was improved significantly by Mg with increased ATP production, decreased mitoROS, repolarized mitochondrial membrane potential, and decreased mitochondrial Ca
2+
overload in DM mice.

Conclusion:
These results indicate that Mg supplementation improved mitochondrial function, reduced oxidative stress, and prevented diastolic dysfunction in DM.
Abstract 551: p22phox Protects the Heart Against Pressure Overload
Authors: Mizushima Wataru , Yang Yanfei , Zhai Peiyong , Sadoshima Junichi
Published: February 2019

Reactive oxygen species (ROS), including superoxide and hydrogen peroxide, play an important role in the stress response in the heart. p22phox is associated with Nox isoforms, thereby forming NADPH oxidase (NOX) complexes and generating ROS in various tissues, including the heart. However, the exact role of p22phox in cardiomyocytes remains to be elucidated. The level of p22phox protein in adult cardiomyocytes (ACM) isolated from mouse hearts subjected to transverse aortic constriction (TAC) for 1 and 4 weeks was significantly higher (150% and 250%, respectively) than in those from sham operated mouse hearts. In order to test the role of endogenous p22phox during TAC, we generated cardiac-specific p22phox knockout (p22phox cKO) mice. These mice did not have any significant cardiac phenotype at baseline. One week after TAC, p22phox cKO mice exhibited a lower left ventricular (LV) ejection fraction (LVEF) and higher lung weight (LW) and LV weight to tibia length (TL) ratios than control mice (LVEF: 64.3±4.3 vs. 46.4±4.8 %, LW/TL: 8.2±0.3 vs. 13.4±4.8, LV/TL: 6.0±0.5 vs. 7.5±0.4 p<0.05), indicating that endogenous p22phox plays a protective role against heart failure during the early phase of pressure overload (PO). Four weeks after TAC, p22phox cKO mice exhibited further deceases in LVEF and increases in LW/TL, and increased cardiac fibrosis compared to control mice (LVEF: 60.2±18.1 vs. 33.7±10.7 %, LW/TL: 13.1±7.2 vs. 26.2±4.3, relative fibrosis: 1±0.75 vs. 4.4±1.0 p<0.02). However, there was no significant difference in LV/TL or cardiomyocyte cell size between p22phox cKO mice and control mice, suggesting that cardiac hypertrophy is suppressed at the later stage of PO. These results indicate that endogenous p22phox is protective against PO and mediates compensatory cardiac hypertrophy during the late phase of PO.
Abstract 554: Mechanism of Action for the Beneficial Effects of Cortical Bone Stem Cells on the Heart After Myocardial Infarction
Authors: Schena Giana J , Kubo Hajime , Feldsott Eric , Berretta Remus , Mohsin Sadia , Houser Steven R
Published: February 2019

Rationale:
Myocardial infarction (MI) causes the death of a portion of the heart and can lead to adverse remodeling that results in poor cardiac pump function and heart failure. We have previously shown that a novel stem cell type, cortical bone stem cells (CBSCs), causes improved repair of cardiac tissue after MI. When injected into the infarct border zone in both mouse and pig hearts, CBSCs reduced infarct size and induced neovascularization via a largely paracrine manner.

Objectives:
This study investigates the mechanism involved in the angiogenesis alterations implemented by CBSCs, in particular the wound-healing of endothelial cells. Our goal was to comprehend how mCBSCs affected cardiac repair in an inflammatory environment.

Methods and Results:
We performed scratch assays and tubule formation (TF) assays on human umbilical vein endothelial cells (HUVECs) and cardiac endothelial cells (CECs) in mCBSC CM and media controls, and in the presence of pro-inflammatory cytokines such as IL-1β, IL-6, and TNF-α. Both HUVECs and CECs show reduced cell migration and reduced TF. TF was rescued when the cells were plated on Matrigel. We investigated the angiogenesis-related cytokines present within both the mCBSC CM and CM-treated HUVECs and CECs via angiogenesis dot blots. We discovered a significant increase of CXCL-10 and Endostatin/Collagen XVIII relative to murine embryonic fibroblast CM.

Conclusions:
Our findings show that part of the mechanism underlying the wound-healing and neovascularization induced by CBSCs post-MI involves secretion of angiogenesis-related cytokines which alter the behavior of cardiac endothelial cells.
Abstract 581: Determining the Nuclear Transcription Factor Network Controlling Expression of the Cardiac Inotropic Factor S100A1
Authors: Busch Martin , Adrian Lukas , Guenther Fabian , Dieterich Christoph , Katus Hugo A , Boerries Melanie , Most Patrick
Published: February 2019

Down-regulation of cardiac inotropic EF-hand calcium sensor protein S100A1 expression is a hallmark of human heart failure and drives progression and mortality. An AAV-S100A1 gene replacement therapy, which has been shown in preclinical models to rescue chronic heart failure, is in preparation for first clinical trials. However, the nuclear mechanisms that convey S100A1 gene locus silencing in the failing heart have not been determined yet. Given the steady increase of S100A1 expression in the developing heart until young adulthood and its decrease in the aged and failing heart, we developed a novel approach to decipher the mechanisms of S100a1 transcriptional regulation.

We performed serial RNAseq analyses in an in vitro cardiac differentiation model of H9c2 cells that displays robust concurrent S100A1 and e.g. sarcoplasmic reticulum calcium ATPase 2 (SERCA2a) mRNA and protein during differentiation. Potential transcription factors (TF) were derived by computational motif analysis from S100A1’s gene locus regulatory elements that delivered more than 200 candidates. Subsequent computational TF footprint binding motive analysis from all differentially expressed transcripts of the serial RNAseq data provided a smaller group of less than 30 putatively TF families in the cH9C2 model that is actively during the in vitro biological process.

Additional comparative TF expression analyses with developing rat hearts then enabled subtraction of a final TF group of 10 members for RNA interference screens in the cH9C2 model using S100A1 RNA expression as a read-out. Using a siRNA-mediated TF knock-down screen, we identified a small group of TFs such as zink finger and coiled-coil TFs (e.g. KLFs) and signal transducer and activator of transcription (STATs) TFs with an hitherto unknown ability to independently regulate S100A1 expression. Of note, other inotropic factors such as SERCA2a were found to be positively co-regulated by some of the TFs, such as KLFs, that enhance S100A1 expression. Further analyses were performed to confirm these results. In summary, we present a feasible computational filter and experimental strategy to identify relevant TF networks which we have successfully applied to identify cardiac regulatory networks.
A new combination in Sagotia (Euphorbiaceae) with an updated key for the genus
Authors: SECCO RICARDO DE S. , SILVA OTÁVIO LUIS MARQUES DA , CORDEIRO INÊS
Published: February 2019

A new combination in Sagotia, Sagotia heterocalyx, based on Sandwithia heterocalyx is herein proposed once this taxon shares more similarities with Sagotia (such as flowers without nectaries, the pistillate ones with calyx lobes united only near the base and thick styles, and staminate flowers with sessile to subsessile stamens) than with Sandwithia (whose flowers are provided with nectaries, the pistillate ones with calyx lobes united for more than half of their length and thin styles, and staminate flowers with conspicuous filaments).Comments on morphological affinities between Sandwithia and Sagotia and an updated key for identification of species of these two genera are also presented, along with the lectotypification of Sandwithia guyanensis.
A new rainbowfish (Teleostei: Melanotaenioidei: Bedotiidae) from the southeastern highlands of Madagascar, with comments on the biogeography of Bedotia
Authors: SPARKS JOHN S. , RUSH LEILA M.R.
Published: February 2019

Bedotia albomarginata, a new species of Malagasy rainbowfish, is described from forested habitats in the southeastern highlands of Madagascar. The new species is distinguished from congeners by the presence of broad white margins on the second dorsal fin and anal fin in males, a markedly lanceolate caudal fin in adult males, and in life, by a bright yellow to orangish-red anal fin in both sexes. Bedotia albomarginata is known only from small streams and swamps within the upper to middle reaches of the Mananara and Rienana river drainage basins.
Eurycleonus talamellii n. sp. of Cleonine weevil from the Moroccan desert (Coleoptera: Curculionidae: Lixinae: Cleonini)
Authors: MEREGALLI MASSIMO
Published: February 2019

Eurycleonus talamellii n. sp. is described. It is a taxonomic and geographic vicariant of E. gigas (Marseul 1868), from which it mainly differs by the body with less broadened elytra, the vestiture composed of mixed white and brownish scales in irregular patches, the rostrum nearly straight in profile, the antennae with slightly longer segments, the upper margin of the scrobe sinuate and nearly reaching the lower part of the eye. Remarks on ecology, biogeography and phylogenetic relationships are given.Kew words: Curculionidae, Eurycleonus, Eurycleonus talamellii, new species, taxonomy, biogeography, host plants, Morocco
New species of Middle Asian Longitarsus Latreille with discussion of their subgeneric placement (Coleoptera: Chrysomelidae)
Authors: KONSTANTINOV ALEXANDER S.
Published: February 2019

The subgenus Testergus Weise of Longitarsus Latreille is redefined based on the characters of male genitalia and four new species are described and illustrated: L. borisi sp. nov. (Tadzhikistan), L. danilevskyi sp. nov. (Kazakhstan), L. igori sp. nov. (Tadzhikistan), and L. nadiae sp. nov. (Kirgizstan). The lectotypes for L. fuscoaeneus Redtenbacher, L. tmetopterus Jacobson and L. nurataicus Palij are designated. A key to the known Testergus species from Greece, Caucasus and Middle Asia is provided.
The megisthanid mites (Mesostigmata: Megisthanidae) of Australia
Authors: SEEMAN OWEN D.
Published: February 2019

The Australian Megisthanidae are revised, resulting in the description of five new species from passalid beetles (Coleoptera: Passalidae) in Queensland: M. manonae sp. nov. from Mastachilus australasicus; M. simoneae sp. nov. from Mastachilus polyphyllus; M. southcotti sp. nov. from Aulacocyclus fracticornis; M. womersleyi sp. nov. from Protomocoelus australis; and M. zachariei sp. nov. from Aulacocyclus kaupii. Megisthanus womersleyi is also based on material from Misima Island, Papua New Guinea, originally identified as Megisthanus doreianus Thorell, 1882. Megisthanus modestus Berlese, 1910, is redescribed based on material from Pharochilus spp. collected from Canberra, New South Wales, Queensland and Tasmania. The Papua New Guinean species Mastachilus papuanus Womersley, 1937 is diagnosed and discussed in relation to the other species from New Guinea. Additional collections of Megisthanus leviathanicus Seeman, 2017 and M. thorelli Womersley, 1937 are also reported. A genus description and a key to the eight Australian species of Megisthanus are provided.
Phylogenetic Classification of the Atlides Section of the Eumaeini (Lepidoptera, Lycaenidae)
Authors: MARTINS ANANDA REGINA P. , DUARTE MARCELO , ROBBINS ROBERT K.
Published: February 2019

This paper provides the first phylogenetic classification of the Atlides Section (Lycaenidae: Theclinae, Eumaeini).  It is based on a recently published morphological phylogenetic study, in which the Atlides Section proved to be monophyletic in all analyses. In particular, that study identified a hindwing cleft anal lobe in all members of the Atlides Section that is lacking in all other Eumaeini (except for some species of Panthiades Hübner). The included genera are Theritas Hübner; Arcas Swainson; Lucilda d'Abrera & Bálint; Pseudolycaena Wallengren; Brangas Hübner; Atlides Hübner; and Denivia K. Johnson. Each is characterized by synapomorphies. Margaritheclus Bálint and Dabreras Bálint are new generic synonyms of Lucilda and Brangas, respectively. We recognize 71 species. Distribution and habitat are provided for each, and nomenclature is updated. Atlides centralis Salazar & Henao is a new synonym of Atlides browni Constantino, Salazar & K. Johnson; Brangas contrastus Bálint is a new synonym of Brangas felderi (Goodson); Denivia grava Bálint, K. Johnson & Kroenlein is a new synonym of Denivia deniva (Hewitson); Denivia ponsanota Bálint, K. Johnson & Kroenlein is a new synonym of Atlides zava (Hewitson); Denivia striata Bálint, K. Johnson & Kroenlein is a new synonym of Atlides zava (Hewitson); Margaritheclus boliboyeri Bálint & Wojtusiak is a new synonym of Margaritheclus boliboyerus Bálint & Wojtusiak; and Theritas gozmanyi Bálint & Wojtusiak is a new synonym of Theritas paupera (C. Felder & R. Felder). New combinations are Lucilda margaritacea (Draudt), Lucilda danaus (C. Felder & R. Felder), Lucilda dabrerus (Bálint), Lucilda boliboyerus (Bálint & Wojtusiak), Denivia curitabaensis (K. Johnson), Denivia augustinula (Goodson), Denivia theocritus (Fabricius), Denivia augustula (W.F. Kirby), Denivia arene (Goodson), Denivia monica (Hewitson), Denivia hemon (Cramer), Denivia phegeus (Hewitson), Denivia acontius (Goodson), Denivia chaluma (Schaus), Denivia viresco (H.H. Druce), Denivia silma (Martins, Faynel & Robbins), and Denivia lisus (Stoll).
First record of the suborder Colomastigidea (Amphipoda) from Brazilian waters, with description of a new species of Colomastix Grube, 1861
Authors: SILVANY LIZ , ALVES JESSIKA , SENNA ANDRÉ R.
Published: February 2019

The suborder Colomastigidea consists essentially of small commensal amphipods and, to the date, no species are known from Brazilian waters. Here, a new species (Colomastix trispinosa sp. nov.) of the genus Colomastix is described from the Northeastern Brazilian coast, Ceará state. The new species is distinguished from the others in the genus especially by the male morphology of the palm of gnathopod 2 and the apex of inner ramus of uropod 1, as well as for the combination of other characters. In addition, it is the first Atlantic species to have a pleated apex on dactylus of female gnathopod 2.
Description of two new species of Rhodostrophia Hübner, 1823 from China (Lepidoptera, Geometridae)
Authors: CUI LE , XUE DAYONG , JIANG NAN
Published: February 2019

Two new species of the genus Rhodostrophia Hübner, 1823, Rhodostrophia reisseri sp. nov. and Rhodostrophia stueningi sp. nov. are described from China. The Chinese species of Rhodostrophia are reviewed. Diagnoses for all discussed Chinese species are provided.
A new species of the genus Phytocoris (Hemiptera: Miridae), with an identification key to amygdali-group species of the subgenus Compsocerocoris found in Iran
Authors: HOSSEINI REZA , MOHAMMADI SAADI
Published: February 2019

A new species, Phytocoris (Compsocerocoris) darakiensis sp. nov. is described from Kurdistan province, Iran. A taxonomic key to the species of amygdali-group of the subgenus Compsocerocoris Reuter known in Iran, male and female habitus photographs and illustrations of male genitalia of the new taxon are provided. Diagnosis of the new species is based on a comparison with other congeneric found from Iran. The type specimens were deposited in the insect collection of the University of Guilan, Rasht, Iran.
Out of Gay, and Into Class Closet: On Politics of Identity and Reflexive Sociology in Didier Eribon and Éduard Louis: Conversation Between Kate Korycki and Anna Zawadzka
Authors: Zawadzka Anna , Korycki Kate
Published: February 2019

The conversation starts with an in-depth analysis of two autobiographical works, Returning to Reims by Didier Eribon (2013) and The End of Eddy by Éduard Louis (2017). The discussion concerns, among other things, the double exclusion due to non-heteronormativity and class origin. Does gay emancipation occur exclusively within dominating social classes? What is the price of emancipation for individuals from dominated classes? Is it possible to come to terms with the stigma of being both gay and of working class origin? Why has the problematization of heteronormativity been abundantly represented in literature and arts, whereas that of classism continues to be a taboo as a subject of both autobiographies and academic studies?
A Sea Level Stratospheric Ozone Intrusion Event Induced within a Thunderstorm Gust Front
Authors: Dreessen Joel
Published: February 2019

Ozone from a stratospheric intrusion (SI) reached sea level in association with a thunderstorm gust front during the predawn hours of 16 April 2018. The event caused surface ozone concentration increases of 30 to more than 50 ppbv in a matter of minutes in a band from approximately Richmond, Virginia, to Philadelphia, Pennsylvania. Peak hourly ozone concentrations reached 74 ppbv in northeastern Maryland despite absent photochemistry and ongoing convective activity. An intense jet stream with velocities >80 kt (41 m s−1) less than 1 km above ground level was observed associated with a deepening cyclone. Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), showed a filament of ozone with concentrations greater than 90 ppbv extending downward from the stratosphere to the lower troposphere. This SI filament became collocated with an ongoing severe squall line, and stratospheric ozone was transported directly to sea level when entrained into the squall-line gust front. Weather radar and in situ observations confirmed surface ozone increased with the thunderstorm gust front, while a concurrent reduction in carbon monoxide confirmed air within the gust front had stratospheric origins. While rare, such coupling events are important to troposphere–stratosphere exchanges and in overall atmospheric chemistry and climate. This may be the first event of its type and magnitude documented.
Severe Hail Fall and Hailstorm Detection Using Remote Sensing Observations
Authors: Murillo Elisa M. , Homeyer Cameron R.
Published: February 2019

Severe hail days account for the vast majority of severe weather–induced property losses in the United States each year. In the United States, real-time detection of severe storms is largely conducted using ground-based radar observations, mostly using the operational Next Generation Weather Radar network (NEXRAD), which provides three-dimensional information on the physics and dynamics of storms at ~5-min time intervals. Recent NEXRAD upgrades to higher resolution and to dual-polarization capabilities have provided improved hydrometeor discrimination in real time. New geostationary satellite platforms have also led to significant changes in observing capabilities over the United States beginning in 2016, with spatiotemporal resolution that is comparable to that of NEXRAD. Given these recent improvements, a thorough assessment of their ability to identify hailstorms and hail occurrence and to discriminate between hail sizes is needed. This study provides a comprehensive comparative analysis of existing observational radar and satellite products from more than 10 000 storms objectively identified via radar echo-top tracking and nearly 6000 hail reports during 30 recent severe weather days (2013–present). It is found that radar observations provide the most skillful discrimination between severe and nonsevere hailstorms and identification of individual hail occurrence. Single-polarization and dual-polarization radar observations perform similarly at these tasks, with the greatest skill found from combining both single- and dual-polarization metrics. In addition, revisions to the “maximum expected size of hail” (MESH) metric are proposed and are shown to improve spatiotemporal comparisons between reported hail sizes and radar-based estimates for the cases studied.