scholarly journals Suppression of Skeletal Muscle Turnover in Cancer Cachexia: Evidence from the Transcriptome in Sequential Human Muscle Biopsies

2012 ◽  
Vol 18 (10) ◽  
pp. 2817-2827 ◽  
Author(s):  
Iain J. Gallagher ◽  
Nathan A. Stephens ◽  
Alisdair J. MacDonald ◽  
Richard J.E. Skipworth ◽  
Holger Husi ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Cancer Cachexia ◽  
Human Muscle ◽  
Muscle Biopsies

scholarly journals Contraction-mediated inactivation of glycogen synthase is accompanied by inactivation of glycogen synthase phosphatase in human skeletal muscle

1989 ◽  
Vol 259 (3) ◽  
pp. 901-904 ◽  
Author(s):  
Y Kida ◽  
A Katz ◽  
A D Lee ◽  
D M Mott
Keyword(s):  
Skeletal Muscle ◽  
Isometric Contraction ◽  
Human Skeletal Muscle ◽  
Glycogen Synthase ◽  
Active Form ◽  
Human Muscle ◽  
Maximal Voluntary Force ◽  
Before And After ◽  
Muscle Biopsies

Activities of glycogen synthase (GS) and GS phosphatase were determined on human muscle biopsies before and after isometric contraction at 2/3 maximal voluntary force. Total GS activity did not change during contraction (4.92 +/- 0.70 at rest versus 5.00 +/- 0.42 mmol/min per kg dry wt.; mean +/- S.E.M.), whereas both the active form of GS and the ratio of active form to total GS decreased by approximately 35% (P less than 0.01). GS phosphatase was inactivated in all subjects by an average of 39%, from 5.95 +/- 1.30 to 3.63 +/- 0.97 mmol/min per kg dry wt. (P less than 0.01). It is suggested that at least part of the contraction-induced inactivation of GS is due to an inactivation of GS phosphatase.

scholarly journals Unmasking Potential Intracellular Roles For Dysferlin through Improved Immunolabeling Methods

2011 ◽  
Vol 59 (11) ◽  
pp. 964-975 ◽  
Author(s):  
Joseph A. Roche ◽  
Lisa W. Ru ◽  
Andrea M. O’Neill ◽  
Wendy G. Resneck ◽  
Richard M. Lovering ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Wasting ◽  
Potential Role ◽  
Human Muscle ◽  
Rat Skeletal Muscle ◽  
Mouse Muscle ◽  
Contraction Coupling ◽  
Dihydropyridine Receptors ◽  
And Control ◽  
Muscle Biopsies

Mutations in the DYSF gene that severely reduce the levels of the protein dysferlin are implicated in muscle-wasting syndromes known as dysferlinopathies. Although studies of its function in skeletal muscle have focused on its potential role in repairing the plasma membrane, dysferlin has also been found, albeit inconsistently, in the sarcoplasm of muscle fibers. The aim of this article is to study the localization of dysferlin in skeletal muscle through optimized immunolabeling methods. We studied the localization of dysferlin in control rat skeletal muscle using several different methods of tissue collection and subsequent immunolabeling. We then applied our optimized immunolabeling methods on human cadaveric muscle, control and dystrophic human muscle biopsies, and control and dysferlin-deficient mouse muscle. Our data suggest that dysferlin is present in a reticulum of the sarcoplasm, similar but not identical to those containing the dihydropyridine receptors and distinct from the distribution of the sarcolemmal protein dystrophin. Our data illustrate the importance of tissue fixation and antigen unmasking for proper immunolocalization of dysferlin. They suggest that dysferlin has an important function in the internal membrane systems of skeletal muscle, involved in calcium homeostasis and excitation-contraction coupling.

scholarly journals Enhanced methods for needle biopsy and cryopreservation of skeletal muscle in older adults

2019 ◽  
Author(s):  
Cathy C. Lee ◽  
Austin Hoang ◽  
David Segovia ◽  
Allen Herbst ◽  
Florian Barthelemy ◽  
...  
Keyword(s):  
Older Adults ◽  
Skeletal Muscle ◽  
Liquid Nitrogen ◽  
Muscle Biopsy ◽  
Human Muscle ◽  
High Quality ◽  
Mouse Muscle ◽  
Muscle Sample ◽  
Quick Recovery ◽  
Muscle Biopsies

Abstract Background Human muscle biopsies are increasingly important for diagnosis, research, and to monitor therapeutic trials. We examined the use of a self-contained, vacuum-assisted biopsy system and a novel muscle freezing technique to improve, simplify, and standardize human muscle biopsy collection and cryopreservation in older adults. Methods The Vacora vacuum-assisted biopsy system was deployed in muscle biopsies of 12 individuals ranging in age from 57 to 80 years. This office-based approach was well tolerated as it is minimally invasive, uses only local anesthetic, and has a quick recovery. To maximize biopsy sample quality and reproducibility, we developed a novel muscle sample freezing protocol. Fresh human and mouse muscle biopsy samples were placed into readily available tissue cassettes followed by direct freezing in liquid nitrogen. After this modified snap freezing protocol, frozen muscle samples were enrobed in OCT for cryosectioning. We examined the effect of this freezing approach in histological sections of rodent and human muscle samples. ResultsThe Vacora Biopsy System provided as many as four skeletal muscle core samples from a single biopsy site. Biopsy samples from 12 older adults weighed an average of 147.5 ± 11 mg each and had a consistent size and shape. There were no complications, and the residual scar is less than 1cm. The freezing method using standard tissue cassettes with direct freezing in liquid nitrogen yielded high quality cryopreserved muscle tissue suitable for histological analysis without the need for isopentane and with little to no freeze-thaw damage. Conclusions These enhancements have streamlined and improved the consistency of our muscle biopsy protocol and provide sufficient high-quality sample for multi-dimensional downstream studies of human muscle in aging and disease.

scholarly journals Deep muscle-proteomic analysis of freeze-dried human muscle biopsies reveals fiber type-specific adaptations to exercise training

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
A. S. Deshmukh ◽  
D. E. Steenberg ◽  
M. Hostrup ◽  
J. B. Birk ◽  
J. K. Larsen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Exercise Training ◽  
Fiber Type ◽  
Muscle Fibers ◽  
Human Muscle ◽  
Fiber Types ◽  
Freeze Dried ◽  
Fast Twitch Muscle ◽  
Fast Twitch ◽  
Muscle Biopsies

AbstractSkeletal muscle conveys several of the health-promoting effects of exercise; yet the underlying mechanisms are not fully elucidated. Studying skeletal muscle is challenging due to its different fiber types and the presence of non-muscle cells. This can be circumvented by isolation of single muscle fibers. Here, we develop a workflow enabling proteomics analysis of pools of isolated muscle fibers from freeze-dried human muscle biopsies. We identify more than 4000 proteins in slow- and fast-twitch muscle fibers. Exercise training alters expression of 237 and 172 proteins in slow- and fast-twitch muscle fibers, respectively. Interestingly, expression levels of secreted proteins and proteins involved in transcription, mitochondrial metabolism, Ca2+ signaling, and fat and glucose metabolism adapts to training in a fiber type-specific manner. Our data provide a resource to elucidate molecular mechanisms underlying muscle function and health, and our workflow allows fiber type-specific proteomic analyses of snap-frozen non-embedded human muscle biopsies.

scholarly journals Antiangiogenic VEGF Isoform in Inflammatory Myopathies

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Nila Volpi ◽  
Alessandra Pecorelli ◽  
Paola Lorenzoni ◽  
Francesco Di Lazzaro ◽  
Giuseppe Belmonte ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Western Blot ◽  
Inflammatory Cells ◽  
Human Muscle ◽  
Vascular Endothelial ◽  
Inflammatory Myopathies ◽  
Vegf Expression ◽  
Inflammatory Score ◽  
Endothelial Growth Factor ◽  
Muscle Biopsies

Objective. To investigate expression of vascular endothelial growth factor (VEGF) antiangiogenic isoformA-165bon human muscle in idiopathic inflammatory myopathies (IIM) and to compare distribution of angiogenic/antiangiogenic VEGFs, as isoforms shifts are described in other autoimmune disorders.Subjects and Methods. We analyzedVEGF-A165band VEGF-A by western blot and immunohistochemistry on skeletal muscle biopsies from 21 patients affected with IIM (polymyositis, dermatomyositis, and inclusion body myositis) and 6 control muscle samples. TGF-β, a prominent VEGF inductor, was analogously evaluated. Intergroup differences of western blot bands density were statistically examined. Endomysial vascularization, inflammatory score, and muscle regeneration, as pathological parameters of IIM, were quantitatively determined and their levels were confronted with VEGF expression.Results.VEGF-A165bwas significantly upregulated in IIM, as well as TGF-β. VEGF-A was diffusely expressed on unaffected myofibers, whereas regenerating/atrophic myofibres strongly reacted for both VEGF-A isoforms. Most inflammatory cells and endomysial vessels expressed both isoforms.VEGF-A165blevels were in positive correlation to inflammatory score, endomysial vascularization, and TGF-β.Conclusions. Our findings indicate skeletal muscle expression of antiangiogenicVEGF-A165band preferential upregulation in IIM, suggesting that modulation of VEGF-A isoforms may occur in myositides.

scholarly journals A Time-Course Comparison of Skeletal Muscle Metabolomic Alterations in Walker-256 Tumour-Bearing Rats at Different Stages of Life

Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 404
Author(s):  
Gabriela de Matuoka e Chiocchetti ◽  
Leisa Lopes-Aguiar ◽  
Natália Angelo da Silva Miyaguti ◽  
Lais Rosa Viana ◽  
Carla de Moraes Salgado ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Time Course ◽  
Cancer Cachexia ◽  
Tumour Bearing ◽  
Walker 256 Tumour ◽  
Walker 256 ◽  
Muscle Changes ◽  
The Right ◽  
Biomarker Research ◽  
Host Metabolism

Cancer cachexia is a severe wasting condition that needs further study to find ways to minimise the effects of damage and poor prognosis. Skeletal muscle is the most impacted tissue in cancer cachexia; thus, elucidation of its metabolic alterations could provide a direct clue for biomarker research and be applied to detect this syndrome earlier. In addition, concerning the significant changes in the host metabolism across life, this study aimed to compare the metabolic muscle changes in cachectic tumour-bearing hosts at different ages. We performed 1H-NMR metabolomics in the gastrocnemius muscle in weanling and young adult Walker-256 tumour-bearing rats at different stages of tumour evolution (initial, intermediate, and advanced). Among the 49 metabolites identified, 24 were significantly affected throughout tumour evolution and 21 were significantly affected regarding animal age. The altered metabolites were mainly related to increased amino acid levels and changed energetic metabolism in the skeletal muscle, suggesting an expressive catabolic process and diverted energy production, especially in advanced tumour stages in both groups. Moreover, these changes were more severe in weanling hosts throughout tumour evolution, suggesting the distinct impact of cancer cachexia regarding the host’s age, highlighting the need to adopting the right animal age when studying cancer cachexia.

scholarly journals Glycogenin is Dispensable for Glycogen Synthesis in Human Muscle, and Glycogenin Deficiency Causes Polyglucosan Storage

2019 ◽  
Vol 105 (2) ◽  
pp. 557-566 ◽  
Author(s):  
Kittichate Visuttijai ◽  
Carola Hedberg-Oldfors ◽  
Christer Thomsen ◽  
Emma Glamuzina ◽  
Cornelia Kornblum ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Skeletal Muscle ◽  
Western Blot ◽  
Cardiac Muscle ◽  
Glycogen Synthesis ◽  
Muscle Fibers ◽  
Human Muscle ◽  
Missense Mutations ◽  
Skeletal Muscle Fibers ◽  
Glycogen Biosynthesis

Abstract Context Glycogenin is considered to be an essential primer for glycogen biosynthesis. Nevertheless, patients with glycogenin-1 deficiency due to biallelic GYG1 (NM_004130.3) mutations can store glycogen in muscle. Glycogenin-2 has been suggested as an alternative primer for glycogen synthesis in patients with glycogenin-1 deficiency. Objective The objective of this article is to investigate the importance of glycogenin-1 and glycogenin-2 for glycogen synthesis in skeletal and cardiac muscle. Design, Setting, and Patients Glycogenin-1 and glycogenin-2 expression was analyzed by Western blot, mass spectrometry, and immunohistochemistry in liver, heart, and skeletal muscle from controls and in skeletal and cardiac muscle from patients with glycogenin-1 deficiency. Results Glycogenin-1 and glycogenin-2 both were found to be expressed in the liver, but only glycogenin-1 was identified in heart and skeletal muscle from controls. In patients with truncating GYG1 mutations, neither glycogenin-1 nor glycogenin-2 was expressed in skeletal muscle. However, nonfunctional glycogenin-1 but not glycogenin-2 was identified in cardiac muscle from patients with cardiomyopathy due to GYG1 missense mutations. By immunohistochemistry, the mutated glycogenin-1 colocalized with the storage of glycogen and polyglucosan in cardiomyocytes. Conclusions Glycogen can be synthesized in the absence of glycogenin, and glycogenin-1 deficiency is not compensated for by upregulation of functional glycogenin-2. Absence of glycogenin-1 leads to the focal accumulation of glycogen and polyglucosan in skeletal muscle fibers. Expression of mutated glycogenin-1 in the heart is deleterious, and it leads to storage of abnormal glycogen and cardiomyopathy.

Sign in / Sign up

Export Citation Format

Share Document