Human serum albumin (HSA) is associated with several physiological functions, such as maintaining oncotic pressure and microvascular integrity, among others. It also represents the major and predominant antioxidant in plasma due to the presence of the Cys34 sulfhydryl group.In this study, we assessed qualitative and quantitative changes in HSA in patients with heart failure (HF) and their relationship with the severity of the disease. We detected by means of mass spectrometry a global decrease of the HSA content in the plasma of HF patients in respect to control subjects, a significant increase of thio-HSA with a concomitant decrease in the reduced form of albumin. Cysteine and, at a lesser extent, homocysteine represent the most abundant thiol bound to HSA. A strong inverse correlation was also observed between cysteine-HSA and peak VO2/kg, an index of oxygen consumption associated with HF severity. Moreover, in HL-1 cardiomyocytes incubated with H2O2, we showed a significant decrease of cell viability in cells treated with thio-HSA in respect to restored native-HSA. In conclusion, we found for the first time that S-thiolation of albumin is increased in the plasma of HF patients and induced changes in the structure and antioxidant function of HSA, likely contributing to HF progression.

Extracellular vesicles (EVs) are lipid-bound vesicles released from cells under physiological and pathological conditions. Basing on biogenesis, dimension, content and route of secretion, they can be classified into exosomes, microvesicles (MVs) and apoptotic bodies. EVs have a key role as bioactive mediators in intercellular communication, but they are also involved in other physiological processes like immune response, blood coagulation, and tissue repair. The interest in studying EVs has increased over the years due to their involvement in several diseases, such as cardiovascular diseases (CVDs), and their potential role as biomarkers in diagnosis, therapy, and in drug delivery system development. Nowadays, the improvement of mass spectrometry (MS)-based techniques allows the characterization of the EV protein composition to deeply understand their role in several diseases. In this review, a critical overview is provided on the EV’s origin and physical properties, as well as their emerging functional role in both physiological and disease conditions, focusing attention on the role of exosomes in CVDs. The most important cardiac exosome proteomic studies will be discussed giving a qualitative and quantitative characterization of the exosomal proteins that could be used in future as new potential diagnostic markers or targets for specific therapies.

Platelets are a heterogeneous small anucleate blood cell population with a central role both in physiological haemostasis and in pathological states, spanning from thrombosis to inflammation, and cancer. Recent advances in proteomic studies provided additional important information concerning the platelet biology and the response of platelets to several pathophysiological pathways. Platelets circulate systemically and can be easily isolated from human samples, making proteomic application very interesting for characterizing the complexity of platelet functions in health and disease as well as for identifying and quantifying potential platelet proteins as biomarkers and novel antiplatelet therapeutic targets. To date, the highly dynamic protein content of platelets has been studied in resting and activated platelets, and several subproteomes have been characterized including platelet-derived microparticles, platelet granules, platelet releasates, platelet membrane proteins, and specific platelet post-translational modifications. In this review, a critical overview is provided on principal platelet proteomic studies focused on platelet biology from signaling to granules content, platelet proteome changes in several diseases, and the impact of drugs on platelet functions. Moreover, recent advances in quantitative platelet proteomics are discussed, emphasizing the importance of targeted quantification methods for more precise, robust and accurate quantification of selected proteins, which might be used as biomarkers for disease diagnosis, prognosis and therapy, and their strong clinical impact in the near future.