Effects of hypoxia on endothelial/pericytic co-culture model of the blood–brain barrier

Hayashi, Kentarō; Nakao, Shinobu; Nakaoke, Ryota; Nakagawa, Shinsuke; Kitagawa, Naoki; Níwa, Masami

doi:10.1016/j.regpep.2004.05.023

Cited by 140 publications

(105 citation statements)

References 23 publications

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“…It also implies that endothelial cells in the in vitro model may be more sensitive to H and H/R due to the lack of pericytes, glia, and neurons, which constitute the intact neurovascular unit. This concept is supported by studies (2,27,42,43) that show that endothelial cells co-cultured with glia and/or neurons respond differently to stimuli than do endothelial cells cultured alone. A second explanation for the differences between the in vitro and in vivo H models may be the level of H and duration of the hypoxic exposure.…”

Section: Discussionmentioning

confidence: 87%

Activation of PKC modulates blood-brain barrier endothelial cell permeability changes induced by hypoxia and posthypoxic reoxygenation

Fleegal

Hom

Borg

et al. 2005

American Journal of Physiology-Heart and Circulatory Physiology

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-The blood-brain barrier (BBB) is a metabolic and physiological barrier important for maintaining brain homeostasis. The aim of this study was to determine the role of PKC activation in BBB paracellular permeability changes induced by hypoxia and posthypoxic reoxygenation using in vitro and in vivo BBB models. In rat brain microvessel endothelial cells (RMECs) exposed to hypoxia (1% O 2-99% N2; 24 h), a significant increase in total PKC activity was observed, and this was reduced by posthypoxic reoxygenation (95% room air-5% CO 2) for 2 h. The expression of PKC-␤II, PKC-␥, PKC-, PKC-, and PKC-also increased following hypoxia (1% O 2-99% N2; 24 h), and these protein levels remained elevated following posthypoxic reoxygenation (95% room air-5% CO 2; 2 h). Increases in the expression of PKC-⑀ and PKC-were also observed following posthypoxic reoxygenation (95% room air-5% CO 2; 2 h). Moreover, inhibition of PKC with chelerythrine chloride (10 M) attenuated the hypoxiainduced increases in [ 14 C]sucrose permeability. Similar to what was observed in RMECs, total PKC activity was also stimulated in cerebral microvessels isolated from rats exposed to hypoxia (6% O 2-94% N2; 1 h) and posthypoxic reoxygenation (room air; 10 min). In contrast, hypoxia (6% O2-94% N2; 1 h) and posthypoxic reoxygenation (room air; 10 min) significantly increased the expression levels of only PKC-␥ and PKC-in the in vivo hypoxia model. These data demonstrate that hypoxia-induced BBB paracellular permeability changes occur via a PKC-dependent mechanism, possibly by differentially regulating the protein expression of the 11 PKC isozymes. protein kinase C; paracellular; neurovascular unit; rat THE BLOOD-BRAIN BARRIER (BBB) is a metabolic and physiological barrier important for maintaining cerebral homeostasis. Brain microvessels that form the BBB are lined with specialized endothelial cells surrounded by pericytes, astroglial processes, and the extracellular matrix. Compared with the peripheral microvasculature, cerebral microvessels are highly specialized because they lack vesicular transport and fenestrations while having a high level of metabolic activity. This lack of fenestrations is due to the presence of tight junctions (TJ) and adherens junctions, which restrict paracellular movement of molecules across the BBB (29,31,40).Stroke is a leading cause of death and disability in the United States (3). It has been demonstrated that the BBB is compromised during stroke (29). The effects of stroke on the cerebral vasculature significantly contribute to the brain damage caused by stroke. It has been determined that the lack of oxygen (hypoxia, H) followed by reperfusion (posthypoxic reoxygenation, H/R) during stroke contributes to both neuronal and vascular damage. Both H and H/R cause increases in cerebrovascular permeability with concomitant increases in vasogenic cerebral edema (1,36,47).Previous studies (36, 47) have demonstrated that H and H/R cause changes in paracellular permeability to [ 14 C]sucrose in cerebral vascular endothelial cells....

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Section: Discussionmentioning

confidence: 87%

Activation of PKC modulates blood-brain barrier endothelial cell permeability changes induced by hypoxia and posthypoxic reoxygenation

Fleegal

Hom

Borg

et al. 2005

American Journal of Physiology-Heart and Circulatory Physiology

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“…Consequently, it is important to study their pathophysiological mechanisms in experimental contests where the interactions between these two cell types are preserved. Even though some studies in the literature used EC-pericyte co-cultures [16][17][18], in our knowledge this is the first time in which pericytes and EC of human origin have been utilized.…”

Section: Discussionmentioning

confidence: 99%

“…Evidence in the literature shows that smooth muscle cells, grown on the outer surface of the same type of membrane used in this work, send out cytoplasmic projections able to penetrate the pores and make intimate contact with EC [19] and the same membrane has been used to create other direct co-culture models [16].…”

Section: Discussionmentioning

confidence: 99%

Human pericyte–endothelial cell interactions in co-culture models mimicking the diabetic retinal microvascular environment

et al. 2012

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“…This result suggested that A2AP might affect the transcellular diffusion of Evans Blue, although it is not at this point clear how A2AP would mediate this effect. When we performed the in vitro permeability experiment using the tracer FITC-Dextran (molecular mass of 4 kDa; Sigma), which only uses the paracellular pathway to go across BMEC monolayer (Hayashi et al, 2004;Neuhaus et al, 2008), only K104Stop-MCP1 was able to substantially enhance the leakage of the tracer across the co-culture system in the presence of A2AP (supplementary material Fig. S2).…”

Section: Truncation By Plasmin Promotes Mcp1-induced Bbb Compromisementioning

confidence: 99%

Truncation of monocyte chemoattractant protein 1 by plasmin promotes blood–brain barrier disruption

Yao

Tsirka

2011

Journal of Cell Science

102

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SummaryPrevious studies have shown that plasmin cleaves monocyte chemoattractant protein 1 (MCP1; officially known as C-C motif chemokine 2, CCL2) at K104, and this cleavage enhances its chemotactic potency significantly. Accumulating evidence reveals that MCP1 also disrupts the integrity of the blood-brain barrier (BBB). Here, we show that K104Stop-MCP1, truncated at the K104 where plasmin would normally cleave, is more efficient than the full-length protein (FL-MCP1) in compromising the integrity of the BBB in in vitro and in vivo models. K104Stop-MCP1 increases the permeability of BBB in both wild-type mice and mice deficient for tissue plasminogen activator (tPA), which converts plasminogen into active plasmin, suggesting that plasmin-mediated truncation of MCP1 plays an important role in BBB compromise. Furthermore, we show that the mechanisms underlying MCP1-induced BBB disruption involve redistribution of tight junction proteins (occludin and ZO-1) and reorganization of the actin cytoskeleton. Finally, we show that the redistribution of ZO-1 is mediated by phosphorylation of ezrin-radixin-moesin (ERM) proteins. These findings identify plasmin as a key signaling molecule in the regulation of BBB integrity and suggest that plasmin inhibitors might be used to modulate diseases accompanied by BBB compromise.

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Effects of hypoxia on endothelial/pericytic co-culture model of the blood–brain barrier

Cited by 140 publications

References 23 publications

Activation of PKC modulates blood-brain barrier endothelial cell permeability changes induced by hypoxia and posthypoxic reoxygenation

Activation of PKC modulates blood-brain barrier endothelial cell permeability changes induced by hypoxia and posthypoxic reoxygenation

Human pericyte–endothelial cell interactions in co-culture models mimicking the diabetic retinal microvascular environment

Truncation of monocyte chemoattractant protein 1 by plasmin promotes blood–brain barrier disruption

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