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Ex vivo and in vivo regulation of lipocalin-2, a novel adipokine, by insulin

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Tan, Bee K., Adya, Raghu, Shan, Xiaoye, Syed, Farhatullah, Levandowski, Krzysztof C., O'Hare, J. Paul and Randeva, Harpal S.. (2009) Ex vivo and in vivo regulation of lipocalin-2, a novel adipokine, by insulin. Diabetes Care, Vol.32 (No.1). pp. 129-131. ISSN 0149-5992

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Official URL: http://dx.doi.org/10.2337/dc08-1236

Abstract

OBJECTIVE - Lipocalin-2, a novel adipokine, has been shown to be elevated in obese, insulin-resistant, and diabetic Subjects. We therefore sought to study the ex vivo and in vivo effects of insulin on lipocalin-2 levels in humans.

RESEARCH DESIGN AND METHODS - We investigated the in vivo effects of insulin (hyperinsulinemia) on circulating lipocalin-2 levels by enzyme-linked immunosorbent assay via a prolonged insulin-glucose infusion. The ex vivo effect of insulin on adipose tissue lipocalin-2 protein production and secretion into conditioned media was assessed by Western blotting and enzyme-linked immunosorbent assay, respectively.

RESULTS - Hyperinsulinemic induction in human subjects significantly increased circulating lipocalin-2 levels (P < 0.01). Also, in omental adipose tissue explants, insulin caused a significant dose-dependent increase in lipocalin-2 protein production and secretion into conditioned media (P < 0.05, P < 0.01, respectively); these effects were negated by both phosphatidylinositol 3-kinase and mitogen-activated protein kinase kinase inhibitions.

CONCLUSIONS - Lipocalin-2 is upregulated by insulin via phosphatidylinositol 3-kinasc and mitogen-activated protein kinase signaling pathways.

Item Type:

Journal Article

Subjects:

Q Science > QP Physiology
R Medicine > RC Internal medicine

Divisions:

Faculty of Medicine > Warwick Medical School > Translational & Systems Medicine > Metabolic and Vascular Health
Faculty of Medicine > Warwick Medical School

Library of Congress Subject Headings (LCSH):

Adipose tissues, Obesity -- Pathophysiology, Insulin resistance

Journal or Publication Title:

Diabetes Care

Publisher:

American Diabetes Association

ISSN:

0149-5992

Official Date:

January 2009

Dates:

Date	Event
January 2009	Published

Volume:

Vol.32

Number:

No.1

Number of Pages:

Page Range:

pp. 129-131

Identification Number:

10.2337/dc08-1236

Status:

Peer Reviewed

Publication Status:

Published

Access rights to Published version:

Restricted or Subscription Access

Funder:

General Charities of the City of Coventry (GCCC)

References:

1. Eckel RH, Grundy SM, Zimmet PZ: The
metabolic syndrome. Lancet 365:1415–
1428, 2005
2. Kershaw EE, Flier JS: Adipose tissue as an
endocrine organ. J Clin Endocrinol Metab
89:2548–2556, 2004
3. Yan QW, Yang Q, Mody N, Graham TE,
Hsu CH, Xu Z, Houstis NE, Kahn BB,
Rosen ED: The adipokine lipocalin 2 is
regulated by obesity and promotes insulin
resistance. Diabetes 56:2533–2540, 2007
4. Wang Y, Lam KS, Kraegen EW, Sweeney
G, Zhang J, Tso AW, Chow WS, Wat NM,
Xu JY, Hoo RL, Xu A: Lipocalin-2 is an
inflammatory marker closely associated
with obesity, insulin resistance, and hyperglycemia
in humans. Clin Chem 53:
34–41, 2007
5. Lewandowski K, Randeva HS, O’Callaghan
CJ, Horn R, Medley GF, Hillhouse EW, Brabant
G, O’Hare P: Effects of insulin and glucocorticoids
on the leptin system are
mediated through free leptin. Clin Endocrinol
(Oxf) 54:533–539, 2001
6. Tan BK, Chen J, Lehnert H, Kennedy R,
Randeva HS: Raised serum, adipocyte and
adipose tissue Retinol-Binding Protein 4
(RBP4) in overweight women with polycystic
ovary syndrome: effects of gonadal
and adrenal steroids. J Clin Endocrinol
Metab 92:2764–2772, 2007