title: High-content screening identifies small molecules that remove nuclear foci, affect MBNL distribution and CELF1 protein levels via a PKC-independent pathway in myotonic dystrophy cell lines.
abstract: Myotonic dystrophy (DM) is a multi-system neuromuscular disorder for which there is no treatment. We have developed a medium throughput phenotypic assay, based on the identification of nuclear foci in DM patient cell lines using in situ hybridization and high-content imaging to screen for potentially useful therapeutic compounds. A series of further assays based on molecular features of DM have also been employed. Two compounds that reduce and/or remove nuclear foci have been identified, Ro 31-8220 and chromomycin A3. Ro 31-8220 is a PKC inhibitor, previously shown to affect the hyperphosphorylation of CELF1 and ameliorate the cardiac phenotype in a DM1 mouse model. We show that the same compound eliminates nuclear foci, reduces MBNL1 protein in the nucleus, affects ATP2A1 alternative splicing and reduces steady-state levels of CELF1 protein. We demonstrate that this effect is independent of PKC activity and conclude that this compound may be acting on alternative kinase targets within DM pathophysiology. Understanding the activity profile for this compound is key for the development of targeted therapeutics in the treatment of DM.
authors.affiliation: School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham NG7 2UH, UK.
authors.forename: Ami
authors.initials: A
authors.lastname: Ketley
authors.forename: Catherine Z
authors.initials: CZ
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Sukrat
authors.initials: S
authors.lastname: Arya
authors.forename: Thelma E
authors.initials: TE
authors.lastname: Robinson
authors.forename: Javier
authors.initials: J
authors.lastname: Granados-Riveron
authors.forename: Inyang
authors.initials: I
authors.lastname: Udosen
authors.forename: Glenn E
authors.initials: GE
authors.lastname: Morris
authors.forename: Ian
authors.initials: I
authors.lastname: Holt
authors.forename: Denis
authors.initials: D
authors.lastname: Furling
authors.forename: Soraya
authors.initials: S
authors.lastname: Chaouch
authors.forename: Ben
authors.initials: B
authors.lastname: Haworth
authors.forename: Noel
authors.initials: N
authors.lastname: Southall
authors.forename: Paul
authors.initials: P
authors.lastname: Shinn
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Austin
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hayes
authors.forename: J David
authors.initials: JD
authors.lastname: Brook
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D000067879:CELF1 Protein; D002467:Cell Nucleus / Q000187:drug effects* / Q000473:pathology; D002478:Cells, Cultured; D014128:Chromomycin A3 / Q000494:pharmacology*; D004195:Disease Models, Animal; D005786:Gene Expression Regulation; D057166:High-Throughput Screening Assays; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D009223:Myotonic Dystrophy / Q000473:pathology*; D019151:Peptide Library; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D015027:Zebrafish
chemical_list: D000067879:CELF1 Protein; C102843:CELF1 protein, human; D007211:Indoles; C493663:MBNL1 protein, human; D019151:Peptide Library; D016601:RNA-Binding Proteins; D014128:Chromomycin A3; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; C506943:ATP2A1 protein, human; C064758:Ro 31-8220