Proteomics has made tremendous progress over recent years. It has contributed to a better understanding of numerous diseases, including cardiovascular disease. Nonetheless, cardiovascular disease is receiving comparable little attention by the proteomics community. This is surprising as cardiovascular disease is the major cause of morbidity and mortality in the Western world, as well as being on the rise in emerging economies. Back in 2008, Professor van Eyk and I co-edited a special issue on cardiovascular proteomics. This follow-up series shall further emphasize the importance of blood vessels.
Initiatives, such as the Human Protein Atlas project, provide a great resource by capturing the in vivo location of proteins in different tissues and by making these data publically available (www.proteinatlas.org). Apart from the inherent limitations of antibody-based detection (antibody specificity, epitope masking, etc.), the only cardiovascular relevant tissue in the Human Protein Atlas is the heart. No large blood vessels are included in the tissue bank. Of course, small vessels are present in almost every tissue, but the protein composition and function of large and small vessels is clearly not the same. Even within the human aorta, the thoracic and abdominal part is structurally and functionally distinct. In comparison to the underrepresentation of the cardiovascular system, 14 different types of skin and soft tissues are included. With regards to diseases, the Human Protein Atlas focuses on various types of cancers. Atherosclerotic plaques are not assessed, although cardiovascular diseases account for more deaths than all cancers taken together (www.heartstats.org). The medical importance of the vascular system warrants its inclusion in the Human Protein Atlas in future.
This review series on “Vascular Proteomics” attempts to raise awareness about vascular disease among the proteomics community. Included in this issue are five review articles: First, Hernandez-Fernaud et al review the quantitative mass spectrometry-based proteomic strategies to study angiogenesis, the formation of new blood vessels. Angiogenesis plays a critical role not only in the physiological development of the vascular system but also in malignant diseases such as cancer and complications of diabetes, such as retinopathy, to name just a few. The effect of aging on the vascular proteome is reviewed by Fu et al. Age is one of the main risk factors for cardiovascular disease. Bleijerveld et al summarize the proteomics literature on atherosclerosis. Besides atherosclerosis, aortic aneurysms are another vascular disease associated with high mortality, particularly in the elderly. Abdulkareem et al review the proteomic literature on aortic aneurysms and introduce methods for the use of proteomics to study the vascular extracellular matrix. Similarly, Patterson et al focus on the importance of proteomics to uncover extracellular matrix interactions during cardiac remodelling after ischemia, a consequence of occluded coronary arteries, the blood vessels supplying cardiac tissue_ENREF_8. At present, functional analysis tools do not capture some of the most differentially expressed cardiovascular extracellular proteins because these proteins are either only expressed during disease and/or incorrectly annotated in the public databases. Thus, besides vessels, there is a need for further proteomic investigations of diseased cardiac tissue.
Our current understanding of the pathophysiology of vascular diseases is limited and data on specificities or commonalities between different vessels is sparse. It will be essential that high-quality vascular proteomic data investigating changes in the vessel wall with aging and disease are made publically accessible to advance the field. I thank all authors for their valuable contributions!