Name: a microphysiologic platform for human fat: sandwiched white adipose tissue
Uploaded: 2018-08-15T14:00:00
Description: Watch this Scientific Journal Video about A Microphysiologic Platform for Human Fat: Sandwiched White Adipose Tissue at JoVE.com

The authors would like to acknowledge the institutional support provided by LSU Health Sciences Center, which funded the project.

All tasks were performed in adherence to protocols #8759 and #9189, as approved by the IRB Office of LSUHSC-NO. All animal work was performed in adherence to protocol #3285 approved by the IACUC Office at LSUHSC-NO.
1. Seeding of Sandwiching Cell Sheets
NOTE: See Figure 1.
<ol>
	<li>Seed ADSCs at approximately 80% confluency in tissue culture plates (6 cm or 6-well plates). For each well of SWAT desired, seed 1 conventional tissue cul...

<ol>
	<li>Cawley, J., Meyerhoefer, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+medical+costs+of+obesity:+An+instrumental+variables+approach.">The medical costs of obesity: An instrumental variables approach.</a> Journal of Health Economics. 31 (1), 219-230 (2012).</li><li>Pi-Sunyer, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Medical+Risks+of+Obesity.">The Medical Risks of Obesity.</a> Postgraduate Medicine. 121 (6), 21-33 (2009).</li><li>Smith, U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphologic+studies+of+human+subcutaneous+adipose+tissue+in+vitro.">Morphologic studies of human subcutaneous adipose tissue in vitro.</a> Anatomical Record. 169 (1), 97-104 (1971).</li><li>Sugihara, H., Yonemitsu, N., Miyabara, S., Yun, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Primary+cultures+of+unilocular+fat+cells:+characteristics+of+growth+in+vitro+and+changes+in+differentiation+properties.">Primary cultures of unilocular fat cells: characteristics of growth in vitro and changes in differentiation properties.</a> Differentiation. 31 (1), 42-49 (1986).</li><li>Sugihara, H., Yonemitsu, N., Toda, S., Miyabara, S., Funatsumaru, S., Matsumoto, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unilocular+fat+cells+in+three-dimensional+collagen+gel+matrix+culture.">Unilocular fat cells in three-dimensional collagen gel matrix culture.</a> The Journal of Lipid Research. 29, 691-697 (1988).</li><li>Hazen, S. A., Rowe, W. A., Lynch, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monolayer+cell+culture+of+freshly+isolated+adipocytes+using+extracellular+basement+membrane+components.">Monolayer cell culture of freshly isolated adipocytes using extracellular basement membrane components.</a> The Journal of Lipid Research. 36, 868-875 (1995).</li><li>Fried, S. K., Kral, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sex+differences+in+regional+distribution+of+fat+cell+size+and+lipoprotein+lipase+activity+in+morbidly+obese+patients.">Sex differences in regional distribution of fat cell size and lipoprotein lipase activity in morbidly obese patients.</a> International Journal of Obesity. 11 (2), 129-140 (1987).</li><li>Sutherland, M. L., Fabre, K. M., Tagle, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+National+Institutes+of+Health.+Microphysiological+Systems+Program+focuses+on+a+critical+challenge+in+the+drug+discovery+pipeline.">The National Institutes of Health. Microphysiological Systems Program focuses on a critical challenge in the drug discovery pipeline.</a> Stem Cell Research and Therapy. 4, (2013).</li><li>Wikswo, J. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+relevance+and+potential+roles+of+microphysiological+systems+in+biology+and+medicine.">The relevance and potential roles of microphysiological systems in biology and medicine.</a> Experimental Biology and Medicine. 239 (9), 1061-1072 (2014).</li><li>. NIH-CASIS Coordinated Microphysiological Systems Program for Translational Research in Space (#RFA-TR-18-001) Available from: <a target="_blank" href="https://grants.nih.gov/grants/guide/rfa-files/RFA-TR-18-001.html">https://grants.nih.gov/grants/guide/rfa-files/RFA-TR-18-001.html</a> (2017)</li><li>Lau, F. H., Vogel, K., Luckett, J. P., Hunt, M., Meyer, A., Rogers, C. L., Tessler, O., Dupin, C. L., St Hilaire, H., Islam, K. N., Frazier, T., Gimble, J. M., Scahill, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sandwiched+White+Adipose+Tissue:+A+Microphysiological+System+of+Primary+Human+Adipose+Tissue.">Sandwiched White Adipose Tissue: A Microphysiological System of Primary Human Adipose Tissue.</a> Tissue Engineering Part C: Methods. 24 (3), (2018).</li><li>Ebara, M., Hoffman, J. M., Stayton, P. S., Hoffman, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Surface+modification+of+microfluidic+channels+by+UV-mediated+graft+polymerization+of+non-fouling+and+'smart'+polymers.">Surface modification of microfluidic channels by UV-mediated graft polymerization of non-fouling and 'smart' polymers.</a> Radiation Physics and Chemistry. 76, 1409-1413 (2007).</li><li>Lin, J. B., Isenberg, B. C., Shen, Y., Schorsch, K., Sazonova, O. V., Wong, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermo-responsive+poly(N-isopropylacrylamide)+grafted+onto+microtextured+poly(dimethylsiloxane)+for+aligned+cell+sheet+engineering.">Thermo-responsive poly(N-isopropylacrylamide) grafted onto microtextured poly(dimethylsiloxane) for aligned cell sheet engineering.</a> Colloids and Surfaces B: Biointerfaces. 99, 108-115 (2012).</li><li>Turner, W. S., Sandhu, N., McCloskey, K. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue+Engineering:+Construction+of+a+Multicellular+3D+Scaffold+for+the+Delivery+of+Layered+Cell+Sheets.">Tissue Engineering: Construction of a Multicellular 3D Scaffold for the Delivery of Layered Cell Sheets.</a> Journal of Visualized Experiments. (92), e51044 (2014).</li><li>Bunnell, B., Flaat, M., Gagliardi, C., Patel, B., Ripoll, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adipose-derived+stem+cells:+Isolation,+expansion+and+differentiation.">Adipose-derived stem cells: Isolation, expansion and differentiation.</a> Methods. 45 (2), 115-120 (2008).</li><li>Akiyama, Y., Kikuchi, A., Yamato, M., Okano, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrathin+poly(N-isopropylacrylamide)+grafted+layer+on+polystyrene+surfaces+for+cell+adhesion/detachment+control.">Ultrathin poly(N-isopropylacrylamide) grafted layer on polystyrene surfaces for cell adhesion/detachment control.</a> Langmuir. 20 (13), 5506-5511 (2004).</li><li>Fried, S. K., Russell, C. D., Grauso, N. L., Brolin, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lipoprotein+lipase+regulation+by+insulin+and+glucocorticoid+in+subcutaneous+and+omental+adipose+tissues+of+obese+women+and+men.">Lipoprotein lipase regulation by insulin and glucocorticoid in subcutaneous and omental adipose tissues of obese women and men.</a> Journal of Clinical Investigation. 92 (5), 2191-2198 (1993).</li><li>Keipert, S., Jastroch, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brite/beige+fat+and+UCP1+-+is+it+thermogenesis?.">Brite/beige fat and UCP1 - is it thermogenesis?.</a> Biochimica et Biophysica Acta. 1837 (7), 1075-1082 (2014).</li></ol>

This protocol details the use of ADSCs to sandwich human white adipose tissue; human ADSC cell lines can be isolated via well-established protocols15. However, the system can be adapted for individualized research requirements (such as using 3T3L-1 cells to sandwich mouse WAT). This process involves handling primary human tissue. Standard safety precautions should be employed; handle human tissues as BSL-2 pathogens (e.g., HIV, HepC). Only handle tissue directly under a BSC. Wear all appr...

Adipose tissue is the primary organ of obesity, which carries direct annual medical costs between $147 billion and $210 billion in the U.S.1. The accumulation of adipose tissue also contributes to other leading causes of death such as heart disease, type II diabetes, and certain types of cancer2. In vitro culture models are essential for metabolic studies and drug development, but current research models of adipose tissue have major deficiencies. Adipocytes are fragile, buoyant, and terminally differentiated cells that will not adhere to cell culture plastics, and therefore cannot be cultured using conventional cell culture methods. Since the 1970s, several methods have been used in attempts to overcome these barriers, including the use of glass coverslips, ceiling culture, suspension culture, and extracellular matrices3,4,5,6,7. However, these methods have been marked by cell death and dedifferentiation, and they are typically used for no more than a two-week study period. Moreover, these models do not attempt recapitulate the native adipose microenvironment as they do not maintain the intact ECM, the interactions between adipocytes and stromal support cells, nor the contractile forces cells exert on each other in in vivo WAT.
In the absence of a gold-standard primary adipose culture method, adipose research has relied primarily on differentiated pre-adipocytes (diffAds). DiffAds are multilocular, adherent, and metabolically active. By contrast, primary white adipocytes are unilocular, nonadherent, and demonstrate relatively low metabolism. The failure of current adipose culture models to recapitulate the physiology of healthy mature adipose tissue is likely a major factor in the absence of FDA-approved medications that directly target adipocytes. In fact, the lack of physiologic in vitro organ models is a major problem across most organs and disease.
In its position paper announcing the creation of its Microphysiological Systems (MPS) program, the National Institutes of Health (NIH) reported that the 2013 success rate across all human pharmaceutical clinical trials was only 18% for phase II and 50% for phase III clinical trials8.The MPS program is designed to directly address the inability of in vitro monoculture to model human physiology. The NIH defines MPSs as culture systems comprised of human primary or stem cells in multicellular 3D constructs that recapitulate organ functioning. Unlike reductionist models of homogeneous, immortalized cell cultures, MPSs should accurately model cell-cell, drug-cell, drug-drug, and organ-drug interactions9. Unlike short-term primary culture methods, NIH standards dictate MPS sustainability over 4 weeks in culture8. Further details of the MPS program can be found at the NIH&#39;s RFAs (#RFA-TR-18-001)10.
We have developed a simple, novel, adaptable, and inexpensive adipose MPS termed &#34;sandwiched white adipose tissue&#34; (SWAT)11. We overcome the natural buoyancy of adipocytes by &#34;sandwiching&#34; minced primary adipose tissue between sheets of adipose-derived stromal cells (ADSCs) (Figure 1). The resulting 3D construct recapitulates the cell-cell contact and the native adipose microenvironment by surrounding mature adipocytes with a natural adipocyte support cell population. SWAT has been validated by demonstrating 8-week viability, response to exogenous signaling, adipokine secretion, and engraftment into an animal model.

<table border="0" cellpadding="0" cellspacing="0" width="817">
	<tbody>
		<tr height="20">
			<td height="20" style="height:20px;width:219px;">10x HBSS</td>
			<td style="width:92px;">Thermofisher</td>
			<td style="width:115px;">14185052</td>
			<td style="width:393px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Gelatin</td>
			<td>Sigma-aldrich</td>
			<td>G9391</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Collagenase</td>
			<td>Sigma-aldrich</td>
			<td>C5138</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Adenosine</td>
			<td>Sigma-aldrich</td>
			<td>A9251</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">DMEM</td>
			<td>Thermofisher</td>
			<td>11995065</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">M199 Media</td>
			<td>Thermofisher</td>
			<td>11043023</td>
			<td>Phenol red-free&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">250&#181;m Mesh Filter</td>
			<td>Pierce</td>
			<td>87791</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">0.2&#181;m Syringe Filter</td>
			<td>Celltreat</td>
			<td>229747</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">5mL Luer-Lok syringes&#160;</td>
			<td>BD</td>
			<td>309646</td>
			<td></td>
		</tr>
		<tr height="160">
			<td height="160" style="height:160px;">Metal Washers</td>
			<td></td>
			<td></td>
			<td style="width:393px;">These are simple metal washers and can be bought at any hardware store. They simply add leight weight to the backs of the plugers to ensure even contact between cells and gelatin, while being easy to stock and sterilize. Approximate mass: 6.3g&#160;</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Heated Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;">Incubated Orbital Shaker</td>
			<td>VWR</td>
			<td>10020-988</td>
			<td style="width:393px;">Samples should be pitched at 45&#176; angle to facilitate collagenase digestion</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Heat Block</td>
			<td></td>
			<td></td>
			<td style="width:393px;">Set to 37-40&#176;C and placed under Biosafety Cabinet</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Water Bath</td>
			<td></td>
			<td></td>
			<td style="width:393px;">Set to ~75&#176;C</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;">Specialized Plastics</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="180">
			<td height="180" style="height:180px;">Upcell Dishes 6cm of 6-multiwell</td>
			<td>Nunc</td>
			<td>174902&#160; or 174901</td>
			<td style="width:393px;">These are commerically available pNIPAAm-coated dishes which can be used to grow the upper sheet of ADSCs. Alternatively, pNIPAAm-coated plates can be produced in-lab. diameter: &#60;6cm for 6cm dish, &#60;3.5cm for 6-well plate; approximate mass: 6.7g for 6cm dish, 5.1g for 6-well plate</td>
		</tr>
		<tr height="160">
			<td height="160" style="height:160px;">Plastic Plunger Apparatus</td>
			<td></td>
			<td></td>
			<td style="width:393px;">These can be fashioned to fit within desired pNIPAAm-coated plastics (multiwell plates, petri dishes). They are comprised of a simple stem attached to a circular disk. They can be produced in-lab or by any facility that can fashion acrylic plastics</td>
		</tr>
	</tbody>
</table>

a microphysiologic platform for human fat: sandwiched white adipose tissue

White adipose tissue (WAT) plays a crucial role in regulating weight and everyday health. Still, there are significant limitations to available primary culture models, all of which have failed to faithfully recapitulate the adipose microenvironment or extend WAT viability beyond two weeks. The lack of a reliable primary culture model severely impedes research in WAT metabolism and drug development. To this end we have utilized NIH's standards of a microphysiologic system to develop a novel platform for WAT primary culture called 'SWAT' (sandwiched white adipose tissue). We overcome the natural buoyancy of adipocytes by sandwiching minced WAT clusters between sheets of adipose-derived stromal cells. In this construct, WAT samples are viable over eight weeks in culture. SWAT maintains the intact ECM, cell-to-cell contacts, and physical pressures of in vivo WAT conditions; additionally, SWAT maintains a robust transcriptional profile, sensitivity to exogenous chemical signaling, and whole tissue function. SWAT represents a simple, reproducible, and effective method of primary adipose culture. Potentially, it is a broadly applicable platform for research in WAT physiology, pathophysiology, metabolism, and pharmaceutical development.

Viability of SWAT was initially assessed by serial brightfield imaging of individual WAT clusters (n = 12) over approximately 7.6 weeks. Clusters remained secured in place on the monolayer throughout this time. Slight morphological changes were observed with individual adipocytes warping slightly or shifting positions. However, adipocytes neither become multilocular over time, indicating a lack of dedifferentiation, nor did they exhibit any visible signs of cell death such as cellular ble...

Watch this Scientific Journal Video about A Microphysiologic Platform for Human Fat: Sandwiched White Adipose Tissue at JoVE.com

A Microphysiologic Platform for Human Fat: Sandwiched White Adipose Tissue

White adipose tissue (WAT) has critical deficiencies in its current primary culture models, hindering pharmacological development and metabolic studies. Here, we present a protocol to produce an adipose microphysiological system by sandwiching WAT between sheets of stromal cells. This construct provides a stable and adaptable platform for primary WAT culture.

White adipose tissue (WAT) plays a crucial role in regulating weight and everyday health.  Still, there are significant limitations to available primary ...

This breakthrough method allows us, for the first time, to keep fat alive and healthy ex vivo for several consecutive weeks for the study of adipose biology. The main advantage of this technique is that the tissue remains stable over eight weeks in the culture while recapitulating the adipose microenvironment including the surrounding native adipose stromal support cells. Begin by seeding ASC at an approximately 80%confluency in tissue culture plates.For each well of SWAT desired, seed one conventional tissue culture well and one well of corresponding size on a PNIPAAm coated tissue culture plastic plate. Maintain the ASC in complete culture medium at 37 degrees Celsius and 5%CO2 for six to eight days, changing the medium every two days. Twenty-four hours before the SWAT seeding, wrap the rim of the plunger disk of each plunger for the SWAT seeding apparatus at least two times with lab tape to prevent leakage of the gelatin solution.In an ethanol-disinfected biosafety cabinet, spray down a 15 milliliter conical tube rack containing empty, uncapped 15 milliliter conical tubes, as well as each tape wrapped plunger with 70%ethanol, placing each plunger into an empty tube as it is disinfected. Spray approximately 6.3 gram metal washers and place them on the rack along with a pair of hooked forceps. Then close the cabinet sash and turn on the UV light to facilitate overnight drying and sterilization of the seeding apparatus materials.When the cells reach 100%confluency and demonstrate a striated pattern, add 0.75 grams of gelatin powder to 10 milliliters of HBSS. And balance the pH of the solution with 100 microliters of sodium hydroxide. Add the gelatin to a 75-degree Celsius water bath and shake the tube vigorously every five minutes until the powder dissolves into solution.Strain the homogenous gelatin solution through a syringe filter and apply the gelatin to the plungers. The taped edges of the plungers will serve as a mold while the gelatin solidifies. When the gelatin has solidified unwrap the tape and use the hooked forceps to remove the gelatin from the outer edge of the plunger, taking care that the remaining gelatin in the center of the plunger is completely level, to maximize the contact with the ASC sheet.Once the gelatin has been removed from all of the plungers, gently apply each plunger to a PNIPAAm coated ASC plate using the metal washers to weigh down the plungers. After a 1.5-hour incubation at room temperature, transfer the plates to an ice-water bath for another 1.5 hours to complete the dissociation of the cell sheet from the PNIPAAm coated plate surface. Then, clean the bottom of the PNIPAAm coated plates to remove any non-sterile water.Upon receipt of the human adipose tissue, add cold cell culture medium to one 1.5 milliliter microcentrifuge tube per culture to be seeded. And wash large segments of the adipose tissue three times in sterile PBS, removing as much PBS as possible between washes. After the last wash, use forceps and a sterile razor to coarsely mince the tissue, removing as much vasculature and fascia as possible until the solution takes on thick liquid consistency with as few visible individual segments of white adipose tissue as possible.Once a proper tissue consistency has been reached, use a modified P1000 micro-pipette tip to transfer the appropriate volume of minced tissue to each previously prepared 1.5 milliliter tube and briefly mix the minced tissue with the medium within the tubes. Next, replace the medium in each ASC culture with one volume of white adipose tissue solution, and gently transfer the gelatin plungers to the white adipose tissue mixture on the base ASC plates. Examine the monolayers in the PNIPAAm coated plates under a microscope to confirm cellular detachment and move the plates to the surface of a 37 to 40 degree Celsius heat block in the biosafety cabinet.Then add two to three milliliters of warmed culture medium to incubate the cells and to facilitate gelatin melting. After 30 minutes gently remove the plungers from the plate surface, cover the cultures with the appropriate plate lids and place the plates in the cell culture incubator. When the gelatin has completely liquified, aspirate and replace the cell culture medium with the appropriate volume of phenol red free M199 medium supplemented with insulin, dexamethasone, and antibiotics.Over 7.5 weeks of culture, the SWAT clusters remain secured in place on the monolayer with only slight morphological changes observed in individual adipocytes. Clear Nile red staining of unilocular adipocyte clusters at two weeks of culture demonstrates that the cells are indeed adipocytes with intact membranes, rather than artifact, cysts, or dead adipocytes. Propidium iodide staining of 53-day-old SWAT and Oil Red O staining of 51-day-old SWAT cultures confirm that the adipocytes maintain viability even at advanced time points.Immunocytochemistry demonstrates the appropriate expected protein expression and localization of mature adipocyte markers within the SWAT and quantitative PCR indicates the expression of key adipocyte genes at the transcriptional level. The evaluation of basil endocrine function indicates basil leptin secretion from the SWAT cultures as detected by ELISA, and glycerol release is also able to be induced in response to chemical stimulation. Xenotransplantation of SWAT-cultured adipocytes reveals clearly visible and readily recovered fat deposits 10 days after transplant that stain for human but not mouse adipocyte markers.Once mastered, this technique can be completed in about five hours if it is performed properly. It's important to remember to process the primary tissue quickly to minimize cell death. Following this procedure, other methods like real time quantitative PCR, immunostaining, or functional assays can be performed to answer additional questions about how adipocytes respond to various drugs or toxins.After watching this video you should have a good understanding of how to perform SWAT culture as a stable and reliable platform for your adipose research. Don't forget that working with primary human tissue can be hazardous, and that precautions such as wearing the proper PPE and handling the tissue under biosafety cabinets should always be taken while performing this procedure.

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Research

JoVE Journal

Behavior

Fat Preference: A Novel Model of Eating Behavior in Rats

Obesity is a growing problem in the United States of America, with more than a third of the population classified as obese. One factor contributing to this multifactorial disorder is the consumption of a high fat diet, a behavior that has been shown to increase both caloric intake and body fat content. However, the elements regulating preference for high fat food over other foods remain understudied.
To overcome this deficit, a model to quickly and easily test changes in the preference for dietary fat was developed. The Fat Preference model presents rats with a series of choices between foods with differing fat content. Like humans, rats have a natural bias toward consuming high fat food, making the rat model ideal for translational studies. Changes in preference can be ascribed to the effect of either genetic differences or pharmacological interventions. This model allows for the exploration of determinates of fat preference and screening pharmacotherapeutic agents that influence acquisition of obesity.

Dietary fat content influences both energy intake and body fat composition in mammals. By examining rats&#8217; preference for high fat food in a series of choice experiments, it is possible to test genetic differences and pharmacological interventions on their preference for high fat food.

Obesity is a growing problem in the United States of America, with more than a third of the population classified as obese. One factor contributing to ...

Flat-floored Air-lifted Platform: A New Method for Combining Behavior with Microscopy or Electrophysiology on Awake Freely Moving Rodents

It is widely acknowledged that the use of general anesthetics can undermine the relevance of electrophysiological or microscopical data obtained from a living animal&#8217;s brain. Moreover, the lengthy recovery from anesthesia limits the frequency of repeated recording/imaging episodes in longitudinal studies. Hence, new methods that would allow stable recordings from non-anesthetized behaving mice are expected to advance the fields of cellular and cognitive neurosciences. Existing solutions range from mere physical restraint to more sophisticated approaches, such as linear and spherical treadmills used in combination with computer-generated virtual reality. Here, a novel method is described where a head-fixed mouse can move around an air-lifted mobile homecage and explore its environment under stress-free conditions. This method allows researchers to perform behavioral tests (e.g., learning, habituation or novel object recognition) simultaneously with two-photon microscopic imaging and/or patch-clamp recordings, all combined in a single experiment. This video-article describes the use of the awake animal head fixation device (mobile homecage), demonstrates the procedures of animal habituation, and exemplifies a number of possible applications of the method.

This method creates a tangible, familiar environment for the mouse to navigate and explore during microscopic imaging or single-cell electrophysiological recordings, which require firm fixation of the animal&#8217;s head.

It is widely acknowledged that the use of general anesthetics can undermine the relevance of electrophysiological or microscopical data obtained from a ...

Determining Pain Detection and Tolerance Thresholds Using an Integrated, Multi-Modal Pain Task Battery

Human pain models are useful in the assessing the analgesic effect of drugs, providing information about a drug&#39;s pharmacology and identify potentially suitable therapeutic populations. The need to use a comprehensive battery of pain models is highlighted by studies whereby only a single pain model, thought to relate to the clinical situation, demonstrates lack of efficacy. No single experimental model can mimic the complex nature of clinical pain. The integrated, multi-modal pain task&#160;battery presented here encompasses the electrical stimulation task, pressure stimulation task, cold pressor task, the UVB inflammatory model which includes a thermal task and a paradigm for inhibitory conditioned pain modulation. These human pain models have been tested for predicative validity and reliability both in their own right and in combination, and can be used repeatedly, quickly, in short succession, with minimum burden for the subject and with a modest quantity of equipment. This allows a drug to be fully characterized and profiled for analgesic effect which is especially useful for drugs with a novel or untested mechanism of action.

Human pain models are valuable tools used to assess the analgesic potential of novel compounds and predict their clinical efficacy, especially when used in an integrated manner. Although implementation of these models is complex, with proper execution, the pain models described in this protocol can provide predictive and reliable results.

Human pain models are useful in the assessing the analgesic effect of drugs, providing information about a drug&#39;s pharmacology and identify ...

Substantiating Appropriate Motion Capture Techniques for the Assessment of Nordic Walking Gait and Posture in Older Adults

Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques have been employed, each with positives and negatives. The aim was to determine the effect of NW on older adult gait and posture and to determine optimal use of different data collection systems in both short and long duration analysis. Gait and posture during NW and normal walking were assessed in 17 healthy older adults (age: 69 &#177; 7.3). Participants performed two trials of 6 Minute Walk Tests (6MWT) (1 with poles (WP) and 1 without poles (NP)) and 6 trials of a 5m walk (3 WP and 3 NP). Motion was recorded using two systems, a 6-sensor accelerometry system and an 8-camera 3-dimensional motion capture system, in order to quantify spatial-temporal, kinematic, and kinetic parameters.
With both systems, participants demonstrated increased stride length and double support and decreased gait speed and cadence WP compared to NP (p &#60;0.05). Also, with motion capture, larger single support time was found WP (p &#60;0.05). With 3-D capture, smaller hip power generation and moments of force were found at heel contact and pre-swing as well as smaller knee power absorption at heel contact, pre-swing, and terminal swing WP compared to NP, when assessed over one cycle (p &#60;0.05). Also, WP yielded smaller moments of force at heel contact and terminal swing along with larger moments at mid-stance of a gait cycle (p &#60;0.05). No changes were found for posture.
NW seems appropriate for promoting a normal gait pattern in older adults. Three-dimensional motion capture should primarily be used during short duration gait analysis (i.e. single gait cycle), while accelerometry systems should be primarily employed in instances requiring longer duration analysis such as during the 6MWT.

The aim was to substantiate optimal use of data collection techniques for Nordic walking gait and posture analysis. Three-dimensional motion capture should be used during short duration analysis (i.e. single gait cycle), while accelerometry should be employed for longer duration analysis (i.e. repeated cycles) like a 6 Minute Walk Test.

Nordic walking (NW) has become a safe and simple form of exercise in recent years, and in studying this gait pattern, various data collection techniques ...

Methods of Pairing and Pair Maintenance of New Zealand White Rabbits (Oryctolagus Cuniculus) Via Behavioral Ethogram, Monitoring, and Interventions

New Zealand White (NZW) laboratory rabbits (Oryctolagus cuniculus), as well as their ancestors the European Rabbit, are a social species that exhibit numerous benefits to being housed accordingly. Although these rabbits are innately gregarious, certain behaviors can still arise when kept in captivity, which if left unchecked, can confound research results or lead to wounding, which in extreme cases can be severe. To prevent these issues, there must be a well-structured plan for the monitoring and maintenance of paired laboratory rabbits. The purpose of this protocol is to present effective procedures for establishing newly paired NZW rabbits as well as methods for successful maintenance. Multiple methods have been tested for the creation of newly paired female rabbits from the vendor, but the most efficacious technique emphasizes capitalizing on the stress bonding from transport, urine marking, pairing in a neutral cage with no forced sharing of resources and a system of monitoring and intervention. To determine the best method of housing paired rabbits in a standard caging environment, data were collected to generate a behavioral ethogram. Behaviors were then quantified as positive, neutral or negative and were tracked across the lifespan of the pair to determine which behaviors indicated pair success or failure. With the newfound knowledge of socially housed laboratory NZW rabbit behavior, enrichment intervention was applied to alleviate aggression and prevent wounding, thus resulting in a higher percentage of successful pairs. Through several years of trialing different pairing methods, the development of the ethogram and the resulting enrichment interventions, understanding of the highly complex social constructs that dominate pair housed rabbit behavior has dramatically increased and allowed for the provision of more species-specific care and increased standards of welfare.

Methods of Pairing and Pair Maintenance of New Zealand White Rabbits Oryctolagus Cuniculus Via Behavioral Ethogram, Monitoring, and Interventions

Though European rabbits are a social species, socially housing them can be challenging. Therefore, there must be a thorough understanding of behaviors and social structures of pair-housed laboratory rabbits. Here we present a protocol to identify pairing methods, species-typical hierarchy establishment behaviors and behaviors that warrant appropriate intervention.

New Zealand White (NZW) laboratory rabbits (Oryctolagus cuniculus), as well as their ancestors the European Rabbit, are a social species that exhibit ...

A Novel Single Animal Motor Function Tracking System Using Simple, Readily Available Software

We have recently demonstrated that implanting intracortical microelectrodes in the motor corteces of rats&#160;results in immediate and lasting motor deficits. Motor impairments were manually quantified through an open field grid test to measure the gross motor function and through a ladder test to measure the fine motor function. Here, we discuss a technique for the automated quantification of the video-recorded tests using our custom Capadona Behavioral Video Analysis System: Grid and Ladder Test, or BVAS. Leveraging simple and readily available coding software (see the Table of Materials), this program allows for the tracking of a single animal on both the open field grid and the ladder tests. In open field grid tracking, the code thresholds the video for intensity, tracks the position of the rat over the 3 min duration of the grid test, and analyzes the path. It then computes and returns measurements for the total distance traveled, the maximum velocity achieved, the number of left- and right-handed turns, and the total number of grid lines crossed by the rat. In ladder tracking, the code again thresholds the video for intensity, tracks the movement of the rat across the ladder, and returns calculated measurements including the time it took the rat to cross the ladder, the number of paw slips occurring below the plane of the ladder rungs, and the incidence of failures due to stagnation or reversals. We envision that the BVAS developed here can be employed for the analysis of motor function in a variety of applications, including many injury or disease models.

The current study aimed to automate the quantification of motor deficits in rats. The initial evaluation model assesses motor loss resulting from an intracortical microelectrode implantation in the motor cortex. We report on the development and use of a tracking algorithm using easily adaptable, simple, and readily available coding software.

We have recently demonstrated that implanting intracortical microelectrodes in the motor corteces of rats&#160;results in immediate and lasting motor ...

A Novel Digital Platform for a Monitored Home-based Cardiac Rehabilitation Program

Despite the evidence that cardiac rehabilitation (CR) reduces the risk of recurrent cardiac events, only a minority of eligible patients are willing to join existing programs at cardiac rehabilitation centers. The unique remote patient monitoring system presented here enables healthcare providers to monitor CR patients at home in real-time and at low cost. The system combines mobile technology, artificial intelligence, and supportive services, expanding the delivery of medical care to the patient&#39;s home. The primary aim of the study is to increase the long-term adherence to physical activity in patients who participate in CR via the addition of a home-based digitally monitored CR component to the standard CR program in patients with ischemic heart disease (IHD), with the idea of forming new habitual health behaviors and increasing the long-term motivation for physical exercise (PE) habits at home. Secondary aims are to assess the program&#39;s impact on the physical activity level measured by average steps per day, minutes of exercise per week, blood pressure, metabolic parameters, body mass index, and waist-to-hip ratio, as well as a quality-of-life (QoL) questionnaire.The study has two arms: (1) home-based monitored exercise using a smart digital garment and wristband, in addition to motivation and reinforcement via text messages; (2) standard CR facility-based exercise. The study design is a randomized, controlled trial comparing standard CR to a home-based monitoring and reinforcement program. The study program is designed for 12 weeks.Clinical tests and anthropometric measurements are performed before and after the study, measuring height, weight, waist circumference, visceral fat and body mass index (BMI), blood pressure, and HbA1c and lipid profile. Patients have to complete a baseline survey including socio-demographic characteristics and QoL questionnaire SF-36. At the end of the study, patients complete a survey regarding the use of the smart digital garment&#39;s benefits and usability. The study is currently underway.

The aim is to promote a new approach to cardiac rehabilitation (CR), using a unique remote patient monitoring system that will enable healthcare providers to monitor CR patients at home at low cost, with the intention of making CR services more accessible and improving compliance. The study is currently underway.

Despite the evidence that cardiac rehabilitation (CR) reduces the risk of recurrent cardiac events, only a minority of eligible patients are willing to ...

High-Throughput Method for Measuring Alcohol Sedation Time of Individual Drosophila melanogaster

Drosophila melanogaster provides an excellent model to study the genetic underpinnings of alcohol sensitivity. In contrast to studies in human populations, the Drosophila model allows strict control over genetic background, and virtually unlimited numbers of individuals of the same genotype can be reared rapidly under well-controlled environmental conditions without regulatory restrictions and at relatively low cost. Flies exposed to ethanol undergo physiological and behavioral changes that resemble human alcohol intoxication, including loss of postural control, sedation, and development of tolerance. Here, we describe a simple, low-cost, high-throughput assay for assessing alcohol sedation sensitivity in large numbers of single flies. The assay is based on video recording of single flies introduced without anesthesia in 24-well cell culture plates in a set-up that enables synchronous initiation of alcohol exposure. The system enables a single person to collect individual ethanol sedation data on as many as 2,000 flies within an 8 h work period. The assay can, in principle, be extended to assess the effects of exposure to any volatile substance and applied to measure effects of acute toxicity of volatiles on other insects, including other fly species.

High-Throughput Method for Measuring Alcohol Sedation Time of Individual Drosophila melanogaster

Current methods to measure alcohol sensitivity in Drosophila are designed to test groups of flies. We present a simple, low-cost, high-throughput assay for assessing alcohol sedation sensitivity in large numbers of single flies. The method does not require specialized tools and can be performed in any laboratory using common materials.

Drosophila melanogaster provides an excellent model to study the genetic underpinnings of alcohol sensitivity. In contrast to studies in human ...

Tactile Vibrating Toolkit and Driving Simulation Platform for Driving-Related Research

Collision warning system plays a key role in the prevention of driving distractions and drowsy driving. Previous studies have proven the advantages of tactile warnings in reducing driver&#8217;s brake response time. At the same time, tactile warnings have been proved effective in take-over request (TOR) for partially autonomous vehicles.
How the performance of tactile warnings can be optimized is an ongoing hot research topic in this field. Thus, the presented low-cost driving simulation software and methods are introduced to attract more researchers to take part in the investigation. The presented protocol has been divided into five sections: 1) participants, 2) driving simulation software configuration, 3) driving simulator preparation, 4) vibrating toolkit configuration and preparation, and 5) conducting the experiment.
In the exemplar study, participants wore the tactile vibrating toolkit and performed an established car-following task using the customized driving simulation software. The front vehicle braked intermittently, and vibrating warnings were delivered whenever the front vehicle was braking. Participants were instructed to respond as quickly as possible to the sudden brakes of the front vehicle. Driving dynamics, such as the brake response time and brake response rate, were recorded by the simulation software for data analysis.
The presented protocol offers insight into the exploration of the effectiveness of tactile warnings on different body locations. In addition to the car-following task that is demonstrated in the exemplar experiment, this protocol also provides options&#160;to apply other paradigms to the driving simulation studies by making simple software configuration without any code development. However, it is important to note that due to its affordable price, the driving simulation software and hardware introduced here may not be able to fully compete with other high-fidelity commercial driving simulators. Nevertheless, this protocol can act as an affordable and user-friendly alternative to the general high-fidelity commercial driving simulators.

This protocol describes a driving simulation platform and a tactile vibrating toolkit for the investigation of driving-related research. An exemplar experiment exploring the effectiveness of tactile warnings is also presented.&#160;

Collision warning system plays a key role in the prevention of driving distractions and drowsy driving. Previous studies have proven the advantages of ...

Using a Murine Model of Psychosocial Stress in Pregnancy as a Translationally Relevant Paradigm for Psychiatric Disorders in Mothers and Infants

The peripartum period is considered a sensitive period where adverse maternal exposures can result in long-term negative consequences for both mother and offspring, including the development of neuropsychiatric disorders. Risk factors linked to the emergence of affective dysregulation in the maternal-infant dyad have been extensively studied. Exposure to psychosocial stress during pregnancy has consistently emerged as one of the strongest predictors. Several rodent models have been created to explore this association; however, these models rely on the use of physical stressors or a limited number of psychosocial stressors presented in a repetitive fashion, which do not accurately capture the type, intensity, and frequency of stressors experienced by women. To overcome these limitations, a chronic psychosocial stress (CGS) paradigm was generated that employs various psychosocial insults of different intensity presented in an unpredictable fashion. The manuscript describes this novel CGS paradigm where pregnant female mice, from gestational day 6.5 to 17.5, are exposed to various stressors during the day and overnight. Day stressors, two per day separated by a 2 h break, range from exposure to foreign objects or predator odor to frequent changes in bedding, removal of bedding, and cage tilting. Overnight stressors include continuous light exposure, changing cage mates, or wetting bedding. We have previously shown that exposure to CGS results in the development of maternal neuroendocrine and behavioral abnormalities, including increased stress reactivity, the emergence of fragmented maternal care patterns, anhedonia, and anxiety-related behaviors, core features of women suffering from perinatal mood and anxiety disorders. This CGS model, therefore, becomes a unique tool that can be used to elucidate molecular defects underlying maternal affective dysregulation, as well as trans-placental mechanisms that impact fetal neurodevelopment and result in negative long-term behavioral consequences in the offspring.

The chronic psychosocial stress (CGS) paradigm employs clinically relevant stressors during pregnancy in mice to model psychiatric disorders of mothers and infants. Here, we provide a step-by-step procedure of applying the CGS paradigm and downstream assessments to validate this model.

The peripartum period is considered a sensitive period where adverse maternal exposures can result in long-term negative consequences for both mother and ...