scholarly journals Desmin-related cardiomyopathy: an unfolding story

2011 ◽  
Vol 301 (4) ◽  
pp. H1220-H1228 ◽  
Author(s):  
Patrick M. McLendon ◽  
Jeffrey Robbins

The intermediate filament protein desmin is an integral component of the cardiomyocyte and serves to maintain the overall structure and cytoskeletal organization within striated muscle cells. Desmin-related myopathy can be caused by mutations in desmin or associated proteins, which leads to intracellular accumulation of misfolded protein and production of soluble pre-amyloid oligomers, which leads to weakened skeletal and cardiac muscle. In this review, we examine the cellular phenotypes in relevant animal models of desmin-related cardiomyopathy. These models display characteristic sarcoplasmic protein aggregates. Aberrant protein aggregation leads to mitochondrial dysfunction, abnormal metabolism, and altered cardiomyocyte structure. These deficits to cardiomyocyte function may stem from impaired cellular proteolytic mechanisms. The data obtained from these models allow a more complete picture of the pathology in desmin-related cardiomyopathy to be described. Moreover, these studies highlight the importance of desmin in maintaining cardiomyocyte structure and illustrate how disrupting this network can be deleterious to the heart. We emphasize the similarities observed between desmin-related cardiomyopathy and other protein conformational disorders and speculate that therapies to treat this disease may be broadly applicable to diverse protein aggregation-based disorders.

1994 ◽  
Vol 42 (11) ◽  
pp. 1499-1502 ◽  
Author(s):  
B P Hierck ◽  
L V Iperen ◽  
A C Gittenberger-De Groot ◽  
R E Poelmann

The indirect immunodetection method is powerful in detecting antigens in situ, but to date mouse monoclonal antibodies (MAbs) could not be used in immunohistochemical studies of murine tissues without severe background staining. We report here a modification of this method in which mouse MAbs are used to detect murine antigens in cryosections. Before application to the section, mouse MAbs and conjugated anti-mouse antiserum were allowed to complex in vitro. After blocking of the unbound secondary antiserum with normal mouse serum, standard immunohistochemistry was performed. Fifty percent of a randomly chosen panel of over 40 mouse MAbs recognized their antigens in our model system. Adaptation of, for example, the fixation protocol can probably even increase this number. An MAb to the intermediate filament protein desmin, staining both smooth and striated muscle, was used to demonstrate this technique in cryosections of 15-day-old mouse embryos. In contrast to standard immunohistochemistry with the same antibodies under the same conditions, background staining was completely absent with this technique. With this modification to the well-established indirect detection method, the usefulness of mouse MAbs is significantly increased.


Author(s):  
Yukiko Sugi

In cultured skeletal muscle cells of chick, one intermediate filament protein, vimentin, is primarily formed and then synthesis of desmin follows. Coexistence of vimentin and desmin has been immunocytochemically confirmed in chick embryonic skeletal musclecells. Immunofluorescent localization of vimentin and desmin has been described in developing myocardial cells of hamster. However, initial localization of desmin and vimentin in early embryonic heart has not been reported in detail. By quick-freeze deep-etch method a loose network of intermediate filaments was revealed to exist surrounding myofibrils. In this report, immunocytochemical localization of desmin and vimentin is visualized in early stages of chick embryonic my ocardium.Chick embryos, Hamburger-Hamilton (H-H) stage 8 to hatch, and 1 day old postnatal chicks were used in this study. For immunofluorescence study, each embryo was fixed with 4% paraformaldehyde and embedded in Epon 812. De-epoxinized with sodium methoxide, semithin sections were stained with primary antibodies (rabbit anti-desmin antibody and anti-vimentin antibody)and secondary antibody (RITC conjugated goat-anti rabbit IgG).


2020 ◽  
Author(s):  
Shiyu Luo ◽  
Qifei Li ◽  
Jasmine Lin ◽  
Quinn Murphy ◽  
Isabelle Marty ◽  
...  

Abstract SPEG, a member of the myosin light chain kinase family, is localized at the level of triad surrounding myofibrils in skeletal muscles. In humans, SPEG mutations are associated with centronuclear myopathy and cardiomyopathy. Using a striated muscle specific Speg-knockout (KO) mouse model, we have previously shown that SPEG is critical for triad maintenance and calcium handling. Here we further examined the molecular function of SPEG and characterized the effects of SPEG deficiency on triad and focal adhesion proteins. We used yeast two-hybrid assay, and identified desmin, an intermediate filament protein, to interact with SPEG and confirmed this interaction by co-immunoprecipitation. Using domain-mapping assay, we defined that Ig-like and fibronectin III domains of SPEG interact with rod domain of desmin. In skeletal muscles, SPEG depletion leads to desmin aggregates in vivo and a shift in desmin equilibrium from soluble to insoluble fraction. We also profiled the expression and localization of triadic proteins in Speg-KO mice using western blot and immunofluorescence. The amounts of RyR1 and triadin were markedly reduced, whereas DHPRα1, SERCA1, and triadin were abnormally accumulated in discrete areas of Speg-KO myofibers. In addition, Speg-KO muscles exhibited internalized vinculin and β1 integrin, both of which are critical components of the focal adhesion complex. Further, β1 integrin was abnormally accumulated in early endosomes of Speg-KO myofibers. These results demonstrate that SPEG-deficient skeletal muscles exhibit several pathological features similar to those seen in MTM1 deficiency. Defects of shared cellular pathways may underlie these structural and functional abnormalities in both types of diseases.


2005 ◽  
Vol 280 (17) ◽  
pp. 16882-16890 ◽  
Author(s):  
Svetlana Ermakova ◽  
Bu Young Choi ◽  
Hong Seok Choi ◽  
Bong Seok Kang ◽  
Ann M. Bode ◽  
...  

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