A nontargeted proteomic approach to the study of visceral and subcutaneous adipose tissue in human obesity.

Subcutaneous (SAT) and visceral adipose tissue (VAT) differ in biochemical and metabolic properties, especially when obesity is present. We submitted paired SAT and VAT samples from six morbidly obese patients and six non-obese persons to two-dimensional differential gel electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight mass spectrometry. Compared with non-obese subjects, obese patients presented with increased carboxylesterase-1, zinc finger protein 324A, annexin A5, ubiquitin carboxyl-terminal hydrolase, α-crystallin B chain, osteoglycin, retinal dehydrogenase-1 and 14-3-3 protein γ, and decreased transferrin, complement C3, fibrinogen γ chain, albumin, α1-antitrypsin and peroxiredoxin-6, irrespective of the adipose tissue depot studied. SAT and VAT differed in protein species of fibrinogen and osteoglycin, whereas adipose tissue depot and obesity interacted on the protein abundance of actin, α-actinin 1, one protein species of carboxylesterase-1, retinal dehydrogenase-1 and 14-3-3 protein γ. Our nontargeted proteomic approach identified novel protein species that may be involved in the development of obesity in humans.