title: Valproic acid increases SMN2 expression and modulates SF2/ASF and hnRNPA1 expression in SMA fibroblast cell lines.
abstract: Spinal muscular atrophy (SMA) is a common autosomal recessive neuromuscular disorder that is caused by loss of the survival motor neuron gene, SMN1. SMA treatment strategies have focused on production of the SMN protein from the almost identical gene, SMN2. Valproic acid (VPA) is a histone deacetylase inhibitor that can increase SMN levels in some SMA cells or SMA patients through activation of SMN2 transcription or splicing correction of SMN2 exon 7. It remains to be clarified what concentration of VPA is required and by what mechanisms the SMN production from SMN2 is elicited. We observed that in two fibroblast cell lines from Japanese SMA patients, more than 1mM of VPA increased SMN2 expression at both the transcript and protein levels. VPA increased not only full-length (FL) transcript level but also exon 7-excluding (Δ7) transcript level in the cell lines and did not change the ratio of FL/Δ7, suggesting that SMN2 transcription was mainly activated. We also found that VPA modulated splicing factor expression: VPA increased the expression of splicing factor 2/alternative splicing factor (SF2/ASF) and decreased the expression of heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1). In conclusion, more than 1mM of VPA activated SMN2 transcription and modulated the expression of splicing factors in our SMA fibroblast cell lines.
authors.affiliation: Department of Community Medicine and Social Healthcare Science, Kobe University Graduate School of Medicine, Kobe, Japan.
authors.forename: Indra Sari Kusuma
authors.initials: IS
authors.lastname: Harahap
authors.forename: Toshio
authors.initials: T
authors.lastname: Saito
authors.forename: Lai Poh
authors.initials: LP
authors.lastname: San
authors.forename: Naoko
authors.initials: N
authors.lastname: Sasaki
authors.lastname: Gunadi
authors.forename: Dian Kesuma Pramudya
authors.initials: DK
authors.lastname: Nurputra
authors.forename: Surini
authors.initials: S
authors.lastname: Yusoff
authors.forename: Tomoto
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Satoru
authors.initials: S
authors.lastname: Morikawa
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Nishimura
authors.forename: Myeong Jin
authors.initials: MJ
authors.lastname: Lee
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takeshima
authors.forename: Masafumi
authors.initials: M
authors.lastname: Matsuo
authors.forename: Hisahide
authors.initials: H
authors.lastname: Nishio
mesh_terms: D000328:Adult; D015153:Blotting, Western; D002460:Cell Line; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects*; D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B / Q000096:biosynthesis*; D006801:Humans; D007223:Infant; D009134:Muscular Atrophy, Spinal / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D009687:Nuclear Proteins / Q000096:biosynthesis*; D016601:RNA-Binding Proteins / Q000096:biosynthesis*; D060888:Real-Time Polymerase Chain Reaction; D000068103:Serine-Arginine Splicing Factors; D055540:Survival of Motor Neuron 2 Protein / Q000096:biosynthesis; D014158:Transcription, Genetic / Q000187:drug effects; D014635:Valproic Acid / Q000494:pharmacology*
chemical_list: D000076245:Heterogeneous Nuclear Ribonucleoprotein A1; D034481:Heterogeneous-Nuclear Ribonucleoprotein Group A-B; D018696:Neuroprotective Agents; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; C526477:SMN2 protein, human; D055540:Survival of Motor Neuron 2 Protein; C000619656:hnRNPA1 protein, human; D000068103:Serine-Arginine Splicing Factors; D014635:Valproic Acid