title: MicroRNA-125a-5p induces mouse granulosa cell apoptosis by targeting signal transducer and activator of transcription 3.
abstract: OBJECTIVE
  Premature ovarian failure, a reproductive dysfunction characterized by follicle loss leads to premature menopause. Apoptosis of granulosa cells may be responsible for the associated follicle depletion. MicroRNAs are expressed abundantly in granulosa cells and play an important role in follicular atresia. Evidence suggests that signal transducer and activator of transcription 3 (STAT3) is involved in follicle growth and female fertility.
  
  
  METHODS
  We incubated cultured mouse granulosa cells (mGCs) with increasing doses of cisplatin (CP) for varying periods. Cell proliferation and apoptosis were measured by Cell Counting Kit-8 assay, flow cytometry, and protein expression of cleaved caspase-3. Western blot analysis was used to assess STAT3 and phospho-STAT3 after mGCs were transfected with a microRNA-125a-5p (miR-125a-5p) mimic and a miR-125a-5p inhibitor, respectively. Luciferase reporter assay was conducted to determine the relationship between miR-125a-5p and STAT3.
  
  
  RESULTS
  CP reduced mGC viability, progesterone levels, and estradiol levels. miR-125a-5p was up-regulated in CP-treated mGCs, whereas STAT3 was down-regulated. Increased apoptosis and cleaved caspase-3 were observed in mGCs transfected with a miR-125a-5p mimic or STAT3 interference fragment. Protein expression of STAT3 and phospho-STAT3 was up-regulated or down-regulated when transfected with a miR-125a-5p inhibitor or miR-125a-5p mimic, respectively. Luciferase reporter assays indicated that miR-125a-5p targets the 3' untranslated region of STAT3.
  
  
  CONCLUSIONS
  Overexpression of miR-125a-5p promotes mGC apoptosis by targeting STAT3. Our findings imply the important role of miR-125a-5p in the pathogenesis of premature ovarian failure.
authors.affiliation: State Key Laboratory of Reproductive Medicine, Department of Obstetrics and Gynecology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China.
authors.forename: Chaojun
authors.initials: C
authors.lastname: Wang
authors.forename: Donghua
authors.initials: D
authors.lastname: Li
authors.forename: Suyun
authors.initials: S
authors.lastname: Zhang
authors.forename: Yan
authors.initials: Y
authors.lastname: Xing
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Gao
authors.forename: Jie
authors.initials: J
authors.lastname: Wu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D049109:Cell Proliferation / Q000235:genetics; D015536:Down-Regulation; D005260:Female; D006107:Granulosa Cells / Q000378:metabolism*; D051379:Mice; D035683:MicroRNAs / Q000378:metabolism*; D016649:Primary Ovarian Insufficiency / Q000235:genetics / Q000503:physiopathology; D050796:STAT3 Transcription Factor / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D035683:MicroRNAs; C527468:Mirn125 microRNA, mouse; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse