The study of using siRNA technology to silence expression of LT gene of Enterotoxigenic Escherichia coli / 国际检验医学杂志

ABSTRACT

The distinctive LT siRNAs were designed according to the LT sequence .During the process of cultivation ,siRNA targeting the LT gene ,non‐specific control siRNA ,negative control siRNA and culture medium were added into siRNA group (siRNA‐LT1 group , siRNA‐LT2 group) ,siRNA‐coa3 group ,siRNA‐NC group and blank control group ,respectively ,and three times in each group (1 nmol each time) .After siRNA added at the first time ,bacteria was collected in 45 min (A) ,90 min (B) and 135 min (C) time points .The expression of mRNA in three time points (A ,B and C) were detected by real‐time fluorescence quantitative PCR .The protein level of LT in siRNA‐LT1 group ,siRNA‐LT2 group and blank control group were detected by Western blot in three time points .Results The results of real‐time fluorescence quantitative PCR showed that inhibition of siRNA‐LT1 on the expression of LT mRNA at the three time points(A ,B and C)were 70 .9% ,70 .1% ,72 .5% respectively ,and inhibition of siRNA‐LT2 on the ex‐pression of LT mRNA at the three time points(A ,B and C)were 70 .1% ,69 .2% and 70 .5% respectively .In the three time points (A ,B and C)the inhibition rate of the expression of LT mRNA in siRNA‐LT1 group and siRNA‐LT2 group were statistically lower than that in the siRNA‐NC group ,siRNA‐coa3 group and blank control group (P<0 .05) .The results of Western blot showed that in siRNA‐LT1 group the inhibitory rate of expression of LT protein in the three time points were 43 .1% ,18 .4% and 5 .0% ,re‐spectively ;in the siRNA‐LT2 group were 38 .2% ,15 .4% and 30 .1% ,respectively .Conclusion The specific siRNA could inhibit the expression of LT gene in vitro .