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Slupe AM, Villasana L, Wright KM. GABAergic neurons are susceptible to BAX-dependent apoptosis following isoflurane exposure in the neonatal period. PLoS One 2021; 16:e0238799. [PMID: 33434191 PMCID: PMC7802958 DOI: 10.1371/journal.pone.0238799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 12/27/2020] [Indexed: 12/18/2022] Open
Abstract
Exposure to volatile anesthetics during the neonatal period results in acute neuron death. Prior work suggests that apoptosis is the dominant mechanism mediating neuron death. We show that Bax deficiency blocks neuronal death following exposure to isoflurane during the neonatal period. Blocking Bax-mediated neuron death attenuated the neuroinflammatory response of microglia following isoflurane exposure. We find that GABAergic interneurons are disproportionately overrepresented among dying neurons. Despite the increase in neuronal apoptosis induced by isoflurane exposure during the neonatal period, seizure susceptibility, spatial memory retention, and contextual fear memory were unaffected later in life. However, Bax deficiency alone led to mild deficiencies in spatial memory and contextual fear memory, suggesting that normal developmental apoptotic death is important for cognitive function. Collectively, these findings show that while GABAergic neurons in the neonatal brain undergo elevated Bax-dependent apoptotic cell death following exposure to isoflurane, this does not appear to have long-lasting consequences on overall neurological function later in life.
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Affiliation(s)
- Andrew M. Slupe
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Laura Villasana
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Kevin M. Wright
- Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail:
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Reyna DE, Garner TP, Lopez A, Kopp F, Choudhary GS, Sridharan A, Narayanagari SR, Mitchell K, Dong B, Bartholdy BA, Walensky LD, Verma A, Steidl U, Gavathiotis E. Direct Activation of BAX by BTSA1 Overcomes Apoptosis Resistance in Acute Myeloid Leukemia. Cancer Cell 2017; 32:490-505.e10. [PMID: 29017059 PMCID: PMC5793879 DOI: 10.1016/j.ccell.2017.09.001] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 06/28/2017] [Accepted: 08/30/2017] [Indexed: 12/28/2022]
Abstract
The BCL-2 family protein BAX is a central mediator of apoptosis. Overexpression of anti-apoptotic BCL-2 proteins contributes to tumor development and resistance to therapy by suppressing BAX and its activators. We report the discovery of BTSA1, a pharmacologically optimized BAX activator that binds with high affinity and specificity to the N-terminal activation site and induces conformational changes to BAX leading to BAX-mediated apoptosis. BTSA1-induced BAX activation effectively promotes apoptosis in leukemia cell lines and patient samples while sparing healthy cells. BAX expression levels and cytosolic conformation regulate sensitivity to BTSA1. BTSA1 potently suppressed human acute myeloid leukemia (AML) xenografts and increased host survival without toxicity. This study provides proof-of-concept for direct BAX activation as a treatment strategy in AML.
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Affiliation(s)
- Denis E Reyna
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Thomas P Garner
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Andrea Lopez
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Felix Kopp
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Gaurav S Choudhary
- Department of Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Ashwin Sridharan
- Department of Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Swathi-Rao Narayanagari
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Kelly Mitchell
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Baoxia Dong
- Department of Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Boris A Bartholdy
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Loren D Walensky
- Department of Pediatric Oncology and the Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Amit Verma
- Department of Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY 10461, USA
| | - Ulrich Steidl
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Evripidis Gavathiotis
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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3
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Cheng X, Hou Z, Sun J, Huang Y, Wang L, Zhou Z, Zhou LH, Cai Y. Protective effects of Tongxinluo on cerebral ischemia/reperfusion injury related to Connexin 43/Calpain II/Bax/Caspase-3 pathway in rat. J Ethnopharmacol 2017; 198:148-157. [PMID: 28065778 DOI: 10.1016/j.jep.2017.01.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 12/22/2016] [Accepted: 01/04/2017] [Indexed: 06/06/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Tongxinluo (TXL) is a multifunctional traditional Chinese medicine and has been widely used in the treatment of cardiovascular and cerebrovascular diseases. Numerous studies demonstrate that TXL is a novel neuroprotective drug, however, the mechanisms are largely unknown. AIM OF THE STUDY we aimed to demonstrate the protective effect of TXL on cerebral ischemia/reperfusion (I/R) injury and provide the evidence for the involvement of Connexin 43/Calpain II/ Bax/Caspase-3 pathway in TXL-mediated neuroprotection. METHODS Focal cerebral I/R injury were induced by transient middle cerebral artery occlusion (MCAO, for 90min) in adult male Sprague-Dawley rats. We estimated the effects of TXL on I/R injury including neurological deficit assessment and cerebral infarct volume measurement via TTC staining, and detected the protein expression of Connexin 43 (Cx43) by western blot. Furthermore, after the intracerebroventricular injection of carbenoxolone (CBX, the inhibitor of Cx43) at 30min before MCAO surgery, Calpain II, Bax and cleaved Caspased-3 immunoreactivity in ischemic penumbra region was detected by immunofluorescent staining, and cell apoptosis was detected by TUNEL staining. RESULTS TXL treatment greatly improved neurological deficit and reduced the infarction volume compared to MCAO with buffer treatment (P<0.05), and TXL pre-post treatment showed better results than TXL pre-treatment. TXL pre-post treatment significantly up-regulated Cx43 protein expression at 3d, 7d and 14d post-injury compared to MCAO with buffer treatment (P<0.05). Meanwhile, the immunoreactivity of Calpain II, Bax and cleaved Caspase-3 in ischemic penumbra region was obviously decreased by TXL pre-post treatment compared to MCAO group (P<0.05). However, with the treatment of the Cx43 inhibitor, CBX, the down-regulated effect of TXL on Calpain II, Bax and cleaved Caspase-3 immunoreactivity was abolished (P<0.05). Moreover, the protective effect of TXL against neuron apoptosis in penumbra region was conteracted by CBX (P<0.05). CONCLUSIONS TXL could effectively protect against I/R injury and reduced cell death via Cx43/Calpain II/Bax/Caspase-3 pathway, which contribute to I/R injury prevention and therapy.
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Affiliation(s)
- Xiao Cheng
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
| | - Zijun Hou
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China; Medical Experimental Center, Nanyang Institute of Technology, Nanyang 473004, P.R. China.
| | - Jingbo Sun
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
| | - Yan Huang
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
| | - Lixin Wang
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
| | - Ziyi Zhou
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
| | - Li-Hua Zhou
- Department of Anatomy, Zhong Shan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China.
| | - Yefeng Cai
- Department of Neurology, Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou 510120, China; The Second Institute of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
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Sarosiek KA, Fraser C, Muthalagu N, Bhola PD, Chang W, McBrayer SK, Cantlon A, Fisch S, Golomb-Mello G, Ryan JA, Deng J, Jian B, Corbett C, Goldenberg M, Madsen JR, Liao R, Walsh D, Sedivy J, Murphy DJ, Carrasco DR, Robinson S, Moslehi J, Letai A. Developmental Regulation of Mitochondrial Apoptosis by c-Myc Governs Age- and Tissue-Specific Sensitivity to Cancer Therapeutics. Cancer Cell 2017; 31:142-156. [PMID: 28017613 PMCID: PMC5363285 DOI: 10.1016/j.ccell.2016.11.011] [Citation(s) in RCA: 166] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 09/13/2016] [Accepted: 11/17/2016] [Indexed: 01/20/2023]
Abstract
It is not understood why healthy tissues can exhibit varying levels of sensitivity to the same toxic stimuli. Using BH3 profiling, we find that mitochondria of many adult somatic tissues, including brain, heart, and kidneys, are profoundly refractory to pro-apoptotic signaling, leading to cellular resistance to cytotoxic chemotherapies and ionizing radiation. In contrast, mitochondria from these tissues in young mice and humans are primed for apoptosis, predisposing them to undergo cell death in response to genotoxic damage. While expression of the apoptotic protein machinery is nearly absent by adulthood, in young tissues its expression is driven by c-Myc, linking developmental growth to cell death. These differences may explain why pediatric cancer patients have a higher risk of developing treatment-associated toxicities.
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Affiliation(s)
- Kristopher A Sarosiek
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Mayer 430, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Cameron Fraser
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Mayer 430, Boston, MA 02115, USA
| | | | - Patrick D Bhola
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Mayer 430, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Weiting Chang
- Harvard Medical School, Boston, MA 02115, USA; Division of Genetics and Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Samuel K McBrayer
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Mayer 430, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Adam Cantlon
- Harvard Medical School, Boston, MA 02115, USA; Division of Genetics and Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Sudeshna Fisch
- Harvard Medical School, Boston, MA 02115, USA; Division of Genetics and Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Gail Golomb-Mello
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Jeremy A Ryan
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Mayer 430, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Jing Deng
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Mayer 430, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Brian Jian
- Department of Neurosurgery, Kaiser Permanente, Sacramento, CA 95815, USA
| | - Chris Corbett
- Department of Neurosurgery, Boston Children's Hospital, Boston, MA 02115, USA
| | - Marti Goldenberg
- Department of Neurosurgery, Boston Children's Hospital, Boston, MA 02115, USA
| | - Joseph R Madsen
- Harvard Medical School, Boston, MA 02115, USA; Department of Neurosurgery, Boston Children's Hospital, Boston, MA 02115, USA
| | - Ronglih Liao
- Harvard Medical School, Boston, MA 02115, USA; Division of Genetics and Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - Dominic Walsh
- Harvard Medical School, Boston, MA 02115, USA; Division of Genetics and Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, MA 02115, USA
| | - John Sedivy
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI 02912, USA
| | - Daniel J Murphy
- Cancer Research UK Beatson Institute, Glasgow G61 1BD, Scotland; Institute of Cancer Sciences, University of Glasgow, Glasgow G61 1BD, Scotland
| | - Daniel Ruben Carrasco
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Mayer 430, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Shenandoah Robinson
- Harvard Medical School, Boston, MA 02115, USA; Department of Neurosurgery, Boston Children's Hospital, Boston, MA 02115, USA
| | - Javid Moslehi
- Division of Cardiovascular Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Division of Hematology-Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA; Cardio-Oncology Program, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Anthony Letai
- Department of Medical Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Mayer 430, Boston, MA 02115, USA; Harvard Medical School, Boston, MA 02115, USA.
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Eid R, Boucher E, Gharib N, Khoury C, Arab NTT, Murray A, Young PG, Mandato CA, Greenwood MT. Identification of human ferritin, heavy polypeptide 1 (FTH1) and yeast RGI1 (YER067W) as pro-survival sequences that counteract the effects of Bax and copper in Saccharomyces cerevisiae. Exp Cell Res 2016; 342:52-61. [PMID: 26886577 DOI: 10.1016/j.yexcr.2016.02.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/09/2016] [Accepted: 02/12/2016] [Indexed: 02/06/2023]
Abstract
Ferritin is a sub-family of iron binding proteins that form multi-subunit nanotype iron storage structures and prevent oxidative stress induced apoptosis. Here we describe the identification and characterization of human ferritin, heavy polypeptide 1 (FTH1) as a suppressor of the pro-apoptotic murine Bax sequence in yeast. In addition we demonstrate that FTH1 is a general pro-survival sequence since it also prevents the cell death inducing effects of copper when heterologously expressed in yeast. Although ferritins are phylogenetically widely distributed and are present in most species of Bacteria, Archaea and Eukarya, ferritin is conspicuously absent in most fungal species including Saccharomyces cerevisiae. An in silico analysis of the yeast proteome lead to the identification of the 161 residue RGI1 (YER067W) encoded protein as a candidate for being a yeast ferritin. In addition to sharing 20% sequence identity with the 183 residue FTH1, RGI1 also has similar pro-survival properties as ferritin when overexpressed in yeast. Analysis of recombinant protein by SDS-PAGE and by electron microscopy revealed the expected formation of higher-order structures for FTH1 that was not observed with Rgi1p. Further analysis revealed that cells overexpressing RGI1 do not show increased resistance to iron toxicity and do not have enhanced capacity to store iron. In contrast, cells lacking RGI1 were found to be hypersensitive to the toxic effects of iron. Overall, our results suggest that Rgi1p is a novel pro-survival protein whose function is not related to ferritin but nevertheless it may have a role in regulating yeast sensitivity to iron stress.
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Affiliation(s)
- Rawan Eid
- Department of Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario, Canada; Department of Biology, Queen's University, Kingston, Ontario, Canada
| | - Eric Boucher
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Nada Gharib
- Department of Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario, Canada
| | - Chamel Khoury
- Department of Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario, Canada; Department of Biology, Queen's University, Kingston, Ontario, Canada; Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Nagla T T Arab
- Department of Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario, Canada; Department of Biology, Queen's University, Kingston, Ontario, Canada
| | - Alistair Murray
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Paul G Young
- Department of Biology, Queen's University, Kingston, Ontario, Canada
| | - Craig A Mandato
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | - Michael T Greenwood
- Department of Chemistry and Chemical Engineering, Royal Military College, Kingston, Ontario, Canada.
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Aoyagi T, Morii T, Ohtsuka K, Ohnishi H, Tajima T, Yoshiyama A, Mochizuki K, Satomi K, Ichimura S. Lung cancer cell line sensitivity to Zoledronic acid is BAX-dependent. Anticancer Res 2013; 33:5357-5363. [PMID: 24324070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND Zoledronate (Zol), an anti-osteoclastic and anticancer drug, is used to control bone metastasis in several cancer types, including non-small cell lung cancer (NSCLC). However, the mechanisms behind Zol resistance in NSCLC are unclear. MATERIALS AND METHODS Zol-resistant cell lines were developed by repeated treatment of A549 and H1650 NSCLC cell lines with Zol. We measured cell proliferation and apoptosis following Zol treatment and also examined the BCL2 superfamily expression. RNAi was used to confirm the role of key molecules in development of resistance. RESULTS Repeated Zol treatment engendered resistance, in which apoptosis induction was attenuated. From the BCL2 superfamily, BAX was commonly down-regulated in resistant cells, and silencing of BAX in parental cell lines also induced drug resistance. CONCLUSION Repeated treatment of NSCLC cell lines with Zol leads to drug resistance, which is in part due to BAX down-regulation.
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Affiliation(s)
- Takayuki Aoyagi
- Department of Orthopaedic Surgery, Faculty of Medicine, Kyorin University, 6-20-2 Shinkawa, Mitaka, Tokyo 181-8611 Japan.
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Ahern TH, Krug S, Carr AV, Murray EK, Fitzpatrick E, Bengston L, McCutcheon J, De Vries GJ, Forger NG. Cell death atlas of the postnatal mouse ventral forebrain and hypothalamus: effects of age and sex. J Comp Neurol 2013; 521:2551-69. [PMID: 23296992 PMCID: PMC4968939 DOI: 10.1002/cne.23298] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 11/28/2012] [Accepted: 12/26/2012] [Indexed: 01/21/2023]
Abstract
Naturally occurring cell death is essential to the development of the mammalian nervous system. Although the importance of developmental cell death has been appreciated for decades, there is no comprehensive account of cell death across brain areas in the mouse. Moreover, several regional sex differences in cell death have been described for the ventral forebrain and hypothalamus, but it is not known how widespread the phenomenon is. We used immunohistochemical detection of activated caspase-3 to identify dying cells in the brains of male and female mice from postnatal day (P) 1 to P11. Cell death density, total number of dying cells, and regional volume were determined in 16 regions of the hypothalamus and ventral forebrain (the anterior hypothalamus, arcuate nucleus, anteroventral periventricular nucleus, medial preoptic nucleus, paraventricular nucleus, suprachiasmatic nucleus, and ventromedial nucleus of the hypothalamus; the basolateral, central, and medial amygdala; the lateral and principal nuclei of the bed nuclei of the stria terminalis; the caudate-putamen; the globus pallidus; the lateral septum; and the islands of Calleja). All regions showed a significant effect of age on cell death. The timing of peak cell death varied between P1 to P7, and the average rate of cell death varied tenfold among regions. Several significant sex differences in cell death and/or regional volume were detected. These data address large gaps in the developmental literature and suggest interesting region-specific differences in the prevalence and timing of cell death in the hypothalamus and ventral forebrain.
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Affiliation(s)
- Todd H. Ahern
- Center for Behavioral Neuroscience, Department of Psychology, Quinnipiac University, Hamden, Connecticut 06518
- Department of Psychology, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003
| | - Stefanie Krug
- Department of Psychology, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003
| | - Audrey V. Carr
- Department of Psychology, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003
| | - Elaine K. Murray
- Department of Psychology, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003
| | - Emmett Fitzpatrick
- Department of Psychology, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003
| | - Lynn Bengston
- Department of Psychology, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003
| | - Jill McCutcheon
- Department of Psychology, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003
| | - Geert J. De Vries
- Department of Psychology, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003
- Neuroscience Institute, Georgia State University, Atlanta, Georgia 30303
| | - Nancy G. Forger
- Department of Psychology, Center for Neuroendocrine Studies, University of Massachusetts, Amherst, Massachusetts 01003
- Neuroscience Institute, Georgia State University, Atlanta, Georgia 30303
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8
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Zamorano S, Rojas-Rivera D, Lisbona F, Parra V, Court FA, Villegas R, Cheng EH, Korsmeyer SJ, Lavandero S, Hetz C. A BAX/BAK and cyclophilin D-independent intrinsic apoptosis pathway. PLoS One 2012; 7:e37782. [PMID: 22719850 PMCID: PMC3373601 DOI: 10.1371/journal.pone.0037782] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 04/26/2012] [Indexed: 11/19/2022] Open
Abstract
Most intrinsic death signals converge into the activation of pro-apoptotic BCL-2 family members BAX and BAK at the mitochondria, resulting in the release of cytochrome c and apoptosome activation. Chronic endoplasmic reticulum (ER) stress leads to apoptosis through the upregulation of a subset of pro-apoptotic BH3-only proteins, activating BAX and BAK at the mitochondria. Here we provide evidence indicating that the full resistance of BAX and BAK double deficient (DKO) cells to ER stress is reverted by stimulation in combination with mild serum withdrawal. Cell death under these conditions was characterized by the appearance of classical apoptosis markers, caspase-9 activation, release of cytochrome c, and was inhibited by knocking down caspase-9, but insensitive to BCL-X(L) overexpression. Similarly, the resistance of BIM and PUMA double deficient cells to ER stress was reverted by mild serum withdrawal. Surprisingly, BAX/BAK-independent cell death did not require Cyclophilin D (CypD) expression, an important regulator of the mitochondrial permeability transition pore. Our results suggest the existence of an alternative intrinsic apoptosis pathway emerging from a cross talk between the ER and the mitochondria.
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Affiliation(s)
- Sebastián Zamorano
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile
- Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Diego Rojas-Rivera
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile
- Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Fernanda Lisbona
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile
- Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Valentina Parra
- Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
- Faculty of Chemical & Pharmaceutical Sciences, University of Chile, Santiago, Chile
| | - Felipe A. Court
- Millennium Nucleus for Regenerative Biology, Faculty of Biology, P. Catholic University of Chile, Santiago, Chile
| | - Rosario Villegas
- Millennium Nucleus for Regenerative Biology, Faculty of Biology, P. Catholic University of Chile, Santiago, Chile
| | - Emily H. Cheng
- Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York, New York, United States of America
| | - Stanley J. Korsmeyer
- Dana–Farber Cancer Institute, and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sergio Lavandero
- Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
- Faculty of Chemical & Pharmaceutical Sciences, University of Chile, Santiago, Chile
- Cardiology Division, Department of Internal medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Claudio Hetz
- Biomedical Neuroscience Institute, Faculty of Medicine, University of Chile, Santiago, Chile
- Center for Molecular Studies of the Cell, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
- Harvard School of Public Health, Boston, Massachusetts, United States of America
- Neurounion Biomedical Foundation, Santiago, Chile
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9
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Mondal S, Bhattacharya K, Mallick A, Sangwan R, Mandal C. Bak compensated for Bax in p53-null cells to release cytochrome c for the initiation of mitochondrial signaling during Withanolide D-induced apoptosis. PLoS One 2012; 7:e34277. [PMID: 22479585 PMCID: PMC3315518 DOI: 10.1371/journal.pone.0034277] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 02/25/2012] [Indexed: 12/02/2022] Open
Abstract
The goal of cancer chemotherapy to induce multi-directional apoptosis as targeting a single pathway is unable to decrease all the downstream effect arises from crosstalk. Present study reports that Withanolide D (WithaD), a steroidal lactone isolated from Withania somnifera, induced cellular apoptosis in which mitochondria and p53 were intricately involved. In MOLT-3 and HCT116p53+/+ cells, WithaD induced crosstalk between intrinsic and extrinsic signaling through Bid, whereas in K562 and HCT116p53−/− cells, only intrinsic pathway was activated where Bid remain unaltered. WithaD showed pronounced activation of p53 in cancer cells. Moreover, lowered apoptogenic effect of HCT116p53−/− over HCT116p53+/+ established a strong correlation between WithaD-mediated apoptosis and p53. WithaD induced Bax and Bak upregulation in HCT116p53+/+, whereas increase only Bak expression in HCT116p53−/− cells, which was coordinated with augmented p53 expression. p53 inhibition substantially reduced Bax level and failed to inhibit Bak upregulation in HCT116p53+/+ cells confirming p53-dependent Bax and p53-independent Bak activation. Additionally, in HCT116p53+/+ cells, combined loss of Bax and Bak (HCT116Bax−Bak−) reduced WithaD-induced apoptosis and completely blocked cytochrome c release whereas single loss of Bax or Bak (HCT116Bax−Bak+/HCT116Bax+Bak−) was only marginally effective after WithaD treatment. In HCT116p53−/− cells, though Bax translocation to mitochondria was abrogated, Bak oligomerization helped the cells to release cytochrome c even before the disruption of mitochondrial membrane potential. WithaD also showed in vitro growth-inhibitory activity against an array of p53 wild type and null cancer cells and K562 xenograft in vivo. Taken together, WithaD elicited apoptosis in malignant cells through Bax/Bak dependent pathway in p53-wild type cells, whereas Bak compensated against loss of Bax in p53-null cells.
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Affiliation(s)
- Susmita Mondal
- Cancer and Cell Biology Division, Council of Scientific and Industrial Research - Indian Institute of Chemical Biology, Jadavpur, Kolkata, West Bengal, India
| | - Kaushik Bhattacharya
- Cancer and Cell Biology Division, Council of Scientific and Industrial Research - Indian Institute of Chemical Biology, Jadavpur, Kolkata, West Bengal, India
| | - Asish Mallick
- Cancer and Cell Biology Division, Council of Scientific and Industrial Research - Indian Institute of Chemical Biology, Jadavpur, Kolkata, West Bengal, India
| | - Rajender Sangwan
- Metabolic and Structural Biology Division, Council of Scientific and Industrial Research - Central Institute of Medicinal and Aromatic Plants, Lucknow, India
| | - Chitra Mandal
- Cancer and Cell Biology Division, Council of Scientific and Industrial Research - Indian Institute of Chemical Biology, Jadavpur, Kolkata, West Bengal, India
- * E-mail:
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10
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Maas C, de Vries E, Tait SWG, Borst J. Bid can mediate a pro-apoptotic response to etoposide and ionizing radiation without cleavage in its unstructured loop and in the absence of p53. Oncogene 2011; 30:3636-47. [PMID: 21423217 PMCID: PMC3158540 DOI: 10.1038/onc.2011.75] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 02/08/2011] [Accepted: 02/08/2011] [Indexed: 11/09/2022]
Abstract
BH3-only protein Bid is a key player in death receptor-induced apoptosis, because it provides the link with the mitochondrial route for caspase activation. In this pathway, Bid is activated upon cleavage by caspase-8. Its BH3 domain-containing carboxy-terminal fragment subsequently provokes mitochondrial outer membrane permeabilization by Bak/Bax activation. Bid has also been implicated in the apoptotic response to ionizing radiation (IR) and the topoisomerase inhibitor etoposide, anti-cancer regimens that cause double-strand (ds)DNA breaks. We confirm the existence of this pathway and show that it is p53-independent. However, the degree of Bid participation in the apoptotic response to dsDNA breaks depends on the nature of cell transformation. We used Bid-deficient mouse embryonic fibroblast (MEF) lines that were reconstituted with Bid to control the cellular background and demonstrated that the Bid-dependent apoptotic pathway induced by IR and etoposide operates in MEFs that are transformed by SV40, but is not evident in E1A/Ras-transformed MEFs. The Bid-dependent apoptotic response in p53-deficient SV40-transformed MEFs contributed to clonogenic execution of the cells, implying relevance for treatment outcome. In these cells, Bid acted in a conventional manner in that it required its BH3 domain to mediate apoptosis in response to IR and etoposide, and triggered apoptotic execution by indirect activation of Bak/Bax, mitochondrial permeabilization and caspase-9 activation. However, the mechanism of Bid activation was unconventional, because elimination of all known or suspected cleavage sites for caspases or other proteolytic enzymes and even complete elimination of its unstructured cleavage loop left Bid's pro-apoptotic role in the response to IR and etoposide unaffected.
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Affiliation(s)
- C Maas
- Division of Immunology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - E de Vries
- Division of Immunology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - S W G Tait
- Division of Immunology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - J Borst
- Division of Immunology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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11
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Abstract
It has recently been found that caspases not only function in apoptosis, but are also crucial for nonapoptotic processes such as NMDA receptor-dependent long-term depression (LTD) of synaptic transmission. It remains unknown, however, how caspases are activated and how neurons escape death in LTD. Here we show that caspase-3 is activated by the BAD-BAX cascade for LTD induction. This cascade is required specifically for NMDA receptor-dependent LTD but not for mGluR-LTD, and its activation is sufficient to induce synaptic depression. In contrast to apoptosis, however, BAD is activated only moderately and transiently and BAX is not translocated to mitochondria, resulting in only modest caspase-3 activation. We further demonstrate that the intensity and duration of caspase-3 activation determine whether it leads to cell death or LTD, thus fine-tuning of caspase-3 activation is critical in distinguishing between these two pathways.
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Affiliation(s)
- Song Jiao
- Unit on Synapse Development and Plasticity, Genes, Cognition and Psychosis Program, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
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12
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Kotipatruni RR, Dasari VR, Veeravalli KK, Dinh DH, Fassett D, Rao JS. p53- and Bax-mediated apoptosis in injured rat spinal cord. Neurochem Res 2011; 36:2063-74. [PMID: 21748659 DOI: 10.1007/s11064-011-0530-2] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2011] [Indexed: 01/07/2023]
Abstract
Spinal cord injury (SCI) induces a series of endogenous biochemical changes that lead to secondary degeneration, including apoptosis. p53-mediated mitochondrial apoptosis is likely to be an important mechanism of cell death in spinal cord injury. However, the signaling cascades that are activated before DNA fragmentation have not yet been determined. DNA damage-induced, p53-activated neuronal cell death has already been identified in several neurodegenerative diseases. To determine DNA damage-induced, p53-mediated apoptosis in spinal cord injury, we performed RT-PCR microarray and analyzed 84 DNA damaging and apoptotic genes. Genes involved in DNA damage and apoptosis were upregulated whereas anti-apoptotic genes were downregulated in injured spinal cords. Western blot analysis showed the upregulation of DNA damage-inducing protein such as ATM, cell cycle checkpoint kinases, 8-hydroxy-2'-deoxyguanosine (8-OHdG), BRCA2 and H2AX in injured spinal cord tissues. Detection of phospho-H2AX in the nucleus and release of 8-OHdG in cytosol were demonstrated by immunohistochemistry. Expression of p53 was observed in the neurons, oligodendrocytes and astrocytes after spinal cord injury. Upregulation of phospho-p53, Bax and downregulation of Bcl2 were detected after spinal cord injury. Sub-cellular distribution of Bax and cytochrome c indicated mitochondrial-mediated apoptosis taking place after spinal cord injury. In addition, we carried out immunohistochemical analysis to confirm Bax translocation into the mitochondria and activated p53 at Ser³⁹². Expression of APAF1, caspase 9 and caspase 3 activities confirmed the intrinsic apoptotic pathway after SCI. Activated p53 and Bax mitochondrial translocation were detected in injured spinal neurons. Taken together, the in vitro data strengthened the in vivo observations of DNA damage-induced p53-mediated mitochondrial apoptosis in the injured spinal cord.
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Affiliation(s)
- Ramaprasada Rao Kotipatruni
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, One Illini Drive, Peoria, IL 61656, USA
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13
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14
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Sun ZM, Xiao Y, Ren LL, Lei XB, Wang JW. [Enterovirus 71 induces apoptosis in a Bax dependent manner]. Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi 2011; 25:49-52. [PMID: 21789855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To explore the molecular mechanism of apoptosis induced by enterovirus 71 (EV71) infection. METHODS The effects of EV71 on Rhabdomyosarcoma (RD) cell viability were detected by CCK8 assay. EV71-induced apoptosis on RD cells were detected by Hoechst 33342 staining and Western blot targeting Caspase 3, 8 and PARP. Bax conformational change was detected by immunoprecipitation with Bax 6A7 antibody. RESULTS EV71 decreased the viability of RD cells and induces the activation of Caspase 3, 8 and PARP. Bax expression increases in RD cells after EV71 infection, and Bax conformational change also can be detected after EV71 infection. CONCLUSION Our study reveals that EV71 induces Caspase-dependent apoptosis by Bax conformational change.
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Affiliation(s)
- Zhen-min Sun
- State Key Laboratory of Molecular Virology and Genetic Engineering, Institute of Pathogen Biology, Peking Union Medical College & Chinese Academy of Medical Sciences, Beijing 100730, China
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15
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McCoy F, Hurwitz J, McTavish N, Paul I, Barnes C, O'Hagan B, Odrzywol K, Murray J, Longley D, McKerr G, Fennell DA. Obatoclax induces Atg7-dependent autophagy independent of beclin-1 and BAX/BAK. Cell Death Dis 2010; 1:e108. [PMID: 21368880 PMCID: PMC3032298 DOI: 10.1038/cddis.2010.86] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 10/11/2010] [Accepted: 10/28/2010] [Indexed: 12/03/2022]
Abstract
Direct pharmacological targeting of the anti-apoptotic B-cell lymphoma-2 (BCL-2) family is an attractive therapeutic strategy for treating cancer. Obatoclax is a pan-BCL-2 family inhibitor currently in clinical development. Here we show that, although obatoclax can induce mitochondrial apoptosis dependent on BCL-2 associated x protein/BCL-2 antagonist killer (BAX/BAK) consistent with its on-target pharmacodynamics, simultaneous silencing of both BAX and BAK did not abolish acute toxicity or loss of clonogenicity. This is despite complete inhibition of apoptosis. Obatoclax dramatically reduced viability without inducing loss of plasma membrane integrity. This was associated with rapid processing of light chain-3 (LC3) and reduction of S6 kinase phosphorylation, consistent with autophagy. Dramatic ultrastructural vacuolation, not typical of autophagy, was also induced. Silencing of beclin-1 failed to prevent LC3 processing, whereas knockout of autophagy-related (Atg)7 abolished LC3 processing but failed to prevent obatoclax-induced loss of clonogenicity or ultrastructural changes. siRNA silencing of Atg7 in BAX/BAK knockout mouse embryonic fibroblasts did not prevent obatoclax-induced loss of viability. Cells selected for obatoclax resistance evaded apoptosis independent of changes in BCL-2 family expression and displayed reduced LC3 processing. In summary, obatoclax exhibits BAX- and BAK-dependent and -independent mechanisms of toxicity and activation of autophagy. Mechanisms other than autophagy and apoptosis are blocked in obatoclax resistant cells and contribute significantly to obatoclax's anticancer efficacy.
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Affiliation(s)
- F McCoy
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - J Hurwitz
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - N McTavish
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - I Paul
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - C Barnes
- FEI Centre for Advanced Imaging, University of Ulster, Ulster, Northern Ireland, UK
| | - B O'Hagan
- FEI Centre for Advanced Imaging, University of Ulster, Ulster, Northern Ireland, UK
| | - K Odrzywol
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - J Murray
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - D Longley
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
| | - G McKerr
- FEI Centre for Advanced Imaging, University of Ulster, Ulster, Northern Ireland, UK
| | - D A Fennell
- Centre for Cancer Research and Cell Biology, Queen's University Belfast, Belfast, Northern Ireland, UK
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Cheng S, Gao N, Zhang Z, Chen G, Budhraja A, Ke Z, Son YO, Wang X, Luo J, Shi X. Quercetin induces tumor-selective apoptosis through downregulation of Mcl-1 and activation of Bax. Clin Cancer Res 2010; 16:5679-91. [PMID: 21138867 PMCID: PMC3069720 DOI: 10.1158/1078-0432.ccr-10-1565] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To investigate the in vivo antitumor efficacy of quercetin in U937 xenografts and the functional roles of Mcl-1 and Bax in quercetin-induced apoptosis in human leukemia. EXPERIMENTAL DESIGN Leukemia cells were treated with quercetin, after which apoptosis, Mcl-1 expression, and Bax activation and translocation were evaluated. The efficacy of quercetin as well as Mcl-1 expression and Bax activation were investigated in xenografts of U937 cells. RESULTS Administration of quercetin caused pronounced apoptosis in both transformed and primary leukemia cells but not in normal blood peripheral mononuclear cells. Quercetin-induced apoptosis was accompanied by Mcl-1 downregulation and Bax conformational change and mitochondrial translocation that triggered cytochrome c release. Knockdown of Bax by siRNA reversed quercetin-induced apoptosis and abrogated the activation of caspase and apoptosis. Ectopic expression of Mcl-1 attenuated quercetin-mediated Bax activation, translocation, and cell death. Conversely, interruption of Mcl-1 by siRNA enhanced Bax activation and translocation, as well as lethality induced by quercetin. However, the absence of Bax had no effect on quercetin-mediated Mcl-1 downregulation. Furthermore, in vivo administration of quercetin attenuated tumor growth in U937 xenografts. The TUNEL-positive apoptotic cells in tumor sections increased in quercetin-treated mice as compared with controls. Mcl-1 downregulation and Bax activation were also observed in xenografts. CONCLUSIONS These data suggest that quercetin may be useful for the treatment of leukemia by preferentially inducing apoptosis in leukemia versus normal hematopoietic cells through a process involving Mcl-1 downregulation, which, in turn, potentiates Bax activation and mitochondrial translocation, culminating in apoptosis.
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Affiliation(s)
- Senping Cheng
- Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Ning Gao
- Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Zhuo Zhang
- Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Gang Chen
- Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Amit Budhraja
- Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Zunji Ke
- Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Young-ok Son
- Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Xin Wang
- Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Jia Luo
- Department of Internal Medicine, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Xianglin Shi
- Graduate Center for Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky
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17
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Malla R, Gopinath S, Alapati K, Gondi CS, Gujrati M, Dinh DH, Mohanam S, Rao JS. Downregulation of uPAR and cathepsin B induces apoptosis via regulation of Bcl-2 and Bax and inhibition of the PI3K/Akt pathway in gliomas. PLoS One 2010; 5:e13731. [PMID: 21060833 PMCID: PMC2966405 DOI: 10.1371/journal.pone.0013731] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 10/07/2010] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Glioma is the most commonly diagnosed primary brain tumor and is characterized by invasive and infiltrative behavior. uPAR and cathepsin B are known to be overexpressed in high-grade gliomas and are strongly correlated with invasive cancer phenotypes. METHODOLOGY/PRINCIPAL FINDINGS In the present study, we observed that simultaneous downregulation of uPAR and cathepsin B induces upregulation of some pro-apoptotic genes and suppression of anti-apoptotic genes in human glioma cells. uPAR and cathepsin B (pCU)-downregulated cells exhibited decreases in the Bcl-2/Bax ratio and initiated the collapse of mitochondrial membrane potential. We also observed that the broad caspase inhibitor, Z-Asp-2, 6-dichlorobenzoylmethylketone rescued pCU-induced apoptosis in U251 cells but not in 5310 cells. Immunoblot analysis of caspase-9 immunoprecipitates for Apaf-1 showed that uPAR and cathepsin B knockdown activated apoptosome complex formation in U251 cells. Downregulation of uPAR and cathepsin B also retarded nuclear translocation and interfered with DNA binding activity of CREB in both U251 and 5310 cells. Further western blotting analysis demonstrated that downregulation of uPAR and cathepsin B significantly decreased expression of the signaling molecules p-PDGFR-β, p-PI3K and p-Akt. An increase in the number of TUNEL-positive cells, increased Bax expression, and decreased Bcl-2 expression in nude mice brain tumor sections and brain tissue lysates confirm our in vitro results. CONCLUSIONS/SIGNIFICANCE In conclusion, RNAi-mediated downregulation of uPAR and cathepsin B initiates caspase-dependent mitochondrial apoptosis in U251 cells and caspase-independent mitochondrial apoptosis in 5310 cells. Thus, targeting uPAR and cathepsin B-mediated signaling using siRNA may serve as a novel therapeutic strategy for the treatment of gliomas.
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Affiliation(s)
- Ramarao Malla
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois, United States of America
| | - Sreelatha Gopinath
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois, United States of America
| | - Kiranmai Alapati
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois, United States of America
| | - Christopher S. Gondi
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois, United States of America
| | - Meena Gujrati
- Department of Pathology, University of Illinois College of Medicine at Peoria, Peoria, Illinois, United States of America
| | - Dzung H. Dinh
- Department of Neurosurgery, University of Illinois College of Medicine at Peoria, Peoria, Illinois, United States of America
| | - Sanjeeva Mohanam
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois, United States of America
| | - Jasti S. Rao
- Department of Cancer Biology and Pharmacology, University of Illinois College of Medicine at Peoria, Peoria, Illinois, United States of America
- Department of Neurosurgery, University of Illinois College of Medicine at Peoria, Peoria, Illinois, United States of America
- * E-mail:
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18
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Wang Q, Sun SY, Khuri F, Curran WJ, Deng X. Mono- or double-site phosphorylation distinctly regulates the proapoptotic function of Bax. PLoS One 2010; 5:e13393. [PMID: 20976235 PMCID: PMC2954808 DOI: 10.1371/journal.pone.0013393] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 09/19/2010] [Indexed: 11/18/2022] Open
Abstract
Bax is the major multidomain proapoptotic molecule that is required for apoptosis. It has been reported that phosphorylation of Bax at serine(S) 163 or S184 activates or inactivates its proapoptotic function, respectively. To uncover the mechanism(s) by which phosphorylation regulates the proapoptotic function of Bax, a series of serine (S)→ alanine/glutamate (A/E) Bax mutants, including S163A, S184A, S163E, S184E, S163E/S184A (EA), S163A/S184E (AE), S163A/S184A (AA) and S163E/S184E (EE), were created to abrogate or mimic, respectively, either single or double-site phosphorylation. The compound Bax mutants (i.e. EA and AE) can flesh out the functional contribution of individual phosphorylation site(s). WT and each of these Bax mutants were overexpressed in Bax−/− MEF or lung cancer H157 cells and the proapoptotic activities were compared. Intriguingly, expression of any of Bax mutants containing the mutation S→A at S184 (i.e. S184A, EA or AA) represents more potent proapoptotic activity as compared to WT Bax in association with increased 6A7 epitope conformational change, mitochondrial localization/insertion and prolonged half-life. In contrast, all Bax mutants containing the mutation S→E at S184 (i.e. S184E, AE or EE) have a mobility-shift and fail to insert into mitochondrial membranes with decreased protein stability and less apoptotic activity. Unexpectedly, mutation either S→A or S→E at S163 site does not significantly affect the proapoptotic activity of Bax. These findings indicate that S184 but not S163 is the major phosphorylation site for functional regulation of Bax's activity. Therefore, manipulation of the phosphorylation status of Bax at S184 may represent a novel strategy for cancer treatment.
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Affiliation(s)
- Qinhong Wang
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Shi-Yong Sun
- Department of Hematology and Medical Oncology, Emory University School of Medicine and Winship Cancer Institute, Emory University, Atlanta, Georgia, United States of America
| | - Fadlo Khuri
- Department of Hematology and Medical Oncology, Emory University School of Medicine and Winship Cancer Institute, Emory University, Atlanta, Georgia, United States of America
| | - Walter J. Curran
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute, Emory University, Atlanta, Georgia, United States of America
| | - Xingming Deng
- Department of Radiation Oncology, Emory University School of Medicine and Winship Cancer Institute, Emory University, Atlanta, Georgia, United States of America
- * E-mail:
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Laloux G, Deghelt M, de Barsy M, Letesson JJ, De Bolle X. Identification of the essential Brucella melitensis porin Omp2b as a suppressor of Bax-induced cell death in yeast in a genome-wide screening. PLoS One 2010; 5:e13274. [PMID: 20949000 PMCID: PMC2952587 DOI: 10.1371/journal.pone.0013274] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Accepted: 09/09/2010] [Indexed: 01/08/2023] Open
Abstract
Background Inhibition of apoptosis is one of the mechanisms selected by numerous intracellular pathogenic bacteria to control their host cell. Brucellae, which are the causative agent of a worldwide zoonosis, prevent apoptosis of infected cells, probably to support survival of their replication niche. Methodology/Principal Findings In order to identify Brucella melitensis anti-apoptotic effector candidates, we performed a genome-wide functional screening in yeast. The B. melitensis ORFeome was screened to identify inhibitors of Bax-induced cell death in S. cerevisiae. B. melitensis porin Omp2b, here shown to be essential, prevents Bax lethal effect in yeast, unlike its close paralog Omp2a. Our results based on Omp2b size variants characterization suggest that signal peptide processing is required for Omp2b effect in yeast. Conclusion/Significance We report here the first application to a bacterial genome-wide library of coding sequences of this “yeast-rescue” screening strategy, previously used to highlight several new apoptosis regulators. Our work provides B. melitensis proteins that are candidates for an anti-apoptotic function, and can be tested in mammalian cells in the future. Hypotheses on possible molecular mechanisms of Bax inhibition by the B. melitensis porin Omp2b are discussed.
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Affiliation(s)
- Géraldine Laloux
- Research Unit in Molecular Biology, Department of Biology, University of Namur (FUNDP), Namur, Belgium
| | - Michaël Deghelt
- Research Unit in Molecular Biology, Department of Biology, University of Namur (FUNDP), Namur, Belgium
| | - Marie de Barsy
- Research Unit in Molecular Biology, Department of Biology, University of Namur (FUNDP), Namur, Belgium
| | - Jean-Jacques Letesson
- Research Unit in Molecular Biology, Department of Biology, University of Namur (FUNDP), Namur, Belgium
| | - Xavier De Bolle
- Research Unit in Molecular Biology, Department of Biology, University of Namur (FUNDP), Namur, Belgium
- * E-mail:
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Guo LX, Liu JH, Xia ZN. Geniposide inhibits CoCl2-induced PC12 cells death via the mitochondrial pathway. Chin Med J (Engl) 2009; 122:2886-2892. [PMID: 20092796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND A number of studies have shown that oxidative stress and mitochondrial involvement are major triggering factors in the development of neurodegenerative diseases. Cobalt chloride (CoCl(2))-induced cell death in PC12 cells may serve a simple and convenient in vitro model of hypoxia-induced neuronal cytotoxicity. To explore the effect of geniposide on CoCl(2) which induced cytotoxicity and mitochondrial function in rat pheochromocytoma PC12 cells, we analyzed the influence of geniposide on the expression of apoptosis-related proteins. METHODS PC12 cells and RNAi PC12 cells were treated with 0, 12.5, 25, 50, 100 micromol/L geniposide for 12 hours and then exposure to 400 micromol/L CoCl(2) for 12 hours. Cell viability, cell morphology, and expression of Bcl-2, Bax, P53 and caspase-9 were determined using Western blotting. RESULTS Pretreatment with geniposide markedly improved the cells viability and morphology, decreased the expression of Bax, P53 and caspase-9, and increased the expression of Bcl-2 in PC12 cells challenged by CoCl(2)2. However, in the RNAi PC12 cells, geniposide had no significant effect on the expression of these proteins. CONCLUSION Geniposide protects PC12 cells from CoCl(2) involved in mitochondrial mediated apoptosis, and GLP-1R might play a critical role in the neuroprotection of geniposide in PC12 cells.
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Affiliation(s)
- Li-xia Guo
- Research Center of Pharmaceutical Chemistry & Chemical Biology, Chongqing Technology and Business University, Chongqing, China
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21
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Songgang L, Jiyu L, Yingbin L, Yiyu Q, Zhiwei Q. Somatostatin enhances the chemosensitivity of GBC-SD cell line to doxorubicin through arresting the cell cycle to S phase rather than through the P53/Bax-depended apoptosis way in vitro. Hepatogastroenterology 2009; 56:1253-1260. [PMID: 19950772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
BACKGROUND/AIMS As one of the mostly aggressive and fatal malignancy, gallbladder carcinoma has been known to be resistant to many anticancer drugs. Although it is under active investigation, it is still difficult to achieve satisfactory effect for most chemo-drugs on this tumor. It has previously reported that somatostatin could increase the chemosensitivity of gallbladder carcinoma cells (GBC-SD) and reduce the therapeutic dose of Doxorubicin in killing GBC-SD cells. SST could enhance the chemosensitivity of gallbladder carcinoma to Doxorubincin (DOX) by transient arresting cell cycle to S phase. We tried to clarify the mechanism by which SST utilized to enhance the chemosensitivity of GBC-SD cells to DOX. We further investigated whether the enhanced chemosensitivity of GBC-SD cells to DOX in the presence of SST is via apoptosis or cell cycle regulation. In addition, we also looked into related factors involved in cell cycle regulation and apoptosis. METHODOLOGY Twenty-four hours after somatostatin treatment, doxorubicin was gradually added and the growth curve of GBC-SD cells was determined according to MTT test. Cell apoptosis was measured by flow cytometry (FCM) using Annexin V/ Propidium Iodide Binding. Cell cycle was also examined by FCM. The somatostatin receptor (SSTR) subtypes in GBC-SD cells were identified using immunocytochemistry and RT-PCR assay. The expressions of p53, Bax and phosphorylated RB (pRB) protein were examined using western blotting assay. RESULTS When GBC-SD cells were treated with SST alone, no significant cell growth inhibition and cell apoptosis were observed. SST could induce a transient S phase arrest in GBC-SD cells. The mRNA expression of SSTR1, 2, 3, 4, 5 were all detected in GBC-SD cells, whereas only SSTR1, 2, 3 were detected in GBC-SD cells using immunocytochemistry assay. After GBC-SD cells were treated with SST for 24h, the expression level of p53 and Bax protein in GBC-SD cells was similar to that of the control group, however up-regulated pRB protein expression was observed (p < 0.05). CONCLUSIONS Our results suggested that the synergistic inhibitory effect of somatostatin and doxorubicin co-treatment on GBC-SD cells was not due to SST induced apoptosis concerning the expression of p53 and Bax protein. Our data clearly showed all 5 SST receptor subtypes expressed in GBC-SD cells by RT-PCR and 3 SST receptors by immunocytochemistry. Accumulated evidence has been proved the relationship between cell cycle regulation and RB protein phosphorylation. In the chemosensitized GBC-SD cell line treated with SST, phosphorylated RB and cell cycle arrest were simultaneously manifested. We reasoned that somatostatin might enhance the chemosensitivity of GBC-SD cells to doxorubin through arresting the cell cycle at S phase, but not P53 and Bax protein induced cell apoptosis.
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Affiliation(s)
- Li Songgang
- Department of General Surgery, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, 1665 Kongjiang Road, Shanghai 200092, PR China
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22
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Scharstuhl A, Mutsaers HAM, Pennings SWC, Russel FGM, Wagener FADTG. Involvement of VDAC, Bax and ceramides in the efflux of AIF from mitochondria during curcumin-induced apoptosis. PLoS One 2009; 4:e6688. [PMID: 19693275 PMCID: PMC2725322 DOI: 10.1371/journal.pone.0006688] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Accepted: 07/26/2009] [Indexed: 11/18/2022] Open
Abstract
Background We previously identified curcumin as a potent inducer of fibroblast apoptosis, which could be used to treat hypertrophic scar formation. Here we investigated the underlying mechanism of this process. Principal Findings Curcumin-induced apoptosis could not be blocked by caspase-inhibitors and we could not detect any caspase-3/7 activity. Curcumin predominantly induced mitochondria-mediated ROS formation and stimulated the expression of the redox-sensitive pro-apoptotic factor p53. Inhibition of the pro-apoptotic signaling enzyme glycogen synthase kinase-3β (GSK-3β) blocked curcumin-induced apoptosis. Apoptosis was associated with high molecular weight DNA damage, a possible indicator of apoptosis-inducing factor (AIF) activity. Indeed, curcumin caused nuclear translocation of AIF, which could be blocked by the antioxidant N-acetyl cysteine. We next investigated how AIF is effluxed from mitochondria in more detail. The permeability transition pore complex (PTPC), of which the voltage-dependent anion channel (VDAC) is a component, could be involved since the VDAC-inhibitor DIDS (4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid) efficiently blocked AIF translocation. However, PTPC is not involved in AIF release since cyclosporine A, a specific inhibitor of the complex did not block apoptosis. Alternatively, the pro-apoptotic protein Bax could have formed mitochondrial channels and interacted with VDAC. Curcumin caused mitochondrial translocation of Bax, which was blocked by DIDS, suggesting a Bax-VDAC interaction. Interestingly, ceramide channels can also release apoptogenic factors from mitochondria and we found that addition of ceramide induced caspase-independent apoptosis. Surprisingly, this process could also be blocked by DIDS, suggesting the concerted action of Bax, VDAC and ceramide in the efflux of AIF from the mitochondrion. Conclusions Curcumin-induced fibroblast apoptosis is totally caspase-independent and relies on the mitochondrial formation of ROS and the subsequent nuclear translocation of AIF, which is released from a mitochondrial pore that involves VDAC, Bax and possibly ceramides. The composition of the AIF-releasing channel seems to be much more complex than previously thought.
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Affiliation(s)
- Alwin Scharstuhl
- Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Henricus A. M. Mutsaers
- Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Sebastiaan W. C. Pennings
- Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Frans G. M. Russel
- Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
| | - Frank A. D. T. G. Wagener
- Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
- Department of Orthodontics and Craniofacial Development, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen, The Netherlands
- * E-mail:
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Abstract
This study reviews the current understanding of the mechanisms that mediate the complex processes involved in apoptosis secondary to ischemia and reperfusion (I/R) and is not intended as a complete literature review of apoptosis. Several biochemical reactions trigger a cascade of events, which activate caspases. These caspases exert their effect through downstream proteolysis until the final effector caspases mediate the nuclear features characteristic of apoptosis, DNA fragmentation and condensation. Within the context of ischemia, the hypoxic environment initiates the expression of several genes involved in inflammation, the immune response, and apoptosis. Many of these same genes are activated during reperfusion injury in response to radical oxygen species generation. It is plausible that inhibition of specific apoptotic pathways via inactivation or downregulation of those genes responsible for the initiation of inflammation, immune response, and apoptosis may provide promising molecular targets for ameliorating reperfusion injury in I/R-related processes. Such inhibitory mechanisms are discussed in this review. Important targets in I/R-related pathologies include the brain during stroke, the heart during myocardial infarction, and the organs during harvesting and/or storage for transplantation. In addition, we present data from our ongoing research of specific signal transduction-related elements and their role in ischemia/reperfusion injury. These data address the potential therapeutic application of anti-inflammatory and anti-ischemic compounds in the prevention of I/R damage.
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Affiliation(s)
- Fernando Lopez-Neblina
- Trauma, Surgery Research, and Molecular Biology, Borgess Research Institute, Kalamazoo, Michigan 49048, USA
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Kaestner P, Stolz A, Bastians H. Determinants for the efficiency of anticancer drugs targeting either Aurora-A or Aurora-B kinases in human colon carcinoma cells. Mol Cancer Ther 2009; 8:2046-56. [PMID: 19584233 DOI: 10.1158/1535-7163.mct-09-0323] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The mitotic Aurora kinases, including Aurora-A and Aurora- B, are attractive novel targets for anticancer therapy, and inhibitory drugs have been developed that are currently undergoing clinical trials. However, the molecular mechanisms how these drugs induce tumor cell death are poorly understood. We have addressed this question by comparing the requirements for an efficient induction of apoptosis in response to MLN8054, a selective inhibitor of Aurora-A, and the selective Aurora-B inhibitor ZM447439 in human colon carcinoma cells. By using various isogenic knockout as well as inducible colon carcinoma cell lines, we found that treatment with MLN8054 induces defects in mitotic spindle assembly, which causes a transient spindle checkpoint-dependent mitotic arrest. This cell cycle arrest is not maintained due to the activity of MLN8054 to override the spindle checkpoint. Subsequently, MLN8054-treated cells exit from mitosis and activate a p53-dependent postmitotic G(1) checkpoint, which subsequently induces p21 and Bax, leading to G(1) arrest followed by the induction of apoptosis. In contrast, inhibition of Aurora-B by ZM447439 also interferes with normal chromosome alignment during mitosis and overrides the mitotic spindle checkpoint but allows a subsequent endoreduplication, although ZM447439 potently activates the p53-dependent postmitotic G(1) checkpoint. Moreover, the ZM447439-induced endoreduplication is a prerequisite for the efficiency of the drug. Thus, our results obtained in human colon carcinoma cells indicate that although both Aurora kinase inhibitors are potent inducers of tumor cell death, the pathways leading to the induction of apoptosis in response to these drugs are distinct.
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Affiliation(s)
- Phillip Kaestner
- Institute for Molecular Biology and Tumor Research, Philipps University Marburg, Marburg, Germany
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25
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Abstract
In multicellular organisms, the total number of cells is a balance between the cell-generating effects of mitosis and cell death that is induced through apoptosis. A disruption of this delicate balance can lead to the development of cancer. This Timeline article focuses on how the field of apoptosis biology has developed in the context of its contribution to our understanding of cell death, or lack of it, in the development of malignant disease. It traces the course of research from key discoveries in fundamental biology to potential therapeutic applications.
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Affiliation(s)
- Thomas G Cotter
- Tumour Biology Laboratory, Department of Biochemistry, University College Cork, Cork, Ireland.
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26
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Mousavi SH, Tavakkol-Afshari J, Brook A, Jafari-Anarkooli I. Role of caspases and Bax protein in saffron-induced apoptosis in MCF-7 cells. Food Chem Toxicol 2009; 47:1909-13. [PMID: 19457443 DOI: 10.1016/j.fct.2009.05.017] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 04/14/2009] [Accepted: 05/07/2009] [Indexed: 11/17/2022]
Abstract
Saffron (Crocus sativus), widely used as a spice in Middle Eastern cuisine and is known for anti-cancer properties. The mechanism of saffron-induced cytotoxicity, in tumor cells has not been adequately explored. Therefore, we investigated the role of caspases and Bax protein in saffron-induced apoptosis in MCF-7 cells, a commonly used cell culture system for in vitro studies on breast cancer. Cells were incubated with different concentrations of saffron extract. Cell viability was quantitated by MTT assay. Apoptotic cells were determined using PI staining of DNA fragmentation by flow cytometry (sub-G1 peak). Role of caspase were studied using the pan-caspase inhibitor. Bax protein expression was analysed by western blotting. Saffron extract (200-2000 microg/ml) decreased cell viability in MCF-7 cells as a concentration- and time-dependent manner with an IC50 of 400+/-18.5 microg/ml after 48 h. Analysis of DNA fragmentation by flow cytometry showed apoptotic cell death in MCF-7 cell treated with saffron extract. Saffron-induced apoptosis could be inhibited by pan-caspase inhibitors, indicating caspase-dependent pathway was induced by saffron in MCF-7 cells. Bax protein expression was also increased in saffron-treated cells. Thus saffron exerts proapoptotic effects in a breast cancer-derived cell line and could be considered as a potential chemotherapeutic agent in breast cancer.
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Affiliation(s)
- Seyed Hadi Mousavi
- Department of Pharmacology and Pharmacological Research Centre of Medicinal Plants, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
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Jourdain A, Martinou JC. Mitochondrial outer-membrane permeabilization and remodelling in apoptosis. Int J Biochem Cell Biol 2009; 41:1884-9. [PMID: 19439192 DOI: 10.1016/j.biocel.2009.05.001] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2009] [Revised: 05/01/2009] [Accepted: 05/04/2009] [Indexed: 11/18/2022]
Abstract
Many human pathologies are associated with defects in mitochondria such as diabetes, neurodegenerative diseases or cancer. This tiny organelle is involved in a plethora of processes in mammalian cells, including energy production, lipid metabolism and cell death. In the so-called intrinsic apoptotic pathway, the outer mitochondrial membrane (MOM) is premeabilized by the pro-apoptotic Bcl-2 members Bax and Bak, allowing the release of apoptogenic factors such as cytochrome c from the inter-membrane space into the cytosol. At the same time, mitochondria fragment in response to Drp-1 activation suggesting that mitochondrial fission could play a role in mitochondrial outer-membrane permeabilization (MOMP). In this review, we will discuss the link that could exist between mitochondrial fission and fusion machinery, Bcl-2 family members and MOMP.
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Affiliation(s)
- Alexis Jourdain
- Department of Cell Biology, University of Geneva, Quai Ernest-Ansermet 30, 1211 Geneva 4, Switzerland
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Cook MS, Coveney D, Batchvarov I, Nadeau JH, Capel B. BAX-mediated cell death affects early germ cell loss and incidence of testicular teratomas in Dnd1(Ter/Ter) mice. Dev Biol 2009; 328:377-83. [PMID: 19389346 PMCID: PMC2689365 DOI: 10.1016/j.ydbio.2009.01.041] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 01/28/2009] [Accepted: 01/28/2009] [Indexed: 11/16/2022]
Abstract
A homozygous nonsense mutation (Ter) in murine Dnd1 (Dnd1(Ter/Ter)) results in a significant early loss of primordial germ cells (PGCs) prior to colonization of the gonad in both sexes and all genetic backgrounds tested. The same mutation also leads to testicular teratomas only on the 129Sv/J background. Male mutants on other genetic backgrounds ultimately lose all PGCs with no incidence of teratoma formation. It is not clear how these PGCs are lost or what factors directly control the strain-specific phenotype variation. To determine the mechanism underlying early PGC loss we crossed Dnd1(Ter/Ter) embryos to a Bax-null background and found that germ cells were partially rescued. Surprisingly, on a mixed genetic background, rescued male germ cells also generated fully developed teratomas at a high rate. Double-mutant females on a mixed background did not develop teratomas, but were fertile and produced viable off-spring. However, when Dnd1(Ter/Ter) XX germ cells developed in a testicular environment they gave rise to the same neoplastic clusters as mutant XY germ cells in a testis. We conclude that BAX-mediated apoptosis plays a role in early germ cell loss and protects from testicular teratoma formation on a mixed genetic background.
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Affiliation(s)
- Matthew S Cook
- Department of Cell Biology, Duke University, Durham, NC, USA.
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Huang F, Nie C, Yang Y, Yue W, Ren Y, Shang Y, Wang X, Jin H, Xu C, Chen Q. Selenite induces redox-dependent Bax activation and apoptosis in colorectal cancer cells. Free Radic Biol Med 2009; 46:1186-96. [PMID: 19439215 DOI: 10.1016/j.freeradbiomed.2009.01.026] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 01/21/2009] [Accepted: 01/22/2009] [Indexed: 12/29/2022]
Abstract
Emerging evidence suggests that selenium has chemotherapeutic potential by inducing cancer cell apoptosis with minimal side effects to normal cells. However, the mechanism by which selenium induces apoptosis is not well understood. We have investigated the role of Bax, a Bcl-2 family protein and a critical regulator of the mitochondrial apoptotic pathway, in selenite-induced apoptosis in colorectal cancer cells. We found that supranutritional doses of selenite could induce typical apoptosis in colorectal cancer cells in vitro and in xenograft tumors. Selenite triggers a conformational change in Bax, as detected by the 6A7 antibody, and leads to Bax translocation into the mitochondria, where Bax forms oligomers to mediate cytochrome c release. Importantly, we show that the two conserved cysteine residues of Bax seem to be critical for sensing the intracellular ROS to initiate Bax conformational changes and subsequent apoptosis. Our results show for the first time that selenite can activate the apoptotic machinery through redox-dependent activation of Bax and further suggest that selenite could be useful in cancer therapy.
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Affiliation(s)
- Fang Huang
- National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
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Xiao D, Zeng Y, Hahm ER, Kim YA, Ramalingam S, Singh SV. Diallyl trisulfide selectively causes Bax- and Bak-mediated apoptosis in human lung cancer cells. Environ Mol Mutagen 2009; 50:201-212. [PMID: 18800351 PMCID: PMC2656596 DOI: 10.1002/em.20431] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Garlic-derived organosulfur compounds (OSCs) are highly effective in affording protection against chemically induced pulmonary carcinogenesis in animal models. We now demonstrate that garlic constituent diallyl trisulfide (DATS) suppresses viability of cultured human lung cancer cell lines H358 (anon-small cell lung cancer cell line) and H460 (a large cell lung cancer cell line) by causing G2-M phase cell cycle arrest and apoptotic cell death. On the other hand, a normal human bronchial epithelial cell line BEAS-2B was significantly more resistant to growth inhibition and apoptosis induction by DATS compared with lung cancer cells. We also found that even a subtle change in the OSC structure could have a significant impact on its biological activity. For example, DATS was significantly more effective than either diallyl sulfide or diallyl disulfide against proliferation of lung cancer cells. The DATS-mediated G2-M phase cell cycle arrest was explained by down-regulation of cyclin-dependent kinase 1 (Cdk1) and cell division cycle 25C protein expression leading to accumulation of Tyr15 phosphorylated (inactive) Cdk1. The DATS-induced apoptosis correlated with induction of pro-apoptotic proteins Bax, Bak and BID, and a decrease in the expression of anti-apoptotic proteins Bcl-2 and Bcl-xL in lung cancer cells but not in BEAS-2B. Knockdown of Bax and Bak proteins conferred significant protection against DATS-induced apoptotic cytoplasmic histone-associated DNA fragmentation. On the other hand, BID protein was dispensable for DATS-induced apoptosis. In conclusion, the present study indicates that Bax and Bak proteins are critical targets of DATS-induced apoptosis in human lung cancer cells.
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Affiliation(s)
- Dong Xiao
- Department of Pharmacology & Chemical Biology and University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Yan Zeng
- Department of Pharmacology & Chemical Biology and University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Eun-Ryeong Hahm
- Department of Pharmacology & Chemical Biology and University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Young-Ae Kim
- Department of Pharmacology & Chemical Biology and University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | | | - Shivendra V. Singh
- Department of Pharmacology & Chemical Biology and University of Pittsburgh Cancer Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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31
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Janumyan Y, Cui Q, Yan L, Sansam CG, Valentin M, Yang E. G0 function of BCL2 and BCL-xL requires BAX, BAK, and p27 phosphorylation by Mirk, revealing a novel role of BAX and BAK in quiescence regulation. J Biol Chem 2008; 283:34108-20. [PMID: 18818203 PMCID: PMC2590681 DOI: 10.1074/jbc.m806294200] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Revised: 09/25/2008] [Indexed: 11/06/2022] Open
Abstract
BCL2 and BCL-x(L) facilitate G(0) quiescence by decreasing RNA content and cell size and up-regulating p27 protein, but the precise mechanism is not understood. We investigated the relationship between cell cycle regulation and the anti-apoptosis function of BCL2 and BCL-x(L). Neither caspase inhibition nor abrogation of mitochondria-dependent apoptosis by BAX and BAK deletion fully recapitulated the G(0) effects of BCL2 or BCL-x(L), suggesting that mechanisms in addition to anti-apoptosis are involved in the cell cycle arrest function of BCL2 or BCL-x(L). We found that BCL2 and BCL-x(L) expression in bax(-/-) bak(-/-) cells did not confer cell cycle effects, consistent with the G(0) function of BCL2 and BCL-x(L) being mediated through BAX or BAK. Stabilization of p27 in G(0) in BCL2 or BCL-x(L) cells was due to phosphorylation of p27 at Ser(10) by the kinase Mirk. In bax(-/-) bak(-/-) cells, total p27 and p27 phosphorylated at Ser(10) were elevated. Re-expression of BAX in bax(-/-) bak(-/-) cells and silencing of BAX and BAK in wild type cells confirmed that endogenous BAX and BAK modulated p27. These data revealed a novel role for BAX and BAK in the regulation of G(0) quiescence.
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Affiliation(s)
- Yelena Janumyan
- Department of Pediatrics, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA
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Abstract
Insulin resistance is a primary characteristic of type 2 diabetes. Several lines of evidence suggest that accumulation of free fatty acids in skeletal muscle may at least in part contribute to insulin resistance and may be linked to mitochondrial dysfunction, leading to apoptosis. Palmitate treatment of several cell lines in vitro results in apoptosis and inhibits protein kinase B (Akt) activity in response to insulin. However, the role of Bax and Bcl-2 in regulating palmitate-induced apoptosis has not been well studied. Therefore, the purpose of this study was to determine whether palmitate-induced apoptosis in C(2)C(12) myotubes is dependent on Bax to Bcl-2 binding. An additional purpose of this study was to determine whether the changes in Bax to Bcl-2 binding corresponded to decreases in Akt signaling in palmitate-treated myoblasts. Apoptotic signaling proteins were examined in C(2)C(12) myotubes treated overnight with palmitate. Bax to Bcl-2 binding was determined through a coimmunoprecipitation assay that was performed in myotubes after 2 h of serum starvation, followed by 10 min of serum reintroduction. This experiment evaluated whether temporal Akt activity coincided with Bax to Bcl-2 binding. Last, the contribution of Bax to palmitate-induced apoptosis was determined by treatment with Bax siRNA. Palmitate treatment increased apoptosis in C(2)C(12) myotubes as shown by a twofold increase in DNA fragmentation, an approximately fivefold increase in caspase-3 activity, and a 2.5-fold increase in caspase-9 activity. Palmitate treatment significantly reduced Akt protein expression and Akt activity. In addition, there was a fourfold reduction in Bax to Bcl-2 binding with palmitate treatment, which mirrored the reduction in Akt(Ser473) phosphorylation. Furthermore, treatment of the C(2)C(12) myotubes with Bax siRNA attenuated the apoptotic effects of palmitate treatment. These data show that palmitate induces Bax-mediated apoptosis in C(2)C(12) myotubes and that this effect corresponds to reductions in Akt(Ser473) phosphorylation.
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Li T, Brustovetsky T, Antonsson B, Brustovetsky N. Oligomeric BAX induces mitochondrial permeability transition and complete cytochrome c release without oxidative stress. Biochim Biophys Acta 2008; 1777:1409-21. [PMID: 18771651 PMCID: PMC2613194 DOI: 10.1016/j.bbabio.2008.08.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2008] [Revised: 08/07/2008] [Accepted: 08/08/2008] [Indexed: 01/26/2023]
Abstract
In the present study, we investigated the mechanism of cytochrome c release from isolated brain mitochondria induced by recombinant oligomeric BAX (BAX(oligo)). We found that BAX(oligo) caused a complete release of cytochrome c in a concentration- and time-dependent manner. The release was similar to those induced by alamethicin, which causes maximal mitochondrial swelling and eliminates barrier properties of the OMM. BAX(oligo) also produced large amplitude mitochondrial swelling as judged by light scattering assay and transmission electron microscopy. In addition, BAX(oligo) resulted in a strong mitochondrial depolarization. ATP or a combination of cyclosporin A and ADP, inhibitors of the mPT, suppressed BAX(oligo)-induced mitochondrial swelling and depolarization as well as cytochrome c release but did not influence BAX(oligo) insertion into the OMM. Both BAX(oligo)- and alamethicin-induced cytochrome c releases were accompanied by inhibition of ROS generation, which was assessed by measuring mitochondrial H(2)O(2) release with an Amplex Red assay. The mPT inhibitors antagonized suppression of ROS generation caused by BAX(oligo) but not by alamethicin. Thus, BAX(oligo) resulted in a complete cytochrome c release from isolated brain mitochondria in the mPT-dependent manner without involvement of oxidative stress by the mechanism requiring mitochondrial remodeling and permeabilization of the OMM.
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Affiliation(s)
- Tsyregma Li
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
| | - Tatiana Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
| | - Bruno Antonsson
- Geneva Research Center, Merck Serono International, Geneva, Switzerland
| | - Nickolay Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
- Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis IN 46202, USA
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Cox AG, Brown KK, Arner ESJ, Hampton MB. The thioredoxin reductase inhibitor auranofin triggers apoptosis through a Bax/Bak-dependent process that involves peroxiredoxin 3 oxidation. Biochem Pharmacol 2008; 76:1097-109. [PMID: 18789312 DOI: 10.1016/j.bcp.2008.08.021] [Citation(s) in RCA: 124] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 08/10/2008] [Accepted: 08/14/2008] [Indexed: 01/14/2023]
Abstract
Thioredoxin reductase (TrxR) is a key selenoprotein antioxidant enzyme and a potential target for anti-cancer drugs. One potent inhibitor of TrxR is the gold (I) compound auranofin, which can trigger mitochondrial-dependent apoptosis pathways. The exact mechanism of apoptosis induction by auranofin is not yet clear, but there are indications that mitochondrial oxidative stress is a central event. We assessed the redox state of the peroxiredoxins (Prxs) in Jurkat T-lymphoma cells treated with auranofin, and found that mitochondrial Prx3 was considerably more sensitive to oxidation than the cytosolic Prx1 and 2, indicating selective mitochondrial stress. Prx3 oxidation was detected at apoptotic doses of auranofin in several cell types, and occurred before other mitochondrial events including cytochrome c release and mitochondrial depolarisation. Auranofin was also able to sensitise U937 cells to TNF-alpha-mediated apoptosis. Auranofin-induced apoptosis was effectively blocked by the overexpression of Bcl-2, and Bax/Bak deficient mouse embryonic fibroblasts were also resistant to apoptosis, indicating a central role for the pro-apoptotic proteins of this family in auranofin-triggered apoptosis. Auranofin exposure inhibited the proliferation of apoptosis-resistant cells, and at higher doses of auranofin could cause cell death through necrosis. We conclude that auranofin induces apoptosis in cells through a Bax/Bak-dependent mechanism associated with selective disruption of mitochondrial redox homeostasis in conjunction with oxidation of Prx3.
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Affiliation(s)
- Andrew G Cox
- Free Radical Research Group, Department of Pathology, University of Otago, Christchurch, New Zealand
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Gomez-Lazaro M, Bonekamp NA, Galindo MF, Jordán J, Schrader M. 6-Hydroxydopamine (6-OHDA) induces Drp1-dependent mitochondrial fragmentation in SH-SY5Y cells. Free Radic Biol Med 2008; 44:1960-9. [PMID: 18395527 DOI: 10.1016/j.freeradbiomed.2008.03.009] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2007] [Revised: 02/21/2008] [Accepted: 03/11/2008] [Indexed: 11/30/2022]
Abstract
Mitochondrial alterations have been associated with the cytotoxic effect of 6-hydroxydopamine (6-OHDA), a widely used neurotoxin to study Parkinson's disease. Herein we studied the potential effects of 6-OHDA on mitochondrial morphology in SH-SY5Y neuroblastoma cells. By immunofluorescence and time-lapse fluorescence microscopy we demonstrated that 6-OHDA induced profound mitochondrial fragmentation in SH-SY5Y cells, an event that was similar to mitochondrial fission induced by overexpression of Fis1p, a membrane adaptor for the dynamin-related protein 1 (DLP1/Drp1). 6-OHDA failed to induce any changes in peroxisome morphology. Biochemical experiments revealed that 6-OHDA-induced mitochondrial fragmentation is an early event preceding the collapse of the mitochondrial membrane potential and cytochrome c release in SH-SY5Y cells. Silencing of DLP1/Drp1, which is involved in mitochondrial and peroxisomal fission, prevented 6-OHDA-induced fragmentation of mitochondria. Furthermore, in cells silenced for Drp1, 6-OHDA-induced cell death was reduced, indicating that a block in mitochondrial fission protects SH-SY5Y cells against 6-OHDA toxicity. Experiments in mouse embryonic fibroblasts deficient in Bax or p53 revealed that both proteins are not essential for 6-OHDA-induced mitochondrial fragmentation. Our data demonstrate for the first time an involvement of mitochondrial fragmentation and Drp1 function in 6-OHDA-induced apoptosis.
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Affiliation(s)
- Maria Gomez-Lazaro
- Grupo de Neurofarmacología, Department Ciencias Médicas, Facultad de Medicina, Universidad de Castilla-La Mancha-Centro Regional de Investigaciones Biomédicas, Albacete, Spain
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Nogueiras R, López M, Lage R, Perez-Tilve D, Pfluger P, Mendieta-Zerón H, Sakkou M, Wiedmer P, Benoit SC, Datta R, Dong JZ, Culler M, Sleeman M, Vidal-Puig A, Horvath T, Treier M, Diéguez C, Tschöp MH. Bsx, a novel hypothalamic factor linking feeding with locomotor activity, is regulated by energy availability. Endocrinology 2008; 149:3009-15. [PMID: 18308842 PMCID: PMC2408820 DOI: 10.1210/en.2007-1684] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We recently reported that the hypothalamic homeobox domain transcription factor Bsx plays an essential role in the central nervous system control of spontaneous physical activity and the generation of hyperphagic responses. Moreover, we found Bsx to be a master regulator for the hypothalamic expression of key orexigenic neuropeptide Y and agouti gene-related protein. We now hypothesized that Bsx, which is expressed in the dorsomedial and arcuate nucleus (ARC) of the hypothalamus, is regulated by afferent signals in response to peripheral energy balance. Bsx expression was analyzed using in situ hybridization in fed vs. fasted (24 h) and ghrelin vs. leptin-treated rats, as well as in mice deficient for leptin or the ghrelin signaling. Ghrelin administration increased, whereas ghrelin receptor antagonist decreased ARC Bsx expression. Leptin injection attenuated the fasting-induced increase in ARC Bsx levels but had no effect in fed rats. Dorsomedial hypothalamic nucleus Bsx expression was unaffected by pharmacological modifications of leptin or ghrelin signaling. Obese leptin-deficient (ob/ob) mice, but not obese melanocortin 4 receptor-knockout mice, showed higher expression of Bsx, consistent with dependency from afferent leptin rather than increased adiposity per se. Interestingly, exposure to a high-fat diet triggered Bsx expression, consistent with the concept that decreased leptin signaling due to a high-fat diet induced leptin resistance. Our data indicate that ARC Bsx expression is specifically regulated by afferent energy balance signals, including input from leptin and ghrelin. Future studies will be necessary to test if Bsx may be involved in the pathogenesis of leptin resistance.
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Affiliation(s)
- Ruben Nogueiras
- Department of Psychiatry, Obesity Research Center, University of Cincinnati, Cincinnati, Ohio 45237, USA
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37
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Khwaja TA, Wajahat T, Ahmad I, Hoessli DC, Walker-Nasir E, Kaleem A, Qazi WM, Shakoori AR, Din NU. In silico modulation of apoptotic Bcl-2 proteins by mistletoe lectin-1: functional consequences of protein modifications. J Cell Biochem 2008; 103:479-91. [PMID: 17583555 DOI: 10.1002/jcb.21412] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The mistletoe lectin-1 (ML-1) modulates tumor cell apoptosis by triggering signaling cascades through the complex interplay of phosphorylation and O-linked N-acetylglucosamine (O-GlcNAc) modification in pro- and anti-apoptotic proteins. In particular, ML-1 is predicted to induce dephosphorylation of Bcl-2-family proteins and their alternative O-GlcNAc modification at specific, conserved Ser/Thr residues. The sites for phosphorylation and glycosylation were predicted and analyzed using Netphos 2.0 and YinOYang 1.2. The involvement of modified Ser/Thr, and among them the potential Yin Yang sites that may undergo both types of posttranslational modification, is proposed to mediate apoptosis modulation by ML-1.
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Affiliation(s)
- Tasneem A Khwaja
- Institute of Molecular Sciences and Bioinformatics, Lahore, Pakistan
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Golbano JM, Lóppez-Aparicio P, Recio MN, Pérez-Albarsanz MA. Finasteride induces apoptosis via Bcl-2, Bcl-xL, Bax and caspase-3 proteins in LNCaP human prostate cancer cell line. Int J Oncol 2008; 32:919-924. [PMID: 18360719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
We investigated the effects of finasteride, a 5alpha-reductase inhibitor, on cell death machinery through the induction of apoptosis in an in vitro model for prostate cancer. Finasteride treatment of the LNCaP hormone-dependent human prostate cancer cell line caused the loss of cell viability and accelerated apoptosis in a concentration-dependent manner. The contents of immunoreactive procaspase-3 were examined by immunoblot analysis and the results suggest that the apoptosis induced by finasteride involves the increase of caspase-3 activity. Early cell changes that occur during apoptosis are associated with mitochondrial changes mediated by members of the Bcl-2 family of proteins. Therefore, Bcl-2, Bcl-xL and Bax were evaluated by the Western blot analysis. The immunoreactivity for pro-apoptotic Bax was markedly increased whereas antiapoptotic Bcl-2 and Bcl-xL expression was significantly reduced after incubation of cells with finasteride. These findings suggest that finasteride induces apoptosis in LNCaP cells via proteins of the Bcl-2 and caspase family.
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Affiliation(s)
- Jesús M Golbano
- Servicio de Urología, Hospital General Universitario de Guadalajara, Guadalajara, Spain
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Radogna F, Cristofanon S, Paternoster L, D'Alessio M, De Nicola M, Cerella C, Dicato M, Diederich M, Ghibelli L. Melatonin antagonizes the intrinsic pathway of apoptosis via mitochondrial targeting of Bcl-2. J Pineal Res 2008; 44:316-25. [PMID: 18339127 DOI: 10.1111/j.1600-079x.2007.00532.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have recently shown that melatonin antagonizes damage-induced apoptosis by interaction with the MT-1/MT-2 plasma membrane receptors. Here, we show that melatonin interferes with the intrinsic pathway of apoptosis at the mitochondrial level. In response to an apoptogenic stimulus, melatonin allows mitochondrial translocation of the pro-apoptotic protein Bax, but it impairs its activation/dimerization The downstream apoptotic events, i.e. cytochrome c release, caspase 9 and 3 activation and nuclear vesiculation are equally impaired, indicating that melatonin interferes with Bax activation within mitochondria. Interestingly, we found that melatonin induces a strong re-localization of Bcl-2, the main Bax antagonist to mitochondria, suggesting that Bax activation may in fact be antagonized by Bcl-2 at the mitochondrial level. Indeed, we inhibit the melatonin anti-apoptotic effect (i) by silencing Bcl-2 with small interfering RNAs, or with small-molecular inhibitors targeted at the BH3 binding pocket in Bcl-2 (i.e. the one interacting with Bax); and (ii) by inhibiting melatonin-induced Bcl-2 mitochondrial re-localization with the MT1/MT2 receptor antagonist luzindole. This evidence provides a mechanism that may explain how melatonin through interaction with the MT1/MT2 receptors, elicits a pathway that interferes with the Bcl-2 family, thus modulating the cell life/death balance.
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Affiliation(s)
- Flavia Radogna
- Dipartimento di Biologia, Università di Roma Tor Vergata, Rome, Italy
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40
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Li XP, Gao MH. [Effect of peptide seals specific to CD59 on the expression of apoptosis-related genes in HeLa cells]. Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi 2008; 24:20-22. [PMID: 18177611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
AIM To study the effect of peptide seals specific to CD59 on the expression of apoptosis-related survivin, caspase-3 and bax in HeLa cells and investigate the mechanism of peptide seals specific to CD59 in inducing apoptosis of HeLa cells. METHODS The peptide seals specific to CD59 were put into HeLa cells and HeLa cells with CD59-transfected gene, respectively. After 24 hours of interaction, the inhibitory ratio of cell proliferation was measured by MTT and the expression of survivin, caspase-3 and bax was detected by immunohistochemistry. RESULTS The inhibitory ratio of HeLa cells with CD59-transfected gene + peptide seal group was higher than that of HeLa cells + peptide seal group. There was a significant difference in depressing the proliferation between two groups (P < 0.01). Compared with HeLa cells + peptide seal group, the survivin expression of HeLa cells with CD59-transfected gene + peptide seal group was decreased (P < 0.05) while caspase-3 expression was increased (P < 0.05). There was no significant difference in the expression of bax in four groups. CONCLUSION The peptide seal specific to CD59 can down-regulate the expression of survivin, activate caspase-3 and enhance the apoptosis of HeLa cells.
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Affiliation(s)
- Xian-ping Li
- Department of Immunology, Medical College of Qingdao University, Qingdao 266021, China.
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Zopf S, Neureiter D, Bouralexis S, Abt T, Glaser KB, Okamoto K, Ganslmayer M, Hahn EG, Herold C, Ocker M. Differential response of p53 and p21 on HDAC inhibitor-mediated apoptosis in HCT116 colon cancer cells in vitro and in vivo. Int J Oncol 2007; 31:1391-1402. [PMID: 17982666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023] Open
Abstract
We investigated the effect of a novel histone deacetylase inhibitor, A-423378.0, on the colon carcinoma cell line HCT116 and genetically modified derivatives lacking either p21(cip1/waf1) or p53. HCT116 cell lines were incubated with A-423378.0 at different concentrations for 3-120 h. Cell viability, proliferation and apoptosis rates were determined and verified by western blot, detection of mitochondrial membrane potential breakdown DeltaPsi(m), activation of caspases-3, -8 and cytokeratin 18 cleavage. A subcutaneous xenograft model was established in NMRI mice with daily intraperitoneal injections of 10 mg/kg for 14 days. All three HCT116 cell lines responded to A-423378.0 treatment in a dose- and time-dependent manner via induction of apoptosis as measured by breakdown of DeltaPsi(m) and BrdU incorporation. We identified that A-423378.0 induced the expression of TRAIL and TRAIL receptor, especially TRAIL-R2/hDR5, which was up-regulated in HCT116 cells after treatment with A-423378.0. In vivo, a growth inhibitory effect was observed with HDAC-I treatment, which was paralleled by a down-regulation of PCNA and a concomitant induction of apoptosis. Treatment of wild-type or knock-out HCT116 cells with A-423378.0 exerts potent anti-proliferative and pro-apoptotic effects in vitro and in vivo. A-423378.0 was able to induce apoptosis in both p21(WAF1) and p53 deficient tumour cells, which appeared to be mediated by the intrinsic cell death pathway. Interestingly, the effects of A-423378.0 on the extrinsic cell death pathway through activation of TRAIL and its signalling pathway indicate that A-423378.0 may be a potent new therapeutic compound for the treatment of advanced colorectal cancer.
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Affiliation(s)
- Steffen Zopf
- Department of Medicine 1, University Hospital Erlangen, D-91054, Erlangen, Germany
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42
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Janssen K, Pohlmann S, Jänicke RU, Schulze-Osthoff K, Fischer U. Apaf-1 and caspase-9 deficiency prevents apoptosis in a Bax-controlled pathway and promotes clonogenic survival during paclitaxel treatment. Blood 2007; 110:3662-72. [PMID: 17652622 DOI: 10.1182/blood-2007-02-073213] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Taxane derivatives such as paclitaxel elicit their antitumor effects at least in part by induction of apoptosis, but the underlying mechanisms are incompletely understood. Here, we used different cellular models with deficiencies in key regulators of apoptosis to elucidate the mechanism of paclitaxel-induced cell death. Apoptosis by paclitaxel was reported to depend on the activation of the initiator caspase-10; however, we clearly demonstrate that paclitaxel kills murine embryonic fibroblasts (MEFs) devoid of caspase-10 as well as human tumor cell lines deficient in caspase-10, caspase-8, or Fas-associating protein with death domain. In contrast, the lack of Apaf-1 or caspase-9, key regulators of the mitochondrial pathway, not only entirely protected against paclitaxel-induced apoptosis but could even confer clonogenic survival, depending on the cell type and drug concentration. Thus, paclitaxel triggers apoptosis not through caspase-10, but via caspase-9 activation at the apoptosome. This conclusion is supported by the fact that Bcl-2-overexpressing cells and Bax/Bak doubly-deficient MEFs were entirely resistant to paclitaxel-induced apoptosis. Interestingly, also the single knockout of Bim or Bax, but not that of Bak or Bid, conferred partial resistance, suggesting a particular role of these mediators in the cell-death pathway activated by paclitaxel.
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Affiliation(s)
- Katja Janssen
- Institute of Molecular Medicine, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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43
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Abstract
Bid, a member of the pro-apoptotic Bcl-2 protein family, is activated through caspase-8-mediated cleavage into a truncated form (p15 tBid) during TNF-alpha(tumor necrosis factor alpha)-induced apoptosis. Activated tBid can induce Bax oligomerization and translocation to mitochondria, triggering the release of cytochrome c, caspase-3 activation and cell apoptosis. However, it is debatable that whether Bid and tBid can interact directly with Bax in living cells. In this study, we used confocal fluorescence microscope, combined with both FRET (fluorescence resonance energy transfer) and acceptor photobleaching techniques, to study the dynamic interaction between Bid and Bax during TNF-alpha-induced apoptosis in single living cell. In ASTC-a-1 cells, full length Bid induced Bax translocation to mitochondria by directly interacting with Bax transiently in response to TNF-alpha treatment before cell shrinkage. Next, we demonstrated that, in both ASTC-a-1 and HeLa cells, Bid was not cleaved before cell shrinkage even under the condition that caspase-8 had been activated, but in MCF-7 cells Bid was cleaved. In addition, in ASTC-a-1 cells, caspase-3 activation was a biphasic process and Bid was cleaved after the second activation of caspase-3. In summary, these findings indicate that, FL-Bid (full length-Bid) directly regulated the activation of Bax during TNF-alpha-induced apoptosis in ASTC-a-1 cells and that the cleavage of Bid occurred in advanced apoptosis.
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Affiliation(s)
- Yihui Pei
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China
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44
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Xu M, Dong J. Involvement of nitric oxide signaling in mammalian Bax-induced terpenoid indole alkaloid production of Catharanthus roseus cells. ACTA ACUST UNITED AC 2007; 50:799-807. [PMID: 17914641 DOI: 10.1007/s11427-007-0096-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2007] [Accepted: 09/07/2007] [Indexed: 12/23/2022]
Abstract
Bax, a mammalian pro-apoptotic member of the Bcl-2 family, has been demonstrated to be a potential regulatory factor for plant secondary metabolite biosynthesis recently. To investigate the molecular mechanism of Bax-induced secondary metabolite biosynthesis, we determined the contents of nitric oxide (NO) of the transgenic Catharanthus roseus cells overexpressing a mouse Bax protein and checked the effects of NO specific scavenger 2,4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPITO) on Bax-induced terpenoid indole alkaloid (TIA) production of the cells. The data showed that overexpression of the mouse Bax in C. roseus cells triggered NO generation of the cells. Treatment of cPITO not only inhibited the Bax-triggered NO burst but also suppressed the Bax-induced TIA production. The results indicated that the mouse Bax might activate the NO signaling in C. roseus cells and induce TIA production through the NO-dependent signal pathway in the cells. Furthermore, the activities of nitric oxide synthase (NOS) were significantly increased in the transgenic Bax cells as compared to those in the control cells, showing that the mouse Bax may induce NOS of C. roseus cells. Treatment of the transgenic Bax cells with NOS inhibitor PBITU blocked both Bax-induced NO generation and TIA production, which suggested that the mouse Bax might trigger NO generation and TIA production through NOS. However, the NOS-like activities and NO generation in the transgenic Bax cells did not match kinetically and the Bax-induced NOS-like activity was much later and lower than NO production. Moreover, the Bax-induced NO generation and TIA production were only partially inhibited by PBITU. Thus, our results suggested that the Bax-induced NO production and secondary metabolite biosynthesis in C. roseus cells was not entirely dependent on NOS or NOS-like enzymes.
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Affiliation(s)
- MaoJun Xu
- Department of Biotechnology, Zhejiang Gongshang University, Hangzhou, 310035, China.
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45
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Abstract
Homo-oligomerization of Bax (or Bak) has been hypothesized to be responsible for cell death through the mitochondria-dependent apoptosis pathway. However, partly due to a lack of structural information on the Bax homo-oligomerization and apoptosis inducing domain(s), this hypothesis has remained difficult to test. In this study, we identified a three-helix unit, comprised of the BH3 (helix 2) and BH1 domains (helix 4 and helix 5), as the homo-oligomerization domain of Bax. When targeted to mitochondria, this minimum oligomerization unit induced apoptosis in Bax(-/-)Bak(-/-) mouse embryonic fibroblasts (DKO). Strikingly, the central helix of Bax (helix 5), when replacing the corresponding helix (helix 5) of Bcl-xL, an anti-apoptotic Bcl-2 family protein structurally homologous to Bax, converted Bcl-xL into a Bax-like molecule capable of forming oligomers and causing apoptosis in the DKO cells. Finally, a series of systematic mutagenesis analyses revealed that homo-oligomerization is both necessary and sufficient for the apoptotic activity of Bax. These results suggest that active Bax causes mitochondrial damage through homo-oligomers of a three-helix functional unit.
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Affiliation(s)
- Nicholas M. George
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
| | - Jacquelynn J.D. Evans
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
| | - Xu Luo
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
- Corresponding author.E-MAIL ; FAX (402) 559-3739
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Park OH, Lee KJ, Rhyu IJ, Geum D, Kim H, Buss R, Oppenheim RW, Sun W. Bax-dependent and -independent death of motoneurons after facial nerve injury in adult mice. Eur J Neurosci 2007; 26:1421-32. [PMID: 17822434 DOI: 10.1111/j.1460-9568.2007.05787.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Nerve injury-induced neuronal death may occur after accidental trauma or nerve inflammation. Although the response to facial root avulsion has been examined in rodent models, there are conflicting results as to whether motoneuron (MN) death is mediated by apoptosis or necrosis. We examined the response of MNs and proximal nerves after facial nerve avulsion in adult mice. Following facial nerve avulsion in 4-5-week-old mice, we observed a progressive reduction of MNs such that by 4 weeks less than 10% of avulsed MNs remained compared with the control side. The profile of MN degeneration was distinct from axotomy-induced responses. For example, the onset of MN death was more rapid, and the extent of MN loss was greater compared with axotomy. Furthermore, the degeneration of oligodendrocytes and the activation of microglia were increased in the proximal nerve after avulsion. Ultrastructural observations suggested that root avulsion mainly induces non-apoptotic neuronal death, although a small subset of neurons appeared to die via apoptosis. To evaluate the contribution of apoptotic death, we evaluated MN responses in Bax-knockout (KO) mice in which neurons are rescued from apoptotic death. Surprisingly, although the majority of Bax-KO mice exhibited only a moderate MN loss after avulsion, a subset of Bax-KO mice (25%) exhibited extensive MN death and injury-induced changes in the nerve that were indistinguishable from events in wild-type littermates. These results suggest that both Bax-dependent and -independent forms of cell death are evoked by root avulsion, and that programmed cell death may be involved in triggering a robust necrotic response.
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Affiliation(s)
- Ok-hee Park
- Department of Anatomy, College of Medicine, Korea University, 126-1 Anam-Dong, Sungbuk-Gu, Seoul, Korea 136-705
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Neise D, Graupner V, Gillissen BF, Daniel PT, Schulze-Osthoff K, Jänicke RU, Essmann F. Activation of the mitochondrial death pathway is commonly mediated by a preferential engagement of Bak. Oncogene 2007; 27:1387-96. [PMID: 17724463 DOI: 10.1038/sj.onc.1210773] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Among the members of the Bcl-2 family, the multidomain proteins Bax and Bak are crucial for the activation of mitochondria. However, it is still unclear whether they act in a unique and distinct manner or whether they exhibit redundant functions. To systematically investigate their activation on a single-cell level, we established MCF-7 cell lines stably expressing GFP-fusion variants of these proteins. We found that MCF-7/GFP-Bak cells showed an increased sensitivity to apoptosis induction by staurosporine, actinomycin D, TRAIL and overexpression of Puma compared to GFP-Bax-expressing cells. Independently of the death stimulus used, oligomerization of endogenous and exogenous Bak was mostly detected prior to an activation of Bax, whereas cells displaying oligomerized Bax in the absence of Bak clusters were not observed. In addition, activation of Bax but not Bak was attenuated by a caspase inhibitor. Consistent with this, caspase-3-deficient MCF-7 cells displayed a significantly reduced activation of endogenous Bax than caspase-3-proficient MCF-7 cells. Thus, our data strongly suggest that diverse apoptotic stimuli preferentially engage the Bak pathway, whereas the triggering of Bax occurs, at least partially, downstream of mitochondrial caspase activation, most likely constituting a positive feedback loop for the amplification of the death signal.
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Affiliation(s)
- D Neise
- Institute of Molecular Medicine, University of Düsseldorf, Düsseldorf, Germany
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48
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Shim HY, Park JH, Paik HD, Nah SY, Kim DSHL, Han YS. Acacetin-induced apoptosis of human breast cancer MCF-7 cells involves caspase cascade, mitochondria-mediated death signaling and SAPK/JNK1/2-c-Jun activation. Mol Cells 2007; 24:95-104. [PMID: 17846503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023] Open
Abstract
The mechanism of acacetin-induced apoptosis of human breast cancer MCF-7 cells was investigated. Acacetin caused 50% growth inhibition (IC50) of MCF-7 cells at 26.4% 0.7% M over 24 h in the MTT assay. Apoptosis was characterized by DNA fragmentation and an increase of sub-G1 cells and involved activation of caspase-7 and PARP (poly-ADP-ribose polymerase). Maximum caspase 7 activity was observed with 100 microM acacetin for 24 h. Caspase 8 and 9 activation cascades mediated the activation of caspase 7. Acacetin caused a reduction of Bcl-2 expression leading to an increase of the Bax:Bcl-2 ratio. It also caused a loss of mitochondrial membrane potential that induced release of cytochrome c and apoptosis inducing factor (AIF) into the cytoplasm, enhancing ROS generation and subsequently resulting in apoptosis. Pretreatment of cells with N-acetylcysteine (NAC) reduced ROS generation and cell growth inhibition, and pretreatment with NAC or a caspase 8 inhibitor (Z-IETD-FMK) inhibited the acacetin-induced loss of mitochondrial membrane potential and release of cytochrome c and AIF. Stress-activated protein kinase/c-Jun NH4-terminal kinase 1/2 (SAPK/ JNK1/2) and c-Jun were activated by acacetin but extracellular-regulated kinase 1/2 (Erk1/2) nor p38 mitogen-activated protein kinase (MAPK) were not. Our results show that acacetin-induced apoptosis of MCF-7 cells is mediated by caspase activation cascades, ROS generation, mitochondria-mediated cell death signaling and the SAPK/JNK1/2-c-Jun signaling pathway, activated by acacetin-induced ROS generation.
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Affiliation(s)
- Hye-Young Shim
- Department of Advanced Technology Fusion and Bio/Molecular Informatics Center, Konkuk University, Seoul 143-701, Korea
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Wang XB, Gao HY, Hou BL, Huang J, Xi RG, Wu LJ. Nanoparticle realgar powders induce apoptosis in U937 cells through caspase MAPK and mitochondrial pathways. Arch Pharm Res 2007; 30:653-8. [PMID: 17615687 DOI: 10.1007/bf02977662] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Nanoparticle realgar powders (NRP) inhibited U937 cell growth in a time and dose-dependent manner. U937 cells treated with NRP showed typical characteristics of apoptosis including the morphological changes and DNA fragmentation. Caspase family inhibitor (z-VAD-fmk), caspase-8, -9 inhibitor (z-IETD-fmk, Ac-LEHD-CHO, respectively) and caspase-3 inhibitor (z-DEVD-fmk) partially prevented NRP -induced apoptosis. Moreover, the classical substrates of caspase-3, poly-ADP ribose polymerase (PARP) was degraded after U937 cells treatment with NRP. In addition, NRP increased the ratio of Bax/Bcl-2 protein expression. Although p38 inhibitor (SB203580) and ERK inhibitor (PD98059) failed to block cell death, JNK inhibitor (SP600125) had marked inhibitory effects on NRP -induced apoptosis. Furthermore, the phosphorylation of JNK was up-regulated, suggesting that JNK was responsible for NRP -induced apoptosis in U937 cells. These results suggested that the caspase, mitochondria and MAPK signal pathways were involved in NRP-induced U937 apoptosis.
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Affiliation(s)
- Xiao-Bo Wang
- School of Traditional Chinese Medicines, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, China
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Jones RG, Bui T, White C, Madesh M, Krawczyk CM, Lindsten T, Hawkins BJ, Kubek S, Frauwirth KA, Wang YL, Conway SJ, Roderick HL, Bootman MD, Shen H, Foskett JK, Thompson CB. The proapoptotic factors Bax and Bak regulate T Cell proliferation through control of endoplasmic reticulum Ca(2+) homeostasis. Immunity 2007; 27:268-80. [PMID: 17692540 PMCID: PMC2714273 DOI: 10.1016/j.immuni.2007.05.023] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2006] [Revised: 05/09/2007] [Accepted: 05/31/2007] [Indexed: 11/25/2022]
Abstract
The Bcl-2-associated X protein (Bax) and Bcl-2-antagonist/killer (Bak) are essential regulators of lymphocyte apoptosis, but whether they play a role in viable T cell function remains unclear. Here, we report that T cells lacking both Bax and Bak display defects in antigen-specific proliferation because of Ca(2+)-signaling defects. Bax(-/-), Bak(-/-) T cells displayed defective T cell receptor (TCR)- and inositol-1,4,5-trisphosphate (IP(3))-dependent Ca(2+) mobilization because of altered endoplasmic reticulum (ER) Ca(2+) regulation that was reversed by Bax's reintroduction. The ability of TCR-dependent Ca(2+) signals to stimulate mitochondrial NADH production in excess of that utilized for ATP synthesis was dependent on Bax and Bak. Blunting of Ca(2+)-induced mitochondrial NADH elevation in the absence of Bax and Bak resulted in decreased reactive-oxygen-species production, which was required for T cell proliferation. Together, the data establish that Bax and Bak play an essential role in the control of T cell proliferation by modulating ER Ca(2+) release.
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Affiliation(s)
- Russell G Jones
- Department of Cancer Biology, Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
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