scholarly journals A Systems Biology Approach Using Transcriptomic Data Reveals Genes and Pathways in Porcine Skeletal Muscle Affected by Dietary Lysine

2017 ◽  
Author(s):  
Taiji Wang ◽  
Jean M. Feugang ◽  
Mark A. Crenshaw ◽  
Naresh Regmi ◽  
John R. Blanton Jr. ◽  
...  
Keyword(s):  
Protein Degradation ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Muscle Growth ◽  
Transcriptomic Data ◽  
Ubiquitination Pathway ◽  
Porcine Gene ◽  
Muscle Protein Degradation ◽  
Glycine Synthesis ◽  
Dietary Treatments

Nine crossbred finishing barrows randomly assigned to 3 dietary treatments were used to investigate the effects of dietary lysine on muscle growth related metabolic and signaling pathways. Muscle samples were collected from the longissimus dorsi of individual pigs after feeding the lysine-deficient, lysine-adequate, or lysine-excess diet for 5 weeks, and the total RNA was extracted afterwards. Affymetrix Porcine Gene 1.0 ST Array was used to quantify the expression levels of 19,211 genes. A total of 674 transcripts were differentially expressed (P ≤ 0.05); 60 out of 131 transcripts (P ≤ 0.01) were annotated in the NetAffx database. Ingenuity pathway analysis showed that dietary lysine deficiency may lead to (1) increased muscle protein degradation via the ubiquitination pathway as indicated by the up-regulated DNAJA1, HSP90AB1 and UBE2B mRNA, (2) reduced muscle protein synthesis via the up-regulated RND3 and ZIC1 mRNA, (3) increased serine and glycine synthesis via the up-regulated PHGDH and PSPH mRNA, and (4) increased lipid accumulation via the up-regulated ME1, SCD, and CIDEC mRNA. Dietary lysine excess may lead to (1) decreased muscle protein degradation via the down-regulated DNAJA1, HSP90AA1, HSPH1, and UBE2D3 mRNA, and (2) reduced lipid biosynthesis via the down-regulated CFD and ME1 mRNA.

scholarly journals Comparison of protein synthesis and degradation in incubated and perfused muscle

1983 ◽  
Vol 212 (3) ◽  
pp. 649-653 ◽  
Author(s):  
A S Clark ◽  
W E Mitch
Keyword(s):  
Protein Synthesis ◽  
Protein Degradation ◽  
Insulin Treatment ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Muscle Protein Degradation ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Rates of muscle protein synthesis and degradation measured in the perfused hindquarter were compared with those in incubated epitrochlearis muscles. With fed or starved mature rats, results without insulin treatment were identical. With insulin treatment, protein synthesis in perfused hindquarters was greater, though protein degradation was the same. Thus rates of muscle protein degradation estimated by these two methods in vitro correspond closely.

Quercetin enhances the antitumor effect of trichostatin A and suppresses muscle wasting in tumor-bearing mice

2018 ◽  
Vol 9 (2) ◽  
pp. 871-879 ◽  
Author(s):  
Shu-Ting Chan ◽  
Cheng-Hung Chuang ◽  
Yi-Chin Lin ◽  
Jiunn-Wang Liao ◽  
Chong-Kuei Lii ◽  
...  
Keyword(s):  
Protein Degradation ◽  
Antitumor Effect ◽  
Muscle Wasting ◽  
Muscle Protein ◽  
Trichostatin A ◽  
Tumor Bearing ◽  
Muscle Protein Degradation

Quercetin prevents TSA-induced muscle wasting by down-regulating FOXO1 mediated muscle protein degradation.

Mechanism of induction of muscle protein degradation by angiotensin II

2006 ◽  
Vol 18 (7) ◽  
pp. 1087-1096 ◽  
Author(s):  
Steven T. Russell ◽  
Stacey M. Wyke ◽  
Michael J. Tisdale
Keyword(s):  
Angiotensin Ii ◽  
Protein Degradation ◽  
Muscle Protein ◽  
Muscle Protein Degradation

scholarly journals Proteasome- and Calpain-Mediated Proteolysis, but Not Autophagy, Is Required for Leucine-Induced Protein Synthesis in C2C12 Myotubes

Physiologia ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 22-33
Author(s):  
Shelby C. Osburn ◽  
Christopher G. Vann ◽  
David D. Church ◽  
Arny A. Ferrando ◽  
Michael D. Roberts
Keyword(s):  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Muscle Growth ◽  
Proteasome Inhibition ◽  
Coupled Processes ◽  
C2c12 Myotubes ◽  
Calpain Inhibitor ◽  
Tightly Coupled

Muscle protein synthesis and proteolysis are tightly coupled processes. Given that muscle growth is promoted by increases in net protein balance, it stands to reason that bolstering protein synthesis through amino acids while reducing or inhibiting proteolysis could be a synergistic strategy in enhancing anabolism. However, there is contradictory evidence suggesting that the proper functioning of proteolytic systems in muscle is required for homeostasis. To add clarity to this issue, we sought to determine if inhibiting different proteolytic systems in C2C12 myotubes in conjunction with acute and chronic leucine treatments affected markers of anabolism. In Experiment 1, myotubes underwent 1-h, 6-h, and 24-h treatments with serum and leucine-free DMEM containing the following compounds (n = 6 wells per treatment): (i) DMSO vehicle (CTL), (ii) 2 mM leucine + vehicle (Leu-only), (iii) 2 mM leucine + 40 μM MG132 (20S proteasome inhibitor) (Leu + MG132), (iv) 2 mM leucine + 50 μM calpeptin (calpain inhibitor) (Leu + CALP), and (v) 2 mM leucine + 1 μM 3-methyladenine (autophagy inhibitor) (Leu + 3MA). Protein synthesis levels significantly increased (p < 0.05) in the Leu-only and Leu + 3MA 6-h treatments compared to CTL, and levels were significantly lower in Leu + MG132 and Leu + CALP versus Leu-only and CTL. With 24-h treatments, total protein yield was significantly lower in Leu + MG132 cells versus other treatments. Additionally, the intracellular essential amino acid (EAA) pool was significantly greater in 24-h Leu + MG132 treatments versus other treatments. In a follow-up experiment, myotubes were treated for 48 h with CTL, Leu-only, and Leu + MG132 for morphological assessments. Results indicated Leu + MG132 yielded significantly smaller myotubes compared to CTL and Leu-only. Our data are limited in scope due to the utilization of select proteolysis inhibitors. However, this is the first evidence to suggest proteasome and calpain inhibition with MG132 and CALP, respectively, abrogate leucine-induced protein synthesis in myotubes. Additionally, longer-term Leu + MG132 treatments translated to an atrophy phenotype. Whether or not proteasome inhibition in vivo reduces leucine- or EAA-induced anabolism remains to be determined.

scholarly journals Integrin signaling: linking mechanical stimulation to skeletal muscle hypertrophy

2019 ◽  
Vol 317 (4) ◽  
pp. C629-C641 ◽  
Author(s):  
Marni D. Boppart ◽  
Ziad S. Mahmassani
Keyword(s):  
Skeletal Muscle ◽  
Mechanical Load ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Muscle Growth ◽  
Mammalian Target Of Rapamycin ◽  
Integrin Subunit ◽  
Resistance Exercise Training ◽  
Adhesion Protein ◽  
Subunit Mrna

The α7β1-integrin is a transmembrane adhesion protein that connects laminin in the extracellular matrix (ECM) with actin in skeletal muscle fibers. The α7β1-integrin is highly expressed in skeletal muscle and is concentrated at costameres and myotendious junctions, providing the opportunity to transmit longitudinal and lateral forces across the membrane. Studies have demonstrated that α7-integrin subunit mRNA and protein are upregulated following eccentric contractions as a mechanism to reinforce load-bearing structures and resist injury with repeated bouts of exercise. It has been hypothesized for many years that the integrin can also promote protein turnover in a manner that can promote beneficial adaptations with resistance exercise training, including hypertrophy. This review provides basic information about integrin structure and activation and then explores its potential to serve as a critical mechanosensor and activator of muscle protein synthesis and growth. Overall, the hypothesis is proposed that the α7β1-integrin can contribute to mechanical-load induced skeletal muscle growth via an mammalian target of rapamycin complex 1-independent mechanism.

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