THE HISTOPATHOLOGICAL CHANGE AND DYSTROPHIN EXPRESSION IN THE MDX MICE BY BONE MARROW CELL TRANSPLANTATION
C. Zhang*; W. Zhang; Z. Liu; X. Lu; X. Wang
Dept Neurol, First Affiliated Hosp, Guangzhou, China
[Objective] To observe the histopathological change and dystrophin expression in the mdx mice by bone marrow cell transplantation.
[Methods] Different amounts of bone marrow cells, suspension cells and stromal cells were cultured in vitro from C57BL male mice, and the cells were transplanted intravenously into the 14 irradiated (8 Gy) mdx mice . The survival rate and survival time were investigated. 1, 2, 3, and 4 months after transplantation, the muscle histopathological analysis was assessed with immunofluorescent technique. Sex determined region of the Y chromosome from the transplantation female mdx mice were examined by means of PCR.
[Results] 3 months after transplantation, 10 mice were alive, and 4 mice died. A few dystrophin was observed in the mdx mice muscle about 1 or 2 months after transplantation. By 3 months after bone marrow cells, suspension cells, and stromal cells transplantation, about 10 %, 8 % and 6 % of the muscle fiber expressed dystrophin respectively. About 449 bp DNA fragments from Y chromosome were amplified in the female mdx mice.
[Conclusion] This study shows that most mdx mice can survive by being transplanted bone marrow cells, suspension cells, and stromal cells. Dystrophin can be expressed by different component of marrow cell transplantation, and the expression time of dystrophin can keep on at least over three months.
Supported by the National Nature Science foundation of China (39870804), Guangdong Nature Science foundation (970061)

 

MANGANESE QUENCH RATES AND STEADY STATE CALCIUM CONCENTRATIONS IN CULTURED DYSTROPHIC MYOTUBES AND FRESHLY EXCISED ADULT DYSTROPHIC FIBERS.
C.G. Carlson*; R. Ashmore; A. Gueorguiev; D. Roshek; J. Chu
Dept. of Physiology, Kirksville College of Osteopathic Medicine, Kirksville, MO, USA
To examine the potential role of elevated intracellular [Ca] and enhanced resting Ca influx (RCI) in the pathogenesis of myopathies, steady state [Ca] was estimated from F340/F380 ratios and known [Ca] standards, and RCI was estimated from the rate of Mn quenching of intracellular signal in both FURA PE3 loaded spontaneously inactive cultured myotubes and freshly excised triangularis sterni (TS) muscle fibers. Initial studies indicated a significant effect of genotype on both F340/F380 ratios (p<0.05) and Mn quench rates (p<0.05), with utrophin-mdx double knockout (DKO) myotubes exhibiting a [Ca] (59.9 nM, 10.2SEM) that was about 68% larger than nondystrophic and 123% larger than mdx myotubes. In the presence of 100 microM ACh, both mdx and DKO myotubes had elevated Mn (1 mM) quench rates with DKO myotubes having rates (25.9 x 10(-4) sec(-1)) that were about 2.5 fold larger than mdx myotubes. Adult mdx TS muscle fibers, which are severely dystrophic, had significantly (p<0.001) elevated F340/F380 ratios and an estimated mean [Ca] of 218 nM in comparison to 113 nM in nondystrophic fibers. In the presence of Ca, the Mn (0.5 mM) quench rate in mdx TS fibers was elevated in comparison to nondystrophic fibers, but the difference failed to reach statistical significance (p>0.05). Quench rates (1.5 mM Mn) obtained in the absence of Ca were identical between nondystrophic and mdx TS fibers (2.2 x 10(-4) sec(-1)). These results are consistent with the general hypothesis that elevated steady state Ca concentrations promote the destruction of muscle fibers in myopathies.
Supported by: an SRI award from KCOM.