CYB5A
Cytochrome b5 (Microsomal cytochrome b5 type A) (MCB5) [CYB5]
Publications[править]
The ovaries and adrenals are sources of androgens in women. Although dehydroepiandrosterone (DHEA), DHEA sulfate (DHEAS), and testosterone (T) all decline with age, these C19 steroids correlate poorly with parameters of androgen action in postmenopausal women. To comprehensively compare the androgen profiles of pre- and postmenopausal women. We quantified 19 steroids-including DHEA; DHEAS; T; androstenedione (A4); and the following adrenal-specific 11-oxygenated C19 steroids (11oxyandrogens): 11β-hydroxytestosterone (11OHT), 11-ketotestosterone (11KT), 11β-hydroxyandrostenedione (11OHA4), and 11-ketoandrostenedione (11KA4)-using liquid chromatography-tandem mass spectrometry in morning serum obtained from 100 premenopausal (age 20 to 40 years) and 100 postmenopausal (age ≥ 60 years) women. Double immunofluorescence of 3β-hydroxysteroid dehydrogenase type 2 (HSD3B2) with cytochrome b5 (CYB5A) or sulfotransferase 2A1 (SULT2A1) was performed in normal adrenal glands obtained from eight premenopausal and eight postmenopausal women. DHEA, DHEAS, A4, and T were significantly higher in pre- than in postmenopausal women (2.9, 2.8, 2.9, and 1.6-fold, respectively; P < 0.0001). In contrast, the 11-oxyandrogens did not decrease with aging, and the 11OHT/T and 11OHA4/A4 ratios showed strong positive correlations with age (r = 0.5 and 0.8, respectively; P < 0.0001). Double immunofluorescence analysis showed that with the involution of the zona reticularis in the old adrenals, the sharp zonal segregation of HSD3B2 and CYB5A becomes less distinct, and areas of HSD3B2 and CYB5A overlap are observed. Unlike DHEA, DHEAS, A4, and T, the 11oxyandrogens do not decline in aging women. Structural changes within the adrenal cortex might explain the evolution of androgen profiles in aging women.
MeSH Terms
- Adrenal Cortex
- Adult
- Aged
- Aging
- Androstenes
- Cytochromes b5
- Female
- Humans
- Middle Aged
- Oxygen
- Postmenopause
- Progesterone Reductase
- Sulfotransferases
- Young Adult
Androstenedione is a common precursor of sex steroids produced and secreted in the human adrenal gland and produced by 3β-hydroxysteroid dehydrogenase (3βHSD), 17β-hydroxylase/17,20-lyase (CYP17) and cytochrome b5 (CYB5A). 3βHSD is expressed in the zona glomerulosa (ZG) and fasciculata (ZF), CYP17 in the ZF and zona reticularis (ZR) and CYB5A in the ZR, respectively. We previously demonstrated the presence of cortical parenchymal cells co-expressing 3βHSD and CYB5A with hybrid features of both ZF and ZR in human adrenal cortex and hypothesized that these cells may play an important role in androstenedione production in human adrenal gland. Age-related morphologic development of these hybrid cells has, however, not been studied. Therefore, in this study, 48 human adrenal specimens from various age groups were retrieved. Double-immunohistochemical analyses were used in order to study the correlation between this hybrid cell type and age. In both male and female adrenal cortex, the means of total adrenocortical area, the area positive for CYB5A and its ratio reached highest peak in the 21-40-year-old (y.o.) group. The greatest overlap between 3βHSD and CYB5A in both total and relative area was present in the 13-20 y.o. group. For all the markers mentioned above, statistically significant differences were detected among the different age groups examined (p < 0.05). These findings indicated that both area and ratio of 3βHSD and CYB5A double positive cells, which could represent the hybrid cells of ZF and ZR, are correlated with human adrenal development and could subsequently influence age-related serum androstenedione levels.
MeSH Terms
- 17-Hydroxysteroid Dehydrogenases
- Adolescent
- Adrenal Cortex
- Adult
- Aged
- Aged, 80 and over
- Aging
- Child
- Child, Preschool
- Cytochromes b5
- Female
- Humans
- Male
- Middle Aged
- Young Adult
Keywords
- 3β-Hydroxysteroid dehydrogenase
- cytochrome b5
- development
- double-immunohistochemistry
- human adrenal gland