Differential expression of the protooncogene bcl-2 in normal and osteoarthritic human articular cartilage.
OBJECTIVE
To investigate the expression of bcl-2 in healthy and osteoarthritic articular cartilage at the transcriptional level and at the protein level.


METHODS
bcl-2 mRNA was detected by reverse transcriptase/polymerase chain reaction. The expression of bcl-2 protein was studied using flow cytometry analysis with a monoclonal antibody against intracellular bcl-2 and by immunohistochemistry.


RESULTS
mRNA for bcl-2 was detectable in chondrocytes of both healthy and osteoarthritic cartilage. bcl-2 protein was present in the chondrocytes of the middle layer of cartilage by immunohistochemical staining. In osteoarthritis (OA), chondrocytes adjacent to cartilage defects expressed a particularly high signal intensity. Flow cytometry analysis demonstrated the presence of bcl-2 protein in virtually all chondrocytes.


CONCLUSIONS
Our results show that bcl-2 is expressed in healthy adult and osteoarthritic human cartilage. The increased staining of chondrocytes adjacent to osteoarthritic defects indicates a differential regulation of programmed cell death during the degenerative process in OA.
Erlacher
L
L
Department of Internal Medicine III, University of Vienna, Austria.
Maier
R
R
Ullrich
R
R
Kiener
H
H
Aringer
M
M
Menschik
M
M
Graninger
W
W
D000328:Adult; D000368:Aged; D001483:Base Sequence; D002358:Cartilage, Articular / Q000737:chemistry*; D016923:Cell Death / Q000235:genetics; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010003:Osteoarthritis / Q000235:genetics* / Q000473:pathology; D016133:Polymerase Chain Reaction; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D019253:Proto-Oncogene Proteins c-bcl-2; D011519:Proto-Oncogenes / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis*
D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger