MyoD Deficiency Helps Muscle Stem Cells

Minneapolis, MN -

MyoD is a basic helix-loop-helix myogenic transcription factor involved in differentiation of muscle cells.

In a recent paper (Asakura et al. Increased survival of muscle stem cells lacking the MyoD gene after transplantation into regenerating skeletal muscle.Proc Natl Acad Sci U S A. 2007 Oct 16;104(42):16552-7) scientists wanted to determine whether muscle stem cells (satellite cells) that lack MyoD are comparable to wild-type satellite cells in terms of myoregenerative properties.

The authors performed injections of these cells into regenerating skeletal muscle was performed after muscle injury. They found:

1. MyoD knock out derived satellite cells integrate into regenerating muscle at a much higher level as compared to wild-type satellite cells.

2. The MyoD knock out satellite cells are found in the anatomical areas associated with self-renewal (underneath basal lamina of myofibrils).

3. Lack of MyoD was associated with increased "stemness" and resistance to apoptosis.

These data suggest that it may be interesting to use siRNA to silence MyoD when performing stem cell therapy for diseases such as muscular dystrophy.