title: A novel evaluation method of survival motor neuron protein as a biomarker of spinal muscular atrophy by imaging flow cytometry.
abstract: Spinal muscular atrophy (SMA) is caused by mutations within the survival motor neuron 1 (SMN1) gene. These mutations result in the reduction of survival motor neuron (SMN) protein expression and SMN complex in spinal motor neurons and other tissues. SMN protein has been used as a therapeutic biomarker in recent SMA clinical studies using enzyme-linked immunosorbent assay (ELISA). Here, we investigated whether imaging flow cytometry can be a viable source of quantitative information on the SMN protein. Using a FlowSight imaging flow cytometer (Merck-Millipore, Germany), we demonstrated that imaging flow cytometry could successfully identify different expression patterns and subcellular localization of SMN protein in healthy human fibroblasts and SMA patient-derived fibroblasts. In addition, we could also evaluate the therapeutic effects of SMN protein expression by valproic acid treatment of SMA patient-derived cells in vitro. Therefore, we suggest that imaging flow cytometry technology has the potential for identifying SMN protein expression level and pattern as an evaluation tool of clinical studies.
authors.affiliation: Institute of Microbial Chemistry (BIKAKEN), Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan. Electronic address: arakawam@bikaken.or.jp.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Arakawa
authors.affiliation: Institute of Medical Genetics, Tokyo Women's Medical University, 10-22 Kawadacho, Shinjyuku-ku, Tokyo 162-0054, Japan.
authors.forename: Reiko
authors.initials: R
authors.lastname: Arakawa
authors.affiliation: Merck Millipore Merck Ltd., Arco Tower 5F, 1-8-1 Shimomeguro, Megro-ku, Tokyo 153-8927, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Tatsumi
authors.affiliation: Institute of Medical Genetics, Tokyo Women's Medical University, 10-22 Kawadacho, Shinjyuku-ku, Tokyo 162-0054, Japan.
authors.forename: Ryoko
authors.initials: R
authors.lastname: Aoki
authors.affiliation: Institute of Medical Genetics, Tokyo Women's Medical University, 10-22 Kawadacho, Shinjyuku-ku, Tokyo 162-0054, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Saito
authors.affiliation: Institute of Microbial Chemistry (BIKAKEN), Tokyo, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141-0021, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Nomoto
mesh_terms: D001483:Base Sequence; D015415:Biomarkers / Q000378:metabolism*; D002478:Cells, Cultured; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry / Q000379:methods*; D006801:Humans; D009134:Muscular Atrophy, Spinal / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013347:Subcellular Fractions / Q000378:metabolism; D055533:Survival of Motor Neuron 1 Protein / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D017931:DNA Primers; C526471:SMN1 protein, human; D055533:Survival of Motor Neuron 1 Protein
keywords: Biomarker; Imaging flow cytometry; Spinal muscular atrophy; Survival motor protein; Valproic acid