Abnormal myotonic dystrophy protein kinase levels produce only mild myopathy in mice.
Myotonic dystrophy (DM) is commonly associated with CTG repeat expansions within the gene for DM-protein kinase (DMPK). The effect of altered expression levels of DMPK, which is ubiquitously expressed in all muscle cell lineages during development, was examined by disrupting the endogenous Dmpk gene and overexpressing a normal human DMPK transgene in mice. Nullizygous (-/-) mice showed only inconsistent and minor size changes in head and neck muscle fibres at older age, animals with the highest DMPK transgene expression showed hypertrophic cardiomyopathy and enhanced neonatal mortality. However, both models lack other frequent DM symptoms including the fibre-type dependent atrophy, myotonia, cataract and male-infertility. These results strengthen the contention that simple loss- or gain-of-expression of DMPK is not the only crucial requirement for development of the disease.
Jansen
G
G
Department of Cell Biology and Histology, Medical Faculty, University of Nijmegen, The Netherlands.
Groenen
P J
PJ
Bächner
D
D
Jap
P H
PH
Coerwinkel
M
M
Oerlemans
F
F
van den Broek
W
W
Gohlsch
B
B
Pette
D
D
Plomp
J J
JJ
Molenaar
P C
PC
Nederhoff
M G
MG
van Echteld
C J
CJ
Dekker
M
M
Berns
A
A
Hameister
H
H
Wieringa
B
B
D000818:Animals; D001483:Base Sequence; D006332:Cardiomegaly / Q000235:genetics / Q000473:pathology*; D018507:Gene Expression Regulation, Developmental; D006720:Homozygote; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D018485:Muscle Fibers, Skeletal / Q000473:pathology; D009154:Mutation; D009223:Myotonic Dystrophy / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D065636:Myotonin-Protein Kinase; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis* / Q000172:deficiency / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D014018:Tissue Distribution
C585517:DMPK protein, human; C585516:DMPK protein, mouse; D012333:RNA, Messenger; D065636:Myotonin-Protein Kinase; D017346:Protein Serine-Threonine Kinases