Name: quantitative multispectral analysis following fluorescent tissue transplant for visualization of cell origins, types, and interactions
Uploaded: 2013-09-22T20:30:00
Description: Watch this Scientific Journal Video about Quantitative Multispectral Analysis Following Fluorescent Tissue Transplant for Visualization of Cell Origins, Types, and Interactions at JoVE.com

We are grateful to the discussions, guidance and support from Drs. Michael Andreeff MD, PhD., and Jared Burks PhD. from the MD Anderson Flow Cytometry and Cellular Imaging Core Facility. This work was supported in part by grants from the National Cancer Institute (RC1-CA146381, CA-083639, R01NS06994, CA116199 and CA109451 for FCM. ELS is also supported by the Army Department of Defense (BC083397).

Syngeneic Murine Bone Marrow Transplantation (BMT) as approved by institutional IACUC protocols (Note: Success of this protocol requires utilization of any labeled cell type(s) as the target for multispectral analysis, and to facilitate the downstream analysis, one can exploit any genetic or stable cellular labeling. We suggest that any cell, tissue, or organ-to-be can be applied to a transplant model and that the transplant can contain as many unique labeled populations as the research deems useful. Add...

<ol>
	<li>Kidd, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Origins+of+the+tumor+microenvironment:+quantitative+assessment+of+adipose-derived+and+bone+marrow-derived+stroma.">Origins of the tumor microenvironment: quantitative assessment of adipose-derived and bone marrow-derived stroma.</a> PLoS ONE. 7, e30563 (2012).</li><li>Quintavalla, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescently+labeled+mesenchymal+stem+cells+(MSCs)+maintain+multilineage+potential+and+can+be+detected+following+implantation+into+articular+cartilage+defects.">Fluorescently labeled mesenchymal stem cells (MSCs) maintain multilineage potential and can be detected following implantation into articular cartilage defects.</a> Biomaterials. 23, 109-119 (2002).</li><li>Sasaki, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesenchymal+stem+cells+are+recruited+into+wounded+skin+and+contribute+to+wound+repair+by+transdifferentiation+into+multiple+skin+cell+type.">Mesenchymal stem cells are recruited into wounded skin and contribute to wound repair by transdifferentiation into multiple skin cell type.</a> Journal of immunology. 180, 2581-2587 (2008).</li><li>Spaeth, E. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mesenchymal+stem+cell+transition+to+tumor-associated+fibroblasts+contributes+to+fibrovascular+network+expansion+and+tumor+progression.">Mesenchymal stem cell transition to tumor-associated fibroblasts contributes to fibrovascular network expansion and tumor progression.</a> PLoS ONE. 4, e4992 (2009).</li><li>Wels, J., Kaplan, R. N., Rafii, S., Lyden, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Migratory+neighbors+and+distant+invaders:+Tumor-associated+niche+cells.">Migratory neighbors and distant invaders: Tumor-associated niche cells.</a> Genes and Development. 22, 559-574 (2008).</li><li>Weis, S. M., Cheresh, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tumor+angiogenesis:+molecular+pathways+and+therapeutic+targets.">Tumor angiogenesis: molecular pathways and therapeutic targets.</a> Nat. Med. 17, 1359-1370 (2011).</li><li>Bataille, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiparameter+immunofluorescence+on+paraffin-embedded+tissue+sections.">Multiparameter immunofluorescence on paraffin-embedded tissue sections.</a> Applied immunohistochemistry &amp; molecular morphology : AIMM / official publication of the Society for Applied Immunohistochemistry. 14, 225-228 (1097).</li><li>van Vlierberghe, R. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Four-color+staining+combining+fluorescence+and+brightfield+microscopy+for+simultaneous+immune+cell+phenotyping+and+localization+in+tumor+tissue+sections.">Four-color staining combining fluorescence and brightfield microscopy for simultaneous immune cell phenotyping and localization in tumor tissue sections.</a> Microscopy research and technique. 67, 15-21 (2005).</li><li>Robertson, D., Savage, K., Reis-Filho, J. S., Isacke, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+immunofluorescence+labelling+of+formalin-fixed+paraffin-embedded+(FFPE)+tissue.">Multiple immunofluorescence labelling of formalin-fixed paraffin-embedded (FFPE) tissue.</a> BMC cell biology. 9, 13 (2008).</li><li>Qiu, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extracting+a+cellular+hierarchy+from+high-dimensional+cytometry+data+with+SPADE.">Extracting a cellular hierarchy from high-dimensional cytometry data with SPADE.</a> Nat Biotechnol. 29, 886-891 (2011).</li><li>Belizario, J. E., Akamini, P., Wolf, P., Strauss, B., Xavier-Neto, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+routes+for+transgenesis+of+the+mouse.">New routes for transgenesis of the mouse.</a> Journal of applied. 53, 295-315 (2012).</li></ol>

Herein we describe the application of multispectral imaging we describe as MIMicc- multispectral interrogation of Multiplexed cellular compositions, to analyze the bone marrow derived stromal components of the tumor microenvironment, however this methodology and concept can be applied to deciphering other cellular elements that compose a complex tissues such as those seen during wound healing reactions or during a regenerative tissue. In these experiments we utilize transgenic mice to fluorescently distinguish the...

Understanding tissue development and repair is significant to elucidating participating cellular components in wound healing,2,3 regenerative medicine, developmental biology and tumor biology. Under circumstances of repair, numerous cell types infiltrate the surrounding microenvironment to aid in vascularization, ECM deposition, proliferation and tissue restructuring. Cellular factors and phenotypes can be identified based on multiparameter, multiplexed markers that can identify the localization, differentiation status and interaction between cellular components within the investigated microenvironment. Herein, we describe tumor development as a prototypical example for this multicolor-multicellular transplant model followed by multispectral imaging and spectral unmixing methodology.	
	Tumor progression is a multistep process that is marked by several acquired capabilities that include enhanced proliferation, antiapoptotic, invasive and angiogenic properties.4 Tumor development is facilitated by non-neoplastic cells that are recruited into the surrounding environment to provide growth factors, structural matrices, vascular networks and immune modulation.1,5,6 This microhabitat consists of cells derived from local, neighboring tissues such as adipose, and blood vessels and distant sources such as bone marrow derived cells 1. The extent of non-neoplastic cell incorporation depends on the demand from the tumor, which often corresponds with the stage/grade of the tumor. To comprehend the role of the tumor supportive microenvironment, one must understand the origin and the differentiation potential of the non-neoplastic cell populations.	
	This protocol has been designed to aid in the interpretation of tumor progression through the visualization of both the bone marrow derived cellular components, and the local tissue derived cells. Utilizing fluorescent reporter gene-expressing transgenic mice, we transplanted GFP (green-fluorescent protein) bone marrow into a lethally irradiated RFP (red-fluorescent protein) mouse. Following successful bone marrow engraftment, a syngeneic tumor cell line is injected orthotopically and allowed to engraft for 4-8 weeks. The resulting tumor is excised from the mouse and processed for immunofluorescent (IF) staining to visualize the stromal components. 	Multiplexing IF markers is a commonly used technique that involves significant optimization7-9, however using a multispectral imaging/unmixing platform improves the potential for fluorescent marker combinations that possess spectral overlap. Herein we present a technique we call MIMicc- multispectral interrogation of Multiplexed cellular compositions to stain and analyze up to eight markers within a tumor section on a single slide in order to analyze the cellular origins, cellular differentiation status and cell-cell interactions of components within the tumor microenvironment. This simplified example has the potential to be expanded upon in order to analyze five, six, or more markers utilizing antibodies or intracellular promoter-driven fluorescent expression. Table 1 lists potential fluorescent antibody staining combinations with appropriate species taken into account.

<table border="1" fo:keep-together.within-page="always">
		<tbody>
		 <tr>
			<td>Name of the reagent</td>
			<td>Company</td>
			<td>Catalogue number</td>
			<td></td>
		 </tr>
		 <tr>
			<td>.2 &mu;m filter</td>
			<td >Fisher</td>
			<td>09-740-35A</td>
			<td></td>
		 </tr>
		 <tr>
			<td>10 ml lure lock </td>
			<td >BD</td>
			<td>309604</td>
			<td></td>
		 </tr>
		 <tr>
			<td>25 G needle</td>
			<td >Cardinal</td>
			<td>BF305122</td>
			<td></td>
		 </tr>
		 <tr>
			<td>40nm filter</td>
			<td >BD</td>
			<td>352340</td>
			<td></td>
		 </tr>
		 <tr>
			<td>50 ml conical tube</td>
			<td >Fisher</td>
			<td>1495949A</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Alexafluor 488-ms1</td>
			<td >invitrogen</td>
			<td>A21121</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Alexafluor 594-Rb</td>
			<td >invitrogen</td>
			<td>A21207</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Alexafluor 647-ch</td>
			<td >Invitrogen</td>
			<td>A21449</td>
			<td></td>
		 </tr>
		 <tr>
			<td>BSA</td>
			<td >Sigma</td>
			<td>A7906-500G</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Cover slips</td>
			<td >Corning</td>
			<td>2940-243</td>
			<td></td>
		 </tr>
		 <tr>
			<td>CRI-Nuance</td>
			<td>Caliper Life Sciences</td>
			<td></td>
			<td></td>
		 </tr>
		 <tr>
			<td>Dapi</td>
			<td >Invitrogen</td>
			<td>D1306</td>
			<td></td>
		 </tr>
		 <tr>
			<td>DMEM</td>
			<td >CellGro</td>
			<td>10-017-CV</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Ethanol</td>
			<td >Dharmacon</td>
			<td>4004-DV</td>
			<td></td>
		 </tr>
		 <tr>
			<td>FBS</td>
			<td >invitrogen</td>
			<td>16000-044</td>
			<td></td>
		 </tr>
		 <tr>
			<td>GFP-ms1</td>
			<td >Abcam</td>
			<td>ab38689</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Insulin needle</td>
			<td >BD</td>
			<td>329424</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Maleic acid</td>
			<td >Acros</td>
			<td>100-16-7</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Moisture chamber box</td>
			<td >Evergreen</td>
			<td>240-9020-Z10</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Mounting media</td>
			<td >dako</td>
			<td>S3023</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Nail hardener</td>
			<td >Sally Hansen</td>
			<td>2103</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Pap pen</td>
			<td >Abcam</td>
			<td>Ab2601</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Pen/Strep L Glut</td>
			<td >invitrogen</td>
			<td>10378016</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Steril PBS</td>
			<td >invitrogen</td>
			<td>14040-182</td>
			<td></td>
		 </tr>
		 <tr>
			<td>Trypsin</td>
			<td >invitrogen</td>
			<td>252000-56</td>
			<td> </td>
		 </tr>
 <tr>
 	<td></td>
 <td></td>
 <td></td>
 <td>
 Blocking Buffer	
	<table border="1" fo:keep-together.within-page="always">
 <tbody>
 <tr>
 <td>maleic acid</td>
 <td>14.51 g </td>
 </tr>
 <tr>
 <td>NaCl</td>
 <td>10.95 g</td>
 </tr>
 <tr>
 <td>NaOH pellets (to 7.5pH)</td>
 <td>9+g</td>
 </tr>
 <tr>
 <td>Distilled water</td>
 <td>250 ml</td>
 </tr>
 </tbody>
 </table>
	*add 0.2% Tween-20 to 1x solution for blocking buffer with 2%BSA/2%FBS. Stir and filter. 
	Antigen retrieval buffers:
	<table border="1" fo:keep-together.within-page="always">
 <tbody>
 <tr>
 <td colspan="2">Tris-EDTA Buffer (10 mM Tris Base, 1 mM EDTA Solution, 0.05% Tween 20, pH 9.0)</td>
 </tr>
 <tr>
 <td>Tris Base</td>
 <td>1.21 g</td>
 </tr>
 <tr>
 <td>EDTA</td>
 <td>0.37 g</td>
 </tr>
 <tr>
 <td>Distilled water</td>
 <td>1000 ml (100 ml to make 10x, 50 ml to make 20x)</td>
 </tr>
 <tr>
 <td>Tween 20</td>
 <td>0.5 ml</td>
 </tr>
 </tbody>
 </table>
	*Store at RT for 3 months or at 4 &deg; C for longer
	<table border="1" fo:keep-together.within-page="always">
 <tbody>
 <tr>
 <td colspan="2">Sodium Citrate Buffer (10 mM Sodium Citrate, 0.05% Tween 20, pH 6.0)</td>
 </tr>
 <tr>
 <td>Tri-sodium citrate (dihydrate)</td>
 <td>2.94 g</td>
 </tr>
 <tr>
 <td>Distilled water</td>
 <td>1000 ml</td>
 </tr>
 <tr>
 <td>HCl (adjust pH to 6.0)</td>
 <td>1N</td>
 </tr>
 <tr>
 <td>Tween 20</td>
 <td>0.5 ml</td>
 </tr>
 </tbody>
 </table>
 </td>
 </tr>
		</tbody>
 </table>

quantitative multispectral analysis following fluorescent tissue transplant for visualization of cell origins, types, and interactions

With the desire to understand the contributions of multiple cellular elements to the development of a complex tissue; such as the numerous cell types that participate in regenerating tissue, tumor formation, or vasculogenesis, we devised a multi-colored cellular transplant model of tumor development in which cell populations originate from different fluorescently colored reporter gene mice and are transplanted, engrafted or injected in and around a developing tumor. These colored cells are then recruited and incorporated into the tumor stroma. In order to quantitatively assess bone marrow derived tumor stromal cells, we transplanted GFP expressing transgenic whole bone marrow into lethally irradiated RFP expressing mice as approved by IACUC. 0ovarian tumors that were orthotopically injected into the transplanted mice were excised 6-8 weeks post engraftment and analyzed for bone marrow marker of origin (GFP) as well as antibody markers to detect tumor associated stroma using multispectral imaging techniques. We then adapted a methodology we call MIMicc- Multispectral Interrogation of Multiplexed cellular compositions, using multispectral unmixing of fluoroprobes to quantitatively assess which labeled cell came from which starting populations (based on original reporter gene labels), and as our ability to unmix 4, 5, 6 or more spectra per slide increases, we&#39;ve added additional immunohistochemistry associated with cell lineages or differentiation to increase precision. Utilizing software to detect co-localized multiplexed-fluorescent signals, tumor stromal populations can be traced, enumerated and characterized based on marker staining.1

Using a multispectral imaging technique to analyze tumors engrafted in our transgenic BMT mouse model, we are able to discern stromal tumor components that are of bone marrow origin. The initial BMT was confirmed three weeks post-transplant by flow cytometry (Figure 1). Orthotopically injected unlabeled ovarian tumors following BMT engraftment confirmations were excised and formalin fixed 6 weeks following initial tumor injection. Paraffin embedded tumor sections were sectioned in &lt;8 &mu;m slic...

Watch this Scientific Journal Video about Quantitative Multispectral Analysis Following Fluorescent Tissue Transplant for Visualization of Cell Origins, Types, and Interactions at JoVE.com

Quantitative Multispectral Analysis Following Fluorescent Tissue Transplant for Visualization of Cell Origins, Types, and Interactions

Complex tissue masses, from organs to tumors, are composed of various cellular elements. We elucidated the contribution of cellular phenotypes within a tissue utilizing multi-labeled fluorescent transgenic mice in combination with multiparameter immunofluorescent staining followed by spectral unmixing to decipher cell origin as well as cell characteristics based on protein expression.

With the desire to understand the contributions of multiple cellular elements to the development of a complex tissue; such as the numerous cell types that ...

quantitative-multispectral-analysis-following-fluorescent-tissue

Research

JoVE Journal

Medicine

Quantitative Visualization and Detection of Skin Cancer Using Dynamic Thermal Imaging

In 2010 approximately 68,720 melanomas will be diagnosed in the US alone, with around 8,650 resulting in death 1. To date, the only effective treatment for melanoma remains surgical excision, therefore, the key to extended survival is early detection 2,3. Considering the large numbers of patients diagnosed every year and the limitations in accessing specialized care quickly, the development of objective in vivo diagnostic instruments to aid the diagnosis is essential. New techniques to detect skin cancer, especially non-invasive diagnostic tools, are being explored in numerous laboratories. Along with the surgical methods, techniques such as digital photography, dermoscopy, multispectral imaging systems (MelaFind), laser-based systems (confocal scanning laser microscopy, laser doppler perfusion imaging, optical coherence tomography), ultrasound, magnetic resonance imaging, are being tested. Each technique offers unique advantages and disadvantages, many of which pose a compromise between effectiveness and accuracy versus ease of use and cost considerations. Details about these techniques and comparisons are available in the literature 4.
Infrared (IR) imaging was shown to be a useful method to diagnose the signs of certain diseases by measuring the local skin temperature. There is a large body of evidence showing that disease or deviation from normal functioning are accompanied by changes of the temperature of the body, which again affect the temperature of the skin 5,6. Accurate data about the temperature of the human body and skin can provide a wealth of information on the processes responsible for heat generation and thermoregulation, in particular the deviation from normal conditions, often caused by disease. However, IR imaging has not been widely recognized in medicine due to the premature use of the technology 7,8 several decades ago, when temperature measurement accuracy and the spatial resolution were inadequate and sophisticated image processing tools were unavailable. This situation changed dramatically in the late 1990s-2000s. Advances in IR instrumentation, implementation of digital image processing algorithms and dynamic IR imaging, which enables scientists to analyze not only the spatial, but also the temporal thermal behavior of the skin 9, allowed breakthroughs in the field.
In our research, we explore the feasibility of IR imaging, combined with theoretical and experimental studies, as a cost effective, non-invasive, in vivo optical measurement technique for tumor detection, with emphasis on the screening and early detection of melanoma 10-13. In this study, we show data obtained in a patient study in which patients that possess a pigmented lesion with a clinical indication for biopsy are selected for imaging. We compared the difference in thermal responses between healthy and malignant tissue and compared our data with biopsy results. We concluded that the increased metabolic activity of the melanoma lesion can be detected by dynamic infrared imaging.

We demonstrated that malignant pigmented lesions with increased metabolic activity generate quantifiable amounts of heat and the measurement of the transient thermal response of the skin to a cooling excitation allows quantitative identification of melanoma and other skin cancers (vs. non-proliferative nevi) at an early stage of the disease.

In 2010 approximately 68,720 melanomas will be diagnosed in the US alone, with around 8,650 resulting in death 1. To date, the only effective treatment ...

Improved Visualization of Lung Metastases at Single Cell Resolution in Mice by Combined In-situ Perfusion of Lung Tissue and X-Gal Staining of lacZ-Tagged Tumor Cells

Metastasis is the main cause of death in the majority of cancer types and consequently a main focus in cancer research. However, the detection of micrometastases by radiologic imaging and the success in their therapeutic eradication remain limited.
While animal models have proven to be invaluable tools for cancer research1, the monitoring/visualization of micrometastases remains a challenge and inaccurate evaluation of metastatic spread in preclinical studies potentially leads to disappointing results in clinical trials2. Consequently, there is great interest in refining the methods to finally allow reproducible and reliable detection of metastases down to the single cell level in normal tissue. The main focus therefore is on techniques, which allow the detection of tumor cells in vivo, like micro-computer tomography (micro-CT), positron emission tomography (PET), bioluminescence or fluorescence imaging3,4. We are currently optimizing these techniques for in vivo monitoring of primary tumor growth and metastasis in different osteosarcoma models. Some of these techniques can also be used for ex vivo analysis of metastasis beside classical methods like qPCR5, FACS6 or different types of histological staining. As a benchmark, we have established in the present study the stable transfection or transduction of tumor cells with the lacZ gene encoding the bacterial enzyme &beta;-galactosidase that metabolizes the chromogenic substrate 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal) to an insoluble indigo blue dye7 and allows highly sensitive and selective histochemical blue staining of tumor cells in mouse tissue ex vivo down to the single cell level as shown here. This is a low-cost and not equipment-intensive tool, which allows precise validation of metastasis8 in studies assessing new anticancer therapies9-11. A limiting factor of X-gal staining is the low contrast to e.g. blood-related red staining of well vascularized tissues. In lung tissue this problem can be solved by in-situ lung perfusion, a technique that was recently established by Borsig et al.12 who perfused the lungs of mice under anesthesia to clear them from blood and to fix and embed them in-situ under inflation through the trachea. This method prevents also the collapse of the lung and thereby maintains the morphology of functional lung alveoli, which improves the quality of the tissue for histological analysis. In the present study, we describe a new protocol, which takes advantage of a combination of X-gal staining of lacZ-expressing tumor cells and in-situ perfusion and fixation of lung tissue. This refined protocol allows high-sensitivity detection of single metastatic cells in the lung and enabled us in a recent study to detect "dormant" lung micrometastases in a mouse model13, which was originally described to be non-metastatic14.

Improved Visualization of Lung Metastases at Single Cell Resolution in Mice by Combined In-situ Perfusion of Lung Tissue and X-Gal Staining of lacZ-Tagged Tumor Cells

The novel protocol reported in the present study allows selective detection of lung metastases at single cell resolution in mice by combined in-situ lung perfusion and fixation and X-Gal staining of lacZ-tagged tumor cells.

Metastasis is the main cause of death in the majority of cancer types and consequently a main focus in cancer research. However, the detection of ...

Isolation of Cardiomyocyte Nuclei from Post-mortem Tissue

Identification of cardiomyocyte nuclei has been challenging in tissue sections as most strategies rely only on cytoplasmic marker proteins1. Rare events in cardiac myocytes such as proliferation and apoptosis require an accurate identification of cardiac myocyte nuclei to analyze cellular renewal in homeostasis and in pathological conditions2. Here, we provide a method to isolate cardiomyocyte nuclei from post mortem tissue by density sedimentation and immunolabeling with antibodies against pericentriolar material 1 (PCM-1) and subsequent flow cytometry sorting. This strategy allows a high throughput analysis and isolation with the advantage of working equally well on fresh tissue and frozen archival material. This makes it possible to study material already collected in biobanks. This technique is applicable and tested in a wide range of species and suitable for multiple downstream applications such as carbon-14 dating3, cell-cycle analysis4, visualization of thymidine analogues (e.g. BrdU and IdU)4, transcriptome and epigenetic analysis.

Cardiac nuclei are isolated via density sedimentation and immunolabeled with antibodies against pericentriolar material 1 (PCM-1) to identify and sort cardiomyocyte nuclei by flow cytometry.

Identification of cardiomyocyte nuclei has been challenging in tissue sections as most strategies rely only on cytoplasmic marker proteins1. Rare events ...

Quantitative Analysis of Chromatin Proteomes in Disease

In the nucleus reside the proteomes whose functions are most intimately linked with gene regulation. Adult mammalian cardiomyocyte nuclei are unique due to the high percentage of binucleated cells,1 the predominantly heterochromatic state of the DNA, and the non-dividing nature of the cardiomyocyte which renders adult nuclei in a permanent state of interphase.2 Transcriptional regulation during development and disease have been well studied in this organ,3-5 but what remains relatively unexplored is the role played by the nuclear proteins responsible for DNA packaging and expression, and how these proteins control changes in transcriptional programs that occur during disease.6 In the developed world, heart disease is the number one cause of mortality for both men and women.7 Insight on how nuclear proteins cooperate to regulate the progression of this disease is critical for advancing the current treatment options.
Mass spectrometry is the ideal tool for addressing these questions as it allows for an unbiased annotation of the nuclear proteome and relative quantification for how the abundance of these proteins changes with disease. While there have been several proteomic studies for mammalian nuclear protein complexes,8-13 until recently14 there has been only one study examining the cardiac nuclear proteome, and it considered the entire nucleus, rather than exploring the proteome at the level of nuclear sub compartments.15 In large part, this shortage of work is due to the difficulty of isolating cardiac nuclei. Cardiac nuclei occur within a rigid and dense actin-myosin apparatus to which they are connected via multiple extensions from the endoplasmic reticulum, to the extent that myocyte contraction alters their overall shape.16 Additionally, cardiomyocytes are 40% mitochondria by volume17 which necessitates enrichment of the nucleus apart from the other organelles. Here we describe a protocol for cardiac nuclear enrichment and further fractionation into biologically-relevant compartments. Furthermore, we detail methods for label-free quantitative mass spectrometric dissection of these fractions-techniques amenable to in vivo experimentation in various animal models and organ systems where metabolic labeling is not feasible.

Advances in mass spectrometry have allowed the high throughput analysis of protein expression and modification in a host of tissues. Combined with subcellular fractionation and disease models, quantitative mass spectrometry and bioinformatics can reveal new properties in biological systems. The method described herein analyzes chromatin-associated proteins in the setting of heart disease and is readily applicable to other in vivo models of human disease.

In the nucleus reside the proteomes whose functions are most intimately linked with gene regulation. Adult mammalian cardiomyocyte nuclei are unique due ...

Murine Heterotopic Heart Transplant Technique

It is now over forty years since this technique was first reported by Corry, Wynn and Russell. Although it took some years for other labs to become proficient in and utilize this technique, it is now widely used by many laboratories around the world. A significant refinement to the original technique was developed and reported in 2001 by Niimi. Described here are the techniques that have evolved over more than a decade in the hands of three surgeons (Plenter, Grazia, Pietra) in our center. These techniques are now being passed on to a younger generation of surgeons and researchers.
Based largely on the Niimi experience, the procedures used have evolved in the fine details - details which we will endeavor to relate here in such a way that others may be able to use this very useful model. Like Niimi, we have found that a video aid to learning is a priceless resource for the beginner.

The manuscript describes the steps required to perform the heterotopic heart transplant in the mouse.

It is now over forty years since this technique was first reported by Corry, Wynn and Russell. Although it took some years for other labs to become ...

Multi-electrode Array Recordings of Human Epileptic Postoperative Cortical Tissue

Epilepsy, affecting about 1% of the population, comprises a group of neurological disorders characterized by the periodic occurrence of seizures, which disrupt normal brain function. Despite treatment with currently available antiepileptic drugs targeting neuronal functions, one third of patients with epilepsy are pharmacoresistant. In this condition, surgical resection of the brain area generating seizures remains the only alternative treatment. Studying human epileptic tissues has contributed to understand new epileptogenic mechanisms during the last 10 years. Indeed, these tissues generate spontaneous interictal epileptic discharges as well as pharmacologically-induced ictal events which can be recorded with classical electrophysiology techniques. Remarkably, multi-electrode arrays (MEAs), which are microfabricated devices embedding an array of spatially arranged microelectrodes, provide the unique opportunity to simultaneously stimulate and record field potentials, as well as action potentials of multiple neurons from different areas of the tissue. Thus MEAs recordings offer an excellent approach to study the spatio-temporal patterns of spontaneous interictal and evoked seizure-like events and the mechanisms underlying seizure onset and propagation. Here we describe how to prepare human cortical slices from surgically resected tissue and to record with MEAs interictal and ictal-like events ex vivo.

We here describe how to perform multi-electrode array recordings of human epileptic cortical tissue. Epileptic tissue resection, slice preparation and multi-electrode array recordings of interictal and ictal events are demonstrated in detail.

Epilepsy, affecting about 1% of the population, comprises a group of neurological disorders characterized by the periodic occurrence of seizures, which ...

Murine Kidney Transplant Technique

The first mouse kidney transplant technique was published in 19731 by the Russell laboratory. Although it took some years for other labs to become proficient in and utilize this technique, it is now widely used by many laboratories around the world. A significant refinement to the original technique using the donor aorta to form the arterial anastomosis instead of the renal artery was developed and reported in 1993 by Kalina and Mottram 2 with a further advancement coming from the same laboratory in 1999 3. While one can become proficient in this model, a search of the literature reveals that many labs still experience a high proportion of graft loss due to arterial thrombosis. We describe here a technique that was devised in our laboratory that vastly reduces the arterial thrombus reported by others 4,5. This is achieved by forming a heel-and-toe cuff of the donor infra-renal aorta that facilitates a larger anastomosis and straighter blood flow into the kidney.

The goal of this manuscript is to describe the steps required to perform a kidney transplant in a mouse, paying particular attention to the details of the arterial anastomosis.

The first mouse kidney transplant technique was published in 19731 by the Russell laboratory. Although it took some years for other labs to become ...

Vein Interposition Model: A Suitable Model to Study Bypass Graft Patency

Bypass grafting is an established treatment method for coronary artery disease. Graft patency continues to be the Achilles heel of saphenous vein grafts. Research models for bypass graft failure are essential for a better understanding of pathobiological and pathophysiological processes during graft patency loss. Large animal models, such as pigs or sheep, resemble human anatomical structures but require special facilities and equipment. This video describes a rat vein interposition model to investigate vein graft patency loss. Rats are inexpensive and easy to handle. Compared to mouse models, the convenient size of rats permits better operability and enables a sufficient amount of material to be obtained for further diverse analysis. In brief, the inferior epigastric vein of a donor rat is harvested and used to replace a segment of the femoral artery. Anastomosis is conducted via single stitches and sealed with fibrin glue. Graft patency can be monitored non-invasively using duplex sonography. Myointimal hyperplasia, which is the main cause for graft patency loss, develops progressively over time and can be calculated from histological cross sections.

This video demonstrates a model to study the development of myointimal hyperplasia after venous interposition surgery in rats.

Bypass grafting is an established treatment method for coronary artery disease. Graft patency continues to be the Achilles heel of saphenous vein grafts. ...

Quantitative Visualization of Leukocyte Infiltrate in a Murine Model of Fulminant Myocarditis by Light Sheet Microscopy

Light-sheet fluorescence microscopy (LSFM), in combination with chemical clearing protocols, has become the gold standard for analyzing fluorescently labelled structures in large biological specimens, and is down to cellular resolution. Meanwhile, the constant refinement of underlying protocols and the enhanced availability of specialized commercial systems enable us to investigate the microstructure of whole mouse organs and even allow for the characterization of cellular behavior in various live-cell imaging approaches. Here, we describe a protocol for the spatial whole-mount visualization and quantification of the CD45+ leukocyte population in inflamed mouse hearts. The method employs a transgenic mouse strain (CD11c.DTR)that has recently been shown to serve as a robust, inducible model for the study of the development of fulminant fatal myocarditis, characterized by lethal cardiac arrhythmias. This protocol includes myocarditis induction, intravital antibody-mediated cell staining, organ preparation, and LSFM with subsequent computer-assisted image post-processing. Although presented as a highly-adapted method for our particular scientific question, the protocol represents the blueprint of an easily adjustable system that can also target completely different fluorescent structures in other organs and even in other species.

Here, we describe a light-sheet microscopy approach to visualize the cardiac CD45+ leukocyte infiltrate in a murine model of aseptic fulminant myocarditis, which is induced by the intratracheal diphtheria toxin treatment of CD11c.DTR mice.

Light-sheet fluorescence microscopy (LSFM), in combination with chemical clearing protocols, has become the gold standard for analyzing fluorescently ...

Balloon-based Injury to Induce Myointimal Hyperplasia in the Mouse Abdominal Aorta

The use of animal models is essential for a better understanding of MH, one major cause for arterial stenosis.In this article, we demonstrate a murine balloon denudation model, which is comparable with established vessel injury models in large animals. The aorta denudation model with balloon catheters mimics the clinical setting and leads to comparable pathobiological and physiological changes. Briefly, after performing a horizontal incision in the aorta abdominalis, a balloon catheter will be inserted into the vessel, inflated, and introduced retrogradely. Inflation of the balloon will lead to intima injury and overdistension of the vessel. After removing the catheter, the aortic incision will be closed with single stiches. The model shown in this article is reproducible, easy to perform, and can be established quickly and reliably. It is especially suitable for evaluating expensive experimental therapeutic agents, which can be applied in an economical fashion. By using different knockout-mouse strains, the impact of different genes on MH development can be assessed.

This article demonstrates a murine model to study the development of myointimal hyperplasia (MH) after aortic balloon injury.

The use of animal models is essential for a better understanding of MH, one major cause for arterial stenosis.In this article, we demonstrate a murine ...