scholarly journals Myogenic Response to Increasing Concentrations of Ammonia Differs between Mammalian, Avian, and Fish Species: Cell Differentiation and Genetic Study

Genes ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 840
Author(s):  
Emily Miramontes ◽  
Bartosz Kempisty ◽  
James Petitte ◽  
Srinivasan Dasarathy ◽  
Magdalena Kulus ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Untreated Control ◽  
Sodium Acetate ◽  
Ammonium Acetate ◽  
Negative Regulator ◽  
C2c12 Cells ◽  
Myogenic Response ◽  
Mammalian Skeletal Muscle ◽  
Significant Difference ◽  
Myoblast Cells

Ammonia is very toxic to the body and has detrimental effects on many different organ systems. Using cultured myoblast cells, we examined ammonia’s effect on myostatin expression, a negative regulator of skeletal muscle growth, and myotube diameters. The objective of this study was to examine how murine, avian, and fish cells respond to increasing levels of ammonia up to 50 mM. The murine myoblast cell line (C2C12), primary chick, and primary tilapia myoblast cells were cultured and then exposed to 10, 25, and 50 mM ammonium acetate, sodium acetate, and an untreated control for 24 h. High levels of ammonia were detrimental to the C2C12 cells, causing increased Myostatin (MSTN) expression and decreased myotube diameters between 10 and 25 mM (p < 0.002). Ammonia at 10 mM continued the positive myogenic response in the chick, with lower MSTN expression than the C2C12 cells and larger myotube diameters, but the myotube diameter at 50 mM ammonium acetate was significantly smaller than those at 10 and 25 mM (p < 0.001). However, chick myotubes at 50 mM were still significantly larger than the sodium acetate-treated and untreated control (p < 0.001). The tilapia cells showed no significant difference in MSTN expression or myotube diameter in response to increasing the concentrations of ammonia. Overall, these results confirm that increasing concentrations of ammonia are detrimental to mammalian skeletal muscle, while chick cells responded positively at lower levels but began to exhibit a negative response at higher levels, as the tilapia experienced no detrimental effects. The differences in ammonia metabolism strategies between fish, avian, and mammalian species could potentially contribute to the differences between species in response to high levels of ammonia. Understanding how ammonia affects skeletal muscle is important for the treatment of muscle wasting observed in liver failure patients.

scholarly journals Daily Oral Administration of Protease-Treated Royal Jelly Protects Against Denervation-Induced Skeletal Muscle Atrophy

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3089
Author(s):  
Tomohiko Shirakawa ◽  
Aki Miyawaki ◽  
Takuma Matsubara ◽  
Nobuaki Okumura ◽  
Hideto Okamoto ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Royal Jelly ◽  
Muscle Metabolism ◽  
Sebacic Acid ◽  
C2c12 Cells ◽  
Skeletal Muscle Atrophy ◽  
Muscle Weight ◽  
Age Related ◽  
Myoblast Cells

Honeybees produce royal jelly (RJ) from their cephalic glands. Royal jelly is a source of nutrition for the queen honey bee throughout its lifespan and is also involved in fertility and longevity. Royal jelly has long been considered beneficial to human health. We recently observed that RJ delayed impairment of motor function during aging, affecting muscle fiber size. However, how RJ affects skeletal muscle metabolism and the functional component of RJ is as of yet unidentified. We demonstrate that feeding mice with RJ daily prevents a decrease in myofiber size following denervation without affecting total muscle weight. RJ did not affect atrophy-related genes but stimulated the expression of myogenesis-related genes, including IGF-1 and IGF receptor. Trans-10-hydroxy-2-decenoic acid (10H2DA) and 10-hydroxydecanoic acid (10HDAA), two major fatty acids contained in RJ. After ingestion, 10H2DA and 10HDAA are metabolized into 2-decenedioic acid (2DA) and sebacic acid (SA) respectively. We found that 10H2DA, 10HDAA, 2DA, and SA all regulated myogenesis of C2C12 cells, murine myoblast cells. These novel findings may be useful for potential preventative and therapeutic applications for muscle atrophy disease included in Sarcopenia, an age-related decline in skeletal muscle mass and strength.

scholarly journals Neurogranin is expressed in mammalian skeletal muscle and inhibits calcineurin signaling and myoblast fusion

2019 ◽  
Vol 317 (5) ◽  
pp. C1025-C1033 ◽  
Author(s):  
Val A. Fajardo ◽  
Colton J. F. Watson ◽  
Kirsten N. Bott ◽  
Fereshteh Moradi ◽  
Lucas A. Maddalena ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Myogenic Differentiation ◽  
Vastus Lateralis ◽  
Critical Role ◽  
Myoblast Fusion ◽  
C2c12 Cells ◽  
C2c12 Myotubes ◽  
Mammalian Skeletal Muscle ◽  
Mrna Levels ◽  
Calcineurin Signaling

Calcineurin is a Ca2+/calmodulin (CaM)-dependent phosphatase that plays a critical role in promoting the slow fiber phenotype and myoblast fusion in skeletal muscle, thereby making calcineurin an attractive cellular target for enhancing fatigue resistance, muscle metabolism, and muscle repair. Neurogranin (Ng) is a CaM-binding protein thought to be expressed solely in brain and neurons, where it inhibits calcineurin signaling by sequestering CaM, thus lowering its cellular availability. Here, we demonstrate for the first time the expression of Ng protein and mRNA in mammalian skeletal muscle. Both protein and mRNA levels are greater in slow-oxidative compared with fast-glycolytic muscles. Coimmunoprecipitation of CaM with Ng in homogenates of C2C12 myotubes, mouse soleus, and human vastus lateralis suggests that these proteins physically interact. To determine whether Ng inhibits calcineurin signaling in muscle, we used Ng siRNA with C2C12 myotubes to reduce Ng protein levels by 60%. As a result of reduced Ng expression, C2C12 myotubes had enhanced CaM-calcineurin binding and calcineurin signaling as indicated by reduced phosphorylation of nuclear factor of activated T cells and increased utrophin mRNA. In addition, calcineurin signaling affects the expression of myogenin and stabilin-2, which are involved in myogenic differentiation and myoblast fusion, respectively. Here, we found that both myogenin and stabilin-2 were significantly elevated by Ng siRNA in C2C12 cells, concomitantly with an increased fusion index. Taken together, these results demonstrate the expression of Ng in mammalian skeletal muscle where it appears to be a novel regulator of calcineurin signaling.

scholarly journals Differentiation of Murine C2C12 Myoblasts Strongly Reduces the Effects of Myostatin on Intracellular Signaling

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 695
Author(s):  
Juulia H. Lautaoja ◽  
Satu Pekkala ◽  
Arja Pasternack ◽  
Mika Laitinen ◽  
Olli Ritvos ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Intracellular Signaling ◽  
Negative Regulator ◽  
C2c12 Cells ◽  
C2c12 Myotubes ◽  
Receptor Ligands ◽  
In Vivo Models ◽  
Altered Expression ◽  
Activin Receptor ◽  
Noncanonical Signaling

Alongside in vivo models, a simpler and more mechanistic approach is required to study the effects of myostatin on skeletal muscle because myostatin is an important negative regulator of muscle size. In this study, myostatin was administered to murine (C2C12) and human (CHQ) myoblasts and myotubes. Canonical and noncanonical signaling downstream to myostatin, related ligands, and their receptor were analyzed. The effects of tumorkines were analyzed after coculture of C2C12 and colon cancer-C26 cells. The effects of myostatin on canonical and noncanonical signaling were strongly reduced in C2C12 cells after differentiation. This may be explained by increased follistatin, an endogenous blocker of myostatin and altered expression of activin receptor ligands. In contrast, CHQ cells were equally responsive to myostatin, and follistatin remained unaltered. Both myostatin administration and the coculture stimulated pathways associated with inflammation, especially in C2C12 cells. In conclusion, the effects of myostatin on intracellular signaling may be cell line- or organism-specific, and C2C12 myotubes seem to be a nonoptimal in vitro model for investigating the effects of myostatin on canonical and noncanonical signaling in skeletal muscle. This may be due to altered expression of activin receptor ligands and their regulators during muscle cell differentiation.

MicroRNA-129-5p Inhibited C2C12 Myogenesis and Repressed Slow Fiber Gene Expression in vitro

2021 ◽  
Author(s):  
Ying Peng ◽  
Meixue Xu ◽  
Mingle Dou ◽  
Xin'E Shi ◽  
Gongshe Yang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Skeletal Muscle ◽  
Myogenic Differentiation ◽  
C2c12 Cell ◽  
Negative Regulator ◽  
C2c12 Cells ◽  
Loss Of Function ◽  
Mouse Tissues ◽  
Slow Fiber ◽  
Fiber Gene

The miR-129 family is widely reported as tumor repressors, while, their roles in skeletal muscle have not been fully investigated. Here, the function and mechanism of miR-129-5p in skeletal muscle, a member of the miR-129 family, were explored using C2C12 cell line. Our study shown that miR-129-5p was widely detected in mouse tissues, with the highest expression in skeletal muscle. Gain- and loss-of-function study shown that miR-129-5p could negatively regulate myogenic differentiation, indicated by reduced ratio of MyHC-positive myofibers and repressed expression of myogenic genes, such as MyoD, MyoG and MyHC. Furthermore, miR-129-5p was more enriched in fast extensor digitalis lateralis (EDL) than in slow soleus (SOL). Enhanced miR-129-5p could significantly reduce the expression of mitochondrial cox family, together with that of MyHC I, and knockdown of miR-129-5p conversely increased the expression of cox genes and MyHC I. Mechanistically, miR-129-5p directly targeted the 3'-UTR of Mef2a, which was suppressed by miR-129-5p agomir at both mRNA and protein levels in C2C12 cells. Moreover, overexpression of Mef2a could rescue the inhibitory effects of miR-129-5p on the expression of myogenic factors and MyHC I. Collectively, our data revealed that miR-129-5p as a negative regulator of myogenic differentiation and slow fiber gene expression, thus affecting body metabolic homeostasis.

scholarly journals PO-064 A potential role of stretch-activated channels in anabolic mechanotransduction in the atrophied rat soleus muscle

2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Timur Mirzoev ◽  
Sergey Tyganov ◽  
Boris Shenkman
Keyword(s):  
Skeletal Muscle ◽  
Soleus Muscle ◽  
Contractile Function ◽  
Mammalian Skeletal Muscle ◽  
Mechanical Unloading ◽  
Mtorc1 Signaling ◽  
Significant Difference ◽  
Rat Soleus Muscle ◽  
Isolated Rat

Objective Prolonged immobilization or unloading of skeletal muscle causes muscle disuse atrophy, which is characterized by a reduction in muscle cross-sectional area and compromised contractile function. To date, the mechanisms of anabolic mechanotransduction in the atrophied mammalian skeletal muscle remain poorly understood. The aim of the present study was to assess a possible role of stretch-activated ion channels (SAC) in the propagation of a mechanical signal to anabolic signaling and protein synthesis (PS) in an isolated rat soleus muscle following mechanical unloading. Methods The mechanical unloading was performed via hindlimb suspension (HS). Twenty-eight male Wistar rats weighing were randomly assigned to the following 4 groups (n=7/group): 1) vivarium control (C), 2) control + SAC inhibitor (gadolinium) (C+Gd3+), 3) 7-day HS (HS), 4) 7-day HS + SAC inhibitor (HS+Gd3+). Following unloading, an isolated rat soleus was placed in an organ culture medium and subjected to a bout of eccentric contractions (EC). Upon completion of the EC, muscles were collected for Western blot analyses to determine the content of the key anabolic markers. The rate of PS was measured by SUnSET technique. Results EC-induced increase in PS was significantly less in the HS and HS+ Gd3+ groups vs. the C group. There was no statistically significant difference between the HS and HS+ Gd3+ groups in terms of EC-induced increase in muscle PS. A decrease in EC-induced phosphorylation of p70S6K, 4E-BP1, RPS6 and GSK-3beta in the 7-day unloaded soleus treated with SAC inhibitor did not differ from that of the 7-day unloaded soleus without SAC blockade. Thus, the inhibition of SAC with gadolinium did not lead to further decline in EC-induced phosphorylation of the key anabolic markers and muscle PS. Conclusions The results of the study suggest that attenuation of mTORC1-signaling and PS in response to EC in unloaded soleus muscle may be associated with inactivation of SAC. The study was supported by the RFBR grant # 16-34-60055.

scholarly journals Novel Ultrashort Self-Assembling Peptide Bioinks for 3D Culture of Muscle Myoblast Cells

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Wafaa Arab ◽  
Sakandar Rauf ◽  
Ohoud Al-Harbi ◽  
Charlotte Hauser
Keyword(s):  
Skeletal Muscle ◽  
Tissue Engineering ◽  
Muscle Tissue ◽  
3D Culture ◽  
Skeletal Muscle Tissue ◽  
C2c12 Cells ◽  
Self Assembling ◽  
3D Network ◽  
Myoblast Cells ◽  
Peptide Hydrogels

The ability of skeletal muscle to self-repair after a traumatic injury, tumor ablation, or muscular disease is slow and limited, and the capacity of skeletal muscle to self-regenerate declines steeply with age. Tissue engineering of functional skeletal muscle using 3D bioprinting technology is promising for creating tissue constructs that repair and promote regeneration of damaged tissue. Hydrogel scaffolds used as biomaterials for skeletal muscle tissue engineering can provide chemical, physical and mechanical cues to the cells in three dimensions thus promoting regeneration. Herein, we have developed two synthetically designed novel tetramer peptide biomaterials. These peptides are self-assembling into a nanofibrous 3D network, entrapping 99.9% water and mimicking the native collagen of an extracellular matrix. Different biocompatibility assays including MTT, 3D cell viability assay, cytotoxicity assay and live-dead assay confirm the biocompatibility of these peptide hydrogels for mouse myoblast cells (C2C12). Immunofluorescence analysis of cell-laden hydrogels revealed that the proliferation of C2C12 cells was well-aligned in the peptide hydrogels compared to the alginate-gelatin control. These results indicate that these peptide hydrogels are suitable for skeletal muscle tissue engineering. Finally, we tested the printability of the peptide bioinks using a commercially available 3D bioprinter. The ability to print these hydrogels will enable future development of 3D bioprinted scaffolds containing skeletal muscle myoblasts for tissue engineering applications.

Improved Muscle Healing after Contusion Injury by the Inhibitory Effect of Suramin on Myostatin, a Negative Regulator of Muscle Growth

2008 ◽  
Vol 36 (12) ◽  
pp. 2354-2362 ◽  
Author(s):  
Masahiro Nozaki ◽  
Yong Li ◽  
Jinhong Zhu ◽  
Fabrisia Ambrosio ◽  
Kenji Uehara ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Functional Recovery ◽  
Muscle Regeneration ◽  
Inhibitory Effect ◽  
Negative Regulator ◽  
C2c12 Cells ◽  
Dependent Manner ◽  
Contusion Injury

Background Muscle contusions are the most common muscle injuries in sports medicine. Although these injuries are capable of healing, incomplete functional recovery often occurs. Hypothesis Suramin enhances muscle healing by both stimulating muscle regeneration and preventing fibrosis in contused skeletal muscle. Study Design Controlled laboratory study. Methods In vitro: Myoblasts (C2C12 cells) and muscle-derived stem cells (MDSCs) were cultured with suramin, and the potential of suramin to induce their differentiation was evaluated. Furthermore, MDSCs were cocultured with suramin and myostatin (MSTN) to monitor the capability of suramin to neutralize the effect of MSTN. In vivo: Varying concentrations of suramin were injected in the tibialis anterior muscle of mice 2 weeks after muscle contusion injury. Muscle regeneration and scar tissue formation were evaluated by histologic analysis and functional recovery was measured by physiologic testing Results In vitro: Suramin stimulated the differentiation of myoblasts and MDSCs in a dose-dependent manner. Moreover, suramin neutralized the inhibitory effect of MSTN on MDSC differentiation. In vivo: Suramin treatment significantly promoted muscle regeneration, decreased fibrosis formation, reduced myostatin expression in injured muscle, and increased muscle strength after contusion injury. Conclusion Intramuscular injection of suramin after a contusion injury improved overall skeletal muscle healing. Suramin enhanced myoblast and MDSC differentiation and neutralized MSTN's negative effect on myogenic differentiation in vitro, which suggests a possible mechanism for the beneficial effects that this pharmacologic agent exhibits in vivo. Clinical Relevance These findings could contribute to the development of biological treatments to aid in muscle healing after experiencing a muscle injury.

Sieving of electrolytes at capillary wall of cat skeletal muscle by osmotic water flow

1993 ◽  
Vol 265 (6) ◽  
pp. H1869-H1874 ◽  
Author(s):  
P. D. Watson
Keyword(s):  
Skeletal Muscle ◽  
Water Flow ◽  
Water Movement ◽  
Significant Proportion ◽  
Free Water ◽  
Mammalian Skeletal Muscle ◽  
Sodium Potassium ◽  
Osmotic Water ◽  
Significant Difference ◽  
Plasma Electrolytes

To test the hypothesis that a significant proportion of transcapillary water flow occurs through solute-restricting channels, we investigated the effects of transcapillary water movement on plasma electrolytes in isolated perfused cat skeletal muscle. The lower hindlimbs of anesthetized cats were perfused with a plasma-albumin solution and were weighed to determine transcapillary water movement. Osmolality was increased 60–70 mosmol/kgH2O with sucrose, creating water fluxes of 8–10 ml.min-1.100 g-1, and the changes in the venous concentrations of sodium, potassium, and chloride were determined. The ion concentrations were all reduced by 6–7% with no significant difference between them. The amount of reduction was quantitatively explained by the flow of ion-free water from the interstitial space into plasma and the diffusion of electrolyte in the same direction. These findings support the hypothesis that important water-only transcapillary channels exist in mammalian skeletal muscle. The observations may also explain some of the electrolyte changes seen in intense exercise.

Sign in / Sign up

Export Citation Format

Share Document