Inflammasomes are multimeric protein complexes that comprise a sensor (e.g. NLRP3), an adaptor (ASC/Pycard) and a protease (pro-caspase-1) (1). An inflammasome assembles in response to a diverse range of pathogen-associated or danger-associated molecular patterns (PAMPs or DAMPs), or perturbations in cytoplasmic homeostasis (term 'homeostasis-altering molecular processes' (HAMPs)) (2). The inflammasome platform leads to activation of caspase-1, which further induces maturation of interleukin-1β and -18 (IL-1β and IL-18) through proteolytic cleavage of pro-IL-1β and pro-IL-18. Activated caspase-1, and also the recently characterized caspase-11 non-canonical inflammasome pathway, cleave the newly discovered intracellular protein Gasdermin D (3, 4). The Gasdermin family members contain N-terminal domains that are capable of forming membrane pores, whereas the C-terminal domains of Gasdermins function as inhibitors of such cytolysis through intramolecular domain association. Caspase-1 or -11 cleavage of Gasdermin D is required for regulation of Pyroptosis: upon caspase-1/11 cleavage of the Gasdermin N- and C-domain linker, the cleaved N-terminal fragment of Gasdermin D oligomerizes and forms pores on the host cell membrane (5), leading to a cell death called pyroptosis and further activation of inflammasomes by triggering K+ efflux (6). Gasdermin D forming pores regulate the non-conventional secretion of cytokines such as IL-1β, in response to cytosolic LPS and other activators of the inflammasome (7). Neutrophil extrusion of neutrophil extracellular traps (NETs) and concomitant cell death (NETosis), a particular neutrophil defense against pathogens, are dependent on Gasdermin D cleavage by caspase-11 (8). Gasdermin D-mediated pyroptosis is regulated at the level of lipid peroxidation (9) and seems to be a key effector in the LPS-induced lethal sepsis (10).

Caspase-8, an upstream activator of caspase-3, controls apoptotic cell death and prevents RIPK3–MLKL-dependent necroptosis. Caspase-8, activated by the Yersinia effector protein YopJ, also triggers Gasdermin D processing and cell death with different Yersinia species (11).

After formation of the pore at the cellular membrane by Gasdermin D N-terminal fragment, the role and fate of the C-terminus fragment of Gasdermin D is still unclear. Using the Gasdermin D (mouse) ELISA Kit (Prod. No. AG-45B-0011), that detects the C-terminal part of Gasdermin D (as well as the full-length protein), a signal is detected in the supernatant of cells dying by pyroptosis, suggesting that the C-terminal fragment is released from cells, either by chance due to the presence of a pore or for a specific task not yet clear.

Literature References:

1. The inflammasome: a molecular platform triggering activation of inflammatory caspases and processing of proIL-beta: F. Martinon, et al.; Mol. Cell 10, 417 (2002)
2. Homeostasis-altering molecular processes as mechanisms of inflammasome activation: A. Liston & S.L. Masters; Nat. Rev. Immunol. 17, 208 (2017)
3. Caspase-11 cleaves gasdermin D for non-canonical inflammasome signalling: N. Kayagaki, et al.; Nature 526, 666 (2015)
4. Mechanisms of Gasdermin Family Members in Inflammasome Signaling and Cell Death: S. Feng, et al.; J. Mol. Biol. 430, 3068 (2018)
5. Inflammasome-activated gasdermin D causes pyroptosis by forming membrane pores: X. Liu, et al.; Nature 535, 153 (2016)
6. Gasdermin D Restrains Type I Interferon Response to Cytosolic DNA by Disrupting Ionic Homeostasis: I. Banerjee, et al.; Immunity 49, 413 (2018)
7. The Pore-Forming Protein Gasdermin D Regulates Interleukin-1 Secretion from Living Macrophages: C.L. Evavold, et al.; Immunity 48, 35 (2018)
8. Noncanonical inflammasome signaling elicits gasdermin D-dependent neutrophil extracellular traps: K.W. Chen, et al.; Sci. Immunol. 3, 26 (2018)
9. Lipid Peroxidation Drives Gasdermin D-mediated Pyroptosis in Lethal Polymicrobial Sepsis: R. Kang, et al.; Cell Host Microbe 24, 97 (2018)
10. Chemical disruption of the pyroptotic pore-forming protein gasdermin D inhibits inflammatory cell death and sepsis: J.K. Rathkey, et al.; Sci. Immunol. 3, 26 (2018)
11. Pathogen blockade of TAK1 triggers caspase-8-dependent cleavage of gasdermin D and cell death: P. Orning, et al.; Science (Epub ahead of print) 26 (2018)

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New Reagents for Gasdermin Research

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NEW Gasdermin D (mouse) ELISA Kit

The Gasdermin D (mouse) ELISA Kit (Prod. No. AG-45B-0011) is a sandwich ELISA for quantitative determination of mouse Gasdermin D in cell culture supernatants and in cell extracts. This ELISA is specific for the measurement of natural and recombinant mouse Gasdermin D (full-length and C-terminus cleaved fragment). It does not detect human Gasdermin D.

Download the ELISA Kit Manual

Download the Scientific Poster presented at the EMBO Inflammasome Symposia 2018 in Munich

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NEW Gasdermin E (human) ELISA Kit

Gasdermin E (GSDME), also called DFNA5, is a member of the gasdermin family. Recent studies found that GSDME features a caspase-3 cleavage motif in its linker region. Similar to GSDMD, cleavage of GSDME by caspases-3/-7 liberates the N-terminal pyroptosis-inducing domain (GSDMENT) from its autoinhibitory C-terminal regulatory domain to trigger membrane pores and pyroptosis. Mutations in GSDME in human are associated with development of heritable, nonsyndromal deafness. Abnormalities in pyroptotic cell deaths are associated with a range of human diseases including infections, autoinflammatory disease, neurodegenerative disease and cancer. The Gasdermin E (human) ELISA Kit (AG-45B-0024) detects the C-terminal domain of  human Gasdermin E as well as the full-length protein. Upon cleavage of Gasdermin E and pore formation, the C-terminus fragment should be released in the extracellular space and is found in serum/plasma. The role of the C-terminus fragment of Gasdermin protein family is unclear.

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NEW anti-Gasdermin D (mouse), pAb (IN110) 

AdipoGen Life Sciences' anti-Gasdermin D (mouse), pAb (IN110) (Prod. No. AG-25B-0036) is a polyclonal antibody immunised with the recombinant C-terminus domain of mouse Gasdermin D. The antibody recognizes full-length and the cleaved C-terminus of mouse Gasdermin D, does not cross-react with human Gasdermin D and works specifically in Western Blot application to detect the cleaved C-terminal Gasdermin D.

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The Standard Inflammasome Research Antibodies - Validated Reliable Antibodies used by the Experts

AdipoGen Life Sciences is the "No. 1" manufacturer and supplier of inflammasome signaling research reagents. The validated high quality inflammasome research tools are used and published by the experts in inflammasome research on a daily basis.  

For Inflammasmome Research Protocols using AdipoGen Life Sciences' Validated Antibodies visit our Inflammasome Page

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NEW IL-1β (human) ELISA Kit - HIGH SENSITIVITY

The IL-1β (human) ELISA Kit (Prod. No. AG-45B-0021) is a sandwich ELISA for quantitative determination of human IL-1β in cell culture supernatants, serum and plasma samples. This ELISA assay is specific and highly sensitive (0.7pg/ml) for the measurement of natural and recombinant human IL-1β.

Active IL-1β has known roles in initiating and propagating sterile inflammation, including macrophage recruitment, activation of the pro-inflammatory cytokine interleukin-6 (IL-6) and modulating chemokine expression. IL-1β, inflammatory caspases and inflammasomes play important roles in several diseases such as sepsis, rheumatoid arthritis, inflammatory bowel disease, atherosclerosis, neuronal injuries, such as Alzheimer's disease, Parkinson's disease, stroke, cerebral ischemic cell death, multiple sclerosis and Down syndrome. Some human hereditary or acquired diseases have been linked to elevated IL-1β such as cryopyrin-associated periodic syndroms (CAPS) directly linked to NLRP3 mutations. 

Download the ELISA Kit Manual

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The Key Inflammasome Activators and Inhibitors - Including New Gasdermin Inhibitor

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Priming Step of Inflammasome Activation

The most prominent function of the NLRP3 inflammasome is the processing and activation of pro-interleukin-1β (pro-IL-1β). Yet most cells do not express pro-IL-1β and thus prior expression of pro-IL-1β is required. This can be achieved by stimulating receptors such as TLRs (e.g. through LPS), Nods, TNF-Rs (e.g. through TNF-α) or IL-1R1 (through IL-1α and IL-1β) that activate NF-κB and initiate pro-IL-1β transcription. This process is called priming. Priming also induces NF-κB-dependent transcription of NLRP3.

 

See a Panel of ready-to-use LPS Solutions for Inflammasome Priming Activation

Do not bother anymore to solubilize your LPS, choose and use AdipoGen Life Sciences' homogenous ready-to-use LPS solutions.

- Kdo2-Lipid A (ready-to-use)  (THE STANDARD)

- LPS (Universal) from Salmonella abortus equi (S-form) TLRpure™ Sterile Solution  (THE STANDARD)

- LPS from E. coli R515 (Re) TLRpure™ Sterile Solution  (THE STANDARD)

- LPS from E. coli O8:K27 (S-form) TLRpure™ Sterile Solution

- LPS from Salmonella minnesota R345 (Rb) TLRpure™ Sterile Solution

- LPS from Salmonella minnesota R595 (Re) TLRpure™ Sterile Solution

See our Panel of TNF-α Proteins for Inflammasome Priming Activation

- TNF-α, Soluble (human) (rec.)

- TNF-α (human) (multimeric) (rec.)

- TNF-α (mouse) (multimeric) (rec.)

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