A novel hindlimb immobilization procedure for studying skeletal muscle atrophy and recovery in mouse

2009 ◽  
Vol 106 (6) ◽  
pp. 2049-2059 ◽  
Author(s):  
Annabelle Z. Caron ◽  
Geneviève Drouin ◽  
Justine Desrosiers ◽  
Frédéric Trensz ◽  
Guillaume Grenier
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Uncoupling Protein ◽  
Ring Finger ◽  
Muscle Metabolism ◽  
Skeletal Muscle Atrophy ◽  
Peroxisome Proliferator ◽  
Cast Immobilization ◽  
Peroxisome Proliferator Activated Receptor ◽  
Molecular Events

Skeletal muscle atrophy is a serious concern for patients afflicted by limb restriction due to surgery (e.g., arthrodesis), several articular pathologies (e.g., arthralgia), or simply following cast immobilization. To study the molecular events involved in this immobilization-induced debilitating condition, a convenient mouse model for atrophy is lacking. Here we provide a new immobilization procedure exploiting the normal flexion of the mouse hindlimb using a surgical staple to fix the ventral part of the foot to the distal part of the calf. Histological analysis revealed that our approach induced significant skeletal muscle atrophy by reducing the myofiber size of the tibialis anterior (TA) muscle by 36% compared with the untreated contralateral TA within a few days postimmobilization. Two molecular markers for atrophy, atrogin-1/muscle atrophy F-box (atrogin-1/MAFbx) and muscle ring finger 1 (MuRF-1) mRNAs, were significantly upregulated by 1.9- and 5.9-fold, respectively. Interestingly, our model also revealed the presence of an early inflammatory process during atrophy, characterized by the mRNA upregulation of TNF-α, IL-1, and IL-6 (1.9-, 2.4-, and 3.4-fold, respectively) simultaneously with the upregulation of the common leukocyte marker CD45 (6.1-fold). Moreover, muscle rapidly recovered on remobilization, an event associated with significantly increased levels of uncoupling protein-3 and peroxisome proliferator-activated receptor γ coactivator-1α mRNA, key components of prooxidative muscle metabolism. This model offers unexpected new insights into the molecular events involved in immobilization atrophy.

scholarly journals Antioxidant Apigenin Relieves Age-Related Muscle Atrophy by Inhibiting Oxidative Stress and Hyperactive Mitophagy and Apoptosis in Skeletal Muscle of Mice

2020 ◽  
Vol 75 (11) ◽  
pp. 2081-2088
Author(s):  
Dongtao Wang ◽  
Yajun Yang ◽  
Xiaohu Zou ◽  
Jing Zhang ◽  
Zena Zheng ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Frailty Index ◽  
Skeletal Muscle Atrophy ◽  
Peroxisome Proliferator ◽  
Peroxisome Proliferator Activated Receptor ◽  
Interacting Protein ◽  
Aged Mice ◽  
Age Related

Abstract Skeletal muscle atrophy in the aged causes loss in muscle mass and functions. Naturally occurring antioxidant flavonoid apigenin is able to ameliorate obesity- and denervation-induced muscle atrophies, but its effects on age-related muscle atrophy remain unknown. We hypothesized that apigenin can relieve muscle atrophy in aged mice, probably through special effects on reactive oxygen species and enzymes with antioxidant functions. For the male mice of the study, apigenin showed significant dose-dependent effects in relieving aging-related muscle atrophy according to results of frailty index as indicator of frailty associated with aging, grip strength, and running distance. Apigenin also improved myofiber size and morphological features and increased mitochondria number and volume, as manifested by succinate dehydrogenase staining and transmission electron microscopy. Our tests also suggested that apigenin promoted activities of enzymes such as superoxide dismutase and glutathione peroxidase for antioxidation and those for aerobic respiration such as mitochondrial respiratory enzyme complexes I, II, and IV, increased ATP, and enhanced expression of genes such as peroxisome proliferator-activated receptor-γ coactivator 1α, mitochondrial transcription factor A, nuclear respiratory factor-1, and ATP5B involved in mitochondrial biogenesis. The data also suggested that apigenin inhibited Bcl-2/adenovirus E1B 19kD-interacting protein 3 and DNA fragmentation as indicators of mitophagy and apoptosis in aged mice with skeletal muscle atrophy. Together, the results suggest that apigenin relieves age-related skeletal muscle atrophy through reducing oxidative stress and inhibiting hyperactive autophagy and apoptosis.

scholarly journals Effect of short-term hindlimb immobilization on skeletal muscle atrophy and the transcriptome in a low compared with high responder to endurance training model

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0261723
Author(s):  
Jamie-Lee M. Thompson ◽  
Daniel W. D. West ◽  
Thomas M. Doering ◽  
Boris P. Budiono ◽  
Sarah J. Lessard ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Endurance Training ◽  
Muscle Atrophy ◽  
Female Rats ◽  
Skeletal Muscle Atrophy ◽  
Biological Processes ◽  
Short Term ◽  
Cast Immobilization ◽  
Protein Ubiquitination ◽  
Differential Gene

Skeletal muscle atrophy is a physiological response to disuse, aging, and disease. We compared changes in muscle mass and the transcriptome profile after short-term immobilization in a divergent model of high and low responders to endurance training to identify biological processes associated with the early atrophy response. Female rats selectively bred for high response to endurance training (HRT) and low response to endurance training (LRT; n = 6/group; generation 19) underwent 3 day hindlimb cast immobilization to compare atrophy of plantaris and soleus muscles with line-matched controls (n = 6/group). RNA sequencing was utilized to identify Gene Ontology Biological Processes with differential gene set enrichment. Aerobic training performed prior to the intervention showed HRT improved running distance (+60.6 ± 29.6%), while LRT were unchanged (-0.3 ± 13.3%). Soleus atrophy was greater in LRT vs. HRT (-9.0 ±8.8 vs. 6.2 ±8.2%; P<0.05) and there was a similar trend in plantaris (-16.4 ±5.6% vs. -8.5 ±7.4%; P = 0.064). A total of 140 and 118 biological processes were differentially enriched in plantaris and soleus muscles, respectively. Soleus muscle exhibited divergent LRT and HRT responses in processes including autophagy and immune response. In plantaris, processes associated with protein ubiquitination, as well as the atrogenes (Trim63 and Fbxo32), were more positively enriched in LRT. Overall, LRT demonstrate exacerbated atrophy compared to HRT, associated with differential gene enrichments of biological processes. This indicates that genetic factors that result in divergent adaptations to endurance exercise, may also regulate biological processes associated with short-term muscle unloading.

The microRNA miR-696 regulates PGC-1α in mouse skeletal muscle in response to physical activity

2010 ◽  
Vol 298 (4) ◽  
pp. E799-E806 ◽  
Author(s):  
Wataru Aoi ◽  
Yuji Naito ◽  
Katsura Mizushima ◽  
Yoshikazu Takanami ◽  
Yukari Kawai ◽  
...  
Keyword(s):  
Physical Activity ◽  
Skeletal Muscle ◽  
Stress Responses ◽  
Translational Regulation ◽  
Muscle Metabolism ◽  
Exercise Group ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Nutrient Metabolism ◽  
Peroxisome Proliferator Activated Receptor

MicroRNAs (miRNAs) are small noncoding RNAs involved in posttranscriptional gene regulation that have been shown to be involved in growth, development, function, and stress responses of various organs. The purpose of this study was to identify the miRNA response to physical activity, which was related to functions such as nutrient metabolism, although the miRNAs involved are currently unknown. C57BL/6 mice were divided into exercise and control groups. The exercise group performed running exercise, with a gradual increase of the load over 4 wk. On the other hand, to examine the effect of muscle inactivity, the unilateral hindlimbs of other mice were fixed in a cast for 5 days. Microarray analysis for miRNA in gastrocnemius revealed that miR-696 was markedly affected by both exercise and immobilization, showing opposite responses to these two interventions. Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), which was increased by exercise and decreased by immobilization in the protein level, was predicted as a target regulated by miR-696. In cultured myocytes, intracellular miR-696 variation led to negative regulation of PGC-1α protein along with the expression of mRNAs for downstream genes. In addition, we found decreases in the biogenesis of mitochondria and fatty acid oxidation in miR-696-overexpressing myocytes compared with normal control myocytes. These observations demonstrate that miR-696 is a physical activity-dependent miRNA involved in the translational regulation of PGC-1α and skeletal muscle metabolism in mice.

scholarly journals Identification and characterization of Fbxl22, a novel skeletal muscle atrophy-promoting E3 ubiquitin ligase

2020 ◽  
Vol 319 (4) ◽  
pp. C700-C719 ◽  
Author(s):  
David C. Hughes ◽  
Leslie M. Baehr ◽  
Julia R. Driscoll ◽  
Sarah A. Lynch ◽  
David S. Waddell ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Splice Variant ◽  
Splice Variants ◽  
Ring Finger ◽  
Ubiquitin Ligases ◽  
Skeletal Muscle Atrophy ◽  
E3 Ubiquitin Ligases ◽  
Muscle Mass Loss

Muscle-specific E3 ubiquitin ligases have been identified in muscle atrophy-inducing conditions. The purpose of the current study was to explore the functional role of F-box and leucine-rich protein 22 (Fbxl22), and a newly identified splice variant (Fbxl22–193), in skeletal muscle homeostasis and neurogenic muscle atrophy. In mouse C2C12 muscle cells, promoter fragments of the Fbxl22 gene were cloned and fused with the secreted alkaline phosphatase reporter gene to assess the transcriptional regulation of Fbxl22. The tibialis anterior muscles of male C57/BL6 mice (12–16 wk old) were electroporated with expression plasmids containing the cDNA of two Fbxl22 splice variants and tissues collected after 7, 14, and 28 days. Gastrocnemius muscles of wild-type and muscle-specific RING finger 1 knockout (MuRF1 KO) mice were electroporated with an Fbxl22 RNAi or empty plasmid and denervated 3 days posttransfection, and tissues were collected 7 days postdenervation. The full-length gene and novel splice variant are transcriptionally induced early (after 3 days) during neurogenic muscle atrophy. In vivo overexpression of Fbxl22 isoforms in mouse skeletal muscle leads to evidence of myopathy/atrophy, suggesting that both are involved in the process of neurogenic muscle atrophy. Knockdown of Fbxl22 in the muscles of MuRF1 KO mice resulted in significant additive muscle sparing 7 days after denervation. Targeting two E3 ubiquitin ligases appears to have a strong additive effect on protecting muscle mass loss with denervation, and these findings have important implications in the development of therapeutic strategies to treat muscle atrophy.

scholarly journals miR-23a is decreased during muscle atrophy by a mechanism that includes calcineurin signaling and exosome-mediated export

2014 ◽  
Vol 306 (6) ◽  
pp. C551-C558 ◽  
Author(s):  
Matthew B. Hudson ◽  
Myra E. Woodworth-Hobbs ◽  
Bin Zheng ◽  
Jill A. Rahnert ◽  
Mitsi A. Blount ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Ring Finger ◽  
Skeletal Muscle Atrophy ◽  
C2c12 Myotubes ◽  
Activated T Cells ◽  
Streptozotocin Induced Diabetes ◽  
The Media ◽  
The Relationship ◽  
Deficient Mice

Skeletal muscle atrophy is prevalent in chronic diseases, and microRNAs (miRs) may play a key role in the wasting process. miR-23a was previously shown to inhibit the expression of atrogin-1 and muscle RING-finger protein-1 (MuRF1) in muscle. It also was reported to be regulated by cytoplasmic nuclear factor of activated T cells 3 (NFATc3) in cardiomyocytes. The objective of this study was to determine if miR-23a is regulated during muscle atrophy and to evaluate the relationship between calcineurin (Cn)/NFAT signaling and miR-23a expression in skeletal muscle cells during atrophy. miR-23a was decreased in the gastrocnemius of rats with acute streptozotocin-induced diabetes, a condition known to increase atrogin-1 and MuRF1 expression and cause atrophy. Treatment of C2C12 myotubes with dexamethasone (Dex) for 48 h also reduced miR-23a as well as RCAN1.4 mRNA, which is transcriptionally regulated by NFAT. NFATc3 nuclear localization and the amount of miR-23a decreased rapidly within 1 h of Dex administration, suggesting a link between Cn signaling and miR-23a. The level of miR-23a was lower in primary myotubes from mice lacking the α- or β-isoform of the CnA catalytic subunit than wild-type mice. Dex did not further suppress miR-23a in myotubes from Cn-deficient mice. Overexpression of CnAβ in C2C12 myotubes prevented Dex-induced suppression of miR-23a. Finally, miR-23a was present in exosomes isolated from the media of C2C12 myotubes, and Dex increased its exosomal abundance. Dex did not alter the number of exosomes released into the media. We conclude that atrophy-inducing conditions downregulate miR-23a in muscle by mechanisms involving attenuated Cn/NFAT signaling and selective packaging into exosomes.

scholarly journals Electrical stimulation prevents doxorubicin-induced atrophy and mitochondrial loss in cultured myotubes

2019 ◽  
Vol 317 (6) ◽  
pp. C1213-C1228 ◽  
Author(s):  
Blas A. Guigni ◽  
Dennis K. Fix ◽  
Joseph J. Bivona ◽  
Bradley M. Palmer ◽  
James A. Carson ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Ring Finger ◽  
Mechanical Stretch ◽  
Skeletal Muscle Atrophy ◽  
C2c12 Myotubes ◽  
Peroxisome Proliferator ◽  
Ros Production ◽  
Mitochondrial Content ◽  
Peroxisome Proliferator Activated Receptor

Muscle contraction may protect against the effects of chemotherapy to cause skeletal muscle atrophy, but the mechanisms underlying these benefits are unclear. To address this question, we utilized in vitro modeling of contraction and mechanotransduction in C2C12 myotubes treated with doxorubicin (DOX; 0.2 μM for 3 days). Myotubes expressed contractile proteins and organized these into functional myofilaments, as electrical field stimulation (STIM) induced intracellular calcium (Ca2+) transients and contractions, both of which were prevented by inhibition of membrane depolarization. DOX treatment reduced myotube myosin content, protein synthesis, and Akt (S308) and forkhead box O3a (FoxO3a; S253) phosphorylation and increased muscle RING finger 1 (MuRF1) expression. STIM (1 h/day) prevented DOX-induced reductions in myotube myosin content and Akt and FoxO3a phosphorylation, as well as increases in MuRF1 expression, but did not prevent DOX-induced reductions in protein synthesis. Inhibition of myosin-actin interaction during STIM prevented contraction and the antiatrophic effects of STIM without affecting Ca2+ cycling, suggesting that the beneficial effect of STIM derives from mechanotransductive pathways. Further supporting this conclusion, mechanical stretch of myotubes recapitulated the effects of STIM to prevent DOX suppression of FoxO3a phosphorylation and upregulation of MuRF1. DOX also increased reactive oxygen species (ROS) production, which led to a decrease in mitochondrial content. Although STIM did not alter DOX-induced ROS production, peroxisome proliferator-activated receptor-γ coactivator-1α and antioxidant enzyme expression were upregulated, and mitochondrial loss was prevented. Our results suggest that the activation of mechanotransductive pathways that downregulate proteolysis and preserve mitochondrial content protects against the atrophic effects of chemotherapeutics.

scholarly journals Hydrogen sulphide ameliorating skeletal muscle atrophy in db/db mice via Muscle RING finger 1 S‐sulfhydration

2020 ◽  
Vol 24 (16) ◽  
pp. 9362-9377 ◽  
Author(s):  
Fangping Lu ◽  
Baoling Lu ◽  
Linxue Zhang ◽  
JingChen Wen ◽  
Mengyi Wang ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Atrophy ◽  
Hydrogen Sulphide ◽  
Ring Finger ◽  
Skeletal Muscle Atrophy
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