Molecular Proteomics and Signalling of Human Platelets in Health and Disease

Abstract

Platelets are small anucleate blood cells that play vital roles in haemostasis and thrombosis, besides other physiological and pathophysiological processes. These roles are tightly regulated by a complex network of signalling pathways. Mass spectrometry-based proteomic techniques are contributing not only to the identification and quantification of new platelet proteins, but also reveal post-translational modifications of these molecules, such as acetylation, glycosylation and phosphorylation. Moreover, target proteomic analysis of platelets can provide molecular biomarkers for genetic aberrations with established or non-established links to platelet dysfunctions. In this report, we review 67 reports regarding platelet proteomic analysis and signalling on a molecular base. Collectively, these provide detailed insight into the: (i) technical developments and limitations of the assessment of platelet (sub)proteomes; (ii) molecular protein changes upon ageing of platelets; (iii) complexity of platelet signalling pathways and functions in response to collagen, rhodocytin, thrombin, thromboxane A2 and ADP; (iv) proteomic effects of endothelial-derived mediators such as prostacyclin and the anti-platelet drug aspirin; and (v) molecular protein changes in platelets from patients with congenital disorders or cardiovascular disease. However, sample sizes are still low and the roles of differentially expressed proteins are often unknown. Based on the practical and technical possibilities and limitations, we provide a perspective for further improvements of the platelet proteomic field.

Phosphoproteomics reveals content and signaling differences between neonatal and adult platelets

“…First, we noted mild platelet activation during platelet isolation ( Figure 1 ). This was an unavoidable consequence of platelet processing, which is important to recognize in order to provide context for potential changes in protein-based signaling or activation-related phosphorylation activities [75]. However, our samples clustered well based on developmental status irrespective of P-selectin MFI, and analyses performed after excluding potential outliers did not substantively change the results (data not shown).…”

Mechanisms Underlying Dichotomous Procoagulant COAT Platelet Generation—A Conceptual Review Summarizing Current Knowledge

“…Moreover, since Ca 2+ influxes are important to trigger the procoagulant response, physiological levels of Ca 2+ are required in the medium [ 45 , 46 ]. Nowadays, convulxin/thrombin (COAT) dual agonist stimulation in Ca 2+ buffer—generally recognized as standard—is extensively used by many research groups to assess procoagulant function of platelets [ 3 , 4 , 12 , 22 , 47 , 48 , 49 , 50 , 51 ]. Common model such as procoagulant COAT platelets are required in order to compare observations between research groups [ 51 ].…”

“…Nowadays, convulxin/thrombin (COAT) dual agonist stimulation in Ca 2+ buffer—generally recognized as standard—is extensively used by many research groups to assess procoagulant function of platelets [ 3 , 4 , 12 , 22 , 47 , 48 , 49 , 50 , 51 ]. Common model such as procoagulant COAT platelets are required in order to compare observations between research groups [ 51 ]. However, other agonists (e.g., adenosine diphosphate (ADP) [ 52 ], arachidonic acid [ 52 ], ionophore A23187 [ 36 ], or thrombin receptor activating peptide 6 (TRAP6) [ 52 ]) or inhibitors (e.g., epinephrine [ 53 ] or antibodies [ 36 ]) are also used to assess platelet procoagulant response through different pathways.…”

Is autologous platelet activation the key step in ovarian therapy for fertility recovery and menopause reversal?

“…Despite being anucleate, PLTs do have residual mRNA and translation enzymes needed for protein synthesis which is left over from their megakaryocyte ancestor [ 14 ]. PLTs thus offer a stable proteome for transcription and ribosomal translation analysis [ 15 , 16 ].…”