Aberrant Glycosylation of Lumican in Aortic Valve Stenosis Revealed by Proteomic Analysis

Abstract

SummaryTo identify proteins related to the pathophysiology of aortic valve stenosis (AS), we investigated the protein profiles of AS aortic valves. Specifically, proteins were extracted from a thickened and calcified area (AS-C) and an apparently non-thickened and non-calcified area (AS-N) in an identical aortic valve leaflet in each of 6 AS patients. The proteins were then separated by 2-dimensional gel electrophoresis (2DE). Protein spots detected by 2DE were compared between the AS-C and AS-N samples. Protein spots of interest were subjected to protein identification by mass spectrometry.In total, 670 protein spots were detected by 2DE, 28 of which showed more than 1.5-fold different intensity (P < 0.05) between the AS-C and AS-N samples. Proteins were identified in 17 out of the 28 spots. Fibrinogen and lumican were identified in 9 and 3 spots, respectively. Intensity of these 12 spots was lower in the AS-C samples than in the AS-N samples. In the 1D-Western blot analysis, 4 lumican bands (80 kDa, 75 kDa, 65 kDa, and 53 kDa) were detected, of which 2 bands with 80 kDa and 75 kDa showed lower intensity in the AS-C samples than in the AS-N samples. When de-glycosylated protein samples were used in the 1D-Western blot, only a single lumican band with ~40 kDa was detected, indicating that lumican was variously glycosylated and that highly glycosylated lumican molecules were decreased in AS-C.Collectively, insufficient glycosylation of lumican in the thickened and calcified areas of AS aortic valves may be involved in the pathophysiology of AS. (Int Heart J 2016; 57: 104-111) Key words: Calcification, 2-dimensional gel electrophoresis, Mass spectrometry, Peptide:N-glycosidase F, Proteoglycan A ortic valve stenosis (AS) is one of the most common cardiovascular diseases. Several decades ago, the main cause of AS used to be rheumatic fever, however, it was recently replaced by degenerative changes with calcification.

Integrative Multi-Omics Analysis in Calcific Aortic Valve Disease Reveals a Link to the Formation of Amyloid-Like Deposits

“…The initial search yielded 196 unique records for miRNA transcriptomics, 482 for mRNA transcriptomics and 93 for proteomics in CAVD. After applying the inclusion and exclusion criteria, 5 miRNA transcriptomics [ 18 , 19 , 20 , 21 , 22 ], 5 mRNA transcriptomics [ 15 , 20 , 23 , 24 , 25 ] and 10 proteomics [ 15 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ] records were eligible for the subsequent analyses ( Figure 1 A, Supplementary Figure S1, Supplementary Tables S1–S3 ). We identified only one single metabolomics study, which was only considered for integration analysis.…”

A Proteomic Approach for Understanding the Mechanisms of Delayed Corneal Wound Healing in Diabetic Keratopathy Using Diabetic Model Rat

“…In the cornea, lumican is expressed as the keratin sulfate proteoglycan, and is considered to possess the heterogeneous glycosaminoglycan [ 32 , 35 ]. Previously, various molecular weights of lumican between 37 and 250 kDa due to differences in glycosylation were detected from cell extracts by Western blot [ 36 , 37 , 38 , 39 , 40 ]. Our results also showed that various molecular weights of lumican between 37 and 250 kDa were observed in the cornea of rat, and increased lumican expression was observed in the cornea of the STZ rat (STZ) as compared to in that of the normal rat (Normal) ( Figure 4 ).…”

Patient Management in Aortic Stenosis: Towards Precision Medicine through Protein Analysis, Imaging and Diagnostic Tests

“…In a later analysis, proteins related to inflammation, oxidative stress, cytoskeleton, and transport were discovered using isobaric tags for relative and absolute quantitation (iTRAQ) methodology, which allowed the identification of a specific protein profile linked to the disease and highlighted the importance of extracellular matrix proteins [74]. Procollagen C-endopeptidase enhancer 1, extracellular superoxide dismutase (Cu-Zn), immunoglobulin gamma-1 chain C region, fibrinogens, and lumican have also been shown to be altered in AS in a study using proteins extracted from thickened and calcified areas and non-diseased areas from the same valve leaflet [75]. The latter study also revealed the importance of post-translational modifications, specifically that low levels of glycosylation of lumican in the thickened and calcified areas of AS aortic valves may be associated with the pathophysiology of AS.…”