Telomerase alone extends the replicative life span of human skeletal muscle cells without compromising genomic stability.
Continuous cycles of muscle fiber necrosis and regeneration are characteristic of the muscular dystrophies, and in some cases this leads to premature replicative senescence of myoblasts in vitro. The molecular mechanism of senescence in human myoblasts is poorly understood but there is evidence to suggest that telomeric attrition may be one of the ways by which this is achieved. We report here, for the first time, the extension of normal human skeletal muscle cell replicative life span by the reconstitution of telomerase activity. The telomerase-expressing cells show no features of transformation in vitro and have stable genomes with diploid karyotypes, do not express exceptionally high levels of c-myc and have wild-type, unmethylated CDKN2A genes. In vivo, they regenerate to repair muscle injury in immunosuppressed RAG-1 mice. This work suggests that telomerase expression to repair short telomeres may aid the expansion of diploid human muscle cells and consequently attempts at gene therapy for muscle diseases.
The Department of Pathology, University of Glasgow, Glasgow G11 6NT, UK.
Martha
M
Wootton
Karen
K
Steeghs
Diana
D
Watt
June
J
Munro
Katrina
K
Gordon
Hazel
H
Ireland
Vivienne
V
Morrison
Wilhelmina
W
Behan
E Kenneth
EK
Parkinson
D000328:Adult; D000483:Alleles; D015153:Blotting, Western; D001973:Bromodeoxyuridine / Q000494:pharmacology; D002454:Cell Differentiation; D002455:Cell Division; D002460:Cell Line; D002478:Cells, Cultured; D016922:Cellular Senescence; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D005260:Female; D015316:Genetic Therapy; D016678:Genome; D005838:Genotype; D006367:HeLa Cells; D006579:Heterozygote; D006801:Humans; D007150:Immunohistochemistry; D007621:Karyotyping; D008297:Male; D018895:Microsatellite Repeats; D032342:Muscle Cells / Q000166:cytology; D018482:Muscle, Skeletal / Q000166:cytology* / Q000201:enzymology; D009132:Muscles / Q000166:cytology / Q000293:injuries / Q000378:metabolism; D009336:Necrosis; D009368:Neoplasm Transplantation; D012038:Regeneration; D017422:Sequence Analysis, DNA; D013447:Sulfites / Q000494:pharmacology; D019098:Telomerase / Q000378:metabolism*; D016615:Telomere / Q000648:ultrastructure; D013997:Time Factors; D001616:beta-Galactosidase / Q000378:metabolism
D019941:Cyclin-Dependent Kinase Inhibitor p16; D013447:Sulfites; D019098:Telomerase; D001616:beta-Galactosidase; D001973:Bromodeoxyuridine; C009279:sodium bisulfite