title: Spinal muscular atrophy phenotype is ameliorated in human motor neurons by SMN increase via different novel RNA therapeutic approaches.
abstract: Spinal muscular atrophy (SMA) is a primary genetic cause of infant mortality due to mutations in the Survival Motor Neuron (SMN) 1 gene. No cure is available. Antisense oligonucleotides (ASOs) aimed at increasing SMN levels from the paralogous SMN2 gene represent a possible therapeutic strategy. Here, we tested in SMA human induced pluripotent stem cells (iPSCs) and iPSC-differentiated motor neurons, three different RNA approaches based on morpholino antisense targeting of the ISSN-1, exon-specific U1 small nuclear RNA (ExSpeU1), and Transcription Activator-Like Effector-Transcription Factor (TALE-TF). All strategies act modulating SMN2 RNA: ASO affects exon 7 splicing, TALE-TF increase SMN2 RNA acting on the promoter, while ExSpeU1 improves pre-mRNA processing. These approaches induced up-regulation of full-length SMN mRNA and differentially affected the Delta-7 isoform: ASO reduced this isoform, while ExSpeU1 and TALE-TF increased it. All approaches upregulate the SMN protein and significantly improve the in vitro SMA motor neurons survival. Thus, these findings demonstrate that therapeutic tools that act on SMN2 RNA are able to rescue the SMA disease phenotype. Our data confirm the feasibility of SMA iPSCs as in vitro disease models and we propose novel RNA approaches as potential therapeutic strategies for treating SMA and other genetic neurological disorders.
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Nizzardo
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Simone
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Sara
authors.initials: S
authors.lastname: Dametti
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Salani
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Gianna
authors.initials: G
authors.lastname: Ulzi
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Pagliarani
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Rizzo
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Frattini
authors.affiliation: Human Molecular Genetics, International Centre for Genetic Engineering and Biotechnology, Trieste, Italy.
authors.forename: Franco
authors.initials: F
authors.lastname: Pagani
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Nereo
authors.initials: N
authors.lastname: Bresolin
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Giacomo
authors.initials: G
authors.lastname: Comi
authors.affiliation: Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Corti
mesh_terms: D001483:Base Sequence; D002470:Cell Survival; D002478:Cells, Cultured; D005260:Female; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D015316:Genetic Therapy; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000502:physiology; D008297:Male; D060172:Morpholinos / Q000235:genetics; D009046:Motor Neurons / Q000378:metabolism*; D009134:Muscular Atrophy, Spinal / Q000235:genetics / Q000378:metabolism / Q000628:therapy*; D010641:Phenotype; D011401:Promoter Regions, Genetic; D012342:RNA, Small Nuclear / Q000235:genetics; D055540:Survival of Motor Neuron 2 Protein / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics
chemical_list: D060172:Morpholinos; D012342:RNA, Small Nuclear; C526477:SMN2 protein, human; D055540:Survival of Motor Neuron 2 Protein; D014157:Transcription Factors; C405483:U1 small nuclear RNA