Tetrandrine Attenuated Cerebral Ischemia/Reperfusion Injury and Induced Differential Proteomic Changes in a MCAO Mice Model Using 2-D DIGE

Abstract

Ischemic stroke is the most common type of stroke and brings about a big disease burden because of high mortality and disability in China. Tetrandrine, a bisbenzylisoquinoline alkaloid isolated from the Chinese herb Radix Stephania tetrandra, has been demonstrated to possess anti-inflammatory and free radical scavenging effects and even regulate astrocyte activation, but the possible role of tetrandrine in ameliorating cerebral ischemia/reperfusion injury of ischemic stroke remains unknown. The aim of this study was to determine the effects of tetrandrine on neurological injury and differential proteomic changes induced by transient reversible middle cerebral artery occlusion (MCAO) in mice. Male Balb/c mice were divided into sham (n=30), MCAO+saline as control (n=30), and MCAO+Tet as tetrandrine-treated (n=30) groups. Mice in the control and tetrandrine-treated groups underwent 120min of MCAO following reperfusion. Immediately and 2h after MCAO, the mice received either normal saline (sham operated and control groups) or tetrandrine (tetrandrine-treated group) intraperitoneally. Neurological defects, brain water content, and infarct volume at 24h after stoke were used to evaluate neurological injury extent. Treatment with tetrandrine not only mitigated cerebral neurological deficits (P<0.05) and infarct size (P<0.01), but also decreased brian edema in the ischemic brain (P<0.05). Then, fluorescence two-dimensional difference in gel electrophoresis was used to detect our systematic differential profiling of proteomic changes responding to tetrandrine administration. We validated that the expression of GRP78, DJ-1 and HYOU1 was associated with neuroprotective effect of tetrandrine in MCAO model by Western blotting. These findings indicate a potential neuroprotective role of tetrandrine for ischemic stroke and yield insights into cellular and molecular mechanisms of tetrandrine taking place in ischemic stroke.