1
|
Xu Y, Chu C, Shi Z, Zhang J. The role of hepatocyte mitochondrial DNA in liver injury. Biomed Pharmacother 2023; 168:115692. [PMID: 37844357 DOI: 10.1016/j.biopha.2023.115692] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 09/30/2023] [Accepted: 10/09/2023] [Indexed: 10/18/2023] Open
Abstract
Hepatocytes, the predominant cellular constituents of the liver, exhibit the highest mitochondrial density within the human body. Remarkably, experimental insights from the latter part of the previous century involving extracellular injection of mitochondrial DNA (mtDNA) elucidated its potential to incite autoimmune disorders. Consequently, in instances of liver injury, the substantial release of mtDNA has the potential to trigger the activation of the innate immune response, thereby inducing sustained pathogenic consequences within the organism. This article provides a comprehensive retrospective analysis of recent literature pertaining to the impact of mtDNA release on various hepatic cell populations, elucidating its role and potential mechanisms in liver injury. The findings underscore the central role of mtDNA in modulating the immune system, primarily through the orchestration of a cytokine storm, further exacerbating the occurrence of liver injury.
Collapse
Affiliation(s)
- Yunkai Xu
- School of Public Health, Anhui Medical University, Hefei, Anhui, China; The First School of Clinical Medicine, Anhui Medical University, Hefei, Anhui, China
| | - Chenshuang Chu
- The First School of Clinical Medicine, Anhui Medical University, Hefei, Anhui, China
| | - Ziyang Shi
- The First School of Clinical Medicine, Anhui Medical University, Hefei, Anhui, China
| | - Jiaxiang Zhang
- School of Public Health, Anhui Medical University, Hefei, Anhui, China.
| |
Collapse
|
2
|
Zhao Y, Yin L, Dong F, Zhang W, Hu F. Effects of tris (2-chloroethyl) phosphate (TCEP) on survival, growth, histological changes and gene expressions in juvenile yellow catfish Pelteobagrus fulvidraco. Environ Toxicol Pharmacol 2021; 87:103699. [PMID: 34237467 DOI: 10.1016/j.etap.2021.103699] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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: 05/22/2021] [Revised: 06/18/2021] [Accepted: 07/04/2021] [Indexed: 06/13/2023]
Abstract
Tris (2-chloroethyl) phosphate (TCEP) is an emerging aquatic environmental pollutant. In the present study, juvenile yellow catfish (Pelteobagrus fulvidraco) were exposed to environmentally relevant concentrations of TCEP for 30 days. The results showed that TCEP exposure decreased the survival rate (100 μg/L), body weight (10 and 100 μg/L) and specific growth rate (10 and 100 μg/L) of juvenile yellow catfish. Exposure to TCEP resulted in pronounced damages of gill structures. Gene transcription analysis showed that the antioxidant capacity of the liver and gills was affected; CYP1A1 might contribute to phase I metabolism of TCEP in the liver rather than CYP1B1; TCEP stress might increase the demand of ion transport in fish gill; TCEP could stimulate the immune response and might induce apoptosis via a p53-Bax pathway and caspase-dependent pathway in gills. Collectively, these findings provide new insights into the toxic effects of TCEP on fish.
Collapse
Affiliation(s)
- Yixin Zhao
- Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Li Yin
- Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Feilong Dong
- Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Weini Zhang
- Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Fengxiao Hu
- Key Laboratory of Marine Biotechnology of Fujian Province, Institute of Oceanology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| |
Collapse
|
3
|
Abstract
In 1999 V. P. Skulachev proposed the term "mitoptosis" to refer to the programmed elimination of mitochondria in living cells. According to the initial thought, mitoptosis serves to protect cells from malfunctioning of the damaged mitochondria. At the same time, a new mechanism of the complete mitochondria elimination was found under the conditions of massive mitochondrial damage associated with oxidative stress. In this experimental model, mitochondrial cluster formation in the perinuclear region leads to the formation of "mitoptotic body" surrounded by a single-layer membrane and subsequent release of mitochondria from the cell. Later, it was found that mitoptosis plays an important role in various normal and pathological processes that are not necessarily associated with the mitochondrial damage. It was found that mitoptosis takes place during cell differentiation, self-maintenance of hematopoietic stem cells, metabolic remodelling, and elimination of the paternal mitochondria in organisms with the maternal inheritance of the mitochondrial DNA. Moreover, the associated with mitoptosis release of mitochondrial components into the blood may be involved in the transmission of signals between cells, but also leads to the development of inflammatory and autoimmune diseases. Mitoptosis can be attributed to the asymmetric inheritance of mitochondria in the division of yeast and some animal cells, when the defective mitochondria are transferred to one of the newly formed cells. Finally, a specific form of mitoptosis appears to be selective elimination of mitochondria with deleterious mutations in whole follicular ovarian cells in mammals. During formation of the primary follicle, the mitochondrial DNA copy number is significantly reduced. After division, the cells that receive predominantly mitochondria with deleterious mutations in their mtDNA die, thereby reducing the likelihood of transmission of these mutations to offspring. Further study of the mechanisms of mitoptosis in normal and pathological conditions is important both for understanding the processes of development and aging, and for designing therapeutic approaches for inflammatory, neurodegenerative and other diseases.
Collapse
Affiliation(s)
- K G Lyamzaev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - D A Knorre
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.,Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, 119991, Russia
| | - B V Chernyak
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
| |
Collapse
|
4
|
Abstract
Mitochondria are cellular organelles that orchestrate a vast range of biological processes, from energy production and metabolism to cell death and inflammation. Despite this seemingly symbiotic relationship, mitochondria harbour within them a potent agonist of innate immunity: their own genome. Release of mitochondrial DNA into the cytoplasm and out into the extracellular milieu activates a plethora of different pattern recognition receptors and innate immune responses, including cGAS‐STING, TLR9 and inflammasome formation leading to, among others, robust type I interferon responses. In this Review, we discuss how mtDNA can be released from the mitochondria, the various inflammatory pathways triggered by mtDNA release and its myriad biological consequences for health and disease.
Collapse
Affiliation(s)
- Joel S Riley
- Cancer Research UK Beatson Institute, Glasgow, UK.,Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Stephen Wg Tait
- Cancer Research UK Beatson Institute, Glasgow, UK.,Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| |
Collapse
|
5
|
Anwar F, Khan R, Sachan R, Kazmi I, Rawat A, Sabih A, Singh R, Afzal M, Ahmad A, Al-Orab AS, Al-Abbasi FA, Bhatt PC, Kumar V. Therapeutic role of calcium and vitamin K3 in chemically induced hepatocarcinogenesis - new tools for cancer treatment. Arch Physiol Biochem 2019; 125:270-275. [PMID: 29663832 DOI: 10.1080/13813455.2018.1455708] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
HCC has been reported to be immensely occurring carcinoma worldwide. Recent days the mortality occurred due to liver cancer has also been found to be increased at an alarming speed affecting mostly the young patients. The aim of the current study was to decipher the role of calcium and vitamin K3 in the treatment of chemically induced hepatocarcinogenesis in the male Wistar rats. Liver cancer was induced via a subnecrogenic dose of 160 mg/kg body weight, diethylnitrosamine (DENA) when associated with fasting/refeeding in male Wistar rats. It elevated the serum glutamate oxaloacetate (SGOT), serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), bilirubin, total cholesterol (CH), triglycerides (TG), alfa-fetoprotein (AFP) and reduced high-density lipoprotein (HDL). Histopathological examination of liver tissue showed marked carcinogenicity of the chemical carcinogen. Food, water intake and animal weights were also assessed, respectively. The animals exposed to DENA showed a significant decrease in the body weight. The elevated levels of serum SGOT, SGPT, ALP, AFP, TC and TG were restored by administration of calcium and Vit K (ad libitum) combination at higher dose than the normal dietary requirement (3 mg/kg) daily for 12 weeks p.o. Physiological and biochemical analysis showed the beneficial effects of calcium and vitamin K3 combination in the animals exposed to DENA. The results deciphered the beneficial effects of calcium and vitamin K3 in combination.
Collapse
Affiliation(s)
- Firoz Anwar
- a Department of Biochemistry , Faculty of Science, King Abdulaziz University , Jeddah , Saudi Arabia
| | - Ruqaiyah Khan
- b Siddhartha Institute of Pharmacy , Dehradun , India
| | - Richa Sachan
- c School of Pharmacy, Sungkyunkwan University , Republic of Korea
| | - Imran Kazmi
- d Glocal School of Pharmacy, Glocal University , Saharanpur , Uttar Pradesh, India
| | - Alisha Rawat
- b Siddhartha Institute of Pharmacy , Dehradun , India
| | | | - Rajbala Singh
- b Siddhartha Institute of Pharmacy , Dehradun , India
| | - Muhammad Afzal
- e Department of Pharmacology , Jouf University , Sakaka , Kingdom of Saudi Arabia
| | - Aftab Ahmad
- a Department of Biochemistry , Faculty of Science, King Abdulaziz University , Jeddah , Saudi Arabia
| | - Abdulaziz S Al-Orab
- a Department of Biochemistry , Faculty of Science, King Abdulaziz University , Jeddah , Saudi Arabia
| | - F A Al-Abbasi
- a Department of Biochemistry , Faculty of Science, King Abdulaziz University , Jeddah , Saudi Arabia
| | - Prakash Chandra Bhatt
- f Centre for Advanced Research in Pharmaceutical Sciences, Microbial and Pharmaceutical Biotechnology Laboratory, Faculty of Pharmacy , JamiaHamdard , New Delhi, India
| | - Vikas Kumar
- g Natural Product Drug Discovery Laboratory, Department of Pharmaceutical Sciences, Shalom Institute of Health & Allied Sciences , Sam Higginbottom University of Agriculture, Technology & Sciences (SHUATS) , Allahabad , Uttar Pradesh, India
| |
Collapse
|
6
|
Abstract
Excess oral iron in the intestinal tract usually produces reactive oxygen species via Fenton and Haber-Weiss reaction, so oxidative stress is triggered. Lipid peroxidation procedurally appears, ferroptosis, apoptosis and necrosis are often induced, subsequently, mitochondrial damage, endoplasmic reticulum dysfunction and even cell death occur. As a result, the intestinal epithelial cells are destroyed, leading to the incompleteness of intestinal mechanical barrier. Simultaneously, iron supplement can change the compositions and metabolic processes of intestinal microbes, and the intestinal inflammatory may be worsened. In principle, the easier dissociation of Fe2+ from oral iron supplements is, the more serious intestinal inflammation will occur. Fortunately, some interventions have been developed to alleviate these side effects. For instance, some antioxidants e.g. VE and ferulic acid have been used to prevent the formation of free radicals or to neutralize the formed free radicals. Furthermore, some new iron supplements with the ability of slow-releasing Fe2+, e.g. ferrous citrate liposome and EDTA iron sodium, have been successfully prepared. In order to recover the intestinal micro-ecological balance, probiotics and prebiotics, bacterial consortium transplantation, and fecal microbiota transplantation have been developed. This study is meaningful for us to develop safer oral iron supplements and to maintain intestinal micro-ecological health.
Collapse
Affiliation(s)
- Xiao Qi
- College of Food Science and Technology, Northwest University, Xi'an, Shaanxi, China.,School of Chemical Engineering, Northwest University, Xi'an, Shaanxi, China
| | - Yuanxiao Zhang
- School of Chemical Engineering, Northwest University, Xi'an, Shaanxi, China
| | - Hang Guo
- School of Chemical Engineering, Northwest University, Xi'an, Shaanxi, China
| | - Yu Hai
- College of Food Science and Technology, Northwest University, Xi'an, Shaanxi, China
| | - Yane Luo
- College of Food Science and Technology, Northwest University, Xi'an, Shaanxi, China
| | - Tianli Yue
- College of Food Science and Technology, Northwest University, Xi'an, Shaanxi, China.,Ministry of Agriculture, Laboratory of Quality and Safety Risk Assessment for Agro-products (Yangling), Beijing, China
| |
Collapse
|
7
|
Riley JS, Quarato G, Cloix C, Lopez J, O'Prey J, Pearson M, Chapman J, Sesaki H, Carlin LM, Passos JF, Wheeler AP, Oberst A, Ryan KM, Tait SW. Mitochondrial inner membrane permeabilisation enables mtDNA release during apoptosis. EMBO J 2018; 37:e99238. [PMID: 30049712 PMCID: PMC6120664 DOI: 10.15252/embj.201899238] [Citation(s) in RCA: 280] [Impact Index Per Article: 46.7] [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: 02/19/2017] [Revised: 06/11/2018] [Accepted: 06/18/2018] [Indexed: 12/16/2022] Open
Abstract
During apoptosis, pro-apoptotic BAX and BAK are activated, causing mitochondrial outer membrane permeabilisation (MOMP), caspase activation and cell death. However, even in the absence of caspase activity, cells usually die following MOMP Such caspase-independent cell death is accompanied by inflammation that requires mitochondrial DNA (mtDNA) activation of cGAS-STING signalling. Because the mitochondrial inner membrane is thought to remain intact during apoptosis, we sought to address how matrix mtDNA could activate the cytosolic cGAS-STING signalling pathway. Using super-resolution imaging, we show that mtDNA is efficiently released from mitochondria following MOMP In a temporal manner, we find that following MOMP, BAX/BAK-mediated mitochondrial outer membrane pores gradually widen. This allows extrusion of the mitochondrial inner membrane into the cytosol whereupon it permeablises allowing mtDNA release. Our data demonstrate that mitochondrial inner membrane permeabilisation (MIMP) can occur during cell death following BAX/BAK-dependent MOMP Importantly, by enabling the cytosolic release of mtDNA, inner membrane permeabilisation underpins the immunogenic effects of caspase-independent cell death.
Collapse
Affiliation(s)
- Joel S Riley
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Giovanni Quarato
- Department of Immunology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Catherine Cloix
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Jonathan Lopez
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Jim O'Prey
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Matthew Pearson
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, UK
| | - James Chapman
- Ageing Research Laboratories, Newcastle University Institute for Ageing, LLHW Centre for Ageing and Vitality, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK
| | - Hiromi Sesaki
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Leo M Carlin
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - João F Passos
- Ageing Research Laboratories, Newcastle University Institute for Ageing, LLHW Centre for Ageing and Vitality, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Ann P Wheeler
- MRC Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine, The University of Edinburgh, Edinburgh, UK
| | - Andrew Oberst
- Department of Immunology, University of Washington, Seattle, WA, USA
- Center for Innate Immunity and Immune Disease, University of Washington, Seattle, WA, USA
| | - Kevin M Ryan
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Stephen Wg Tait
- Cancer Research UK Beatson Institute, Glasgow, UK
- Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| |
Collapse
|
8
|
Shi D, Zhou J, Zhao L, Rong X, Fan Y, Hamid H, Li W, Ji C, Ma Q. Alleviation of mycotoxin biodegradation agent on zearalenone and deoxynivalenol toxicosis in immature gilts. J Anim Sci Biotechnol 2018; 9:42. [PMID: 29796255 PMCID: PMC5956560 DOI: 10.1186/s40104-018-0255-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 04/17/2018] [Indexed: 11/21/2022] Open
Abstract
Background The current study was carried out to evaluate the effects of mycotoxin biodegradation agent (MBA, composed of Bacillus subtilis ANSB01G and Devosia sp. ANSB714) on relieving zearalenone (ZEA) and deoxynivalenol (DON) toxicosis in immature gilts. Methods A total of forty pre-pubertal female gilts (61.42 ± 1.18 kg) were randomly allocated to four diet treatments: CO (positive control); MO (negative control, ZEA 596.86 μg/kg feed and DON 796 μg/kg feed); COA (CO + 2 g MBA/kg feed); MOA (MO + 2 g MBA/kg feed). Each treatment contained 10 replicates with 1 gilt per replicate. Gilts were housed in an environmentally controlled room with the partially slatted floor. Results During the entire experimental period of 28 d, average daily gain (ADG) and average daily feed intake (ADFI) of gilts in MO group was significantly reduced compared with those in CO group. The vulva size of gilts was significantly higher in MO group than CO group. In addition, significant increases in the plasma levels of IgA, IgG, IL-8, IL-10 and PRL were determined in MO group compared with that in CO group. ZEA and DON in the diet up-regulated apoptotic caspase-3 in ovaries and uteri, along with down-regulated the anti-apoptotic protein Bcl-2 in ovaries. The supplementation of MBA into diets co-contaminated with ZEA and DON significantly increased ADG, decreased the vulva sizes, reduced the levels of IgG, IL-8 and PRL in plasma, and regulated apoptosis in ovaries and uteri of gilts. Conclusions The present results indicated that feeding diet contaminated with ZEA and DON simultaneously (596.86 μg/kg + 796 μg/kg) had detrimental effects on growth performance, plasma immune function and reproductive status of gilts. And MBA could reduce the negative impacts of these two toxins, believed as a promising feed additive for mitigating toxicosis of ZEA and DON at low levels in gilts.
Collapse
Affiliation(s)
- Donghui Shi
- 1State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 People's Republic of China.,2Liaoning Medical University, Jinzhou, 121001 People's Republic of China
| | - Jianchuan Zhou
- 1State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 People's Republic of China.,Fuqing Fengze Agricultural Science and Technology Development Co. Ltd., Fuzhou, 350011 People's Republic of China
| | - Lihong Zhao
- 1State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 People's Republic of China
| | - Xiaoping Rong
- 1State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 People's Republic of China
| | - Yu Fan
- 1State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 People's Republic of China.,State Key Laboratory of Direct-Fed Microbial Engineering, Beijing, 100193 People's Republic of China
| | - Humera Hamid
- 1State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 People's Republic of China
| | - Wenqiang Li
- 1State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 People's Republic of China.,2Liaoning Medical University, Jinzhou, 121001 People's Republic of China
| | - Cheng Ji
- 1State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 People's Republic of China
| | - Qiugang Ma
- 1State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, 100193 People's Republic of China
| |
Collapse
|
9
|
Ji S, Lee JY, Schrör J, Mazumder A, Jang DM, Chateauvieux S, Schnekenburger M, Hong CR, Christov C, Kang HJ, Lee Y, Han BW, Kim KW, Shin HY, Dicato M, Cerella C, König GM, Orlikova B, Diederich M. The dialkyl resorcinol stemphol disrupts calcium homeostasis to trigger programmed immunogenic necrosis in cancer. Cancer Lett 2018; 416:109-123. [DOI: 10.1016/j.canlet.2017.12.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 12/06/2017] [Accepted: 12/07/2017] [Indexed: 01/18/2023]
|
10
|
Chen Y, Chen S, Liang H, Yang H, Liu L, Zhou K, Xu L, Liu J, Yun L, Lai B, Song L, Luo H, Peng J, Liu Z, Xiao Y, Chen W, Tang H. Bcl-2 protects TK6 cells against hydroquinone-induced apoptosis through PARP-1 cytoplasm translocation and stabilizing mitochondrial membrane potential. Environ Mol Mutagen 2018; 59:49-59. [PMID: 28843007 DOI: 10.1002/em.22126] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 03/21/2017] [Revised: 07/25/2017] [Accepted: 07/26/2017] [Indexed: 06/07/2023]
Abstract
B cell leukemia/lymphoma-2 (Bcl-2) suppresses apoptosis by binding the BH3 domain of proapoptotic factors and thereby regulating mitochondrial membrane potential (MMP). This study aimed to investigate the role of Bcl-2 in controlling the mitochondrial pathway of apoptosis during hydroquinone (HQ)-induced TK6 cytotoxicity. In this study, HQ, one metabolite of benzene, decreased the MMP in a concentration-dependent manner and induced the generation of reactive oxygen species (ROS), the activation of the DNA damage marker γ-H2AX, and production of the DNA damage-responsive enzyme poly(ADP-ribose)polymerase-1 (PARP-1). Exposure of TK6 cells to HQ leads to an increase in Bcl-2 and co-localization with PARP-1 in the cytoplasm. Inhibition of Bcl-2 using the BH3 mimetic, ABT-737, suppressed the PARP-1 nuclear to cytoplasm translocation and sensitized TK6 cells to HQ-induced apoptosis through depolarization of the MMP. Western blot analysis indicated that ABT-737 combined with HQ increased the levels of cleaved PARP and γ-H2AX, but significantly decreased the level of P53. Thus, ABT-737 can influence PARP-1 translocation and induce apoptosis via mitochondria-mediated apoptotic pathway, independently of P53. In addition, we found that knockdown of PARP-1 attenuated the HQ-induced production of cleaved PARP and P53. These results identify Bcl-2 as a protective mediator of HQ-induced apoptosis and show that upregulation of Bcl-2 helps to localize PARP-1 to the cytoplasm and stabilize MMP. Environ. Mol. Mutagen. 59:49-59, 2018. © 2017 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Yuting Chen
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Shaoyun Chen
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Hairong Liang
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Hui Yang
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Linhua Liu
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Kairu Zhou
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Longmei Xu
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Jiaxian Liu
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Lin Yun
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Bei Lai
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Li Song
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Hao Luo
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| | - Jianming Peng
- Huizhou Prevention and Treatment Centre for Occupational Disease, Huizhou, 516000, China
| | - Zhidong Liu
- Huizhou Prevention and Treatment Centre for Occupational Disease, Huizhou, 516000, China
| | - Yongmei Xiao
- Guangzhou Key Laboratory of Environmental Pollution and Health Risk Assessment, Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Wen Chen
- Guangzhou Key Laboratory of Environmental Pollution and Health Risk Assessment, Department of Toxicology, School of Public Health, Sun Yat-sen University, Guangzhou, 510080, China
| | - Huanwen Tang
- Department of Environmental and Occupational Health, Dongguan Key Laboratory of Environmental Medicine, School of Public Health, Guangdong Medical University, Dongguan, 523808, China
| |
Collapse
|
11
|
Jeena MT, Palanikumar L, Go EM, Kim I, Kang MG, Lee S, Park S, Choi H, Kim C, Jin SM, Bae SC, Rhee HW, Lee E, Kwak SK, Ryu JH. Mitochondria localization induced self-assembly of peptide amphiphiles for cellular dysfunction. Nat Commun 2017. [PMID: 28638095 PMCID: PMC5479829 DOI: 10.1038/s41467-017-00047-z] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Achieving spatiotemporal control of molecular self-assembly associated with actuation of biological functions inside living cells remains a challenge owing to the complexity of the cellular environments and the lack of characterization tools. We present, for the first time, the organelle-localized self-assembly of a peptide amphiphile as a powerful strategy for controlling cellular fate. A phenylalanine dipeptide (FF) with a mitochondria-targeting moiety, triphenyl phosphonium (Mito-FF), preferentially accumulates inside mitochondria and reaches the critical aggregation concentration to form a fibrous nanostructure, which is monitored by confocal laser scanning microscopy and transmission electron microscopy. The Mito-FF fibrils induce mitochondrial dysfunction via membrane disruption to cause apoptosis. The organelle-specific supramolecular system provides a new opportunity for therapeutics and in-depth investigations of cellular functions.Spatiotemporal control of intracellular molecular self-assembly holds promise for therapeutic applications. Here the authors develop a peptide consisting of a phenylalanine dipeptide with a mitochondrial targeting moiety to form self-assembling fibrous nanostructures within mitochondria, leading to apoptosis.
Collapse
Affiliation(s)
- M T Jeena
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - L Palanikumar
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Eun Min Go
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Inhye Kim
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Myoung Gyun Kang
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Seonik Lee
- Department of Biological Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Sooham Park
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Huyeon Choi
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Chaekyu Kim
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Seon-Mi Jin
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea
| | - Sung Chul Bae
- Department of Biological Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Hyun Woo Rhee
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea
| | - Eunji Lee
- Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea.
| | - Sang Kyu Kwak
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
| | - Ja-Hyoung Ryu
- Department of Chemistry, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
| |
Collapse
|
12
|
Zhao H, Liu YJ, Liu ZR, Tang DD, Chen XW, Chen YH, Zhou RN, Chen SQ, Niu HX. Role of mitochondrial dysfunction in renal fibrosis promoted by hypochlorite-modified albumin in a remnant kidney model and protective effects of antioxidant peptide SS-31. Eur J Pharmacol 2017; 804:57-67. [PMID: 28322835 DOI: 10.1016/j.ejphar.2017.03.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/13/2017] [Accepted: 03/16/2017] [Indexed: 12/22/2022]
Abstract
Oxidative stress aggravates renal fibrosis, a pathway involved in almost all forms of chronic kidney disease (CKD). However, the underlying mechanism involved in the pathogenesis of renal oxidative stress has not been completely elucidated. In this study, we explored the role and mechanism of hypochlorite-modified albumin (HOCl-alb) in mediating oxidative stress and fibrotic response in a remnant-kidney rat model. Five-sixths nephrectomy (5/6 NX) was performed on the rats and then the animals were randomly assigned to intravenous treatment with either vehicle alone, or HOCl-rat serum albumin (RSA) in the presence or absence of SS-31 (administered intraperitoneally). A sham-operation control group was set up concurrently. Compared with the control group, 5/6 NX animals displayed marked mitochondrial (mt) dysfunction, as evidenced by decrease of mitochondrial membrane potential (MMP), ATP production, mtDNA copy number alterations and manganese superoxide dismutase (MnSOD) activity, release of cytochrome C (Cyto C) from mitochondria to the cytoplasm, and increase of mitochondrial reactive oxygen species in renal tissues. They also displayed increased levels of HOCl-alb in both plasma and renal tissues. These changes were accompanied by accumulation of extracellular matrix, worsened proteinuria, deteriorated renal function, and a marked increase of macrophage infiltration along with up-regulation of monocyte chemoattractant protein (MCP)-1 and transforming growth factor (TGF)-β1 expression. HOCl-alb challenge further exacerbated the above biological effects in 5/6 NX animals, but these adverse effects were prevented by administration of SS-31, a mitochondrial targeted antioxidant peptide. These data suggest that accumulation of HOCl-alb may promote renal inflammation and fibrosis, probably related to mitochondrial oxidative stress and dysfunction and that the mitochondrial targeted peptide SS-31 might be a novel therapy for renal fibrosis and chronic renal failure (CRF).
Collapse
Affiliation(s)
- Hao Zhao
- Division of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Yan-Jun Liu
- Department of Immunology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515,China
| | - Zong-Rui Liu
- Division of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Division of Nephrology, Taian City Central Hospital, Taian 271000, China
| | - Dong-Dong Tang
- Division of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China; Division of Nephrology, Huadu District people's Hospital, Southern Medical University, Guangzhou 510800, China
| | - Xiao-Wen Chen
- Division of Nephrology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Yi-Hua Chen
- Division of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Ru-Ning Zhou
- Southern Medical University, Guangzhou 510515, China
| | - Si-Qi Chen
- Division of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
| | - Hong-Xin Niu
- Division of Nephrology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
| |
Collapse
|
13
|
Dagistan Y, Cukur S, Dagistan E, Gezici AR. Role of Expression of Inflammatory Mediators in Primary and Recurrent Lumbar Disc Herniation. J Korean Neurosurg Soc 2016; 60:40-46. [PMID: 28061491 PMCID: PMC5223765 DOI: 10.3340/jkns.2015.0911.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 06/08/2016] [Accepted: 06/21/2016] [Indexed: 01/22/2023] Open
Abstract
Objective To assess role of some inflammatory mediators in patients with primary and recurrent lumbar disc herniation. Expression of IL-6, transforming growth factor (TGF)-1, insulin-like growth factor (IGF)-1, and Bcl-2-associated X protein (BAX) have been shown to be more intense in the primary group than the recurrent goup, but this mediators may be important aspects prognostic. Methods 19 patients underwent primary and revision operations between June 1, 2009 and June 1, 2014, and they were included in this study. The 19 patients’ intervertebral disc specimens obtained from the primary procedures and reoperations were evaluated. Expression of IL-6, TGF-1, IGF-1, and BAX were examined immunohistochemically in the 38 biopsy tissues obtained from the primary and recurrent herniated intervertebral discs during the operation. Results For IL-6 expression in the intervertebral disc specimens, there was no difference between the groups. The immunohistochemical study showed that the intervertebral disc specimens in the primary group were stained intensely by TGF-1 compared with the recurrent group. Expression of IGF-1 in the primary group was found moderate. In contrast, in the recurrent group of patients was mild expression of IGF-1. The primary group intervertebral disc specimens were stained moderately by BAX compared with the recurrent group. Conclusion The results of our prognostic evaluation of patients in the recurrent group who were operated due to disc herniation suggest that mediators may be important parameters.
Collapse
Affiliation(s)
- Yasar Dagistan
- Department of Neurosurgery, Abant Izzet Baysal University Medical School, Izzet Baysal Training and Research Hospital, Bolu, Turkey
| | - Selma Cukur
- Department of Pathology, Abant Izzet Baysal University Medical School, Izzet Baysal Training and Research Hospital, Bolu, Turkey
| | - Emine Dagistan
- Department of Radiology, Abant Izzet Baysal University Medical School, Izzet Baysal Training and Research Hospital, Bolu, Turkey
| | - Ali Riza Gezici
- Department of Neurosurgery, Abant Izzet Baysal University Medical School, Izzet Baysal Training and Research Hospital, Bolu, Turkey
| |
Collapse
|
14
|
Abstract
As the heart is an energy-demanding organ, impaired cardiac energy metabolism and mitochondrial function have been inexorably linked to cardiac dysfunction. There is a growing recognition that mitochondrial dysfunction contributes to impaired myocardial energetics and increased oxidative stress in cardiomyopathies, cardiac ischemic damage and heart failure (HF), and mitochondrial permeability transition pore opening has been reported a critical trigger of myocyte death and myocardial remodeling. It is well established that mitochondria play pivotal roles in intracellular signaling in both cell death as well as in cardioprotective pathways. Moreover, recent studies have shown that defects in mitochondrial dynamics affecting biogenesis and turnover are linked to cardiac senescence and HF. Accordingly, there has been an increasing interest in targeting mitochondria for HF therapy. This article reviews the background and recent evidence of mitochondrial involvement in several types of cell death (apoptosis, necrosis and autophagy) occurring in HF. In addition, potential strategies for targeting mitochondria are examined, and their utility in HF therapy considered.
Collapse
|
15
|
Kuwana T, Olson NH, Kiosses WB, Peters B, Newmeyer DD. Pro-apoptotic Bax molecules densely populate the edges of membrane pores. Sci Rep 2016; 6:27299. [PMID: 27255832 DOI: 10.1038/srep27299] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 05/16/2016] [Indexed: 11/28/2022] Open
Abstract
How the pro-apoptotic Bax protein permeabilizes the mitochondrial outer membrane is not fully understood. Previously, using cryo-electron microscopy (cryo-EM), we showed that activated Bax forms large, growing pores. Whether formed in liposomes or in mitochondrial outer membranes, Bax-induced pores exhibit the same morphology, with negative curvature flanking the edges and with no visible protein structure protruding from the membranes. Here we used cryo-EM to show that gold-labeled Bax molecules, after activation by Bid, became localized strictly at pore edges. This argues that Bax acts at short range to deform the membrane. Also, Bax molecules populated the walls of both small and large pores at the same density, implying that Bax is continuously recruited to the pores as they widen. Moreover, because all Bax molecules became oligomerized after membrane insertion, we infer that Bax oligomers are present at pore edges. We suggest that oligomerization may promote pore enlargement.
Collapse
|
16
|
Hockings C, Anwari K, Ninnis RL, Brouwer J, O'Hely M, Evangelista M, Hinds MG, Czabotar PE, Lee EF, Fairlie WD, Dewson G, Kluck RM. Bid chimeras indicate that most BH3-only proteins can directly activate Bak and Bax, and show no preference for Bak versus Bax. Cell Death Dis 2015; 6:e1735. [PMID: 25906158 PMCID: PMC4650538 DOI: 10.1038/cddis.2015.105] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 03/17/2015] [Accepted: 03/17/2015] [Indexed: 01/01/2023]
Abstract
The mitochondrial pathway of apoptosis is initiated by Bcl-2 homology region 3 (BH3)-only members of the Bcl-2 protein family. On upregulation or activation, certain BH3-only proteins can directly bind and activate Bak and Bax to induce conformation change, oligomerization and pore formation in mitochondria. BH3-only proteins, with the exception of Bid, are intrinsically disordered and therefore, functional studies often utilize peptides based on just their BH3 domains. However, these reagents do not possess the hydrophobic membrane targeting domains found on the native BH3-only molecule. To generate each BH3-only protein as a recombinant protein that could efficiently target mitochondria, we developed recombinant Bid chimeras in which the BH3 domain was replaced with that of other BH3-only proteins (Bim, Puma, Noxa, Bad, Bmf, Bik and Hrk). The chimeras were stable following purification, and each immunoprecipitated with full-length Bcl-xL according to the specificity reported for the related BH3 peptide. When tested for activation of Bak and Bax in mitochondrial permeabilization assays, Bid chimeras were ~1000-fold more effective than the related BH3 peptides. BH3 sequences from Bid and Bim were the strongest activators, followed by Puma, Hrk, Bmf and Bik, while Bad and Noxa were not activators. Notably, chimeras and peptides showed no apparent preference for activating Bak or Bax. In addition, within the BH3 domain, the h0 position recently found to be important for Bax activation, was important also for Bak activation. Together, our data with full-length proteins indicate that most BH3-only proteins can directly activate both Bak and Bax.
Collapse
Affiliation(s)
- C Hockings
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - K Anwari
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - R L Ninnis
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - J Brouwer
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - M O'Hely
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - M Evangelista
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - M G Hinds
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | - P E Czabotar
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - E F Lee
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - W D Fairlie
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - G Dewson
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - R M Kluck
- 1] The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia [2] Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| |
Collapse
|
17
|
Indo HP, Yen HC, Nakanishi I, Matsumoto KI, Tamura M, Nagano Y, Matsui H, Gusev O, Cornette R, Okuda T, Minamiyama Y, Ichikawa H, Suenaga S, Oki M, Sato T, Ozawa T, Clair DKS, Majima HJ. A mitochondrial superoxide theory for oxidative stress diseases and aging. J Clin Biochem Nutr 2014; 56:1-7. [PMID: 25834301 PMCID: PMC4306659 DOI: 10.3164/jcbn.14-42] [Citation(s) in RCA: 209] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 08/08/2014] [Indexed: 11/26/2022] Open
Abstract
Fridovich identified CuZnSOD in 1969 and manganese superoxide dismutase (MnSOD) in 1973, and proposed ”the Superoxide Theory,” which postulates that superoxide (O2•−) is the origin of most reactive oxygen species (ROS) and that it undergoes a chain reaction in a cell, playing a central role in the ROS producing system. Increased oxidative stress on an organism causes damage to cells, the smallest constituent unit of an organism, which can lead to the onset of a variety of chronic diseases, such as Alzheimer’s, Parkinson’s, amyotrophic lateral sclerosis and other neurological diseases caused by abnormalities in biological defenses or increased intracellular reactive oxygen levels. Oxidative stress also plays a role in aging. Antioxidant systems, including non-enzyme low-molecular-weight antioxidants (such as, vitamins A, C and E, polyphenols, glutathione, and coenzyme Q10) and antioxidant enzymes, fight against oxidants in cells. Superoxide is considered to be a major factor in oxidant toxicity, and mitochondrial MnSOD enzymes constitute an essential defense against superoxide. Mitochondria are the major source of superoxide. The reaction of superoxide generated from mitochondria with nitric oxide is faster than SOD catalyzed reaction, and produces peroxynitrite. Thus, based on research conducted after Fridovich’s seminal studies, we now propose a modified superoxide theory; i.e., superoxide is the origin of reactive oxygen and nitrogen species (RONS) and, as such, causes various redox related diseases and aging.
Collapse
Affiliation(s)
- Hiroko P Indo
- Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8544, Japan ; Department of Space Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8544, Japan ; Graduate Center of Toxicology and Markey Cancer Center, University of Kentucky College of Medicine, Lexington, Kentucky 40506, USA
| | - Hsiu-Chuan Yen
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Kwei-Shan, Tao-Yuan 333, Taiwan
| | - Ikuo Nakanishi
- Radio-Redox-Response Research Team, Advanced Particle Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba 263-8555, Japan
| | - Ken-Ichiro Matsumoto
- Radio-Redox-Response Research Team, Advanced Particle Radiation Biology Research Program, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba 263-8555, Japan
| | - Masato Tamura
- Division of Gastroenterology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yumiko Nagano
- Division of Gastroenterology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hirofumi Matsui
- Division of Gastroenterology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Oleg Gusev
- Department of Invertebrates Zoology and Functional Morphology, Institute of Fundamental Medicine and Biology, Kazan Federal University, Kremevskaya str., 17 Kazan 420-008, Russia ; Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, ISS Science Project Office, Ibaraki 305-8505, Japan ; Anhydrobiosis Research Unit, National Institute of Agrobiological Sciences, Ohwashi 1-2, Tsukuba, Ibaraki 305-8634, Japan
| | - Richard Cornette
- Anhydrobiosis Research Unit, National Institute of Agrobiological Sciences, Ohwashi 1-2, Tsukuba, Ibaraki 305-8634, Japan
| | - Takashi Okuda
- Anhydrobiosis Research Unit, National Institute of Agrobiological Sciences, Ohwashi 1-2, Tsukuba, Ibaraki 305-8634, Japan
| | - Yukiko Minamiyama
- Food Hygiene and Environmental Health Division of Applied Life Science, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Sakyo-ku, Kyoto 606-8522, Japan
| | - Hiroshi Ichikawa
- Department of Medical Life Systems, Graduate School of Life and Medical Sciences, Doshishia University, Kyoto 610-0394, Japan
| | - Shigeaki Suenaga
- Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8544, Japan
| | - Misato Oki
- Department of Space Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8544, Japan
| | - Tsuyoshi Sato
- Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8544, Japan
| | - Toshihiko Ozawa
- Division of Oxidative Stress Research, Showa Pharmaceutical University, Machida, Tokyo 194-8543, Japan
| | - Daret K St Clair
- Graduate Center of Toxicology and Markey Cancer Center, University of Kentucky College of Medicine, Lexington, Kentucky 40506, USA
| | - Hideyuki J Majima
- Department of Oncology, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8544, Japan ; Department of Space Environmental Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8544, Japan
| |
Collapse
|
18
|
Renault TT, Floros KV, Elkholi R, Corrigan KA, Kushnareva Y, Wieder SY, Lindtner C, Serasinghe MN, Asciolla JJ, Buettner C, Newmeyer DD, Chipuk JE. Mitochondrial shape governs BAX-induced membrane permeabilization and apoptosis. Mol Cell 2014; 57:69-82. [PMID: 25482509 DOI: 10.1016/j.molcel.2014.10.028] [Citation(s) in RCA: 155] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 08/20/2014] [Accepted: 10/31/2014] [Indexed: 12/24/2022]
Abstract
Proapoptotic BCL-2 proteins converge upon the outer mitochondrial membrane (OMM) to promote mitochondrial outer membrane permeabilization (MOMP) and apoptosis. Here we investigated the mechanistic relationship between mitochondrial shape and MOMP and provide evidence that BAX requires a distinct mitochondrial size to induce MOMP. We utilized the terminal unfolded protein response pathway to systematically define proapoptotic BCL-2 protein composition after stress and then directly interrogated their requirement for a productive mitochondrial size. Complementary biochemical, cellular, in vivo, and ex vivo studies reveal that Mfn1, a GTPase involved in mitochondrial fusion, establishes a mitochondrial size that is permissive for proapoptotic BCL-2 family function. Cells with hyperfragmented mitochondria, along with size-restricted OMM model systems, fail to support BAX-dependent membrane association and permeabilization due to an inability to stabilize BAXα9·membrane interactions. This work identifies a mechanistic contribution of mitochondrial size in dictating BAX activation, MOMP, and apoptosis.
Collapse
Affiliation(s)
- Thibaud T Renault
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Konstantinos V Floros
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Rana Elkholi
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Kelly-Ann Corrigan
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Yulia Kushnareva
- Division of Immune Regulation, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA 92037, USA
| | - Shira Y Wieder
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Claudia Lindtner
- Department of Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Madhavika N Serasinghe
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - James J Asciolla
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Christoph Buettner
- The Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; Department of Medicine, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; Department of Neuroscience, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Donald D Newmeyer
- Division of Immune Regulation, La Jolla Institute for Allergy and Immunology, 9420 Athena Circle, La Jolla, CA 92037, USA
| | - Jerry E Chipuk
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA; Department of Dermatology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA.
| |
Collapse
|
19
|
McManus MJ, Murphy MP, Franklin JL. Mitochondria-derived reactive oxygen species mediate caspase-dependent and -independent neuronal deaths. Mol Cell Neurosci 2014; 63:13-23. [PMID: 25239010 DOI: 10.1016/j.mcn.2014.09.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/03/2014] [Accepted: 09/12/2014] [Indexed: 01/04/2023] Open
Abstract
Mitochondrial dysfunction and oxidative stress are implicated in many neurodegenerative diseases. Mitochondria-targeted drugs that effectively decrease oxidative stress, protect mitochondrial energetics, and prevent neuronal loss may therefore lend therapeutic benefit to these currently incurable diseases. To investigate the efficacy of such drugs, we examined the effects of mitochondria-targeted antioxidants MitoQ10 and MitoE2 on neuronal death induced by neurotrophin deficiency. Our results indicate that MitoQ10 blocked apoptosis by preventing increased mitochondria-derived reactive oxygen species (ROS) and subsequent cytochrome c release, caspase activation, and mitochondrial damage in nerve growth factor (NGF)-deprived sympathetic neurons, while MitoE2 was largely ineffective. In this paradigm, the most proximal point of divergence was the ability of MitoQ10 to scavenge mitochondrial superoxide (O2(-)). MitoQ10 also prevented caspase-independent neuronal death in these cells demonstrating that the mitochondrial redox state significantly influences both apoptotic and nonapoptotic pathways leading to neuronal death. We suggest that mitochondria-targeted antioxidants may provide tools for delineating the role and significance of mitochondrial ROS in neuronal death and provide a new therapeutic approach for neurodegenerative conditions involving trophic factor deficits and multiple modes of cell death.
Collapse
|
20
|
Renault TT, Elkholi R, Bharti A, Chipuk JE. B cell lymphoma-2 (BCL-2) homology domain 3 (BH3) mimetics demonstrate differential activities dependent upon the functional repertoire of pro- and anti-apoptotic BCL-2 family proteins. J Biol Chem 2014; 289:26481-26491. [PMID: 25096574 DOI: 10.1074/jbc.m114.569632] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The B cell lymphoma-2 (BCL-2) family is the key mediator of cellular sensitivity to apoptosis during pharmacological interventions for numerous human pathologies, including cancer. There is tremendous interest to understand how the proapoptotic BCL-2 effector members (e.g. BCL-2-associated X protein, BAX) cooperate with the BCL-2 homology domain only (BH3-only) subclass (e.g. BCL-2 interacting mediator of death, BIM; BCL-2 interacting-domain death agonist, BID) to induce mitochondrial outer membrane permeabilization (MOMP) and apoptosis and whether these mechanisms may be pharmacologically exploited to enhance the killing of cancer cells. Indeed, small molecule inhibitors of the anti-apoptotic BCL-2 family members have been designed rationally. However, the success of these "BH3 mimetics" in the clinic has been limited, likely due to an incomplete understanding of how these drugs function in the presence of multiple BCL-2 family members. To increase our mechanistic understanding of how BH3 mimetics cooperate with multiple BCL-2 family members in vitro, we directly compared the activity of several BH3-mimetic compounds (i.e. ABT-263, ABT-737, GX15-070, HA14.1, TW-37) in biochemically defined large unilamellar vesicle model systems that faithfully recapitulate BAX-dependent mitochondrial outer membrane permeabilization. Our investigations revealed that the presence of BAX, BID, and BIM differentially regulated the ability of BH3 mimetics to derepress proapoptotic molecules from anti-apoptotic proteins. Using mitochondria loaded with fluorescent BH3 peptides and cells treated with inducers of cell death, these differences were supported. Together, these data suggest that although the presence of anti-apoptotic BCL-2 proteins primarily dictates cellular sensitivity to BH3 mimetics, additional specificity is conferred by proapoptotic BCL-2 proteins.
Collapse
Affiliation(s)
- Thibaud T Renault
- Departments of Oncological Sciences and Icahn School of Medicine at Mount Sinai, New York, New York 10029; Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Rana Elkholi
- Departments of Oncological Sciences and Icahn School of Medicine at Mount Sinai, New York, New York 10029; Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029; Graduate School of Biomedical Sciences, and Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Archana Bharti
- Departments of Oncological Sciences and Icahn School of Medicine at Mount Sinai, New York, New York 10029; Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029
| | - Jerry E Chipuk
- Departments of Oncological Sciences and Icahn School of Medicine at Mount Sinai, New York, New York 10029; Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029; Graduate School of Biomedical Sciences, and Icahn School of Medicine at Mount Sinai, New York, New York 10029; Departments of Dermatology, Icahn School of Medicine at Mount Sinai, New York, New York 10029; Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, New York 10029.
| |
Collapse
|
21
|
Abstract
The field of mitochondrial ion channels has recently seen substantial progress, including the molecular identification of some of the channels. An integrative approach using genetics, electrophysiology, pharmacology, and cell biology to clarify the roles of these channels has thus become possible. It is by now clear that many of these channels are important for energy supply by the mitochondria and have a major impact on the fate of the entire cell as well. The purpose of this review is to provide an up-to-date overview of the electrophysiological properties, molecular identity, and pathophysiological functions of the mitochondrial ion channels studied so far and to highlight possible therapeutic perspectives based on current information.
Collapse
|
22
|
Stewart SE, Kondos SC, Matthews AY, D'Angelo ME, Dunstone MA, Whisstock JC, Trapani JA, Bird PI. The perforin pore facilitates the delivery of cationic cargos. J Biol Chem 2014; 289:9172-81. [PMID: 24558045 DOI: 10.1074/jbc.m113.544890] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cytotoxic lymphocytes eliminate virally infected or neoplastic cells through the action of cytotoxic proteases (granzymes). The pore-forming protein perforin is essential for delivery of granzymes into the cytoplasm of target cells; however the mechanism of this delivery is incompletely understood. Perforin contains a membrane attack complex/perforin (MACPF) domain and oligomerizes to form an aqueous pore in the plasma membrane; therefore the simplest (and best supported) model suggests that granzymes passively diffuse through the perforin pore into the cytoplasm of the target cell. Here we demonstrate that perforin preferentially delivers cationic molecules while anionic and neutral cargoes are delivered inefficiently. Furthermore, another distantly related pore-forming MACPF protein, pleurotolysin (from the oyster mushroom), also favors the delivery of cationic molecules, and efficiently delivers human granzyme B. We propose that this facilitated diffusion is due to conserved features of oligomerized MACPF proteins, which may include an anionic lumen.
Collapse
|
23
|
Ye R, Yang Q, Kong X, Li N, Zhang Y, Han J, Xiong L, Liu X, Zhao G. Sevoflurane preconditioning improves mitochondrial function and long-term neurologic sequelae after transient cerebral ischemia: role of mitochondrial permeability transition. Crit Care Med 2012; 40:2685-93. [PMID: 22732280 DOI: 10.1097/CCM.0b013e318258fb90] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
OBJECTIVE Anesthetic preconditioning appears to be a viable strategy to treat ischemic cerebral injury. Here we investigated 1) whether the protection conferred by sevoflurane preconditioning sustains in time; 2) whether sevoflurane preconditioning diminishes mitochondrial dysfunction following cerebral ischemia; and 3) whether mitochondrial permeability transition pore plays a crucial role in the sevoflurane preconditioning. DESIGN Laboratory investigation. SETTING University research laboratory. SUBJECTS : Sprague-Dawley rats. INTERVENTIONS Rats underwent 2 hrs of focal cerebral ischemia induced by middle cerebral artery occlusion. Preconditioning was elicited with sevoflurane (2.3%) for 60 mins at 24 hrs before ischemia. The involvement of mitochondrial permeability transition pore was determined with a mitochondrial permeability transition pore opener atractyloside and a specific mitochondrial permeability transition pore inhibitor cyclosporin A. In vitro study was performed on acutely isolated mitochondria subjected to calcium overload. MEASUREMENTS AND MAIN RESULTS Sevoflurane preconditioning significantly decreased the infarct size by 35.9% (95% confidence interval 6.5-28.4, p < .001). This reduction of injury volume was associated with a long-term improvement of neurological function according to modified neurological severity score (F = 13.6, p = .001) and sticky-tape test (F = 29.1, p < .001) for 42 days after ischemia. Furthermore, sevoflurane preconditioning markedly protected mitochondria, as indicated by preserved respiratory chain complex activities and membrane potential, lowered mitochondrial hydrogen-peroxide production, and attenuated mitochondrial permeability transition pore opening. Isolated mitochondria also demonstrated a reduced sensitivity to Ca-induced mitochondrial permeability transition pore opening after pre-exposure to sevoflurane in vitro (95% confidence interval 24.2-196.5,p = .006). Inhibiting mitochondrial permeability transition pore using cyclosporin A resulted in protective effects similar to those seen with sevoflurane preconditioning, whereas pharmacologically opening the mitochondrial permeability transition pore with atractyloside abrogated all the positive effects of sevoflurane preconditioning and cyclosporin A, including suppression of mitochondrial permeability transition pore opening, counteraction of mitochondria-dependent apoptotic pathway, and subsequent histological and behavioral improvements. CONCLUSIONS Sevoflurane preconditioning protects mitochondria from cerebral ischemia/reperfusion injury and ameliorates long-term neurological deficits. Inhibition of mitochondrial permeability transition pore opening is a crucial step in mediating the neuroprotection of sevoflurane preconditioning.
Collapse
|
24
|
Kushnareva Y, Andreyev AY, Kuwana T, Newmeyer DD. Bax activation initiates the assembly of a multimeric catalyst that facilitates Bax pore formation in mitochondrial outer membranes. PLoS Biol 2012; 10:e1001394. [PMID: 23049480 DOI: 10.1371/journal.pbio.1001394] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 08/15/2012] [Indexed: 11/19/2022] Open
Abstract
Bax/Bak-mediated mitochondrial outer membrane permeabilization (MOMP) is essential for "intrinsic" apoptotic cell death. Published studies used synthetic liposomes to reveal an intrinsic pore-forming activity of Bax, but it is unclear how other mitochondrial outer membrane (MOM) proteins might facilitate this function. We carefully analyzed the kinetics of Bax-mediated pore formation in isolated MOMs, with some unexpected results. Native MOMs were more sensitive than liposomes to added Bax, and MOMs displayed a lag phase not observed with liposomes. Heat-labile MOM proteins were required for this enhanced response. A two-tiered mathematical model closely fit the kinetic data: first, Bax activation promotes the assembly of a multimeric complex, which then catalyzes the second reaction, Bax-dependent pore formation. Bax insertion occurred immediately upon Bax addition, prior to the end of the lag phase. Permeabilization kinetics were affected in a reciprocal manner by [cBid] and [Bax], confirming the "hit-and-run" hypothesis of cBid-induced direct Bax activation. Surprisingly, MOMP rate constants were linearly related to [Bax], implying that Bax acts non-cooperatively. Thus, the oligomeric catalyst is distinct from Bax. Moreover, contrary to common assumption, pore formation kinetics depend on Bax monomers, not oligomers. Catalyst formation exhibited a sharp transition in activation energy at ∼28°C, suggesting a role for membrane lipid packing. Furthermore, catalyst formation was strongly inhibited by chemical antagonists of the yeast mitochondrial fission protein, Dnm1. However, the mammalian ortholog, Drp1, was undetectable in mitochondrial outer membranes. Moreover, ATP and GTP were dispensable for MOMP. Thus, the data argue that oligomerization of a catalyst protein, distinct from Bax and Drp1, facilitates MOMP, possibly through a membrane-remodeling event.
Collapse
|
25
|
Perera MN, Lin SH, Peterson YK, Bielawska A, Szulc ZM, Bittman R, Colombini M. Bax and Bcl-xL exert their regulation on different sites of the ceramide channel. Biochem J 2012; 445:81-91. [PMID: 22494048 DOI: 10.1042/BJ20112103] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The present study demonstrates the important structural features of ceramide required for proper regulation, binding and identification by both pro-apoptotic and anti-apoptotic Bcl-2 family proteins. The C-4=C-5 trans-double bond has little influence on the ability of Bax and Bcl-xL to identify and bind to these channels. The stereochemistry of the headgroup and access to the amide group of ceramide is indispensible for Bax binding, indicating that Bax may interact with the polar portion of the ceramide channel facing the bulk phase. In contrast, Bcl-xL binding to ceramide channels is tolerant of stereochemical changes in the headgroup. The present study also revealed that Bcl-xL has an optimal interaction with long-chain ceramides that are elevated early in apoptosis, whereas short-chain ceramides are not well regulated. Inhibitors specific for the hydrophobic groove of Bcl-xL, including 2-methoxyantimycin A3, ABT-737 and ABT-263 provide insights into the region of Bcl-xL involved in binding to ceramide channels. Molecular docking simulations of the lowest-energy binding poses of ceramides and Bcl-xL inhibitors to Bcl-xL were consistent with the results of our functional studies and propose potential binding modes.
Collapse
|
26
|
Sutton VR, Sedelies K, Dewson G, Christensen ME, Bird PI, Johnstone RW, Kluck RM, Trapani JA, Waterhouse NJ. Granzyme B triggers a prolonged pressure to die in Bcl-2 overexpressing cells, defining a window of opportunity for effective treatment with ABT-737. Cell Death Dis 2012; 3:e344. [PMID: 22764103 PMCID: PMC3406577 DOI: 10.1038/cddis.2012.73] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [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: 12/19/2011] [Revised: 04/23/2012] [Accepted: 05/02/2012] [Indexed: 01/08/2023]
Abstract
Overexpression of Bcl-2 contributes to resistance of cancer cells to human cytotoxic lymphocytes (CL) by blocking granzyme B (GraB)-induced mitochondrial outer membrane permeabilization (MOMP). Drugs that neutralise Bcl-2 (e.g., ABT-737) may therefore be effective adjuvants for immunotherapeutic strategies that use CL to kill cancer cells. Consistent with this we found that ABT-737 effectively restored MOMP in Bcl-2 overexpressing cells treated with GraB or natural killer cells. This effect was observed even if ABT-737 was added up to 16 h after GraB, after which the cells reset their resistant phenotype. Sensitivity to ABT-737 required initial cleavage of Bid by GraB (gctBid) but did not require ongoing GraB activity once Bid had been cleaved. This gctBid remained detectable in cells that were sensitive to ABT-737, but Bax and Bak were only activated if ABT-737 was added to the cells. These studies demonstrate that GraB generates a prolonged pro-apoptotic signal that must remain active for ABT-737 to be effective. The duration of this signal is determined by the longevity of gctBid but not activation of Bax or Bak. This defines a therapeutic window in which ABT-737 and CL synergise to cause maximum death of cancer cells that are resistant to either treatment alone, which will be essential in defining optimum treatment regimens.
Collapse
Affiliation(s)
- V R Sutton
- Cancer Cell Death Laboratory, Cancer Immunology Program, Peter MacCallum Cancer Centre, Locked Bag 1, A'Beckett Street, Melbourne, Victoria 8006, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - K Sedelies
- Cancer Cell Death Laboratory, Cancer Immunology Program, Peter MacCallum Cancer Centre, Locked Bag 1, A'Beckett Street, Melbourne, Victoria 8006, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Victoria 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - G Dewson
- Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - M E Christensen
- Apoptosis and Cytotoxicity Laboratory, Mater Medical Research Institute, Aubigny Place, Raymond Terrace, South Brisbane, Queensland 4101, Australia
| | - P I Bird
- Department of Biochemistry and Molecular Biology, Monash University, Melbourne, Victoria 3800, Australia
| | - R W Johnstone
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Victoria 3052, Australia
- Gene Regulation Laboratory, Cancer Therapeutics Program, Peter MacCallum Cancer Centre, Locked Bag 1, A'Beckett Street, Melbourne, Victoria 8006, Australia
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3052, Australia
- Victorian Comprehensive Cancer Centre, Parkville, Victoria 3052, Australia
| | - R M Kluck
- Molecular Genetics of Cancer Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3050, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - J A Trapani
- Cancer Cell Death Laboratory, Cancer Immunology Program, Peter MacCallum Cancer Centre, Locked Bag 1, A'Beckett Street, Melbourne, Victoria 8006, Australia
- Sir Peter MacCallum Department of Oncology, The University of Melbourne, Melbourne, Victoria 3052, Australia
- Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3052, Australia
- Victorian Comprehensive Cancer Centre, Parkville, Victoria 3052, Australia
| | - N J Waterhouse
- Apoptosis and Cytotoxicity Laboratory, Mater Medical Research Institute, Aubigny Place, Raymond Terrace, South Brisbane, Queensland 4101, Australia
- Department of Medicine, University of Queensland, St Lucia, Queensland, Australia
| |
Collapse
|
27
|
Abstract
Redox-dependent processes influence most cellular functions, such as differentiation, proliferation, and apoptosis. Mitochondria are at the center of these processes, as mitochondria both generate reactive oxygen species (ROS) that drive redox-sensitive events and respond to ROS-mediated changes in the cellular redox state. In this review, we examine the regulation of cellular ROS, their modes of production and removal, and the redox-sensitive targets that are modified by their flux. In particular, we focus on the actions of redox-sensitive targets that alter mitochondrial function and the role of these redox modifications on metabolism, mitochondrial biogenesis, receptor-mediated signaling, and apoptotic pathways. We also consider the role of mitochondria in modulating these pathways, and discuss how redox-dependent events may contribute to pathobiology by altering mitochondrial function.
Collapse
Affiliation(s)
- Diane E Handy
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | |
Collapse
|
28
|
Piplani H, Vaish V, Rana C, Sanyal SN. Up-regulation of p53 and mitochondrial signaling pathway in apoptosis by a combination of COX-2 inhibitor, Celecoxib and Dolastatin 15, a marine mollusk linear peptide in experimental colon carcinogenesis. Mol Carcinog 2012; 52:845-58. [PMID: 22623379 DOI: 10.1002/mc.21925] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 04/07/2012] [Accepted: 04/24/2012] [Indexed: 11/06/2022]
Abstract
Programmed cell death, also known as apoptosis, is an active process occurring in eukaryotic cells and it depends on various sets of pro and anti-apoptotic proteins. Chemoprevention of colorectal cancer can be achieved by inducing apoptosis using synthetic compound, Celecoxib and natural peptide, Dolastatin 15 in an effective manner. But the apoptotic signaling by these two drugs remain unclear. The present study was thus focused on the role of Bcl2 family of proteins and their interplay with p53 in rats during the chemoprevention by these two drugs. After treatment for 6 wk with 1, 2-dimethylhydrazine (DMH), animals showed a marked occurrence of multiple plaque lesions. However, a simultaneous treatment with Celecoxib and Dolastatin 15 decreases such number to a significant level. DMH treatment also decreases the number of apoptotic cells in the colonic enterocytes which were corrected to the normal level by Celecoxib and Dolastatin 15. An increased expression of Bcl2 while other proteins like Bax, Apaf-1, cyt c, and caspases in the apoptotic pathway, and the tumor suppressor proteins, p53 and p21 get down-regulated after DMH treatment which were reverted back to normal with Celecoxib and Dolastatin 15. Also, cells having high mitochondrial membrane potential had been seen to increase to significant levels which were reduced after the administration of these anti-inflammatory drugs. In silico molecular docking studies also showed that Dolastatin 15 and Celecoxib may bind to the active site pocket of Bcl2 , thus revealing the direct target of Dolastatin 15 and Celecoxib apart from binding to COX-2.
Collapse
Affiliation(s)
- Honit Piplani
- Department of Biophysics, Panjab University, Chandigarh, India
| | | | | | | |
Collapse
|
29
|
Chipuk JE, McStay GP, Bharti A, Kuwana T, Clarke CJ, Siskind LJ, Obeid LM, Green DR. Sphingolipid metabolism cooperates with BAK and BAX to promote the mitochondrial pathway of apoptosis. Cell 2012; 148:988-1000. [PMID: 22385963 DOI: 10.1016/j.cell.2012.01.038] [Citation(s) in RCA: 327] [Impact Index Per Article: 27.3] [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: 07/06/2010] [Revised: 08/10/2011] [Accepted: 01/20/2012] [Indexed: 01/28/2023]
Abstract
Mitochondria are functionally and physically associated with heterotypic membranes, yet little is known about how these interactions impact mitochondrial outer-membrane permeabilization (MOMP) and apoptosis. We observed that dissociation of heterotypic membranes from mitochondria inhibited BAK/BAX-dependent cytochrome c (cyto c) release. Biochemical purification of neutral sphingomyelinases that correlated with MOMP sensitization suggested that sphingolipid metabolism coordinates BAK/BAX activation. Using purified lipids and enzymes, sensitivity to MOMP was achieved by in vitro reconstitution of the sphingolipid metabolic pathway. Sphingolipid metabolism inhibitors blocked MOMP from heavy membrane preparations but failed to influence MOMP in the presence of sphingolipid-reconstituted, purified mitochondria. Furthermore, the sphingolipid products, sphingosine-1-PO(4) and hexadecenal, cooperated specifically with BAK and BAX, respectively. Sphingolipid metabolism was also required for cellular responses to apoptosis. Our studies suggest that BAK/BAX activation and apoptosis are coordinated through BH3-only proteins and a specific lipid milieu that is maintained by heterotypic membrane-mitochondrial interactions.
Collapse
Affiliation(s)
- Jerry E Chipuk
- Mount Sinai School of Medicine, Department of Oncological Sciences, New York, NY 10029, USA.
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Abstract
Cell death plays an essential role in the development of tissues and organisms, the etiology of disease, and the responses of cells to therapeutic drugs. Here we review progress made over the last decade in using mathematical models and quantitative, often single-cell, data to study apoptosis. We discuss the delay that follows exposure of cells to prodeath stimuli, control of mitochondrial outer membrane permeabilization, switch-like activation of effector caspases, and variability in the timing and probability of death from one cell to the next. Finally, we discuss challenges facing the fields of biochemical modeling and systems pharmacology.
Collapse
Affiliation(s)
- Sabrina L. Spencer
- Center for Cell Decision Processes, Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Peter K. Sorger
- Center for Cell Decision Processes, Department of Systems Biology, Harvard Medical School, Boston, MA 02115, USA
- Correspondence:
| |
Collapse
|
31
|
Abstract
Xenopus egg extracts execute spontaneous apoptosis without the requirement of transcription and translation, and this intrinsic mechanism is supposed to be involved in the physiological elimination of aged eggs. Although apoptosis in this system is carried out by maternally stockpiled materials, the endogenous apoptosis regulators present in egg extracts are still poorly characterized. Here we examined the mRNA expression profiles and apoptosis-regulating functions of 13 Xenopus Bcl-2 family proteins in egg extracts. Among these, we found that endogenous Xenopus Mcl-1 (xMcl-1) physiologically inhibited apoptosis by counteracting the pro-apoptotic activity of endogenous Xenopus Bid in egg extracts. Exogenously added recombinant xMcl-1 was rapidly degraded by proteasome in egg extracts, and we identified the destabilizing region in the N terminus of xMcl-1. Our results suggest that the proteolytic decay of xMcl-1 may change the functional balance between pro- and anti-apoptotic activities of Bcl-2 family proteins, thereby regulating the timing of cytochrome c release in egg extracts.
Collapse
Affiliation(s)
- Yuichi Tsuchiya
- Department of Biochemistry, Toho University School of Medicine, Tokyo, Japan
| | | |
Collapse
|
32
|
Tam ZY, Cai YH, Gunawan R. Elucidating cytochrome C release from mitochondria: insights from an in silico three-dimensional model. Biophys J 2011; 99:3155-63. [PMID: 21081062 DOI: 10.1016/j.bpj.2010.09.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2010] [Revised: 09/06/2010] [Accepted: 09/13/2010] [Indexed: 11/28/2022] Open
Abstract
Mitochondrial regulation of apoptosis depends on the programmed release of proapoptotic proteins such as cytochrome c (Cyt c) through the outer mitochondrial membrane (OMM). Although a few key processes involved in this release have been identified, including the liberation of inner membrane-bound Cyt c and formation of diffusible pores on the OMM, other details like the transport of Cyt c within complex mitochondrial compartments, e.g., the cristae and crista junctions, are not yet fully understood (to our knowledge). In particular, a remodeling of the inner mitochondrial membrane accompanying apoptosis seen in a few studies, in which crista junctions widen, has been hypothesized to be a necessary step in the Cyt c release. Using a three-dimensional spatial modeling of mitochondrial crista and the crista junction, model simulations and analysis illustrated how the interplay among solubilization of Cyt c, fast diffusion of Cyt c, and OMM permeabilization gives rise to the observed experimental release profile. Importantly, the widening of the crista junction was found to have a negligible effect on the transport of free Cyt c from cristae. Finally, model simulations showed that increasing the fraction of free/loosely-bound Cyt c can sensitize the cell to apoptotic stimuli in a threshold manner, which may explain increased sensitivity to cell death associated with aging.
Collapse
Affiliation(s)
- Zhi Yang Tam
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore
| | | | | |
Collapse
|
33
|
Brustovetsky T, Li T, Yang Y, Zhang JT, Antonsson B, Brustovetsky N. BAX insertion, oligomerization, and outer membrane permeabilization in brain mitochondria: role of permeability transition and SH-redox regulation. Biochim Biophys Acta 2010; 1797:1795-806. [PMID: 20655869 PMCID: PMC2933961 DOI: 10.1016/j.bbabio.2010.07.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [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: 04/22/2010] [Revised: 07/05/2010] [Accepted: 07/11/2010] [Indexed: 10/19/2022]
Abstract
BAX cooperates with truncated BID (tBID) and Ca(2+) in permeabilizing the outer mitochondrial membrane (OMM) and releasing mitochondrial apoptogenic proteins. The mechanisms of this cooperation are still unclear. Here we show that in isolated brain mitochondria, recombinant BAX readily self-integrates/oligomerizes in the OMM but produces only a minuscule release of cytochrome c, indicating that BAX insertion/oligomerization in the OMM does not always lead to massive OMM permeabilization. Ca(2+) in a mitochondrial permeability transition (mPT)-dependent and recombinant tBID in an mPT-independent manner promoted BAX insertion/ oligomerization in the OMM and augmented cytochrome c release. Neither tBID nor Ca(2+) induced BAX oligomerization in the solution without mitochondria, suggesting that BAX oligomerization required interaction with the organelles and followed rather than preceded BAX insertion in the OMM. Recombinant Bcl-xL failed to prevent BAX insertion/oligomerization in the OMM but strongly attenuated cytochrome c release. On the other hand, a reducing agent, dithiothreitol (DTT), inhibited BAX insertion/oligomerization augmented by tBID or Ca(2+) and suppressed the BAX-mediated release of cytochrome c and Smac/DIABLO but failed to inhibit Ca(2+)-induced swelling. Altogether, these data suggest that in brain mitochondria, BAX insertion/oligomerization can be dissociated from OMM permeabilization and that tBID and Ca(2+) stimulate BAX insertion/oligomerization and BAX-mediated OMM permeabilization by different mechanisms involving mPT induction and modulation of the SH-redox state.
Collapse
Affiliation(s)
- Tatiana Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
| | - Tsyregma Li
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
| | - Youyun Yang
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
- Simon Cancer Center, Indiana University School of Medicine, Indianapolis IN 46202, USA
| | - Jiang-Ting Zhang
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
- Simon Cancer Center, Indiana University School of Medicine, Indianapolis IN 46202, USA
| | | | - 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
| |
Collapse
|
34
|
Abstract
Mitochondrial bioenergetic function is a key to cell life and death. Cells need energy not only to support their vital functions but also to die gracefully. Execution of an apoptotic program includes energy-dependent steps, including kinase signaling, formation of the apoptosome, and effector caspase activation. Under conditions of bioenergetic collapse, cells are diverted toward necrotic demise. Mitochondrial outer membrane permeabilization (MOMP) is a decisive event in the execution of apoptosis. It is also causally linked to a decline in bioenergetic function via different mechanisms, not merely due to cytochrome c dispersion. MOMP-induced bioenergetic deficiency is usually irreversible and commits cells to die, even when caspases are inactive. Here, we discuss the mechanisms by which MOMP impacts bioenergetics in different cell death paradigms.
Collapse
Affiliation(s)
- Yulia Kushnareva
- La Jolla Institute for Allergy and Immunology, La Jolla, California 92037, USA
| | | |
Collapse
|
35
|
Perkins GA, Ellisman MH. Mitochondrial configurations in peripheral nerve suggest differential ATP production. J Struct Biol 2010; 173:117-27. [PMID: 20600951 DOI: 10.1016/j.jsb.2010.06.017] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 06/21/2010] [Indexed: 12/25/2022]
Abstract
Physiological states of mitochondria often correlate with distinctive morphology. Electron microscopy and tomographic reconstruction were used to investigate the three-dimensional structure of axonal mitochondria and mitochondria in the surrounding Schwann cells of the peripheral nervous system (PNS), both in the vicinity of nodes of Ranvier and far from these nodes. Condensed mitochondria were found to be abundant in the axoplasm, but not in the Schwann cell. Uncharacteristic of the classical morphology of condensed mitochondria, the outer and inner boundary membranes are in close apposition and the crista junctions are narrow, consistent with their function as gates for the diffusion of macromolecules. There is also less cristae surface area and lower density of crista junctions in these mitochondria. The density of mitochondria was greater at the paranode-node-paranode (PNP) as was the crista junction opening, yet there were fewer cristae in these organelles compared to those in the internodal region. The greater density of condensed mitochondria in the PNS axoplasm and in particular at the PNP suggests a need for these organelles to operate at a high workload of ATP production.
Collapse
Affiliation(s)
- Guy A Perkins
- National Center for Microscopy and Imaging Research, Center for Research in Biological Systems, University of California, San Diego, La Jolla, CA 92093-0608, United States.
| | | |
Collapse
|
36
|
Chen Y, Lewis W, Diwan A, Cheng EHY, Matkovich SJ, Dorn GW. Dual autonomous mitochondrial cell death pathways are activated by Nix/BNip3L and induce cardiomyopathy. Proc Natl Acad Sci U S A 2010; 107:9035-42. [PMID: 20418503 PMCID: PMC2889094 DOI: 10.1073/pnas.0914013107] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.9] [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: 01/18/2023] Open
Abstract
Dysregulation of programmed cell death due to abnormal expression of Bcl-2 proteins is implicated in cancer, neurodegenerative diseases, and heart failure. Among Bcl-2 family members, BNip proteins uniquely stimulate cell death with features of both apoptosis and necrosis. Localization of these factors to mitochondria and endoplasmic reticulum (ER) provides additional complexity. Previously, we observed regulation of intracellular calcium stores by reticular Nix. Here, we report effects of Nix targeting to mitochondria or ER on cell death pathways and heart failure progression. Nix-deficient fibroblasts expressing mitochondrial-directed or ER-directed Nix mutants exhibited similar cytochrome c release, caspase activation, annexin V and TUNEL labeling, and cell death. ER-Nix cells, but not mitochondrial-Nix cells, showed dissipation of mitochondrial inner membrane potential, Deltapsi(m), and were protected from cell death by cyclosporine A or ppif ablation, implicating the mitochondrial permeability transition pore (MPTP). ER-Nix cells were not protected from death by caspase inhibition or combined ablation of Bax and Bak. Combined inhibition of caspases and the MPTP fully protected against Nix-mediated cell death. To determine the role of the dual pathways in heart failure, mice conditionally overexpressing Nix or Nix mutants in hearts were created. Cardiomyocte death caused by mitochondrial- and ER-directed Nix was equivalent, but ppif ablation fully protected only ER-Nix. Thus, Nix stimulates dual autonomous death pathways, determined by its subcellular localization. Mitochondrial Nix activates Bax/Bak- and caspase-dependent apoptosis, whereas ER-Nix activates Bax/Bak-independent, MPTP-dependent necrosis. Complete protection against programmed cell death mediated by Nix and related factors can be achieved by simultaneous inhibition of both pathways.
Collapse
Affiliation(s)
- Yun Chen
- Department of Medicine, Center for Pharmacogenomics, and
| | - William Lewis
- Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322
| | - Abhinav Diwan
- Department of Medicine, Center for Pharmacogenomics, and
| | - Emily H.-Y. Cheng
- Departments of Medicine and Pathology and Immunology, Division of Molecular Oncology, Washington University School of Medicine, St. Louis, MO 63110; and
| | | | - Gerald W. Dorn
- Department of Medicine, Center for Pharmacogenomics, and
| |
Collapse
|
37
|
Borillo GA, Mason M, Quijada P, Völkers M, Cottage C, McGregor M, Din S, Fischer K, Gude N, Avitable D, Barlow S, Gustafsson AB, Glembotski C, Gottlieb RA, Brown JH, Sussman MA. Pim-1 kinase protects mitochondrial integrity in cardiomyocytes. Circ Res 2010; 106:1265-74. [PMID: 20203306 PMCID: PMC2864233 DOI: 10.1161/circresaha.109.212035] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [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] [Indexed: 01/11/2023]
Abstract
RATIONALE Cardioprotective signaling mediates antiapoptotic actions through multiple mechanisms including maintenance of mitochondrial integrity. Pim-1 kinase is an essential downstream effector of AKT-mediated cardioprotection but the mechanistic basis for maintenance of mitochondrial integrity by Pim-1 remains unexplored. This study details antiapoptotic actions responsible for enhanced cell survival in cardiomyocytes with elevated Pim-1 activity. OBJECTIVE The purpose of this study is to demonstrate that the cardioprotective kinase Pim-1 acts to inhibit cell death by preserving mitochondrial integrity in cardiomyocytes. METHODS AND RESULTS A combination of biochemical, molecular, and microscopic analyses demonstrate beneficial effects of Pim-1 on mitochondrial integrity. Pim-1 protein level increases in the mitochondrial fraction with a corresponding decrease in the cytosolic fraction of myocardial lysates from hearts subjected to 30 minutes of ischemia followed by 30 minutes of reperfusion. Cardiac-specific overexpression of Pim-1 results in higher levels of antiapoptotic Bcl-X(L) and Bcl-2 compared to samples from normal hearts. In response to oxidative stress challenge, Pim-1 preserves the inner mitochondrial membrane potential. Ultrastructure of the mitochondria is maintained by Pim-1 activity, which prevents swelling induced by calcium overload. Finally, mitochondria isolated from hearts created with cardiac-specific overexpression of Pim-1 show inhibition of cytochrome c release triggered by a truncated form of proapoptotic Bid. CONCLUSION Cardioprotective action of Pim-1 kinase includes preservation of mitochondrial integrity during cardiomyopathic challenge conditions, thereby raising the potential for Pim-1 kinase activation as a therapeutic interventional approach to inhibit cell death by antagonizing proapoptotic Bcl-2 family members that regulate the intrinsic apoptotic pathway.
Collapse
MESH Headings
- Animals
- Animals, Newborn
- Apoptosis
- BH3 Interacting Domain Death Agonist Protein/metabolism
- Cell Survival
- Cells, Cultured
- Cytochromes c/metabolism
- Disease Models, Animal
- Humans
- Membrane Potential, Mitochondrial
- Mice
- Mice, Transgenic
- Mitochondria, Heart/enzymology
- Mitochondria, Heart/ultrastructure
- Mitochondrial Swelling
- Myocardial Reperfusion Injury/enzymology
- Myocardial Reperfusion Injury/genetics
- Myocardial Reperfusion Injury/pathology
- Myocardial Reperfusion Injury/prevention & control
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/ultrastructure
- Oxidative Stress
- Protein Transport
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Proto-Oncogene Proteins c-pim-1/genetics
- Proto-Oncogene Proteins c-pim-1/metabolism
- Rats
- Rats, Sprague-Dawley
- Recombinant Fusion Proteins/metabolism
- Time Factors
- Transfection
- bcl-X Protein/metabolism
Collapse
Affiliation(s)
- Gwynngelle A. Borillo
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Matt Mason
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Pearl Quijada
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Mirko Völkers
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Christopher Cottage
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Michael McGregor
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Shabana Din
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Kimberlee Fischer
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Natalie Gude
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Daniele Avitable
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Steven Barlow
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Asa B. Gustafsson
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | | | - Roberta A. Gottlieb
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| | - Joan Heller Brown
- Department of Pharmacology, University of California, San Diego, CA 92093-0636, USA
| | - Mark A. Sussman
- San Diego State Heart Institute, San Diego State University, San Diego, CA 92182, USA
| |
Collapse
|
38
|
Shoshan-Barmatz V, De Pinto V, Zweckstetter M, Raviv Z, Keinan N, Arbel N. VDAC, a multi-functional mitochondrial protein regulating cell life and death. Mol Aspects Med 2010; 31:227-85. [PMID: 20346371 DOI: 10.1016/j.mam.2010.03.002] [Citation(s) in RCA: 523] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Accepted: 03/17/2010] [Indexed: 01/22/2023]
Abstract
Research over the past decade has extended the prevailing view of the mitochondrion to include functions well beyond the generation of cellular energy. It is now recognized that mitochondria play a crucial role in cell signaling events, inter-organellar communication, aging, cell proliferation, diseases and cell death. Thus, mitochondria play a central role in the regulation of apoptosis (programmed cell death) and serve as the venue for cellular decisions leading to cell life or death. One of the mitochondrial proteins controlling cell life and death is the voltage-dependent anion channel (VDAC), also known as mitochondrial porin. VDAC, located in the mitochondrial outer membrane, functions as gatekeeper for the entry and exit of mitochondrial metabolites, thereby controlling cross-talk between mitochondria and the rest of the cell. VDAC is also a key player in mitochondria-mediated apoptosis. Thus, in addition to regulating the metabolic and energetic functions of mitochondria, VDAC appears to be a convergence point for a variety of cell survival and cell death signals mediated by its association with various ligands and proteins. In this article, we review what is known about the VDAC channel in terms of its structure, relevance to ATP rationing, Ca(2+) homeostasis, protection against oxidative stress, regulation of apoptosis, involvement in several diseases and its role in the action of different drugs. In light of our recent findings and the recently solved NMR- and crystallography-based 3D structures of VDAC1, the focus of this review will be on the central role of VDAC in cell life and death, addressing VDAC function in the regulation of mitochondria-mediated apoptosis with an emphasis on structure-function relations. Understanding structure-function relationships of VDAC is critical for deciphering how this channel can perform such a variety of functions, all important for cell life and death. This review also provides insight into the potential of VDAC1 as a rational target for new therapeutics.
Collapse
|
39
|
Quinsay MN, Lee Y, Rikka S, Sayen MR, Molkentin JD, Gottlieb RA, Gustafsson AB. Bnip3 mediates permeabilization of mitochondria and release of cytochrome c via a novel mechanism. J Mol Cell Cardiol 2009; 48:1146-56. [PMID: 20025887 DOI: 10.1016/j.yjmcc.2009.12.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2009] [Revised: 12/02/2009] [Accepted: 12/05/2009] [Indexed: 01/10/2023]
Abstract
Bnip3 is a member of the BH3-only subfamily of pro-apoptotic Bcl-2 proteins and is associated with loss of cardiac myocytes after a myocardial infarction. Previous studies have demonstrated that Bnip3 induces mitochondrial dysfunction, but the mechanisms involved in this process remain unknown. In this study, we demonstrate that Bnip3 induces permeabilization of the mitochondria via a novel mechanism that is different from other BH3-only proteins. We found that Bnip3 induced mitochondrial swelling and cytochrome c release in isolated heart mitochondria in vitro. Another BH3-only protein, tBid, also caused release of cytochrome c but failed to induce swelling of mitochondria. Swelling of mitochondria is a characteristic of mitochondrial permeability transition pore (mPTP) opening, but Bnip3-mediated mitochondrial swelling was insensitive to cyclosporine A, an inhibitor of the mPTP and independent of cyclophilin D (cypD), an essential component of the mPTP. Bnip3 also induced permeabilization of the mitochondrial membranes as evident by calcein release from the matrix in both wild type (WT) and cypD deficient mouse embryonic fibroblasts (MEFs). Moreover, Bnip3 induced mitochondrial matrix remodeling and large amplitude swelling of the inner membrane, which led to disassembly of OPA1 complexes and release from the mitochondria. Thus, these studies suggest that Bnip3 mediates mitochondrial permeabilization by a novel mechanism that is different from other BH3-only proteins.
Collapse
Affiliation(s)
- Melissa N Quinsay
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive MC 0748, La Jolla, CA 92093-0748, USA
| | | | | | | | | | | | | |
Collapse
|
40
|
Lartigue L, Kushnareva Y, Seong Y, Lin H, Faustin B, Newmeyer DD. Caspase-independent mitochondrial cell death results from loss of respiration, not cytotoxic protein release. Mol Biol Cell 2009; 20:4871-84. [PMID: 19793916 PMCID: PMC2785731 DOI: 10.1091/mbc.e09-07-0649] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Revised: 09/17/2009] [Accepted: 09/23/2009] [Indexed: 01/29/2023] Open
Abstract
In apoptosis, mitochondrial outer membrane permeabilization (MOMP) triggers caspase-dependent death. However, cells undergo clonogenic death even if caspases are blocked. One proposed mechanism involved the release of cytotoxic proteins (e.g., AIF and endoG) from mitochondria. To initiate MOMP directly without side effects, we created a tamoxifen-switchable BimS fusion protein. Surprisingly, even after MOMP, caspase-inhibited cells replicated DNA and divided for approximately 48 h before undergoing proliferation arrest. AIF and endoG remained in mitochondria. However, cells gradually lost mitochondrial membrane potential and ATP content, and DNA synthesis slowed to a halt by 72 h. These defects resulted from a partial loss of respiratory function, occurring 4-8 h after MOMP, that was not merely due to dispersion of cytochrome c. In particular, Complex I activity was completely lost, and Complex IV activity was reduced by approximately 70%, whereas Complex II was unaffected. Later, cells exhibited a more profound loss of mitochondrial protein constituents. Thus, under caspase inhibition, MOMP-induced clonogenic death results from a progressive loss of mitochondrial function, rather than the release of cytotoxic proteins from mitochondria.
Collapse
Affiliation(s)
- Lydia Lartigue
- *La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037; and
| | - Yulia Kushnareva
- *La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037; and
| | - Youngmo Seong
- *La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037; and
| | - Helen Lin
- *La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037; and
| | | | | |
Collapse
|
41
|
Li T, Brustovetsky T, Antonsson B, Brustovetsky N. Dissimilar mechanisms of cytochrome c release induced by octyl glucoside-activated BAX and by BAX activated with truncated BID. Biochim Biophys Acta 2010; 1797:52-62. [PMID: 19664589 DOI: 10.1016/j.bbabio.2009.07.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Revised: 07/20/2009] [Accepted: 07/27/2009] [Indexed: 11/21/2022]
Abstract
In the present study, we compared alkali-resistant BAX insertion into the outer mitochondrial membrane, mitochondrial remodeling, mitochondrial membrane potential changes, and cytochrome c (Cyt c) release from isolated brain mitochondria triggered by recombinant BAX oligomerized with 1% octyl glucoside (BAX(oligo)) and by a combination of monomeric BAX (BAX(mono)) and caspase 8-cleaved C-terminal fragment of recombinant BID (truncated BID, t(c)BID). We also examined whether the effects induced by BAX(oligo) or by BAX(mono) activated with t(c)BID depended on induction of the mitochondrial permeability transition. The results obtained in this study revealed that t(c)BID plus BAX(mono) produced BAX insertion and Cyt c release without overt changes in mitochondrial morphology. On the contrary, treatment of mitochondria with BAX(oligo) resulted in BAX insertion and Cyt c release, which were accompanied by gross distortion of mitochondrial morphology. The effects of BAX(oligo) could be at least partially suppressed by mitochondrial depolarization. The effects of t(c)BID plus BAX(mono) were insensitive to depolarization. BAX(oligo) produced similar BAX insertion, mitochondrial remodeling, and Cyt c release in KCl- and in N-methyl-D-glucamine-based incubation media indicating a non-essential role for K+ influx into mitochondria in these processes. A combination of cyclosporin A and ADP, inhibitors of the mitochondrial permeability transition, attenuated Cyt c release, mitochondrial remodeling, and depolarization induced by BAX(oligo), but failed to influence the effects produced by t(c)BID plus BAX(mono). Thus, our results suggest a significant difference in the mechanisms of the outer mitochondrial membrane permeabilization and Cyt c release induced by detergent-oligomerized BAX(oligo) and by BAX activated with t(c)BID.
Collapse
|
42
|
Li H, Fujikura D, Harada T, Uehara J, Kawai T, Akira S, Reed JC, Iwai A, Miyazaki T. IPS-1 is crucial for DAP3-mediated anoikis induction by caspase-8 activation. Cell Death Differ 2009; 16:1615-21. [DOI: 10.1038/cdd.2009.97] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
|
43
|
Perkins G, Bossy-Wetzel E, Ellisman MH. New insights into mitochondrial structure during cell death. Exp Neurol 2009; 218:183-92. [PMID: 19464290 DOI: 10.1016/j.expneurol.2009.05.021] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 04/30/2009] [Accepted: 05/08/2009] [Indexed: 01/06/2023]
Abstract
Mitochondria play a pivotal role in the cascade of events associated with cell death pathways that are involved with several forms of neurodegeneration. Recent findings show that in the Bax/Bak-dependent pathway of apoptosis, the release of cytochrome c from mitochondria is a consequence of two carefully coordinated events: opening of crista junctions triggered by OPA1 oligomer disassembly and formation of outer membrane pores. Both steps are necessary for the complete release of pro-apoptotic proteins. The remodeling of mitochondrial structure accompanies this pathway, including mitochondrial fission, and cristae and crista junction alterations. Yet, there is controversy surrounding the timing of certain remodeling events and whether they are necessary early events required for the release of pro-apoptotic factors or are simply a downstream after-effect. Here, we analyze the current knowledge of mitochondrial remodeling during cell death and discuss what structural alterations occur to this organelle during neurodegeneration, focusing on the higher resolution structural correlates obtained by electron microscopy and electron tomography.
Collapse
|
44
|
Saitoh T, Tsuchiya Y, Kinoshita T, Itoh M, Yamashita S. Pro-apoptotic activity and mono-/diubiquitylation of Xenopus Bid in egg extracts. Biochem Biophys Res Commun 2009; 384:491-4. [PMID: 19426713 DOI: 10.1016/j.bbrc.2009.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Accepted: 05/04/2009] [Indexed: 01/25/2023]
Abstract
Apoptosis in Xenopus egg extracts is carried out by maternally stockpiled materials, but the contributions of endogenous apoptosis regulators are still poorly characterized. Here we examined the physiological role of Xenopus Bid (xBid), a pro-apoptotic BH3-only member of Bcl-2 family proteins. We found that endogenous xBid was a physiological accelerator of apoptosis in egg extracts. Interestingly, xBid was mono-/diubiquitylated but not degraded by proteasome in egg extracts, and we identified three ubiquitylated Lys residues in the N-terminal propeptide region. Comparison with human Bid suggested that mono-/diubiquitylation is a specific feature of xBid.
Collapse
|
45
|
Abstract
Defects in apoptotic pathways can promote cancer cell survival and also confer resistance to antineoplastic drugs. One pathway being targeted for antineoplastic therapy is the anti-apoptotic B-cell lymphoma-2 (Bcl-2) family of proteins (Bcl-2, Bcl-XL, Bcl-w, Mcl-1, Bfl1/A-1, and Bcl-B) that bind to and inactivate BH3-domain pro-apoptotic proteins. Signals transmitted by cellular damage (including antineoplastic drugs) or cytokine deprivation can initiate apoptosis via the intrinsic apoptotic pathway. It is controversial whether some BH3-domain proteins (Bim or tBid) directly activate multidomain pro-apoptotic proteins (e.g., Bax and Bak) or act via inhibition of those anti-apoptotic Bcl-2 proteins (Bcl-2, Bcl-XL, Bcl-w, Mcl-1, Bfl1/A-1, and Bcl-B) that stabilize pro-apoptotic proteins. Overexpression of anti-apoptotic Bcl-2 family members has been associated with chemotherapy resistance in various human cancers, and preclinical studies have shown that agents targeting anti-apoptotic Bcl-2 family members have preclinical activity as single agents and in combination with other antineoplastic agents. Clinical trials of several investigational drugs targeting the Bcl-2 family (oblimersen sodium, AT-101, ABT-263, GX15-070) are ongoing. Here, we review the role of the Bcl-2 family in apoptotic pathways and those agents that are known and/or designed to inhibit the anti-apoptotic Bcl-2 family of proteins.
Collapse
Affiliation(s)
- Min H Kang
- Cancer Center and the Department of Cell Biology and Biochemistry, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas 79430, USA
| | | |
Collapse
|
46
|
Baines CP. The mitochondrial permeability transition pore and ischemia-reperfusion injury. Basic Res Cardiol. 2009;104:181-188. [PMID: 19242640 DOI: 10.1007/s00395-009-0004-8] [Citation(s) in RCA: 182] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 01/22/2009] [Accepted: 01/26/2009] [Indexed: 12/27/2022]
Abstract
Mitochondrial dysfunction is an underlying cause of ischemia-reperfusion injury. In particular, ischemic injury induces dramatic increases in mitochondrial permeability, thereby instigating a chain of events that leads to both apoptotic and necrotic cardiomyocyte death. The mitochondrial permeability transition (MPT) pore, a large, non-specific channel that spans the inner mitochondrial membrane, is known to mediate the lethal permeability changes that initiate mitochondrial-driven cardiomyocyte death. The purpose of this review is to focus on the role of the MPT pore in ischemia-reperfusion injury, the mechanisms involved, and, in particular, what we do and do not know regarding the pore's molecular composition.
Collapse
|
47
|
Kumarswamy R, Chandna S. Putative partners in Bax mediated cytochrome-c release: ANT, CypD, VDAC or none of them? Mitochondrion 2009; 9:1-8. [PMID: 18992370 DOI: 10.1016/j.mito.2008.10.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [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: 06/15/2008] [Revised: 10/09/2008] [Accepted: 10/16/2008] [Indexed: 11/20/2022]
Abstract
Release of cytochrome-c from mitochondria is a key regulatory event in the intrinsic pathway of apoptosis, and its mechanism has been the subject of extensive debate with investigators proposing different and contrasting models. While some models suggest that cytochrome-c release can occur in absence of permeability transition and is mediated by the pro-apoptotic protein Bax, some suggest involvement of various components of permeability transition pore with or without cooperative action of Bax. Various models of PTP-dependent or -independent cytochrome-c release are discussed in this review with special emphasis on all the independent/cooperative roles of Bax evidenced so far.
Collapse
Affiliation(s)
- R Kumarswamy
- Natural Radiation Response Mechanisms Group, Division of Radiation Biosciences, Institute of Nuclear Medicine and Allied Sciences, Brig. SK Mazumdar Road, Delhi 110054, India
| | | |
Collapse
|
48
|
J. Majima H, P. Indo H, Tomita K, Iwashita Y, Suzuki H, Masuda D, Shimazu T, Tanigaki F, Umemura S, Yano S, Fukui K, Higashibata A, Q Yamazaki T, Kameyama M, Suenaga S, Sato T, Yen HC, Gusev O, Okuda T, Matsui H, Ozawa T, Ishioka N. Bio-Assessment of RISK in Long-Term Manned Space Exploration-Cell Death Factors in Space Radiation and/or Microgravity: A Review-. ACTA ACUST UNITED AC 2009. [DOI: 10.2187/bss.23.43] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
49
|
Chipuk JE, Fisher JC, Dillon CP, Kriwacki RW, Kuwana T, Green DR. Mechanism of apoptosis induction by inhibition of the anti-apoptotic BCL-2 proteins. Proc Natl Acad Sci U S A 2008; 105:20327-32. [PMID: 19074266 DOI: 10.1073/pnas.0808036105] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Normal cellular lifespan is contingent upon preserving outer mitochondrial membrane (OMM) integrity, as permeabilization promotes apoptosis. BCL-2 family proteins control mitochondrial outer membrane permeabilization (MOMP) by regulating the activation of the pro-apoptotic BCL-2 effector molecules, BAX and BAK. Sustainable cellular stress induces proteins (e.g., BID, BIM, and cytosolic p53) capable of directly activating BAX and/or BAK, but these direct activators are sequestered by the anti-apoptotic BCL-2 proteins (e.g., BCL-2, BCL-xL, and MCL-1). In the event of accumulated or marked cellular stress, a coordinated effort between previously sequestered and nascent BH3-only proteins inhibits the anti-apoptotic BCL-2 repertoire to promote direct activator protein-mediated MOMP. We examined the effect of ABT-737, a BCL-2 antagonist, and PUMA, a BH3-only protein that inhibits the entire anti-apoptotic BCL-2 repertoire, with cells and mitochondria that sequestered direct activator proteins. ABT-737 and PUMA cooperated with sequestered direct activator proteins to promote MOMP and apoptosis, which in the absence of ABT-737 or PUMA did not influence OMM integrity or cellular survival. Our data show that the induction of apoptosis by inhibition of the anti-apoptotic BCL-2 repertoire requires "covert" levels of direct activators of BAX and BAK at the OMM.
Collapse
|
50
|
Albeck JG, Burke JM, Spencer SL, Lauffenburger DA, Sorger PK. Modeling a snap-action, variable-delay switch controlling extrinsic cell death. PLoS Biol 2008; 6:2831-52. [PMID: 19053173 PMCID: PMC2592357 DOI: 10.1371/journal.pbio.0060299] [Citation(s) in RCA: 224] [Impact Index Per Article: 14.0] [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: 10/16/2007] [Accepted: 10/20/2008] [Indexed: 01/02/2023] Open
Abstract
When exposed to tumor necrosis factor (TNF) or TNF-related apoptosis-inducing ligand (TRAIL), a closely related death ligand and investigational therapeutic, cells enter a protracted period of variable duration in which only upstream initiator caspases are active. A subsequent and sudden transition marks activation of the downstream effector caspases that rapidly dismantle the cell. Thus, extrinsic apoptosis is controlled by an unusual variable-delay, snap-action switch that enforces an unambiguous choice between life and death. To understand how the extrinsic apoptosis switch functions in quantitative terms, we constructed a mathematical model based on a mass-action representation of known reaction pathways. The model was trained against experimental data obtained by live-cell imaging, flow cytometry, and immunoblotting of cells perturbed by protein depletion and overexpression. The trained model accurately reproduces the behavior of normal and perturbed cells exposed to TRAIL, making it possible to study switching mechanisms in detail. Model analysis shows, and experiments confirm, that the duration of the delay prior to effector caspase activation is determined by initiator caspase-8 activity and the rates of other reactions lying immediately downstream of the TRAIL receptor. Sudden activation of effector caspases is achieved downstream by reactions involved in permeabilization of the mitochondrial membrane and relocalization of proteins such as Smac. We find that the pattern of interactions among Bcl-2 family members, the partitioning of Smac from its binding partner XIAP, and the mechanics of pore assembly are all critical for snap-action control.
Collapse
Affiliation(s)
- John G Albeck
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - John M Burke
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
- Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Sabrina L Spencer
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
- Computational and Systems Biology Initiative, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Douglas A Lauffenburger
- Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- Computational and Systems Biology Initiative, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Peter K Sorger
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts, United States of America
- Biological Engineering Department, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
- * To whom correspondence should be addressed. E-mail:
| |
Collapse
|