HSD3B1 is a human gene that encodes for a 3beta-hydroxysteroid dehydrogenase/delta(5)-delta(4)isomerase type I or hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 1. [5] While it can carry out the same function as HSD3B2, it localizes primarily to different tissues, such as the placenta and nonsteroidogenic tissues. Its requirement for the production of progesterone by the placenta, which has a vital role in pregnancy, may be one reason why no disease based on mutations in this gene has been identified to date, besides prostate cancer.
The 1245C allele (HSD3B1 adrenal-permissive homozygous genotype 1245 C/C) encodes for a missense and hyperactive enzyme that increases extragonadal androgen synthesis and is associated with poorer outcomes after androgen deprivation therapy in prostate cancer. [6] [7] [8]
Congenital adrenal hyperplasia due to 3β-hydroxysteroid dehydrogenase deficiency is an uncommon form of congenital adrenal hyperplasia (CAH) resulting from a mutation in the gene for one of the key enzymes in cortisol synthesis by the adrenal gland, 3β-hydroxysteroid dehydrogenase (3β-HSD) type II (HSD3B2). As a result, higher levels of 17α-hydroxypregnenolone appear in the blood with adrenocorticotropic hormone (ACTH) challenge, which stimulates adrenal corticosteroid synthesis.
3β-Hydroxysteroid dehydrogenase/Δ5-4 isomerase (3β-HSD) is an enzyme that catalyzes the biosynthesis of the steroid progesterone from pregnenolone, 17α-hydroxyprogesterone from 17α-hydroxypregnenolone, and androstenedione from dehydroepiandrosterone (DHEA) in the adrenal gland. It is the only enzyme in the adrenal pathway of corticosteroid synthesis that is not a member of the cytochrome P450 family. It is also present in other steroid-producing tissues, including the ovary, testis and placenta. In humans, there are two 3β-HSD isozymes encoded by the HSD3B1 and HSD3B2 genes.
17β-Hydroxysteroid dehydrogenases, also 17-ketosteroid reductases (17-KSR), are a group of alcohol oxidoreductases which catalyze the reduction of 17-ketosteroids and the dehydrogenation of 17β-hydroxysteroids in steroidogenesis and steroid metabolism. This includes interconversion of DHEA and androstenediol, androstenedione and testosterone, and estrone and estradiol.
The human gene SRD5A2 encodes the 3-oxo-5α-steroid 4-dehydrogenase 2 enzyme, also known as 5α-reductase type 2 (5αR2), one of three isozymes of 5α-reductase.
17β-Hydroxysteroid dehydrogenase 1 (17β-HSD1) is an enzyme that in humans is encoded by the HSD17B1 gene. This enzyme oxidizes or reduces the C17 hydroxy/keto group of androgens and estrogens and hence is able to regulate the potency of these sex steroids
HSD3B2 is a human gene that encodes for 3beta-hydroxysteroid dehydrogenase/delta(5)-delta(4)isomerase type II or hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase 2. It is expressed principally in steroidogenic tissues and is essential for steroid hormone production. A notable exception is the placenta, where HSD3B1 is critical for progesterone production by this tissue.
Aldo-keto reductase family 1 member C3 (AKR1C3), also known as 17β-hydroxysteroid dehydrogenase type 5 or 3α-hydroxysteroid dehydrogenase type 2 (3α-HSD2) is a steroidogenic enzyme that in humans is encoded by the AKR1C3 gene.
Aldo-keto reductase family 1 member C1 also known as 20α-hydroxysteroid dehydrogenase, 3α-hydroxysteroid dehydrogenase, and dihydrodiol dehydrogenase 1/2 is an enzyme that in humans is encoded by the AKR1C1 gene.
17β-Hydroxysteroid dehydrogenase 2 (17β-HSD2) is an enzyme of the 17β-hydroxysteroid dehydrogenase (17β-HSD) family that in humans is encoded by the HSD17B2 gene.
Aldo-keto reductase family 1 member C4, also known as 3α-Hydroxysteroid dehydrogenase type 1 (3α-HSD1), is an enzyme that in humans is encoded by the AKR1C4 gene. It is known to be necessary for the synthesis of the endogenous neurosteroids allopregnanolone, tetrahydrodeoxycorticosterone, and 3α-androstanediol. It is also known to catalyze the reversible conversion of 3α-androstanediol (5α-androstane-3α,17β-diol) to dihydrotestosterone and vice versa.
17β-Hydroxysteroid dehydrogenase 3 (17β-HSD3) is an enzyme that in humans is encoded by the HSD17B3 gene and is involved in androgen steroidogenesis.
Hydroxysteroid 17-beta dehydrogenase 6 is an enzyme that in humans is encoded by the HSD17B6 gene.
Epiandrosterone, or isoandrosterone, also known as 3β-androsterone, 3β-hydroxy-5α-androstan-17-one, or 5α-androstan-3β-ol-17-one, is a steroid hormone with weak androgenic activity. It is a metabolite of testosterone and dihydrotestosterone (DHT). It was first isolated in 1931, by Adolf Friedrich Johann Butenandt and Kurt Tscherning. They distilled over 17,000 litres of male urine, from which they got 50 milligrams of crystalline androsterone, which was sufficient to find that the chemical formula was very similar to estrone.
An azasteroid is a type of steroid derivative which has one of the carbon atoms in the steroid ring system replaced by a nitrogen atom. Two azasteroids, finasteride and dutasteride, are used clinically as 5α-reductase inhibitors.
11β-Hydroxyprogesterone (11β-OHP), also known as 21-deoxycorticosterone, as well as 11β-hydroxypregn-4-ene-3,20-dione, is a naturally occurring, endogenous steroid and derivative of progesterone. It is a potent mineralocorticoid. Syntheses of 11β-OHP from progesterone is catalyzed by the steroid 11β-hydroxylase (CYP11B1) enzyme, and, to a lesser extent, by the aldosterone synthase enzyme (CYP11B2).
Adrenal steroids are steroids that are derived from the adrenal glands. They include corticosteroids, which consist of glucocorticoids like cortisol and mineralocorticoids like aldosterone, adrenal androgens like dehydroepiandrosterone (DHEA), DHEA sulfate (DHEA-S), and androstenedione (A4), and neurosteroids like DHEA and DHEA-S, as well as pregnenolone and pregnenolone sulfate (P5-S). Adrenal steroids are specifically produced in the adrenal cortex.
Steroidogenic enzymes are enzymes that are involved in steroidogenesis and steroid biosynthesis. They are responsible for the biosynthesis of the steroid hormones, including sex steroids and corticosteroids, as well as neurosteroids, from cholesterol. Steroidogenic enzymes are most highly expressed in classical steroidogenic tissues, such as the testis, ovary, and adrenal cortex, but are also present in other tissues in the body.
Aldo-keto reductase family 1 member C2, also known as bile acid binding protein, 3α-hydroxysteroid dehydrogenase type 3 (3α-HSD3), and dihydrodiol dehydrogenase type 2, is an enzyme that in humans is encoded by the AKR1C2 gene.
3α-Hydroxysteroid dehydrogenase (3α-HSD) is an enzyme (1.1.1.50) that plays a role in the metabolism of steroids and non-steroidal compounds in humans and other species, such as bacteria, fungi, plants, and so on. This enzyme catalyzes the chemical reaction of conversion of 3-ketosteroids into 3α-hydroxysteroids. The enzyme has various protein isoforms (isozymes).