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. 2017 Apr 20;24(4):507-514.e4.
doi: 10.1016/j.chembiol.2017.03.009. Epub 2017 Apr 6.

Pyroptosis and Apoptosis Pathways Engage in Bidirectional Crosstalk in Monocytes and Macrophages

Cornelius Y Taabazuing  1 , Marian C Okondo  1 , Daniel A Bachovchin  2
Affiliations

Pyroptosis and Apoptosis Pathways Engage in Bidirectional Crosstalk in Monocytes and Macrophages

Cornelius Y Taabazuing et al. Cell Chem Biol. .

"V体育官网入口" Abstract

Pyroptosis is a lytic form of programmed cell death mediated by the inflammatory caspase-1, -4, and -5. We recently discovered that small-molecule inhibitors of the serine peptidases DPP8 and DPP9 (DPP8/9) induce pro-caspase-1-dependent pyroptosis in monocytes and macrophages. Notably, DPP8/9 inhibitors, unlike microbial agents, absolutely require caspase-1 to induce cell death. Therefore, DPP8/9 inhibitors are useful probes to study caspase-1 in cells. Here, we show that, in the absence of the pyroptosis-mediating substrate gasdermin D (GSDMD), caspase-1 activates caspase-3 and -7 and induces apoptosis, demonstrating that GSDMD is the only caspase-1 substrate that induces pyroptosis. Conversely, we found that, during apoptosis, caspase-3/-7 specifically block pyroptosis by cleaving GSDMD at a distinct site from the inflammatory caspases that inactivates the protein VSports手机版. Overall, this work reveals bidirectional crosstalk between apoptosis and pyroptosis in monocytes and macrophages, further illuminating the complex interplay between cell death pathways in the innate immune system. .

Keywords: DPP8/9 inhibitors; apoptosis; caspase-1; caspase-3; caspase-7; cell death; gasdermin D; macrophages; monocytes; pyroptosis V体育安卓版. .

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Figures

Figure 1
Figure 1. Val-boroPro induces apoptosis in Gsdmd−/− macrophages. See also Fig. S1 and Movies S1–4
(A) The structure of Val-boroPro. (B) Confirmation of Gsdmd knockout (KO) in RAW 264.7 macrophages by immunoblotting. An asterisk (*) indicates a background band. (C) LDH release from Gsdmd−/− RAW 264.7 cells treated with Val-boroPro was delayed, but not prevented. Caspase-1 is required for Val-boroPro-induced cell death. Data are means ± SEM of 3 independent experiments. *** p < 0.001 for GFP versus Gsdmd KO cells. (D) Static brightfield images of control and Gsdmd KO1 RAW 264.7 cells treated with Val-boroPro or etoposide. Arrows indicate dying cells. The images are representative of four randomly selected fields. (E) Immunoblotting reveals Parp cleavage in Gsdmd−/−, but not in control or Casp−/−, RAW 264.7 cells treated with Val-boroPro. As expected, etoposide induced Parp cleavage in all cells tested here. VbP, Val-boroPro; Etop., etoposide; FL, full-length; CL, cleaved.
Figure 2
Figure 2. Val-boroPro activates caspases-3/7 in GSDMD knockout cells. See also Figs. S1-4
(A) Immunoblotting reveals PARP cleavage in GSDMD−/−, but not in control or CASP−/−, THP-1 cells treated with Val-boroPro. In control cells, Val-boroPro induces the cleavage of GSDMD into the pyroptotic p30 fragment. Etoposide unexpectedly triggered the formation of a p43 fragment of GSDMD in control and CASP−/− cells. (B) Val-boroPro induces Annexin V positive/propidium iodide (PI) negative staining in GSDMD−/− THP-1 cells. Data are means ± SEM of 3 independent experiments. *** p < 0.001 compared to DMSO treated cells. (C–E) Effects of Val-boroPro, LPS plus nigericin, and etoposide on PARP and GSDMD in wild-type (C), GSDMD KO1 (D), and CASP1 KO1 (E) THP-1 cells as determined by immunoblotting. Nig, nigericin. (F) Val-boroPro induces cleavage of caspases-3 and -7 in GSDMD knockout cells. (G) Caspase-3/7 activity is elevated in GSMD KO THP-1 cells treated with Val-boroPro. Data are means ± SEM of 3 independent experiments. *** p < 0.001 compared to DMSO treated cells.
Figure 3
Figure 3. Caspases-3/7 cleave GSDMD into p43 fragment during apoptosis
(A) Immunoblotting of lysates from THP-1 cells treated with the indicated apoptotic stimuli reveals GSDMD cleavage into a p43 fragment. (B,C) Lysates from HEK 293T cells expressing C-terminally tagged human (B) or mouse (C) GSDMD were incubated (2 h, 37 °C) with the indicated recombinant caspases and cleavage was evaluated by immunoblotting.
Figure 4
Figure 4. Apoptotic caspase cleavage at D87 inactivates GSDMD
(A) A predicted caspase-3 cleavage site in GSDMD is conserved across the indicated species. (B) Schematic of GSDMD cleavage fragments. (C) Lysates from HEK 293T cells expressing C-terminally tagged human GSDMD D87A were incubated with recombinant caspases (2 h, 37 °C). While caspase-1 still cleaves this mutant protein at D275, caspases-3/7 cleavage was completely abolished. (D–G) HEK 293T cells were transiently transfected with the indicated GSDMD fragments. Each fragment possessed a C-terminal V5 tag. Expression of the fragment was evaluated by immunoblotting (D,F) and cell death was evaluated using an LDH assay (E,G). Data are means ± SEM of 3 independent experiments. *** p < 0.001 compared to GFP expressing cells.
Figure 5
Figure 5. Apoptosis and pyroptosis interplay in monocytes and macrophages
Schematic depicting the bidirectional crosstalk between the apoptotic and pyroptotic cell death pathways in monocytes and macrophages. The dashed red arrow indicates that caspase-1 activates caspase-3/7 in cells, but that it is not yet definitively established if this is due to direct or indirect cleavage in vivo.
See this image and copyright information in PMC

"VSports在线直播" References

    1. Aachoui Y, Leaf IA, Hagar JA, Fontana MF, Campos CG, Zak DE, Tan MH, Cotter PA, Vance RE, Aderem A, et al. Caspase-11 protects against bacteria that escape the vacuole. Science. 2013;339:975–978. - PMC - PubMed
    1. Akhter A, Gavrilin MA, Frantz L, Washington S, Ditty C, Limoli D, Day C, Sarkar A, Newland C, Butchar J, et al. Caspase-7 activation by the Nlrc4/Ipaf inflammasome restricts Legionella pneumophila infection. PLoS Pathog. 2009;5:e1000361. - "VSports最新版本" PMC - PubMed
    1. Bergsbaken T, Fink SL, Cookson BT. Pyroptosis: host cell death and inflammation. Nat Rev Microbiol. 2009;7:99–109. - PMC - PubMed
    1. Boyden ED, Dietrich WF. Nalp1b controls mouse macrophage susceptibility to anthrax lethal toxin. Nat Genet. 2006;38:240–244. - PubMed
    1. Broz P. Immunology: Caspase target drives pyroptosis. Nature. 2015;526:642–643. - PubMed

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