Limits...
Isolation, characterization, and molecular regulation of muscle stem cells.

Fukada S, Ma Y, Ohtani T, Watanabe Y, Murakami S, Yamaguchi M - Front Physiol (2013)

Bottom Line: In this review, we summarize the methodology of direct isolation, characterization, and molecular regulation of satellite cells based on our results.The relationship between the regenerative capacity of satellite cells and progression of muscular disorders is also summarized.In the last part, we discuss application of the accumulating scientific information on satellite cells to treatment of patients with muscular disorders.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University Osaka, Japan.

ABSTRACT
Skeletal muscle has great regenerative capacity which is dependent on muscle stem cells, also known as satellite cells. A loss of satellite cells and/or their function impairs skeletal muscle regeneration and leads to a loss of skeletal muscle power; therefore, the molecular mechanisms for maintaining satellite cells in a quiescent and undifferentiated state are of great interest in skeletal muscle biology. Many studies have demonstrated proteins expressed by satellite cells, including Pax7, M-cadherin, Cxcr4, syndecan3/4, and c-met. To further characterize satellite cells, we established a method to directly isolate satellite cells using a monoclonal antibody, SM/C-2.6. Using SM/C-2.6 and microarrays, we measured the genes expressed in quiescent satellite cells and demonstrated that Hesr3 may complement Hesr1 in generating quiescent satellite cells. Although Hesr1- or Hesr3-single knockout mice show a normal skeletal muscle phenotype, including satellite cells, Hesr1/Hesr3-double knockout mice show a gradual decrease in the number of satellite cells and increase in regenerative defects dependent on satellite cell numbers. We also observed that a mouse's genetic background affects the regenerative capacity of its skeletal muscle and have established a line of DBA/2-background mdx mice that has a much more severe phenotype than the frequently used C57BL/10-mdx mice. The phenotype of DBA/2-mdx mice also seems to depend on the function of satellite cells. In this review, we summarize the methodology of direct isolation, characterization, and molecular regulation of satellite cells based on our results. The relationship between the regenerative capacity of satellite cells and progression of muscular disorders is also summarized. In the last part, we discuss application of the accumulating scientific information on satellite cells to treatment of patients with muscular disorders.

No MeSH data available.


Related in: MedlinePlus

Proteins expressed in quiescent muscle satellite cells. (A) Location of satellite cells. PM, plasma membrane; BL, basal lamina; SC, satellite cell. (B) Satellite cell molecules whose protein expressions are confirmed. Red indicates “quiescence genes.”
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3824104&req=5

Figure 1: Proteins expressed in quiescent muscle satellite cells. (A) Location of satellite cells. PM, plasma membrane; BL, basal lamina; SC, satellite cell. (B) Satellite cell molecules whose protein expressions are confirmed. Red indicates “quiescence genes.”

Mentions: Satellite cells were discovered by Dr. Alexander Mauro as mononuclear cells attached to myofibers in frog muscle (Mauro, 1961). Subsequently, satellite cells were found in mammalian skeletal muscle. The name is derived from their location between the basal lamina and sarcolemma (plasma membrane of myofiber) (Figure 1A). Like other stem cells, satellite cells are maintained in an undifferentiated and quiescent state in uninjured muscles (Schultz et al., 1978), and therefore, transcriptional activity is much lower than in proliferating myoblasts. In fact, the nucleus occupies most of the cell area, and only small portions are observed as cytoplasm by electronic microscopy (Figure 1A). In addition, the RNA content of quiescent satellite cells is about one fourth of that of cultured myoblasts (Fukada et al., 2007). Freter et al. demonstrated global suppression of RNA polymerase II serine-2 phosphorylation, which triggers productive transcription elongation, mRNA processing, and release of the mature mRNA in adult stem cells including satellite cells (Freter et al., 2010). However, recent studies show that the quiescent state is not “passive,” but rather a highly regulated cell state that is rapidly activated in response to injury or damage (Liu et al., 2013), therefore the “active” molecular regulation of stem cells is of great interest in the field of stem cell research.


Isolation, characterization, and molecular regulation of muscle stem cells.

Fukada S, Ma Y, Ohtani T, Watanabe Y, Murakami S, Yamaguchi M - Front Physiol (2013)

Proteins expressed in quiescent muscle satellite cells. (A) Location of satellite cells. PM, plasma membrane; BL, basal lamina; SC, satellite cell. (B) Satellite cell molecules whose protein expressions are confirmed. Red indicates “quiescence genes.”
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3824104&req=5

Figure 1: Proteins expressed in quiescent muscle satellite cells. (A) Location of satellite cells. PM, plasma membrane; BL, basal lamina; SC, satellite cell. (B) Satellite cell molecules whose protein expressions are confirmed. Red indicates “quiescence genes.”
Mentions: Satellite cells were discovered by Dr. Alexander Mauro as mononuclear cells attached to myofibers in frog muscle (Mauro, 1961). Subsequently, satellite cells were found in mammalian skeletal muscle. The name is derived from their location between the basal lamina and sarcolemma (plasma membrane of myofiber) (Figure 1A). Like other stem cells, satellite cells are maintained in an undifferentiated and quiescent state in uninjured muscles (Schultz et al., 1978), and therefore, transcriptional activity is much lower than in proliferating myoblasts. In fact, the nucleus occupies most of the cell area, and only small portions are observed as cytoplasm by electronic microscopy (Figure 1A). In addition, the RNA content of quiescent satellite cells is about one fourth of that of cultured myoblasts (Fukada et al., 2007). Freter et al. demonstrated global suppression of RNA polymerase II serine-2 phosphorylation, which triggers productive transcription elongation, mRNA processing, and release of the mature mRNA in adult stem cells including satellite cells (Freter et al., 2010). However, recent studies show that the quiescent state is not “passive,” but rather a highly regulated cell state that is rapidly activated in response to injury or damage (Liu et al., 2013), therefore the “active” molecular regulation of stem cells is of great interest in the field of stem cell research.

Bottom Line: In this review, we summarize the methodology of direct isolation, characterization, and molecular regulation of satellite cells based on our results.The relationship between the regenerative capacity of satellite cells and progression of muscular disorders is also summarized.In the last part, we discuss application of the accumulating scientific information on satellite cells to treatment of patients with muscular disorders.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Molecular and Cellular Physiology, Graduate School of Pharmaceutical Sciences, Osaka University Osaka, Japan.

ABSTRACT
Skeletal muscle has great regenerative capacity which is dependent on muscle stem cells, also known as satellite cells. A loss of satellite cells and/or their function impairs skeletal muscle regeneration and leads to a loss of skeletal muscle power; therefore, the molecular mechanisms for maintaining satellite cells in a quiescent and undifferentiated state are of great interest in skeletal muscle biology. Many studies have demonstrated proteins expressed by satellite cells, including Pax7, M-cadherin, Cxcr4, syndecan3/4, and c-met. To further characterize satellite cells, we established a method to directly isolate satellite cells using a monoclonal antibody, SM/C-2.6. Using SM/C-2.6 and microarrays, we measured the genes expressed in quiescent satellite cells and demonstrated that Hesr3 may complement Hesr1 in generating quiescent satellite cells. Although Hesr1- or Hesr3-single knockout mice show a normal skeletal muscle phenotype, including satellite cells, Hesr1/Hesr3-double knockout mice show a gradual decrease in the number of satellite cells and increase in regenerative defects dependent on satellite cell numbers. We also observed that a mouse's genetic background affects the regenerative capacity of its skeletal muscle and have established a line of DBA/2-background mdx mice that has a much more severe phenotype than the frequently used C57BL/10-mdx mice. The phenotype of DBA/2-mdx mice also seems to depend on the function of satellite cells. In this review, we summarize the methodology of direct isolation, characterization, and molecular regulation of satellite cells based on our results. The relationship between the regenerative capacity of satellite cells and progression of muscular disorders is also summarized. In the last part, we discuss application of the accumulating scientific information on satellite cells to treatment of patients with muscular disorders.

No MeSH data available.


Related in: MedlinePlus