Roles of Type 10 17beta-Hydroxysteroid Dehydrogenase in Intracrinology and Metabolism of Isoleucine and Fatty Acids

Human type 10 17beta-hydroxysteroid dehydrogenase (HSD), also known as short chain L-3-hydroxyacyl-CoA dehydrogenase (SCHSD), was a mitochondrial enzyme crucial for metabolizing branched-chain fatty acids and isoleucine, and was expressed in various tissues including the prostate, brain, liver, and heart. It inactivated 17beta-estradiol and converted 5alpha-androstanediol and allopregnanolone into 5alpha-dihydrotestosterone (5alpha-DHT) and 5alpha-dihydroprogesterone, respectively. High levels of this enzyme were found in malignant prostatic epithelial cells and activated astrocytes in Alzheimer's disease patients. It enabled prostate cancer cells to produce 5alpha-DHT without testosterone and modulated the GABA(A) receptor by inactivating allopregnanolone. While it had an affinity for amyloid-beta peptide, its role in Alzheimer's disease pathogenesis was unclear. Understanding this enzyme could aid in developing treatments for neurological diseases and certain cancers.