@article{APS9187,
author = {Jia-yuan Wu and Mei Li and Li-juan Cao and Mei-ling Sun and Dong Chen and Hai-gang Ren and Qin Xia and Zhou-teng Tao and Zheng-hong Qin and Qing-song Hu and Guang-hui Wang},
title = {Protease Omi cleaving Hax-1 protein contributes to OGD/R-induced mitochondrial damage in neuroblastoma N2a cells and cerebral injury in MCAO mice},
journal = {Acta Pharmacologica Sinica},
volume = {36},
number = {9},
year = {2017},
keywords = {},
abstract = {Aim: In the penumbra after focal cerebral ischemia, an increase of protease Omi is linked to a decrease of Hs1-associated protein X-1 (Hax-1), a protein belonging to the Bcl-2 family. In this study we investigated the mechanisms underlying the regulation of Hax-1 by protease Omi in cerebral ischemia/reperfusion (I/R) injury.
Methods: Mouse neuroblastoma N2a cells were subjected to oxygen-glucose deprivation and reoxygenation (OGD/R); cell viability was assessed with MTT assay. Mice underwent 2-h middle cerebral artery occlusion (MCAO) and reperfusion, and the infarct volume was determined with TTC staining. The expression of Omi and Hax-1 was detected using immunoblot and immunofluorescence assays. The mitochondrial membrane potential was measured using TMRM staining.
Results: In the brains of MCAO mice, the protein level of Omi was significantly increased, while the protein level of Hax-1 was decreased. Similar changes were observed in OGD/R-treated N2a cells, but the mRNA level of Hax-1 was not changed. Furthermore, in OGD/R-treated N2a cells, knockdown of Omi significantly increased Hax-1 protein level. Immunofluorescence assay showed that Omi and Hax-1 were co-localized in mitochondria of N2a cells. OGD/R caused marked mitochondrial damage and apoptosis in N2a cells, while inhibition of Omi protease activity with UCF-101 (10 μmol/L) or overexpression of Hax-1 could restore the mitochondrial membrane potential and attenuate cell apoptosis. Moreover, pretreatment of MCAO mice with UCF-101 (7.15 mg/kg, ip) could restore Hax-1 expression, inhibit caspase activation, and significantly reduce the infarct volume.
Conclusion: Protease Omi impairs mitochondrial function by cleaving Hax-1, which induces apoptosis in OGD/R-treated N2a cells and causes I/R injury in MCAO mice.},
issn = {1745-7254}, url = {http://www.chinaphar.com/article/view/9187}
}