The authors would like to thank the Advanced Optical Microscopy Facility (www.aomf.ca) at the University Health Network for assistance with microscopy, and Mr. Jason Ellis from the Princess Margaret Cancer Center Machine Shop for manufacturing the WC and the imaging stage. We would also like to thank Dr. Iris Kulbatski for manuscript editing.

NOTE: All animal work was carried out under protocol #2615 approved by the University Health Network Institutional Animal Care and Use Committee.
1. Surgical Preparation of Mouse
<ol>
	<li>Prior to surgery, sterilize all surgical instruments and the window chamber (WC) by autoclaving. Supplement the drinking water with 50 mg/kg body weight of amoxicillin 2 days prior to surgery. Inject the mouse with 0.1 mg/kg body weight of buprenorphine intraperitoneally 4 hr prior to surgery.</li>
	<li>Anesthetize the athymic...

<ol>
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B., 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=IL-17-producing+[ggr][dgr]+T+cells+and+neutrophils+conspire+to+promote+breast+cancer+metastasis.">IL-17-producing [ggr][dgr] T cells and neutrophils conspire to promote breast cancer metastasis.</a> Nature. 522 (7556), 345-348 (2015).</li><li>Kitamura, T., Qian, B. Z., Pollard, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immune+cell+promotion+of+metastasis.">Immune cell promotion of metastasis.</a> Nat Rev Immunol. 15 (2), 73-86 (2015).</li><li>Granot, Z., 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=Tumor+entrained+neutrophils+inhibit+seeding+in+the+premetastatic+lung.">Tumor entrained neutrophils inhibit seeding in the premetastatic lung.</a> Cancer Cell. 20 (3), 300-314 (2011).</li><li>Travlos, G. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Normal+structure,+function,+and+histology+of+the+bone+marrow.">Normal structure, function, and histology of the bone marrow.</a> Toxicol Pathol. 34 (5), 548-565 (2006).</li><li>Pittet, M. 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Real-time, serial imaging of the dynamic cellular processes in bone marrow provides information that is otherwise challenging to obtain using conventional techniques such as histology and total blood counts. The femur WC model described here provides unique opportunities to investigate cellular and structural alterations in the bone marrow over time. Although a femur WC model has been previously reported, our novel design provides a larger imaging field of view and smaller overall WC size, which are more compatible for u...

Bone marrow is an important organ involved in hematopoiesis and immune regulation. It consists of a hematopoietic component containing hematopoietic stem and progenitor cells (HSPCs), and a stromal component containing non-hematopoietic progenitor cells that give rise to mesenchymal cells1. Two-thirds of hematopoietic activity is dedicated to the generation of myeloid cells2. In particular, a large number of neutrophils are produced in the bone marrow, with 1-2 x 1011 cells generated per day in a normal adult human2. Neutrophils are the first line of defense against microbial infections and are mostly reserved in the bone marrow until stress triggers their mobilization to supplement peripheral neutrophils1,3. In addition to their anti-microbial effects, recent studies suggest an important role of neutrophils in cancer biology, having both pro- and anti-tumorigenic phenotypes depending on transforming growth factor beta (TGF-&#946;) signaling in the tumor microenvironment4,5. Moreover, studies demonstrated that neutrophils that accumulate in primary tumors exert pro-tumorigenic and metastatic effects by suppressing the cytotoxic function of T cells6,7, while neutrophils in circulation exert a cytotoxic, anti-metastatic effect8. As such, investigation of hematopoietic cells in the bone marrow, particularly neutrophils, is crucial to elucidating their role in immune and tumor regulation.
Histopathology and a complete peripheral blood count are routinely used to evaluate cellular and structural alterations in the bone marrow9. However, these methods only provide static information of different cell populations or tissue microstructures. Longitudinal in vivo imaging can be used in combination with the standard methods to assess the dynamics of multiple cellular, vascular and stromal components as well as cell-to-cell interactions in a longitudinal manner. Intravital microscopy (IVM), defined as imaging of living animals at microscopic resolution10, is particularly useful for assessing dynamic cellular processes over time in the same sample, reducing the number of experimental animal required. IVM is often combined with a chronically transplanted window chamber (WC) to access the organ of interest for imaging over a duration of weeks to months. Cranial and dorsal-skinfold WC models have the longest history of use dating back to the mid 1990s. More recently, other organ-specific WC models such as those of the mammary fat pad and various abdominal organs have been developed11.
The typical approach for imaging bone marrow in vivo has mainly involved exposure of the calvaria of mice, where the thinned bone enables direct visualization of single cells with minimal surgical intervention12-14. However, the calvarial bone marrow may be distinct from that of other bones, such as the long bone, as demonstrated by a lower number of HSPCs and hypoxic cells in calvaria, which indicates reduced maintenance and development of HSPCs15. Therefore, alternative approaches for assessing cellular components in the long bone have been investigated. These include direct exposure of the femoral bone marrow16 and ectopic transplantation of split femur in the dorsal skinfold WC17. However, the former is a terminal procedure that does not permit tracking of cellular, structural and functional alterations over longer time periods, and the latter likely disturbs normal bone marrow function due to the transplantation of femur to an ectopic site inside the dorsal skinfold WC. Another method that enables orthotopic serial imaging of femoral bone marrow over time is the use of a WC in the femoral bone. One previous report demonstrated long-term imaging of microcirculation in the femoral bone marrow using a femur WC in mice18. Additionally, the authors demonstrated visualization of tumor cells in the femur, indicating its utility in monitoring bone marrow metastasis. However, this WC design was limited by its large size (1.2 cm diameter) and relatively small imaging area (4 mm diameter), which was only suitable for large mice (26-34 g, 3-6 months of age) thereby making the approach impractical for routine use.
Therefore, a new WC with a smaller overall size and larger inner imaging area was designed for the purpose of this study. The goal of this study was to provide a method for imaging various cell types in the femoral bone marrow. The femur WC model was developed in-house and was used to visualize and track neutrophils within the 3D vascular network. Using this model, IVM of the bone marrow can be performed serially over 40 days. This approach can be applied to a variety of fields for elucidating the processes of hematopoiesis, immune regulation and tumor development.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>NRCNU-F athymic nude mice</td>
			<td>Taconic</td>
			<td>Ncr nude</td>
			<td>8-10 weeks old, female</td>
		</tr>
		<tr>
			<td>Saline</td>
			<td>Baxter</td>
			<td>JB1302P</td>
			<td></td>
		</tr>
		<tr>
			<td>Ketamine hydrochloride</td>
			<td>Bioniche Animal Health Canada, Inc.&#160;</td>
			<td>DIN 01989529</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylazine</td>
			<td>Bayer HealthCare, Bayer Inc.</td>
			<td>DIN 02169592</td>
			<td></td>
		</tr>
		<tr>
			<td>Surgical drape</td>
			<td>Proxima</td>
			<td>DYNJP2405</td>
			<td></td>
		</tr>
		<tr>
			<td>Electric heating pad</td>
			<td>Life Brand</td>
			<td>57800827375</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereomicroscope</td>
			<td>Leica</td>
			<td>Leica M60</td>
			<td></td>
		</tr>
		<tr>
			<td>Eye ointment (tear gel)</td>
			<td>Novartis&#160;</td>
			<td>T296/2</td>
			<td></td>
		</tr>
		<tr>
			<td>7.5% betadine</td>
			<td>Purdue Frederick Co</td>
			<td>67618-151-16</td>
			<td></td>
		</tr>
		<tr>
			<td>70% isopropyl alcohol</td>
			<td>GreenField</td>
			<td>P010IP7P</td>
			<td></td>
		</tr>
		<tr>
			<td>10% betadine</td>
			<td>Purdue Frederick Co</td>
			<td>67618-150-05</td>
			<td></td>
		</tr>
		<tr>
			<td>Scalpel handle (#3)</td>
			<td>Fine Science Tools</td>
			<td>10003-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Scalpel blade (#15)</td>
			<td>VWR</td>
			<td>89176-368</td>
			<td></td>
		</tr>
		<tr>
			<td>Spring Scissors curved</td>
			<td>Fine science Tools</td>
			<td>15023-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Baby-Mixter Hemostat</td>
			<td>Fine science Tools</td>
			<td>13013-14</td>
			<td></td>
		</tr>
		<tr>
			<td>Fine Scissors</td>
			<td>Fine science Tools</td>
			<td>14094-11</td>
			<td></td>
		</tr>
		<tr>
			<td>Extra Fine Graefe Forceps</td>
			<td>Fine science Tools</td>
			<td>11151-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Halsted-Mosquito Hemostats</td>
			<td>Fine science Tools</td>
			<td>13008-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro-drill</td>
			<td>Harvard Apparaus</td>
			<td>72-6065</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro-drill burrs</td>
			<td>Fine Science Tools</td>
			<td>19007-14</td>
			<td></td>
		</tr>
		<tr>
			<td>Femur window chamber</td>
			<td>PMCC machine shop</td>
			<td>custom design</td>
			<td>9.1mm- 8.5mm- 7.5 mm (outer to inner diameter), 2.16 mm (radius of two holes), 13.9mm (distance between two holes), 0.7mm (thickness)</td>
		</tr>
		<tr>
			<td>U-shaped bar</td>
			<td>PMCC machine shop</td>
			<td>custom design</td>
			<td>13.8mm (length), 1.6 mm (width), 3.7mm (height)</td>
		</tr>
		<tr>
			<td>Coverglass (8mm)</td>
			<td>Warner Instruments&#160;</td>
			<td>HBIO 64-0701 CS-8R</td>
			<td></td>
		</tr>
		<tr>
			<td>Retaining ring (8mm)</td>
			<td>ACKLANDS GRAINGER</td>
			<td>UNSPSC # 31163202</td>
			<td></td>
		</tr>
		<tr>
			<td>Nuts (hexagon stainless steel)</td>
			<td>Fastenal</td>
			<td>70701</td>
			<td></td>
		</tr>
		<tr>
			<td>Dental cement</td>
			<td>3M</td>
			<td>RelyX U200</td>
			<td></td>
		</tr>
		<tr>
			<td>Suture (5-0 Monosof black)</td>
			<td>Covioien</td>
			<td>SN-5698</td>
			<td></td>
		</tr>
		<tr>
			<td>Halsey needle holder</td>
			<td>Fine Science Tools</td>
			<td>12501-13</td>
			<td></td>
		</tr>
		<tr>
			<td>Buprenorphine (Temgesic)</td>
			<td>Reckitt Benckiser</td>
			<td>DIN 0281251</td>
			<td></td>
		</tr>
		<tr>
			<td>Meloxicam (Metacam)</td>
			<td>Boehringer Ingelheim</td>
			<td>DIN 02240463</td>
			<td></td>
		</tr>
		<tr>
			<td>Amoxicillin (Clamavox)</td>
			<td>Pfizer</td>
			<td>DIN 02027879</td>
			<td></td>
		</tr>
		<tr>
			<td>FITC-Dextran</td>
			<td>Sigma-Aldrich</td>
			<td>FD2000S</td>
			<td></td>
		</tr>
		<tr>
			<td>APC- Anti-Mouse Ly-6G (Gr-1)&#160;</td>
			<td>eBioscience</td>
			<td>17-9668</td>
			<td></td>
		</tr>
		<tr>
			<td>Two-photon microscope LSM 710</td>
			<td>Carl Zeiss</td>
			<td>Zeiss LSM 710 NLO</td>
			<td></td>
		</tr>
		<tr>
			<td>Imaging stage</td>
			<td>PMCC machine shop</td>
			<td>custom design</td>
			<td>15.9cm (length), 11cm (width), 0,9cm (height)</td>
		</tr>
		<tr>
			<td>Imaris software</td>
			<td>Bitplane</td>
			<td>Imaris 8.0</td>
			<td>Image analysis software described in Section 3 of the Protocol&#160;</td>
		</tr>
		<tr>
			<td>Zen 2012</td>
			<td>Zeiss</td>
			<td>Zen 2012</td>
			<td>Image acqusition software described in Section 2 of the Protocol&#160;</td>
		</tr>
	</tbody>
</table>

femur window chamber model for in vivo cell tracking in the murine bone marrow

Bone marrow is a complex organ that contains various hematopoietic and non-hematopoietic cells. These cells are involved in many biological processes, including hematopoiesis, immune regulation and tumor regulation. Commonly used methods for understanding cellular actions in the bone marrow, such as histology and blood counts, provide static information rather than capturing the dynamic action of multiple cellular components in vivo. To complement the standard methods, a window chamber (WC)-based model was developed to enable serial in vivo imaging of cells and structures in the murine bone marrow. This protocol describes a surgical procedure for installing the WC in the femur, in order to facilitate long-term optical access to the femoral bone marrow. In particular, to demonstrate its experimental utility, this WC approach was used to image and track neutrophils within the vascular network of the femur, thereby providing a novel method to visualize and quantify immune cell trafficking and regulation in the bone marrow. This method can be applied to study various biological processes in the murine bone marrow, such as hematopoiesis, stem cell transplantation, and immune responses in pathological conditions, including cancer.

Murine femoral bone marrow is successfully accessed using the WC to enable visualization of individual neutrophils and vascular networks. Figure 1 shows the WC instrument and describes the surgical procedure, which involves exposure of the femoral bone and thinning of cortical bone to gain optical access inside the bone. The surgery is well-tolerated in mice; they were assessed for adverse physical reactions, such as hind limb swelling, non-weight bearing on limb, self-mu...

Watch this Scientific Journal Video about Femur Window Chamber Model for In Vivo Cell Tracking in the Murine Bone Marrow at JoVE.com

Femur Window Chamber Model for In Vivo Cell Tracking in the Murine Bone Marrow

The protocol describes a novel murine femur window chamber model that can be used to track movement of cells in the femoral bone marrow in vivo. Intravital multiphoton fluorescence microscopy is used to image three components of the femoral bone marrow (vasculature, collagen matrix, and neutrophils) over time.

Femur Window Chamber Model for In Vivo Cell Tracking in the Murine Bone Marrow

Bone marrow is a complex organ that contains various hematopoietic and non-hematopoietic cells. These cells are involved in many biological processes, ...

The overall goal of this procedure is to perform long-term microscopic imaging and tracking of neutrophils in vascular structures within the murine bone marrow through an implanted chronic window chamber over the femoral bone. This method can help answer key questions in immunology and oncology about the role of monocytes in the regulation of an infection, tumorigenesis, and tumor metastasis. The main advantages of this technique are that it enables long-term microscopic access to the femoral bone marrow, a central site of hematopoiesis, and provides dynamic information otherwise difficult to obtain by conventional methods.Though this method is specific to neutrophil imaging within a vascular network, it may also be used to visualize other immune cell populations of interest. On the day of the surgery, confirm the appropriate level of sedation by lack of response to a toe pinch of an athymic nude mouse. Then, place the mouse on an electric heating pad, covered with a surgical drape, under a stereo microscope.Next, apply ointment to the animal's eyes, and sterilize the surgical area with two sequential wipes with 7.5%povidone-iodine, 70%isopropyl alcohol, and 10%povidone-iodine. When the animal has been prepped, use a scalpel with a number 15 blade to make a 10 millimeter longitudinal skin incision approaching the femur from the lateral side. Then, blunt dissect with forceps and hemostats to expose the femur between the flexor and the extensor muscles.When the femur can be observed, insert a U-shaped bar under the bone, and install the window chamber. Using two nuts, secure the bar to the window. Then, tighten the nuts with forceps.Use the forceps to readjust the musculature of the flexors and extensors back to their original locations. Fill the space between the bone and the window chamber with dental cement to fix the window chamber in place. Then, use a micro drill to grind a six by two millimeter area into the cortical bone to gain optical access to the marrow cavity.When an almost transparent periosteal layer of the bone has been obtained, place an eight millimeter cover glass onto the window, and use a snap ring to secure the cover glass in place. Now, close the dermis with a 5-0 suture and a needle holder. Then, place the mouse in a new cage with clean bedding, with monitoring until it is fully recovered.To obtain combined multiphoton and confocal microscopy images through the window chamber, first, inject the appropriate fluorescent vasculature neutrophil labeling solutions into the mouse by tail vein. Clamp the ends of the window chamber with alligator clips to affix the mouse to custom-made stage. Then, place the imaging stage onto the combined multiphoton and confocal microscope.When the mouse is secure, turn on the two-photon laser and the confocal system, and click Start System to launch the image acquisition software. To set up the imaging channels, under the Acquisition tab, click Smart Setup, and select the lasers for imaging. Choose Best signal, and click Apply.Manually add the second harmonic generation image acquisition channel by turning on the two-photon laser in the Laser window, and setting the appropriate acquisition wavelengths for second harmonic generation. Under the Locate tab, click Oculars online, and locate the region of interest through the microscope by visual inspection. Click Oculars offline, and open the Acquisition tab.In the Channels window, select the FITC Track, and click on Live to preview the FITC-Dextran image with a 5x objective. Adjust the focus as necessary. Then, click Stop under the Acquisition tab to stop the preview.Now, manually select the 20x water objective and view the FITC-Dextran image again, adjusting the master Gain and Pinhole under the Channels window to achieve the best signal and contrast. When an optimal image has been obtained for all three channels, select all of the channels in the Channels window, and click Snap under the Acquisition tab to acquire a 2D snapshot. Next, to acquire a 2D time-lapse image, select the Time Series to open the Time Series window, and enter zero for the intervals and 40 for the total number of scans to obtain 40 images continuously without a time interval.To analyze the images, open the appropriate image analysis software, and open an image file. To generate object tracks using the time-lapse images, in the Surpass view, open the image to be analyzed, and click on the icon with an image of orange dots to open the new Spots window. After setting Tracking parameters, click the Fill gaps with all detected objects box to start the tracking.And click the blue arrow to go to the next step. Under the Filter Type, select the Track Duration filter, and click on the green arrow to finish the tracking. Then, check the generated tracks, going back to the previous step as necessary.To measure the cellular movement, defined by the Object tracks in the time-lapse images, under the Edit Tracks window, select the Tracks box, and select a track that corresponds to the movement of the cell of interest. The selected track will be highlighted in yellow in the time series image. Finally, under the Statistics tab, click on the icon with an image of a graph to open the Statistics window.Then, under Selection, click on the down arrow to generate the Track Speed Mean. Vasculature within the bone marrow can be visualized by intravascular dyes, such as FITC-Dextran. Since the contrast is dependent on the injection of the dye, the acquired image represents the functional vasculature where there is sufficient blood flow.These images of the same area of the bone marrow at different time points demonstrate the presence of neutrophils in both the intravascular and extravascular spaces over a period of several days. The imaging of this cortical bone, mainly composed of collagen fibers, was performed by second harmonic generation, further illustrating the infiltration of the vascular tissue by neutrophils. These neutrophils were tracked in the bone marrow vascular niche with no additional time interval between each scan, allowing for the accurate tracking of their movement.The speed of the tracks generated by the image analysis software can then be measured to analyze the velocity of each cell. Following this procedure, other methods, such as using ex vivo label cells or transgenic reporter mice, can be used to evaluate other biological processes in situ, such as the influence of immune cells on tumor progression and metastasis. After watching this video, you should have a good understanding of how to install window chamber on the murine femoral bone for tracking neutrophils through the bone marrow vascular niche and collagen structures.

femur-window-chamber-model-for-vivo-cell-tracking-murine-bone

Research

JoVE Journal

Immunology and Infection

8.1K ビュー.  Princess Margaret Cancer Centre. The overall goal of this procedure is to perform long-term microscopic imaging and tracking of neutrophils in vascular structures within the murine bone marrow through an implanted chronic window chamber over the femoral bone. This method can help answer key questions in immunology and oncology about the role of monocytes in the regulation of an infection, tumorigenesis, and tumor metastasis. The main advantages of this technique are that it enables long-term microscopic access to the femoral...

ビデオ: Femur Window Chamber Model for In Vivo Cell Tracking in the Murine Bone Marrow

The protocol describes a novel murine femur window chamber model that can be used to track movement of cells in the femoral bone marrow in vivo. Intravital multiphoton fluorescence microscopy is used to image three components of the femoral bone marrow (vasculature, collagen matrix, and neutrophils) over...

in vivo two-photon imaging of megakaryocytes and proplatelets in the mouse skull bone marrow

In Vivo Two-photon Imaging of Megakaryocytes and Proplatelets in the Mouse Skull Bone Marrow

We describe here the method for imaging megakaryocytes and proplatelets in the marrow of the skull bone of living mice using two-photon microscopy.

In Vivo Two-photon Imaging of Megakaryocytes and Proplatelets in the Mouse Skull Bone Marrow

tracking mouse bone marrow monocytes in vivo

Tracking Mouse Bone Marrow Monocytes In Vivo

Monocytes are key regulators of innate immunity and play a critical role in the renewal of the peripheral mononuclear phagocytic system and in case of inflammation. This manuscript describes the procedure of real time imaging of the mouse calvaria bone marrow to study the monocyte mobilisation mechanism.

Tracking Mouse Bone Marrow Monocytes In Vivo

simplified intrafemoral injections using live mice allow for continuous bone marrow analysis

Author Spotlight: A Technique for Engraftment of Cells into the Mouse Femur for Bone Marrow Studies

This protocol describes the intrafemoral injection of a few hematopoietic or leukemic stem cells, including gene-edited cells, in murine xenograft models, which will not only enable the quick and safe transplantation of cells but also serial analyses of the bone...

Intrafemoral Injection for Bone Marrow Study in Live Mice

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in vivo 4-dimensional tracking of hematopoietic stem and progenitor cells in adult mouse calvarial bone marrow

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

The nature of the interactions between hematopoietic stem and progenitor cells (HSPCs) and bone marrow niches is poorly understood. Custom hardware modifications and a multi-step acquisition protocol allow the use of two-photon and confocal microscopy to image ex vivo labeled HSPCs homed within bone marrow areas, tracking interactions and...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

the preparation of primary hematopoietic cell cultures from murine bone marrow for electroporation

The Preparation of Primary Hematopoietic Cell Cultures From Murine Bone Marrow for Electroporation

This procedure describes how to establish primary hematopoietic cell cultures from murine bone marrow and is followed by transfection using the Gene Pulser MXCell electroporation...

identifying bone marrow microenvironmental populations in myelodysplastic syndrome and acute myeloid leukemia

Author Spotlight: Analyzing Bone Marrow Microenvironment in Murine Hematological Malignancies 

Here a detailed protocol to isolate and characterize bone marrow microenvironmental populations from murine models of myelodysplastic syndromes and acute myeloid leukemia is presented. This technique identifies changes in the non-hematopoietic bone marrow niche, including the endothelial and mesenchymal stromal cells, with disease progression.

Isolation and Characterization of Bone Marrow Microenvironment in Myeloid Neoplasms

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in vivo imaging and tracking of technetium-99m labeled bone marrow mesenchymal stem cells in equine tendinopathy

In Vivo Imaging and Tracking of Technetium-99m Labeled Bone Marrow Mesenchymal Stem Cells in Equine Tendinopathy

This protocol describes the radiolabeling of equine mesenchymal stem cells and their implantation into tendon injuries in the horse in order to determine cell survival and tissue distribution using gamma...

In Vivo Imaging and Tracking of Technetium-99m Labeled Bone Marrow Mesenchymal Stem Cells in Equine Tendinopathy

generation and labeling of murine bone marrow-derived dendritic cells with qdot nanocrystals for tracking studies

Generation and Labeling of Murine Bone Marrow-derived Dendritic Cells with Qdot Nanocrystals for Tracking Studies

Dendritic cells uptake antigens and migrate towards immune organs to present processed antigens to T cells. Qdot nanocrystal labeling provides a long-lasting and stable fluorescent signal. This allows tracking of dendritic cells to different organs by fluorescent microscopy.

utilizing low oxygen tension to reduce hematopoietic cells in murine bone marrow stromal cell cultures

Utilizing Low Oxygen Tension to Reduce Hematopoietic Cells in Murine Bone Marrow Stromal Cell Cultures

A routine culture of bone marrow stromal cells (BMSCs) leads to the isolation of heterogeneous cell populations, with many cells being of hematopoietic origins. Here, we describe a method that utilizes low oxygen tension to greatly reduce hematopoietic contaminants in murine BMSC...

cranial ring assembly installation in mouse model: a surgical procedure to implant visualization window assembly on murine skull for high-resolution skull bone marrow imaging

In this video, we describe a surgical procedure to implant a cranial ring assembly on the exposed skull bone and further immobilize the mouse&#8217;s head for high-resolution brain imaging for a long...

Cranial Ring Assembly Installation in Mouse Model: A Surgical Procedure to Implant Visualization Window Assembly on Murine Skull for High-resolution Skull Bone Marrow Imaging

in vivo 19f mri for cell tracking

In vivo 19F MRI for Cell Tracking

We describe a general protocol for in vivo cell tracking using MRI in a mouse model with ex vivo labeled cells. A typical protocol for cell labeling, image acquisition processing and quantification is...

In vivo 19F MRI for Cell Tracking

flow cytometry analysis of immune cell subsets within the murine spleen, bone marrow, lymph nodes and synovial tissue in an osteoarthritis model

Flow Cytometry Analysis of Immune Cell Subsets within the Murine Spleen, Bone Marrow, Lymph Nodes and Synovial Tissue in an Osteoarthritis Model

Here, we describe a detailed and reproducible flow cytometry protocol to identify monocyte/macrophage and T-cell subsets using both extra- and intracellular staining assays within the murine spleen, bone marrow, lymph nodes and synovial tissue, utilizing an established surgical model of murine...

using quantitative real-time pcr to determine donor cell engraftment in a competitive murine bone marrow transplantation model

Using Quantitative Real-time PCR to Determine Donor Cell Engraftment in a Competitive Murine Bone Marrow Transplantation Model

Determining donor cell engraftment presents a challenge in mouse bone marrow transplant models that lack well-defined phenotypical markers. We described a methodology to quantify male donor cell engraftment in female transplant recipient mice. This method can be used in all mouse strains for the study of HSC...

Expose the skull with tweezers. Then, use scissors and tweezers to carefully remove the periosteum. Use a sterile cotton swab soaked in physiological saline to remove all the periosteum and any debris or hair which could alter the imaging. Rinse the skull with saline to remove any blood traces, and rapidly dry the bone with a cotton...

murine hind limb long bone dissection and bone marrow isolation

Murine Hind Limb Long Bone Dissection and Bone Marrow Isolation

Here we present a protocol for the dissection of hind limb long bones (femurs and tibiae) from the laboratory mouse. We further describe a rapid technique for bone marrow isolation from these bones that utilizes centrifugation for removal of bone marrow from the bone marrow...

in vivo evaluation of fracture callus development during bone healing in mice using an mri-compatible osteosynthesis device for the mouse femur

In Vivo Evaluation of Fracture Callus Development During Bone Healing in Mice Using an MRI-compatible Osteosynthesis Device for the Mouse Femur

The evaluation of tissue development in the fracture callus during endochondral bone healing is essential to monitor the healing process. Here, we report the use of a magnetic resonance imaging (MRI)-compatible external fixator for the mouse femur to allow MRI scans during bone regeneration in...

In Vivo Evaluation of Fracture Callus Development During Bone Healing in Mice Using an MRI-compatible Osteosynthesis Device for the Mouse Femur

real time in vivo tracking of thymocytes in the anterior chamber of the eye by laser scanning microscopy

Real Time In Vivo Tracking of Thymocytes in the Anterior Chamber of the Eye by Laser Scanning Microscopy

The goal of the protocol is to show longitudinal intravital real-time tracking of thymocytes by laser scanning microscopy in thymic implants in the anterior chamber of the mouse eye. The transparency of the cornea and vascularization of the graft allows for continuously recording progenitor cell recruitment and mature T-cell...

Real Time In Vivo Tracking of Thymocytes in the Anterior Chamber of the Eye by Laser Scanning Microscopy

In vitro Biofilm Formation in an 8-well Chamber Slide

The chronic nature of many diseases is attributed to the formation of bacterial biofilms which are recalcitrant to traditional antibiotic therapy. Biofilms are community-associated bacteria attached to a surface and encased in a matrix. The role of the extracellular matrix is multifaceted, including facilitating nutrient acquisition, and offers significant protection against environmental stresses (e.g. host immune responses). In an effort to acquire a better understanding as to how the bacteria within a biofilm respond to environmental stresses we have used a protocol wherein we visualize bacterial biofilms which have formed in an 8-well chamber slide. The biofilms were stained with the BacLight Live/Dead stain and examined using a confocal microscope to characterize the relative biofilm size, and structure under varying incubation conditions. Z-stack images were collected via confocal microscopy and analyzed by COMSTAT. This protocol can be used to help elucidate the mechanism and kinetics by which biofilms form, as well as identify components that are important to biofilm structure and stability.

In vitro Biofilm Formation in an 8-well Chamber Slide

This article describes the procedure for the formation and visualization of a bacterial biofilm grown within an 8-well chamber slide

The chronic nature of many diseases is attributed to the formation of bacterial biofilms which are recalcitrant to traditional antibiotic therapy. ...

Dendritic cells (DCs) are professional antigen presenting cells (APCs) found in peripheral tissues and in immunological organs such as thymus, bone marrow, spleen, lymph nodes and Peyer's patches 1-3. DCs present in peripheral tissues sample the organism for the presence of antigens, which they take up, process and present in their surface in the context of major histocompatibility molecules (MHC). Then, antigen-loaded DCs migrate to immunological organs where they present the processed antigen to T lymphocytes triggering specific immune responses. One way to evaluate the migratory capabilities of DCs is to label them with fluorescent dyes 4.
Herewith we demonstrate the use of Qdot fluorescent nanocrystals to label murine bone marrow-derived DC. The advantage of this labeling is that Qdot nanocrystals possess stable and long lasting fluorescence that make them ideal for detecting labeled cells in recovered tissues. To accomplish this, first cells will be recovered from murine bone marrows and cultured for 8 days in the presence of granulocyte macrophage-colony stimulating factor in order to induce DC differentiation. These cells will be then labeled with fluorescent Qdots by short in vitro incubation. Stained cells can be visualized with a fluorescent microscopy. Cells can be injected into experimental animals at this point or can be into mature cells upon in vitro incubation with inflammatory stimuli. In our hands, DC maturation did not determine loss of fluorescent signal nor does Qdot staining affect the biological properties of DCs. Upon injection, these cells can be identified in immune organs by fluorescent microscopy following typical dissection and fixation procedures.

Dendritic cells uptake antigens and migrate towards immune organs to present processed antigens to T cells. Qdot nanocrystal labeling provides a long-lasting and stable fluorescent signal. This allows tracking of dendritic cells to different organs by fluorescent microscopy.

Dendritic cells (DCs) are professional antigen presenting cells (APCs) found in peripheral tissues and in immunological organs such as thymus, bone ...

Induction of Graft-versus-host Disease and In Vivo T Cell Monitoring Using an MHC-matched Murine Model

Graft-versus-host disease (GVHD) is the limiting barrier to the broad use of bone marrow transplant as a curative therapy for a variety of hematological deficiencies. GVHD is caused by mature alloreactive T cells present in the bone marrow graft that are infused into the recipient and cause damage to host organs. However, in mice, T cells must be added to the bone marrow inoculum to cause GVHD. Although extensive work has been done to characterize T cell responses post transplant, bioluminescent imaging technology is a non-invasive method to monitor T cell trafficking patterns in vivo. 
Following lethal irradiation, recipient mice are transplanted with bone marrow cells and splenocytes from donor mice. T cell subsets from L2G85.B6 (transgenic mice that constitutively express luciferase) are included in the transplant. By only transplanting certain T cell subsets, one is able to track specific T cell subsets in vivo, and based on their location, develop hypotheses regarding the role of specific T cell subsets in promoting GVHD at various time points. At predetermined intervals post transplant, recipient mice are imaged using a Xenogen IVIS CCD camera. Light intensity can be quantified using Living Image software to generate a pseudo-color image based on photon intensity (red = high intensity, violet = low intensity). 
Between 4-7 days post transplant, recipient mice begin to show clinical signs of GVHD. Cooke et al.1 developed a scoring system to quantitate disease progression based on the recipient mice fur texture, skin integrity, activity, weight loss, and posture. Mice are scored daily, and euthanized when they become moribund. Recipient mice generally become moribund 20-30 days post transplant. 
Murine models are valuable tools for studying the immunology of GVHD. Selectively transplanting particular T cell subsets allows for careful identification of the roles each subset plays. Non-invasively tracking T cell responses in vivo adds another layer of value to murine GVHD models.

Induction of Graft-versus-host Disease and In Vivo T Cell Monitoring Using an MHC-matched Murine Model

Murine bone marrow transplantation is a widely used technique to study immunological mechanisms governing graft-versus-host disease in humans. The ability to monitor T cell trafficking patterns in vivo allows for detailed analysis of the development and perpetuation of T cell responses during graft-versus-host disease.

Graft-versus-host disease (GVHD) is the limiting barrier to the broad use of bone marrow transplant as a curative therapy for a variety of hematological ...

Isolation and Intravenous Injection of Murine Bone Marrow Derived Monocytes

As a subtype of leukocytes and progenitors of macrophages, monocytes are involved in many important processes of organisms and are often the subject of various fields in biomedical science. The method described below is a simple and effective way to isolate murine monocytes from heterogeneous bone marrow.
Bone marrow from the femur and tibia of Balb/c mice is harvested by flushing with phosphate buffered saline (PBS). Cell suspension is supplemented with macrophage-colony stimulating factor (M-CSF) and cultured on ultra-low attachment surfaces to avoid adhesion-triggered differentiation of monocytes. The properties and differentiation of monocytes are characterized at various intervals. Fluorescence activated cell sorting (FACS), with markers like CD11b, CD115, and F4/80, is used for phenotyping. At the end of cultivation, the suspension consists of 45%&#177; 12% monocytes. By removing adhesive macrophages, the purity can be raised up to 86%&#177; 6%. After the isolation, monocytes can be utilized in various ways, and one of the most effective and common methods for in vivo delivery is intravenous tail vein injection. 
This technique of isolation and application is important for mouse model studies, especially in the fields of inflammation or immunology. Monocytes can also be used therapeutically in mouse disease models.

Here we present a protocol that generates large amounts of murine monocytes from heterogeneous bone marrow for translational applications. In comparison to others, this new method helps reduce the number of sacrificed animals and lowers costs by avoiding expensive methods such as high gradient magnetic cell separation (MACS).

As a subtype of leukocytes and progenitors of macrophages, monocytes are involved in many important processes of organisms and are often the subject of ...

Real time multiphoton imaging provides a great opportunity to study cell trafficking and cell-to-cell interactions in their physiological 3-dimensionnal environment. Biological activities of immune cells mainly rely on their motility capacities. Blood monocytes have short half-life in the bloodstream; they originate in the bone marrow and are constitutively released from it. In inflammatory condition, this process is enhanced, leading to blood monocytosis and subsequent infiltration of the peripheral inflammatory tissues. Identifying the biomechanical events controlling monocyte trafficking from the bone marrow towards the vascular network is an important step to understand monocyte physiopathological relevance. We performed in vivo time-lapse imaging by two-photon microscopy of the skull bone marrow of the Csf1r-Gal4VP16/UAS-ECFP (MacBlue) mouse. The MacBlue mouse expresses the fluorescent reporters enhanced cyan fluorescent protein (ECFP) under the control of a myeloid specific promoter 1, in combination with vascular network labelling. We describe how this approach enables the tracking of individual medullar monocytes in real time to further quantify the migratory behaviour within the bone marrow parenchyma and the vasculature, as well as cell-to-cell interactions. This approach provides novel insights into the biology of the bone marrow monocyte subsets and allows to further address how these cells can be influenced in specific pathological conditions.

Monocytes are key regulators of innate immunity and play a critical role in the renewal of the peripheral mononuclear phagocytic system and in case of inflammation. This manuscript describes the procedure of real time imaging of the mouse calvaria bone marrow to study the monocyte mobilisation mechanism.

Real time multiphoton imaging provides a great opportunity to study cell trafficking and cell-to-cell interactions in their physiological 3-dimensionnal ...

Investigation of the bone and the bone marrow is critical in many research fields including basic bone biology, immunology, hematology, cancer metastasis, biomechanics, and stem cell biology. Despite the importance of the bone in healthy and pathologic states, however, it is a largely under-researched organ due to lack of specialized knowledge of bone dissection and bone marrow isolation. Mice are a common model organism to study effects on bone and bone marrow, necessitating a standardized and efficient method for long bone dissection and bone marrow isolation for processing of large experimental cohorts. We describe a straightforward dissection procedure for the removal of the femur and tibia that is suitable for downstream applications, including but not limited to histomorphologic analysis and strength testing. In addition, we outline a rapid procedure for isolation of bone marrow from the long bones via centrifugation with limited handling time, ideal for cell sorting, primary cell culture, or DNA, RNA, and protein extraction. The protocol is streamlined for rapid processing of samples to limit experimental error, and is standardized to minimize user-to-user variability.

Here we present a protocol for the dissection of hind limb long bones (femurs and tibiae) from the laboratory mouse. We further describe a rapid technique for bone marrow isolation from these bones that utilizes centrifugation for removal of bone marrow from the bone marrow space.

Investigation of the bone and the bone marrow is critical in many research fields including basic bone biology, immunology, hematology, cancer metastasis, ...

Fluorescence-activated Cell Sorting for Purification of Plasmacytoid Dendritic Cells from the Mouse Bone Marrow

Fluorescence-activated cell sorting (FACS) is a technique to purify specific cell populations based on phenotypes detected by flow cytometry. This method enables researchers to better understand the characteristics of a single cell population without the influence of other cells. Compared to other methods of cell enrichment, such as magnetic-activated cell sorting (MCS), FACS is more flexible and accurate for cell separation due to the ability of phenotype detection by flow cytometry. In addition, FACS is usually capable of separating multiple cell populations simultaneously, which improves the efficiency and diversity of experiments. Although FACS has some limitations, it has been broadly used to purify cells for functional studies in both in vitro and in vivo settings. Here we report a protocol using fluorescence-activated cell sorting to isolate a very rare population of immune cells, plasmacytoid dendritic cells (pDC), with high purity from the bone marrow of lupus-prone mice for in vitro functional studies of pDC.

We report a protocol using fluorescence-activated cell sorting to isolate plasmacytoid dendritic cells (pDC) with high purity from the bone marrow of lupus-prone mice for functional studies of pDC.

Fluorescence-activated cell sorting (FACS) is a technique to purify specific cell populations based on phenotypes detected by flow cytometry. This method ...

Detection of Inflammasome Activation and Pyroptotic Cell Death in Murine Bone Marrow-derived Macrophages

Inflammasomes are innate immune signaling platforms that are required for the successful control of many pathogenic organisms, but also promote inflammatory and autoinflammatory diseases. Inflammasomes are activated by cytosolic pattern recognition receptors, including members of the NOD-like receptor (NLR) family. These receptors oligomerize upon the detection of microbial or damage-associated stimuli. Subsequent recruitment of the adaptor protein ASC forms a microscopically visible inflammasome complex, which activates caspase-1 through proximity-induced auto-activation. Following the activation, caspase-1 cleaves pro-IL-1&#946; and pro-IL-18, leading to the activation and secretion of these pro-inflammatory cytokines. Caspase-1 also mediates the inflammatory form of cell death termed pyroptosis, which features the loss of membrane integrity and cell lysis. Caspase-1 cleaves gasdermin D, releasing the N-terminal fragment which forms plasma membrane pores, leading to osmotic lysis.
In vitro, the activation of caspase-1 can be determined by labeling bone marrow-derived macrophages with the caspase-1 activity probe FAM-YVAD-FMK and by labeling the cells with antibodies against the adaptor protein ASC. This technique allows the identification of inflammasome formation and caspase-1 activation in individual cells using fluorescence microscopy. Pyroptotic cell death can be detected by measuring the release of cytosolic lactate dehydrogenase into the medium. This procedure is simple, cost effective and performed in a 96-well plate format, allowing adaptation for screening. In this manuscript, we show that activation of the NLRP3 inflammasome by nigericin leads to the co-localization of the adaptor protein ASC and active caspase-1, leading to pyroptosis.

We describe the detection of NLRP3 inflammasome activation on cellular basis using fluorescence microscopy and staining for active caspase-1 and the adaptor, ASC. A lactate dehydrogenase release assay is presented to detect pyroptotic lysis on a population basis. These techniques can be adapted to study many aspects of inflammasome biology.

Inflammasomes are innate immune signaling platforms that are required for the successful control of many pathogenic organisms, but also promote ...

Long-term In Vivo Tracking of Inflammatory Cell Dynamics Within Drosophila Pupae

During the rapid inflammatory response to tissue damage, cells of the innate immune system are quickly recruited to the injury site. Once at the wound, innate immune cells perform a number of essential functions, such as fighting infection, clearing necrotic debris, and stimulating matrix deposition. In order to fully understand the diverse signaling events that regulate this immune response, it is crucial to observe the complex behaviors of (and interactions that occur between) multiple cell lineages in vivo, and in real-time, with the high spatio-temporal resolution. The optical translucency and the genetic tractability of Drosophila embryos have established Drosophila as an invaluable model to live-image and dissect fundamental aspects of inflammatory cell behavior, including mechanisms of developmental dispersal, clearance of apoptotic corpses&#160;and/or microbial pathogens, and recruitment to wounds. However, more recent work has now demonstrated that employing a much later stage in the Drosophila lifecycle &#8211; the Drosophila pupa &#8211; offers a number of distinct advantages, including improved RNAi efficiency, longer imaging periods, and significantly greater immune cell numbers. Here we describe a protocol for imaging wound repair and the associated inflammatory response at the high spatio-temporal resolution in live Drosophila pupae. To follow the dynamics of both re-epithelialization and inflammation, we use a number of specific in vivo fluorescent markers for both the epithelium and innate immune cells. We also demonstrate the effectiveness of photo-convertible fluorophores, such as Kaede, for following the specific immune cell subsets, to track their behavior as they migrate to, and resolve from, the injury site.

Long-term In Vivo Tracking of Inflammatory Cell Dynamics Within Drosophila Pupae

Here we present a protocol for live-imaging wound repair and the associated inflammatory response at high spatio-temporal resolution in vivo. This method utilizes the pupal stage of Drosophila development to enable long-term imaging and tracking of specific cell populations over time and is compatible with efficient RNAi-mediated gene inactivation.

During the rapid inflammatory response to tissue damage, cells of the innate immune system are quickly recruited to the injury site. Once at the wound, ...

An In Vivo Mouse Model to Measure Na&#239;ve CD4 T Cell Activation, Proliferation and Th1 Differentiation Induced by Bone Marrow-derived Dendritic Cells

Quantification of na&#239;ve CD4 T cell activation, proliferation, and differentiation to T helper 1 (Th1) cells is a useful way to assess the role played by T cells in an immune response. This protocol describes the in vitro differentiation of bone marrow (BM) progenitors to obtain granulocyte macrophage colony-stimulating factor (GM-CSF) derived-dendritic cells (DCs). The protocol also describes the adoptive transfer of ovalbumin peptide (OVAp)-loaded GM-CSF-derived DCs and na&#239;ve CD4 T cells from OTII transgenic mice in order to analyze the in vivo activation, proliferation, and Th1 differentiation of the transferred CD4 T cells. This protocol circumvents the limitation of purely in vivo methods imposed by the inability to specifically manipulate or select the studied cell population. Moreover, this protocol allows studies in an in vivo environment, thus avoiding alterations to functional factors that may occur in vitro and including the influence of cell types and other factors only found in intact organs. The protocol is a useful tool for generating changes in DCs and T cells that modify adaptive immune responses, potentially providing important results to understand the origin or development of numerous immune associated diseases.

An &lt;em&gt;In Vivo&lt;/em&gt; Mouse Model to Measure Na&amp;#239;ve CD4 T Cell Activation, Proliferation and Th1 Differentiation Induced by Bone Marrow-derived Dendritic Cells

Here, we present a protocol for the in vivo determination of na&#239;ve CD4 T cell (T cell) activation, proliferation, and Th1 differentiation induced by GM-CSF bone marrow (BM)-derived dendritic cells (DCs). In addition, this protocol describes BM and T-cell isolation, DC generation, and DC and T-cell adoptive transfer.

Quantification of na&#239;ve CD4 T cell activation, proliferation, and differentiation to T helper 1 (Th1) cells is a useful way to assess the role played ...