The storage lesion of platelets: ultrastructural and functional aspects

Key Points• TAILS proteomics identified 2938 human platelet proteins, pervasive proteolytic processing, and precise proteolytic cleavage sites in stored platelets.• During storage, metalloproteinases were predominantly involved in proteolytic processing, while other proteinases were mainly involved in degradation.Proteases, and specifically metalloproteinases, have been linked to the loss of platelet function during storage before transfusion, but the underlying mechanisms remain unknown. We used a dedicated N-terminomics technique, iTRAQ terminal amine isotopic labeling of substrates (TAILS), to characterize the human platelet N-terminome, proteome, and posttranslational modifications throughout platelet storage over 9 days under blood-banking conditions. From the identified 2938 proteins and 7503 unique peptides, we characterized N-terminal methionine excision, co-and posttranslational Na acetylation, protein maturation, and proteolytic processing of proteins in human platelets. We also identified for the first time 10 proteins previously classified by the Human Proteome Organization as "missing" in the human proteome. Most N termini (77%) were internal neo-N termini (105 were novel potential alternative translation start sites, and 2180 represented stable proteolytic products), thus highlighting a prominent yet previously uncharacterized role of proteolytic processing during platelet storage. Protease inhibitor studies revealed metalloproteinases as being primarily responsible for proteolytic processing (as opposed to degradation) during storage. System-wide identification of metalloproteinase and other proteinase substrates and their respective cleavage sites suggests novel mechanisms of the effect of proteases on protein activity and platelet function during storage. All data sets and metadata are available through ProteomeXchange with the data set identifier PXD000906. (Blood. 2014;124(26):e49-e60)

Section: Introductionmentioning

confidence: 99%

TAILS N-terminomics of human platelets reveals pervasive metalloproteinase-dependent proteolytic processing in storage

Prudova

Serrano

Eckhard

et al. 2014

“…1 The main characteristics of PSL are: (1) shape change, (2) reduced activation in response to agonists, such as adenosine diphosphate (ADP), thromboxane A 2 (TxA 2 ), or epinephrine, (3) secretion of platelet granules, and (4) exposure of phosphatidylserine on the outer leaflet of the plasma membrane accompanied by blebbing of microparticles. 2 Furthermore, the surface expression of the glycoproteins GPIb-␣ and GPV, subunits of the von Willebrand factor (VWF) receptor complex, is altered during long-term storage, 3,4 mainly by metalloproteinase-mediated proteolysis of their ectodomain. The major sheddase for GPIb-␣ and GPV is tumor necrosis factor-␣ converting enzyme (TACE; ADAM17), 5,6 which is a type I metalloproteinase involved in the shedding of several transmembrane proteins (cytokines, growth factors, receptors, or adhesion molecules) and implicated in developmental and inflammatory processes.…”

Section: Introductionmentioning

confidence: 99%

p38 mitogen-activated protein kinase activation during platelet storage: consequences for platelet recovery and hemostatic function in vivo

Canault

Duerschmied

Brill

et al. 2010

110

Platelets undergo several modifications during storage that reduce their posttransfusion survival and functionality. One important feature of these changes, which are known as platelet storage lesion, is the shedding of the surface glycoproteins GPIb-␣ and GPV. We recently demonstrated that tumor necrosis factor-␣ converting enzyme (TACE/ADAM17) mediates mitochondrial injury-induced shedding of adhesion receptors and that TACE activity correlates with reduced posttransfusion survival of these cells. We now confirm that TACE mediates receptor shedding and clearance of platelets stored for 16 hours at 37°C or 22°C. We further demonstrate that both storage and mitochondrial injury lead to the phosphorylation of p38 mitogen-activated kinase (MAPK) in platelets and that TACEmediated receptor shedding from mouse and human platelets requires p38 MAP kinase signaling. Protein kinase C, extracellular regulated-signal kinase MAPK, and caspases were not involved in TACE activation. Both inhibition of p38 MAPK and inactivation of TACE during platelet storage led to a markedly improved posttransfusion recovery and hemostatic function of platelets in mice. p38 MAPK inhibitors had only minor effects on the aggregation of fresh platelets under static or flow conditions in vitro. In summary, our data suggest that inhibition of p38 MAPK or TACE during storage may significantly improve the quality of stored platelets. (Blood.

“…The PSL is characterized by mitochondrial damage (⌬ m ), increased PS, loss of discoid morphology, fragmentation of the plasma membrane, microvesiculation, and ectodomain shedding of GPIb. 40,41 Reductions in the levels of Bcl-xl, cytochrome-c release, caspase activation, and gelsolin proteolysis have also been reported during platelet storage. 40 Functionally, these platelets have reduced adhesive function, increased procoagulant activity, and reduced survival after transfusion to a recipient.…”

Section: Apoptotic and Necrotic Death Pathways: Implications For The mentioning

confidence: 99%

“…Much of the current effort into improving the viability of stored platelet concentrates has focused on reducing platelet activation, maintaining pH, buffering lactate production and enhancing gas exchange. This has been achieved with the use of platelet activation inhibitors (NO, phosphodiesterase inhibitors, apyrase and prostacyclin, protease inhibitors), [50][51][52][53][54][55][56][57] through inclusion of additives such as acetate, phosphate, gluconate, potassium, and magnesium 41,[43][44][45][46][47][58][59][60] and through the implementation of modified storage bags with agitation. 61 However, these measures have provided only modest improvements in platelet viability.…”

Section: Apoptotic and Necrotic Death Pathways: Implications For The mentioning

confidence: 99%

Procoagulant platelets: are they necrotic?

Jackson

Schoenwaelder

2010

141

Apoptosis and necrosis represent distinct cell death processes that regulate mammalian development, physiology and disease. Apoptosis characteristically leads to the silent destruction and removal of cells in the absence of an inflammatory response. In contrast, necrotic cell death can induce physiologic inflammatory responses linked to tissue defense and repair. Although anucleate, platelets undergo programmed cell death, with apoptosis playing an important role in clearing effete platelets from the circulation. While it has long been recognized that procoagulant platelets exhibit characteristic features of dying cells, recent studies have demonstrated that platelet procoagulant function can occur independent of apoptosis. A growing body of evidence suggest that the biochemical, morphologic and functional changes underlying agonist-induced platelet procoagulant function are broadly consistent with cell necrosis, raising the possibility that distinct death pathways regulate platelet function and survival. In this article, we will discuss the mechanisms underlying apoptotic and necrotic cell death pathways and examine the evidence linking these pathways to the platelet procoagulant response. We will also discuss the potential contribution of these pathways to the platelet storage lesion and propose a simplified nomenclature to describe procoagulant platelets. IntroductionUntil the early 1970s it was thought that all cells die as a result of necrosis (Table 1); a form of cell death that is prominent when tissues undergo extensive damage from trauma or disease. This concept changed dramatically in 1972 after the landmark observations of Kerr and colleagues, 9 who described a new form of cell death, termed apoptosis (Table 1). Since then, the genetic and biochemical processes responsible for apoptotic cell death have been extensively investigated. It is now well defined that apoptosis is a key process underlying human development, normal physiology and a range of common human diseases. 10 In contrast, the concepts underlying necrosis have become less clear-cut. While it has long been assumed that necrosis is predominantly a pathologic process resulting from tissue injury, there is growing evidence that cells can orchestrate their own demise through programmed cell necrosis in a manner that initiates physiologic inflammatory and repair responses. [2][3][4][6][7][8] Although anucleate, platelets have the capacity to undergo programmed cell death (Table 1). This has been most clearly demonstrated with platelet apoptosis; a process that is important for clearance of effete platelets from the circulation. 1,11 Many of the features of apoptosis (membrane fragmentation, cytoskeletal disruption, microvesiculation, caspase activation and phosphatidylserine [PS] exposure) are observed during prolonged platelet storage ex vivo and during the conversion of activated platelets to a procoagulant state, raising the possibility that apoptosis may also regulate platelet function. However, recent studies have demonstrated that the m...