1
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Nguyen D, Osterlund E, Kale J, Andrews DW. The C-terminal sequences of Bcl-2 family proteins mediate interactions that regulate cell death. Biochem J 2024; 481:903-922. [PMID: 38985308 DOI: 10.1042/bcj20210352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 07/11/2024]
Abstract
Programmed cell death via the both intrinsic and extrinsic pathways is regulated by interactions of the Bcl-2 family protein members that determine whether the cell commits to apoptosis via mitochondrial outer membrane permeabilization (MOMP). Recently the conserved C-terminal sequences (CTSs) that mediate localization of Bcl-2 family proteins to intracellular membranes, have been shown to have additional protein-protein binding functions that contribute to the functions of these proteins in regulating MOMP. Here we review the pivotal role of CTSs in Bcl-2 family interactions including: (1) homotypic interactions between the pro-apoptotic executioner proteins that cause MOMP, (2) heterotypic interactions between pro-apoptotic and anti-apoptotic proteins that prevent MOMP, and (3) heterotypic interactions between the pro-apoptotic executioner proteins and the pro-apoptotic direct activator proteins that promote MOMP.
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Affiliation(s)
- Dang Nguyen
- Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Canada
- Biological Sciences Platform, Odette Cancer Program, Sunnybrook Research Institute, Toronto, Canada
| | - Elizabeth Osterlund
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Science, McMaster University, Hamilton, Canada
| | - Justin Kale
- Biological Sciences Platform, Odette Cancer Program, Sunnybrook Research Institute, Toronto, Canada
| | - David W Andrews
- Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Canada
- Biological Sciences Platform, Odette Cancer Program, Sunnybrook Research Institute, Toronto, Canada
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Canada
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2
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Glover HL, Schreiner A, Dewson G, Tait SWG. Mitochondria and cell death. Nat Cell Biol 2024:10.1038/s41556-024-01429-4. [PMID: 38902422 DOI: 10.1038/s41556-024-01429-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 04/26/2024] [Indexed: 06/22/2024]
Abstract
Mitochondria are cellular factories for energy production, calcium homeostasis and iron metabolism, but they also have an unequivocal and central role in intrinsic apoptosis through the release of cytochrome c. While the subsequent activation of proteolytic caspases ensures that cell death proceeds in the absence of collateral inflammation, other phlogistic cell death pathways have been implicated in using, or engaging, mitochondria. Here we discuss the emerging complexities of intrinsic apoptosis controlled by the BCL-2 family of proteins. We highlight the emerging theory that non-lethal mitochondrial apoptotic signalling has diverse biological roles that impact cancer, innate immunity and ageing. Finally, we delineate the role of mitochondria in other forms of cell death, such as pyroptosis, ferroptosis and necroptosis, and discuss mitochondria as central hubs for the intersection and coordination of cell death signalling pathways, underscoring their potential for therapeutic manipulation.
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Affiliation(s)
- Hannah L Glover
- Cancer Research UK Scotland Institute, Glasgow, UK
- School of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Annabell Schreiner
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia
| | - Grant Dewson
- Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia.
| | - Stephen W G Tait
- Cancer Research UK Scotland Institute, Glasgow, UK.
- School of Cancer Sciences, University of Glasgow, Glasgow, UK.
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3
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Subas Satish HP, Iyer S, Shi MX, Wong AW, Fischer KC, Wardak AZ, Lio D, Brouwer JM, Uren RT, Czabotar PE, Miller MS, Kluck RM. A novel inhibitory BAK antibody enables assessment of non-activated BAK in cancer cells. Cell Death Differ 2024; 31:711-721. [PMID: 38582955 PMCID: PMC11164899 DOI: 10.1038/s41418-024-01289-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 03/21/2024] [Accepted: 03/22/2024] [Indexed: 04/08/2024] Open
Abstract
BAX and BAK are pro-apoptotic members of the BCL2 family that are required to permeabilize the mitochondrial outer membrane. The proteins can adopt a non-activated monomeric conformation, or an activated conformation in which the exposed BH3 domain facilitates binding either to a prosurvival protein or to another activated BAK or BAX protein to promote pore formation. Certain cancer cells are proposed to have high levels of activated BAK sequestered by MCL1 or BCLXL, thus priming these cells to undergo apoptosis in response to BH3 mimetic compounds that target MCL1 or BCLXL. Here we report the first antibody, 14G6, that is specific for the non-activated BAK conformer. A crystal structure of 14G6 Fab bound to BAK revealed a binding site encompassing both the α1 helix and α5-α6 hinge regions of BAK, two sites involved in the unfolding of BAK during its activation. In mitochondrial experiments, 14G6 inhibited BAK unfolding triggered by three diverse BAK activators, supporting crucial roles for both α1 dissociation and separation of the core (α2-α5) and latch (α6-α9) regions in BAK activation. 14G6 bound the majority of BAK in several leukaemia cell lines, and binding decreased following treatment with BH3 mimetics, indicating only minor levels of constitutively activated BAK in those cells. In summary, 14G6 provides a new means of assessing BAK status in response to anti-cancer treatments.
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Affiliation(s)
- Hema Preethi Subas Satish
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, 37232, USA
| | - Sweta Iyer
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Melissa X Shi
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Agnes W Wong
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Karla C Fischer
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Ahmad Z Wardak
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Daisy Lio
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Jason M Brouwer
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Rachel T Uren
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Peter E Czabotar
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia
| | - Michelle S Miller
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia.
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia.
| | - Ruth M Kluck
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC, 3052, Australia.
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, 3010, Australia.
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4
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Marques-Carvalho A, Silva B, Pereira FB, Kim HN, Almeida M, Sardão VA. Oestradiol and osteoclast differentiation: Effects on p53 and mitochondrial metabolism. Eur J Clin Invest 2024; 54:e14195. [PMID: 38519718 DOI: 10.1111/eci.14195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 02/05/2024] [Accepted: 02/24/2024] [Indexed: 03/25/2024]
Abstract
BACKGROUND Oestrogen deficiency increases bone resorption, contributing to osteoporosis development. Yet, the mechanisms mediating the effects of oestrogen on osteoclasts remain unclear. This study aimed to elucidate the early metabolic alteration induced by RANKL, the essential cytokine in osteoclastogenesis and 17-beta-oestradiol (E2) on osteoclast progenitor cells, using RAW 264.7 macrophage cell line and primary bone marrow-derived macrophages as biological models. RESULTS This research demonstrated that, in osteoclast precursors, RANKL stimulates complex I activity, oxidative phosphorylation (OXPHOS) and mitochondria-derived ATP production as early as 3 h of exposure. This effect on mitochondrial bioenergetics is associated with an increased capacity to oxidize TCA cycle substrates, fatty acids and amino acids. E2 inhibited all effects of RANKL on mitochondria metabolism. In the presence of RANKL, E2 also decreased cell number and stimulated the mitochondrial-mediated apoptotic pathway, detected as early as 3 h. Further, the pro-apoptotic effects of E2 during osteoclast differentiation were associated with an accumulation of p392S-p53 in mitochondria. CONCLUSIONS These findings elucidate the early effects of RANKL on osteoclast progenitor metabolism and suggest novel p53-mediated mechanisms that contribute to postmenopausal osteoporosis.
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Affiliation(s)
- Adriana Marques-Carvalho
- CNC-Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
- PhD Programme in Experimental Biology and Biomedicine (PDBEB), Institute for Interdisciplinary Research (IIIUC), University of Coimbra, Coimbra, Portugal
| | - Beatriz Silva
- Centre for Informatics and Systems, University of Coimbra, Coimbra, Portugal
| | - Francisco B Pereira
- Centre for Informatics and Systems, University of Coimbra, Coimbra, Portugal
- Polytechnic Institute of Coimbra, Coimbra Institute of Engineering, Coimbra, Portugal
| | - Ha-Neui Kim
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Maria Almeida
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, USA
- Department of Orthopedic Surgery, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Vilma A Sardão
- CNC-Center for Neuroscience and Cell Biology, CIBB - Centre for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal
- Multidisciplinary Institute of Aging (MIA-Portugal), University of Coimbra, Portugal
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5
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Miller MS, Cowan AD, Brouwer JM, Smyth ST, Peng L, Wardak AZ, Uren RT, Luo C, Roy MJ, Shah S, Tan Z, Reid GE, Colman PM, Czabotar PE. Sequence differences between BAX and BAK core domains manifest as differences in their interactions with lipids. FEBS J 2024; 291:2335-2353. [PMID: 38088212 DOI: 10.1111/febs.17031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 11/07/2023] [Accepted: 12/11/2023] [Indexed: 01/21/2024]
Abstract
The B-cell lymphoma 2 (BCL2) family members, BCL2-associated protein X (BAX) and BCL2 homologous antagonist killer (BAK), are required for programmed cell death via the mitochondrial pathway. When cells are stressed, damaged or redundant, the balance of power between the BCL2 family of proteins shifts towards BAX and BAK, allowing their transition from an inactive, monomeric state to a membrane-active oligomeric form that releases cytochrome c from the mitochondrial intermembrane space. That oligomeric state has an essential intermediate, a symmetric homodimer of BAX or BAK. Here we describe crystal structures of dimers of the core domain of BAX, comprising its helices α2-α5. These structures provide an atomic resolution description of the interactions that drive BAX homo-dimerisation and insights into potential interaction between core domain dimers and membrane lipids. The previously identified BAK lipid-interacting sites are not conserved with BAX and are likely to determine the differences between them in their interactions with lipids. We also describe structures of heterodimers of BAK/BAX core domains, yielding further insight into the differences in lipid binding between BAX and BAK.
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Affiliation(s)
- Michelle S Miller
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Angus D Cowan
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Jason M Brouwer
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Sean T Smyth
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
| | - Liuyu Peng
- School of Chemistry, University of Melbourne, Parkville, Vic., Australia
| | - Ahmad Z Wardak
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
| | - Rachel T Uren
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Cindy Luo
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
| | - Michael J Roy
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Sayali Shah
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Ziwen Tan
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Gavin E Reid
- School of Chemistry, University of Melbourne, Parkville, Vic., Australia
- Department of Biochemistry and Pharmacology, University of Melbourne, Parkville, Vic., Australia
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Vic., Australia
| | - Peter M Colman
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
| | - Peter E Czabotar
- Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
- Department of Medical Biology, University of Melbourne, Parkville, Vic., Australia
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6
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Jenner A, Garcia-Saez AJ. The regulation of the apoptotic pore-An immunological tightrope walk. Adv Immunol 2024; 162:59-108. [PMID: 38866439 DOI: 10.1016/bs.ai.2024.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
Apoptotic pore formation in mitochondria is the pivotal point for cell death during mitochondrial apoptosis. It is regulated by BCL-2 family proteins in response to various cellular stress triggers and mediates mitochondrial outer membrane permeabilization (MOMP). This allows the release of mitochondrial contents into the cytosol, which triggers rapid cell death and clearance through the activation of caspases. However, under conditions of low caspase activity, the mitochondrial contents released into the cytosol through apoptotic pores serve as inflammatory signals and activate various inflammatory responses. In this chapter, we discuss how the formation of the apoptotic pore is regulated by BCL-2 proteins as well as other cellular or mitochondrial proteins and membrane lipids. Moreover, we highlight the importance of sublethal MOMP in the regulation of mitochondrial-activated inflammation and discuss its physiological consequences in the context of pathogen infection and disease and how it can potentially be exploited therapeutically, for example to improve cancer treatment.
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Affiliation(s)
- Andreas Jenner
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Ana J Garcia-Saez
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany.
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7
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Zeng X, Wang Z, Yu L, Wang L, Liu Y, Chen Y, Wang C. Zinc Supplementation Reduces Testicular Cell Apoptosis in Mice and Improves Spermatogenic Dysfunction Caused by Marginal Zinc Deficiency. Biol Trace Elem Res 2024; 202:1656-1668. [PMID: 37515670 DOI: 10.1007/s12011-023-03789-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 07/18/2023] [Indexed: 07/31/2023]
Abstract
Zinc (Zn) is an important trace element in the human body and plays an important role in growth, development, and male reproductive functions. Marginal zinc deficiency (MZD) is common in the human population and can cause spermatogenic dysfunction in males. Therefore, the aim of this study was to investigate methods to improve spermatogenic dysfunction caused by MZD and to further explore its mechanism of action. A total of 75 4-week-old male SPF ICR mice were randomly divided into five groups (control, MZD, MZD + ZnY2, MZD + ZnY4, and MZD + ZnY8, 15 mice per group). The dietary Zn content was 30 mg/kg in the control group and 10 mg/kg in the other groups. From low to high, the Zn supplementation doses administered to the three groups were 2, 4, and 8 mg/kg·bw. After 35 days, the zinc content, sperm quality, activity of spermatogenic enzymes, oxidative stress level, and apoptosis level of the testes in mice were determined. The results showed that MZD decreased the level of Zn in the serum, sperm quality, and activity of spermatogenic enzymes in mice. After Zn supplementation, the Zn level in the serum increased, sperm quality was significantly improved, and spermatogenic enzyme activity was restored. In addition, MZD reduced the content of antioxidants (copper-zinc superoxide dismutase (Cu-Zn SOD), metallothionein (MT), and glutathione (GSH) and promoted malondialdehyde (MDA) production. The apoptosis index of the testis also increased significantly in the MZD group. After Zn supplementation, the level of oxidative stress decreased, and the apoptosis index in the testis was reduced. Furthermore, quantitative real-time polymerase chain reaction (qRT-PCR) showed that the expression of B-cell lymphoma-2 (Bcl-2) mRNA and Bcl-2/BCL2-associated X (Bax) in the control group decreased in testicular cells, and their expression was restored after Zn supplementation. The results of this study indicated that Zn supplementation can reduce the level of oxidative stress and increase the ability of testicular cells to resist apoptosis, thereby improving spermatogenic dysfunction caused by MZD in mice.
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Affiliation(s)
- Xiangchao Zeng
- Department of Toxicology, School of Public Health, Wuhan University, Wuhan, 430071, Hubei Province, People's Republic of China
| | - Ziqiong Wang
- Department of Toxicology, School of Public Health, Wuhan University, Wuhan, 430071, Hubei Province, People's Republic of China
| | - Lu Yu
- Department of Toxicology, School of Public Health, Wuhan University, Wuhan, 430071, Hubei Province, People's Republic of China
| | - Lei Wang
- Department of Toxicology, School of Public Health, Wuhan University, Wuhan, 430071, Hubei Province, People's Republic of China
| | - Yueling Liu
- Department of Toxicology, School of Public Health, Wuhan University, Wuhan, 430071, Hubei Province, People's Republic of China
| | - Yuxin Chen
- Department of Toxicology, School of Public Health, Wuhan University, Wuhan, 430071, Hubei Province, People's Republic of China
| | - Chunhong Wang
- Department of Toxicology, School of Public Health, Wuhan University, Wuhan, 430071, Hubei Province, People's Republic of China.
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8
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Nakamura K, Seno M, Yoshimura Y, Suzuki O. Long-term culture induces Bax-dependent apoptosis in rat preimplantation embryos. Mol Reprod Dev 2024; 91:e23711. [PMID: 37831754 DOI: 10.1002/mrd.23711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 09/06/2023] [Accepted: 09/20/2023] [Indexed: 10/15/2023]
Abstract
Although rat preimplantation embryos are necessary for producing genetically modified rats, their in vitro culture remains a challenge. Rat zygotes can develop from the one-cell stage to the blastocyst stage in vitro; however, long-term culture reduces their developmental competence via an unknown mechanism. In this study, we examined how in vitro conditions affect rat preimplantation embryos, which may explain this reduced competence. Comprehensive gene expression analysis showed that genes related to apoptosis and energy metabolism were differentially expressed in rat embryos cultured long-term in vitro compared with those developed in vivo. Furthermore, we found that the expression of Bak1 and Bax, which are responsible for mitochondrial outer membrane permeabilization, were more upregulated in embryos cultured in vitro than those developed in vivo. Similarly, apoptosis-dependent DNA fragmentation was also exacerbated in in vitro culture conditions. Finally, gene disruption using CRISPR/Cas9 showed that Bax, but not Bak1, was responsible for these effects. These findings suggest that long-term in vitro culture induces Bax-dependent apoptosis through the mitochondrial pathway and may provide clues to improve the long-term culture of rat preimplantation embryos for genetic engineering research.
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Affiliation(s)
- Kazuomi Nakamura
- Advanced Medicine, Innovation and Clinical Research Center, Tottori University Hospital, Yonago, Tottori, Japan
| | - Misako Seno
- Advanced Medicine & Translational Research Center, Organization for Research Initiative and Promotion, Tottori University, Yonago, Tottori, Japan
| | - Yuki Yoshimura
- Division of Integrative Physiology, Faculty of Medicine, Tottori University, Yonago, Tottori, Japan
| | - Osamu Suzuki
- Laboratory of Animal Models for Human Diseases, National Institutes of Biomedical Innovation, Health and Nutrition, Ibaraki, Osaka, Japan
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9
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Dehghan S, Kheshtchin N, Hassannezhad S, Soleimani M. Cell death classification: A new insight based on molecular mechanisms. Exp Cell Res 2023; 433:113860. [PMID: 38013091 DOI: 10.1016/j.yexcr.2023.113860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 11/17/2023] [Accepted: 11/18/2023] [Indexed: 11/29/2023]
Abstract
Cells tend to disintegrate themselves or are forced to undergo such destructive processes in critical circumstances. This complex cellular function necessitates various mechanisms and molecular pathways in order to be executed. The very nature of cell death is essentially important and vital for maintaining homeostasis, thus any type of disturbing occurrence might lead to different sorts of diseases and dysfunctions. Cell death has various modalities and yet, every now and then, a new type of this elegant procedure gets to be discovered. The diversity of cell death compels the need for a universal organizing system in order to facilitate further studies, therapeutic strategies and the invention of new methods of research. Considering all that, we attempted to review most of the known cell death mechanisms and sort them all into one arranging system that operates under a simple but subtle decision-making (If \ Else) order as a sorting algorithm, in which it decides to place and sort an input data (a type of cell death) into its proper set, then a subset and finally a group of cell death. By proposing this algorithm, the authors hope it may solve the problems regarding newer and/or undiscovered types of cell death and facilitate research and therapeutic applications of cell death.
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Affiliation(s)
- Sepehr Dehghan
- Department of Medical Basic Sciences, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Nasim Kheshtchin
- Department of Immunology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Maryam Soleimani
- Department of Medical Basic Sciences, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran.
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10
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Czabotar PE, Garcia-Saez AJ. Mechanisms of BCL-2 family proteins in mitochondrial apoptosis. Nat Rev Mol Cell Biol 2023; 24:732-748. [PMID: 37438560 DOI: 10.1038/s41580-023-00629-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2023] [Indexed: 07/14/2023]
Abstract
The proteins of the BCL-2 family are key regulators of mitochondrial apoptosis, acting as either promoters or inhibitors of cell death. The functional interplay and balance between the opposing BCL-2 family members control permeabilization of the outer mitochondrial membrane, leading to the release of activators of the caspase cascade into the cytosol and ultimately resulting in cell death. Despite considerable research, our knowledge about the mechanisms of the BCL-2 family of proteins remains insufficient, which complicates cell fate predictions and does not allow us to fully exploit these proteins as targets for drug discovery. Detailed understanding of the formation and molecular architecture of the apoptotic pore in the outer mitochondrial membrane remains a holy grail in the field, but new studies allow us to begin constructing a structural model of its arrangement. Recent literature has also revealed unexpected activities for several BCL-2 family members that challenge established concepts of how they regulate mitochondrial permeabilization. In this Review, we revisit the most important advances in the field and integrate them into a new structure-function-based classification of the BCL-2 family members that intends to provide a comprehensive model for BCL-2 action in apoptosis. We close this Review by discussing the potential of drugging the BCL-2 family in diseases characterized by aberrant apoptosis.
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Affiliation(s)
- Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Victoria, Australia.
- Department of Medical Biology, University of Melbourne, Melbourne, Victoria, Australia.
| | - Ana J Garcia-Saez
- Membrane Biophysics, Institute of Genetics, CECAD, University of Cologne, Cologne, Germany.
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11
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Yao M, Li G, Zhou LY, Zheng Z, Sun YL, Liu SF, Wang YJ, Cui XJ. Shikonin inhibits neuronal apoptosis via regulating endoplasmic reticulum stress in the rat model of double-level chronic cervical cord compression. Cell Biol Toxicol 2023; 39:907-928. [PMID: 35028790 DOI: 10.1007/s10565-021-09648-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 08/17/2021] [Indexed: 01/16/2023]
Abstract
Cervical spondylotic myelopathy (CSM) is a clinically symptomatic entity arising from the spinal cord compression by degenerative diseases. Although endoplasmic reticulum (ER) stress has been commonly observed in several neurodegenerative diseases, the relationship between ER stress and CSM remains unknown. Shikonin is known to protect PC12 by inhibiting apoptosis in vitro. This study hypothesised that ER stress was vital in neuronal apoptosis in CSM. Shikonin might inhibit such responses by regulating ER stress through the protein kinase-like ER kinase-eukaryotic translation initiation factor 2 α-subunit-C/EBP homologous protein (PERK-eIF2α-CHOP) signalling pathway. Thus, the aim of this study was evaluating the neuroprotective effect of shikonin in rats with double-level chronic cervical cord compression, as well as primary rat cortical neurons with glutamate-induced neurotoxicity. The result showed that ER stress-related upregulation of PERK-eIF2α-CHOP resulted in rat neuronal apoptosis after chronic cervical cord compression; then, shikonin promoted motor recovery and inhibited neuronal apoptosis by attenuating PERK-eIF2α-CHOP and prevented Bax translocation from cytoplasm to mitochondrion induced by CHOP of neurons in rats with chronic compression. Also, it was found that shikonin could protect rat primary cortical neuron against glutamate toxicity by regulating ER stress through the PERK-eIF2α-CHOP pathway in vitro. In conclusion, shikonin might inhibit neuronal apoptosis by regulating ER stress through attenuating the activation of PERK-eIF2α-CHOP.
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Affiliation(s)
- Min Yao
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, 725 South Wanping Road, Shanghai, 200032, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China
| | - Gan Li
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, 725 South Wanping Road, Shanghai, 200032, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China
| | - Long-Yun Zhou
- Rehabilitation Medicine Center, Jiangsu Provincial People's Hospital, Jiangsu, 210029, China
| | - Zhong Zheng
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, 725 South Wanping Road, Shanghai, 200032, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China
| | - Yue-Li Sun
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, 725 South Wanping Road, Shanghai, 200032, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China
| | - Shu-Fen Liu
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, 725 South Wanping Road, Shanghai, 200032, China
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China
| | - Yong-Jun Wang
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, 725 South Wanping Road, Shanghai, 200032, China.
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China.
| | - Xue-Jun Cui
- Spine Disease Institute, Longhua Hospital, Shanghai University of Traditional Chinese Medicine, 725 South Wanping Road, Shanghai, 200032, China.
- Key Laboratory of Theory and Therapy of Muscles and Bones, Ministry of Education, Shanghai University of Traditional Chinese Medicine, Shanghai, 200032, China.
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12
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Gonzalo Ó, Benedi A, Vela L, Anel A, Naval J, Marzo I. Study of the Bcl-2 Interactome by BiFC Reveals Differences in the Activation Mechanism of Bax and Bak. Cells 2023; 12:cells12050800. [PMID: 36899936 PMCID: PMC10000386 DOI: 10.3390/cells12050800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 02/23/2023] [Accepted: 02/28/2023] [Indexed: 03/08/2023] Open
Abstract
Evasion of apoptosis is one of the hallmarks of cancer cells. Proteins of the Bcl-2 family are key regulators of the intrinsic pathway of apoptosis, and alterations in some of these proteins are frequently found in cancer cells. Permeabilization of the outer mitochondrial membrane, regulated by pro- and antiapoptotic members of the Bcl-2 family of proteins, is essential for the release of apoptogenic factors leading to caspase activation, cell dismantlement, and death. Mitochondrial permeabilization depends on the formation of oligomers of the effector proteins Bax and Bak after an activation event mediated by BH3-only proteins and regulated by antiapoptotic members of the Bcl-2 family. In the present work, we have studied interactions between different members of the Bcl-2 family in living cells via the BiFC technique. Despite the limitations of this technique, present data suggest that native proteins of the Bcl-2 family acting inside living cells establish a complex network of interactions, which would fit nicely into "mixed" models recently proposed by others. Furthermore, our results point to differences in the regulation of Bax and Bak activation by proteins of the antiapoptotic and BH3-only subfamilies. We have also applied the BiFC technique to explore the different molecular models proposed for Bax and Bak oligomerization. Bax and Bak's mutants lacking the BH3 domain were still able to associate and give BiFC signals, suggesting the existence of alternative surfaces of interaction between two Bax or Bak molecules. These results agree with the widely accepted symmetric model for the dimerization of these proteins and also suggest that other regions, different from the α6 helix, could be involved in the oligomerization of BH3-in groove dimers.
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13
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Moldoveanu T. Apoptotic mitochondrial poration by a growing list of pore-forming BCL-2 family proteins. Bioessays 2023; 45:e2200221. [PMID: 36650950 PMCID: PMC9975053 DOI: 10.1002/bies.202200221] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/31/2022] [Accepted: 01/02/2023] [Indexed: 01/19/2023]
Abstract
The pore-forming BCL-2 family proteins are effectors of mitochondrial poration in apoptosis initiation. Two atypical effectors-BOK and truncated BID (tBID)-join the canonical effectors BAK and BAX. Gene knockout revealed developmental phenotypes in the absence the effectors, supporting their roles in vivo. During apoptosis effectors are activated and change shape from dormant monomers to dynamic oligomers that associate with and permeabilize mitochondria. BID is activated by proteolysis, BOK accumulates on inhibition of its degradation by the E3 ligase gp78, while BAK and BAX undergo direct activation by BH3-only initiators, autoactivation, and crossactivation. Except tBID, effector oligomers on the mitochondria appear as arcs and rings in super-resolution microscopy images. The BH3-in-groove dimers of BAK and BAX, the tBID monomers, and uncharacterized BOK species are the putative building blocks of apoptotic pores. Effectors interact with lipids and bilayers but the mechanism of membrane poration remains elusive. I discuss effector-mediated mitochondrial poration.
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Affiliation(s)
- Tudor Moldoveanu
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences,Correspondence:
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14
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Sevim Nalkiran H, Akcora Yildiz D, Saydam F, Guzel AI, Nalkiran I. Targeting the anaphase-promoting complex/cyclosome (APC/C) enhanced antiproliferative and apoptotic response in bladder cancer. Saudi J Biol Sci 2023; 30:103564. [PMID: 36794046 PMCID: PMC9923226 DOI: 10.1016/j.sjbs.2023.103564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 12/13/2022] [Accepted: 01/17/2023] [Indexed: 01/24/2023] Open
Abstract
Improving the chemotherapy sensitivity of bladder cancer is a current clinical challenge. It is critical to seek out effective combination therapies that include low doses of cisplatin due to its dose-limiting toxicity. This study aims to investigate the cytotoxic effects of the combination therapy including proTAME, a small molecule inhibitor, targeting Cdc-20 and to determine the expression levels of several APC/C pathway-related genes that may play a role in the chemotherapy response of RT-4 (bladder cancer) and ARPE-19 (normal epithelial) cells. The IC20 and IC50 values were determined by MTS assay. The expression levels of apoptosis-associated (Bax and Bcl-2) and APC/C-associated (Cdc-20, Cyclin-B1, Securin, and Cdh-1) genes were assessed by qRT-PCR. Cell colonization ability and apoptosis were examined by clonogenic survival experiment and Annexin V/PI staining, respectively. Low-dose combination therapy showed a superior inhibition effect on RT-4 cells by increasing cell death and inhibiting colony formation. Triple-agent combination therapy further increased the percentage of late apoptotic and necrotic cells compared to the doublet-therapy with gemcitabine and cisplatin. ProTAME-containing combination therapies resulted in an elevation in Bax/Bcl-2 ratio in RT-4 cells, while a significant decrease was observed in proTAME-treated ARPE-19 cells. Cdc-20 expression in proTAME combined treatment groups were found to be decreased compared to their control groups. Low-dose triple-agent combination induced cytotoxicity and apoptosis in RT-4 cells effectively. It is essential to evaluate the role of APC/C pathway-associated potential biomarkers as therapeutic targets and define new combination therapy regimens to achieve improved tolerability in bladder cancer patients in the future.
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Affiliation(s)
- Hatice Sevim Nalkiran
- Department of Medical Biology, Faculty of Medicine, Recep Tayyip Erdogan University, Rize, Turkey,Corresponding author at: Department of Medical Biology, Faculty of Medicine, Recep Tayyip Erdogan University, Islampasa, 53100 Rize, Turkey.
| | - Dilara Akcora Yildiz
- Department of Biology, Faculty of Arts and Sciences, Mehmet Akif Ersoy University, Burdur, Turkey
| | - Faruk Saydam
- Department of Medical Biology, Faculty of Medicine, Recep Tayyip Erdogan University, Rize, Turkey
| | - Ali Irfan Guzel
- Department of Medical Biology, Faculty of Medicine, Bilecik Seyh Edebali University, Bilecik, Turkey
| | - Ihsan Nalkiran
- Department of Medical Biology, Faculty of Medicine, Recep Tayyip Erdogan University, Rize, Turkey
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15
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Mitochondrial DNA in cell death and inflammation. Biochem Soc Trans 2023; 51:457-472. [PMID: 36815695 PMCID: PMC9988000 DOI: 10.1042/bst20221525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/24/2023]
Abstract
Cytosolic DNA is recognized by the innate immune system as a potential threat. During apoptotic cell death, mitochondrial DNA (mtDNA) release activates the DNA sensor cyclic GMP-AMP synthase (cGAS) to promote a pro-inflammatory type I interferon response. Inflammation following mtDNA release during apoptotic cell death can be exploited to engage anti-tumor immunity and represents a potential avenue for cancer therapy. Additionally, various studies have described leakage of mtDNA, independent of cell death, with different underlying cues such as pathogenic infections, changes in mtDNA packaging, mtDNA stress or reduced mitochondrial clearance. The interferon response in these scenarios can be beneficial but also potentially disadvantageous, as suggested by a variety of disease phenotypes. In this review, we discuss mechanisms underlying mtDNA release governed by cell death pathways and summarize release mechanisms independent of cell death. We further highlight the similarities and differences in mtDNA release pathways, outlining gaps in our knowledge and questions for further research. Together, a deeper understanding of how and when mtDNA is released may enable the development of drugs to specifically target or inhibit mtDNA release in different disease settings.
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16
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Dihydromyricetin Inhibits Pseudorabies Virus Multiplication In Vitro by Regulating NF-κB Signaling Pathway and Apoptosis. Vet Sci 2023; 10:vetsci10020111. [PMID: 36851415 PMCID: PMC9961748 DOI: 10.3390/vetsci10020111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/12/2023] [Accepted: 01/29/2023] [Indexed: 02/05/2023] Open
Abstract
Pseudorabies virus (PRV) infections have caused huge economic losses to the breeding industry worldwide, especially pig husbandry. PRV could threaten human health as an easily ignored zoonotic pathogen. The emergence of new mutants significantly reduced the protective effect of vaccination, indicating an urgent need to develop specific therapeutic drugs for PRV infection. In this study, we found that dihydromyricetin (DMY) could dose-dependently restrain PRV infection in vitro with an IC50 of 161.34 μM; the inhibition rate of DMY at a concentration of 500 μM was 92.16 %. Moreover, the mode of action showed that DMY directly inactivated PRV virion and inhibited viral adsorption and cellular replication. DMY treatment could improve PRV-induced abnormal changes of the NF-κB signaling pathway and excessive inflammatory response through regulation of the contents of IκBα and p-P65/P65 and the transcriptional levels of cytokines (TNF-α, IL-1β and IL-6). Furthermore, DMY promoted the apoptosis of PRV-infected cells through the regulation of the expressions of Bax and Bcl-xl and the transcriptional levels of Caspase-3, Bax, Bcl-2 and Bcl-xl, thereby limiting the production of progeny virus. These findings indicated that DMY could be a candidate drug for the treatment of PRV infection.
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17
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Role of C-terminal domain of Mycobacterium tuberculosis PE6 (Rv0335c) protein in host mitochondrial stress and macrophage apoptosis. Apoptosis 2023; 28:136-165. [PMID: 36258102 PMCID: PMC9579591 DOI: 10.1007/s10495-022-01778-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2022] [Indexed: 11/02/2022]
Abstract
PE/PPE proteins of Mycobacterium tuberculosis (Mtb) target the host organelles to dictate the outcome of infection. This study investigated the significance of PE6/Rv0335c protein's unique C-terminal in causing host mitochondrial perturbations and apoptosis. In-silico analysis revealed that similar to eukaryotic apoptotic Bcl2 proteins, Rv0335c had disordered, hydrophobic C-terminal and two BH3-like motifs in which one was located at C-terminal. Also, Rv0335c's N terminal had mitochondrial targeting sequence. Since, C-terminal of Bcl2 proteins are crucial for mitochondria targeting and apoptosis; it became relevant to evaluate the role of Rv0335c's C-terminal domain in modulating host mitochondrial functions and apoptosis. To confirm this, in-vitro experiments were conducted with Rv0335c whole protein and Rv0335c∆Cterm (C-terminal domain deleted Rv0335c) protein. Rv0335c∆Cterm caused significant reduction in mitochondrial perturbations and Caspase-mediated apoptosis of THP1 macrophages in comparison to Rv0335c. However, the deletion of C-terminal domain didn't affect Rv0335c's ability to localize to mitochondria. Nine Ca2+ binding residues were predicted within Rv0335c and four of them were at the C-terminal. In-vitro studies confirmed that Rv0335c caused significant increase in intracellular calcium influx whereas Rv0335c∆Cterm had insignificant effect on Ca2+ influx. Rv0335c has been reported to be a TLR4 agonist and, we observed a significant reduction in the expression of TLR4-HLA-DR-TNF-α in response to Rv0335c∆Cterm protein also suggesting the role of Rv0335c's C-terminal domain in host-pathogen interaction. These findings indicate the possibility of Rv0335c as a molecular mimic of eukaryotic Bcl2 proteins which equips it to cause host mitochondrial perturbations and apoptosis that may facilitate pathogen persistence.
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18
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Pore-forming proteins as drivers of membrane permeabilization in cell death pathways. Nat Rev Mol Cell Biol 2022; 24:312-333. [PMID: 36543934 DOI: 10.1038/s41580-022-00564-w] [Citation(s) in RCA: 63] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/08/2022] [Indexed: 12/24/2022]
Abstract
Regulated cell death (RCD) relies on activation and recruitment of pore-forming proteins (PFPs) that function as executioners of specific cell death pathways: apoptosis regulator BAX (BAX), BCL-2 homologous antagonist/killer (BAK) and BCL-2-related ovarian killer protein (BOK) for apoptosis, gasdermins (GSDMs) for pyroptosis and mixed lineage kinase domain-like protein (MLKL) for necroptosis. Inactive precursors of PFPs are converted into pore-forming entities through activation, membrane recruitment, membrane insertion and oligomerization. These mechanisms involve protein-protein and protein-lipid interactions, proteolytic processing and phosphorylation. In this Review, we discuss the structural rearrangements incurred by RCD-related PFPs and describe the mechanisms that manifest conversion from autoinhibited to membrane-embedded molecular states. We further discuss the formation and maturation of membrane pores formed by BAX/BAK/BOK, GSDMs and MLKL, leading to diverse pore architectures. Lastly, we highlight commonalities and differences of PFP mechanisms involving BAX/BAK/BOK, GSDMs and MLKL and conclude with a discussion on how, in a population of challenged cells, the coexistence of cell death modalities may have profound physiological and pathophysiological implications.
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19
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Riche K, Lenard NR. Quercetin's Effects on Glutamate Cytotoxicity. Molecules 2022; 27:7620. [PMID: 36364448 PMCID: PMC9657878 DOI: 10.3390/molecules27217620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 11/03/2022] [Accepted: 11/04/2022] [Indexed: 08/13/2023] Open
Abstract
The potentially therapeutic effects of the naturally abundant plant flavonoid quercetin have been extensively studied. An extensive body of literature suggests that quercetin's powerful antioxidant effects may relate to its ability to treat disease. Glutamate excitotoxicity occurs when a neuron is overstimulated by the neurotransmitter glutamate and causes dysregulation of intracellular calcium concentrations. Quercetin has been shown to be preventative against many forms of neuronal cell death resulting from glutamate excitotoxicity, such as oncosis, intrinsic apoptosis, mitochondrial permeability transition, ferroptosis, phagoptosis, lysosomal cell death, parthanatos, and death by reactive oxygen species (ROS)/reactive nitrogen species (RNS) generation. The clinical importance for the attenuation of glutamate excitotoxicity arises from the need to deter the continuous formation of tissue infarction caused by various neurological diseases, such as ischemic stroke, seizures, neurodegenerative diseases, and trauma. This review aims to summarize what is known concerning glutamate physiology and glutamate excitotoxic pathophysiology and provide further insight into quercetin's potential to hinder neuronal death caused by cell death pathways activated by glutamate excitotoxicity. Quercetin's bioavailability may limit its use clinically, however. Thus, future research into ways to increase its bioavailability are warranted.
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Affiliation(s)
| | - Natalie R. Lenard
- Department of Biology, School of Arts and Sciences, Franciscan Missionaries of Our Lady University, 5414 Brittany Drive, Baton Rouge, LA 70808, USA
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20
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Wolf P, Schoeniger A, Edlich F. Pro-apoptotic complexes of BAX and BAK on the outer mitochondrial membrane. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119317. [PMID: 35752202 DOI: 10.1016/j.bbamcr.2022.119317] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 06/02/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
In multicellular organisms the regulated cell death apoptosis is critically important for both ontogeny and homeostasis. Mitochondria are indispensable for stress-induced apoptosis. The BCL-2 protein family controls mitochondrial apoptosis and initiates cell death through the pro-apoptotic activities of BAX and BAK at the outer mitochondrial membrane (OMM). Cellular survival is ensured by the retrotranslocation of mitochondrial BAX and BAK into the cytosol by anti-apoptotic BCL-2 proteins. BAX/BAK-dependent OMM permeabilization releases the mitochondrial cytochrome c (cyt c), which initiates activation of caspase-9. The caspase cascade leads to cell shrinkage, plasma membrane blebbing, chromatin condensation, and apoptotic body formation. Although it is clear that ultimately complexes of active BAX and BAK commit the cell to apoptosis, the nature of these complexes is still enigmatic. Excessive research has described a range of complexes, varying from a few molecules to several 10,000, in different systems. BAX/BAK complexes potentially form ring-like structures that could expose the inner mitochondrial membrane. It has been suggested that these pores allow the efflux of small proteins and even mitochondrial DNA. Here we summarize the current state of knowledge for mitochondrial BAX/BAK complexes and the interactions between these proteins and the membrane.
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Affiliation(s)
- Philipp Wolf
- Institute of Biochemistry, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Axel Schoeniger
- Institute of Biochemistry, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany
| | - Frank Edlich
- Institute of Biochemistry, Faculty of Veterinary Medicine, University of Leipzig, 04103 Leipzig, Germany.
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21
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Sekar G, Singh G, Qin X, Guibao CD, Schwam B, Inde Z, Grace CR, Zhang W, Slavish PJ, Lin W, Chen T, Lee RE, Rankovic Z, Sarosiek K, Moldoveanu T. Small molecule SJ572946 activates BAK to initiate apoptosis. iScience 2022; 25:105064. [PMID: 36147946 PMCID: PMC9485059 DOI: 10.1016/j.isci.2022.105064] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 06/29/2022] [Accepted: 08/30/2022] [Indexed: 01/11/2023] Open
Abstract
Poration of the outer mitochondrial membrane by the effector BCL-2 proteins BAK and BAX initiates apoptosis. BH3-only initiators BID and BIM trigger conformational changes in BAK and BAX transforming them from globular dormant proteins to oligomers of the apoptotic pores. Small molecules that can directly activate effectors are being sought for applications in cancer treatment. Here, we describe the small molecule SJ572946, discovered in a fragment-based screen that binds to the activation groove of BAK and selectively triggers BAK activation over that of BAX in liposome and mitochondrial permeabilization assays. SJ572946 independently kills BAK-expressing BCL2allKO HCT116 cells revealing on target cellular activity. In combination with apoptotic inducers and BH3 mimetics, SJ572946 kills experimental cancer cell lines. SJ572946 also cooperates with the endogenous BAK activator BID in activating a misfolded BAK mutant substantially impaired in activation. SJ572946 is a proof-of-concept tool for probing BAK-mediated apoptosis in preclinical cancer research.
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Affiliation(s)
- Giridhar Sekar
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Geetika Singh
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Children’s GMP, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Xingping Qin
- John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston,02115 MA, USA,Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, 02115 MA, USA,Laboratory of Systems Pharmacology, Harvard Medical School, Boston,02115 MA, USA
| | - Cristina D. Guibao
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Brittany Schwam
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Zintis Inde
- John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston,02115 MA, USA,Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, 02115 MA, USA,Laboratory of Systems Pharmacology, Harvard Medical School, Boston,02115 MA, USA
| | - Christy R. Grace
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Weixing Zhang
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - P. Jake Slavish
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Wenwei Lin
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Taosheng Chen
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Richard E. Lee
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Zoran Rankovic
- Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA
| | - Kristopher Sarosiek
- John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston,02115 MA, USA,Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard School of Public Health, Boston, 02115 MA, USA,Laboratory of Systems Pharmacology, Harvard Medical School, Boston,02115 MA, USA
| | - Tudor Moldoveanu
- Department of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Department of Chemical Biology and Therapeutics, St. Jude Children’s Research Hospital, Memphis, TN 38105, USA,Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Roeck, AR 72205, USA,Corresponding author
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22
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Robin AY, Miller MS, Iyer S, Shi MX, Wardak AZ, Lio D, Smith NA, Smith BJ, Birkinshaw RW, Czabotar PE, Kluck RM, Colman PM. Structure of the BAK-activating antibody 7D10 bound to BAK reveals an unexpected role for the α1-α2 loop in BAK activation. Cell Death Differ 2022; 29:1757-1768. [PMID: 35279694 PMCID: PMC9433411 DOI: 10.1038/s41418-022-00961-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 02/13/2022] [Accepted: 02/17/2022] [Indexed: 11/08/2022] Open
Abstract
Pro-apoptotic BAK and BAX are activated by BH3-only proteins to permeabilise the outer mitochondrial membrane. The antibody 7D10 also activates BAK on mitochondria and its epitope has previously been mapped to BAK residues in the loop connecting helices α1 and α2 of BAK. A crystal structure of the complex between the Fv fragment of 7D10 and the BAK mutant L100A suggests a possible mechanism of activation involving the α1-α2 loop residue M60. M60 mutants of BAK have reduced stability and elevated sensitivity to activation by BID, illustrating that M60, through its contacts with residues in helices α1, α5 and α6, is a linchpin stabilising the inert, monomeric structure of BAK. Our data demonstrate that BAK's α1-α2 loop is not a passive covalent connector between secondary structure elements, but a direct restraint on BAK's activation.
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Affiliation(s)
- Adeline Y Robin
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Michelle S Miller
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Sweta Iyer
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Melissa X Shi
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Ahmad Z Wardak
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Daisy Lio
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Nicholas A Smith
- Department of Chemistry and Physics, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Brian J Smith
- Department of Chemistry and Physics, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Richard W Birkinshaw
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Peter E Czabotar
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia
| | - Ruth M Kluck
- Blood Cells and Blood Cancer Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia.
| | - Peter M Colman
- Structural Biology Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC, 3052, Australia.
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23
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Mohammed JN, Gelles JD, Chipuk JE. FLAMBE: A kinetic fluorescence polarization assay to study activation of monomeric BAX. STAR Protoc 2022; 3:101252. [PMID: 35313708 PMCID: PMC8933840 DOI: 10.1016/j.xpro.2022.101252] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
BAX activation techniques are crucial to studying the intrinsic pathway of apoptosis- thousands of pro-apoptotic signals converge on BAX activation. Current methodologies are predominantly limited to membrane permeabilization studies, which assess endpoint functionality of oligomeric BAX, but overlook early activation steps of cytosolic BAX. Here we detail FLAMBE: a fluorescence polarization ligand assay for monitoring BAX early-activation in solution. We also describe a dual-metric parameterization strategy for distillation of kinetic data and comparative analyses when studying candidate ligands. For complete details on the use and execution of this protocol, please refer to Gelles et al. (2022).
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Affiliation(s)
- Jarvier N. Mohammed
- Laboratory of Mitochondrial Biology in Human Health and Disease, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- 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
- 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
| | - Jesse D. Gelles
- Laboratory of Mitochondrial Biology in Human Health and Disease, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- 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
- The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Jerry Edward Chipuk
- Laboratory of Mitochondrial Biology in Human Health and Disease, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- 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
- 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
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24
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Wang L, Liu X, Kang Q, Pan C, Zhang T, Feng C, Chen L, Wei S, Wang J. Nrf2 Overexpression Decreases Vincristine Chemotherapy Sensitivity Through the PI3K-AKT Pathway in Adult B-Cell Acute Lymphoblastic Leukemia. Front Oncol 2022; 12:876556. [PMID: 35646695 PMCID: PMC9134735 DOI: 10.3389/fonc.2022.876556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/19/2022] [Indexed: 01/08/2023] Open
Abstract
Uncontrolled proliferation is an important cancer cell biomarker, which plays a critical role in carcinogenesis, progression and development of resistance to chemotherapy. An improved understanding of novel genes modulating cancer cell proliferation and mechanism will help develop new therapeutic strategies. The nuclear factor erythroid 2-related factor 2 (Nrf2), a transcription factor, decreases apoptosis when its expression is upregulated. However, the relationship between Nrf2 and Vincristine (VCR) chemotherapy resistance in B-cell acute lymphoblastic leukemia (B-ALL) is not yet established. Our results showed that Nrf2 levels could sufficiently modulate the sensitivity of B-ALL cells to VCRby regulating an apoptotic protein, i.e., the Bcl-2 agonist of cell death (BAD). Chemotherapeutic agents used for the treatment of B-ALL induced Nrf2 overactivation and PI3K-AKT pathway activation in the cells, independent of the resistance to chemotherapy; thus, a potential resistance loop during treatment for B-ALL with a drug combination is established. Therefore, B-ALL patients with a high expression of Nrf2 might mean induction chemotherapy with VCR effective little.
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Affiliation(s)
- Li Wang
- Clinical Medical College, Guizhou Medical University, Guiyang, China
| | - Xin Liu
- Clinical Medical College, Guizhou Medical University, Guiyang, China
| | - Qian Kang
- Department of Hematology, Guizhou Province Institute of Hematology, Guizhou Province Laboratory of Haematopoietic Stem Cell Transplantation Centre, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Chengyun Pan
- Department of Hematology, Guizhou Province Institute of Hematology, Guizhou Province Laboratory of Haematopoietic Stem Cell Transplantation Centre, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Tianzhuo Zhang
- Clinical Medical College, Guizhou Medical University, Guiyang, China
| | - Cheng Feng
- Clinical Medical College, Guizhou Medical University, Guiyang, China
| | - Lu Chen
- Clinical Medical College, Guizhou Medical University, Guiyang, China
| | - Sixi Wei
- Center for Clinical Laboratories, The Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Jishi Wang
- Department of Hematology, Guizhou Province Institute of Hematology, Guizhou Province Laboratory of Haematopoietic Stem Cell Transplantation Centre, Affiliated Hospital of Guizhou Medical University, Guiyang, China.,National Clinical Research Center for Hematologic Diseases, The First Affiliated Hospital of Soochow University, Jiangsu, China
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25
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Sora V, Papaleo E. Structural Details of BH3 Motifs and BH3-Mediated Interactions: an Updated Perspective. Front Mol Biosci 2022; 9:864874. [PMID: 35685242 PMCID: PMC9171138 DOI: 10.3389/fmolb.2022.864874] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/13/2022] [Indexed: 11/18/2022] Open
Abstract
Apoptosis is a mechanism of programmed cell death crucial in organism development, maintenance of tissue homeostasis, and several pathogenic processes. The B cell lymphoma 2 (BCL2) protein family lies at the core of the apoptotic process, and the delicate balance between its pro- and anti-apoptotic members ultimately decides the cell fate. BCL2 proteins can bind with each other and several other biological partners through the BCL2 homology domain 3 (BH3), which has been also classified as a possible Short Linear Motif and whose distinctive features remain elusive even after decades of studies. Here, we aim to provide an updated overview of the structural features characterizing BH3s and BH3-mediated interactions (with a focus on human proteins), elaborating on the plasticity of BCL2 proteins and the motif properties. We also discussed the implication of these findings for the discovery of interactors of the BH3-binding groove of BCL2 proteins and the design of mimetics for therapeutic purposes.
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Affiliation(s)
- Valentina Sora
- Cancer Structural Biology, Danish Cancer Society Research Center, Copenhagen, Denmark
- Cancer Systems Biology, Section for Bioinformatics, Department of Health and Technology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Elena Papaleo
- Cancer Structural Biology, Danish Cancer Society Research Center, Copenhagen, Denmark
- Cancer Systems Biology, Section for Bioinformatics, Department of Health and Technology, Technical University of Denmark, Kongens Lyngby, Denmark
- *Correspondence: Elena Papaleo, ,
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26
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Protein-protein and protein-lipid interactions of pore-forming BCL-2 family proteins in apoptosis initiation. Biochem Soc Trans 2022; 50:1091-1103. [PMID: 35521828 DOI: 10.1042/bst20220323] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/07/2022] [Accepted: 04/08/2022] [Indexed: 01/26/2023]
Abstract
Apoptosis is a common cell death program that is important in human health and disease. Signaling in apoptosis is largely driven through protein-protein interactions. The BCL-2 family proteins function in protein-protein interactions as key regulators of mitochondrial poration, the process that initiates apoptosis through the release of cytochrome c, which activates the apoptotic caspase cascade leading to cellular demolition. The BCL-2 pore-forming proteins BAK and BAX are the key executors of mitochondrial poration. We review the state of knowledge of protein-protein and protein-lipid interactions governing the apoptotic function of BAK and BAX, as determined through X-ray crystallography and NMR spectroscopy studies. BAK and BAX are dormant, globular α-helical proteins that participate in protein-protein interactions with other pro-death BCL-2 family proteins, transforming them into active, partially unfolded proteins that dimerize and associate with and permeabilize mitochondrial membranes. We compare the protein-protein interactions observed in high-resolution structures with those derived in silico by AlphaFold, making predictions based on combining experimental and in silico approaches to delineate the structural basis for novel protein-protein interaction complexes of BCL-2 family proteins.
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27
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Gelles JD, Mohammed JN, Chen Y, Sebastian TM, Chipuk JE. A kinetic fluorescence polarization ligand assay for monitoring BAX early activation. CELL REPORTS METHODS 2022; 2:100174. [PMID: 35419554 PMCID: PMC9004659 DOI: 10.1016/j.crmeth.2022.100174] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 12/20/2021] [Accepted: 02/02/2022] [Indexed: 12/23/2022]
Abstract
Developmental, homeostatic, and pharmacological pro-apoptotic signals converge by activating the BCL-2 family member BAX. Studies investigating molecular regulation of BAX are commonly limited to methodologies measuring endpoint phenotypes and do not assess activation of monomeric BAX. Here, we present FLAMBE, a fluorescence polarization ligand assay for monitoring BAX early activation, that measures activation-induced release of a peptide probe in real time. Using complementary parallel and tandem biochemical techniques, we validate, corroborate, and apply FLAMBE to a contemporary repertoire of BAX modulators, characterizing their contributions within the early steps of BAX activation. Additionally, we use FLAMBE to reveal that historically "dead" BAX mutants remain responsive to activation as quasi-functional monomers. We also identify data metrics for comparative analyses and demonstrate that FLAMBE data align with downstream functional observations. Collectively, FLAMBE advances our understanding of BAX activation and fills a methodological void for studying BAX with broad applications in cell biology and therapeutic development. MOTIVATION In vitro BAX activation studies are invaluable platforms for studying cellular and pharmacological modulators of apoptosis. The gold standard for studying BAX function relies on membrane permeabilization assays, which assess the pore-forming activity of oligomeric BAX. However, there are currently no rapid or kinetic assays to interrogate real-time activation of monomeric BAX in solution, thereby limiting any molecular insights that occur upstream of mitochondrial permeabilization. Furthermore, available methods to observe the activation of monomeric BAX suffer from low throughput and static observations. To address this methodological gap, we developed FLAMBE, a kinetic fluorescence polarization-based assay to measure monomeric BAX activation in solution via concomitant displacement of a labeled peptide. This approach maintains the benefits of rapid kinetic data generation in a low-cost microplate format without requiring specialized equipment or large quantities of protein. FLAMBE compliments available experimental strategies and expands the accessibility of investigators to monitor early steps within the BAX activation continuum.
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Affiliation(s)
- Jesse D. Gelles
- Laboratory of Mitochondrial Biology in Human Health and Disease, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- 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
- The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Jarvier N. Mohammed
- Laboratory of Mitochondrial Biology in Human Health and Disease, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- 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
- 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
| | - Yiyang Chen
- Laboratory of Mitochondrial Biology in Human Health and Disease, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- 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
- 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
| | - Tara M. Sebastian
- Laboratory of Mitochondrial Biology in Human Health and Disease, 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
| | - Jerry Edward Chipuk
- Laboratory of Mitochondrial Biology in Human Health and Disease, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
- 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
- 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
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28
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The concept of intrinsic versus extrinsic apoptosis. Biochem J 2022; 479:357-384. [PMID: 35147165 DOI: 10.1042/bcj20210854] [Citation(s) in RCA: 74] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 12/12/2022]
Abstract
Regulated cell death is a vital and dynamic process in multicellular organisms that maintains tissue homeostasis and eliminates potentially dangerous cells. Apoptosis, one of the better-known forms of regulated cell death, is activated when cell-surface death receptors like Fas are engaged by their ligands (the extrinsic pathway) or when BCL-2-family pro-apoptotic proteins cause the permeabilization of the mitochondrial outer membrane (the intrinsic pathway). Both the intrinsic and extrinsic pathways of apoptosis lead to the activation of a family of proteases, the caspases, which are responsible for the final cell demise in the so-called execution phase of apoptosis. In this review, I will first discuss the most common types of regulated cell death on a morphological basis. I will then consider in detail the molecular pathways of intrinsic and extrinsic apoptosis, discussing how they are activated in response to specific stimuli and are sometimes overlapping. In-depth knowledge of the cellular mechanisms of apoptosis is becoming more and more important not only in the field of cellular and molecular biology but also for its translational potential in several pathologies, including neurodegeneration and cancer.
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29
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Apoptosis, Pyroptosis, and Necroptosis-Oh My! The Many Ways a Cell Can Die. J Mol Biol 2021; 434:167378. [PMID: 34838807 DOI: 10.1016/j.jmb.2021.167378] [Citation(s) in RCA: 134] [Impact Index Per Article: 44.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/12/2021] [Accepted: 11/21/2021] [Indexed: 12/12/2022]
Abstract
Cell death is an essential process in all living organisms and occurs through different mechanisms. The three main types of programmed cell death are apoptosis, pyroptosis, and necroptosis, and each of these pathways employs complex molecular and cellular mechanisms. Although there are mechanisms and outcomes specific to each pathway, they share common components and features. In this review, we discuss recent discoveries in these three best understood modes of cell death, highlighting their singularities, and examining the intriguing notion that common players shape different individual pathways in this highly interconnected and coordinated cell death system. Understanding the similarities and differences of these cell death processes is crucial to enable targeted strategies to manipulate these pathways for therapeutic benefit.
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30
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Sandow JJ, Tan IK, Huang AS, Masaldan S, Bernardini JP, Wardak AZ, Birkinshaw RW, Ninnis RL, Liu Z, Dalseno D, Lio D, Infusini G, Czabotar PE, Webb AI, Dewson G. Dynamic reconfiguration of pro-apoptotic BAK on membranes. EMBO J 2021; 40:e107237. [PMID: 34523147 DOI: 10.15252/embj.2020107237] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 08/02/2021] [Accepted: 08/06/2021] [Indexed: 12/16/2022] Open
Abstract
BAK and BAX, the effectors of intrinsic apoptosis, each undergo major reconfiguration to an activated conformer that self-associates to damage mitochondria and cause cell death. However, the dynamic structural mechanisms of this reconfiguration in the presence of a membrane have yet to be fully elucidated. To explore the metamorphosis of membrane-bound BAK, we employed hydrogen-deuterium exchange mass spectrometry (HDX-MS). The HDX-MS profile of BAK on liposomes comprising mitochondrial lipids was consistent with known solution structures of inactive BAK. Following activation, HDX-MS resolved major reconfigurations in BAK. Mutagenesis guided by our HDX-MS profiling revealed that the BCL-2 homology (BH) 4 domain maintains the inactive conformation of BAK, and disrupting this domain is sufficient for constitutive BAK activation. Moreover, the entire N-terminal region preceding the BAK oligomerisation domains became disordered post-activation and remained disordered in the activated oligomer. Removal of the disordered N-terminus did not impair, but rather slightly potentiated, BAK-mediated membrane permeabilisation of liposomes and mitochondria. Together, our HDX-MS analyses reveal new insights into the dynamic nature of BAK activation on a membrane, which may provide new opportunities for therapeutic targeting.
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Affiliation(s)
- Jarrod J Sandow
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Iris Kl Tan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Alan S Huang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Shashank Masaldan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Jonathan P Bernardini
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Ahmad Z Wardak
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
| | - Richard W Birkinshaw
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Robert L Ninnis
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Ziyan Liu
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Destiny Dalseno
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Daisy Lio
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia
| | - Giuseppi Infusini
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Andrew I Webb
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
| | - Grant Dewson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Vic., Australia.,Department of Medical Biology, The University of Melbourne, Melbourne, Vic., Australia
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31
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Lv F, Qi F, Zhang Z, Wen M, Kale J, Piai A, Du L, Wang S, Zhou L, Yang Y, Wu B, Liu Z, Del Rosario J, Pogmore J, Chou JJ, Andrews DW, Lin J, OuYang B. An amphipathic Bax core dimer forms part of the apoptotic pore wall in the mitochondrial␣membrane. EMBO J 2021; 40:e106438. [PMID: 34101209 PMCID: PMC8280806 DOI: 10.15252/embj.2020106438] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 04/17/2021] [Accepted: 04/27/2021] [Indexed: 02/01/2023] Open
Abstract
Bax proteins form pores in the mitochondrial outer membrane to initiate apoptosis. This might involve their embedding in the cytosolic leaflet of the lipid bilayer, thus generating tension to induce a lipid pore with radially arranged lipids forming the wall. Alternatively, Bax proteins might comprise part of the pore wall. However, there is no unambiguous structural evidence for either hypothesis. Using NMR, we determined a high-resolution structure of the Bax core region, revealing a dimer with the nonpolar surface covering the lipid bilayer edge and the polar surface exposed to water. The dimer tilts from the bilayer normal, not only maximizing nonpolar interactions with lipid tails but also creating polar interactions between charged residues and lipid heads. Structure-guided mutations demonstrate the importance of both types of protein-lipid interactions in Bax pore assembly and core dimer configuration. Therefore, the Bax core dimer forms part of the proteolipid pore wall to permeabilize mitochondria.
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Affiliation(s)
- Fujiao Lv
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Fei Qi
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Zhi Zhang
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Maorong Wen
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Justin Kale
- Biological Sciences, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Alessandro Piai
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Lingyu Du
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
| | - Shuqing Wang
- School of Pharmacy, Tianjin Medical University, Tianjin, China
| | - Liujuan Zhou
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Yaqing Yang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Bin Wu
- National Facility for Protein Science in Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Zhijun Liu
- National Facility for Protein Science in Shanghai, Chinese Academy of Sciences, Shanghai, China
| | - Juan Del Rosario
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Justin Pogmore
- Biological Sciences, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - James J Chou
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - David W Andrews
- Biological Sciences, Sunnybrook Research Institute, University of Toronto, Toronto, ON, Canada
| | - Jialing Lin
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.,Stephenson Cancer Center, Oklahoma City, OK, USA
| | - Bo OuYang
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, CAS Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
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32
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Birkinshaw RW, Iyer S, Lio D, Luo CS, Brouwer JM, Miller MS, Robin AY, Uren RT, Dewson G, Kluck RM, Colman PM, Czabotar PE. Structure of detergent-activated BAK dimers derived from the inert monomer. Mol Cell 2021; 81:2123-2134.e5. [PMID: 33794146 DOI: 10.1016/j.molcel.2021.03.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 01/11/2021] [Accepted: 03/09/2021] [Indexed: 01/27/2023]
Abstract
A body of data supports the existence of core (α2-α5) dimers of BAK and BAX in the oligomeric, membrane-perturbing conformation of these essential apoptotic effector molecules. Molecular structures for these dimers have only been captured for truncated constructs encompassing the core domain alone. Here, we report a crystal structure of BAK α2-α8 dimers (i.e., minus its flexible N-terminal helix and membrane-anchoring C-terminal segment) that has been obtained through the activation of monomeric BAK with the detergent C12E8. Core dimers are evident, linked through the crystal by contacts via latch (α6-α8) domains. This crystal structure shows activated BAK dimers with the extended latch domain present. Our data provide direct evidence for the conformational change converting BAK from inert monomer to the functional dimer that destroys mitochondrial integrity. This dimer is the smallest functional unit for recombinant BAK or BAX described so far.
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Affiliation(s)
- Richard W Birkinshaw
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia.
| | - Sweta Iyer
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Daisy Lio
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Cindy S Luo
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Jason M Brouwer
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Michelle S Miller
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Adeline Y Robin
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Rachel T Uren
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Grant Dewson
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Ruth M Kluck
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Peter M Colman
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia
| | - Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Melbourne, VIC 3052, Australia; Department of Medical Biology, University of Melbourne, Melbourne, VIC 3010, Australia.
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33
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Dadsena S, Jenner A, García-Sáez AJ. Mitochondrial outer membrane permeabilization at the single molecule level. Cell Mol Life Sci 2021; 78:3777-3790. [PMID: 33576840 PMCID: PMC8106609 DOI: 10.1007/s00018-021-03771-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/08/2021] [Indexed: 12/12/2022]
Abstract
Apoptotic cell death is essential for development, immune function or tissue homeostasis, and its mis-regulation is linked to various diseases. Mitochondrial outer membrane permeabilization (MOMP) is a central event in the intrinsic apoptotic pathway and essential to control the execution of cell death. Here we review current concepts in regulation of MOMP focusing on the interaction network of the Bcl-2 family proteins as well as further regulatory elements influencing MOMP. As MOMP is a complex spatially and temporally controlled process, we point out the importance of single-molecule techniques to unveil processes which would be masked by ensemble measurements. We report key single-molecule studies applied to decipher the composition, assembly mechanism and structure of protein complexes involved in MOMP regulation.
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Affiliation(s)
- Shashank Dadsena
- Institute for Genetics, CECAD Research Center, University of Cologne, Cologne, Germany
| | - Andreas Jenner
- Institute for Genetics, CECAD Research Center, University of Cologne, Cologne, Germany
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Ana J García-Sáez
- Institute for Genetics, CECAD Research Center, University of Cologne, Cologne, Germany.
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34
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Mechanisms of mitochondrial cell death. Biochem Soc Trans 2021; 49:663-674. [PMID: 33704419 DOI: 10.1042/bst20200522] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 12/23/2022]
Abstract
Mitochondria are double-membrane bound organelles that not only provide energy for intracellular metabolism, but also play a key role in the regulation of cell death. Mitochondrial outer membrane permeabilization (MOMP), allowing the release of intermembrane space proteins like cytochrome c, is considered a point of no return in apoptosis. MOMP is controlled by the proteins of the B-cell lymphoma 2 (BCL-2) family, including pro-and anti-apoptotic members, whose balance determines the decision between cell death and survival. Other factors such as membrane lipid environment, membrane dynamics, and inter-organelle communications are also known to influence this process. MOMP and apoptosis have been acknowledged as immunologically silent. Remarkably, a growing body of evidence indicates that MOMP can engage in various pro-inflammatory signaling functions. In this mini-review, we discuss about our current knowledge on the mechanisms of mitochondrial apoptosis, as well as the involvement of mitochondria in other kinds of programmed cell death pathways.
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35
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Li Q, Shi N, Cai C, Zhang M, He J, Tan Y, Fu W. The Role of Mitochondria in Pyroptosis. Front Cell Dev Biol 2021; 8:630771. [PMID: 33553170 PMCID: PMC7859326 DOI: 10.3389/fcell.2020.630771] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 12/28/2020] [Indexed: 11/25/2022] Open
Abstract
Pyroptosis is a recently discovered aspartic aspart-specific cysteine protease (Caspase-1/4/5/11) dependent mode of gene-regulated cell death cell death, which is represented by the rupture of cell membrane perforations and the production of proinflammatory mediaters like interleukin-18(IL-18) and interleukin-1β (IL-1β). Mitochondria also play an important role in apoptotic cell death. When it comes to apoptosis of mitochondrion, mitochondrial outer membrane permeabilization (MOMP) is commonly known to cause cell death. As a downstream pathological process of apoptotic signaling, MOMP participates in the leakage of cytochrome-c from mitochondrion to the cytosol and subsequently activate caspase proteases. Hence, targeting MOMP for the sake of manipulating cell death presents potential therapeutic effects among various types of diseases, such as autoimmune disorders, neurodegenerative diseases, and cancer. In this review, we highlights the roles and significance of mitochondria in pyroptosis to provide unexplored strategies that target the mitochondria to regulate cell death for clinical benefits.
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Affiliation(s)
- Qian Li
- Department of Emergency Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Nengxian Shi
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Chen Cai
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Mingming Zhang
- Department of Burns, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jing He
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ying Tan
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Weijun Fu
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, China
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36
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The Mysteries around the BCL-2 Family Member BOK. Biomolecules 2020; 10:biom10121638. [PMID: 33291826 PMCID: PMC7762061 DOI: 10.3390/biom10121638] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 12/19/2022] Open
Abstract
BOK is an evolutionarily conserved BCL-2 family member that resembles the apoptotic effectors BAK and BAX in sequence and structure. Based on these similarities, BOK has traditionally been classified as a BAX-like pro-apoptotic protein. However, the mechanism of action and cellular functions of BOK remains controversial. While some studies propose that BOK could replace BAK and BAX to elicit apoptosis, others attribute to this protein an indirect way of apoptosis regulation. Adding to the debate, BOK has been associated with a plethora of non-apoptotic functions that makes this protein unpredictable when dictating cell fate. Here, we compile the current knowledge and open questions about this paradoxical protein with a special focus on its structural features as the key aspect to understand BOK biological functions.
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37
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Flores‐Romero H, Ros U, Garcia‐Saez AJ. Pore formation in regulated cell death. EMBO J 2020; 39:e105753. [PMID: 33124082 PMCID: PMC7705454 DOI: 10.15252/embj.2020105753] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/13/2020] [Accepted: 10/06/2020] [Indexed: 12/21/2022] Open
Abstract
The discovery of alternative signaling pathways that regulate cell death has revealed multiple strategies for promoting cell death with diverse consequences at the tissue and organism level. Despite the divergence in the molecular components involved, membrane permeabilization is a common theme in the execution of regulated cell death. In apoptosis, the permeabilization of the outer mitochondrial membrane by BAX and BAK releases apoptotic factors that initiate the caspase cascade and is considered the point of no return in cell death commitment. Pyroptosis and necroptosis also require the perforation of the plasma membrane at the execution step, which involves Gasdermins in pyroptosis, and MLKL in the case of necroptosis. Although BAX/BAK, Gasdermins and MLKL share certain molecular features like oligomerization, they form pores in different cellular membranes via distinct mechanisms. Here, we compare and contrast how BAX/BAK, Gasdermins, and MLKL alter membrane permeability from a structural and biophysical perspective and discuss the general principles of membrane permeabilization in the execution of regulated cell death.
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Affiliation(s)
- Hector Flores‐Romero
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Uris Ros
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
| | - Ana J Garcia‐Saez
- Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD)University of CologneCologneGermany
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38
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Kim HN, Ponte F, Nookaew I, Ucer Ozgurel S, Marques-Carvalho A, Iyer S, Warren A, Aykin-Burns N, Krager K, Sardao VA, Han L, de Cabo R, Zhao H, Jilka RL, Manolagas SC, Almeida M. Estrogens decrease osteoclast number by attenuating mitochondria oxidative phosphorylation and ATP production in early osteoclast precursors. Sci Rep 2020; 10:11933. [PMID: 32686739 PMCID: PMC7371870 DOI: 10.1038/s41598-020-68890-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 06/02/2020] [Indexed: 02/08/2023] Open
Abstract
Loss of estrogens at menopause is a major cause of osteoporosis and increased fracture risk. Estrogens protect against bone loss by decreasing osteoclast number through direct actions on cells of the myeloid lineage. Here, we investigated the molecular mechanism of this effect. We report that 17β-estradiol (E2) decreased osteoclast number by promoting the apoptosis of early osteoclast progenitors, but not mature osteoclasts. This effect was abrogated in cells lacking Bak/Bax-two pro-apoptotic members of the Bcl-2 family of proteins required for mitochondrial apoptotic death. FasL has been previously implicated in the pro-apoptotic actions of E2. However, we show herein that FasL-deficient mice lose bone mass following ovariectomy indistinguishably from FasL-intact controls, indicating that FasL is not a major contributor to the anti-osteoclastogenic actions of estrogens. Instead, using microarray analysis we have elucidated that ERα-mediated estrogen signaling in osteoclast progenitors decreases "oxidative phosphorylation" and the expression of mitochondria complex I genes. Additionally, E2 decreased the activity of complex I and oxygen consumption rate. Similar to E2, the complex I inhibitor Rotenone decreased osteoclastogenesis by promoting osteoclast progenitor apoptosis via Bak/Bax. These findings demonstrate that estrogens decrease osteoclast number by attenuating respiration, and thereby, promoting mitochondrial apoptotic death of early osteoclast progenitors.
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Affiliation(s)
- Ha-Neui Kim
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, 4301 W. Markham St. #587, Little Rock, 72205-7199, USA
| | - Filipa Ponte
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, 4301 W. Markham St. #587, Little Rock, 72205-7199, USA
| | - Intawat Nookaew
- Department of Biomedical Informatics, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Serra Ucer Ozgurel
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, 4301 W. Markham St. #587, Little Rock, 72205-7199, USA
| | - Adriana Marques-Carvalho
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, UC-Biotech, Biocant Park, Cantanhede, Portugal
| | - Srividhya Iyer
- Department of Orthopedic Surgery, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Aaron Warren
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, 4301 W. Markham St. #587, Little Rock, 72205-7199, USA
| | - Nukhet Aykin-Burns
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Kimberly Krager
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, USA
| | - Vilma A Sardao
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, UC-Biotech, Biocant Park, Cantanhede, Portugal
| | - Li Han
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, 4301 W. Markham St. #587, Little Rock, 72205-7199, USA
| | - Rafael de Cabo
- Translational Gerontology Branch, NIA, NIH, Baltimore, MD, USA
| | - Haibo Zhao
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, 4301 W. Markham St. #587, Little Rock, 72205-7199, USA
| | - Robert L Jilka
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, 4301 W. Markham St. #587, Little Rock, 72205-7199, USA
| | - Stavros C Manolagas
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, 4301 W. Markham St. #587, Little Rock, 72205-7199, USA.,Department of Orthopedic Surgery, University of Arkansas for Medical Sciences, Little Rock, USA.,Central Arkansas Veterans Healthcare System, Little Rock, AR, 72205, USA
| | - Maria Almeida
- Division of Endocrinology and Metabolism, Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, 4301 W. Markham St. #587, Little Rock, 72205-7199, USA. .,Department of Orthopedic Surgery, University of Arkansas for Medical Sciences, Little Rock, USA. .,Central Arkansas Veterans Healthcare System, Little Rock, AR, 72205, USA.
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39
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Hauseman ZJ, Harvey EP, Newman CE, Wales TE, Bucci JC, Mintseris J, Schweppe DK, David L, Fan L, Cohen DT, Herce HD, Mourtada R, Ben-Nun Y, Bloch NB, Hansen SB, Wu H, Gygi SP, Engen JR, Walensky LD. Homogeneous Oligomers of Pro-apoptotic BAX Reveal Structural Determinants of Mitochondrial Membrane Permeabilization. Mol Cell 2020; 79:68-83.e7. [PMID: 32533918 PMCID: PMC7472837 DOI: 10.1016/j.molcel.2020.05.029] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/13/2020] [Accepted: 05/20/2020] [Indexed: 10/24/2022]
Abstract
BAX is a pro-apoptotic protein that transforms from a cytosolic monomer into a toxic oligomer that permeabilizes the mitochondrial outer membrane. How BAX monomers assemble into a higher-order conformation, and the structural determinants essential to membrane permeabilization, remain a mechanistic mystery. A key hurdle has been the inability to generate a homogeneous BAX oligomer (BAXO) for analysis. Here, we report the production and characterization of a full-length BAXO that recapitulates physiologic BAX activation. Multidisciplinary studies revealed striking conformational consequences of oligomerization and insight into the macromolecular structure of oligomeric BAX. Importantly, BAXO enabled the assignment of specific roles to particular residues and α helices that mediate individual steps of the BAX activation pathway, including unexpected functionalities of BAX α6 and α9 in driving membrane disruption. Our results provide the first glimpse of a full-length and functional BAXO, revealing structural requirements for the elusive execution phase of mitochondrial apoptosis.
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Affiliation(s)
- Zachary J Hauseman
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA; Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Edward P Harvey
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA; Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Catherine E Newman
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA; Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Thomas E Wales
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
| | - Joel C Bucci
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
| | - Julian Mintseris
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Devin K Schweppe
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Liron David
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Lixin Fan
- Small Angle X-ray Scattering Core, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA
| | - Daniel T Cohen
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA; Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Henry D Herce
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA; Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Rida Mourtada
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA; Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Yael Ben-Nun
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA; Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Noah B Bloch
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA; Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Scott B Hansen
- The Scripps Research Institute-Florida, Jupiter, FL 33458, USA
| | - Hao Wu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115, USA
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - John R Engen
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA
| | - Loren D Walensky
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA; Linde Program in Cancer Chemical Biology, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA 02215, USA.
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40
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Robust autoactivation for apoptosis by BAK but not BAX highlights BAK as an important therapeutic target. Cell Death Dis 2020; 11:268. [PMID: 32327636 PMCID: PMC7181796 DOI: 10.1038/s41419-020-2463-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/05/2020] [Accepted: 04/06/2020] [Indexed: 02/08/2023]
Abstract
BAK and BAX, which drive commitment to apoptosis, are activated principally by certain BH3-only proteins that bind them and trigger major rearrangements. One crucial conformation change is exposure of their BH3 domain which allows BAK or BAX to form homodimers, and potentially to autoactivate other BAK and BAX molecules to ensure robust pore formation and cell death. Here, we test whether full-length BAK or mitochondrial BAX that are specifically activated by antibodies can then activate other BAK or BAX molecules. We found that antibody-activated BAK efficiently activated BAK as well as mitochondrial or cytosolic BAX, but antibody-activated BAX unexpectedly proved a poor activator. Notably, autoactivation by BAK involved transient interactions, as BAK and BAX molecules it activated could dissociate and homodimerize. The results suggest that BAK-driven autoactivation may play a substantial role in apoptosis, including recruitment of BAX to the mitochondria. Hence, directly targeting BAK rather than BAX may prove particularly effective in inhibiting unwanted apoptosis, or alternatively, inducing apoptosis in cancer cells.
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41
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Moldoveanu T, Czabotar PE. BAX, BAK, and BOK: A Coming of Age for the BCL-2 Family Effector Proteins. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a036319. [PMID: 31570337 DOI: 10.1101/cshperspect.a036319] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The BCL-2 family of proteins control a key checkpoint in apoptosis, that of mitochondrial outer membrane permeabilization or, simply, mitochondrial poration. The family consists of three subgroups: BH3-only initiators that respond to apoptotic stimuli; antiapoptotic guardians that protect against cell death; and the membrane permeabilizing effectors BAX, BAK, and BOK. On activation, effector proteins are converted from inert monomers into membrane permeabilizing oligomers. For many years, this process has been poorly understood at the molecular level, but a number of recent advances have provided important insights. We review the regulation of these effectors, their activation, subsequent conformational changes, and the ensuing oligomerization events that enable mitochondrial poration, which initiates apoptosis through release of key signaling factors such as cytochrome c We highlight the mysteries that remain in understanding these important proteins in an endeavor to provide a comprehensive picture of where the field currently sits and where it is moving toward.
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Affiliation(s)
- Tudor Moldoveanu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA.,Department of Chemical Biology and Therapeutics, St. Jude Children's Research Hospital, Memphis Tennessee 38105, USA
| | - Peter E Czabotar
- Walter and Eliza Hall Institute of Medical Research, University of Melbourne, Parkville, Victoria 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria 3010, Australia
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42
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Kuwana T, King LE, Cosentino K, Suess J, Garcia-Saez AJ, Gilmore AP, Newmeyer DD. Mitochondrial residence of the apoptosis inducer BAX is more important than BAX oligomerization in promoting membrane permeabilization. J Biol Chem 2020; 295:1623-1636. [PMID: 31901077 PMCID: PMC7008371 DOI: 10.1074/jbc.ra119.011635] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 12/27/2019] [Indexed: 12/31/2022] Open
Abstract
Permeabilization of the mitochondrial outer membrane is a key step in the intrinsic apoptosis pathway, triggered by the release of mitochondrial intermembrane space proteins into the cytoplasm. The BCL-2-associated X apoptosis regulator (BAX) protein critically contributes to this process by forming pores in the mitochondrial outer membrane. However, the relative roles of the mitochondrial residence of BAX and its oligomerization in promoting membrane permeabilization are unclear. To this end, using both cell-free and cellular experimental systems, including membrane permeabilization, size-exclusion chromatography-based oligomer, and retrotranslocation assays, along with confocal microscopy analysis, here we studied two BAX C-terminal variants, T182I and G179P. Neither variant formed large oligomers when activated in liposomes. Nevertheless, the G179P variant could permeabilize liposome membranes, suggesting that large BAX oligomers are not essential for the permeabilization. However, when G179P was transduced into BAX/BCL2 agonist killer (BAK) double-knockout mouse embryonic fibroblasts, its location was solely cytoplasmic, and it then failed to mediate cell death. In contrast, T182I was inefficient in both liposome insertion and permeabilization. Yet, when transduced into cells, BAXT182I resided predominantly on mitochondria, because of its slow retrotranslocation and mediated apoptosis as efficiently as WT BAX. We conclude that BAX's mitochondrial residence in vivo, regulated by both targeting and retrotranslocation, is more significant for its pro-apoptotic activity than its ability to insert and to form higher-order oligomers in model membranes. We propose that this finding should be taken into account when developing drugs that modulate BAX activity.
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Affiliation(s)
- Tomomi Kuwana
- La Jolla Institute for Immunology, La Jolla, California 92037.
| | - Louise E King
- Wellcome Trust Centre for Cell/Matrix Research, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom M13 9PT
| | - Katia Cosentino
- Interfaculty Institute of Biochemistry, University of Tubingen, 72076 Tubingen, Germany
| | | | | | - Andrew P Gilmore
- Wellcome Trust Centre for Cell/Matrix Research, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom M13 9PT
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43
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Bock FJ, Tait SWG. Mitochondria as multifaceted regulators of cell death. Nat Rev Mol Cell Biol 2020; 21:85-100. [PMID: 31636403 DOI: 10.1038/s41580-019-0173-8] [Citation(s) in RCA: 1215] [Impact Index Per Article: 303.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2019] [Indexed: 12/12/2022]
Abstract
Through their many and varied metabolic functions, mitochondria power life. Paradoxically, mitochondria also have a central role in apoptotic cell death. Upon induction of mitochondrial apoptosis, mitochondrial outer membrane permeabilization (MOMP) usually commits a cell to die. Apoptotic signalling downstream of MOMP involves cytochrome c release from mitochondria and subsequent caspase activation. As such, targeting MOMP in order to manipulate cell death holds tremendous therapeutic potential across different diseases, including neurodegenerative diseases, autoimmune disorders and cancer. In this Review, we discuss new insights into how mitochondria regulate apoptotic cell death. Surprisingly, recent data demonstrate that besides eliciting caspase activation, MOMP engages various pro-inflammatory signalling functions. As we highlight, together with new findings demonstrating cell survival following MOMP, this pro-inflammatory role suggests that mitochondria-derived signalling downstream of pro-apoptotic cues may also have non-lethal functions. Finally, we discuss the importance and roles of mitochondria in other forms of regulated cell death, including necroptosis, ferroptosis and pyroptosis. Collectively, these new findings offer exciting, unexplored opportunities to target mitochondrial regulation of cell death for clinical benefit.
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Affiliation(s)
- Florian J Bock
- Cancer Research UK Beatson Institute, Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Stephen W G Tait
- Cancer Research UK Beatson Institute, Institute of Cancer Sciences, University of Glasgow, Glasgow, UK.
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44
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Huo C, Xiao C, She R, Liu T, Tian J, Dong H, Tian H, Hu Y. Chronic heat stress negatively affects the immune functions of both spleens and intestinal mucosal system in pigs through the inhibition of apoptosis. Microb Pathog 2019; 136:103672. [PMID: 31442574 DOI: 10.1016/j.micpath.2019.103672] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/13/2019] [Accepted: 08/19/2019] [Indexed: 12/28/2022]
Abstract
With the globe warming, chronic heat stress (CHS) has been considered to be a common hazard that could negatively affect pig's growth and reproduction performance. However, the effects of CHS on the immune functions of pigs were seldom reported, especially the cellular immune functions of intestinal mucosal system. In order to resolve this problem, a pig CHS model was built firstly and the effects of CHS on numbers of T cells in spleen and small intestines were observed. Exposure to a temperature of 39 °C, 4 h/d for 10d, the expression of heat stress protein 70 (HSP70) was increased dramatically. Under CHS condition, the numbers of CD3+ T cells were increased dramatically in both spleens and small intestines. Besides, the numbers of CD4+T cells and the value of CD4+/CD8+T cells in spleens were also significantly increased. The results highly revealed that CHS made the equilibrium state of immune function destroyed. Furthermore, CHS mainly promoted the expression of anti-apoptosis factor B cell lymphoma-2 (Bcl-2) and thus inhibited the apoptosis of lymphocytes in spleens and intestinal mucosa. This study demonstrates for the first time that CHS negatively affects the immune functions of both spleens and intestinal mucosal system in pigs through the inhibition of apoptosis. Our study can richer the data for study of mechanism of CHS and provide new knowledge for reference of making new strategy to control the disease induced by CHS.
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Affiliation(s)
- Caiyun Huo
- Department of Veterinary Pathology, College of Veterinary Medicine, China Agricultural University, Beijing, PR China
| | - Chong Xiao
- Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, PR China
| | - Ruiping She
- Department of Veterinary Pathology, College of Veterinary Medicine, China Agricultural University, Beijing, PR China
| | - Tianlong Liu
- Department of Veterinary Pathology, College of Veterinary Medicine, China Agricultural University, Beijing, PR China
| | - Jijing Tian
- Department of Veterinary Pathology, College of Veterinary Medicine, China Agricultural University, Beijing, PR China
| | - Hong Dong
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Beijing University of Agriculture, Beijing, PR China
| | - Haiyan Tian
- Department of Veterinary Pathology, College of Veterinary Medicine, China Agricultural University, Beijing, PR China
| | - Yanxin Hu
- Department of Veterinary Pathology, College of Veterinary Medicine, China Agricultural University, Beijing, PR China.
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45
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Dhuriya YK, Sharma D, Naik AA. Cellular demolition: Proteins as molecular players of programmed cell death. Int J Biol Macromol 2019; 138:492-503. [PMID: 31330212 DOI: 10.1016/j.ijbiomac.2019.07.113] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 06/25/2019] [Accepted: 07/19/2019] [Indexed: 12/11/2022]
Abstract
Apoptosis, a well-characterized and regulated cell death programme in eukaryotes plays a fundamental role in developing or later-life periods to dispose of unwanted cells to maintain typical tissue architecture, homeostasis in a spatiotemporal manner. This silent cellular death occurs without affecting any neighboring cells/tissue and avoids triggering of immunological response. Furthermore, diminished forms of apoptosis result in cancer and autoimmune diseases, whereas unregulated apoptosis may also lead to the development of a myriad of neurodegenerative diseases. Unraveling the mechanistic events in depth will provide new insights into understanding physiological control of apoptosis, pathological consequences of abnormal apoptosis and development of novel therapeutics for diseases. Here we provide a brief overview of molecular players of programmed cell death with discussion on the role of caspases, modifications, ubiquitylation in apoptosis, removal of the apoptotic body and its relevance to diseases.
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Affiliation(s)
- Yogesh Kumar Dhuriya
- Developmental Toxicology Laboratory, Systems Toxicology and Health Risk Assessment Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), Vishvigyan Bhawan, 31, Mahatma Gandhi Marg, Lucknow 226 001, India
| | - Divakar Sharma
- Department of Biochemistry, National JALMA Institute for Leprosy and Other Mycobacterial Diseases, Tajganj, Agra, India; Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India.
| | - Aijaz A Naik
- Neurology, School of Medicine, University of Virginia, Charlottesville 22908, United States of America
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Qu W, Mai Z, Zhang C, Du M, Yang F, Chen T. Time-lapse FRET analysis reveals the ability of Bax dimer to trigger mitochondrial outer membrane permeabilization. Biochem Biophys Res Commun 2019; 514:881-887. [PMID: 31084935 DOI: 10.1016/j.bbrc.2019.05.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 05/04/2019] [Indexed: 10/26/2022]
Abstract
Bax oligomerization is essential for triggering mitochondrial outer membrane permeabilization (MOMP) in many apoptotic programs. However, it is controversial whether Bax dimer is sufficient to trigger MOMP. In this report, multiple Gaussian function-based FRET analysis (Multi-Gaussian FRET analysis) was used to dissect the dimerization and then tetramerization of Bax in relation to MOMP. Multi-Gaussian FRET analysis on the time-lapse FRET images of single living cells co-expressing CFP-Bax and YFP-Bax revealed that formation of mitochondrial Bax homodimers preceded MOMP within 3 min and Bax dimer transformed into tetramer within 6 min concomitantly with complete MOMP within 10 min, providing direct evidence in support of the sufficient ability of Bax dimers to trigger MOMP at least in natural cells.
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Affiliation(s)
- Wenfeng Qu
- MOE Key Laboratory of Laser Life Science & College of Biophotonics, South China Normal University, Guangzhou, 510631, China
| | - Zihao Mai
- MOE Key Laboratory of Laser Life Science & College of Biophotonics, South China Normal University, Guangzhou, 510631, China
| | - Chenshuang Zhang
- MOE Key Laboratory of Laser Life Science & College of Biophotonics, South China Normal University, Guangzhou, 510631, China
| | - Mengyan Du
- MOE Key Laboratory of Laser Life Science & College of Biophotonics, South China Normal University, Guangzhou, 510631, China
| | - Fangfang Yang
- MOE Key Laboratory of Laser Life Science & College of Biophotonics, South China Normal University, Guangzhou, 510631, China
| | - Tongsheng Chen
- MOE Key Laboratory of Laser Life Science & College of Biophotonics, South China Normal University, Guangzhou, 510631, China.
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Icariin Inhibits AGE-Induced Injury in PC12 Cells by Directly Targeting Apoptosis Regulator Bax. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:7940808. [PMID: 31178973 PMCID: PMC6501163 DOI: 10.1155/2019/7940808] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 01/31/2019] [Accepted: 03/03/2019] [Indexed: 02/07/2023]
Abstract
Diabetic encephalopathy (DE) is a serious complication caused by long-term cognitive impairment in diabetic patients. At present, there is no effective treatment for DE. Icariin (ICA) is a bioactive ingredient isolated from Epimedium. Previous research indicated that ICA was neuroprotective against Aβ-induced PC12 cell insult; however, the effect of ICA on an advanced glycosylation end product- (AGE-) induced neural injury model has not been studied. In this study, we investigated the neuroprotective effects of ICA on AGE-induced injury in PC12 cells. Our findings revealed that ICA could effectively protect PC12 cells from AGE-induced cell apoptosis by suppressing oxidative stress. Moreover, we observed that ICA could significantly protect against mitochondrial depolarization following AGE stimulation and inactivate the mitochondria-dependent caspase-9/3 apoptosis pathway. Most notably, we identified the direct target protein of ICA as apoptosis regulator Bax by a pulldown assay. We found that ICA could specifically target Bax protein and inhibit Bax dimer formation and migration to mitochondria. Furthermore, a siRNA knockdown experiment revealed that ICA could inhibit PC12 cell apoptosis and oxidative stress through targeting Bax. Taken together, our findings demonstrated that ICA could attenuate AGE-induced oxidative stress and mitochondrial apoptosis by specifically targeting Bax and further regulating the biological function of Bax on mitochondria.
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48
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Ke FFS, Vanyai HK, Cowan AD, Delbridge ARD, Whitehead L, Grabow S, Czabotar PE, Voss AK, Strasser A. Embryogenesis and Adult Life in the Absence of Intrinsic Apoptosis Effectors BAX, BAK, and BOK. Cell 2019; 173:1217-1230.e17. [PMID: 29775594 DOI: 10.1016/j.cell.2018.04.036] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 01/31/2018] [Accepted: 04/25/2018] [Indexed: 12/01/2022]
Abstract
Intrinsic apoptosis, reliant on BAX and BAK, has been postulated to be fundamental for morphogenesis, but its precise contribution to this process has not been fully explored in mammals. Our structural analysis of BOK suggests close resemblance to BAX and BAK structures. Notably, Bok-/-Bax-/-Bak-/- animals exhibited more severe defects and died earlier than Bax-/-Bak-/- mice, implying that BOK has overlapping roles with BAX and BAK during developmental cell death. By analyzing Bok-/-Bax-/-Bak-/- triple-knockout mice whose cells are incapable of undergoing intrinsic apoptosis, we identified tissues that formed well without this process. We provide evidence that necroptosis, pyroptosis, or autophagy does not substantially substitute for the loss of apoptosis. Albeit very rare, unexpected attainment of adult Bok-/-Bax-/-Bak-/- mice suggests that morphogenesis can proceed entirely without apoptosis mediated by these proteins and possibly without cell death in general.
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Affiliation(s)
- Francine F S Ke
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia.
| | - Hannah K Vanyai
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Angus D Cowan
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Alex R D Delbridge
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Lachlan Whitehead
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia
| | - Stephanie Grabow
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia
| | - Anne K Voss
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia.
| | - Andreas Strasser
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia; Department of Medical Biology, The University of Melbourne, Melbourne, Victoria 3052, Australia.
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49
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Bax to the future - A novel, high-yielding approach for purification and expression of full-length Bax protein for structural studies. Protein Expr Purif 2019; 158:20-26. [PMID: 30738180 DOI: 10.1016/j.pep.2019.02.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 01/18/2019] [Accepted: 02/05/2019] [Indexed: 01/27/2023]
Abstract
Mitochondria-mediated apoptosis (programmed cell death) involves a sophisticated signaling and regulatory network that is regulated by the Bcl-2 protein family. Members of this family have either pro- or anti-apoptotic functions. An important pro-apoptotic member of this family is the cytosolic Bax. This protein is crucial for the onset of apoptosis by perforating the mitochondrial outer membrane (MOM). This process can be seen as point of no return, since disintegration of the MOM leads to the release of apotogenic factors such as cytochrome c into the cytosol triggering the activation of caspases and subsequent apoptotic steps. Bax is able to interact with the MOM with both its termini, making it inherently difficult to express in E. coli. In this study, we present a novel approach to express and purify full-length Bax with significantly increased yields, when compared to the commonly applied strategy. Using a double fusion approach with an N-terminal GST-tag and a C-terminal Intein-CBD-tag, we were able to render both Bax termini inactive and prevent disruptive interactions from occurring during gene expression. By deploying an Intein-CBD-tag at the C-terminus we were further able to avoid the introduction of any artificial residues, hence ensuring the native like activity of the membrane-penetrating C-terminus of Bax. Further, by engineering a His6-tag to the C-terminus of the CBD-tag we greatly improved the robustness of the purification procedure. We report yields for pure, full-length Bax protein that are increased by an order of magnitude, when compared to commonly used Bax expression protocols.
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50
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Ader NR, Hoffmann PC, Ganeva I, Borgeaud AC, Wang C, Youle RJ, Kukulski W. Molecular and topological reorganizations in mitochondrial architecture interplay during Bax-mediated steps of apoptosis. eLife 2019; 8:40712. [PMID: 30714902 PMCID: PMC6361589 DOI: 10.7554/elife.40712] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 01/22/2019] [Indexed: 12/25/2022] Open
Abstract
During apoptosis, Bcl-2 proteins such as Bax and Bak mediate the release of pro-apoptotic proteins from the mitochondria by clustering on the outer mitochondrial membrane and thereby permeabilizing it. However, it remains unclear how outer membrane openings form. Here, we combined different correlative microscopy and electron cryo-tomography approaches to visualize the effects of Bax activity on mitochondria in human cells. Our data show that Bax clusters localize near outer membrane ruptures of highly variable size. Bax clusters contain structural elements suggesting a higher order organization of their components. Furthermore, unfolding of inner membrane cristae is coupled to changes in the supramolecular assembly of ATP synthases, particularly pronounced at membrane segments exposed to the cytosol by ruptures. Based on our results, we propose a comprehensive model in which molecular reorganizations of the inner membrane and sequestration of outer membrane components into Bax clusters interplay in the formation of outer membrane ruptures. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
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Affiliation(s)
- Nicholas R Ader
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.,Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Patrick C Hoffmann
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Iva Ganeva
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Alicia C Borgeaud
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
| | - Chunxin Wang
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Richard J Youle
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | - Wanda Kukulski
- Cell Biology Division, MRC Laboratory of Molecular Biology, Cambridge, United Kingdom
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