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Jia J, Li M, Li Y, Xiao J, Dai H. The mtDNA-STING pathway plays an important role in both navitoclax- and S63845-induced autophagy and enhances cell death. Cell Biol Toxicol 2023; 39:2821-2839. [PMID: 37002446 DOI: 10.1007/s10565-023-09804-x] [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: 05/20/2022] [Accepted: 03/24/2023] [Indexed: 04/03/2023]
Abstract
Targeting BCL2 family proteins to induce cancer cell death has been successful in the treatment of cancer. BH3 mimetics such as ABT-737 not only induce cell death, but also activate autophagy. The molecular mechanism by which the BH3 mimetics induce autophagy is still controversial. In this study, we show that the BCL2/BCLXL/BCLw inhibitor navitoclax and the MCL1 inhibitor S63845 induce both apoptosis and autophagy in mouse embryonic fibroblasts (MEFs) and leukemia cell lines, while autophagy induced by navticlax and S63845 in leukemia cell lines requires the inhibition of caspase activities. Further experiments demonstrate that the autophagy induced by navitoclax or S63845 does not depend on Beclin 1, but downstream of Bax/Bak. Moreover, both navitoclax and S63845 treatment induce mtDNA release in MEFs, which activates STING and thereby induces autophagy, while STING KO inhibits both navitoclax- and S63845-induced autophagy. Furthermore, STING KO diminishes navitoclax- or S63845-induced apoptosis, suggesting that STING activation enhances rather than inhibits apoptosis. Thus, our findings provide new insights into the regulations of navitoclax- or S63845-induced autophagy and cell death.
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Affiliation(s)
- Jia Jia
- Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health & Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, Anhui, China
- University of Science and Technology of China, Hefei, 230026, Anhui, China
- Department of Pathology and Laboratory Medicine, Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, 230031, China
| | - Mengqing Li
- Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health & Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, Anhui, China
- Department of Pathology and Laboratory Medicine, Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, 230031, China
| | - Yunjian Li
- Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health & Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, Anhui, China
- Department of Pathology and Laboratory Medicine, Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, 230031, China
| | - Jun Xiao
- Department of Urology, the First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230001, China.
| | - Haiming Dai
- Anhui Province Key Laboratory of Medical Physics and Technology, Institute of Health & Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, 230031, Anhui, China.
- Department of Pathology and Laboratory Medicine, Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, 230031, China.
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2
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Chiou JT, Wu YY, Lee YC, Chang LS. BCL2L1 inhibitor A-1331852 inhibits MCL1 transcription and triggers apoptosis in acute myeloid leukemia cells. Biochem Pharmacol 2023; 215:115738. [PMID: 37562509 DOI: 10.1016/j.bcp.2023.115738] [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: 04/13/2023] [Revised: 08/04/2023] [Accepted: 08/07/2023] [Indexed: 08/12/2023]
Abstract
BH3 mimetics exert anticancer activity by inhibiting anti-apoptotic BCL2 proteins. However, accumulating evidence indicates that the off-target effects of these drugs tightly modulates their anticancer activities. In this study, we investigated whether the BCL2L1 inhibitor A-1331852 induced the death of U937 acute myeloid leukemia (AML) cells through a non-BCL2L1-targeted effect. A-1331852-induced apoptosis in U937 cells was characterized by increased ROS production, downregulation of MCL1, and loss of mitochondrial membrane potential. Ectopic expression of MCL1 alleviated A-1331852-induced mitochondrial depolarization and cytotoxicity in U937 cells. A-1331852-induced ROS production increased p38 MAPK phosphorylation and inhibited MCL1 transcription. Inhibition of p38 MAPK activation restored MCL1 expression in A-1331852-treated cells. A-1331852 triggered p38 MAPK-mediated Cullin 3 downregulation, which in turn increased PP2Acα expression, thereby reducing CREB phosphorylation. A-1331852 reduced the binding of CREB to the MCL1 promoter, leading to the inhibition of CREB-mediated MCL1 transcription. Furthermore, A-1331852 acted synergistically with the BCL2 inhibitor ABT-199 to induce U937 and ABT-199-resistant U937 cell death by inhibiting MCL1 expression. A similar phenomenon caused A-1331852-induced MCL1 downregulation and cytotoxicity in AML HL-60 cells. Collectively, our data suggest that A-1331852 shows an off-target effect of inhibiting MCL1 transcription, ultimately leading to U937 and HL-60 cell death.
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Affiliation(s)
- Jing-Ting Chiou
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Yu-Ying Wu
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Yuan-Chin Lee
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan
| | - Long-Sen Chang
- Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan; Department of Biotechnology, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
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3
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Alizadeh J, Kavoosi M, Singh N, Lorzadeh S, Ravandi A, Kidane B, Ahmed N, Mraiche F, Mowat MR, Ghavami S. Regulation of Autophagy via Carbohydrate and Lipid Metabolism in Cancer. Cancers (Basel) 2023; 15:cancers15082195. [PMID: 37190124 DOI: 10.3390/cancers15082195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/21/2023] [Accepted: 03/28/2023] [Indexed: 05/17/2023] Open
Abstract
Metabolic changes are an important component of tumor cell progression. Tumor cells adapt to environmental stresses via changes to carbohydrate and lipid metabolism. Autophagy, a physiological process in mammalian cells that digests damaged organelles and misfolded proteins via lysosomal degradation, is closely associated with metabolism in mammalian cells, acting as a meter of cellular ATP levels. In this review, we discuss the changes in glycolytic and lipid biosynthetic pathways in mammalian cells and their impact on carcinogenesis via the autophagy pathway. In addition, we discuss the impact of these metabolic pathways on autophagy in lung cancer.
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Affiliation(s)
- Javad Alizadeh
- Department of Human Anatomy and Cell Science, College of Medicine, University of Manitoba, Winnipeg, MB R3E 0V9, Canada
| | - Mahboubeh Kavoosi
- Department of Human Anatomy and Cell Science, College of Medicine, University of Manitoba, Winnipeg, MB R3E 0V9, Canada
| | - Navjit Singh
- Department of Human Anatomy and Cell Science, College of Medicine, University of Manitoba, Winnipeg, MB R3E 0V9, Canada
| | - Shahrokh Lorzadeh
- Department of Human Anatomy and Cell Science, College of Medicine, University of Manitoba, Winnipeg, MB R3E 0V9, Canada
| | - Amir Ravandi
- Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, Institute of Cardiovascular Sciences, Albrechtsen Research Centre, St. Boniface Hospital, Winnipeg, MB R2H 2A6, Canada
| | - Biniam Kidane
- Section of Thoracic Surgery, Department of Surgery, Health Sciences Centre, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3T 6C5, Canada
- CancerCare Manitoba Research Institute, Winnipeg, MB R3E 0V9, Canada
| | - Naseer Ahmed
- CancerCare Manitoba Research Institute, Winnipeg, MB R3E 0V9, Canada
- Department of Radiology, Section of Radiation Oncology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Fatima Mraiche
- College of Pharmacy, QU Health, Qatar University, Doha 2713, Qatar
- Department of Pharmacology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Michael R Mowat
- CancerCare Manitoba Research Institute, Winnipeg, MB R3E 0V9, Canada
- Department of Biochemistry & Medical Genetics, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Saeid Ghavami
- Department of Human Anatomy and Cell Science, College of Medicine, University of Manitoba, Winnipeg, MB R3E 0V9, Canada
- Research Institute of Oncology and Hematology, Winnipeg, MB R3E 0V9, Canada
- Faculty of Medicine in Zabrze, Academia of Silesia, 41-800 Zabrze, Poland
- Biology of Breathing Theme, Children Hospital Research Institute of Manitoba, University of Manitoba, Winnipeg, MB R3E 3P5, Canada
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4
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The cross-talk of autophagy and apoptosis in breast carcinoma: implications for novel therapies? Biochem J 2022; 479:1581-1608. [PMID: 35904454 DOI: 10.1042/bcj20210676] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 07/05/2022] [Accepted: 07/06/2022] [Indexed: 12/12/2022]
Abstract
Breast cancer is still the most common cancer in women worldwide. Resistance to drugs and recurrence of the disease are two leading causes of failure in treatment. For a more efficient treatment of patients, the development of novel therapeutic regimes is needed. Recent studies indicate that modulation of autophagy in concert with apoptosis induction may provide a promising novel strategy in breast cancer treatment. Apoptosis and autophagy are two tightly regulated distinct cellular processes. To maintain tissue homeostasis abnormal cells are disposed largely by means of apoptosis. Autophagy, however, contributes to tissue homeostasis and cell fitness by scavenging of damaged organelles, lipids, proteins, and DNA. Defects in autophagy promote tumorigenesis, whereas upon tumor formation rapidly proliferating cancer cells may rely on autophagy to survive. Given that evasion of apoptosis is one of the characteristic hallmarks of cancer cells, inhibiting autophagy and promoting apoptosis can negatively influence cancer cell survival and increase cell death. Hence, combination of antiautophagic agents with the enhancement of apoptosis may restore apoptosis and provide a therapeutic advantage against breast cancer. In this review, we discuss the cross-talk of autophagy and apoptosis and the diverse facets of autophagy in breast cancer cells leading to novel models for more effective therapeutic strategies.
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JNK initiates Beclin-1 dependent autophagic cell death against Akt activation. Exp Cell Res 2022; 414:113105. [DOI: 10.1016/j.yexcr.2022.113105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 11/24/2022]
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Tran S, Fairlie WD, Lee EF. BECLIN1: Protein Structure, Function and Regulation. Cells 2021; 10:cells10061522. [PMID: 34204202 PMCID: PMC8235419 DOI: 10.3390/cells10061522] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/15/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
BECLIN1 is a well-established regulator of autophagy, a process essential for mammalian survival. It functions in conjunction with other proteins to form Class III Phosphoinositide 3-Kinase (PI3K) complexes to generate phosphorylated phosphatidylinositol (PtdIns), lipids essential for not only autophagy but other membrane trafficking processes. Over the years, studies have elucidated the structural, biophysical, and biochemical properties of BECLIN1, which have shed light on how this protein functions to allosterically regulate these critical processes of autophagy and membrane trafficking. Here, we review these findings and how BECLIN1’s diverse protein interactome regulates it, as well as its impact on organismal physiology.
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Affiliation(s)
- Sharon Tran
- Olivia Newton-John Cancer Research Institute, Heidelberg, VIC 3084, Australia;
- School of Cancer Medicine, La Trobe University, Bundoora, VIC 3086, Australia
| | - W. Douglas Fairlie
- Olivia Newton-John Cancer Research Institute, Heidelberg, VIC 3084, Australia;
- School of Cancer Medicine, La Trobe University, Bundoora, VIC 3086, Australia
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Correspondence: (W.D.F.); (E.F.L.)
| | - Erinna F. Lee
- Olivia Newton-John Cancer Research Institute, Heidelberg, VIC 3084, Australia;
- School of Cancer Medicine, La Trobe University, Bundoora, VIC 3086, Australia
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC 3086, Australia
- Correspondence: (W.D.F.); (E.F.L.)
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7
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Malignant pleural mesothelioma co-opts BCL-X L and autophagy to escape apoptosis. Cell Death Dis 2021; 12:406. [PMID: 33859162 PMCID: PMC8050302 DOI: 10.1038/s41419-021-03668-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 03/22/2021] [Accepted: 03/22/2021] [Indexed: 12/15/2022]
Abstract
Escape from programmed cell death is a hallmark of cancer. In this study, we investigated the anti-apoptotic mechanisms and explored the therapeutic potential of BCL-2 homology domain-3 (BH3) mimetics in malignant pleural mesothelioma (MPM), a lethal thoracic malignancy with an extreme dearth of treatment options. By implementing integrated analysis of functional genomic data of MPM cells and quantitative proteomics of patients’ tumors, we identified BCL-XL as an anti-apoptotic driver that is overexpressed and confers an oncogenic dependency in MPM. MPM cells harboring genetic alterations that inactivate the NF2/LATS1/2 signaling are associated with increased sensitivity to A-1155463, a BCL-XL-selective BH3 mimetic. Importantly, BCL-XL inhibition elicits protective autophagy, and concomitant blockade of BCL-XL and autophagic machinery with A-1155463 and hydroxychloroquine (HCQ), the US Food and Drug Administration (FDA)-approved autophagy inhibitor, synergistically enhances anti-MPM effects in vitro and in vivo. Together, our work delineates the molecular basis underlying resistance to apoptosis and uncovers an evasive mechanism that limits response to BH3 mimetics in MPM, suggesting a novel strategy to target this aggressive disease.
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8
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Zhang Y, Tang LH, Lu J, Xu LM, Cheng BL, Xiong JY. ABT-263 enhanced bacterial phagocytosis of macrophages in aged mouse through Beclin-1-dependent autophagy. BMC Geriatr 2021; 21:225. [PMID: 33794800 PMCID: PMC8017763 DOI: 10.1186/s12877-021-02173-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 03/23/2021] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Sepsis is a critical challenge for the older adults as the immune function is less responsive by aging. Although cell numbers seem preserved in the older adults, macrophages present age-related function decline, which including reduced chemokines, phagocytosis, and autophagy. ABT-263, an inhibitor of the anti-apoptotic protein Bcl-2, is reported had a senolytic effect which can selectively clear the senescent cells in vivo and rejuvenate the aged tissues. METHODS We treated the aged (12-16 months) and young (4-6 months) C57BL/6 mouse with ABT-263, then gave the animals cecal slurry injection to induce sepsis to observe the effect of senolytic compound ABT-263 on the survival rate of sepsis. Additionally, we isolated peritoneal macrophages from the aged mouse to investigate the cell function and molecular mechanism. 3-methyladenine (3-MA), a phosphatidylinositol 3-kinases (PI3K) inhibitor, and rapamycin, an autophagy-enhancer, were used to block or mimic the autophagy, respectively. RT-PCR and Western Blot were used to detect autophagy related gene and protein changes in sepsis. EGFP-expressing E. coli was used as a marker to evaluate the phagocytic ability of macrophages. RESULTS The results showed ABT-263 treatment improved the survival rate of sepsis in the aged mouse which related to autophagy, while blocking the autophagy can eliminate this effect. It is revealed that ABT-263 enhanced the phagocytic ability of the peritoneal macrophages by increasing the Trem-2 receptor. Additionally, ABT-263 blocked the binding of Bcl-2 to Beclin-1, thus induced Beclin-1-dependent autophagy. CONCLUSION ABT-263 enhanced the macrophage function in aged mouse by increasing the Trem-2 receptors and inducing a beclin-1-dependent autophagy, consequently, protected the aged mouse from sepsis.
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Affiliation(s)
- Yu Zhang
- Department of Anesthesiology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Li-Hua Tang
- Department of Anesthesiology, The Second Hospital of Dalian Medical University, 467 Zhongshan Road, Dalian, ZIP: 116027, Liaoning, China
| | - Jia Lu
- Department of Anesthesiology, The Second Hospital of Dalian Medical University, 467 Zhongshan Road, Dalian, ZIP: 116027, Liaoning, China
| | - Li-Ming Xu
- Research Center, The Second Hospital of Dalian Medical University, Dalian, China
| | - Bao-Li Cheng
- Department of Anesthesiology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China
| | - Jun-Yu Xiong
- Department of Anesthesiology, The Second Hospital of Dalian Medical University, 467 Zhongshan Road, Dalian, ZIP: 116027, Liaoning, China.
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9
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Fairlie WD, Tran S, Lee EF. Crosstalk between apoptosis and autophagy signaling pathways. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 352:115-158. [DOI: 10.1016/bs.ircmb.2020.01.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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10
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Frank D, Vaux DL, Murphy JM, Vince JE, Lindqvist LM. Activated MLKL attenuates autophagy following its translocation to intracellular membranes. J Cell Sci 2019; 132:jcs.220996. [PMID: 30709919 DOI: 10.1242/jcs.220996] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 01/25/2019] [Indexed: 12/27/2022] Open
Abstract
Necroptosis is an inflammatory form of programmed cell death mediated by the pseudokinase mixed-lineage kinase domain-like protein (MLKL). Upon phosphorylation by receptor-interacting protein kinase-3 (RIPK3), MLKL oligomerizes, and translocates to and disrupts the plasma membrane, thereby causing necroptotic cell lysis. Herein, we show that activation of necroptosis in mouse dermal fibroblasts (MDFs) and HT-29 human colorectal cancer cells results in accumulation of the autophagic marker, lipidated LC3B (also known as MAP1LC3B), in an MLKL-dependent manner. Unexpectedly, the necroptosis-induced increase in lipidated LC3B was due to inhibition of autophagic flux, not the activation of autophagy. Inhibition of autophagy by MLKL correlated with a decrease in autophagosome and/or autolysosome function, and required the association of activated MLKL with intracellular membranes. Collectively, our findings uncover an additional role for the MLKL pseudokinase, namely to inhibit autophagy during necroptosis.
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Affiliation(s)
- Daniel Frank
- Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3050, Australia
| | - David L Vaux
- Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3050, Australia
| | - James M Murphy
- Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Melbourne, Victoria 3052, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3050, Australia
| | - James E Vince
- Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3050, Australia .,Inflammation Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Melbourne, Victoria 3052, Australia
| | - Lisa M Lindqvist
- Cell Signalling and Cell Death Division, The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Melbourne, Victoria 3052, Australia .,Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3050, Australia
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11
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Lee EF, Smith NA, Soares da Costa TP, Meftahi N, Yao S, Harris TJ, Tran S, Pettikiriarachchi A, Perugini MA, Keizer DW, Evangelista M, Smith BJ, Fairlie WD. Structural insights into BCL2 pro-survival protein interactions with the key autophagy regulator BECN1 following phosphorylation by STK4/MST1. Autophagy 2019; 15:785-795. [PMID: 30626284 DOI: 10.1080/15548627.2018.1564557] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
BECN1/Beclin 1 is a critical protein in the initiation of autophagosome formation. Recent studies have shown that phosphorylation of BECN1 by STK4/MST1 at threonine 108 (T108) within its BH3 domain blocks macroautophagy/autophagy by increasing BECN1 affinity for its negative regulators, the anti-apoptotic proteins BCL2/Bcl-2 and BCL2L1/Bcl-xL. It was proposed that this increased binding is due to formation of an electrostatic interaction with a conserved histidine residue on the anti-apoptotic molecules. Here, we performed biophysical studies which demonstrated that a peptide corresponding to the BECN1 BH3 domain in which T108 is phosphorylated (p-T108) does show increased affinity for anti-apoptotic proteins that is significant, though only minor (<2-fold). We also determined X-ray crystal structures of BCL2 and BCL2L1 with T108-modified BECN1 BH3 peptides, but only showed evidence of an interaction between the BH3 peptide and the conserved histidine residue when the histidine flexibility was restrained due to crystal contacts. These data, together with molecular dynamics studies, indicate that the histidine is highly flexible, even when complexed with BECN1 BH3. Binding studies also showed that detergent can increase the affinity of the interaction. Although this increase was similar for both the phosphorylated and non-phosphorylated peptides, it suggests factors such as membranes could impact on the interaction between BECN1 and BCL2 proteins, and therefore, on the regulation of autophagy. Hence, we propose that phosphorylation of BECN1 by STK4/MST1 can increase the affinity of the interaction between BECN1 and anti-apoptotic proteins and this interaction can be stabilized by local environmental factors. Abbreviations: asu: asymmetric unit; BH3: BCL2/Bcl-2 homology 3; DAPK: death associated protein kinase; MD: molecular dynamics; MST: microscale thermophoresis; NMR: nuclear magnetic resonance; PDB: protein data bank; p-T: phosphothreonine; SPR: surface plasmon resonance; STK4/MST1: serine/threonine kinase 4.
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Affiliation(s)
- Erinna F Lee
- a La Trobe Institute for Molecular Science , La Trobe University , Melbourne , Australia.,b Cell Death and Survival Group , Olivia Newton-John Cancer Research Institute , Heidelberg , Australia.,c School of Cancer Medicine , La Trobe University , Melbourne , Australia
| | - Nicholas A Smith
- a La Trobe Institute for Molecular Science , La Trobe University , Melbourne , Australia
| | | | - Nastaran Meftahi
- a La Trobe Institute for Molecular Science , La Trobe University , Melbourne , Australia
| | - Shenggen Yao
- d Bio21 Molecular Science and Biotechnology Institute , The University of Melbourne , Parkville , Australia
| | - Tiffany J Harris
- b Cell Death and Survival Group , Olivia Newton-John Cancer Research Institute , Heidelberg , Australia
| | - Sharon Tran
- b Cell Death and Survival Group , Olivia Newton-John Cancer Research Institute , Heidelberg , Australia.,c School of Cancer Medicine , La Trobe University , Melbourne , Australia
| | - Anne Pettikiriarachchi
- e Structural Biology Division , The Walter and Eliza Hall Institute of Medical Research , Parkville , Australia
| | - Matthew A Perugini
- a La Trobe Institute for Molecular Science , La Trobe University , Melbourne , Australia
| | - David W Keizer
- d Bio21 Molecular Science and Biotechnology Institute , The University of Melbourne , Parkville , Australia
| | - Marco Evangelista
- b Cell Death and Survival Group , Olivia Newton-John Cancer Research Institute , Heidelberg , Australia
| | - Brian J Smith
- a La Trobe Institute for Molecular Science , La Trobe University , Melbourne , Australia
| | - W Douglas Fairlie
- a La Trobe Institute for Molecular Science , La Trobe University , Melbourne , Australia.,b Cell Death and Survival Group , Olivia Newton-John Cancer Research Institute , Heidelberg , Australia.,c School of Cancer Medicine , La Trobe University , Melbourne , Australia
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12
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Autophagy induced during apoptosis degrades mitochondria and inhibits type I interferon secretion. Cell Death Differ 2017; 25:784-796. [PMID: 29229994 DOI: 10.1038/s41418-017-0017-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 10/10/2017] [Accepted: 10/18/2017] [Indexed: 02/08/2023] Open
Abstract
Cells undergoing Bax/Bak-mediated apoptosis exhibit signs of autophagy, but how it is activated and its significance is unknown. By directly activating Bax/Bak with BH3-only proteins or BH3 mimetic compounds, we demonstrate that mitochondrial damage correlated with a rapid increase in intracellular [AMP]/[ATP], phosphorylation of 5' AMP-activated protein kinase (AMPK), and activation of unc-51 like autophagy activating kinase 1 (ULK1). Consequently, autophagic flux was triggered early in the apoptotic pathway, as activation of the apoptosome and caspases were not necessary for its induction. Bax/Bak-triggered autophagy resulted in the clearance of damaged mitochondria in an ATG5/7-dependent manner that did not require Parkin. Importantly, Bax/Bak-mediated autophagy inhibited the secretion of the pro-inflammatory cytokine interferon-β (IFN-β) produced in response to mitochondrial damage, but not another cytokine interleukin-6 (IL-6). These findings show that Bax/Bak stimulated autophagy is essential for ensuring immunological silence during apoptosis.
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13
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ABT-263 induces G 1/G 0-phase arrest, apoptosis and autophagy in human esophageal cancer cells in vitro. Acta Pharmacol Sin 2017; 38:1632-1641. [PMID: 28713162 DOI: 10.1038/aps.2017.78] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 02/21/2017] [Indexed: 12/11/2022] Open
Abstract
Both the anti- and pro-apoptotic members of the Bcl-2 family are regulated by a conserved Bcl-2 homology (BH3) domain. ABT-263 (Navitoclax), a novel BH3 mimetic and orally bioavailable Bcl-2 family inhibitor with high affinity for Bcl-xL, Bcl-2 and Bcl-w has entered clinical trials for cancer treatment. But the anticancer mechanisms of ABT-263 have not been fully elucidated. In this study we investigated the effects of ABT-263 on human esophageal cancer cells in vitro and to explore its anticancer mechanisms. Treatment with ABT-263 dose-dependently suppressed the viability of 3 human esophageal cancer cells with IC50 values of 10.7±1.4, 7.1±1.5 and 8.2±1.6 μmol/L, in EC109, HKESC-2 and CaES-17 cells, respectively. ABT-263 (5-20 μmol/L) dose-dependently induced G1/G0-phase arrest in the 3 cancer cell lines and induced apoptosis evidenced by increased the Annexin V-positive cell population and elevated levels of cleaved caspase 3, cleaved caspase 9 and PARP. We further demonstrated that ABT-263 treatment markedly increased the expression of p21Waf1/Cip1 and decreased the expression of cyclin D1 and phospho-Rb (retinoblastoma tumor suppressor protein) (Ser780) proteins that contributed to the G1/G0-phase arrest. Knockdown of p21Waf1/Cip1 attenuated ABT-263-induced G1/G0-phase arrest. Moreover, ABT-263 treatment enhanced pro-survival autophagy, shown as the increased LC3-II levels and decreased p62 levels, which counteracted its anticancer activity. Our results suggest that ABT-263 exerts cytostatic and cytotoxic effects on human esophageal cancer cells in vitro and enhances pro-survival autophagy, which counteracts its anticancer activity.
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14
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Pihán P, Carreras-Sureda A, Hetz C. BCL-2 family: integrating stress responses at the ER to control cell demise. Cell Death Differ 2017. [PMID: 28622296 DOI: 10.1038/cdd.2017.82] [Citation(s) in RCA: 173] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In the last decade, the endoplasmic reticulum (ER) has emerged as a central organelle regulating the core mitochondrial apoptosis pathway. At the ER membrane, a variety of stress signals are integrated toward determining cell fate, involving a complex cross talk between key homeostatic pathways including the unfolded protein response, autophagy, calcium signaling and mitochondrial bioenergetics. In this context, key regulators of cell death of the BCL-2 and TMBIM/BI-1 family of proteins have relevant functions as stress rheostats mediated by the formation of distinct protein complexes that regulate the switch between adaptive and proapoptotic phases under stress. Here, we overview recent advances on our molecular understanding of how the apoptotic machinery integrates stress signals toward cell fate decisions upstream of the mitochondrial gateway of death.
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Affiliation(s)
- Philippe Pihán
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.,Faculty of Medicine, Center for Geroscience, Brain Health and Metabolism, University of Chile, Santiago, Chile
| | - Amado Carreras-Sureda
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.,Faculty of Medicine, Center for Geroscience, Brain Health and Metabolism, University of Chile, Santiago, Chile
| | - Claudio Hetz
- Faculty of Medicine, Biomedical Neuroscience Institute, University of Chile, Santiago, Chile.,Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, University of Chile, Santiago, Chile.,Faculty of Medicine, Center for Geroscience, Brain Health and Metabolism, University of Chile, Santiago, Chile.,Buck Institute for Research on Aging, Novato, CA 94945, USA.,Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston MA 02115, USA
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15
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Towers CG, Thorburn A. Therapeutic Targeting of Autophagy. EBioMedicine 2016; 14:15-23. [PMID: 28029600 PMCID: PMC5161418 DOI: 10.1016/j.ebiom.2016.10.034] [Citation(s) in RCA: 208] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 10/20/2016] [Accepted: 10/20/2016] [Indexed: 01/19/2023] Open
Abstract
Autophagy is a catabolic process that facilitates nutrient recycling via degradation of damaged organelles and proteins through lysosomal mediated degradation. Alterations in this complex, and tightly regulated process, lead to disease. Autophagy is widely accepted as cytoprotective against neurodegenerative diseases and a variety of clinical interventions are moving forward to increase autophagy as a therapeutic intervention. Autophagy has both positive and negative roles in cancer and this has led to controversy over whether or how autophagy manipulation should be attempted in cancer therapy. Nevertheless, cancer is the disease where most current activity in trying to manipulate autophagy for therapy is taking place and dozens of clinical trials are using autophagy inhibition with Chloroquine or Hydroxychloroquine in combination with other drugs for the treatment of multiple neoplasms. Here, we review recent literature implicating autophagy in neurodegenerative diseases and cancer and highlight some of the opportunities, controversies and potential pitfalls of therapeutically targeting autophagy.
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Affiliation(s)
- Christina G Towers
- Department of Pharmacology, University of Colorado School of Medicine, 12801 E. 17th Ave, Aurora, CO 80045, USA
| | - Andrew Thorburn
- Department of Pharmacology, University of Colorado School of Medicine, 12801 E. 17th Ave, Aurora, CO 80045, USA.
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16
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Ohmer M, Weber A, Sutter G, Ehrhardt K, Zimmermann A, Häcker G. Anti-apoptotic Bcl-XL but not Mcl-1 contributes to protection against virus-induced apoptosis. Cell Death Dis 2016; 7:e2340. [PMID: 27537523 PMCID: PMC5108327 DOI: 10.1038/cddis.2016.242] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 06/29/2016] [Accepted: 07/01/2016] [Indexed: 11/23/2022]
Abstract
Infection of mammalian cells with viruses often induces apoptosis. How the recognition of viruses leads to apoptosis of the infected cell and which host cell factors regulate this cell death is incompletely understood. In this study, we focussed on two major anti-apoptotic proteins of the host cell, whose abundance and activity are important for cell survival, the Bcl-2-like proteins Mcl-1 and Bcl-XL. During infection of epithelial cells and fibroblasts with modified vaccinia virus Ankara (MVA), Mcl-1 protein levels dropped but the MVA Bcl-2-like protein F1L could replace Mcl-1 functionally; a similar activity was found in vaccinia virus (VACV)-infected cells. During infection with murine cytomegalovirus (MCMV), Mcl-1-levels were not reduced but a viral Mcl-1-like activity was also generated. Infection of mouse macrophages with any of these viruses, on the other hand, induced apoptosis. Virus-induced macrophage apoptosis was unaltered in the absence of Mcl-1. However, apoptosis was substantially increased in infected Bcl-XL-deficient macrophages or macrophages treated with the Bcl-2/Bcl-XL-inhibitor ABT-737. Genetic loss of Bcl-XL or treatment of macrophages with ABT-737 reduced the generation of infectious VACV. These data show that Mcl-1 is dispensable for the regulation of apoptosis during infection with different large DNA viruses, either because the viruses replace its function (in fibroblasts and epithelial cells) or because the pro-apoptotic activity generated by the infection appears not to be blocked by it (in macrophages). Bcl-XL, on the other hand, can be important to maintain survival of virus-infected cells, and its activity can determine outcome of the infection.
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Affiliation(s)
- Michaela Ohmer
- Institute of Medical Microbiology and Hygiene, University Medical Center Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Arnim Weber
- Institute of Medical Microbiology and Hygiene, University Medical Center Freiburg, Freiburg, Germany
| | - Gerd Sutter
- Institute for Infectious Diseases and Zoonoses, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Katrin Ehrhardt
- Institute of Virology, University Medical Center Freiburg, Freiburg, Germany
| | - Albert Zimmermann
- Institute for Virology, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - Georg Häcker
- Institute of Medical Microbiology and Hygiene, University Medical Center Freiburg, Freiburg, Germany
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