Extracellular vesicles(EVs)from mesenchymal stromal cells(MSCs)have previously been shown to protect against brain injury caused by hypoxia-ischemia(HI).The neuroprotective effects have been found to relate to the ant...Extracellular vesicles(EVs)from mesenchymal stromal cells(MSCs)have previously been shown to protect against brain injury caused by hypoxia-ischemia(HI).The neuroprotective effects have been found to relate to the anti-inflammatory effects of EVs.However,the underlying mechanisms have not previously been determined.In this study,we induced oxygen-glucose deprivation in BV-2 cells(a microglia cell line),which mimics HI in vitro,and found that treatment with MSCs-EVs increased the cell viability.The treatment was also found to reduce the expression of pro-inflammatory cytokines,induce the polarization of microglia towards the M2 phenotype,and suppress the phosphorylation of selective signal transducer and activator of transcription 3(STAT3)in the microglia.These results were also obtained in vivo using neonatal mice with induced HI.We investigated the potential role of miR-21a-5p in mediating these effects,as it is the most highly expressed miRNA in MSCs-EVs and interacts with the STAT3 pathway.We found that treatment with MSCs-EVs increased the levels of miR-21a-5p in BV-2 cells,which had been lowered following oxygen-glucose deprivation.When the level of miR-21a-5p in the MSCs-EVs was reduced,the effects on microglial polarization and STAT3 phosphorylation were reduced,for both the in vitro and in vivo HI models.These results indicate that MSCs-EVs attenuate HI brain injury in neonatal mice by shuttling miR-21a-5p,which induces microglial M2 polarization by targeting STAT3.展开更多
AIMTo compare the effectiveness and safety between bevacizumab and ranibizumab in the treatment of age-related macular degeneration (AMD) through a systematic review and meta-analysis.
To recycle the returned alloy effectively, effects of returns proportion on alloy composition, microstructure and compression properties of superalloy GH4169 were studied by means of scanning electron microscopy(SEM),...To recycle the returned alloy effectively, effects of returns proportion on alloy composition, microstructure and compression properties of superalloy GH4169 were studied by means of scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and thermal-mechanical simulator. The results show that returns addition has no significant effect on the main alloy elements content and the principle precipitates, but increases the volume fraction of Al_2O_3 inclusions, resulting in the increase of oxygen level of GH4169 alloy. Returns addition does not change the elastic and plastic deformation process at room temperature or at 1,150 °C, but high returns proportion GH4169 alloy shows improved compression strength and yield strength. The alloy with 100% returns shows a maximum compression strength 1,153.45 MPa at room temperature, while the alloy with 80% returns has a maximum value 69.3 MPa at 1,150 °C. Returns addition increases fluctuation range and reduces the stability of yield strength and compression strength of GH4169 alloy at room temperature. It is noted that the volume fraction and the size of Al_2O_3, and the fraction of Laves phase reach their maximum values in the GH4169 alloy with 60% returns, which exhibits maximum yield strength of 516.65 MPa at room temperature and 62.17 MPa at 1,150 °C.展开更多
基金supported by the National Natural Science Foundation of China,Nos.81873768,82072535,81671213(to ZW),81770436(to WQC)the National Key Project of Chronic Non-Communicable Disease of China,No.2016YFC1300403(to WQC).
文摘Extracellular vesicles(EVs)from mesenchymal stromal cells(MSCs)have previously been shown to protect against brain injury caused by hypoxia-ischemia(HI).The neuroprotective effects have been found to relate to the anti-inflammatory effects of EVs.However,the underlying mechanisms have not previously been determined.In this study,we induced oxygen-glucose deprivation in BV-2 cells(a microglia cell line),which mimics HI in vitro,and found that treatment with MSCs-EVs increased the cell viability.The treatment was also found to reduce the expression of pro-inflammatory cytokines,induce the polarization of microglia towards the M2 phenotype,and suppress the phosphorylation of selective signal transducer and activator of transcription 3(STAT3)in the microglia.These results were also obtained in vivo using neonatal mice with induced HI.We investigated the potential role of miR-21a-5p in mediating these effects,as it is the most highly expressed miRNA in MSCs-EVs and interacts with the STAT3 pathway.We found that treatment with MSCs-EVs increased the levels of miR-21a-5p in BV-2 cells,which had been lowered following oxygen-glucose deprivation.When the level of miR-21a-5p in the MSCs-EVs was reduced,the effects on microglial polarization and STAT3 phosphorylation were reduced,for both the in vitro and in vivo HI models.These results indicate that MSCs-EVs attenuate HI brain injury in neonatal mice by shuttling miR-21a-5p,which induces microglial M2 polarization by targeting STAT3.
文摘AIMTo compare the effectiveness and safety between bevacizumab and ranibizumab in the treatment of age-related macular degeneration (AMD) through a systematic review and meta-analysis.
基金financially supported by the National Key Basic Research Program of China under grant No.2012CB722806
文摘To recycle the returned alloy effectively, effects of returns proportion on alloy composition, microstructure and compression properties of superalloy GH4169 were studied by means of scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS) and thermal-mechanical simulator. The results show that returns addition has no significant effect on the main alloy elements content and the principle precipitates, but increases the volume fraction of Al_2O_3 inclusions, resulting in the increase of oxygen level of GH4169 alloy. Returns addition does not change the elastic and plastic deformation process at room temperature or at 1,150 °C, but high returns proportion GH4169 alloy shows improved compression strength and yield strength. The alloy with 100% returns shows a maximum compression strength 1,153.45 MPa at room temperature, while the alloy with 80% returns has a maximum value 69.3 MPa at 1,150 °C. Returns addition increases fluctuation range and reduces the stability of yield strength and compression strength of GH4169 alloy at room temperature. It is noted that the volume fraction and the size of Al_2O_3, and the fraction of Laves phase reach their maximum values in the GH4169 alloy with 60% returns, which exhibits maximum yield strength of 516.65 MPa at room temperature and 62.17 MPa at 1,150 °C.
