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Pham, M. A.

Publications and source records attributed to Pham, M. A..

2 recordsLinked to original sources

NLRP10 Cleaves Oxidized DNA inhibited by OGG1 inhibitors: A Newly Identified Role in DNA Damage Processing and Senescence Regulation.

Mitochondrial DNA (mtDNA) release into the cytosol is a critical event in innate immune activation, often acting as a damage-associated molecular pattern (DAMP) that triggers inflammasome assembly. Here, we demonstrate that NLRP3 plays a direct role in cleaving and facilitating the release of D-loop mtDNA into the cytosol. We further show that NLRP3 interacts with NLRP10. NLRP10-mediated ox-DNA cleavage involves a Schiff base intermediate and is inhibited by small molecules known to inhibit glycosylases. These findings support a model where NLRP10 interaction with oxidized DNA may contribute to long-term senescence secretory phenotype and modulate inflammasome activation. Our study highlights a novel mechanism by which NLRP10 can respond to mitochondrial stress signals to influence innate immunity and suggests therapeutic potential for targeting these interactions in inflammatory diseases.

immunology↗

Small molecule inhibitor binds to NLRP3 and prevents inflammasome activation

Despite recent advances in the mechanism of oxidized DNA activating NLRP3, the molecular mechanism and consequence of oxidized DNA associating with NLRP3 remains unknown. Cytosolic NLRP3 binds oxidized DNA which has been released from the mitochondria, which subsequently triggers inflammasome activation. Human glycosylase (hOGG1) repairs oxidized DNA damage which inhibits inflammasome activation. The fold of NLRP3 pyrin domain contains amino acids and a protein fold similar to hOGG1. Amino acids that enable hOGG1 to bind and cleave oxidized DNA are conserved in NLRP3. We found NLRP3 could bind and cleave oxidized guanine within mitochondrial DNA. The binding of oxidized DNA to NLRP3 was prevented by small molecule drugs which also inhibit hOGG1. These same drugs also inhibited inflammasome activation. Elucidating this mechanism will enable design of drug memetics that treat inflammasome pathologies, illustrated herein by NLRP3 pyrin domain inhibitors which suppressed interleukin-1{beta} (IL-1{beta}) production in macrophages. One-Sentence SummaryNLRP3 cleaves oxidized DNA and small molecule drug binding inhibits inflammasome activation.

immunology↗