title: Reduced microRNA-188-3p expression contributes to apoptosis of spermatogenic cells in patients with azoospermia.
abstract: OBJECTIVE
  Human mutL homologl (MLH1) works coordinately in sequential steps to initiate repair of DNA mismatches, and aberrant MLH1 expression is related to spermatogenetic malfunction. In the present study, MLH1 expression in patients with azoospermia was investigated, and moderating effects of miR-188-3p on MLH1 expression and spermatogenesis were identified.
  
  
  METHODS
  Testicular tissues from 16 patients with obstructive azoospermia (OA) and non-obstructive azoospermia (NOA), and tissues of eight healthy patients were collected. Real-time PCR, Western blotting and immunohistochemical staining were used to detect MLH1 expression. Chromatin immunoprecipitation assay and luciferase reporter assay were performed to evaluate histone acetylation level of miR-188-3p and relationships between miR-188-3p and MLH1.
  
  
  RESULTS
  Testicular MLH1 expression at mRNA and protein levels was significantly increased, while miR-188-3p expression was lower in patients with OA and NOA than that in controls. Reduced histone acetylation level of miR-188-3p promoter was observed in patients with azoospermia. Overexpression/inhibition of HDAC1, but not HDAC2, contributed to the significant reduction/increase of miR-188-3p expression. miR-188-3p targeted 3' UTR of MLH1 and regulated MLH1 expression. miR-188-3p inhibitor led to elevation of apoptotic level of spermatogenic cells in mice, while this effect was reversed by si-MLH1.
  
  
  CONCLUSIONS
  Down-regulation of miR-188-3p by reducing histone acetylation up-regulated MLH1 expression and contributed to promotion of apoptosis in spermatogenic cells, in patients with azoospermia.
authors.affiliation: Reproductive Medicine Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Wen-Yan
authors.initials: WY
authors.lastname: Song
authors.affiliation: Pathology Department, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Meng
authors.affiliation: Reproductive Medicine Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Xue-Gai
authors.initials: XG
authors.lastname: Wang
authors.affiliation: Reproductive Medicine Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Hai-Xia
authors.initials: HX
authors.lastname: Jin
authors.affiliation: Reproductive Medicine Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Gui-Dong
authors.initials: GD
authors.lastname: Yao
authors.affiliation: Reproductive Medicine Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Sen-Lin
authors.initials: SL
authors.lastname: Shi
authors.affiliation: Reproductive Medicine Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Wu
authors.affiliation: Reproductive Medicine Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Xiang-Yang
authors.initials: XY
authors.lastname: Zhang
authors.affiliation: Reproductive Medicine Center, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Ying-Pu
authors.initials: YP
authors.lastname: Sun
mesh_terms: D000107:Acetylation; D000818:Animals; D000070416:Antagomirs / Q000378:metabolism; D017209:Apoptosis / Q000235:genetics*; D053713:Azoospermia / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D001483:Base Sequence; D002460:Cell Line; D015536:Down-Regulation; D056284:Histone Deacetylase 1 / Q000235:genetics / Q000378:metabolism; D056464:Histone Deacetylase 2 / Q000235:genetics / Q000378:metabolism; D006657:Histones / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000070957:MutL Protein Homolog 1 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic / Q000235:genetics; D034622:RNA Interference; D016415:Sequence Alignment; D013090:Spermatocytes / Q000166:cytology*; D013091:Spermatogenesis
chemical_list: D000070416:Antagomirs; D006657:Histones; C501486:MLH1 protein, human; D035683:MicroRNAs; C110550:HDAC1 protein, human; C533423:HDAC2 protein, human; D056284:Histone Deacetylase 1; D056464:Histone Deacetylase 2; D000070957:MutL Protein Homolog 1