Total Saponins of Panax notoginseng Activate Akt/mTOR Pathway and Exhibit Neuroprotection in vitro and in vivo against Ischemic Damage / 中国结合医学杂志

OBJECTIVE@#To reveal the neuroprotective effect and the underlying mechanisms of a mixture of the main components of Panax notoginseng saponins (TSPN) on cerebral ischemia-reperfusion injury and oxygen-glucose deprivation/reoxygenation (OGD/R) of cultured cortical neurons.@*METHODS@#The neuroprotective effect of TSPN was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, flow cytometry and live/dead cell assays. The morphology of dendrites was detected by immunofluorescence. Middle cerebral artery occlusion (MCAO) was developed in rats as a model of cerebral ischemia-reperfusion. The neuroprotective effect of TSPN was evaluated by neurological scoring, tail suspension test, 2,3,5-triphenyltetrazolium chloride (TTC) and Nissl stainings. Western blot analysis, immunohistochemistry and immunofluorescence were used to measure the changes in the Akt/mammalian target of rapamycin (mTOR) signaling pathway.@*RESULTS@#MTT showed that TSPN (50, 25 and 12.5 µ g/mL) protected cortical neurons after OGD/R treatment (P<0.01 or P<0.05). Flow cytometry and live/dead cell assays indicated that 25 µ g/mL TSPN decreased neuronal apoptosis (P<0.05), and immunofluorescence showed that 25 µ g/mL TSPN restored the dendritic morphology of damaged neurons (P<0.05). Moreover, 12.5 µ g/mL TSPN downregulated the expression of Beclin-1, Cleaved-caspase 3 and LC3B-II/LC3B-I, and upregulated the levels of phosphorylated (p)-Akt and p-mTOR (P<0.01 or P<0.05). In the MCAO model, 50 µ g/mL TSPN improved defective neurological behavior and reduced infarct volume (P<0.05). Moreover, the expression of Beclin-1 and LC3B in cerebral ischemic penumbra was downregulated after 50 µ g/mL TSPN treatment, whereas the p-mTOR level was upregulated (P<0.05 or P<0.01).@*CONCLUSION@#TSPN promoted neuronal survival and protected dendrite integrity after OGD/R and had a potential therapeutic effect by alleviating neurological deficits and reversing neuronal loss. TSPN promoted p-mTOR and inhibited Beclin-1 to alleviate ischemic damage, which may be the mechanism that underlies the neuroprotective activity of TSPN.

Silencing of circular RNA ANRIL attenuates oxygen-glucose deprivation and reoxygenation-induced injury in human brain microvascular endothelial cells by sponging miR-622

BACKGROUND: Circular RNA (circRNA) is highly expressed in the brain tissue, but its molecular mechanism in cerebral ischemia-reperfusion remains unclear. Here, we explored the role and underlying mechanisms of circRNA antisense non-coding RNA in the INK4 locus (circ_ANRIL) in oxygen-glucose deprivation and reoxygenation (OGD/R)-induced cell injury. RESULTS: The expression of circ_ANRIL in OGD/R-induced human brain microvascular endothelial cells (HBMECs) was significantly up-regulated, while that of miR-622 was significantly down-regulated. Overexpression of circ_ANRIL significantly inhibited the proliferation of OGD/R-induced HBMECs and aggravated OGD/R-induced cell apoptosis. Moreover, circ_ANRIL overexpression further increased the secretion of interleukin (IL)-1ß, IL-6, tumor necrosis factor-a, and monocyte chemoattractant protein-1 in OGD/R-treated HBMECs. The results of bioinformatics analysis and luciferase reporter assay indicated that circ_ANRIL served as an miR-622 sponge to negatively regulate the expression of miR-622 in OGD/R-treated HBMECs. Additionally, circ_ANRIL silencing exerted anti-apoptotic and anti-inflammatory effects by positively regulating the expression of miR-622. Furthermore, inhibition of OGD/R-induced activation of the nuclear factor (NF)-kB pathway by circ_ANRIL silencing was significantly reversed by treatment with miR-622 inhibitor. CONCLUSIONS: Knockdown of circ_ANRIL improved OGD/R-induced cell damage, apoptosis, and inflammatory responses by inhibiting the NF-κB pathway through sponging miR-622.

The early protective effect of NADPH on OGD/R injury of human umbilical vein endothelial cells / 天津医药

Objective To study the early protective effect of NADPH on human umbilical vein endothelial cells (HUVECs) and the expression of occludin and MMP9 induced by oxygen glucose deprivation and reoxygenation (OGD/R). Methods HUVECs were cultured and divided into blank control group, OGD/R group and OGD/R+NADPH 20 μmol/L group. The proliferation of HUVECs after treatment was detected by CCK-8 assay. The cytotoxicity was detected by LDH release assay. The morphological changes of HUVECs were observed by inverted microscope. Superoxide dismutase (SOD MDA) activity and malondialdehyde (MDA) were detected by commercially available kit. The expressions of occludin and MMP9 were detected by Western blot assay. Results Compared with the OGD/R, NADPH enhanced the cell viability significantly (P<0.05), reduced the release of LDH (P<0.05), promoted the maintance of HUVECs morphology, reduced MDA generation (P<0.05) and increased SOD activity (P<0.05). Following OGD/R,the treatment of NADPH can inhibit MMP9 level (P<0.05) and promote the recovery of occludin level (P<0.05). Conclusion NADPH can protect HUVECs from the damage induced by OGD/R by reducing oxidative stress and regulating the expressions of MMP9 and occludin.

Relationship between morphological changes of autophagy and apoptosis in PC12 cells induced by oxygen-glucose deprivation and reoxygenation / 中国病理生理杂志

[ ABSTRACT] AIM:To investigate the relationship between morphological changes of autophagy and apoptosis in the PC12 cells induced by oxygen-glucose deprivation and reoxygenation .METHODS:The PC12 cells were randomly di-vided into normal control group , oxygen-glucose deprivation and reoxygenation group , autophagy inhibitor group and auto-phagy activator group .The cells in oxygen-glucose deprivation and reoxygenation group , autophagy inhibitor group and au-tophagy activator group were exposed to reoxygenation (12 h) after 3 h of oxygen-glucose deprivation, and autophagy inhib-itor 3-methyladenine and autophagy activator rapamycin were added into the cells at the same time .Using transmission elec-tron microscope and monodansylcadaverine fluorescence staining , the morphological changes of autophagosome were ob-served.The apoptosis of the PC12 cells were analyzed by flow cytometry with Annexin V-FITC/PI staining and TUNEL method.RESULTS: Compared with normal control group , the numbers of autophagosomes and the apoptotic rates in-creased in oxygen-glucose deprivation and reoxygenation group (P<0.05).Compared with oxygen-glucose deprivation and reoxygenation group , the numbers of autophagosomes decreased obviously ( P<0.05 ) and the apoptotic rates increased markedly in autophagy inhibitor group (P<0.05).The numbers of autophagosomes increased obviously (P<0.05), the apoptotic rates decreased markedly ( P<0.05 ) , the autophagosomes became bigger in size , and autolysosomes was also found in autophagy activator group .CONCLUSION: Oxygen-glucose deprivation and reoxygenation induce autophagy in PC12 cells, and autophagy inhibits cell apoptosis to play a protective role .

Inhibition of Toll-like receptor 9 activation in microglia after oxygen-glu-cose deprivation and reoxygenation protects neurons from damage / 中国病理生理杂志

AIM:To observe the Toll-like receptor 9 (TLR9) activation in microglia BV-2 cells after oxygen-glucose deprivation and reoxygenation ( OGDR) , and its effects on neuronal apoptosis.METHODS:The BV-2 cell super-natants were collected after the corresponding treatment and added to mouse primary cortical neurons after OGDR for 4 h, followed by normal culture for 24 h.The cells were divided into normal BV-2 group, NC-siRNA group, TLR9-siRNA group, OGDR group, OGDR+NC-siRNA group, OGDR+TLR9-siRNA group and control group (without adding BV-2 cell supernatant) .The changes of the neuronal morphology were observed under an inverted phase-contrast microscope, and the neuronal apoptosis was detected by TUNEL.The protein expression of cleaved caspase-3 was detected by Western blot-ting.RESULTS:After OGDR, the axon turned thin, twisted and broken, and neuronal swelling, decrease in refraction and vacuolar degeneration were observed.The green-stained apoptotic bodies in the neurons in all groups were positive. Compared with control group, the caspase-3 protein levels in other groups were increased.Compared with the normal BV-2 group, the caspase-3 protein in OGDR group and TLR9-siRNA group was increased.Compared with OGDR+TLR9-siRNA group, the caspase-3 protein in TLR9-siRNA group and OGDR group was decreased.CONCLUSION: After OGDR, TLR9 activation in BV-2 cells induces neuronal apoptosis with the increase in caspase-3 protein level.Inhibition of TLR9 expression reduces neuronal damage.