Gene expression of different adipose tissues of severely obese women with or without a dysmetabolic profile

Abstract

Despite well-established variations in the health risks posed by visceral vs. subcutaneous abdominal (SCABD) fat depots, surprisingly little is known on the differences within a given adipose tissue (AT) among severely obese patients displaying varying metabolic dysfunction. We thus compared, by quantitative PCR, the expression profile of a number of genes in the SCABD, omental (OME), and mesenteric (MES) depots of severely obese women with (DYS; n = 25) or without (NDYS; n = 23) a dysmetabolic profile. Fasting insulinemia and HOmeostasis Model Assessment-insulin resistance (HOMA-IR) were higher and plasma adiponectin level lower in DYS women (p < 0.05). Among enzymes involved in fatty acid metabolism and local cortisol production, phosphodiesterase-3B expression was lower in SCABD and MES fat, while 11β-hydroxysteroid dehydrogenase type 1 mRNA levels were higher in visceral depots of DYS women (p < 0.05). Regarding vascular homeostasis and inflammation, plasminogen activator inhibitor-1 and interleukin-6 mRNA levels were higher in OME fat, while adiponectin expression was lower in SCABD and OME ATs of DYS women (p < 0.05). Finally, HOMA-IR was positively associated with SCABD AT IL6 mRNA, only in DYS women (r = 0.47; p < 0.05). In conclusion, although metabolic and secretory characteristics of all depots vary with subjects' metabolic profile, we find little evidence for a protective role of SCABD AT and no evidence for a further deleterious role of MES fat in DYS vs. NDYS severely obese women. Regional variation in the overall gene expression revealed that OME and MES fat were more closely related to each other in DYS women, while SCABD and MES depots showed greater resemblance in NDYS women.

Keywords: Adipogenesis; Adipokines; Adipose tissue; Fatty acid metabolism; Inflammation; Insulin resistance.