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Lee JW, Cho JY, Thuy PX, Moon EY. HeLa Cervical Cancer Cells Are Maintained by Nephronophthisis 3-Associated Primary Cilium Formation via ROS-Induced ERK and HIF-1α Activation under Serum-Deprived Normoxic Condition. Int J Mol Sci 2022; 23:ijms232314500. [PMID: 36498831 PMCID: PMC9739938 DOI: 10.3390/ijms232314500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/28/2022] [Accepted: 11/03/2022] [Indexed: 11/23/2022] Open
Abstract
The primary cilium (PC) is a microtubule-based antenna-like organelle projecting from the surface of the cell membrane. We previously reported that PC formation could be regulated by nephronophthisis 3 (NPHP3) expression followed by its interaction with thymosin β4. Here, we investigated whether cancer cell viability is regulated by NPHP3-mediated PC formation. The total and viable cell number were reduced by incubating cells under serum deprivation (SD) without fetal bovine serum (-FBS). PC frequency was increased by SD which enhanced NPHP3 expression and hypoxia inducible factor (HIF)-1α. The role of HIF-1α on NPHP3 expression and PC formation was confirmed by the binding of HIF-1α to the NPHP3 promoter and siRNA-based inhibition of HIF-1α (siHIF-1α), respectively. HIF-1α-stabilizing dimethyloxallyl glycine (DMOG) and hypoxic conditions increased NPHP3 expression and PC formation. In addition, as SD elevated the reactive oxygen species (ROS), PC frequency and NPHP3 expression were inhibited by a treatment with N-acetylcysteine (NAC), a ROS scavenger. PC formation was increased by H2O2 treatment, which was inhibited by siHIF-1α. The inhibition of ERK with P98059 decreased the frequency of PC formation and NPHP3 expression. Cell viability was reduced by a treatment with ciliobrevin A (CilioA) to inhibit PC formation, which was re-affirmed by using PC-deficient IFT88-/- cells. Taken together, the results imply that PC formation in cancer cells could be controlled by NPHP3 expression through ROS-induced HIF-1α and ERK activation under SD conditions. It suggests that cancer cell viability under SD conditions could be maintained by NPHP3 expression to regulate PC formation.
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Affiliation(s)
| | | | | | - Eun-Yi Moon
- Correspondence: ; Tel.: +82-2-3408-3768; Fax: +82-2-3408-4334
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2
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Colombaioni L, Onor M, Benedetti E, Bramanti E. Thallium stimulates ethanol production in immortalized hippocampal neurons. PLoS One 2017; 12:e0188351. [PMID: 29161327 PMCID: PMC5697870 DOI: 10.1371/journal.pone.0188351] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 11/06/2017] [Indexed: 02/07/2023] Open
Abstract
Lactate and ethanol (EtOH) were determined in cell culture medium (CCM) of immortalized hippocampal neurons (HN9.10e cell line) before and after incubation with Thallium (Tl). This cell line is a reliable, in vitro model of one of the most vulnerable regions of central nervous system. Cells were incubated for 48 h with three different single Tl doses: 1, 10, 100 μg/L (corresponding to 4.9, 49 and 490 nM, respectively). After 48 h, neurons were "reperfused" with fresh CCM every 24/48 h until 7 days after the treatment and the removed CCM was collected and analysed. Confocal microscopy was employed to observe morphological changes. EtOH was determined by head space-solid phase microextraction -gas chromatography -mass spectrometry (HS-SPME-GCMS), lactate by RP-HPLC with UV detection. Tl exposure had significant effects on neuronal growth rate and morphology. The damage degree was dose-dependent. In not exposed cells, EtOH concentration was 0.18 ± 0.013 mM, which represents about 5% of lactate concentration (3.4 ± 0.10 mM). After Tl exposure lactate and EtOH increased. In CCM of 100 and 10 μg/L Tl-treated cells, lactate increased 24 h after reperfusion up to 2 and 3.3 times the control value, respectively. In CCM of 10 and 100 μg/L Tl-treated cells 24 h after reperfusion, EtOH increased up to 0.3 and 0.58 mmol/L. respectively. These results are consistent with significant alterations in energy metabolism, despite the low doses of Tl employed and the relatively short incubation time.
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Affiliation(s)
| | - Massimo Onor
- National Research Council of Italy, C.N.R., Institute of Chemsitry of Organo Metallic Compounds-ICCOM, Pisa, Italy
| | - Edoardo Benedetti
- Hematology Unit, Department of Oncology, University of Pisa, Pisa, Italy
| | - Emilia Bramanti
- National Research Council of Italy, C.N.R., Institute of Chemsitry of Organo Metallic Compounds-ICCOM, Pisa, Italy
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3
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Nuclear Lipids in the Nervous System: What they do in Health and Disease. Neurochem Res 2016; 42:321-336. [PMID: 27766461 DOI: 10.1007/s11064-016-2085-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 09/21/2016] [Accepted: 10/11/2016] [Indexed: 12/18/2022]
Abstract
In the last 20 years it has been widely demonstrated that cell nucleus contains neutral and polar lipids localized in nuclear membranes, nucleoli, nuclear matrix and chromatin. Nuclear lipids may show specific organization forming nuclear lipid microdomains and have both structural and functional roles. Depending on their localization, nuclear lipids play different roles such as the regulation of nuclear membrane and nuclear matrix fluidity but they also can act as platforms for vitamin and hormone function, for active chromatin anchoring, and for the regulation of gene expression, DNA duplication and transcription. Crosstalk among different kinds of lipid signalling pathways influence the physiopathology of numerous cell types. In neural cells the nuclear lipids are involved in cell proliferation, differentiation, inflammation, migration and apoptosis. Abnormal metabolism of nuclear lipids might be closely associated with tumorigenesis and neurodegenerative diseases such as Alzheimer disease and Parkinson disease among others.
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Kim AD, Kang KA, Piao MJ, Kim KC, Zheng J, Yao CW, Cha JW, Hyun CL, Kang HK, Lee NH, Hyun JW. Cytoprotective effect of eckol against oxidative stress-induced mitochondrial dysfunction: involvement of the FoxO3a/AMPK pathway. J Cell Biochem 2015; 115:1403-11. [PMID: 24700636 DOI: 10.1002/jcb.24790] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 02/14/2014] [Indexed: 11/08/2022]
Abstract
This study investigated the cytoprotective effect of Ecklonia cava-derived eckol against H2O2-induced mitochondrial dysfunction in Chang liver cells. While H2O2 augmented levels of mitochondrial reactive oxygen species (ROS), eckol decreased it. Eckol also attenuated high intracellular Ca(2+) levels stimulated by H2O2 and recovered H2O2-diminished ATP levels and succinate dehydrogenase activity. Eckol time-dependently increased the expression of manganese superoxide dismutase (Mn SOD), a mitochondrial antioxidant enzyme with cytoprotective effect against oxidative stress. Eckol recovered Mn SOD expression and activity that were decreased by H2O2. Finally, eckol induced Mn SOD through phosphorylated AMP-activated protein kinase (AMPK) and forkhead box O3a (FoxO3a). Specific silencing RNAs (siRNAs) against FoxO3a and AMPK reduced eckol-stimulated Mn SOD expression, and diethyldithiocarbamate (Mn SOD inhibitor) and siRNA against Mn SOD reduced the cytoprotective effect of eckol against H2O2-provoked cell death. These results demonstrate that eckol protects cells from mitochondrial oxidative stress by activating AMPK/FoxO3a-mediated induction of Mn SOD.
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Affiliation(s)
- Areum Daseul Kim
- School of Medicine, Jeju National University, Jeju, 690-756, Korea
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5
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Garcia-Gil M, Lazzarini A, Lazzarini R, Floridi E, Cataldi S, Floridi A, Albi E. Serum deprivation alters lipid profile in HN9.10e embryonic hippocampal cells. Neurosci Lett 2014; 589:83-7. [PMID: 25556686 DOI: 10.1016/j.neulet.2014.12.059] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/29/2014] [Accepted: 12/30/2014] [Indexed: 12/21/2022]
Abstract
The understanding of the mechanism of apoptosis is important to improve the use of stem cells for the treatment of neurodegenerative disorders. Sphingolipids are bioactive molecules involved in the regulation of cell fate. In HN9.10e embryonic hippocampal cells, serum deprivation induces apoptosis preceded by sphingomyelinase activation and raise of ceramide levels. Increasing evidence indicates that individual ceramide species regulated by specific pathways in distinct subcellular compartments might carry out distinct cellular functions, but the ceramides species involved in embryonic hippocampal cell death induced by growth factor deprivation are unknown. In the present paper, by using the UFLC-MS/MS methodology, we have investigated the effect of serum deprivation on the lipid profile in HN9.10e cells. At 48h of serum deprivation, we detected a decrease in cholesterol and increase in sphingosine-1-phoshate 18:1, phosphatidylcholine 18:1 18:0, sphingomyelin 18:1 16:0 and in ceramides 18:1 16:0; we also found an increase in saturated/unsaturated fatty acid ratio in sphingomyelin. We hypothesize that the rearrangement of sphingo- and glycerolipids with increase of saturated fatty acids in serum-deprivated, neural cells might represent a cellular response aimed at holding cholesterol inside the cells.
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Affiliation(s)
| | - Andrea Lazzarini
- Laboratory of Nuclear Lipid BioPathology, Research Center of Biochemical-Specialized Analyses, 06100 Perugia, Italy
| | - Remo Lazzarini
- Laboratory of Nuclear Lipid BioPathology, Research Center of Biochemical-Specialized Analyses, 06100 Perugia, Italy
| | - Emanuela Floridi
- Laboratory of Nuclear Lipid BioPathology, Research Center of Biochemical-Specialized Analyses, 06100 Perugia, Italy
| | - Samuela Cataldi
- Laboratory of Nuclear Lipid BioPathology, Research Center of Biochemical-Specialized Analyses, 06100 Perugia, Italy
| | - Alessandro Floridi
- Laboratory of Nuclear Lipid BioPathology, Research Center of Biochemical-Specialized Analyses, 06100 Perugia, Italy
| | - Elisabetta Albi
- Laboratory of Nuclear Lipid BioPathology, Research Center of Biochemical-Specialized Analyses, 06100 Perugia, Italy
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6
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Mukwena NT, Al-Rubeai M. Apoptosis and its suppression in hepatocytes culture. Cytotechnology 2008; 46:79-95. [PMID: 19003264 DOI: 10.1007/s10616-005-8306-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2004] [Accepted: 05/18/2005] [Indexed: 11/25/2022] Open
Abstract
In order to achieve the goal of developing extracorporeal liver support devices, it is necessary to optimise bioprocess environment such that viability and function are maximised. Optimising culture medium composition and controlling the constitution of the cellular microenvironment within the bioreactor have for many years been considered vital to achieving these aims. Coupled to this is the need to understand apoptosis, the prime suspect in the demise of animal cultures, including those of hepatocytes. Results presented here show that absent nutrients including glucose and amino acids play a substantial part in the induction of apoptosis. The use of chemical apoptosis inhibitors was utilised to investigate key components of hepatic apoptosis where caspases, predominantly caspase 8, were implicated in staurosporine (STS)-induced HepZ apoptosis. Caspase 9 and 3 activation although recorded was of less significance. Interestingly, these results were not consistent with those of mitochondrial membrane depolarisation where inhibition of caspase activation appeared to drive depolarisation. Inhibition of mitochondrial permeability transition and use of anti-oxidants was unsuccessful in reducing apoptosis, caspase activation and mitochondrial membrane depolarisation. In further studies, the anti-apoptotic gene bcl-2 was over-expressed in HepZ, resulting in a cell line that was more robust and resistant to death induced by glucose and cystine deprivation and treatment with STS. Bcl-2 did not however show significant cytoprotectivity where apoptosis was stimulated by deprivation of glutamine and serum. Overall, results indicated that although apoptosis can be curbed by use of chemical inhibitors and genetic manipulation, their success is dependent on apoptotic stimuli.
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Affiliation(s)
- Nyaradzo T Mukwena
- Department of Chemical Engineering, University of Birmingham, Birmingham, B15 2TT, UK
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7
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Moon EY. Serum Deprivation Enhances Apoptotic Cell Death by Increasing Mitochondrial Enzyme Activity. Biomol Ther (Seoul) 2008. [DOI: 10.4062/biomolther.2008.16.1.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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8
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Voccoli V, Mazzoni F, Garcia-Gil M, Colombaioni L. Serum-withdrawal-dependent apoptosis of hippocampal neuroblasts involves Ca++ release by endoplasmic reticulum and caspase-12 activation. Brain Res 2007; 1147:1-11. [PMID: 17399692 DOI: 10.1016/j.brainres.2007.01.145] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2006] [Revised: 12/09/2006] [Accepted: 01/02/2007] [Indexed: 01/08/2023]
Abstract
Apoptotic death caused by diseases or toxic insults is preceded and determined by endoplasmic reticulum dysfunction and altered intraluminar calcium homeostasis in many different cell types. With the present study we have explored the possibility that the ER stress could be involved also in apoptotic death induced by serum deprivation in neuronal cells. We have chosen as a model of study the cell line HN9.10e, constituted by immortalized hippocampal neuroblasts. The Ca(++) concentration in the lumen of the ER has been evaluated by using the low affinity Ca(++) probe Mag-fluo-4. We show that serum deprivation lowers the ER Ca(++) concentration with a time course closely related to the increase of apoptosis incidence. Serum deprivation also enhances the expression of a well-known marker of ER stress, the glucose-regulated protein-78 (GRP-78), a member of the heat shock/stress response protein family. Moreover, in serum-deprived neuroblasts, following GRP-78 up-regulation, the ER-associated procaspase-12 is cleaved with a time course which parallels the ER calcium loss while activation of caspase-3 is a later event. Depletion of ER Ca(++) by thapsigargin, a specific inhibitor of the ER-associated Ca(++) ATPase, also produces caspase-12 processing and apoptotic cell death, whereas agents capable of reducing the ER calcium loss protect the cells from serum-deprivation-induced apoptosis. These findings indicate that, in hippocampal neuroblasts, Ca(++) mobilization from ER and caspase-12 activation are components of the molecular pathway that leads to apoptosis triggered by serum deprivation and may constitute an amplifying loop of the mitochondrial pathway.
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Affiliation(s)
- Vladimir Voccoli
- Istituto di Neuroscienze CNR, Via G. Moruzzi 1, 56100 Pisa, Italy
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9
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Posse de Chaves EI. Sphingolipids in apoptosis, survival and regeneration in the nervous system. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2006; 1758:1995-2015. [PMID: 17084809 DOI: 10.1016/j.bbamem.2006.09.018] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2006] [Revised: 09/20/2006] [Accepted: 09/21/2006] [Indexed: 12/27/2022]
Abstract
Simple sphingolipids such as ceramide, sphingosine and sphingosine 1-phosphate are key regulators of diverse cellular functions. Their roles in the nervous system are supported by extensive evidence derived primarily from studies in cultured cells. More recently animal studies and studies with human samples have revealed the importance of ceramide and its metabolites in the development and progression of neurodegenerative disorders. The roles of sphingolipids in neurons and glial cells are complex, cell dependent, and many times contradictory. In this review I will summarize the effects elicited by ceramide and ceramide metabolites in cells of the nervous system, in particular those effects related to cell survival and death, emphasizing the molecular mechanisms involved. I also discuss recent evidence for the implication of sphingolipids in the development and progression of certain dementias.
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Affiliation(s)
- Elena I Posse de Chaves
- Centre for Alzheimer and Neurodegenerative Research, Signal Transduction Research Group and Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada T6G 2H7.
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10
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Cervia D, Martini D, Garcia-Gil M, Di Giuseppe G, Guella G, Dini F, Bagnoli P. Cytotoxic effects and apoptotic signalling mechanisms of the sesquiterpenoid euplotin C, a secondary metabolite of the marine ciliate Euplotes crassus, in tumour cells. Apoptosis 2006; 11:829-43. [PMID: 16534550 DOI: 10.1007/s10495-006-5700-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Most antitumour agents with cytotoxic properties induce apoptosis. The lipophilic compound euplotin C, isolated from the ciliate Euplotes crassus, is toxic to a number of different opportunistic or pathogenic microorganisms, although its mechanism of action is currently unknown. We report here that euplotin C is a powerful cytotoxic and pro-apoptotic agent in mouse AtT-20 and rat PC12 tumour-derived cell lines. In addition, we provide evidence that euplotin C treatment results in rapid activation of ryanodine receptors, depletion of Ca2+ stores in the endoplasmic reticulum (ER), the release of cytochrome c from the mitochondria, activation of caspase-12, and activation of caspase-3, leading to apoptosis. Intracellular Ca2+ overload is an early event which induces apoptosis and is parallelled by ER stress and the release of cytochrome c, whereas caspase-12 may be activated by euplotin C at a later stage in the apoptosis pathway. These events, either independently or concomitantly, lead to the activation of the caspase-3 and its downstream effectors, triggering the cell to undergo apoptosis. These results demonstrate that euplotin C may be considered for the design of cytotoxic and pro-apoptotic new drugs.
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Affiliation(s)
- D Cervia
- Dipartimento di Fisiologia e Biochimica G. Moruzzi, via S. Zeno, 56127, Pisa, Italy.
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11
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Zhuge J, Cederbaum AI. Serum deprivation-induced HepG2 cell death is potentiated by CYP2E1. Free Radic Biol Med 2006; 40:63-74. [PMID: 16337880 DOI: 10.1016/j.freeradbiomed.2005.08.012] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2005] [Revised: 08/08/2005] [Accepted: 08/12/2005] [Indexed: 01/16/2023]
Abstract
Induction of oxidative stress plays a key role in serum deprivation-induced apoptosis. CYP2E1 plays an important role in toxicity of many chemicals and ethanol and produces oxidant stress. We investigated whether CYP2E1 expression can sensitize HepG2 cells to toxicity as a consequence of serum deprivation. The models used were HepG2 E47 cells that express human CYP2E1, and C34 HepG2 cells which do not express CYP2E1. E47 cells showed greater growth inhibition and enhanced cell death after serum deprivation, as compared to the C34 cells. DNA ladder and flow cytometry assays indicated that apoptosis occurred at earlier times after serum deprivation in E47 than C34 cells. Serum withdrawal-induced E47 cell death could be rescued by antioxidants, the mitochondrial permeability transition inhibitor cyclosporine A, z-DEVD-fmk, and a CYP2E1 inhibitor 4-methylpyrazole. Increased production of reactive oxygen species (ROS) and lipid peroxidation occurred in E47 cells after serum deprivation, and there was a corresponding decline in the E47 cell mitochondrial membrane potential and reduced glutathione (GSH) levels. We propose that the mechanism of this serum withdrawal plus CYP2E1 toxicity involves increased production of intracellular ROS, lipid peroxidation, and decline of GSH levels, which results in mitochondrial membrane damage and loss of membrane potential, followed by apoptosis. Potentiation of serum deprivation-induced cell death by CYP2E1 may contribute to the sensitivity of the liver to alcohol-induced ischemia and growth factor deprivation.
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Affiliation(s)
- Jian Zhuge
- Department of Pharmacology and Biological Chemistry, Mount Sinai School of Medicine, One Gustave L. Place, New York, NY 10029, USA
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12
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Albi E, Cataldi S, Bartoccini E, Magni MV, Marini F, Mazzoni F, Rainaldi G, Evangelista M, Garcia-Gil M. Nuclear sphingomyelin pathway in serum deprivation-induced apoptosis of embryonic hippocampal cells. J Cell Physiol 2005; 206:189-95. [PMID: 16021626 DOI: 10.1002/jcp.20448] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Sphingomyelin (SM) cycle has been involved in the regulation of proliferation, differentiation, and apoptosis. Increases in ceramide have been found after a larger number of apoptotic stimuli including cytokines, cytotoxic drugs, and environmental stresses. Accumulating evidence suggest that the subcellular localization of ceramide generation is a critical factor in determining the cellular behavior. Since recently enzymes involved in ceramide metabolism such as sphingomyelinase, SM synthase, sphingosine kinase and ceramidase have been found in the nucleus of hepatocyte cells, we have studied first the presence and the physicochemical characteristics of SM metabolism enzymes in nuclei isolated from embryonic hippocampal cells (cell line HN9.10e). The activities of sphingomyelinase and SM-synthase have been assayed and the ceramide production evaluated at different times after serum deprivation in these neurones cultivated in serum-deficient medium. We report that both enzymes are present in the nucleus of embryonic hippocampal cells and differ from those present in the homogenate in optimum pH. After serum deprivation, that induces a time-dependent decrease in cell viability and increase of the cell percentage in G1 phase of the cell cycle, a nuclear sphingomyelinase activation together with SM-synthase inhibition and a consequent increase of nuclear ceramide pool have been demonstrated. No similar enzyme activity modifications in homogenate have been identified. The possible role of nuclear sphingomyelinase/sphingomyelin-synthase balance in serum deprivation-induced apoptosis in the embryonic hippocampal cell is discussed.
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Affiliation(s)
- Elisabetta Albi
- Department of Clinic and Experimental Medicine, Physiopathology, Policlinico Monteluce, Perugia, Italy
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13
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Akasaka Y, Ito K, Fujita K, Komiyama K, Ono I, Ishikawa Y, Akishima Y, Sato H, Ishii T. Activated caspase expression and apoptosis increase in keloids: cytochrome c release and caspase-9 activation during the apoptosis of keloid fibroblast lines. Wound Repair Regen 2005; 13:373-82. [PMID: 16008726 DOI: 10.1111/j.1067-1927.2005.130404.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To characterize apoptosis in keloids and the mechanisms responsible for this process, the expression of activated caspase-9 and -3 in fibroblasts obtained from keloids was analyzed. Immunohistochemistry revealed that the number of fibroblasts positive for terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL) or activated caspase-9 or -3 was low but was significantly higher in keloid tissues than in normal scar tissues. Significant relationships between the number of caspase-positive fibroblasts and TUNEL-positive fibroblasts suggested that the activation of caspase-9 and -3 induces apoptosis in a subpopulation of keloid fibroblasts. All keloid fibroblast cell lines established in this study showed activation of caspase-9 and -3 after serum deprivation for 3 or 4 hours, as shown using Western blotting. Furthermore, serum deprivation-induced apoptosis in a keloid fibroblast line was blocked by a caspase-9 inhibitor (acetyl-Leu-Glu-His-Asp-al), indicating that activation of caspase-9 was necessary for the process of apoptosis in keloid fibroblasts. Although serum deprivation did not significantly change the level of apoptosis protease activating factor-1 in any of the lines, cytochrome c release was detected in cytosolic fractions of the lines after serum deprivation for 3 or 4 hours. These results strongly suggest that keloid fibroblasts are predisposed to apoptosis and cytochrome c release and that caspase-9 activation may underlie regulation of apoptosis in keloid fibroblasts in vivo.
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Affiliation(s)
- Yoshikiyo Akasaka
- Department of Pathology, School of Medicine, Toho University, Tokyo, Japan.
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14
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Bota DA, Ngo JK, Davies KJA. Downregulation of the human Lon protease impairs mitochondrial structure and function and causes cell death. Free Radic Biol Med 2005; 38:665-77. [PMID: 15683722 DOI: 10.1016/j.freeradbiomed.2004.11.017] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2004] [Revised: 11/10/2004] [Accepted: 11/11/2004] [Indexed: 10/26/2022]
Abstract
Lon now emerges as a major regulator of multiple mitochondrial functions in human beings. Lon catalyzes the degradation of oxidatively modified matrix proteins, chaperones the assembly of inner membrane complexes, and participates in the regulation of mitochondrial gene expression and genome integrity. An early result of Lon downregulation in WI-38 VA-13 human lung fibroblasts is massive caspase 3 activation and extensive (although not universal) apoptotic death. At a later stage, the surviving cells fail to divide, display highly abnormal mitochondrial function and morphology, and rely almost exclusively on anaerobic metabolism. In a selected subpopulation of cells, the mitochondrial mass decreases probably as a result of mitochondrial inability to divide. At this final point the Lon-deficient cells are not engaged anymore in apoptosis, and are lost by necrosis or "mitoptosis." Our results indicate that mitochondrial Lon is required for normal survival and proliferation; a clear impetus for Lon's evolutionary conservation.
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Affiliation(s)
- Daniela A Bota
- Ethel Percy Andrus Gerontology Center, and Division of Molecular and Computational Biology, 3715 McClintock Avenue, University of Southern California, Los Angeles, CA 90089-0191, USA
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15
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Neurotrophic signaling cascades are major long-term targets for lithium: clinical implications. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.cnr.2004.09.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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Colombaioni L, Garcia-Gil M. Sphingolipid metabolites in neural signalling and function. ACTA ACUST UNITED AC 2004; 46:328-55. [PMID: 15571774 DOI: 10.1016/j.brainresrev.2004.07.014] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/26/2004] [Indexed: 11/20/2022]
Abstract
Sphingolipid metabolites, such as ceramide, sphingosine, sphingosine-1-phosphate (S1P) and complex sphingolipids (gangliosides), are recognized as molecules capable of regulating a variety of cellular processes. The role of sphingolipid metabolites has been studied mainly in non-neuronal tissues. These studies have underscored their importance as signals transducers, involved in control of proliferation, survival, differentiation and apoptosis. In this review, we will focus on studies performed over the last years in the nervous system, discussing the recent developments and the current perspectives in sphingolipid metabolism and functions.
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17
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Wang CB, Huang MQ, Tao GL, Yu GY, Han ZW, Yang ZH, Wang YJ. Polypeptide from Chlamys farreri protects HaCaT cells from UVB-induced apoptosis. Chem Biol Interact 2004; 147:119-27. [PMID: 15013814 DOI: 10.1016/j.cbi.2003.11.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/20/2003] [Indexed: 11/24/2022]
Abstract
A natural polypeptide from marine Chlamys farreri (a kind of scallop) (PCF), has been recently been found to be an effective photoprotective agent against ultraviolet rays B (UVB)-induced mitochondria damage in normal human fibroblasts. To investigate whether PCF has the antiapoptotic effect on human keratinocytes, in the present study, we established an apoptotic model on HaCaT cell line by means of UVB radiance of 30 mJ/cm(2) and compared the effect of different PCF treatments on UVB-radiated cells. Flow cytometry analyses showed that PCF treatment before UVB-irradiation inhibited UVB-induced apoptosis, the loss of mitochondrial membrane potential (Deltapsim) and the increase of free Ca(2+) level in HaCaT cells. In parallel with these results, UVB-irradiation enhanced activities of caspases-3, 8, 9, while this enhancement was inhibited by PCF treatment prior to irradiation. PCF added after irradiation neither reduced UVB-induced activities of the three caspases nor synergized the effect of pre-added PCF. Cellular ultrastructural features obtained from transmission electron microscopy further confirmed the antiapoptotic effect of PCF pre-treatment. It is concluded that the antiapoptotic effect of PCF is not therapeutic but prophylactic. Caspases-3, 8, 9, Deltapsim and calcium are involved in UVB-induced apoptosis, while prophylactic PCF inhibits apoptosis of UVB-irradiated HaCaT cells by blocking the caspases activities, the Deltapsim lost and the elevation of intracellular free Ca(2+) level.
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Affiliation(s)
- Chun Bo Wang
- Department of Pharmacology, Medical College, Qingdao University, Qingdao 266021, China
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