BackgroundInherited platelet disorders (IPDs) are a heterogeneous group of rare diseases that are caused by the defects in early megakaryopoiesis, proplatelet formation, and/or mature platelet... Show moreBackgroundInherited platelet disorders (IPDs) are a heterogeneous group of rare diseases that are caused by the defects in early megakaryopoiesis, proplatelet formation, and/or mature platelet function. Although genomic sequencing is increasingly used to identify genetic variants underlying IPD, this technique does not disclose resulting molecular changes that impact platelet function. Proteins are the functional units that shape platelet function; however, insights into how variants that cause IPDs impact platelet proteomes are limited.ObjectivesThe objective of this study was to profile the platelet proteomics signatures of IPDs.MethodsWe performed unbiased label-free quantitative mass spectrometry (MS)–based proteome profiling on platelets of 34 patients with IPDs with variants in 13 ISTH TIER1 genes that affect different stages of platelet development.ResultsIn line with the phenotypical heterogeneity between IPDs, proteomes were diverse between IPDs. We observed extensive proteomic alterations in patients with a GFI1B variant and for genetic variants in genes encoding proteins that impact cytoskeletal processes (MYH9, TUBB1, and WAS). Using the diversity between IPDs, we clustered protein dynamics, revealing disrupted protein-protein complexes. This analysis furthermore grouped proteins with similar cellular function and location, classifying mitochondrial protein constituents and identifying both known and putative novel alpha granule associated proteins.ConclusionsWith this study, we demonstrate a MS–based proteomics perspective to IPDs. By integrating the effects of IPDs that impact different aspects of platelet function, we dissected the biological contexts of protein alterations to gain further insights into the biology of platelet (dys)function. Show less
Background: Many patients who are diagnosed with coronavirus disease 2019 (COVID-19) suffer from venous thromboembolic complications despite the use of stringent anticoagulant prophylaxis. Studies... Show moreBackground: Many patients who are diagnosed with coronavirus disease 2019 (COVID-19) suffer from venous thromboembolic complications despite the use of stringent anticoagulant prophylaxis. Studies on the exact mechanism(s) underlying thrombosis in COVID-19 are limited as animal models commonly used to study venous thrombosis pathophysiology (i.e. rats and mice) are naturally not susceptible to Severe Acute Respiratory Syn-drome Coronavirus 2 (SARS-CoV-2). Ferrets are susceptible to SARS-CoV-2 infection, successfully used to study virus transmission, and have been previously used to study activation of coagulation and thrombosis during influenza virus infection.Objectives: This study aimed to explore the use of (heat-inactivated) plasma and lung material from SARS-CoV-2-inoculated ferrets studying COVID-19-associated changes in coagulation and thrombosis. Material and methods: Histology and longitudinal plasma profiling using mass spectrometry-based proteomics approach was performed.Results: Lungs of ferrets inoculated intranasally with SARS-CoV-2 demonstrated alveolar septa that were mildly expanded by macrophages, and diffuse interstitial histiocytic pneumonia. However, no macroscopical or microscopical evidence of vascular thrombosis in the lungs of SARS-CoV-2-inoculated ferrets was found. Lon-gitudinal plasma profiling revealed minor differences in plasma protein profiles in SARS-CoV-2-inoculated ferrets up to 2 weeks post-infection. The majority of plasma coagulation factors were stable and demonstrated a low coefficient of variation.Conclusions: We conclude that while ferrets are an essential and well-suited animal model to study SARS-CoV-2 transmission, their use to study SARS-CoV-2-related changes relevant to thrombotic disease is limited. Show less
