Abstract TP268: Huwe1 Is Neuroprotective Against Monkey Cerebral Ischemia-reperfusion Injury By Regulating P53- And Mcl1- Dependent Apoptotic Pathways

Abstract

Background: Neural cell apoptosis is one of the dominated mechanisms of cerebral ischemia-reperfusion injury (IRI). Anti-apotosis factor Mcl1 and apotosis factor p53 have been confirmed to play crucial roles in the apoptotic regulation previously. Mcl1 and p53 are the substrates of the ubiquitin ligases Huwe1, and which has been suggested as a potent therapeutic target in regulating cell apoptosis. Our aim is to explore whether Huwe1 modulates neural apoptosis by degrading Mcl1, p53 in cerebral ischemia-reperfusion injury. Methods: Eight health male adult rhesus monkeys were recruited in our study and were randomly devided into four groups: sham, PBS, siRNA silencing Huwe1 lentiviral vector and empty vector group. Except the sham group, the other groups were received corespondant intracranial injections and transient right middle cerebral occlusion (MCAO). A series of neurological evaluation and MRI were ulitized to evaluate animals. GFP flurescence was used to test transfection efficiency and apoptosis was detected by TUNEL staining. The expression level of related factors in causatum, putamen, temporal lobe and hippocampus were analyzed with western blot, QPCR, and immunohistochemistry. Results: The neurological deficit was much more serious in the silencing Huwe1 group than both empty vector and PBS group. The expression of Huwe1, Mcl1 and P53 were appeared a tendency to upregulate in the right caudatum and putament in model group than sham group in both protein and nucleotides level. Moreover, the number of apoptosis cells tested by TUNEL was the highest in the silencing Huwe 1 group, induced by decreasing expression of Huwe1 and obviously upragulating P53 expression. However, none of them has significant difference in other remote positions. Conclusion: Our study provides a potential novel mechnism that Huwe1 palys an important role in regulating neural apoptosis by regadading Mcl1 and P53 in cerebral IRI. In addition, for the first time, we confirm that the anti-apoptosis factor Mcl1 engages in the pathogenesis of cerebral IRI. It is possible that Huwe1 can be a potential therapeutic target for cerebral ischemia.