bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 308: Papaverine Inhibits Force of Human Saphenous Vein Through Actin Depolymerization and Myosin Light Chain Dephosphorylation
Authors: Hocking Kyle M , Brophy Colleen M , Putumbaka Gowthami , Komalavilas Padmini
Published: July 2021

Background

Papaverine has been used to combat vasospasm in human saphenous veins (HSV) as an alternative to high pressure distension techniques. Papaverine acts as a nonspecific inhibitor of phosphodiesterases, increasing both cGMP and cAMP. We hypothesized that the mechanism by which papaverine reduces force through regulation of actin depolymerization and myosin light chain dephosphorylation.

Methods

HSV was pretreated with 1 mM papaverine followed by 5 μM norepinephrine. Force and intracellular [Ca
2+
]
i
levels were concurrently measured using a Fluoroplex. Tissue was snap frozen for biochemical analyses.

Results

Papaverine completely inhibited norepinephrine-induced force development and intracellular [Ca
2+
]
i
. Papaverine pretreatment led to increases in the phosphorylation of heat shock-related protein 20 (HSPB6), dephosphorylation of myosin light chain, and depolymerization of actin. Pretreament of papaverine led to an association of HSPB6 with 14-3-3 eta as determined by immunoprecipitation and mass spectrometry analysis. The interaction of HSPB6 with 14-3-3 leads to dissociation and activation of cofilin, an actin depolymerizing protein.

Conclusions

These results suggest that papaverine-induced force inhibition of HSV involves decreases in intracellular [Ca
2+
]
i
by inhibiting the calcium regulatory pathways, leading to the dephosphorylation of myosin light chain. Additionally papaverine induces the phosphorylation of HSPB6, which leads to depolymerization of actin. Papaverine inhibits HSV spasm via multiple molecular mechanisms.
Abstract 319: Protein Kinase C-delta Regulates Pro-inflammatory Chemokine Expression Through the NF?B Pathway in Vascular Smooth Muscle Cells
Authors: Ren Jun , Wang Qiwei , Morgan Stephanie , Ravichander Aarthi , Singh Ravneet , Liu Bo
Published: July 2021

Objective-

Inflammation is a key contributor to a plethora of vascular diseases including atherosclerosis and aneurysm. Pro-inflammatory chemokines released by vascular smooth muscle cells (SMCs) play a critical role in vascular inflammation. Previously, we showed protein kinase C-delta (PKCδ) was upregulated in SMCs of inflamed arteries. PKCδ-/- mice are resistant to inflammation as well as apoptosis in models of abdominal aortic aneurysm. We hypothesize that PKCδ modulates the inflammatory response in part through regulation of pro-inflammatory chemokine expression in SMCs.

Method and Results-

To identify PKCδ-regulated chemokines, we used microarray to compare transcription profiles of SMCs infected with AdPKCδ or AdNull. Results showed that 45 out of 203 differentially expressed genes have known inflammatory response roles. RT-PCR analyses confirmed the regulatory effect of PKCδ on selected inflammatory chemokines, including MCP1/CCL2, CCL7, CXCL16 and CX3CL1. Using a mouse aneurysm model, we showed all of these chemokines were elevated in aortae of wildtype, but not PKCδ-/- mice. We postulate that PKCδ regulates chemokine expression via the NFκB pathway. Using MCP-1 as a prototype, a detailed analysis showed PKCδ induced MCP1 mRNA expression (4.25±0.57 fold, n=5, p<0.05) and protein secretion (4.41±0.21 fold, n=3, p<0.05). Analysis of pre-mRNA and mRNA indicated that PKCδ stimulated MCP1 expression at the transcription level rather than by controlling its mRNA stability. Using a NFκB inhibitor (Andrographolide) or siRNA knockdown of NFκB subunit p65 eliminated PKCδ’s effect on MCP1 expression. Physical interaction between PKCδ and p65 was shown in cultured SMCs and aneurysmal aortae by the in situ proximity ligation assay. PKCδ/p65 complexes were detected largely outside the nucleus, indicating the two pathways intersect in the cytosol. This notion is supported by the lack of effect of PKCδ translocation peptides on MCP1. Furthermore, we demonstrated that PKCδ enhanced Ser536 phosphorylation and DNA-binding affinity of p65.

Conclusion-

Our results show PKCδ plays a key role in inflammation through the NFκB-mediated chemokine expression pathway in vascular SMCs and may serve as a suitable target for novel anti-inflammatory therapy.
Abstract 342: Coagulation Pathways Drive Substantial Leukocyte Recruitment Relative to Solitary TLR4-mediated Pathways
Authors: Moerland Matthijs , Naaborgh Lisanne , Kluft Cornelis , Burggraaf Jacobus , Malone Karen
Published: July 2021

Recruitment of leukocytes is critical for controlling infections. However, chronic leukocyte activity is deleterious in a variety of pathological conditions. As such, leukocyte behavior is an attractive pharmacological target, although knowledge is lacking on the exact triggers driving leukocyte migration. We explored the contribution of coagulation pathways versus TLR4 signaling on the leukocyte recruitment by mimicking non-sterile and sterile leukocyte activation. A sterile inflammatory milieu was generated by spontaneous ex-vivo coagulation of human whole blood, a non-sterile milieu by incubating human whole blood with LPS (at the maximal effective dose), inducing TLR-4 mediated cytokines. The chemoattractant activity of supernatant obtained from these conditions was compared by assessment of primary human leukocyte recruitment in transwell cultures, microscopically and by flow cytometry. Human recombinant IL-8 (100 ng/mL) was used as control chemoattractant.

Ex-vivo coagulation resulted in a strong release of IL-8 (119±58 ng/mL), being 5-fold higher than LPS-induced IL-8 release. Leukocyte recruitment (mainly identified as granulocytes) towards the sterile milieu was greater than TLR4-driven chemoattraction. Comparison of recombinant IL-8-induced and coagulation-induced chemotaxis indicated that chemotaxis towards the coagulated milieu was driven by more factors than IL-8 alone. Additional experiments indicated that fibrinogen cleavage product fibrinopeptide B may be involved, as this dose-dependently increased leukocyte migration.

Coagulation activation drives substantial neutrophil recruitment, primarily mediated by IL-8. For this ex-vivo coagulation model, a stronger and differently mediated leukocyte response was observed compared to TLR4-driven chemoattraction. The model can be used to study the involvement of extracellular coagulation pathways in specific inflammatory pathways that differ distinctly from pathways involved in non-sterile inflammatory conditions. This model, when further optimized, may be helpful as a methodological tool for early evaluation of new treatment modalities for chronic inflammatory diseases.
Abstract 360: Cardiometabolic Effects of Young Adult Overweight and Obesity
Authors: Bernstein Stephen A
Published: July 2021

INTRODUCTION

Little data exists referencing the cardiometabolic effects in young adult. BMI does not account well for body shape and size and has weaknesses. Waist:height ratio along with other modalities have been assessed for improving health metrics for patient care with balancing strength and utility problems with ease of use.

METHODS

Baseline and sequential anthropometric data was collected from 42 deployed overweight Army soldiers command directed to battalion medical for weight loss while in the combat zone. This data is presented for discussion and correlation with their individual success/failure to lose weight while being supervised to pass the Army’s calculated percentage body fat standards.

RESULTS

Baseline mean waist circumference was 96cm for females, 106cm for males. Initial mean glucose was 102mg/dl for females, 106mg/dl for males. Initial mean HDL was 52 mg/dl for females, 37 mg/dl. Total cholesterol and triglyceride levels were normal for 75%. With intervention, fasting glucose normalized. All began with waist circumference over 55% of their waist:height ratio. Those who brought their waist:height below 55% passed Army standards. Internal motivation was key.

DISCUSSION

Often young adults do not seek healthcare, do not carry health insurance, and do not seek preventive health. Adolescence issues carry into adulthood and with the current obesity trends, only points to more severe and earlier issues with cardiovascular diseases. This group already had metabolic or pre-metabolic syndrome, highlighting the cardiometabolic hazards present. No comparative data exists–this age has largely been ignored/unaddressed. As opposed to BMI, measuring waist circumference is simple, easy, office based measurement. Waist circumference gives a better marker of central adiposity, which correlates to cardiometabolic risk. Adding this measurement helps refine meaning to BMI. Athletes have higher BMIs but normal waist:height ratios and are more normal. Likewise, the ratio may improve defining metabolic syndrome criteria, where 55% should be the trigger. Measuring waist circumference is easy in the office and patient friendly at home–providing a better target and guidance for helping patients improve their overall heart health.
Abstract 362: Characterization of Triglyceride-Rich Remnant Lipoproteins in the Hypertriglyceridemic Fredrickson-Levy Dyslipidemic Phenotypes without Chylomicrons: The Very Large Database of Lipids (VLDL-6)
Authors: Hassan Kamran , Jones Steven R , Martin Seth S , Joshi Parag H , Blaha Michael J , Elshazly Mohamed , Kulkarni Krishnaji R , Toth Peter P
Published: July 2021

Background

The major dyslipidemia (DL) classes are relatively rare with limited phenotypic characterization across large populations.

Methods

We studied 1,340,614 U.S. adults from the Very Large Database of Lipids. Lipid testing was by ultracentrifugation (VAP, Atherotech, Birmingham, AL). Distributions of total cholesterol (TC), HDL-C, LDL-C and triglycerides (TG) in the database were superimposable with those in the NHANES 2007-2008 survey. We used the following criteria to classify the excess lipoprotein components of DL in subjects with TG >130 mg/dL without chylomicrons (CM): VLDL-C or LDLr-C (directly measured LDL-C - Lp(a)-C -IDL-C) > 90
th
percentile, Type III DL remnant lipoprotein cholesterol (RLP-C = VLDL3-C + IDL-C) excess by criterion of VLDL-C/TG > 0.3. The remaining subjects (continuum) not classified by DL criteria were further stratified by TG/HDL-C <3 vs. >3, associated with insulin resistance.

Results

VLDL3-C/ IDL-C ratio was approximately 1 across DL and the continuum groups. The highest concentration of RLP-C was in Type III DL; lesser RLP-C elevation is present in all DL characterized by VLDL excess. The highest non-HDL-C was present in type IIb with lesser elevations in types III and IV. RLP-C was higher in the TG/HDL-C>3 continuum than TG/HDL-C<3 continuum reference group (Table).

In addition to type III, the major non-CM DL is frequently associated with excess RLP-C. RLP-C tended to be normal in the continuum subjects, trending higher in those with TG/HDL-C>3.
Abstract 365: Increased Plasma Cholesterol Esterification by Lecithin-Cholesterol Acyltransferase Prevents Dysfunction of Red Blood Cells and Platelets and Protects from Development of Diet-Induced Atherosclerosis
Authors: Thacker Seth G , Rousset Xavier , Vaisman Boris L , Amar Marcelo J , Freeman Lita A , Esmail Safiya , Stonik John A , Remaley Alan T
Published: July 2021

Introduction

Free cholesterol plays a vital role in maintaining cell membrane fluidity and function. Elevated levels of cholesterol in red blood cells (RBC) and platelets have been demonstrated to impair the function of these cells. In circulation, free cholesterol freely exchanges between cells and lipoproteins and lecithin-cholesterol acyltransferase (LCAT) plays a role in this exchange. The esterification of cholesterol by LCAT sequesters it in the interior of lipoprotein particles and thereby limits its movement between lipoproteins and cells. Previously, SR-B1 KO mice have been shown to have dysfunctional RBCs and platelets and this dysfunction is exacerbated by a high fat diet. These mice have a partial defect in cholesterol esterification and are susceptible to diet induced atherosclerosis.

Hypothesis

We assessed in SR-BI KO mice whether increased cholesterol esterification by LCAT would improve numbers of RBCs and platelets, as well as prevent the development of atherosclerosis.

Methods and Results

Control (C57BL/6), SR-B1 KO, SR-B1 KO x LCAT KO(DKO), and SR-B1 KO x LCAT-Trg(LCAT-Trg) mice were maintained on a western diet for 7 months. As previously observed, SR-B1 KO mice had decrease numbers of RBCs and platelets compared to control mice, and over expression of LCAT restored levels to that of wild type mice, while loss of LCAT further abrogated the decrease in cell counts(n=10). Unexpectedly, LCAT-Trg mice has the highest levels of cholesterol in plasma, but RBC and platelets showed the lowest levels of free cholesterol, as assessed by filipin staining. Atherosclerosis in western diet fed mice was assessed by Oil Red O in two ways by looking at the aortic root(n=4) and by en face analysis of the aorta(n=10). In the aortic root SRB-1KO and DKO mice showed 3x the amount of lesion size as controls, while LCAT-Trg mice had levels comparable to the controls mice. The en face analysis also showed that DKO mice had 3x the amount of lesions, while LCAT-Trg and SRB-1KO mice had levels comparable to control mice.

Conclusion

LCAT is able to modulate the movement of cholesterol between circulating cells and lipoproteins thereby protecting RBCs and platelets. Our results further demonstrate a possible benefit of LCAT on the progression of atherosclerosis.
Abstract 375: Inducible ApoE Gene Repair in HypoE Mice Deficient in the LDL Receptor Promotes Atheroma Stabilization with a Human-like Lipoprotein Profile
Authors: Luk Fu Sang , Eberle Delphine , Kim Roy Y , Olivas Victor , Kumar Nikit , Posada Jessica M , Li Kang , Gaudreault Nathalie , Rapp Joseph H , Raffai Robert L
Published: July 2021

Studies of atherosclerosis regression often investigated the process in the setting of a plasma lipoprotein profile dominated by HDL. To better model humans subjected to lipid lowering therapy, we sought to study atherosclerosis regression in mice that displayed moderately elevated plasma LDL. To achieve this goal, we made use of our HypoE mice deficient in the LDL receptor (Apoeh/hLdlr−/−Mx1-Cre mice) that develop spontaneous hyperlipidemia and atherosclerosis on a chow diet due to reduced apoE expression levels. Twenty-week old mice were studied before and after inducible Cre-mediated Apoe gene repair. After 1 week, induced mice displayed a 2-fold reduction in plasma cholesterol and triglyceride to 337±27 mg/dl and 182±15 mg/dl respectively. This led to a rise in plasma HDL and apoAI levels as well as large apoE-rich HDL. The resulting non-HDL:HDL cholesterol ratio decreased from 7 (87%:13%) to 1.5 (60%:40%). These plasma lipid changes occurred in mice that were fed a chow diet throughout the study, allowing us to study atheroma remodeling in the absence of potential confounding effects due to feeding or withdrawal of a high fat diet. Normalizing Apoe gene expression halted atherosclerosis progression and promoted lesional macrophage loss and collagen accumulation for up to 8 weeks. However, this did not lead to a significant loss of arterial lipid. Concomitantly, blood Ly-6Chi monocytes were decreased by 2-fold but lesional macrophage apoptosis was unchanged. The expression of several genes involved in extra-cellular matrix remodeling and cell migration were changed in lesional macrophages isolated by laser capture microdissection 1 week after Apoe gene repair. However, mRNA levels of numerous genes involved in cholesterol efflux were not significantly changed at this time point. Collectively, our data demonstrate that an abrupt reduction of hyperlipidemia to a normal human-like ratio of plasma non-HDL:HDL cholesterol, can promote lesion stabilization in the absence of arterial lipid loss. Future studies of circulating monocytes and lesional macrophages in our model will seek to uncover genetic pathways that can be manipulated therapeutically to promote atherosclerosis stabilization and regression in the setting of moderately elevated LDL.
Abstract 4: Apolipoprotein A-iv Enhances Triglyceride Secretion and Reduces Hepatic Lipid Content by Promoting Apob Containing-lipoprotein Particle Expansion in Livers of Steatotic Mice
Authors: VerHague Melissa , MacArthur Philip , Brown Amanda , Cheng Dongmei , Weinberg Richard , Shelness Gregory
Published: July 2021

Apolipoprotein A-IV (apoA-IV) is a lipid binding protein expressed in mammalian intestine, as well as rodent liver. While previous in vitro studies demonstrated that apoA-IV promotes cellular triglyceride (TG) secretion by modulating apoB secretory trafficking and lipoprotein size, evidence that apoA-IV affects TG secretion in vivo is lacking. To explore the possible role of apoA-IV in controlling hepatic VLDL-mediated lipid efflux we assessed whether apoA-IV is regulated by liver lipid accumulation and if its deficiency or overexpression affects hepatic TG secretion. Under conditions of high fat diet-induced hepatic steatosis and steatosis caused by transgenic overexpression of SREBP-1a (SREBP-1aTg), a ~40-fold induction of hepatic apoA-IV mRNA and protein was observed. In both systems there was a linear correlation between hepatic TG content and apoA-IV mRNA abundance (r2 = 0.8965). To establish whether the induction of apoA-IV impacted TG secretion, SREBP-1aTg mice were crossed with apoA-IV knock out mice (A4-KO). Based on the Triton block method, SREBP1aTg/A4-KO mice demonstrated a 24% reduction in hepatic TG secretion rate, relative to SREBP1aTg controls. The basis for the decrease in TG secretion was not due to decreased particle number, as apoB production was unaffected; however, negative stain electron microscopy revealed a 33% decrease in the abundance of large diameter (>120 nm) VLDL particles. To explore the impact of human apoA-IV overexpression, a recombinant apoA-IV adenovirus (AdA4) was developed. Mice infected with AdA4 demonstrated abundant hepatic expression of human apoA-IV, and a 50% increase in hepatic TG secretion rate, relative to the LacZ control. In addition, after only three days of expression AdA4 reduced liver TG content by 40%. Although again, apoA-IV expression did not impact apoB secretion, negative stain electron microscopy revealed a 1.8-fold increase in the abundance of large diameter VLDL particles. In conclusion, we demonstrate that in steatotic mice, hepatic apoA-IV expression increases TG secretion by promoting lipoprotein particle expansion, thereby dramatically reducing hepatic lipid burden without increasing atherogenic lipoprotein particle number.
Abstract 404: Altered Interaction of Modified High Density Lipoprotein with Scavenger Receptor BI
Authors: Chadwick Alexandra C , Holme Rebecca L , Nesbeth Paula-Dene C , Pritchard Kirkwood A , Sahoo Daisy
Published: July 2021

High density lipoprotein (HDL) combats atherosclerosis, largely through its role in the reverse cholesterol transport (RCT) pathway where excess cholesterol from peripheral tissues is transported by HDL to the liver for excretion. High HDL-cholesterol (HDL-C) levels have been traditionally linked to a lower risk for cardiovascular disease (CVD). However, recent evidence suggests that HDL “function”, rather than HDL levels, is a better indicator of CVD risk as modifications to HDL under oxidative stress can render the particles “dysfunctional”. Scavenger receptor BI (SR-BI), the HDL receptor, mediates the selective uptake of HDL-cholesteryl ester (CE) into the liver during RCT. We hypothesized that SR-BI would be unable to mediate its cholesterol transport functions in the presence of oxidized or modified HDL due to an inability to engage in productive binding interactions with modified ligands. To test this hypothesis, we assessed HDL binding and selective uptake of HDL-CE in COS7 cells transiently expressing SR-BI using native HDL or HDL modified with: 1) copper (Cu2+), 2) 4-hydroxynonenal (HNE), or 3) acrolein. Our data revealed that, compared to native HDL, SR-BI bound 20-50% less Cu2+-HDL and acrolein-HDL, and mediated 40%-60% less selective uptake of CE from these modified particles, respectively. On the other hand, while SR-BI was able to bind HNE-HDL, it could not efficiently mediate cholesterol uptake (20% less compared to native HDL). Interestingly, our data also revealed that the ability of SR-BI to mediate the release of free cholesterol from COS7 cells did not differ when modified HDL served as acceptor particles, as compared to native HDL. Taken together, only the HDL binding and HDL-CE selective uptake functions of SR-BI are influenced by the type of modification on the HDL particle. These data have significant implications as they suggest that higher levels of plasma HDL-C may, in part, be the result of the inability of SR-BI to recognize and mediate cholesterol removal from HDL particles that have been exposed to oxidative stress. More detailed investigations of the interactions between SR-BI and various populations of oxidized HDL will improve our understanding of the mechanisms that render HDL dysfunctional, and ultimately, atherogenic.
Abstract 417: Using Self-management Support (sms) Goal Setting for Weight Control in Diabetic Patients at an Ambulatory Internal Medicine Center
Authors: Jiang Bo , Shi Qi , Jia Jihua , Tadros Sherine , Novak Gregg , Seth Jigneth , Thomas-Hemak Linda
Published: July 2021

Introduction

Obesity is a major comorbidity that compounds the health consequences of diabetes. Effective weight control through behavior modification is an effective component for diabetic management, and can easily be counseled and implemented through primary care visits. Setting self-management Support (SMS) goals, which incorporates the needs, goals, and life experiences of patients, may improve clinical outcomes, health status, and quality of life. We hypothesized that setting SMS goals in primary care visits empowers diabetic patients to lose weight.

Methods

A chart review was conducted on a total of 205 diabetic patients. SMS goals of weight-control plan (diet and/or exercise) were incorporated into patients’ electronic medical records. A total of 115 (56%) patients included SMS goals in their treatment plan, and 90 (44%) patients did not contain SMS goals. Body weights of these patients were assessed at baseline and after 6 months of follow up.

Results

35 (17 %) diabetic patients were overweight and 152 (74 %) were obese in our practice. During 6 months of follow up, 64/115 (56%) patients with SMS goals documented lost weight ( ≥ 5 lb weight loss), compared to 9/31 (29 %) in patients with no SMS goal set. When comparing effect of diet only with the combination of diet and exercise, we found that 47/73 (64 %) patients with the combination SMS goal settings lost weight, while only 17/42 (40 %) of patients with the diet only SMS plans lost body weight.

Discussion

Our study highlights the importance of educating patients to maintain physical activity and healthy diet, but more importantly shows that empowering patients to agree upon and be active in goal setting is a powerful tool for disease management. Setting SMS goals may assist providers in giving patients their self-defined circle of support, so that patients can manage their conditions on a daily basis, and develop the confidence to sustain healthy behaviors for a lifetime. In addition, SMS goal-setting and progress-monitoring during each encounter help providers to assess the motivation and engagement of patients for behavior modification. Last, the dynamic physician-patient relationship during goal setting and assessment facilitates patient compliance and eventually successful weight loss.
Abstract 420: The Ratio of L-arginine to Asymmetric Dimethylarginine is Associated With Brachial-ankle Pulse Wave Velocity in Patients Undergoing Coronary Angiography
Authors: Masaki Nobuyuki , Shiraishi Yasunaga , Nakaya Yuko , Kujiraoka Takehiko , Yada Hirotaka , Hakuno Daihiko , Isoda Kikuo , Kimura Kazuo , Miyazaki Koji , Adachi Takeshi
Published: July 2021

Background

Endothelial dysfunction decrease vasomotor function and cause vascular stiffening in addition to the structural changes. Relative L-arginine deficiency to ADMA influencing NO synthesis may increase arterial stiffness in elderly individuals. We investigated the relationship between the L-arginine / ADMA ratio and brachial ankle pulse wave velocity (baPWV) of the patients with suspected or already known coronary artery disease (CAD).

Methods and Results

The cross-sectional study enrolled 74 patients (67 ± 10 y/o) undergoing coronary angiography. There were 54 (73%) patients with CAD including 3 of coronary bypass surgery, and 11 of old myocardial infarction. Exclusion criteria were ankle brachial index (ABI) less than 0.9 in both lower extremities and hemodialysis. baPWV and ABI were obtained using an automatic waveform analyzer. Serum L-arginine, ADMA were measured by high-performance liquid chromatography. The ratio of L-arginine to ADMA was associated with baPWV (γ= -0.323, p=0.005) (Figure). Although the value of baPWV was dependent on systolic blood pressure and heart rate at measurement as reported previously, the ratio was a significant predictor of baPWV in multivariate analysis (β= -0.448, p<0.001). Additionally, serum L-arginine, and L-arginine / ADMA ratio were also independent contributing factors to baPWV in the subgroup of 46 elderly patients (>64 y/o).

Conclusion

We observed that many ageing patients with cardiovascular disease had low L-arginine / ADMA ratio accompanied with high baPWV. The findings suggested that correction of serum L-arginine level can be a therapeutic option to recover arterial compliance for the population.
Abstract 434: Insig-2a Links CREBH Signaling to Hepatic Lipogenesis and Systemic Hyperlipidemia
Authors: Wang Hai , Su Qiaozhu
Published: July 2021

The sterol regulatory element binding proteins (SREBPs) are master transcription factors that regulate hepatic de novo lipogenesis. Perturbation of SREBPs functionality is closely related to the onset of hyperlipidemia. The current investigation sought to advance our understanding on the activation of SREBP-1c via the interplay between the cAMP responsive element binding protein H (CREBH) and the liver specific insulin-induced gene 2a isoform (Insig-2a). Genetic depletion of CREBH specifically down regulated expression of both Insign-2a mRNA and protein levels which resulted in the hyperactivation of SREBP-1c and the subsequent hypertriglyceridemia. Challenging wild type (WT) mice with a high fat diet

(HFD) specifically stimulated expression of Insig-2a mRNA and protein in the WT mice. In contrast, HFD failed to enhance expressions of Insig-2a mRNA and protein in CREBH-null mice. No alterations were detected on the mRNA transcription of another Insig-2 isoform, Insig-2b, in the livers of WT mice and CREBH-null mice under both chow and HFD conditions. Decrease of Insig-2a caused activation of hepatic de novo lipogenesis, mainly via SREBP-1c activation, which contributed to the development of sever systemic hypertriglyceridemia and hepatic steatosis in CREBH-null mice. Consistent with the in vivo observation, forced expression of CREBH cDNA in a rat hepatoma cell line, McA cells, specifically increased expressions of both Insig-2a mRNA and protein which in turn inhibited activation of SCREBP-1c. Analyzing the gene promoter of Insig-2a, we identified a CREB binding site at the promoter of the Insig-2a and a ChIP assay further confirmed the physical association between CREBH and the Insig-2a promoter. These data identify Insig-2a as a target gene of CREBH. Modulation of Insig-2a expression by CREBH is essentially involved in regulating hepatic triglyceride metabolism. Given the role of CREBH in hepatic acute phage response signaling, this finding further reveals the cross-talk between inflammatory and insulin signal pathways in maintaining systemic lipid homeostasis and may provide rationale for pharmaceutical design to specifically target CREBH and insig-2a in the prevention and treatment of hypertriglyceridemia.
Abstract 48: Deletion of the Neuronal Guidance Molecule Epha2 Reduces Inflammation in Experimental Atherosclerosis
Authors: Funk Steven D , Yurdagul Arif , Green Jonette , Albert Patrick , McInnis Marshall , Chen Jin , Kevil Christopher G , Orr Wayne
Published: July 2021

Neuronal guidance molecules are increasingly implicated in inflammatory responses. Recently, our group demonstrated enhanced expression of the neuronal guidance molecule EphA2 and its ephrinA1 ligand in mouse and human atherosclerotic plaques, and elucidated a novel proinflammatory function for EphA2 perpetuating proinflammatory gene expression during endothelial cell activation. However, a direct role for Eph/ephrins in atherosclerosis has never been demonstrated. We now show that knocking out the EphA2 gene in Western diet-fed ApoE mice blunts atherosclerotic plaque location at multiple sites. This reduction in atherosclerosis is associated with decreased monocyte infiltration and diminished expression of proinflammatory genes. EphA2 reduction may affect monocyte homing through multiple mechanisms, since reducing EphA2 expression in cytokine-activated endothelial cells does not affect endothelial adhesion molecule expression or monocyte rolling but significantly decreases firm adhesion in primary human monocytes. Like endothelial cells, plaque macrophages also express EphA2, and macrophages derived from EphA2 deficient mice show diminished expression of M1 marker genes and enhanced expression of M2 marker genes compared to their ApoE counterparts. Surprisingly, EphA2 deficient mice show significantly elevated plasma cholesterol. However, this elevation does not involve increased LDL levels but instead occurs due to elevations in plasma HDL levels. Taken together, the current data suggest EphA2 inhibition results in a multifaceted protective effect on experimental atherosclerosis characterized by reduced endothelial cell activation, monocyte recruitment, and M1/M2 polarization and enhanced circulating HDL levels.
Abstract 484: Real World Experience with the Use of Dabigatran
Authors: Rajdev Archana , Bradley Jacqueline , Santos Eric , Penciu Oanal , Alexander Jonathan
Published: July 2021

Background

The RE-LY trial in 2009 ushered in a new era in anticoagulation options for stroke prevention in atrial fibrillation.We sought to determine the safety, efficacy, and tolerability of dabigatran in a community setting.

Methods

We retrospectively reviewed demographics, bleeding rates, stroke rates, and reasons for discontinuation in patients on dabigatran for non-valvular atrial fibrillation.

Results

Of the 263 patients, mean age was 73.8 years (32 to 96) and 41.06% were female. The 150 mg BID dose was used in 93.54% of patients and 75 mg BID in 6.46%. Major bleeding was noted in 4 (1.52%), minor bleeding in 25 (9.5%), and rate of discontinuation was 22.3%. Patients who experienced major bleeding were more likely to be older, male, have higher HAS-BLED scores, and a history of gastrointestinal bleeds. All these patients were managed conservatively with no mortality.Of note, three of the four patients with major bleeds were on amiodarone in addition to dabigatran 150 mg BID.Two presented with transient ischemic attacks and had elevated PTTs suggesting compliance with dabigatran. Four patients who were admitted to the hospital with pneumonia, atrial fibrillation, and COPD exacerbation had elevated troponins without accompanying symptoms of acute coronary syndrome. In patients maintained on the 75 mg BID dose, minor bleeding was noted in two, who were also on dronedarone. No strokes or intracranial bleeds were noted in patients on either dose of dabigatran

Conclusions

This retrospective analysis demonstrates safety and efficacy of dabigatran as an oral anticoagulant in patients with non-valvular atrial fibrillation over a two-year follow-up while describing the factors associated with increased bleeding risk.It is the first study to describe experience with use of 75 mg of dabigatran. Drug interactions are a common and avoidable reason for dabigatran-associated bleeding and were noted with both amiodarone and dronedarone in our study. There was no increased incidence of myocardial infarction noted. In our study population, dabigatran is safe, effective, and convenient when there is careful patient selection with consideration of renal function and possible drug-drug interactions
Abstract 495: MicroRNA-155 Modulates Endothelial Intracellular Adhesion Molecule-1 Expression
Authors: Virtue Anthony , Wang Hong , Yang Xiao-Feng
Published: July 2021

The endothelium is essential in maintaining vascular tone, thrombosis, vascular remodeling, signal transduction, and inflammation by directly producing cytokines and chemokines which act in cell signaling and the recruitment of lymphocytes. In addition, the up-regulation of adhesion molecules such as vascular adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), E-selectin, and P-selectin aid in leukocyte adherence and diapedesis. This collective alteration in the physiological characteristics of endothelial cells is commonly referred to as endothelial activation. Currently, microRNA regulation of endothelial cell activation remains poorly characterized. Specifically, microRNA-155 (miR-155) has been found to play an important role in the development and function of several immune cell types such as dendritic cells, macrophages, B-cells, and T-cells. However, the capacity of miR-155 to participate in a phenotypic change in non-traditional immune cells to a pro-inflammatory state has yet to be examined. In order to address this short-coming, our research focuses on whether the expression miR-155, affects endothelial activation. Thus far, we have determined that the expression of miR-155 can be modulated by pro-inflammatory mediators traditionally associated with endothelial activation such as disturbed flow, TNF-α, IL-1β and lipopolysaccharide. In addition to its inducible expression within endothelial cells, we have found that miR-155 can specifically alter ICAM-1 expression. Western blots with protein from excised aortas of miR-155
-/-
mice reveal significantly reduced ICAM-1 expression when compared to WT mice. This data was further confirmed
in vitro
with protein gathered from cultured mouse aortic endothelial cells. Additionally, in accordance with the modulated ICAM-1 expression, we found monocyte adhesion to endothelial cells over-expressing miR-155 to be increased. In conclusion, these preliminary findings suggest that miR-155 plays a major role in endothelial activation, and therefore regulation of miR-155 expression holds significant therapeutic potential in the treatment of cardiovascular diseases.
Abstract 528: Nogo-B Receptor is Essential for Primitive Blood Vessel Formation and Vasculature Development in Mouse Embryo
Authors: Liu Zhong , Rana Ujala , Zhao Baofeng , Miao Qing R
Published: July 2021

Nogo-B was previously identified as a protein that is expressed in endothelial cells and vascular smooth muscle cells. Nogo-A/B deficient mice show exaggerated neointimal proliferation and abnormal remodeling. Nogo-B receptor (NgBR) is a type I receptor, which was identified as a receptor specific for Nogo-B. Our previous work has shown that Nogo-B and its receptor (NgBR) are essential for chemotaxis and morphogenesis of endothelial cells in vitro and intersomitic vessel formation via Akt pathway in zebrafish. Our recent work reveals that NgBR is a critic membrane scaffold protein required for Ras translocation and activation, which is essential for VEGF-stimulated Ras-PI3K-Akt signaling pathway. Here, we further demonstrate the roles of NgBR in regulating primitive blood vessel formation in embryoid body culture systems and vasculature development in mouse embryo. Murine NgBR gene-targeting embryonic stem cells (ESC) were generated by homologous recombination approaches. Homozygous knockout of NgBR in ESC results in cell apoptosis. Heterozygous knockout of NgBR does not affect ESC cell survival, but reduces the formation and branching of primitive blood vessels in embryoid body culture systems. In addition, our preliminary results show that NgBR homozygous knockout mice are embryonic lethal happened at E6.5 or earlier, and endothelial cell specific NgBR knockout mice are embryonic lethal happened at E11.5 and have severe blood vessel formation defects in embryo. Mechanistically, NgBR has two potential regulatory roles during embryonic vasculature development. NgBR knockdown not only decreases both Nogo-B and VEGF-stimulated endothelial cell migration by abolishing Akt phosphorylation, but also impairs endothelial cell lineage commitment by delaying BMP4 production during the period of mesoderm formation. These results suggest that NgBR may be one of important genes coordinating the vasculature development.
Abstract 538: Effects of Mechanical and Biological Factors on Responses of Vascular Smooth Muscle Cells
Authors: Kadapure Tejaswi , Tambe Pranjali , Jadeja Path , Chiao Jung-Chih , Chuong Cheng-Jen , Nguyen Kytai T
Published: July 2021

Biomechanical factors, including stretch, play a very important role in normal vascular function and in the early development of vascular diseases such as atherosclerosis. Although the cause(s) for vascular diseases have yet to be determined, we believe that effects of combined biological and biomechanical factors on smooth muscle cell (SMC) responses may play an important role in the maintenance of normal vascular functions and the disease development. Thus the main objective of this research is to investigate the responses of HASMCs (Human aortic smooth muscle cells) towards stretch and growth factors using the novel microarray stretch system developed in our group. HASMCs seeded on plasma-treated, fibronectin-coated PDMS microwells were exposed to either with or without various growth factors (i.e. EGF, FGF, VEGF, and TGFbeta) while stretching for a period of 72 hours. These cells were then observed under the microscope to evaluate the alignment and were analyzed for cell responses, including cell growth using the PicoGreen DNA assays. Static cells exposed with growth factors were also studied for comparison. We observed that HASMCs responded extensively to stretch as the cells aligned in the direction perpendicular to the direction of stretch, unlike the static conditions that showed random alignment. The addition of growth factors (10ng/ml) didn’t alter this cell alignment. Physiological level of stretch (10% strain) inhibited the cell proliferation induced by all of the studied growth factors with the highest inhibition observed in cells exposed to stretch and FGF. Our results indicate that we can apply our novel microarray stretch system to evaluate cell responses to stretch and various biological factors and that stretch and growth factors did alter cell behaviors. These results will also help us to better understand SMC responses to physical and biological changes and the involved mechanisms.
Abstract 539: MicroRNA-27b Regulates Salt-Inducible Kinase 1 (SIK1) in Vascular Fibrosis
Authors: Brion Laura , Chernogubova Ekaterina , Eken Suzanne M , Jin Hong , Eriksson Per , Bertorello Alejandro , Maegdefessel Lars
Published: July 2021

Arterial fibrosis is one of the main underlying causes of vascular stiffness and various associated diseases, such as hypertension, congestive heart failure, aortic aneurysm development and renal failure. Consequently there is a growing interest in (patho)-mechanisms governing the underlying process of arterial fibrosis and successive vascular stiffness. Recently, a novel class of small noncoding RNAs, termed microRNAs (miRs), have emerged as powerful cellular regulators in disease processes. Furthermore, they have become an intriguing target for therapeutic intervention. Aim of the present study was to explore whether miRs are regulating the expression of salt-inducible kinase 1 (SIK1), which we previously identified as a crucial regulator of fibrosis in heart-/kidney- failure and arterial hypertension.

Using different bioinformatic target prediction algorithms, we identified several miRs with predicted conserved sites on the Sik1 gene, including miRs-27a/b, -130a, -148a/b and -152. By analyzing aorta, heart and kidney specimen from Sik-/- and Sik+/+ mice, we were able to detect that miR-27b was the only miR being significantly altered in all three tissues. We proceeded by treating human aortic smooth muscle cells as well as adventitial fibroblasts with TGF-β, to induce a pro-fibrotic response. Interestingly, treatment with TGF-β substantially increased miR-27b expression as well as other components of the extracellular matrix, such as collagen (Col1a1) and fibronectin (Fn1) through repression of SIK1. Overexpression of miR-27b, utilizing a pre-miR precursor, substantially decreased SIK-1 expression and further augmented the pro-fibrotic response, as indicated by raising collagen and Fn1 expressions.

The present study explores the regulatory role of miR-27b in different vascular fibrosis associated pathologies. We were able to show that miR-27b, a novel downstream-target of TGF-β signalling pathways, suppresses the expression of SIK1, which itself has been identified as a key regulator of arterial hypertension and consequential heart and kidney failure. On-going studies, utilizing inhibition of miR-27b can become an interesting novel therapeutic strategy to regulate SIK1 levels in vascular fibrosis and arterial stiffness.
Abstract 541: RAGE Regulates Cellular Migration and Adhesion Through Proteolysis of Its Ectodomain
Authors: Jules Joel , Harja Evis , Hudson Barry I
Published: July 2021

Introduction

Enhanced expression of the Receptor for Advanced Glycation End-products (RAGE) not only plays deleterious roles in various vascular diseases but also affects many vascular properties including endothelial permeability, leukocyte adhesion and transmigration. Decreased serum level of soluble RAGE (sRAGE), which inhibits RAGE functions, has been associated with various inflammatory diseases including atherosclerosis. Notably, several studies have shown that the release of sRAGE ectodomain (ECD) occurs by proteolysis from the cell surface. However, little is known about how this process is regulated and the functional effects of RAGE ECD shedding.

Hypothesis

We hypothesize that shedding of RAGE ECD is a fundamental process regulating cell signaling pathways leading to altered cell function.

Methods & Results

Toward this end, we first demonstrated that RAGE ECD shedding is a conserved mechanism in humans and mice. Next, we showed that common activators of ECD shedding, such as the protein kinase C activator PMA; the metalloproteinase-activator APMA; and the calcium ionophore ionomycin, can induce RAGE ECD release. Furthermore, various inflammatory mediators including CRP and TNF-alpha can induce RAGE ECD shedding. Inhibition studies revealed RAGE ECD shedding could be blocked by metalloproteinase, PKC, and various MAP kinase inhibitors. Finally, utilizing a proteolytically resistant splice variant of RAGE lacking the ECD shedding site (RAGEv4), we investigated the cellular function of RAGE shedding. Compared to cell expressing RAGE or empty vector, the expression of RAGEv4 resulted in impeded cell migration. Moreover, RAGEv4 reduced cellular adhesion as compared to vector control and RAGE expressing cells. Key downstream signaling pathways affected by RAGE ECD shedding are being currently investigated.

Conclusions

RAGE ECD shedding is a conserved and tightly regulated mechanism involving distinct signaling pathways. Shedding of RAGE regulates key cellular properties including adhesion and migration. Our data suggest that proteolysis of RAGE is a major regulatory process and may emerge as a novel therapeutic target for cardiovascular diseases.
Abstract 55: Recruitment of Ly6Chigh Monocytes is Required for the Enhancement of Anti-inflammatory (M2) Macrophage Phenotype in Atherosclerosis Regression in vivo
Authors: Vengrenyuk Yuliya , Girgis Natasha , Loke Png , Fisher Edward A
Published: July 2021

Regression of atherosclerotic lesions is an important clinical goal. We’ve reported several mouse models of atherosclerosis regression in which an improvement of plasma lipoprotein profiles results in a rapid reduction of lesion macrophage content. Another common feature was a dramatic phenotypic enrichment of plaque CD68+ cells (macrophages) in markers of the anti-inflammatory (M2) state. Here, we investigate the origin of M2 macrophages in regression by modifying our aortic transplantation model to include recipients whose monocytes lack the major receptors responsible for their recruitment into tissues. Aortic arches from hyperlipidemic apoE
-/-
mice were transplanted into CCR2
-/-
, CX3CR1
-/-
, or CCR5
-/-
mice, in addition to WT and apoE
-/-
controls. Macrophage marker CD68
+
area quantification data showed that the lack of CCR2 or CX3CR1 in transplant recipients blocked regression despite the reversal of dyslipidemia, while CCR5 deficiency had no effect. Since inflammation-prone Ly6C
high
monocytes require both CCR2 and CX3CR1 to enter atherosclerotic lesions, our results suggest that the recruitment of new Ly6C
high
monocytes is required for regression. Furthermore, CCR2
-/-
and CX3CR1
-/-
recipients lacked M2 macrophages in atherosclerotic lesions, suggesting that the M2 macrophages in regression are derived from the recruitment of Ly6C
high
monocytes. Finally, we tested if M2 enrichment in regression follows the classical IL/4-STAT6 pathway by using STAT6
-/-
mice as transplant recipients. The lack of STAT6 not only prevented upregulation of M2 markers, but also resulted in impaired lesion regression.
In conclusion
, we showed that newly recruited Ly6C
high
monocytes give rise to the anti-inflammatory M2 macrophages under regression conditions in a STAT6-dependent manner, and that both the recruitment of new cells and a functioning STAT6 pathway are also required for atherosclerosis regression. The results argue against the possibility that M1 macrophages repolarize to the M2 phenotype under regression conditions
in vivo
and support the notion that regression is not a rewinding of progression, but requires the participation of newly recruited inflammation-prone monocytes that in this context promote the resolution of inflammation.