RESUMEN
PURPOSE: To identify and validate serum biomarkers for the progression of Duchenne muscular dystrophy (DMD) using a MS-based bottom-up pipeline. EXPERIMENTAL DESIGN: We used a bottom-up proteomics approach, including a protein concentration equalization step, different proteolytic digestions, and MS detection schemes, to identify candidate biomarkers in serum samples from control subjects and DMD patients. Fibronectin was chosen for follow-up based on the differences in peptide spectral counts and sequence coverage observed between the DMD and control groups. Subsequently, fibronectin levels were determined with ELISA in 68 DMD patients, 38 milder Becker muscular dystrophy patients, 33 patients with other neuromuscular disorders, and 15 age-matched adult and child controls. RESULTS: There was a significant increase in fibronectin levels in DMD patients compared to age-matched controls. Fibronectin levels in patients with Becker muscular dystrophy, Bethlem myopathy, or myasthenia gravis were comparable to control levels. Progressive elevation in fibronectin levels was observed in longitudinal samples from 22 DMD patients followed up for a period of 6 months up to 4 years. CONCLUSION AND CLINICAL RELEVANCE: This study suggests that serum fibronectin levels may constitute a promising biomarker to monitor disease progression in DMD patients.
Asunto(s)
Biomarcadores/sangre , Fibronectinas/sangre , Músculo Esquelético/metabolismo , Distrofia Muscular de Duchenne/sangre , Adolescente , Adulto , Niño , Preescolar , Contractura/sangre , Contractura/genética , Contractura/patología , Femenino , Fibronectinas/genética , Humanos , Masculino , Espectrometría de Masas , Persona de Mediana Edad , Músculo Esquelético/patología , Distrofias Musculares/sangre , Distrofias Musculares/congénito , Distrofias Musculares/genética , Distrofias Musculares/patología , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patología , Miastenia Gravis/sangre , Miastenia Gravis/genética , Miastenia Gravis/patologíaRESUMEN
The Kruppel-like factor (KLF) family of transcription factors regulates diverse cell biological processes including proliferation, differentiation, survival and growth. Previous studies have shown that KLF15 inhibits cardiac hypertrophy by repressing the activity of pivotal cardiac transcription factors such as GATA4, MEF2 and myocardin. We set out this study to characterize the interaction of KLF15 with putative other transcription factors. We first show that KLF15 interacts with myocardin-related transcription factors (MRTFs) and strongly represses the transcriptional activity of MRTF-A and MRTF-B. Second, we identified a region within the C-terminal zinc fingers of KLF15 that contains the nuclear localization signal. Third, we investigated whether overexpression of KLF15 in the heart would have therapeutic potential. Using recombinant adeno-associated viruses (rAAV) we have overexpressed KLF15 specifically in the mouse heart and provide the first evidence that elevation of cardiac KLF15 levels prevents the development of cardiac hypertrophy in a model of Angiotensin II induced hypertrophy.