Effects Of Caveolin-1in Human Umbilical Vein Endothelial Cell Induced By The Serum Of ESRD Patientts On Maintenance Hemodialysis

Background and objective It is an increased tendency that the ESRDpatients on maintenance hemodialysis (MHD) are liable to develop thecardiovascular disease resulting from accelerated atherosclerosis. Inendothelial cells (ECs), caveolin-1and caveolae play a proatherogenic role.The aim of our study was to assess the changes of caveolin-1in ECsinduced by the serum of hemodialysis patients and to explore thesignificance of caveolin-1alteration, plasma concentrations of lipid profileand the link between them.Method Blood samples were taken from ESRD patients beforemaintenance hemodialysis served as MHD1group and after maintenancehemodialysis served as MHD2group and from healthy volunteers atmorning before breakfast served as H group. Lipid parameters weredetermined and Human umbilical vein endothelial cells (HUVECs) wereexposed to serum samples. The inductive concentration and the inductivetime of serum samples were determined by MTT assay. Oil-red staining method was to determine whether lipid droplet appeared. Changes ofcaveolin-1in HUVECs were studied by RT-PCR and cellimmunofluorescence.Result The levels of TC in the MHD1group and MHD2group werelower than the H group, and the levels of TC in the MHD2group washigher than in the MHD1group, but there were no significant differencesbetween them(p>0.05).Although there were no significant differences ofthe parameters of TG and HDL-C between the MHD1group and MHD2group, there were increased concentrations of TG (p<0.01) and decreasedconcentrations of HDL-C(p<0.05) both in the MHD1and MHD2group,compared to the H group. LDL-C levels in MHD1group were significantlylower than in the H group and MHD2group (p<0.05). The lipid droplets inHUVECs appeared in all the groups, there was no significant differencebetween them. Compared to MHD1group, the mRNA and protein levels ofcaveoiln-1in HUVECs improved notably in MHD2group and H group(p<0.05).Corelation analysis: The LDL-C values in serum correlated positivelyand linearly with the values of the caveoiln-1mRNA expressions(r=0.776, p<0.01). We did not find a relationship between them thatcontains TC values，TG values and HDL-C values and the values of thecaveoiln-1mRNA expressions.Conclusion Hemodialysis can not improve dyslipidemia in ESRD patients, while it can make caveolin-1in ECs improved. The LDL-C levelsin serum positively correlated with mRNA levels of caveoiln-1, so bothLDL-C levels in serum and caveolin-1in ECs may be involved inatherosclerosis in ESRD patients on maintenance hemodialysis together.