Plasma Proteome Profiling of Coronary Artery Disease Patients: Downregulation of Transthyretin—An Important Event

Abstract

Coronary artery disease (CAD) is a prevalent chronic inflammatory cardiac disorder. An early diagnosis is likely to help in the prevention and proper management of this disease. As the study of proteomics provides the potential markers for detection of a disease, in the present investigation, attempt has been made to identify disease-associated differential proteins involved in CAD pathogenesis. For this study, a total of 200 selected CAD patients were considered, who were recruited for percutaneous coronary intervention (PCI) treatment. The proteomic analysis was performed using two-dimensional gel electrophoresis (2-DE) and MALDI-TOF MS/MS. Samples were also subjected to Western blot analysis, enzyme-linked immunosorbent assay (ELISA), peripheral blood mononuclear cells isolation immunofluorescence (IF) analysis, analytical screening by fluorescence-activated cell sorting (FACS), and in silico analysis. The representative data were shown as mean ± SD of at least three experiments. A total of 19 proteins were identified. Among them, the most abundant five proteins (serotransferrin, talin-1, alpha-2HS glycoprotein, transthyretin (TTR), fibrinogen-α chain) were found to have altered level in CAD. Serotransferrin, talin-1, alpha-2HS glycoprotein, and transthyretin (TTR) were found to have lower level, whereas fibrinogen-α chain was found to have higher level in CAD plasma compared to healthy, confirmed by Western blot analysis. TTR, an important acute phase transport protein, was validated low level in 200 CAD patients who confirmed to undergo PCI treatment. Further, in silico and in vitro studies of TTR indicated a downexpression of CAD in plasma as compared to the plasma of healthy individuals. Lower level of plasma TTR was determined to be an important risk marker in the atherosclerotic-approved CAD patients. We suggest that the TTR lower level predicts disease severity and hence may serve as an important marker tool for CAD screening. However, further large-scale studies are required to determine the clinical significance of TTR.

Plasma Exosome Profile in ST-Elevation Myocardial Infarction Patients with and without Out-of-Hospital Cardiac Arrest

“…In agreement with the association between low circulating levels of transthyretin and cardiovascular disease [39,40], we detected lower expression of transthyretin in exosomes of STEMI than in those of CCS patients. Conversely to the higher level of circulating ceruloplasmin found in myocardial infarction patients, exosomes isolated from STEMI displayed a reduced level of ceruloplasmin, suggesting that exosome protein expression does not necessarily reflect circulating free-form levels of this positive acute-phase protein [20,39].…”

“…Moreover, among the acute-phase proteins investigated in our study, only transthyretin and ceruloplasmin discriminated between STEMI and CCS patients. These two proteins have been associated with cardiovascular diseases [22,[39][40][41] and used as markers of inflammation. Indeed, during the acute-phase response/increased inflammation, the plasma level of ceruloplasmin increases, whereas the concentration of transthyretin drops [29,[42][43][44][45].…”

Poor Clearance of Free Hemoglobin Due to Lower Active Haptoglobin Availability is Associated with Osteoarthritis Inflammation

“…Plasma samples were also pooled and proteins (80µg) were subjected to 2DE: 27 , 28 the first dimension with isoelectric focusing and the second with SDS-PAGE. Gels were then silver-stained using standard protocols.…”

“…Gels were then silver-stained using standard protocols. 28 , 29 Experiments were repeated at least thrice using different pooled samples. Based on densitometry values, protein spots with fold change ≥2 in TKR/UKR compared to HCs were screened for protein identification (see details in Supplementary material ).…”

Transthyretin and Receptor for Advanced Glycation End Product’s Differential Levels Associated with the Pathogenesis of Rheumatoid Arthritis

“…Three different pooled plasma (RA, and HC n=5, each) of same age and sex were used; the 2-DE gel was run using plasma protein sample (70 µg). Silver-stained spots were digested overnight at 37°C with trypsin (Promega, USA) and analyzed 18 , 19 (details in supplementary). For SWATH-MS analysis, pooled plasma samples were taken from each group of RA and HC (n=10 each); albumin was depleted (Pierce™ Albumin depletion kit), protein concentration were estimated by Bicinchoninic Acid (BCA) and digested with trypsin.…”