Radiometal-labeled anti-VCAM-1 nanobodies as molecular tracers for atherosclerosis – impact of radiochemistry on pharmacokinetics

2019 ◽  
Vol 400 (3) ◽  
pp. 323-332 ◽  
Author(s):  
Gezim Bala ◽  
Maxine Crauwels ◽  
Anneleen Blykers ◽  
Isabel Remory ◽  
Andrea L.J. Marschall ◽  
...  
Keyword(s):  
Specific Activity ◽  
Clinical Routine ◽  
Time Points ◽  
Specific Targeting ◽  
Atherosclerotic Lesions ◽  
Specific Uptake ◽  
Molecular Tracers ◽  
The Impact ◽  
First Time

Abstract Radiolabeling of nanobodies with radiometals by chelation has the advantage of being simple, fast and easy to implement in clinical routine. In this study, we validated 68Ga/111In-labeled anti-VCAM-1 nanobodies as potential radiometal-based tracers for molecular imaging of atherosclerosis. Both showed specific targeting of atherosclerotic lesions in ApoE−/− mice. Nevertheless, uptake in lesions and constitutively VCAM-1 expressing organs was lower than previously reported for the 99mTc-labeled analog. We further investigated the impact of different radiolabeling strategies on the in vivo biodistribution of nanobody-based tracers. Comparison of the pharmacokinetics between 68Ga-, 18F-, 111In- and 99mTc-labeled anti-VCAM-1 nanobodies showed highest specific uptake for 99mTc-nanobody at all time-points, followed by the 68Ga-, 111In- and 18F-labeled tracer. No correlation was found with the estimated number of radioisotopes per nanobody, and mimicking specific activity of other radiolabeling methods did not result in an analogous biodistribution. We also demonstrated specificity of the tracer using mice with a VCAM-1 knocked-down phenotype, while showing for the first time the in vivo visualization of a protein knock-down using intrabodies. Conclusively, the chosen radiochemistry does have an important impact on the biodistribution of nanobodies, in particular on the specific targeting, but differences are not purely due to the tracer’s specific activity.

scholarly journals Latent Antigen Vaccination in a Model Gammaherpesvirus Infection

2001 ◽  
Vol 75 (17) ◽  
pp. 8283-8288 ◽  
Author(s):  
Edward J. Usherwood ◽  
Kimberley A. Ward ◽  
Marcia A. Blackman ◽  
James P. Stewart ◽  
David L. Woodland
Keyword(s):  
Latent Infection ◽  
Model Systems ◽  
Murine Gammaherpesvirus ◽  
Latently Infected ◽  
Associated Proteins ◽  
Infected Cells ◽  
The Impact ◽  
First Time

ABSTRACT Vaccines that can reduce the load of latent gammaherpesvirus infections are eagerly sought. One attractive strategy is vaccination against latency-associated proteins, which may increase the efficiency with which T cells recognize and eliminate latently infected cells. However, due to the lack of tractable animal model systems, the effect of latent-antigen vaccination on gammaherpesvirus latency is not known. Here we use the murine gammaherpesvirus model to investigate the impact of vaccination with the latency-associated M2 antigen. As expected, vaccination had no effect on the acute lung infection. However, there was a significant reduction in the load of latently infected cells in the initial stages of the latent infection, when M2 is expressed. These data show for the first time that latent-antigen vaccination can reduce the level of latency in vivo and suggest that vaccination strategies involving other latent antigens may ultimately be successfully used to reduce the long-term latent infection.

scholarly journals Time Course of Microbiologic Outcome and Gene Expression in Candida albicans during and following In Vitro and In Vivo Exposure to Fluconazole

2006 ◽  
Vol 50 (4) ◽  
pp. 1311-1319 ◽  
Author(s):  
A. Lepak ◽  
J. Nett ◽  
L. Lincoln ◽  
K. Marchillo ◽  
D. Andes
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Time Course ◽  
Dependent Manner ◽  
Time Points ◽  
In Vivo Expression ◽  
The Impact ◽  
The Relationship

ABSTRACT Pharmacodynamics (PD) considers the relationship between drug exposure and effect. The two factors that have been used to distinguish the PD behaviors of antimicrobials are the impact of concentration on the extent of organism killing and the duration of persistent microbiologic suppression (postantibiotic effect). The goals of these studies were (i) to examine the relationship between antimicrobial PD and gene expression and (ii) to gain insight into the mechanism of fluconazole effects persisting following exposure. Microarrays were used to estimate the transcriptional response of Candida albicans to a supra-MIC F exposure over time in vitro. Fluconazole at four times the MIC was added to a log-phase C. albicans culture, and cells were collected to determine viable growth and for microarray analyses. We identified differential expression of 18% of all genes for at least one of the time points. More genes were upregulated (n = 1,053 [16%]) than downregulated (174 [3%]). Of genes with known function that were upregulated during exposure, most were related to plasma membrane/cell wall synthesis (18%), stress responses (7%), and metabolism (6%). The categories of downregulated genes during exposure included protein synthesis (15%), DNA synthesis/repair (7%), and transport (7%) genes. The majority of genes identified at the postexposure time points were from the protein (17%) and DNA (7%) synthesis categories. In subsequent studies, three genes (CDR1, CDR2, and ERG11) were examined in greater detail (more concentration and time points) following fluconazole exposure in vitro and in vivo. Expression levels from the in vitro and in vivo studies were congruent. CDR1 and CDR2 transcripts were reduced during in vitro fluconazole exposure and during supra-MIC exposure in vivo. However, in the postexposure period, the mRNA abundance of both pumps increased. ERG11 expression increased during exposure and fell in the postexposure period. The expression of the three genes responded in a dose-dependent manner. In sum, the microarray data obtained during and following fluconazole exposure identified genes both known and unknown to be affected by this drug class. The expanded in vitro and in vivo expression data set underscores the importance of considering the time course of exposure in pharmacogenomic investigations.

scholarly journals Pharmacological Inhibition of mTORC2 Reduces Migration and Metastasis in Melanoma

2020 ◽  
Vol 22 (1) ◽  
pp. 30
Author(s):  
Jessica Guenzle ◽  
Harue Akasaka ◽  
Katharina Joechle ◽  
Wilfried Reichardt ◽  
Aina Venkatasamy ◽  
...  
Keyword(s):  
Liver Metastasis ◽  
Specific Inhibitor ◽  
Migration And Invasion ◽  
Anti Cancer ◽  
Metastasis Model ◽  
Pharmacological Blockade ◽  
Apoptotic Pathways ◽  
The Impact ◽  
First Time

Despite recent advances in therapy, liver metastasis from melanoma is still associated with poor prognosis. Although targeting the mTOR signaling pathway exerts potent anti-tumor activity, little is known about specific mTORC2 inhibition regarding liver metastasis. Using the novel mTORC2 specific inhibitor JR-AB2-011, we show significantly reduced migration and invasion capacity by impaired activation of MMP2 in melanoma cells. In addition, blockade of mTORC2 induces cell death by non-apoptotic pathways and reduces tumor cell proliferation rate dose-dependently. Furthermore, a significant reduction of liver metastasis was detected in a syngeneic murine metastasis model upon therapy with JR-AB2-011 as determined by in vivo imaging and necropsy. Hence, our study for the first time highlights the impact of the pharmacological blockade of mTORC2 as a potent novel anti-cancer approach for liver metastasis from melanoma.

scholarly journals [99mTc]Tc-DB1 Mimics with Different-Length PEG Spacers: Preclinical Comparison in GRPR-Positive Models

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3418
Author(s):  
Panagiotis Kanellopoulos ◽  
Emmanouil Lymperis ◽  
Aikaterini Kaloudi ◽  
Marion de Jong ◽  
Eric P. Krenning ◽  
...  
Keyword(s):  
Severe Combined Immunodeficiency ◽  
Tumor Uptake ◽  
Single Digit ◽  
Spacer Length ◽  
Uptake Rates ◽  
Specific Uptake ◽  
Immunodeficiency Disease ◽  
Grpr Antagonist ◽  
The Impact

Background: The frequent overexpression of gastrin-releasing peptide receptors (GRPRs) in human cancers provides the rationale for delivering clinically useful radionuclides to tumor sites using peptide carriers. Radiolabeled GRPR antagonists, besides being safer for human use, have often shown higher tumor uptake and faster background clearance than agonists. We herein compared the biological profiles of the GRPR-antagonist-based radiotracers [99mTc]Tc-[N4-PEGx-DPhe6,Leu-NHEt13]BBN(6-13) (N4: 6-(carboxy)-1,4,8,11-tetraazaundecane; PEG: polyethyleneglycol): (i) [99mTc]Tc-DB7 (x = 2), (ii) [99mTc]Tc-DB13 (x = 3), and (iii) [99mTc]Tc-DB14 (x = 4), in GRPR-positive cells and animal models. The impact of in situ neprilysin (NEP)-inhibition on in vivo stability and tumor uptake was also assessed by treatment of mice with phosphoramidon (PA). Methods: The GRPR affinity of DB7/DB13/DB14 was determined in PC-3 cell membranes, and cell binding of the respective [99mTc]Tc-radioligands was assessed in PC-3 cells. Each of [99mTc]Tc-DB7, [99mTc]Tc-DB13, and [99mTc]Tc-DB14 was injected into mice without or with PA coinjection and 5 min blood samples were analyzed by HPLC. Biodistribution was conducted at 4 h postinjection (pi) in severe combined immunodeficiency disease (SCID) mice bearing PC-3 xenografts without or with PA coinjection. Results: DB7, -13, and -14 displayed single-digit nanomolar affinities for GRPR. The uptake rates of [99mTc]Tc-DB7, [99mTc]Tc-DB13, and [99mTc]Tc-DB14 in PC-3 cells was comparable and consistent with a radioantagonist profile. The radiotracers were found to be ≈70% intact in mouse blood and >94% intact after coinjection of PA. Treatment of mice with PA enhanced tumor uptake. Conclusions: The present study showed that increase of PEG-spacer length in the [99mTc]Tc-DB7–[99mTc]Tc-DB13–[99mTc]Tc-DB14 series had little effect on GRPR affinity, specific uptake in PC-3 cells, in vivo stability, or tumor uptake. A significant change in in vivo stability and tumor uptake was observed only after treatment of mice with PA, without compromising the favorably low background radioactivity levels.

scholarly journals Metallothionein-3 promotes cisplatin chemoresistance remodelling in neuroblastoma

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Miguel Angel Merlos Rodrigo ◽  
Hana Michalkova ◽  
Vladislav Strmiska ◽  
Berta Casar ◽  
Piero Crespo ◽  
...  
Keyword(s):  
Cisplatin Resistance ◽  
Neuroblastoma Cells ◽  
Chorioallantoic Membrane ◽  
In Vivo Model ◽  
Chick Chorioallantoic Membrane ◽  
High Level ◽  
Cisplatin Chemoresistance ◽  
The Impact ◽  
First Time

AbstractMetallothionein-3 has poorly characterized functions in neuroblastoma. Cisplatin-based chemotherapy is a major regimen to treat neuroblastoma, but its clinical efficacy is limited by chemoresistance. We investigated the impact of human metallothionein-3 (hMT3) up-regulation in neuroblastoma cells and the mechanisms underlying the cisplatin-resistance. We confirmed the cisplatin-metallothionein complex formation using mass spectrometry. Overexpression of hMT3 decreased the sensitivity of neuroblastoma UKF-NB-4 cells to cisplatin. We report, for the first time, cisplatin-sensitive human UKF-NB-4 cells remodelled into cisplatin-resistant cells via high and constitutive hMT3 expression in an in vivo model using chick chorioallantoic membrane assay. Comparative proteomic analysis demonstrated that several biological pathways related to apoptosis, transport, proteasome, and cellular stress were involved in cisplatin-resistance in hMT3 overexpressing UKF-NB-4 cells. Overall, our data confirmed that up-regulation of hMT3 positively correlated with increased cisplatin-chemoresistance in neuroblastoma, and a high level of hMT3 could be one of the causes of frequent tumour relapses.

Systolic axial artery length reduction: an overlooked phenomenon in vivo

2001 ◽  
Vol 280 (5) ◽  
pp. H2300-H2305 ◽  
Author(s):  
P. Tozzi ◽  
D. Hayoz ◽  
C. Oedman ◽  
I. Mallabiabarrena ◽  
L. K. Von Segesser
Keyword(s):  
Pulse Pressure ◽  
Cardiac Cycle ◽  
Tracking System ◽  
Axial Strain ◽  
Axial Position ◽  
Animal Data ◽  
Echo Tracking ◽  
The Impact ◽  
First Time

To demonstrate axial artery motion during the cardiac cycle, the common carotid arteries (CCA) of 10 pigs were exposed and equipped with piezoelectric crystals sutured onto the artery as axial position detectors. An echo-tracking system was used to simultaneously measure the CCA diameter. For each animal, data for pressure, length, and diameter were collected at a frequency of 457 Hz. At a mean pulse pressure of 33 ± 8 mmHg, the mean systolodiastolic length difference was 0.3 ± 0.01 mm for a mean arterial segment of 11.35 ± 1.25 mm. Systolic and diastolic diameters were 4.1 ± 0.3 and 3.9 ± 0.2 mm, respectively. The examined CCA segment displayed a mean axial systolic shortening of 2.7%. This study clearly demonstrates, for the first time, that the length of a segment of the CCA changes during the cardiac cycle and that this movement is inversely correlated with pulse pressure. It is also apparent that the segmental axial strain is significantly smaller than the diameter variation during the cardiac cycle and that the impact of the axial strain for compliance computation should be further evaluated.

Role of blue light in bactericidal effect against meat-borne pathogens and freshness maintaining of beef

2021 ◽  
Author(s):  
Shuanghua Luo ◽  
Xi Yang ◽  
Shuyan Wu ◽  
Minmin Liu ◽  
Xiujuan Zhang ◽  
...  
Keyword(s):  
Blue Light ◽  
Amino Acid Content ◽  
Bactericidal Effect ◽  
In Vivo Studies ◽  
Dependent Inactivation ◽  
A Minor ◽  
The Impact ◽  
First Time

Beef is rich in various nutrients while easily spoils due to contamination by pathogens, thus it is of great significance to develop a bactericidal method to inactivate meat-borne pathogens and meanwhile maintain the freshness of beef. For the first time, the present study investigated the bactericidal effect of blue light (BL) at 415 nm against four meat-borne pathogens (methicillin-resistant Staphylococcus aureus , Escherichia coli , Salmonella Typhimurium and Listeria monocytogenes ) in vitro and inoculated on the surface of fresh beef, respectively. When the non-illuminated beef was used as control, the population of the four pathogens did not change significantly ( P > 0.05), while BL-illuminated beef showed dose-dependent inactivation effect in both in vitro and in vivo studies. The experiments on beef cuts showed that 109.44 J/cm 2 of BL inactivated 90% of inoculated cells for the tested strains ( P < 0.05), and the impact of BL inactivation could be sustained in 7 days of cold storage. Notably, changes of lipid oxidation rate, water holding capacity and cooking loss value between the control and beef illuminated by 109.44 J/cm 2 at the same time were scarcely detected during the storage. BL had a minor but insignificant influence on surface color and free amino acid content. Moreover, the pH of illuminated beef increased slower ( P < 0.05) than that of non-illuminated beef. The present work demonstrated that BL could be a novel bactericidal and freshness-maintaining method for fresh beef.

scholarly journals In Vivo Assessment of the Impact of Regional Intracranial Atherosclerotic Lesions on Brain Arterial 3D Hemodynamics

2017 ◽  
Vol 38 (3) ◽  
pp. 515-522 ◽  
Author(s):  
C. Wu ◽  
S. Schnell ◽  
P. Vakil ◽  
A.R. Honarmand ◽  
S.A. Ansari ◽  
...  
Keyword(s):  
Atherosclerotic Lesions ◽  
The Impact ◽  
In Vivo Assessment

Abstract 5790: Dual Molecular Imaging for Assessment of Matrix Metalloproteinase and Apoptosis in Atherosclerotic Lesions before and after Statin Therapy

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Shinichiro Fujimoto ◽  
Dagmar Hartung ◽  
D. Scott Edwards ◽  
Michael Azure ◽  
Jun Zhou ◽  
...  
Keyword(s):  
Molecular Imaging ◽  
Matrix Metalloproteinase ◽  
Statin Therapy ◽  
Ex Vivo ◽  
Tracer Uptake ◽  
Lipid Lowering ◽  
Atherosclerotic Lesions ◽  
Normal Chow ◽  
The Impact

We evaluated the correlation between matrix metalloproteinase (MMP) and apoptotic activities in atherosclerosis lesions, and the impact of lipid lowering by dietary modification and statin therapy employing molecular imaging with Tc-99m broad MMP inhibitor (MPI) and indium-111 annexin A5 (AA5). Atherosclerosis was produced in 13 New Zealand White rabbits by balloon deendothelialization and hypercholesterolemic diet for 4 months; 6 unmanipulated rabbits on normal chow were used as controls. In the last month, 3 of the 13 atherosclerotic rabbits were changed to normal chow, and 4 received fluvastatin (1mg/kg) once a day. MPI and AA5 imaging were performed using micro-SPECT/micro-CT. After in vivo imaging, aortas were explanted to acquire ex vivo images and calculate percent injected dose per gram (%ID/g) uptake. Histological and immunohistochemical characterization and extent of MMP and apoptosis were evaluated in representative aortic samples. Both MPI and Annexin uptake were clearly visualized in the atherosclerotic lesions by noninvasive imaging; No uptake were observed after diet withdrawal, fluvastatin, and in normal control groups. %ID/g MPI and AA5 uptakes in the atherosclerotic lesions (0.09 ± 0.02%, 0.03 ± 0.01%) were significantly higher than the uptake in control abdominal aorta (0.014 ± 0.004%, 0.0007 ± 0.0002%; p<0.0001). The quantitative uptake in fluvastatin (0.053 ± 0.013%, 0.02 ± 0.01%; p<0.05) and diet withdrawal (0.047 ± 0.005%, 0.02 ± 0.004%; p<0.05) groups were statistically significantly lower compared to diet uninterrupted group. There were significant direct relationship betweem MPI and AA5 uptake in all experimental group (r=0.62, p<0.0001). The decrease in the tracer uptake maintained the relationship in the fluvastatin group (r=0.62, p<0.0001) but became less apparent in the diet withdrawal (r=0.24, p<0.05). Histopathological and immunohisto-chemical studies revealed a significant correlation of both MPI and Annexin uptake with macrophage infiltration, MMP-2, 9 expression and the extent of apoptosis. Dual imaging with MPI and AA5 showed good correlation between apoptosis and MMP expression except diet withdrawal group.

scholarly journals Unraveling Endothelial Cell Phenotypic Regulation By Spatial Hemodynamic Flows With Microfluidics

2020 ◽  
Author(s):  
Sarvesh Varma ◽  
Guillermo Garcia-Cardena ◽  
Joel Voldman
Keyword(s):  
Cardiovascular Health ◽  
Disease Susceptibility ◽  
Disease Risk ◽  
Interventional Cardiology ◽  
Blood Flows ◽  
Biological Studies ◽  
The Impact ◽  
First Time

AbstractHuman endothelial cells (hECs) experience complex spatiotemporal hemodynamic flows and that directly regulate hEC function and susceptibility to cardiovascular disease. Recent medical imaging studies reveal that helical flows strongly correlate with lowered disease susceptibility, as contrasted to multidirectional disturbed flows. However, a lack of platforms to replicate these spatial profiles of flow (SPF) has prevented biological studies to investigate the role hECs play in tuning the observed SPF-correlated disease susceptibility. Here, we utilize microfluidic devices to apply varying SPF upon hECs for the first time, and discover that these flows can differentially impact hEC morphology, transcription, and polarization. Collectively, our platform and studies significantly advance our ability to delineate flow-regulated hEC function and disease susceptibility.Significance StatementIn vivo, hECs experience complex hemodynamic flows, including those that are spatially helical or disturbed, which is in stark contrast to the unidirectional flows typically used to study hECs in vitro. Understanding the impact of SPF on hEC function informs our understanding of the pathophysiology of hEC dysfunction and can lead to interventional solutions that specifically perturb SPF to lower disease risk. Here, we leverage microfluidics to apply and discover the specific impact of SPF on hECs for the first time. Broadly, our platform bridges the mutual interests of the vascular biology and interventional cardiology communities to collectively understand how cardiovascular health is tied to the way blood flows upon the endothelium.

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