title: Hormonal regulation of sertoli cell micro-RNAs at spermiation.
abstract: Spermatogenesis is absolutely dependent on FSH and androgens; suppression of these hormones inhibits germ cell development and thus sperm production. The final release of spermatids by the Sertoli cell, a process known as spermiation, is particularly sensitive to hormone suppression. To define the molecular mechanisms that mediate FSH and androgen effects in the Sertoli cell, we investigated the expression and regulation of micro-RNAs (miRNAs), small noncoding RNAs that regulate protein translation and modify cellular responses. By array analysis, we identified 23 miRNAs up-regulated more than 2-fold after hormone suppression in vivo and in vitro in primary Sertoli cell cultures. The regulation of four of these miRNAs (miR-23b, -30c, -30d, and -690) was confirmed by quantitative RT-PCR. Bioinformatic analysis of potential targets of hormonally regulated miRNAs identified genes important for focal adhesion and regulation of the actin cytoskeleton, processes known to be intimately associated with adhesion of spermatids to Sertoli cells. Two of the identified genes, Pten, an intracellular phosphatase, and Eps15, a mediator of endocytosis, were down-regulated by the withdrawal of hormones in vivo and possess miR-23b target sites in their 3'-untranslated regions. Overexpression of miR-23b in vitro resulted in decreased translation of PTEN and EPS15 protein as assessed by Western blot and luciferase analysis. We conclude that FSH and androgens act on Sertoli cells in stage VIII to control the expression of miRNAs that operate in a coordinated manner to regulate cell adhesion pathways and male fertility and that miRNA transcription is a new paradigm in the hormone dependence of spermiation.
authors.affiliation: Prince Henry's Institute, Monash Medical Centre, Clayton 3152, Victoria, Australia.
authors.forename: Peter K
authors.initials: PK
authors.lastname: Nicholls
authors.forename: Craig A
authors.initials: CA
authors.lastname: Harrison
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Walton
authors.forename: Robert I
authors.initials: RI
authors.lastname: McLachlan
authors.forename: Liza
authors.initials: L
authors.lastname: O'Donnell
authors.forename: Peter G
authors.initials: PG
authors.lastname: Stanton
mesh_terms: D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D019295:Computational Biology; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D051059:PTEN Phosphohydrolase / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012671:Seminiferous Tubules / Q000166:cytology; D012708:Sertoli Cells / Q000187:drug effects* / Q000378:metabolism*; D013737:Testis / Q000166:cytology / Q000378:metabolism
chemical_list: D000728:Androgens; D002135:Calcium-Binding Proteins; C526966:Eps15 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D035683:MicroRNAs; D005640:Follicle Stimulating Hormone; D051059:PTEN Phosphohydrolase