Proteomics Analysis Of Normal Renal Tissue And Classification Of Renal Amyloidosis

Backgroud:Mass spectrometry-based proteomics techniques have become an important means of diagnosing and studing kidney disease.Establishing normal glomerular and renal medulla protein expression profile by mass spectrometry proteomics is important for understanding glomerular and renal medulla protein composition,biological process,pathological mechanisms,and finding biomarkers for kidney diseases.Laser microdissection and mass spectrometry(LMD/MS)can not only be used to obtain normal glomeruli and renal medullary tissue protein expression profile,but also to explore kidney diseases.In recent years,LMD/MS has been applied in the field of renal amyloidosis classification,it can detect new amyloidosis subtype,as well as detecting amino acid sequence mutation of amyloid proteins,LMD/MS could be useful in the clinical diagnosis of amyloidosis and guiding treatment.Methods:In the first part,we collected 6 cases of normal adjacent renal tissue by pathological examination,LMD/MS was used to obtain glomerular and renal medullary tissue and establish protein expression profile.In the second part of the work,we analyzed 45 cases of AL amyloidosis patients admitted during last 5 years,analyzed their clinical manifestations and pathological typing,then selected 20 cases with inconclusive renal biopsy immunofluorescence classification,and put them through immunohistochemistry and mass spectrometry classification.In the third part,9 cases of unknown amyloidosis subtyping were analyzed by LMD/MS,meanwhile SAA protein was screened for amino acid sequence mutation.Results:In the first part,1373 and 1673 proteins were detected in glomeruli and renal medulla respectively.Compared with previous studies,472 glomeruli proteins were uniquely detected in our study.Normal human renal medullary proteome was established.Bioinfonnatics analysis gave more information on protein component and function.In the second part of the work,we found both immunohistochemistry and LMD/MS technology were efficient in amyloid subtyping,LMD/MS was even better.In the third part of the work,9 difficult cases of amyloidosis were analyzed by LMD/MS analysis,four cases of AL type amyloidosis,one case of Apo A IV type amyloidosis,one case of AA type amyloidosis and one case of AH type amyloidosis were confirmed.Both SAA1 and SAA2 proteins were detected in AA amyloid patient renal tissue,no amino acid sequence mutation was detected.Conclusion:In this study,the proteomics and bioinformatics information of glomeruli and renal medullary tissue was obtained by LMD/MS,normal renal medullary protein expression profile was obtained.Comparison of immunohistochemistry and LMD/MS showed that LMD/MS was a better diagnostic method.The last part of the work showed LMD/MS technology is a practical and effective method for subtyping of difficult or rare amyloidosis cases..