title: Proteomics profiling of urine reveals specific titin fragments as biomarkers of Duchenne muscular dystrophy.
abstract: Diagnosis of muscular dystrophies is currently based on invasive methods requiring muscle biopsies or blood tests. The aim of the present study was to identify urinary biomarkers as a diagnostic tool for muscular dystrophies. Here, the urinary proteomes of Duchenne muscular dystrophy (DMD) patients and healthy donors were compared with a bottom-up proteomic approach. Label-free analysis of more than 1100 identified proteins revealed that 32 of them were differentially expressed between healthy controls and DMD patients. Among these 32 proteins, titin showed the highest fold change between healthy subjects and DMD patients. Interestingly, most of the sequenced peptides belong to the N-terminal and C-terminal parts of titin, and the presence of the corresponding fragments in the urine of DMD patients was confirmed by Western blot analysis. Analysis of a large cohort of DMD patients and age-matched controls (a total of 104 individuals aged from 3 to 20 years) confirmed presence of the N-ter fragment in all but two patients. In two DMD patients aged 16 and 20 years this fragment was undetectable and two healthy controls of 16 and 19 years with serum CK >800 IU/L demonstrated a low level of the fragment. N- and C-terminal titin fragments were also detected in urine from patients with other muscular dystrophies such as Becker muscular dystrophy and Limb-girdle muscular dystrophy (type 1D, 2D and 2J) but not in neurogenic spinal muscular atrophy. They were also present in urine of dystrophin-deficient animal models (GRMD dogs and mdx mice). Titin is the first urinary biomarker that offers the possibility to develop a simple, non-invasive and easy-to-use test for pre-screening of muscular dystrophies, and may also prove to be useful for the non-invasive follow up of DMD patients under treatment.
authors.affiliation: Généthon, Evry, France.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Rouillon
authors.affiliation: Généthon, Evry, France.
authors.forename: Aleksandar
authors.initials: A
authors.lastname: Zocevic
authors.affiliation: Plateforme Protéomique/Spectrométrie de masse, Institut Jacques-Monod, Paris, France.
authors.forename: Thibaut
authors.initials: T
authors.lastname: Leger
authors.affiliation: Plateforme Protéomique/Spectrométrie de masse, Institut Jacques-Monod, Paris, France.
authors.forename: Camille
authors.initials: C
authors.lastname: Garcia
authors.affiliation: Plateforme Protéomique/Spectrométrie de masse, Institut Jacques-Monod, Paris, France.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Camadro
authors.affiliation: Folkhälsan Institute of Genetics and Department of Medical Genetics, Haartman Institute, University of Helsinki, Helsinki, Finland; Neuromuscular Research Center, Tampere University and University Hospital, Tampere, Finland; Department of Neurology, Vaasa Central Hospital, Vaasa, Finland.
authors.forename: Bjarne
authors.initials: B
authors.lastname: Udd
authors.affiliation: Division of Pediatric Neurology, Cincinnati Children's Hospital Medical Center, USA.
authors.forename: Brenda
authors.initials: B
authors.lastname: Wong
authors.affiliation: Service of Clinical Trials and Databases, Institut de Myologie, Paris, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Servais
authors.affiliation: UPMC INSERM UMR 974, CNRS FRE 3617, Myology Research Centre, Paris, France; Université Pierre et Marie Curie-Paris 6, Institut de Myologie, GH Pitié-Salpêtrière, Paris, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Voit
authors.affiliation: Généthon, Evry, France. Electronic address: svinar@genethon.fr.
authors.forename: Fedor
authors.initials: F
authors.lastname: Svinartchouk
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000818:Animals; D015415:Biomarkers / Q000652:urine; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D064211:Connectin / Q000235:genetics / Q000652:urine*; D052283:Creatine Kinase, MM Form / Q000097:blood; D004285:Dogs; D005260:Female; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009043:Motor Activity / Q000502:physiology; D020388:Muscular Dystrophy, Duchenne / Q000652:urine*; D011494:Protein Kinases / Q000235:genetics / Q000652:urine; D040901:Proteomics / Q000379:methods*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D064211:Connectin; C577285:TTN protein, human; D011494:Protein Kinases; C579730:titin protein, mouse; D052283:Creatine Kinase, MM Form
keywords: Biomarkers; DMD diagnosis; Dystrophin; Muscular dystrophy; Titin fragments