title: Nuclear factor-kappa-B-inhibitor alpha (NFKBIA) is a developmental marker of NF-κB/p65 activation during in vitro oocyte maturation and early embryogenesis.
abstract: BACKGROUND
  The oocyte-to-embryo transition (OET) requires a co-ordinated transcriptional programme acting through evolutionarily conserved events, and transcription factors (TFs) are known to control these processes. Here, we focus on nuclear factor (NF)-κB, a TF involved in several cellular processes, studying NFκB-inhibitor (NFKBIA) mRNA and its protein product, IκBα, during OET. NFKBIA and IκBα are part of a regulatory loop, as IκBα is the major down-regulator of NF-κB activation while NFKBIA transcription is activated by NF-κB.
  
  
  RESULTS
  We found a dynamic correlation between NFKBIA transcript, expression of IκBα-protein and activation of NF-κB/p65 in bovine oocyte and embryo. During the transition from immature to in vitro matured bovine oocyte, we observed a decrease in maternal NFKBIA mRNA and a parallel increase of the IκBα-protein (both P < 0.05). In the embryo, NFKBIA neo-synthesis is activated as a consequence of embryo genome activation (EGA), and IκBα decreases. NF-κB/p65-binding activity was detectable at low levels in immature oocyte, disappeared in dormant metaphase II oocyte and was strong in the embryo, during embryonic NFKBIA synthesis. The level of NF-κB/p65 DNA binding correlates with the timing of meiotic silencing during bovine oocyte maturation and embryonic transcription reprogramming.
  
  
  CONCLUSIONS
  The IκBα/NF-κB circuit appears to be a tightly stage-controlled mechanism that could govern OET, being activated at EGA. Our findings represent the first characterization of NFKBIA and IκBα as maternal effectors in both the bovine oocyte and embryo. We suggest a role for NFKBIA as a marker of NF-κB/p65 activation in the human oocyte and early embryo.
authors.affiliation: Institute of Genetics and Biophysics 'Adriano Buzzati Traverso' CNR, Via Pietro Castellino, 111, 80131 Naples, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Paciolla
authors.forename: R
authors.initials: R
authors.lastname: Boni
authors.forename: F
authors.initials: F
authors.lastname: Fusco
authors.forename: A
authors.initials: A
authors.lastname: Pescatore
authors.forename: L
authors.initials: L
authors.lastname: Poeta
authors.forename: M V
authors.initials: MV
authors.lastname: Ursini
authors.forename: M B
authors.initials: MB
authors.lastname: Lioi
authors.forename: M G
authors.initials: MG
authors.lastname: Miano
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D047108:Embryonic Development / Q000235:genetics / Q000502:physiology*; D004789:Enzyme Activation; D020672:I-kappa B Proteins / Q000032:analysis / Q000378:metabolism / Q000502:physiology*; D008969:Molecular Sequence Data; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D009865:Oocytes / Q000254:growth & development* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D016415:Sequence Alignment; D051996:Transcription Factor RelA / Q000032:analysis / Q000378:metabolism* / Q000502:physiology
chemical_list: D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D012333:RNA, Messenger; D051996:Transcription Factor RelA; D000072000:NF-KappaB Inhibitor alpha