Name: a morphometric and cellular analysis method for the murine mandibular condyle
Uploaded: 2018-01-11T12:30:00
Description: Watch this Scientific Journal Video about A Morphometric and Cellular Analysis Method for the Murine Mandibular Condyle at JoVE.com

The authors would like to thank Dr. David Rowe for kindly providing the transgenic mice and Li Chen for the histological assistance. 
The research reported in this publication was supported by the National Institute of Dental &amp; Craniofacial Research of the National Institutes of Health under Award Number K08DE025914 and by the American Association of Orthodontic Foundation to Sumit Yadav.

The institutional animal care committee of the University of Connecticut Health Center approved all animal procedures.
1. Compressive Static TMJ Loading: Mouth Forced Open
Note: Four-week-old transgenic mice harboring fluorescent reporters for collagen (Col2a1XCol10a1), kindly provided by Dr. David Rowe (University of Connecticut), were used for the experiments described in this manuscript (n = 8; 4 males and 4 females). The Col2a1 cyan (blue) transgene is expressed i...

<ol>
	<li>LeResche, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epidemiology+of+Temporomandibular+Disorders:+Implications+for+the+Investigation+of+Etiologic+Factors.">Epidemiology of Temporomandibular Disorders: Implications for the Investigation of Etiologic Factors.</a> Crit Rev Oral Biol Med. 8 (3), 291-305 (1997).</li><li>Chen, 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=Altered+functional+loading+causes+differential+effects+in+the+subchondral+bone+and+condylar+cartilage+in+the+temporomandibular+joint+from+young+mice.">Altered functional loading causes differential effects in the subchondral bone and condylar cartilage in the temporomandibular joint from young mice.</a> Osteoarthr Cartil. 17 (3), 354-361 (2009).</li><li>Pirttiniemi, P., Kantomaa, T., Sorsa, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effect+of+decreased+loading+on+the+metabolic+activity+of+the+mandibular+condylar+cartilage+in+the+rat.">Effect of decreased loading on the metabolic activity of the mandibular condylar cartilage in the rat.</a> Eur J Orthod. 26 (1), 1-5 (2004).</li><li>Chavan, S. J., Bhad, W. A., Doshi, U. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+temporomandibular+joint+changes+in+Twin+Block+and+Bionator+appliance+therapy:+a+magnetic+resonance+imaging+study.">Comparison of temporomandibular joint changes in Twin Block and Bionator appliance therapy: a magnetic resonance imaging study.</a> Prog Orthod. 15 (57), (2014).</li><li>Dutra, E. H., 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=Cellular+and+Matrix+Response+of+the+Mandibular+Condylar+Cartilage+to+Botulinum+Toxin.">Cellular and Matrix Response of the Mandibular Condylar Cartilage to Botulinum Toxin.</a> PLoS ONE. 11 (10), 0164599 (2016).</li><li>Benjamin, M., Ralphs, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biology+of+fibrocartilage+cells.">Biology of fibrocartilage cells.</a> Int Rev Cytol. 233, 1-45 (2004).</li><li>Shen, G., Darendeliler, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Adaptive+Remodeling+of+Condylar+Cartilage-+A+Transition+from+Chondrogenesis+to+Osteogenesis.">The Adaptive Remodeling of Condylar Cartilage- A Transition from Chondrogenesis to Osteogenesis.</a> J Dent Res. 84 (8), 691-699 (2005).</li><li>Utreja, A., 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=Cell+and+matrix+response+of+temporomandibular+cartilage+to+mechanical+loading.">Cell and matrix response of temporomandibular cartilage to mechanical loading.</a> Osteoarthr Cartil. 24 (2), 335-344 (2016).</li><li>Kaul, R., 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=The+Effect+of+Altered+Loading+on+Mandibular+Condylar+Cartilage.">The Effect of Altered Loading on Mandibular Condylar Cartilage.</a> PLoS ONE. 11 (7), 0160121 (2016).</li><li>Dyment, N. A., 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=High-Throughput,+Multi-Image+Cryohistology+of+Mineralized+Tissues.">High-Throughput, Multi-Image Cryohistology of Mineralized Tissues.</a> J Vis Exp. , e54468 (2016).</li><li>Kawamoto, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+a+new+adhesive+film+for+the+preparation+of+multi-purpose+fresh-frozen+sections+from+hard+tissues,+whole-animals,+insects+and+plants.">Use of a new adhesive film for the preparation of multi-purpose fresh-frozen sections from hard tissues, whole-animals, insects and plants.</a> Arch Histol Cytol. 66 (2), 123-143 (2003).</li><li>Hayman, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tartrate-resistant+acid+phosphatase+(TRAP)+and+the+osteoclast/immune+cell+dichotomy.">Tartrate-resistant acid phosphatase (TRAP) and the osteoclast/immune cell dichotomy.</a> Autoimmunity. 41 (3), 218-223 (2008).</li></ol>

This manuscript described methods for the morphometric measurement and cellular analysis of murine mandibular condyles and mandibles. The radiographic morphometric measurements can also be used to analyze other bones from small experimental animals. In addition, the cellular analysis (cell quantification and cartilage distance mapping) are not limited to the rodent mandibular condyle, but can be used to quantify histological sections of numerous tissues. 
Transgenic mouse models expressing flu...

The TMJ is a unique load-bearing joint located in the craniofacial region and is formed of fibrocartilage. The MCC of the TMJ is essential for joint function, including unhindered jaw movement while speaking and masticating, but it is commonly affected by degenerative diseases, including osteoarthritis1. The TMJ has the capacity to adapt to external stimuli and loading alterations, leading to structural and cellular changes to the components of the MCC2,3,4,5. The load-bearing properties of the MCC can be explained by the interactions between its constituents, including water, the collagen network, and densely packed proteoglycans. The MCC has four distinct cellular zones that express different types of collagen and non-collagen proteins: 1) the superficial or articular zone; 2) the proliferative zone, composed of undifferentiated mesenchymal cells and that responds to loading demands; 3) the prehypertrophic zone, composed of mature chondrocytes expressing collagen type 2; and 4) the hypertrophic zone, the region where the hypertrophic chondrocytes expressing collagen type 10 die and undergo calcification. The non-mineralized region is rich in proteoglycans which provide resistance to compressive forces6.
There is continuous mineralization at the hypertrophic zone of the MCC, where the transition from chondrogenesis to osteogenesis occurs, guaranteeing the robust mineral structure of the subchondral bone of the mandibular condyle7. Cellular changes in the unmineralized and mineralized regions ultimately lead to morphological and structural changes in the mandibular condyle and mandible. Maintenance of the homeostasis of all cellular regions of the MCC and the mineralization of the subchondral portion are essential to the health, load-bearing capacity, and integrity of the TMJ.
The multiple collagen transgenic mouse model (as described by Utreja et al.)8 is a great tool to use to understand changes in collagen expression because all transgenes are expressed in the MCC. For an in-depth histological evaluation, histological stains are used to study matrix deposition, mineralization, cell proliferation, and apoptosis, as well as protein expression at the different cell layers of the MCC.
In this manuscript, histological and morphometric analyses are used to evaluate cellular and structural changes in the MCC and subchondral bone of the mandibular condyle of mice. In addition, a cell quantification method, for analyzing fluorescent histological images and for mapping light microscope slides, is described. The compressive static TMJ loading method, which causes cellular and morphological changes at the MCC and subchondral bone9, is also illustrated to validate our methods.
The methods described here can be used to determine morphometric and histological changes in the mandibular condyle and mandible of rodents or to analyze other regions of endochondral ossification and the morphology of additional mineralized tissues.

<table width="896">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">MX20 Radiography System</td>
			<td style="width:219px;">Faxitron X-Ray LLC&#160;</td>
			<td style="width:119px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Digimizer Image software&#160;</td>
			<td style="width:219px;">MedCalc Software</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">Shandon Cryomatrix embedding resin</td>
			<td style="width:219px;">Thermo Scientific</td>
			<td style="width:119px;">6769006</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">Manual microscope Axio Imager Z1</td>
			<td style="width:219px;">Carl Zeiss</td>
			<td style="width:119px;">208562</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">yellow fluorescent protein filter&#160; - EYFP</td>
			<td style="width:219px;">Chroma Technology Corp</td>
			<td style="width:119px;">49003</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">cyan fluorescent protein filter - ECFP</td>
			<td style="width:219px;">Chroma Technology Corp</td>
			<td style="width:119px;">49001</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">red fluoresecent protein filter - Cy5</td>
			<td style="width:219px;">Chroma Technology Corp</td>
			<td style="width:119px;">49009</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">sodium acetate anhydrous</td>
			<td style="width:219px;">Sigma-Aldrich</td>
			<td style="width:119px;">S2889</td>
			<td></td>
		</tr>
		<tr height="23">
			<td height="23" style="width:392px;height:23px;">sodium L-tartrate dibasic dihydrate&#160;</td>
			<td style="width:219px;">Sigma-Aldrich</td>
			<td style="width:119px;">228729</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">sodium nitrite&#160;</td>
			<td style="width:219px;">Sigma-Aldrich</td>
			<td style="width:119px;">237213</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">ELF97 substrate</td>
			<td style="width:219px;">Thermo Fisher Scientific</td>
			<td style="width:119px;">E6600</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">ClickiT EdU Alexa Fluor 594 HCS kit</td>
			<td style="width:219px;">Life Technologies</td>
			<td style="width:119px;">C10339&#160;</td>
			<td>includes EdU (5-ethynyl-2&#39;-deoxyuridine)&#160;</td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">DAPI (4&#39;,6-Diamidino-2-Phenylindole, Dihydrochloride)</td>
			<td style="width:219px;">Thermo Scientific</td>
			<td style="width:119px;">D1306</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">Sodium phosphate dibasic&#160;</td>
			<td style="width:219px;">Sigma-Aldrich</td>
			<td>S3264</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">Sodium phosphate monobasic&#160;</td>
			<td style="width:219px;">Sigma-Aldrich</td>
			<td style="width:119px;">71505</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="width:392px;height:21px;">Toluidine Blue O&#160;</td>
			<td style="width:219px;">Sigma-Aldrich</td>
			<td style="width:119px;">T3260</td>
			<td></td>
		</tr>
		<tr height="25">
			<td height="25" style="width:392px;height:25px;">Adobe Photoshop&#160;</td>
			<td style="width:219px;">Adobe Systems Incorporated</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="24">
			<td height="24" style="width:392px;height:24px;">Phosphate buffered saline tablets (PBS)</td>
			<td style="width:219px;">Research Products International</td>
			<td style="width:119px;">P32080-100T</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">CNA Beta III Nickel-Free Archwire</td>
			<td>Ortho Organizers, Inc.</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">GraphPad Prism&#160;</td>
			<td>GraphPad Software, Inc.</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
	</tbody>
</table>

a morphometric and cellular analysis method for the murine mandibular condyle

The temporomandibular joint (TMJ) has the capacity to adapt to external stimuli, and loading changes can affect the position of condyles, as well as the structural and cellular components of the mandibular condylar cartilage (MCC). This manuscript describes methods for analyzing these changes and a method for altering the loading of the TMJ in mice (i.e., compressive static TMJ loading). The structural evaluation illustrated here is a simple morphometric approach that uses the Digimizer software and is performed in radiographs of small bones. In addition, the analysis of cellular changes leading to alterations in collagen expression, bone remodeling, cell division, and proteoglycan distribution in the MCC is described. The quantification of these changes in histological sections - by counting the positive fluorescent pixels using image software and measuring the distance mapping and stained area with Digimizer - is also demonstrated. The methods shown here are not limited to the murine TMJ, but could be used on additional bones of small experimental animals and in other regions of endochondral ossification.

Descriptive statistics were performed to examine the distribution of morphometric measurements (mandibular length, condylar length, condylar width) and histological analyses. Outcomes were compared between the loaded group (i.e., mice subjected to compressive loading with the beta titanium spring) and the control group (i.e., matching control mice that did not receive any procedure). Statistically significant differences between means were determined by unpaired t-test, ...

Watch this Scientific Journal Video about A Morphometric and Cellular Analysis Method for the Murine Mandibular Condyle at JoVE.com

A Morphometric and Cellular Analysis Method for the Murine Mandibular Condyle

This manuscript presents methods for analyzing morphometric and cellular changes within the mandibular condyle of rodents.

The temporomandibular joint (TMJ) has the capacity to adapt to external stimuli, and loading changes can affect the position of condyles, as well as the ...

The overall goal of this experiment is to observe the effects of compressive loading in the mandibular condylar cartilage of mice using Morphometric measurements in radiographs and histological analysis. These metrics can help answer key questions regarding the structural and cellular changes within the mandible condyle of rodents. The main advantage of the technique shown here is that they could be used to analyze other small born or participated animals.For this protocol, have isolated, dissected mouse mandibles ready for use. On a Petri dish, transfer the mandibles into an x-ray cabinet system. Then, take radiographs at 26 kilovolts for five seconds.Now, open the images in the analysis software to make Morphometric measurements. First, use the unit button to setup the scale bar. Next, select six anatomical points using marker style 2.First, select the most posterior points of the mandibular condyle as point one. Next, select the incisored process for point two. Then, select the deepest point at the sigmoid notch for point three.Next, select the deepest point in the concavity of the mandibular ramus, point four and then, select the most anterior point of the condylar articular surface, point five. Now, select the most posterior point of the condylar articular surface as point six and proceed with taking length measurements using the length tool. Next, use the perpendicular line tool from points three to four to measure the condyle head length, which is the length of the perpendicular, from point one to the line between points three and four.Then, measure the mandibular length, between points one and two. Lastly, measure the condyle head width, which is between points five and six. To save the data, copy the measurement list on the right side of the screen.Before embedding the fixed, but not decalcified mandibles, soak them overnight in 30 percent sucrose in PBS. The next day, dissect away any excess soft tissue and carefully cut the mandibular condyle. Now, place the samples in plastic molds, with the medial surface of the condyle against the base of the mold and the sample parallel to the bottom of the mold.Then, immerse them in embedding resin and cool the resin with a piece of dry ice. Next, top off the molds with more embedding resin. Transfer them into cold two methyl butane, cooled by a freezer or by dry ice.Once chilled, store the specimens at negative 20 degrees Celsius or at negative 80 degrees Celsius for sectioning. To quantify Col10a1 expression in the MCC of sagittal sections of condyles, open the histological images in an image analysis software package and select the area of interest using the lasso tool. In this case, the MCC region is selected.Take note of the number of pixels in the area, which is reported in the histogram box. Next, select the Col10a1 red pixels by adjusting the color range. Use the eye dropper tool to select a red pixel from the image and click OK.Then, record the number of red pixels in the area, as reported in the histogram box.The fraction of red pixels in the area represents the amount of Col10a1 expression. Now, using the same basic technique, quantify the TRAP activity in the MCC and subchondral bone. First, select the cartilage in subchondral bone regions as the areas to analyze and take note of the total pixels.Then, select the yellow pixels generated by the ELF97 substrate. Take note of the number of positive pixels and calculate the fraction of TRAP positive pixels. Now, quantify the EDU positive cells that are counter-stained in blue by DEPI.Again, select the area of interest and then quantify the blue pixels within it. Also use this method to determine the number of the EDU positive pixels in the same region. Morphometric measurements of mice, subjected to compressive TMJ loading, showed that the loading significantly increased mandible and condyle head length.Nevertheless, loading did not result in a significant change in condyle width. Quantification of the Collagen distribution revealed a significant increase in Col10a1 expression and the MCC of the condyles of loaded animals. On the other hand, Col2a1 expression was not much different from control.TRAP activity increased in the subchondral region of condyles and loaded mice as did sub proliferation. EDU staining denotes number of proliferative cells. Proteoglycan distribution in the MCC was quantified by evaluating the Toluidine blue stained area and the distance map.There was a significant increase in distance mapping in the MCC of condyles of the loaded group. However, the proteoglycan stained area was not statistically different between groups. After watching this video, you should have a good understanding of how to analyze the cellular and the structural changes in the mandibular condyle of rodents.

a-morphometric-cellular-analysis-method-for-murine-mandibular

Research

JoVE Journal

Biology

Use of Rotorod as a Method for the Qualitative Analysis of Walking in Rat

High speed videoanalysis of the details of movement can provide a source of information about qualitative aspects of walking movements. When walking on a rotorod, animals remain in approximately the same place making repetitive movements of stepping. Thus the task provides a rich source of information on the details of foot stepping movements. Subjects were hemi-Parkinson analogue rats, produced by injection of 6-hydroxydopamine (6-OHDA) into the right nigrostriatal bundle to deplete nigrostriatal dopamine (DA). The present report provides a video analysis illustration of animals previously were filmed from frontal, lateral, and posterior views as they walked (15). Rating scales and frame-by-frame replay of the video records of stepping behavior indicated that the hemi-Parkinson rats were chronically impaired in posture and limb use contralateral to the DA-depletion. The contralateral limbs participated less in initiating and sustaining propulsion than the ipsilateral limbs. These deficits secondary to unilateral DA-depletion show that the rotorod provides a use task for the analysis of stepping movements.

The rotorod test is used to assess motor status in the walking movement of hemi-Parkinson analogue rats.

High speed videoanalysis of the details of movement can provide a source of information about qualitative aspects of walking movements. When walking on a ...

Murine Renal Transplantation Procedure

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell et al over 30 years ago (1) and refined by Zhang et al years later (2), few people in the world have mastered this procedure. In our laboratory we have successfully performed 1200 orthotopic kidney transplantations with &gt; 90% survival rate. The key points for success include stringent control of reperfusion injury, bleeding and thrombosis, both during the procedure and post-transplantation, and use of 10-0 instead of 11-0 suture for anastomoses.
Post-operative care and treatment of the recipient is extremely important to transplant success and evaluation. All renal graft recipients receive antibiotics in the form of an injection of penicillin immediately post-transplant and sulfatrim in the drinking water continually. Overall animal health is evaluated daily and whole blood creatinine analyses are performed routinely with a portable I-STAT machine to assess graft function.

Renal transplantation in mice is a technically challenging procedure that requires careful post-operative care and treatment for success.

Renal orthotopic transplantation in mice is a technically challenging procedure. Although the first kidney transplants in mice were performed by Russell ...

A Neuronal and Astrocyte Co-Culture Assay for High Content Analysis of Neurotoxicity

High Content Analysis (HCA) assays combine cells and detection reagents with automated imaging and powerful image analysis algorithms, allowing measurement of multiple cellular phenotypes within a single assay. In this study, we utilized HCA to develop a novel assay for neurotoxicity. Neurotoxicity assessment represents an important part of drug safety evaluation, as well as being a significant focus of environmental protection efforts. Additionally, neurotoxicity is also a well-accepted in vitro marker of the development of neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Recently, the application of HCA to neuronal screening has been reported. By labeling neuronal cells with &beta;III-tubulin, HCA assays can provide high-throughput, non-subjective, quantitative measurements of parameters such as neuronal number, neurite count and neurite length, all of which can indicate neurotoxic effects. However, the role of astrocytes remains unexplored in these models. Astrocytes have an integral role in the maintenance of central nervous system (CNS) homeostasis, and are associated with both neuroprotection and neurodegradation when they are activated in response to toxic substances or disease states. GFAP is an intermediate filament protein expressed predominantly in the astrocytes of the CNS. Astrocytic activation (gliosis) leads to the upregulation of GFAP, commonly accompanied by astrocyte proliferation and hypertrophy. This process of reactive gliosis has been proposed as an early marker of damage to the nervous system. The traditional method for GFAP quantitation is by immunoassay. This approach is limited by an inability to provide information on cellular localization, morphology and cell number. We determined that HCA could be used to overcome these limitations and to simultaneously measure multiple features associated with gliosis - changes in GFAP expression, astrocyte hypertrophy, and astrocyte proliferation - within a single assay. In co-culture studies, astrocytes have been shown to protect neurons against several types of toxic insult and to critically influence neuronal survival. Recent studies have suggested that the use of astrocytes in an in vitro neurotoxicity test system may prove more relevant to human CNS structure and function than neuronal cells alone. Accordingly, we have developed an HCA assay for co-culture of neurons and astrocytes, comprised of protocols and validated, target-specific detection reagents for profiling &beta;III-tubulin and glial fibrillary acidic protein (GFAP). This assay enables simultaneous analysis of neurotoxicity, neurite outgrowth, gliosis, neuronal and astrocytic morphology and neuronal and astrocytic development in a wide variety of cellular models, representing a novel, non-subjective, high-throughput assay for neurotoxicity assessment. The assay holds great potential for enhanced detection of neurotoxicity and improved productivity in neuroscience research and drug discovery.

This article describes a novel protocol and reagent set designed for sensitive measurement of neurotoxic effects of compounds and treatments on co-cultures of neurons and astrocytes using high content analysis. Results demonstrate that high content analysis represents an exciting novel technology for neurotoxicity assessment.

High Content Analysis (HCA) assays combine cells and detection reagents with automated imaging and powerful image analysis algorithms, allowing ...

A high-throughput method to globally study the organelle morphology in S. cerevisiae

High-throughput methods to examine protein localization or organelle morphology is an effective tool for studying protein interactions and can help achieve an comprehensive understanding of molecular pathways. In Saccharomyces cerevisiae, with the development of the non-essential gene deletion array, we can globally study the morphology of different organelles like the endoplasmic reticulum (ER) and the mitochondria using GFP (or variant)-markers in different gene backgrounds. However, incorporating GFP markers in each single mutant individually is a labor-intensive process. Here, we describe a procedure that is routinely used in our laboratory. By using a robotic system to handle high-density yeast arrays and drug selection techniques, we can significantly shorten the time required and improve reproducibility. In brief, we cross a GFP-tagged mitochondrial marker (Apc1-GFP) to a high-density array of 4,672 nonessential gene deletion mutants by robotic replica pinning.  Through diploid selection, sporulation, germination and dual marker selection, we recover both alleles. As a result, each haploid single mutant contains Apc1-GFP incorporated at its genomic locus. Now, we can study the morphology of mitochondria in all non-essential mutant background. Using this high-throughput approach, we can conveniently study and delineate the pathways and genes involved in the inheritance and the formation of organelles in a genome-wide setting.

GFP-fusion proteins are widely used to visualize organelles by confocal microscopy. However, screening for mutations that affect the morphology of organelles generally requires individual mutagenesis and is time consuming. Here, we demonstrate a method to simultaneously incorporate organelle-GFP markers in almost 5,000 non-essential genes in yeast.

High-throughput methods to examine protein localization or organelle morphology is an effective tool for studying protein interactions and can help ...

A High-Throughput Method For Zebrafish Sperm Cryopreservation and In Vitro Fertilization

This is a method for zebrafish sperm cryopreservation that is an adaptation of the Harvey method (Harvey et al., 1982).  We have introduced two changes to the original protocol that both streamline the procedure and increase sample uniformity.  First, we normalize all sperm volumes using freezing media that does not contain the cryoprotectant. Second, cryopreserved sperm are stored in cryovials instead of capillary tubes.  The rates of sperm freezing and thawing (&delta;&deg;C/time) are probably the two most critical variables to control in this procedure.  For this reason, do not substitute different tubes for those specified.  Working in teams of 2 it is possible to freeze the sperm of 100 males per team in ~2 hrs.  Sperm cryopreserved using this protocol has an average of 25% fertility (measured as the number of viable embryos generated in an in vitro fertilization divided by the total number of eggs fertilized) and this percent fertility is stable over many years.

A High-Throughput Method For Zebrafish Sperm Cryopreservation and In Vitro Fertilization

This is a high-throughput sperm cryopreservation protocol for zebrafish. Sperm cryopreserved using this protocol has an average of 25% fertility in subsequent vitro fertilization and is stable over many years.

This is a method for zebrafish sperm cryopreservation that is an adaptation of the Harvey method (Harvey et al., 1982).  We have introduced two changes to ...

A Rapid High-throughput Method for Mapping Ribonucleoproteins (RNPs) on Human pre-mRNA

Sequencing RNAs that co-immunoprecipitate (co-IP) with RNA binding proteins has increased our understanding of splicing by demonstrating that binding location often influences function of a splicing factor.  However, as with any sampling strategy the chance of identifying an RNA bound to a splicing factor is proportional to its cellular abundance.  We have developed a novel in vitro approach for surveying binding specificity on otherwise transient pre-mRNA. This approach utilizes a specifically designed oligonucleotide pool that tiles across introns, exons, splice junctions, or other pre-mRNA.  The pool is subjected to some kind of molecular selection. Here, we demonstrate the method by separating the oligonucleotide into a bound and unbound fraction and utilize a two color array strategy to record the enrichment of each oligonucleotide in the bound fraction. The array data generates high-resolution maps with the ability to identify sequence-specific and structural determinates of ribonucleoprotein (RNP) binding on pre-mRNA.  A unique advantage to this method is its ability to avoid the sampling bias towards mRNA associated with current IP and SELEX techniques, as the pool is specifically designed and synthesized from pre-mRNA sequence. The flexibility of the oligonucleotide pool is another advantage since the experimenter chooses which regions to study and tile across, tailoring the pool to their individual needs.  Using this technique, one can assay the effects of polymorphisms or mutations on binding on a large scale or clone the library into a functional splicing reporter and identify oligonucleotides that are enriched in the included fraction.  This novel in vitro high-resolution mapping scheme provides a unique way to study RNP interactions with transient pre-mRNA species, whose low abundance makes them difficult to study with current in vivo techniques.  



A Rapid High-throughput Method for Mapping Ribonucleoproteins RNPs on Human pre-mRNA

Due to the transient nature of pre-mRNA, it can be difficult to isolate and study in vivo. Here, we present a novel in vitro approach to investigate RNA-protein interactions using a synthetic oligo pool that tiles across selected regions of pre-mRNA.

Sequencing RNAs that co-immunoprecipitate (co-IP) with RNA binding proteins has increased our understanding of splicing by demonstrating that binding ...

An Explant Assay for Assessing Cellular Behavior of the Cranial Mesenchyme

The central nervous system is derived from the neural plate that undergoes a series of complex morphogenetic movements resulting in formation of the neural tube in a process known as neurulation. During neurulation, morphogenesis of the mesenchyme that underlies the neural plate is believed to drive neural fold elevation. The cranial mesenchyme is comprised of the paraxial mesoderm and neural crest cells. The cells of the cranial mesenchyme form a pourous meshwork composed of stellate shaped cells and intermingling extracellular matrix (ECM) strands that support the neural folds. During neurulation, the cranial mesenchyme undergoes stereotypical rearrangements resulting in its expansion and these movements are believed to provide a driving force for neural fold elevation. However, the pathways and cellular behaviors that drive cranial mesenchyme morphogenesis remain poorly studied. Interactions between the ECM and the cells of the cranial mesenchyme underly these cell behaviors. Here we describe a simple ex vivo explant assay devised to characterize the behaviors of these cells. This assay is amendable to pharmacological manipulations to dissect the signaling pathways involved and live imaging analyses to further characterize the behavior of these cells. We present a representative experiment demonstrating the utility of this assay in characterizing the migratory properties of the cranial mesenchyme on a variety of ECM components.

The cranial mesenchyme undergoes dramatic morphogenic movements that likely provides a driving force for elevation of the neural folds1,2. Here we describe a simple ex vivo explant assay to characterize the cellular behaviors of the cranial mesenchyme during neurulation. This assay has numerous applications including being amenable to pharmacological manipulations and live imaging analyses.

The central nervous system is derived from the neural plate that undergoes a series of complex morphogenetic movements resulting in formation of the ...

Single-cell Microinjection for Cell Communication Analysis

Gap junctions are intercellular channels that allow the communication of neighboring cells. This communication depends on the contribution of a hemichannel by each neighboring cell to form the gap junction. In mammalian cells, the hemichannel is formed by six connexins, monomers with four transmembrane domains and a C and N terminal within the cytoplasm. Gap junctions permit the exchange of ions, second messengers, and small metabolites. In addition, they have important roles in many forms of cellular communication within physiological processes such as synaptic transmission, heart contraction, cell growth and differentiation. We detail how to perform a single-cell microinjection of Lucifer Yellow to visualize cellular communication via gap-junctions in living cells. It is expected that in functional gap junctions, the dye will diffuse from the loaded cell to the connected cells. It is a very useful technique to study gap junctions since you can evaluate the diffusion of the fluorescence in real time. We discuss how to prepare the cells and the micropipette, how to use a micromanipulator and inject a low molecular weight fluorescent dye in an epithelial cell line.

We describe here how to perform a single-cell microinjection of Lucifer Yellow to visualize cellular communication via gap-junctions in living cells, and provide some useful tips. We expect that this paper will help everyone to evaluate the degree of cellular coupling due to functional gap junctions. Everything described here could be, in principle, adapted to other fluorescent dyes with molecular weight below 1,000 Daltons.

Gap junctions are intercellular channels that allow the communication of neighboring cells. This communication depends on the contribution of a ...

Isolation of Murine Valve Endothelial Cells

Normal valve structures consist of stratified layers of specialized extracellular matrix (ECM) interspersed with valve interstitial cells (VICs) and surrounded by a monolayer of valve endothelial cells (VECs). VECs play essential roles in establishing the valve structures during embryonic development, and are important for maintaining life-long valve integrity and function. In contrast to a continuous endothelium over the surface of healthy valve leaflets, VEC disruption is commonly observed in malfunctioning valves and is associated with pathological processes that promote valve disease and dysfunction. Despite the clinical relevance, focused studies determining the contribution of VECs to development and disease processes are limited. The isolation of VECs from animal models would allow for cell-specific experimentation. VECs have been isolated from large animal adult models but due to their small population size, fragileness, and lack of specific markers, no reports of VEC isolations in embryos or adult small animal models have been reported. Here we describe a novel method that allows for the direct isolation of VECs from mice at embryonic and adult stages. Utilizing the Tie2-GFP reporter model that labels all endothelial cells with Green Fluorescent Protein (GFP), we have been successful in isolating GFP-positive (and negative) cells from the semilunar and atrioventricular valve regions using fluorescence activated cell sorting (FACS). Isolated GFP-positive VECs are enriched for endothelial markers, including CD31 and von Willebrand Factor (vWF), and retain endothelial cell expression when cultured; while, GFP-negative cells exhibit molecular profiles and cell shapes consistent with VIC phenotypes. The ability to isolate embryonic and adult murine VECs allows for previously unattainable molecular and functional studies to be carried out on a specific valve cell population, which will greatly improve our understanding of valve development and disease mechanisms.

The ability to isolate heart valve endothelial cells (VECs) is critical for understanding mechanisms of valve development, maintenance, and disease. Here we describe the isolation of VECs from embryonic and adult Tie2-GFP mice using FACS that will allow for studies determining the contribution of VECs in developmental and disease processes.

Normal valve structures consist of stratified layers of specialized extracellular matrix (ECM) interspersed with valve interstitial cells (VICs) and ...

Isolation of Murine Coronary Vascular Smooth Muscle Cells

While the isolation and culture of vascular smooth muscle cells (VSMCs) from large vessels is well established, we sought to isolate and culture VSMCs from the coronary circulation. Hearts with intact aortic arches were removed and perfused via retrograde Langendorff with digestion solution containing 300 Units/ml of collagenase type II, 0.1 mg/ml soybean trypsin inhibitor and 1 M CaCl2. The perfusates were collected at 15 min intervals for 90 min, pelleted by centrifugation, resuspended in plating media, and plated on tissue culture dishes. VSMCs were characterized by presence of SM22&#945;, &#945;-SMA, and vimentin. One of the main advantages of using this technique is the ability to isolate VSMCs from the coronary circulation of mice. Although the small number of cells obtained can limit some of the applications for which the cells can be utilized, isolated coronary VSMCs can be used in a variety of well-established cell culture techniques and assays. Studies investigating VSMCs from genetically modified mice can provide further information about structure-function and signaling processes associated with vascular pathologies.

The purpose of this protocol is to demonstrate the isolation and culture techniques of murine primary vascular smooth muscle cells (VSMCs) from the coronary circulation. Once VSMCs have been isolated, they can be used for many standard culture techniques.

While the isolation and culture of vascular smooth muscle cells (VSMCs) from large vessels is well established, we sought to isolate and culture VSMCs ...