Preparation and identification of anti-transforming growth factor beta1 U1 small nuclear RNA chimeric ribozyme in vitro.
OBJECTIVE
To study the preparation and cleavage activity of anti-transforming growth factor (TGF)beta1 U1 small nuclear (sn) RNA chimeric hammerhead ribozymes in vitro.


METHODS
TGFbeta1 partial gene fragment was cloned into T-vector at the downstream of T7 promoter. (32)p-labeled TGFbeta1 partial transcripts as target RNA were transcribed in vitro and purified by denaturing polyacrylamide gel electrophoresis (PAGE). Anti-TGFbeta1 ribozymes were designed by computer, then synthetic ribozyme fragments were cloned into the U1 ribozyme vector pZeoU1EcoSpe containing U1 snRNA promoter/enhancer and terminator. (32)p-labeled U1 snRNA chimeric ribozyme transcripts were gel-purified, incubated with target-RNAs at different conditions and autoradiographed after running denaturing PAGE.


RESULTS
Active U1snRNA chimeric ribozyme (U1Rz803) had the best cleavage activity at 50 degrees; at 37 degrees, it was active, K(m)=34.48 nmol/L, K(cat)=0.14 min(-1); while the point mutant ribozyme U1Rz803(m) had no cleavage activity, so these indicated the design of U1Rz803 was correct.


CONCLUSIONS
U1Rz803 prepared in this study possessed the perfect specific catalytic cleavage activity. These results indicate U1 snRNA chimeric ribozyme U1Rz803 may suppress the expression of TGFbeta1 in vivo, therefore it may provide a new avenue for the treatment of liver fibrosis in the future.
Lin
Ju-Sheng
JS
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031,China.
Song
Yu-Hu
YH
Kong
Xin-Juan
XJ
Li
Bin
B
Liu
Nan-Zhi
NZ
Wu
Xiao-Li
XL
Jin
You-Xin
YX
D000818:Animals; D002461:Cell Line, Transformed; D003001:Cloning, Molecular; D012313:RNA / Q000187:drug effects*; D016337:RNA, Catalytic / Q000494:pharmacology*; D012342:RNA, Small Nuclear / Q000494:pharmacology*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors* / Q000235:genetics*; D053773:Transforming Growth Factor beta1
D016337:RNA, Catalytic; D012342:RNA, Small Nuclear; D011993:Recombinant Fusion Proteins; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C405483:U1 small nuclear RNA; C427204:hammerhead ribozyme; D012313:RNA