title: Aβ(1-42) oligomer-induced leakage in an in vitro blood-brain barrier model is associated with up-regulation of RAGE and metalloproteinases, and down-regulation of tight junction scaffold proteins.
abstract: Accumulating evidence indicates that abnormal deposition of amyloid-β (Aβ) peptide in the brain is responsible for endothelial cell damage and consequently leads to blood-brain barrier (BBB) leakage. However, the mechanisms underlying BBB disruption are not well described. We employed an monolayer BBB model comprising bEnd.3 cell and found that BBB leakage was induced by treatment with Aβ(1-42), and the levels of tight junction (TJ) scaffold proteins (ZO-1, Claudin-5, and Occludin) were decreased. Through comparisons of the effects of the different components of Aβ(1-42), including monomer (Aβ(1-42)-Mono), oligomer (Aβ(1-42)-Oligo), and fibril (Aβ(1-42)-Fibril), our data confirmed that Aβ(1-42)-Oligo is likely to be the most important damage factor that results in TJ damage and BBB leakage in Alzheimer's disease. We found that the incubation of bEnd.3 cells with Aβ(1-42) significantly up-regulated the level of receptor for advanced glycation end-products (RAGE). Co-incubation of a polyclonal antibody to RAGE and Aβ(1-42)-Oligo in bEnd.3 cells blocked RAGE suppression of Aβ(1-42)-Oligo-induced alterations in TJ scaffold proteins and reversed Aβ(1-42)-Oligo-induced up-regulation of RAGE, matrix metalloproteinase (MMP)-2, and MMP-9. Furthermore, we found that these effects induced by Aβ(1-42)-Oligo treatment were effectively suppressed by knockdown of RAGE using small interfering RNA (siRNA) transfection. We also found that GM 6001, a broad-spectrum MMP inhibitor, partially reversed the Aβ(1-42)-Oligo-induced inhibitor effects in bEnd.3 cells. Thus, these results suggested that RAGE played an important role in Aβ-induced BBB leakage and alterations of TJ scaffold proteins, through a mechanism that involved up-regulation of MMP-2 and MMP-9.
authors: Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, China.
authors: Wenbin
authors: W
authors: Wan
authors: State Key Laboratory of Medical Neurobiology, Department of Neurobiology and Institutes of Brain Science, School of Basic Medical Science, Fudan University, Shanghai, China.
authors: Lan
authors: L
authors: Cao
authors: Geriatrics Department of Chinese Medicine, Huadong Hospital, Fudan University, Shanghai, China.
authors: Lumei
authors: L
authors: Liu
authors: Department of Chinese Medicine, Dongfang Hospital, Tongji University, Shanghai, China.
authors: Chunyan
authors: C
authors: Zhang
authors: Department of Perinatal Medicine Pregnancy Research Centre and University of Melbourne Department of Obstetrics and Gynaecology, Royal Women's Hospital, Parkville, VIC, Australia.
authors: Bill
authors: B
authors: Kalionis
authors: School of Acupuncture, Massage and Rehabilitation, Yunnan University of Traditional Chinese Medicine, Kunming, China.
authors: Xiantao
authors: X
authors: Tai
authors: Geriatrics Department of Chinese Medicine, Huadong Hospital, Fudan University, Shanghai, China.
authors: Yaming
authors: Y
authors: Li
authors: Shanghai Institute of Geriatrics, Huadong Hospital, Fudan University, Shanghai, China.
authors: Shijin
authors: S
authors: Xia
mesh_terms: D016229:Amyloid beta-Peptides / Q000633:toxicity*; D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism / Q000473:pathology*; D015153:Blotting, Western; D002199:Capillary Permeability / Q000502:physiology*; D002460:Cell Line; D055785:Gene Knockdown Techniques; D006801:Humans; D066298:In Vitro Techniques; D045726:Metalloproteases / Q000096:biosynthesis*; D051379:Mice; D010446:Peptide Fragments / Q000633:toxicity*; D034741:RNA, Small Interfering; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D062725:Tight Junction Proteins / Q000096:biosynthesis*
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D034741:RNA, Small Interfering; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic; D062725:Tight Junction Proteins; C075222:amyloid beta-protein (1-42); D045726:Metalloproteases
keywords: Alzheimer's disease; amyloid beta; blood-brain barrier; receptor for advanced glycation end-products; tight junction