title: Utilizing Ultrasound to Transiently Increase Blood-Brain Barrier Permeability, Modulate of the Tight Junction Proteins, and Alter Cytoskeletal Structure.
abstract: The central nervous system is protected by the blood-brain barrier (BBB). The tight junction (TJ) proteins claudin-5 and zonula occludens-1 (ZO-1) as well as the cytoskeletal component F-actin play key roles in maintaining homeostasis of the BBB. Increases in BBB permeability may be beneficial for the delivery of pharmacological substances into the brain. Therefore, here, we assessed the use of ultrasound to induce transient enhancement of BBB permeability. We used fluorescein isothiocyanate (FITC)-dextran 40 to detect changes in the membrane permeability of bEnd.3 cells during ultrasound treatment. Ultrasound increased FITC-dextran 40 uptake into bEnd.3 cells for 2-6 h after treatment; however, normal levels returned after 24 h. An insignificant increase in lactate dehydrogenase (LDH) leakage also occurred 3 and 6 h after ultrasound treatment, whereas at 24 h, LDH leakage was indistinguishable between the control and treatment groups. Expression of claudin-5, ZO-1, and F-actin at the messenger RNA (mRNA) and protein levels was assessed with real-time polymerase chain reaction and western blotting. Ultrasound induced a transient decrease in claudin-5 mRNA and protein expression within 2 h of treatment; however, no significant changes in ZO-1 and F-actin expression were observed. Claudin-5, ZO-1, and F-actin immunofluorescence demonstrated that the cellular structures incorporating these proteins were transiently impaired by ultrasound. In conclusion, our ultrasound technique can temporarily increase BBB permeability without cytotoxicity to exposed cells, and the method can be exploited in the delivery of drugs to the brain with minimal damage.
authors.forename: Mi Jung
authors.initials: MJ
authors.lastname: Bae
authors.forename: Young Mi
authors.initials: YM
authors.lastname: Lee
authors.forename: Yeoun Hee
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Physiology, Kyungpook National University School of Medicine, 101 Dongin 2 Ga, Jung Gu, Daegu 700-422, Republic of Korea. hshan@knu.ac.kr.
authors.forename: Hyung Soo
authors.initials: HS
authors.lastname: Han
authors.forename: Hak Jong
authors.initials: HJ
authors.lastname: Lee
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000502:physiology*; D002461:Cell Line, Transformed; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism*; D042783:Endothelial Cells; D005786:Gene Expression Regulation / Q000502:physiology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D051379:Mice; D010539:Permeability; D012333:RNA, Messenger / Q000378:metabolism; D020127:Recovery of Function; D062725:Tight Junction Proteins / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014465:Ultrasonics
chemical_list: D012333:RNA, Messenger; D062725:Tight Junction Proteins; D007770:L-Lactate Dehydrogenase