Role Of HSP22 In Ox-LDL-induced Endothelial Dysfunction And Its Related Protection Mechanisms

Objective: To observed the effect of HSP22 and PPAR? agonist pioglitazone in human umbilical vein endothelial cells(HUVECs) dealed with the oxidation of low density lipoprotein(ox-LDL), and to investigate the potential role in endothelial function and monocyte adhesion and the possible molecular mechanism.Method:(1)Different concentrations of ox-LDL were used to intervene HUVECs for 24 h, Western blot to detecte eNOS, ICAM1, HSP22, PPAR? protein expression to observed ox-LDL dose effect.(2) The experiment had three groups: HSP22 shRNA plasmid transfection group, HSP22 overexpression plasmid transfection group, the empty plasmid transfection control group(con group) were transfected into HUVECs 48 h, then added 80 ug / m L ox-LDL in HUVECs for 24 h, detect ditto marks(1), using fluorescence microscopy and Microplate reader to detect monocytes adhesion situation.(3) PBS control group, different concentrations(0?M/L,1?M/L,10?M/L,30?M/L)of PPAR? agonist pioglitazone were used to pretreat HUVECs for 12 h, then carried out 80 ug / m L ox-LDL intervention HUVECs for 24 h, Western blot to detecte HSP22 protein expression and qPCR to detect HSP22 m RNA.It may help to understand the relationship between HSP22 and PPAR?.(4)With HSP22 overexpressing plasmid transfected into HUVECs for 48 h, respectively PPAR? inhibitors T0070907 10 nM/L,or PBS pretreatment for 12 h, then add 80 ug / mL ox-LDL to intervene HUVECs for 24 h, Western blot to detecte HUVECs eNOS, ICAM1 protein expression, fluorescence microscopy and microplate reader to detect monocyte adhesion situation.Result:1.ox-LDL appropriate intervention concentrations: With increasing concentration of ox-LDL, eNOS protein expression significantly decreased compared with the untreated group(P<0.05), the expression of HSP22 protein reached to the highest(P<0.05), ICAM1 and PPAR? expression significantly increased(P<0.05). 2. The effect of HSP22 protein on endothelial function and monocyte adhesion: Under the same conditions of the intervention, inflammatory cytokines ICAM1 in HSP22 overexpression group was significantly lower than the empty plasmid group and HSP22 shRNA group(P <0.05), eNOS protein was significantly higher than the other two groups(P <0.05), monocyte adhesion was significantly lower than the other two groups(P <0.05),PPAR? protein and mRNA in each group had no significant change(P >0.05). 3, the relationship between HSP22 and PPAR? in HUVEC: With increasing concentration of PPAR? agonists pioglitazone, ICAM1 expression decreased compared with the control group(P <0.05), eNOS expression increased(P <0.05), HSP22 expression decreased(P <0.05).4, The effect on endothelial function and monocytes adhesion and its possible mechanisms of HSP22 in HUVECs intervented by ox-LDL treatment:on the same conditions, in HSP22 overexpression +PPAR? inhibitor group, inflammatory cytokines ICAM1 expression and monocyte adhesion were higher than HSP22 overexpression group.But they were not statistically significant(P>0.05). eNOS protein was not observed significant changes. Conclusion:1.ox-LDL can damage HUVECs and induce HSP22, PPAR? expression,increase ICAM1 expression,and reduce expression of eNOS.2.HSP22 suppresses inflammatory cytokine ICAM1 production and monocytes adhesion and promotes the expression of eNOS to improve endothelial function in HUVECs induced by ox-LDL. but it has no significant effect on PPAR? expression.3.PPAR? agonist pioglitazone inhibits inflammatory cytokine ICAM1 expression in HUVEC induced by ox-LDL and promote eNOS expression,but it has no significant effect on the expression of HSP22.4.the protective effect of HSP22 on endothelial cell dysfunction induced by ox-LDL may has little relation with the PPAR? anti-inflammatory pathway.