ABSTRACT
BACKGROUND: As a substrate of apoER2, Reelin has been verified to exert neuroprotection by preventing memory impairment. Pinocembrin is the most abundant natural flavonoid found in propolis, and it has been used to exert neuroprotection, blood-brain barrier protection, anti-oxidation, and inflammation diminishing, both in vitro and in vivo. However, the roles and molecular mechanisms of pinocembrin in neurobehavioral outcomes and neuronal repair after vascular dementia are still under investigation. PURPOSE: To explore the role of pinocembrin in the involvement of the Reelin-dab1 signaling pathway in improving memory impairment, both in cell culture and animals experiments. MATERIAL AND METHODS: Behavioral tests were conducted on day 48 to confirm the protection of pinocembrin against cognitive impairment. Cell and molecular biology experiments demonstrated that the Reelin-dab1 pathway mediates the underlying mechanism of cognitive improvement by pinocembrin. RESULTS: It was showed that pinocembrin alleviated learning and memory deficits induced by vascular dementia, by inducing the expression of Reelin, apoER2, and p-dab1 in the hippocampus. The expression of Reelin and p-dab1 was both inhibited following Reelin RNA interference in SH-SY5Y prior to oxygen glucose deprivation (OGD) injury, suggesting that Reelin played a core role in pinocembrin's effect on OGD in vitro. CONCLUSION: Pinocembrin improves the cognition via the Reelin-dab1 signaling pathway.
Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Cell Adhesion Molecules, Neuronal/metabolism , Cognitive Dysfunction/drug therapy , Dementia, Vascular/drug therapy , Extracellular Matrix Proteins/metabolism , Flavanones/pharmacology , Nerve Tissue Proteins/metabolism , Serine Endopeptidases/metabolism , Adaptor Proteins, Signal Transducing/antagonists & inhibitors , Adaptor Proteins, Signal Transducing/genetics , Animals , Behavior, Animal/drug effects , Cell Adhesion Molecules, Neuronal/antagonists & inhibitors , Cell Adhesion Molecules, Neuronal/genetics , Cell Line, Tumor , Cell Survival/drug effects , Cells, Cultured , Cognitive Dysfunction/metabolism , Cognitive Dysfunction/pathology , Dementia, Vascular/metabolism , Dementia, Vascular/pathology , Dose-Response Relationship, Drug , Extracellular Matrix Proteins/antagonists & inhibitors , Extracellular Matrix Proteins/genetics , Humans , Male , Nerve Tissue Proteins/antagonists & inhibitors , Nerve Tissue Proteins/genetics , RNA, Small Interfering/pharmacology , Rats , Rats, Wistar , Reelin Protein , Serine Endopeptidases/genetics , Signal Transduction/drug effectsABSTRACT
Salvianolic acid A (SAA) is a water-soluble component from the root of Salvia Miltiorrhiza Bge, a traditional Chinese medicine, which has been used for the treatment of cerebrovascular diseases for centuries. The present study aimed to determine the brain protective effects of SAA against cerebral ischemia reperfusion injury in rats, and to figure out whether SAA could protect the blood brain barrier (BBB) through matrix metallopeptidase 9 (MMP-9) inhibition. A focal cerebral ischemia reperfusion model was induced by middle cerebral artery occlusion (MCAO) for 1.5-h followed by 24-h reperfusion. SAA was administered intravenously at doses of 5, 10, and 20 mg·kg-1. SAA significantly reduced the infarct volumes and neurological deficit scores. Immunohistochemical analyses showed that SAA treatments could also improve the morphology of neurons in hippocampus CA1 and CA3 regions and increase the number of neurons. Western blotting analyses showed that SAA downregulated the levels of MMP-9 and upregulated the levels of tissue inhibitor of metalloproteinase 1 (TIMP-1) to attenuate BBB injury. SAA treatment significantly prevented MMP-9-induced degradation of ZO-1, claudin-5 and occludin proteins. SAA also prevented cerebral NF-κB p65 activation and reduced inflammation response. Our results suggested that SAA could be a promising agent to attenuate cerebral ischemia reperfusion injury through MMP-9 inhibition and anti-inflammation activities.
Subject(s)
Anti-Inflammatory Agents/administration & dosage , Blood-Brain Barrier/enzymology , Brain Ischemia/drug therapy , Caffeic Acids/administration & dosage , Drugs, Chinese Herbal/administration & dosage , Lactates/administration & dosage , Matrix Metalloproteinase 9/metabolism , Reperfusion Injury/prevention & control , Salvia miltiorrhiza/chemistry , Animals , Blood-Brain Barrier/drug effects , Blood-Brain Barrier/immunology , Brain , Brain Ischemia/enzymology , Brain Ischemia/genetics , Humans , Male , Matrix Metalloproteinase 9/genetics , Rats , Rats, Sprague-Dawley , Reperfusion Injury/enzymology , Reperfusion Injury/genetics , Reperfusion Injury/immunology , Tissue Inhibitor of Metalloproteinase-1/genetics , Tissue Inhibitor of Metalloproteinase-1/metabolism , Transcription Factor RelA/genetics , Transcription Factor RelA/immunologyABSTRACT
The aim of present study is to investigate the protective effects and mechanism of salvianolic acid A (SAA) on cerebral ischemia-reperfusion injury in rats. The model was established with middle cerebral artery occlusion and reperfusion (MCAO/R) with ischemia for 1.5 h and reperfusion for 24 h in adult male SD rats. After the behavior assessment, TTC assay was used to calculate the infarct volume of rat brain; the distribution of Nrf2 in nuclear and cytoplasm and expression of HO-1 were detected by Western blot. The PC12 cells injury model was established with oxygen-glucose deprivation for 6 h and reintroduction for 24 h. Cell viability was determined with MTT assay, and the expression of Nrf2 and HO-1 were detected through immunofluorescence staining. The mechanisms were investigated in PC12 cells with Nrf2 knocking down by siRNA. SAA (10 and 20 mg·kg(-1)) significantly reduced the neuronal damage in MCAO/R model, and SAA(0.5 and 5 µmol·L(-1)) increased cell viability in PC12 cells injury model. Meanwhile, the nuclear translocation of Nrf-2 and the expression of HO-1 were increased in PC12 cell and rats brain. SAA exhibited anti-cerebral ischemia- reperfusion effects. The mechanism may be related to activation of Nrf2/HO-1 signaling pathway, which promotes the synthesis and nuclear translocation of Nrf2 to enhance the expression of the antioxidant protein HO-1.