Efficacy and Pharmacology of the NLRP3 Inflammasome Inhibitor CP-456,773 (CRID3) in Murine Models of Dermal and Pulmonary Inflammation

Abstract

A critical component of innate immune response to infection and tissue damage is the NACHT, LRR, and PYD domains–containing protein 3 (NLRP3) inflammasome, and this pathway and its activation products have been implicated in the pathophysiology of a variety of diseases. NLRP3 inflammasome activation leads to the cleavage of pro–IL-1β and pro–IL-18, as well as the subsequent release of biologically active IL-1β, IL-18, and other soluble mediators of inflammation. In this study, we further define the pharmacology of the previously reported NLRP3 inflammasome–selective, IL-1β processing inhibitor CP-456,773 (also known as MCC950), and we demonstrate its efficacy in two in vivo models of inflammation. Specifically, we show that in human and mouse innate immune cells CP-456,773 is an inhibitor of the cellular release of IL-1β, IL-1α, and IL-18, that CP-456,773 prevents inflammasome activation induced by disease-relevant soluble and crystalline NLRP3 stimuli, and that CP-456,773 inhibits R848- and imiquimod-induced IL-1β release. In mice, CP-456,773 demonstrates potent inhibition of the release of proinflammatory cytokines following acute i.p. challenge with LPS plus ATP in a manner that is proportional to the free/unbound concentrations of the drug, thereby establishing an in vivo pharmacokinetic/pharmacodynamic model for CP-456,773. Furthermore, CP-456,773 reduces ear swelling in an imiquimod cream–induced mouse model of skin inflammation, and it reduces airway inflammation in mice following acute challenge with house dust mite extract. These data implicate the NLRP3 inflammasome in the pathogenesis of dermal and airway inflammation, and they highlight the utility of CP-456,773 for interrogating the contribution of the NLRP3 inflammasome and its outputs in preclinical models of inflammation and disease.

Potential of IL-1, IL-18 and Inflammasome Inhibition for the Treatment of Inflammatory Skin Diseases

“…MCC950 is a small-molecule able to block canonical and non-canonical NLRP3-induced ASC oligomerization without interfering with NLRC4 and AIM2 activity or TLR signaling (Coll et al, 2015). MCC950 has been shown to be effective for the treatment of CAPS in mice harboring activating Nlrp3 mutations (Coll et al, 2015) and in mouse models of dermal and airway inflammation (Primiano et al, 2016). β-hydroxybutyrate (BHB) is an anti-inflammatory molecule that specifically targets NLRP3 activity.…”

“…Small molecule inhibitors were shown to be beneficial in mice models of FCAS and MWS; the anti-inflammatory molecule BHB inhibits constitutive NLRP3 inflammasome activity (Youm et al, 2015). Additionally, the specific NLRP3 inhibitor MCC950 showed efficacy in mouse models of CAPS harboring activating NLRP3 mutations (Coll et al, 2015), and in mouse models for dermal and airway inflammation (Primiano et al, 2016). …”

A new lead to NLRP3 inhibition

“…Jiang et al (2017) also showed that CY-09 can be used for limiting NLRP3 inflammasome activation in vivo. CY-09 showed favorable in vivo and ex vivo pharmacokinetic properties for stability, safety, and oral bioavailability, resembling those of MCC950/CRID3 (Coll et al, 2015; Primiano et al, 2016; Jiang et al, 2017). MCC950/CRID3 was shown to inhibit NLRP3-dependent pathology in preclinical disease models, including the Nlrp3 Ala350Val-neoR knock-in mouse model of CAPS (cryopyrin-associated autoinflammatory syndromes), the experimental autoimmune encephalomyelitis mouse model of multiple sclerosis, the imiquimod cream–induced mouse model of skin inflammation, and house dust mite–induced acute airway inflammation in mice (Coll et al, 2015; Primiano et al, 2016).…”

“…CY-09 showed favorable in vivo and ex vivo pharmacokinetic properties for stability, safety, and oral bioavailability, resembling those of MCC950/CRID3 (Coll et al, 2015; Primiano et al, 2016; Jiang et al, 2017). MCC950/CRID3 was shown to inhibit NLRP3-dependent pathology in preclinical disease models, including the Nlrp3 Ala350Val-neoR knock-in mouse model of CAPS (cryopyrin-associated autoinflammatory syndromes), the experimental autoimmune encephalomyelitis mouse model of multiple sclerosis, the imiquimod cream–induced mouse model of skin inflammation, and house dust mite–induced acute airway inflammation in mice (Coll et al, 2015; Primiano et al, 2016). CY-09 also prevented neonatal lethality in the Nlrp3 Ala350Val-neoR knock-in mouse model of CAPS, it improved diabetic symptoms in mice given a high-fat diet and blocked NLRP3-dependent caspase-1 activation and IL-1β secretion from human peripheral blood mononuclear cells (PBMCs) of healthy donors and synovial fluid cells of gouty arthritis patients (Jiang et al, 2017).…”

“…Glyburide was the first compound shown to selectively inhibit PAMP-, DAMP-, and crystal-induced activation of the NLRP3 inflammasome without interfering with other inflammasome pathways (Lamkanfi et al, 2009). Currently, MCC950/CRID3 and related diarylsulfonylurea compounds that are structurally related to glyburide are the most potent reported inhibitors of the NLRP3 inflammasome with IC 50 values around 20 nM (Perregaux et al, 2001; Coll et al, 2015; Primiano et al, 2016). MCC950/CRID3 was shown to block activation of the NLRP3 inflammasome in ex vivo–stimulated murine and human macrophages and monocytes.…”