scholarly journals Caveolin-3: A Causative Process of Chicken Muscular Dystrophy

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1206
Author(s):  
Tateki Kikuchi

The etiology of chicken muscular dystrophy is the synthesis of aberrant WW domain containing E3 ubiquitin-protein ligase 1 (WWP1) protein made by a missense mutation of WWP1 gene. The β-dystroglycan that confers stability to sarcolemma was identified as a substrate of WWP protein, which induces the next molecular collapse. The aberrant WWP1 increases the ubiquitin ligase-mediated ubiquitination following severe degradation of sarcolemmal and cytoplasmic β-dystroglycan, and an erased β-dystroglycan in dystrophic αW fibers will lead to molecular imperfection of the dystrophin-glycoprotein complex (DGC). The DGC is a core protein of costamere that is an essential part of force transduction and protects the muscle fibers from contraction-induced damage. Caveolin-3 (Cav-3) and dystrophin bind competitively to the same site of β-dystroglycan, and excessive Cav-3 on sarcolemma will block the interaction of dystrophin with β-dystroglycan, which is another reason for the disruption of the DGC. It is known that fast-twitch glycolytic fibers are more sensitive and vulnerable to contraction-induced small tears than slow-twitch oxidative fibers under a variety of diseased conditions. Accordingly, the fast glycolytic αW fibers must be easy with rapid damage of sarcolemma corruption seen in chicken muscular dystrophy, but the slow oxidative fibers are able to escape from these damages.

Author(s):  
Stéphanie Daval ◽  
Chantal Rocher ◽  
Yan Cherel ◽  
Elisabeth Rumeur

AbstractThe dystrophin-glycoprotein complex (DGC) is a large trans-sarcolemmal complex that provides a linkage between the subsarcolemmal cytoskeleton and the extracellular matrix. In skeletal muscle, it consists of the dystroglycan, sarcoglycan and cytoplasmic complexes, with dystrophin forming the core protein. The DGC has been described as being absent or greatly reduced in dystrophin-deficient muscles, and this lack is considered to be involved in the dystrophic phenotype. Such a decrease in the DGC content was observed in dystrophin-deficient muscle from humans with muscular dystrophy and in mice with X-linked muscular dystrophy (mdx mice). These deficits were observed in total muscle homogenates and in partially membrane-purified muscle fractions, the so-called KCl-washed microsomes. Here, we report that most of the proteins of the DGC are actually present at normal levels in the mdx mouse muscle plasma membrane. The proteins are detected in dystrophic animal muscles when the immunoblot assay is performed with crude surface membrane fractions instead of the usually employed KCl-washed microsomes. We propose that these proteins form SDS-insoluble membrane complexes when dystrophin is absent.


2006 ◽  
Vol 290 (2) ◽  
pp. C577-C582 ◽  
Author(s):  
Stefania Assereto ◽  
Silvia Stringara ◽  
Federica Sotgia ◽  
Gloria Bonuccelli ◽  
Aldobrando Broccolini ◽  
...  

In this report, we have developed a novel method to identify compounds that rescue the dystrophin-glycoprotein complex (DGC) in patients with Duchenne or Becker muscular dystrophy. Briefly, freshly isolated skeletal muscle biopsies (termed skeletal muscle explants) from patients with Duchenne or Becker muscular dystrophy were maintained under defined cell culture conditions for a 24-h period in the absence or presence of a specific candidate compound. Using this approach, we have demonstrated that treatment with a well-characterized proteasome inhibitor, MG-132, is sufficient to rescue the expression of dystrophin, β-dystroglycan, and α-sarcoglycan in skeletal muscle explants from patients with Duchenne or Becker muscular dystrophy. These data are consistent with our previous findings regarding systemic treatment with MG-132 in a dystrophin-deficient mdx mouse model (Bonuccelli G, Sotgia F, Schubert W, Park D, Frank PG, Woodman SE, Insabato L, Cammer M, Minetti C, and Lisanti MP. Am J Pathol 163: 1663–1675, 2003). Our present results may have important new implications for the possible pharmacological treatment of Duchenne or Becker muscular dystrophy in humans.


2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Yuka Morikawa ◽  
Todd Heallen ◽  
John Leach ◽  
Yang Xiao ◽  
James Martin

Regeneration of mammalian heart is limited due to the extremely low renewal rate of cardiomyocytes and their inability to reenter the cell cycle. The Hippo pathway controls heart size during development and represses postnatal heart regeneration by repressing cardiomyocyte proliferation. Our approach for activating adult heart regeneration is to uncover the mechanisms responsible for repression of cardiomyocyte proliferation. We have previously found that deletion of Salv, a modulator of the Hippo pathway, results in myocardial damage repair in postnatal and adult hearts. Deletion of Salv results in activation of the transcription factor, Yap, which positively regulates cytoskeleton and cell cycle genes. We also found that the components of dystrophin glycoprotein complex (DGC) are the target of Yap and DGC regulates heart regeneration. The dystrophin glycoprotein complex (DGC) is essential for muscle maintenance by anchoring the cytoskeleton and extracellular matrix. Disruption of the DGC results in muscular dystrophies, including Duchenne muscular dystrophy, resulting in both skeletal and cardiac myopathies. To explore the connection between DGC and the Hippo pathway, we conditionally deleted Salv in the mdx background, a mouse model of muscular dystrophy. We found that simultaneous disruption of the DGC and the Hippo pathway leads an increased cardiomyocyte proliferation after heart damage. This is associated with increased activity of Yap, suggesting DGC negatively regulate Yap to repress proliferation. We also found that one of the components DGC, dystroglycan directly binds Yap and anchors to the membrane. Our findings provide new insights into the mechanisms leading to heart repair through proliferation of endogenous cardiomyocytes.


2002 ◽  
Vol 283 (4) ◽  
pp. C1090-C1101 ◽  
Author(s):  
Robert W. Grange ◽  
Thomas G. Gainer ◽  
Krista M. Marschner ◽  
Robert J. Talmadge ◽  
James T. Stull

Loss of the dystrophin-glycoprotein complex from muscle sarcolemma in Duchenne's muscular dystrophy (DMD) renders the membrane susceptible to mechanical injury, leaky to Ca2+, and disrupts signaling, but the precise mechanism(s) leading to the onset of DMD remain unclear. To assess the role of mechanical injury in the onset of DMD, extensor digitorum longus (EDL) muscles from C57 (control), mdx, and mdx-utrophin-deficient [ mdx:utrn(−/−); dystrophic] pups aged 9–12 days were subjected to an acute stretch-injury or no-stretch protocol in vitro. Before the stretches, isometric stress was attenuated for mdx:utrn(−/−) compared with control muscles at all stimulation frequencies ( P< 0.05). During the stretches, EDL muscles for each genotype demonstrated similar mean stiffness values. After the stretches, isometric stress during a tetanus was decreased significantly for both mdx and mdx:utrn(−/−) muscles compared with control muscles ( P < 0.05). Membrane injury assessed by uptake of procion orange dye was greater for dystrophic compared with control EDL ( P < 0.05), but, within each genotype, the percentage of total cells taking up dye was not different for the no-stretch vs. stretch condition. These data suggest that the sarcolemma of maturing dystrophic EDL muscles are resistant to acute mechanical injury.


2007 ◽  
Vol 17 (4) ◽  
pp. 285-289 ◽  
Author(s):  
Heather MacLeod ◽  
Peter Pytel ◽  
Robert Wollmann ◽  
Ewa Chelmicka-Schorr ◽  
Kenneth Silver ◽  
...  

2008 ◽  
Vol 294 (2) ◽  
pp. C627-C640 ◽  
Author(s):  
Jianming Liu ◽  
Dean J. Burkin ◽  
Stephen J. Kaufman

The dystrophin-glycoprotein complex maintains the integrity of skeletal muscle by associating laminin in the extracellular matrix with the actin cytoskeleton. Several human muscular dystrophies arise from defects in the components of this complex. The α7β1-integrin also binds laminin and links the extracellular matrix with the cytoskeleton. Enhancement of α7-integrin levels alleviates pathology in mdx/utrn−/− mice, a model of Duchenne muscular dystrophy, and thus the integrin may functionally compensate for the absence of dystrophin. To test whether increasing α7-integrin levels affects transcription and cellular functions, we generated α7-integrin-inducible C2C12 cells and transgenic mice that overexpress the integrin in skeletal muscle. C2C12 myoblasts with elevated levels of integrin exhibited increased adhesion to laminin, faster proliferation when serum was limited, resistance to staurosporine-induced apoptosis, and normal differentiation. Transgenic expression of eightfold more integrin in skeletal muscle did not result in notable toxic effects in vivo. Moreover, high levels of α7-integrin in both myoblasts and in skeletal muscle did not disrupt global gene expression profiles. Thus increasing integrin levels can compensate for defects in the extracellular matrix and cytoskeleton linkage caused by compromises in the dystrophin-glycoprotein complex without triggering apparent overt negative side effects. These results support the use of integrin enhancement as a therapy for muscular dystrophy.


2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Jessica D. Gumerson ◽  
Daniel E. Michele

Muscular dystrophies are genetically diverse but share common phenotypic features of muscle weakness, degeneration, and progressive decline in muscle function. Previous work has focused on understanding how disruptions in the dystrophin-glycoprotein complex result in muscular dystrophy, supporting a hypothesis that the muscle sarcolemma is fragile and susceptible to contraction-induced injury in multiple forms of dystrophy. Although benign in healthy muscle, contractions in dystrophic muscle may contribute to a higher degree of muscle damage which eventually overwhelms muscle regeneration capacity. While increased susceptibility of muscle to mechanical injury is thought to be an important contributor to disease pathology, it is becoming clear that not all DGC-associated diseases share this supposed hallmark feature. This paper outlines experimental support for a function of the DGC in preventing muscle damage and examines the evidence that supports novel functions for this complex in muscle that when impaired, may contribute to the pathogenesis of muscular dystrophy.


Sign in / Sign up

Export Citation Format

Share Document