1. Academic Validation
  2. A novel Nlrp3 knock-in mouse model with hyperactive inflammasome in development of lethal inflammation

A novel Nlrp3 knock-in mouse model with hyperactive inflammasome in development of lethal inflammation

  • Clin Exp Immunol. 2023 Aug 18;uxad097. doi: 10.1093/cei/uxad097.
Yongting Zhou 1 Xiyue Yang 1 Lei Zhu 1
Affiliations

Affiliation

  • 1 Department of Pharmacology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College; Medical Epigenetics Research Center, Chinese Academy of Medical Sciences, Beijing 100005, P.R. China.
Abstract

NOD-like receptor family, pyrin domain-containing 3 (NLRP3) is a central protein contributing to human inflammatory disorders, including cryopyrin associated periodic syndrome and sepsis. However, the molecular mechanisms and functions of NLRP3 activation in various diseases remain unknow. Here, we generated gain-of-function knock-in mice associated with Muckle-Wells syndromes using the Cre-LoxP system allowing for the constitutive T346M mutation of NLRP3 to be globally expressed in all cells under the control of tamoxifen. The mice were treated with tamoxifen for 4 days before determining their genotype by PCR and sequence analysis. In vitro, we found that bone marrow-derived macrophage from homozygous T346M mutation mice displayed a robust ability to produce IL-1β in response to lipopolysaccharide exposure. Moreover, ASC specks and oligomerisation were observed in the homozygous mutant bone marrow-derived macrophages in the presence of lipopolysaccharides alone. Mechanistically, K + and Ca2 + depletion and mitochondrial depolarization contribute to the hyperactivation of mutant NLRP3. In vivo, homozygous mice carrying the T346M mutation exhibit weight loss and mild inflammation in the resting state. In an lipopolysaccharide-mediated sepsis model, homozygous mutant mice exhibited higher mortality and increased serum circulating cytokine levels, accompanied by serious liver injury. Furthermore, an increase in myeloid cells in the spleen has been suggested to be a risk factor for inducing sepsis sensitivity. Altogether, we describe a cryopyrin-associated syndrome animal model with the T346M mutation of NLRP3 and suggest that the hyperactivated inflammasome aggregated by the mutant NLRP3 lowers the inflammatory response threshold both in vitro and in vivo.

Keywords

Cryopyrin associated periodic syndrome; NOD-like receptor family; T346M mutation in Nlrp3; pyrin domain containing 3; sepsis.

Figures
Products