| 1. |
- Aftab, Obaid, 1984-, et al.
(författare)
-
Label free high throughput screening for apoptosis inducing chemicals using time-lapse microscopy signal processing
- 2014
-
Ingår i: Apoptosis (London). - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 19:9, s. 1411-1418
-
Tidskriftsartikel (refereegranskat)abstract
- Label free time-lapse microscopy has opened a new avenue to the study of time evolving events in living cells. When combined with automated image analysis it provides a powerful tool that enables automated large-scale spatiotemporal quantification at the cell population level. Very few attempts, however, have been reported regarding the design of image analysis algorithms dedicated to the detection of apoptotic cells in such time-lapse microscopy images. In particular, none of the reported attempts is based on sufficiently fast signal processing algorithms to enable large-scale detection of apoptosis within hours/days without access to high-end computers. Here we show that it is indeed possible to successfully detect chemically induced apoptosis by applying a two-dimensional linear matched filter tailored to the detection of objects with the typical features of an apoptotic cell in phase-contrast images. First a set of recorded computational detections of apoptosis was validated by comparison with apoptosis specific caspase activity readouts obtained via a fluorescence based assay. Then a large screen encompassing 2,866 drug like compounds was performed using the human colorectal carcinoma cell line HCT116. In addition to many well known inducers (positive controls) the screening resulted in the detection of two compounds here reported for the first time to induce apoptosis.
|
|
| 2. |
- Barathan, Muttiah, et al.
(författare)
-
Chronic hepatitis C virus infection triggers spontaneous differential expression of biosignatures associated with T cell exhaustion and apoptosis signaling in peripheral blood mononucleocytes
- 2015
-
Ingår i: Apoptosis (London). - : Springer Verlag (Germany). - 1360-8185 .- 1573-675X. ; 20:4, s. 466-480
-
Tidskriftsartikel (refereegranskat)abstract
- Persistent hepatitis C virus (HCV) infection appears to trigger the onset of immune exhaustion to potentially assist viral persistence in the host, eventually leading to hepatocellular carcinoma. The role of HCV on the spontaneous expression of markers suggestive of immune exhaustion and spontaneous apoptosis in immune cells of chronic HCV (CHC) disease largely remain elusive. We investigated the peripheral blood mononuclear cells of CHC patients to determine the spontaneous recruitment of cellular reactive oxygen species (cROS), immunoregulatory and exhaustion markers relative to healthy controls. Using a commercial QuantiGenePlex(A (R)) 2.0 assay, we determined the spontaneous expression profile of 80 different pro- and anti-apoptotic genes in persistent HCV disease. Onset of spontaneous apoptosis significantly correlated with the up-regulation of cROS, indoleamine 2,3-dioxygenase (IDO), cyclooxygenase-2/prostaglandin H synthase (COX-2/PGHS), Foxp3, Dtx1, Blimp1, Lag3 and Cd160. Besides, spontaneous differential surface protein expression suggestive of T cell inhibition viz., TRAIL, TIM-3, PD-1 and BTLA on CD4+ and CD8+ T cells, and CTLA-4 on CD4+ T cells was also evident. Increased up-regulation of Tnf, Tp73, Casp14, Tnfrsf11b, Bik and Birc8 was observed, whereas FasLG, Fas, Ripk2, Casp3, Dapk1, Tnfrsf21, and Cflar were moderately up-regulated in HCV-infected subjects. Our observation suggests the spontaneous onset of apoptosis signaling and T cell exhaustion in chronic HCV disease.
|
|
| 3. |
- Beckman, M, et al.
(författare)
-
Degradation of GFP-labelled POM121, a non-invasive sensor of nuclear apoptosis, precedes clustering of nuclear pores and externalisation of phosphatidylserine
- 2004
-
Ingår i: Apoptosis (London). - 1360-8185 .- 1573-675X. ; 9:3, s. 363-368
-
Tidskriftsartikel (refereegranskat)abstract
- The nuclear pore membrane protein POM121 is specifically degraded during apoptosis by a caspase-3-dependent process enabling early detection of apoptosis in living cells expressing POM121-GFP. Here we further investigated temporal aspects of apoptotic degradation of POM121-GFP. We demonstrate that decreased POM121-GFP fluorescence precedes annexin V-labelling of apoptotic cells. This indicates that degradation of the nuclear pore complex starts prior to redistribution of plasma membrane phosphatidylserine, which serves as a signal for phagocytotic elimination of apoptotic cells. Furthermore, a caspase-resistant GFP-labelled mutant of POM121 resisted degradation even in late apoptosis and was detected in clustered nuclear pores. Thus, it can be concluded that loss of POM121-GFP is a specific sensor of the activation of caspase-3-dependent proteolysis at the nuclear pores.
|
|
| 4. |
- Bilyy, Rostyslav, et al.
(författare)
-
AMID : new insights on its intracellular localization and expression at apoptosis
- 2008
-
Ingår i: Apoptosis (London). - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 13:5, s. 729-732
-
Tidskriftsartikel (refereegranskat)abstract
- AMID (apoptosis-inducing factor (AIF)-like mitochondrion-associated inducer of death) is a poorly studied member of the AIF family; despite the given name AMID, predicting its association with mitochondria, its real cellular localization, as well as its role and changes during apoptosis are currently unclear. By means of MALDI-TOF mass spectrometry, we have identified as AMID (accession number AAH38129, sequence coverage 31%) the protein isolated by Pisum sativum lectin-affinity chromatography from the plasma membrane fraction of apoptotic murine leukemia L1210 cells, lacking in the intact cells. The obtained results suggest its possible glycosylation that was further suggested by finding N-glycosylation sequon in the signal peptide of AMID protein (in silica), and by predicting transmembrane localization of its N-terminal part. Using monoclonal antibodies to AMID, we demonstrated an increased expression of AMID in human leukemia Jurkat T-cells after apoptosis induction. Immunocytochemical study suggested its association to the plasma membrane.
|
|
| 5. |
- Bivik, Cecilia, et al.
(författare)
-
JNK mediates UVB-induced apoptosis upstream lysosomal membrane permeabilization and Bcl-2 family proteins
- 2008
-
Ingår i: Apoptosis (London). - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 13:9, s. 1111-1120
-
Tidskriftsartikel (refereegranskat)abstract
- UVB irradiation induced phosphorylation of JNK and subsequent apoptosis in human melanocytes. Depletion of both JNK1 and JNK2 expression using siRNA transfection, protected against apoptosis, as detected by decreased nuclear fragmentation and caspase-3 activity, as well as reduced translocation of Bax to mitochondria. Moreover, release of cathepsin B and D from lysosomes to the cytosol was reduced when JNK expression was suppressed by siRNA, demonstrating a JNK dependent regulation of lysosomal membrane permeabilization. In unirradiated control melanocytes, coimmunoprecipitation showed that Bim was sequestered by Mcl-1, which had a pro-survival function. After UVB irradiation, a significant decrease in Mcl-1 protein level was found, which was prevented by addition of a proteasome inhibitor. The interaction between Bim and Mcl-1 was reduced in response to UVB irradiation and Bim was phosphorylated in a JNK dependent manner. In conclusion, these findings Suggest JNK to have an important pro-apoptotic function following UVB irradiation in human melanocytes, by acting upstream of lysosomal membrane permeabilization and Bim phosphorylation.
|
|
| 6. |
- Blomberg, Jeanette, et al.
(författare)
-
Inhibition of cellular FLICE-like inhibitory protein abolishes insensitivity to interferon-α in a resistant variant of the human U937 cell line
- 2011
-
Ingår i: Apoptosis (London). - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 16:8, s. 783-794
-
Tidskriftsartikel (refereegranskat)abstract
- Type I interferons constitute a family of pleiotropic cytokines that have a key role in both adaptive and innate immunity. The interferon signalling pathways mediate transcriptional regulation of hundreds of genes, which result in mRNA degradation, decreased protein synthesis, cell cycle inhibition and induction of apoptosis. To elucidate regulatory networks important for interferon induced cell death, we generated interferon resistant U937 cells by selection in progressively increasing concentrations of interferon-α (IFN-α). The results show that IFN-α activates the death receptor signalling pathway and that IFN resistance was associated with cross-resistance to several death receptor ligands in a manner similar to previously described Fas resistant U937 cell lines. Increased expression of the long splice variant of the cellular FLICE-like inhibitor protein (cFLIP-L) was associated with the resistance to death receptor and IFN-α stimulation. Accordingly, inhibition of cFLIP-L expression with cycloheximide or through cFLIP short harpin RNA interference restored sensitivity to Fas and/or IFN-α. Thus, we now show that selection for interferon resistance can generate cells with increased expression of cFLIP, which protects the cells from both IFN-α and death receptor mediated apoptosis.
|
|
| 7. |
- Blomgren, Klas, 1963, et al.
(författare)
-
Pathological apoptosis in the developing brain
- 2007
-
Ingår i: Apoptosis. - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 12:5, s. 993-1010
-
Forskningsöversikt (refereegranskat)abstract
- More than half of the initially-formed neurons are deleted in certain brain regions during normal development. This process, whereby cells are discretely removed without interfering with the further development of remaining cells, is called programmed cell death (PCD). The term apoptosis is used to describe certain morphological manifestations of PCD. Many of the effectors of this developmental cell death program are highly expressed in the developing brain, making it more susceptible to accidental activation of the death machinery, e.g. following hypoxia-ischemia or irradiation. Recent evidence suggests, however, that activation and regulation of cell death mechanisms under pathological conditions do not exactly mirror physiological, developmentally regulated PCD. It may be argued that the conditions after e.g. ischemia are not even compatible with the execution of PCD as we know it. Under pathological conditions cells are exposed to various stressors, including energy failure, oxidative stress and unbalanced ion fluxes. This results in parallel triggering and potential overshooting of several different cell death pathways, which then interact with one another and result in complex patterns of biochemical manifestations and cellular morphological features. These types of cell death are here called "pathological apoptosis," where classical hallmarks of PCD, like pyknosis, nuclear condensation and caspase-3 activation, are combined with non-PCD features of cell death. Here we review our current knowledge of the mechanisms involved, with special focus on the potential for therapeutic intervention tailored to the needs of the developing brain.
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Gogvadze, V, et al.
(författare)
-
Mitochondria as targets for chemotherapy
- 2009
-
Ingår i: Apoptosis : an international journal on programmed cell death. - : Springer Science and Business Media LLC. - 1573-675X. ; 14:4, s. 624-640
-
Tidskriftsartikel (refereegranskat)
|
|
| 11. |
- Gu, G, et al.
(författare)
-
Estrogen protects primary osteocytes against glucocorticoid-induced apoptosis
- 2005
-
Ingår i: Apoptosis. - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 10:3, s. 583-595
-
Tidskriftsartikel (refereegranskat)abstract
- Glucocorticoid-induced osteoporosis may be at least in part due to the increased apoptosis of osteocytes. To study the role of osteocyte apoptosis in glucocorticoid-induced osteoporosis, we isolated primary osteocytes from murine calvaria for the analysis of the effects of dexamethasone in in vitro culture. The cells were identified by morphology, cytochemical staining, immunocytochemical staining and mRNA expression of phosphate-regulating gene with homology to endopeptidases on the X chromosome (PHEX) and sclerosteosis/van Buchem disease gene (SOST). We found that dexamethasone induced osteocyte apoptosis in a dose-dependent manner. A glucocorticoid receptor antagonist, mifepristone (RU486), suppressed dexamethasone-Induced osteocyte apoptosis, suggesting that it was mediated by glucocorticoid receptor. Immunocytochemical stainings showed that glucocorticoid receptors are present in primary osteocytes, and they were translocated to nuclei after the exposure to dexamethasone. Addition of estrogen prevented glucocorticoid receptor translocation into nuclei. Corresponding antiapoptotic effects in primary osteocytes were also seen after the pretreatment of primary osteocytes with a picomolar concentration of estrogen. The pure antiestrogen ICI 182,780 inhibited estrogen effect on apoptosis induced by dexamethasone. These data suggest that glucocorticoid receptors play an important role in glucocorticoid-induced osteocyte apoptosis. Most importantly, estrogen has a protective effect against osteocyte apoptosis. To conclude, the mechanism of glucocorticoid-induced osteoporosis may be due to the apoptosis of osteocytes, which can be opposed by estrogen.
|
|
| 12. |
|
|
| 13. |
- Johansson, Ann-Charlotte, et al.
(författare)
-
Regulation of apoptosis-associated lysosomal membrane permeabilization
- 2010
-
Ingår i: APOPTOSIS. - : Springer Science Business Media. - 1360-8185 .- 1573-675X. ; 15:5, s. 527-540
-
Tidskriftsartikel (refereegranskat)abstract
- Lysosomal membrane permeabilization (LMP) occurs in response to a large variety of cell death stimuli causing release of cathepsins from the lysosomal lumen into the cytosol where they participate in apoptosis signaling. In some settings, apoptosis induction is dependent on an early release of cathepsins, while under other circumstances LMP occurs late in the cell death process and contributes to amplification of the death signal. The mechanism underlying LMP is still incompletely understood; however, a growing body of evidence suggests that LMP may be governed by several distinct mechanisms that are likely engaged in a death stimulus- and cell-type-dependent fashion. In this review, factors contributing to permeabilization of the lysosomal membrane including reactive oxygen species, lysosomal membrane lipid composition, proteases, p53, and Bcl-2 family proteins, are described. Potential mechanisms to safeguard lysosomal integrity and confer resistance to lysosome-dependent cell death are also discussed.
|
|
| 14. |
- Johnsen, J, et al.
(författare)
-
Embryonal neural tumours and cell death
- 2009
-
Ingår i: Apoptosis : an international journal on programmed cell death. - : Springer Science and Business Media LLC. - 1573-675X. ; 14:4, s. 424-438
-
Tidskriftsartikel (refereegranskat)
|
|
| 15. |
- Kallio, A, et al.
(författare)
-
Role of mitochondria in tamoxifen-induced rapid death of MCF-7 breast cancer cells
- 2005
-
Ingår i: Apoptosis. - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 10:6, s. 1395-1410
-
Tidskriftsartikel (refereegranskat)abstract
- Tamoxifen (Tam) is widely used in chemotherapy of estrogen receptor-positive breast cancer. It inhibits proliferation and induces apoptosis of breast cancer cells by estrogen receptor-dependent modulation of gene expression, but recent reports have shown that Tam (especially at pharmacological concentrations) has also rapid nongenomic effects. Here we studied the mechanisms by which Tam exerts rapid effects on breast cancer cell viability. In serum-free medium 5-7 mu M Tam induced death of MCF-7 and MDA-MB-231 cells in a time-dependent manner in less than 60 min. This was associated with release of mitochondrial cytochrome c, a decrease of mitochondrial membrane potential and an increase in production of reactive oxygen species (ROS). This suggests that disruption of mitochondrial function has a primary role in the acute death response of the cells. Accordingly, bongkrekic acid, an inhibitor of mitochondrial permeability transition, was able to protect MCF-7 cells against Tam. Rapid cell death induction by Tam was not associated with immediate activation of caspase-9 or cleavage of poly (ADP-ribose) polymerase. It was not blocked by the caspase inhibitor z-Val-Ala-Asp-fluoromethylketone either. Diphenylene ionodium (DPI), an inhibitor of NADPH oxidase, was able to prevent Tam-induced cell death but not cytochrome c release, which suggests that ROS act distal to cytochrome c. The pure antiestrogen ICI 182780 (1 mu M) could partly oppose the effect of Tam in estrogen receptor positive MCF-7 cells, but not in estrogen receptor negative MDA-MB-231 cells. Pre-culturing MCF-7 cells in the absence of 17 beta-estradiol (E-2) or in the presence of a low Tam concentration (1 mu M) made the cells even more susceptible to rapid death induction by 5 or 7 mu M Tam. This effect was associated with decreased levels of the anti-apoptotic proteins Bcl-X-L and Bcl-2. In conclusion, our results demonstrate induction of a rapid mitochondrial cell death program in breast cancer cells at pharmacological concentrations of Tam, which are achievable in tumor tissue of Tam-treated breast cancer patients. These mechanisms may contribute to the ability of Tam therapy to induce death of breast cancer cells.
|
|
| 16. |
|
|
| 17. |
|
|
| 18. |
- Neuzil, Jiri, 1958-, et al.
(författare)
-
Vitamin E analogs : A new class of multiple action agents with anti-neoplastic and anti-atherogenic activity
- 2002
-
Ingår i: Apoptosis (London). - 1360-8185 .- 1573-675X. ; 7:2, s. 179-187
-
Tidskriftsartikel (refereegranskat)abstract
- The incidence of cancer and atherosclerosis, two most common causes of death in developed countries, has been stagnating or, even, increasing. Drugs effective against such conditions are needed and, in this regard, the potential anti-atherosclerotic activity of vitamin E analogs has been studied extensively. Surprisingly, recent results indicate that these agents may also exert anti-neoplastic effects. Here we review the evidence that particular analogs of vitamin E may act as both anti-atherogenic and anti-cancer agents, and discuss the possible molecular bases for these actions.
|
|
| 19. |
- Nilsson, Cathrine, 1978-, et al.
(författare)
-
Cytosolic acidification and lysosomal alkalinization during TNF-α induced apoptosis in U937 cells
- 2006
-
Ingår i: Apoptosis (London). - : Springer Netherlands. - 1360-8185 .- 1573-675X. ; 11:7, s. 1149-1159
-
Tidskriftsartikel (refereegranskat)abstract
- Apoptosis is often associated with acidification of the cytosol and since loss of lysosomal proton gradient and release of lysosomal content are early events during apoptosis, we investigated if the lysosomal compartment could contribute to cytosolic acidification. After exposure of U937 cells to tumor necrosis factor-α, three populations; healthy, pre-apoptotic, and apoptotic cells, were identified by flow cytometry. These populations were investigated regarding intra-cellular pH and apoptosis-associated events. There was a drop in cytosolic pH from 7.2 ± 0.1 in healthy cells to 6.8 ± 0.1 in pre-apoptotic, caspase-negative cells. In apoptotic, caspase-positive cells, the pH was further decreased to 5.7 ± 0.04. The cytosolic acidification was not affected by addition of specific inhibitors towards caspases or the mitochondrial F0F1-ATPase. In parallel to the cytosolic acidification, a rise in lysosomal pH from 4.3 ± 0.3, in the healthy population, to 4.8 ± 0.3 and 5.5 ± 0.3 in the pre-apoptotic- and apoptotic populations, respectively, was detected. In addition, lysosomal membrane permeability increased as detected as release of cathepsin D from lysosomes to the cytosol in pre-apoptotic and apoptotic cells. We, thus, suggest that lysosomal proton release is the cause of the cytosolic acidification of U937 cells exposed to TNF-α.
|
|
| 20. |
- Ott, M, et al.
(författare)
-
Mitochondria, oxidative stress and cell death
- 2007
-
Ingår i: Apoptosis : an international journal on programmed cell death. - : Springer Science and Business Media LLC. - 1360-8185. ; 12:5, s. 913-922
-
Tidskriftsartikel (refereegranskat)
|
|
| 21. |
- Sa Ferreira, Karine, et al.
(författare)
-
Caspase-3 feeds back on caspase-8, Bid and XIAP in type I Fas signaling in primary mouse hepatocytes
- 2012
-
Ingår i: Apoptosis (London). - : Springer Verlag (Germany). - 1360-8185 .- 1573-675X. ; 17:5, s. 503-515
-
Tidskriftsartikel (refereegranskat)abstract
- The TNF-R1 like receptor Fas is highly expressed on the plasma membrane of hepatocytes and plays an essential role in liver homeostasis. We recently showed that in collagen-cultured primary mouse hepatocytes, Fas stimulation triggers apoptosis via the so-called type I extrinsic signaling pathway. Central to this pathway is the direct caspase-8-mediated cleavage and activation of caspase-3 as compared to the type II pathway which first requires caspase-8-mediated Bid cleavage to trigger mitochondrial cytochrome c release for caspase-3 activation. Mathematical modeling can be used to understand complex signaling systems such as crosstalks and feedback or feedforward loops. A previously published model predicted a positive feedback loop between active caspases-3 and -8 in both type I and type II FasL signaling in lymphocytes and Hela cells, respectively. Here we experimentally tested this hypothesis in our hepatocytic type I Fas signaling pathway by using wild-type and XIAP-deficient primary hepatocytes and two recently characterized, selective caspase-3/-7 inhibitors (AB06 and AB13). Caspase-3/-7 activity assays and quantitative western blotting confirmed that fully processed, active p17 caspase-3 feeds back on caspase-8 by cleaving its partially processed p43 form into the fully processed p18 species. Our data do not discriminate if p18 positively or negatively influences FasL-induced apoptosis or is responsible for non-apoptotic aspects of FasL signaling. However, we found that caspase-3 also feeds back on Bid and degrades its own inhibitor XIAP, both events that may enhance caspase-3 activity and apoptosis. Thus, potent, selective caspase-3 inhibitors are useful tools to understand complex signaling circuitries in apoptosis.
|
|
| 22. |
- Sachet, M, et al.
(författare)
-
The immune response to secondary necrotic cells
- 2017
-
Ingår i: Apoptosis : an international journal on programmed cell death. - : Springer Science and Business Media LLC. - 1573-675X. ; 22:10, s. 1189-1204
-
Tidskriftsartikel (refereegranskat)
|
|
| 23. |
|
|
| 24. |
- Viktorsson, K, et al.
(författare)
-
Increased apoptosis and increased clonogenic survival of 12V-H-ras transformed rat fibroblasts in response to cisplatin
- 2000
-
Ingår i: Apoptosis (London). - 1360-8185 .- 1573-675X. ; 5:4, s. 355-367
-
Tidskriftsartikel (refereegranskat)abstract
- Mutationally activated Ras is involved in tumor progression and likely also in drug resistance. Using survival, viability and apoptosis assays, we have here compared the cisplatin sensitivities of FR3T3 rat fibroblasts and a 12V-H-ras transformed subline (Ras2:3). Around 24 h after cisplatin treatment Ras2:3 cells showed higher apoptosis levels and lower viability than FR3T3. This increased sensitivity correlated with weaker cisplatin-induced activation of Jun N-terminal kinase (JNK). In contrast to apoptosis assays, colony formation assays showed that Ras2:3 were more resistant to cisplatin than were FR3T3. This was partly due to the increased cisplatin sensitivity of FR3T3 seeded at low densities, as required in colony formation assays. In addition, Ras2:3 cisplatin survivors had a higher relative proliferative capacity. Cell cycle analyses showed that FR3T3 cells initially responded with a dose-dependent G2 arrest, while Ras2:3 accumulated in S-phase. Experiments with an anti-apoptotic mutant of MEKK1 suggested that the apoptotic response of Ras2:3 cells is not specific to the S-phase fraction. In summary, the cisplatin response of ras-transformed fibroblasts is distinct from that of parental cells, in that they show increased apoptosis, a different cell cycle response and increased post-treatment proliferative capacity. The results illustrate the need to carefully consider methods and protocols for in vitro studies on chemotherapy sensitivity.
|
|
| 25. |
- Wolbers, F., et al.
(författare)
-
Apoptosis induced kinetic changes in autofluorescence of cultured HL60 cells-possible application for single cell analysis on chip
- 2004
-
Ingår i: Apoptosis (London). - 1360-8185 .- 1573-675X. ; 9:6, s. 749-755
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: This paper presents a new method using natural cellular fluorescence (autofluorescence, AF) to study apoptosis. Measurement of AF reduces sample preparation time and avoids cellular toxicity due to the fact that no labelling is required. Methods: Human promyelocytic leukemic HL60 cells were incubated with camptothecin (CPT), tumour necrosis factor (TNF)-alpha in combination with cycloheximide (CHX), or irradiated with 6 or 10 Gray, during varying time periods, to initiate apoptosis. AF was measured at the flow cytometer. Results: Induction of apoptosis results in the shrinkage of the cell and the fragmentation into apoptotic bodies. With flow cytometry, 4 subpopulations, viable, early apoptotic, late apoptotic and the necrotic cells, can be distinguished. Induction of apoptosis results in a decrease in AF intensity compared to untreated HL60 cells, especially seen in the late apoptotic subpopulation. The AF intensity is found to decrease significantly in time (between 2 h and 24 h) for all the four apoptotic inducers used. Conclusions: Our results show that it is possible to specifically measure the apoptotic-induced kinetic changes in AF in HL60 cells. A decrease in AF intensity is seen from 2 h till 24 h. These results open a door for future developments in single-cell analysis.
|
|
| 26. |
|
|
| 27. |
- Åberg, Mikael, et al.
(författare)
-
Activation of β1 integrins and caveolin-1 by TF/FVIIa promotes IGF-1R signaling and cell survival
- 2020
-
Ingår i: Apoptosis (London). - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 25, s. 519-534
-
Tidskriftsartikel (refereegranskat)abstract
- The tissue factor/coagulation factor VIIa (TF/FVIIa) complex induces transactivation of the IGF-1 receptor (IGF-1R) in a number of different cell types. The mechanism is largely unknown. The transactivation leads to protection from apoptosis and nuclear translocation of the IGF-1R. The aim of this study was to clarify the signaling pathway between TF and IGF-1R after FVIIa treatment with PC3 and DU145 prostate or MDA-MB-231 breast cancer cells as model systems. Protein interactions, levels, and phosphorylations were assessed by proximity ligation assay or flow cytometry in intact cells and by western blot on cell lysates. The transactivation of the IGF-1R was found dependent on TF/FVIIa-induced activation of β1-integrins. A series of experiments led to the conclusion that the caveolae protein caveolin-1 prevented IGF-1R activation in resting cells via its scaffolding domain. TF/FVIIa/β1-integrins terminated this inhibition by activation of Src family kinases and subsequent phosphorylation of caveolin-1 on tyrosine 14. This phosphorylation was not seen after treatment with PAR1 or PAR2 agonists. Consequently, the protective effect of FVIIa against apoptosis induced by the death receptor agonist TRAIL and the de novo synthesis of cyclin D1 induced by nuclear IGF-1R accumulation were both significantly reduced by down-regulation of β1-integrins or overexpression of the caveolin-1 scaffolding domain. In conclusion, we present a plausible mechanism for the interplay between TF and IGF-1R involving FVIIa, β1-integrins, Src family proteins, and caveolin-1. Our results increase the knowledge of diseases associated with TF and IGF-1R overexpression in general but specifically of TF-mediated signaling with focus on cell survival.
|
|
| 28. |
|
|
| 29. |
|
|
| 30. |
|
|
| 31. |
|
|
| 32. |
|
|
