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Zhu M, Chu Z, Dai X, Pan F, Luo Y, Feng X, Hu Y, Wang H, Liu Y. Effect of Celastrus Orbiculatus Extract on proliferation and apoptosis of human Burkitt lymphoma cells. Front Pharmacol 2024; 15:1361371. [PMID: 38633608 PMCID: PMC11021594 DOI: 10.3389/fphar.2024.1361371] [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: 12/25/2023] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
The lymphoma incidence rate is on the rise, with invasive forms particularly prone to relapse following conventional treatment, posing a significant threat to human life and wellbeing. Numerous studies have shown that traditional Chinese botanical drug medicine offers promising therapeutic benefits for various malignancies, with previous experimental findings indicating that Celastrus orbiculatus extract effectively combats digestive tract tumors. However, its impact on lymphoma remains unexplored. This study aims to investigate the impact and underlying mechanisms of COE on the proliferation and apoptosis of Burkitt lymphoma cells. We diluted COE in RPMI-1640 medium to create various working concentrations and introduced it to human Burkitt lymphoma Raji and Ramos cells. To evaluate cell viability, we used the CCK-8 assay, and we observed morphological changes using HE staining. We also conducted Annexin V-PI and JC-1 staining experiments to assess apoptosis. By combining the cell cycle experiment with the EDU assay, we gained insights into the effects of COE on DNA replication in lymphoma cells. Using Western blotting, we detected alterations in apoptosis-related proteins. In vivo experiments revealed that following COE intervention, tumor volume decreased, survival time was prolonged, spleen size reduced, and the expression of tumor apoptosis-related proteins changed. Our findings indicate that COE effectively inhibits lymphoma cell proliferation and promotes apoptosis by regulating these apoptosis-related proteins.
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Affiliation(s)
- Miao Zhu
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
- The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou University, Yangzhou, China
- Clinical Medical College of Yangzhou University, Yangzhou, China
| | - Zewen Chu
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
- The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou University, Yangzhou, China
| | - Xiaojun Dai
- The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou University, Yangzhou, China
- Traditional Chinese Medicine Hospital of Yangzhou, Yangzhou, China
| | - Fan Pan
- Clinical Medical College of Yangzhou University, Yangzhou, China
| | - Yuanyuan Luo
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
- The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou University, Yangzhou, China
| | - Xingyi Feng
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
- The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou University, Yangzhou, China
| | - Yaqi Hu
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
- The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou University, Yangzhou, China
| | - Haibo Wang
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
- The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou University, Yangzhou, China
| | - Yanqing Liu
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou, China
- The Key Laboratory of Syndrome Differentiation and Treatment of Gastric Cancer of the State Administration of Traditional Chinese Medicine, Yangzhou University, Yangzhou, China
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2
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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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3
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Apoptotic priming is defined by the dynamic exchange of Bcl-2 proteins between mitochondria and cytosol. Cell Death Differ 2022; 29:2262-2274. [PMID: 35585181 PMCID: PMC9613888 DOI: 10.1038/s41418-022-01013-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 04/19/2022] [Accepted: 04/22/2022] [Indexed: 11/15/2022] Open
Abstract
Apoptosis is regulated by interactions between the BH3-only and multi-domain Bcl-2 family proteins. These interactions are integrated on the outer mitochondrial membrane (OMM) where they set the threshold for apoptosis, known as mitochondrial priming. However, how mitochondrial priming is controlled at the level of single cells remains unclear. Retrotranslocation of Bcl-XL has been proposed as one mechanism, removing pro-apoptotic Bcl-2 proteins from the OMM, thus reducing priming. Contrary to this view, we now show that Bcl-XL retrotranslocation is inhibited by binding to its BH3-only partners, resulting in accumulation of these protein complexes on mitochondria. We find that Bcl-XL retrotranslocation dynamics are tightly coupled to mitochondrial priming. Quantifying these dynamics indicates the heterogeneity in priming between cells within a population and predicts how they subsequently respond to a pro-apoptotic signal.
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Cui XZ, Zheng MX, Yang SY, Bai R, Zhang L. Roles of calpain in the apoptosis of Eimeria tenella host cells at the middle and late developmental stages. Parasitol Res 2022; 121:1639-1649. [PMID: 35412077 DOI: 10.1007/s00436-022-07496-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 03/14/2022] [Indexed: 11/26/2022]
Abstract
This study investigated the role of calpain in Eimeria tenella-induced host cell apoptosis. Chick embryo cecal epithelial cell culture technology, flow cytometry, enzyme-linked immunosorbent assays, and fluorescence quantitative PCR were used to detect the E. tenella host cell apoptotic rate, Bax and Bid expression levels, and calpain activity. The results demonstrated that Bax, Bid, and calpain levels were upregulated and apoptosis was increased following E. tenella infection at 24-120 h. Calpain levels were reduced by pharmacological inhibition of calpain using SJA6017 or by blocking Ca2+ entry into the cell using BAPTA/AM at 24-120 h. The mRNA and protein levels of Bax and Bid, the E. tenella infection rate, and the early apoptotic and late apoptotic (necrosis) rates were decreased by using SJA6017 at 24-120 h. These results indicated that E. tenella-promoted host cell apoptosis is regulated by calpain via Bid and Bax at 24-120 h. Thus, manipulation of calpain levels could be used to manage E. tenella infection in chickens in the middle and late developmental stages.
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Affiliation(s)
- Xiao-Zhen Cui
- College of Animal Medicine, Shanxi Agriculture University, Taiyuan, Shanxi Province, 030036, People's Republic of China
| | - Ming-Xue Zheng
- College of Animal Medicine, Shanxi Agriculture University, Taiyuan, Shanxi Province, 030036, People's Republic of China.
| | - Shi-Yu Yang
- Department of Clinical Neurosciences, UCL Institute of Neurology, Rowland Hill Street, London, NW3 2PF, UK
| | - Rui Bai
- College of Animal Medicine, Shanxi Agriculture University, Taiyuan, Shanxi Province, 030036, People's Republic of China
| | - Li Zhang
- College of Animal Medicine, Shanxi Agriculture University, Taiyuan, Shanxi Province, 030036, People's Republic of China
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5
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Jang DM, Oh EK, Hahn H, Kim HS, Han BW. Structural insights into apoptotic regulation of human Bfk as a novel Bcl-2 family member. Comput Struct Biotechnol J 2022; 20:745-756. [PMID: 35140891 PMCID: PMC8814693 DOI: 10.1016/j.csbj.2022.01.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/18/2022] [Accepted: 01/23/2022] [Indexed: 11/29/2022] Open
Affiliation(s)
- Dong Man Jang
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
- Research Institute, National Cancer Center, Goyang, Gyeonggi 10408, Republic of Korea
| | - Eun Kyung Oh
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyunggu Hahn
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyoun Sook Kim
- Research Institute, National Cancer Center, Goyang, Gyeonggi 10408, Republic of Korea
- Corresponding authors.
| | - Byung Woo Han
- Research Institute of Pharmaceutical Sciences, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
- Corresponding authors.
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6
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Cui J, Zhao S, Li Y, Zhang D, Wang B, Xie J, Wang J. Regulated cell death: discovery, features and implications for neurodegenerative diseases. Cell Commun Signal 2021; 19:120. [PMID: 34922574 PMCID: PMC8684172 DOI: 10.1186/s12964-021-00799-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 10/30/2021] [Indexed: 12/18/2022] Open
Abstract
Regulated cell death (RCD) is a ubiquitous process in living organisms that is essential for tissue homeostasis or to restore biological balance under stress. Over the decades, various forms of RCD have been reported and are increasingly being found to involve in human pathologies and clinical outcomes. We focus on five high-profile forms of RCD, including apoptosis, pyroptosis, autophagy-dependent cell death, necroptosis and ferroptosis. Cumulative evidence supports that not only they have different features and various pathways, but also there are extensive cross-talks between modes of cell death. As the understanding of RCD pathway in evolution, development, physiology and disease continues to improve. Here we review an updated classification of RCD on the discovery and features of processes. The prominent focus will be placed on key mechanisms of RCD and its critical role in neurodegenerative disease. Video abstract.
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Affiliation(s)
- Juntao Cui
- School of Basic Medicine, Qingdao University, Qingdao, 266071 China
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, 266071 China
| | - Suhan Zhao
- School of Basic Medicine, Qingdao University, Qingdao, 266071 China
- School of Clinical Medicine, Qingdao University, Qingdao, 266071 China
| | - Yinghui Li
- School of Basic Medicine, Qingdao University, Qingdao, 266071 China
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, 266071 China
| | - Danyang Zhang
- School of Basic Medicine, Qingdao University, Qingdao, 266071 China
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, 266071 China
| | - Bingjing Wang
- School of Basic Medicine, Qingdao University, Qingdao, 266071 China
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, 266071 China
| | - Junxia Xie
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, 266071 China
| | - Jun Wang
- School of Basic Medicine, Qingdao University, Qingdao, 266071 China
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, 266071 China
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7
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Pei X, Chu M, Tang P, Zhang H, Zhang X, Zheng X, Li J, Mei J, Wang T, Yin S. Effects of acute hypoxia and reoxygenation on oxygen sensors, respiratory metabolism, oxidative stress, and apoptosis in hybrid yellow catfish "Huangyou-1". FISH PHYSIOLOGY AND BIOCHEMISTRY 2021; 47:1429-1448. [PMID: 34313912 DOI: 10.1007/s10695-021-00989-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 07/08/2021] [Indexed: 06/13/2023]
Abstract
The regulation mechanism of the hybrid yellow catfish "Huangyou-1" was assessed under conditions of hypoxia and reoxygenation by examination of oxygen sensors and by monitoring respiratory metabolism, oxidative stress, and apoptosis. The expressions of genes related to oxygen sensors (HIF-1α, HIF-2α, VHL, HIF-1β, PHD2, and FIH-1) were upregulated in the brain and liver during hypoxia, and recovered compared with control upon reoxygenation. The expressions of genes related to glycolysis (HK1, PGK1, PGAM2, PFK, and LDH) were increased during hypoxia and then recovered compared with control upon reoxygenation. The mRNA levels of CS did not change during hypoxia in the brain and liver, but increased during reoxygenation. The mRNA levels of SDH decreased significantly only in the liver during hypoxia, but later increased compared with control upon reoxygenation in both tissues. Under hypoxic conditions, the expressions of genes related to oxidative stress (SOD1, SOD2, GSH-Px, and CAT) and the activity of antioxidant enzymes (SOD, CAT, and GSH-Px) and MDA were upregulated compared with control. The expressions of genes related to apoptosis (Apaf-1, Bax, Caspase 3, Caspase 9, and p53) were higher than those in control during hypoxic exposure, while the expressions of Bcl-2 and Cyt C were decreased. The findings of the transcriptional analyses will provide insights into the molecular mechanisms of hybrid yellow catfish "Huangyou-1" under conditions of hypoxia and reoxygenation. Overall, these findings showed that oxygen sensors of "Huangyou-1" are potentially useful biomarkers of environmental hypoxic exposure. Together with genes related to respiratory metabolism, oxidative stress and apoptosis occupy a quite high position in enhancing hypoxia tolerance. Our findings provided new insights into the molecular regulatory mechanism of hypoxia in "Huangyou-1."
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Affiliation(s)
- Xueying Pei
- College of Marine Science and Engineering, Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
- Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, 222005, Jiangsu, China
| | - Mingxu Chu
- College of Marine Science and Engineering, Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
- Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, 222005, Jiangsu, China
| | - Peng Tang
- College of Marine Science and Engineering, Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
- Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, 222005, Jiangsu, China
| | - Hongyan Zhang
- College of Marine Science and Engineering, Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
- Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, 222005, Jiangsu, China
| | - Xinyu Zhang
- College of Marine Science and Engineering, Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
- Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, 222005, Jiangsu, China
| | - Xiang Zheng
- College of Marine Science and Engineering, Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
- Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, 222005, Jiangsu, China
| | - Jie Li
- College of Marine Science and Engineering, Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, Nanjing Normal University, Nanjing, 210023, Jiangsu, China
- Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, 222005, Jiangsu, China
| | - Jie Mei
- College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Tao Wang
- College of Marine Science and Engineering, Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, Nanjing Normal University, Nanjing, 210023, Jiangsu, China.
- Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, 222005, Jiangsu, China.
| | - Shaowu Yin
- College of Marine Science and Engineering, Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, Nanjing Normal University, Nanjing, 210023, Jiangsu, China.
- Co-Innovation Center for Marine Bio-Industry Technology of Jiangsu Province, Lianyungang, 222005, Jiangsu, China.
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8
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Effects of Cardiolipin on the Conformational Dynamics of Membrane-Anchored Bcl-xL. Int J Mol Sci 2021; 22:ijms22179388. [PMID: 34502299 PMCID: PMC8431346 DOI: 10.3390/ijms22179388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 08/24/2021] [Accepted: 08/26/2021] [Indexed: 02/06/2023] Open
Abstract
The anti-apoptotic protein Bcl-xL regulates apoptosis by preventing the permeation of the mitochondrial outer membrane by pro-apoptotic pore-forming proteins, which release apoptotic factors into the cytosol that ultimately lead to cell death. Two different membrane-integrated Bcl-xL constructs have been identified: a membrane-anchored and a membrane-inserted conformation. Here, we use molecular dynamics simulations to study the effect of the mitochondrial specific lipid cardiolipin and the protein protonation state on the conformational dynamics of membrane-anchored Bcl-xL. The analysis reveals that the protonation state of the protein and cardiolipin content of the membrane modulate the orientation of the soluble head region (helices α1 through α7) and hence the exposure of its BH3-binding groove, which is required for its interaction with pro-apoptotic proteins.
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9
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Pogmore JP, Uehling D, Andrews DW. Pharmacological Targeting of Executioner Proteins: Controlling Life and Death. J Med Chem 2021; 64:5276-5290. [PMID: 33939407 DOI: 10.1021/acs.jmedchem.0c02200] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Small-molecule mediated modulation of protein interactions of Bcl-2 (B-cell lymphoma-2) family proteins was clinically validated in 2015 when Venetoclax, a selective inhibitor of the antiapoptotic protein BCL-2, achieved breakthrough status designation by the FDA for treatment of lymphoid malignancies. Since then, substantial progress has been made in identifying inhibitors of other interactions of antiapoptosis proteins. However, targeting their pro-apoptotic counterparts, the "executioners" BAX, BAK, and BOK that both initiate and commit the cell to dying, has lagged behind. However, recent publications demonstrate that these proteins can be positively or negatively regulated using small molecule tool compounds. The results obtained with these molecules suggest that pharmaceutical regulation of apoptosis will have broad implications that extend beyond activating cell death in cancer. We review recent advances in identifying compounds and their utility in the exogenous control of life and death by regulating executioner proteins, with emphasis on the prototype BAX.
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Affiliation(s)
- Justin P Pogmore
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1J7, Canada.,Biological Sciences, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario M4N 3M5, Canada
| | - David Uehling
- Drug Discovery Program, Ontario Institute for Cancer Research, Toronto, Ontario M5G 1M1, Canada
| | - David W Andrews
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1J7, Canada.,Biological Sciences, Sunnybrook Research Institute, University of Toronto, Toronto, Ontario M4N 3M5, Canada
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10
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Mushtaq AU, Ådén J, Clifton LA, Wacklin-Knecht H, Campana M, Dingeldein APG, Persson C, Sparrman T, Gröbner G. Neutron reflectometry and NMR spectroscopy of full-length Bcl-2 protein reveal its membrane localization and conformation. Commun Biol 2021; 4:507. [PMID: 33907308 PMCID: PMC8079415 DOI: 10.1038/s42003-021-02032-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 03/25/2021] [Indexed: 12/20/2022] Open
Abstract
B-cell lymphoma 2 (Bcl-2) proteins are the main regulators of mitochondrial apoptosis. Anti-apoptotic Bcl-2 proteins possess a hydrophobic tail-anchor enabling them to translocate to their target membrane and to shift into an active conformation where they inhibit pro-apoptotic Bcl-2 proteins to ensure cell survival. To address the unknown molecular basis of their cell-protecting functionality, we used intact human Bcl-2 protein natively residing at the mitochondrial outer membrane and applied neutron reflectometry and NMR spectroscopy. Here we show that the active full-length protein is entirely buried into its target membrane except for the regulatory flexible loop domain (FLD), which stretches into the aqueous exterior. The membrane location of Bcl-2 and its conformational state seems to be important for its cell-protecting activity, often infamously upregulated in cancers. Most likely, this situation enables the Bcl-2 protein to sequester pro-apoptotic Bcl-2 proteins at the membrane level while sensing cytosolic regulative signals via its FLD region.
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Affiliation(s)
| | - Jörgen Ådén
- Department of Chemistry, University of Umeå, Umeå, Sweden
| | - Luke A Clifton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science&Innovation Campus, Didcot, Oxfordshire, UK
| | - Hanna Wacklin-Knecht
- European Spallation Source ERIC, ESS, Lund, Sweden
- Department of Chemistry, Division of Physical Chemistry, Lund University, Lund, Sweden
| | - Mario Campana
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science&Innovation Campus, Didcot, Oxfordshire, UK
| | | | - Cecilia Persson
- The Swedish NMR Center, University of Gothenburg, Gothenburg, Sweden
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11
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Wu G, Tu Z, Yang F, Mai Z, Chen H, Tang Q, Ye X, Wang K, Wang X, Chen T. Evaluating the inhibitory priority of Bcl-xL to Bad, tBid and Bax by using live-cell imaging assay. Cytometry A 2021; 99:1091-1101. [PMID: 33843148 DOI: 10.1002/cyto.a.24351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 03/17/2021] [Accepted: 04/07/2021] [Indexed: 01/02/2023]
Abstract
Molecular regulatory network among the B cell leukemia-2 (Bcl-2) family proteins is a research hotspot on apoptosis. The inhibitory priority of anti-apoptotic Bcl-2 family proteins (such as Bcl-xL) to pro-apoptotic Bcl-2 family proteins (such as Bad, tBid and Bax) determines the outcome of their interactions. Based on over-expression model system, we here evaluate the inhibitory priority of Bcl-xL to Bad, tBid and Bax by using live-cell imaging assay on cell viability. Fluorescence images of living cells co-expressing CFP-Bcl-xL and YFP-Bad or YFP-tBid or YFP-Bax showed that Bcl-xL markedly inhibited Bad/tBid/Bax-mediated apoptosis, revealing that Bcl-xL inhibits the proapoptotic function of Bad, tBid and Bax. In the case of equimolar co-expression of Bad and CFP-Bcl-xL, the inhibition of Bcl-xL on tBid/Bax mediate-apoptosis was completely relieved. Moreover, co-expression of tBid-P2A-CFP-Bcl-xL significantly relieved the inhibition of Bcl-xL on the pro-apoptotic ability Bax, suggesting that Bcl-xL preferentially inhibits the pro-apoptotic ability of Bad over tBid, subsequently to Bax.
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Affiliation(s)
- Ge Wu
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
| | - Zhuang Tu
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
| | - Fangfang Yang
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
| | - Zihao Mai
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
| | - Hongce Chen
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
| | - Qiling Tang
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
| | - Xianxin Ye
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
| | - Kunhao Wang
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China
| | - Xiaoping Wang
- Department of Pain Management, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Tongsheng Chen
- Key Laboratory of Laser Life Science, Ministry of Education, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, Guangdong, China.,SCNU Qingyuan Institute of Science and Technology Innovation Co. Ltd., South China Normal University, Qingyuan, China
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12
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Wang Y, Huang Z. Transforming Growth Factor Beta 1 Affects Gastric Cancer Cell Proliferation, Migration, and Invasion by Regulating Phosphatase and Tensin Homolog. J BIOMATER TISS ENG 2021. [DOI: 10.1166/jbt.2021.2578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Gastric cancer (GC) is a common tumor with high incidence and poor prognosis. So far, the pathogenesis of GC has not been fully elucidated, which has brought great difficulty to the treatment. TGF-β regulates cell growth and differentiation. As a key member, TGF-β1 is abnormally
expressed in various tumors, but its role on GC and related mechanisms have not been elucidated. Gastric cancer and adjacent tissues were collected to measure TGF-β1 level by real-time PCR. SGC-7901 cell was assigned into control group, mock group, and TGF-β1 siRNA group followed
by analysis of TGF-β1 level by ELISA, cell proliferation by MTT assay, apoptosis by flow cytometry, cell migration by cell scratch test, cell invasion by Transwell chamber assay, and Bcl-2, Bax, and PTEN level by Western blot. TGF-β1 was significantly upregulated in GC tissues (P
<0.05) and increased with TNM stage dependence. TGF-β1 siRNA transfection significantly decreased TGF-β1 mRNA level and secretion, inhibited cell proliferation, increased apoptosis rate, and attenuated cell migration and invasion along with downregulated Bcl-2 and elevated Bax
and PTEN expression (P <0.05). Downregulation of TGF-β1 can promote gastric cancer cell apoptosis, inhibit proliferation, migration, and invasion by regulating PTEN.
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Affiliation(s)
- Yuchen Wang
- Department of General Surgery, Fujian Elderly Hospital, Fuzhou, Fujian, 350009, China
| | - Zhimin Huang
- Department of General Surgery, Fujian Elderly Hospital, Fuzhou, Fujian, 350009, China
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13
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Liu Y, Jiang J, Liu C, Zhao W, Ma Y, Zheng Z, Zhou Q, Zhao Y. Synergistic anti-tumor effect of anti-PD-L1 antibody cationic microbubbles for delivery of the miR-34a gene combined with ultrasound on cervical carcinoma. Am J Transl Res 2021; 13:988-1005. [PMID: 33841635 PMCID: PMC8014418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 12/18/2020] [Indexed: 06/12/2023]
Abstract
This study explored the synergistic effect of anti-PD-L1 antibody cationic microbubbles (MBs) for delivery of the miR-34a gene combined with ultrasound in inhibiting the cervical cancer. H&E stain, TUNEL, immunohistochemistry and RT-PCR were used to detect the change of apoptosis regulatory factors, and immunofluorescence, Flow cytometry and LDH assays were applied to evaluate the changing of immunomodulatory. In this experiment the PD-L1 Ab/miR-34a-MBs were prepared successfully. The cell targeting assay showed that U14 cells were surrounded by the PD-L1 Ab/miR-34a-MBs and microbubbles had well contrast imaging capability in vivo. With the irradiation power was 1 W/cm2 and the irradiation time was 25 s, the gene transfection efficiency was the highest using EGFP plasmid lorded microbubbles. In vivo anti-tumor assays, the PD-L1 Ab/miR-34a-MBs showed a great potential in inhibiting tumor growth with a TGI of >50%. PD-L1 Ab/miR-34a-MBs treatment enhanced the anti-tumor effect compared with that induced by PD-L1 Ab or miR-34a alone. Firstly, PD-L1 Ab/miR-34a-MBs could gather miR-34a with high-concentration aggregation and releasing around the cervical cancer, which takes a significant role in promoting apoptosis by downregulated Bcl-2 and upregulated Bax. Furthermore, combination therapy was found to augment the activation of T lymphocytes proliferation and increase CD8+ T cells infiltration, to enhance antitumor immune killing effect. The anti-PD-L1 antibody microbubbles for delivery miR-34a gene with ultrasound were considered to be a promising combination therapy regimen via initiating apoptotic mechanism of the tumor and anti-tumor immune regulation.
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Affiliation(s)
- Yun Liu
- Echo Laboratory, Department of Ultrasound Imaging, Renmin Hospital of Wuhan UniversityWuhan, China
| | - Jinjun Jiang
- Medical College of China Three Gorges UniversityYichang, China
| | - Chaoqi Liu
- Medical College of China Three Gorges UniversityYichang, China
- Hubei Key Laboratory of Tumor Microenvironment and ImmunotherapyYichang, China
| | - Wensi Zhao
- Cancer Center, Renmin Hospital of Wuhan UniversityWuhan, China
| | - Yao Ma
- Medical College of China Three Gorges UniversityYichang, China
| | - Zhiwei Zheng
- Medical College of China Three Gorges UniversityYichang, China
| | - Qing Zhou
- Echo Laboratory, Department of Ultrasound Imaging, Renmin Hospital of Wuhan UniversityWuhan, China
| | - Yun Zhao
- Medical College of China Three Gorges UniversityYichang, China
- Hubei Key Laboratory of Tumor Microenvironment and ImmunotherapyYichang, China
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14
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Zhang Z, Huang B, Zhang XC, Lin J. Cysteine-based crosslinking approach for characterization of oligomeric pore-forming proteins in the mitochondrial membranes. Methods Enzymol 2021; 649:371-396. [PMID: 33712193 DOI: 10.1016/bs.mie.2021.01.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Mitochondria are important not only to healthy but also dying cells. In particular, apoptotic cell death initiates when the mitochondrial outer membrane is permeabilized by Bax, a protein of the Bcl-2 family. Bax shares a structural fold with some α-helical bacterial pore-forming toxins before these proteins actively engage membranes. Despite decades of intensive research, the structures of the pores formed by these proteins are mostly unknown, mainly because the pores are assembled by different numbers of the proteins whose conformation and interaction are highly dynamic. Site-specific crosslinking of the pore-forming proteins in cellular membranes where the pores are assembled is a powerful approach to assess the biological pore structure, dynamics and function. In this chapter, we describe a cysteine-based site-specific crosslinking protocol for the Bax protein in the mitochondrial membrane. We discuss the expected results and the resulting structural-functional models for the pore-forming Bax oligomer, in comparison with other crosslinking approaches that have been used to study other mitochondrial protein complexes. At the end, we highlight the advantages of the crosslinking approaches as well as the limitations and alternative approaches.
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Affiliation(s)
- Zhi Zhang
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Bo Huang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Xuejun C Zhang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jialing Lin
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States; Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States.
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15
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Abdul Rahman SF, Xiang Lian BS, Mohana-Kumaran N. Targeting the B-cell lymphoma 2 anti-apoptotic proteins for cervical cancer treatment. Future Oncol 2020; 16:2235-2249. [PMID: 32715755 DOI: 10.2217/fon-2020-0389] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The B-cell lymphoma 2 (BCL-2) anti-apoptotic proteins have become attractive therapeutic targets especially with the development of BH3-mimetics which selectively target these proteins. However, it is important to note that expression levels of the anti-apoptotic proteins and their relevance in inhibiting apoptosis varies between different cell lineages. This addiction to certain anti-apoptotic proteins for survival, can be determined with various techniques and targeted effectively with selective BH3-mimetics. Studies have highlighted that anti-apoptotic proteins BCL-XL and MCL-1 are crucial for cervical cancer cell survival. Co-targeting BCL-XL and MCL-1 with selective BH3-mimetics yielded promising results in cervical cancer cell lines. In this review, we focus on the expression levels of the anti-apoptotic proteins in cervical cancer tissues and how to possibly target them with BH3-mimetics.
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Affiliation(s)
| | - Benedict Shi Xiang Lian
- Division of Biological Science, Graduate School of Science & Technology, Nara Institute of Science & Technology (NAIST), Ikoma, Nara 630-0101, Japan
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16
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Yang F, Qu W, Du M, Mai Z, Wang B, Ma Y, Wang X, Chen T. Stoichiometry and regulation network of Bcl-2 family complexes quantified by live-cell FRET assay. Cell Mol Life Sci 2020; 77:2387-2406. [PMID: 31492967 PMCID: PMC11104934 DOI: 10.1007/s00018-019-03286-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/26/2019] [Accepted: 08/23/2019] [Indexed: 01/07/2023]
Abstract
The stoichiometry and affinity of Bcl-2 family complexes are essential information for understanding how their interactome network is orchestrated to regulate mitochondrial permeabilization and apoptosis. Based on over-expression model system, FRET analysis was used to quantify the protein-protein interactions among Bax, Bcl-xL, Bad and tBid in healthy and apoptotic cells. Our data indicate that the stoichiometry and affinity of Bcl-2 complexes are dependent on their membrane environment. Bcl-xL, Bad and tBid can form hetero-trimers in mitochondria. Bcl-xL binds preferentially to Bad, then to tBid and Bax in mitochondria, whilst Bcl-xL displays higher affinity to Bad or tBid than to itself. Strikingly, Bax can bind to Bcl-xL in cytosol. In cytosol of apoptotic cells, Bcl-xL associates with Bax to form hetero-trimer with 1:2 stoichiometry, while Bcl-xL associates with Bad to form hetero-trimer with 2:1 stoichiometry and Bcl-xL associates with tBid to form hetero-dimer. In mitochondria, Bcl-xL associates with Bax/Bad to form hetero-dimer in healthy cells, while Bcl-xL associates with Bad to form hetero-tetramer with 3:1 stoichiometry in apoptotic cells.
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Affiliation(s)
- Fangfang Yang
- MOE Key Laboratory of Laser Life Science and College of Biophotonics, South China Normal University, Guangzhou, China
| | - Wenfeng Qu
- MOE Key Laboratory of Laser Life Science and College of Biophotonics, South China Normal University, Guangzhou, China
| | - Mengyan Du
- MOE Key Laboratory of Laser Life Science and College of Biophotonics, South China Normal University, Guangzhou, China
| | - Zihao Mai
- MOE Key Laboratory of Laser Life Science and College of Biophotonics, South China Normal University, Guangzhou, China
| | - Bin Wang
- MOE Key Laboratory of Laser Life Science and College of Biophotonics, South China Normal University, Guangzhou, China
| | - Yunyun Ma
- MOE Key Laboratory of Laser Life Science and College of Biophotonics, South China Normal University, Guangzhou, China
| | - Xiaoping Wang
- Department of Pain Management, The First Affiliated Hospital of Jinan University, Guangzhou, China.
| | - Tongsheng Chen
- MOE Key Laboratory of Laser Life Science and College of Biophotonics, South China Normal University, Guangzhou, China.
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17
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Panuzzo C, Jovanovski A, Pergolizzi B, Pironi L, Stanga S, Fava C, Cilloni D. Mitochondria: A Galaxy in the Hematopoietic and Leukemic Stem Cell Universe. Int J Mol Sci 2020; 21:ijms21113928. [PMID: 32486249 PMCID: PMC7312164 DOI: 10.3390/ijms21113928] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 05/24/2020] [Accepted: 05/28/2020] [Indexed: 12/17/2022] Open
Abstract
Mitochondria are the main fascinating energetic source into the cells. Their number, shape, and dynamism are controlled by the cell’s type and current behavior. The perturbation of the mitochondrial inward system via stress response and/or oncogenic insults could activate several trafficking molecular mechanisms with the intention to solve the problem. In this review, we aimed to clarify the crucial pathways in the mitochondrial system, dissecting the different metabolic defects, with a special emphasis on hematological malignancies. We investigated the pivotal role of mitochondria in the maintenance of hematopoietic stem cells (HSCs) and their main alterations that could induce malignant transformation, culminating in the generation of leukemic stem cells (LSCs). In addition, we presented an overview of LSCs mitochondrial dysregulated mechanisms in terms of (1) increasing in oxidative phosphorylation program (OXPHOS), as a crucial process for survival and self-renewal of LSCs,(2) low levels of reactive oxygen species (ROS), and (3) aberrant expression of B-cell lymphoma 2 (Bcl-2) with sustained mitophagy. Furthermore, these peculiarities may represent attractive new “hot spots” for mitochondrial-targeted therapy. Finally, we remark the potential of the LCS metabolic effectors to be exploited as novel therapeutic targets.
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Affiliation(s)
- Cristina Panuzzo
- Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy; (A.J.); (B.P.); (L.P.); (C.F.)
- Correspondence: (C.P.); (D.C.)
| | - Aleksandar Jovanovski
- Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy; (A.J.); (B.P.); (L.P.); (C.F.)
| | - Barbara Pergolizzi
- Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy; (A.J.); (B.P.); (L.P.); (C.F.)
| | - Lucrezia Pironi
- Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy; (A.J.); (B.P.); (L.P.); (C.F.)
| | - Serena Stanga
- Department of Neuroscience Rita Levi Montalcini, 10124 Turin, Italy;
- Neuroscience Institute Cavalieri Ottolenghi, University of Turin, 10043 Orbassano, Italy
| | - Carmen Fava
- Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy; (A.J.); (B.P.); (L.P.); (C.F.)
| | - Daniela Cilloni
- Department of Clinical and Biological Sciences, University of Turin, 10043 Orbassano, Italy; (A.J.); (B.P.); (L.P.); (C.F.)
- Correspondence: (C.P.); (D.C.)
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18
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Ivanova H, Vervliet T, Monaco G, Terry LE, Rosa N, Baker MR, Parys JB, Serysheva II, Yule DI, Bultynck G. Bcl-2-Protein Family as Modulators of IP 3 Receptors and Other Organellar Ca 2+ Channels. Cold Spring Harb Perspect Biol 2020; 12:cshperspect.a035089. [PMID: 31501195 DOI: 10.1101/cshperspect.a035089] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The pro- and antiapoptotic proteins belonging to the B-cell lymphoma-2 (Bcl-2) family exert a critical control over cell-death processes by enabling or counteracting mitochondrial outer membrane permeabilization. Beyond this mitochondrial function, several Bcl-2 family members have emerged as critical modulators of intracellular Ca2+ homeostasis and dynamics, showing proapoptotic and antiapoptotic functions. Bcl-2 family proteins specifically target several intracellular Ca2+-transport systems, including organellar Ca2+ channels: inositol 1,4,5-trisphosphate receptors (IP3Rs) and ryanodine receptors (RyRs), Ca2+-release channels mediating Ca2+ flux from the endoplasmic reticulum, as well as voltage-dependent anion channels (VDACs), which mediate Ca2+ flux across the mitochondrial outer membrane into the mitochondria. Although the formation of protein complexes between Bcl-2 proteins and these channels has been extensively studied, a major advance during recent years has been elucidating the complex interaction of Bcl-2 proteins with IP3Rs. Distinct interaction sites for different Bcl-2 family members were identified in the primary structure of IP3Rs. The unique molecular profiles of these Bcl-2 proteins may account for their distinct functional outcomes when bound to IP3Rs. Furthermore, Bcl-2 inhibitors used in cancer therapy may affect IP3R function as part of their proapoptotic effect and/or as an adverse effect in healthy cells.
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Affiliation(s)
- Hristina Ivanova
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, B-3000 Leuven, Belgium
| | - Tim Vervliet
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, B-3000 Leuven, Belgium
| | - Giovanni Monaco
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, B-3000 Leuven, Belgium
| | - Lara E Terry
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642
| | - Nicolas Rosa
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, B-3000 Leuven, Belgium
| | - Mariah R Baker
- Department of Biochemistry and Molecular Biology, McGovern Medical School at The University of Texas Health Science Center at Houston, Structural Biology Imaging Center, Houston, Texas 77030
| | - Jan B Parys
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, B-3000 Leuven, Belgium
| | - Irina I Serysheva
- Department of Biochemistry and Molecular Biology, McGovern Medical School at The University of Texas Health Science Center at Houston, Structural Biology Imaging Center, Houston, Texas 77030
| | - David I Yule
- Department of Pharmacology and Physiology, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, KU Leuven, B-3000 Leuven, Belgium
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19
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Conformational Switching in Bcl-xL: Enabling Non-Canonic Inhibition of Apoptosis Involves Multiple Intermediates and Lipid Interactions. Cells 2020; 9:cells9030539. [PMID: 32111007 PMCID: PMC7140517 DOI: 10.3390/cells9030539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/13/2020] [Accepted: 02/17/2020] [Indexed: 12/21/2022] Open
Abstract
The inhibition of mitochondrial permeabilization by the anti-apoptotic protein Bcl-xL is crucial for cell survival and homeostasis. Its inhibitory role requires the partitioning of Bcl-xL to the mitochondrial outer membrane from an inactive state in the cytosol, leading to its extensive refolding. The molecular mechanisms behind these events and the resulting conformations in the bilayer are unclear, and different models have been proposed to explain them. In the most recently proposed non-canonical model, the active form of Bcl-xL employs its N-terminal BH4 helix to bind and block its pro-apoptotic target. Here, we used a combination of various spectroscopic techniques to study the release of the BH4 helix (α1) during the membrane insertion of Bcl-xL. This refolding was characterized by a gradual increase in helicity due to the lipid-dependent partitioning-coupled folding and formation of new helix αX (presumably in the originally disordered loop between helices α1 and α2). Notably, a comparison of various fluorescence and circular dichroism measurements suggested the presence of multiple Bcl-xL conformations in the bilayer. This conclusion was explicitly confirmed by single-molecule measurements of Förster Resonance Energy Transfer from Alexa-Fluor-488-labeled Bcl-xL D189C to a mCherry fluorescent protein attached at the N-terminus. These measurements clearly indicated that the refolding of Bcl-xL in the bilayer is not a two-state transition and involves multiple membranous intermediates of variable compactness.
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20
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Bogner C, Kale J, Pogmore J, Chi X, Shamas-Din A, Fradin C, Leber B, Andrews DW. Allosteric Regulation of BH3 Proteins in Bcl-x L Complexes Enables Switch-like Activation of Bax. Mol Cell 2020; 77:901-912.e9. [PMID: 32001105 DOI: 10.1016/j.molcel.2019.12.025] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 09/17/2019] [Accepted: 12/20/2019] [Indexed: 01/01/2023]
Abstract
Current models of apoptosis regulation by the Bcl-2 family of proteins postulate that heterodimeric interactions between family members determine whether Bax and Bak are activated to trigger cell death. Thus, the relative abundance and binding affinities between pro- and anti-apoptotic proteins determines the outcome of these interactions. Examination of these interactions using purified mitochondria and liposomes with full-length recombinant proteins revealed that Bcl-xL inhibits apoptosis as a higher-order complex that binds multiple BH3 proteins. Allosteric regulation of this complex by the BH3 sensitizer Bad confers switch-like activity to the indirect activation of Bax. The BH3 activator cBid sequestered by Bcl-xL complexes changes from an inactive to an active form while bound to a Bcl-xL complex only when Bad is also bound. Bcl-xL complexes enable Bad to function as a non-competitive inhibitor of Bcl-xL and allosterically activate cBid, dramatically enhancing the pro-apoptotic potency of Bad.
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Affiliation(s)
- Christian Bogner
- Sunnybrook Research Institute, University of Toronto, Toronto, ON M5S 1A1, Canada; Third Department of Medicine, Klinikum Rechts der Isar, Technische Universität München, München 80333, Germany
| | - Justin Kale
- Sunnybrook Research Institute, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Justin Pogmore
- Sunnybrook Research Institute, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Xiaoke Chi
- Sunnybrook Research Institute, University of Toronto, Toronto, ON M5S 1A1, Canada
| | - Aisha Shamas-Din
- Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2C1, Canada
| | - Cécile Fradin
- Departments of Biomedical Sciences and Biochemistry, McMaster University, Hamilton, ON L8S 4L8, Canada; Departments of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Brian Leber
- Departments of Biomedical Sciences and Biochemistry, McMaster University, Hamilton, ON L8S 4L8, Canada; Department of Medicine, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - David W Andrews
- Sunnybrook Research Institute, University of Toronto, Toronto, ON M5S 1A1, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5S 1A1, Canada; Departments of Biomedical Sciences and Biochemistry, McMaster University, Hamilton, ON L8S 4L8, Canada.
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21
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Chi X, Nguyen D, Pemberton JM, Osterlund EJ, Liu Q, Brahmbhatt H, Zhang Z, Lin J, Leber B, Andrews DW. The carboxyl-terminal sequence of bim enables bax activation and killing of unprimed cells. eLife 2020; 9:44525. [PMID: 31976859 PMCID: PMC6980855 DOI: 10.7554/elife.44525] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Accepted: 01/03/2020] [Indexed: 12/12/2022] Open
Abstract
The Bcl-2 family BH3 protein Bim promotes apoptosis at mitochondria by activating the pore-forming proteins Bax and Bak and by inhibiting the anti-apoptotic proteins Bcl-XL, Bcl-2 and Mcl-1. Bim binds to these proteins via its BH3 domain and to the mitochondrial membrane by a carboxyl-terminal sequence (CTS). In cells killed by Bim, the expression of a Bim mutant in which the CTS was deleted (BimL-dCTS) triggered apoptosis that correlated with inhibition of anti-apoptotic proteins being sufficient to permeabilize mitochondria isolated from the same cells. Detailed analysis of the molecular mechanism demonstrated that BimL-dCTS inhibited Bcl-XL but did not activate Bax. Examination of additional point mutants unexpectedly revealed that the CTS of Bim directly interacts with Bax, is required for physiological concentrations of Bim to activate Bax and that different residues in the CTS enable Bax activation and binding to membranes.
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Affiliation(s)
- Xiaoke Chi
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Canada.,Biological Sciences, Sunnybrook Research Institute, Toronto, Canada
| | - Dang Nguyen
- Biological Sciences, Sunnybrook Research Institute, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Ontario, Canada
| | - James M Pemberton
- Biological Sciences, Sunnybrook Research Institute, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Ontario, Canada
| | - Elizabeth J Osterlund
- Biological Sciences, Sunnybrook Research Institute, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Qian Liu
- Biological Sciences, Sunnybrook Research Institute, Toronto, Canada
| | - Hetal Brahmbhatt
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Canada.,Biological Sciences, Sunnybrook Research Institute, Toronto, Canada.,Department of Medicine, McMaster University, Hamilton, Canada
| | - Zhi Zhang
- Department of Biochemistry, University of Oklahoma Health Sciences Center, Oklahoma City, United States.,Molecular Biology and Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, United States
| | - Jialing Lin
- Department of Biochemistry, University of Oklahoma Health Sciences Center, Oklahoma City, United States.,Molecular Biology and Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, United States
| | - Brian Leber
- Department of Medicine, McMaster University, Hamilton, Canada
| | - David W Andrews
- Biological Sciences, Sunnybrook Research Institute, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
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22
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Gao Y, Yan Y, Fang Q, Zhang N, Kumar G, Zhang J, Song LJ, Yu J, Zhao L, Zhang HT, Ma CG. The Rho kinase inhibitor fasudil attenuates Aβ 1-42-induced apoptosis via the ASK1/JNK signal pathway in primary cultures of hippocampal neurons. Metab Brain Dis 2019; 34:1787-1801. [PMID: 31482248 DOI: 10.1007/s11011-019-00487-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 08/27/2019] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD), a chronic, progressive, neurodegenerative disorder, is the most common type of dementia. Beta amyloid (Aβ) peptide aggregation and phosphorylated tau protein accumulation are considered as one of the causes for AD. Our previous studies have demonstrated the neuroprotective effect of the Rho kinase inhibitor fasudil, but the mechanism remains elucidated. In the present study, we examined the effects of fasudil on Aβ1-42 aggregation and apoptosis and identified the intracellular signaling pathways involved in these actions in primary cultures of mouse hippocampal neurons. The results showed that fasudil increased neurite outgrowth (52.84%), decreased Aβ burden (46.65%), Tau phosphorylation (96.84%), and ROCK-II expression. In addition, fasudil reversed Aβ1-42-induced decreased expression of Bcl-2 and increases in caspase-3, cleaved-PARP, phospho-JNK(Thr183/Tyr185), and phospho-ASK1(Ser966). Further, fasudil decreased mitochondrial membrane potential and intracellular calcium overload in the neurons treated with Aβ1-42. These results suggest that inhibition of Rho kinase by fasudil reverses Aβ1-42-induced neuronal apoptosis via the ASK1/JNK signal pathway, calcium ions, and mitochondrial membrane potential. Fasudil could be a drug of choice for treatment of Alzheimer's disease.
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Affiliation(s)
- Ye Gao
- Institute of Brain Science, Shanxi Key Laboratory of Inflammatory Neurodegenerative Diseases, Medical School of Shanxi Datong University, Datong, China
| | - Yuqing Yan
- Institute of Brain Science, Shanxi Key Laboratory of Inflammatory Neurodegenerative Diseases, Medical School of Shanxi Datong University, Datong, China.
| | - Qingli Fang
- Institute of Brain Science, Shanxi Key Laboratory of Inflammatory Neurodegenerative Diseases, Medical School of Shanxi Datong University, Datong, China
| | - Nianping Zhang
- Institute of Brain Science, Shanxi Key Laboratory of Inflammatory Neurodegenerative Diseases, Medical School of Shanxi Datong University, Datong, China
| | - Gajendra Kumar
- Department of Biomedical Sciences, City University of Hong Kong, Tat Chee Avenue, Hong Kong
- Bio-Signal technologies (HK) Limited, 9th Floor, Amtel Building,148 Des Voeux Road Central, Central, Hong Kong
| | - Jihong Zhang
- Institute of Brain Science, Shanxi Key Laboratory of Inflammatory Neurodegenerative Diseases, Medical School of Shanxi Datong University, Datong, China
| | - Li-Juan Song
- The Key Research Laboratory of Benefiting Qi for Acting Blood Circulation Method to Treat Multiple Sclerosis of State Administration of Traditional Chinese Medicine/Research Center of Neurobiology, Shanxi University of Chinese Medicine, Taiyuan, China
| | - Jiezhong Yu
- Institute of Brain Science, Shanxi Key Laboratory of Inflammatory Neurodegenerative Diseases, Medical School of Shanxi Datong University, Datong, China
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Linhu Zhao
- Institute of Brain Science, Shanxi Key Laboratory of Inflammatory Neurodegenerative Diseases, Medical School of Shanxi Datong University, Datong, China
| | - Han-Ting Zhang
- Departments of Neuroscience and Behavioral Medicine & Psychiatry, the Rockefeller Neurosciences Institute, West Virginia University Health Sciences Center, Morgantown, WV, 26506, USA.
| | - Cun-Gen Ma
- Institute of Brain Science, Shanxi Key Laboratory of Inflammatory Neurodegenerative Diseases, Medical School of Shanxi Datong University, Datong, China.
- The Key Research Laboratory of Benefiting Qi for Acting Blood Circulation Method to Treat Multiple Sclerosis of State Administration of Traditional Chinese Medicine/Research Center of Neurobiology, Shanxi University of Chinese Medicine, Taiyuan, China.
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23
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Sonego MS, Segatto NV, Damé L, Fronza M, Gomes CB, Oliveira TL, Seixas FK, Savegnago L, Schachtschneider KM, Alves D, Collares T. 7-Chloroquinoline-1,2,3-triazoyl carboxamides induce cell cycle arrest and apoptosis in human bladder carcinoma cells. Invest New Drugs 2019; 38:1020-1030. [DOI: 10.1007/s10637-019-00861-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 09/27/2019] [Indexed: 12/17/2022]
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24
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Ji Y, Shen J, Li M, Zhu X, Wang Y, Ding J, Jiang S, Chen L, Wei W. RMP/URI inhibits both intrinsic and extrinsic apoptosis through different signaling pathways. Int J Biol Sci 2019; 15:2692-2706. [PMID: 31754340 PMCID: PMC6854365 DOI: 10.7150/ijbs.36829] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Accepted: 08/24/2019] [Indexed: 02/06/2023] Open
Abstract
The evading apoptosis of tumor cells may result in chemotherapy resistance. Therefore, investigating what molecular events contribute to drug-induced apoptosis, and how tumors evade apoptotic death, provides a paradigm to explain the relationship between cancer genetics and treatment sensitivity. In this study, we focused on the role of RMP/URI both in cisplatin-induced endogenous apoptosis and in TRAIL-induced exogenous apoptosis in HCC cells. Although flow cytometric analysis indicated that RMP overexpression reduced the apoptosis rate of HCC cells treated with both cisplatin and TRAIL, there was a difference in mechanism between the two treatments. Western blot showed that in intrinsic apoptosis induced by cisplatin, the overexpression of RMP promoted the Bcl-xl expression both in vitro and in vivo. Besides, RMP activated NF-κB/p65(rel) through the phosphorylation of ATM. However, in TRAIL-induced extrinsic apoptosis, RMP significantly suppressed the transcription and expression of P53. Moreover, the forced expression of P53 could offset this inhibitory effect. In conclusion, we presumed that RMP inhibited both intrinsic and extrinsic apoptosis through different signaling pathways. NF-κB was distinctively involved in the RMP circumvention of intrinsic apoptosis, but not in the extrinsic apoptosis of HCC cells. RMP might play an important role in defects of apoptosis, hence the chemotherapeutic resistance in hepatocellular carcinoma. These studies are promising to shed light on a more rational approach to clinical anticancer drug design and therapy.
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Affiliation(s)
- Yuan Ji
- Department of Cell Biology, Institute of Bioengineering, School of Medicine, Soochow University, Suzhou 215123, China
| | - Jian Shen
- Department of Interventional Radiology, First Affiliated Hospital of Soochow University, Suzhou, 215006, China
| | - Min Li
- Department of Tumor, People Hospital of Maanshan, Maanshan, 243000, China
| | - Xiaoxiao Zhu
- Department of Cell Biology, Institute of Bioengineering, School of Medicine, Soochow University, Suzhou 215123, China
| | - Yanyan Wang
- Department of Cell Biology, Institute of Bioengineering, School of Medicine, Soochow University, Suzhou 215123, China
| | - Jiazheng Ding
- Department of Cell Biology, Institute of Bioengineering, School of Medicine, Soochow University, Suzhou 215123, China
| | - Shunyao Jiang
- Department of Cell Biology, Institute of Bioengineering, School of Medicine, Soochow University, Suzhou 215123, China
| | - Linqi Chen
- Department of Endocrinology, Children's Hospital affiliated to Soochow University, Suzhou, 215000, China
| | - Wenxiang Wei
- Department of Cell Biology, Institute of Bioengineering, School of Medicine, Soochow University, Suzhou 215123, China
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25
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健愉 冯, 玉山 朱, 陈 权, 凌 林, Jianyu F, Yushan Z, Quan C, Jialing L. [Physiological Function and Structural Basis of Bcl-2 Family Proteins]. ZHONGGUO XI BAO SHENG WU XUE XUE BAO 2019; 41:1477-1489. [PMID: 34249113 PMCID: PMC8265309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Apoptosis is an important biological process that plays a key role in the regulation of cell fate and homeostasis. The B-cell lymphoma-2 (Bcl-2) family proteins are important regulators of the apoptotic pathway, and their dysfunction is associated with a variety of diseases, including cancer, neurodegenerative and autoimmune diseases. In the past decade, a large number of research work on the physiological functions and atomic structures of Bcl-2 family proteins have been reported, which has deepened our understanding of the molecular mechanism and pathological significance of Bcl-2 family proteins. Recently, new drugs targeting different Bcl-2 proteins have been developed and used in clinics or tested in clinical trials. However, the complexity and diversity in functions and structures of Bcl-2 family have left many unsolved problems. This article summarizes current knowledge of the structure and function of Bcl-2 family proteins and discusses the pharmacological significance of Bcl-2 proteins as effective therapeutic targets.
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Affiliation(s)
| | | | | | - 林家 凌
- 俄克拉荷马大学健康科学中心生物化学与分子生物学系, 俄克拉何马城 73126-0901
| | - Feng Jianyu
- College of Life Sciences, Nankai University, Tianjin 300074, China
| | - Zhu Yushan
- College of Life Sciences, Nankai University, Tianjin 300074, China
| | - Chen Quan
- College of Life Sciences, Nankai University, Tianjin 300074, China
| | - Lin Jialing
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma 73126, USA
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26
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Dynamic PGAM5 multimers dephosphorylate BCL-xL or FUNDC1 to regulate mitochondrial and cellular fate. Cell Death Differ 2019; 27:1036-1051. [PMID: 31367011 DOI: 10.1038/s41418-019-0396-4] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 06/26/2019] [Accepted: 07/08/2019] [Indexed: 11/08/2022] Open
Abstract
Mitochondria are highly dynamic organelles and respond to stress by changing their fission-fusion cycle, undergoing mitophagy, or releasing apoptotic proteins to initiate cell death. The molecular mechanisms that sense different stresses and coordinate distinct effectors still await full characterization. Here, we show that PGAM5, which exists in an equilibrium between dimeric and multimeric states, dephosphorylates BCL-xL to inhibit apoptosis or FUNDC1 to activate mitofission and mitophagy in response to distinct stresses. In vinblastine-treated cells, PGAM5 dephosphorylates BCL-xL at Ser62 to restore BCL-xL sequestration of BAX and BAK and thereby resistance to apoptosis. Selenite-induced oxidative stress increases the multimerization of PGAM5, resulting in its dissociation from BCL-xL, which causes increased BCL-xL phosphorylation and apoptosis. Once freed, the more multimeric and active PGAM5 dephosphorylates FUNDC1 to initiate mitofission and mitophagy. The reciprocal interaction of PGAM5 with FUNDC1 and BCL-xL, controlled by PGAM5 multimerization, serves as a molecular switch between mitofission/mitophagy and apoptosis.
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27
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Xu J, Cai X, Teng S, Lu J, Zhou Y, Wang X, Meng Z. The Pro-Apoptotic Activity of Tamarixetin on Liver Cancer Cells Via Regulation Mitochondrial Apoptotic Pathway. Appl Biochem Biotechnol 2019; 189:647-660. [PMID: 31093908 DOI: 10.1007/s12010-019-03033-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/22/2019] [Indexed: 12/18/2022]
Affiliation(s)
- Jing Xu
- Cardiovascular Disease Center, First Hospital of Jilin University, Jilin University, Changchun, 130021, Jilin, China
| | - Xinhao Cai
- School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Shanshan Teng
- School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Jiahui Lu
- School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Yulin Zhou
- School of Life Sciences, Jilin University, Changchun, 130012, China
| | - Xiaofeng Wang
- Department of Stomatology, China-Japan Union Hospital of Jilin University, Jilin University, Changchun, 130033, China.
| | - Zhaoli Meng
- School of Life Sciences, Jilin University, Changchun, 130012, China.
- Department of Translational Medicine, First Hospital of Jilin University, Jilin University, Changchun, 130021, Jilin, China.
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28
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Abstract
The Bcl-2 family of proteins regulates mitochondrial outer membrane permeability thereby making life or death decisions for cells. Most of Bcl-2 proteins contain hydrophobic regions that are embedded in intracellular membranes such as mitochondria. These membrane proteins are difficult to express and purify thereby preluding biochemical and biophysical characterizations. Here, we describe a photocrosslinking approach based on in vitro synthesis of Bcl-2 proteins with photoreactive amino acid analogs incorporated at specific locations. These photoreactive proteins are reconstituted into liposomal membranes with defined phospholipids or mitochondrial membranes isolated from animals, and their interactions with other Bcl-2 proteins are detected by photocrosslinking.
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29
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Abstract
BCL-2 family proteins interact in a network that regulates apoptosis. The BH3 amino acid sequence motif serves to bind together this conglomerate protein family, both literally and figuratively. BH3 motifs are present in antiapoptotic and proapoptotic BCL-2 homologs, and in a separate group of unrelated BH3-only proteins often appended to the BCL-2 family. BH3-containing helices mediate many of their physical interactions to determine cell death versus survival, leading to the development of BH3 mimetics as therapeutics. Here we provide an overview of BCL-2 family interactions, their relevance in health and disease, and the progress toward regulating their interactions therapeutically.
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Affiliation(s)
- Jason D Huska
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - Heather M Lamb
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA
| | - J Marie Hardwick
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA.
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30
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Flores-Romero H, Landeta O, Ugarte-Uribe B, Cosentino K, García-Porras M, García-Sáez AJ, Basañez G. BFL1 modulates apoptosis at the membrane level through a bifunctional and multimodal mechanism showing key differences with BCLXL. Cell Death Differ 2018; 26:1880-1894. [PMID: 30560933 PMCID: PMC6748131 DOI: 10.1038/s41418-018-0258-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 11/13/2018] [Accepted: 11/27/2018] [Indexed: 12/17/2022] Open
Abstract
BFL1 is a relatively understudied member of the BCL2 protein family which has been implicated in the pathogenesis and chemoresistance of a variety of human cancers, including hematological malignancies and solid tumours. BFL1 is generally considered to have an antiapoptotic function, although its precise mode of action remains unclear. By quantitatively analyzing BFL1 action in synthetic membrane models and in cells, we found that BFL1 inhibits apoptosis through three distinct mechanisms which are similar but not identical to those of BCLXL, the paradigmatic antiapoptotic BCL2 family protein. Strikingly, alterations in lipid composition during apoptosis activate a prodeath function of BFL1 that is based on noncanonical oligomerization of the protein and breaching of the permeability barrier of the outer mitochondrial membrane (OMM). This lipid-triggered prodeath function of BFL1 is absent in BCLXL and also differs from that of the apoptotic effector BAX, which sets it apart from other BCL2 family members. Our findings support a new model in which BFL1 modulates apoptosis through a bifunctional and multimodal mode of action that is distinctly regulated by OMM lipids compared to BCLXL.
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Affiliation(s)
- Hector Flores-Romero
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, Leioa, 48940, Bizkaia, Spain. .,Interfaculty Institute of Biochemistry, Eberhard Karls University Tübingen, Hoppe-Seyler-Str. 4, Tübingen, 72076, Germany.
| | - Olatz Landeta
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, Leioa, 48940, Bizkaia, Spain.,Departmento de Bioquímica y Biología Molecular, Universidad del País Vasco (UPV/EHU), Barrio Sarriena s/n, Leioa, 48940, Bizkaia, Spain
| | - Begoña Ugarte-Uribe
- Interfaculty Institute of Biochemistry, Eberhard Karls University Tübingen, Hoppe-Seyler-Str. 4, Tübingen, 72076, Germany.,Departmento de Bioquímica y Biología Molecular, Universidad del País Vasco (UPV/EHU), Barrio Sarriena s/n, Leioa, 48940, Bizkaia, Spain
| | - Katia Cosentino
- Interfaculty Institute of Biochemistry, Eberhard Karls University Tübingen, Hoppe-Seyler-Str. 4, Tübingen, 72076, Germany
| | - Miguel García-Porras
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, Leioa, 48940, Bizkaia, Spain
| | - Ana J García-Sáez
- Interfaculty Institute of Biochemistry, Eberhard Karls University Tübingen, Hoppe-Seyler-Str. 4, Tübingen, 72076, Germany
| | - Gorka Basañez
- Instituto Biofisika (CSIC, UPV/EHU), Parque Científico de la UPV/EHU, Barrio Sarriena s/n, Leioa, 48940, Bizkaia, Spain.
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31
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Hantusch A, Das KK, García-Sáez AJ, Brunner T, Rehm M. Bax retrotranslocation potentiates Bcl-x L's antiapoptotic activity and is essential for switch-like transitions between MOMP competency and resistance. Cell Death Dis 2018; 9:430. [PMID: 29567940 PMCID: PMC5864878 DOI: 10.1038/s41419-018-0464-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 01/25/2018] [Accepted: 02/05/2018] [Indexed: 12/26/2022]
Abstract
The rapid, typically all-or-none process of mitochondrial outer membrane permeabilization (MOMP) constitutes a primary cell death decision that is controlled by the Bcl-2 family interactome. However, how strict all-or-none MOMP decisions are governed by and emanate from the dynamic interplay of pro- and antiapoptotic Bcl-2 family members remains incompletely understood. In particular, it is unclear to which extent the shuttling of Bcl-2 family species between lipid and aqueous phases contributes to regulating MOMP sensitivity. Here, we studied the interplay of tBid, Bax, and Bcl-xL, using a combined approach of deterministic mathematical modeling and retrospective as well as prospective experimental testing of model predictions. Systems modeling of the tBid–Bax interplay and their fluxes between cytosol and mitochondrial membranes reproduced experimental data on tBid-triggered Bax activation and oligomerization highly accurately. Extending these studies to analyze the cell-protective role of Bcl-xL strikingly revealed that the activity of Bcl-xL to retrotranslocate activated Bax from membranes back into the cytosol is essential to reproduce or correctly predict experimental outcomes. These included the potency of Bcl-xL in suppressing Bax oligomerization, its role in limiting Bax membrane recruitment, the resistance threshold to low concentrations of MOMP triggers as well as a response potentiaton arising from combinations of tBid and sensitizer BH3-only peptides. Importantly, retrotranslocation activity of Bcl-xL is necessary to strictly separate conditions of MOMP competency and resistance. Our results therefore identify Bax retrotranslocation by Bcl-xL as an indispensable component of the molecular switch by which Bcl-2 family members govern cellular death decisions.
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Affiliation(s)
- Annika Hantusch
- Department of Biology, Chair of Biochemical Pharmacology, University of Konstanz, 78457, Konstanz, Germany.,Konstanz Research School Chemical Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Kushal K Das
- Interfaculty Institute of Biochemistry, Eberhard Karls University Tübingen, Hoppe-Seyler-Str. 4, 72076, Tübingen, Germany
| | - Ana J García-Sáez
- Interfaculty Institute of Biochemistry, Eberhard Karls University Tübingen, Hoppe-Seyler-Str. 4, 72076, Tübingen, Germany
| | - Thomas Brunner
- Department of Biology, Chair of Biochemical Pharmacology, University of Konstanz, 78457, Konstanz, Germany.,Konstanz Research School Chemical Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Markus Rehm
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin 2, Ireland. .,Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin 2, Ireland. .,Institute of Cell Biology and Immunology, University of Stuttgart, 70569, Stuttgart, Germany. .,Stuttgart Research Center Systems Biology, University of Stuttgart, 70569, Stuttgart, Germany.
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32
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Zhuang J, Liu Y, Yuan Q, Liu J, Liu Y, Li H, Wang D. Blue light-induced apoptosis of human promyelocytic leukemia cells via the mitochondrial-mediated signaling pathway. Oncol Lett 2018; 15:6291-6296. [PMID: 29731847 PMCID: PMC5921239 DOI: 10.3892/ol.2018.8162] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 02/28/2018] [Indexed: 02/06/2023] Open
Abstract
Acute promyelocytic leukemia is frequently associated with dizziness, fever, nausea, hematochezia and anemia. Blue light, or light with wavelengths of 400–480 nm, transmits high levels of energy. The aim of the present study was to determine the pro-apoptotic effects of blue light (wavelength, 456 nm; radiation power, 0.25 mW/cm2) and the underlying mechanisms in a human promyelocytic leukemia cell line (HL60). Blue light reduced the viability and enhanced the mortality of HL60 cells in a time-dependent manner. Exposure to blue light for 24 h caused depolarization of the mitochondrial membrane potential and the overproduction of reactive oxygen species in HL60 cells. In a nude mouse model, 9-day exposure to blue light markedly suppressed the growth of HL60-xenografted tumors; however, it had no effect on hepatic and renal tissues. In addition, blue light abrogated the expression of B-cell lymphoma (Bcl)-2 and Bcl extra-long, while enhancing the levels of Bcl-2-associated X protein, cytochrome c, and cleaved caspases-3 and −9 in tumor tissues. The results suggested that the pro-apoptotic effects of blue light in human promyelocytic leukemia cells may be associated with the mitochondrial apoptosis signaling pathway.
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Affiliation(s)
- Jianjian Zhuang
- State Key Laboratory of Superhard Materials, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Yange Liu
- School of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Qingxia Yuan
- School of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Junsong Liu
- State Key Laboratory of Superhard Materials, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Yan Liu
- School of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Hongdong Li
- State Key Laboratory of Superhard Materials, Jilin University, Changchun, Jilin 130012, P.R. China
| | - Di Wang
- School of Life Sciences, Jilin University, Changchun, Jilin 130012, P.R. China
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33
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Vuillier C, Lohard S, Fétiveau A, Allègre J, Kayaci C, King LE, Braun F, Barillé-Nion S, Gautier F, Dubrez L, Gilmore AP, Juin PP, Maillet L. E2F1 interacts with BCL-xL and regulates its subcellular localization dynamics to trigger cell death. EMBO Rep 2018; 19:234-243. [PMID: 29233828 PMCID: PMC5797968 DOI: 10.15252/embr.201744046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 11/06/2017] [Accepted: 11/16/2017] [Indexed: 11/09/2022] Open
Abstract
E2F1 is the main pro-apoptotic effector of the pRB-regulated tumor suppressor pathway by promoting the transcription of various pro-apoptotic proteins. We report here that E2F1 partly localizes to mitochondria, where it favors mitochondrial outer membrane permeabilization. E2F1 interacts with BCL-xL independently from its BH3 binding interface and induces a stabilization of BCL-xL at mitochondrial membranes. This prevents efficient control of BCL-xL over its binding partners, in particular over BAK resulting in the induction of cell death. We thus identify a new, non-BH3-binding regulator of BCL-xL localization dynamics that influences its anti-apoptotic activity.
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Affiliation(s)
| | - Steven Lohard
- CRCINA, INSERM, U1232, Université de Nantes, Nantes, France
| | | | - Jennifer Allègre
- LNC, INSERM, UMR866, Université de Bourgogne Franche-Comté, Dijon, France
| | - Cémile Kayaci
- LNC, INSERM, UMR866, Université de Bourgogne Franche-Comté, Dijon, France
| | - Louise E King
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | | | | | - Fabien Gautier
- CRCINA, INSERM, U1232, Université de Nantes, Nantes, France
- ICO René Gauducheau, Saint Herblain, France
| | - Laurence Dubrez
- LNC, INSERM, UMR866, Université de Bourgogne Franche-Comté, Dijon, France
| | - Andrew P Gilmore
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Sciences Centre, University of Manchester, Manchester, UK
| | - Philippe P Juin
- CRCINA, INSERM, U1232, Université de Nantes, Nantes, France
- ICO René Gauducheau, Saint Herblain, France
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34
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Lian S, Guo J, Wang L, Li W, Wang J, Ji H, Kong F, Xu B, Li S, Yang H. Impact of prenatal cold stress on placental physiology, inflammatory response, and apoptosis in rats. Oncotarget 2017; 8:115304-115314. [PMID: 29383161 PMCID: PMC5777773 DOI: 10.18632/oncotarget.23257] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 12/04/2017] [Indexed: 11/25/2022] Open
Abstract
Prenatal cold stress is one of the earliest factors affecting mammalian health, and is associated with neonatal growth retardation and immune dysfunction, thus increasing disease susceptibility. The mechanisms underlying these observations remain unclear; hence, the objective of this study was to elucidate placental responses to cold stress. 60 maternal rats were randomly allocated to either stressed (n = 30) or non-stressed (control, n = 30) treatment conditions and 30 pubs (n=15) were used for the pups analysis. We found that maternal exposure to cold stress resulted in decreased body temperature, increased food intake without body weight gain, and a high level of plasma corticosterone (CORT) between gestational day (GD) 14 and GD21. In addition, gestation cold stress induced the placental expression of heat shock protein 70 (HSP70), IκBα, glucocorticoid receptor (GR), mineralocorticoid receptor (MR), 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2), interferon (IFN) regulatory factor 3 (IRF3), Caspase-3 proteins and altered the ratio of B-cell lymphoma-extra large (Bcl-xL) to Bcl-associated x (Bax) proteins on gestational GD15, GD17, GD19, and GD21, also resulted in the production of interleukin (IL)-1β. Next, gestational cold stress provoked a decrease in plasma GH levels of 21-day-old offspring, and the body weights of offspring were have no differences from postnatal day (PD) 1–21. Taken together, our results indicate that gestational cold stress induces placental apoptosis and the activation of NF-kB via HSP70/TLR4/NF-κB signaling pathways in the placenta, these changes may affect placental function and fetus development.
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Affiliation(s)
- Shuai Lian
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, P. R. China
| | - Jingru Guo
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, P. R. China
| | - Lipeng Wang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, P. R. China
| | - Wenjie Li
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, P. R. China
| | - Jianfa Wang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, P. R. China
| | - Hong Ji
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, P. R. China
| | - Fanzhi Kong
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, P. R. China
| | - Bin Xu
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, P. R. China
| | - Shize Li
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, P. R. China
| | - Huanmin Yang
- College of Animal Science and Veterinary Medicine, Heilongjiang Bayi Agricultural University, Daqing 163319, P. R. China
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35
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BCL-2 family proteins: changing partners in the dance towards death. Cell Death Differ 2017; 25:65-80. [PMID: 29149100 PMCID: PMC5729540 DOI: 10.1038/cdd.2017.186] [Citation(s) in RCA: 904] [Impact Index Per Article: 129.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Revised: 09/17/2017] [Accepted: 09/19/2017] [Indexed: 02/06/2023] Open
Abstract
The BCL-2 family of proteins controls cell death primarily by direct binding interactions that regulate mitochondrial outer membrane permeabilization (MOMP) leading to the irreversible release of intermembrane space proteins, subsequent caspase activation and apoptosis. The affinities and relative abundance of the BCL-2 family proteins dictate the predominate interactions between anti-apoptotic and pro-apoptotic BCL-2 family proteins that regulate MOMP. We highlight the core mechanisms of BCL-2 family regulation of MOMP with an emphasis on how the interactions between the BCL-2 family proteins govern cell fate. We address the critical importance of both the concentration and affinities of BCL-2 family proteins and show how differences in either can greatly change the outcome. Further, we explain the importance of using full-length BCL-2 family proteins (versus truncated versions or peptides) to parse out the core mechanisms of MOMP regulation by the BCL-2 family. Finally, we discuss how post-translational modifications and differing intracellular localizations alter the mechanisms of apoptosis regulation by BCL-2 family proteins. Successful therapeutic intervention of MOMP regulation in human disease requires an understanding of the factors that mediate the major binding interactions between BCL-2 family proteins in cells.
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36
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Why do BCL-2 inhibitors work and where should we use them in the clinic? Cell Death Differ 2017; 25:56-64. [PMID: 29077093 PMCID: PMC5729538 DOI: 10.1038/cdd.2017.183] [Citation(s) in RCA: 204] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 08/14/2017] [Accepted: 08/31/2017] [Indexed: 01/22/2023] Open
Abstract
Intrinsic apoptosis is controlled by the BCL-2 family of proteins but the complexity of intra-family interactions makes it challenging to predict cell fate via standard molecular biology techniques. We discuss BCL-2 family regulation and how to determine cells’ readiness for apoptosis and anti-apoptotic dependence. Cancer cells often adopt anti-apoptotic defense mechanisms in response to oncogenic stress or anti-cancer therapy. However, by determining their anti-apoptotic addiction, we can use novel BH3 mimetics to overwhelm this apoptotic blockade. We outline the development and uses of these unique anti-apoptotic inhibitors and how to possibly combine them with other anti-cancer agents using dynamic BH3 profiling (DBP) to improve personalized cancer treatment.
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Xu H, Wang J, Zhang J, Li M. Protective effect of TSG against oxygen-glucose deprivation in cardiomyoblast cell line H9c2: involvement of Bcl-2 family, Caspase 3/9, and Akt signaling pathway. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2017; 10:10584-10592. [PMID: 31966400 PMCID: PMC6965788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/08/2016] [Indexed: 06/10/2023]
Abstract
OBJECTIVE This study was designed to investigate the effect of TSG (2, 3, 5, 4'-tetrahydroxystibene-2-O-β-D-glucoside) on ischemic cardiomyopathy (ICM) related cell apoptosis and the mechanism related to it in vitro. METHODS Rat cardiomyoblast cell line H9c2 was cultured in oxygen-glucose withdrawal medium for 8 hours to establish an in vitro cell model of oxygen-glucose deprivation (OGD). Cells were pretreated with TSG to test the protective effect of it against OGD. Cell viability, apoptosis, mitochondrial transmembrane potential (ΔΨm), and apoptosis related proteins were detected using appropriated methods. Differences between treatments were analyzed. RESULTS OGD treatment inhibited cell viability, expression of Akt and Bax, induced loss of ΔΨm, cell apoptosis, and triggered expression of Bcl-2 and Caspase-3/9. TSG pretreatment, on the contrary, suppressed OGD-induced cell apoptosis, ΔΨm loss, Bcl-2 and Caspase-3/9 expression, and promoted OGD-inhibited cell viability, Bax and Akt expression. CONCLUSION We concluded that TSG's protective effect against OGD-induced in vitro ischemic cell model was associated to Akt/Caspase-3 pathway. TSG might be explored as a therapeutic target for ICM.
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Affiliation(s)
- Haiyang Xu
- The First Hospital of Jilin University No. 71 Xinmin Street, Changchun 130021, Jilin, China
| | - Jinghua Wang
- The First Hospital of Jilin University No. 71 Xinmin Street, Changchun 130021, Jilin, China
| | - Jingjing Zhang
- The First Hospital of Jilin University No. 71 Xinmin Street, Changchun 130021, Jilin, China
| | - Mingxian Li
- The First Hospital of Jilin University No. 71 Xinmin Street, Changchun 130021, Jilin, China
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Xu D, Si Y, Meroueh SO. A Computational Investigation of Small-Molecule Engagement of Hot Spots at Protein-Protein Interaction Interfaces. J Chem Inf Model 2017; 57:2250-2272. [PMID: 28766941 DOI: 10.1021/acs.jcim.7b00181] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The binding affinity of a protein-protein interaction is concentrated at amino acids known as hot spots. It has been suggested that small molecules disrupt protein-protein interactions by either (i) engaging receptor protein hot spots or (ii) mimicking hot spots of the protein ligand. Yet, no systematic studies have been done to explore how effectively existing small-molecule protein-protein interaction inhibitors mimic or engage hot spots at protein interfaces. Here, we employ explicit-solvent molecular dynamics simulations and end-point MM-GBSA free energy calculations to explore this question. We select 36 compounds for which high-quality binding affinity and cocrystal structures are available. Five complexes that belong to three classes of protein-protein interactions (primary, secondary, and tertiary) were considered, namely, BRD4•H4, XIAP•Smac, MDM2•p53, Bcl-xL•Bak, and IL-2•IL-2Rα. Computational alanine scanning using MM-GBSA identified hot-spot residues at the interface of these protein interactions. Decomposition energies compared the interaction of small molecules with individual receptor hot spots to those of the native protein ligand. Pharmacophore analysis was used to investigate how effectively small molecules mimic the position of hot spots of the protein ligand. Finally, we study whether small molecules mimic the effects of the native protein ligand on the receptor dynamics. Our results show that, in general, existing small-molecule inhibitors of protein-protein interactions do not optimally mimic protein-ligand hot spots, nor do they effectively engage protein receptor hot spots. The more effective use of hot spots in future drug design efforts may result in smaller compounds with higher ligand efficiencies that may lead to greater success in clinical trials.
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Affiliation(s)
- David Xu
- Department of BioHealth Informatics, Indiana University School of Informatics and Computing , Indianapolis, Indiana 46202, United States
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Li J, Jin H, Yu H, Wang B, Tang J. miRNA‑1284 inhibits cell growth and induces apoptosis of lung cancer cells. Mol Med Rep 2017; 16:3049-3054. [PMID: 28713980 PMCID: PMC5547959 DOI: 10.3892/mmr.2017.6949] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 03/07/2017] [Indexed: 01/20/2023] Open
Abstract
Lung cancer is the most common cancer worldwide, and morbidity and mortality associated with lung cancer has been increasing annually in recent decades. MicroRNAs (miRNAs), which are short non-coding RNA sequences that are involved in the regulation of gene expression, have been previously demonstrated to be key regulators in cancer. The present study aimed to clarify the role of miRNA (miR)-1284 in lung cancer. A549 lung carcinoma cells were transfected with miR-1284 mimic or miR-1284 inhibitor using Lipofectamine 2000. Subsequently, cell viability, growth and apoptosis of A459 cells in the miR-1284 mimic, miR-1284 inhibitor and control groups were assayed by MTT assay, bromodeoxyuridine assay and flow cytometry, respectively. Furthermore, the protein expression levels of p27, p21, Bax, pro-caspase-3, activated caspase-3 and Myc were detected by western blot analysis to investigate the molecular mechanisms underlying the effect of miR-1284 on A549 cells. The cell viability and growth of A549 cells were significantly decreased in the miR-1284 mimic group compared with the control group, whereas the percentage of apoptotic cells was significantly increased. By contrast, miR-1284 inhibitor transfection significantly increased the cell viability and growth compared with control, and decreased apoptosis. Furthermore, expression of p27 was increased in miR-1284 mimic-transfected A549 cells compared with the control group, whereas p21 was unaffected by miR-1284 overexpression or inhibition. The expression of Myc was decreased by miR-1284 mimic transfection compared with the control group. For the other apoptosis-associated proteins that were investigated (Bax, pro-caspase-3 and active caspase-3), the expression levels in the miR-1284 mimic transfected cells were higher than in the other two groups (control and miR-1284 inhibitor). In conclusion, the results suggest that miR-1284 affects cell proliferation and apoptosis of lung cancer cells, indicating that miR-1284 may have a key role in lung tumorigenesis.
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Affiliation(s)
- Jie Li
- Department of Thoracic Surgery, Chinese PLA General Hospital, Beijing 100853, P.R. China
| | - Hairong Jin
- Department of Thoracic Surgery, Chinese PLA General Hospital, Beijing 100853, P.R. China
| | - Hua Yu
- Department of Thoracic Surgery, Chinese PLA General Hospital, Beijing 100853, P.R. China
| | - Bin Wang
- Department of Thoracic Surgery, Chinese PLA General Hospital, Beijing 100853, P.R. China
| | - Jian Tang
- Department of Cardio‑Thoracic Surgery, First Affiliated Hospital of Chinese PLA General Hospital, Beijing 100048, P.R. China
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Das KK, Shalaby R, García-Sáez AJ. Determinants of BH3 Sequence Specificity for the Disruption of Bcl-xL/cBid Complexes in Membranes. ACS Chem Biol 2017; 12:989-1000. [PMID: 28170214 DOI: 10.1021/acschembio.6b01084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The prosurvival Bcl-2 proteins exhibit a specific pattern of interactions with BH3-only proteins that determines the cellular dependence on apoptotic stress. This specificity is crucial for the development of BH3 mimetics, a class of anticancer molecules based on the BH3 domain with promising activity in clinical trials. Although complex formation mainly takes place in the mitochondrial outer membrane, most studies so far addressed the interaction between BH3 peptides and truncated Bcl-2 proteins in solution. As a consequence, quantitative understanding of the sequence specificity determinants of BH3 peptides in the membrane environment is missing. Here, we tackle this issue by systematically quantifying the ability of BH3 peptides to compete for the complexes between cBid and Bcl-xL in giant unilamellar vesicles and compare it with solution and mitochondria. We show that the BH3 peptides derived from Hrk, Bim, Bid, and Bad are the most efficient in disrupting cBid/Bcl-xL complexes in the membrane, which correlates with their activity in mitochondria. Our findings support the targeting to the membrane of small molecules that bind Bcl-2 proteins as a strategy to improve their efficiency.
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Affiliation(s)
- Kushal Kumar Das
- Interfaculty Institute of Biochemistry, Eberhard Karls University Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany
| | - Raed Shalaby
- Interfaculty Institute of Biochemistry, Eberhard Karls University Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany
| | - Ana J. García-Sáez
- Interfaculty Institute of Biochemistry, Eberhard Karls University Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany
- Max Planck Institute for Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany
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41
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Affiliation(s)
- Anthony Letai
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02215
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42
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Garner TP, Reyna DE, Priyadarshi A, Chen HC, Li S, Wu Y, Ganesan YT, Malashkevich VN, Cheng EH, Gavathiotis E. An Autoinhibited Dimeric Form of BAX Regulates the BAX Activation Pathway. Mol Cell 2016; 63:485-97. [PMID: 27425408 PMCID: PMC4975667 DOI: 10.1016/j.molcel.2016.06.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 04/22/2016] [Accepted: 05/06/2016] [Indexed: 12/21/2022]
Abstract
Pro-apoptotic BAX is a cell fate regulator playing an important role in cellular homeostasis and pathological cell death. BAX is predominantly localized in the cytosol, where it has a quiescent monomer conformation. Following a pro-apoptotic trigger, cytosolic BAX is activated and translocates to the mitochondria to initiate mitochondrial dysfunction and apoptosis. Here, cellular, biochemical, and structural data unexpectedly demonstrate that cytosolic BAX also has an inactive dimer conformation that regulates its activation. The full-length crystal structure of the inactive BAX dimer revealed an asymmetric interaction consistent with inhibition of the N-terminal conformational change of one protomer and the displacement of the C-terminal helix α9 of the second protomer. This autoinhibited BAX dimer dissociates to BAX monomers before BAX can be activated. Our data support a model whereby the degree of apoptosis induction is regulated by the conformation of cytosolic BAX and identify an unprecedented mechanism of cytosolic BAX inhibition.
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Affiliation(s)
- Thomas P Garner
- Department of Biochemistry and Department of Medicine, Albert Einstein Cancer Center, Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Denis E Reyna
- Department of Biochemistry and Department of Medicine, Albert Einstein Cancer Center, Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Amit Priyadarshi
- Department of Biochemistry and Department of Medicine, Albert Einstein Cancer Center, Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Hui-Chen Chen
- Human Oncology and Pathogenesis Program and Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Sheng Li
- Department of Medicine and UCSD DXMS Proteomics Resource, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yang Wu
- Department of Biochemistry and Department of Medicine, Albert Einstein Cancer Center, Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Yogesh Tengarai Ganesan
- Human Oncology and Pathogenesis Program and Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Vladimir N Malashkevich
- Department of Biochemistry and Department of Biophysics and Physiology, Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Emily H Cheng
- Human Oncology and Pathogenesis Program and Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA
| | - Evripidis Gavathiotis
- Department of Biochemistry and Department of Medicine, Albert Einstein Cancer Center, Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Gerber VEM, Wijenayake S, Storey KB. Anti-apoptotic response during anoxia and recovery in a freeze-tolerant wood frog (Rana sylvatica). PeerJ 2016; 4:e1834. [PMID: 27042393 PMCID: PMC4811176 DOI: 10.7717/peerj.1834] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 03/01/2016] [Indexed: 11/29/2022] Open
Abstract
The common wood frog, Rana sylvatica, utilizes freeze tolerance as a means of winter survival. Concealed beneath a layer of leaf litter and blanketed by snow, these frogs withstand subzero temperatures by allowing approximately 65–70% of total body water to freeze. Freezing is generally considered to be an ischemic event in which the blood oxygen supply is impeded and may lead to low levels of ATP production and exposure to oxidative stress. Therefore, it is as important to selectively upregulate cytoprotective mechanisms such as the heat shock protein (HSP) response and expression of antioxidants as it is to shut down majority of ATP consuming processes in the cell. The objective of this study was to investigate another probable cytoprotective mechanism, anti-apoptosis during oxygen deprivation and recovery in the anoxia tolerant wood frog. In particular, relative protein expression levels of two important apoptotic regulator proteins, Bax and p-p53 (S46), and five anti-apoptotic/pro-survival proteins, Bcl-2, p-Bcl-2 (S70), Bcl-xL, x-IAP, and c-IAP in response to normoxic, 24 Hr anoxic exposure, and 4 Hr recovery stages were assessed in the liver and skeletal muscle using western immunoblotting. The results suggest a tissue-specific regulation of the anti-apoptotic pathway in the wood frog, where both liver and skeletal muscle shows an overall decrease in apoptosis and an increase in cell survival. This type of cytoprotective mechanism could be aimed at preserving the existing cellular components during long-term anoxia and oxygen recovery phases in the wood frog.
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Affiliation(s)
- Victoria E M Gerber
- Department of Biology, Carleton University, Ottawa, ON, Canada; Current affiliation: Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | | | - Kenneth B Storey
- Institute of Biochemistry, Department of Biology and Chemistry, Carleton University , Ottawa, ON , Canada
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Shahzad M, Small DM, Morais C, Wojcikowski K, Shabbir A, Gobe GC. Protection against oxidative stress-induced apoptosis in kidney epithelium by Angelica and Astragalus. JOURNAL OF ETHNOPHARMACOLOGY 2016; 179:412-9. [PMID: 26719285 DOI: 10.1016/j.jep.2015.12.027] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 12/06/2015] [Accepted: 12/20/2015] [Indexed: 05/21/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Astragalus membranaceus either alone or in combination with Angelica sinensis has been used traditionally for kidney disease in East Asia and China for thousands of years. Previous studies using in vivo animal models have shown the benefits of these medicinal herbs in kidney diseases that involve oxidative stress. However, the mechanisms by which these medicinal herbs protect kidney cells remain largely unknown. AIM OF THE STUDY To investigate the mechanisms by which ethanol, methanol and aqueous crude extracts of roots of A. membranaceus and A. sinensis afford protection to human kidney proximal tubular epithelial cells, using an in vitro model of oxidative stress. MATERIALS AND METHODS Ethanol, methanol and aqueous extracts of roots of A. membranaceus and A. sinensis were prepared by a three-solvent sequential process. HK2 human kidney proximal tubular epithelial cells were treated with H2O2 alone (0.5mM) or in combination with different concentrations of extracts. Cell mitosis and death (microscopy) and cell viability (MTT assay) were compared. Western immunoblot was used to study expression of apoptosis-related proteins (pro-apoptotic Bax andanti-apoptotic Bcl-XL), and cell survival (NFκB subunits p65 and p50), pro-inflammatory (TNF-α) and protective (TGFβ1) proteins. RESULTS H2O2-induced oxidative stress significantly increased apoptosis and reduced cell survival; upregulated pro-apoptotic and down-regulated Bcl-XL; increased NFκB (p65, p50); increased TNFα and decreased TGFβ1. All changes indicated kidney damage and dysfunction. All were modulated by all extracts of both plant species, except for NFκB which was only modulated by extracts of A. membranaceus. CONCLUSIONS In conclusion, in a model of oxidative stress that might occur after nephrotoxicity, the plant extracts were protective via anti-apoptotic and anti-inflammatory mechanisms.
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Affiliation(s)
- Muhammad Shahzad
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Brisbane, Australia; Department of Pharmacology, University of Health Sciences, Lahore, Pakistan
| | - David M Small
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Brisbane, Australia
| | - Christudas Morais
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Brisbane, Australia
| | - Ken Wojcikowski
- Department of Natural and Complementary Medicine, Southern Cross University, Lismore, Australia
| | - Arham Shabbir
- Department of Pharmacology, University of Health Sciences, Lahore, Pakistan
| | - Glenda C Gobe
- Centre for Kidney Disease Research, School of Medicine, University of Queensland, Translational Research Institute, Brisbane, Australia.
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45
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Le Pen J, Maillet L, Sarosiek K, Vuillier C, Gautier F, Montessuit S, Martinou JC, Letaï A, Braun F, Juin PP. Constitutive p53 heightens mitochondrial apoptotic priming and favors cell death induction by BH3 mimetic inhibitors of BCL-xL. Cell Death Dis 2016; 7:e2083. [PMID: 26844698 PMCID: PMC4849148 DOI: 10.1038/cddis.2015.400] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 12/07/2015] [Accepted: 12/09/2015] [Indexed: 01/08/2023]
Abstract
Proapoptotic molecules directly targeting the BCL-2 family network are promising anticancer therapeutics, but an understanding of the cellular stress signals that render them effective is still elusive. We show here that the tumor suppressor p53, at least in part by transcription independent mechanisms, contributes to cell death induction and full activation of BAX by BH3 mimetic inhibitors of BCL-xL. In addition to mildly facilitating the ability of compounds to derepress BAX from BCL-xL, p53 also provides a death signal downstream of anti-apoptotic proteins inhibition. This death signal cooperates with BH3-induced activation of BAX and it is independent from PUMA, as enhanced p53 can substitute for PUMA to promote BAX activation in response to BH3 mimetics. The acute sensitivity of mitochondrial priming to p53 revealed here is likely to be critical for the clinical use of BH3 mimetics.
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Affiliation(s)
- J Le Pen
- UMR 892 INSERM/6299 CNRS/Université de Nantes, Team 8 'Cell Survival And Tumor Escape In Breast Cancer', Institut de Recherche en Santé de l'Université de Nantes, Nantes, France
| | - L Maillet
- UMR 892 INSERM/6299 CNRS/Université de Nantes, Team 8 'Cell Survival And Tumor Escape In Breast Cancer', Institut de Recherche en Santé de l'Université de Nantes, Nantes, France
| | - K Sarosiek
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - C Vuillier
- UMR 892 INSERM/6299 CNRS/Université de Nantes, Team 8 'Cell Survival And Tumor Escape In Breast Cancer', Institut de Recherche en Santé de l'Université de Nantes, Nantes, France
| | - F Gautier
- UMR 892 INSERM/6299 CNRS/Université de Nantes, Team 8 'Cell Survival And Tumor Escape In Breast Cancer', Institut de Recherche en Santé de l'Université de Nantes, Nantes, France.,Institut de Cancérologie de l'Ouest, Centre de Lutte contre le Cancer René Gauducheau, Saint Herblain, France
| | - S Montessuit
- Department of Cell Biology, University of Geneva, Geneva,Switzerland
| | - J C Martinou
- Department of Cell Biology, University of Geneva, Geneva,Switzerland
| | - A Letaï
- Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, USA
| | - F Braun
- UMR 892 INSERM/6299 CNRS/Université de Nantes, Team 8 'Cell Survival And Tumor Escape In Breast Cancer', Institut de Recherche en Santé de l'Université de Nantes, Nantes, France
| | - P P Juin
- UMR 892 INSERM/6299 CNRS/Université de Nantes, Team 8 'Cell Survival And Tumor Escape In Breast Cancer', Institut de Recherche en Santé de l'Université de Nantes, Nantes, France.,Institut de Cancérologie de l'Ouest, Centre de Lutte contre le Cancer René Gauducheau, Saint Herblain, France
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Wang D, Zhang Y, Lu J, Wang Y, Wang J, Meng Q, Lee RJ, Wang D, Teng L. Cordycepin, a Natural Antineoplastic Agent, Induces Apoptosis of Breast Cancer Cells via Caspase-dependent Pathways. Nat Prod Commun 2016. [DOI: 10.1177/1934578x1601100119] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cordycepin, a major compound separated from Cordyceps sinensis, is known as a potential novel candidate for cancer therapy. Breast cancer, the most typical cancer diagnosed among women, remains a global health problem. In this study, the anti-breast cancer property of cordycepin and its underlying mechanisms was investigated. The direct effects of cordycepin on breast cancer cells both in in vitro and in vivo experiments were evaluated. Cordycepin exerted cytotoxicity in MCF-7 and MDA-MB-231 cells confirmed by reduced cell viability, inhibition of cell proliferation, enhanced lactate dehydrogenase release and reactive oxygen species accumulation, induced mitochondrial dysfunction and nuclear apoptosis in human breast cancer cells. Cordycepin increased the activation of pro-apoptotic proteins, including caspase-8, caspase-9, caspase-3 and Bax, and suppressed the expression of the anti-apoptotic protein, B-cell lymphoma 2 (Bcl-2). The inhibition on MCF-7-xenografted tumor growth in nude mice further confirmed cordycepin's anti-breast cancer effect. These aforementioned results reveal that cordycepin induces apoptosis in human breast cancer cells via caspase-dependent pathways. The data shed light on the possibility of cordycepin being a safe agent for breast cancer treatment.
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Affiliation(s)
- Di Wang
- School of Life Sciences, Jilin University, Changchun 130012, China
| | - Yongfeng Zhang
- School of Life Sciences, Jilin University, Changchun 130012, China
| | - Jiahui Lu
- School of Life Sciences, Jilin University, Changchun 130012, China
| | - Yang Wang
- School of Life Sciences, Jilin University, Changchun 130012, China
| | - Junyue Wang
- School of Life Sciences, Jilin University, Changchun 130012, China
| | - Qingfan Meng
- School of Life Sciences, Jilin University, Changchun 130012, China
| | - Robert J. Lee
- School of Life Sciences, Jilin University, Changchun 130012, China
- Division of Pharmaceutics, College of Pharmacy, The Ohio State University, Columbus, OH, USA
| | - Di Wang
- School of Life Sciences, Jilin University, Changchun 130012, China
| | - Lesheng Teng
- School of Life Sciences, Jilin University, Changchun 130012, China
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47
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Zhang Z, Subramaniam S, Kale J, Liao C, Huang B, Brahmbhatt H, Condon SGF, Lapolla SM, Hays FA, Ding J, He F, Zhang XC, Li J, Senes A, Andrews DW, Lin J. BH3-in-groove dimerization initiates and helix 9 dimerization expands Bax pore assembly in membranes. EMBO J 2015; 35:208-36. [PMID: 26702098 DOI: 10.15252/embj.201591552] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 11/18/2015] [Indexed: 01/08/2023] Open
Abstract
Pro-apoptotic Bax induces mitochondrial outer membrane permeabilization (MOMP) by forming oligomers through a largely undefined process. Using site-specific disulfide crosslinking, compartment-specific chemical labeling, and mutational analysis, we found that activated integral membrane Bax proteins form a BH3-in-groove dimer interface on the MOM surface similar to that observed in crystals. However, after the α5 helix was released into the MOM, the remaining interface with α2, α3, and α4 helices was rearranged. Another dimer interface was formed inside the MOM by two intersected or parallel α9 helices. Combinations of these interfaces generated oligomers in the MOM. Oligomerization was initiated by BH3-in-groove dimerization, without which neither the other dimerizations nor MOMP occurred. In contrast, α9 dimerization occurred downstream and was required for release of large but not small proteins from mitochondria. Moreover, the release of large proteins was facilitated by α9 insertion into the MOM and localization to the pore rim. Therefore, the BH3-in-groove dimerization on the MOM nucleates the assembly of an oligomeric Bax pore that is enlarged by α9 dimerization at the rim.
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Affiliation(s)
- Zhi Zhang
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | | | - Justin Kale
- Biological Sciences, Sunnybrook Research Institute, Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Chenyi Liao
- Department of Chemistry, University of Vermont, Burlington, VT, USA
| | - Bo Huang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Hetal Brahmbhatt
- Biological Sciences, Sunnybrook Research Institute, Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Samson G F Condon
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Suzanne M Lapolla
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Franklin A Hays
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Jingzhen Ding
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Feng He
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Xuejun C Zhang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - Jianing Li
- Department of Chemistry, University of Vermont, Burlington, VT, USA
| | - Alessandro Senes
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - David W Andrews
- Biological Sciences, Sunnybrook Research Institute, Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Jialing Lin
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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MAC inhibitors antagonize the pro-apoptotic effects of tBid and disassemble Bax / Bak oligomers. J Bioenerg Biomembr 2015; 49:65-74. [PMID: 26698318 DOI: 10.1007/s10863-015-9635-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 12/06/2015] [Indexed: 01/06/2023]
Abstract
Mitochondrial Apoptotic Channel inhibitors or iMACs are di-bromocarbazole derivatives with anti-apoptotic function which have been tested and validated in several mouse models of brain injury and neurodegeneration. Owing to the increased therapeutic potential of these compounds, we sought to expand our knowledge of their mechanism of action. We investigated the kinetics of MAC inhibition in mitochondria from wild type, Bak, and Bax knockout cell lines using patch clamp electrophysiology, fluorescence microscopy, ELISA, and semiquantitative western blot analyses. Our results show that iMACs work through at least two mechanisms: 1) by blocking relocation of the cytoplasmic Bax protein to mitochondria and 2) by disassembling Bax and Bak oligomers in the mitochondrial outer membrane. iMACs exert comparable effects on channel conductance of Bax or Bak and similarly affect cytochrome c release from Bax or Bak-containing mitochondria. Interestingly, wild type mitochondria were more susceptible to inhibition than the Bak or Bax knockouts. Western blot analysis showed that wild type mitochondria had lower steady state levels of Bak in the absence of apoptotic stimulation.
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Uchime O, Dai Z, Biris N, Lee D, Sidhu SS, Li S, Lai JR, Gavathiotis E. Synthetic Antibodies Inhibit Bcl-2-associated X Protein (BAX) through Blockade of the N-terminal Activation Site. J Biol Chem 2015; 291:89-102. [PMID: 26565029 DOI: 10.1074/jbc.m115.680918] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 11/06/2022] Open
Abstract
The BCL-2 protein family plays a critical role in regulating cellular commitment to mitochondrial apoptosis. Pro-apoptotic Bcl-2-associated X protein (BAX) is an executioner protein of the BCL-2 family that represents the gateway to mitochondrial apoptosis. Following cellular stresses that induce apoptosis, cytosolic BAX is activated and translocates to the mitochondria, where it inserts into the mitochondrial outer membrane to form a toxic pore. How the BAX activation pathway proceeds and how this may be inhibited is not yet completely understood. Here we describe synthetic antibody fragments (Fabs) as structural and biochemical probes to investigate the potential mechanisms of BAX regulation. These synthetic Fabs bind with high affinity to BAX and inhibit its activation by the BH3-only protein tBID (truncated Bcl2 interacting protein) in assays using liposomal membranes. Inhibition of BAX by a representative Fab, 3G11, prevented mitochondrial translocation of BAX and BAX-mediated cytochrome c release. Using NMR and hydrogen-deuterium exchange mass spectrometry, we showed that 3G11 forms a stoichiometric and stable complex without inducing a significant conformational change on monomeric and inactive BAX. We identified that the Fab-binding site on BAX involves residues of helices α1/α6 and the α1-α2 loop. Therefore, the inhibitory binding surface of 3G11 overlaps with the N-terminal activation site of BAX, suggesting a novel mechanism of BAX inhibition through direct binding to the BAX N-terminal activation site. The synthetic Fabs reported here reveal, as probes, novel mechanistic insights into BAX inhibition and provide a blueprint for developing inhibitors of BAX activation.
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Affiliation(s)
- Onyinyechukwu Uchime
- From the Departments of Biochemistry and Medicine, Albert Einstein Cancer Center, Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Zhou Dai
- the Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Nikolaos Biris
- From the Departments of Biochemistry and Medicine, Albert Einstein Cancer Center, Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York 10461
| | - David Lee
- the School of Medicine, University of California, San Diego, San Diego, California 92093, and
| | - Sachdev S Sidhu
- the Banting and Best Department of Medical Research and Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Sheng Li
- the School of Medicine, University of California, San Diego, San Diego, California 92093, and
| | - Jonathan R Lai
- the Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461,
| | - Evripidis Gavathiotis
- From the Departments of Biochemistry and Medicine, Albert Einstein Cancer Center, Wilf Family Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, New York 10461,
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Redefining the BH3 Death Domain as a 'Short Linear Motif'. Trends Biochem Sci 2015; 40:736-748. [PMID: 26541461 PMCID: PMC5056427 DOI: 10.1016/j.tibs.2015.09.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 09/18/2015] [Accepted: 09/24/2015] [Indexed: 01/06/2023]
Abstract
B cell lymphoma-2 (BCL-2)-related proteins control programmed cell death through a complex network of protein–protein interactions mediated by BCL-2 homology 3 (BH3) domains. Given their roles as dynamic linchpins, the discovery of novel BH3-containing proteins has attracted considerable attention. However, without a clearly defined BH3 signature sequence the BCL-2 family has expanded to include a nebulous group of nonhomologous BH3-only proteins, now justified by an intriguing twist. We present evidence that BH3s from both ordered and disordered proteins represent a new class of short linear motifs (SLiMs) or molecular recognition features (MoRFs) and are diverse in their evolutionary histories. The implied corollaries are that BH3s have a broad phylogenetic distribution and could potentially bind to non-BCL-2-like structural domains with distinct functions. BCL-2 family interactions are mediated by evolutionarily diverse BH3 motifs to regulate apoptosis. Given their key roles, BH3 mimetics are in clinical trials as cancer therapies. The discovery of novel BH3-only proteins represents a major endeavor in the cell death field. As a result, BH3 motifs are reportedly present in a nebulous conglomerate of different proteins, both structured and intrinsically disordered. There is no rigorous definition of a BH3 motif. Currently available BH3 signatures are diverse and elusive for predicting new functional BH3-containing proteins. Redefining the BH3 motif as a new type of short linear motif (SLiM) or molecular recognition feature (MoRF) reconciles many puzzling features of this motif and opens up new avenues for research.
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