Effects of Tripterypium Wilfordii Hook f (TWH) on sperm atozoa in the epi- didym is and splenic NK cells activity in m ale m ice w ere observed using MTT assay and silver impregnation m ethods. The results show ed t...Effects of Tripterypium Wilfordii Hook f (TWH) on sperm atozoa in the epi- didym is and splenic NK cells activity in m ale m ice w ere observed using MTT assay and silver impregnation m ethods. The results show ed that the density, viability and m otility of the epididym alsperm atozoa in the experim entalgroupstreated w ith TWH w ere m ore significantly reduced than those in the controlgroup (P< 0.01). The head sw elling, head separation from tailin the groups treated w ith TWH w ere observed. The inhibition of splenicNK cellsactivity in m iceby TWH w asdose-dependent. Inhi- bition by TⅡand TWH athigh dose on the NK cells activity w as significant (P< 0.01 and P< 0.05), w hileinhibitory effectsof TWH atinterm ediateand low doseson the NK cells activity w ere notobserved (P> 0.05). Itw as concluded thatTWH at low er antifertility dose did not significantly inhibit the splenic NK cells activity. It m ightbe usefulforevaluating thetherapeuticeffectsof TWH in futureclinicalprac- tice.展开更多
Astragali Radix(AR)is a clinically used herbal medicine with multiple immunomodulatory activities that can strengthen the activity and cytotoxicity of natural killer(NK)cells.However,owing to the complexity of its com...Astragali Radix(AR)is a clinically used herbal medicine with multiple immunomodulatory activities that can strengthen the activity and cytotoxicity of natural killer(NK)cells.However,owing to the complexity of its composition,the specific active ingredients in AR that act on NK cells are not clear yet.Cell membrane chromatography(CMC)is mainly used to screen the active ingredients in a complex system of herbal medicines.In this study,a new comprehensive two-dimensional(2D)NK-92MI CMC/C18 column/time-of-flight mass spectrometry(TOFMS)system was established to screen for potential NK cell activators.To obtain a higher column efficiency,3-mercaptopropyltrimethoxysilane-modified silica was synthesized to prepare the NK-92MI CMC column.In total,nine components in AR were screened from this system,which could be washed out from the NK-92MI/CMC column after 10 min,and they showed good affinity for NK-92MI/CMC column.Two representative active compounds of AR,isoastragaloside Ⅰ and astragaloside IV,promoted the killing effect of NK cells on K562 cells in a dose-dependent manner.It can thus suggest that isoastragaloside Ⅰ and astragaloside Ⅳ are the main immunomodulatory components of AR.This comprehensive 2D NK-92MI CMC analytical system is a practical method for screening immune cell activators from other herbal medicines with immunomodulatory effects.展开更多
One of the hallmarks of live cells is the asymmetric distribution of lipids across their plasma membrane.Changes in this asymmetry due to lipid"scrambling"result in phosphatidylserine exposure at the cell su...One of the hallmarks of live cells is the asymmetric distribution of lipids across their plasma membrane.Changes in this asymmetry due to lipid"scrambling"result in phosphatidylserine exposure at the cell surface that is detected by annexin V staining.This alteration is observed during cell death processes such as apoptosis,and during physiological responses such as platelet degranulation and membrane repair.Previous studies have shown that activation of NK cells is accompanied by exposure of phosphatidylserine at the cell surface.While this response was thought to be indicative of ongoing NK cell death,it may also reflect the regulation of NK cell activation in the absence of cell death.Herein,we found that NK cell activation was accompanied by rapid phosphatidylserine exposure to an extent proportional to the degree of NK cell activation.Through enforced expression of a lipid scramblase,we provided evidence that activation-induced lipid scrambling in NK cells is reversible and does not lead to cell death.In contrast,lipid scrambling attenuates NKcell activation.This response was accompanied by reduced cell surface expression of activating receptors such as 2B4,and by loss of binding of Src family protein tyrosine kinases Fyn and Lck to the inner leaflet of the plasma membrane.Hence,lipid scrambling during NK cell activation is,at least in part,a physiological response that reduces the NK cell activation level.This effect is due to the ability of lipid scrambling to alter the distribution of membrane-associated receptors and kinases required for NK cell activation.展开更多
文摘Effects of Tripterypium Wilfordii Hook f (TWH) on sperm atozoa in the epi- didym is and splenic NK cells activity in m ale m ice w ere observed using MTT assay and silver impregnation m ethods. The results show ed that the density, viability and m otility of the epididym alsperm atozoa in the experim entalgroupstreated w ith TWH w ere m ore significantly reduced than those in the controlgroup (P< 0.01). The head sw elling, head separation from tailin the groups treated w ith TWH w ere observed. The inhibition of splenicNK cellsactivity in m iceby TWH w asdose-dependent. Inhi- bition by TⅡand TWH athigh dose on the NK cells activity w as significant (P< 0.01 and P< 0.05), w hileinhibitory effectsof TWH atinterm ediateand low doseson the NK cells activity w ere notobserved (P> 0.05). Itw as concluded thatTWH at low er antifertility dose did not significantly inhibit the splenic NK cells activity. It m ightbe usefulforevaluating thetherapeuticeffectsof TWH in futureclinicalprac- tice.
基金supported by the National Natural Science Foundation of China(Grant Nos.:82073814,81973291,82122066,and 82003909)the Rising-Star Program of Shanghai Science and Technology Committee(Grant No.:19QA1411500).
文摘Astragali Radix(AR)is a clinically used herbal medicine with multiple immunomodulatory activities that can strengthen the activity and cytotoxicity of natural killer(NK)cells.However,owing to the complexity of its composition,the specific active ingredients in AR that act on NK cells are not clear yet.Cell membrane chromatography(CMC)is mainly used to screen the active ingredients in a complex system of herbal medicines.In this study,a new comprehensive two-dimensional(2D)NK-92MI CMC/C18 column/time-of-flight mass spectrometry(TOFMS)system was established to screen for potential NK cell activators.To obtain a higher column efficiency,3-mercaptopropyltrimethoxysilane-modified silica was synthesized to prepare the NK-92MI CMC column.In total,nine components in AR were screened from this system,which could be washed out from the NK-92MI/CMC column after 10 min,and they showed good affinity for NK-92MI/CMC column.Two representative active compounds of AR,isoastragaloside Ⅰ and astragaloside IV,promoted the killing effect of NK cells on K562 cells in a dose-dependent manner.It can thus suggest that isoastragaloside Ⅰ and astragaloside Ⅳ are the main immunomodulatory components of AR.This comprehensive 2D NK-92MI CMC analytical system is a practical method for screening immune cell activators from other herbal medicines with immunomodulatory effects.
基金supported by grants from the Canadian Institutes of Health Research(CIHR)MT-14429,MOP-82906,and FDN-143338 to A.V.NSFC-31870863 from the National Natural Science Foundation of China to N.W.supported by a Postdoctoral Fellowship from Fonds de recherche du Quebec Santr(FRQS)。
文摘One of the hallmarks of live cells is the asymmetric distribution of lipids across their plasma membrane.Changes in this asymmetry due to lipid"scrambling"result in phosphatidylserine exposure at the cell surface that is detected by annexin V staining.This alteration is observed during cell death processes such as apoptosis,and during physiological responses such as platelet degranulation and membrane repair.Previous studies have shown that activation of NK cells is accompanied by exposure of phosphatidylserine at the cell surface.While this response was thought to be indicative of ongoing NK cell death,it may also reflect the regulation of NK cell activation in the absence of cell death.Herein,we found that NK cell activation was accompanied by rapid phosphatidylserine exposure to an extent proportional to the degree of NK cell activation.Through enforced expression of a lipid scramblase,we provided evidence that activation-induced lipid scrambling in NK cells is reversible and does not lead to cell death.In contrast,lipid scrambling attenuates NKcell activation.This response was accompanied by reduced cell surface expression of activating receptors such as 2B4,and by loss of binding of Src family protein tyrosine kinases Fyn and Lck to the inner leaflet of the plasma membrane.Hence,lipid scrambling during NK cell activation is,at least in part,a physiological response that reduces the NK cell activation level.This effect is due to the ability of lipid scrambling to alter the distribution of membrane-associated receptors and kinases required for NK cell activation.