Using a similar mouse model, Shi et al. treated animals with the antimalarial drug artemisinin, showing that this treatment results in inhibition of NFkB and presumably the NLRP3 inflammasome (13)
One of the canonical pathways of this innate immune response evoked by Abeta is the activation of the NOD-like receptor (NLR) family, pyrin domain containing 3 (NLRP3) inflammasome that became a focus of intense research
NLRP3 inflammasome activation results from TLR ligation and concomitant uptake of Ab in models of AD
NLRP3 inflammasome formation and subsequent activation of caspase-1 cleavage capacity was instrumental for Abeta-induced nitric oxide production and TNF-a release
Further data, showing “neuronal pyroptosis” of Abeta exposed neurons in a NLRP1- dependent and caspase-1-mediated manner may point to a vicious cycle, by which NLRP1 is causing neurodegeneration in response to increased Abeta production (14)
Using the herbizide, N,N0-dimethyl-4,40-bipyridinium dichloride (paraquat) as a mitochondrial toxin, which is known to induce oxidative stress, Chen et al. found increased levels of caspase-1 and IL-1b in brain of wild type and APP/PS1 transgenic mice (2), suggesting that those were due to NLRP3 inflammasome activation
Activation of the NLRP3 inflammasome by fibrillar Abeta has been described first by Halle et al. in 2008
Recently, Kaushal et al. described the involvement of NLRP1 inflammasome activation in neurons. In these experiments, serum deprivation induced NLRP1-dependent caspase-1 activity and ASC speck formation, which resulted in caspase-6 activation and an increase in the Ab42/total Ab ratio (11)
Activation of NLRP3 leads to the generation of interleukin-1b (IL-1b) and interleukin 18 (IL-18), which are being cleaved by caspase-1 from their inactive precursors and subsequently
This finding was associated with spatial memory dysfunction and an increase in Abeta plaque deposition
Soluble Abeta (sAbeta)-induces NLRP3 inflammasome activation, however it requires the presence of the surface receptor CD36 (12)
NLRP3 activation was characterized by ASC speck formation in an immune-activated microglial cell line and required a dual signal to become effective: the phagocytic uptake of Abeta and cathepsin B release after lysosomal disruption
The combined effect of the increased IDE production and phagocytic Abeta clearance reduced the cerebral Abeta load substantially, even at late life. Since immunohistochemistry found NLRP3 exclusively expressed in microglial cells, it has been concluded that the observed changes were entirely due to NLRP3 inflammasome modulation in these cells
BEL Commons is developed and maintained in an academic capacity by Charles Tapley Hoyt and Daniel Domingo-Fernández at the Fraunhofer SCAI Department of Bioinformatics with support from the IMI project, AETIONOMY. It is built on top of PyBEL, an open source project. Please feel free to contact us here to give us feedback or report any issues. Also, see our Publishing Notes and Data Protection information.
If you find BEL Commons useful in your work, please consider citing: Hoyt, C. T., Domingo-Fernández, D., & Hofmann-Apitius, M. (2018). BEL Commons: an environment for exploration and analysis of networks encoded in Biological Expression Language. Database, 2018(3), 1–11.