scholarly journals Mitochondrial-targeted antioxidants protect skeletal muscle against immobilization-induced muscle atrophy

2011 ◽  
Vol 111 (5) ◽  
pp. 1459-1466 ◽  
Author(s):  
Kisuk Min ◽  
Ashley J. Smuder ◽  
Oh-sung Kwon ◽  
Andreas N. Kavazis ◽  
Hazel H. Szeto ◽  
...  

Prolonged periods of muscular inactivity (e.g., limb immobilization) result in skeletal muscle atrophy. Although it is established that reactive oxygen species (ROS) play a role in inactivity-induced skeletal muscle atrophy, the cellular pathway(s) responsible for inactivity-induced ROS production remain(s) unclear. To investigate this important issue, we tested the hypothesis that elevated mitochondrial ROS production contributes to immobilization-induced increases in oxidative stress, protease activation, and myofiber atrophy in skeletal muscle. Cause-and-effect was determined by administration of a novel mitochondrial-targeted antioxidant (SS-31) to prevent immobilization-induced mitochondrial ROS production in skeletal muscle fibers. Compared with ambulatory controls, 14 days of muscle immobilization resulted in significant muscle atrophy, along with increased mitochondrial ROS production, muscle oxidative damage, and protease activation. Importantly, treatment with a mitochondrial-targeted antioxidant attenuated the inactivity-induced increase in mitochondrial ROS production and prevented oxidative stress, protease activation, and myofiber atrophy. These results support the hypothesis that redox disturbances contribute to immobilization-induced skeletal muscle atrophy and that mitochondria are an important source of ROS production in muscle fibers during prolonged periods of inactivity.

2011 ◽  
Vol 110 (4) ◽  
pp. 935-942 ◽  
Author(s):  
Ashley J. Smuder ◽  
Andreas N. Kavazis ◽  
Kisuk Min ◽  
Scott K. Powers

Doxorubicin (Dox) is a potent antitumor agent used in cancer treatment. Unfortunately, Dox is myotoxic and results in significant reductions in skeletal muscle mass and function. Complete knowledge of the mechanism(s) by which Dox induces toxicity in skeletal muscle is incomplete, but it is established that Dox-induced toxicity is associated with increased generation of reactive oxygen species and oxidative damage within muscle fibers. Since muscular exercise promotes the expression of numerous cytoprotective proteins (e.g., antioxidant enzymes, heat shock protein 72), we hypothesized that muscular exercise will attenuate Dox-induced damage in exercise-trained muscle fibers. To test this postulate, Sprague-Dawley rats were randomly assigned to the following groups: sedentary, exercise, sedentary with Dox, or exercise with Dox. Our results show increased oxidative stress and activation of cellular proteases (calpain and caspase-3) in skeletal muscle of animals treated with Dox. Importantly, our findings reveal that exercise can prevent the Dox-induced oxidative damage and protease activation in the trained muscle. This exercise-induced protection against Dox-induced toxicity may be due, at least in part, to an exercise-induced increase in muscle levels of antioxidant enzymes and heat shock protein 72. Together, these novel results demonstrate that muscular exercise is a useful countermeasure that can protect skeletal muscle against Dox treatment-induced oxidative stress and protease activation in skeletal muscles.


2018 ◽  
Vol 315 (5) ◽  
pp. C609-C622 ◽  
Author(s):  
Avisek Majumder ◽  
Mahavir Singh ◽  
Jyotirmaya Behera ◽  
Nicholas T. Theilen ◽  
Akash K. George ◽  
...  

Although hyperhomocysteinemia (HHcy) occurs because of the deficiency in cystathionine-β-synthase (CBS) causing skeletal muscle dysfunction, it is still unclear whether this effect is mediated through oxidative stress, endoplasmic reticulum (ER) stress, or both. Nevertheless, there is no treatment option available to improve HHcy-mediated muscle injury. Hydrogen sulfide (H2S) is an antioxidant compound, and patients with CBS mutation do not produce H2S. In this study, we hypothesized that H2S mitigates HHcy-induced redox imbalance/ER stress during skeletal muscle atrophy via JNK phosphorylation. We used CBS+/−mice to study HHcy-mediated muscle atrophy, and treated them with sodium hydrogen sulfide (NaHS; an H2S donor). Proteins and mRNAs were examined by Western blots and quantitative PCR. Proinflammatory cytokines were also measured. Muscle mass and strength were studied via fatigue susceptibility test. Our data revealed that HHcy was detrimental to skeletal mass, particularly gastrocnemius and quadriceps muscle weight. We noticed that oxidative stress was reversed by NaHS in homocysteine (Hcy)-treated C2C12 cells. Interestingly, ER stress markers (GRP78, ATF6, pIRE1α, and pJNK) were elevated in vivo and in vitro, and NaHS mitigated these effects. Additionally, we observed that JNK phosphorylation was upregulated in C2C12 after Hcy treatment, but NaHS could not reduce this effect. Furthermore, inflammatory cytokines IL-6 and TNF-α were higher in plasma from CBS as compared with wild-type mice. FOXO1-mediated Atrogin-1 and MuRF-1 upregulation were attenuated by NaHS. Functional studies revealed that NaHS administration improved muscle fatigability in CBS+/−mice. In conclusion, our work provides evidence that NaHS is beneficial in mitigating HHcy-mediated skeletal injury incited by oxidative/ER stress responses.


Nutrients ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2180
Author(s):  
Mari Noguchi ◽  
Tomoya Kitakaze ◽  
Yasuyuki Kobayashi ◽  
Katsuyuki Mukai ◽  
Naoki Harada ◽  
...  

We investigated the effects of β-cryptoxanthin on skeletal muscle atrophy in senescence-accelerated mouse-prone 1 (SAMP1) mice. For 15 weeks, SAMP1 mice were intragastrically administered vehicle or β-cryptoxanthin. At 35 weeks of age, the skeletal muscle mass in SAMP1 mice was reduced compared with that in control senescence-accelerated mouse-resistant 1 (SAMR1) mice. β-cryptoxanthin increased muscle mass with an increase in the size of muscle fibers in the soleus muscle of SAMP1 mice. The expressions of autophagy-related factors such as beclin-1, p62, LC3-I, and LC3-II were increased in the soleus muscle of SAMP1 mice; however, β-cryptoxanthin administration inhibited this increase. Unlike in SAMR1 mice, p62 was punctately distributed throughout the cytosol in the soleus muscle fibers of SAMP1 mice; however, β-cryptoxanthin inhibited this punctate distribution. The cross-sectional area of p62-positive fiber was smaller than that of p62-negative fiber, and the ratio of p62-positive fibers to p62-negative fibers was increased in SAMP1 mice. β-cryptoxanthin decreased this ratio in SAMP1 mice. Furthermore, β-cryptoxanthin decreased the autophagy-related factor expression in murine C2C12 myotube. The autophagy inhibitor bafilomycin A1, but not the proteasome inhibitor MG132, inhibited the β-cryptoxanthin-induced decrease in p62 and LC3-II expressions. These results indicate that β-cryptoxanthin inhibits the p62 accumulation in fibers and improves muscle atrophy in the soleus muscle of SAMP1 mice.


2007 ◽  
Vol 293 (3) ◽  
pp. R1159-R1168 ◽  
Author(s):  
Florian L. Muller ◽  
Wook Song ◽  
Youngmok C. Jang ◽  
Yuhong Liu ◽  
Marian Sabia ◽  
...  

Reactive oxygen species (ROS), especially mitochondrial ROS, are postulated to play a significant role in muscle atrophy. We report a dramatic increase in mitochondrial ROS generation in three conditions associated with muscle atrophy: in aging, in mice lacking CuZn-SOD ( Sod1−/−), and in the neurodegenerative disease, amyotrophic lateral sclerosis (ALS). ROS generation in muscle mitochondria is nearly threefold higher in 28- to 32-mo-old than in 10-mo-old mice and is associated with a 30% loss in gastrocnemius mass. In Sod1−/− mice, muscle mitochondrial ROS production is increased >100% in 20-mo compared with 5-mo-old mice along with a >50% loss in muscle mass. ALS G93A mutant mice show a 75% loss of muscle mass during disease progression and up to 12-fold higher muscle mitochondrial ROS generation. In a second ALS mutant model, H46RH48Q mice, ROS production is approximately fourfold higher than in control mice and is associated with a less dramatic loss (30%) in muscle mass. Thus ROS production is strongly correlated with the extent of muscle atrophy in these models. Because each of the models of muscle atrophy studied are associated to some degree with a loss of innervation, we were interested in determining whether denervation plays a role in ROS generation in muscle mitochondria isolated from hindlimb muscle following surgical sciatic nerve transection. Seven days postdenervation, muscle mitochondrial ROS production increased nearly 30-fold. We conclude that enhanced generation of mitochondrial ROS may be a common factor in the mechanism underlying denervation-induced atrophy.


Sign in / Sign up

Export Citation Format

Share Document