Selective inhibition of NLRP3 inflammasome by designed peptide originating from ASC

Abstract

NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome is a multiprotein complex which forms within cells in response to various microbial and self-derived triggers. Mutations in the gene encoding NLRP3 cause rare cryopyrin-associated periodic syndromes (CAPS) and growing evidence links NLRP3 inflammasome to common diseases such as Alzheimer´s disease. In order to modulate different stages of NLRP3 inflammasome assembly nine peptides whose sequences correspond to segments of inflammasome components NLRP3 and apoptosis-associated speck-like protein containing a CARD (ASC) were selected. Five peptides inhibited IL-1β release, caspase-1 activation and ASC oligomerization in response to soluble and particulate NLRP3 triggers. Modulatory peptides also attenuated IL-1β maturation induced by constitutive CAPS-associated NLRP3 mutants. Peptide corresponding to H2-H3 segment of ASC pyrin domain selectively inhibited NLRP3 inflammasome by binding to NLRP3 pyrin domain in the micromolar range. The peptide had no effect on AIM2 and NLRC4 inflammasomes as well as NF-κB pathway. The peptide effectively dampened neutrophil infiltration in the silica-induced peritonitis and when equipped with Antennapedia or Angiopep-2 motifs crossed the blood-brain barrier in a mouse model. Our study demonstrates that peptides represent an important tool for targeting multiprotein inflammatory complexes and can serve as the basis for the development of novel anti-inflammatory strategies for neurodegeneration.

An update on the regulatory mechanisms of NLRP3 inflammasome activation

“…Recent studies identified several peptides that modulate different stages of NLRP3 inflammasome assembly and inhibit IL-1β release, caspase-1 activation, and ASC oligomerization. 262 Among these candidates, a peptide with a sequence corresponding to the H2-H3 segment of ASC PYD showed selective inhibitory activity against NLRP3 but was not absent in melanoma 2 (AIM2) and NLR family CARD domain-containing protein 4 (NLRC4) inflammasomes. 262 There is a great deal of research interest in the inflammasome.…”

“…262 Among these candidates, a peptide with a sequence corresponding to the H2-H3 segment of ASC PYD showed selective inhibitory activity against NLRP3 but was not absent in melanoma 2 (AIM2) and NLR family CARD domain-containing protein 4 (NLRC4) inflammasomes. 262 There is a great deal of research interest in the inflammasome. A wide range of natural and synthetic inhibitors have been reported to have inflammasome-inhibiting activity.…”

Acetate Improves the Killing of Streptococcus pneumoniae by Alveolar Macrophages via NLRP3 Inflammasome and Glycolysis-HIF-1α Axis

“…In accordance, pro-IL-1β protein levels were also increased by acetate and even enhanced in the presence of S. pneumoniae ( Figure 4C ). To better understand the role of NLRP3 inflammasome in acetate-mediated IL-1β secretion, S. pneumoniae -conditioned macrophages were treated with KCl and CY-09, two well described NLRP3 inflammasome inhibitors ( 33 , 34 ). As depicted in Figure 4D , acetate-mediated IL-1β production by S. pneumoniae -conditioned macrophages was largely dependent on NLRP3 inflammasome activity.…”

Differential Effect of Extracellular Acidic Environment on IL-1β Released from Human and Mouse Phagocytes

“…Immunofluorescent labeling of endogenous ASC was performed in fixed and permeabilized WT iBMDMs, as previously described [45,47]. ASC specks were detected using purified anti-ASC (TMS-1, clone HASC-71) primary antibodies (1:500, Biolegend, San Diego, CA, USA) and Alexa Fluor 633 goat anti-mouse IgG (H+L) (1:200, Invitrogen, Thermo Scientific, Waltham, MA, USA) as secondary antibodies.…”