Alteration of gene expression in intervertebral disc degeneration of passive cigarette- smoking rats: separate quantitation in separated nucleus pulposus and annulus fibrosus.
OBJECTIVE
We constructed a passive cigarette-smoking model with rats to investigate the molecular mechanism of intervertebral disc degeneration, and found by gene expression analysis that passive cigarette smoking stimulated the stress-responsive signal pathway and inhibited the apoptotic pathway. In this study, to clarify that these changes were derived from either nucleus pulposus (NP) or annulus fibrosus (AF), we separately collected NP and AF and quantitatively analyzed gene expression.


METHODS
Total RNA was extracted from NP and AF of the lumbar intervertebral discs from rats which were kept in a smoking box for 4 and 8 weeks. Gene expression was measured by real-time PCR of cDNA synthesized from the total RNA.


RESULTS
Stress-responsive protein, heat shock protein 70, was expressed similarly in NP and AF, and was upregulated to the same degree after 8 weeks of passive cigarette smoking. The protein tyrosine phosphatase gene was expressed more strongly in AF than in NP, and was upregulated after 8 weeks of smoking in both tissue parts. The type II collagen and aggrecan genes were predominantly expressed in AF and NP, respectively.


CONCLUSIONS
These results indicate that passive cigarette smoking stimulates both NP and AF, and induces the stress-responsible genes such as heat shock protein 70 and protein tyrosine phosphatase in both.
Ogawa
Takeshi
T
Department of Orthopedic Surgery, Nihon University School of Medicine, Tokyo, Japan.
Matsuzaki
Hiromi
H
Uei
Hiroshi
H
Nakajima
Shinya
S
Tokuhashi
Yasuaki
Y
Esumi
Mariko
M
D053674:Aggrecans; D000818:Animals; D024043:Collagen Type II / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000235:genetics; D020869:Gene Expression Profiling; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D007403:Intervertebral Disc / Q000378:metabolism / Q000473:pathology; D007405:Intervertebral Disc Displacement / Q000235:genetics*; D037181:Lectins, C-Type; D008297:Male; D017027:Protein Tyrosine Phosphatases / Q000235:genetics; D011509:Proteoglycans / Q000235:genetics; D012313:RNA / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014028:Tobacco Smoke Pollution
C508321:Acan protein, rat; D053674:Aggrecans; D024043:Collagen Type II; D016326:Extracellular Matrix Proteins; D018840:HSP70 Heat-Shock Proteins; D037181:Lectins, C-Type; D011509:Proteoglycans; D014028:Tobacco Smoke Pollution; D012313:RNA; D017027:Protein Tyrosine Phosphatases