Abstract 13383: The Vascular Endothelial Barrier: A Novel Therapeutic Target for Preventing Atrial Fibrillation

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Louisa Mezache ◽  
Heather Struckman ◽  
Anna Phillips ◽  
Stephen Baine ◽  
Amara Greer-short ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Ex Vivo ◽  
Vascular Dysfunction ◽  
Super Resolution ◽  
Vascular Endothelial ◽  
Vascular Leak ◽  
Barrier Breakdown ◽  
Endothelial Growth Factor ◽  
Intercalated Disk

Atrial fibrillation (AF), the most common arrhythmia, is associated with inflammation and vascular dysfunction. AF patients have elevated levels of vascular endothelial growth factor (VEGF; 90-580 pg/ml), which promotes vascular leak and edema. We have previously identified edema-induced disruption of sodium channel (Na V 1.5) -rich intercalated disk (ID) nanodomains as a novel arrhythmia mechanism. We hypothesized that (i) elevated VEGF levels promote AF by disrupting ID nanodomains, and slowing atrial conduction, and (ii) protection of the vascular barrier can prevent these arrhythmias. Clinically-relevant VEGF levels (500 pg/ml, 60 minutes) increased FITC-dextran extravasation (99.3% vs. 24.3% in vehicle controls) in WT mouse hearts, consistent with increased vascular leak. Electron microscopy revealed ID nanodomain swelling, near both gap junctions (perinexi; 64±9nm vs 17±1nm) and mechanical junctions (63±4nm vs 27±2nm) in VEGF-treated hearts relative to controls. Super-resolution STORM microscopy revealed Na V 1.5 enrichment at perinexi (9±2 fold) and N-cadherin-rich sites (7±1 fold) relative to non-junctional ID sites in control hearts. VEGF reduced Na V 1.5 enrichment at both sites (6±1 and 4±1 fold, respectively), consistent with Na V 1.5 translocation from ID nanodomains. Atrial conduction, assessed by optical mapping, was slowed by VEGF (10±0.4 cm/s vs 21.3±1.3 cm/s at baseline). VEGF increased atrial arrhythmia burden both ex vivo (80% vs 0% in vehicle controls) and in vivo (70% vs 20% in vehicle controls). Next, we tested two strategies shown to prevent vascular barrier breakdown. Blocking connexin43 hemichannels (αCT11 peptide) decreased both incidence (40%) and duration (1.45±3.42s) of VEGF-induced arrhythmias. Likewise, blocking pannexin1 channels (Panx1-IL2 peptide) shortened VEGF-induced arrhythmias (2.48±0.83s). Mefloquine and spironolactone, which are small molecules that respectively inhibit Cx43 hemichannels and pannexin channels, were also found to effectively prevent VEGF-induced atrial arrhythmias. These results highlight VEGF-induced vascular leak as a novel mechanism for AF, and suggest vascular barrier protection as an anti-arrhythmic strategy.

scholarly journals MicroRNA targeting VEGF are related to vascular dysfunction in preeclampsia

2021 ◽  
Author(s):  
Isabel Witvrouwen ◽  
Dominique Mannaerts ◽  
Jessica Ratajczak ◽  
Evi Boeren ◽  
Ellen Faes ◽  
...  
Keyword(s):  
Vascular Function ◽  
Augmentation Index ◽  
Vascular Dysfunction ◽  
Flow Mediated Dilation ◽  
Vascular Endothelial ◽  
Diagnostic Biomarkers ◽  
Transcriptional Dysregulation ◽  
Vegf Pathway ◽  
Endothelial Growth Factor

In preeclampsia (PE) pre-existent maternal endothelial dysfunction leads to impaired placentation and vascular maladaptation. The vascular endothelial growth factor (VEGF) pathway is essential in the placentation process and VEGF expression is regulated through post-transcriptional modification by microRNAs. We investigated the expression of VEGF related circulating miR-16, miR-29b, miR-126, miR-155 and miR-200c in PE versus healthy pregnancies (HP), and their relation with vascular function, oxidative stress and systemic inflammation.In this case-control study, 24 women with early PE (in vivo vascular function (flow mediated dilation (FMD), modified FMD (mFMD), carotid-femoral pulse wave velocity (CF-PWV), augmentation index (AIx75) and reactive hyperaemia index (RHI)). FMD, CF-PWV, AIx75 and RHI were all significantly impaired in PE (p<0.05). PE patients had reduced levels of miR-16 (5.53±0.36vs5.84±0.61) and increased levels of miR-200c (1.34±0.57vs0.97±0.68) (p<0.05). Independent of age and parity, miR-16 was related to impaired FMD (ß 2.771, 95% C.I. 0.023-5.519, p=0.048) and mFMD (ß3.401, 95% C.I. 0.201-6.602, p=0.038). Likewise, miR-200c was independently associated with CF-PWV (ß0.513, 95% C.I. 0.034-0.992, p=0.036). In conclusion, circulating levels of miR-16 were lower in PE, which correlated with impaired endothelial function. Circulating miR-200c was increased in PE and correlated with higher arterial stiffness. These findings suggest a post-transcriptional dysregulation of the VEGF pathway in PE and identify miR-16 and miR-200c as possible diagnostic biomarkers for PE.

Abstract P333: The Vascular Barrier: A Common Anti-arrhythmic Target In Atrial Fibrillation And Myocardial Infarction

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Louisa Mezache ◽  
Gerard Nuovo ◽  
Rengasayee Veeraraghavan
Keyword(s):  
Myocardial Infarction ◽  
Atrial Fibrillation ◽  
Early Stage ◽  
Border Zone ◽  
Vascular Endothelial ◽  
Vascular Leak ◽  
Localization Analysis ◽  
Inflammatory Insult ◽  
Antiarrhythmic Efficacy

Vascular leak is a major sequela of inflammation, which is associated with arrhythmic pathologies such as atrial fibrillation (AF) and myocardial infarction (MI). We recently demonstrated that the vascular leak-inducing cytokine vascular endothelial growth factor (VEGF; 90-580 pg/ml - levels found in AF patients) induces acute remodeling (30-60 minutes) of sodium channel (Na V 1.5) -rich intercalated disk (ID) nanodomains, disrupting their ultrastructure and prompting translocation of Na V 1.5 from these sites. This in turn disrupted impulse propagation and promoted arrhythmias in murine atria. Here, we tested the hypotheses that i) similar acute pro-arrhythmic remodeling occurs in the ventricles of MI patients, and ii) protecting the vascular barrier may prevent arrhythmias following an acute inflammatory insult. First, we examined myocardial samples from five human MI patients. VEGF was overexpressed in both cardiomyocytes and vascular endothelium in the border zone surrounding <6 month-old infarcts. Notably, co-localization analysis showed significantly reduced Na V 1.5 near both connexin43 and N-cadherin within the border zone in 1-, 3-, and 9-day-old infarcts, paralleling our observations in mouse atria. Next, we returned to our murine model of AF induced by acute inflammatory insult (100 pg/ml VEGF for 60 minutes) to test the antiarrhythmic efficacy of protecting the vascular endothelial barrier. Overall, median in vivo arrhythmia burden was higher in VEGF-treated mice relative to vehicle controls (7.5±11 vs. 0±6 s/hr). We tested two strategies shown to prevent vascular barrier breakdown: Blocking connexin43 hemichannels (αCT11 peptide) decreased in vivo arrhythmia burden to 0 ± 6.07 s/hr. Panx1-IL2 (a peptide inhibitor of Panx1 channels) treatment decreased also in vivo arrhythmia burden (0 ± 15.57 s/hr with 1.6 μM Panx1-IL2). Similar antiarrhythmic efficacy was also achieved with small molecule inhibitors of Cx43 and Panx1. These results highlight VEGF-induced vascular leak as a novel mechanism for acute arrhythmias both in the early stage AF and following MI. Indeed, this mechanism may contribute to post-MI AF. Importantly, vascular-barrier protection may be a viable strategy to prevent these arrhythmias.

scholarly journals Vascular endothelial growth factor promotes atrial arrhythmias by inducing acute intercalated disk remodeling

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Louisa Mezache ◽  
Heather L. Struckman ◽  
Amara Greer-Short ◽  
Stephen Baine ◽  
Sándor Györke ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
P Wave ◽  
Cardiac Conduction ◽  
Vascular Endothelial ◽  
Atrial Arrhythmias ◽  
Vascular Leak ◽  
Cardiac Sodium Channels ◽  
Endothelial Growth Factor ◽  
Intercalated Disk

AbstractAtrial fibrillation (AF) is the most common arrhythmia and is associated with inflammation. AF patients have elevated levels of inflammatory cytokines known to promote vascular leak, such as vascular endothelial growth factor A (VEGF). However, the contribution of vascular leak and consequent cardiac edema to the genesis of atrial arrhythmias remains unknown. Previous work suggests that interstitial edema in the heart can acutely promote ventricular arrhythmias by disrupting ventricular myocyte intercalated disk (ID) nanodomains rich in cardiac sodium channels (NaV1.5) and slowing cardiac conduction. Interestingly, similar disruption of ID nanodomains has been identified in atrial samples from AF patients. Therefore, we tested the hypothesis that VEGF-induced vascular leak can acutely increase atrial arrhythmia susceptibility by disrupting ID nanodomains and slowing atrial conduction. Treatment of murine hearts with VEGF (30–60 min, at clinically relevant levels) prolonged the electrocardiographic P wave and increased susceptibility to burst pacing-induced atrial arrhythmias. Optical voltage mapping revealed slower atrial conduction following VEGF treatment (10 ± 0.4 cm/s vs. 21 ± 1 cm/s at baseline, p < 0.05). Transmission electron microscopy revealed increased intermembrane spacing at ID sites adjacent to gap junctions (GJs; 64 ± 9 nm versus 17 ± 1 nm in controls, p < 0.05), as well as sites next to mechanical junctions (MJs; 63 ± 4 nm versus 27 ± 2 nm in controls, p < 0.05) in VEGF–treated hearts relative to controls. Importantly, super-resolution microscopy and quantitative image analysis revealed reorganization of NaV1.5 away from dense clusters localized near GJs and MJs to a more diffuse distribution throughout the ID. Taken together, these data suggest that VEGF can acutely predispose otherwise normal hearts to atrial arrhythmias by dynamically disrupting NaV1.5-rich ID nanodomains and slowing atrial conduction. These data highlight inflammation-induced vascular leak as a potential factor in the development and progression of AF.

scholarly journals Inhibition of Hippo Signaling Improves Skin Lesions in a Rosacea-Like Mouse Model

2021 ◽  
Vol 22 (2) ◽  
pp. 931
Author(s):  
Jihyun Lee ◽  
Yujin Jung ◽  
Seo won Jeong ◽  
Ga Hee Jeong ◽  
Gue Tae Moon ◽  
...  
Keyword(s):  
Mouse Model ◽  
Signaling Pathway ◽  
Normal Skin ◽  
Skin Lesions ◽  
Hippo Signaling ◽  
Vascular Endothelial ◽  
Expression Levels ◽  
Hippo Signaling Pathway ◽  
Endothelial Growth Factor

The Hippo signaling pathway plays a key role in regulating organ size and tissue homeostasis. Hippo and two of its main effectors, yes-associated protein (YAP) and WWTR1 (WW domain-containing transcription regulator 1, commonly listed as TAZ), play critical roles in angiogenesis. This study investigated the role of the Hippo signaling pathway in the pathogenesis of rosacea. We performed immunohistochemical analyses to compare the expression levels of YAP and TAZ between rosacea skin and normal skin in humans. Furthermore, we used a rosacea-like BALB/c mouse model induced by LL-37 injections to determine the roles of YAP and TAZ in rosacea in vivo. We found that the expression levels of YAP and TAZ were upregulated in patients with rosacea. In the rosacea-like mouse model, we observed that the clinical features of rosacea, including telangiectasia and erythema, improved after the injection of a YAP/TAZ inhibitor. Additionally, treatment with a YAP/TAZ inhibitor reduced the expression levels of YAP and TAZ and diminished vascular endothelial growth factor (VEGF) immunoreactivity in the rosacea-like mouse model. Our findings suggest that YAP/TAZ inhibitors can attenuate angiogenesis associated with the pathogenesis of rosacea and that both YAP and TAZ are potential therapeutic targets for patients with rosacea.

scholarly journals Organic Nanocarriers for Bevacizumab Delivery: An Overview of Development, Characterization and Applications

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4127
Author(s):  
Aline de Cristo Soares Alves ◽  
Franciele Aline Bruinsmann ◽  
Silvia Stanisçuaski Guterres ◽  
Adriana Raffin Pohlmann
Keyword(s):  
Monoclonal Antibody ◽  
Physicochemical Characterization ◽  
Vascular Endothelial ◽  
Organic Nanoparticles ◽  
Humanized Monoclonal Antibody ◽  
Angiogenesis Process ◽  
Endothelial Growth Factor ◽  
Drug Pharmacokinetics

Bevacizumab (BCZ) is a recombinant humanized monoclonal antibody against the vascular endothelial growth factor, which is involved in the angiogenesis process. Pathologic angiogenesis is observed in several diseases including ophthalmic disorders and cancer. The multiple administrations of BCZ can cause adverse effects. In this way, the development of controlled release systems for BCZ delivery can promote the modification of drug pharmacokinetics and, consequently, decrease the dose, toxicity, and cost due to improved efficacy. This review highlights BCZ formulated in organic nanoparticles providing an overview of the physicochemical characterization and in vitro and in vivo biological evaluations. Moreover, the main advantages and limitations of the different approaches are discussed. Despite difficulties in working with antibodies, those nanocarriers provided advantages in BCZ protection against degradation guaranteeing bioactivity maintenance.

Effect of co-treatment with doxorubicin and verapamil loaded into chitosan nanoparticles on diethylnitrosamine-induced hepatocellular carcinoma in mice

2020 ◽  
Vol 39 (11) ◽  
pp. 1528-1544 ◽  
Author(s):  
HE Abo Mansour ◽  
MM El-Batsh ◽  
NS Badawy ◽  
ET Mehanna ◽  
NM Mesbah ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Anticancer Activity ◽  
Hepg2 Cells ◽  
Chitosan Nanoparticles ◽  
B Cell Lymphoma ◽  
Favorable Effect ◽  
Vascular Endothelial ◽  
Factor Α ◽  
Endothelial Growth Factor

This study aimed to investigate the potential role of co-treatment with doxorubicin (DOX) and verapamil (VRP) nanoparticles in experimentally induced hepatocellular carcinoma in mice and to investigate the possible mechanisms behind the potential favorable effect of the co-treatment. DOX and VRP were loaded into chitosan nanoparticles (CHNPs), and cytotoxicity of loaded and unloaded drugs against HepG2 cells was evaluated. Male albino mice were divided into eight groups ( n = 15): (1) normal control, (2) diethylnitrosamine, (3) CHNPs, (4) free DOX, (5) CHNPs DOX, (6) free VRP, (7) CHNPs VRP, and (8) CHNPs DOX + CHNPs VRP. Either VRP or DOX loaded into CHNPs showed stronger growth inhibition of HepG2 cells than their free forms. DOX or VRP nanoparticles displayed pronounced anticancer activity in vivo through the decline of vascular endothelial growth factor and B cell lymphoma-2 contents in liver tissues, upregulation of antioxidant enzymes, and downregulation of multidrug resistance 1. Moreover, reduced cardiotoxicity was evident from decreased level of tumor necrosis factor-α and malondialdehyde in heart tissues coupled with decreased serum activity of creatine kinase-myocardial band and lactate dehydrogenase. Co-treatment with CHNPs DOX and CHNPs VRP showed superior results versus other treatments. Liver sections from the co-treatment group revealed the absence of necrosis, enhanced apoptosis, and nearly normal hepatic lobule architecture. Co-treatment with CHNPs DOX and CHNPs VRP revealed enhanced anticancer activity and decreased cardiotoxicity versus the corresponding free forms.

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