1. Origin and hierarchy of basal lamina-forming and -non-forming myogenic cells in mouse skeletal muscle in relation to adhesive capacity and Pax7 expression in vitro.
- Author
-
Tamaki T, Tono K, Uchiyama Y, Okada Y, Masuda M, Soeda S, Nitta M, and Akatsuka A
- Subjects
- Animals, Cell Adhesion, Cell Line, Cells, Cultured, Desmin analysis, Desmin genetics, Integrin beta1 genetics, Laminin analysis, Laminin genetics, Mice, Mice, Inbred C57BL, Muscle Fibers, Skeletal metabolism, Muscle, Skeletal ultrastructure, MyoD Protein analysis, MyoD Protein genetics, Myogenin analysis, Myogenin genetics, PAX7 Transcription Factor analysis, Reverse Transcriptase Polymerase Chain Reaction, Gene Expression Regulation, Developmental, Muscle Development, Muscle Fibers, Skeletal cytology, Muscle, Skeletal cytology, PAX7 Transcription Factor genetics
- Abstract
As a novel approach to distinguish skeletal myogenic cell populations, basal lamina (BL) formation of myogenic cells was examined in the mouse compensatory enlarged plantaris muscles in vivo and in fiber-bundle cultures in vitro. MyoD(+) myogenic cells located inside the regenerative muscle fiber BL were laminin(-) but interstitial MyoD(+) cells were laminin(+). This was also confirmed by electron microscopy as structural BL formation. Similar trends were observed in the fiber-bundle cultures including satellite cells and interstitial myogenic cells and laminin(+) myogenic cells predominantly showed non-adhesive (non-Ad) behavior with Pax7(-), whereas laminin(-) cells were adhesive (Ad) with Pax7(+). Moreover, non-Ad/laminin(+) and Ad/laminin(-) myotubes were also observed and the former type showed spontaneous contractions, while the latter type did not. The origin and hierarchy of Ad/Pax7(+)/laminin(-) and non-Ad/Pax7(-)/laminin(+) myogenic cells were also examined using skeletal muscle interstitium-derived CD34(+)/45(-) (Sk-34) and CD34(-)/45(-) (Sk-DN) multipotent stem cells, which were composed of non-committed myogenic cells with a few (<1%) Pax7(+) cells in the Sk-DN cells at fresh isolation. Both cell types were separated by Ad/non-Ad capacity in repetitive culture. As expected, both Ad/Pax7(+)/laminin(-) and non-Ad/Pax7(-)/laminin(+) myogenic cells consistently appeared in the Ad and non-Ad cell culture. However, Ad/Pax7(+)/laminin(-) cells were repeatedly detected in the non-Ad cell culture, while the opposite phenomenon did not occur. This indicates that the source of non-Ad/ Pax7(-)/laminin(+) myogenic cells was present in the Sk-34 and Sk-DN stem cells and they were able to produce Ad/ Pax7(+)/ laminin(-) myogenic cells during myogenesis as primary myoblasts and situated hierarchically upstream of the latter cells.
- Published
- 2011
- Full Text
- View/download PDF