Neuroprotective and Angiogenesis Effects of Levetiracetam Following Ischemic Stroke in Rats.

Objective: The present study explored whether levetiracetam (LEV) could protect against experimental brain ischemia and enhance angiogenesis in rats, and investigated the potential mechanisms in vivo and in vitro. Methods: The middle cerebral artery was occluded for 60 min to induce middle cerebral artery occlusion (MCAO). The Morris water maze was used to measure cognitive ability. The rotation test was used to assess locomotor function. T2-weighted MRI was used to assess infarct volume. The neuronal cells in the cortex area were stained with cresyl purple. The anti-inflammatory effects of LEV on microglia were observed by immunohistochemistry. Enzyme-linked immunosorbent assays (ELISA) were used to measure the production of pro-inflammatory cytokines. Western blotting was used to detect the levels of heat shock protein 70 (HSP70), vascular endothelial growth factor (VEGF), and hypoxia-inducible factor-1α (HIF-1α) in extracts from the ischemic cortex. Flow cytometry was used to observe the effect of LEV on neuronal cell apoptosis. Results: LEV treatment significantly increased the density of the surviving neurons in the cerebral cortex and reduced the infarct size (17.8 ± 3.3% vs. 12.9 ± 1.4%, p < 0.01) after MCAO. Concurrently, the time required to reach the platform for LEV-treated rats was shorter than that in the saline group on day 11 after MCAO (p < 0.01). LEV treatment prolonged the rotarod retention time on day 14 after MCAO (84.5 ± 6.7 s vs. 59.1 ± 6.2 s on day 14 compared with the saline-treated groups, p < 0.01). It also suppressed the activation of microglia and inhibited TNF-α and Il-1β in the ischemic brain (135.6 ± 5.2 pg/ml vs. 255.3 ± 12.5 pg/ml, 18.5 ± 1.3 pg/ml vs. 38.9 ± 2.3 pg/ml on day 14 compared with the saline-treated groups, p < 0.01). LEV treatment resulted in a significant increase in HIF-1α, VEGF, and HSP70 levels in extracts from the ischemic cerebral cortex. At the same time, LEV reduced neuronal cell cytotoxicity and apoptosis induced by an ischemic stroke (p < 0.01). Conclusion: LEV treatment promoted angiogenesis and functional recovery after cerebral ischemia in rats. These effects seem to be mediated through anti-inflammatory and antiapoptotic activities, as well as inducing the expression of HSP70, VEGF, and HIF-1α.

Yao X ，Yang W ，Ren Z ，Zhang H ，Shi D ，Li Y ，Yu Z ，Guo Q ，Yang G ，Gu Y ，Zhao H ，Ren K ... -  《Frontiers in Pharmacology》

Melittin protects against neural cell damage in rats following ischemic stroke.

In this study, we explored the neuroprotective effect of melittin (MEL) after brain ischemia using a rat model. The rats underwent middle cerebral artery occlusion (MCAO) for 60 min and were randomly divided into the control group, saline group, and MEL group. Rats in each group were injected intraperitoneally with MEL one day before MCAO until sacrificed. Morris water maze and rotation test were used to assess locomotor function and cognitive ability. The 9.4 Tesla MRI was used to scan and assess the infarct volume of the rat brains. Immunohistochemistry was used to detect the sites of action of MEL on microglia. Western blot and ELISA were used to measure the effect of MEL on the production of pro-inflammatory cytokines. The effect of MEL on neuronal cell apoptosis was observed by flow cytometry. Compared with the saline group, MEL treatment significantly increased the density of neurons in the cerebral cortical and reduced the cerebral infarct size after MCAO (33.9 ± 8.8% vs. 15.8 ± 3.9%, P < 0.05). Meanwhile, the time for MEL-treated rats to complete the water maze task on the 11th day after MCAO was significantly shorter than that of rats in the saline group (P < 0.05). MEL treatment also prolonged the rotarod retention time on day 14 after MCAO. Immunohistochemistry analysis showed that MEL inhibited the activation of microglia and suppressed the expression of TNF-α, IL-6, and IL-1β in the brain after ischemia. MEL treatment resulted in a significant decrease in TLR4, MyD88, and NF-κB p65 levels in extracts from the ischemic cerebral cortex. Finally, MEL reduced neuronal apoptosis induced by ischemic stroke (P < 0.05). MEL treatment promotes neurological function recovery after cerebral ischemia in rats. These effects are potentially mediated through anti-inflammatory and anti-apoptotic mechanisms.

Yao X ，Kang J ，Li Y ，Zhang H ，Zhang H ，Chen E ... -  《-》

Post-stroke Constraint-induced Movement Therapy Increases Functional Recovery, Angiogenesis, and Neurogenesis with Enhanced Expression of HIF-1α and VEGF.

Constraint-Induced Movement Therapy (CIMT) is one efficient approach to improve functional recovery after ischemic stroke. The underlying molecular mechanism remains unclear. In the current study, we investigated the effects of CIMT on angiogenesis and neurogenesis. To start linking our findings to molecular mediators, we further examined the expression of Hypoxia-Inducible Factor-1α (HIF-1α), Factor Inhibiting HIF-1 (FIH-1) and Vascular Endothelial Growth Factor (VEGF). Rats were randomly assigned into three groups: a Middle Cerebral Artery Occlusion group (MCAO), a therapeutic group (CIMT+MCAO), and a sham middle cerebral artery occlusion group (Sham). Seven days after surgery, a plaster cast was placed around the unimpaired upper limb of the rats in the CIMT+MCAO group for 14 days. CIMT was performed on a horizontal ladder. Neurobehavioral consequences were evaluated using the Open-Field Test (OFT) and the Foot-Fault Test (FFT). The number of new neurons, the length of vessels as well as the expression of HIF-1α, FIH-1, and VEGF were examined before and after 14 days of CIMT. The CIMT+MCAO group showed a significant increase in the total length of microvessels and increased number of Bromodeoxyuridine+ (BrdU+)/NeuN+ double-labeled cells. These changes were correlated with an increase in HIF-1α and VEGF expressions and a decrease in FIH-1expression. FFT showed that the CIMT+MCAO group exhibited marked improvement in neurobehavioral outcome when compared to the MCAO group. Adverse effects on total activities or anxiety were not observed using open field analysis. CIMT-induced neuroprotection and functional recovery following cerebral ischemia were possibly mediated by an increase in endogenous HIF-1α and VEGF expression with subsequent neurogenesis and angiogenesis.

Li C ，Zhang B ，Zhu Y ，Li Y ，Liu P ，Gao B ，Tian S ，Du L ，Bai Y ... -  《-》

Multiple effects of 2ME2 and D609 on the cortical expression of HIF-1alpha and apoptotic genes in a middle cerebral artery occlusion-induced focal ischemia rat model.

Chen C ，Hu Q ，Yan J ，Lei J ，Qin L ，Shi X ，Luan L ，Yang L ，Wang K ，Han J ，Nanda A ，Zhou C ... -  《JOURNAL OF NEUROCHEMISTRY》

Chronic valproate treatment enhances postischemic angiogenesis and promotes functional recovery in a rat model of ischemic stroke.

Wang Z ，Tsai LK ，Munasinghe J ，Leng Y ，Fessler EB ，Chibane F ，Leeds P ，Chuang DM ... -  《-》