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| 2. |
- Hangen, E, et al.
(författare)
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A brain-specific isoform of mitochondrial apoptosis-inducing factor: AIF2.
- 2010
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Ingår i: Cell death and differentiation. - : Springer Science and Business Media LLC. - 1476-5403 .- 1350-9047. ; 17:7, s. 1155-66
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Tidskriftsartikel (refereegranskat)abstract
- Apoptosis-inducing factor (AIF) has important supportive as well as potentially lethal roles in neurons. Under normal physiological conditions, AIF is a vital redox-active mitochondrial enzyme, whereas in pathological situations, it translocates from mitochondria to the nuclei of injured neurons and mediates apoptotic chromatin condensation and cell death. In this study, we reveal the existence of a brain-specific isoform of AIF, AIF2, whose expression increases as neuronal precursor cells differentiate. AIF2 arises from the utilization of the alternative exon 2b, yet uses the same remaining 15 exons as the ubiquitous AIF1 isoform. AIF1 and AIF2 are similarly imported to mitochondria in which they anchor to the inner membrane facing the intermembrane space. However, the mitochondrial inner membrane sorting signal encoded in the exon 2b of AIF2 is more hydrophobic than that of AIF1, indicating a stronger membrane anchorage of AIF2 than AIF1. AIF2 is more difficult to be desorbed from mitochondria than AIF1 on exposure to non-ionic detergents or basic pH. Furthermore, AIF2 dimerizes with AIF1, thereby preventing its release from mitochondria. Conversely, it is conceivable that a neuron-specific AIF isoform, AIF2, may have been 'designed' to be retained in mitochondria and to minimize its potential neurotoxic activity.Cell Death and Differentiation advance online publication, 29 January 2010; doi:10.1038/cdd.2009.211.
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| 3. |
- Martins, I, et al.
(författare)
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Anticancer chemotherapy and radiotherapy trigger both non-cell-autonomous and cell-autonomous death
- 2018
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Ingår i: Cell death & disease. - : Springer Science and Business Media LLC. - 2041-4889. ; 9:7, s. 716-
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Tidskriftsartikel (refereegranskat)abstract
- Even though cell death modalities elicited by anticancer chemotherapy and radiotherapy have been extensively studied, the ability of anticancer treatments to induce non-cell-autonomous death has never been investigated. By means of multispectral imaging flow-cytometry-based technology, we analyzed the lethal fate of cancer cells that were treated with conventional anticancer agents and co-cultured with untreated cells, observing that anticancer agents can simultaneously trigger cell-autonomous and non-cell-autonomous death in treated and untreated cells. After ionizing radiation, oxaliplatin, or cisplatin treatment, fractions of treated cancer cell populations were eliminated through cell-autonomous death mechanisms, while other fractions of the treated cancer cells engulfed and killed neighboring cells through non-cell-autonomous processes, including cellular cannibalism. Under conditions of treatment with paclitaxel, non-cell-autonomous and cell-autonomous death were both detected in the treated cell population, while untreated neighboring cells exhibited features of apoptotic demise. The transcriptional activity of p53 tumor-suppressor protein contributed to the execution of cell-autonomous death, yet failed to affect the non-cell-autonomous death by cannibalism for the majority of tested anticancer agents, indicating that the induction of non-cell-autonomous death can occur under conditions in which cell-autonomous death was impaired. Altogether, these results reveal that chemotherapy and radiotherapy can induce both non-cell-autonomous and cell-autonomous death of cancer cells, highlighting the heterogeneity of cell death responses to anticancer treatments and the unsuspected potential contribution of non-cell-autonomous death to the global effects of anticancer treatment.
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| 5. |
- Osato, Kazuhiro, et al.
(författare)
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Apoptosis-inducing factor deficiency decreases the proliferation rate and protects the subventricular zone against ionizing radiation.
- 2010
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Ingår i: Cell death & disease. - : Springer Science and Business Media LLC. - 2041-4889. ; 1
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Tidskriftsartikel (refereegranskat)abstract
- Cranial radiotherapy in children often leads to progressive cognitive decline. We have established a rodent model of irradiation-induced injury to the young brain. A single dose of 8Gy was administered to the left hemisphere of postnatal day 10 (P10) mice. Harlequin (Hq) mice, carrying the hypomorphic apoptosis-inducing factor AIF(Hq) mutation, express 60% less AIF at P10 and displayed significantly fewer dying cells in the subventricular zone (SVZ) 6h after IR, compared with wild type (Wt) littermates. Irradiated cyclophilin A-deficient (CypA(-/-)) mice confirmed that CypA has an essential role in AIF-induced apoptosis after IR. Hq mice displayed no reduction in SVZ size 7 days after IR, whereas 48% of the SVZ was lost in Wt mice. The proliferation rate was lower in the SVZ of Hq mice. Cultured neural precursor cells from the SVZ of Hq mice displayed a slower proliferation rate and were more resistant to IR. IR preferentially kills proliferating cells, and the slower proliferation rate in the SVZ of Hq mice may, at least partly, explain the protective effect of the Hq mutation. Together, these results indicate that targeting AIF may provide a fruitful strategy for protection of normal brain tissue against the detrimental side effects of IR.
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| 7. |
- Sun, Yanyan, et al.
(författare)
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Haploinsufficiency in the mitochondrial protein CHCHD4 reduces brain injury in a mouse model of neonatal hypoxia-ischemia
- 2017
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Ingår i: Cell Death & Disease. - : Springer Science and Business Media LLC. - 2041-4889. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Mitochondria contribute to neonatal hypoxic-ischemic brain injury by releasing potentially toxic proteins into the cytosol. CHCHD4 is a mitochondrial intermembrane space protein that plays a major role in the import of intermembrane proteins and physically interacts with apoptosis-inducing factor (AIF). The purpose of this study was to investigate the impact of CHCHD4 haploinsufficiency on mitochondrial function and brain injury after cerebral hypoxia-ischemia (HI) in neonatal mice. CHCHD4(+/-) and wild-type littermate mouse pups were subjected to unilateral cerebral HI on postnatal day 9. CHCHD4 haploinsufficiency reduced insult-related AIF and superoxide dismutase 2 release from the mitochondria and reduced neuronal cell death. The total brain injury volume was reduced by 21.5% at 3 days and by 31.3% at 4 weeks after HI in CHCHD4(+/-) mice. However, CHCHD4 haploinsufficiency had no influence on mitochondrial biogenesis, fusion, or fission; neural stem cell proliferation; or neural progenitor cell differentiation. There were no significant changes in the expression or distribution of p53 protein or p53 pathway-related genes under physiological conditions or after HI. These results suggest that CHCHD4 haploinsufficiency afforded persistent neuroprotection related to reduced release of mitochondrial intermembrane space proteins. The CHCHD4-dependent import pathway might thus be a potential therapeutic target for preventing or treating neonatal brain injury.
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| 9. |
- Zhu, Changlian, 1964, et al.
(författare)
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Cyclophilin A participates in the nuclear translocation of apoptosis-inducing factor in neurons after cerebral hypoxia-ischemia
- 2007
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Ingår i: J Exp Med. - : Rockefeller University Press. - 0022-1007. ; 204:8, s. 1741-8
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Tidskriftsartikel (refereegranskat)abstract
- Upon cerebral hypoxia-ischemia (HI), apoptosis-inducing factor (AIF) can move from mitochondria to nuclei, participate in chromatinolysis, and contribute to the execution of cell death. Previous work (Cande, C., N. Vahsen, I. Kouranti, E. Schmitt, E. Daugas, C. Spahr, J. Luban, R.T. Kroemer, F. Giordanetto, C. Garrido, et al. 2004. Oncogene. 23:1514-1521) performed in vitro suggests that AIF must interact with cyclophilin A (CypA) to form a proapoptotic DNA degradation complex. We addressed the question as to whether elimination of CypA may afford neuroprotection in vivo. 9-d-old wild-type (WT), CypA(+/-), or CypA(-/-) mice were subjected to unilateral cerebral HI. The infarct volume after HI was reduced by 47% (P = 0.0089) in CypA(-/-) mice compared with their WT littermates. Importantly, CypA(-/-) neurons failed to manifest the HI-induced nuclear translocation of AIF that was observed in WT neurons. Conversely, CypA accumulated within the nuclei of damaged neurons after HI, and this nuclear translocation of CypA was suppressed in AIF-deficient harlequin mice. Immunoprecipitation of AIF revealed coprecipitation of CypA, but only in injured, ischemic tissue. Surface plasmon resonance revealed direct molecular interactions between recombinant AIF and CypA. These data indicate that the lethal translocation of AIF to the nucleus requires interaction with CypA, suggesting a model in which two proteins that normally reside in separate cytoplasmic compartments acquire novel properties when moving together to the nucleus.
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