Type-II collagen gene expression is transiently upregulated in experimentally induced degeneration of rabbit intervertebral disc.
To clarify phenotypic alterations of intervertebral disc cells during the repair process, we cloned partial type-II collagen cDNA from rabbits and analyzed the level of expression of type-II collagen mRNA in disc degeneration. An animal model was created by surgical denucleation of rabbit intervertebral discs through an extraperitoneal approach. Eight animals each from an experimental and a control group were killed at 2, 4, 8, or 16 weeks postoperatively, and the disc samples were used for this study. Round chondrocyte-like cells that filled the herniated space showed intense signal of type-II collagen mRNA and significant pericellular immunostaining of type-II collagen but no clear staining of type-I collagen. Northern blot analysis revealed that the expression of type-II collagen mRNA of the repair disc cells was transiently increased at 4 weeks postoperatively. The cells were able to change their morphology in response to mechanical stimulation by surgical denucleation and to induce a significant increase in the gene expression of type-II collagen at an early phase of disc degeneration. The present results indicate the transient enhancement of repair activity in the degenerative process of injured fibrocartilage.
Takaishi
H
H
Department of Orthopaedic Surgery, National Defense Medical College, Keio University School of Medicine, Tokyo, Japan.
Nemoto
O
O
Shiota
M
M
Kikuchi
T
T
Yamada
H
H
Yamagishi
M
M
Yabe
Y
Y
D000818:Animals; D015152:Blotting, Northern; D002358:Cartilage, Articular / Q000737:chemistry / Q000473:pathology; D019902:Chondrocytes / Q000737:chemistry / Q000502:physiology; D003001:Cloning, Molecular; D003094:Collagen / Q000032:analysis / Q000235:genetics*; D018076:DNA, Complementary / Q000302:isolation & purification; D005260:Female; D015870:Gene Expression / Q000502:physiology; D017403:In Situ Hybridization; D007403:Intervertebral Disc / Q000166:cytology / Q000473:pathology* / Q000601:surgery; D010641:Phenotype; D011347:Procollagen / Q000032:analysis / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits; D015854:Up-Regulation
D018076:DNA, Complementary; D011347:Procollagen; D012333:RNA, Messenger; D003094:Collagen