Targeted Near-Infrared Imaging of the Erythropoietin Receptor in Human Lung Cancer Xenografts

Doleschel, Dennis; Mundigl, Olaf; Wessner, Axel; Gremse, Felix; Bachmann, Julie; Rodríguez, Alicia; Klingmüller, Ursula; Jarsch, Michael; Kießling, Fabian; Lederle, Wiltrud

doi:10.2967/jnumed.111.091124

Cited by 24 publications

(35 citation statements)

References 30 publications

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“…50 More recently Doleschel and colleagues used fluorescent EPO as a probe and examined EpoR expression in murine organs by fluorescence-mediated tomography. 79 The in vivo results showed that exogenous EPO is accumulated in the kidney and in vitro results validated the specific binding of labeled EPO to EpoR. 79 Now, our findings provided proof of functional EpoR in the kidney.…”

Section: Discussionsupporting

confidence: 57%

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The erythropoietin receptor is a downstream effector of Klotho-induced cytoprotection

Shi

Cho

et al. 2013

Kidney International

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Although the role of the erythropoietin (Epo) receptor (EpoR) in erythropoiesis has been known for decades, its role in non-hematopoietic tissues is still not well defined. Klotho has been shown and Epo has been suggested to protect against acute ischemia-reperfusion injury in the kidney. Here we found in rat kidney and in a rat renal tubular epithelial cell line (NRK cells) EpoR transcript and antigen, and EpoR activity signified as Epo-induced phosphorylation of Jak2, ErK, Akt, and Stat5 indicating the presence of functional EpoR. Transgenic overexpression of Klotho or addition of exogenous recombinant Klotho increased kidney EpoR protein and transcript. In NRK cells, Klotho increased EpoR protein, enhanced Epo-triggered phosphorylation of Jak2 and Stat5, the nuclear translocation of phospho-Stat5, and protected NRK cells from hydrogen peroxide cytotoxicity. Knock-down of endogenous EpoR rendered NRK cells more vulnerable, and overexpression of EpoR more resistant to peroxide-induced cytotoxicity, indicating that EpoR mitigates oxidative damage. Knock-down of EpoR by siRNA abolished Epo-induced Jak2, and Stat5 phosphorylation, and blunted the protective effect of Klotho against peroxide-induced cytotoxicity. Thus in the kidney, EpoR and its activity are downstream effectors of Klotho enabling it to function as cytoprotective protein against oxidative injury.

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Section: Discussionsupporting

confidence: 57%

“…79 The in vivo results showed that exogenous EPO is accumulated in the kidney and in vitro results validated the specific binding of labeled EPO to EpoR. 79 Now, our findings provided proof of functional EpoR in the kidney.…”

Section: Discussionsupporting

confidence: 57%

The erythropoietin receptor is a downstream effector of Klotho-induced cytoprotection

Shi

Cho

et al. 2013

Kidney International

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“…Phantoms and mice were imaged subsequently in µCT (Tomoscope DUO, CT-Imaging, Erlangen, Germany) and FMT (FMT2500, PerkinElmer, Waltham, USA) 2,28. The FMT uses a thermoelectrically-cooled back-illuminated 16 bit CCD camera (512x512 pixels, CCD size 12.3x12.3 mm).…”

Section: Methodsmentioning

confidence: 99%

Absorption Reconstruction Improves Biodistribution Assessment of Fluorescent Nanoprobes Using Hybrid Fluorescence-mediated Tomography

et al. 2014

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Aim: Fluorescence-mediated tomography (FMT) holds potential for accelerating diagnostic and theranostic drug development. However, for proper quantitative fluorescence reconstruction, knowledge on optical scattering and absorption, which are highly heterogeneous in different (mouse) tissues, is required. We here describe methods to assess these parameters using co-registered micro Computed Tomography (µCT) data and nonlinear whole-animal absorption reconstruction, and evaluate their importance for assessment of the biodistribution and target site accumulation of fluorophore-labeled drug delivery systems.Methods: Besides phantoms with varying degrees of absorption, mice bearing A431 tumors were imaged 15 min and 48 h after i.v. injection of a fluorophore-labeled polymeric drug carrier (pHPMA-Dy750) using µCT-FMT. The outer shape of mice and a scattering map were derived using automated segmentation of the µCT data. Furthermore, a 3D absorption map was reconstructed from the trans-illumination data. We determined the absorption of five interactively segmented regions (heart, liver, kidney, muscle, tumor). Since blood is the main near-infrared absorber in vivo, the absorption was also estimated from the relative blood volume (rBV), determined by contrast-enhanced µCT. We compared the reconstructed absorption with the rBV-based values and analyzed the effect of using the absorption map on the fluorescence reconstruction.Results: Phantom experiments demonstrated that absorption reconstruction is possible and necessary for quantitative fluorescence reconstruction. In vivo, the reconstructed absorption showed high values in strongly blood-perfused organs such as the heart, liver and kidney. The absorption values correlated strongly with the rBV-based absorption values, confirming the accuracy of the absorption reconstruction. Usage of homogenous absorption instead of the reconstructed absorption map resulted in reduced values in the heart, liver and kidney, by factors of 3.5, 2.1 and 1.4, respectively. For muscle and subcutaneous tumors, which have a much lower rBV and absorption, absorption reconstruction was less important.Conclusion: Quantitative whole-animal absorption reconstruction is possible and can be validated in vivo using the rBV. Usage of an absorption map is important when quantitatively assessing the biodistribution of fluorescently labeled drugs and drug delivery systems, to avoid a systematic underestimation of fluorescence in strongly absorbing organs, such as the heart, liver and kidney.

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“…We use commercially available and widely used FMT and µCT devices 3,11,[15][16][17]21 . While the protocol requires a specific FMT, the µCT can be replaced by another µCT with similar functionality and comparable scanning parameters, e. g., the field of view should be large enough to cover the mouse bed including the markers.…”

Section: Discussionmentioning

confidence: 99%

“…This is important to assess the dynamic behavior of probes, i.e., their target accumulation, biodistribution and excretion 10,15 , or to assess the disease progression 16 . When imaging several mice at multiple time points, a large amount of image data sets arises.…”

Section: Introductionmentioning

confidence: 99%

Hybrid µCT-FMT imaging and image analysis

Gremse

Doleschel

Zafarnia

et al. 2015

JoVE

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Fluorescence-mediated tomography (FMT) enables longitudinal and quantitative determination of the fluorescence distribution in vivo and can be used to assess the biodistribution of novel probes and to assess disease progression using established molecular probes or reporter genes. The combination with an anatomical modality, e.g., micro computed tomography (µCT), is beneficial for image analysis and for fluorescence reconstruction. We describe a protocol for multimodal µCT-FMT imaging including the image processing steps necessary to extract quantitative measurements. After preparing the mice and performing the imaging, the multimodal data sets are registered. Subsequently, an improved fluorescence reconstruction is performed, which takes into account the shape of the mouse. For quantitative analysis, organ segmentations are generated based on the anatomical data using our interactive segmentation tool. Finally, the biodistribution curves are generated using a batchprocessing feature. We show the applicability of the method by assessing the biodistribution of a well-known probe that binds to bones and joints.

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Targeted Near-Infrared Imaging of the Erythropoietin Receptor in Human Lung Cancer Xenografts

Cited by 24 publications

References 30 publications

The erythropoietin receptor is a downstream effector of Klotho-induced cytoprotection

The erythropoietin receptor is a downstream effector of Klotho-induced cytoprotection

Absorption Reconstruction Improves Biodistribution Assessment of Fluorescent Nanoprobes Using Hybrid Fluorescence-mediated Tomography

Hybrid µCT-FMT imaging and image analysis

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Targeted Near-Infrared Imaging of the Erythropoietin Receptor in Human Lung Cancer Xenografts

Cited by 24 publications

References 30 publications

The erythropoietin receptor is a downstream effector of Klotho-induced cytoprotection

The erythropoietin receptor is a downstream effector of Klotho-induced cytoprotection

Absorption Reconstruction Improves Biodistribution Assessment of Fluorescent Nanoprobes Using Hybrid Fluorescence-mediated Tomography

Hybrid &#181;CT-FMT imaging and image analysis

Contact Info

Product

Resources

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Hybrid µCT-FMT imaging and image analysis