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A Limited Role for PI(3,4,5)P3 Regulation in Controlling Skeletal Muscle Mass in Response to Resistance Exercise
A Limited Role for PI(3,4,5)P3 Regulation in Controlling Skeletal Muscle Mass in Response to Resistance Exercise
- Source :
- PLoS ONE, PLoS ONE, Vol 5, Iss 7, p e11624 (2010), PloS one, vol 5, iss 7
- Publication Year :
- 2010
- Publisher :
- Public Library of Science, 2010.
-
Abstract
- Background: Since activation of the PI3K/(protein kinase B; PKB/akt) pathway has been shown to alter muscle mass and growth, the aim of this study was to determine whether resistance exercise increased insulin like growth factor (IGF) I/ phosphoinositide 3-kinase (PI3K) signalling and whether altering PI(3,4,5)P3 metabolism genetically would increase load induced muscle growth. Methodology/Principal Findings: Acute and chronic resistance exercise in wild type and muscle specific PTEN knockout mice were used to address the role of PI(3,4,5)P3 regulation in the development of skeletal muscle hypertrophy. Acute resistance exercise did not increase either IGF-1 receptor phosphorylation or IRS1/2 associated p85. Since insulin/IGF signalling to PI3K was unchanged, we next sought to determine whether inactivation of PTEN played a role in load-induced muscle growth. Muscle specific knockout of PTEN resulted in small but significant increases in heart (PTEN+/+ = 5.00±0.02 mg/g, PTEN-/- = 5.50±0.09 mg/g), and TA (PTEN+/+ = 1.74±0.04 mg/g, PTEN-/- = 1.89 ±0.03) muscle mass, while the GTN, SOL, EDL and PLN remain unchanged. Following ablation, hypertrophy of the PLN, SOL or EDL muscles was similar between PTEN-/- and PTEN+/+ animals. Even though there were some changes in overload-induced PKB and S6K1 phosphorylation, 1 hr following acute resistance exercise there was no difference in the phosphorylation state of S6K1 Thr389 between genotypes. Conclusions/Significance: These data suggest that physiological loading does not lead to the enhanced activation of the PI3K/PKB/mTORC1 axis and that neither PI3K activation nor PTEN, and by extension PI(3,4,5)P3 levels, play a significant role in adult skeletal muscle growth.
- Subjects :
- Male
medicine.medical_treatment
lcsh:Medicine
Cardiovascular
Phosphatidylinositols
Physical education and training
Muscle hypertrophy
Physiology/Muscle and Connective Tissue
Receptor, IGF Type 1
Insulin-like growth factor
Mice
0302 clinical medicine
2.1 Biological and endogenous factors
Aetiology
Phosphorylation
lcsh:Science
Mice, Knockout
0303 health sciences
Multidisciplinary
biology
Blotting
Skeletal
Immunohistochemistry
Exercise Physiological aspects
medicine.anatomical_structure
Muscle
Female
Western
Receptor
Research Article
medicine.medical_specialty
Genotype
General Science & Technology
1.1 Normal biological development and functioning
Knockout
Blotting, Western
P70-S6 Kinase 1
In Vitro Techniques
Stress
Ribosomal Protein S6 Kinases, 90-kDa
90-kDa
03 medical and health sciences
Underpinning research
Internal medicine
Molecular Biology/Translational Regulation
medicine
PTEN
Animals
IGF Type 1
Muscle, Skeletal
Protein kinase B
PI3K/AKT/mTOR pathway
030304 developmental biology
Muscle strength
Ribosomal Protein S6 Kinases
Myocardium
lcsh:R
PTEN Phosphohydrolase
Skeletal muscle
Mechanical
IRS1
Endocrinology
Musculoskeletal
biology.protein
Physiology/Cell Signaling
lcsh:Q
Stress, Mechanical
030217 neurology & neurosurgery
Subjects
Details
- Language :
- English
- ISSN :
- 19326203
- Volume :
- 5
- Issue :
- 7
- Database :
- OpenAIRE
- Journal :
- PLoS ONE
- Accession number :
- edsair.doi.dedup.....440b5d9f14b0b261670f4b3d17fd99a8