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- Karsten, Stella, et al.
(författare)
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MTH1 as a target to alleviate T cell driven diseases by selective suppression of activated T cells
- 2021
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Ingår i: Cell Death & Differentiation. - Stockholm : Karolinska Institutet, Dept of Oncology-Pathology. - 1350-9047 .- 1476-5403.
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Tidskriftsartikel (refereegranskat)abstract
- T cell-driven diseases account for considerable morbidity and disability globally and there is an urgent need for new targeted therapies. Both cancer cells and activated T cells have an altered redox balance, and up-regulate the DNA repair protein MTH1 that sanitizes the oxidized nucleotide pool to avoid DNA damage and cell death. Herein we suggest that the up-regulation of MTH1 in activated T cells correlates with their redox status, but occurs before the ROS levels increase, challenging the established conception of MTH1 increasing as a direct response to an increased ROS status. We also propose a heterogeneity in MTH1 levels among activated T cells, where a smaller subset of activated T cells does not upregulate MTH1 despite activation and proliferation. The study suggests that the vast majority of activated T cells have high MTH1 levels and are sensitive to the MTH1 inhibitor TH1579 (Karonudib) via induction of DNA damage and cell cycle arrest. TH1579 further drives the surviving cells to the MTH1[superscript low] phenotype with altered redox status. TH1579 does not affect resting T cells, as opposed to the established immunosuppressor Azathioprine, and no sensitivity among other major immune cell types regarding their function can be observed. Finally, we demonstrate a therapeutic effect in a murine model of experimental autoimmune encephalomyelitis. In conclusion, we show proof of concept of the existence of MTH1[superscript high] and MTH1[superscript low] activated T cells, and that MTH1 inhibition by TH1579 selectively suppresses pro-inflammatory activated T cells. Thus, MTH1 inhibition by TH1579 may serve as a novel treatment option against autoreactive T cells in autoimmune diseases, such as multiple sclerosis.
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| 2. |
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| 3. |
- Albert, Marie Christine, et al.
(författare)
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Identification of FasL as a crucial host factor driving COVID-19 pathology and lethality
- 2024
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Ingår i: Cell Death and Differentiation. - 1350-9047.
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Tidskriftsartikel (refereegranskat)abstract
- The dysregulated immune response and inflammation resulting in severe COVID-19 are still incompletely understood. Having recently determined that aberrant death-ligand-induced cell death can cause lethal inflammation, we hypothesized that this process might also cause or contribute to inflammatory disease and lung failure following SARS-CoV-2 infection. To test this hypothesis, we developed a novel mouse-adapted SARS-CoV-2 model (MA20) that recapitulates key pathological features of COVID-19. Concomitantly with occurrence of cell death and inflammation, FasL expression was significantly increased on inflammatory monocytic macrophages and NK cells in the lungs of MA20-infected mice. Importantly, therapeutic FasL inhibition markedly increased survival of both, young and old MA20-infected mice coincident with substantially reduced cell death and inflammation in their lungs. Intriguingly, FasL was also increased in the bronchoalveolar lavage fluid of critically-ill COVID-19 patients. Together, these results identify FasL as a crucial host factor driving the immuno-pathology that underlies COVID-19 severity and lethality, and imply that patients with severe COVID-19 may significantly benefit from therapeutic inhibition of FasL.
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| 5. |
- Allagnat, F., et al.
(författare)
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C/EBP homologous protein contributes to cytokine-induced pro-inflammatory responses and apoptosis in beta-cells
- 2012
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Ingår i: Cell Death and Differentiation. - : Springer Science and Business Media LLC. - 1350-9047 .- 1476-5403. ; 19:11, s. 1836-1846
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Tidskriftsartikel (refereegranskat)abstract
- Induction of the C/EBP homologous protein (CHOP) is considered a key event for endoplasmic reticulum (ER) stress-mediated apoptosis. Type 1 diabetes (T1D) is characterized by an autoimmune destruction of the pancreatic beta-cells. Pro-inflammatory cytokines are early mediators of beta-cell death in T1D. Cytokines induce ER stress and CHOP overexpression in beta-cells, but the role for CHOP overexpression in cytokine-induced beta-cell apoptosis remains controversial. We presently observed that CHOP knockdown (KD) prevents cytokine-mediated degradation of the anti-apoptotic proteins B-cell lymphoma 2 (Bcl-2) and myeloid cell leukemia sequence 1 (Mcl-1), thereby decreasing the cleavage of executioner caspases 9 and 3, and apoptosis. Nuclear factor-kappa B (NF-kappa B) is a crucial transcription factor regulating beta-cell apoptosis and inflammation. CHOP KD resulted in reduced cytokine-induced NF-kappa B activity and expression of key NF-kappa B target genes involved in apoptosis and inflammation, including iNOS, FAS, IRF-7, IL-15, CCL5 and CXCL10. This was due to decreased I kappa B degradation and p65 translocation to the nucleus. The present data suggest that CHOP has a dual role in promoting beta-cell death: (1) CHOP directly contributes to cytokine-induced beta-cell apoptosis by promoting cytokine-induced mitochondrial pathways of apoptosis; and (2) by supporting the NF-kappa B activation and subsequent cytokine/chemokine expression, CHOP may contribute to apoptosis and the chemo attraction of mononuclear cells to the islets during insulitis. Cell Death and Differentiation (2012) 19, 1836-1846; doi:10.1038/cdd.2012.67; published online 1 June 2012
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| 8. |
- Araujo, I. M., et al.
(författare)
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Changes in calcium dynamics following the reversal of the sodium-calcium exchanger have a key role in AMPA receptor-mediated neurodegeneration via calpain activation in hippocampal neurons
- 2007
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Ingår i: Cell Death and Differentiation. - : Springer Science and Business Media LLC. - 1350-9047 .- 1476-5403. ; 14:9, s. 1635-1646
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Tidskriftsartikel (refereegranskat)abstract
- Proteolytic cleavage of the Na+/Ca2+ exchanger (NCX) by calpains impairs calcium homeostasis, leading to a delayed calcium overload and excitotoxic cell death. However, it is not known whether reversal of the exchanger contributes to activate calpains and trigger neuronal death. We investigated the role of the reversal of the NCX in Ca2+ dynamics, calpain activation and cell viability, in alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptor-stimulated hippocampal neurons. Selective overactivation of AMPA receptors caused the reversal of the NCX, which accounted for approximately 30% of the rise in intracellular free calcium concentration ([Ca2+](i)). The NCX reverse-mode inhibitor, 2-[2-[4-(4-nitrobenzyloxy) phenyl]ethyl] isothiourea (KB-R7943), partially inhibited the initial increase in [Ca2+](i), and prevented a delayed increase in [Ca2+](i). In parallel, overactivation of AMPA receptors strongly activated calpains and led to the proteolysis of NCX3. KB-R7943 prevented calpain activation, cleavage of NCX3 and was neuroprotective. Silencing of NCX3 reduced Ca2+ uptake, calpain activation and was neuroprotective. Our data show for the first time that NCX reversal is an early event following AMPA receptor stimulation and is linked to the activation of calpains. Since calpain activation subsequently inactivates NCX, causing a secondary Ca2+ entry, NCX may be viewed as a new suicide substrate operating in a Ca2+-dependent loop that triggers cell death and as a target for neuroprotection.
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| 9. |
- Arvidsson, Yvonne, 1960, et al.
(författare)
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ASK1 resistant neuroblastoma is deficient in activation of p38 kinase.
- 2001
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Ingår i: Cell death and differentiation. - : Springer Science and Business Media LLC. - 1350-9047 .- 1476-5403. ; 8:10, s. 1029-37
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Tidskriftsartikel (refereegranskat)abstract
- Apoptosis Signal-regulating Kinase 1 (ASK1) is known to either induce apoptosis or differentiation in various cell lines of neuronal origin. We analyzed the effect of the constitutively active mutant of ASK1 (ASK1-Delta N) in an adenoviral vector in four neuroblastoma cell lines, two murine, C1300 and NXS2, and two human, SH-SY5Y and IMR-32. Already after 24 h upon infection, C1300 and SH-SY5Y cells arrested in growth when judged by [(3)H]thymidine incorporation, and the majority of the cells demonstrated apoptotic appearance, which was confirmed by DNA-laddering in gel electrophoresis. In contrast, NXS2 and IMR-32 cell lines remained unaffected. Immunoblotting revealed strongly phosphorylated p38 MAPK accompanied by weakly phosphorylated JNK in C1300 and SH-SY5Y, whereas none of these kinases were activated by adenoviruses expressing the kinase negative ASK1 mutant or beta-galactosidase. There was no expression of phosphorylated kinases in IMR-32 cells, but NXS2 showed a faint band of phosphorylated p38 MAPK. Addition of the p38 MAPK specific inhibitor, SB203580, protected C1300 and SH-SY5Y cells from apoptosis induced by ASK1-Delta N. The anti-neoplastic agent, paclitaxel, activates ASK1 and JNK, and promotes the in vitro assembly of stable microtubules. Addition of 10 nM paclitaxel sensitised the NXS2 cell line to ASK1-induced cell death. Our results indicate that ASK1 induces apoptosis in neuroblastoma cells mainly via the p38 MAPK pathway, and resistant neuroblastoma cells can be sensitised to ASK1 by paclitaxel.
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