Name: functional imaging of brown fat in mice with 18f-fdg micro-pet/ct
Uploaded: 2012-11-23T12:00:00
Description: Watch this Scientific Journal Video about Functional Imaging of Brown Fat in Mice with 18F-FDG micro-PET/CT at JoVE.com

The authors would like to thank Laura Diaz, Kevin Phillips, Willa A. Hsueh, and King C. Li for their helpful comments and technical support in developing this method.

1.	Animal Preparation and Cold Treatment
<ol>
 <li>Locate and inspect a 4 &deg;C cold room that has been approved for accommodating laboratory mice.</li>
 <li>Pre-chill animal cages overnight in the cold room. The cages are assembled without feed and bedding but with a bottle of water.</li>
 <li>In the morning of the experimental day, place mice one by one into each of the pre-chilled cages at 30 min intervals. Each singly caged mouse should stay in the cold room for nearly 4 hr before it is transported to ...

<ol>
	<li>Cypess, A. M., Kahn, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+and+importance+of+brown+adipose+tissue+in+energy+homeostasis.">The role and importance of brown adipose tissue in energy homeostasis.</a> Curr. Opin. Pediatr. 22, 478-484 (2010).</li><li>Cannon, B., Nedergaard, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brown+adipose+tissue:+function+and+physiological+significance.">Brown adipose tissue: function and physiological significance.</a> Physiol. Rev. 84, 277-359 (2004).</li><li>Collins, S., Surwit, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+beta-adrenergic+receptors+and+the+control+of+adipose+tissue+metabolism+and+thermogenesis.">The beta-adrenergic receptors and the control of adipose tissue metabolism and thermogenesis.</a> Recent Prog. Horm. Res. 56, 309-328 (2001).</li><li>Ouellet, V., 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=Outdoor+temperature,+age,+sex,+body+mass+index,+and+diabetic+status+determine+the+prevalence,+mass,+and+glucose-uptake+activity+of+18F-FDG-detected+BAT+in+humans.">Outdoor temperature, age, sex, body mass index, and diabetic status determine the prevalence, mass, and glucose-uptake activity of 18F-FDG-detected BAT in humans.</a> J. Clin. Endocrinol. Metab. 96, 1115-1125 (2011).</li><li>Cypess, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+and+importance+of+brown+adipose+tissue+in+adult+humans.">Identification and importance of brown adipose tissue in adult humans.</a> N. Engl. J. Med. 360, 1509-1517 (2009).</li><li>Fruhbeck, G., Becerril, S., Sainz, N., Garrastachu, P., Garcia-Velloso, 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=BAT:+a+new+target+for+human+obesity.">BAT: a new target for human obesity.</a> Trends Pharmacol. Sci. 30, 387-396 (2009).</li><li>Cypess, A. M., Kahn, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Brown+fat+as+a+therapy+for+obesity+and+diabetes.">Brown fat as a therapy for obesity and diabetes.</a> Curr. Opin. Endocrinol. Diabetes Obes. 17, 143-149 (2010).</li><li>Virtanen, K. 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=Functional+brown+adipose+tissue+in+healthy+adults.">Functional brown adipose tissue in healthy adults.</a> N. Engl. J. Med. 360, 1518-1525 (2009).</li><li>van Marken Lichtenbelt, W. D., 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=Cold-activated+brown+adipose+tissue+in+healthy+men.">Cold-activated brown adipose tissue in healthy men.</a> N. Engl. J. Med. 360, 1500-1508 (2009).</li><li>Cohade, C., Mourtzikos, K. A., Wahl, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term="USA-Fat":+prevalence+is+related+to+ambient+outdoor+temperature-evaluation+with+18F-FDG+PET/CT.">"USA-Fat": prevalence is related to ambient outdoor temperature-evaluation with 18F-FDG PET/CT.</a> J. Nucl. Med. 44, 1267-1270 (2003).</li><li>Garcia, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduction+of+brown+fat+2-deoxy-2-[F-18]fluoro-D-glucose+uptake+by+controlling+environmental+temperature+prior+to+positron+emission+tomography+scan.">Reduction of brown fat 2-deoxy-2-[F-18]fluoro-D-glucose uptake by controlling environmental temperature prior to positron emission tomography scan.</a> Mol. Imaging Biol. 8, 24-29 (2006).</li><li>Saito, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+incidence+of+metabolically+active+brown+adipose+tissue+in+healthy+adult+humans:+effects+of+cold+exposure+and+adiposity.">High incidence of metabolically active brown adipose tissue in healthy adult humans: effects of cold exposure and adiposity.</a> Diabetes. 58, 1526-1531 (2009).</li><li>Agrawal, A., Nair, N., Baghel, N. 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+novel+approach+for+reduction+of+brown+fat+uptake+on+FDG+PET.">A novel approach for reduction of brown fat uptake on FDG PET.</a> Br. J. Radiol. 82, 626-631 (2009).</li><li>Soderlund, V., Larsson, S. A., Jacobsson, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reduction+of+FDG+uptake+in+brown+adipose+tissue+in+clinical+patients+by+a+single+dose+of+propranolol.">Reduction of FDG uptake in brown adipose tissue in clinical patients by a single dose of propranolol.</a> Eur. J. Nucl. Med. Mol. Imaging. 34, 1018-1022 (2007).</li><li>Zhao, J., Cannon, B., Nedergaard, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermogenesis+is+beta3-+but+not+beta1-adrenergically+mediated+in+rat+brown+fat+cells,+even+after+cold+acclimation.">Thermogenesis is beta3- but not beta1-adrenergically mediated in rat brown fat cells, even after cold acclimation.</a> Am. J. Physiol. 275, 2002-2011 (1998).</li><li>Rowland, D. J., Garbow, J. R., Laforest, R., Snyder, A. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Registration+of+[18F]FDG+microPET+and+small-animal+MRI.">Registration of [18F]FDG microPET and small-animal MRI.</a> Nucl. Med. Biol. 32, 567-5672 (2005).</li></ol>

In this study a micro-PET/CT-based imaging method has been developed for detecting BAT activities in adult mice which simply requires a cold treatment and one injection of commercially available 18F-FDG. The whole procedure can be done in one day following a treatment and imaging sequence which starts every 30 minutes until all animals are treated and imaged. Under the experimental conditions outlined, a total of 10 mice (or 2 groups of 5 mice) can be tested on the same day with a single imaging system...

<table border="1">
 <tbody>
 <tr>
 <td>Name of the reagent</td>
 <td>Company</td>
 <td>Catalogue number</td>
 <td>Comments (optional)</td>
 </tr>
 <tr>
 <td>Micro-PET/CT Imaging System</td>
 <td>Siemens Medical Solutions USA, Inc.</td>
 <td>Inveon Dedicated PET System and Inveon Multimodality CT/SPECT System (docked)</td>
 <td></td>
 </tr>
 <tr>
 <td>Propranolol</td>
 <td>Sigma</td>
 <td>P0884</td>
 <td></td>
 </tr>
 <tr>
 <td>BRL 37344</td>
 <td>Sigma</td>
 <td>B169</td>
 <td></td>
 </tr>
 <tr>
 <td>18F-FDG</td>
 <td>Cyclotope Inc.</td>
 <td></td>
 <td></td>
 </tr>
 <tr>
 <td>C57BL/6J Male Mice</td>
 <td>Jackson Laboratory</td>
 <td>000664</td>
 <td>3-4 months old</td>
 </tr>
 </tbody>
</table>

functional imaging of brown fat in mice with 18f-fdg micro-pet/ct

Brown adipose tissue (BAT) differs from white adipose tissue (WAT) by its discrete location and a brown-red color due to rich vascularization and high density of mitochondria. BAT plays a major role in energy expenditure and non-shivering thermogenesis in newborn mammals as well as the adults 1. BAT-mediated thermogenesis is highly regulated by the sympathetic nervous system, predominantly via &beta; adrenergic receptor 2, 3. Recent studies have shown that BAT activities in human adults are negatively correlated with body mass index (BMI) and other diabetic parameters 4-6. BAT has thus been proposed as a potential target for anti-obesity/anti-diabetes therapy focusing on modulation of energy balance 6-8. While several cold challenge-based positron emission tomography (PET) methods are established for detecting human BAT 9-13, there is essentially no standardized protocol for imaging and quantification of BAT in small animal models such as mice. Here we describe a robust PET/CT imaging method for functional assessment of BAT in mice. Briefly, adult C57BL/6J mice were cold treated under fasting conditions for a duration of 4 hours before they received one dose of 18F-Fluorodeoxyglucose (FDG). The mice were remained in the cold for one additional hour post FDG injection, and then scanned with a small animal-dedicated micro-PET/CT system. The acquired PET images were co-registered with the CT images for anatomical references and analyzed for FDG uptake in the interscapular BAT area to present BAT activity. This standardized cold-treatment and imaging protocol has been validated through testing BAT activities during pharmacological interventions, for example, the suppressed BAT activation by the treatment of &beta;-adrenoceptor antagonist propranolol 14, 15, or the enhanced BAT activation by &beta;3 agonist BRL37344 16. The method described here can be applied to screen for drugs/compounds that modulate BAT activity, or to identify genes/pathways that are involved in BAT development and regulation in various preclinical and basic studies.

An example of micro-PET/CT imaging of mouse BAT is shown in Figure 1. While the CT imaging provides anatomical information, the PET imaging encodes the distribution and quantity of 18F-FDG uptake throughout the whole body. These imaging data can be viewed separately ( Figure 1A and 1B), fused (Figure 1C), or demonstrated with a 3D feature such as maximal intensity projection (MIP, 1D). With the help of a 3D imaging tool, a volume of interest (VOI), her...

Watch this Scientific Journal Video about Functional Imaging of Brown Fat in Mice with 18F-FDG micro-PET/CT at JoVE.com

Functional Imaging of Brown Fat in Mice with 18F-FDG micro-PET/CT

A method of functional imaging of mouse brown adipose tissue (BAT) is described in which cold-stimulated uptake of 18F-Fluorodeoxyglucose (FDG) in BAT is non-invasively assessed with a standardized micro-PET/CT protocol. This method is robust and sensitive to detect differences in BAT activities in mouse models.

Functional Imaging of Brown Fat in Mice with 18F-FDG micro-PET/CT

Brown adipose tissue (BAT) differs from white adipose  tissue (WAT) by its discrete location and a brown-red color due to rich  vascularization and high ...

Research

JoVE Journal

Biology

Light/dark Transition Test for Mice

Although all of the mouse genome sequences have been determined, we do not yet know the functions of most of these genes. Gene-targeting techniques, ...

Labeling hESCs and hMSCs with Iron Oxide Nanoparticles for Non-Invasive in vivo Tracking with MR Imaging

In recent years, stem cell research has led to a better understanding of developmental biology, various diseases and its potential impact on regenerative ...

Labeling Stem Cells with Fluorescent Dyes for non-invasive Detection with Optical Imaging

Optical imaging (OI) is an easy, fast and inexpensive tool for in vivo monitoring of new stem cell based therapies. The technique is based on ex vivo ...

Functional Imaging with Reinforcement, Eyetracking, and Physiological Monitoring

We use functional brain imaging (fMRI) to study neural circuits that underlie decision-making.  To understand how outcomes affect decision processes, ...

Elevated Plus Maze for Mice

Although the mouse genome is now completely sequenced, the functions of most of the genes expressed in the brain are not known. The influence of a given ...

Assembly, Loading, and Alignment of an Analytical Ultracentrifuge Sample Cell

The analytical ultracentrifuge (AUC) is a powerful biophysical tool that allows us to record macromolecular sedimentation profiles during high speed ...

An Alternant Method to the Traditional NASA Hindlimb Unloading Model in Mice

The Morey-Holton hindlimb unloading (HU) method is a widely accepted National Aeronautics and Space Administration (NASA) ground-based model for studying ...

Mapping the After-effects of Theta Burst Stimulation on the Human Auditory Cortex with Functional Imaging

Auditory cortex pertains to the processing of sound, which is at the basis of speech or music-related processing1. However, despite considerable recent ...

Photodiode-Based Optical Imaging for Recording Network Dynamics with Single-Neuron Resolution in Non-Transgenic Invertebrates

The development of transgenic invertebrate preparations in which the activity of specifiable sets of neurons can be recorded and manipulated with light ...