<abstract xmlns="http://www.w3.org/1999/xhtml"> Background: Ischemic stroke, an acute neurological injury lacking an effective therapy, is a leading cause of death worldwide. The unmet need in stroke research is to identify viable therapeutic targets and to understand their interplay during cerebral ischemia-reperfusion (I/R) injury. Objective: To explore the protective effects and molecular mechanism of NG-nitro-L-arginine methyl ester (L-NAME) in cerebral ischemia-reperfusion injury-induced blood-brain barrier (BBB) dysfunction. Methods: Two hundred fifty-six rats were randomly assigned to a sham operation group, I/R group, and I/R with L-NAME treatment group. Brain water content was determined by calculating dry/wet weight. The permeability of the BBB was observed using an electron microscope and by determining the Evans Blue leakage from brain tissue on the ischemic side. The expression of brain MMP-9 and GFAP was determined using an immunohistochemical method. The expression of ZO-1 protein was determined by western blotting. Results: We found that L-NAME remarkably attenuated the permeability of the BBB after I/R as assessed by Evans Blue leakage and brain water content (p &lt; 0.05). This was further confirmed by examination of the ultrastructural morphology of the BBB using a transmission electron microscope. Furthermore, we found that expression of the zonae occludens-1 (ZO-1) was decreased in endothelial cells, and expression of MMP-9 and GFAP was increased in the basement membrane and astrocyte end-feet in vehicle control groups, respectively, but these changes could be prevented by L-NAME pretreatment. Conclusion: These results suggested that the neuroprotective effects of L-NAME against BBB damage induced by I/R might be related to the upregulation of tight junction proteins and inhibition of MMP-9 and GFAP expression. L-NAME can be used as a potential MMP-9-based multiple targeting therapeutic strategy in cerebral I/R injury. </abstract>

Background: Ischemic stroke, an acute neurological injury lacking an effective therapy, is a leading cause of death worldwide. The unmet need in stroke research is to identify viable therapeutic targets and to understand their interplay during cerebral ischemia-reperfusion (I/R) injury. Objective: To explore the protective effects and molecular mechanism of NG-nitro-L-arginine methyl ester (L-NAME) in cerebral ischemia-reperfusion injury-induced blood-brain barrier (BBB) dysfunction. Methods: Two hundred fifty-six rats were randomly assigned to a sham operation group, I/R group, and I/R with L-NAME treatment group. Brain water content was determined by calculating dry/wet weight. The permeability of the BBB was observed using an electron microscope and by determining the Evans Blue leakage from brain tissue on the ischemic side. The expression of brain MMP-9 and GFAP was determined using an immunohistochemical method. The expression of ZO-1 protein was determined by western blotting. Results: We found that L-NAME remarkably attenuated the permeability of the BBB after I/R as assessed by Evans Blue leakage and brain water content (p < 0.05). This was further confirmed by examination of the ultrastructural morphology of the BBB using a transmission electron microscope. Furthermore, we found that expression of the zonae occludens-1 (ZO-1) was decreased in endothelial cells, and expression of MMP-9 and GFAP was increased in the basement membrane and astrocyte end-feet in vehicle control groups, respectively, but these changes could be prevented by L-NAME pretreatment. Conclusion: These results suggested that the neuroprotective effects of L-NAME against BBB damage induced by I/R might be related to the upregulation of tight junction proteins and inhibition of MMP-9 and GFAP expression. L-NAME can be used as a potential MMP-9-based multiple targeting therapeutic strategy in cerebral I/R injury.

Molecular mechanisms for NG-nitro-L-arginine methyl ester action against cerebral ischemia–reperfusion injury-induced blood–brain barrier dysfunction

Department of Ultrasound, Shanghai First People’s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai 200080, China

Hong Hui Hospital, Xi’an Jiaotong University College of Medicine, Shaanxi 710054,

Correspondence to: Hong Hui Hospital, Xi’an Jiaotong University College of Medicine, Shaanxi, 710054,

Department of Ultrasound, Shanghai First People’s Hospital Afiliated to Shanghai Jiaotong University School of Medicine, Shanghai 200080, China

Asian Biomedicine

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Molecular mechanisms for N-nitro-L-arginine methyl ester action against cerebral ischemia–reperfusion injury-induced blood–brain barrier dysfunction

Background: Ischemic stroke, an acute neurological injury lacking an effective therapy, is a leading cause of death worldwide. The unmet need in stroke...

Molecular mechanisms for N^G-nitro-L-arginine methyl ester action against cerebral ischemia–reperfusion injury-induced blood–brain barrier dysfunction

Article Category: Original article

Published Online: Feb 04, 2017

Page range: 173 - 184

DOI: https://doi.org/10.5372/1905-7415.0802.277

Keywords
blood-brain barrier, cerebral ischemia-reperfusion injury, glial fibrillary acidic protein, matrix metalloproteinase, NG-nitro-L-arginine methyl ester, zonae occludens-1

© 2017

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Molecular mechanisms for NG-nitro-L-arginine methyl ester action against cerebral ischemia–reperfusion injury-induced blood–brain barrier dysfunction

Article Category: Original article

Published Online: Feb 04, 2017

Page range: 173 - 184

DOI: https://doi.org/10.5372/1905-7415.0802.277

Keywordsblood-brain barrier, cerebral ischemia-reperfusion injury, glial fibrillary acidic protein, matrix metalloproteinase, NG-nitro-L-arginine methyl ester, zonae occludens-1

© 2017

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Molecular mechanisms for N^G-nitro-L-arginine methyl ester action against cerebral ischemia–reperfusion injury-induced blood–brain barrier dysfunction

Keywords
blood-brain barrier, cerebral ischemia-reperfusion injury, glial fibrillary acidic protein, matrix metalloproteinase, NG-nitro-L-arginine methyl ester, zonae occludens-1