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Translational Vision Science &... Sep 2020To study the medial rectus (MR) muscle of zebrafish () with respect to the pattern of distribution of desmin and its correlation to distinct types of myofibers and motor...
PURPOSE
To study the medial rectus (MR) muscle of zebrafish () with respect to the pattern of distribution of desmin and its correlation to distinct types of myofibers and motor endplates.
METHODS
The MRs of zebrafish were examined using confocal microscopy in whole-mount longitudinal specimens and in cross sections processed for immunohistochemistry with antibodies against desmin, myosin heavy chain isoforms, and innervation markers. Desmin patterns were correlated to major myofiber type and type of innervation. A total of 1382 myofibers in nine MR muscles were analyzed.
RESULTS
Four distinct desmin immunolabeling patterns were found in the zebrafish MRs. Approximately a third of all slow myofibers lacked desmin, representing 8.5% of the total myofiber population. The adult zebrafish MR muscle displayed en grappe, en plaque, and multiterminal en plaque neuromuscular junctions (NMJs) with intricate patterns of desmin immunolabeling.
CONCLUSIONS
The MRs of zebrafish showed important similarities with the human extraocular muscles with regard to the pattern of desmin distribution and presence of the major types of NMJs and can be regarded as an adequate model to further study the role of desmin and the implications of heterogeneity in cytoskeletal protein composition.
TRANSLATIONAL RELEVANCE
The establishment of a zebrafish model to study the cytoskeleton in muscles that are particularly resistant to muscle disease opens new avenues to understand human myopathies and muscle dystrophies and may provide clues to new therapies.
Topics: Animals; Desmin; Humans; Motor Endplate; Myosin Heavy Chains; Oculomotor Muscles; Zebrafish
PubMed: 32953241
DOI: 10.1167/tvst.9.10.1 -
Journal of Cachexia, Sarcopenia and... Oct 2020Desminopathy is a clinically heterogeneous muscle disease caused by over 60 different mutations in desmin. The most common mutation with a clinical phenotype in humans...
BACKGROUND
Desminopathy is a clinically heterogeneous muscle disease caused by over 60 different mutations in desmin. The most common mutation with a clinical phenotype in humans is an exchange of arginine to proline at position 350 of desmin leading to p.R350P. We created the first CRISPR-Cas9 engineered rat model for a muscle disease by mirroring the R350P mutation in humans.
METHODS
Using CRISPR-Cas9 technology, Des c.1045-1046 (AGG > CCG) was introduced into exon 6 of the rat genome causing p.R349P. The genotype of each animal was confirmed via quantitative PCR. Six male rats with a mutation in desmin (n = 6) between the age of 120-150 days and an equal number of wild type littermates (n = 6) were used for experiments. Maximal plantar flexion force was measured in vivo and combined with the collection of muscle weights, immunoblotting, and histological analysis. In addition to the baseline phenotyping, we performed a synergist ablation study in the same animals.
RESULTS
We found a difference in the number of central nuclei between desmin mutants (1 ± 0.4%) and wild type littermates (0.2 ± 0.1%; P < 0.05). While muscle weights did not differ, we found the levels of many structural proteins to be altered in mutant animals. Dystrophin and syntrophin were increased 54% and 45% in desmin mutants, respectively (P < 0.05). Dysferlin and Annexin A2, proteins associated with membrane repair, were increased two-fold and 32%, respectively, in mutants (P < 0.05). Synergist ablation caused similar increases in muscle weight between mutant and wild type animals, but changes in fibre diameter revealed that fibre hypertrophy in desmin mutants was hampered compared with wild type animals (P < 0.05).
CONCLUSIONS
We created a novel animal model for desminopathy that will be a useful tool in furthering our understanding of the disease. While mutant animals at an age corresponding to a preclinical age in humans show no macroscopic differences, microscopic and molecular changes are already present. Future studies should aim to further decipher those biological changes that precede the clinical progression of disease and test therapeutic approaches to delay disease progression.
Topics: Animals; CRISPR-Cas Systems; Desmin; Dystrophin; Male; Mice; Muscular Diseases; Mutation; Rats
PubMed: 32893996
DOI: 10.1002/jcsm.12619 -
Proceedings of the National Academy of... Feb 2021Low complexity (LC) head domains 92 and 108 residues in length are, respectively, required for assembly of neurofilament light (NFL) and desmin intermediate filaments...
Low complexity (LC) head domains 92 and 108 residues in length are, respectively, required for assembly of neurofilament light (NFL) and desmin intermediate filaments (IFs). As studied in isolation, these IF head domains interconvert between states of conformational disorder and labile, β-strand-enriched polymers. Solid-state NMR (ss-NMR) spectroscopic studies of NFL and desmin head domain polymers reveal spectral patterns consistent with structural order. A combination of intein chemistry and segmental isotope labeling allowed preparation of fully assembled NFL and desmin IFs that could also be studied by ss-NMR. Assembled IFs revealed spectra overlapping with those observed for β-strand-enriched polymers formed from the isolated NFL and desmin head domains. Phosphorylation and disease-causing mutations reciprocally alter NFL and desmin head domain self-association yet commonly impede IF assembly. These observations show how facultative structural assembly of LC domains via labile, β-strand-enriched self-interactions may broadly influence cell morphology.
Topics: Desmin; Humans; Intermediate Filaments; Phosphorylation; Protein Conformation; Protein Domains
PubMed: 33593918
DOI: 10.1073/pnas.2022121118 -
American Journal of Physiology. Cell... May 2019Mitochondria perform a central role in life and death of the eukaryotic cell. They are major players in the generation of macroergic compounds and function as integrated... (Review)
Review
Mitochondria perform a central role in life and death of the eukaryotic cell. They are major players in the generation of macroergic compounds and function as integrated signaling pathways, including the regulation of Ca signals and apoptosis. A growing amount of evidence is demonstrating that mitochondria of muscle cells use cytoskeletal proteins (both microtubules and intermediate filaments) not only for their movement and proper cellular positioning, but also to maintain their biogenesis, morphology, function, and regulation of energy fluxes through the outer mitochondrial membrane (MOM). Here we consider the known literature data concerning the role of tubulin, plectin, desmin and vimentin in bioenergetic function of mitochondria in striated muscle cells, as well as in controlling the permeability of MOM for adenine nucleotides (ADNs). This is of great interest since dysfunctionality of these cytoskeletal proteins has been shown to result in severe myopathy associated with pronounced mitochondrial dysfunction. Further efforts are needed to uncover the pathways by which the cytoskeleton supports the functional capacity of mitochondria and transport of ADN(s) across the MOM (through voltage-dependent anion channel).
Topics: Animals; Desmin; Humans; Mitochondria; Mitochondrial Membranes; Muscle Cells; Plectin; Tubulin; Vimentin
PubMed: 30811221
DOI: 10.1152/ajpcell.00303.2018 -
International Journal of Molecular... Oct 2022Desmin mutations cause familial and sporadic cardiomyopathies. In addition to perturbing the contractile apparatus, both desmin deficiency and mutated desmin negatively...
Desmin mutations cause familial and sporadic cardiomyopathies. In addition to perturbing the contractile apparatus, both desmin deficiency and mutated desmin negatively impact mitochondria. Impaired myocardial metabolism secondary to mitochondrial defects could conceivably exacerbate cardiac contractile dysfunction. We performed metabolic myocardial phenotyping in left ventricular cardiac muscle tissue in desmin knock-out mice. Our analyses revealed decreased mitochondrial number, ultrastructural mitochondrial defects, and impaired mitochondria-related metabolic pathways including fatty acid transport, activation, and catabolism. Glucose transporter 1 and hexokinase-1 expression and hexokinase activity were increased. While mitochondrial creatine kinase expression was reduced, fetal creatine kinase expression was increased. Proteomic analysis revealed reduced expression of proteins involved in electron transport mainly of complexes I and II, oxidative phosphorylation, citrate cycle, beta-oxidation including auxiliary pathways, amino acid catabolism, and redox reactions and oxidative stress. Thus, desmin deficiency elicits a secondary cardiac mitochondriopathy with severely impaired oxidative phosphorylation and fatty and amino acid metabolism. Increased glucose utilization and fetal creatine kinase upregulation likely portray attempts to maintain myocardial energy supply. It may be prudent to avoid medications worsening mitochondrial function and other metabolic stressors. Therapeutic interventions for mitochondriopathies might also improve the metabolic condition in desmin deficient hearts.
Topics: Amino Acids; Animals; Cardiomyopathies; Citrates; Creatine Kinase, Mitochondrial Form; Desmin; Fatty Acids; Glucose; Glucose Transporter Type 1; Hexokinase; Mice; Mice, Knockout; Myocardium; Oxidative Phosphorylation; Proteomics
PubMed: 36233322
DOI: 10.3390/ijms231912020 -
Brazilian Journal of Medical and... Dec 2004Desmin is the intermediate filament (IF) protein occurring exclusively in muscle and endothelial cells. There are other IF proteins in muscle such as nestin, peripherin,... (Review)
Review
Desmin is the intermediate filament (IF) protein occurring exclusively in muscle and endothelial cells. There are other IF proteins in muscle such as nestin, peripherin, and vimentin, besides the ubiquitous lamins, but they are not unique to muscle. Desmin was purified in 1977, the desmin gene was characterized in 1989, and knock-out animals were generated in 1996. Several isoforms have been described. Desmin IFs are present throughout smooth, cardiac and skeletal muscle cells, but can be more concentrated in some particular structures, such as dense bodies, around the nuclei, around the Z-line or in costameres. Desmin is up-regulated in muscle-derived cellular adaptations, including conductive fibers in the heart, electric organs, some myopathies, and experimental treatments with drugs that induce muscle degeneration, like phorbol esters. Many molecules have been reported to associate with desmin, such as other IF proteins (including members of the membrane dystroglycan complex), nebulin, the actin and tubulin binding protein plectin, the molecular motor dynein, the gene regulatory protein MyoD, DNA, the chaperone alphaB-crystallin, and proteases such as calpain and caspase. Desmin has an important medical role, since it is used as a marker of tumors' origin. More recently, several myopathies have been described, with accumulation of desmin deposits. Yet, after almost 30 years since its identification, the function of desmin is still unclear. Suggested functions include myofibrillogenesis, mechanical support for the muscle, mitochondrial localization, gene expression regulation, and intracellular signaling. This review focuses on the biochemical interactions of desmin, with a discussion of its putative functions.
Topics: Animals; Desmin; Fluorescent Antibody Technique; Gene Expression Regulation; Humans; Muscle Development; Muscles; Muscular Diseases
PubMed: 15558188
DOI: 10.1590/s0100-879x2004001200007 -
Neurology India Sep 2005Protein aggregate myopathies (PAM) are an emerging group of muscle diseases characterized by structural abnormalities. Protein aggregate myopathies are marked by the... (Review)
Review
Protein aggregate myopathies (PAM) are an emerging group of muscle diseases characterized by structural abnormalities. Protein aggregate myopathies are marked by the aggregation of intrinsic proteins within muscle fibers and fall into four major groups or conditions: (1) desmin-related myopathies (DRM) that include desminopathies, a-B crystallinopathies, selenoproteinopathies caused by mutations in the, a-B crystallin and selenoprotein N1 genes, (2) hereditary inclusion body myopathies, several of which have been linked to different chromosomal gene loci, but with as yet unidentified protein product, (3) actinopathies marked by mutations in the sarcomeric ACTA1 gene, and (4) myosinopathy marked by a mutation in the MYH-7 gene. While PAM forms 1 and 2 are probably based on impaired extralysosomal protein degradation, resulting in the accumulation of numerous and diverse proteins (in familial types in addition to respective mutant proteins), PAM forms 3 and 4 may represent anabolic or developmental defects because of preservation of sarcomeres outside of the actin and myosin aggregates and dearth or absence of other proteins in these actin or myosin aggregates, respectively. The pathogenetic principles governing protein aggregation within muscle fibers and subsequent structural sarcomeres are still largely unknown in both the putative catabolic and anabolic forms of PAM. Presence of inclusions and their protein composition in other congenital myopathies such as reducing bodies, cylindrical spirals, tubular aggregates and others await clarification. The hitherto described PAMs were first identified by immunohistochemistry of proteins and subsequently by molecular analysis of their genes.
Topics: Actins; Chromosome Mapping; Desmin; Humans; Mutation; Myopathies, Structural, Congenital; Proteins
PubMed: 16230791
DOI: 10.4103/0028-3886.16921 -
What does desmin do: A bibliometric assessment of the functions of the muscle intermediate filament.Experimental Biology and Medicine... Apr 2022Intermediate filaments were first described in muscle in 1968, and desmin was biochemically identified about 10 years afterwards. Its importance grew after the...
Intermediate filaments were first described in muscle in 1968, and desmin was biochemically identified about 10 years afterwards. Its importance grew after the identification of desminopathies and desmin mutations that cause mostly cardiopathies. Since its characterization until recently, different functions have been attributed to desmin. Here, we use bibliometric tools to evaluate the articles published about desmin and to assess its several putative functions. We identified the most productive authors and the relationships between research groups. We studied the more frequent words among 9734 articles (September 2021) containing "desmin" on the title and abstract, to identify the major research focus. We generated an interactive spreadsheet with the 934 papers that contain "desmin" only on the title that can be used to search and quantify terms in the abstract. We further selected the articles that contained the terms "function" or "role" from the spreadsheet, which we then classified according to type of function, organelle, or tissue involved. Based on the bibliographic analysis, we assess comparatively the putative functions, and we propose an alternative explanation for the desmin function.
Topics: Cytoskeleton; Desmin; Intermediate Filaments; Muscles; Mutation
PubMed: 35130760
DOI: 10.1177/15353702221075035 -
American Journal of Physiology. Cell... Aug 2020Skeletal muscle is a target of contraction-induced loading (CiL), leading to protein unfolding or cellular perturbations, respectively. While cytoskeletal desmin is...
Skeletal muscle is a target of contraction-induced loading (CiL), leading to protein unfolding or cellular perturbations, respectively. While cytoskeletal desmin is responsible for ongoing structural stabilization, in the immediate response to CiL, alpha-crystallin B (CRYAB) is phosphorylated at serine 59 (CRYAB) by P38, acutely protecting the cytoskeleton. To reveal adaptation and deadaptation of these myofibrillar subsystems to CiL, we examined CRYAB, P38, and desmin regulation following resistance exercise at diverse time points of a chronic training period. Mechanosensitive JNK phosphorylation (JNK) was determined to indicate the presence of mechanical components in CiL. Within 6 wk, subjects performed 13 resistance exercise bouts at the 8-12 repetition maximum, followed by 10 days detraining and a final 14th bout. Biopsies were taken at baseline and after the 1st, 3rd, 7th, 10th, 13th, and 14th bout. To assess whether potential desensitization to CiL can be mitigated, one group trained with progressive and a second with constant loading. As no group differences were found, all subjects were combined for statistics. Total and phosphorylated P38 was not regulated over the time course. CRYAB and JNK strongly increased following the unaccustomed first bout. This exercise-induced CRYAB/JNK increase disappeared with the 10th until 13th bout. As response to the detraining period, the 14th bout led to a renewed increase in CRYAB. Desmin content followed CRYAB inversely, i.e., was up- when CRYAB was downregulated and vice versa. In conclusion, the CRYAB response indicates increase and decrease in resistance to CiL, in which a reinforced desmin network could play an essential role by structurally stabilizing the cells.
Topics: Adaptation, Physiological; Adult; Cytoskeleton; Desmin; Gene Expression Regulation; Humans; Male; Muscle Contraction; Muscle, Skeletal; Phosphorylation; Resistance Training; Young Adult; alpha-Crystallin B Chain
PubMed: 32520607
DOI: 10.1152/ajpcell.00087.2020 -
Molecular Biology of the Cell Feb 2009Desmin interacts with nebulin establishing a direct link between the intermediate filament network and sarcomeres at the Z-discs. Here, we examined a desmin mutation,...
Desmin interacts with nebulin establishing a direct link between the intermediate filament network and sarcomeres at the Z-discs. Here, we examined a desmin mutation, E245D, that is located within the coil IB (nebulin-binding) region of desmin and that has been reported to cause human cardiomyopathy and skeletal muscle atrophy. We show that the coil IB region of desmin binds to C-terminal nebulin (modules 160-164) with high affinity, whereas binding of this desmin region containing the E245D mutation appears to enhance its interaction with nebulin in solid-phase binding assays. Expression of the desmin-E245D mutant in myocytes displaces endogenous desmin and C-terminal nebulin from the Z-discs with a concomitant increase in the formation of intracellular aggregates, reminiscent of a major histological hallmark of desmin-related myopathies. Actin filament architecture was strikingly perturbed in myocytes expressing the desmin-E245D mutant because most sarcomeres contained elongated or shorter actin filaments. Our findings reveal a novel role for desmin intermediate filaments in modulating actin filament lengths and organization. Collectively, these data suggest that the desmin E245D mutation interferes with the ability of nebulin to precisely regulate thin filament lengths, providing new insights into the potential molecular consequences of expression of certain disease-associated desmin mutations.
Topics: Actin Cytoskeleton; Amino Acid Substitution; Animals; Chick Embryo; Cytoplasm; Desmin; Green Fluorescent Proteins; Humans; Mice; Muscle Proteins; Muscle, Striated; Muscular Diseases; Mutant Proteins; Mutation; Myocytes, Cardiac; Myosins; Protein Binding; Protein Structure, Quaternary; Protein Structure, Secondary; Rats; Recombinant Fusion Proteins
PubMed: 19005210
DOI: 10.1091/mbc.e08-07-0753