Proteomic Analysis Of Serum Proteins Adsorbed On Different Dialysis Membranes

Objective: Hemodialysis is one of the most important therapies for patients with uremia,and the dialysis membrane is the predominant factor that impacts the efficiency of dialysis.Here,we investigated protein adsorption on different membranes in order to understand the biochemical reaction of the surface of the dialysis membrane and to provide a basis for improving dialysis materials.Methods: Two cases treated with Polyflux14 L low-flux dialyzer and FX8 low-flux dialyzer during two continuous therapies were selected.Two cases treated with Polyflux14 L low-flux dialyzer and Polyflux140 H high-flux dialyzer during two continuous therapies were chosen.They were divided into material-variance group(Polyflux14L,FX8)and flux-variance group(Polyflux14L,Polyflux140H),respectively.Dialyzers(N=8)were infused with ionic liquid(C12Im-Cl)to elute adsorbed proteins.The chemical labeling liquid was utilized to mark the peptides then mix the samples.The pre-dialysis and post-dialysis serum proteins were obtained then labeled the digested peptides with chemical labeling liquid.Liquid chromatography-tandem mass spectrometry(LC-MS/MS)was used to identify the proteins.The molecular information and function of detected proteins were analyzed by bioinformatic analysis.Results: According to the ratio(light labeling/heavy labeling),the eluted proteins were divided into three groups: significantly higher,significantly lower,and no significant differences with a ratio of >2,<0.5,and 0.5-2,respectively.1.Amount of absorbed proteins of different membranes: The material-variance group: Compared with Polyflux14 L,there were 45 up-regulated proteins and 253 down-regulated proteins retained by Fx8.The flux-variance group: Compared with Polyflux140 H,there were284 up-regulated proteins and 174 down-regulated proteins retained by Polyflux14 L.2.The distribution of p I and MW: There were no significant differences in p I values and MW between the dialyzers of material-variance group(P>0.05).The flux-variance group: the proteins with p I>7.5 and MW<40k Da tended to deposit on Polyflux140H(p I:46% vs.29%,c2=11.293,P=0.001,MW: 71% vs.57%,c2=8.133,P=0.004).The proteins with p I ranged from 5.5 to 7.5 and MW ranged from 40 k Da to 100 k Da tended to deposit on Polyflux14L(p I: 41% vs.30%,c2=4.906,P=0.027,MW: 33% vs.22%,c2=5.978,P=0.014).The types of decreased serum proteins adsorbed by different dialysis membrane surfaces were different.In material-variance group,MASP1 and GAL-1 were observed on the membrane of PAES/PVP/PA uniquely,and HSP70 was observed on the membrane of PS/PVP.In flux-variance group,?2-MG was detected on the high-flux membrane uniquely.Conclusion: The quantity of adsorbed proteins,p I values,MW and the protein types were different in different dialysis membranes.According to the functions of proteins,the significantly different proteins adsorbed by different membranes were related to immune system,stress response and inflammatory reaction.