Effects And Mechannisms Of Annexin-1 On Macrophages In Mice

Effects of exogenous Annexin-1 on lipopolysaccharide inducedproliferation and reactive oxygen species production partially throughmodulation of CRAC channels but independent of NF-κB pathwayObjective:To investigate the effects of exogenous Annexin-1 (ANXA1) onlipopolysaccharide induced proliferation,reactive oxygen species productionand calcium signal transduction in RAW264.7 macrophages.Methods:RAW264.7 macrophages were treated with or without LPS in theabsence or presence of ANXA1.The proliferation effects were detected by CellCounting Kit-8 assay.Reative oxygen species were quantified by flowcytometry and fluorescence microscopy.The intracellular [Ca²⁺]_i was analyzedby laser confocal scanning microscopy.IκBαdegradation and NF-κBtranslocation were tested by Western blot.Results:(1) Exogenous Annexin-1 inhibited LPS-induced proliferation andreactive oxygen species production in a dose dependent manner.The inhibitoryeffects of exogenous Annexin-1 on LPS-induced reactive oxygen species production changed with action time.(2) LPS evoked [Ca²⁺]_i increase throughCRAC channels,Annexin-1 suppressed LPS-induced intracellular [Ca²⁺]_iincrease in a dose dependent manner.(3) The CRAC channels were associatedwith LPS-induced proliferation and reactive oxygen species production.(4)Exogenous Annexin-1 had no effect on LPS-induced IκB degradation andNF-κB translocation.Conclusions:Exogenous Annexin-1 inhibited LPS-induced proliferation andreactive oxygen species production in RAW264.7 macrophages partiallythrough modulation of CRAC channels but independent of NF-κB pathway.