ABSTRACT
Blood-brain barrier breakdown and ROS overproduction are important events during the progression of ischemic stroke aggravating brain damage. Geraniol, a natural monoterpenoid, possesses anti-apoptotic, cytoprotective, anti-oxidant, and anti-inflammatory activities. Our study aimed to investigate the effect and underlying mechanisms of geraniol in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced human brain microvascular endothelial cells (HBMECs). Apoptosis, caspase-3 activity, and cytotoxicity of HBMECs were evaluated using TUNEL, caspase-3 activity, and CCK-8 assays, respectively. The permeability of HBMECs was examined using FITC-dextran assay. Reactive oxygen species (ROS) production was measured using the fluorescent probe DCFH-DA. The protein levels of zonula occludens-1 (ZO-1), occludin, claudin-5, ß-catenin, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) were determined by western blotting. Geraniol showed no cytotoxicity in HBMECs. Geraniol and ROS scavenger N-acetylcysteine (NAC) both attenuated OGD/R-induced apoptosis and increase of caspase-3 activity and the permeability to FITC-dextran in HBMECs. Geraniol relieved OGD/R-induced ROS accumulation and decrease of expression of ZO-1, occludin, claudin-5, and ß-catenin in HBMECs. Furthermore, we found that geraniol activated Nrf2/HO-1 pathway to inhibit ROS in HBMECs. In conclusion, geraniol attenuated OGD/R-induced ROS-dependent apoptosis and permeability in HBMECs through activating the Nrf2/HO-1 pathway.
Subject(s)
Acyclic Monoterpenes , Apoptosis , Endothelial Cells , Glucose , Heme Oxygenase-1 , NF-E2-Related Factor 2 , Reactive Oxygen Species , Humans , Apoptosis/drug effects , Acyclic Monoterpenes/pharmacology , Reactive Oxygen Species/metabolism , NF-E2-Related Factor 2/metabolism , Endothelial Cells/metabolism , Endothelial Cells/drug effects , Glucose/metabolism , Heme Oxygenase-1/metabolism , Oxygen/metabolism , Brain/metabolism , Brain/blood supply , Microvessels/metabolism , Microvessels/pathology , Microvessels/drug effectsABSTRACT
Sinensetin is a polymethoxylated flavone with anti-inflammatory and anti-oxidative activities. This work aimed to explore the function and mechanism of sinensetin in oxygen and glucose deprivation/reperfusion (OGD/R)-induced neurotoxicity. The overlapping target genes of cerebral stroke and sinensetin were determined according to GeneCards and ParmMapper tools and were subjected to Gene Ontology (GO) annotations and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Human cerebral microvascular endothelial cells (HCMECs) were stimulated with OGD/R. Neurotoxicity was investigated by Cell Counting Kit-8, lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) level, qRT-PCR, and TUNEL analysis. The proteins (p38, JNK, and ERK) in mitogen-activated protein kinase (MAPK) signaling were measured using Western blotting. Total of 50 overlapping target genes of cerebral stroke and sinensetin were predicted. Pathway analysis showed they might be involved in the MAPK pathway. Sinensetin attenuated OGD/R-induced neurotoxicity by mitigating viability reduction, LDH release, ROS generation, inflammatory response, and apoptosis in HCMECs. Sinensetin weakened OGD/R-induced activation of the MAPK pathway via decreasing the phosphorylation of p38, JNK, and ERK. The pathway inhibitors mitigated the activation of the MAPK signaling, and sinensetin exacerbated this effect. The inhibitors reversed OGD/R-induced neurotoxicity in HCMECs, and sinensetin contributed to this role. Overall, sinensetin prevents OGD/R-induced neurotoxicity through decreasing the activation of MAPK pathway.
