An assay to measure angiogenesis in human fat tissue.
BACKGROUND
Inhibition of angiogenesis reverses rodent obesity. A validated assay in human fat tissue is needed to study the role of angiogenesis in human obesity.


METHODS
Human fat tissue fragments from surgery were placed in 96-well plates, embedded in fibrin thrombin clot and overlaid with cell culture media containing 20% fetal bovine serum. After 15 days, the clots were examined by histology and electron microscopy. The effect of taxol, cobalt chloride and a heparin-steroid combination was tested in the fat tissue assay and compared to the validated human placental vein angiogenesis model (HPVAM).


RESULTS
Blood vessels initiated growth and elongated from the fat tissue fragments over 15 days. Presence of blood vessels was confirmed with histology and electron microscopy. Taxol at 10(-6) and 10(-7) M completely inhibited angiogenesis, while Taxol 10(-8) and 10(-9) M and the heparin-steroid partially inhibited angiogenesis. The response to taxol and heparin-steroid was similar to that of the HPVAM, a validated angiogenesis assay. Cobalt chloride, a stimulator of vascular endothelial growth factor (VEGF) stimulated angiogenesis initiation at 10(-9) M in fat tissue and the HPVAM, but at 10(-10) M blood vessel growth was stimulated only in the fat assay.


CONCLUSIONS
This angiogenesis assay based on human fat tissue uses three-dimensionally intact human tissue. The vessels are derived from quiescient vessels within the fat. These properties allow the angiogenic switch to be evaluated in an in vitro setting. The angiogenic response of fat tissue is not identical to placental tissue. This assay allows exploration of angiogenesis in fat tissue.
Greenway
Frank L
FL
Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA. greenwfl@pbrc.edu
Liu
Zhijun
Z
Yu
Ying
Y
Caruso
Mary K
MK
Roberts
Andrew T
AT
Lyons
John
J
Schwimer
Joshua E
JE
Gupta
Alok K
AK
Bellanger
Drake E
DE
Guillot
Thomas S
TS
Woltering
Eugene A
EA
D015119:Aminocaproic Acid; D043924:Angiogenesis Modulating Agents / Q000494:pharmacology; D001681:Biological Assay / Q000379:methods*; D005340:Fibrinogen; D006801:Humans; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000502:physiology*; D009767:Obesity, Morbid / Q000473:pathology; D010920:Placenta / Q000098:blood supply; D015203:Reproducibility of Results; D050507:Subcutaneous Fat, Abdominal / Q000098:blood supply* / Q000187:drug effects / Q000473:pathology; D013917:Thrombin; D046509:Tissue Culture Techniques
D043924:Angiogenesis Modulating Agents; D005340:Fibrinogen; D013917:Thrombin; D015119:Aminocaproic Acid