Abstract 3366: Imaging of Peroxidase Activity in Injured Myocardium

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Matthias Nahrendorf ◽  
David E Sosnovik ◽  
John Chen ◽  
Jose-Luis Figueiredo ◽  
Peter Panizzi ◽  
...  
Keyword(s):  
Myocardial Injury ◽  
Matrix Proteins ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Non Invasive ◽  
Injured Myocardium ◽  
Reactive Chlorinating Species ◽  
Injury Causes ◽  
In Vivo Assessment

Ischemic myocardial injury causes timed recruitment of neutrophils and monocyte/macrophages, which produce significant amounts of myeloperoxidase (MPO). MPO leads to the formation of reactive chlorinating species capable of oxidizing proteins. We developed a small molecule based MPO substrate for MRI, Gd-bis-5-HT-DPTA, which is first radicalized, and then oligomerized and covalently bound to matrix proteins, all leading to enhanced R1-relaxivity and delayed wash out kinetics. Mice were subjected to coronary artery ligation and injected with 0.3mmol/kg Gd-bis-5-HT-DPTA (or Gd-DTPA as control). We performed T1-weighted cardio-respiratory gated MRI 10–120min later, followed by immunoreactive staining for MPO. 3 mice each were studied at day 1, 2, 4, 8, and >1 month after MI. Subsequently, MPO tissue activity was determined with the guaiacol method. MPO activity peaked 2 days after MI (contrast-to-noise-ratio (CNR) day 1, 26+/−4; day 2, 39+/−10; day 4, 29+/−3), and tissue levels of MPO over time correlated well with probe activity in vivo (r2=0.65, p<0.01). CNR following Gd-DTPA peaked ten minutes after injection (10.5+/−0.2), and returned to pre-injection values at 60min. In contradistinction, following injection Gd-bis-5-HT-DPTA, CNR was higher and peaked later (p<0.05 vs. Gd-DTPA, arrows depict MI in figure ). Immunoreactive staining for MPO correlated well with enhancement (r2=0.92, p<0.05). Gd-bis-5-HT-DPTA facilitates in-vivo assessment of MPO activity in injured myocardium. This approach allows non-invasive probing of the inflammatory response to ischemia and has the potential to guide the development and application of novel cardioprotective therapies.

scholarly journals Acoustoelasticity Analysis of Transient Waves for Non-Invasive In Vivo Assessment of Urinary Bladder

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mahdi Bayat ◽  
Saba Adabi ◽  
Viksit Kumar ◽  
Adriana Gregory ◽  
Jeremy Webb ◽  
...  
Keyword(s):  
Urinary Bladder ◽  
Transient Waves ◽  
Non Invasive ◽  
In Vivo Assessment

Abstract 365: Targeted Delivery of IGF-1 Following Acute Myocardial Infarction

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Raffay S Khan ◽  
Jay C Sy ◽  
Milton Brown ◽  
Mario D Martinez ◽  
Niren Murthy ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Targeted Delivery ◽  
Coronary Artery Ligation ◽  
Nuclear Staining ◽  
Post Injection ◽  
Artery Ligation ◽  
Intact Cells ◽  
Double Stranded Dna

During acute myocardial infarction (MI) there is excessive necrosis of myocardial cells, leading to the release of large amounts of DNA, representing a potential target for drug delivery. Hoechst, a commonly used molecule for staining nuclei, binds to the minor groove of double-stranded DNA and can be functionalized to contain reactive groups such as free amines, sulfhydryls, and biotin moieties. Insulin-like growth factor-1 (IGF-1), a small molecule with a short half-life is protective immediately following MI, though there is potential for long-term toxicity and off-target effects. Therefore, we hypothesized that conjugating IGF-1 to Hoechst would increase targeting of IGF-1 to the injured myocardium. Hoechst-IGF1 (H-IGF1) was synthesized by binding Hoechst-biotin to biotinylated IGF-1 via a fluorescent streptavidin linker. Intact cells did not show nuclear staining with H-IGF1, while permeabilized cells had a significant increase in blue fluorescent Hoechst staining, indicating H-IGF1 was cell impermeable but could still bind DNA. Activity of H-IGF1 was demonstrated by Akt phosphorylation in cultured cardiac progenitor cells and was similar to native IGF-1. To determine in-vivo targeting of H-IGF1 to MI, mice underwent 30 minutes of coronary artery ligation followed by reperfusion (I/R). Six hours following MI, mice were injected intravenously with 70ng of H-IGF1, S-IGF1 (streptavidin bound IGF-1 only) or PBS followed by in vivo imaging at 30 and 120 minutes post-injection. At 30 minutes post-injection, we found 3.2% (2.2 of 70ng) of the injected dose of H-IGF1 in infarcted hearts compared with 1.8% (1.3 of 70ng) of S-IGF1 (n=5-7; p<0.05). To confirm that targeting of H-IGF1 was dependent on binding DNA, H-IGF1 pre-bound to double-stranded DNA was injected intravenously after I/R. This led to a significant (p<0.05) decrease in targeted IGF-1 levels. IGF-1 levels determined by ELISA 2 hours post-injection demonstrated a similar trend with increased targeting of H-IGF1 compared with S-IGF1 treated mice (4.2±0.6 ng vs. 2.4±0.2 ng; p<0.05). In conclusion, our data demonstrate that intravenous delivery of Hoechst-conjugated IGF-1 increases myocardial targeting. This provides a novel strategy for delivery of growth factors for the treatment of MI.

scholarly journals Inhibition of N-type calcium channels in cardiac sympathetic neurons attenuates ventricular arrhythmogenesis in heart failure

2020 ◽  
Author(s):  
Dongze Zhang ◽  
Huiyin Tu ◽  
Chaojun Wang ◽  
Liang Cao ◽  
Wenfeng Hu ◽  
...  
Keyword(s):  
Heart Failure ◽  
Coronary Artery ◽  
Ventricular Arrhythmias ◽  
Sympathetic Neurons ◽  
Coronary Artery Ligation ◽  
Channel Blockers ◽  
Artery Ligation ◽  
Cell Excitability ◽  
Ventricular Arrhythmogenesis

Abstract Aims Cardiac sympathetic overactivation is an important trigger of ventricular arrhythmias in patients with chronic heart failure (CHF). Our previous study demonstrated that N-type calcium (Cav2.2) currents in cardiac sympathetic post-ganglionic (CSP) neurons were increased in CHF. This study investigated the contribution of Cav2.2 channels in cardiac sympathetic overactivation and ventricular arrhythmogenesis in CHF. Methods and results Rat CHF was induced by surgical ligation of the left coronary artery. Lentiviral Cav2.2-α shRNA or scrambled shRNA was transfected in vivo into stellate ganglia (SG) in CHF rats. Final experiments were performed at 14 weeks after coronary artery ligation. Real-time polymerase chain reaction and western blot data showed that in vivo transfection of Cav2.2-α shRNA reduced the expression of Cav2.2-α mRNA and protein in the SG in CHF rats. Cav2.2-α shRNA also reduced Cav2.2 currents and cell excitability of CSP neurons and attenuated cardiac sympathetic nerve activities (CSNA) in CHF rats. The power spectral analysis of heart rate variability (HRV) further revealed that transfection of Cav2.2-α shRNA in the SG normalized CHF-caused cardiac sympathetic overactivation in conscious rats. Twenty-four-hour continuous telemetry electrocardiogram recording revealed that this Cav2.2-α shRNA not only decreased incidence and duration of ventricular tachycardia/ventricular fibrillation but also improved CHF-induced heterogeneity of ventricular electrical activity in conscious CHF rats. Cav2.2-α shRNA also decreased susceptibility to ventricular arrhythmias in anaesthetized CHF rats. However, Cav2.2-α shRNA failed to improve CHF-induced cardiac contractile dysfunction. Scrambled shRNA did not affect Cav2.2 currents and cell excitability of CSP neurons, CSNA, HRV, and ventricular arrhythmogenesis in CHF rats. Conclusions Overactivation of Cav2.2 channels in CSP neurons contributes to cardiac sympathetic hyperactivation and ventricular arrhythmogenesis in CHF. This suggests that discovering purely selective and potent small-molecule Cav2.2 channel blockers could be a potential therapeutic strategy to decrease fatal ventricular arrhythmias in CHF.

scholarly journals Importance of the coronary circulation for cardiac and metabolic performance in rainbow trout ( Oncorhynchus mykiss )

2018 ◽  
Vol 14 (7) ◽  
pp. 20180063 ◽  
Author(s):  
Andreas Ekström ◽  
Michael Axelsson ◽  
Albin Gräns ◽  
Jeroen Brijs ◽  
Erik Sandblom
Keyword(s):  
Heart Rate ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Metabolic Rate ◽  
Oxygen Supply ◽  
Coronary Artery Ligation ◽  
Artery Ligation ◽  
Coronary Ligation ◽  
Metabolic Performance

Cardiac oxygenation is achieved via both coronary arterial and luminal venous oxygen supply routes in many fish species. However, the relative importance of these supplies for cardiac and aerobic metabolic performance is not fully understood. Here, we investigated how coronary artery ligation in rainbow trout ( Oncorhynchus mykiss ), implanted with heart rate loggers, affected cardiorespiratory performance in vivo . While coronary ligation significantly elevated resting heart rate, the standard metabolic rate was unchanged compared to sham-treated controls. However, coronary ligation reduced the maximum metabolic rate while heart rate remained unchanged following enforced exercise. Thus, coronary ligation reduced metabolic and heart rate scopes by 29% and 74%, respectively. Our findings highlight the importance of coronary oxygen supply for overall cardiorespiratory performance in salmonid fish, and suggest that pathological conditions that impair coronary flow (e.g. coronary arteriosclerosis) constrain the ability of fish to cope with metabolically demanding challenges such as spawning migrations and environmental warming.

An antibody to leukocyte integrins attenuates coronary vascular injury due to ischemia and reperfusion in dogs

1997 ◽  
Vol 272 (2) ◽  
pp. H618-H624 ◽  
Author(s):  
L. D. Horwitz ◽  
D. Kaufman ◽  
Y. Kong
Keyword(s):  
Coronary Artery ◽  
Leukocyte Adhesion ◽  
Microvascular Permeability ◽  
Coronary Artery Ligation ◽  
Ischemia And Reperfusion ◽  
Artery Ligation ◽  
Isotope Technique ◽  
Coronary Ischemia

Ischemia and reperfusion cause coronary vascular and myocardial injury, which may be due to leukocyte-mediated processes. Antileukocyte measures have reduced injury after brief reperfusion periods of 1-3 h, but there has been little information on whether benefits are apparent after longer periods of reperfusion. We examined the effect of pretreatment with a monoclonal antibody (R15.7) to the CD18 family of leukocyte adhesion molecules (beta2-integrins) in dogs exposed to regional coronary ischemia for 1 h of left anterior descending coronary artery ligation and then reperfused for 48 h. Coronary microvascular permeability was assessed in vivo by measurement of protein leak index (PLI), using a double-isotope technique with autologous radiolabeled transferrin and erythrocytes. Vasorelaxation was measured in vitro with preconstricted epicardial coronary artery rings subjected to increasing concentrations of the endothelium-dependent vasodilators bradykinin (BK) and ADP and the endothelium-independent vasodilator nitroprusside. At 48 h of reperfusion in untreated dogs there were substantial increases in PLI in the previously ischemic regions, indicative of increased extravascular transferrin. These abnormalities were decreased, but not abolished, in the dogs treated with R15.7. Relaxation of rings from the ischemic/reperfused artery to BK and ADP were blunted in the untreated dogs. R15.7 resulted in improvement in some, but not all, indexes of relaxation in response to BK and ADP. Relaxation to nitroprusside was normal in ischemic/reperfused coronary rings from both treated and untreated dogs. Therefore, after 1 h of regional coronary ischemia and 48 h of reperfusion, coronary endothelial injury, which was manifested by increased coronary microvascular permeability and abnormalities in coronary endothelium-dependent relaxation, was reduced by pretreatment with the anti-CD18 integrin antibody R15.7.

scholarly journals Melanin distribution from the dermal–epidermal junction to the stratum corneum: non-invasive in vivo assessment by fluorescence and Raman microspectroscopy

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
B. P. Yakimov ◽  
E. A. Shirshin ◽  
J. Schleusener ◽  
A. S. Allenova ◽  
V. V. Fadeev ◽  
...  
Keyword(s):  
Stratum Corneum ◽  
Raman Microspectroscopy ◽  
Non Invasive ◽  
In Vivo Assessment

scholarly journals Integrative System Biology Analyses Identify Seven MicroRNAs to Predict Heart Failure

2019 ◽  
Vol 5 (1) ◽  
pp. 22 ◽  
Author(s):  
Henri Charrier ◽  
Marie Cuvelliez ◽  
Emilie Dubois-Deruy ◽  
Paul Mulder ◽  
Vincent Richard ◽  
...  
Keyword(s):  
Heart Failure ◽  
Systems Biology ◽  
Ventricular Remodeling ◽  
Left Ventricular Remodeling ◽  
Left Ventricular ◽  
Coronary Artery Ligation ◽  
Mirna Signature ◽  
Artery Ligation ◽  
Proteomic Data

Heart failure (HF) has several etiologies including myocardial infarction (MI) and left ventricular remodeling (LVR), but its progression remains difficult to predict in clinical practice. Systems biology analyses of LVR after MI provide molecular insights into this event such as modulation of microRNA (miRNA) that could be used as a signature of HF progression. To define a miRNA signature of LVR after MI, we use 2 systems biology approaches, integrating either proteomic data generated from LV of post-MI rat induced by left coronary artery ligation or multi-omics data (proteins and non-coding RNAs) generated from plasma of post-MI patients from the REVE-2 study. The first approach predicted that 13 miRNAs and 3 of these miRNAs would be validated to be associated with LVR in vivo: miR-21-5p, miR-23a-3p and miR-222-3p. The second approach predicted that 24 miRNAs among 1310 molecules and 6 of these miRNAs would be selected to be associated with LVR in silico: miR-17-5p, miR-21-5p, miR-26b-5p, miR-222-3p, miR-335-5p and miR-375. We identified a signature of 7 microRNAs associated with LVR after MI that support the interest of integrative systems biology analyses to define a miRNA signature of HF progression.

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