bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 499: Lower Diastolic Wall Strain Is Associated With Percutaneous Coronary Intervention in Patients With Normal Left Ventricular Systolic Function
Authors: Kang Min-Kyung , Kim Soo Ho , Choi Jaehuk , Mun Hee-Sun , Choi Seonghoon , Cho Jung Rae , Lee Namho
Published: July 2021

Background:
Left ventricular (LV) diastolic dysfunction occurs before LV systolic dysfunction and electrocardiographic changes in ischemic cascade. Diastolic wall strain (DWS) has been proposed as a marker of LV diastolic stiffness. Therefore, the objectives of this study were to defined the relationship between DWS and percutaneous coronary intervention (PCI) and see other echocardiographic parameters in patients who undergoing coronary angiography (CAG).

Methods:
254 patients (mean age: 61 ± 10, 136 (54%) men) undergoing CAG and normal left ventricular systolic function without regional wall motion abnormalities were enrolled, and among them, 68 (27%) patients performed PCI. All patients performed echocardiography before CAG and DWS defined using posterior wall thickness (PWT) measurements from standard echocardiographic images (DWS =[PWT(systole)-PWTdiastole)]/PWT(systole)).

Results:
Patients who performed PCI showed significantly lower DWS (0.27 ± 0.09 vs. 0.39 ± 0.08, p < 0.001). Age did not differ between the two groups (61.6 ± 10.6 vs. 60.9 ± 10.4, p = 0.623), and LV ejection fraction was also similar (62.8 ± 4.6 vs. 63.5 ± 5.2%, p = 0.380). Other echocardiographic parameters did not show significance differences but E/E’ ratio was slightly but significantly elevated in patients performed PCI (10.9 ± 4.8 vs 9.2 ± 3.3, p = 0.011). In multiple regression analysis, lower DWS was an independent predictor for PCI (Cut-off value: 0.34, sensitivity: 89%, AUC: 0.870, SE: 0.025, p < 0.001).

Conclusion:
DWS, a simple parameter that can be calculated from routine 2D echocardiography, is inversely associated with presence of coronary artery disease and PCI.
Abstract 51: LincAQPEP, an Adipocyte-Specific Intergenic Noncoding RNA, Modulates Lipid Metabolism in Human Adipocytes
Authors: Zhang Xuan , Xue Chenyi , Han Yumiao , Garcia Benjamin , Soccio Raymond , Li Mingyao , Reilly Muredach P
Published: July 2021

Long intergenic noncoding RNAs (lincRNAs) have emerged as key mediators of cellular functions and are increasingly implicated in human diseases. Recently a set of lincRNAs was identified to regulate adipogenesis in mice and humans. Here we report that lincAQPEP, a lincRNA predominantly expressed in adipose tissue, is one of the most abundant lincRNAs detected in human fat by RNA sequencing. It is highly expressed in mature adipocytes but not detected in pre-adipocytes, monocytes or macrophages, indicating its adipocyte specificity. Interestingly, no syntenic or conserved RNA transcript was detected in mouse genome for lincAQPEP, suggesting it might be a human specific lincRNA. A binding motif for PPAR gamma (PPARγ), a critical transcription factor in adipogenesis, was found in the promoter region of lincAQPEP (-612 to -596 bp relative to transcription start site). In addition, chromatin immunoprecipitation sequencing confirmed high occupancy of PPARγ around lincAQPEP transcription start site in human adipose tissue and cultured adipocytes, suggesting PPARγ may mediate adipocyte-specific lincAQPEP transcription. LincAQPEP knockdown (~70%) by lentiviral-based short hairpin RNAs resulted in ~35% decrease in triglyceride content as well as 30-70% reduction of lipogenic gene expression (e.g. SREBP1, FASN, FABP4) in human adipocytes, suggesting a modulatory role of lincAQPEP in adipocyte function. To investigate the molecular mechanisms of its regulatory function, we performed RNA pulldown assays with biotinylated lincAQPEP and lincAQPEP antisense transcript (negative control), followed by mass spectrometry to discover potential lincAQPEP-interacting proteins. IGF2BP3 (Insulin-like growth factor 2 mRNA-binding protein 3), implicated in post-transcriptional regulation of gene expression, was identified as one of top candidates to physically bind lincAQPEP. Interestingly, lincAQPEP knockdown resulted in ~30% reduction in IGF2BP3 mRNA abundance. These data suggested that lincAQPEP may impact mRNA stability and translation of specific genes by interacting with IGF2BP3. In summary, our data indicate that lincAQPEP, an adipose-specific lincRNA, plays important roles in adipocyte biology likely through interaction with IGF2BP3.
Abstract 522: Scavenger Receptor-BI’s Cholesterol Transport Functions are Dependent on its Extracellular Tryptophan Residues
Authors: Holme Rebecca L , Miller James J , Sahoo Daisy
Published: July 2021

High density lipoprotein (HDL) functions as an anti-atherogenic particle, primarily due to its role in reverse cholesterol transport whereby HDL delivers cholesterol to the liver for excretion upon interaction with its receptor, scavenger receptor BI (SR-BI). The extracellular domain of SR-BI is required for its cholesterol transport functions, yet our understanding of the molecular and structural features of this domain remains limited. We designed experiments to test the hypothesis that one or more of the six highly conserved extracellular tryptophan (Trp; W) residues are critical for mediating receptor function. Towards this end, we created a series of Trp-to-Phe mutant receptors of SR-BI, as well as Trp-free SR-BI and assessed the ability of these mutant receptors to mediate cholesterol transport. Wild-type (WT) or mutant SR-BI receptors were transiently expressed in COS7 cells and proper cell surface expression was confirmed by immunoblotting, confocal microscopy and flow cytometry. Next, we showed that Trp-free- and W415F-SR-BI had a significantly decreased ability to bind HDL (12.7% and 31.3% of WT levels, respectively) and promote selective uptake of HDL-cholesteryl esters (35.2% and 70.1% of WT levels, respectively). Interestingly, only Trp-free-, but not W415F-SR-BI, showed an impaired ability to mediate efflux of free cholesterol (FC) (90.8% decrease vs. WT). Furthermore, both W415F- and Trp-free SR-BI were unable to reorganize plasma membrane pools of FC based on lack of sensitivity of FC to exogenous cholesterol oxidase. We then designed an additional set of mutant SR-BI receptors to determine whether restoration of Trp415 alone (or in combination with other Trp residues) could rescue SR-BI function. Restoration of Trp415 into Trp-free-SR-BI partially rescued cholesterol transport functions. Addition of any of the other 5 extracellular Trp residues was also not sufficient to restore WT cholesterol transport function in combination with Trp415. In summary, loss of all Trp residues in SR-BI impairs its cholesterol transport functions, mostly due to the loss of Trp415. Homology modeling of SR-BI based on the crystal structure of LIMP-2, a member of the same protein family, may help identify the importance of this residue in future studies.
Abstract 525: Transplanted LRP1-Deficient Periaortic Adipose Tissue Accelerates Atherosclerosis in Carotid Arteries of LDL Receptor Knockout Mice
Authors: Kuhel David G
Published: July 2021

Perivascular adipose tissue (PVAT) expands in obesity and is anatomically colocalized with atherosclerotic plaques in humans. Moreover, PVAT inflammation is upregulated in the setting of atherosclerosis. Local factors expressed in PVAT that influence adipose tissue inflammation and adipocyte expansion could modulate “outside-in” signals involved in the progression of atherosclerosis. Previous studies have shown that mice with adipose tissue deficient for the LDL receptor-related protein 1 (

ad-Lrp1
-/-

) display reduced adipocyte size and resistance to diet-induced obesity. To assess the contribution LRP1 in PVAT on the progression of atherosclerosis, we utilized an adipose allograft model. Briefly, PVAT taken from the aortic arch of

ad-Lrp1
-/-

and

ad-Lrp1
+/+

mice were transplanted to the left common carotid arteries of LDL-receptor deficient (Ldlr
-/-
) mice. Following a four week engraftment period mice were fed western diet for 12 weeks. Carotid arteries were then analyzed for lesion formation and the surrounding adipose tissue was analyzed for inflammatory markers. Carotid arteries of

LDLR
-/-

mice receiving

ad-LRP1
-/-

transplanted adipose tissue exhibited >3 fold increase in plaque size compared to mice transplanted with

ad-Lrp1
+/+

adipose tissues. Plasma lipid levels and atherosclerotic lesions in the contralateral carotid arteries, without PVAT transplant, were similar between the two recipient groups. When compared to wild-type,

ad-Lrp1
-/-

transplanted PVAT had a 1.9 fold increased number of CD68+ cells determined by both immunohistochemistry and mRNA. Pro-inflammatory cytokines, IL6 (2.7 fold), TNFα (4.7 fold), and MCP1 (2.1 fold) mRNA were also increased in

ad-Lrp1
-/-

transplanted PVAT. In addition,

ad-Lrp1
-/-

transplanted PVAT retained a decreased cell size as observed prior to and after transplantation indicating either increased triglyceride lipolysis or defective triglyceride storage. These findings suggest that deficiency of LRP1 in PVAT accelerates atherosclerosis via enhancing local vascular inflammation.
Abstract 528: ApoA-I Mimetic Peptide Treatment Improves Left Ventricular Diastolic Dysfunction and Decreases Iron Content in Coronary Plaques in Rabbits
Authors: Nachar Walid , Busseuil David , Shi Yanfen , Mihalache-Avram Teodora , Mecteau Mélanie , Brand Geneviève , Theberge-Julien Gabriel , Rhéaume Éric , Tardif Jean-Claude
Published: July 2021

Introduction:
Left ventricular diastolic dysfunction (LVDD) is characterized by the disturbance of ventricle’s performance due to its abnormal relaxation or to its increased stiffness. Hypertrophy, inflammation, fibrosis and oxidative stress are often associated with LVDD.

Hypothesis:
Given the reported anti-inflammatory and anti-oxidant properties of HDL, we assessed the potential of an apoA-I mimetic peptide to improve LVDD in a recently developed rabbit model.

Methods:
Forty-two rabbits were fed a normal diet (n=7) or a 0.5% cholesterol-enriched diet supplemented with vitamin D2 (n=35) for an average of 16 weeks. The hypercholesterolemic rabbits were randomised to receive 6 infusions of saline (n=11), 10 mg/kg (n=12) or 30 mg/kg of an apoA-I mimetic peptide over a period of 2 weeks. Serial echocardiography was used to assess LVDD. RT-qPCR and histological staining were performed on left ventricular homogenates and sections, respectively.

Results:
LVDD was improved in treated groups compared to saline as shown by decreased E/Em and increased Em/Am ratio assessed by echocardiography (p≤0.05). The apoA-I mimetic decreased transferrin receptor mRNA expression (p=0.039 for 10 mg/kg group) and increased ferritin heavy chain mRNA (p=0.053 for 30 mg/kg group) compared to saline. These changes were associated with a large decrease of non-heme iron content in LV sections of the treated groups (-90% in 10 mg/kg group, p≤0.01; -72% in 30 mg/kg group, p=0.1) compared to the saline-treated group as detected by Prussian blue staining. Significant reduction of RAM-11 macrophage staining was observed in treated groups compared to saline. A correlation was observed between iron and macrophage contents in LV (R=0.59 and p=0.0002). Most of the non-heme iron and macrophage stainings were seen in coronary arteries and plaques. Anti-oxidant enzyme (SOD2) mRNA was numerically increased in the 30 mg/kg group compared to saline (p=0.08).

Conclusion:
ApoA-I mimetic treatment improves LVDD. The observed decrease of left ventricular iron content may lead to reduce oxidative stress as iron contributes to reactive oxygen species formation. Further work is ongoing to validate whether decreased iron-mediated toxicity is a new benefit of apoA-I mimetic therapy.
Abstract 585: E3 ubiquitin-protein Ligase Casitas B Lineage Lymphoma b Deficiency Aggravates Atherosclerosis
Authors: Smeets Esther , Seijkens Tom , den Toom Myrthe , Meiler Svenja , Lutgens Esther
Published: July 2021

E3 ubiquitin ligase Casitas B lineage Lymphoma b (Cbl-b) is a negative regulator in peripheral T cell activation. Cbl-b deficient T cells are hyper-reactive due to CD28-independent activation. Here we studied the effect of Cbl-b deficiency on T cell homeostasis in hypercholesterolemia and on atherogenesis in 20 wk old Cbl-b-/-/ApoE-/- mice.

Flow cytometric analysis of lymphoid tissues and aortic arches showed decreased CD4+:CD8+ T cell ratios in Cbl-b-/-/ApoE-/- mice. Cbl-b deficiency induced central memory CD8+ T cells expansion, whereas the proportion of naïve T cells decreased. We found that Cbl-b deficient CD8+ T cells are less apoptotic as indicated by decreased AnnexinV positivity and elevated expression of anti-apoptosis markers, such as Bcl-2. Pro-inflammatory, TNFa and IFNy, and cytotoxicity markers, granzyme B, are increased in Cbl-b deficient CD8+ T cells.

As expected from the increase of CD8+ T-cells in the aortic arch, Cbl-b-/-/ApoE-/- mice showed significantly more plaque development in the aortic root. The plaques contained higher leukocyte and T cell counts, but contained surprisingly less macrophages. The latter is caused by decreased monocyte recruitment resulting from lower MCP-1 levels. Moreover, the excess of CD8+ T cells induced enhanced cell death of macrophages. In vitro co-culture of Cbl-b deficient and wildtype CD8+ T cells with bone marrow derived macrophages revealed enhanced macrophage apoptosis in increased CD8+:macrophage ratios, irrespective of the CD8+ T cell genotype. Expression of the M1 macrophage markers, CD115 and CD64 was upregulated in Cbl-b deficient aortic arches, whereas M2 markers, CD206 and Arg-1, were decreased.

In conclusion, we show that Cbl-b deficiency decreases CD4+:CD8+ T cell ratio during hypercholesterolemia, through reduced apoptosis and possibly less susceptibility of CD8+ T cells to regulatory T cell suppression. This contributes to exacerbated atherosclerosis in Cbl-b deficient mice. Although plaques contained an excess of lymphocytes and T-cells, and macrophages where of an M1 phenotype, macrophage counts were decreased. This was caused by low MCP-1 levels due to CD8+ T cell induced macrophage apoptosis. These results reveal that Cbl-b balances immune reactions in atherosclerosis.
Abstract 605: Activation of NLRP3 Inflammasome Complex Regulates the Onset of Hypoxia Induced Thrombosis
Authors: Gupta Neha , Sharma Manish , Chatterjee Tathagata , Tyagi Tarun , Sahu Anita , Prabhakar Amit , Ashraf Mohammad Zahid
Published: July 2021

Objective:
Besides well known predisposing conditions such as cancer, diabetes, cardiovascular disease and surgery; hypoxia per se has been suggested to be an additional risk factor for venous thrombosis (VT). We have recently shown that hypoxia, either localized due to stasis, or systemic, due to environmental factors such as high altitude exposure, results in a prothrombotic milieu. The proteomic analysis implicated some novel plasma factors that could trigger thrombotic propensity; however, the exact mechanism involved still remains poorly understood.

Methods & Results:
Effect of hypoxia on coagulation system was analysed using inferior vena cava ligation and simulated hypobaric hypoxia rat models. Data demonstrated that hypoxia modulates both coagulation and fibrinolytic pathways and thrombus developed under hypoxic atmospheres is an aggravated form of thrombus progression under normoxic environments. Moreover, the whole transcriptome analysis using RNA sequencing approach implicated the novel role of NOD Like receptors3 (NLRP3) and inflammasome in thrombus formation suggesting the hypoxia induced thrombosis to be an episode of sterile inflammation. The cytokine array profiling and immunofloroscence data also supported the role of innate immune components. Both pharmacological inhibition and siRNA mediated knockdown of caspase-1 and NLRP-3 respectively reinforced that the activation of NLRP3-inflammasome complex critically regulates thrombogenesis in response to hypoxia. This complex is likely to be activated as an early response to hypoxia, which precedes the platelet aggregation and hence, onset of thrombosis. The translational implication of this novel finding was evident by activation of NLRP3 inflammasome components in human patients who developed VT under hypoxic environments.

Conclusions:
The current study reveals a novel role of NLRP3 inflammasome in thrombosis induced by localised as well as systemic hypoxic environments. Further, the production of IL-1β by NLRP3 inflammasome augments platelet aggregation, the key event for thrombogenesis.
Abstract 61: Deficiency of the RNA Editing Enzyme ADAR2 Impairs Inflammation, Neovascularization and Functional Recovery of Ischemic Tissues
Authors: Stellos Konstantinos , Gatsiou Aikaterini , Lunella Federica , Fischer Ariane , Amrhein Carolin , Zeiher Andreas , Dimmeler Stefanie
Published: July 2021

Background:
Adenosine deaminase acting on RNA-2 (ADAR2) enzyme catalyzes adenosine-to-inosine (A-to-I) RNA editing of mRNAs and microRNAs and controls brain development. However, the role of endothelial cell ADAR2 in vascular biology and inflammation has not been described so far.

Methods and Results:
ADAR2 is expressed in human and murine endothelial cells and is 2-fold induced by hypoxia or hind limb ischemia in mice (P<0.05 for all). ADAR2 deficiency resulted in 73±12% impairment of leukocyte infiltration, in 53±4% reduced neovascularization, and a 40±6% decreased blood-flow recovery of ischemic muscle tissues in a hindlimb ischemia mouse model (P<0.001 for all). Mechanistically, among the highly ADAR2-regulated transcripts was interleukin-6 signal transducer (IL6ST or gp130), the receptor of interleukin-6 (IL-6). Silencing of ADAR2 resulted in a downregulation of gp130 mRNA and protein expression in endothelial cells by 65±5% and 50±5%, respectively (P<0.001 for both). Similarly, the expression of gp130 mRNA was decreased by 50±25% (P<0.05) in murine lung endothelial cells, which derived from transgenic ADAR2-null mice. In order to investigate the physiological relevance we treated endothelial cells, which were transfected with a siRNA against ADAR2 or scrambled control, with IL-6 and sIL6Ra. Silencing of ADAR2 reduced by at least 2-fold the IL-6-mediated STAT3 phosphorylation, the mRNA expression of the IL-6-induced downstream genes MCP-1, VCAM-1 and E-selectin, and the IL-6-induced platelet and leukocyte adhesion on endothelial cells and endothelial cell network formation (P<0.05 for all). Of interest, ADAR2 regulated gp130 mRNA stability. Co-silencing of ADAR2 and Drosha completely restored the ADAR2-regulated gp130 mRNA expression indicating that ADAR2 regulates the maturation of specific miRNAs. Indeed, ADAR2 regulates by at least 2-fold the expression of 20 microRNAs, including of miR-579 and miR-320e, which are predicted to bind to the 3’-untranslated region of IL6ST mRNA.

Conclusions:
Taken together, ADAR2 constitutes a potential candidate for therapeutic modulation of angiogenesis and inflammation in ischemic tissues.
Abstract 624: Resolvin E1 Inhibits Thromboxane-Induced Contraction of Rat Aorta and Human Pulmonary Artery
Authors: Jannaway Melanie , Torrens Christopher , Warner Jane A , Sampson Anthony P
Published: July 2021

Thromboxane is a vasoactive omega-6-derived lipid implicated in hypertension. Omega-3 fatty acid derivatives including resolvin (Rv) E1 have important roles in the resolution of inflammation, but their ability to mediate vasomotor activity is unknown. We assessed whether RvE1 modulates contraction of rat thoracic aorta and human pulmonary artery (HPA) in vitro.

Rats were culled by CO2 inhalation and cervical dislocation, and the thoracic aorta was removed. HPA were obtained with informed consent from lung tissue of surgical patients at Southampton General Hospital. Segments of aorta or HPA were incubated in DMEM-F12 with or without RvE1 (10 nM, 100 nM or 300 nM) for 1 or 24 hours, and then mounted on a wire myograph. Mounted segments were bathed at 37[[Unable to Display Character: ]]C in Kreb’s buffer, gassed (95%/5% O2/CO2) and set to 1.5 g of baseline tension. Functional integrity was confirmed by a contractile response to 125 mM KPSS. After washing to restore baseline tension, a cumulative concentration-response curve was defined to the stable thromboxane A2 mimetic U46619 (1 nM - 1 μM). Contractions are expressed as percent of KPSS response and differences determined by two-way ANOVA and by pairwise comparisons.

In rat aorta, treatment with RvE1 (10 nM) significantly shifted the U46619 curve rightwards, increasing the EC50 value 13-fold from 0.13 μM to 1.75 μM after 1 hour (n=5), and 4-fold from 0.093 μM to 0.41 μM after 24 hours (n=5). In contrast, 300 nM RvE1 caused no significant change in EC50 (1 hour 0.11 μM; 24 hours 0.097 μM, n=5).

In HPA segments, RvE1 (10 nM, 1 hour) increased the U46619 EC50 value 7-fold from 0.0079 μM to 0.054 μM (n=3), with a preliminary experiment suggesting a similar outcome after 24 hours. Higher concentrations of RvE1 had no significant effect, suggesting the relaxant action of RVE1 has a bell-shaped response curve. In preliminary experiments, RvE1 inhibited U-46619 contractions of bronchiolar airways from the same human donors.

Resolvin E1 is known for its immunomodulatory actions on leukocytes and also inhibits U46619-induced aggregation of platelets, but our results are the first evidence that this pro-resolution mediator can also inhibit contractions of intact vasculature from rat and human lung induced by a thromboxane mimetic.
Abstract 627: Regulation of Nuclear Factor of Activated T Cells by BMP-Binding Endothelial Regulator Signaling
Authors: Lockyer Pamela P , Mao Hua , Li Xi , Pi Xinchun
Published: July 2021

Dysfunction of the vascular endothelium results in various cardiovascular, circulatory and blood diseases and exemplifies the importance of endothelial integrity. BMP-binding endothelial regulator (BMPER), a well recognized extracellular modulator of Bone morphogenetic protein (BMP) signaling, has been identified as a vital component in the vascular response to stress. Microarray analysis revealed nuclear factor of activated T cells (NFAT) as one of the genes found to be most highly upregulated by BMPER treatment in mouse endothelial cells (MECs), as well as many genes with NFAT consensus binding sites. Therefore we hypothesize that BMPER is an important regulator of NFAT transcriptional activity. Initially we have investigated the effect of BMPER on NFATc1 activation with MECs and human primary endothelial cells. Our data show that the translocation of NFATc1 from the cytoplasm to the nucleus following BMPER treatment, determined by immunofluorescent analysis. By using the nuclear fractionation assays, we observed the similar result that the translocation of NFATc1 to the nucleus of HUVECs took place after 30 minutes of BMPER treatment. Next, we wanted to determine whether the increased NFATc1 protein level in nucleus results in the enhanced transcriptional activity. Indeed, when HUVECs are treated with BMPER and then analyzed with luciferase reporter assay, a 1.5-fold significant increase in NFAT activity over baseline was observed. Our previous data demonstrate that LDL receptor related protein (LRP1) interacts with BMPER and regulates BMPER’s activity through endocytosis in endothelial cells. Interesting, we observe that LRP1 also interacts with NF45, the 45-kDa subunit of NFAT protein. It strongly suggests that BMPER positively regulates NFAT activity through LRP1. This novel signaling pathway indicates that BMPER may acts as a new ligand and exhibits BMP-independent activity in endothelial cells and therefore contribute to the regulation of vascular homeostasis.
Abstract 644: Role of Micro RNA LET-7F in Cigarette Smoke-Induced Impairment of Neovascularization
Authors: Dhahri Wahiba , Dussault Sylvie , Haddad Paola , Turgeon Julie , Tremblay Sophie , Desjarlais Michel , Mathieu Raphaël , Rivard Alain
Published: July 2021

Background:
Exposure to cigarette smoke is associated with impaired neovascularization in response to ischemia. The precise mechanisms involved in that process remain to be determined. Micro RNA (miR) are emerging as key regulators of several physiological processes, including angiogenesis. Here we investigated the potential role of miRs for the modulation of neovascularization in the context of cigarette smoking.

Methods and Results:
Human Umbilical Vascular Endothelial Cells (HUVECs) were exposed or not to cigarette smoke extracts (CSE). Using Affimetrix GeneChip miRNA array analysis, we found that the pro-angiogenic miR let-7f was downregulated by 40% in HUVECs exposed to CSE. Using an inhibitor of let-7f, we demonstrated reduced migration and tube formation in HUVECs, reproducing the phenotype induced by CSE. A let-7f mimic could rescue cellular migration and tube formation in HUVECs exposed to CSE. Moreover, the expression of let-7f is significantly reduced in the ischemic muscles of mice exposed to cigarette smoke (CS). In vivo, hindlimb ischemia was surgically provoked by femoral artery removal to mice exposed (SMK) or not to CS for two weeks with a local injection of a control or a let-7f mimic. Let-7f mimic could rescue blood flow recuperation and capillary density in ischemic muscles 21 days post-ischemia associated with improved mobility. We found that CS was associated with reduced number of endothelial progenitor cells (EPCs) and impairment of angiogenic activities. Importantly, let-7f mimic rescued EPC number and EPC functional activities in SMK group. TGF-β-RI and HIF1AN are predicted to be targeted by let-7f and both are increased in SMK mice, whereas the expression of HIF-1a and VEGF are reduced in these mice. Interestingly, SMK mice injected with a let-7f mimic have decreased muscle expression of TGF-β-RI and HIF1AN associated with normalized HIF-1 and VEGF expression.

Conclusion:
Our results suggest that a reduction in the expression of let-7f could be involved in the cigarette smoke-induced inhibition of angiogenesis through modulation of TGF-β-RI and HIF1AN. Overexpression of let-7f using a miR mimic could constitute a novel therapeutic strategy to improve ischemia-induced neovascularization in pathological conditions.
Abstract 660: Inhibition of 14q32 “AngiomiR” MicroRNA-494 Reduces Atherosclerotic Lesion Formation, Increases Plaque Stability and Lowers Cholesterol Levels
Authors: Welten Sabine , Wezel Anouk , Bastiaansen Antonius , de Jong Rob , de Vries Margreet , Goossens Eveline , Peters Erna , Boonstra Martin , Kandimalla Ekambar , Kuiper Johan , Quax Paul , Bot Ilze , Nossent Yael
Published: July 2021

We have shown that inhibition of 14q32 microRNAs (miRs) miR-329, miR-487b, miR-494 and miR-495 increased both angiogenesis and arteriogenesis, leading to a 40% increase in blood flow recovery after ischemia. As many vascular remodelling processes share underlying mechanisms, we also investigated the effects of 14q32 microRNA inhibition in atherosclerosis

When looking at expression patterns of 14q32 “angiomiRs”, we found that miR-494 was abundantly expressed in murine tissues involved in atherosclerosis, including the liver, spleen and carotid arteries. When looking at human carotid artery lesions, we found that miR-494 expression was doubled in vulnerable plaques compared to plaques of a stable phenotype.

We used Gene Silencing Oligonucleotides (GSOs) to inhibit miR-494 in ApoE-/- mice, after placing semi-constrictive collars around both carotid arteries for 28 days to induce atherosclerotic lesion formation. We observed efficient uptake of IRD-800CW-labeled GSO-494 into the carotid artery, leading to a 50% reduction of miR-494 expression and significant upregulation of multiple anti-atherogenic target genes. Atherosclerotic lesion formation was drastically reduced in mice treated with GSO-494 (GSO-Control: 47 ± 11*103 μm2; GSO-494: 16 ± 3*103 μm2), while plaque stability was increased, determined by both a decrease in necrotic core size and an increase in plaque collagen content. Furthermore, inhibition of miR-494 resulted in increased cholesterol efflux in vitro (p<0,05). Indeed, in vivo, plasma total cholesterol levels and VLDL fractions were decreased after miR-494 inhibition (GSO-Control: 30.4 ± 1.1 mM; GSO-494: 26.4 ± 0.7 mM).

In conclusion, inhibition of miR-494 results in smaller, more stable, atherosclerotic lesions, while simultaneously improving neovascularization. The so-called Janus phenomenon, which is a major drawback in translation towards the clinic, is hereby circumvented. The 14q32 miR-494 therefore provides a promising novel therapeutic target in prevention and treatment of atherosclerotic diseases.
Abstract 665: Conditional Deficiency of Myeloid Cell Hif-2α Activity Promotes Aneurysmal Aortic Degeneration
Authors: Furusho Yuko , Xu Baohui , Fujimura Naoki , Xuan Haojun , Deng Hongping , Glover Keith J , Dalman Ronald L
Published: July 2021

Abdominal aortic aneurysm (AAA) is a chronic degenerative disease mediated by myeloid cells, particularly macrophages. The transcription factor hypoxia inducible factor (HIF)-2α is a potent modulator of macrophage activation/ polarization. A potential role for HIF-2α in aneurysm pathogenesis has yet to be demonstrated. To consider this role, we created experimental AAA in conditional, myeloid cell-specific HIF-2α deficient mice (CKO) by intra-aortic infusion of porcine pancreatic elastase (PPE). Following PPE infusion, serial ultrasound imaging demonstrated progressively larger aneurysms in HIF-2α CKO mice, characterized by increased aortic medial elastin fragmentation and smooth muscle cell depletion, compared to WT controls. Aortic accumulation of CD68+ macrophages and CD4+ T cells, as well as aortic mural CD31+ neovessel formation were also augmented in HIF-2α CKO mice. These observations suggest that myeloid cell-derived HIF-2α activity may limit aneurysm pathogenesis and influence progression of AAA disease.
Abstract 679: Modeling Thoracic Aortic Aneurysm of Bicuspid Aortic Valve Patients with Induced Pluripotent Stem Cells Reveals Distinct Phenotypes of Smooth Muscle Cells from Different LIneages
Authors: Jiao Jiao , Xiong Wei , Wang Lunchang , Chen Eugene , Yang Bo
Published: July 2021

Ascending aortic aneurysm occurs in 35%-68% patients with bicuspid aortic valves (BAV), which is more frequently than it does in patients with normal trileaflet aortic valves (TAV). In contrast to recurrent aneurysms of the ascending aorta, descending aortic aneurysms is very rare in patients with BAV. Vascular Smooth Muscle Cells (SMCs) make up the media of the aortic walls, and their contractile properties help sustain vessel tone. Interestingly, ascending aorta is populated by SMCs arising from neural crest and descending aorta by SMCs from paraxial mesoderm. An intriguing hypothesis is that the distinct susceptibility of aneurysm in the ascending and descending aorta in patients with BAV is due in part to disparities in SMC embryonic origins.

To prove our hypothesis, we used an induced Pluripotent Stem Cells (iPS) model system to generate SMCs from neural crest and paraxial mesoderm. Firstly, iPSCs were established from a patient with BAV and ascending thoracic aortic aneurysm (BAV/TAA) and two control patients with normal aorta and TAV. The iPSCs pluripotency was verified by standard stem cell markers and teratoma formation. Neural crest stem cells (NCSCs) were differentiated from iPSCs and expressed neural crest markers, including P75, HNK1, AP2 and Sox9. In parallel, paraxial mesoderm cells (PMCs) were differentiated from iPSCs and expressed specific markers, including TCF15, TBX6, Meox1 and Pax1. The SMCs differentiated from both lineages had expression of SMC markers including MYH11, CNN1, ACTA2, SM22α. Interestingly, SMCs derived from BAV-NCSCs had significantly decreased in MYH11 and ACTA2 gene expression and impaired contractile property by gel contraction assay compared to SMCs derived from control-NCSCs. However, SMCs from BAV-PMCs had similar level of expression of MYH11 and ACTA2, and strong contractile activity with Carbacol treatment compared to SMCs derived from control PMCs. In conclusion, the iPS model system revealed decreased expression of contractile proteins and impairment of contractility in SMCs derived from NCSCs in BAV patient, but not in the SMCs derived from paraxial mesoderm cells. The high susceptibility of aneurysm in the ascending aorta in patients with BAV might be partly due to embryonic origin of the SMCs.
Abstract 702: Walnut Treatment Reduces Specific Pro-inflammatory Lipid Mediators While Increasing Anti-inflammatory Ones: An RCT subanalysis
Authors: Shearer Gregory C , Newman John W , Holt Roberta R , Keen Carl L , Hackman Robert M
Published: July 2021

Background:
Lipid mediators are transported in plasma, inducing pro- or anti-inflammatory responses in target tissues. Each daily nut serving is associated with 30% reduction in risk for cardiovascular or ischemic heart disease. Walnuts are an abundant source of bioactives and of precursors to lipid mediator synthesis: linoleic (LA) and alpha-linolenic (aLA) acids. How walnuts impact plasma lipid mediators either by providing more substrate or more specifically via other bioactives is unknown.

Objective:
Measure lipid mediators from the cyclooxygenase (COX), lipoxygenase (LOX), cytochrome p450 (CYP), and auto-oxidative pathways in plasma from subjects consuming large and small amounts of walnuts.

Design:
40 hypercholesterolemic, postmenopausal females were randomly assigned to a null dose (5g/d) or an active dose (40 g/d) of walnuts for 4 weeks. In a subset of 20 subjects, plasma lipid mediators synthesized from LA, aLA and other polyunsaturated fatty acids were measured by LC/MS/MS at baseline and final visits. Differences are reported as mean, 95% CIs.

Results:
Walnuts did not alter the compositional abundance of any plasma fatty acid except aLA, which was increased 1.46 fold [1.83, 1.16], p=0.003. Walnuts did modify plasma lipid mediator composition: specific pro-inflammatory COX metabolites, PGD2 and PGJ2/delta-12-PGJ2 were reduced by -72% [-43, -86] and -55% [-9, -77] respectively. LOX metabolites were almost uniformly depressed: the immediate mid-chain alcohols of LA (HODEs), dgLA (HETrEs), AA (HETEs), EPA (HEPEs) and DHA (HDoHEs) were reduced by 50-75% (p≤0.007), but aLA (HOTEs) were not. Metabolites of 5-LOX further downstream were also reduced: 5-KETE by 79% [-91, -50], and 6-trans-LTB4 by -89% [-76, -95]. Conversely, anti-inflammatory CYP-epoxides of LA (EpOME) and aLA (EpODE) were increased 82% [3, 223] and 143% [37, 331]. Epoxides of eicosanoids and docosanoids were unchanged (AA EpETrEs or EETs; EPA EpETEs; DHA EpDPEs).

Conclusion:
Walnut feeding reduces plasma pro-inflammatory COX and LOX metabolites while increasing some anti-inflammatory CYP metabolites. The effect occurs largely without changes in fatty acids, suggesting a molecular mechanism independent of simple changes in precursor abundance.
Abstract 722: Treatment of Acute and Chronic Limb Ischemia with Intermedin (IMD) in Mouse Models
Authors: Yao Luyu , Dong Honglin , Gu Allen , Gu Xin , Yao Kai , Shi Runhua , Zhang Wayne W
Published: July 2021

Objectives:
This experiment proposes a novel mouse model to simulate long-term chronic ischemia caused by peripheral artery disease (PAD) using a partial ligation method to narrow down the femoral artery lumen in C57Bl/6 mice. This model will be compared to the typical occlusion model while testing Intermedin (IMD) as a possible treatment for ischemia.

Methods:
Partial hindlimb ligation technique: we use a strand of 11-0 nylon sutures to pierce the middle of the artery and suture half of the artery shut at both the proximal and distal end of the femoral artery. The typical occlusion model: we use a 7-0 silk suture to completely ligate the distal and proximal femoral artery. Hindlimb blood flow was monitored daily by Laser Doppler perfusion monitor before and after the surgery. IMD was administered at 150 μg/kg, ip, immediately following ligation and twice daily afterwards for up to one week, while in the control group saline was injected instead of IMD. Gastrocnemius muscle samples were collected at day 3 and day 7 for histology and molecular biology study.

Results:
Ischemic/non-ischemic leg blood perfusion ratio in the partial ligation model is significantly higher than in the typical model. It is also significantly increased in IMD-treated groups in both models. Compared to the tissue in complete ligation models, it is apparent that partial ligation model tissue is less severely affected upon initial ligation but maintains ischemia over the one week testing period as would be expected. Compared to the untreated ischemia groups in acute and chronic hindlimb ischemia models, IMD-treated animals had less severe ischemic injuries.

Conclusion:
Our study indicates that our chronic hindlimb ischemia model was successful with expected less ischemia status than complete occlusion. The partial occlusion model presented here more closely mimics human PAD, where atherosclerotic plaque builds up slowly, resulting in a lower pressure difference between the proximal and distal artery preventing adequate shunting of the blood into collateral circulation. Moreover, our study suggests that IMD has promise as a therapeutic treatment in acute and chronic hindlimb ischemia models to prevent necrosis in muscle tissue following ischemic events.
Valve Replacement for Aortic Stenosis in Patients With Poor Left Ventricular Function
Authors: Collinson Julian , Henein Michael , Flather Marcus , Pepper John R. , Gibson Derek G.
Published: July 2021

Background
—Long-standing aortic stenosis causes significant left ventricular (LV) dysfunction, which may progress irreversibly. In many cases, LV function can be salvaged by aortic valve surgery, although debate exists regarding the best valve prosthesis to use.

Methods and Results
—We studied 33 patients retrospectively who had significant aortic stenosis and impaired LV systolic function, as assessed by transthoracic Doppler echocardiography. Patients were assessed preoperatively and before discharge from the hospital. A total of 20 patients received a stentless (homograft or Toronto) valve, and 13, a stented valve. No patient had significant aortic regurgitation or other valvular disease. Preoperatively, fractional shortening was 18.8±5.5% in the stentless group and 18.6±3.8% in the stented group. Postoperatively, it was 25.6±6.9% (
P
<0.001 compared with baseline) and 17.0±2.8%, respectively (
P
<0.001 compared with stentless group). Fractional shortening improved because of a reduction in LV end-systolic and end-diastolic dimensions in the stentless group. Systolic long axis function at the LV free wall also recovered, with an increase in systolic excursion and both peak shortening and lengthening rates. No change was noted in mitral valve Doppler patterns.

Conclusions
—Patients who received a stentless valve demonstrated a significantly greater early improvement in LV systolic function compared with those who received a stented valve.
Five-Year Follow-Up of the Medicine, Angioplasty, or Surgery Study (MASS)
Authors: Hueb Whady A. , Soares Paulo Rogério , Almeida de Oliveira Sérgio , Ariê Shiguemituzo , Cardoso Rita Helena A. , Wajsbrot Dalia Ballas , Cesar Luiz A. M. , Jatene Adib D. , Ramires José Antonio F.
Published: July 2021

Background
—Although coronary angioplasty and myocardial bypass surgery are routinely used, there is no conclusive evidence that these interventional methods offer greater benefit than medical therapy alone. This study is intended to evaluate, in a prospective, randomized, and comparative analysis, the benefit of the 3 current therapeutic strategies for patients with stable angina and single proximal left anterior descending coronary artery stenosis.

Methods and Results
—In a single institution, 214 patients with stable angina, normal ventricular function, and severe proximal stenosis (>80%) on the left anterior descending artery were selected for the study. After random assignment, 70 patients were referred to surgical treatment, 72 to angioplasty, and 72 to medical treatment. The primary end points were the occurrence of acute myocardial infarction or death and presence of refractory angina. After a 5-year follow-up, these combined events were reported in only 6 patients referred to surgery as compared with 29 patients treated with angioplasty and 17 patients who only received medical treatment (
P
=0.001). However, no differences were noted in relation to the occurrence of cardiac-related death in the 3 treatment groups (
P
=0.622). No patient assigned to surgery needed repeat operation, whereas 8 patients assigned to angioplasty and 8 patients assigned to medical treatment required surgical bypass after the initial random assignment. Surgery and angioplasty reduced anginal symptoms and stress-induced ischemia considerably. However, all 3 treatments effectively improved limiting angina.

Conclusions
—Bypass surgery for single-vessel coronary artery disease is associated with a lower incidence of medium-term and long-term events as well as fewer anginal symptoms than that found in the patients who underwent angioplasty or medical therapy. In this study, coronary angioplasty was only superior to medical strategies in relation to the anginal status. However, the 3 treatment regimens yielded a similar incidence of acute myocardial infarction and death. Such information should be useful when choosing the best therapeutic option for similar patients.
Regional Left Ventricular Systolic Function in Humans During Off-Pump Coronary Bypass Surgery
Authors: Brown Philip M. , Kim Victor B. , Boyer Bret J. , Lust Robert M. , Chitwood W. Randolph , Elbeery Joseph R.
Published: July 2021

Background
—Controversy exists as to whether off-pump CABG with local occlusion results in clinically significant myocardial ischemia during the occlusion period. This study was undertaken to delineate the effects of transient local coronary artery occlusion on regional systolic function.

Methods and Results
—Eight consenting patients undergoing left internal mammary to left anterior descending coronary artery (LAD) bypass were instrumented with a left ventricular pressure catheter and 2 subepicardial cylindrical ultrasonic dimension transducers placed in the minor axis dimension in the region served by the LAD. A digital sonomicrometer was used to collect data before, during, and after coronary occlusion from which percent systolic shortening and pressure-dimension loops were derived. Measuring devices were removed immediately after the final time point. All patients tolerated the procedure well, and there were no complications. Average duration of local occlusion needed for CABG was 15.9±4.4 minutes (range, 12 to 26 minutes). Local occlusion was associated with a decrease in peak systolic shortening from 5.8±0.8% to 1.8±0.8%. In all cases, function returned to baseline after restoration of flow. Pressure-dimension loops confirmed these findings and no evidence of diastolic creep. Linear repression analysis of degree of stenosis versus change in segmental shortening revealed a significant inverse correlation.

Conclusions
—Local occlusion of the LAD resulted in a transient decrease in myocardial function during occlusion with complete recovery during reperfusion. This change was less significant with increasing degrees of coronary stenosis. These data suggest that local occlusion is not associated with permanent myocardial injury but that ischemic changes do occur that may be clinically significant, especially in patients with lesser degrees of coronary stenosis.
Ascending Aortic Replacement With Aortic Valve Reimplantation
Authors: Harringer Wolfgang , Pethig Klaus , Hagl Christian , Meyer Gerd P. , Haverich Axel
Published: July 2021

Background
—Reimplantation of the native, structurally intact aortic valve within a Dacron tube graft in patients with aortic root aneurysms corrects annular ectasia and dilatation of the sinotubular junction. The durability of this valve repair with respect to the increased mechanical stress on valve cusps has been discussed, is quite controversial, and is yet unknown.

Methods and Results
—From July 1993 to November 1998, a replacement of the ascending aorta with a repair of the aortic valve was performed in 75 patients (53 men and 22 women aged 50±19 years). Twenty-one patients (28%) had Marfan syndrome, and 11 patients (15%) had an aortic dissection, type Stanford A (6 acute, 5 chronic). In 17 patients (23%), concomitant replacement of the aortic arch was necessary. Clinical and echocardiographic follow-up was performed in 6- to 12-month intervals for a cumulative study period of 137 patient-years. No operative deaths occurred. Two patients (3%) died 5 and 20 months postoperatively. One additional patient experienced a transient ischemic attack within the first postoperative week. Three patients (4%) with progressive aortic insufficiency required aortic valve replacement after 9, 11, and 14 months. All other patients had no or mild aortic insufficiency. The repairs have now remained stable for ≤65 months (mean, 22±20 months). Other valve-related complications did not occur.

Conclusions
—Our results demonstrate that this type of aortic valve repair achieves excellent results in selected patients. Perfect coaptation of valve cusps during the repair with no or only trace aortic insufficiency at initial echocardiography seems to be essential for durability.
Vasopressin Deficiency and Pressor Hypersensitivity In Hemodynamically Unstable Organ Donors
Authors: Chen Jonathan M. , Cullinane Suzanne , Spanier Talia B. , Artrip John H. , John Ranjit , Edwards Niloo M. , Oz Mehmet C. , Landry Donald W.
Published: July 2021

Background
—Solid organ donors often develop hypotension due to vasodilation, and recently we observed that a variety of vasodilatory states are characterized by vasopressin deficiency and hypersensitivity. Thus, we investigated the prevalence of vasopressin deficiency in hypotensive solid organ donors without clinical evidence of diabetes insipidus; we also investigated the vasopressor effect of vasopressin replacement in hypotensive donors.

Methods and Results
—Fifty organ donors were evaluated for hemodynamic instability, (mean arterial pressure [MAP]≤ 70 mm Hg despite the use of catecholamine vasopressors), and in those unstable donors who were not already receiving exogenous vasopressin, low-dose vasopressin was administered as a continuous infusion (0.04 to 0.1 U/min). MAP, catecholamine requirements, serum vasopressin, and serum osmolality were obtained before and after vasopressin administration. Ten patients meeting the enrollment criteria received vasopressin and MAP increased from 72.2±3.5 to 89.8±4.2 mm Hg, (
P
<0.05), allowing for complete discontinuation of catecholamine pressors in 4 (40%) patients and a decrement in pressor dose in 4 (40%). Plasma vasopressin levels (2.9±0.8 pg/mL) were low for the degree of hypotension.

Conclusions
—Hemodynamically unstable organ donors without clinically apparent diabetes insipidus display a defect in the baroreflex-mediated secretion of vasopressin. In these patients, low-dose vasopressin significantly increases blood pressure with a pressor response sufficient to reduce catecholamine administration.