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Protein expression in foetal brain with or without chromosome 21 trisomy (Down’s syndrome) was analyzed by two-dimensional gel electrophoresis and mass spectrometry. Data generated by in-gel digestion and matrix-assisted laser desorption/ionization mass spectrometry allowed identification of 40 proteins. Most of these are common to syndrome and healthy subjects and represent different types of protein. However, a few proteins, identified as truncated structural proteins (tubulin, actin), were present in part of the trisomy samples but absent from the controls. This is interpreted to indicate increased proteolysis in the syndrome samples but could also reflect some altered expression or processing. Independent of the apparently increased proteolysis in the syndrome samples, and in spite of the use of total brain tissues, the results show that two-dimensional protein separation patterns are largely similar between the syndrome and control samples upon silver-staining, but that differences associated with structural components can be detected and identified. [ABSTRACT FROM AUTHOR]

Proteins differential expression in type 2 diabetes mellitus (T2DM) can be due to etiological factors or pathological changes, such proteins can be utilized as biomarkers. Identification of a marker protein out of thousands became a feasible task during the proteomics era by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this study, blood samples were obtained from 80 Bahraini subjects with and without T2DM, a subset was used for proteomic analysis by LC-MS/MS, while all samples were used for ELISA analysis of 3 proteins, TATA-box binding protein-associated factor RNA polymerase-1-C (TAF1C), ceruloplasmin (CERP) and fibronectin (FN). The former 2 proteins were selected from the T2DM-protein-panel identified by LC-MS/MS, and the latter was analyzed for validation of the setting. The main findings of the proteomic analysis are i. Identifications of 62 differentially expressed proteins in T2DM, ii. Upregulation of 71% of the identified proteins. While the ELISA analysis showed that; both TAF1C and FN were significantly increased in T2DM (P 0.015 and P 0.001, respectively), while CERP was not (P 0.088). Logistic regression analysis: i. confirmed the above associations after correction for covariates, ii. Revealed an interaction between age and gender that affect the association of the proteins with T2DM. In conclusion, knowing that TAF1C is a prerequisite in ribosomal biogenesis, our ELISA results are suggestive of increased protein synthesis in T2DM, explaining the observed upregulation of the proteins identified by LC-MSMS. The association between T2DM and TAF1C is a novel finding that might open a new avenue in DM research. • LC-MS/MS proteomic analysis revealed novel association of 37 peptides (including TAF1C & CERP) with T2DM. • ELISA confirmed the strong association of TAF1C and weak association of CERP peptides with T2DM. • Novel association of TAF1C with T2DM suggests increased ribosomal biogenesis. • ELISA disclosed marked elevation of blood fibronectin (Fn) inT2DM, and validated the setting. • Age/gender interaction affects the association of the above peptides with T2DM. [ABSTRACT FROM AUTHOR]

Psoriasis is a disease with considerable heterogeneity in clinical presentation. This is the first study using two-dimensional gel electrophoresis to compare global protein expression patterns in lesional and non-lesional skin from subjects with acute guttate psoriasis associated with streptococcal throat infection and chronic plaque psoriasis. Samples from experimentally induced contact eczema and normal skin from healthy controls were also included. Proteins with statistically significant differences in expression were used in hierarchical cluster analyses resulting in separation of the different samples into groups. Chronic plaque and guttate psoriasis samples were distinctly separated, indicating that they represent discrete phenotypes at the protein expression level. Interestingly, there was a trend in which guttate psoriasis lesions clustered closer to eczema than to chronic plaque psoriasis lesions, indicating that the duration of the inflammatory reaction may affect clustering. Several of the differentially expressed proteins were identified by mass spectrometry. [ABSTRACT FROM AUTHOR]