title: Upregulation of lipocalin 2 in adipose tissues of severely obese women: positive relationship with proinflammatory cytokines.
abstract: Because the role of lipocalin 2 (LCN2) in morbid obesity is still not well defined, the aim of this study was to evaluate the circulating levels and the expression of LCN2 in visceral (VAT) and subcutaneous adipose tissue (SAT) in severely obese (SO) women. We also analyzed its relationship with inflammatory cytokines in the same subjects. The study comprised 90 white women, 39 of whom were lean controls (BMI ≤25 kg/m(2)) and 51 SO (BMI ≥40 kg/m(2)). Both circulating and adipose tissue levels of LCN2 were quantified by enzyme-linked immunosorbent assays. LCN2 mRNA levels from VAT and SAT were assessed by real-time reverse transcriptase-PCR (n = 60). LCN2 serum levels were significantly higher in the SO women than in the lean controls (P = 0.042), and were found to be strongly correlated with tumor necrosis factor receptor I (TNFR1) circulating levels. In the SO cohort, LCN2 serum levels were also associated with higher BMI values, but not with the homeostasis model assessments of insulin resistance (HOMA2-IR). LCN2 mRNA expression was markedly higher in SO women than in lean women in both VAT (P = 0.043) and SAT (P = 0.031). In SAT, LCN2 was negatively correlated with adiponectin and adiponectin receptor-2 expression, and positively with interleukin-6 (IL-6) expression. A strong positive correlation was also found between LCN2 expression and the mean diameter of adipocytes in VAT. Our results revealed that the circulating level of LCN2 is associated with obesity and BMI. LCN2 mRNA is over-expressed in adipose tissue from SO subjects. Finally, the expression of LCN2 is strongly related to an expression profile of proinflammatory cytokines but not to insulin resistance in nondiabetic SO women.
authors: Servei Medicina Interna, Hospital Universitari Joan XXIII Tarragona, Tarragona, Spain.
authors: Teresa
authors: T
authors: Auguet
authors: Yunuen
authors: Y
authors: Quintero
authors: Ximena
authors: X
authors: Terra
authors: Salomé
authors: S
authors: Martínez
authors: Anna
authors: A
authors: Lucas
authors: Silvia
authors: S
authors: Pellitero
authors: Carmen
authors: C
authors: Aguilar
authors: Mercè
authors: M
authors: Hernández
authors: Daniel
authors: D
authors: del Castillo
authors: Cristobal
authors: C
authors: Richart
mesh_terms: D050153:Abdominal Fat / Q000378:metabolism*; D017667:Adipocytes / Q000502:physiology; D052242:Adiponectin / Q000378:metabolism; D000328:Adult; D015992:Body Mass Index; D016022:Case-Control Studies; D015331:Cohort Studies; D016207:Cytokines / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism*; D007333:Insulin Resistance; D015850:Interleukin-6 / Q000378:metabolism; D054834:Lipocalins / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D009767:Obesity, Morbid / Q000097:blood / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D054419:Receptors, Adiponectin / Q000378:metabolism; D047888:Receptors, Tumor Necrosis Factor, Type I / Q000097:blood; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
chemical_list: C475420:ADIPOR2 protein, human; D052242:Adiponectin; D016207:Cytokines; D018836:Inflammation Mediators; D015850:Interleukin-6; D054834:Lipocalins; D012333:RNA, Messenger; D054419:Receptors, Adiponectin; D047888:Receptors, Tumor Necrosis Factor, Type I