TY - JOUR
T1 - Mitochondrial myopathy
T2 - correlation between oxidative defect and mitochondrial DNA deletions at single fiber level
AU - Prelle, A.
AU - Fagiolari, G.
AU - Checcarelli, N.
AU - Moggio, M.
AU - Battistel, A.
AU - Comi, G. P.
AU - Bazzi, P.
AU - Bordoni, A.
AU - Zeviani, M.
AU - Scarlato, G.
PY - 1994/4
Y1 - 1994/4
N2 - In situ hybridization combined with immunohistochemical techniques has been applied to study patients affected by mitochondrial myopathies with large mitochondrial (mt)DNA deletions. All patients' muscle biopsies showed ragged red fibers (RRFs) and cytochrome oxidase (COX) deficiency. Two digoxygenin-labeled, polymerase chain reaction (PCR)-amplifed DNAs were used as probes. One probe was designed to hybridize only with wild-type mtDNAs, while the other recognized both wild-type and deleted mtDNAs. Concomitant immunocytochemical analysis using antibodies against subunits II, III, (encoded by mtDNA) and IV (encoded by nuclear DNA) of COX was carried out. In our patients deleted mtDNAs are overexpressed in COX-negative RRFs, while wild-type mtDNAs are decreased in the same fibers. Immunohistochemistry studies show that COX IV is overexpressed in RRFs and that COX II and COX III subunits are still present. Deleted mtDNAs are spatially segregated in muscle fibers, where they interfere with the local population of normal mitochondrial genomes, causing a regional deficiency of the mitochondrial respiratory activity.
AB - In situ hybridization combined with immunohistochemical techniques has been applied to study patients affected by mitochondrial myopathies with large mitochondrial (mt)DNA deletions. All patients' muscle biopsies showed ragged red fibers (RRFs) and cytochrome oxidase (COX) deficiency. Two digoxygenin-labeled, polymerase chain reaction (PCR)-amplifed DNAs were used as probes. One probe was designed to hybridize only with wild-type mtDNAs, while the other recognized both wild-type and deleted mtDNAs. Concomitant immunocytochemical analysis using antibodies against subunits II, III, (encoded by mtDNA) and IV (encoded by nuclear DNA) of COX was carried out. In our patients deleted mtDNAs are overexpressed in COX-negative RRFs, while wild-type mtDNAs are decreased in the same fibers. Immunohistochemistry studies show that COX IV is overexpressed in RRFs and that COX II and COX III subunits are still present. Deleted mtDNAs are spatially segregated in muscle fibers, where they interfere with the local population of normal mitochondrial genomes, causing a regional deficiency of the mitochondrial respiratory activity.
KW - Immunohistochemistry
KW - In situ hybridization
KW - Mitochondrial myopathy
KW - Ragged red fibers
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U2 - 10.1007/BF00313606
DO - 10.1007/BF00313606
M3 - Article
C2 - 8017172
AN - SCOPUS:0028323212
VL - 87
SP - 371
EP - 376
JO - Acta Neuropathologica
JF - Acta Neuropathologica
SN - 0001-6322
IS - 4
ER -