scholarly journals A unique death pathway keeps RIPK1 D325A mutant mice in check at embryonic day 10.5

PLoS Biology ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. e3001304
Author(s):  
Yingying Zhang ◽  
Kai Huang ◽  
Yuxia Zhang ◽  
Tao Han ◽  
Lang Li ◽  
...  
Keyword(s):  
Tumor Necrosis ◽  
Caspase 3 ◽  
Tumor Necrosis Factor Receptor ◽  
Caspase 8 ◽  
Unexpected Death ◽  
Serine Threonine Kinase ◽  
Threonine Kinase ◽  
Pleiotropic Functions ◽  
Necrosis Factor ◽  
Active Caspase

Tumor necrosis factor receptor-1 (TNFR1) signaling, apart from its pleiotropic functions in inflammation, plays a role in embryogenesis as deficiency of varieties of its downstream molecules leads to embryonic lethality in mice. Caspase-8 noncleavable receptor interacting serine/threonine kinase 1 (RIPK1) mutations occur naturally in humans, and the corresponding D325A mutation in murine RIPK1 leads to death at early midgestation. It is known that both the demise of Ripk1D325A/D325A embryos and the death of Casp8−/− mice are initiated by TNFR1, but they are mediated by apoptosis and necroptosis, respectively. Here, we show that the defects in Ripk1D325A/D325A embryos occur at embryonic day 10.5 (E10.5), earlier than that caused by Casp8 knockout. By analyzing a series of genetically mutated mice, we elucidated a mechanism that leads to the lethality of Ripk1D325A/D325A embryos and compared it with that underlies Casp8 deletion-mediated lethality. We revealed that the apoptosis in Ripk1D325A/D325A embryos requires a scaffold function of RIPK3 and enzymatically active caspase-8. Unexpectedly, caspase-1 and caspase-11 are downstream of activated caspase-8, and concurrent depletion of Casp1 and Casp11 postpones the E10.5 lethality to embryonic day 13.5 (E13.5). Moreover, caspase-3 is an executioner of apoptosis at E10.5 in Ripk1D325A/D325A mice as its deletion extends life of Ripk1D325A/D325A mice to embryonic day 11.5 (E11.5). Hence, an unexpected death pathway of TNFR1 controls RIPK1 D325A mutation-induced lethality at E10.5.

Increased sensitivity of T lymphocytes to tumor necrosis factor receptor 1 (TNFR1)– and TNFR2-mediated apoptosis in HIV infection: relation to expression of Bcl-2 and active caspase-8 and caspase-3

Blood ◽  
2002 ◽  
Vol 99 (5) ◽  
pp. 1666-1675 ◽  
Author(s):  
Luzia Maria de Oliveira Pinto ◽  
Sylvie Garcia ◽  
Hervé Lecoeur ◽  
Christophe Rapp ◽  
Marie-Lise Gougeon
Keyword(s):  
T Cells ◽  
Cell Death ◽  
Tumor Necrosis Factor ◽  
Hiv Infection ◽  
Tumor Necrosis ◽  
Caspase 3 ◽  
Tumor Necrosis Factor Receptor ◽  
Caspase 8 ◽  
Hiv Patients ◽  
Necrosis Factor

The destruction of CD4 T cells in human immunodeficiency virus (HIV) infection is associated with activation of apoptotic programs, partly mediated by death receptors. The role of CD95L/CD95 in depletion of patients' CD4 T cells is well documented, but the possible contribution of the tumor necrosis factor/tumor necrosis factor receptor (TNF/TNFR) pathway has not been examined. In this study, we found that both TNFR1 and TNFR2 induced marked apoptosis in peripheral T cells from HIV-infected persons, involving both CD4 and CD8 T cells. Longitudinal follow-up of HIV+ patients suggests an association between the in vivo evolution of CD4 T-cell numbers and variations in susceptibility to TNFR-induced apoptosis. Analysis of molecular mechanisms involved showed that it was not related to altered ex vivo expression of TNFR1-associated death domain, receptor interacting protein, or TNFR-associated factor 2. Susceptibility to TNFR-mediated apoptosis was rather related to Bcl-2 expression, because patients' T cells expressing high levels of Bcl-2 were completely protected from TNFR1- and TNFR2-induced cell death, whereas T cells expressing normal levels of Bcl-2 were not protected in patients in contrast to controls. Early recruitment of caspase-8 and caspase-3 is needed to transduce the apoptotic signals, and expression of both caspases in their active form was detected in blood T cells from HIV+ patients, whereas it was hardly detected in controls. Moreover, ligation of TNFRs induced increased activation of both caspases in patients' T cells. Together these data demonstrate that exacerbated TNFR-mediated cell death of T cells from HIV-infected individuals is associated with both alteration of Bcl-2 expression and activation of caspase-8 and caspase-3 and may contribute to the pathogenesis of acquired immunodeficiency syndrome.

scholarly journals LIGHT, a Member of the Tumor Necrosis Factor Ligand Superfamily, Prevents Tumor Necrosis Factor-α-mediated Human Primary Hepatocyte Apoptosis, but Not Fas-mediated Apoptosis

2002 ◽  
Vol 277 (51) ◽  
pp. 50054-50061 ◽  
Author(s):  
Hideki Matsui ◽  
Yukiko Hikichi ◽  
Isamu Tsuji ◽  
Takao Yamada ◽  
Yasushi Shintani
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Time Course ◽  
Caspase 3 ◽  
Nuclear Factor Κb ◽  
Caspase 8 ◽  
Death Domain ◽  
Human Primary Hepatocytes ◽  
Induced Apoptosis ◽  
Necrosis Factor

LIGHT is a member of tumor necrosis factor (TNF) superfamily, and its receptors have been identified as lymphotoxin-β receptor (LTβR) and the herpesvirus entry mediator (HVEM)/ATAR/TR2, both of which lack the cytoplasmic sequence termed the “death domain.” The present study has demonstrated that LIGHT inhibits TNFα-mediated apoptosis of human primary hepatocytes sensitized by actinomycin D (ActD), but not Fas- or TRAIL-mediated apoptosis. Furthermore, LIGHT does not prevent some cell lines such as HepG2 or HeLa from undergoing ActD/TNFα-induced apoptosis. This protective effect requires LIGHT pretreatment at least 3 h prior to ActD sensitization. LIGHT stimulates nuclear factor-κB (NF-κB)-dependent transcriptional activity in human hepatocytes like TNFα. The time course of NF-κB activation after LIGHT administration is similar to that of the pretreatment required for the anti-apoptotic effect of LIGHT. LIGHT inhibits caspase-3 processing on the apoptotic protease cascade in TNFα-mediated apoptosis but not Fas-mediated apoptosis. In addition, increased caspase-3 and caspase-8 activities in ActD/TNFα-treated cells are effectively blocked by LIGHT pretreatment. However, LIGHT does not change the expression of TNFRp55, TNFRp75, and Fas. These results indicate that LIGHT may act as an anti-apoptotic agent against TNFα-mediated liver injury by blocking the activation of both caspase-3 and caspase-8.

Caspases Mediate Tumor Necrosis Factor-–Induced Neutrophil Apoptosis and Downregulation of Reactive Oxygen Production

Blood ◽  
1999 ◽  
Vol 93 (2) ◽  
pp. 674-685 ◽  
Author(s):  
Kouhei Yamashita ◽  
Atsushi Takahashi ◽  
Susumu Kobayashi ◽  
Hirokazu Hirata ◽  
Peter W. Mesner ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Caspase 3 ◽  
Reactive Oxygen ◽  
Caspase 8 ◽  
Neutrophil Apoptosis ◽  
Oxygen Production ◽  
Caspase Activation ◽  
Necrosis Factor ◽  
Superoxide Release

Tumor necrosis factor- (TNF-) exerts two separate effects on neutrophils, stimulating effector functions while simultaneously inducing apoptosis. We examined here the involvement of caspases in neutrophil apoptosis and the effect of TNF-–induced apoptosis on reactive oxygen production. Immunoblotting and affinity labeling showed activation of caspase-8, caspase-3, and a caspase with a large subunit of 18 kD (T18) in TNF-–treated neutrophils. Active caspase-6 and -7 were not detectable in this cell type. Caspase-8 activated caspase-3 and T18 in neutrophil cytoplasmic extracts. zVAD-fmk blocked neutrophil apoptosis, in parallel with the inhibition of caspase activation. TNF-–induced caspase activation was accompanied by a decrease in the ability of neutrophils to release superoxide anion. Conversely, TNF- treatment in the presence of zVAD-fmk caused a prolonged augmentation of superoxide release. Granulocyte-macrophage colony-stimulating factor inhibited TNF-–induced caspase activation and apoptosis, while reversing the diminution in superoxide release. These observations not only suggest that a caspase cascade mediates apoptotic events and downregulates oxygen radical production in TNF-–treated neutrophils, but also raise the possibility that suppression of caspase activation with enhanced proinflammatory actions of TNF- may underlie the pathogenesis of inflammatory diseases.

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