scholarly journals Inhibition of MicroRNA‐155 Supports Endothelial Tight Junction Integrity Following Oxygen‐Glucose Deprivation

2018 ◽  
Vol 7 (13) ◽  
Author(s):  
Juan Carlos Pena‐Philippides ◽  
Amy Sabrina Gardiner ◽  
Ernesto Caballero‐Garrido ◽  
Rong Pan ◽  
Yiliang Zhu ◽  
...  
Keyword(s):  
Tight Junction ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation ◽  
Endothelial Tight Junction

Autophagy inhibition preserves tight junction of human cerebral microvascular endothelium under oxygen glucose deprivation

2020 ◽  
Vol 17 ◽  
Author(s):  
Shuyan Wang ◽  
Jihong Xu ◽  
Jin Xi ◽  
John R. Grothusen ◽  
Renyu Liu
Keyword(s):  
Electron Microscopy ◽  
Endothelial Cells ◽  
Tight Junction ◽  
Human Brain ◽  
Cell Viability ◽  
Tight Junctions ◽  
Glucose Deprivation ◽  
Oxygen Glucose Deprivation ◽  
Brain Endothelial Cells

Aims:: To investigate the role of autophagy in the tight junction of human brain endothelial cells during hypoxia and ischemia. Background:: Endothelial cells play an important role in the initiation, progression and recovery from ischemic stroke. The role of autophagy on human brain endothelial cells (HBECs) subjected to oxygen-glucose deprivation (OGD) is not fully elucidated. Objective:: The objective of this study was to investigate the effect of autophagy on HBECs during OGD. Methods:: HBECs were cultured in a 96-well plate and underwent 4 hours of OGD. For drug treatment, 3-Methyladenine (3- MA) (5mmol/L), an inhibitor of autophagy, was added at the start of OGD. Cell viability and cytotoxicity were tested by cell counting kit-8 (CCK-8) and lactate dehydrogenase (LDH) assays. Morphological changes in cells were examined by immunofluorescence microscopy. The protein expression of light chain 3 (LC3) was measured. Autophagosomes and endothelial cell tight junctions were observed using transmission electron microscopy. Results:: The results showed that OGD induced serious damage to HBECs. Cell viability was decreased significantly and LDH release increased significantly (p<0.05) following OGD. 3-MA protected HBECs from damage. Immunostaining further confirmed these results. Since 3-MA is an inhibitor of autophagy, we chose to examine alterations in the amount of LC3, a marker of autophagy. The ratios of LC3-Ⅱ to LC3-Ⅰwere significantly lower in the 3-MA treated OGD group than in the non-3-MA treated OGD group (p<0.05). Electron microscopy showed that 3-MA inhibited the formation of autophagolysosomes and revealed that the tight junction ultrastructure of HBECs, which was destroyed by OGD, was significantly protected by treatment with 3-MA. Conclusions:: Autophagy is a key response to oxygen-glucose deprivation stress and its detrimental effects are closely related with destruction of tight junctions of human brain endothelial cells. Strategies to inhibit autophagy could help to preserve tight junctions.

Resveratrol Reduces Matrix Metalloproteinase-2 Activity Induced by Oxygen-Glucose Deprivation and Reoxygenation in Human Cerebral Microvascular Endothelial Cells

2012 ◽  
Vol 82 (4) ◽  
pp. 267-274 ◽  
Author(s):  
Zahide Cavdar ◽  
Mehtap Y. Egrilmez ◽  
Zekiye S. Altun ◽  
Nur Arslan ◽  
Nilgun Yener ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Neurovascular Unit ◽  
Glucose Deprivation ◽  
Matrix Metalloproteinase 2 ◽  
Microvascular Endothelial Cells ◽  
Oxygen Glucose Deprivation ◽  
Microvascular Endothelial

The main pathophysiology in cerebral ischemia is the structural alteration in the neurovascular unit, coinciding with neurovascular matrix degradation. Among the human matrix metalloproteinases (MMPs), MMP-2 and -9, known as gelatinases, are the key enzymes for degrading type IV collagen, which is the major component of the basal membrane that surrounds the cerebral blood vessel. In the present study, we investigated the effects of resveratrol on cytotoxicity, reactive oxygen species (ROS), and gelatinases (MMP-2 and -9) in human cerebral microvascular endothelial cells exposed to 6 hours of oxygen-glucose deprivation and a subsequent 24 hours of reoxygenation with glucose (OGD/R), to mimic ischemia/reperfusion in vivo. Lactate dehydrogenase increased significantly, in comparison to that in the normoxia group. ROS was markedly increased in the OGD/R group, compared to normoxia. Correspondingly, ROS was significantly reduced with 50 μM of resveratrol. The proMMP-2 activity in the OGD/R group showed a statistically significant increase from the control cells. Resveratrol preconditioning decreased significantly the proMMP-2 in the cells exposed to OGD/R in comparison to that in the OGD/R group. Our results indicate that resveratrol regulates MMP-2 activity induced by OGD/R via its antioxidant effect, implying a possible mechanism related to the neuroprotective effect of resveratrol.

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