European Journal of Nutrition

, Volume 52, Issue 6, pp 1587–1595

Six-transmembrane epithelial antigen of prostate 4 and neutrophil gelatinase-associated lipocalin expression in visceral adipose tissue is related to iron status and inflammation in human obesity

Authors

    • Metabolic Research LaboratoryClínica Universidad de Navarra
    • CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III
  • Javier Gómez-Ambrosi
    • Metabolic Research LaboratoryClínica Universidad de Navarra
    • CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III
  • Amaia Rodríguez
    • Metabolic Research LaboratoryClínica Universidad de Navarra
    • CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III
  • Beatriz Ramírez
    • Metabolic Research LaboratoryClínica Universidad de Navarra
    • CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III
  • Fernando Rotellar
    • Department of SurgeryClínica Universidad de Navarra
    • CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III
  • Victor Valentí
    • Department of SurgeryClínica Universidad de Navarra
    • CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III
  • Camilo Silva
    • Department of Endocrinology and NutritionClínica Universidad de Navarra
    • CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III
  • María J. Gil
    • Department of BiochemistryClínica Universidad de Navarra
    • CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III
  • Javier Salvador
    • Department of Endocrinology and NutritionClínica Universidad de Navarra
    • CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III
  • Gema Frühbeck
    • Metabolic Research LaboratoryClínica Universidad de Navarra
    • Department of Endocrinology and NutritionClínica Universidad de Navarra
    • CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III
Original Contribution

DOI: 10.1007/s00394-012-0464-8

Cite this article as:
Catalán, V., Gómez-Ambrosi, J., Rodríguez, A. et al. Eur J Nutr (2013) 52: 1587. doi:10.1007/s00394-012-0464-8

Abstract

Purpose

Six-transmembrane epithelial antigen of prostate (STEAP)-4 and neutrophil gelatinase-associated lipocalin (NGAL) are novel adipokines related to iron homeostasis with potential roles in insulin resistance and inflammation. The aim of the present work was to evaluate the effect of obesity and iron status on gene expression levels of STEAP-4 and NGAL in visceral adipose tissue (VAT) and its implication in inflammation.

Methods

VAT biopsies obtained from 53 subjects were used in the study. Real-time PCR and Western-blot were performed to quantify the levels of STEAP4 and NGAL in VAT as well as the association with other genes implicated in inflammatory pathways. Circulating ferritin and free iron concentrations were also determined.

Results

Obese patients exhibited significantly increased STEAP4 and NGAL mRNA expression levels (P < 0.001) compared to lean subjects. Protein expression levels of NGAL (P < 0.05) and STEAP4 were also higher in the visceral fat depot of obese patients, although protein levels of STEAP4 did not reach statistical significance. A negative correlation (P < 0.05) between free iron concentrations and gene expression levels of both STEAP4 and NGAL was found, while circulating ferritin concentrations were positively correlated (P < 0.05) with NGAL mRNA after body fat (BF) adjustment. Furthermore, a significant positive association between STEAP4 and NGAL gene expression levels with inflammatory markers was also detected (P < 0.01).

Conclusion

These findings represent the first observation that STEAP4 and NGAL mRNA and protein levels in human VAT are related to iron status. Moreover, STEAP4 and NGAL are associated with pro-inflammatory markers suggesting their potential involvement in the low-grade chronic inflammation accompanying obesity.

Keywords

Iron homeostasis Ferritin Obesity Inflammation STAMP2 Lipocalin-2

Copyright information

© Springer-Verlag Berlin Heidelberg 2012