Disruption of LH-induced testosterone biosynthesis in testicular Leydig cells by triclosan: probable mechanism of action.
Triclosan (TCS) is an antimicrobial chemical widely used in different commercial preparations. The present study demonstrated the mechanism of action of TCS-induced anti-androgenicity in rat Leydig cells. Treatment of purified cells with increasing concentrations of TCS (0.001, 0.01, 0.1, 1 and 10 microM) resulted in a significantly decreased activity of adenylyl cyclase enzyme which was followed by a decreased synthesis of cAMP. This decreased cAMP level resulted in the disruption of entire steroidogenic cascade causing a depressed synthesis of testosterone. However, TCS-induced decrease in the production of testosterone returned to normalcy when cells were treated with forskolin (an adenylyl cyclase activator). Transcription followed by translational of four prominent steroidogenic enzyme/proteins, cytochrome P450 side chain cleavage (P450scc), 3beta-hydroxysteroid dehydrogenase (3beta-HSD), 17beta-hydroxysteroid dehydrogenase (17beta-HSD) and steroidogenic acute regulatory (StAR) protein, also decreased in a dose-dependent manner in TCS-treated Leydig cells as determined by RT-PCR, enzyme assay and Western blot. These results suggested that the disruption of the activity of adenylyl cyclase enzyme by TCS in turn leads to the disruption of intermediate steroidogenic cascade causing a depressed testosterone production. The study further confirmed the anti-androgenic activity of TCS in Leydig cells with highest effective concentration at 1 microM.
Kumar
Vikas
V
Molecular Endocrinology Laboratory, Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India.
Balomajumder
Chandrajeet
C
Roy
Partha
P
D015067:17-Hydroxysteroid Dehydrogenases / Q000096:biosynthesis; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific) / Q000096:biosynthesis; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D000891:Anti-Infective Agents, Local / Q000633:toxicity*; D015153:Blotting, Western; D002469:Cell Separation; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D000242:Cyclic AMP / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000633:toxicity*; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000037:antagonists & inhibitors* / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013739:Testosterone / Q000096:biosynthesis*; D013778:Tetrazolium Salts; D013844:Thiazoles; D014260:Triclosan / Q000633:toxicity*
D000891:Anti-Infective Agents, Local; D052244:Endocrine Disruptors; D013778:Tetrazolium Salts; D013844:Thiazoles; D013739:Testosterone; D014260:Triclosan; D007986:Luteinizing Hormone; D000242:Cyclic AMP; D015067:17-Hydroxysteroid Dehydrogenases; D045002:3-alpha-Hydroxysteroid Dehydrogenase (B-Specific); D000262:Adenylyl Cyclases; C022616:thiazolyl blue