Proteomic identification of elevated saliva kallikrein levels in the mouse model of Duchenne muscular dystrophy.

Dystrophinopathies are multi-system disorders that affect the skeletal musculature, the cardio-respiratory system and the central nervous system. The systematic screening of suitable biofluids for released or altered proteins promises new insights into the highly complex pathophysiology of X-linked muscular dystrophy. However, standard detection approaches using antibody-based assays often fail to reproducibly detect low-abundance protein isoforms in dilute biological fluids.

Dataset on the comparative proteomic profiling of mouse saliva and serum from wild type versus the dystrophic mouse model of dystrophinopathy.

The comparative proteomic data presented in this article provide supporting information to the related research article "Proteomic identification of elevated saliva kallikrein levels in the mouse model of Duchenne muscular dystrophy " (Murphy et al., 2018). Here we provide additional datasets on the comparative proteomic analysis of saliva and serum proteins and the mass spectrometric identification of kallikrein isoform Klk-1 in wild type versus saliva specimens.

Proteomic profiling of liver tissue from the - mouse model of Duchenne muscular dystrophy.

Background: Duchenne muscular dystrophy is a highly complex multi-system disease caused by primary abnormalities in the membrane cytoskeletal protein dystrophin. Besides progressive skeletal muscle degeneration, this neuromuscular disorder is also associated with pathophysiological perturbations in many other organs including the liver. To determine potential proteome-wide alterations in liver tissue, we have used a comparative and mass spectrometry-based approach to study the dystrophic - mouse model of dystrophinopathy.

Chemical crosslinking analysis of β-dystroglycan in dystrophin-deficient skeletal muscle.

: In Duchenne muscular dystrophy, primary abnormalities in the membrane cytoskeletal protein dystrophin trigger the loss of sarcolemmal linkage between the extracellular matrix component laminin-211 and the intracellular cortical actin membrane cytoskeleton. The disintegration of the dystrophin-associated glycoprotein complex renders the plasma membrane of contractile fibres more susceptible to micro-rupturing, which is associated with abnormal calcium handling and impaired cellular signalling in dystrophinopathy. : The oligomerisation pattern of β-dystroglycan, an integral membrane protein belonging to the core dystrophin complex, was studied using immunoprecipitation and chemical crosslinking analysis.

Subproteomic profiling of sarcolemma from dystrophic skeletal muscle.

The proteomic data presented in this article provide supporting information to the related research article "Proteomic analysis of the sarcolemma-enriched fraction from dystrophic skeletal muscle" (Murphy et al., 2018) [1]. In the associated research article, the sarcolemma from normal versus dystrophic skeletal muscle was analyzed by mass spectrometry-based proteomics.

Comparative gel-based proteomic analysis of chemically crosslinked complexes in dystrophic skeletal muscle.

Duchenne muscular dystrophy is a highly progressive muscle wasting disease with a complex pathophysiology that is based on primary abnormalities in the dystrophin gene. In order to study potential changes in the oligomerization of high-molecular-mass protein complexes in dystrophic skeletal muscle, chemical crosslinking was combined with mass spectrometric analysis. The biochemical stabilization of protein interactions was carried out with the homo-bifunctional and amine-reactive agent bis[sulfosuccinimidyl]suberate, followed by protein shift analysis in one-dimensional gels.

Proteomic analysis of the sarcolemma-enriched fraction from dystrophic mdx-4cv skeletal muscle.

The highly progressive neuromuscular disorder dystrophinopathy is triggered by primary abnormalities in the Dmd gene, which causes cytoskeletal instability and loss of sarcolemmal integrity. Comparative organellar proteomics was employed to identify sarcolemma-associated proteins with an altered concentration in dystrophic muscle tissue from the mdx-4cv mouse model of dystrophinopathy. A lectin agglutination method was used to prepare a sarcolemma-enriched fraction and resulted in the identification of 190 significantly changed protein species.

Proteomic serum biomarkers for neuromuscular diseases.

The clinical evaluation of neuromuscular symptoms often includes the assessment of altered blood proteins or changed enzyme activities. However, the blood concentration of many muscle-derived serum markers is not specific for different neuromuscular disorders and also shows alterations in the course of these diseases. Thus, the establishment of more reliable biomarker signatures for improved muscle diagnostics is required.

Immunofluorescence Microscopy for DIGE-Based Proteomics.

Alterations in the proteome of a tissue in different settings, as assessed by difference gel electrophoresis, can be verified for single proteins using immunohistochemistry. In fluorescence immunohistochemistry, an antibody to a particular antigen is applied to tissue sections, and fluorophores conjugated to a secondary antibody allow for the detection of target antigen with fluorescent microscopy. Visual comparison is sufficient for the detection of significant alterations in the abundance of a certain protein in different settings.

Proteomic profiling of mdx-4cv serum reveals highly elevated levels of the inflammation-induced plasma marker haptoglobin in muscular dystrophy.

X-linked muscular dystrophy is caused by primary abnormalities in the Dmd gene and is characterized by the almost complete loss of the membrane cytoskeletal protein dystrophin, which triggers sarcolemmal instability, abnormal calcium homeostasis, increased proteolysis and impaired excitation‑contraction coupling. In addition to progressive necrosis, crucial secondary pathologies are represented by myofibrosis and the invasion of immune cells in damaged muscle fibres. In order to determine whether these substantial changes within the skeletal musculature are reflected by an altered rate of protein release into the circulatory system or other plasma fluctuations, we used label‑free mass spectrometry to characterize serum from the mdx‑4cv model of Duchenne muscular dystrophy.

Proteomic analysis of dystrophin deficiency and associated changes in the aged mdx-4cv heart model of dystrophinopathy-related cardiomyopathy.

Unlabelled: Cardiomyopathy is a serious complication in Duchenne muscular dystrophy, an X-linked neuromuscular disease of childhood that is triggered by primary abnormalities in the dystrophin gene. In order to directly correlate the deficiency in the membrane cytoskeletal protein dystrophin to secondary abnormalities in the dystrophic heart, this study has used label-free mass spectrometry to compare protein expression patterns in the aged mdx-4cv heart model of dystrophinopathy versus wild type heart. This report is the first successful identification of members of the cardiac dystrophin-glycoprotein complex by comparative whole tissue proteomics.

Label-free mass spectrometric analysis reveals complex changes in the brain proteome from the mdx-4cv mouse model of Duchenne muscular dystrophy.

Background: X-linked muscular dystrophy is a primary disease of the neuromuscular system. Primary abnormalities in the Dmd gene result in the absence of the full-length isoform of the membrane cytoskeletal protein dystrophin. Besides progressive skeletal muscle wasting and cardio-respiratory complications, developmental cognitive deficits and behavioural abnormalities are clinical features of Duchenne muscular dystrophy.

Concurrent Label-Free Mass Spectrometric Analysis of Dystrophin Isoform Dp427 and the Myofibrosis Marker Collagen in Crude Extracts from Skeletal Muscles.

The full-length dystrophin protein isoform of 427 kDa (Dp427), the absence of which represents the principal abnormality in X-linked muscular dystrophy, is difficult to identify and characterize by routine proteomic screening approaches of crude tissue extracts. This is probably related to its large molecular size, its close association with the sarcolemmal membrane, and its existence within a heterogeneous glycoprotein complex. Here, we used a careful extraction procedure to isolate the total protein repertoire from normal dystrophic skeletal muscles, in conjunction with label-free mass spectrometry, and successfully identified Dp427 by proteomic means.

Simultaneous Pathoproteomic Evaluation of the Dystrophin-Glycoprotein Complex and Secondary Changes in the mdx-4cv Mouse Model of Duchenne Muscular Dystrophy.

In skeletal muscle, the dystrophin-glycoprotein complex forms a membrane-associated assembly of relatively low abundance, making its detailed proteomic characterization in normal versus dystrophic tissues technically challenging. To overcome this analytical problem, we have enriched the muscle membrane fraction by a minimal differential centrifugation step followed by the comprehensive label-free mass spectrometric analysis of microsomal membrane preparations. This organelle proteomic approach successfully identified dystrophin and its binding partners in normal versus dystrophic hind limb muscles.

Label-free mass spectrometric analysis of the mdx-4cv diaphragm identifies the matricellular protein periostin as a potential factor involved in dystrophinopathy-related fibrosis.

Proteomic profiling plays a decisive role in the identification of novel biomarkers of muscular dystrophy and the elucidation of new pathobiochemical mechanisms that underlie progressive muscle wasting. Building on the findings of recent comparative analyses of tissue samples and body fluids from dystrophic animals and patients afflicted with Duchenne muscular dystrophy, we have used here label-free MS to study the severely dystrophic diaphragm from the not extensively characterized mdx-4cv mouse. This animal model of progressive muscle wasting exhibits less dystrophin-positive revertant fibers than the conventional mdx mouse, making it ideal for the future monitoring of experimental therapies.

Reduction of high background staining by heating unfixed mouse skeletal muscle tissue sections allows for detection of thermostable antigens with murine monoclonal antibodies.

Antigen detection with indirect immunohistochemical methods is hampered by high background staining if the primary antibody is from the same species as the examined tissue. This high background can be eliminated in unfixed cryostat sections of mouse skeletal muscle by boiling sections in PBS, and several proteins including even the low abundant dystrophin protein can then be easily detected with murine monoclonal antibodies. However, not all antigens withstand the boiling procedure.

Age dependence of the human skeletal muscle stem cell in forming muscle tissue.

Human skeletal muscle stem cells from healthy donors aged 2-82 years (n = 13) and from three children suffering from Duchenne Muscular Dystrophy (DMD) were implanted into soleus muscles of immunoincompetent mice and were also expanded in vitro until senescence. Growth of implanted cells was quantified by structural features and by the amount of human DNA present in a muscle. Proliferative capacity in vitro and in vivo was inversely related to age of the donor.

The vast majority of bone-marrow-derived cells integrated into mdx muscle fibers are silent despite long-term engraftment.

Bone-marrow-derived cells can contribute nuclei to skeletal muscle fibers. However, serial sectioning of muscle in mdx mice implanted with GFP-labeled bone marrow reveals that only 20% of the donor nuclei chronically incorporated in muscle fibers show dystrophin (or GFP) expression, which is still higher than the expected frequency of "revertant" fibers, but there is no overall increase above controls over time. Obviously, the vast majority of incorporated nuclei either never or only temporarily turn on myogenic genes; also, incorporated nuclei eventually loose the activation of the beta-actin::GFP transgene.

On the regenerative capacity of human skeletal muscle.

The proliferative capacity of organotypic muscle stem cells, the satellite cells, from nine healthy human donors aged between 2 and 78 years was investigated. There was a loss in proliferative capacity with age, but the oldest donors (76, 78 years) would still be able to replace their musculature several times. Depending on frequency of desmin-positive (i.