title: The expression of osteopontin is increased in vessels with blood-brain barrier impairment.
abstract: OBJECTIVE
  We previously reported that the blood-brain barrier (BBB) function was deteriorated in vessels located along hippocampal fissures in stroke-prone spontaneously hypertensive rats (SHRSP). In this study, we examined changes of gene expression in the BBB-damaged vessels of SHRSP.
  
  
  METHODS
  Vascular samples were microdissected from the hippocampi of SHRSP and Wistar-Kyoto (WKY) as a control and the difference in gene expression between the BBB-damaged vessels in SHRSP and vessels without BBB damage in WKY was examined by a microarray. The differences in gene and protein expression between brain tissues in the two strains of rats were examined using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting and immunohistochemistry.
  
  
  RESULTS
  The microarray assay revealed that the ratio of osteopontin gene expression in the vascular tissue of the hippocampi of SHRSP to that of WKY was the highest among 8435 genes. Real-time RT-PCR analysis revealed that the gene expression of osteopontin was significantly increased in the hippocampal samples of SHRSP compared with that in the hippocampal samples of WKY rats or with that in the cortical samples of SHRSP. Immunohistochemical and Western blot analyses showed that the osteopontin protein expression was seen in perivascular ED1-positive macrophages/microglial cells located around hippocampal fissures and significantly increased in the hippocampi of SHRSP compared with that of WKY.
  
  
  CONCLUSIONS
  These findings indicate that the expression of osteopontin is increased in BBB-damaged vessels in hypertensive SHRSP compared with that in vessels without BBB impairment in WKY rats, suggesting a role for osteopontin in BBB function.
authors.affiliation: Department of Anaesthesiology and Emergency Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Iwanaga
authors.forename: M
authors.initials: M
authors.lastname: Ueno
authors.forename: M
authors.initials: M
authors.lastname: Ueki
authors.forename: C-L
authors.initials: CL
authors.lastname: Huang
authors.forename: S
authors.initials: S
authors.lastname: Tomita
authors.forename: Y
authors.initials: Y
authors.lastname: Okamoto
authors.forename: T
authors.initials: T
authors.lastname: Ogawa
authors.forename: N
authors.initials: N
authors.lastname: Ueda
authors.forename: N
authors.initials: N
authors.lastname: Maekawa
authors.forename: H
authors.initials: H
authors.lastname: Sakamoto
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism* / Q000473:pathology*; D015153:Blotting, Western; D015870:Gene Expression; D006624:Hippocampus / Q000098:blood supply* / Q000378:metabolism* / Q000473:pathology; D006973:Hypertension / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D007150:Immunohistochemistry; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D053495:Osteopontin / Q000096:biosynthesis*; D040081:Protein Array Analysis; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D053495:Osteopontin