Begin by placing a seven to eight week old euthanized male mouse on a clean bench surface. Cut the abdominal skin of the mouse with a pair of scissors towards the lower abdomen. Excise the adipose tissue from the inner thighs.
Place the excised tissue into tube C on ice containing 2.5 milliliters of an enzyme mixture of enzymes D, R, A and 2.35 milliliters of DMEM/F12 without FBS or antibiotics. Using scissors, cut the adipose tissue into approximately two square millimeter sized pieces. Tightly close the cap of tube C and invert the tube.
Attach the tube to the sleeve of a tissue dissociator and digest the samples at 37 degrees Celsius for 40 minutes. Next, prewarm DMEM/F12 media containing FBS and antibiotics to 37 degrees Celsius. After incubation, remove tube C from the tissue dissociator and stop digestion by adding five milliliters of DMEM/F12 with FBS and antibiotics.
Gently pipette four times. Centrifuge the suspension at 700 g for 10 minutes at 20 degrees Celsius. Without disturbing the cell palette, carefully aspirate the supernatant.
Resuspend the pellet in 10 milliliters of DMEM/F12 containing FBS and antibiotics, and gently pipette five times. Filter the cell suspension through a 70 micron diameter cell strainer placed on a 50 milliliter tube. Centrifuge the filtrate at 250 g for five minutes.
Resuspend the pellet in 10 milliliters of PBS. Before plating, centrifuge the cell suspension at 500 g for five minutes. Discard the supernatant.
Resuspend the pellet in 10 milliliters of DMEM/F12 containing FBS and antibiotics. Mix by pipetting the suspension gently, 10 times. Plate 10 milliliters of the suspension on a 10 centimeter collagen coated dish.
Place the dish in a cell culture incubator. Aspirate the medium and wash the cells three times with three milliliters of PBS per wash. Add 10 milliliters of DMEM/F12 containing FBS and antibiotics and incubate.
Oil Red O staining showed lipid laden adipocytes seven days after inducing adipocyte differentiation. The degree of full differentiation was confirmed by mRNA expression analysis of adipogenesis regulators. Rosiglitazone induced a dose dependent effect on the expression levels of brown fat specific genes such as Ucp1 and Ppargc1a.
However, for Fabp4, the effect saturated at 0.1 micromole rosiglitazone concentration. Differentiated adipocytes can be used for various functional and mechanistic analyses such as oxygen consumption rate analysis and chromatin immunoprecipitation.
