Premium
In Vivo Ultrasound Microbubble‐Mediated Gene Transfection and Expression Monitoring in the Renal Medulla of Rats
Author(s) -
Li Ningjun,
Xia Min,
Dobson Crystal S,
Li PinLan
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a438-c
Subject(s) - renal medulla , in vivo , transfection , medulla , kidney , green fluorescent protein , ex vivo , gene expression , microbiology and biotechnology , ultrasound , chemistry , pathology , biology , gene , medicine , anatomy , endocrinology , radiology , biochemistry
Ultrasound microbubble technique has been reported as an effective in vivo non‐viral gene delivery method through intra‐arterial injection. The present study explored the applicability of this technique for gene transfection locally in the renal medulla by interstitial infusion. Expression vectors constructed with a rat full‐length prolyl hydroxylase domain‐containing protein 2 (PHD2) and plasmids expressing red fluorescent protein (RFP) were infused into the renal medulla of Sprague‐Dawley rats in a mixture of DNA and microbubble (Optison). Then, an ultrasound transducer was directly applied onto the kidney in the middle and at the end of the infusion. At day 2, 5 and 7 after the infusion, the kidneys were collected and sagittally cut. The fluorescence of RFP on the semi section of the kidney was detected by an in vivo fluorescent imaging system. The ex‐vivo fluorescent images showed a strong red fluorescence within the renal medulla compared with the empty vector‐transfected kidneys, even on the second day after infusion. RFP expression sustained over a 7‐day monitoring. Real time RT‐PCR analyses showed that the PHD2 mRNA levels in the renal medulla were increased by two folds in PHD2 transfected kidneys compared with control rat kidneys. In rats with renal medullary overexpression of PHD2 gene, mean arterial pressure increased by 20 mmHg in response to high salt. These results demonstrate that ultrasound microbubble technique can efficiently deliver the gene expression vectors into the renal medulla and produce functional changes. An in vivo fluorescent imaging system may dynamically monitor the gene expression in local tissue or cells, which provides a powerful tool for monitoring localized gene expression in transfected tissues or cells in the rat renal medulla (supported by NIH grants HL 70726 and DK 054927).