Résumé
Aim To investigate the potential applica-tion of a non-viral gene carrier Tat-LK15 for delivering siRNA targeting nNOS in vitro, which provides evi-dence of Tat-LK15 mediating siRNA targeting nNOS in vivo for treatment of neuropathic pain. Methods 1. Tat-LK15 was mixed with siRNA, then the mixture was analyzed the best ratio by Gel retardation. The trans-fection efficiency of FAM-siRNA mediated by Tat-LK15 on RGC-5 cells was examined by Flow Cytome-try. The apoptosis ratio of RGC-5 was identified by Flow Cytometry 24 h after treated with the different do-ses of Tat-LK15 (1, 2. 5, 5, 10 and 20 μg). 2. The model of RGC-5 cell overexpression of nNOS protein was prepared. 3. RGC-5 cells were randomly divided into 5 groups:control group,model group, Tat-S group ( Tat-LK15 mediate nNOS/siRNA transfection model cell) , Lipo-S group ( LipofectamineTM RNAiMAX me-diate nNOS/siRNA transfection model cell) and Tat-N group ( Tat-LK15 mediate NCsiRNA transfection model cell) . Real-time Quantitative polymerase chain reac-tion( Q-PCR) and Western blot were used to evaluate nNOS expression level assay. Results It indicated that the Tat-LK15/siRNA complex completely formed at the weight ratio of 2∶ 1 (μg/μg) , and the transfec-tion efficiency was (84. 4 ± 3. 9)%. It caused cotytox-icity when Tat-LK15 dose was 20 μg ( 6. 1 μmol · L-1 ) , and the apoptosis rate more than control group [(10. 3 ± 1. 1)% vs (7. 4 ± 0. 9)%, P<0. 05]. The nNOS protein level of RGC-5 cells was significantly el-evated after modeling. Compared with that of model group, Tat-LK15/siRNA efficiently inhibited the ex-pression of nNOS at transcriptional level or protein leve1 of Tat-S group ( P <0. 05 ) , and there was no significant difference of the efficiency inhibited between Tat-S group and Lipo-S group. Conclusions Tat-LK15’ advantage is with high efficiency, low cytotox-icity. The Tat-LK15 can deliver siRNA targeting nNOS in vitro efficiently and safely.