Ephedrine alleviates middle cerebral artery occlusion-induced neurological deficits and hippocampal neuronal damage in rats by activating PI3K/AKT signaling pathway

Vitexin Improves Cerebral ischemia‑reperfusion Injury by Attenuating Oxidative Injury and Ferroptosis via Keap1/Nrf2/HO-1signaling

Cerebral ischemia/reperfusion involves multiple pathological processes and ferroptosis played a crucial role in the disease progression. Nevertheless, whether Vitexin could ameliorate ischemia/reperfusion injury via meditate the ferroptosis still remains unknown. In this study, we established the oxygen-glucose deprivation and reoxygenation (OGD/R) neuron cell and middle cerebral artery occlusion/reperfusion (MCAO/R) rat model. The cell viability, cell apoptosis and reactive oxygen species (ROS) levels were tested by CCK-8 assay and Flow cytometry, respectively. Hematoxylin-eosin staining, TTC, TEM, immunofluorescence analysis and western blot were used to investigate the effects of Vitexin. The results demonstrated that Vitexin could enhanced the cell viability and decreased the cell apoptosis in OGD/R cell model. Meanwhile, incubation with Vitexin maintained the neuroprotective effects in OGD/R induced generation of lipid ROS and neuronal cell ferroptosis via regulated the expressions of Keap1/Nrf2/HO-1 relative protein levels. Moreover, treatment with Vitexin reversed brain infracted volume, the normal histopathology and mitochondrial function in MCAO/R rat model. Vitexin significantly decreased the Nrf2 transfer ration from nuclear to cytosol and regulated the expression of Keap1/Nrf2/HO-1 signaling both in vitro and in vivo. Nevertheless, the protective effects of Vitexin were blocked with the Nrf2 inhibitor ML385. Vitexin could protect the neuron cell and brain related with the Keap1/Nrf2/HO-1 signaling pathway. Vitexin was a useful candidate for stroke therapy and our research may provide an attractive therapeutic target for the treatment of stroke.

Valorization of rice straw, sugarcane bagasse and sweet sorghum bagasse for the production of bioethanol and phenylacetylcarbinol

Open burning of agricultural residues causes numerous complications including particulate matter pollution in the air, soil degradation, global warming and many more. Since they possess bio-conversion potential, agro-industrial residues including sugarcane bagasse (SCB), rice straw (RS), corncob (CC) and sweet sorghum bagasse (SSB) were chosen for the study. Yeast strains, Candida tropicalis, C. shehatae, Saccharomyces cerevisiae, and Kluyveromyces marxianus var. marxianus were compared for their production potential of bioethanol and phenylacetylcarbinol (PAC), an intermediate in the manufacture of crucial pharmaceuticals, namely, ephedrine, and pseudoephedrine. Among the substrates and yeasts evaluated, RS cultivated with C. tropicalis produced significantly (p ≤ 0.05) higher ethanol concentration at 15.3 g L^-1 after 24 h cultivation. The product per substrate yield (Y_eth/s) was 0.38 g g^-1 with the volumetric productivity (Q_p) of 0.64 g L^-1 h^-1 and fermentation efficiency of 73.6% based on a theoretical yield of 0.51 g ethanol/g glucose. C. tropicalis grown in RS medium produced 0.303 U mL^-1 pyruvate decarboxylase (PDC), a key enzyme that catalyzes the production of PAC, with a specific activity of 0.400 U mg^-1 protein after 24 h cultivation. This present study also compared the whole cells biomass of C. tropicalis with its partially purified PDC preparation for PAC biotransformation. The whole cells C. tropicalis PDC at 1.29 U mL^-1 produced an overall concentration of 62.3 mM PAC, which was 68.4% higher when compared to partially purified enzyme preparation. The results suggest that the valorization of lignocellulosic residues into bioethanol and PAC will not only aid in mitigating the environmental challenge posed by their surroundings but also has the potential to improve the bioeconomy.

Potential Molecular Mechanisms of Ephedra Herb in the Treatment of Nephrotic Syndrome Based on Network Pharmacology and Molecular Docking

Objective

To explore the possible mechanisms of Ephedra herb (EH) in the treatment of nephrotic syndrome (NS) by using network pharmacology and molecular docking in this study.

Methods

Active ingredients and related targets of EH were obtained from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database, and the gene names corresponding to the proteins were found through the UniProt database. Then, target genes related to NS were screened out from GeneCards, PharmGKB, and OMIM databases. Next, the intersection targets were obtained successfully through Venn diagram, which were also seen as key target genes of EH and NS. Cytoscape 3.9.0 software was used to construct the effective “active ingredient-target” network diagram, and “drug-ingredient-target-disease (D-I-T-D)” network diagram. After that, the STRING database was used to construct a protein-protein interaction (PPI) network. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment involved in the targets were performed by the DAVID database and ClueGO plugin in Cytoscape. Finally, AutoDockTools software was used for molecular docking to verify the binding strength between main active ingredients and key target proteins.

Results

A total of 22 main active ingredients such as quercetin, kaempferol, luteolin, and naringenin were obtained, which could act on 105 targets related to NS. Through PPI network, 53 core targets such as AKT1, TNF, IL6, VEGFA, and IL1B were found, which might play a crucial role in the treatment of NS. Meanwhile, these targets were significantly involved in PI3K-Akt signaling pathway, TNF signaling pathway, AGE-RAGE signaling pathway, hepatitis B, and pathways in cancer through GO and KEGG enrichment analysis. The docking results indicated that active ingredients such as kaempferol, luteolin, quercetin, and naringenin all had good binding to the target protein AKT1 or TNF. Among them, luteolin and naringenin binding with AKT1 showed the best binding energy (-6.2 kcal/mol).

Conclusion

This study indicated that the potential mechanism of EH in treating NS may be related to PI3K-Akt signaling pathway, TNF signaling pathway, and AGE-RAGE signaling pathway, which provided better approaches for exploring the mechanism in treating NS and new ideas for further in vivo and in vitro experimental verifications.

Neuroprotective Effect of Physical Activity in Ischemic Stroke: Focus on the Neurovascular Unit

Cerebral ischemia is one of the major diseases associated with death or disability among patients. To date, there is a lack of effective treatments, with the exception of thrombolytic therapy that can be administered during the acute phase of ischemic stroke. Cerebral ischemia can cause a variety of pathological changes, including microvascular basal membrane matrix, endothelial cell activation, and astrocyte adhesion, which may affect signal transduction between the microvessels and neurons. Therefore, researchers put forward the concept of neurovascular unit, including neurons, axons, astrocytes, microvasculature (including endothelial cells, basal membrane matrix, and pericyte), and oligodendrocytes. Numerous studies have demonstrated that exercise can produce protective effects in cerebral ischemia, and that exercise may protect the integrity of the blood-brain barrier, promote neovascularization, reduce neuronal apoptosis, and eventually lead to an improvement in neurological function after cerebral ischemia. In this review, we summarized the potential mechanisms on the effect of exercise on cerebral ischemia, by mainly focusing on the neurovascular unit, with the aim of providing a novel therapeutic strategy for future treatment of cerebral ischemia.

Knockdown of circular RNA tousled-like kinase 1 relieves ischemic stroke in middle cerebral artery occlusion mice and oxygen-glucose deprivation and reoxygenation-induced N2a cell damage

Ischemic stroke (IS) is an essential contributor to the neurological morbidity and mortality throughout the world. The significance of circular RNA tousled-like kinase 1 (circTLK1) in IS has been documented. This study set out to explore the mechanism of circTLK1 in IS. Middle cerebral artery occlusion (MCAO) mouse models in vivo and oxygen-glucose deprivation and reoxygenation (OGD/R) cell models in vitro were first established, followed by evaluation of infarct volume and neurological impairment, and cell viability and apoptosis. The expression patterns of circTLK1, miR-26a-5p, phosphatase and tensin homolog (PTEN), insulin-like growth factor type 1 receptor (IGF-1 R), and glucose transporter type 1 (GLUT1) were detected by RT-qPCR and Western blotting. Co-localization of circTLK1 and miR-26a-5p in N2a cells was tested by fluorescence in situ hybridization assay. The binding relationships among circTLK1, PTEN, and miR-26a-5p were verified by dual-luciferase assay and RNA pull-down. circTLK1 and PTEN were highly expressed while miR-26a-5p was under-expressed in IS models. circTLK1 knockdown decreased infarct volume and neurological impairment in MCAO mouse models and relieved OGD/R-induced neuronal injury in vitro. circTLK1 and miR-26a-5p were co-located in the N2a cell cytoplasm. circTLK1 regulated PTEN as a sponge of miR-26a-5p. PTEN positively regulated IGF-1 R and GLUT1 expressions. miR-26a-5p inhibitor annulled the repressive effects of circTLK1 silencing on OGD/R-induced neuronal injury. sh-PTEN partially annulled the effects of the miR-26a-5p inhibitor on OGD/R-induced neuronal injury. In conclusion, circTLK1 knockdown relieved IS via the miR-26a-5p/PTEN/IGF-1 R/GLUT1 axis. These results may provide a new direction to IS potential therapeutic targets.

LncRNA GAS5/miR-137 Is a Hypoxia-Responsive Axis Involved in Cardiac Arrest and Cardiopulmonary Cerebral Resuscitation

Background

Cardiac arrest/cardiopulmonary resuscitation (CA/CPR) represents one of the devastating medical emergencies and is associated with high mortality and neuro-disability. Post-cardiac arrest syndrome (PCAS) is mechanistically ascribed to acute systemic ischemia/reperfusion(I/R) injury. The lncRNA/microRNA/mRNA networks have been found to play crucial roles in the pathogenesis of the hypoxia-responsive diseases. Nonetheless, the precise molecular mechanisms by which lncRNA/miRNA/mRNA axes are involved in the astrocyte-microglia crosstalk in CA/CPR have not been fully elucidated.

Methods

We collected and purified the exosomes from the blood of CA/CPR patients and supernatant of OGD/R-stimulated astrocytes. On the basis of microarray analysis, bioinformatic study, and luciferase activity determination, we speculated that lncRNA GAS5/miR-137 is implicated in the astrocyte-microglia crosstalk under the insult of systemic I/R injury. The regulation of lncRNA GAS5/miR-137 on INPP4B was examined by cellular transfection in OGD/R cell culture and by lateral ventricle injection with miR-137 agomir in CA/CPR mice model. Flow cytometry and immunofluorescence staining were performed to detect the microglial apoptosis, M1/M2 phenotype transformation, and neuroinflammation. Neurological scoring and behavior tests were conducted in CA/CPR group, with miR-137 agomir lateral-ventricle infusion and in their controls.

Results

In all the micRNAs, miR-137 was among the top 10 micRNAs that experienced greatest changes, in both the blood of CA/CPR patients and supernatant of OGD/R-stimulated astrocytes. Bioinformatic analysis revealed that miR-137 was sponged by lncRNA GAS5, targeting INPP4B, and the result was confirmed by Luciferase activity assay. qRT-PCR and Western blotting showed that lncRNA GAS5 and INPP4B were over-expressed whereas miR-137 was downregulated in the blood of CA/CPR patients, OGD/R-stimulated astrocytes, and brain tissue of CA/CPR mice. Silencing lncRNA GAS5 suppressed INPP4B expression, but over-expression of miR-137 negatively modulated its expression. Western blotting exhibited that PI3K and Akt phosphorylation was increased when lncRNA GAS5 was silenced or miR-137 was over-expressed. However, PI3K and Akt phosphorylation was notably suppressed in the absence of miR-137, almost reversing their phosphorylation in the silencing lncRNA GAS5 group. Then we found that GAS5 siRNA or miR-137 mimic significantly increased cell viability and alleviated apoptosis after OGD/R injury. Furthermore, over-expression of miR-137 attenuated microglial apoptosis and neuroinflammation in CA/CPR mice model, exhibiting significantly better behavioral tests after CA/CPR.

Conclusion

LncRNA GAS5/miR-137 may be involved in the astrocyte-microglia communication that inhibits PI3K/Akt signaling activation via regulation of INPP4B during CA/CPR.

The protective effects of Pimavanserin against cerebral ischemia-induced brain injury

The integrity of the blood-brain barrier (BBB) is mainly maintained by the brain vascular endothelial cells and the tight junctions amongst them. Pimavanserin is a novel agent approved for the treatment of Parkinson’s disease and exerts neuroprotective properties. The present study aims to explore the possibility that Pimavanserin might be an effective agent used for the treatment of cerebral ischemia stroke. Middle cerebral artery occlusion (MCAO) was established in mice, and oxygen-glucose deprivation/reoxygenation (OGD/R) was established in brain bEND.3 endothelial cells. Mice were randomly divided into four groups: (1) Sham operation group; (2). Pimavanserin (1 mg/kg); (3). MCAO; (4). Pimavanserin+ MCAO. We found that compared to the Sham group, the elevated neurological deficit score and brain water content increased production of inflammatory factors, increased BBB permeability, and downregulated Claudin 5 expression were observed in the MCAO group and were all dramatically reversed by the administration of Pimavanserin. Brain bEND.3 endothelial cells were treated with Pimavanserin before the exposure to OGD/R. The significantly increased lactate dehydrogenase (LDH) release, declined cell viability, increased endothelial permeability, downregulated Claudin 5 and Krüppel-like factors 6 (KLF6) were observed in the OGD/R group and were all reversed by the introduction of Pimavanserin. Lastly, the effects of Pimavanserin on the expression level of Claudin 5 and endothelial permeability in OGD/R-challenged endothelial cells were both abolished by the knockdown of KLF6. Taken together, our data revealed that Pimavanserin protected against cerebral ischemia injury by regulating the BBB integrity in a KLF6-dependent manner.