Prostaglandin D2 and its metabolites induce caspase-dependent granulocyte apoptosis that is mediated via inhibition of I kappa B alpha degradation using a peroxisome proliferator-activated receptor-gamma-independent mechanism.
Many inflammatory mediators retard granulocyte apoptosis. Most natural PGs studied herein (e.g., PGE(2), PGA(2), PGA(1), PGF(2 alpha)) either delayed apoptosis or had no effect, whereas PGD(2) and its metabolite PGJ(2) selectively induced eosinophil, but not neutrophil apoptosis. This novel proapoptotic effect does not appear to be mediated via classical PG receptor ligation or by elevation of intracellular cAMP or Ca(2+). Intriguingly, the sequential metabolites Delta(12)PGJ(2) and 15-deoxy-Delta(12,) Delta(14)-PGJ(2) (15dPGJ(2)) induced caspase-dependent apoptosis in both granulocytes, an effect that did not involve de novo protein synthesis. Despite the fact that Delta(12)PGJ(2) and 15dPGJ(2) are peroxisome proliferator-activated receptor-gamma (PPAR-gamma) activators, apoptosis was not mimicked by synthetic PPAR-gamma and PPAR-alpha ligands or blocked by an irreversible PPAR-gamma antagonist. Furthermore, Delta(12)PGJ(2) and 15dPGJ(2) inhibited LPS-induced I kappa B alpha degradation and subsequent inhibition of neutrophil apoptosis, suggesting that apoptosis is mediated via PPAR-gamma-independent inhibition of NF-kappa B activation. In addition, we show that TNF-alpha-mediated loss of cytoplasmic I kappa B alpha in eosinophils is inhibited by 15dPGJ(2) in a concentration-dependent manner. The selective induction of eosinophil apoptosis by PGD(2) and PGJ(2) may help define novel therapeutic pathways in diseases in which it would be desirable to specifically remove eosinophils but retain neutrophils for antibacterial host defense. The powerful proapoptotic effects of Delta(12)PGJ(2) and 15dPGJ(2) in both granulocyte types suggest that these natural products control the longevity of key inflammatory cells and may be relevant to understanding the control and resolution of inflammation.
Ward
Carol
C
Rayne Laboratory, Respiratory Medicine Unit, Medical Research Council Center for Inflammation Research, University of Edinburgh Medical School, Edinburgh, United Kingdom.
Dransfield
Ian
I
Murray
Joanna
J
Farrow
Stuart N
SN
Haslett
Christopher
C
Rossi
Adriano G
AG
D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D001665:Binding Sites / Q000187:drug effects / Q000502:physiology; D020169:Caspases / Q000378:metabolism / Q000502:physiology*; D016923:Cell Death / Q000502:physiology; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D015237:Dinoprost / Q000378:metabolism; D004789:Enzyme Activation / Q000502:physiology; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D006098:Granulocytes / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D006801:Humans; D006868:Hydrolysis / Q000187:drug effects; D020672:I-kappa B Proteins; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors*; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D020675:Peroxisomes / Q000378:metabolism*; D015230:Prostaglandin D2 / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D014176:Protein Biosynthesis; D018160:Receptors, Cytoplasmic and Nuclear / Q000819:agonists / Q000378:metabolism / Q000502:physiology*; D011971:Receptors, Immunologic; D011982:Receptors, Prostaglandin / Q000378:metabolism / Q000502:physiology; D000077154:Rosiglitazone; D013844:Thiazoles / Q000494:pharmacology; D045162:Thiazolidinediones; D014157:Transcription Factors / Q000819:agonists / Q000378:metabolism / Q000502:physiology*
C097240:15-deoxy-delta(12,14)-prostaglandin J2; D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D018160:Receptors, Cytoplasmic and Nuclear; D011971:Receptors, Immunologic; D011982:Receptors, Prostaglandin; D013844:Thiazoles; D045162:Thiazolidinediones; D014157:Transcription Factors; C034671:prostaglandin F2alpha receptor; D000077154:Rosiglitazone; D000072000:NF-KappaB Inhibitor alpha; C037112:9-deoxy-delta-9-prostaglandin D2; C040810:9-deoxy-9,10-didehydro-12,13-didehydro-13,14-dihydroprostaglandin D2; D015237:Dinoprost; D020169:Caspases; D015230:Prostaglandin D2; C036293:prostaglandin D2 receptor