Role of CYP27A1 in progesterone metabolism in vitro and in vivo.

In the kidney, progesterone is inactivated to 20alpha-dihydro-progesterone (20alpha-DH-progesterone) to protect the mineralocorticoid receptor from progesterone excess. In an attempt to clone the enzyme with 20alpha-hydroxysteroid activity using expression cloning in CHOP cells and a human kidney expression library, serendipitously cDNA encoding CYP27A1 was isolated. Overexpression of CYP27A1 in CHOP cells decreased progesterone conversion to 20alpha-DH-progesterone in a dose-dependent manner, an effect enhanced by cotransfection with adrenodoxin and adrenodoxin reductase.

Identification of the 11 beta-hydroxysteroid dehydrogenase type 1 mRNA and protein in human mononuclear leukocytes.

The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) catalyzes the interconversion between inactive 11-ketoglucocorticoids and their active 11beta-hydroxy derivatives, such as cortisol and corticosterone. We have investigated the expression of 11beta-HSD1 in freshly isolated human peripheral mononuclear leukocytes (MNL). The presence of 11beta-HSD1 mRNA was demonstrated in total RNA by RT-PCR using specific primers designed on the 4th and 5th exons of the human 11beta-HSD1 gene.

Enhancing apolipoprotein A-I-dependent cholesterol efflux elevates cholesterol export from macrophages in vivo.

Eight proteins potentially involved in cholesterol efflux [ABCA1, ABCG1, CYP27A1, phospholipid transfer protein (PLTP), scavenger receptor type BI (SR-BI), caveolin-1, cholesteryl ester transfer protein, and apolipoprotein A-I (apoA-I)] were overexpressed alone or in combination in RAW 264.7 macrophages. When apoA-I was used as an acceptor, overexpression of the combination of ABCA1, CYP27A1, PLTP, and SR-BI (Combination I) enhanced the efflux by 4.

Hexose-6-phosphate dehydrogenase and 11beta-hydroxysteroid dehydrogenase-1 tissue distribution in the rat.

Intracellular concentrations of the glucocorticoids cortisol and corticosterone are modulated by the enzymes 11beta-hydroxysteroid dehydrogenase (11beta-HSD) 1 and 2. 11beta-HSD1 is a reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent microsomal reductase that converts the inactive glucocorticoids cortisone and 11-dehydrocorticosterone to their active forms, cortisol and corticosterone. Hexose-6-phosphate dehydrogenase (H6PDH) is an enzyme that generates NADPH from oxidized NADP (NADP(+)) within the endoplasmic reticulum.

Altered activity of 11beta-hydroxysteroid dehydrogenase types 1 and 2 in skeletal muscle confers metabolic protection in subjects with type 2 diabetes.

Context: There is little information regarding the regulation of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) enzymes in skeletal muscle in the setting of type 2 diabetes.

Objective: Our objective was to investigate whether there is differential mRNA expression and enzyme activity of 11beta-HSD1 and 11beta-HSD2 in the skeletal muscle of diabetic subjects compared with controls at baseline and in response to dexamethasone.

Design: Participants underwent muscle biopsy of vastus lateralis at baseline and after dexamethasone.