Cloning of cDNA encoding a regeneration-associated muscle protease whose expression is attenuated in cell lines derived from Duchenne muscular dystrophy patients.
In the dystrophin-mutant mdx mouse, an animal model for Duchenne muscular dystrophy (DMD), damaged skeletal muscles are efficiently regenerated and thus the animals thrive. The phenotypic differences between DMD patients and the mdx mice suggest the existence of factors that modulate the muscle wasting in the mdx mice. To identify these factors, we searched for mRNAs affected by the mdx mutation by using cDNA microarrays with newly established skeletal muscle cell lines from mdx and normal mice. We found that in the mdx muscle cell line, 12 genes, including L-arginine:glycine amidinotransferase and thymosin beta4, are up-regulated, whereas 7 genes, including selenoprotein P and a novel regeneration-associated muscle protease (RAMP), are down-regulated. Northern blot analysis and in situ hybridization revealed that RAMP mRNA is predominantly expressed in normal skeletal muscle and brain, and its production is enhanced in the regenerating area of injured skeletal muscle in mice. RAMP expression was much lower in individual muscle cell lines derived from biopsies of six DMD patients compared to a normal muscle cell line. These results suggest that RAMP may play a role in the regeneration of skeletal muscle and that its down-regulation could be involved in the progression of DMD in humans.
Nakayama
Yuki
Y
Department of Tumor Biochemistry, The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Tokyo, Japan..
Nara
Noriko
N
Kawakita
Yukiko
Y
Takeshima
Yasuhiro
Y
Arakawa
Masayuki
M
Katoh
Masaki
M
Morita
Sumiyo
S
Iwatsuki
Ken
K
Tanaka
Kiyoko
K
Okamoto
Shiki
S
Kitamura
Toshio
T
Seki
Naohiko
N
Matsuda
Ryoichi
R
Matsuo
Masafumi
M
Saito
Kayoko
K
Hara
Takahiko
T
D000595:Amino Acid Sequence; D000818:Animals; D001706:Biopsy; D015152:Blotting, Northern; D015153:Blotting, Western; D002460:Cell Line; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000378:metabolism; D004195:Disease Models, Animal; D015536:Down-Regulation; D016189:Dystrophin / Q000378:metabolism; D010450:Endopeptidases / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008666:Metalloendopeptidases / Q000235:genetics* / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018101:Mice, Inbred mdx; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D009132:Muscles / Q000201:enzymology*; D020388:Muscular Dystrophy, Duchenne / Q000235:genetics*; D020411:Oligonucleotide Array Sequence Analysis; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012038:Regeneration; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D057057:Serine Proteases; D014162:Transfection; D015854:Up-Regulation
D018076:DNA, Complementary; D016189:Dystrophin; D012333:RNA, Messenger; D012313:RNA; D010450:Endopeptidases; D057057:Serine Proteases; D008666:Metalloendopeptidases; C486046:PAMR1 protein, human