Method: L6 cell, rat skeletal myoblast, was cultured in the low mitogen medium and caveolin-3 expression was observed both by immunocytochemistry and western blot analysis. Localization of caveolin-3 within the muscle tissue was investigated and compared to that of dystrophin. Results: While caveolin-3 was not expressed in the proliferating myolast, caveolin-3 was expressed in the differentiated myoblast. Caveolin-3 and dystrophin were co-expressed in the membrane of muscle tissue and integrated density of caveolin-3 was elevated in the area of muscle injury. In the Duchenne muscular dystrophy, caveolin-3 was expressed in the membrane of muscle tissue, but dystrophin was not.

Conclusion: Caveolin-3 was induced during the myobalst differentiation and its expression was increased during the muscle regeneration. Caveolin-3 was physically associated with dystrophin as a complex, but not absolutely required for the biogenesis of dystrophin complex. (J Korean Acad Rehab Med 2003; 27: 382-387)

Objective: Recently, cultured myoblast transplantation has been extensively studied as a gene complementation approach in such genetic diseases as Duchenne muscular dystrophy (DMD). In the present work we investigated the stimulating effects of the growth factors, such as basic fibroblast growth factor (bFGF), leukemia inhibitory factor (LIF) and interleukin-1 (IL-1), on growth rate and differentiation of myoblast.

Method: Human myoblasts were cultured from biopsy and treated in vitro with various concentration of bFGF, LIF and IL-1. In serum-free defined medium the following observation were made to evaluate differentiation.

Results: bFGF and LIF except IL-1 were found to have stimulating effect of myoblast proliferation comparing to control group (p＜0.05), yet there were no statistically significant differences among each growth factors (p＞0.05). The most significant growth stimulation of myoblasts in culture was achieved by adding 3.0 ng/ml of bFGF, producing a stimulation effect up to 2.01-fold. All myoblasts treated with growth factors differentiated into myotube.

Conclusion: Our findings indicate that bFGF and LIF stimulate the proliferation of myoblast, which may result in an effective way in producing large numbers of myoblasts for clinical myoblast transplantation in DMD patients. (J Korean Acad Rehab Med 2002; 26: 426-431)

Objective: The phenomenon of fibroblast overgrowth is one of the major problems encountered during long-term culture such as myoblast culture. The first goal of the study is to determine the effects of proline analogue and cytosine arabinoside to reduce fibroblasts in myoblast culture. The second goal is to investigate whether the chemicals influence the growth and differentiation of myoblast.

Method: Muscle tissues were obtained from legs of healthy men, and then fibroblasts and myoblasts were isolated and cultured. Those mixed cells were divided into three groups; control group, proline analogue (cis-hydroxyproline) treated group and cytosine arabinoside (araC) treated group. We evaluated the effectiveness of cis-hydroxyproline and araC on selective removal of fibroblasts in culture. We have also determined if cis-hydroxyproline and araC could alter differentiation of myoblast in each group.

Results: The treatment with araC was effective to eliminate fibroblasts comparing to the control group (p＜0.05) while there was no statistically significant difference between proline analogue and control group (p＞0.05). Myoblasts of all three groups were differentiated into myotube.

Conclusion: Using araC, we could reduce a number of fibroblasts in myoblast culture where contamination and subsequent overgrowth with fibroblasts remained a problem.