17β‐hydroxysteroid dehydrogenase type 2 activity, expression and cellular localization in abdominal adipose tissues from women. (31st October 2022)

• Record Type: Journal Article
• Authors: Fouad Mansour, Mohamed; Blanchette, Sophie; Pelletier, Mélissa; Poirier, Donald; Tchernof, André
• Is Part Of: Clinical endocrinology. Volume 98:Number 2(2023)
• Page Start: 229
• Page End: 237
• Publication Date: 2022-10-31
• Subjects: 17β‐HSD -- 17β‐HSD2 -- adipose tissue -- estradiol -- estrone; Endocrinology -- Periodicals; 616.4005
• DOI: 10.1111/cen.14838
• Languages: English
• ISSNs: 0300-0664

Abstract

Abstract: Context : 17β‐hydroxysteroid dehydrogenase type 2 (17β‐HSD2) may be involved in the local modulation of estradiol (E2) availability in adipose tissues. Objective: To assess the conversion of E2 into estrone (E1) as well as the expression of 17β‐HSD2 and its localization in omental (OM) and subcutaneous (SC) adipose tissues obtained from women. Methods: Rates of 14 C‐E1 formation from 14 C‐E2 were measured in OM and SC adipose tissue homogenates from 29 women. Specific 17β‐HSD2 inhibitor EM‐919 was tested in OM and SC adipose tissue homogenates ( n = 6). 17β‐HSD2 mRNA expression was measured in whole OM and SC adipose tissues ( n = 14). Cellular localization of the enzyme was examined using immunohistochemistry. Anthropometric measurements were obtained and body composition as well as body fat distribution were measured. Results: Significant 14 C‐E1 formation from 14 C‐E2 in OM and SC tissue homogenates was detected. The rate of 14 C‐E1 formation was significantly higher in OM than SC adipose tissue ( p < .0001). The conversion of 14 C‐E2 to 14 C‐E1 was significantly inhibited by EM‐919 in OM ( p < .05) and SC ( p < .05) adipose tissues. Significantly higher expression of 17β‐HSD2 mRNA in OM versus SC fat was found ( p = .03). 17β‐HSD2 was localized in the vasculature of OM and SC tissues. Significant negative associations were detected between OM 17β‐HSD2 activity and body mass index, WC, lean body mass as well as SC adipose tissue areas. Conclusion: 17β‐HSD2 converts E2 to E1 in OM and SC adipose tissues of women. The activity of this enzyme decreases with increasing adiposity.