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Characterisation of 11beta-hydroxysteroid dehydrogenase 1 in human orbital adipose tissue: a comparison with subcutaneous and omental fat.

Bujalska IJ, Durrani OM, Abbott J, Onyimba CU, Khosla P, Moosavi AH, Reuser TT, Stewart PM, Tomlinson JW, Walker EA, Rauz S - J. Endocrinol. (2007)

Bottom Line: Using an automated histological characterisation technique, OF adipocytes were found to be significantly smaller (parameters: area, maximum diameter and perimeter) than OM and SC adipocytes (P<0 x 001).Primary cultures of OF preadipocytes demonstrated predominant 11beta-HSD1 oxo-reductase activity with minimal dehydrogenase activity.Orbital adipocytes are smaller, less differentiated, and express low levels of 11beta-HSD1 but abundant GRalpha compared with SC and OM.

View Article: PubMed Central - PubMed

Affiliation: Department of Endocrinology, Division of Medical Sciences, University of Birmingham, Birmingham, UK.

ABSTRACT
Glucocorticoids (GCs) have a profound effect on adipose biology increasing tissue mass causing central obesity. The pre-receptor regulation of GCs by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) that activates cortisol from cortisone has been postulated as a fundamental mechanism underlying the metabolic syndrome mediating adipocyte hyperplasia and hypertrophy in the omental (OM) depot. Orbital adipose tissue (OF) is the site of intense inflammation and tissue remodelling in several orbital inflammatory disease states. In this study, we describe features of the GC metabolic pathways in normal human OF depot and compare it with subcutaneous (SC) and OM depots. Using an automated histological characterisation technique, OF adipocytes were found to be significantly smaller (parameters: area, maximum diameter and perimeter) than OM and SC adipocytes (P<0 x 001). Although immunohistochemical analyses demonstrated resident CD68+ cells in all three whole tissue adipose depots, OF CD68 mRNA and protein expression exceeded that of OM and SC (mRNA, P<0 x 05; protein, P<0 x 001). In addition, there was higher expression of glucocorticoid receptor (GR)alpha mRNA in the OF whole tissue depot (P<0 x 05). Conversely, 11beta-HSD1 mRNA together with the markers of late adipocyte differentiation (FABP4 and G3PDH) were significantly lower in OF. Primary cultures of OF preadipocytes demonstrated predominant 11beta-HSD1 oxo-reductase activity with minimal dehydrogenase activity. Orbital adipocytes are smaller, less differentiated, and express low levels of 11beta-HSD1 but abundant GRalpha compared with SC and OM. OF harbours a large CD68+ population. These characteristics define an orbital microenvironment that has the potential to respond to sight-threatening orbital inflammatory disease.

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Immunohistochemistry using human anti-CD68 for macrophages confirmed a large resident population in the OF depot when compared with SC and OM (A). Results are expressed as median and full range of counts. These findings were endorsed by real-time RT-PCR CD68 mRNA expression in each of the adipose depots (B). Results are expressed as fold-change when compared with orbital fat; dCt are shown in table below (*P<0·05; †P<0·001). Representative sections of OF, SC and OM adipose depots with identified macrophages (Mø) are shown in C, D and E respectively.
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fig2: Immunohistochemistry using human anti-CD68 for macrophages confirmed a large resident population in the OF depot when compared with SC and OM (A). Results are expressed as median and full range of counts. These findings were endorsed by real-time RT-PCR CD68 mRNA expression in each of the adipose depots (B). Results are expressed as fold-change when compared with orbital fat; dCt are shown in table below (*P<0·05; †P<0·001). Representative sections of OF, SC and OM adipose depots with identified macrophages (Mø) are shown in C, D and E respectively.

Mentions: The largest resident CD68+ population was found in the OF depot (median 7·6 (range 3·8–19·6) cell counts/unit area) when compared with SC (median 0·7 (range 0·1–6·5) cell counts/unit area, P<0·001) and OM (median 2·9 (range 0·6–5·2) cell counts/unit area, P<0·001; Fig. 2A). These findings were endorsed by a similar trend in CD68 mRNA expression for each depot (Fig. 2B (OF=1; SC=0·21; P<0·05; OM 0·38<0·05 (fold-change when compared with OF))). Representative photomicrographs showing CD68+ macrophages in each whole adipose tissue depot (OF, SC and OM) are shown in Fig. 2C–E.


Characterisation of 11beta-hydroxysteroid dehydrogenase 1 in human orbital adipose tissue: a comparison with subcutaneous and omental fat.

Bujalska IJ, Durrani OM, Abbott J, Onyimba CU, Khosla P, Moosavi AH, Reuser TT, Stewart PM, Tomlinson JW, Walker EA, Rauz S - J. Endocrinol. (2007)

Immunohistochemistry using human anti-CD68 for macrophages confirmed a large resident population in the OF depot when compared with SC and OM (A). Results are expressed as median and full range of counts. These findings were endorsed by real-time RT-PCR CD68 mRNA expression in each of the adipose depots (B). Results are expressed as fold-change when compared with orbital fat; dCt are shown in table below (*P<0·05; †P<0·001). Representative sections of OF, SC and OM adipose depots with identified macrophages (Mø) are shown in C, D and E respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1994563&req=5

fig2: Immunohistochemistry using human anti-CD68 for macrophages confirmed a large resident population in the OF depot when compared with SC and OM (A). Results are expressed as median and full range of counts. These findings were endorsed by real-time RT-PCR CD68 mRNA expression in each of the adipose depots (B). Results are expressed as fold-change when compared with orbital fat; dCt are shown in table below (*P<0·05; †P<0·001). Representative sections of OF, SC and OM adipose depots with identified macrophages (Mø) are shown in C, D and E respectively.
Mentions: The largest resident CD68+ population was found in the OF depot (median 7·6 (range 3·8–19·6) cell counts/unit area) when compared with SC (median 0·7 (range 0·1–6·5) cell counts/unit area, P<0·001) and OM (median 2·9 (range 0·6–5·2) cell counts/unit area, P<0·001; Fig. 2A). These findings were endorsed by a similar trend in CD68 mRNA expression for each depot (Fig. 2B (OF=1; SC=0·21; P<0·05; OM 0·38<0·05 (fold-change when compared with OF))). Representative photomicrographs showing CD68+ macrophages in each whole adipose tissue depot (OF, SC and OM) are shown in Fig. 2C–E.

Bottom Line: Using an automated histological characterisation technique, OF adipocytes were found to be significantly smaller (parameters: area, maximum diameter and perimeter) than OM and SC adipocytes (P<0 x 001).Primary cultures of OF preadipocytes demonstrated predominant 11beta-HSD1 oxo-reductase activity with minimal dehydrogenase activity.Orbital adipocytes are smaller, less differentiated, and express low levels of 11beta-HSD1 but abundant GRalpha compared with SC and OM.

View Article: PubMed Central - PubMed

Affiliation: Department of Endocrinology, Division of Medical Sciences, University of Birmingham, Birmingham, UK.

ABSTRACT
Glucocorticoids (GCs) have a profound effect on adipose biology increasing tissue mass causing central obesity. The pre-receptor regulation of GCs by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) that activates cortisol from cortisone has been postulated as a fundamental mechanism underlying the metabolic syndrome mediating adipocyte hyperplasia and hypertrophy in the omental (OM) depot. Orbital adipose tissue (OF) is the site of intense inflammation and tissue remodelling in several orbital inflammatory disease states. In this study, we describe features of the GC metabolic pathways in normal human OF depot and compare it with subcutaneous (SC) and OM depots. Using an automated histological characterisation technique, OF adipocytes were found to be significantly smaller (parameters: area, maximum diameter and perimeter) than OM and SC adipocytes (P<0 x 001). Although immunohistochemical analyses demonstrated resident CD68+ cells in all three whole tissue adipose depots, OF CD68 mRNA and protein expression exceeded that of OM and SC (mRNA, P<0 x 05; protein, P<0 x 001). In addition, there was higher expression of glucocorticoid receptor (GR)alpha mRNA in the OF whole tissue depot (P<0 x 05). Conversely, 11beta-HSD1 mRNA together with the markers of late adipocyte differentiation (FABP4 and G3PDH) were significantly lower in OF. Primary cultures of OF preadipocytes demonstrated predominant 11beta-HSD1 oxo-reductase activity with minimal dehydrogenase activity. Orbital adipocytes are smaller, less differentiated, and express low levels of 11beta-HSD1 but abundant GRalpha compared with SC and OM. OF harbours a large CD68+ population. These characteristics define an orbital microenvironment that has the potential to respond to sight-threatening orbital inflammatory disease.

Show MeSH
Related in: MedlinePlus