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Can endurance exercise preconditioning prevention disuse muscle atrophy?

Wiggs MP - Front Physiol (2015)

Bottom Line: Endurance exercise training imposes oxidative, metabolic, and heat stress on skeletal muscle which activates a variety of cellular signaling pathways that ultimately leads to the increased expression of proteins that have been demonstrated to protect muscle from inactivity -induced atrophy.This review will highlight the effect of exercise-induced oxidative stress on endogenous enzymatic antioxidant capacity (i.e., superoxide dismutase, glutathione peroxidase, and catalase), the role of oxidative and metabolic stress on PGC1-α, and finally highlight the effect heat stress and HSP70 induction.Finally, this review will discuss the supporting scientific evidence that these proteins can attenuate muscle atrophy through exercise preconditioning.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Physiology and Kinesiology, Center for Exercise Science, University of Florida Gainesville, FL, USA.

ABSTRACT
Emerging evidence suggests that exercise training can provide a level of protection against disuse muscle atrophy. Endurance exercise training imposes oxidative, metabolic, and heat stress on skeletal muscle which activates a variety of cellular signaling pathways that ultimately leads to the increased expression of proteins that have been demonstrated to protect muscle from inactivity -induced atrophy. This review will highlight the effect of exercise-induced oxidative stress on endogenous enzymatic antioxidant capacity (i.e., superoxide dismutase, glutathione peroxidase, and catalase), the role of oxidative and metabolic stress on PGC1-α, and finally highlight the effect heat stress and HSP70 induction. Finally, this review will discuss the supporting scientific evidence that these proteins can attenuate muscle atrophy through exercise preconditioning.

No MeSH data available.


Related in: MedlinePlus

Pathways regulating skeletal muscle size. The balance between protein synthesis and protein degradation determines muscle size. Muscle protein synthesis is regulated through the Akt/mTOR pathway. There are four pathways of protein degradation to degrade cellular components, caspase-3 removes nuclei (apoptosis) and along with the calpain family of proteins can breakdown the contractile proteins (myofilaments) in muscle into smaller polypeptides. The ubiquitin-proteasome pathway (UPP) breaks down the small peptides and any other protein targeted by ubiquitination for degradation. Finally, autophagy breaks down organelles, such as mitochondria and endoplasmic reticulum, and large protein aggregates.
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Figure 1: Pathways regulating skeletal muscle size. The balance between protein synthesis and protein degradation determines muscle size. Muscle protein synthesis is regulated through the Akt/mTOR pathway. There are four pathways of protein degradation to degrade cellular components, caspase-3 removes nuclei (apoptosis) and along with the calpain family of proteins can breakdown the contractile proteins (myofilaments) in muscle into smaller polypeptides. The ubiquitin-proteasome pathway (UPP) breaks down the small peptides and any other protein targeted by ubiquitination for degradation. Finally, autophagy breaks down organelles, such as mitochondria and endoplasmic reticulum, and large protein aggregates.

Mentions: In regards to proteolysis, skeletal muscle utilizes four complementary pathways to remove damaged, misfolded, or unnecessary proteins (Figure 1). These pathways include calpain, caspase-3, ubiquitin proteasome pathway, and autophagy (reviewed in Jackman and Kandarian, 2004). The calpain family of proteins is calcium dependent proteases that are important in the initiation of the breakdown of actin, myosin, and other structural proteins. Indeed, target pharmacological inhibition of calpain protects against disuse muscle atrophy (Tischler et al., 1990; Goll et al., 2003; Maes et al., 2007; Nelson et al., 2012; Talbert et al., 2013a). Caspase-3 is a member of the cysteine-aspartic acid protease family. Caspase-3 is most often defined by its central role in the removal of nuclei by myonuclear apoptosis; however, recent info also demonstrates the caspase-3 can work in concert with calpain in the cleavage of myofibrillar proteins (Du et al., 2004; Dupont-Versteegden, 2006; Smuder et al., 2010). Similar to calpain, inhibition or genetic knockdown of caspase-3 is sufficient to attenuate disuse muscle atrophy (McClung et al., 2007; Nelson et al., 2012; Talbert et al., 2013a; Zhu et al., 2013). Together, it is believed that calpain and caspase-3 are required for disuse atrophy because they begin the initial breakdown of the contractile apparatus of the muscle (Jackman and Kandarian, 2004). Further breakdown of these proteins is accomplished by the ubiquitin-proteasome pathway (Lecker et al., 1999). The proteasome pathway is also important in the degradation of misfolded, smaller polypeptides, and unnecessary proteins. Presently, the role of autophagy in disuse atrophy remains unclear. Early studies suggested that pharmacological inhibition of autophagy had minimal effects on muscle atrophy (Tischler et al., 1990); however, recent evidence suggests that autophagy may play an important role in disuse atrophy, specifically in the ability to selectively degrade organelles such as mitochondria (i.e., mitophagy) (Sandri, 2013). This will be discussed in greater detail in later sections.


Can endurance exercise preconditioning prevention disuse muscle atrophy?

Wiggs MP - Front Physiol (2015)

Pathways regulating skeletal muscle size. The balance between protein synthesis and protein degradation determines muscle size. Muscle protein synthesis is regulated through the Akt/mTOR pathway. There are four pathways of protein degradation to degrade cellular components, caspase-3 removes nuclei (apoptosis) and along with the calpain family of proteins can breakdown the contractile proteins (myofilaments) in muscle into smaller polypeptides. The ubiquitin-proteasome pathway (UPP) breaks down the small peptides and any other protein targeted by ubiquitination for degradation. Finally, autophagy breaks down organelles, such as mitochondria and endoplasmic reticulum, and large protein aggregates.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4356230&req=5

Figure 1: Pathways regulating skeletal muscle size. The balance between protein synthesis and protein degradation determines muscle size. Muscle protein synthesis is regulated through the Akt/mTOR pathway. There are four pathways of protein degradation to degrade cellular components, caspase-3 removes nuclei (apoptosis) and along with the calpain family of proteins can breakdown the contractile proteins (myofilaments) in muscle into smaller polypeptides. The ubiquitin-proteasome pathway (UPP) breaks down the small peptides and any other protein targeted by ubiquitination for degradation. Finally, autophagy breaks down organelles, such as mitochondria and endoplasmic reticulum, and large protein aggregates.
Mentions: In regards to proteolysis, skeletal muscle utilizes four complementary pathways to remove damaged, misfolded, or unnecessary proteins (Figure 1). These pathways include calpain, caspase-3, ubiquitin proteasome pathway, and autophagy (reviewed in Jackman and Kandarian, 2004). The calpain family of proteins is calcium dependent proteases that are important in the initiation of the breakdown of actin, myosin, and other structural proteins. Indeed, target pharmacological inhibition of calpain protects against disuse muscle atrophy (Tischler et al., 1990; Goll et al., 2003; Maes et al., 2007; Nelson et al., 2012; Talbert et al., 2013a). Caspase-3 is a member of the cysteine-aspartic acid protease family. Caspase-3 is most often defined by its central role in the removal of nuclei by myonuclear apoptosis; however, recent info also demonstrates the caspase-3 can work in concert with calpain in the cleavage of myofibrillar proteins (Du et al., 2004; Dupont-Versteegden, 2006; Smuder et al., 2010). Similar to calpain, inhibition or genetic knockdown of caspase-3 is sufficient to attenuate disuse muscle atrophy (McClung et al., 2007; Nelson et al., 2012; Talbert et al., 2013a; Zhu et al., 2013). Together, it is believed that calpain and caspase-3 are required for disuse atrophy because they begin the initial breakdown of the contractile apparatus of the muscle (Jackman and Kandarian, 2004). Further breakdown of these proteins is accomplished by the ubiquitin-proteasome pathway (Lecker et al., 1999). The proteasome pathway is also important in the degradation of misfolded, smaller polypeptides, and unnecessary proteins. Presently, the role of autophagy in disuse atrophy remains unclear. Early studies suggested that pharmacological inhibition of autophagy had minimal effects on muscle atrophy (Tischler et al., 1990); however, recent evidence suggests that autophagy may play an important role in disuse atrophy, specifically in the ability to selectively degrade organelles such as mitochondria (i.e., mitophagy) (Sandri, 2013). This will be discussed in greater detail in later sections.

Bottom Line: Endurance exercise training imposes oxidative, metabolic, and heat stress on skeletal muscle which activates a variety of cellular signaling pathways that ultimately leads to the increased expression of proteins that have been demonstrated to protect muscle from inactivity -induced atrophy.This review will highlight the effect of exercise-induced oxidative stress on endogenous enzymatic antioxidant capacity (i.e., superoxide dismutase, glutathione peroxidase, and catalase), the role of oxidative and metabolic stress on PGC1-α, and finally highlight the effect heat stress and HSP70 induction.Finally, this review will discuss the supporting scientific evidence that these proteins can attenuate muscle atrophy through exercise preconditioning.

View Article: PubMed Central - PubMed

Affiliation: Department of Applied Physiology and Kinesiology, Center for Exercise Science, University of Florida Gainesville, FL, USA.

ABSTRACT
Emerging evidence suggests that exercise training can provide a level of protection against disuse muscle atrophy. Endurance exercise training imposes oxidative, metabolic, and heat stress on skeletal muscle which activates a variety of cellular signaling pathways that ultimately leads to the increased expression of proteins that have been demonstrated to protect muscle from inactivity -induced atrophy. This review will highlight the effect of exercise-induced oxidative stress on endogenous enzymatic antioxidant capacity (i.e., superoxide dismutase, glutathione peroxidase, and catalase), the role of oxidative and metabolic stress on PGC1-α, and finally highlight the effect heat stress and HSP70 induction. Finally, this review will discuss the supporting scientific evidence that these proteins can attenuate muscle atrophy through exercise preconditioning.

No MeSH data available.


Related in: MedlinePlus