title: Androgen receptor in Sertoli cells regulates DNA double-strand break repair and chromosomal synapsis of spermatocytes partially through intercellular EGF-EGFR signaling.
abstract: Spermatogenesis does not progress beyond the pachytene stages of meiosis in Sertoli cell-specific AR knockout (SCARKO) mice. However, further evidence of meiotic arrest and underlying paracrine signals in SCARKO testes is still lacking. We utilized co-immunostaining of meiotic surface spreads to examine the key events during meiotic prophase I. SCARKO spermatocytes exhibited a failure in chromosomal synapsis observed by SCP1/SCP3 double-staining and CREST foci quantification. In addition, DNA double-strand breaks (DSBs) were formed but were not repaired in the mutant spermatocytes, as revealed by γ-H2AX staining and DNA-dependent protein kinase (DNA-PK) activity examination. The later stages of DSB repair, such as the accumulation of the RAD51 strand exchange protein and the localization of mismatch repair protein MLH1, were correspondingly altered in SCARKO spermatocytes. Notably, the expression of factors that guide RAD51 loading onto sites of DSBs, including TEX15, BRCA1/2 and PALB2, was severely impaired when either AR was down-regulated or EGF was up-regulated. We observed that some ligands in the epidermal growth factor (EGF) family were over-expressed in SCARKO Sertoli cells and that some receptors in the EGF receptor (EGFR) family were ectopically activated in the mutant spermatocytes. When EGF-EGFR signaling was repressed to approximately normal by the specific inhibitor AG1478 in the cultured SCARKO testis tissues, the arrested meiosis was partially rescued, and functional haploid cells were generated. Based on these data, we propose that AR in Sertoli cells regulates DSB repair and chromosomal synapsis of spermatocytes partially through proper intercellular EGF-EGFR signaling.
authors.affiliation: State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Su-Ren
authors.initials: SR
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.|University of Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Hao
authors.affiliation: State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Shou-Long
authors.initials: SL
authors.lastname: Deng
authors.affiliation: State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.|University of Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Zhi-Peng
authors.initials: ZP
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.|University of Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Yu-Qian
authors.initials: YQ
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Xiu-Xia
authors.initials: XX
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Yi-Xun
authors.initials: YX
authors.lastname: Liu
mesh_terms: D000818:Animals; D023902:Chromosome Pairing; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D004815:Epidermal Growth Factor / Q000378:metabolism; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D011944:Receptors, Androgen / Q000378:metabolism*; D012708:Sertoli Cells / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction; D013090:Spermatocytes / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure
chemical_list: D011944:Receptors, Androgen; D004815:Epidermal Growth Factor; D066246:ErbB Receptors
keywords: DNA double-strand breaks; Sertoli cells; androgen receptor; meiosis; synapsis