Proteome Analysis of Glomerular Formalin-Fixed Paraffin Embedded Kidney Samples Distinguishes Diabetic Nephropathy from Controls
Year: 2021
Type: article
Study design: Observational Study
Abstract: Background: Liquid chromatography tandem-mass spectrometry (LC-MS/MS) is a sensitive technique for in depth proteome analysis but its usage as a diagnostic tool for kidney diseases is still in development. We investigated the potential use of LC-MS/MS in diagnosing diabetic nephropathy (DN) in renal biopsies. Methods: Biopsies from 10 DN patients without renal comorbidity were compared to 10 pretransplantation biopsies. Glomerular cross-sections were collected using laser capture microdissection and tryptic peptides were analysed using LC-MS/MS. Resulting spectra were used for protein identification and further analysis. Results: Based on all identified proteins, DN patients and controls clustered separately (Figure 1). Moreover, we identified 47 significant differentially expressed proteins after adjusting for multiple testing. In DN proteins with increased expression included collagens IV, VI and XVIII, fibronectin, vitronectin, fibulin, complement component C3, C4 and C9, complement factor H, clusterin, fibrinogen and apolipoprotein E. Proteins with decreased expression in DN included nephrin, chloride intracellular channel protein 5, Rab GDP dissociation inhibitor alpha and complement receptor 1.Figure 1.: Principal component analysis and clustering on glomerular samples of diabetic nephropathy patients and controls. Principal component analysis and hierarchical clustering on Euclidean distances and complete linkage using the rlog transformed unique peptide counts from microdissected glomerular tissue samples. A major part of the variance between groups can be attributed to differences between diabetic nephropathy and controls. Clustering of the samples within groups and separation of samples between groups can be observed. DN = diabetic nephropathy.Conclusions: Proteins identified by LC-MS/MS from glomerular cross-sections successfully distinguished kidney biopsies with DN from normal kidneys. Moreover, a set of differentially expressed proteins were identified, most of which were previously suggested to play a role in the development of DN, which further emphasizes the applicability of LC-MS/MS as a diagnostic tool. Funding: Private Foundation Support, Government Support - Non-U.S.
Language: English
Subfield: Nephrology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W4396993328