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Pitx genes are redeployed in adult myogenesis where they can act to promote myogenic differentiation in muscle satellite cells
- Source :
- Developmental Biology; Vol 377, Developmental Biology
- Publication Year :
- 2012
-
Abstract
- Skeletal muscle retains a resident stem cell population called satellite cells. Although mitotically quiescent in mature muscle, satellite cells can be activated to produce myoblast progeny to generate myonuclei for skeletal muscle homoeostasis, hypertrophy and repair. Regulation of satellite cell function in adult requires redeployment of many of the regulatory networks fundamental to developmental myogenesis. Involved in such control of muscle stem cell fate in embryos are members of the Pitx gene family of bicoid-class homeodomain proteins. Here, we investigated the expression and function of all three Pitx genes in muscle satellite cells of adult mice. Endogenous Pitx1 was undetectable, whilst Pitx2a, Pitx2b and Pitx2c were at low levels in proliferating satellite cells, but increased during the early stages of myogenic differentiation. By contrast, proliferating satellite cells expressed robust amounts of Pitx3, with levels then decreasing as cells differentiated, although Pitx3 remained expressed in unfused myoblasts. To examine the role of Pitx genes in satellite cell function, retroviral-mediated expression of Pitx1, all Pitx2 isoforms or Pitx3, was used. Constitutive expression of any Pitx isoform suppressed satellite cell proliferation, with the cells undergoing enhanced myogenic differentiation. Conversely, myogenic differentiation into multinucleated myotubes was decreased when Pitx2 or Pitx3 levels were reduced using siRNA. Together, our results show that Pitx genes play a role in regulating satellite cell function during myogenesis in adult.
- Subjects :
- Male
medicine.medical_specialty
Aging
Satellite Cells, Skeletal Muscle
Skeletal muscle
Biology
Muscle Development
Pitx
03 medical and health sciences
Mice
0302 clinical medicine
Multinucleate
Internal medicine
medicine
Myocyte
Animals
Paired Box Transcription Factors
Myogenic differentiation
RNA, Messenger
RNA, Small Interfering
Molecular Biology
030304 developmental biology
0303 health sciences
Stem cell
PITX2
Myogenesis
Cell growth
Gene Expression Profiling
Cell Cycle
Cell Differentiation
Cell Biology
biology.organism_classification
Cell biology
Up-Regulation
Mice, Inbred C57BL
medicine.anatomical_structure
Endocrinology
Gene Knockdown Techniques
Satellite (biology)
Satellite cell
030217 neurology & neurosurgery
Developmental Biology
Subjects
Details
- ISSN :
- 1095564X
- Volume :
- 377
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Developmental biology
- Accession number :
- edsair.doi.dedup.....43058843439975721c5519546ea20e56