scholarly journals Genetic targeting of Card19 is linked to disrupted NINJ1 expression, impaired cell lysis, and increased susceptibility to Yersinia infection

2021 ◽  
Vol 17 (10) ◽  
pp. e1009967
Author(s):  
Elisabet Bjanes ◽  
Reyna Garcia Sillas ◽  
Rina Matsuda ◽  
Benjamin Demarco ◽  
Timothée Fettrelet ◽  
...  

Cell death plays a critical role in inflammatory responses. During pyroptosis, inflammatory caspases cleave Gasdermin D (GSDMD) to release an N-terminal fragment that generates plasma membrane pores that mediate cell lysis and IL-1 cytokine release. Terminal cell lysis and IL-1β release following caspase activation can be uncoupled in certain cell types or in response to particular stimuli, a state termed hyperactivation. However, the factors and mechanisms that regulate terminal cell lysis downstream of GSDMD cleavage remain poorly understood. In the course of studies to define regulation of pyroptosis during Yersinia infection, we identified a line of Card19-deficient mice (Card19lxcn) whose macrophages were protected from cell lysis and showed reduced apoptosis and pyroptosis, yet had wild-type levels of caspase activation, IL-1 secretion, and GSDMD cleavage. Unexpectedly, CARD19, a mitochondrial CARD-containing protein, was not directly responsible for this, as an independently-generated CRISPR/Cas9 Card19 knockout mouse line (Card19Null) showed no defect in macrophage cell lysis. Notably, Card19 is located on chromosome 13, immediately adjacent to Ninj1, which was recently found to regulate cell lysis downstream of GSDMD activation. RNA-seq and western blotting revealed that Card19lxcn BMDMs have significantly reduced NINJ1 expression, and reconstitution of Ninj1 in Card19lxcn immortalized BMDMs restored their ability to undergo cell lysis in response to caspase-dependent cell death stimuli. Card19lxcn mice exhibited increased susceptibility to Yersinia infection, whereas independently-generated Card19Null mice did not, demonstrating that cell lysis itself plays a key role in protection against bacterial infection, and that the increased infection susceptibility of Card19lxcn mice is attributable to loss of NINJ1. Our findings identify genetic targeting of Card19 being responsible for off-target effects on the adjacent gene Ninj1, disrupting the ability of macrophages to undergo plasma membrane rupture downstream of gasdermin cleavage and impacting host survival and bacterial control during Yersinia infection.

2021 ◽  
Author(s):  
Elisabet Bjanes ◽  
Reyna Garcia Sillas ◽  
Rina Matsuda ◽  
Benjamin Demarco ◽  
Timothée Fettrelet ◽  
...  

Cell death plays a critical role in inflammatory responses. During pyroptosis, inflammatory caspases cleave Gasdermin D (GSDMD) to release an N-terminal fragment that generates plasma membrane pores that mediate cell lysis and IL-1 cytokine release. Terminal cell lysis and IL-1β release following caspase activation can be uncoupled in certain cell types or in response to particular stimuli, a state termed hyperactivation. However, the factors and mechanisms that regulate terminal cell lysis downstream of GSDMD cleavage remain poorly understood. In the course of studies to define regulation of pyroptosis during Yersinia infection, we identified a line of Card19-/- mice whose macrophages were protected from cell death and showed reduced pore formation during apoptosis or pyroptosis, yet had wild-type levels of caspase activation, IL-1 secretion, and GSDMD cleavage. Unexpectedly, CARD19, a mitochondrial CARD-containing protein, was not directly responsible for this, as two independently-generated CRISPR/Cas9 Card19 knockout mice showed no defect in macrophage cell lysis. The original Card19-/- line was generated in a 129SvEvBrd background, and SNP analysis revealed a six megabase region of 129 origin co-segregating with the Card19 locus. Card19 is located on chromosome 13, adjacent to Ninj1, which was recently reported to regulate cell lysis downstream of GSDMD activation. Nonetheless, we could not detect major defects in NINJ1 protein expression or mutations in Ninj1 coding sequence in Card19-/- mice. Mice from the original Card19-/- line exhibited significantly increased susceptibility to Yersinia infection, demonstrating that cell lysis itself plays a key role in protection against bacterial infection. Our findings identify a locus on murine chromosome 13 that regulates the ability of macrophages to undergo plasma membrane rupture downstream of gasdermin cleavage, and implicates additional NINJ1-independent factors that control terminal cell lysis.


2015 ◽  
Vol 290 (34) ◽  
pp. 20841-20855 ◽  
Author(s):  
Mercè Garcia-Belinchón ◽  
María Sánchez-Osuna ◽  
Laura Martínez-Escardó ◽  
Carla Granados-Colomina ◽  
Sònia Pascual-Guiral ◽  
...  

Apoptosis is triggered by the activation of caspases and characterized by chromatin condensation and nuclear fragmentation (type II nuclear morphology). Necrosis is depicted by a gain in cell volume (oncosis), swelling of organelles, plasma membrane leakage, and subsequent loss of intracellular contents. Although considered as different cell death entities, there is an overlap between apoptosis and necrosis. In this sense, mounting evidence suggests that both processes can be morphological expressions of a common biochemical network known as “apoptosis-necrosis continuum.” To gain insight into the events driving the apoptosis-necrosis continuum, apoptotically proficient cells were screened facing several apoptotic inducers for the absence of type II apoptotic nuclear morphologies. Chelerythrine was selected for further studies based on its cytotoxicity and the lack of apoptotic nuclear alterations. Chelerythrine triggered an early plasma membrane leakage without condensed chromatin aggregates. Ultrastructural analysis revealed that chelerythrine-mediated cytotoxicity was compatible with a necrotic-like type of cell death. Biochemically, chelerythrine induced the activation of caspases. Moreover, the inhibition of caspases prevented chelerythrine-triggered necrotic-like cell death. Compared with staurosporine, chelerythrine induced stronger caspase activation detectable at earlier times. After using a battery of chemicals, we found that high concentrations of thiolic antioxidants fully prevented chelerythrine-driven caspase activation and necrotic-like cell death. Lower amounts of thiolic antioxidants partially prevented chelerythrine-mediated cytotoxicity and allowed cells to display type II apoptotic nuclear morphology correlating with a delay in caspase-3 activation. Altogether, these data support that an early and pronounced activation of caspases can drive cells to undergo a form of necrotic-like regulated cell death.


2004 ◽  
Vol 24 (11) ◽  
pp. 1272-1279 ◽  
Author(s):  
Alexandra Benchoua ◽  
Jérôme Braudeau ◽  
Aurélia Reis ◽  
Cécile Couriaud ◽  
Brigitte Onténiente

Cathepsins and caspases are two families of proteases that play pivotal roles in ischemic cell death. This study investigated the existence of a cross-talk between cathepsin B and proinflammatory caspases in stroke-induced cell death, as recently suggested by in vitro data. Cortical ischemic damage was induced in mice by distal and permanent occlusion of the middle cerebral artery. Cytoplasmic activation of cathepsin B was observed from the early stages of infarction, and displayed an activation pattern parallel to the activation pattern of caspase-1 and −11. Immunohistochemistry revealed the colocalization of cathepsin B with each caspase in cells of the infarct core. The apical position of cathepsin B in both caspase-activation cascades was confirmed by pretreatment of the animals with the cathepsin B inhibitor CA-074, which also potently protected cortical structures from ischemic damage, indicating involvement of the proteases in the lesion process. The results show that cathepsin B release is an early event following occlusion of cerebral arteries, which eventually triggers the activation of proinflammatory caspases in the absence of reperfusion. This new pathway may play a critical role in brain infarction by promoting inflammatory responses, and/or by amplifying the apoptotic process.


2004 ◽  
Vol 32 (3) ◽  
pp. 447-451 ◽  
Author(s):  
I. Dransfield ◽  
A.G. Rossi

The neutrophil granulocyte is a key factor in cellular innate defence mechanisms against infection or tissue damage. Granulocyte apoptosis is now acknowledged to have a critical role in progression of inflammatory responses. Granulocytes are preprogrammed to die with important physiological mechanisms for non-inflammatory clearance. Shutdown of secretory capacity represents an important aspect of the programme of biochemical events that accompany neutrophil apoptosis together with surface molecular changes that serve to identify apoptotic cells as targets for phagocytic removal. Defining the underlying regulatory mechanisms together with the changes in patterns of gene/protein expression associated with granulocyte death remains a challenge. Use of novel strategies for inducing cell death will allow biochemical approaches to dissect the underlying pathways. Although study of granulocyte cell death has especial difficulties when compared with other cell types, there are clearly potential benefits for new therapeutic approaches to treat inflammatory diseases.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Bo-Ram Bang ◽  
Kyung Ho Han ◽  
Goo-Young Seo ◽  
Michael Croft ◽  
Young Jun Kang

AbstractTwo distinct p38 signaling pathways, classical and alternative, have been identified to regulate inflammatory responses in host defense and disease development. The role of alternative p38 activation in liver inflammation is elusive, while classical p38 signaling in hepatocytes plays a role in regulating the induction of cell death in autoimmune-mediated acute liver injury. In this study, we found that a mutation of alternative p38 in mice augmented the severity of acute liver inflammation. Moreover, TNF-induced hepatocyte death was augmented by a mutation of alternative p38, suggesting that alternative p38 signaling in hepatocytes contributed more significantly to the pathology of acute liver injury. Furthermore, SYK-Vav-1 signaling regulates alternative p38 activation and the downregulation of cell death in hepatocytes. Therefore, it is suggested that alternative p38 signaling in the liver plays a critical role in the induction and subsequent pathological changes of acute liver injury. Collectively, our results imply that p38 signaling in hepatocytes plays a crucial role to prevent excessive liver injury by regulating the induction of cell death and inflammation.


2021 ◽  
Vol 12 ◽  
Author(s):  
Lingling Wang ◽  
Ling Zhou ◽  
Yuhao Zhou ◽  
Lu Liu ◽  
Weiling Jiang ◽  
...  

In the past decades, apoptosis has been the most well-studied regulated cell death (RCD) that has essential functions in tissue homeostasis throughout life. However, a novel form of RCD called necroptosis, which requires receptor-interacting protein kinase-3 (RIPK3) and mixed-lineage kinase domain-like pseudokinase (MLKL), has recently been receiving increasing scientific attention. The phosphorylation of RIPK3 enables the recruitment and phosphorylation of MLKL, which oligomerizes and translocates to the plasma membranes, ultimately leading to plasma membrane rupture and cell death. Although apoptosis elicits no inflammatory responses, necroptosis triggers inflammation or causes an innate immune response to protect the body through the release of damage-associated molecular patterns (DAMPs). Increasing evidence now suggests that necroptosis is implicated in the pathogenesis of several human diseases such as systemic inflammation, respiratory diseases, cardiovascular diseases, neurodegenerative diseases, neurological diseases, and cancer. This review summarizes the emerging insights of necroptosis and its contribution toward the pathogenesis of lung diseases.


Blood ◽  
2018 ◽  
Vol 132 (20) ◽  
pp. 2183-2187 ◽  
Author(s):  
Shigeharu Ueki ◽  
Takahiro Tokunaga ◽  
Rossana C. N. Melo ◽  
Hidekazu Saito ◽  
Kohei Honda ◽  
...  

Abstract Protein crystallization in human tissue rarely occurs. Charcot-Leyden crystals (CLCs) were described in various eosinophilic diseases >150 years ago, but our understanding of CLC formation still remains limited. In this study, we demonstrate that CLCs observed in varied inflamed human tissues are closely associated with eosinophil cell-free granules and nuclear envelope/plasma membrane disintegration with release of filamentous chromatin (extracellular traps), typical morphologies of a regulated pathway of extracellular trap cell death (ETosis). During the process of eosinophil ETosis, eccentrically localized cytoplasmic and perinuclear CLC protein (galectin-10) is homogeneously redistributed in the cytoplasm. Rapid (1-2 minutes) formation of intracytoplasmic CLCs was observed using time-lapse imaging. Plasma membrane rupture enabled the release of both intracellularly formed CLCs and soluble galectin-10 that further contributed to formation of CLCs extracellularly, in parallel with the expulsion of free intact granules and extracellular traps. CLC formation and galectin-10 release were dependent on nicotinamide adenine dinucleotide phosphate oxidase activation. To our knowledge, this is the first demonstration of natural formation of CLCs in association with an active physiological process (ie, ETosis). These results indicate that dynamic changes in intracellular localization and release of galectin-10 contribute to CLC formation in vivo and suggest that CLC/galectin-10 might serve as an indicator of ETosis.


2014 ◽  
Vol 395 (10) ◽  
pp. 1163-1171 ◽  
Author(s):  
Pavel Davidovich ◽  
Conor J. Kearney ◽  
Seamus J. Martin

Abstract Microbial infection and tissue injury are well established as the two major drivers of inflammation. However, although it is widely accepted that necrotic cell death can trigger or potentiate inflammation, precisely how this is achieved still remains relatively obscure. Certain molecules, which have been dubbed ‘damage-associated molecular patterns’ (DAMPs) or alarmins, are thought to promote inflammation upon release from necrotic cells. However, the precise nature and relative potency of DAMPs, compared to conventional pro-inflammatory cytokines or pathogen-associated molecular patterns (PAMPs), remains unclear. How different modes of cell death impact on the immune system also requires further clarification. Apoptosis has long been regarded as a non-inflammatory or even anti-inflammatory mode of cell death, but recent studies suggest that this is not always the case. Necroptosis is a programmed form of necrosis that is engaged under certain conditions when caspase activation is blocked. Necroptosis is also regarded as a highly pro-inflammatory mode of cell death but there has been little explicit examination of this issue. Here we discuss the inflammatory implications of necrosis, necroptosis and apoptosis and some of the unresolved questions concerning how dead cells influence inflammatory responses.


Author(s):  
Lohans Pedrera ◽  
Rafael A. Espiritu ◽  
Uris Ros ◽  
Josephine Weber ◽  
Anja Schmitt ◽  
...  

AbstractFerroptosis is an iron-dependent form of regulated necrosis associated with lipid peroxidation. Despite its key role in the inflammatory outcome of ferroptosis, little is known about the molecular events leading to the disruption of the plasma membrane during this type of cell death. Here we show that a sustained increase in cytosolic Ca2+ is a hallmark of ferroptosis that precedes complete bursting of the cell. We report that plasma membrane damage leading to ferroptosis is associated with membrane nanopores of a few nanometers in radius and that ferroptosis, but not lipid peroxidation, can be delayed by osmoprotectants. Importantly, Ca2+ fluxes during ferroptosis induce the activation of the ESCRT-III-dependent membrane repair machinery, which counterbalances the kinetics of cell death and modulates the immunological signature of ferroptosis. Our findings with ferroptosis provide a unifying concept that sustained increase of cytosolic Ca2+ prior to plasma membrane rupture is a common feature of regulated types of necrosis and position ESCRT-III activation as a general protective mechanism in these lytic cell death pathways.


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