C11-oxy C19 and C11-oxy C21 steroids have been identified as novel steroids but their function remains unclear. This study aimed to investigate the pre-receptor regulation of C11-oxy steroids by 11β-hydroxysteroid dehydrogenase (11βHSD) interconversion and potential agonist and antagonist activity associated with the androgen (AR) and progesterone receptors (PRA and PRB). Steroid conversions were investigated in transiently transfected HEK293 cells expressing 11βHSD1 and 11βHSD2, while CV1 cells were utilised for agonist and antagonist assays. The conversion of C11-hydroxy steroids to C11-oxo steroids by 11βHSD2 occurred more readily than the reverse reaction catalysed by 11βHSD1, while the interconversion of C11-oxy C19 steroids was more efficient than C11-oxy C21 steroids. Furthermore, 11-ketodihydrotestosterone (11KDHT), 11-ketotestosterone (11KT) and 11β-hydroxydihydrotestosterone (11OHDHT) were AR agonists, while only progestogens, 11β-hydroxyprogesterone (11βOHP4), 11β-hydroxydihydroprogesterone (11βOHDHP4), 11α-hydroxyprogesterone (11αOHP4), 11α-hydroxydihydroprogesterone (11αOHDHP4), 11-ketoprogesterone (11KP4), 5α-pregnan-17α-diol-3,11,20-trione (11KPdione) and 21-deoxycortisone (21dE) exhibited antagonist activity. C11-hydroxy C21 steroids, 11βOHP4, 11βOHDHP4 and 11αOHP4 exhibited PRA and PRB agonistic activity, while only C11-oxo steroids, 11KP4 and 11-ketoandrostanediol (11K3αdiol) demonstrated PRB agonism. While no steroids antagonised the PRA, 11OHA4, 11β-hydroxytestosterone (11OHT), 11KT and 11KDHT exhibited PRB antagonism. The regulatory role of 11βHSD isozymes impacting receptor activation is clear—C11-oxo androgens exhibit AR agonist activity; only C11-hydroxy progestogens exhibit PRA and PRB agonist activity. Regulation by the downstream metabolites of active C11-oxy steroids at the receptor level is apparent—C11-hydroxy and C11-oxo metabolites antagonize the AR and PRB, progestogens the former, androgens the latter. The findings highlight the intricate interplay between receptors and active as well as “inactive” C11-oxy steroids, suggesting novel regulatory tiers.
C11-oxy C19 和 C11-oxy C21 类固醇已被确定为新型类固醇,但其功能仍不清楚。本研究旨在通过 11β- 羟类固醇脱氢酶(11βHSD)的相互转化以及与雄激素受体(AR)和孕激素受体(PRA 和 PRB)相关的潜在激动剂和拮抗剂活性,研究 C11-oxy 类固醇的前受体调节。在表达 11βHSD1 和 11βHSD2 的瞬时转染 HEK293 细胞中研究了类固醇的转化,并利用 CV1 细胞进行了激动剂和拮抗剂试验。与 11βHSD1 催化的逆反应相比,11βHSD2 更容易将 C11-hydroxy 类固醇转化为 C11-oxo 类固醇,而 C11-oxy C19 类固醇的相互转化比 C11-oxy C21 类固醇更有效。此外,11-酮二氢睾酮(11KDHT)、11-酮睾酮(11KT)和 11β-羟基二氢睾酮(11OHDHT)是 AR 激动剂,而只有孕激素、11β-羟基黄体酮(11βOHP4)、11β-羟基二氢黄体酮(11βOHDHP4)是 AR 激动剂、11α-羟基黄体酮(11αOHP4)、11α-羟基二氢黄体酮(11αOHDHP4)、11-酮黄体酮(11KP4)、5α-孕甾-17α-二醇-3,11,20-三酮(11KPdione)和 21-脱氧可的松(21dE)具有拮抗活性。C11-hydroxy C21 类固醇、11βOHP4、11βOHDHP4 和 11αOHP4 具有 PRA 和 PRB 激动活性,而只有 C11-oxo 类固醇、11KP4 和 11-ketoandrostanediol (11K3αdiol) 具有 PRB 激动活性。虽然没有类固醇能拮抗 PRA,但 11OHA4、11β-羟基睾酮(11OHT)、11KT 和 11KDHT 表现出 PRB 拮抗作用。影响受体激活的 11βHSD 同工酶的调节作用是明确的--11-氧代雄激素表现出 AR 激动剂活性;只有 C11-羟基孕激素表现出 PRA 和 PRB 激动剂活性。活性 C11-oxy 类固醇的下游代谢物在受体水平的调节作用显而易见--C11-羟基和 C11-oxo 代谢物可拮抗 AR 和 PRB,前者为孕激素,后者为雄激素。这些发现凸显了受体与活性以及 "非活性 "C11-氧类固醇之间错综复杂的相互作用,表明存在新的调节层。