Intracellular sites of photodamage as a factor in apoptotic cell death

2001 ◽  
Vol 05 (02) ◽  
pp. 181-184 ◽  
Author(s):  
D. KESSEL ◽  
Y. LUO
Keyword(s):  
Cell Death ◽  
Photodynamic Therapy ◽  
Cytochrome C ◽  
Cellular Localization ◽  
Proteolytic Enzymes ◽  
Apoptotic Cell ◽  
Immediate Release ◽  
Apoptotic Response ◽  
Apoptotic Morphology

The cytotoxic response to photodynamic therapy can involve apoptosis, necrosis or both. Using agents with known patterns of sub-cellular localization, we assessed different sites of photodamage as a determinant of cell death, using murine leukemia cells in vitro. Mitochondrial or mitochondrial + lysosomal photodamage led to a rapid apoptotic response, associated with the release of cytochrome c from mitochondria into the cytosol. This occurred immediately after irradiation of photosensitized cells. When photodamaged cells were warmed to 37 °C, there was a rapid apoptotic response. Lysosomal photodamage led to the immediate release of cathepsins and other proteolytic enzymes. During a subsequent incubation at 37 °C, there was a slow loss of the mitochondrial membrane potential, with cytochrome c appearing in the cytosol within 30 min. These effects derive from proteolytic effects of lysosomal enzymes on mitochondria. The apoptotic response to lysosomal photodamage was both slow and incomplete, with many non-viable cells not exhibiting apoptotic morphology. The latter result was correlated with photodamage to procaspase-3, an effect not observed when mitochondria were the predominant target for photodamage. Depending on the sub-cellular target, photodynamic therapy can either activate or inhibit critical elements of apoptosis.

Preclinical photodynamic therapy research in Spain 3: Localization of photosensitizers and mechanisms of cell deathin vitro

2009 ◽  
Vol 13 (04n05) ◽  
pp. 544-551 ◽  
Author(s):  
Magdalena Cañete ◽  
Juan C. Stockert ◽  
Angeles Villanueva
Keyword(s):  
Cell Death ◽  
Photodynamic Therapy ◽  
Cell Cultures ◽  
Cellular Localization ◽  
Cell Damage ◽  
Therapeutic Modality ◽  
Action Mechanisms ◽  
Cell Death Mechanisms

Photodynamic therapy (PDT) is a subject of increasing biomedical research and represents a very promising therapeutic modality for palliative or even curative treatment of some superficial or endoscopically accessible tumors. In addition to the first photosensitizers (PSs) applied (hematoporphyrin-based drugs), second generation PSs with improved photophysical and photobiological properties are now studied using cell cultures, experimental tumors and clinical trials. On the other hand, there is a growing interest in the analysis of cell death mechanisms by apoptosis, which is especially relevant in oncology, because many anticancer drugs work, at least in part, by triggering apoptosis in neoplastic cells both in vitro and in vivo. The evaluation of cell death mechanisms is an important parameter to determine the efficacy and the potential toxicity of a treatment, allowing better adjustment of protocol. Using cell cultures, our research team has studied the mechanisms of cell damage and death implicated in the photodynamic processes, as well as the relationship between the cellular localization of the PS and the organelle damage during photosensitization. The results obtained in our laboratory provide a deeper understanding on the action mechanisms that lead to cell inactivation by PDT, and also allow selection of PSs with higher potential for clinical application than those currently in use.

scholarly journals Calcineurin-mediated Bad translocation regulates cyanide-induced neuronal apoptosis

2004 ◽  
Vol 379 (3) ◽  
pp. 805-813 ◽  
Author(s):  
Yan SHOU ◽  
Li LI ◽  
Krishnan PRABHAKARAN ◽  
Joseph L. BOROWITZ ◽  
Gary E. ISOM
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Cyclosporin A ◽  
Apoptotic Cell ◽  
Calcineurin Inhibitors ◽  
Apoptotic Response ◽  
Cytochrome C Release ◽  
Cortical Cells ◽  
Subsequent Activation ◽  
Induced Apoptosis

In cyanide-induced apoptosis, an increase in cytosolic free Ca2+ and generation of reactive oxygen species are initiation stimuli for apoptotic cell death. Previous studies have shown that cyanide-stimulated translocation of Bax (Bcl-associated X protein) to mitochondria is linked with release of cytochrome c and subsequent activation of a caspase cascade [Shou, Li, Prabhakaran, Borowitz and Isom (2003) Toxicol. Sci. 75, 99–107]. In the present study, the relationship of the cyanide-induced increase in cytosolic free Ca2+ to activation of Bad (Bcl-2/Bcl-XL-antagonist, causing cell death) was determined in cortical cells. Bad is a Ca2+-sensitive pro-apoptotic Bcl-2 protein, which on activation translocates from cytosol to mitochondria to initiate cytochrome c release. In cultured primary cortical cells, cyanide produced a concentration- and time-dependent translocation of Bad from cytosol to mitochondria. Translocation occurred early in the apoptotic response, since mitochondrial Bad was detected within 1 h of cyanide treatment. Mitochondrial levels of the protein continued to increase up to 12 h post-cyanide exposure. Concurrent with Bad translocation, a Ca2+-sensitive increase in cellular calcineurin activity was observed. Increased cytosolic Ca2+ and calcineurin activation stimulated Bad translocation since BAPTA [bis-(o-aminophenoxy)ethane-N,N,N´,N´-tetra-acetic acid], an intracellular Ca2+ chelator, and cyclosporin A, a calcineurin inhibitor, significantly reduced translocation. BAPTA also blocked release of cytochrome c from mitochondria as well as apoptosis. Furthermore, treatment of cells with the calcineurin inhibitors cyclosporin A or FK506 blocked the apoptotic response, linking calcineurin activation and the subsequent translocation of Bad to cell death. These observations show that by inducing a rapid increase in cytosolic free Ca2+, cyanide can partially initiate the apoptotic cascade through a calcineurin-mediated translocation of Bad to mitochondria.

scholarly journals Greensporone A, a Fungal Secondary Metabolite Suppressed Constitutively Activated AKT via ROS Generation and Induced Apoptosis in Leukemic Cell Lines

Biomolecules ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 126 ◽  
Author(s):  
Kirti Prabhu ◽  
Kodappully Siveen ◽  
Shilpa Kuttikrishnan ◽  
Anh Jochebeth ◽  
Tayyiba Ali ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Cell Lines ◽  
Apoptotic Cell ◽  
Leukemic Cell ◽  
Apoptotic Cell Death ◽  
Leukemic Cells ◽  
Leukemic Cell Lines ◽  
Fungal Secondary Metabolite

Greensporone A is a fungal secondary metabolite that has exhibited potential in vitro for anti-proliferative activity in vitro. We studied the anticancer activity of greensporone A in a panel of leukemic cell lines. Greensporone A-mediated inhibition of proliferation is found to be associated with the induction of apoptotic cell death. Greensporone A treatment of leukemic cells causes inactivation of constitutively activated AKT and its downstream targets, including members GSK3 and FOXO1, and causes downregulation of antiapoptotic genes such as Inhibitor of Apoptosis (IAPs) and Bcl-2. Furthermore, Bax, a proapoptotic member of the Bcl-2 family, was found to be upregulated in leukemic cell lines treated with greensporone A. Interestingly, gene silencing of AKT using AKT specific siRNA suppressed the expression of Bcl-2 with enhanced expression of Bax. Greensporone A-mediated increase in Bax/Bcl-2 ratio causes permeabilization of the mitochondrial membrane leading to the accumulation of cytochrome c in the cytoplasm. Greensporone A-induced cytochrome c accumulation causes the activation of caspase cascade and cleavage of its effector, poly(ADP-ribose) polymerase (PARP), leading to apoptosis. Greensporone A-mediated apoptosis in leukemic cells occurs through the generation of reactive oxygen species (ROS) due to depletion of glutathione (GSH) levels. Finally, greensporone A potentiated the anticancer activity of imatinib in leukemic cells. In summary, our study showed that greensporone A suppressed the growth of leukemic cells via induction of apoptotic cell death. The apoptotic cell death occurs by inhibition of AKT signaling and activation of the intrinsic apoptotic/caspase pathways. These results raise the possibility that greensporone A could be developed as a therapeutic agent for the treatment of leukemia and other hematological malignancies.

scholarly journals Altered Cytochrome c Display Precedes Apoptotic Cell Death in Drosophila

1999 ◽  
Vol 144 (4) ◽  
pp. 701-710 ◽  
Author(s):  
Johnson Varkey ◽  
Po Chen ◽  
Ronald Jemmerson ◽  
John M. Abrams
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Apoptotic Cell ◽  
In Vitro Models ◽  
Caspase Activity ◽  
Caspase Activation ◽  
Conditional Expression ◽  
Necessary And Sufficient

Drosophila affords a genetically well-defined system to study apoptosis in vivo. It offers a powerful extension to in vitro models that have implicated a requirement for cytochrome c in caspase activation and apoptosis. We found that an overt alteration in cytochrome c anticipates programmed cell death (PCD) in Drosophila tissues, occurring at a time that considerably precedes other known indicators of apoptosis. The altered configuration is manifested by display of an otherwise hidden epitope and occurs without release of the protein into the cytosol. Conditional expression of the Drosophila death activators, reaper or grim, provoked apoptogenic cytochrome c display and, surprisingly, caspase activity was necessary and sufficient to induce this alteration. In cell-free studies, cytosolic caspase activation was triggered by mitochondria from apoptotic cells but identical preparations from healthy cells were inactive. Our observations provide compelling validation of an early role for altered cytochrome c in PCD and suggest propagation of apoptotic physiology through reciprocal, feed-forward amplification involving cytochrome c and caspases.

scholarly journals Multiorganelle Localization of Metallated Phthalocyanine Photosensitizer in Colorectal Cancer Cells (DLD-1 and CaCo-2) Enhances Efficacy of Photodynamic Therapy

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Palesa Rose Sekhejane ◽  
Nicolette Nadene Houreld ◽  
Heidi Abrahamse
Keyword(s):  
Colorectal Cancer ◽  
Cell Death ◽  
Photodynamic Therapy ◽  
Cancer Cells ◽  
Apoptotic Cell ◽  
Morphological Changes ◽  
Annexin V ◽  
Zinc Phthalocyanine ◽  
Cell Death Pathway

Colorectal cancer is the third most commonly diagnosed cancer. Amongst treatments that have been explored, photodynamic therapy (PDT) is a treatment that is of interest as it poses ideal advantages such as affinity for cancer cells. This study aimed to determine the correlation between the localization site of a sulfonated zinc phthalocyanine (ZnPcSmix) photosensitizer (PS) and its associated cell death pathwayin vitroin colorectal cancer cell lines (DLD-1 and CaCo-2). Visible morphological changes were observed in PDT treated cells after 24 h. Reactive oxygen species (ROS) were detected and visualized 1 h after PDT.ZnPcSmixwas predominantly localized in lysosomes and partially in the mitochondria. FITC Annexin V staining showed a significant decrease in the percentage of viable DLD-1 and CaCo-2 cells 24 h after PDT, with an increase in apoptotic cell population. Moreover, there was a significant increase in both cathepsin D and cytochrome C at 1 and 24 h. In conclusion,ZnPcSmixshowed the ability of inducing apoptotic cell death features in PDT treated cells.

UQCRC1 Engages Cytochrome C for Neuronal Apoptotic Cell Death

2020 ◽  
Author(s):  
Yu-Chien Hung ◽  
Kuan-Lin Huang ◽  
Po-Lin Chen ◽  
Han-Yi Lin ◽  
Huei-An Lu ◽  
...  
Keyword(s):  
Cell Death ◽  
Cytochrome C ◽  
Apoptotic Cell ◽  
Apoptotic Cell Death

scholarly journals Individual Expression of Hepatitis A Virus 3C Protease Induces Ferroptosis in Human Cells In Vitro

2021 ◽  
Vol 22 (15) ◽  
pp. 7906
Author(s):  
Alexey A. Komissarov ◽  
Maria A. Karaseva ◽  
Marina P. Roschina ◽  
Andrey V. Shubin ◽  
Nataliya A. Lunina ◽  
...  
Keyword(s):  
Cell Death ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Proteolytic Enzymes ◽  
Morphological Changes ◽  
Human Cells ◽  
Mitochondrial Potential ◽  
3C Protease ◽  
Wide Range

Regulated cell death (RCD) is a fundamental process common to nearly all living beings and essential for the development and tissue homeostasis in animals and humans. A wide range of molecules can induce RCD, including a number of viral proteolytic enzymes. To date, numerous data indicate that picornaviral 3C proteases can induce RCD. In most reported cases, these proteases induce classical caspase-dependent apoptosis. In contrast, the human hepatitis A virus 3C protease (3Cpro) has recently been shown to cause caspase-independent cell death accompanied by previously undescribed features. Here, we expressed 3Cpro in HEK293, HeLa, and A549 human cell lines to characterize 3Cpro-induced cell death morphologically and biochemically using flow cytometry and fluorescence microscopy. We found that dead cells demonstrated necrosis-like morphological changes including permeabilization of the plasma membrane, loss of mitochondrial potential, as well as mitochondria and nuclei swelling. Additionally, we showed that 3Cpro-induced cell death was efficiently blocked by ferroptosis inhibitors and was accompanied by intense lipid peroxidation. Taken together, these results indicate that 3Cpro induces ferroptosis upon its individual expression in human cells. This is the first demonstration that a proteolytic enzyme can induce ferroptosis, the recently discovered and actively studied type of RCD.

scholarly journals Quinacrine-Induced Autophagy in Ovarian Cancer Triggers Cathepsin-L Mediated Lysosomal/Mitochondrial Membrane Permeabilization and Cell Death

Cancers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 2004
Author(s):  
Prabhu Thirusangu ◽  
Christopher L. Pathoulas ◽  
Upasana Ray ◽  
Yinan Xiao ◽  
Julie Staub ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Cell Death ◽  
Cytochrome C ◽  
Cancer Cells ◽  
Apoptotic Cell ◽  
Cathepsin L ◽  
Membrane Permeabilization ◽  
Apoptotic Cell Death ◽  
Ovarian Cancer Cells ◽  
Autophagic Flux

We previously reported that the antimalarial compound quinacrine (QC) induces autophagy in ovarian cancer cells. In the current study, we uncovered that QC significantly upregulates cathepsin L (CTSL) but not cathepsin B and D levels, implicating the specific role of CTSL in promoting QC-induced autophagic flux and apoptotic cell death in OC cells. Using a Magic Red® cathepsin L activity assay and LysoTracker red, we discerned that QC-induced CTSL activation promotes lysosomal membrane permeability (LMP) resulting in the release of active CTSL into the cytosol to promote apoptotic cell death. We found that QC-induced LMP and CTSL activation promotes Bid cleavage, mitochondrial outer membrane permeabilization (MOMP), and mitochondrial cytochrome-c release. Genetic (shRNA) and pharmacological (Z-FY(tBU)-DMK) inhibition of CTSL markedly reduces QC-induced autophagy, LMP, MOMP, apoptosis, and cell death; whereas induced overexpression of CTSL in ovarian cancer cell lines has an opposite effect. Using recombinant CTSL, we identified p62/SQSTM1 as a novel substrate of CTSL, suggesting that CTSL promotes QC-induced autophagic flux. CTSL activation is specific to QC-induced autophagy since no CTSL activation is seen in ATG5 knockout cells or with the anti-malarial autophagy-inhibiting drug chloroquine. Importantly, we showed that upregulation of CTSL in QC-treated HeyA8MDR xenografts corresponds with attenuation of p62, upregulation of LC3BII, cytochrome-c, tBid, cleaved PARP, and caspase3. Taken together, the data suggest that QC-induced autophagy and CTSL upregulation promote a positive feedback loop leading to excessive autophagic flux, LMP, and MOMP to promote QC-induced cell death in ovarian cancer cells.

scholarly journals KUS121 attenuates the progression of monosodium iodoacetate-induced osteoarthritis in rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sachiko Iwai ◽  
Hanako O. Ikeda ◽  
Hisashi Mera ◽  
Kohei Nishitani ◽  
Motoo Saito ◽  
...  
Keyword(s):  
Cell Death ◽  
Er Stress ◽  
Apoptotic Cell ◽  
Intraperitoneal Administration ◽  
Atp Depletion ◽  
Knee Joints ◽  
Cellular Protection ◽  
Monosodium Iodoacetate

AbstractCurrently there is no effective treatment available for osteoarthritis (OA). We have recently developed Kyoto University Substances (KUSs), ATPase inhibitors specific for valosin-containing protein (VCP), as a novel class of medicine for cellular protection. KUSs suppressed intracellular ATP depletion, endoplasmic reticulum (ER) stress, and cell death. In this study, we investigated the effects of KUS121 on chondrocyte cell death. In cultured chondrocytes differentiated from ATDC5 cells, KUS121 suppressed the decline in ATP levels and apoptotic cell death under stress conditions induced by TNFα. KUS121 ameliorated TNFα-induced reduction of gene expression in chondrocytes, such as Sox9 and Col2α. KUS121 also suppressed ER stress and cell death in chondrocytes under tunicamycin load. Furthermore, intraperitoneal administration of KUS121 in vivo suppressed chondrocyte loss and proteoglycan reduction in knee joints of a monosodium iodoacetate-induced OA rat model. Moreover, intra-articular administration of KUS121 more prominently reduced the apoptosis of the affected chondrocytes. These results demonstrate that KUS121 protects chondrocytes from stress-induced cell death in vitro and in vivo, and indicate that KUS121 is a promising novel therapeutic agent to prevent the progression of OA.

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