Preliminary Analysis Of Urinary Proteomics In Children With Steroid-resistant And Steroid-sensitive Idiopathic Nephrotic Syndrome

Objective:To screen and identify the proteins markers in the urine of children with steroid-sensitive and steroid-resistant idiopathic nephrotic syndrome,which might serve as the potential diagnostic and prognostic markers for steroid-resistant nephrotic syndrome(SRNS)and steroid-sensitive nephritic syndrome(SSNS).Methods:Urine samples were collected from children with SSNS, SRNS before and after steroid therapy,and healthy children(5 children in each group).The total proteins were extracted and separated by immobilized pH gradient(IPG)based two-dimensional gel electrophoresis(2-DE).The silver-stained 2-DE gels were scanned with digital Image Scanner and analyzed with Image Master 2-DE Elite 3.01 software.Peptide mass fingerprint(PMF)of differential protein spots was obtained with matrix assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF-MS)and was searched in NCBI protein database by Mascot software,then differential expression proteins were identified and analyzed.Results:Mean protein spots of the 2-DE gels were 206±8,204±5, 55±5 and 105±7 in children with SRNS,SSNS before or after steroid treatment,and healthy children,respectively.In the urine samples,66 protein spots were identified to have differential expression between SRNS and SSNS before steroid therapy.Among the 66 protein spots,24 spots and 27 spots only occurred in SRNS and SSNS before steroid therapy group respectively.Comparison between SSNS group after steroid therapy and healthy control group,75 different protein spots were identified to have differential expression,and 11 protein spots only occurred in SSNS after steroid therapy.18 protein spots speciallly expressed in each group were chose and analyzed by matrix-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF -MS),and 9 types proteins were identified:①Human Serum Albumin Complexed To An Anti-Apoptotic Ligand Directed Against Bcl- xLAnd Bcl-2,②Human Serum Albumin precursor;③Ig kappa chain NIG26 precursor,④alpha-1-antitrypsin,⑤Chain A,Structure Of The B20-4 Fab,A Phage Derived Fab Fragment,In Complex With Vegf alpha-l-antitrypsin,⑥Human Serum Transferrin,⑦A broadly Neutralizing anti-HIV-1 Antibody in Complex with a Peptide Mimotope,⑧Map 19 and⑨Complex-forming glycoprotein HC.Conclusion:There were 9 differential types protein expressed in SRNS and SSNS.Human Serum Albumin Complexed To An AntiApoptotic Ligand Directed Against Bcl- xL And Bcl-2 and Human Serum Albumin precursor in the urine might be the biomarkers of SRNS,Alpha-1-antitrypsin and Human Serum Transferrin might be the biomarkers of SSNS,and Complex-forming glycoprotein HC and Map 19 may be as the potential prognosis targets for NS.