Limits...
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

Stretch induces cellular disruption leading to inflammatory cascade. Subjecting murine cerebrovascular endothelial cells cEND to stretch, alone, or in combination with oxygen glucose deprivation (OGD) results to compromise of cell membrane integrity. Damage to the cell membrane decreases expression of tight junction proteins. Cellular disruption brings about production of reactive oxygen species (ROS), nitric oxide (NO), and lactate dehydrogenase enzyme (LDH), and could also lead to the opening of calcium ion channels inducing the inflammatory cascade.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4543908&req=5

Figure 9: Stretch induces cellular disruption leading to inflammatory cascade. Subjecting murine cerebrovascular endothelial cells cEND to stretch, alone, or in combination with oxygen glucose deprivation (OGD) results to compromise of cell membrane integrity. Damage to the cell membrane decreases expression of tight junction proteins. Cellular disruption brings about production of reactive oxygen species (ROS), nitric oxide (NO), and lactate dehydrogenase enzyme (LDH), and could also lead to the opening of calcium ion channels inducing the inflammatory cascade.

Mentions: TBI is damage to the brain as a result of an external mechanical force i.e., rapid acceleration or deceleration, blast waves, crush, an impact, or penetration by a projectile (Maas et al., 2008). It involves two mechanisms of injury. Primary injury results from the immediate mechanical disruption of brain tissue that occurs at the time of exposure to the external force. It includes contusion, damage to blood vessels and axonal shearing. Meanwhile, secondary injury evolves over minutes to months after the primary injury and is the result of cascades of metabolic, cellular, and molecular events that ultimately lead to brain cell death, tissue damage, and atrophy (Gaetz, 2004; Cernak, 2005). In this paper, stretch was used to simulate the primary mechanical disruption and OGD as a model of ischemia to mimic secondary injury. Inflicting cEND cells with stretch injury was shown to alter their morphology as a result of deformation. As a result of injury, production of cytotoxicity marker lactate dehydrogenase enzyme (LDH), inflammatory markers interleukin (IL)-6, IL-1α, chemokine (C-C motif) ligand 2 (CCL2) and tumor necrosis factor (TNF)-α and total nitric oxide (NO) was induced in the cells. In addition, disruption of cell permeability was shown by microscopy as well as reduction in the amount of tight junction proteins occludin and claudin-5 produced. These parallel some events that occur during primary and secondary injuries in actual TBI (Figure 9).


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)

Stretch induces cellular disruption leading to inflammatory cascade. Subjecting murine cerebrovascular endothelial cells cEND to stretch, alone, or in combination with oxygen glucose deprivation (OGD) results to compromise of cell membrane integrity. Damage to the cell membrane decreases expression of tight junction proteins. Cellular disruption brings about production of reactive oxygen species (ROS), nitric oxide (NO), and lactate dehydrogenase enzyme (LDH), and could also lead to the opening of calcium ion channels inducing the inflammatory cascade.
© Copyright Policy
Related In: Results  -  Collection

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

Figure 9: Stretch induces cellular disruption leading to inflammatory cascade. Subjecting murine cerebrovascular endothelial cells cEND to stretch, alone, or in combination with oxygen glucose deprivation (OGD) results to compromise of cell membrane integrity. Damage to the cell membrane decreases expression of tight junction proteins. Cellular disruption brings about production of reactive oxygen species (ROS), nitric oxide (NO), and lactate dehydrogenase enzyme (LDH), and could also lead to the opening of calcium ion channels inducing the inflammatory cascade.
Mentions: TBI is damage to the brain as a result of an external mechanical force i.e., rapid acceleration or deceleration, blast waves, crush, an impact, or penetration by a projectile (Maas et al., 2008). It involves two mechanisms of injury. Primary injury results from the immediate mechanical disruption of brain tissue that occurs at the time of exposure to the external force. It includes contusion, damage to blood vessels and axonal shearing. Meanwhile, secondary injury evolves over minutes to months after the primary injury and is the result of cascades of metabolic, cellular, and molecular events that ultimately lead to brain cell death, tissue damage, and atrophy (Gaetz, 2004; Cernak, 2005). In this paper, stretch was used to simulate the primary mechanical disruption and OGD as a model of ischemia to mimic secondary injury. Inflicting cEND cells with stretch injury was shown to alter their morphology as a result of deformation. As a result of injury, production of cytotoxicity marker lactate dehydrogenase enzyme (LDH), inflammatory markers interleukin (IL)-6, IL-1α, chemokine (C-C motif) ligand 2 (CCL2) and tumor necrosis factor (TNF)-α and total nitric oxide (NO) was induced in the cells. In addition, disruption of cell permeability was shown by microscopy as well as reduction in the amount of tight junction proteins occludin and claudin-5 produced. These parallel some events that occur during primary and secondary injuries in actual TBI (Figure 9).

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