A stem cell gene found to command skeletal muscle regeneration and slow muscle characteristics

Skeletal muscles are important not only for locomotion but also for metabolism in the whole-body. Muscles have remarkable capacity to regenerate after injury and to adapt in response to exercise training. Researchers from Wihuri Research Institute and the University of Helsinki reported today in Nature Communications that skeletal muscle stem cells called satellite cells express the Prox1 gene, which is important in fetal life for the development of the liver, lymphatic vessels and lens in the eye. The new suprising results show that Prox1 satellite cells differentiate into myofibres in adults only when Prox1 is active. The researchers found that Prox1 was also expressed in slow muscle fibres, which have good endurance capacity and produce muscle energy from fatty acids. About half of the skeletal muscle fibres in adults are slow fibres. Prox1 gene transfer into fast muscles converted them into slow fibers in mice, whereas Prox1 deletion increased the activity of fast fibre genes.

Our new findings on the need of Prox1 in satellite cell differentiation and slow muscle fibre characteristics provides an important novel avenue for studies of muscles and metabolic diseases, such as type 2 diabetes”, says Riikka Kivelä, the lead author. http://rdcu.be/kU9o


More information:

Riikka Kivelä, PhD, Academy Research Fellow

Email: riikka.kivela@helsinki.fi

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Figure: Prox1 is essential for differentiation of skeletal muscle stem cells called satellite celle. During differentiation satellite cells form long, multinuclear myotubes, but if they lack Prox1 gene, they fail to differentiate. In the figure myosin protein in differentiated myotubes have been stained green. Image: Riikka Kivelä