Immunolocalization of cathepsins B, H and L in skeletal muscle of X-linked muscular dystrophy (mdx) mouse.
The amounts of non-collagen proteins (muscle structural proteins) and the activity of creatine kinase were significantly decreased in muscles of 28-day-old mdx mice. The activities of lysosomal thiol proteases such as cathepsins B and L were increased in muscles of mdx mice at as early as 10 days of age. Endogenous thiol proteinase inhibitor and various lysosomal hydrolases also showed increased activities. The localization of cathepsins B, H and L, and endogenous thiol proteinase inhibitor was investigated using the respective specific antibodies. While only invading macrophages were stained strongly with anticathepsin B and H, and anti-thiol proteinase inhibitor antibodies, cathepsin L was localized in muscle cells as well as in invading macrophages. Cathepsin L in muscle cells itself may initially degrade muscle structural proteins, before lysosomal thiol proteases, mainly derived from macrophages, degrade them in skeletal muscles of mdx mice.
Sano
M
M
Department of Neurology, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
Wada
Y
Y
Ii
K
K
Kominami
E
E
Katunuma
N
N
Tsukagoshi
H
H
D000367:Age Factors; D000818:Animals; D002401:Cathepsin B / Q000032:analysis*; D056655:Cathepsin H; D056668:Cathepsin L; D002403:Cathepsins / Q000032:analysis*; D003402:Creatine Kinase / Q000378:metabolism; D003546:Cysteine Endopeptidases; D010450:Endopeptidases; D006867:Hydrolases / Q000378:metabolism; D007150:Immunohistochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D009132:Muscles / Q000032:analysis* / Q000378:metabolism; D009137:Muscular Dystrophy, Animal / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D011480:Protease Inhibitors / Q000378:metabolism
D011480:Protease Inhibitors; D003402:Creatine Kinase; D006867:Hydrolases; D002403:Cathepsins; D010450:Endopeptidases; D010447:Peptide Hydrolases; D003546:Cysteine Endopeptidases; D002401:Cathepsin B; D056668:Cathepsin L; C534278:Ctsl protein, mouse; D056655:Cathepsin H; C534127:Ctsh protein, mouse