Acidosis downregulates platelet haemostatic functions and promotes neutrophil proinflammatory responses mediated by platelets

Summary

Acidosis is one of the hallmarks of tissue injury such as trauma, infection, inflammation, and tumour growth. Although platelets participate in the pathophysiology of all these processes, the impact of acidosis on platelet biology has not been studied outside of the quality control of laboratory aggregation assays or platelet transfusion optimization. Herein, we evaluate the effect of physiologically relevant changes in extracellular acidosis on the biological function of platelets, placing particular emphasis on haemostatic and secretory functions. Platelet haemostatic responses such as adhesion, spreading, activation of α_IIbβ₃ integrin, ATP release, aggregation, thromboxane B₂ generation, clot retraction and procoagulant activity including phosphatidilserine exposure and microparticle formation, showed a statistically significant inhibition of thrombin-induced changes at pH of 7.0 and 6.5 compared to the physiological pH (7.4). The release of alpha granule content was differentially regulated by acidosis. At low pH, thrombin or collagen-induced secretion of vascular endothelial growth factor and endostatin were dramatically reduced. The release of von Willebrand factor and stromal derived factor-1α followed a similar, albeit less dramatic pattern. In contrast, the induction of CD40L was not changed by low pH, and P-selectin exposure was significantly increased. While the generation of mixed platelet-leukocyte aggregates and the increased chemotaxis of neutrophils mediated by platelets were further augmented under acidic conditions in a P-selectin dependent manner, the increased neutrophil survival was independent of P-selectin expression. In conclusion, our results indicate that extracellular acidosis downregulates most of the haemostatic platelet functions, and promotes those involved in amplifying the neutrophil-mediated inflammatory response.

Keywords

Acidosis - platelets - inflammation - P-selectin - neutrophils

• References

• 1 Rosskopf D. Sodium-hydrogen exchange and platelet function. J Thromb Thrombolysis 1999; 08: 15-24.
• 2 DeClerck K, Elble RC. The role of hypoxia and acidosis in promoting metastasis and resistance to chemotherapy. Front Biosci 2010; 15: 213-225.
• 3 Huang Y, McNamara JO. Ischemic stroke: „acidotoxicity“ is a perpetrator. Cell 2004; 118: 665-666.
• 4 Lim S. Metabolic acidosis. Acta Med Indones 2007; 39: 145-150.
• 5 Ricciardolo FL, Gaston B, Hunt J. Acid stress in the pathology of asthma. J Allergy Clin Immunol 2004; 113: 610-619.
• 6 Marumo M, Suehiro A, Kakishita E. et al. Extracellular pH affects platelet aggregation associated with modulation of store-operated Ca(2+) entry. Thromb Res 2001; 104: 353-360.
• 7 Patscheke H. Shape and functional properties of human platelets washed with acid citrate. Haemostasis 1981; 10: 14-27.
• 8 Rogers AB, Des Prez RM. The effect of pH on human platelet aggregation induced by epinephrine and ADP. Proc Soc Exp Biol Med 1972; 139: 1100-1103.
• 9 Watts SE, Tunbridge LJ, Lloyd JV. Storage of platelets for tests of platelet function: effects of pH on platelet aggregation and liberation of beta-thromboglobulin. Thromb Res 1983; 29: 343-353.
• 10 Romaniuk MA, Tribulatti MV, Cattaneo V. et al. Human platelets express and are activated by Galectin-8. Biochem J 2010; 432: 535-547.
• 11 Etulain J, Lapponi MJ, Patrucchi SJ. et al. Hyperthermia inhibits platelet haemostatic functions and selectively regulates the release of alpha-granule proteins. J Thromb Haemost 2011; 09: 1562-1571.
• 12 Obergfell A, Eto K, Mocsai A. et al. Coordinate interactions of Csk, Src, and Syk kinases with [alpha]IIb[beta]3 initiate integrin signaling to the cytoskeleton. J Cell Biol 2002; 157: 265-275.
• 13 Pacienza N, Pozner RG, Bianco GA. et al. The immunoregulatory glycan-binding protein galectin-1 triggers human platelet activation. Faseb J 2008; 22: 1113-1123.
• 14 Negrotto S, Malaver E, Alvarez ME. et al. Aspirin and salicylate suppress polymorphonuclear apoptosis delay mediated by proinflammatory stimuli. J Pharmacol Exp Ther 2006; 319: 972-979.
• 15 Betsuyaku T, Liu F, Senior RM. et al. A functional granulocyte colony-stimulating factor receptor is required for normal chemoattractant-induced neutrophil activation. J Clin Invest 1999; 103: 825-832.
• 16 Nilsson C, Kagedal K, Johansson U. et al. Analysis of cytosolic and lysosomal pH in apoptotic cells by flow cytometry. Methods Cell Sci 2003; 25: 185-194.
• 17 Shattil SJ, Newman PJ. Integrins: dynamic scaffolds for adhesion and signaling in platelets. Blood 2004; 104: 1606-1615.
• 18 Woodside DG, Obergfell A, Leng L. et al. Activation of Syk protein tyrosine kinase through interaction with integrin beta cytoplasmic domains. Curr Biol 2001; 11: 1799-1804.
• 19 Flevaris P, Stojanovic A, Gong H. et al. A molecular switch that controls cell spreading and retraction. J Cell Biol 2007; 179: 553-565.
• 20 Munnix IC, Cosemans JM, Auger JM. et al. Platelet response heterogeneity in thrombus formation. Thromb Haemost 2009; 102: 1149-1156.
• 21 Sinauridze EI, Kireev DA, Popenko NY. et al. Platelet microparticle membranes have 50– to 100-fold higher specific procoagulant activity than activated platelets. Thromb Haemost 2007; 97: 425-434.
• 22 Nurden AT, Nurden P, Sanchez M. et al. Platelets and wound healing. Front Biosci 2008; 13: 3532-3548.
• 23 Wagner DD. New links between inflammation and thrombosis. Arterioscler Thromb Vasc Biol 2005; 25: 1321-1324.
• 24 Italiano Jr. JE, Richardson JL, Patel-Hett S. et al. Angiogenesis is regulated by a novel mechanism: pro- and antiangiogenic proteins are organized into separate platelet alpha granules and differentially released. Blood 2008; 111: 1227-1233.
• 25 Kamykowski J, Carlton P, Sehgal S. et al. Quantitative immunofluorescence mapping reveals little functional co-clustering of proteins within platelet {alpha}-granules. Blood 2011; 118: 1190-1191.
• 26 Ma L, Perini R, McKnight W. et al. Proteinase-activated receptors 1 and 4 counter-regulate endostatin and VEGF release from human platelets. Proc Natl Acad Sci USA 2005; 102: 216-220.
• 27 Nieswandt B, Watson SP. Platelet-collagen interaction: is GPVI the central receptor?. Blood 2003; 102: 449-461.
• 28 Lam FW, Burns AR, Smith CW. et al. Platelets enhance neutrophil transendothelial migration via P-selectin glycoprotein ligand-1. Am J Physiol Heart Circ Physiol 2010; 300: H468-475.
• 29 Trevani AS, Andonegui G, Giordano M. et al. Extracellular acidification induces human neutrophil activation. J Immunol 1999; 162: 4849-4857.
• 30 Brunetti M, Martelli N, Manarini S. et al. Polymorphonuclear leukocyte apoptosis is inhibited by platelet-released mediators, role of TGFbeta-1. Thromb Haemost 2000; 84: 478-483.
• 31 Andonegui G, Trevani AS, Lopez DH. et al. Inhibition of human neutrophil apoptosis by platelets. J Immunol 1997; 158: 3372-3377.
• 32 Maggini J, Raiden S, Salamone G. et al. Regulation of neutrophil apoptosis by cytokines, pathogens and environmental stressors. Front Biosci 2009; 14: 2372-2385.
• 33 Nachmias VT, Yoshida K, Glennon MC. Lowering pH in blood platelets dissociates myosin phosphorylation from shape change and myosin association with the cytoskeleton. J Cell Biol 1987; 105: 1761-1769.
• 34 Herbaczynska-Cedro K, Truskolaski P, Huszczuk A. et al. Hypoventilation and elevation of end-expiratory pressure release a substance which relaxes isolated arteries and disaggregates platelets in the presence of cyclooxygenase inhibitors. Prostaglandins 1981; 21: 707-717.
• 35 van Nispen Tot Pannerden H, de Haas F, Geerts W. et al. The platelet interior revisited: electron tomography reveals tubular alpha granule subtypes. Blood 2010; 116: 1147-1156.
• 36 Sturm A, Hebestreit H, Koenig C. et al. Platelet proinflammatory activity in clinically stable patients with CF starts in early childhood. J Cyst Fibros 2010; 09: 179-186.
• 37 Yaguchi A, Lobo FL, Vincent JL. et al. Platelet function in sepsis. J Thromb Haemost 2004; 02: 2096-2102.
• 38 Babich V, Knipe L, Hewlett L. et al. Differential effect of extracellular acidosis on the release and dispersal of soluble and membrane proteins secreted from the Weibel-Palade body. J Biol Chem 2009; 284: 12459-12468.
• 39 Ho-Tin-Noe B, Goerge T, Wagner DD. Platelets: guardians of tumor vasculature. Cancer Res 2009; 69: 5623-5626.