Biology subjects

Kayagaki, N.

Publications and source records attributed to Kayagaki, N..

6 recordsLinked to original sources

bioRxiv2026

NINJ1 mediates hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury (IRI) results from interrupted perfusion to the liver and contributes to acute liver dysfunction such as following liver transplantation. Lytic cell death pathways are major drivers of IRI and the subsequent inflammatory response. The transmembrane protein ninjurin-1 (NINJ1) was identified as the key executor of terminal plasma membrane rupture across multiple lytic cell death pathways implicated in hepatic IRI. We hypothesized that NINJ1-mediated lytic cell death drives IRI and that its therapeutic inhibition would mitigate liver IRI. Using human liver specimens, we found that NINJ1 is highly expressed in human liver tissue and that its activation correlates with early allograft dysfunction in patients undergoing liver transplantation. Utilizing a segmental hepatic IRI model in mice and rats, Ninj1 genetic deletion or pharmacologic inhibition diminished acute liver injury. Mice with hepatocyte- or macrophage-specific Ninj1 knockout both had reduced hepatocellular injury following IRI, suggesting that NINJ1 within both populations contributes to the resulting liver injury. Mechanistically, we found that hepatocytes and Kupffer cells are highly susceptible to hypoxia-induced NINJ1-mediated plasma membrane rupture, which can be pharmacologically prevented. These data position NINJ1 as a potential new therapeutic target to limit hepatic IRI, with important implications for organ preservation during liver transplantation.

immunology↗

bioRxiv2025

IRF2 degradation tunes the innate immune response

The transcription factor IRF2 protects against skin inflammation in mice and humans but, paradoxically, promotes pyroptosis by inducing Gsdmd. How IRF2 activates some proinflammatory genes, but suppresses others is unclear. We show that skin inflammation in Irf2-deficient mice is driven by IRF1 activation of interferon-stimulated genes (ISGs). Chromatin profiling revealed that IRF1 and IRF2 occupy the same ISG regulatory sites, but as a weaker transcriptional activator, IRF2 limited ISG transcription by IRF1. Toll-like receptor signaling favored IRF1-driven transcription by inducing Irf1. In addition, IRF1 recruited the ubiquitin ligase SPOP to ISG sites, resulting in proteasomal degradation of IRF2. This shift from IRF2 to IRF1 occupancy enhanced ISG transcription. Collectively, these findings define a hierarchical transcriptional circuit in which IRF2 limits IRF1 activity under homeostatic conditions but is displaced during an immune response, allowing IRF1-dependent gene programs central to innate immunity and autoinflammation.

immunology↗

bioRxiv2025

Delivery of caspase inhibitors through GSDMD pores to inhibit pyroptosis

Caspase-1, -4, -5, and -11 activate Gasdermin D (GSDMD) to form pores in the plasma membrane. In addition to releasing interleukin (IL)-1{beta} and IL-18, GSDMD pores cause a lytic, proinflammatory form of cell death called pyroptosis. Blocking this pathway holds therapeutic promise for the treatment of inflammatory disorders, but clinical trials of cell permeable caspase inhibitors have been unsuccessful. Here, we describe covalent inhibitors of proinflammatory caspases that are impermeable to healthy cells but effectively block caspase-1 driven pyroptosis and IL-1{beta} secretion. Their failure to inhibit apoptosis implies inhibitor entry through GSDMD pores. Propidium iodide entered rescued cells, confirming transient membrane permeabilization via caspase-1 and GSDMD. Caspase-1 inhibition prevented rather than delayed cell death, likely due to the activation of membrane repair mechanisms neutralizing the initial GSDMD pores. Notably, inhibiting caspase-1 and -11 suppressed IL-1{beta} and IL-18 production in a mouse model of endotoxic shock. These findings underscore the therapeutic potential of exploiting GSDMD pores for the delivery of caspase inhibitors, offering a novel strategy for treating inflammatory diseases.

cell biology↗

bioRxiv2023

Highly multiplexed, image-based pooled screens in primary cells and tissues with PerturbView

Optical pooled screening (OPS) is a highly scalable method for linking image-based phenotypes with cellular perturbations. However, it has thus far been restricted to relatively low-plex phenotypic readouts in cancer cell lines in culture, due to limitations associated with in situ sequencing (ISS) of perturbation barcodes. Here, we developed PerturbView, an OPS technology that leverages in vitro transcription (IVT) to amplify barcodes prior to ISS, enabling screens with highly multiplexed phenotypic readouts across diverse systems, including primary cells and tissues. We demonstrate PerturbView in iPSC-derived neurons, primary immune cells, and tumor tissue sections from animal models. In a screen of immune signaling pathways in primary bone marrow-derived macrophages, PerturbView uncovered both known and novel regulators of NF{kappa}B signaling. Furthermore, we combined PerturbView with spatial transcriptomics in tissue sections from a mouse xenograft model, paving the way to in vivo screens with rich optical and transcriptomic phenotypes. PerturbView broadens the scope of OPS to a wide range of models and applications.

systems biology↗

bioRxiv2020

Evolutionary loss of inflammasomes in carnivores to facilitate carriage of zoonotic infections

Zoonotic infections, such as COVID-19, reside in animal hosts before jumping species to humans. The Carnivora, like mink, carry many zoonoses yet how diversity in host immune genes across species impact upon pathogen carriage are poorly understood. Here we describe a progressive evolutionary downregulation of pathogen sensing inflammasome pathways in Carnivora. This includes the loss of nucleotide-oligomerisation domain leucine rich repeat receptors (NLRs), acquisition of a unique caspase-1/-4 effector fusion protein that processes gasdermin D pore formation without inducing lytic cell death and the formation of an NLRP3-caspase-8 containing inflammasome that inefficiently processes interleukin-1{beta} (IL-1{beta}). Inflammasomes regulate gut immunity, but the carnivorous diet is antimicrobial suggesting a tolerance to the loss of these immune pathways. The consequences of systemic inflammasome downregulation, however, can reduce the host sensing of specific pathogens such that they can reside undetected in the Carnivora.

immunology↗

bioRxiv2019

MCC950/CRID3 potently targets the NACHT domain of wildtype NLRP3 but not disease-associated mutants for inflammasome inhibition

The NLRP3 inflammasome drives pathological inflammation in a suite of autoimmune, metabolic, malignant and neurodegenerative diseases. Additionally, NLRP3 gain-of-function point mutations cause systemic periodic fever syndromes that are collectively known as cryopyrin-associated periodic syndromes (CAPS). There is significant interest in the discovery and development of diarylsulfonylurea Cytokine Release Inhibitory Drugs (CRIDs) such as MCC950/CRID3, a potent and selective inhibitor of the NLRP3 inflammasome, for the treatment of CAPS and other diseases. However, drug discovery efforts have been constrained by the lack of insight in the molecular target and mechanism by which these CRIDs inhibit the NLRP3 inflammasome. Here, we show that the NACHT domain of NLRP3 is the molecular target of diarylsulfonylurea inhibitors. Interestingly, we find photoaffinity labelling of the NACHT domain requires an intact (d)ATP-binding pocket and is substantially reduced for most CAPS-associated NLRP3 mutants. In concordance, MCC950/CRID3 failed to inhibit NLRP3- driven inflammatory pathology in two mouse models of CAPS. Moreover, it abolished circulating levels of interleukin (IL)-1{beta} and IL-18 in LPS-challenged wildtype mice but not in Nlrp3L351P knock-in mice and ex vivo-stimulated mutant macrophages. These results identify wildtype NLRP3 as the molecular target of MCC950/CRID3, and show that CAPS-related NLRP3 mutants escape efficient MCC950/CRID3 inhibition. Collectively, this work suggests that MCC950/CRID3-based therapies may effectively treat inflammation driven by wildtype NLRP3, but not CAPS-associated mutants.

immunology↗