title: Spermatogonial stem cell self-renewal requires ETV5-mediated downstream activation of Brachyury in mice.
abstract: Insight regarding mechanisms controlling gene expression in the spermatogonial stem cell (SSC) will improve our understanding of the processes regulating spermatogenesis and aid in treating problems associated with male infertility. In the present study, we explored the global gene expression profiles of the glial cell line-derived neurotrophic factor (GDNF)-regulated transcription factors Ets (E-twenty-six) variant gene 5 (Etv5); B-cell chronic lymphocytic leukemia (CLL)/lymphoma 6, member B (Bcl6b); and POU domain, class-3 transcription factor 1 (Pou3f1). We reasoned that these three factors may function as a core set of transcription factors, regulating genes responsible for maintaining the SSC population. Using transient siRNA oligonucleotides to individually target Etv5, Bcl6b, and Pou3f1 within mouse SSC cultures, we examined changes to the global gene expression profiles associated with these transcription factors. Only modest overlaps in the target genes regulated by the three factors were noted, but ETV5 was found to be a critical downstream regulator of GDNF signaling that mediated the expression of several known SSC self-renewal related genes, including Bcl6b and LIM homeobox 1 (Lhx1). Notably, ETV5 was identified as a regulator of Brachyury (T) and CXC chemokine receptor, type 4 (Cxcr4), and we showed that ETV5 binding to the Brachyury (T) gene promoter region is associated with an active state of transcription. Moreover, in vivo transplantation of SSCs following silencing of Brachyury (T) significantly reduced the number of donor cell-derived colonies formed within recipient mouse testes. These results suggest Brachyury is of biological importance and functions as part of GDNF/ETV5 signaling to promote self-renewal of mouse SSCs cultured in vitro.
authors.affiliation: Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Wu
authors.forename: Shaun M
authors.initials: SM
authors.lastname: Goodyear
authors.forename: John W
authors.initials: JW
authors.lastname: Tobias
authors.forename: Mary R
authors.initials: MR
authors.lastname: Avarbock
authors.forename: Ralph L
authors.initials: RL
authors.lastname: Brinster
mesh_terms: D053687:Adult Stem Cells / Q000378:metabolism*; D000818:Animals; D049109:Cell Proliferation; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005326:Fetal Proteins / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism*; D051741:Kruppel-Like Transcription Factors / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D050816:Octamer Transcription Factor-6 / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D034622:RNA Interference; D012097:Repressor Proteins / Q000378:metabolism; D013093:Spermatogonia / Q000378:metabolism*; D020825:T-Box Domain Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D000098908:Brachyury Protein
chemical_list: D004268:DNA-Binding Proteins; D005326:Fetal Proteins; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051741:Kruppel-Like Transcription Factors; D050816:Octamer Transcription Factor-6; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D012097:Repressor Proteins; D020825:T-Box Domain Proteins; D014157:Transcription Factors; D000098908:Brachyury Protein; C113027:Bcl6b protein, mouse; C513242:Etv5 protein, mouse; C494180:Pou3f1 protein, mouse; C513267:Zbtb16 protein, mouse