Tanshinone IIA Promotes Axonal Regeneration in Rats with Focal Cerebral Ischemia Through the Inhibition of Nogo-A/NgR1/RhoA/ROCKII/MLC Signaling.

PURPOSE: The aim of this study was to evaluate the neuroprotective effect of tanshinone IIA (TSA) on focal cerebral ischemia in rats and to investigate whether it was associated with Nogo-A/NgR1/RhoA/Rho-associated protein kinase 2 (ROCKII)/myosin light chain (MLC) signaling. METHODS: In this study, focal cerebral ischemia animal model was used. Neurological deficit scores and infarction volume were investigated to evaluate the neuroprotection of TSA. Hematoxylin-eosin staining, Nissl staining, and immunofluorescence staining were conducted to detect ischemic changes in brain tissue and changes in neurofilament protein 200 (NF200) and growth-associated protein-43 (GAP-43) expression, respectively. Western blotting and qRT-PCR analyses were used to detect the expression levels of NF200, GAP-43 and Nogo-A/NgR1/RhoA/ROCKII/MLC pathway-related signaling molecules. RESULTS: TSA treatment can improve the survival rate of rats, reduce the neurological score and infarct volume, and reduce neuron damage. In addition, TSA also increased axon length and enhanced expression of NF200 and GAP-43. Importantly, TSA significantly attenuated the expression of Nogo-A, NgR1, RhoA, ROCKII, and p-MLC, and thus inhibiting the activation of this signaling pathway. CONCLUSION: TSA promoted axonal regeneration by inhibiting the Nogo-A/NgR1/RhoA/ROCKII/MLC signaling pathway, thereby exerting neuroprotective effects in cerebral ischemia rats, which provided support for the clinical application of TSA in stroke treatment.

Astragaloside IV improves neurobehavior and promotes hippocampal neurogenesis in MCAO rats though BDNF-TrkB signaling pathway.

Astragaloside IV (AST) as the main active ingredient of Astragalus membranaceus. Clinical and laboratory-based studies have demonstrated the effects of AST on cerebral protection and angiogenesis after ischemia stroke. In addition, several reports investigated the effect of AST on proliferation of neural stem cells. The current study was aimed to evaluate the influence of AST on neurogenesis in hippocampal dentate gyrus (DG) of MCAO rats and to explore the possible mechanisms. In this study, the neurobehavioral tests (Ludmila Belayev 12-point scoring, Screen test, fore limb placing test) had been employed to investigate the effect of AST treatment against functional deficit of MCAO rats. The immunofluorescence staining, western-blot and qRT-PCR was performed to evaluate the effects of AST on proliferation, differentiation and maturity of neural stemr cells in hippocampus. Moreover, we investigated the possible mechanism of the AST treatment in promoting neurogenesis after ischemic stroke. The findings indicated that AST treatment ameliorated the neurobehavior of MCAO rats. The results indicated that AST treatment possessed the potential to improve proprioceptive sense and motor function of MCAO rats. AST treatment sustained neuronal viability and stimulates sensorimotor integration functional recovery in MCAO rats. The results suggested that AST improved neurobehavior deficit after ischemic stroke. Furthermore, AST promoted neurogenesis through upregulating the expressing of BNDF/TrkB signaling pathway. Therefore AST might be a promising therapeutic agent for ischemic stroke.

Astragaloside IV regulates the HIF/VEGF/Notch signaling pathway through miRNA-210 to promote angiogenesis after ischemic stroke.

BACKGROUND: Astragaloside IV (AS-IV) is one of the main active ingredients of Astragalusmembranaceus. Studies have shown that AS-IV stimulates angiogenesis, including cell proliferation, migration, and neovascularization. However, the relevant mechanism remains unclear. OBJECTIVE: This study aims to investigate whether AS-IV activates the HIF/VEGF/Notch signaling pathway through miRNA-210 to promote angiogenesisafter ischemic stroke. METHODS: The present study established a rat model of middle cerebral artery occlusion (MCAO) and cultured human umbilical vein endothelial cells (HUVECs) under hypoxic conditions in vitro to investigate the role of AS-IV in promoting angiogenesis and reveal its underlying mechanism. Through in vivo studies, the area of cerebral infarction was determined by 2,3,5-triPhenyltetrazolium chloride (TTC) staining. Immunofluorescence staining and RT-qPCR were used to detect the expression changes of miRNA-210 and ephrinA3 in the ischemic cortex after ischemia. Through in vitro studies, cell proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Subsequently, angiogenesis experiments were performed to observe the angiogenic ability. RESULTS: Results revealed that AS-IV significantly reduced infarct size, promoted cell proliferation and ductal formation, and inhibited the expression of the target gene ephrinA3 by increasing the expression of miRNA-210 and inducing activation of the HIF-VEGF-Notch signaling pathway. CONCLUSIONS: AS-IV promotes cerebral protection following angiogenesis and ischemic brain injury. The specific mechanism was activating the HIF/VEGF/Notch signaling pathway via miRNA-210.

Identification of key genes associated with the effect of osmotic stimuli on intervertebral discs using microarray analysis.

The present study aimed to explore the effect of osmotic stimuli on intervertebral discs (IVDs) using microarray analysis. Gene expression dataset GSE1648 was downloaded from the Gene Expression Omnibus database. There were 11 IVD cell samples in this dataset, which included 4 hyperosmotic stimuli samples, 3 hypoosmotic stimuli samples and 4 isosmotic stimuli samples. The differentially expressed genes (DEGs) in hyperosmotic or hypoosmotic IVD cells (designated DEGs-hyper or DEGs-hypo) were identified, compared with isosmotic cells, using the limma package of R software. The Database for Annotation, Visualization and Integrated Discovery was used to perform a Gene Ontology (GO) term enrichment analysis for the DEG sets. Protein-protein interaction (PPI) network and microRNA (miRNA) gene-regulatory network data for the DEG sets were obtained using the Human Protein Reference Database (HPRD) and the TargetScan database, respectively, and these networks were constructed and visualized using Cytoscape software. There was a total of 43 DEGs in DEGs-hyper and 9 in DEGs-hypo. Analysis of DEGs-hyper revealed that 41 GO terms were significantly enriched. In total, 376 pairs and 382 nodes were involved in the PPI network, and 1,314 miRNA-gene pairs and 422 nodes were contained in the miRNA-gene-regulated network. The results of the present study indicated that potential target genes (including NCOA3, SOS1, XPO1, ZBTB18, EFNB2 and SOBP) may be involved in the effect of osmotic stimuli on IVD, and the biological processes of apoptosis and cell death may be associated with the effect of high osmolality on IVD disease. The potential targets identified in the present study are more reliable than those identified by previous studies.