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297
A novel selective 11b-hydroxysteroid dehydrogenase type 1 inhibitor
prevents human adipogenesis
I J Bujalska, L L Gathercole, J W Tomlinson, C Darimont1, J Ermolieff 2, A N Fanjul2, P A Rejto2
and P M Stewart
Division of Medical Sciences, The Medical School, Institute of Biomedical Research, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
1Nestle Research Center, PO Box 44, Vers-Chez-Les-Blanc, 1000 Lausanne 26, Switzerland
2Pfizer Global Research and Development, La Jolla Laboratories, 10646 Science Center Drive, San Diego, California 92121, USA
(Correspondence should be addressed to P M Stewart; Email: [email protected])
Abstract
Glucocorticoid excess increases fat mass, preferentially within
omental depots; yet circulating cortisol concentrations are
normal in most patients with metabolic syndrome (MS). At a
pre-receptor level, 11b-hydroxysteroid dehydrogenase type 1
(11b-HSD1) activates cortisol from cortisone locally within
adipose tissue, and inhibition of 11b-HSD1 in liver and
adipose tissue has been proposed as a novel therapy to treat
MS by reducing hepatic glucose output and adiposity. Using a
transformed human subcutaneous preadipocyte cell line
(Chub-S7) and human primary preadipocytes, we have
defined the role of glucocorticoids and 11b-HSD1 in
regulating adipose tissue differentiation. Human cells were
differentiated with 1.0 mM cortisol (F), or cortisone (E) with
or without 100 nM of a highly selective 11b-HSD1 inhibitor
PF-877423. 11b-HSD1 mRNA expression increased across
adipocyte differentiation (P!0.001, nZ4), which was
paralleled by an increase in 11b-HSD1 oxo-reductase activity
(from nil on day 0 to 5.9G1.9 pmol/mg per h on day 16,
P!0.01, nZ7). Cortisone enhanced adipocyte differen-
tiation; fatty acid-binding protein 4 expression increased 312-
fold (P!0.001) and glycerol-3-phosphate dehydrogenase
47-fold (P!0.001) versus controls. This was abolished by
co-incubation with PF-877423. In addition, cellular lipid
content decreased significantly. These findings were
confirmed in the primary cultures of human subcutaneous
preadipocytes. The increase in 11b-HSD1 mRNA expression
and activity is essential for the induction of human
adipogenesis. Blocking adipogenesis with a novel and specific
11b-HSD1 inhibitor may represent a novel approach to treat
obesity in patients with MS.
Journal of Endocrinology (2008) 197, 297-307
Introduction
Glucocorticoid excess (Cushing’s syndrome) causes visceral
obesity, insulin resistance, diabetes mellitus, dyslipidaemia,
hypertension and premature vascular mortality; as such it
represents an excellent paradigm for patients with the metabolic
syndrome (MS). However, Cushing’s syndrome is rare and
circulating glucocorticoid levels are usually normal or even
slightly reduced in obese patients (Fraser et al. 1999). Ata cellular
level, glucocorticoids within human adipose tissue, specifically
in omental depots, can be generated from inactive circulating
cortisone (in humans) or 11-dehydrocorticosterone (in rodents)
through the oxo-reductase activity of 11b-hydroxysteroid
dehydrogenase type 1 (11b-HSD1; Bujalska et al. 1997b).
Transgenic mice with adipose tissue-targeted 11b-HSD1
overexpression develop visceral obesity, insulin resistance,
hyperlipidaemia and hypertension without altering circulating
glucocorticoids (Masuzaki et al. 2001, 2003), while mice with
11b-HSD1 overexpression in the liver develop MS without
obesity (Paterson et al. 2004). Conversely, global deletion of
11b-HSD1 caused reduced visceral fat accumulation and
improved insulin sensitivity on a high fat diet (Kotelevtsev
et al. 1997, Morton et al. 2004). At a molecular level,
glucocorticoids exert potent effects upon adipose tissue; in
mature rat adipocytes, dexamethasone decreases glucose uptake
and oxidation (Olefsky 1975, De et al. 1981). Glucocorticoids
increase lipolysis by up-regulating the expression of the rate-
limiting enzyme hormone-sensitive lipase (Slavin et al. 1994), as
well as lipogenic enzyme, lipoprotein lipase (Yang et al. 1993). In
preadipocytes, glucocorticoids are essential for terminal
adipogenesis (Hauner et al. 1987) and limit cell proliferation
(Tomlinson et al. 2002). The process of cellular differentiation is a
highly synchronized cascade of regulated differentiation-
dependent gene expression. Genes such as retinoblastoma
proteins that regulate the cell cycle (Richon et al. 1997)
are followed by adipogenic transcription factors, such as
peroxisome proliferator-activated receptor g (PPARg) and
CCAAT enhancer-binding protein (Rosen & MacDougald
2006). Mature adipocytes express late differentiation genes
involved in lipid metabolism and lipid transport including
Journal of Endocrinology (2008) 197, 297-307 DOI: 10.1677/JOE-08-0050
0022-0795/08/0197-297 q 2008 Society for Endocrinology Printed in Great Britain Online version via http://www.endocrinology-journals.org
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