Objective To determine the effect of the association of ultrasound and microbubble with short
hairpin RNA ( shRNA) silencing Wistar rat brain Toll-like receptor 4 (TLR4).
Methods Wistar rats were divided into 4 groups:normal sodium (NS) group, naked plasmid group
(P), plasmid plus ultrasound (US) irradiation group (P+ultrasound-targeted microbubble destruction
[UTMD]), plasmid plus US irradiation and SonoVue group (P+S+UTMD). Lateral ventricle injection
of plasmid and SonoVue microbubble into rats' brain was performed and the brains were exposed to
extracranial US, the brain TLR4 gene expression efficiency was evaluated 4 days after treatment.
Results Western blot result shows that there is not statistical difference between NS group
and naked plasmid group (NS:0.351±0.030, P:0.339±0.034, t 1, 2=0.590; P >0.05), but plasmid
plus US irradiation group (P+UTMD) and plasmid plus US irradiation and SonoVue group
(P+S+UTMD) shows statistical differences between NS group and naked plasmid group
(P+S+UTMD:0.223±0.009, P+UTMD:0.277±0.013, t 1, 3=4.900, P <0.01; t 1, 4=8.779, P <0.01). Immunohistochemical analysis also shows statistical differences between Ultrasound
Group (P+UTMD group and P+S+UTMD group) and non-Ultrasound group (NS and P)
(P+S+UTMD:0.026±0.0013, P+UTMD:0.058±0.0014, t 1, 3=8.334, P <0.01; t 1, 4=21.027, P <0.01).
There is not statistical difference between NS group and naked plasmid group (NS:0.079±0.0048,
P:0.077±0.0012, t 1, 2=0.797; P >0.05) and P+S+UTMD group has better inhibition effects compared
with P+UTMD group (P+S+UTMD:0.026±0.0013, P+UTMD:0.058±0.0014, t 3, 4=33.254; P <0.05).
Conclusion The present study shows that this method of UTMD combined mediated shRNA can
be used to deliver plasmid deoxyribonucleic acid (DNA) to the brain selectively and effectively.
This noninvasive technique is a promising method for cerebral therapy and could be applied in the
rapidly developing gene therapy for cerebral diseases.
