Targeted Expression of TGFBIp Peptides in Mouse and Human Tissue by MALDI-Mass Spectrometry Imaging
| Autor: | David Bonnel, Jonathan Stauber, Rajamani Lakshminarayanan, Shigeto Shimmura, Guillaume Hochart, Jodhbir S. Mehta, Konstantin Pervushin, Venkatraman Anandalakshmi |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
QC1-999 Proteolysis Mutant matrix-assisted laser desorption ionization (MALDI) TGFBIp Filtration and Separation Peptide Protein aggregation medicine.disease_cause Analytical Chemistry amyloid fibrils lattice corneal dystrophy 03 medical and health sciences 0302 clinical medicine Mutant protein cornea medicine QD1-999 chemistry.chemical_classification Mutation medicine.diagnostic_test Chemistry Physics medicine.disease Molecular biology Phenotype 030104 developmental biology 030221 ophthalmology & optometry Lattice corneal dystrophy mass spectrometry imaging (MSI) |
| Zdroj: | Separations Volume 8 Issue 7 Separations, Vol 8, Iss 97, p 97 (2021) |
| ISSN: | 2297-8739 |
| DOI: | 10.3390/separations8070097 |
| Popis: | Stromal corneal dystrophies are a group of hereditary disorders caused by mutations in the TGFBI gene. The mutant TGFBIp is prone to protein aggregation and the mutant protein gets deposited in the cornea, leading to severe visual impairment. The mutations lead to a corneal specific protein aggregation suggesting the involvement of tissue-specific factors. The exact molecular mechanism of the process of tissue-specific protein aggregation remains to be elucidated. Differential proteolysis of mutant TGFBIp is a critical component of the disease pathology. The differential proteolysis gives rise to shorter peptides that are highly aggregation-prone and initiate the aggregation cascade. Analyzing the proteolytic processing of the different TGFBIp mutant may provide insight to aid in understanding the amyloid aggregation mechanism. We developed a MALDI-MSI methodology to identify expression and spatial localization of TGFBIp peptides in the cornea. Corneal tissue samples were collected from both control and dystrophic patients (with 2 different mutations), embedded in OCT and sectioned. The sections were trypsin digested and subjected to mass spectrometry imaging using a targeted approach to detect TGFBIp. MALDI-MSI identified peptides from TGFBIp that co-localized with the amyloid corneal deposits. In addition to the relative abundance data, the specific location of the peptides across the corneal sections as molecular signatures was also identified. Spatial distribution and intensity of the TGFBIp peptides showed differences between diseased and control models but also between the two LCD phenotypes. The TGFBIp peptide with m/z of 787.474 and m/z of 1179.579 showed increased expression in both LCD mutants compared to the controls. The peptide with m/z of 929.5 showed increased expression in the LCD phenotype with H626R mutation while the peptide with m/z of 1315.802 was abundant in the sample with R124C mutation. This initial report of 2D spatial protein signature and localization of TGFBIp may be expanded to other mutations to understand the proteolytic patterns of TGFBIp in different mutations. |
| Databáze: | OpenAIRE |
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