Altered expression of genes regulating skeletal muscle mass in the portacaval anastamosis rat

2007 ◽  
Vol 292 (4) ◽  
pp. G1105-G1113 ◽  
Author(s):  
Srinivasan Dasarathy ◽  
Sean Muc ◽  
Kola Hisamuddin ◽  
John M. Edmison ◽  
Milan Dodig ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cell ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Cell Function ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Igf I ◽  
Ubiquitin Proteasome ◽  
Forelimb Grip Strength

We examined the temporal relationship between portacaval anastamosis (PCA), weight gain, changes in skeletal muscle mass and molecular markers of protein synthesis, protein breakdown, and satellite cell proliferation and differentiation. Male Sprague-Dawley rats with end to side PCA ( n = 24) were compared with sham-operated pair-fed rats ( n = 24). Whole body weight, lean body mass, and forelimb grip strength were determined at weekly intervals. The skeletal muscle expression of the ubiquitin proteasome system, myostatin, its receptor (the activin 2B receptor) and its signal, cyclin-dependant kinase inhibitor (CDKI) p21, insulin-like growth factor (IGF)-I and its receptor (IGF-I receptor-α), and markers of satellite cell proliferation and differentiation were quantified. PCA rats did not gain body weight and had lower lean body mass, forelimb grip strength, and gastrocnemius muscle weight. The skeletal muscle expression of the mRNA of ubiquitin proteasome components was higher in PCA rats in the first 2 wk followed by a lower expression in the subsequent 2 wk ( P < 0.01). The mRNA and protein of myostatin, activin 2B receptor, and CDKI p21 were higher, whereas IGF-I and its receptor as well as markers of satellite cell function (proliferating nuclear cell antigen, myoD, myf5, and myogenin) were lower at weeks 3 and 4 following PCA ( P < 0.05). We conclude that PCA resulted in uninhibited proteolysis in the initial 2 wk. This was followed by an adaptive response in the later 2 wk consisting of an increased expression of myostatin that may have contributed to reduced muscle protein synthesis, impaired satellite cell function, and lower skeletal muscle mass.

scholarly journals Myostatin and insulin-like growth factor-I and -II expression in the muscle of rats exposed to the microgravity environment of the NeuroLab space shuttle flight

2000 ◽  
Vol 167 (3) ◽  
pp. 417-428 ◽  
Author(s):  
R Lalani ◽  
S Bhasin ◽  
F Byhower ◽  
R Tarnuzzer ◽  
M Grant ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Recovery Period ◽  
Microgravity Environment ◽  
Mrna Levels ◽  
Adult Rats ◽  
Male Adult ◽  
Western Blots ◽  
Igf I

The mechanism of the loss of skeletal muscle mass that occurs during spaceflight is not well understood. Myostatin has been proposed as a negative modulator of muscle mass, and IGF-I and IGF-II are known positive regulators of muscle differentiation and growth. We investigated whether muscle loss associated with spaceflight is accompanied by increased levels of myostatin and a reduction in IGF-I and -II levels in the muscle, and whether these changes correlate with an increase in muscle proteolysis and apoptosis. Twelve male adult rats sent on the 17-day NASA STS-90 NeuroLab space flight were divided upon return to earth into two groups, and killed either 1 day later (R1) or after 13 days of acclimatization (R13). Ground-based control rats were maintained for the same periods in either vivarium (R3 and R15, respectively), or flight-simulated cages (R5 and R17, respectively). RNA and protein were isolated from the tibialis anterior, biceps femoris, quadriceps, and gastrocnemius muscles. Myostatin, IGF-I, IGF-II and proteasome 2c mRNA concentrations were determined by reverse transcription/PCR; myostatin and ubiquitin mRNA were also measured by Northern blot analysis; myostatin protein was estimated by immunohistochemistry; the apoptotic index and the release of 3-methylhistidine were determined respectively by the TUNEL assay and by HPLC. Muscle weights were 19-24% lower in the R1 rats compared with the control R3 and R5 rats, but were not significantly different after the recovery period. The myostatin/beta-actin mRNA ratios (means+/-s.e.m. ) were higher in the muscles of the R1 rats compared with the control R5 rats: 5.0-fold in tibialis (5.35 +/- 1.85 vs 1.07 +/- 0.26), 3.0-fold in biceps (2.46+/-0.70 vs 0.81 +/- 0.04), 1.9-fold in quadriceps (7.84 +/- 1.73 vs 4.08 +/- 0.52), and 2.2-fold in gastrocnemius (0.99 +/- 0.35 vs 0.44 +/- 0.17). These values also normalized upon acclimatization. Our antibody against a myostatin peptide was validated by detection of the recombinant human myostatin protein on Western blots, which also showed that myostatin immunostaining was increased in muscle sections from R1 rats, compared with control R3 rats, and normalized upon acclimatization. In contrast, IGF-II mRNA concentrations in the muscles from R1 rats were 64-89% lower than those in R3 animals. With the exception of the gastrocnemius, IGF-II was also decreased in R5 animals maintained in flight-simulated cages, and normalized upon acclimatization. The intramuscular IGF-I mRNA levels were not significantly different between the spaceflight rats and the controls. No increase was found in the proteolysis markers 3-methyl histidine, ubiquitin mRNA, and proteasome 2C mRNA. In conclusion, the loss of skeletal muscle mass that occurs during spaceflight is associated with increased myostatin mRNA and protein levels in the skeletal muscle, and a decrease in IGF-II mRNA levels. These alterations are normalized upon restoration of normal gravity and caging conditions. These data suggest that reciprocal changes in the expression of myostatin and IGF-II may contribute to the multifactorial pathophysiology of muscle atrophy that occurs during spaceflight.

scholarly journals Inducible Activation of Akt Increases Skeletal Muscle Mass and Force Without Satellite Cell Activation

2010 ◽  
Vol 98 (3) ◽  
pp. 153a ◽  
Author(s):  
Bert Blaauw ◽  
Canato Marta ◽  
Lisa Agatea ◽  
Luana Toniolo ◽  
Cristina Mammucari ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Satellite Cell ◽  
Muscle Mass ◽  
Skeletal Muscle Mass ◽  
Cell Activation ◽  
Satellite Cell Activation ◽  
Inducible Activation

scholarly journals Molecular Regulation and Rejuvenation of Muscle Stem (Satellite) Cell Aging

2015 ◽  
Vol 7 (2) ◽  
pp. 73
Author(s):  
Anna Meiliana ◽  
Nurrani Mustika Dewi ◽  
Andi Wijaya
Keyword(s):  
Skeletal Muscle ◽  
Stem Cells ◽  
Stem Cell ◽  
Satellite Cell ◽  
Muscle Mass ◽  
Satellite Cells ◽  
Cell Function ◽  
Muscle Stem Cell ◽  
Muscle Aging ◽  
Age Related

BACKGROUND: Age-related muscle loss leads to lack of muscle strength, resulting in reduced posture and mobility and an increased risk of falls, all of which contribute to a decrease in quality of life. Skeletal muscle regeneration is a complex process, which is not yet completely understood.CONTENT: Skeletal muscle undergoes a progressive age-related loss in mass and function. Preservation of muscle mass depends in part on satellite cells, the resident stem cells of skeletal muscle. Reduced satellite cell function may contribute to the age-associated decrease in muscle mass. Recent studies have delineated that the aging process in organ stem cells is largely caused by age-specific changes in the differentiated niches, and that regenerative outcomes often depend on the age of the niche, rather than on stem cell age. It is likely that epigenetic states will be better define such key satellite cell features as prolonged quiescence and lineage fidelity. It is also likely that DNA and histone modifications will underlie many of the changes in aged satellite cells that account for age-related declines in functionality and rejuvenation through exposure to the systemic environment.SUMMARY: Skeletal muscle aging results in a gradual loss of skeletal muscle mass, skeletal muscle function and regenerative capacity, which can lead to sarcopenia and increased mortality. Although the mechanisms underlying sarcopenia remain unclear, the skeletal muscle stem cell, or satellite cell, is required for muscle regeneration. Decreased muscle stem cell function in aging has long been shown to depend on altered environmental cues, whereas the contribution of intrinsic mechanisms remained less clear. Signals in the aged niche were shown to cause permanent defects in the ability of satellite cells to return to quiescence, ultimately also impairing the maintenance of self-renewing satellite cells. Therefore, only anti-aging strategies taking both factors, the stem cell niche and the stem cells per se, into consideration may ultimately be successful.KEYWORDS: satellite cell, muscle, aging, niche, regenerations

scholarly journals 343 Wnt/β-catenin pathway is required for porcine satellite cell proliferation and differentiation to promote skeletal muscle growth

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 97-97
Author(s):  
Zong-ming Zhang ◽  
Chun-qi Gao ◽  
Hui-chao Yan ◽  
Xiu-qi Wang
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Satellite Cell ◽  
Muscle Growth ◽  
Control Group ◽  
Skeletal Muscle Growth ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Deficiency Group

Abstract Wnt/β-catenin plays a crucial role in skeletal muscle growth, but its specific mechanism still unclear. In this study, due to the distinct role of lysine in pig industry, we provided it as an entry point to investigate the role of Wnt/β-catenin in governing skeletal muscle growth. Firstly, total 18 weaned piglets were divided into three groups: control group, lysine deficiency group and lysine re-supplementation group (lysine levels added from 0.83% to 1.31% at 14 d). After 28 d experiment, all pigs were slaughtered to measure the change of Wnt/β-catenin in skeletal muscle. Secondly, satellite cell (SC) was isolated and cultured with Wnt activator, such as Wnt3a and WRN (Wnt3a, R-spondin1, Noggin) after lysine deficiency for 48 h to investigate cell proliferation and differentiation ability and the level of Wnt/β-catenin in different conditions. The results showed that compared with the control group, lysine deficiency significantly reduced longissimus dorsi muscle weight and Pax7 positive SC, and inhibited Wnt/β-catenin (P &lt; 0.05). Fortunately, these restrictions were rescued to the control levels by lysine re-supplementation (P &gt; 0.05). Meanwhile, compared with the lysine deficiency group, the MTT and western blotting assay showed cell proliferation ability was significantly increased with re-activated Wnt/β-catenin by re-supplemented lysine, Wnt3a or WRN (P &lt; 0.05), respectively. Moreover, under the condition of cell differentiation, compared with the control group, cell fusion index was significantly decreased in the lysine deficiency group (P &lt; 0.05), whereas it was significantly increased with lysine re-supplementation group, Wnt3a or WRN respective supplementation group in comparison with the lysine deficiency group (P &lt; 0.05). In addition, compared with the lysine deficiency group, the protein levels of myogenic regulatory factors and Wnt/β-catenin pathway were also re-activated by re-supplemented lysine, Wnt3a or WRN (P &lt; 0.05). Collectively, we found Wnt/β-catenin activation is required for porcine SC proliferation and differentiation to promote skeletal muscle growth.

Satellite cell proliferation and differentiation during postnatal growth of porcine skeletal muscle

2002 ◽  
Vol 282 (4) ◽  
pp. C899-C906 ◽  
Author(s):  
N. T Mesires ◽  
M. E. Doumit
Keyword(s):  
Skeletal Muscle ◽  
Cell Proliferation ◽  
Satellite Cell ◽  
Satellite Cells ◽  
Nuclear Antigen ◽  
Positive Staining ◽  
Age Related ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Satellite Cell Proliferation

Age-related changes in satellite cell proliferation and differentiation during rapid growth of porcine skeletal muscle were examined. Satellite cells were isolated from hindlimb muscles of pigs at 1, 7, 14, and 21 wk of age (4 animals/age group). Satellite cells were separated from cellular debris by using Percoll gradient centrifugation and were adsorbed to glass coverslips for fluorescent immunostaining. Positive staining for neural cell adhesion molecule (NCAM) distinguished satellite cells from nonmyogenic cells. The proportion of NCAM-positive cells (satellite cells) in isolates decreased from 1 to 7 wk of age. Greater than 77% of NCAM-positive cells were proliferating cell nuclear antigen positive at all ages studied. Myogenin-positive satellite cells decreased from 30% at 1 wk to 14% at 7 wk of age and remained at constant levels thereafter. These data indicate that a high percentage of satellite cells remain proliferative during rapid postnatal muscle growth. The reduced proportion of myogenin-positive cells during growth may reflect a decrease in the proportion of differentiating satellite cells or accelerated incorporation of myogenin-positive cells into myofibers.

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