Defective Ca2+ metabolism in Duchenne muscular dystrophy: effects on cellular and viral growth.
Normal fibroblasts in medium containing 0.02 mM CaCl2 arrested growth within 24 hr, whereas Duchenne muscular dystrophy fibroblasts continued to grow for 5 days, albeit at 40% of their rate in standard medium (1.8 mM CaCl2). Moreover, Duchenne cells in calcium-deficient medium showed an enhanced rate of protein synthesis (60% over the rate in standard medium), whereas normal cells were unaffected. Previously we described a general assay for detection of mutant cells by using herpes simplex virus I replication as a probe of cellular function. By altering the growth medium, one can elicit changes in viral DNA replication that depend upon cellular differences. Duchenne fibroblasts in calcium-deficient low-serum (0.5%) medium supported viral replication at a rate 7- to 10-fold greater than did normal cells infected under the same conditions. Using this viral assay, we have successfully identified all 10 samples of a blind coded set of Duchenne muscular dystrophy, normal, and heterozygote cells. In addition, differences of a lower magnitude were found between these cell strains as measured by cellular growth or protein synthesis. Therefore, a cell's ability to grow and support viral replication in calcium-deficient medium can be used to readily distinguish Duchenne muscular dystrophy fibroblasts from normal ones. These results suggest that the viral assay could be used as a prenatal diagnostic test. A defect related to calcium metabolism may be fundamental to this disease.
D002118:Calcium / Q000378:metabolism*; D002455:Cell Division; D002460:Cell Line; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D004261:DNA Replication; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008297:Male; D009136:Muscular Dystrophies / Q000378:metabolism* / Q000473:pathology; D018139:Simplexvirus / Q000254:growth & development*; D012867:Skin / Q000166:cytology / Q000378:metabolism; D014779:Virus Replication
D002118:Calcium