Hydrogen Sulfide Intervention Of Ox-LDL-induced Macrophages Expression Of Lp-PLA₂

Background and objective:As the melioration of people’s living standard and improvement of medical level,the social trend of aging is more obvious so that atherosclerosis （atherosclerosis, As）morbidity also present a rising trend. Few studies have shown that inflammationfactor plays an important role in As pathogenesis. Meanwhile, it also has veryimportant significance in the prevention of occurrence and development process ofAs.The study of hydrogen sulfide on ox-LDL induced lipoprotein-associatedphospholipase A₂macrophages expression and the effect of the signal transductionmechanism.Method:1.THP-1cells were treated with different concentrations （0,25,50,100,200μg/ml）, different time （0,6,12,24,48h）.In ox-LDL to select the optimal concentrationand time of incubation, the expression of Lp-PLA₂protein was detected byWestern-blot blotting method.2.THP-1were treated by different concentrations （25,50,100,200μ m mol/L）,different time （6,12,24,48h）. NaHS and ox-LDL （50μ g/ml） were incubated withthe selection of the best concentration and time.Then the expression of Lp-PLA₂protein was detected by Western-blot blotting method.3.Respective using p38MAPK （0.1μ mol/L）SB203580specific inhibitor, NaHSand CBS specific inhibitor PPG after incubation for2hours in accordance with thePPG+SB203580group,NaHS group, PPG group, SB203580group, blank group wereincubated with ox-LDL24h together. Then to explore the H2S on the ox-LDL inducedLp-PLA₂expression in macrophages influence mechanism, respectively, useWestern-blot blot method for detecting the expression of Lp-PLA₂protein andCayman enzyme activity assay kit for detecting LpP-PLA₂activity. 4.Pretreatment with THP-172h attached to the wall induced by phorbol ester,then use the0.1μ mol/L SB203580, NaHS and CBS specific inhibitor PPGpreincubated for2h.At last according to the PPG+SB203580group, NaHS group,PPG group, SB203580group, blank group incubated with ox-LDL for24h,respectively, detect the changes of lipid loaded form in macrophages by oil red Ostaining.Result:1.Compared with0μ g/ml group of cells, the upregulation of expression ofLp-PLA₂protein depend on ox-LDL in a dose and time, with200μ g/mlconcentration decreased obviously （p<0.01）, but the50μ g/ml,100μ g/ml,200μg/ml group had no significant difference （p>0.05）.50μ g/ml was the bestconcentration, in which48h groups of cells increased obviously （p<0.01）. However,the24h group and48h group had no significant difference （p>0.05） that24h is chosento be the best time.2.To compare the25μ mmol/L, NaHS could down-regulate the dependencywhich ox-LDL （50μ g/ml） induce the expression of Lp-PLA₂protein in macrophagesin a dose and time, with200μ mmol/L group decreased obviously （p<0.01）, but nosignificant difference between the100and200μ mmol/L groups （p>0.05）,100μmmol/L was the best concentration in the48h group, the cells increased obviously（p<0.01）.The24h and48h groups had no significant difference （p>0.05）, therefore24h is chosen to be the best time.3.SB203580, NaHS, PPG+SB203580, preincubation for2h can make ox-LDLinduced the expression of Lp-PLA₂protein and Lp-PLA₂enzyme activity.It isdecreased significantly（p<0.01） compared with ox-LDL （50μ g/ml） group.SB203580+ox-LDL group, NaHS+ox-LDL group, PPG+ox-LDL+SB203580group had nosignificant difference between the effects of enzyme activity of ox-LDL induced theexpression of Lp-PLA₂protein and Lp-PLA₂（p>0.05）.4.Using SB203580, NaHS, PPG+SB203580preincubation, can make theox-LDL induce macrophage lipid significantly decreased, compared with use ofox-LDL+PPG group and ox-LDL group. CONCLUSIONS：1.hydrogen sulfide can inhibit the Lp-PLA₂expression induced by ox-LDL andreduce the lipid deposition in THP-1;2.hydrogen sulfide can inhibit the Lp-PLA₂expression and activity induced byox-LDL relevant to p38MAPK pathway;...