scholarly journals RT-QuIC detection of CWD prion seeding activity in white-tailed deer muscle tissues

2021 ◽  
Author(s):  
Manci Li ◽  
Marc D. Schwabenlander ◽  
Gage R. Rowden ◽  
Jeremy M. Schefers ◽  
Michelle Carstensen ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
North America ◽  
Skeletal Muscles ◽  
Economic Losses ◽  
Food Chains ◽  
Sensitive Assay ◽  
Wasting Disease ◽  
Muscle Tissues ◽  
Highly Sensitive

Chronic wasting disease (CWD) is a prion disease circulating in wild and farmed cervid populations throughout North America (United States and Canada), Europe (Finland, Norway, Sweden), and South Korea. CWD is an immediate threat to cervid heritage and the disease is causing substantial economic losses across multiple sectors. In North America, hunting and farming industries focused on the processing and consumption of white-tailed deer (WTD) venison are particularly vulnerable to CWD, as millions of WTD are consumed annually. Real-time quaking-induced conversion (RT-QuIC) is a highly sensitive assay amplifying misfolded CWD prions in vitro and has facilitated CWD prion detection in a variety of tissues and excreta. To date, no study has comprehensively examined CWD prion content across bulk skeletal muscle tissues harvested from individual CWD infected WTD. Here, we use RT-QuIC to quantify prion-seeding activity in a variety of skeletal muscles from both wild and farmed CWD-positive WTD. We successfully detected CWD prions in muscles commonly used for consumption (e.g., backstrap, tenderloin, etc.) as well as within tongue and neck samples of WTD. Our results help to establish the utility of RT-QuIC for monitoring CWD prions in venison and suggest that the method is useful for preventing CWD prions from entering animal and human food chains. Moreover, our work indicates that CWD prions are more widely distributed across skeletal muscles of infected WTD than previously reported.

scholarly journals RT-QuIC detection of CWD prion seeding activity in white-tailed deer muscle tissues

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Manci Li ◽  
Marc D. Schwabenlander ◽  
Gage R. Rowden ◽  
Jeremy M. Schefers ◽  
Christopher S. Jennelle ◽  
...  
Keyword(s):  
North America ◽  
Skeletal Muscles ◽  
Economic Losses ◽  
Food Chains ◽  
Wasting Disease ◽  
Additional Protocol ◽  
Muscle Tissues ◽  
Highly Sensitive

AbstractChronic wasting disease (CWD) is a prion disease circulating in wild and farmed cervid populations throughout North America (United States and Canada), Europe (Finland, Norway, Sweden), and South Korea. CWD is a long-term threat to all cervid populations and to cervid hunting heritage, with the potential to cause substantial economic losses across multiple sectors. In North America, hunting and farming industries focused on the processing and consumption of white-tailed deer (WTD) venison are particularly vulnerable to CWD prion contamination, as millions of WTD are consumed annually. Real-time quaking-induced conversion (RT-QuIC) is a highly sensitive assay amplifying misfolded CWD prions in vitro and has facilitated CWD prion detection in a variety of tissues and excreta. To date, no study has comprehensively examined CWD prion content across bulk skeletal muscle tissues harvested from individual CWD infected WTD. Here, we use RT-QuIC to characterize prion-seeding activity in a variety of skeletal muscles from both wild and farmed CWD-positive WTD. We successfully detected CWD prions in muscles commonly used for consumption (e.g., backstrap, tenderloin, etc.) as well as within tongue and neck samples of WTD. Our results suggest that CWD prions are distributed across the skeletal muscles of infected WTD. We posit that RT-QuIC will be a useful tool for monitoring CWD prions in venison and that the method (with additional protocol optimization and high-throughput functionality) could be used to reduce and/or prevent CWD prions from entering animal and human food chains.

scholarly journals Bioengineered in vitro skeletal muscles as new tools for muscular dystrophies preclinical studies

2021 ◽  
Vol 12 ◽  
pp. 204173142098133
Author(s):  
Juan M. Fernández-Costa ◽  
Xiomara Fernández-Garibay ◽  
Ferran Velasco-Mallorquí ◽  
Javier Ramón-Azcón
Keyword(s):  
Skeletal Muscle ◽  
Tissue Engineering ◽  
Electrical Stimulation ◽  
Skeletal Muscles ◽  
Screening Tools ◽  
Muscular Dystrophies ◽  
Preclinical Studies ◽  
Technological Advances ◽  
Topographical Cues

Muscular dystrophies are a group of highly disabling disorders that share degenerative muscle weakness and wasting as common symptoms. To date, there is not an effective cure for these diseases. In the last years, bioengineered tissues have emerged as powerful tools for preclinical studies. In this review, we summarize the recent technological advances in skeletal muscle tissue engineering. We identify several ground-breaking techniques to fabricate in vitro bioartificial muscles. Accumulating evidence shows that scaffold-based tissue engineering provides topographical cues that enhance the viability and maturation of skeletal muscle. Functional bioartificial muscles have been developed using human myoblasts. These tissues accurately responded to electrical and biological stimulation. Moreover, advanced drug screening tools can be fabricated integrating these tissues in electrical stimulation platforms. However, more work introducing patient-derived cells and integrating these tissues in microdevices is needed to promote the clinical translation of bioengineered skeletal muscle as preclinical tools for muscular dystrophies.

scholarly journals Characterization of Gelatin Hydrogels Cross-Linked with Microbial Transglutaminase as Engineered Skeletal Muscle Substrates

2021 ◽  
Vol 8 (1) ◽  
pp. 6
Author(s):  
Divya Gupta ◽  
Jeffrey W. Santoso ◽  
Megan L. McCain
Keyword(s):  
Skeletal Muscle ◽  
Elastic Modulus ◽  
Ambient Air ◽  
In Vitro Models ◽  
Microbial Transglutaminase ◽  
Conventional Culture ◽  
Muscle Tissues ◽  
Physical Features ◽  
Phosphate Buffered Saline

Engineered in vitro models of skeletal muscle are essential for efficiently screening drug safety and efficacy. However, conventional culture substrates poorly replicate physical features of native muscle and do not support long-term culture, which limits tissue maturity. Micromolded gelatin hydrogels cross-linked with microbial transglutaminase (gelatin-MTG hydrogels) have previously been shown to induce C21C2 myotube alignment and improve culture longevity. However, several properties of gelatin-MTG hydrogels have not been systematically characterized, such as changes in elastic modulus during incubation in culture-like conditions and their ability to support sarcomere maturation. In this study, various gelatin-MTG hydrogels were fabricated and incubated in ambient or culture-like conditions. Elastic modulus, mass, and transmittance were measured over a one- or two-week period. Compared to hydrogels in phosphate buffered saline (PBS) or ambient air, hydrogels in Dulbecco’s Modified Eagle Medium (DMEM) and 5% CO2 demonstrated the most stable elastic modulus. A subset of gelatin-MTG hydrogels was micromolded and seeded with C2C12 or primary chick myoblasts, which aligned and fused into multinucleated myotubes with relatively mature sarcomeres. These data are important for fabricating gelatin-MTG hydrogels with predictable and stable mechanical properties and highlight their advantages as culture substrates for engineering relatively mature and stable muscle tissues.

scholarly journals Skeletal muscle-on-a-chip: an in vitro model to evaluate tissue formation and injury

Lab on a Chip ◽  
2017 ◽  
Vol 17 (20) ◽  
pp. 3447-3461 ◽  
Author(s):  
Gaurav Agrawal ◽  
Aereas Aung ◽  
Shyni Varghese
Keyword(s):  
Skeletal Muscle ◽  
Muscle Injury ◽  
In Vitro Model ◽  
Three Dimensional ◽  
Tissue Formation ◽  
Microfluidic Platform ◽  
Muscle Tissues ◽  
Vitro Model

We introduce a microfluidic platform in which we culture three-dimensional skeletal muscle tissues, while evaluating tissue formation and toxin-induced muscle injury.

scholarly journals Tenogenic Contribution to Skeletal Muscle Regeneration: The Secretome of Scleraxis Overexpressing Mesenchymal Stem Cells Enhances Myogenic Differentiation In Vitro

2020 ◽  
Vol 21 (6) ◽  
pp. 1965
Author(s):  
Maximilian Strenzke ◽  
Paolo Alberton ◽  
Attila Aszodi ◽  
Denitsa Docheva ◽  
Elisabeth Haas ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Regeneration ◽  
Skeletal Muscles ◽  
Myogenic Differentiation ◽  
Muscular Contraction ◽  
Myoblast Fusion ◽  
Skeletal Muscle Regeneration ◽  
Potential Candidate ◽  
Musculoskeletal Tissue

Integrity of the musculoskeletal system is essential for the transfer of muscular contraction force to the associated bones. Tendons and skeletal muscles intertwine, but on a cellular level, the myotendinous junctions (MTJs) display a sharp transition zone with a highly specific molecular adaption. The function of MTJs could go beyond a mere structural role and might include homeostasis of this musculoskeletal tissue compound, thus also being involved in skeletal muscle regeneration. Repair processes recapitulate several developmental mechanisms, and as myotendinous interaction does occur already during development, MTJs could likewise contribute to muscle regeneration. Recent studies identified tendon-related, scleraxis-expressing cells that reside in close proximity to the MTJs and the muscle belly. As the muscle-specific function of these scleraxis positive cells is unknown, we compared the influence of two immortalized mesenchymal stem cell (MSC) lines—differing only by the overexpression of scleraxis—on myoblasts morphology, metabolism, migration, fusion, and alignment. Our results revealed a significant increase in myoblast fusion and metabolic activity when exposed to the secretome derived from scleraxis-overexpressing MSCs. However, we found no significant changes in myoblast migration and myofiber alignment. Further analysis of differentially expressed genes between native MSCs and scleraxis-overexpressing MSCs by RNA sequencing unraveled potential candidate genes, i.e., extracellular matrix (ECM) proteins, transmembrane receptors, or proteases that might enhance myoblast fusion. Our results suggest that musculotendinous interaction is essential for the development and healing of skeletal muscles.

Structural and functional remodeling of skeletal muscle microvasculature is induced by simulated microgravity

2000 ◽  
Vol 278 (6) ◽  
pp. H1866-H1873 ◽  
Author(s):  
Michael D. Delp ◽  
Patrick N. Colleran ◽  
M. Keith Wilkerson ◽  
Matthew R. McCurdy ◽  
Judy Muller-Delp
Keyword(s):  
Skeletal Muscle ◽  
Soleus Muscle ◽  
Skeletal Muscles ◽  
Gastrocnemius Muscle ◽  
Fluid Pressure ◽  
Hindlimb Unloading ◽  
Cross Sectional ◽  
Luminal Diameter ◽  
Structural Remodeling

Hindlimb unloading of rats results in a diminished ability of skeletal muscle arterioles to constrict in vitro and elevate vascular resistance in vivo. The purpose of the present study was to determine whether alterations in the mechanical environment (i.e., reduced fluid pressure and blood flow) of the vasculature in hindlimb skeletal muscles from 2-wk hindlimb-unloaded (HU) rats induces a structural remodeling of arterial microvessels that may account for these observations. Transverse cross sections were used to determine media cross-sectional area (CSA), wall thickness, outer perimeter, number of media nuclei, and vessel luminal diameter of feed arteries and first-order (1A) arterioles from soleus and the superficial portion of gastrocnemius muscles. Endothelium-dependent dilation (ACh) was also determined. Media CSA of resistance arteries was diminished by hindlimb unloading as a result of decreased media thickness (gastrocnemius muscle) or reduced vessel diameter (soleus muscle). ACh-induced dilation was diminished by 2 wk of hindlimb unloading in soleus 1A arterioles, but not in gastrocnemius 1A arterioles. These results indicate that structural remodeling and functional adaptations of the arterial microvasculature occur in skeletal muscles of the HU rat; the data suggest that these alterations may be induced by reductions in transmural pressure (gastrocnemius muscle) and wall shear stress (soleus muscle).

Expression of steroidogenic enzymes and synthesis of sex steroid hormones from DHEA in skeletal muscle of rats

2007 ◽  
Vol 292 (2) ◽  
pp. E577-E584 ◽  
Author(s):  
Katsuji Aizawa ◽  
Motoyuki Iemitsu ◽  
Seiji Maeda ◽  
Subrina Jesmin ◽  
Takeshi Otsuki ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Steroid Hormones ◽  
Skeletal Muscles ◽  
Muscle Cells ◽  
Sex Steroid Hormones ◽  
Sex Steroid ◽  
Dependent Manner ◽  
Steroidogenic Enzymes

The functional importance of sex steroid hormones (testosterone and estrogens), derived from extragonadal tissues, has recently gained significant appreciation. Circulating dehydroepiandrosterone (DHEA) is peripherally taken up and converted to testosterone by 3β-hydroxysteroid dehydrogenase (HSD) and 17β-HSD, and testosterone in turn is irreversibly converted to estrogens by aromatase cytochrome P-450 (P450arom). Although sex steroid hormones have been implicated in skeletal muscle regulation and adaptation, it is unclear whether skeletal muscles have a local steroidogenic enzymatic machinery capable of metabolizing circulating DHEA. Thus, here, we investigate whether the three key steroidogenic enzymes (3β-HSD, 17β-HSD, and P450arom) are present in the skeletal muscle and are capable of generating sex steroid hormones. Consistent with our hypothesis, the present study demonstrates mRNA and protein expression of these enzymes in the skeletal muscle cells of rats both in vivo and in culture (in vitro). Importantly, we also show an intracellular formation of testosterone and estradiol from DHEA or testosterone in cultured muscle cells in a dose-dependent manner. These findings are novel and important in that they provide the first evidence showing that skeletal muscles are capable of locally synthesizing sex steroid hormones from circulating DHEA or testosterone.

scholarly journals In Vivo Activation of STAT3 Signaling in Satellite Cells and Myofibers in Regenerating Rat Skeletal Muscles

2002 ◽  
Vol 50 (12) ◽  
pp. 1579-1589 ◽  
Author(s):  
Katsuya Kami ◽  
Emiko Senba
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cells ◽  
Muscle Regeneration ◽  
Intracellular Signaling ◽  
Skeletal Muscles ◽  
Early Stage ◽  
Skeletal Muscle Regeneration ◽  
Stat3 Signaling

Although growth factors and cytokines play critical roles in skeletal muscle regeneration, intracellular signaling molecules that are activated by these factors in regenerating muscles have been not elucidated. Several lines of evidence suggest that leukemia inhibitory factor (LIF) is an important cytokine for the proliferation and survival of myoblasts in vitro and acceleration of skeletal muscle regeneration. To elucidate the role of LIF signaling in regenerative responses of skeletal muscles, we examined the spatial and temporal activation patterns of an LIF-associated signaling molecule, the signal transducer and activator transcription 3 (STAT3) proteins in regenerating rat skeletal muscles induced by crush injury. At the early stage of regeneration, activated STAT3 proteins were first detected in the nuclei of activated satellite cells and then continued to be activated in proliferating myoblasts expressing both PCNA and MyoD proteins. When muscle regeneration progressed, STAT3 signaling was no longer activated in differentiated myoblasts and myotubes. In addition, activation of STAT3 was also detected in myonuclei within intact sarcolemmas of surviving myofibers that did not show signs of necrosis. These findings suggest that activation of STAT3 signaling is an important molecular event that induces the successful regeneration of injured skeletal muscles.

scholarly journals Bioengineered human myobundles mimic clinical responses of skeletal muscle to drugs

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Lauran Madden ◽  
Mark Juhas ◽  
William E Kraus ◽  
George A Truskey ◽  
Nenad Bursac
Keyword(s):  
Skeletal Muscle ◽  
Acetylcholine Receptors ◽  
In Vitro Models ◽  
Calcium Handling ◽  
Muscle Tissues ◽  
Clinical Responses ◽  
And Function ◽  
Electrical Stimuli ◽  
Toxic Myopathy

Existing in vitro models of human skeletal muscle cannot recapitulate the organization and function of native muscle, limiting their use in physiological and pharmacological studies. Here, we demonstrate engineering of electrically and chemically responsive, contractile human muscle tissues (‘myobundles’) using primary myogenic cells. These biomimetic constructs exhibit aligned architecture, multinucleated and striated myofibers, and a Pax7+ cell pool. They contract spontaneously and respond to electrical stimuli with twitch and tetanic contractions. Positive correlation between contractile force and GCaMP6-reported calcium responses enables non-invasive tracking of myobundle function and drug response. During culture, myobundles maintain functional acetylcholine receptors and structurally and functionally mature, evidenced by increased myofiber diameter and improved calcium handling and contractile strength. In response to diversely acting drugs, myobundles undergo dose-dependent hypertrophy or toxic myopathy similar to clinical outcomes. Human myobundles provide an enabling platform for predictive drug and toxicology screening and development of novel therapeutics for muscle-related disorders.

Glutamine Metabolism in Skeletal Muscle of Glucocorticoid-Treated Rats

1990 ◽  
Vol 79 (2) ◽  
pp. 139-147 ◽  
Author(s):  
M. Salleh M. Ardawi ◽  
Yasir S. Jamal
Keyword(s):  
Skeletal Muscle ◽  
Exchange Rates ◽  
Skeletal Muscles ◽  
Plasma Concentrations ◽  
Maximal Activity ◽  
Glutamine Metabolism ◽  
Dexamethasone Treatment ◽  
Concentration Difference

1. The effect of dexamethasone (30 μg day−-1 100 g−-1 body weight) on the regulation of glutamine metabolism was studied in skeletal muscles of rats after 9 days of treatment. 2. Dexamethasone resulted in negative nitrogen balance, and produced increases in the plasma concentrations of alanine (23.4%) and insulin (158%) but a decrease in the plasma concentration of glutamine (28.7%). 3. Dexamethasone treatment increased the rate of glutamine production in muscle, skin and adipose tissue preparations, with muscle production accounting for over 90% of total glutamine produced by the hindlimb. 4. Blood flow and arteriovenous concentration difference measurements across the hindlimb showed an increase in the net exchange rates of glutamine (25.3%) and alanine (90.5%) in dexamethasone-treated rats compared with corresponding controls. 5. Dexamethasone treatment produced significant decreases in the concentrations of skeletal muscle glutamine (51.8%) and 2-oxoglutarate (50.8%). The concentrations of alanine (16.2%), pyruvate (45.9%), ammonia (43.3%) and inosine 5′-phosphate (141.8%) were increased. 6. The maximal activity of glutamine synthetase was increased (21–34%), but there was no change in that of glutaminase, in muscles of dexamethasone-treated rats. 7. It is concluded that glucocorticoid administration enhances the rates of release of both glutamine and alanine from skeletal muscle of rats (both in vitro and in vivo). This may be due to changes in efflux and/or increased intracellular formation of glutamine and alanine.

Sign in / Sign up

Export Citation Format

Share Document