Adenosine produced from adenine nucleotides through an interaction between apoptotic cells and engulfing macrophages contributes to the appearance of transglutaminase 2 in dying thymocytes
- 289 Downloads
Transglutaminase 2 (TG2) has been known for a long time to be associated with the in vivo apoptosis program of various cell types, including T cells. Though the expression of the enzyme is strongly induced in mouse thymocytes following apoptosis induction in vivo, no significant induction of TG2 can be detected, when thymocytes are induced to die by the same stimuli in vitro indicating that signals arriving from the tissue environment are required for the proper in vivo induction of the enzyme. Previous studies from our laboratory have demonstrated that two of these signals, transforming growth factor-β (TGF-β) and retinoids, are produced by macrophages engulfing apoptotic cells. However, in addition to TGF-β and retinoids, engulfing macrophages produce adenosine as well. Here, we show that in vitro adenosine, adenosine, and retinoic acid or adenosine, TGF-β and retinoic acids together can significantly enhance the TG2 mRNA expression in dying thymocytes. The effect of adenosine is mediated via adenosine A2A receptors (A2ARs) and the A2AR-triggered adenylate cyclase signaling pathway. In accordance, loss of A2ARs in A2AR null mice significantly attenuates the in vivo induction of TG2 following apoptosis induction in the thymus indicating that adenosine indeed contributes in vivo to the apoptosis-related appearance of the enzyme. We also demonstrate that adenosine is produced extracellularly during engulfment of apoptotic thymocytes, partly from adenine nucleotides released via thymocyte pannexin-1 channels. Our data reveal a novel crosstalk between macrophages and apoptotic cells, in which apoptotic cell uptake-related adenosine production contributes to the appearance of TG2 in the dying thymocytes.
KeywordsApoptosis Macrophages Phagocytosis Adenosine Transglutaminase 2
Adenosine A2A receptor
Adenosine A3 receptor
9-cis retinoic acid
Cytokine-induced neutrophil-attracting chemokine
Macrophage inflammatory protein
Transforming growth factor-β
We acknowledge Merck for providing the A3R null mice and Professor Catherine Ledent for providing the A2AR null mice. The help of Zsolt Sarang in putting together the figures and the technical assistance of Edit Komóczi and Zsolt Hartmann are gratefully acknowledged. This study was supported by Hungarian grants from the National Research Fund OTKA T104228 and NK 105046, and the TÁMOP 4.2.2.A-11/1/KONV-2012-0023 “VÉD-ELEM” project. The project is implemented through the New Hungary Development Plan co-financed by the European Social Fund and the European Regional Development Fund.
Compliance with ethical standards
Conflict of interest
There is no competing interest.
In our animal experiments
All applicable international, national, and/or institutional guidelines for the care and use of animals were followed.
- Amendola A, Gougeon ML, Poccia F, Bondurand A, Fesus L, Piacentini M (1996) Induction of “tissue” transglutaminase in HIV pathogenesis: evidence for high rate of apoptosis of CD4+ T lymphocytes and accessory cells in lymphoid tissues. Proc Natl Acad Sci USA 93:11057–11062CrossRefPubMedPubMedCentralGoogle Scholar
- Chekeni FB, Elliott MR, Sandilos JK, Walk SF, Kinchen JM, Lazarowski ER, Armstrong AJ, Penuela S, Laird DW, Salvesen GS, Isakson BE, Bayliss DA, Ravichandran KS (2010) Pannexin-1 channels mediate ‘find-me’ signal release and membrane permeability during apoptosis. Nature 467:863–867CrossRefPubMedPubMedCentralGoogle Scholar
- Csóka B, Németh ZH, Virág L, Gergely P, Leibovich SJ, Pacher P, Sun CX, Blackburn MR, Vizi ES, Deitch EA, Haskó G (2007) A2A adenosine receptors and C/EBPbeta are crucially required for IL-10 production by macrophages exposed to Escherichia coli. Blood 110:2685–2695CrossRefPubMedPubMedCentralGoogle Scholar
- Elliott MR, Chekeni FB, Trampont PC, Lazarowski ER, Kadl A, Walk SF, Park D, Woodson RI, Ostankovich M, Sharma P, Lysiak JJ, Harden TK, Leitinger N, Ravichandran KS (2009) Nucleotides released by apoptotic cells act as a find-me signal to promote phagocytic clearance. Nature 46:282–286CrossRefGoogle Scholar
- Fabbi M, Marimpietri D, Martini S, Brancolini C, Amoresano A, Scaloni A, Bargellesi A, Cosulich E (1999) Tissue transglutaminase is a caspase substrate during apoptosis. Cleavage causes loss of transamidating function and is a biochemical marker of caspase 3 activation. Cell Death Differ 6:992–1001CrossRefPubMedGoogle Scholar
- Fadok VA, Bratton DL, Konowal A, Freed PW, Westcott JY, Henson PM (1998) Macrophages that have ingested apoptotic cells in vitro inhibit proinflammatory cytokine production through autocrine/paracrine mechanisms involving TGF-beta, PGE2, and PAF. J Clin Invest 101:890–898CrossRefPubMedPubMedCentralGoogle Scholar
- Köröskényi K, Duró E, Pallai A, Sarang Z, Kloor D, Ucker DS, Beceiro S, Castrillo A, Chawla A, Ledent CA, Fésüs L, Szondy Z (2011) Involvement of adenosine A2A receptors in engulfment-dependent apoptotic cell suppression of inflammation. J Immunol 186:7144–7155CrossRefPubMedPubMedCentralGoogle Scholar
- Ledent C, Vaugeois JM, Schiffmann SN, Pedrazzini T, El Yacoubi M, Vanderhaeghen JJ, Costentin J, Heath JK, Vassart G, Parmentier M (1977) Aggressiveness, hypoalgesia and high blood pressure in mice lacking the adenosine A2a receptor. Nature 388:674–678Google Scholar
- Petersen CB, Nygård AB, Viuff B, Fredholm M, Aasted B, Salomonsen J (2007) Porcine ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1/CD203a): cloning, transcription, expression, mapping, and identification of an NPP1/CD203a epitope for swine workshop cluster 9 (SWC9) monoclonal antibodies. Dev Comp Immunol 31:618–631CrossRefPubMedGoogle Scholar
- Streitová D, Sefc L, Savvulidi F, Pospísil M, Holá J, Hofer M (2010) Adenosine A(1), A(2a), A(2b), and A(3) receptors in hematopoiesis. 1. Expression of receptor mRNA in four mouse hematopoietic precursor cells. Physiol Rev 59:133–137Google Scholar
- Szondy Z, Sarang Z, Molnar P, Nemeth T, Piacentini M, Mastroberardino PG, Falasca L, Aeschlimann D, Kovacs J, Kiss I, Szegezdi E, Lakos G, Rajnavolgyi E, Birckbichler PJ, Melino G, Fesus L (2003) Transglutaminase 2−/− mice reveal a phagocytosis-associated crosstalk between macrophages and apoptotic cells. Proc Natl Acad Sci USA 100:7812–7817CrossRefPubMedPubMedCentralGoogle Scholar
- van Hassert PJM, van Driel R, Jastorff B (1984) Competitive cAMP antagonists for cAMP-receptor proteins. J Biol Chem 259:10020–10024Google Scholar