Добавил:
kiopkiopkiop18@yandex.ru t.me/Prokururor I Вовсе не секретарь, но почту проверяю Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз: Предмет: Файл:
Ординатура / Офтальмология / Английские материалы / Retinal Degenerative Diseases Laboratory and Therapeutic Investigations_Anderson_2008.pdf
Скачиваний:
0
Добавлен:
28.03.2026
Размер:
10.55 Mб
Скачать

34 Reversible and Size-Selective Opening of the Inner Blood-Retina Barrier

305

34.2.5Assessment of BRB Integrity by Perfusion of Hoechst (H33342)

Following RNAi-mediated ablation of transcripts encoding claudin-5 mice were perfused through the left ventricle of the beating heart and @ 37oC with 500 μl/g body weight of PBS containing 100 μg/ml Hoechst stain H33342 (Sigma Aldrich, Ireland) 24, 48, 72 h and 1 week post-hydrodynamic delivery of claudin-5 siRNA. Following perfusion, the whole eye was dissected and placed in 4% PFA pH 7.4 for 4 h and subsequently washed 4 × 15 mins with PBS. Eyes were cryoprotected using a sucrose gradient, 12 μm cryosections were cut using a cryostat.

34.2.6 Magnetic Resonance Imaging (MRI)

Following injection of siRNA and using appropriate controls, BRB integrity to a molecule of 742 Daltons was assessed via MRI, using a dedicated small rodent Bruker BioSpec 70/30 (i.e. 7T, 30 cm bore) with an actively shielded USR Magnet. BBB integrity was then visualised in high resolution T1 weighted MR images before and after injection of a 0.1 mM /L/kg bolus of Gd-DTPA (Gadolinium diethylenetriamine pentaacetic acid), administered via the tail vein. Following injection of GdDTPA, repeated 3 min T1-weighted scans were performed over a period of 30 min, and images shown are representative of the final scans of this 30 min period.

34.3 Results

34.3.1 Claudin-5 Levels in Retinal Flatmounts

Following hydrodynamic tail vein delivery of siRNA targeting claudin-5, levels of expression of this tight junction protein were shown to dramatically decrease at 24 and 48 h post-injection. The pattern of expression of claudin-5 72 h post-injection of siRNA appeared similar to that of mice receiving a non-targeting siRNA (Fig. 34.2).

34.3.2Perfusion of Hoechst 33342 (562 Da) in Mice Post-Delivery of Claudin-5 Sirna

Following suppression of claudin-5 at the iBRB in mice, Hoechst 33342 was perfused through the left ventricle of the heart. After preparation of 12 μm retinal cryosections, it was observed that iBRB permeability was manifested by INL staining at 24 h post injection of claudin-5 siRNA and both INL and ONL staining 48 h post-injection of siRNA targeting claudin-5. This increase in iBRB permeability