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Stretch and/or oxygen glucose deprivation (OGD) in an in vitro traumatic brain injury (TBI) model induces calcium alteration and inflammatory cascade.

Salvador E, Burek M, Förster CY - Front Cell Neurosci (2015)

Bottom Line: Furthermore, reduction of cell membrane integrity decreased tight junction proteins claudin-5 and occludin expression.Also, since cell damage requires an increased uptake of glucose, expression of glucose transporter glut1 was found to increase at the mRNA level after OGD.Astrocytes potentiate these effects on calcium level in cEND cells.

View Article: PubMed Central - PubMed

Affiliation: Klinik und Poliklinik für Anästhesiologie, Zentrum für Operative Medizin der Universität Würzburg Würzburg, Germany.

ABSTRACT
The blood-brain barrier (BBB), made up of endothelial cells of capillaries in the brain, maintains the microenvironment of the central nervous system. During ischemia and traumatic brain injury (TBI), cellular disruption leading to mechanical insult results to the BBB being compromised. Oxygen glucose deprivation (OGD) is the most commonly used in vitro model for ischemia. On the other hand, stretch injury is currently being used to model TBI in vitro. In this paper, the two methods are used alone or in combination, to assess their effects on cerebrovascular endothelial cells cEND in the presence or absence of astrocytic factors. Applying severe stretch and/or OGD to cEND cells in our experiments resulted to cell swelling and distortion. Damage to the cells induced release of lactate dehydrogenase enzyme (LDH) and nitric oxide (NO) into the cell culture medium. In addition, mRNA expression of inflammatory markers interleukin (I L)-6, IL-1α, chemokine (C-C motif) ligand 2 (CCL2) and tumor necrosis factor (TNF)-α also increased. These events could lead to the opening of calcium ion channels resulting to excitotoxicity. This could be demonstrated by increased calcium level in OGD-subjected cEND cells incubated with astrocyte-conditioned medium. Furthermore, reduction of cell membrane integrity decreased tight junction proteins claudin-5 and occludin expression. In addition, permeability of the endothelial cell monolayer increased. Also, since cell damage requires an increased uptake of glucose, expression of glucose transporter glut1 was found to increase at the mRNA level after OGD. Overall, the effects of OGD on cEND cells appear to be more prominent than that of stretch with regards to TJ proteins, NO, glut1 expression, and calcium level. Astrocytes potentiate these effects on calcium level in cEND cells. Combining both methods to model TBI in vitro shows a promising improvement to currently available models.

No MeSH data available.


Related in: MedlinePlus

Lactate dehydrogenase (LDH) enzyme release into the cell culture medium after stretch injury. LDH released into the culture medium was measured at various time points after stretch induced injury. LDH was expressed as a percent of the total releasable LDH (LDH in media plus cells). Data are mean values ± SEM. The n for every time point is 5. Severely stretched cEND cells released a significantly greater amount of LDH as compared to unstretched cells at all time points (*p < 0.05).
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Figure 2: Lactate dehydrogenase (LDH) enzyme release into the cell culture medium after stretch injury. LDH released into the culture medium was measured at various time points after stretch induced injury. LDH was expressed as a percent of the total releasable LDH (LDH in media plus cells). Data are mean values ± SEM. The n for every time point is 5. Severely stretched cEND cells released a significantly greater amount of LDH as compared to unstretched cells at all time points (*p < 0.05).

Mentions: Lactate dehydrogenase is an enzyme used to indicate the occurrence of cytotoxicity in cells. The release of LDH in the supernatant of the cell culture medium indicates cell damage. It was observed among cells subjected to severe stretch that the amount of LDH released by the cells into the cell culture medium significantly increased immediately (0 min), 15, and 30 min, 1, 2, 4, 8, and 24 h after stretch injury (Figure 2) as compared to cells that were not subjected to stretch or were subjected to low and moderate stretch (p < 0.05). Moreover, cells that were stretched (low, moderate, and severe) and allowed to recover for 24 h post-injury released significantly higher amount of LDH compared to other time points.


Stretch and/or oxygen glucose deprivation (OGD) in an in vitro traumatic brain injury (TBI) model induces calcium alteration and inflammatory cascade.

Salvador E, Burek M, Förster CY - Front Cell Neurosci (2015)

Lactate dehydrogenase (LDH) enzyme release into the cell culture medium after stretch injury. LDH released into the culture medium was measured at various time points after stretch induced injury. LDH was expressed as a percent of the total releasable LDH (LDH in media plus cells). Data are mean values ± SEM. The n for every time point is 5. Severely stretched cEND cells released a significantly greater amount of LDH as compared to unstretched cells at all time points (*p < 0.05).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4543908&req=5

Figure 2: Lactate dehydrogenase (LDH) enzyme release into the cell culture medium after stretch injury. LDH released into the culture medium was measured at various time points after stretch induced injury. LDH was expressed as a percent of the total releasable LDH (LDH in media plus cells). Data are mean values ± SEM. The n for every time point is 5. Severely stretched cEND cells released a significantly greater amount of LDH as compared to unstretched cells at all time points (*p < 0.05).
Mentions: Lactate dehydrogenase is an enzyme used to indicate the occurrence of cytotoxicity in cells. The release of LDH in the supernatant of the cell culture medium indicates cell damage. It was observed among cells subjected to severe stretch that the amount of LDH released by the cells into the cell culture medium significantly increased immediately (0 min), 15, and 30 min, 1, 2, 4, 8, and 24 h after stretch injury (Figure 2) as compared to cells that were not subjected to stretch or were subjected to low and moderate stretch (p < 0.05). Moreover, cells that were stretched (low, moderate, and severe) and allowed to recover for 24 h post-injury released significantly higher amount of LDH compared to other time points.

Bottom Line: Furthermore, reduction of cell membrane integrity decreased tight junction proteins claudin-5 and occludin expression.Also, since cell damage requires an increased uptake of glucose, expression of glucose transporter glut1 was found to increase at the mRNA level after OGD.Astrocytes potentiate these effects on calcium level in cEND cells.

View Article: PubMed Central - PubMed

Affiliation: Klinik und Poliklinik für Anästhesiologie, Zentrum für Operative Medizin der Universität Würzburg Würzburg, Germany.

ABSTRACT
The blood-brain barrier (BBB), made up of endothelial cells of capillaries in the brain, maintains the microenvironment of the central nervous system. During ischemia and traumatic brain injury (TBI), cellular disruption leading to mechanical insult results to the BBB being compromised. Oxygen glucose deprivation (OGD) is the most commonly used in vitro model for ischemia. On the other hand, stretch injury is currently being used to model TBI in vitro. In this paper, the two methods are used alone or in combination, to assess their effects on cerebrovascular endothelial cells cEND in the presence or absence of astrocytic factors. Applying severe stretch and/or OGD to cEND cells in our experiments resulted to cell swelling and distortion. Damage to the cells induced release of lactate dehydrogenase enzyme (LDH) and nitric oxide (NO) into the cell culture medium. In addition, mRNA expression of inflammatory markers interleukin (I L)-6, IL-1α, chemokine (C-C motif) ligand 2 (CCL2) and tumor necrosis factor (TNF)-α also increased. These events could lead to the opening of calcium ion channels resulting to excitotoxicity. This could be demonstrated by increased calcium level in OGD-subjected cEND cells incubated with astrocyte-conditioned medium. Furthermore, reduction of cell membrane integrity decreased tight junction proteins claudin-5 and occludin expression. In addition, permeability of the endothelial cell monolayer increased. Also, since cell damage requires an increased uptake of glucose, expression of glucose transporter glut1 was found to increase at the mRNA level after OGD. Overall, the effects of OGD on cEND cells appear to be more prominent than that of stretch with regards to TJ proteins, NO, glut1 expression, and calcium level. Astrocytes potentiate these effects on calcium level in cEND cells. Combining both methods to model TBI in vitro shows a promising improvement to currently available models.

No MeSH data available.


Related in: MedlinePlus