This work was supported by the Washington University Musculoskeletal Research Center (NIH P30 AR057235), Molecular Imaging Center (NIH P50 CA094056), Mechanobiology Training Grant (NIH 5T32EB018266), NIH R21AR069804, and NIH K01AR069116. The authors would like to thank Patrick Wong for his contributions in data collection.

All animal experiments were performed in compliance with the Washington University in St. Louis Animal Studies Committee.
1. Animals
<ol>
	<li>Obtain two strains of mice: 10-week old BALB/c (n = 6, BALB-M, BALB/cAnNTac) and 10-week old nuclear factor kappa-B-luciferase reporter animals (NF-&#954;&#946;-luc) bred on a BALB/c background (n = 6, BALB/c-Tg(Rela-luc)31Xen).</li>
	<li>Prior to dissection, euthanize animals with CO2 overdose at a flow rate of 2.5-3 L/min for 5 min follow...

<ol>
	<li>Dagenais, S., Caro, J., Haldeman, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+systematic+review+of+low+back+pain+cost+of+illness+studies+in+the+United+States+and+internationally.">A systematic review of low back pain cost of illness studies in the United States and internationally.</a> Spine J. 8 (1), 8-20 (2008).</li><li>Urban, J., Roberts, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Degeneration+of+the+intervertbral+disc.">Degeneration of the intervertbral disc.</a> Arthritis Res Ther. 5 (6), 1-48 (2003).</li><li>Mirza, S. K., White, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomy+of+intervertebral+disc+and+pathophysiology+of+herniated+disc+disease.">Anatomy of intervertebral disc and pathophysiology of herniated disc disease.</a> J Clin Laser Med Surg. 13 (3), 131-142 (1995).</li><li>Acaroglu, E. 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=Degeneration+and+aging+affect+the+tensile+behavior+of+human+lumbar+anulus+fibrosus.">Degeneration and aging affect the tensile behavior of human lumbar anulus fibrosus.</a> Spine. 20 (24), 2690-2701 (1995).</li><li>Abraham, A. C., Liu, J. W., Tang, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Longitudinal+changes+in+the+structure+and+inflammatory+response+of+the+intervertebral+disc+due+to+stab+injury+in+a+murine+organ+culture+model.">Longitudinal changes in the structure and inflammatory response of the intervertebral disc due to stab injury in a murine organ culture model.</a> J Orthop Res. 34 (8), 1431-1438 (2016).</li><li>Ohtori, S., Inoue, G., Miyagi, M., Takahashi, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pathomechanisms+of+discogenic+low+back+pain+in+humans+and+animal+models.">Pathomechanisms of discogenic low back pain in humans and animal models.</a> Spine J. 15 (6), 1347-1355 (2015).</li><li>Pelle, D. W., 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=Genetic+and+functional+studies+of+the+intervertebral+disc:+A+novel+murine+intervertebral+disc+model.">Genetic and functional studies of the intervertebral disc: A novel murine intervertebral disc model.</a> PLoS ONE. 9 (12), (2014).</li><li>Zhang, 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=Time+course+investigation+of+intervertebral+disc+degeneration+produced+by+needle-stab+injury+of+the+rat+caudal+spine.">Time course investigation of intervertebral disc degeneration produced by needle-stab injury of the rat caudal spine.</a> J Neurosurg: Spine. 15 (4), 404-413 (2011).</li><li>Liu, J. W., Abraham, A. C., Tang, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+high-throughput+phenotyping+of+the+viscoelastic+behavior+of+whole+mouse+intervertebral+discs+using+a+novel+method+of+dynamic+mechanical+testing.">The high-throughput phenotyping of the viscoelastic behavior of whole mouse intervertebral discs using a novel method of dynamic mechanical testing.</a> J Biomech. 48 (10), 2189-2194 (2015).</li><li>Lin, K. H., Wu, Q., Leib, D. J., Tang, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+technique+for+the+contrast-enhanced+microCT+imaging+of+murine+intervertebral+discs.">A novel technique for the contrast-enhanced microCT imaging of murine intervertebral discs.</a> J Mech Behav Biomed Mater. 63, (2016).</li><li>Pasparakis, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+tissue+homeostasis+by+NF-kappaB+signalling:+implications+for+inflammatory+diseases.">Regulation of tissue homeostasis by NF-kappaB signalling: implications for inflammatory diseases.</a> Nat Rev: Immunol. 9 (11), 778-788 (2009).</li><li>O&#8217;Connell, G. D., Vresilovic, E. J., Elliott, D. M. <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+animals+used+in+disc+research+to+human+lumbar+disc+geometry.">Comparison of animals used in disc research to human lumbar disc geometry.</a> Spine. 32 (3), 328-333 (2007).</li><li>Lee, C. 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=In+vitro+organ+culture+of+the+bovine+intervertebral+disc:+effects+of+vertebral+endplate+and+potential+for+mechanobiology+studies.">In vitro organ culture of the bovine intervertebral disc: effects of vertebral endplate and potential for mechanobiology studies.</a> Spine. 31, 515-522 (2006).</li><li>Chan, S. C., Gantenbein-Ritter, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+Intact+Bovine+Tail+Intervertebral+Discs+for+Organ+Culture.">Preparation of Intact Bovine Tail Intervertebral Discs for Organ Culture.</a> J. Vis. Exp. (60), e3490 (2012).</li><li>Holguin, N., Aguilar, R., Harland, R. A., Bomar, B. A., Silva, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+aging+mouse+partially+models+the+aging+human+spine:+lumbar+and+coccygeal+disc+height,+composition,+mechanical+properties,+and+Wnt+signaling+in+young+and+old+mice.">The aging mouse partially models the aging human spine: lumbar and coccygeal disc height, composition, mechanical properties, and Wnt signaling in young and old mice.</a> J Appl Physiol. 116 (12), (2014).</li></ol>

This protocol outlines an organ culture of the murine FSU with emphasis on monitoring the biological changes in the IVD. The successful maintenance of these cultures requires careful sterile techniques. In particular, the dissection steps 2.1-2.6 and the culture steps 3.1-3.6 require special care to ensure sterile conditions are maintained, and these steps should be performed preferably in an isolated procedure room with a HEPA airflow to minimize contaminants. Because the dissection proc...

Low back pain (LBP) is the leading factor for global disability and lost productivity in the workplace, and Americans alone spend in excess of 50 billion dollars on LBP treatment1. Although prevalent, the etiology of LBP remains complex and multifactorial. However, intervertebral disc (IVD) degeneration is among the most significant risk factors for LBP2.
The IVD is made of three microstructures: the exterior annulus fibrosis (AF), the interior nucleus pulposus (NP), and two cartilaginous endplates that sandwich the whole structure proximally and distally3. With aging and degeneration, the IVD components change structurally, compositionally, and mechanically4. These changes include the loss of proteoglycans and hydration in the NP, decreased disc height, and deteriorated mechanical competence5. These alterations are often accompanied by cytokines that promote an inflammatory response, as well as neutrophil and dorsal root ganglion intrusion into the joint space culminating in a cascade of events that lead to LBP symptoms6.
Studying the mechanisms of IVD degeneration is challenging in humans because it is often not possible to isolate the cause of the degeneration before the occurrence of low back pain. Thus, a reductionist approach of simplifying the experimental system down to the IVD organ allows mechanistic fine-tuning of causal variables and examining their downstream effects5. The system is reduced to only the native cell population and surrounding extracellular matrix, thus enabling the direct interpretation of the effects of external stimuli on IVD degeneration. Moreover, the lower cost and scalability of murine models, as well as the large number of genetically modified animals7, allow for the rapid targeted screening of IVD degenerative mechanisms and potential therapies. Here, we describe a murine organ culture system in which IVD cellular and tissue stability is maintained over 21 days, with specific focus given to the IVDs&#39; homeostatic, mechanical, structural, and inflammatory patterns. Using this method, we monitor the IVDs&#39; functional changes in a stab-induced injury model8 to understand the mechanisms behind disc degeneration. Furthermore, we describe several applications of this organ culture method to conduct further studies including contrast-enhanced microCT imaging and three-dimensional high-resolution modeling of the IVD.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>96 well plate</td>
			<td>Midwest Scientific</td>
			<td>TP92096</td>
			<td>Used for biochemical assays</td>
		</tr>
		<tr>
			<td>24 well plate</td>
			<td>Midwest Scientific</td>
			<td>TP92024</td>
			<td>Used for organ culture</td>
		</tr>
		<tr>
			<td>25 ml pipettes</td>
			<td>Midwest Scientific</td>
			<td>TP94024</td>
			<td>Used for organ culture</td>
		</tr>
		<tr>
			<td>10 ml pipettes</td>
			<td>Midwest Scientific</td>
			<td>TP94010</td>
			<td>Used for organ culture</td>
		</tr>
		<tr>
			<td>5 ml pipettes</td>
			<td>Midwest Scientific</td>
			<td>TP94005</td>
			<td>Used for organ culture</td>
		</tr>
		<tr>
			<td>500 ml bottle top filters, 22um</td>
			<td>Midwest Scientific</td>
			<td>TP99505</td>
			<td>Used for filter media</td>
		</tr>
		<tr>
			<td>10 ul pipette tips</td>
			<td>Midwest Scientific</td>
			<td>NP89140098</td>
			<td>Used for biochemical assays</td>
		</tr>
		<tr>
			<td>200 ul pipette tips</td>
			<td>Midwest Scientific</td>
			<td>NP89140900</td>
			<td>Used for biochemical assays</td>
		</tr>
		<tr>
			<td>1000 ul pipette tips</td>
			<td>Midwest Scientific</td>
			<td>NP89140920</td>
			<td>Used for biochemical assays</td>
		</tr>
		<tr>
			<td>DMEM /F-12</td>
			<td>Invitrogen</td>
			<td>11330032</td>
			<td>Used for culture media</td>
		</tr>
		<tr>
			<td>Optiray 350</td>
			<td>Guebert</td>
			<td>19133341</td>
			<td>Used for contrast enhanced microCT</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Sigma</td>
			<td>F2442</td>
			<td>Used for culture media</td>
		</tr>
		<tr>
			<td>Penicillin Streptomycin&#160;</td>
			<td>Sigma</td>
			<td>P4333</td>
			<td>Used for culture media</td>
		</tr>
		<tr>
			<td>Tetrazolium Blue Chloride</td>
			<td>Sigma</td>
			<td>T4375</td>
			<td>Used for biochemical assays</td>
		</tr>
		<tr>
			<td>D-Luciferin</td>
			<td>Sigma</td>
			<td>L6152</td>
			<td>Used for bioluminescence imaging</td>
		</tr>
		<tr>
			<td>Chondroitin Sulfate</td>
			<td>Sigma</td>
			<td>C9819</td>
			<td>Used for biochemical assays</td>
		</tr>
		<tr>
			<td>10% Phosphomolybdic Acid Solution</td>
			<td>Sigma</td>
			<td>HT152</td>
			<td>Used for contrast enhanced microCT</td>
		</tr>
		<tr>
			<td>Safranin O</td>
			<td>Sigma</td>
			<td>S8884</td>
			<td>diluted to .1% concentration (in water)</td>
		</tr>
		<tr>
			<td>Fast Green FCF</td>
			<td>Sigma</td>
			<td>F7258</td>
			<td>.001% concentration</td>
		</tr>
		<tr>
			<td>Papain from papaya latex</td>
			<td>Sigma&#160;</td>
			<td>P3125</td>
			<td>Used for biochemical assays</td>
		</tr>
		<tr>
			<td>DAPI</td>
			<td>Sigma-Aldrich</td>
			<td>D9542</td>
			<td>Nucleic acid staining</td>
		</tr>
		<tr>
			<td>Cyanoacrylate Glue</td>
			<td>Loctite</td>
			<td>234790</td>
			<td>Adhesive&#160;</td>
		</tr>
		<tr>
			<td>1.5 ml Microcentrifuge Tubes&#160;</td>
			<td>Fischer Scientific</td>
			<td>S348903</td>
			<td>Used for biochemical assays</td>
		</tr>
		<tr>
			<td>Big Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>BioDent</td>
			<td>ActiveLife</td>
			<td></td>
			<td>For mechanical testing</td>
		</tr>
		<tr>
			<td>Cytation 5</td>
			<td>Biotek</td>
			<td></td>
			<td>Spectrophotometer</td>
		</tr>
		<tr>
			<td>AxioCam503</td>
			<td>Carl Zeiss AG</td>
			<td></td>
			<td>Microscope</td>
		</tr>
		<tr>
			<td>VivaCT40</td>
			<td>Scanco</td>
			<td></td>
			<td>MicroCT</td>
		</tr>
		<tr>
			<td>Analytical balance</td>
			<td>Denver Instrument Company</td>
			<td>A-200DS</td>
			<td>Analytical balance</td>
		</tr>
		<tr>
			<td>Incubator HERAcell 150i</td>
			<td>Thermo Scientific</td>
			<td></td>
			<td>Organ Culture</td>
		</tr>
		<tr>
			<td>Dissection Scope</td>
			<td>VistaVision</td>
			<td></td>
			<td>Used during dissection</td>
		</tr>
		<tr>
			<td>Laser Micrometer</td>
			<td>Keyence</td>
			<td>LK-081</td>
			<td>Measuring disc height</td>
		</tr>
		<tr>
			<td>Microcentrifuge 5810 R</td>
			<td>Eppendorf</td>
			<td></td>
			<td>Used for biochemical assays</td>
		</tr>
		<tr>
			<td>Microtome</td>
			<td>Leica&#160;</td>
			<td>RM2255</td>
			<td>Used for histology</td>
		</tr>
		<tr>
			<td>Software</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Prism 7</td>
			<td>GraphPad</td>
			<td></td>
			<td>For statistics</td>
		</tr>
		<tr>
			<td>MATLAB R2014a</td>
			<td>Mathworks</td>
			<td></td>
			<td>For modeling</td>
		</tr>
		<tr>
			<td>Osiri-LXIV</td>
			<td>Pixmeo</td>
			<td></td>
			<td>Open Source</td>
		</tr>
		<tr>
			<td>MeshLab v1.3.3</td>
			<td>Visual Computing Lab - ISTI - CNR</td>
			<td></td>
			<td>Open Source</td>
		</tr>
		<tr>
			<td>PreView/FEBio 2.3</td>
			<td>Utah MRL &#38; Columbia MBL</td>
			<td></td>
			<td>Open Source</td>
		</tr>
		<tr>
			<td>ImageJ</td>
			<td>NIH</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microsoft Excel</td>
			<td>Windows</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dissection Tools</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cohan-Vannas Spring Scissors&#160;</td>
			<td>Fine Science Tools&#160;&#160;</td>
			<td>15000-02</td>
			<td>Or any nice pair of spring scissors</td>
		</tr>
		<tr>
			<td>Fine Scissors - Sharp&#160; (small)</td>
			<td>Fine Science Tools&#160;&#160;</td>
			<td>14060-09</td>
			<td></td>
		</tr>
		<tr>
			<td>Fine Scissors - Sharp&#160; (larger)</td>
			<td>Fine Science Tools&#160;&#160;</td>
			<td>14060-11</td>
			<td></td>
		</tr>
		<tr>
			<td>Dumont #5 Forceps</td>
			<td>Fine Science Tools&#160;&#160;</td>
			<td>11252-40</td>
			<td>At least 2; can also use #3&#160;</td>
		</tr>
		<tr>
			<td>Extra Fine Graefe Forceps, serrated</td>
			<td>Fine Science Tools&#160;&#160;</td>
			<td>11150-10</td>
			<td>At least 2</td>
		</tr>
		<tr>
			<td>Micro-Adson Forceps, serrated</td>
			<td>World Precision Instruments</td>
			<td>503719-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro-Adson Forceps, teeth</td>
			<td>World Precision Instruments</td>
			<td>501244</td>
			<td></td>
		</tr>
		<tr>
			<td>Scalpel Handle - #3</td>
			<td>Fine Science Tools&#160;&#160;</td>
			<td>10003-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Scalpel Handle - #4</td>
			<td>Fine Science Tools&#160;&#160;</td>
			<td>10004-13</td>
			<td></td>
		</tr>
		<tr>
			<td>Scalpel Blades - #23</td>
			<td>Fine Science Tools&#160;&#160;</td>
			<td>10023-00</td>
			<td></td>
		</tr>
		<tr>
			<td>Insect Pins , size 000</td>
			<td>Fine Science Tools&#160;&#160;</td>
			<td>26000-25</td>
			<td></td>
		</tr>
		<tr>
			<td>27G Needle</td>
			<td>BD PrecisionGlide Needles</td>
			<td>BD305109</td>
			<td></td>
		</tr>
	</tbody>
</table>

an in vitro organ culture model of the murine intervertebral disc

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and dampen loads in the spine. The IVD consists of a proteoglycan-rich nucleus pulposus (NP) and a collagen-rich annulus fibrosis (AF) sandwiched by cartilaginous end-plates. Together with the adjacent vertebrae, the vertebrae-IVD structure forms a functional spine unit (FSU). These microstructures contain unique cell types as well as unique extracellular matrices. Whole organ culture of the FSU preserves the native extracellular matrix, cell differentiation phenotypes, and cellular-matrix interactions. Thus, organ culture techniques are particularly useful for investigating the complex biological mechanisms of the IVD. Here, we describe a high-throughput approach for culturing whole lumbar mouse FSUs that provides an ideal platform for studying disease mechanisms and therapies for the IVD. Furthermore, we describe several applications that utilize this organ culture method to conduct further studies including contrast-enhanced microCT imaging and three-dimensional high-resolution finite element modeling of the IVD.

Figures 2-3 show representative results of proteoglycan distribution, NF-&#954;B expression, stiffness, viscosity, disc height, and wet weight for cultured mouse IVDs. If cultured properly, the IVD parameters of the Control group should not be significantly different from the Fresh group. If the culture is infected or otherwise compromised, the Control group will be different from the Fresh group, especially in NF-&#954;B expression and proteoglycan distribution (results not shown). Figures 4-5</...

Watch this Scientific Journal Video about An In Vitro Organ Culture Model of the Murine Intervertebral Disc at JoVE.com

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Whole organ culture of the intervertebral disc (IVD) preserves the native extracellular matrix, cell phenotypes, and cellular-matrix interactions. Here we describe an IVD culture system using mouse lumbar and caudal IVDs in their functional spinal units and several applications utilizing this system.

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and ...

The overall goal of this in vitro organ culture method is to maintain homeostasis and observe the inflammatory response of intervertebral discs in their native anatomy. This method can help answer key questions in intervertebral disc degeneration and low back pain, and it may aid in discovering new drugs and therapies. The main advantage of this method is that it can be done rapidly while maintaining the anatomy of the disc and other tissues.Generally, individuals new to this method will struggle, because it is hard to maintain sterility, as any contamination my compromise the experimental results. Because of the minute size of mouse intervertebral discs, visual demonstration of the dissection and organ culture steps is critical. Before beginning this protocol, purchase two strains of ten-week-old mice, BALB/c and transgenic animals with the luciferase gene expressed under the control of the nuclear factor kappa B promoter, bred on the BALB/c genetic background.To begin, bathe the previously euthanized mouse in 70%ethanol for two minutes to ensure its skin and coating is disinfected for the dissection. Then, make a longitudinal cut in the animal's dorsal skin using small dissection scissors to expose the body cavity. Proceed with two longitudinal vertical cuts, starting from the L1 vertebrae to the C8 vertebrae on both sides of the spine.Use a scalpel, fine forceps, and fine dissection scissors to carefully remove the L1 to C8 spine fragment from the mouse body cavity. Excise any excess soft tissues that surround the spine. Be careful not to scrape or injure the intervertebral disc, or IVD, on the ventral side.Divide the spinal column into functional spine units, or FSUs, comprising vertebrae disc vertebrae fragments. Then, wash the obtained FSUs in Hank's balanced salt solution supplemented with antibiotics for two minutes. Now that FSUs are washed, assign them randomly to three experimental groups marked as fresh, control, and stab.Immediately after preparation, freeze the fresh FSUs in liquid nitrogen, and store the samples in a negative 20 degree Celsius freezer. To initiate the organ culture, use ten-milliliter serological pipettes to add two milliliters of DMEM/F-12 culture medium into each well of a 24-well culture plate. Then, transfer each dissected and washed FSU to an individual well of the 24-well plate filled with media.Incubate the 24-well plate containing the samples in a disinfected incubator at 37 degrees Celsius, 5%carbon dioxide, 20%oxygen, and greater than 90%humidity. After culturing the samples for 24 hours, use a sterile 27-gauge needle to puncture the annulus fibrosus so as to induce mechanical injury in the samples from the stab group. Every 48 hours, change the media by transferring the samples with tweezers to a new 24-well plate filled with media.On the twenty-first day of culture, transfer all samples into media containing 0.75 milligrams per milliliter nitroblue tetrazolium chloride, and incubate them for an additional 24 hours. After 24 hours of incubation, freeze all the FSUs in liquid nitrogen, and store the samples in a negative 20 degree Celsius freezer for further testing. To assess NF kappa B expression, add ten microliters of a one milligram per milliliter luciferin solution to each well containing FSU isolated from an animal transgenic for NF kappa B luciferase.Then, incubate the plate in a sterile incubator at 37 degrees Celsius for ten minutes. Under the dissection microscope, use a scalpel and tweezers to remove the bony vertebral bodies from each FSU sample. Be careful not to damage or detach the cartilaginous endplates from the IVD.Then, using cyanoacrylate glue, attach the isolated IVDs to a one centimeter by one centimeter by 0.2 centimeter aluminum plate. Subsequently, measure the disc height and width with a laser micrometer, and calculate the disc height ratio as described in the text protocol. Next, transfer the samples to the phosphate-buffered saline bath positioned under the compression machine, and preload the disc to 0.02 newtons.To cyclically compress the disc, apply 20 cycles of a sinusoidal waveform at 1 hertz and conduct three trials for both 1%strain level and 5%strain level. Record the load and displacement data to calculate the average stiffness and loss tangent of the IVD. Presented here are images of the bioluminescent signal corresponding to NF kappa B expression in control and stab samples.The signal in both control and stab samples indicates that the IVD cultured in vitro remains viable and responsive. Additionally, stab samples reveal increased NF kappa B expression compared to the control on days one, five, 13, and 19. Further mechanical testing conducted for the IVDs cultured in vitro confirms that culture conditions do not influence the properties of the control IVDs, such as disc height ratio, stiffness, or loss tangent.In addition, the decreased disc height ratio, stiffness, and loss tangent observed for the stab group further confirms viability and responsiveness of the IVD cultured in vitro. Once this technique has been mastered, up to 18 samples can be prepared for culture in an hour. While attempting this procedure, it's important to work slowly and carefully to ensure that sterility is maintained.Following this procedure, more mechanistic studies can be performed using genetically modified mice to get a better understanding of disc degeneration. This technique can also be used to explore various treatments and therapies for low back pain. After watching this video, you should have a good understanding of how to prepare and culture mouse functional spine units for experimental conditions.Don't forget that working in a lab can be hazardous, and precautions, including personal protective equipment, should always be taken while performing this procedure.

an-in-vitro-organ-culture-model-of-the-murine-intervertebral-disc

Research

JoVE Journal

Bioengineering

9.3K visualizações.  Washington University in St. Louis. The overall goal of this in vitro organ culture method is to maintain homeostasis and observe the inflammatory response of intervertebral discs in their native anatomy. This method can help answer key questions in intervertebral disc degeneration and low back pain, and it may aid in discovering new drugs and therapies. The main advantage of this method is that it can be done rapidly while maintaining the anatomy of the disc and other tissues.Generally, individuals new to this method wi...