Functional improvement of damaged adult mouse muscle by implantation of primary myoblasts.

Abstract

1. Myoblasts from expanded primary cultures were implanted into cryodamaged soleus muscles of adult BALB/c mice. One to four months later isometric tension recordings were performed in vitro, and the male donor cells implanted into female hosts were traced on histological sections using a Y-chromosome-specific probe. The muscles were either mildly or severely cryodamaged, which led to reductions in tetanic muscle force to 33% (n = 9 muscles, 9 animals) and 70% (n = 11) of normal, respectively. Reduced forces resulted from deficits in regeneration of muscle tissue as judged from the reduced desmin-positive cross-sectional areas (34 and 66% of control, respectively). 2. Implantation of 10(6) myogenic cells into severely cryodamaged muscles more than doubled muscle tetanic force (to 70% of normal, n = 14), as well as specific force (to 66% of normal). Absolute and relative amount of desmin-positive muscle cross-sectional areas were significantly increased indicating improved microarchitecture and less fibrosis. Newly formed muscle tissue was fully innervated since the tetanic forces resulting from direct and indirect (nerve-evoked) stimulation were equal. Endplates were found on numerous Y-positive muscle fibres. 3. As judged from their position under basal laminae of muscle fibres and the expression of M-cadherin, donor-derived cells contributed to the pool of satellite cells on small- and large-diameter muscle fibres. 4. Myoblast implantation after mild cryodamage and in undamaged muscles had little or no functional or structural effects; in both preparations only a few Y-positive muscle nuclei were detected. It is concluded that myoblasts from expanded primary cultures-unlike permanent cell lines-significantly contribute to muscle regeneration only when previous muscle damage is extensive and loss of host satellite cells is severe.

• Authors: A Irintchev, M Langer, M Zweyer, R Theisen, A Wernig
• Journal: The Journal of physiology (J Physiol) Vol. 500 ( Pt 3) Pg. 775-85 (May 01 1997) ISSN: 0022-3751 [Print] England
• PMID: 9161990 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Cadherins
• Desmin
• M-cadherin

Topics

• Animals
• Cadherins (biosynthesis)
• Cell Count
• Cell Differentiation
• Cell Transplantation (physiology)
• Cells, Cultured
• Desmin (metabolism)
• Female
• Fluorescent Antibody Technique, Direct
• Freezing
• Immunohistochemistry
• In Situ Hybridization
• Isometric Contraction (physiology)
• Male
• Mice
• Mice, Inbred BALB C
• Muscle Contraction (physiology)
• Muscle Fibers, Skeletal (physiology)
• Muscle, Skeletal (cytology, injuries, physiology)
• Regeneration (physiology)