Abstract WMP31: Neamine, A Angiogenin Inhibitor, Induces Neuroprotection After Acute Ischemic Stroke In Type One Diabetic Rats
Introduction: Angiogenin is a member of the ribonuclease superfamily and promotes degradation of basement membrane and extracellular matrix. After stroke in Type one diabetes (T1DM) rats, Angiogenin is significantly increased and the increased Angiogenin is correlated with worse functional outcome. Neamine, an aminoglycoside antibiotic, blocks nuclear translocation of Angiogenin thereby abolishing the biological activity of Angiogenin. In this study, we therefore investigated the effect and underlying protective mechanisms of Neamine treatment of stroke in T1DM.
Methods: T1DM was induced in male Wistar rats by streptozotocin (60mg/kg, ip) and T1DM rats were subjected to embolic middle cerebral artery occlusion (MCAo). Neamine (10 mg/kg i.p.) was administered at 2h, 24h and 48h after MCAo. A battery functional outcome tests were performed. Brain blood barrier (BBB) leakage, lesion volume, brain hemorrhage volume, were evaluated and immunostaining, Western blot and ELISA were performed.
Results: Neamine treatment of stroke in T1DM rats significantly decreased Evans Blue dye leakage (Neamine: 16.38±2.14 ng/mg vs contro:30.57± 5.88 ng/mg); and lesion volume (23±2% vs 35±3%) as well as improved functional outcome compared to T1DM-control. Neamine also significantly decreased apoptosis (34.2±0.8 vs 42.5±3.6) and cleaved caspase-3 (28.7±3.7 vs 45.2±3.7) in the ischemic brain. Neamine treatment decreased MIP-1, MCP-1 and MMP9 levels in the ischemic brain measured by ELISA array. Using immunostaining, we found that Neamine treatment significantly decreased nuclear Angiogenin (26.7±1.7 vs 57.1±3.6) number, and the positive area of Angeopoietin-2 (7.4±0.3 vs 10.9±0.5), toll-like receptor 4 (TLR4) (5.4±0.9 vs 10.5±1.2), MMP9 (0.29±0.04 vs 0.48±0.09) expression compared to T1DM-MCAo control rats. In vitro data also show that Neamine treatment significantly decreased tPA, Angiogenin, MMP9 and advanced glycation endproducts receptor (RAGE) expression (2-3 fold) in cultured astrocytes and oligodendrocytes.
Conclusion: Neamine treatment of stroke is neuroprotective in T1DM rats. Inhibition of neuroinflammatory factor expression and decrease of BBB leakage may contribute to Neamine induced neuroprotection effects after stroke in T1DM.
- © 2012 by American Heart Association, Inc.