Modulation of 11 beta-hydroxysteroid dehydrogenase type 1 in mature human subcutaneous adipocytes by hypothalamic messengers.
Glucocorticoids are regulated at the prereceptor level by 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD), which interconverts inactive cortisone and active cortisol. In a previous study, we noted that patients with hypothalamic obesity had an increased ratio of cortisol/cortisone metabolites, suggesting enhanced 11 beta-HSD-1 activity. In this in vitro study, we tested the hypothesis that adipose 11 beta-HSD-1 is regulated by the hypothalamus via circulating hormones, sympathetic nervous system innervation, and/or cytokines. Preadipocytes were retrieved from sc fat from healthy nonobese individuals and differentiated in vitro to mature adipocytes. Cells were incubated with several potential effectors, and the activity of 11 beta-HSD-1 was assayed by measuring conversion of added 500 nM cortisone to cortisol. Expression of 11 beta-HSD-1 mRNA was determined by real-time PCR, whereas lipolytic effects were determined by measuring glycerol concentration in the culture medium. CRH down-regulated 11 beta-HSD-1 activity with maximal effect at 10(-9)M (65 +/- 10% of control; P < 0.001) and caused a reduction in lipolysis. Likewise, ACTH down-regulated 11 beta-HSD-1 activity with maximal effect at 10(-9) M (65 +/- 20%; P < 0.05) and reduced medium glycerol. Neither CRH nor ACTH affected 11 beta-HSD-1 mRNA expression. TNF alpha up-regulated 11 beta-HSD-1 activity maximally at 0.6 x 10(-9) M (140 +/- 20%; P < 0.001); the same cytokine increased 11 beta-HSD-1 mRNA levels to 3-fold of control (P < 0.05) and increased medium glycerol levels to 165 +/- 14% of control (P < 0.01). IL-1 beta also up-regulated 11 beta-HSD-1 activity maximally at 0.6 x 10(-9) M (160 +/- 33%; P < 0.001) and caused an increase in glycerol levels (159 +/- 11% of control; P < 0.001). Of the adrenergic agonists, salbutamol up-regulated 11 beta-HSD-1 activity maximally at 10(-7) M (162 +/- 46%; P < 0.02), and clonidine down-regulated it at 10(-7) M (82 +/- 15%; P < 0.005). We conclude that possible distinct hypothalamic mediators regulating adipose tissue 11 beta-HSD-1 might include down-regulation of 11 beta-HSD-1 activity by CRH, ACTH, and alpha 2 sympathetic stimulation, and up-regulation of the enzyme by beta 2 sympathetic stimulation and by the cytokines TNFalpha and IL-1 beta.
Friedberg
Mark
M
Pediatric and Reproductive Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
Zoumakis
Emmanouil
E
Hiroi
Naoki
N
Bader
Tarif
T
Chrousos
George P
GP
Hochberg
Ze'ev
Z
D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1; D017667:Adipocytes / Q000201:enzymology*; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000328:Adult; D000420:Albuterol / Q000494:pharmacology; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology; D005260:Female; D006801:Humans; D006913:Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D007031:Hypothalamus / Q000502:physiology*; D007375:Interleukin-1 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D040521:Subcutaneous Tissue / Q000201:enzymology*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
D000318:Adrenergic beta-Agonists; D007375:Interleukin-1; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D000324:Adrenocorticotropic Hormone; D003346:Corticotropin-Releasing Hormone; D006913:Hydroxysteroid Dehydrogenases; D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1; C468386:HSD11B1 protein, human; D000420:Albuterol