Enhanced gene expression of systemically administered plasmid DNA in the liver with therapeutic ultrasound and microbubbles

B. I. Raju, E. Leyvi, R. Seip, S. Sethuraman, X. Luo, A. Bird, S. Li, D. Koeberl
2013 IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control  
Ultrasound mediated delivery (USMD) of novel therapeutic agents in the presence of microbubbles is a potentially safe and effective method for gene therapy offering many desired characteristics such as low toxicity, potential for repeated treatment, and organ specificity. In this study we tested the capability of USMD to improve gene expression in mice livers using glycogen storage disease Type Ia as a model disease under systemic administration of naked plasmid DNA. Image guided therapeutic
more » ... rasound was used in two studies to provide therapeutic ultrasound to mice liver. In the first study involving wild type mice, control animals received naked plasmid DNA (pG6Pase 150 µg) via the tail vein followed by an infusion of Sonovue microbubbles, while the treated animals additionally received therapeutic ultrasound (1 MHz). Following the procedure, the animals were left to recover and subsequently sacrificed after 2 days when liver samples were extracted. RT-PCR assays using Taqman probes were performed on the samples to quantify mRNA expression. In addition, Western blot assays of FLAGtagged glucose-6-phosphatase (G6Pase) were performed to evaluate protein expression. Ultrasound exposed animals showed a four-fold increase in G6Pase RNA in the liver, in comparison with control animals. Furthermore, results from Western blot analysis demonstrated a two-fold increased protein expression in ultrasound exposed animals after two days (p<0.05). A second pilot study was performed with G6Pase knockout mice, and the animals were monitored for correction of hypoglycemia over a period of 3 weeks prior to tissue analysis. The RT-PCR assays of samples from these animals demonstrated increased G6Pase RNA in the liver following ultrasound treatment. These results demonstrate that ultrasound mediated delivery can increase gene expression of systemically injected naked pDNA in liver and also provide insight into the development of realistic approaches that can be translated into clinical practice. 3
doi:10.1109/tuffc.2013.2540 pmid:23405433 fatcat:mgu7cyasdnbbjj3k27kdichvbq