The role of apoptosis in megakaryocytes and platelets
Corresponding Author
Benjamin T. Kile
The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
Department of Medical Biology, The University of Melbourne, Parkville, Vic., Australia
Correspondence: Benjamin T. Kile, ACRF Chemical Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville 3052, Vic., Australia.
E-mail: [email protected]
Search for more papers by this authorCorresponding Author
Benjamin T. Kile
The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
Department of Medical Biology, The University of Melbourne, Parkville, Vic., Australia
Correspondence: Benjamin T. Kile, ACRF Chemical Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville 3052, Vic., Australia.
E-mail: [email protected]
Search for more papers by this authorSummary
The role of apoptotic pathways in the development and function of the megakaryocyte lineage has generated renewed interest in recent years. This has been driven by the advent of BH3 mimetic drugs that target BCL2 family proteins to induce apoptosis in tumour cells: agents such as ABT-263 (navitoclax, which targets BCL2, BCL-XL [BCL2L1] and BCL2L2) and ABT-199 (a BCL2-specific agent) are showing great promise in early stage clinical trials. However, the major dose-limiting toxicity of navitoclax has proven to be thrombocytopenia, an on-target effect of inhibiting BCL-XL. It transpires that the anucleate platelet contains a classical intrinsic apoptosis pathway, which at steady state regulates its life span in the circulation. BCL-XL is the critical pro-survival protein that restrains apoptosis and maintains platelet viability. These findings have paved the way to a deeper understanding of apoptotic pathways and processes in platelets, and their precursor cell, the megakaryocyte.
References
- Alonzo, M.T.G., Lacuesta, T.L.V., Dimaano, E.M., Kurosu, T., Suarez, L.A.C., Mapua, C.A., Akeda, Y., Matias, R.R., Kuter, D.J., Nagata, S., Natividad, F.F. & Oishi, K. (2012) Platelet apoptosis and apoptotic platelet clearance by macrophages in secondary dengue virus infections. Journal of Infectious Diseases, 205, 1321–1329.
- Ault, K.A. & Knowles, C. (1995) In vivo biotinylation demonstrates that reticulated platelets are the youngest platelets in circulation. Experimental Hematology, 23, 996–1001.
- Bertino, A., Qi, X., Li, J., Xia, Y. & Kuter, D. (2003) Apoptotic markers are increased in platelets stored at 37 degrees C. Transfusion, 43, 857–866.
- Bevers, E.M., Comfurius, P., van Rijn, J.L.M.L. & Hemker, H.C. (1982) Generation of prothrombin-converting activity and the exposure of phosphatidylserine at the outer surface of platelets. European Journal of Biochemistry, 122, 429–436.
- Bouillet, P., Metcalf, D., Huang, D., Tarlinton, D., Kay, T., Kontgen, F., Adams, J. & Strasser, A. (1999) Proapoptotic Bcl-2 relative Bim required for certain apoptotic responses, leukocyte homeostasis, and to preclude autoimmunity. Science, 286, 1735–1738.
- Catani, M., Gasperi, V., Evangelista, D., Finazzi Agrò, A., Avigliano, L. & Maccarrone, M. (2009) Anandamide extends platelets survival through CB(1)-dependent Akt signaling. Cellular and Molecular Life Sciences, 67, 601–610.
- Chauvier, D., Ankri, S., Charriaut-Marlangue, C., Casimir, R. & Jacotot, E. (2007) Broad-spectrum caspase inhibitors: from myth to reality? Cell Death and Differentiation, 14, 387–391.
- Chen, L., Willis, S., Wei, A., Smith, B., Fletcher, J., Hinds, M., Colman, P., Day, C., Adams, J. & Huang, D. (2005) Differential targeting of prosurvival Bcl-2 proteins by their BH3-only ligands allows complementary apoptotic function. Molecular Cell, 17, 393–403.
- Chen, P.K., Chang, H.H., Lin, G.L., Wang, T.P., Lai, Y.L., Lin, T.K., Hsieh, M.C., Kau, J.H., Huang, H.H., Hsu, H.L., Liao, C.Y. & Sun, D.S. (2013) Suppressive effects of anthrax lethal toxin on megakaryopoiesis. PLoS One, 8, e59512.
- Clarke, M., Savill, J., Jones, D., Noble, B. & Brown, S. (2003) Compartmentalized megakaryocyte death generates functional platelets committed to caspase-independent death. Journal of Cell Biology, 160, 5577–5587.
- Cohen, Z., Gonzales, R., Davis-Gorman, G., Copeland, J. & McDonagh, P. (2002) Thrombin activity and platelet microparticle formation are increased in type 2 diabetic platelets: a potential correlation with caspase activation. Thrombosis Research, 107, 217–221.
- Dasgupta, S.K., Argaiz, E.R., Mercado, J.E., Maul, H.O., Garza, J., Enriquez, A.B., Abdel-Monem, H., Prakasam, A., Andreeff, M. & Thiagarajan, P. (2010) Platelet senescence and phosphatidylserine exposure. Transfusion, 50, 2167–2175.
- De Botton, S., Sabri, S., Daugas, E., Zermati, Y., Guidotti, J., Hermine, O., Kroemer, G., Vainchenker, W. & Debili, N. (2002) Platelet formation is the consequence of caspase activation within megakaryocytes. Blood, 100, 1310–1317.
- Debrincat, M.A., Josefsson, E.C., James, C., Henley, K.J., Ellis, S., Lebois, M., Betterman, K.L., Lane, R.M., Rogers, K.L., White, M.J., Roberts, A.W., Harvey, N.L., Metcalf, D. & Kile, B.T. (2012) Mcl-1 and Bcl-xL coordinately regulate megakaryocyte survival. Blood, 119, 5850–5858.
- van Delft, M.F., Smith, D.P., Lahoud, M.H., Huang, D.C.S. & Adams, J.M. (2010) Apoptosis and non-inflammatory phagocytosis can be induced by mitochondrial damage without caspases. Cell Death and Differentiation, 17, 821–832.
- Duke, W. (1910) The relation of blood platelets to hemorrhagic disease. The Journal of the American Medical Association, 250, 1201–1209.
- Duke, W. (1911) The rate of regeneration of blood platelets. Journal of Experimental Medicine, 14, 265–273.
- Ekert, P.G., Read, S.H., Silke, J., Marsden, V.S., Kaufmann, H., Hawkins, C.J., Gerl, R., Kumar, S. & Vaux, D.L. (2004) Apaf-1 and caspase-9 accelerate apoptosis, but do not determine whether factor-deprived or drug-treated cells die. The Journal of Cell Biology, 165, 835–842.
- Ekert, P.G., Jabbour, A.M., Manoharan, A., Heraud, J.E., Yu, J., Pakusch, M., Michalak, E.M., Kelly, P.N., Callus, B., Kiefer, T., Verhagen, A., Silke, J., Strasser, A., Borner, C. & Vaux, D.L. (2006) Cell death provoked by loss of interleukin-3 signaling is independent of Bad, Bim, and PI3 kinase, but depends in part on Puma. Blood, 108, 1461–1468.
- Freireich, E.J., Schmidt, P.J., Schneiderman, M.A. & Frei, E. III (1959) A comparative study of the effect of transfusion of fresh and preserved whole blood on bleeding in patients with acute leukemia. New England Journal of Medicine, 260, 6–11.
- Gandhi, L., Camidge, D.R., Ribeiro de Oliveira, M., Bonomi, P., Gandara, D., Khaira, D., Hann, C.L., McKeegan, E.M., Litvinovich, E., Hemken, P.M., Dive, C., Enschede, S.H., Nolan, C., Chiu, Y.L., Busman, T., Xiong, H., Krivoshik, A.P., Humerickhouse, R., Shapiro, G.I. & Rudin, C.M. (2011) Phase I study of Navitoclax (ABT-263), a novel Bcl-2 family inhibitor, in patients with small-cell lung cancer and other solid tumors. Journal of Clinical Oncology, 29, 909–916.
- Harper, M.T. & Poole, A.W. (2012) Bcl-xL-inhibitory BH3 mimetic ABT-737 depletes platelet calcium stores. Blood, 119, 4337–4338.
- Hatfill, S., Fester, E. & Steytler, J. (1992) Apoptotic megakaryocyte dysplasia in the myelodysplastic syndromes. Hematologic Pathology, 6, 87–93.
- Houwerzijl, E., Blom, N., van der Want, J., Esselink, M., Koornstra, J., Smit, J., Louwes, H., Vellenga, E. & de Wolf, J. (2004) Ultrastructural study shows morphologic features of apoptosis and para-apoptosis in megakaryocytes from patients with idiopathic thrombocytopenic purpura. Blood, 103, 500–506.
- Houwerzijl, E.J., Blom, N.R., van der Want, J.J.L., Louwes, H., Esselink, M.T., Smit, J.W., Vellenga, E. & de Wolf, J.T.M. (2005) Increased peripheral platelet destruction and caspase-3-independent programmed cell death of bone marrow megakaryocytes in myelodysplastic patients. Blood, 105, 3472–3479.
- James, C., Ugo, V., Le Couedic, J.P., Staerk, J., Delhommeau, F., Lacout, C., Garcon, L., Raslova, H., Berger, R., Bennaceur-Griscelli, A., Villeval, J.L., Constantinescu, S.N., Casadevall, N. & Vainchenker, W. (2005) A unique clonal JAK2 mutation leading to constitutive signalling causes polycythaemia vera. Nature, 434, 1144–1148.
- Josefsson, E.C. & Kile, B.T. (2009) Cell death in the hematopoietic system. In: Essentials of Apoptosis (eds. by X.M. Yin & Z. Dong), pp. 443–459. Humana Press Inc., New York, NY.
- Josefsson, E.C., James, C., Henley, K.J., Debrincat, M.A., Rogers, K.L., Dowling, M.R., White, M.J., Kruse, E.A., Lane, R.M., Ellis, S., Nurden, P., Mason, K.D., O'Reilly, L.A., Roberts, A.W., Metcalf, D., Huang, D.C.S. & Kile, B.T. (2011) Megakaryocytes possess a functional intrinsic apoptosis pathway that must be restrained to survive and produce platelets. Journal of Experimental Medicine, 208, 2017–2031.
- Josefsson, E.C., Dowling, M.R., Lebois, M. & Kile, B.T. (2013) The regulation of platelet life span. In: Platelets (ed. by A.D. Michelson), pp. 51–65. Elsevier/Academic Press, Amsterdam, The Netherlands.
10.1016/B978-0-12-387837-3.00003-1 Google Scholar
- Jost, P.J., Grabow, S., Gray, D., Mckenzie, M.D., Nachbur, U., Huang, D.C.S., Bouillet, P., Thomas, H.E., Borner, C., Silke, J., Strasser, A. & Kaufmann, T. (2009) XIAP discriminates between type I and type II FAS-induced apoptosis. Nature, 460, 1035–1039.
- Kaiser, W.J., Upton, J.W., Long, A.B., Livingston-Rosanoff, D., Daley-Bauer, L.P., Hakem, R., Caspary, T. & Mocarski, E.S. (2011) RIP3 mediates the embryonic lethality of caspase-8-deficient mice. Nature, 471, 368–372.
- Kaluzhny, Y., Yu, G., Sun, S., Toselli, P., Nieswandt, B., Jackson, C. & Ravid, K. (2002) BclxL overexpression in megakaryocytes leads to impaired platelet fragmentation. Blood, 100, 1670–1678.
- Kaushansky, K. (1996) The thrombocytopenia of cancer. Prospects for effective cytokine therapy. Hematology/Oncology Clinics of North America, 10, 431–455.
- Kelly, P.N., White, M.J., Goschnick, M.W., Fairfax, K.A., Tarlinton, D.M., Kinkel, S.A., Bouillet, P., Adams, J.M., Kile, B.T. & Strasser, A. (2010) Individual and overlapping roles of BH3-only proteins Bim and Bad in apoptosis of lymphocytes and platelets and in suppression of thymic lymphoma development. Cell Death and Differentiation, 19, 1856–1869.
- Kerr, J., Wyllie, A. & Currie, A. (1972) Apoptosis: a basic biological phenomenon with wide-ranging implications in tissue kinetics. British Journal of Cancer, 26, 239–257.
- Kirito, K., Watanabe, T., Sawada, K.-I., Endo, H., Ozawa, K. & Komatsu, N. (2002) Thrombopoietin regulates Bcl-xL gene expression through Stat5 and phosphatidylinositol 3-kinase activation pathways. The Journal of Biological Chemistry, 277, 8329–8337.
- Kodama, T., Takehara, T., Hikita, H., Shimizu, S., Shigekawa, M., Li, W., Miyagi, T., Hosui, A., Tatsumi, T., Ishida, H., Kanto, T., Hiramatsu, N., Yin, X.M. & Hayashi, N. (2011) BH3-only activator proteins Bid and Bim are dispensable for Bak/Bax-dependent thrombocyte apoptosis induced by Bcl-xL deficiency: molecular requisites for the mitochondrial pathway to apoptosis in platelets. Journal of Biological Chemistry, 286, 13905–13913.
- Kodama, T., Hikita, H., Kawaguchi, T., Shigekawa, M., Shimizu, S., Hayashi, Y., Li, W., Miyagi, T., Hosui, A., Tatsumi, T., Kanto, T., Hiramatsu, N., Kiyomizu, K., Tadokoro, S., Tomiyama, Y., Hayashi, N. & Takehara, T. (2012) Mcl-1 and Bcl-xL regulate Bak/Bax-dependent apoptosis of the megakaryocytic lineage at multistages. Cell Death and Differentiation, 19, 1856–1869.
- Kozuma, Y., Kojima, H., Yuki, S., Suzuki, H. & Nagasawa, T. (2007) Continuous expression of Bcl-xL protein during megakaryopoiesis is post-translationally regulated by thrombopoietin-mediated Akt activation, which prevents the cleavage of Bcl-xL. Journal of Thrombosis and Haemostasis, 5, 1274–1282.
- Kraemer, B.F., Campbell, R.A., Schwertz, H., Franks, Z.G., Vieira de Abreu, A., Grundler, K., Kile, B.T., Dhakal, B.K., Rondina, M.T., Kahr, W.H.A., Mulvey, M.A., Blaylock, R.C., Zimmerman, G.A. & Weyrich, A.S. (2012) Bacteria differentially induce degradation of Bcl-xL, a survival protein, by human platelets. Blood, 120, 5014–5020.
- Lamkanfi, M. & Dixit, V.M. (2012) Inflammasomes and their roles in health and disease. Annual Review of Cell and Developmental Biology, 28, 137–161.
- Leeksma, C. & Cohen, J. (1955) Determination of the life of human blood platelets using labelled diisopropylfluorophosphanate. Nature, 175, 552–553.
- Leytin, V. (2012) Apoptosis in the anucleate platelet. Blood Reviews, 26, 51–63.
- Li, J., Xia, Y., Bertino, A.M., Coburn, J.P. & Kuter, D.J. (2000) The mechanism of apoptosis in human platelets during storage. Transfusion, 40, 1320–1329.
- Lindsten, T. & Thompson, C.B. (2006) Cell death in the absence of Bax and Bak. Cell Death and Differentiation, 13, 1272–1276.
- Lindsten, T., Ross, A., King, A., Zong, W., Rathmell, J., Shiels, H., Ulrich, E., Waymire, K., Mahar, P., Frauwirth, K., Chen, Y., Wei, M., Eng, V., Adelman, D., Simon, M., Ma, A., Golden, J., Evan, G., Korsmeyer, S., MacGregor, G. & Thompson, C. (2000) The combined functions of proapoptotic Bcl-2 family members Bak and Bax are essential for normal development of multiple tissues. Molecular Cell, 6, 1389–1399.
- Marsden, V.S., O'Connor, L., O'Reilly, L.A., Silke, J., Metcalf, D., Ekert, P.G., Huang, D.C.S., Cecconi, F., Kuida, K., Tomaselli, K.J., Roy, S., Nicholson, D.W., Vaux, D.L., Bouillet, P., Adams, J.M. & Strasser, A. (2002) Apoptosis initiated by Bcl-2-regulated caspase activation independently of the cytochrome c/Apaf-1/caspase-9 apoptosome. Nature, 419, 634–637.
- Mason, K.D., Carpinelli, M.R., Fletcher, J.I., Collinge, J.E., Hilton, A.A., Ellis, S., Kelly, P.N., Ekert, P.G., Metcalf, D., Roberts, A.W., Huang, D.C. & Kile, B.T. (2007) Programmed anuclear cell death delimits platelet life span. Cell, 128, 1173–1186.
- Melloni, E., Secchiero, P., Celeghini, C., Campioni, D., Grill, V., Guidotti, L. & Zauli, G. (2005) Functional expression of TRAIL and TRAIL-R2 during human megakaryocytic development. Journal of Cellular Physiology, 204, 975–982.
- Morison, I., Borde, E., Cheesman, E., Cheong, P., Holyoake, A., Fichelson, S., Weeks, R., Lo, A., Davies, S., Wilbanks, S., Fagerlund, R., Ludgate, M., da Silva Tatley, F., Coker, M., Bockett, N., Hughes, G., Pippig, D., Smith, M., Capron, C. & Ledgerwood, E. (2008) A mutation of human cytochrome c enhances the intrinsic apoptotic pathway but causes only thrombocytopenia. Nature Genetics, 40, 387–389.
- Mustard, J., Rowsell, H. & Murphy, E. (1966) Platelet economy (platelet survival and turnover). British Journal of Haematology, 12, 1–24.
- Mutlu, A., Gyulkhandanyan, A.V., Freedman, J. & Leytin, V. (2012) Activation of caspases-9, -3 and -8 in human platelets triggered by BH3-only mimetic ABT-737 and calcium ionophore A23187: caspase-8 is activated via bypass of the death receptors. British Journal of Haematology, 159, 565–571.
- Noisakran, S., Onlamoon, N., Pattanapanyasat, K., Hsiao, H.M., Songprakhon, P., Angkasekwinai, N., Chokephaibulkit, K., Villinger, F., Ansari, A.A. & Perng, G.C. (2012) Role of CD61+ cells in thrombocytopenia of dengue patients. International Journal of Hematology, 96, 600–610.
- Oberst, A., Dillon, C.P., Weinlich, R., Mccormick, L.L., Fitzgerald, P., Pop, C., Hakem, R., Salvesen, G.S. & Green, D.R. (2011) Catalytic activity of the caspase-8-FLIPL complex inhibits RIPK3-dependent necrosis. Nature, 471, 363–367.
- Ogilvy, S., Metcalf, D., Gibson, L., Bath, M., Harris, A. & Adams, J. (1999) Promoter elements of vav drive transgene expression in vivo throughout the hematopoietic compartment. Blood, 94, 1855–1863.
- Oltersdorf, T., Elmore, S.W., Shoemaker, A.R., Armstrong, R.C., Augeri, D.J., Belli, B.A., Bruncko, M., Deckwerth, T.L., Dinges, J., Hajduk, P.J., Joseph, M.K., Kitada, S., Korsmeyer, S.J., Kunzer, A.R., Letai, A., Li, C., Mitten, M.J., Nettesheim, D.G., Ng, S., Nimmer, P.M., O'Connor, J.M., Oleksijew, A., Petros, A.M., Reed, J.C., Shen, W., Tahir, S.K., Thompson, C.B., Tomaselli, K.J., Wang, B., Wendt, M.D., Zhang, H., Fesik, S.W. & Rosenberg, S.H. (2005) An inhibitor of Bcl-2 family proteins induces regression of solid tumours. Nature, 435, 677–681.
- Pardanani, A. (2012) Ruxolitinib for myelofibrosis therapy: current context, pros and cons. Leukemia, 26, 1449–1451.
- Plenchette, S., Moutet, M., Benguella, M., N'Gondara, J., Guigner, F., Coffe, C., Corcos, L., Bettaieb, A. & Solary, E. (2001) Early increase in DcR2 expression and late activation of caspases in the platelet storage lesion. Leukemia, 15, 1572–1581.
- Radley, J. & Haller, C. (1983) Fate of senescent megakaryocytes in the bone marrow. British Journal of Haematology, 53, 277–287.
- Rathmell, J., Lindsten, T., Zong, W. & Thompson, C. (2002) Deficiency in Bak and Bax perturbs thymic selection and lymphoid homeostasis. Nature Immunology, 3, 932–939.
- Ren, D., Tu, H.-C., Kim, H., Wang, G.X., Bean, G.R., Takeuchi, O., Jeffers, J.R., Zambetti, G.P., Hsieh, J.J.-D. & Cheng, E.H.-Y. (2010) BID, BIM, and PUMA are essential for activation of the BAX- and BAK-dependent cell death program. Science, 330, 1390–1393.
- Roberts, A.W., Seymour, J.F., Brown, J.R., Wierda, W.G., Kipps, T.J., Khaw, S.L., Carney, D.A., He, S.Z., Huang, D.C., Xiong, H., Cui, Y., Busman, T.A., McKeegan, E.M., Krivoshik, A.P., Enschede, S.H. & Humerickhouse, R. (2011) Substantial susceptibility of chronic lymphocytic leukemia to BCL2 inhibition: results of a phase i study of navitoclax in patients with relapsed or refractory disease. Journal of Clinical Oncology, 30, 488–496.
- Scaffidi, C., Fulda, S., Srinivasan, A., Friesen, C., Li, F., Tomaselli, K.J., Debatin, K.M., Krammer, P.H. & Peter, M.E. (1998) Two CD95 (APO-1/Fas) signaling pathways. EMBO Journal, 17, 1675–1687.
- Schattner, M., Rivadeneyra, L., Pozner, R.G. & Gomez, R.M. (2013) Pathogenic mechanisms involved in the hematological alterations of arenavirus-induced hemorrhagic fevers. Viruses, 5, 340–351.
- Schoenwaelder, S.M. & Jackson, S.P. (2012) Bcl-xL-inhibitory BH3 mimetics (ABT-737 or ABT-263) and the modulation of cytosolic calcium flux and platelet function. Blood, 119, 1320–1321.
- Schoenwaelder, S.M., Yuan, Y., Josefsson, E.C., White, M.J., Yao, Y., Mason, K.D., O'Reilly, L.A., Henley, K.J., Ono, A., Hsiao, S., Willcox, A., Roberts, A.W., Huang, D.C.S., Salem, H.H., Kile, B.T. & Jackson, S.P. (2009) Two distinct pathways regulate platelet phosphatidylserine exposure and procoagulant function. Blood, 114, 663–666.
- Schoenwaelder, S.M., Jarman, K.E., Gardiner, E.E., Hua, M., Qiao, J., White, M.J., Josefsson, E.C., Alwis, I., Ono, A., Willcox, A., Andrews, R.K., Mason, K.D., Salem, H.H., Huang, D.C.S., Kile, B.T., Roberts, A.W. & Jackson, S.P. (2011) Bcl-xL-inhibitory BH3 mimetics can induce a transient thrombocytopathy that undermines the hemostatic function of platelets. Blood, 118, 1663–1674.
- Souers, A.J., Leverson, J.D., Boghaert, E.R., Ackler, S.L., Catron, N.D., Chen, J., Dayton, B.D., Ding, H., Enschede, S.H., Fairbrother, W.J., Huang, D.C.S., Hymowitz, S.G., Jin, S., Khaw, S.L., Kovar, P.J., Lam, L.T., Lee, J., Maecker, H.L., Marsh, K.C., Mason, K.D., Mitten, M.J., Nimmer, P.M., Oleksijew, A., Park, C.H., Park, C.-M., Phillips, D.C., Roberts, A.W., Sampath, D., Seymour, J.F., Smith, M.L., Sullivan, G.M., Tahir, S.K., Tse, C., Wendt, M.D., Xiao, Y., Xue, J.C., Zhang, H., Humerickhouse, R.A., Rosenberg, S.H. & Elmore, S.W. (2013) ABT-199, a potent and selective BCL-2 inhibitor, achieves antitumor activity while sparing platelets. Nature Medicine, 19, 202–208.
- Stefanini, M. & Dameshek, W. (1953) Collection, preservation and transfusion of platelets; with special reference to the factors affecting the survival rate and the clinical effectiveness of transfused platelets. New England Journal of Medicine, 248, 797–802.
- Temkin, V., Huang, Q., Liu, H., Osada, H. & Pope, R.M. (2006) Inhibition of ADP/ATP exchange in receptor-interacting protein-mediated necrosis. Molecular and Cellular Biology, 26, 2215–2225.
- Thiele, J., Holgado, S., Choritz, H. & Georgii, A. (1983) Density distribution and size of megakaryocytes in inflammatory reactions of the bone marrow (myelitis) and chronic myeloproliferative diseases. Scandinavian Journal of Haematology, 31, 329–341.
- Tse, C., Shoemaker, A.R., Adickes, J., Anderson, M.G., Chen, J., Jin, S., Johnson, E.F., Marsh, K.C., Mitten, M.J., Nimmer, P., Roberts, L., Tahir, S.K., Xiao, Y., Yang, X., Zhang, H., Fesik, S., Rosenberg, S.H. & Elmore, S.W. (2008) ABT-263: a potent and orally bioavailable Bcl-2 family inhibitor. Cancer Research, 68, 3421–3428.
- Vanags, D.M. & Orrenius, S. (1997) Alterations in Bcl-2/Bax protein levels in platelets form part of an ionomycin-induced process that resembles apoptosis. British Journal of Haematology, 99, 824–831.
- Vanlangenakker, N., Vanden Berghe, T. & Vandenabeele, P. (2012) Many stimuli pull the necrotic trigger, an overview. Cell Death and Differentiation, 19, 75–86.
- Vogler, M., Hamali, H.A., Sun, X.M., Bampton, E.T.W., Dinsdale, D., Snowden, R.T., Dyer, M.J.S., Goodall, A.H. & Cohen, G.M. (2011) BCL2/BCL-XL inhibition induces apoptosis, disrupts cellular calcium homeostasis, and prevents platelet activation. Blood, 117, 7145–7154.
- Vogler, M., Goodall, A.H. & Cohen, G.M. (2012) Response: BH3 mimetics modulate calcium homeostasis in platelets. Blood, 119, 1321–1322.
- Waibel, M., Solomon, V.S., Knight, D.A., Ralli, R.A., Kim, S.K., Banks, K.M., Vidacs, E., Virely, C., Sia, K.C., Bracken, L.S., Collins-Underwood, R., Drenberg, C., Ramsey, L.B., Meyer, S.C., Takiguchi, M., Dickins, R.A., Levine, R., Ghysdael, J., Dawson, M.A., Lock, R.B., Mullighan, C.G. & Johnstone, R.W. (2013) Combined Targeting of JAK2 and Bcl-2/Bcl-xL to Cure Mutant JAK2-Driven Malignancies and Overcome Acquired Resistance to JAK2 Inhibitors. Cell Reports, 5, 1047–1059.
- Wei, M.C., Zong, W.X., Cheng, E.H., Lindsten, T., Panoutsakopoulou, V., Ross, A.J., Roth, K.A., MacGregor, G.R., Thompson, C.B. & Korsmeyer, S.J. (2001) Proapoptotic BAX and BAK: a requisite gateway to mitochondrial dysfunction and death. Science, 292, 727–730.
- White, M.J., Schoenwaelder, S.M., Josefsson, E.C., Jarman, K.E., Henley, K.J., James, C., Debrincat, M.A., Jackson, S.P., Huang, D.C.S. & Kile, B.T. (2012) Caspase-9 mediates the apoptotic death of megakaryocytes and platelets, but is dispensable for their generation and function. Blood, 119, 4283–4290.
- Willis, S.N., Fletcher, J.I., Kaufmann, T., van Delft, M.F., Chen, L., Czabotar, P.E., Ierino, H., Lee, E.F., Fairlie, W.D., Bouillet, P., Strasser, A., Kluck, R.M., Adams, J.M. & Huang, D.C. (2007) Apoptosis initiated when BH3 ligands engage multiple Bcl-2 homologs, not Bax or Bak. Science, 315, 856–859.
- Wilson, W.H., O'Connor, O.A., Czuczman, M.S., LaCasce, A.S., Gerecitano, J.F., Leonard, J.P., Tulpule, A., Dunleavy, K., Xiong, H., Chiu, Y.L., Cui, Y., Busman, T., Elmore, S.W., Rosenberg, S.H., Krivoshik, A.P., Enschede, S.H. & Humerickhouse, R.A. (2010) Navitoclax, a targeted high-affinity inhibitor of BCL-2, in lymphoid malignancies: a phase 1 dose-escalation study of safety, pharmacokinetics, pharmacodynamics, and antitumour activity. Lancet Oncology, 11, 1149–1159.
- Winkler, J., Kroiss, S., Rand, M.L., Azzouzi, I., Annie Bang, K.W., Speer, O. & Schmugge, M. (2011) Platelet apoptosis in paediatric immune thrombocytopenia is ameliorated by intravenous immunoglobulin. British Journal of Haematology, 156, 508–515.
- Wolf, B., Goldstein, J., Stennicke, H., Beere, H., Amarante-Mendes, G., Salvesen, G. & Green, D. (1999) Calpain functions in a caspase-independent manner to promote apoptosis-like events during platelet activation. Blood, 94, 1683–1692.
- Wu, Y.-T., Tan, H.-L., Huang, Q., Sun, X.-J., Zhu, X. & Shen, H.-M. (2011) zVAD-induced necroptosis in L929 cells depends on autocrine production of TNFα mediated by the PKC-MAPKs-AP-1 pathway. Cell Death and Differentiation, 18, 26–37.
- Yang, L., Wang, L., Zhao, C.-H., Zhu, X.-J., Hou, Y., Jun, P. & Hou, M. (2010) Contributions of TRAIL-mediated megakaryocyte apoptosis to impaired megakaryocyte and platelet production in immune thrombocytopenia. Blood, 116, 4307–4316.
- Yeh, J.-J., Tsai, S., Wu, D.-C., Wu, J.-Y., Liu, T.-C. & Chen, A. (2010) P-selectin-dependent platelet aggregation and apoptosis may explain the decrease in platelet count during Helicobacter pylori infection. Blood, 115, 4247–4253.
- Yin, X., Wang, K., Gross, A., Zhao, Y., Zinkel, S., Klocke, B., Roth, K. & Korsmeyer, S. (1999) Bid-deficient mice are resistant to Fas-induced hepatocellular apoptosis. Nature, 400, 886–891.
- Youle, R.J. & Strasser, A. (2008) The BCL-2 protein family: opposing activities that mediate cell death. Nature Reviews Molecular Cell Biology, 9, 47–59.
- Zauli, G., Catani, L., Gibellini, D., Re, M., Vianelli, N., Colangeli, V., Celeghini, C., Capitani, S. & La Placa, M. (1996) Impaired survival of bone marrow GPIIb/IIa+ megakaryocytic cells as an additional pathogenetic mechanism of HIV-1-related thrombocytopenia. British Journal of Haematology, 92, 711–717.
- Zauli, G., Vitale, M., Falcieri, E., Gibellini, D., Bassini, A., Celeghini, C., Columbaro, M. & Capitani, S. (1997) In vitro senescence and apoptotic cell death of human megakaryocytes. Blood, 90, 2234–2243.
- Zhang, H., Nimmer, P.M., Tahir, S.K., Chen, J., Fryer, R.M., Hahn, K.R., Iciek, L.A., Morgan, S.J., Nasarre, M.C., Nelson, R., Preusser, L.C., Reinhart, G.A., Smith, M.L., Rosenberg, S.H., Elmore, S.W. & Tse, C. (2007) Bcl-2 family proteins are essential for platelet survival. Cell Death and Differentiation, 14, 943–951.
- Zhang, H., Zhou, X., Mcquade, T., Li, J., Chan, F.K.-M. & Zhang, J. (2011) Functional complementation between FADD and RIP1 in embryos and lymphocytes. Nature, 471, 373–376.
- Zhang, S., Ye, J., Zhang, Y., Xu, X., Liu, J., Zhang, S.H., Kunapuli, S.P. & Ding, Z. (2013) P2Y12 protects platelets from apoptosis via PI3k-dependent Bak/Bax inactivation. Journal of Thrombosis and Haemostasis, 11, 149–160.
- Zucker-Franklin, D., Termin, C. & Cooper, M. (1989) Structural changes in the megakaryocytes of patients infected with the human immune deficiency virus (HIV-1). American Journal of Pathology, 134, 1295–1303.
- Zwaal, R.F., Comfurius, P. & van Deenen, L.L. (1977) Membrane asymmetry and blood coagulation. Nature, 268, 358–360.