Identification and Dissection of Diverse Mouse Adipose Depots

Summary

Adipocytes exist in discrete depots and have diverse roles within their unique microenvironments. As regional differences in adipocyte character and function are uncovered, standardized identification and isolation of depots is crucial for advancement of the field. Herein, we present a detailed protocol for the excision of various mouse adipose depots.

Abstract

Adipose tissues are complex organs with a wide array of functions, including storage and mobilization of energy in response to local and global needs, uncoupling of metabolism to generate heat, and secretion of adipokines to regulate whole-body homeostasis and immune responses. Emerging research is identifying important regional differences in the developmental, molecular, and functional profiles of adipocytes located in discrete depots throughout the body. Different properties of the depots are medically relevant since metabolic diseases often demonstrate depot-specific effects. This protocol will provide investigators with a detailed anatomic atlas and dissection guide for the reproducible and accurate identification and excision of diverse mouse adipose tissues. Standardized dissection of discrete adipose depots will allow detailed comparisons of their molecular and metabolic characteristics and contributions to local and systemic pathologic states under various nutritional and environmental conditions.

Introduction

Adipose tissues play critical roles in whole-body homeostasis, including storage and release of energy in response to local and global needs, thermoregulation, and secretion of adipokines to regulate energy balance, metabolism and immune responses^1,2. Adipocytes are distributed throughout the body in discrete depots, and in some cases serve specialized roles within their microenvironments^3,4,5. Historically, the study of adipose tissue has centered on white adipose tissue (WAT), and its role in maintaining energy home....

Protocol

All animal procedures are performed with the approval of the Institutional Animal Care and Use Committee (IACUC) of the University of Michigan.

1. Euthanization

NOTE: For the purpose of this video protocol, 4 to 6 month-old C57BL/6J mice are used.

1. Place the mouse in an isoflurane vaporizer chamber and adjust the isoflurane flow rate to 5% or greater. Continue isoflurane exposure until one minute after breathing stops. Then remove the mou.......

Discussion

As the importance of the diverse molecular and functional characteristics of discrete adipocyte clusters is increasingly recognized, it is crucial that investigators within the field uniformly identify and excise adipose depots for further analyses. To date, few protocols exist for standardized localization and isolation of the wide range of mouse adipose depots. Previously published methods are focused primarily on one or two depots and lack the details necessary for uniform identification and excision by different inve.......

Materials

Name	Company	Catalog Number	Comments
10% neutral buffered formalin	Fisher Scientific	22-110-869
24-well plates, untreated	Sigma-Aldrich	CLS3738
70% ethanol (dilute from 95%)	Fisher Scientific	04-355-226
Dissecting forceps with curved tips	VWR	89259-946
Dissecting pan	Carolina Biological Supply Company	629004
Dissecting scissors (sharp/blunt tip)	VWR	82027-588
Gauze sponges	Vitality Medical	2634	Curity 4 x 4 inch gauze sponge, 12 ply
Handi-Pins for dissection	Carolina Biological Supply Company	629132
Iris scissors (straight)	VWR	470018-890
Isoflurane	VetOne	501017
Scalpel	VWR	100499-578	Feather scalpel handle with blade, disposable