Search results for "Myogenesis"
showing 10 items of 42 documents
The metalloproteinase-disintegrin ADAM10 is exclusively expressed by type I muscle fibers.
2008
ADAM10 (Kuzbanian) is a member of a recently discovered family of membrane-anchored metalloproteinases with a complex and conserved domain structure. In part, these metalloproteinases have been implicated in muscle formation. Herein the expression pattern of ADAM10 in human skeletal muscle was studied. ADAM10 was found to be present in human myoblasts and to be exclusively expressed in type I fibers, suggesting that it may be critical in muscle fiber differentiation.
MICROWAVE EFFECTS ON ACETYLCHOLINE-INDUCED CHANNELS IN CULTURED CHICK MYOTUBES
1988
The behavior of cultured myotubes from chick embryos exposed to microwaves has been experimentally analyzed. Recordings of acetylcholine-induced currents have been obtained via patch-clamp techniques using both cell-attached (single-channel current recording) and whole-cell (total current recording) configurations. During the exposure to low-power microwaves the frequency of the ACh-activated single channel openings decreased, while the ACh-induced total current showed a faster falling phase. Channel open time and conductance were not affected by microwave irradiation. It is concluded that the exposure to microwaves increases the rate of desensitization and decreases the channel opening pro…
Bortezomib Partially Improves Laminin α2 Chain–Deficient Muscular Dystrophy
2014
Congenital muscular dystrophy, caused by mutations in LAMA2 (the gene encoding laminin α2 chain), is a severe and incapacitating disease for which no therapy is yet available. We have recently demonstrated that proteasome activity is increased in laminin α2 chain-deficient muscle and that treatment with the nonpharmaceutical proteasome inhibitor MG-132 reduces muscle pathology in laminin α2 chain-deficient dy(3K)/dy(3K) mice. Here, we explore the use of the selective and therapeutic proteasome inhibitor bortezomib (currently used for treatment of relapsed multiple myeloma and mantle cell lymphoma) in dy(3K)/dy(3K) mice and in congenital muscular dystrophy type 1A muscle cells. Outcome measu…
Erbb2 regulates neuromuscular synapse formation and is essential for muscle spindle development
2003
Neuregulins and their Erbb receptors have been implicated in neuromuscular synapse formation by regulating gene expression in subsynaptic nuclei. To analyze the function of Erbb2 in this process, we have inactivated the Erbb2 gene in developing muscle fibers by Cre/Lox-mediated gene ablation. Neuromuscular synapses form in the mutant mice, but the synapses are less efficient and contain reduced levels of acetylcholine receptors. Surprisingly, the mutant mice also show proprioceptive defects caused by abnormal muscle spindle development. Sensory Ia afferent neurons establish initial contact with Erbb2-deficient myotubes. However, functional spindles never develop. Taken together, our data su…
Resveratrol initiates differentiation of mouse skeletal muscle-derived C2C12 myoblasts.
2012
Resveratrol is one of the most widely studied bio-active plant polyphenols. While its effect on endothelial blood vessel cells, cancer cells, inflammatory processes and neurodegenerative events is well documented, little is known about the implication of this phytophenol in differentiating processes, particularly in skeletal muscle cells. Here, we report the effects of resveratrol on mouse skeletal muscle-derived cells (C2C12) in either a nondifferentiated (myoblasts) or differentiated state (myotubes) by evaluating resveratrol uptake, cell proliferation, changes in cell shape, and the expression of genes encoding muscle-specific transcription factors or contractile proteins. Resveratrol: (…
Alix protein is substrate of Ozz-E3 ligase and modulates actin remodeling in skeletal muscle
2012
Alix/AIP1 is a multifunctional adaptor protein that participates in basic cellular processes, including membrane trafficking and actin cytoskeleton assembly, by binding selectively to a variety of partner proteins. However, the mechanisms regulating Alix turnover, subcellular distribution, and function in muscle cells are unknown. We now report that Alix is expressed in skeletal muscle throughout myogenic differentiation. In myotubes, a specific pool of Alix colocalizes with Ozz, the substrate-binding component of the muscle-specific ubiquitin ligase complex Ozz-E3. We found that interaction of the two endogenous proteins in the differentiated muscle fibers changes Alix conformation and pro…
Preclinical characterization of antagomiR-218 as a potential treatment for myotonic dystrophy
2021
Myotonic dystrophy type 1 (DM1) is a rare neuromuscular disease caused by expansion of unstable CTG repeats in a non-coding region of the DMPK gene. CUG expansions in mutant DMPK transcripts sequester MBNL1 proteins in ribonuclear foci. Depletion of this protein is a primary contributor to disease symptoms such as muscle weakness and atrophy and myotonia, yet upregulation of endogenous MBNL1 levels may compensate for this sequestration. Having previously demonstrated that antisense oligonucleotides against miR-218 boost MBNL1 expression and rescue phenotypes in disease models, here we provide preclinical characterization of an antagomiR-218 molecule using the HSALR mouse model and patient-d…
Musashi-2 contributes to myotonic dystrophy muscle dysfunction by promoting excessive autophagy through miR-7 biogenesis repression
2021
Skeletal muscle symptoms strongly contribute to mortality of myotonic dystrophy type 1 (DM1) patients. DM1 is a neuromuscular genetic disease caused by CTG repeat expansions that, upon transcription, sequester the Muscleblind-like family of proteins and dysregulate alternative splicing of hundreds of genes. However, mis-splicing does not satisfactorily explain muscle atrophy and wasting, and several other contributing factors have been suggested, including hyperactivated autophagy leading to excessive catabolism. MicroRNA ( miR ) -7 has been demonstrated to be necessary and sufficient to repress the autophagy pathway in cell models of the disease, but the origin of its low levels in DM1 was…
Exercise-Induced Activation and Translocation of αB-Crystallin in Skeletal Muscle Depends upon Fiber Type and Oxidative Stress
2016
Alpha B-crystallin (CRYAB) is a member of the small heat shock proteins implicated in various biological functions, particularly in skeletal muscle tissue [1], where it results to be modulated following exercise-induced reactive oxygen species (ROS) [2]. In this work we aimed to analyse the CRYAB response to acute exercise with respect muscle fiber composition and to identify the underlying molecular mechanism by the utilization of the C2C12 “in vitro” cellular model. Our results highlighted as acute exercise determines a specific increase of phospho-CRYAB both in the red, but not white, gastrocnemius (GS), with an higher amount of oxidative and oxidative-glycolytic fibers, and in soleus (S…
Effects of combined hormone replacement therapy or its effective agents on the IGF-1 pathway in skeletal muscle.
2010
Objectives To investigate the effects of combined hormone replacement therapy (HRT) and its effective agents on the IGF-1 signaling pathway. Design and methods To examine the effects of HRT on skeletal muscle in vivo, we utilized pre- and post-intervention samples from a randomized double blinded trial with 50–57-year-old women. The intervention included the year-long use of either HRT preparation (2 mg 17β-estradiol, E2; 1 mg norethisterone acetate, NETA, n = 10) or placebo (CO, n = 9). Microarray technology and quantitative PCR (qPCR) were used to study the expression of insulin-like growth factor I (IGF-1) and its splice variants as well as IGF-1 receptor, Akt1, mTOR, FOXO1, FOXO3, atrog…