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Nguyen D, Osterlund E, Kale J, Andrews DW. The C-terminal sequences of Bcl-2 family proteins mediate interactions that regulate cell death. Biochem J 2024; 481:903-922. [PMID: 38985308 PMCID: PMC11346437 DOI: 10.1042/bcj20210352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 07/11/2024]
Abstract
Programmed cell death via the both intrinsic and extrinsic pathways is regulated by interactions of the Bcl-2 family protein members that determine whether the cell commits to apoptosis via mitochondrial outer membrane permeabilization (MOMP). Recently the conserved C-terminal sequences (CTSs) that mediate localization of Bcl-2 family proteins to intracellular membranes, have been shown to have additional protein-protein binding functions that contribute to the functions of these proteins in regulating MOMP. Here we review the pivotal role of CTSs in Bcl-2 family interactions including: (1) homotypic interactions between the pro-apoptotic executioner proteins that cause MOMP, (2) heterotypic interactions between pro-apoptotic and anti-apoptotic proteins that prevent MOMP, and (3) heterotypic interactions between the pro-apoptotic executioner proteins and the pro-apoptotic direct activator proteins that promote MOMP.
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Affiliation(s)
- Dang Nguyen
- Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Canada
- Biological Sciences Platform, Odette Cancer Program, Sunnybrook Research Institute, Toronto, Canada
| | - Elizabeth Osterlund
- Department of Biochemistry and Biomedical Sciences, Faculty of Health Science, McMaster University, Hamilton, Canada
| | - Justin Kale
- Biological Sciences Platform, Odette Cancer Program, Sunnybrook Research Institute, Toronto, Canada
| | - David W. Andrews
- Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Canada
- Biological Sciences Platform, Odette Cancer Program, Sunnybrook Research Institute, Toronto, Canada
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Toronto, Canada
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2
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Waguia Kontchou C, Häcker G. Role of mitochondrial outer membrane permeabilization during bacterial infection. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023; 374:83-127. [PMID: 36858657 DOI: 10.1016/bs.ircmb.2022.10.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Beyond the initial 'powerhouse' view, mitochondria have numerous functions in their mammalian cell and contribute to many physiological processes, and many of these we understand only partially. The control of apoptosis by mitochondria is firmly established. Many questions remain however how this function is embedded into physiology, and how other signaling pathways regulate mitochondrial apoptosis; the interplay of bacteria with the mitochondrial apoptosis pathway is one such example. The outer mitochondrial membrane regulates both import into mitochondria and the release of intermembrane, and in some situations also matrix components from mitochondria, and these mitochondrial components can have signaling function in the cytosol. One function is the induction of apoptotic cell death. An exciting, more recently discovered function is the regulation of inflammation. Mitochondrial molecules, both proteins and nucleic acids, have inflammatory activity when released from mitochondria, an activity whose regulation is intertwined with the activation of apoptotic caspases. Bacterial infection can have more general effects on mitochondrial apoptosis-regulation, through effects on host transcription and other pathways, such as signals controlled by pattern recognition. Some specialized bacteria have products that more specifically regulate signaling to the outer mitochondrial membrane, and to apoptosis; both pro- and anti-apoptotic mechanisms have been reported. Among the intriguing recent findings in this area are signaling contributions of porins and the sub-lethal release of intermembrane constituents. We will here review the literature and place the new developments into the established context of mitochondrial signaling during the contact of bacterial pathogens with human cells.
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Affiliation(s)
- Collins Waguia Kontchou
- Institute of Medical Microbiology and Hygiene, Medical Center-University of Freiburg, Faculty of Medicine, Freiburg, Germany
| | - Georg Häcker
- Institute of Medical Microbiology and Hygiene, Medical Center-University of Freiburg, Faculty of Medicine, Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.
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3
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Chen Q, Ruan D, Shi J, Du D, Bian C. The multifaceted roles of natural products in mitochondrial dysfunction. Front Pharmacol 2023; 14:1093038. [PMID: 36860298 PMCID: PMC9968749 DOI: 10.3389/fphar.2023.1093038] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 02/02/2023] [Indexed: 02/16/2023] Open
Abstract
Mitochondria are the primary source of energy production in cells, supporting the metabolic demand of tissue. The dysfunctional mitochondria are implicated in various diseases ranging from neurodegeneration to cancer. Therefore, regulating dysfunctional mitochondria offers a new therapeutic opportunity for diseases with mitochondrial dysfunction. Natural products are pleiotropic and readily obtainable sources of therapeutic agents, which have broad prospects in new drug discovery. Recently, many mitochondria-targeting natural products have been extensively studied and have shown promising pharmacological activity in regulating mitochondrial dysfunction. Hence, we summarize recent advances in natural products in targeting mitochondria and regulating mitochondrial dysfunction in this review. We discuss natural products in terms of their mechanisms on mitochondrial dysfunction, including modulating mitochondrial quality control system and regulating mitochondrial functions. In addition, we describe the future perspective and challenges in the development of mitochondria-targeting natural products, emphasizing the potential value of natural products in mitochondrial dysfunction.
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Affiliation(s)
| | | | - Jiayan Shi
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Gynecology and Obstetrics, Ministry of Education, West China Second Hospital, Sichuan University, Chengdu, China
| | - Dongru Du
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Gynecology and Obstetrics, Ministry of Education, West China Second Hospital, Sichuan University, Chengdu, China
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4
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Gundelia tournefortii inhibits hepatocellular carcinoma progression by lowering gene expression of the cell cycle and hepatocyte proliferation in immunodeficient mice. Biomed Pharmacother 2022; 156:113885. [DOI: 10.1016/j.biopha.2022.113885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 11/19/2022] Open
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5
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Choi HS, Lim ES, Baek KH. Deubiquitinating Enzyme USP12 Regulates the Pro-Apoptosis Protein Bax. Int J Mol Sci 2022; 23:13107. [PMID: 36361894 PMCID: PMC9657785 DOI: 10.3390/ijms232113107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 10/21/2022] [Accepted: 10/26/2022] [Indexed: 08/30/2023] Open
Abstract
The Bax protein is a pro-apoptotic protein belonging to the Bcl-2 family, involved in inducing apoptosis at the mitochondrial level. Regulating the protein levels of Bax is essential to enhancing apoptosis. In the current study, we ascertained the presence of deubiquitinating enzymes (DUBs) associated with Bax by performing the yeast two-hybrid screening (Y2H). We determined that ubiquitin-specific protease 12 (USP12), one of the DUBs, is associated with Bax. The binding of USP12 to Bax shows the interaction as a DUB, which regulates ubiquitination on Bax. Taken together, we believe that USP12 regulates Bax by detaching ubiquitin on K63-linked chains, indicating that USP12 affects the cellular functions of Bax, but it is not related with proteasomal degradation. The half-life of the Bax protein was determined by performing the site-directed mutagenesis of putative ubiquitination sites on Bax (K128R, K189R, and K190R). Of these, Bax (K128R and K190R) showed less ubiquitination; therefore, we compared the half-life of Bax (WT) and Bax K mutant forms in vitro. Interestingly, Bax (K189R) showed a higher ubiquitination level and shorter half-life than Bax (WT), and the (K128R and K190R) mutant form has a longer half-life than Bax (WT).
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Affiliation(s)
| | | | - Kwang-Hyun Baek
- Department of Biomedical Science, CHA University, Seongnam 13488, Gyeonggi-do, Korea
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6
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Jin Z, Tao S, Zhang C, Xu D, Zhu Z. KIF20A promotes the development of fibrosarcoma via PI3K-Akt signaling pathway. Exp Cell Res 2022; 420:113322. [PMID: 36037925 DOI: 10.1016/j.yexcr.2022.113322] [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: 02/28/2022] [Revised: 07/28/2022] [Accepted: 08/16/2022] [Indexed: 11/04/2022]
Abstract
Adult fibrosarcoma is an aggressive subtype of soft tissue sarcoma (STS), in which high expression of KIF20A indicates a poor prognosis. However, the precise role of KIF20A in fibrosarcoma progression remains unknown. In this study, we initially examined KIF20A expression and function in the human fibrosarcoma cell line HT-1080. The results showed that KIF20A was highly expressed in HT-1080, knockdown of KIF20A impaired cell proliferation, migration, invasion and induced G2/M arrest and cell apoptosis. Transcriptome study suggested that PI3K-Akt signal pathway was involved in these biological changes. We confirmed that PI3K-Akt and NF-κB signaling pathways were impaired after the down-regulation of KIF20A, which can be reversed by the Akt activator SC79 in HT-1080 in vitro. In a xenograft mouse model, knockdown of KIF20A inhibited tumor growth, Ki67 expression and liver metastasis. Taken together, our results suggested that KIF20A promoted fibrosarcoma progression via PI3K-Akt signaling pathway and might be a potential therapeutic target for fibrosarcoma.
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Affiliation(s)
- Zheng Jin
- Department of Respirology & Allergy, The Third Affiliated Hospital of Shenzhen University. Shenzhen, Guangdong Province, China
| | - Shuang Tao
- Department of Otorhinolaryngology Head and Neck Surgery, Longgang Central Hospital of Shenzhen, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province, China
| | - Chao Zhang
- Guangzhou Women and Children's Medical Center, Guangdong Provincial Clinical Research Center for Child Health, Guangzhou Medical University, Guangzhou, Guangdong Province, China
| | - Damo Xu
- Department of Respirology & Allergy, The Third Affiliated Hospital of Shenzhen University. Shenzhen, Guangdong Province, China; State Key Laboratory of Respiratory Disease for Allergy at Shenzhen University, Shenzhen Key Laboratory of Allergy and Immunology, Shenzhen University School of Medicine, Shenzhen, Guangdong Province, China.
| | - Zhenhua Zhu
- Department of Orthopaedic Trauma, The Third Affiliated Hospital of Southern Medical University, Guangzhou, Guangdong Province, China.
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7
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Kong B, Han CY, Kim SI, Patten DA, Han Y, Carmona E, Shieh DB, Cheung AC, Mes-Masson AM, Harper ME, Song YS, Tsang BK. Prohibitin 1 interacts with p53 in the regulation of mitochondrial dynamics and chemoresistance in gynecologic cancers. J Ovarian Res 2022; 15:70. [PMID: 35668443 PMCID: PMC9172162 DOI: 10.1186/s13048-022-00999-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 05/13/2022] [Indexed: 12/30/2022] Open
Abstract
Background Mitochondrial dynamics (e.g. fission/fusion) play an important role in controlling chemoresistance in representative gynecologic malignancies, ovarian and cervical cancer. Processing the long form of Optic atrophy (L-Opa)1 is a distinctive character of mitochondrial fragmentation, associated with chemosensitivity. Here, we examined the role of prohibitin (Phb)1 in increasing L-Opa1 processing via the regulating mitochondrial protease, Oma1 and its direct interaction with p-p53 (ser15) and pro-apoptotic Bcl-2 antagonist/killer (Bak) 1 in the signaling axis and if this phenomenon is associated with prognosis of patients. Methods We compared Cisplatin (CDDP)-induced response of mitochondrial dynamics, molecular interaction among p-p53 (ser15)-Phb1-Bak, and chemoresponsiveness in paired chemosensitive and chemoresistant gynecologic cancer cells (ovarian and cervical cancer cell lines) using western blot, immunoprecipitation, sea horse, and immunofluorescence. Translational strategy with proximity ligation assessment in phb1-p-p53 (ser15) in human ovarian tumor sections further confirmed in vitro finding, associated with clinical outcome. Results We report that: (1) Knock-down of Phb1 prevents Cisplatin (cis-diamine-dichloroplatinum; CDDP) -induced changes in mitochondrial fragmentation and Oma1 mediated cleavage, and Opa1 processing; (2) In response to CDDP, Phb1 facilitates the p-p53 (ser15)-Phb1-Bak interaction in mitochondria in chemosensitive gynecologic cancer cells but not in chemoresistant cells; (3) Akt overexpression results in suppressed p-p53(Ser15)-Phb1 interaction and dysregulated mitochondrial dynamics, and (4) Consistent with in vitro findings, proximity ligation assessment (PLA) in human ovarian tumor sections demonstrated that p-p53(ser15)-Phb1-Bak interaction in mitochondria is associated with better chemoresponsiveness and clinical outcome of patients. Determining the molecular mechanisms by which Phb1 facilitates mitochondrial fragmentation and interacts with p53 may advance the current understanding of chemoresistance and pathogenesis of gynecologic cancer. Conclusion Determining the key molecular mechanisms by which Phb1 facilitates the formation of p-p53 (ser15)-Bak-Phb1 and its involvement in the regulation of mitochondrial dynamics and apoptosis may ultimately contribute to the current understanding of molecular and cellular basis of chemoresistance in this gynecologic cancer. Supplementary Information The online version contains supplementary material available at 10.1186/s13048-022-00999-x.
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Affiliation(s)
- Bao Kong
- Departments of Obstetrics and Gynecology and Cellular and Molecular Medicine, Interdisciplinary School of Health Sciences University of Ottawa, and Chronic Disease Program, Ottawa Hospital Research Institute, 501 Smyth Road, Mail Box #511, ON, K1H 8L6, Ottawa, Canada
| | - Chae Young Han
- Departments of Obstetrics and Gynecology and Cellular and Molecular Medicine, Interdisciplinary School of Health Sciences University of Ottawa, and Chronic Disease Program, Ottawa Hospital Research Institute, 501 Smyth Road, Mail Box #511, ON, K1H 8L6, Ottawa, Canada
| | - Se Ik Kim
- Department of Obstetrics and Gynecology and Cancer Research Institute, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - David A Patten
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Youngjin Han
- Department of Obstetrics and Gynecology and Cancer Research Institute, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Euridice Carmona
- Centre de recherche du Centre hospitalier de l'Université de Montréal and Institut du cancer de Montréal, Montréal, Canada
| | - Dar-Bin Shieh
- Institute of Basic Medical Science, Institute of Oral Medicine and Department of Stomatology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, 704, Taiwan
| | - Annie C Cheung
- Department of Pathology, The University of Hong Kong, Hong Kong, SAR, China
| | - Anne-Marie Mes-Masson
- Centre de recherche du Centre hospitalier de l'Université de Montréal and Institut du cancer de Montréal, Montréal, Canada
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa, Ottawa, Canada
| | - Yong Sang Song
- Department of Obstetrics and Gynecology and Cancer Research Institute, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea
| | - Benjamin K Tsang
- Departments of Obstetrics and Gynecology and Cellular and Molecular Medicine, Interdisciplinary School of Health Sciences University of Ottawa, and Chronic Disease Program, Ottawa Hospital Research Institute, 501 Smyth Road, Mail Box #511, ON, K1H 8L6, Ottawa, Canada.
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8
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Wikramanayake TC, Chéret J, Sevilla A, Birch-Machin M, Paus R. Targeting mitochondria in dermatological therapy: Beyond oxidative damage and skin aging. Expert Opin Ther Targets 2022; 26:233-259. [PMID: 35249436 DOI: 10.1080/14728222.2022.2049756] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION The analysis of the role of the mitochondria in oxidative damage and skin aging is a significant aspect of dermatological research. Mitochondria generate most reactive oxygen species (ROS); however, excessive ROS are cytotoxic and DNA-damaging and promote (photo-)aging. ROS also possesses key physiological and regulatory functions and mitochondrial dysfunction is prominent in several skin diseases including skin cancers. Although many standard dermatotherapeutics modulate mitochondrial function, dermatological therapy rarely targets the mitochondria. Accordingly, there is a rationale for "mitochondrial dermatology"-based approaches to be applied to therapeutic research. AREAS COVERED This paper examines the functions of mitochondria in cutaneous physiology beyond energy (ATP) and ROS production. Keratinocyte differentiation and epidermal barrier maintenance, appendage morphogenesis and homeostasis, photoaging and skin cancer are considered. Based on related PubMed search results, the paper evaluates thyroid hormones, glucocorticoids, Vitamin D3 derivatives, retinoids, cannabinoid receptor agonists, PPARγ agonists, thyrotropin, and thyrotropin-releasing hormone as instructive lead compounds. Moreover, the mitochondrial protein MPZL3 as a promising new drug target for future "mitochondrial dermatology" is highlighted. EXPERT OPINION Future dermatological therapeutic research should have a mitochondrial medicine emphasis. Focusing on selected lead agents, protein targets, in silico drug design, and model diseases will fertilize a mito-centric approach.
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Affiliation(s)
- Tongyu C Wikramanayake
- Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, U.S.A.,Molecular Cell and Developmental Biology Program, University of Miami Miller School of Medicine, Miami, FL, U.S.A
| | - Jérémy Chéret
- Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, U.S.A
| | - Alec Sevilla
- Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, U.S.A
| | - Mark Birch-Machin
- Dermatological Sciences, Translational and Clinical Research Institute, and The UK National Innovation Centre for Ageing, Newcastle University, Newcastle upon Tyne, UK
| | - Ralf Paus
- Frost Department of Dermatology & Cutaneous Surgery, University of Miami Miller School of Medicine, Miami, FL, U.S.A.,Monasterium Laboratory, Münster, Germany.,Centre for Dermatology Research, University of Manchester, and NIHR Manchester Biomedical Research Centre, Manchester, UK
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9
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Abstract
Mitochondria are dynamic organelles vital for energy production with now appreciated roles in immune defense. During microbial infection, mitochondria serve as signaling hubs to induce immune responses to counteract invading pathogens like viruses. Mitochondrial functions are central to a variety of antiviral responses including apoptosis and type I interferon signaling (IFN-I). While apoptosis and IFN-I mediated by mitochondrial antiviral signaling (MAVS) are well-established defenses, new dimensions of mitochondrial biology are emerging as battlefronts during viral infection. Increasingly, it has become apparent that mitochondria serve as reservoirs for distinct cues that trigger immune responses and that alterations in mitochondrial morphology may also tip infection outcomes. Furthermore, new data are foreshadowing pivotal roles for classic, homeostatic facets of this organelle as host-virus interfaces, namely, the tricarboxylic acid (TCA) cycle and electron transport chain (ETC) complexes like respiratory supercomplexes. Underscoring the importance of "housekeeping" mitochondrial activities in viral infection is the growing list of viral-encoded inhibitors including mimics derived from cellular genes that antagonize these functions. For example, virologs for ETC factors and several enzymes from the TCA cycle have been recently identified in DNA virus genomes and serve to pinpoint new vulnerabilities during infection. Here, we highlight recent advances for known antiviral functions associated with mitochondria as well as where the next battlegrounds may be based on viral effectors. Collectively, new methodology and mechanistic insights over the coming years will strengthen our understanding of how an ancient molecular truce continues to defend cells against viruses.
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Affiliation(s)
- Mahsa Sorouri
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Tyron Chang
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
- Genetics, Disease, and Development Graduate Program, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Dustin C Hancks
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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10
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Apoptosis during ZIKA Virus Infection: Too Soon or Too Late? Int J Mol Sci 2022; 23:ijms23031287. [PMID: 35163212 PMCID: PMC8835863 DOI: 10.3390/ijms23031287] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 02/07/2023] Open
Abstract
Cell death by apoptosis is a major cellular response in the control of tissue homeostasis and as a defense mechanism in the case of cellular aggression such as an infection. Cell self-destruction is part of antiviral responses, aimed at limiting the spread of a virus. Although it may contribute to the deleterious effects in infectious pathology, apoptosis remains a key mechanism for viral clearance and the resolution of infection. The control mechanisms of cell death processes by viruses have been extensively studied. Apoptosis can be triggered by different viral determinants through different pathways as a result of virally induced cell stresses and innate immune responses. Zika virus (ZIKV) induces Zika disease in humans, which has caused severe neurological forms, birth defects, and microcephaly in newborns during the last epidemics. ZIKV also surprised by revealing an ability to persist in the genital tract and in semen, thus being sexually transmitted. Mechanisms of diverting antiviral responses such as the interferon response, the role of cytopathic effects and apoptosis in the etiology of the disease have been widely studied and debated. In this review, we examined the interplay between ZIKV infection of different cell types and apoptosis and how the virus deals with this cellular response. We illustrate a duality in the effects of ZIKV-controlled apoptosis, depending on whether it occurs too early or too late, respectively, in neuropathogenesis, or in long-term viral persistence. We further discuss a prospective role for apoptosis in ZIKV-related therapies, and the use of ZIKV as an oncolytic agent.
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11
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TÜNCEL Ö, KARA M, YAYLAK B, ERDOĞAN İ, AKGÜL B. Noncoding RNAs in apoptosis: identification and function. Turk J Biol 2021; 46:1-40. [PMID: 37533667 PMCID: PMC10393110 DOI: 10.3906/biy-2109-35] [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: 09/11/2021] [Revised: 02/08/2022] [Accepted: 11/14/2021] [Indexed: 08/04/2023] Open
Abstract
Apoptosis is a vital cellular process that is critical for the maintenance of homeostasis in health and disease. The derailment of apoptotic mechanisms has severe consequences such as abnormal development, cancer, and neurodegenerative diseases. Thus, there exist complex regulatory mechanisms in eukaryotes to preserve the balance between cell growth and cell death. Initially, protein-coding genes were prioritized in the search for such regulatory macromolecules involved in the regulation of apoptosis. However, recent genome annotations and transcriptomics studies have uncovered a plethora of regulatory noncoding RNAs that have the ability to modulate not only apoptosis but also many other biochemical processes in eukaryotes. In this review article, we will cover a brief summary of apoptosis and detection methods followed by an extensive discussion on microRNAs, circular RNAs, and long noncoding RNAs in apoptosis.
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Affiliation(s)
- Özge TÜNCEL
- Non-coding RNA Laboratory, Department of Molecular Biology and Genetics, Faculty of Science, İzmir Institute of Technology, İzmir,
Turkey
| | - Merve KARA
- Non-coding RNA Laboratory, Department of Molecular Biology and Genetics, Faculty of Science, İzmir Institute of Technology, İzmir,
Turkey
| | - Bilge YAYLAK
- Non-coding RNA Laboratory, Department of Molecular Biology and Genetics, Faculty of Science, İzmir Institute of Technology, İzmir,
Turkey
| | - İpek ERDOĞAN
- Non-coding RNA Laboratory, Department of Molecular Biology and Genetics, Faculty of Science, İzmir Institute of Technology, İzmir,
Turkey
| | - Bünyamin AKGÜL
- Non-coding RNA Laboratory, Department of Molecular Biology and Genetics, Faculty of Science, İzmir Institute of Technology, İzmir,
Turkey
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12
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Lenaers G, Neutzner A, Le Dantec Y, Jüschke C, Xiao T, Decembrini S, Swirski S, Kieninger S, Agca C, Kim US, Reynier P, Yu-Wai-Man P, Neidhardt J, Wissinger B. Dominant optic atrophy: Culprit mitochondria in the optic nerve. Prog Retin Eye Res 2021; 83:100935. [PMID: 33340656 DOI: 10.1016/j.preteyeres.2020.100935] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 12/05/2020] [Accepted: 12/09/2020] [Indexed: 12/14/2022]
Abstract
Dominant optic atrophy (DOA) is an inherited mitochondrial disease leading to specific degeneration of retinal ganglion cells (RGCs), thus compromising transmission of visual information from the retina to the brain. Usually, DOA starts during childhood and evolves to poor vision or legal blindness, affecting the central vision, whilst sparing the peripheral visual field. In 20% of cases, DOA presents as syndromic disorder, with secondary symptoms affecting neuronal and muscular functions. Twenty years ago, we demonstrated that heterozygous mutations in OPA1 are the most frequent molecular cause of DOA. Since then, variants in additional genes, whose functions in many instances converge with those of OPA1, have been identified by next generation sequencing. OPA1 encodes a dynamin-related GTPase imported into mitochondria and located to the inner membrane and intermembrane space. The many OPA1 isoforms, resulting from alternative splicing of three exons, form complex homopolymers that structure mitochondrial cristae, and contribute to fusion of the outer membrane, thus shaping the whole mitochondrial network. Moreover, OPA1 is required for oxidative phosphorylation, maintenance of mitochondrial genome, calcium homeostasis and regulation of apoptosis, thus making OPA1 the Swiss army-knife of mitochondria. Understanding DOA pathophysiology requires the understanding of RGC peculiarities with respect to OPA1 functions. Besides the tremendous energy requirements of RGCs to relay visual information from the eye to the brain, these neurons present unique features related to their differential environments in the retina, and to the anatomical transition occurring at the lamina cribrosa, which parallel major adaptations of mitochondrial physiology and shape, in the pre- and post-laminar segments of the optic nerve. Three DOA mouse models, with different Opa1 mutations, have been generated to study intrinsic mechanisms responsible for RGC degeneration, and these have further revealed secondary symptoms related to mitochondrial dysfunctions, mirroring the more severe syndromic phenotypes seen in a subgroup of patients. Metabolomics analyses of cells, mouse organs and patient plasma mutated for OPA1 revealed new unexpected pathophysiological mechanisms related to mitochondrial dysfunction, and biomarkers correlated quantitatively to the severity of the disease. Here, we review and synthesize these data, and propose different approaches for embracing possible therapies to fulfil the unmet clinical needs of this disease, and provide hope to affected DOA patients.
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Affiliation(s)
- Guy Lenaers
- MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, Angers University and Hospital, Angers, France.
| | - Albert Neutzner
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland; Department of Ophthalmology University Hospital Basel, University of Basel, Basel, Switzerland.
| | - Yannick Le Dantec
- MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, Angers University and Hospital, Angers, France
| | - Christoph Jüschke
- Human Genetics, Faculty VI - School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Ting Xiao
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Sarah Decembrini
- Department of Biomedicine, University Hospital Basel, University of Basel, Basel, Switzerland; Department of Ophthalmology University Hospital Basel, University of Basel, Basel, Switzerland
| | - Sebastian Swirski
- Human Genetics, Faculty VI - School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany
| | - Sinja Kieninger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Cavit Agca
- Molecular Biology, Genetics and Bioengineering Program, Sabanci University, Istanbul, Turkey; Nanotechnology Research and Application Center (SUNUM), Sabanci University, Istanbul, Turkey
| | - Ungsoo S Kim
- Kim's Eye Hospital, Seoul, South Korea; Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK; Moorfields Eye Hospital, London, UK
| | - Pascal Reynier
- MitoLab Team, UMR CNRS 6015 - INSERM U1083, Institut MitoVasc, Angers University and Hospital, Angers, France; Department of Biochemistry, University Hospital of Angers, Angers, France
| | - Patrick Yu-Wai-Man
- Cambridge Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK; Moorfields Eye Hospital, London, UK; UCL Institute of Ophthalmology, University College London, London, UK
| | - John Neidhardt
- Human Genetics, Faculty VI - School of Medicine and Health Sciences, University of Oldenburg, Oldenburg, Germany; Research Center Neurosensory Science, University Oldenburg, Oldenburg, Germany.
| | - Bernd Wissinger
- Molecular Genetics Laboratory, Institute for Ophthalmic Research, Center for Ophthalmology, University of Tübingen, Tübingen, Germany.
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Verma A, Sumi S, Seervi M. Heat shock proteins-driven stress granule dynamics: yet another avenue for cell survival. Apoptosis 2021; 26:371-384. [PMID: 33978921 DOI: 10.1007/s10495-021-01678-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2021] [Indexed: 12/24/2022]
Abstract
Heat shock proteins (HSPs) are evolutionary conserved 'stress-response' proteins that facilitate cell survival against various adverse conditions. HSP-mediated cytoprotection was hitherto reported to occur principally in two ways. Firstly, HSPs interact directly or indirectly with apoptosis signaling components and suppress apoptosis. Secondly, through chaperon activity, HSPs suppress proteotoxicity and maintain protein-homeostasis. Recent studies highlight the interaction of HSPs with cytoplasmic stress granules (SGs). SGs are conserved cytoplasmic mRNPs granules that aid in cell survival under stressful conditions. We primarily aim to describe the distinct cell survival strategy mediated by HSPs as the crucial regulators of SGs assembly and disassembly. Based on the growing evidence, HSPs and associated co-chaperones act as important determinants of SG assembly, composition and dissolution. Under cellular stress, as a 'stress-coping mechanism', the formation of SGs reprograms protein translation machinery and modulates signaling pathways indispensable for cell survival. Besides their role in suppressing apoptosis, HSPs also regulate protein-homeostasis by their chaperone activity as well as by their tight regulation of SG dynamics. The intricate molecular signaling in and around the nexus of HSPs-SGs and its importance in diseases has to be unearthed. These studies have significant implications in the management of chronic diseases such as cancer and neurodegenerative diseases where SGs possess pathological functions.
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Affiliation(s)
- Akanksha Verma
- Department of Biotechnology, All India Institute of Medical Sciences (AIIMS), New Delhi, 110029, India
| | - S Sumi
- Cardiovascular Diseases and Diabetes Biology, Rajiv Gandhi Centre for Biotechnology (RGCB), Thiruvananthapuram, Kerala, India
| | - Mahendra Seervi
- Department of Biotechnology, All India Institute of Medical Sciences (AIIMS), New Delhi, 110029, India.
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Oral isoniazid causes oxidative stress, oocyte deterioration and infertility in mice. Toxicology 2021; 455:152749. [PMID: 33771660 DOI: 10.1016/j.tox.2021.152749] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 03/03/2021] [Accepted: 03/09/2021] [Indexed: 11/24/2022]
Abstract
Isoniazid (INH), a synthetic first-line tuberculosis antibiotic, has been widely used in clinical treatment. It has been reported to cause toxic effects at multiple tissue sites and also increases the incidence of adverse pregnancy outcomes; but the mechanism of action of INH on the reproductive system of female mammals remains unclear. Here, we demonstrate that oral INH (40 mg/kg/day every other day for 28 days) severely affects oocyte maturation and fertilization, late blastocyst development and fertility. We found that INH could disrupt standard spindle assembly, chromosome arrangement, and actin filament dynamics, which compromised meiotic progression of mouse oocytes. INH treatment increased the level of reactive oxygen species (ROS) and activated the oxidative stress response pathway, Keap1-Nrf2. It also caused apoptosis of oocytes and mitochondrial dysfunction. Our findings demonstrate that oral INH reduces fertility and damages the mammalian reproductive system by altering cytoskeletal dynamics and Juno expression, inducing oxidative stress and apoptosis, and activating the Keap1-Nrf2 signaling pathway in mouse oocytes.
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Shang Y, Wang Q, Li J, Liu H, Zhao Q, Huang X, Dong H, Chen W, Gui R, Nie X. Zirconia Nanoparticles Induce HeLa Cell Death Through Mitochondrial Apoptosis and Autophagy Pathways Mediated by ROS. Front Chem 2021; 9:522708. [PMID: 33796503 PMCID: PMC8007972 DOI: 10.3389/fchem.2021.522708] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 02/01/2021] [Indexed: 01/07/2023] Open
Abstract
Zirconia nanoparticles (ZrO2 NPs) are commonly used in the field of biomedical materials, but their antitumor activity and mechanism is unclear. Herein, we evaluated the anti-tumor activity of ZrO2 NPs and explored the anti-tumor mechanism. The results of in vitro and in vivo experiments showed that the level of intracellular reactive oxygen species (ROS) in HeLa cells was elevated after ZrO2 NPs treatment. Transmission electron microscopy (TEM) showed that after treatment with ZrO2 NPs, the mitochondria of HeLa cells were swollen, accompanied with the induction of autophagic vacuoles. In addition, flow cytometry analysis showed that the apoptotic rate of HeLa cells increased significantly by Annexin staining after treatment with ZrO2 NPs, and the mitochondrial membrane potential (MMP) was reduced significantly. The proliferation of HeLa cells decreased as indicated by reduced Ki-67 labeling. In contrast, TUNEL-positive cells in tumor tissues increased after treatment with ZrO2 NPs, which is accompanied by increased expression of mitochondrial apoptotic proteins including Bax, Caspase-3, Caspase-9, and Cytochrome C (Cyt C) and increased expression of autophagy-related proteins including Atg5, Atg12, Beclin-1, and LC3-II. Treating HeLa cells with N-acetyl-L-cysteine (NAC) significantly reduced ROS, rate of apoptosis, MMP, and in vivo anti-tumor activity. In addition, apoptosis- and autophagy-related protein expressions were also suppressed. Based on these observations, we conclude that ZrO2 NPs induce HeLa cell death through ROS mediated mitochondrial apoptosis and autophagy.
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Affiliation(s)
- Yinghui Shang
- Department of Blood Transfusion, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Qinghai Wang
- Department of Cardiology, The Second Hospital of Shandong University, Jinan, China
| | - Jian Li
- Department of Blood Transfusion, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Haiting Liu
- Department of Blood Transfusion, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Qiangqiang Zhao
- Department of Blood Transfusion, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xueyuan Huang
- Department of Blood Transfusion, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Hang Dong
- Department of Blood Transfusion, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Wansong Chen
- College of Chemistry and Chemical Engineering, Central South University, Changsha, China
| | - Rong Gui
- Department of Blood Transfusion, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Xinmin Nie
- Clinical Laboratory of the Third Xiangya Hospital, Central South University, Changsha, China
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Antiamylase, Antilipase, Antimicrobial, and Cytotoxic Activity of Nonea obtusifolia (Willd.) DC. from Palestine. BIOMED RESEARCH INTERNATIONAL 2020; 2020:8821319. [PMID: 33344648 PMCID: PMC7725574 DOI: 10.1155/2020/8821319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 11/09/2020] [Accepted: 11/21/2020] [Indexed: 01/14/2023]
Abstract
Background Medicinal plants are widely used in many cultures, traditions, and civilizations worldwide. Plants with high contents of the valuable biological compounds can efficiently cure many diseases. This study is aimed at assessing, for the first time, the anti-α-amylase, antilipase, antimicrobial, and cytotoxic activities of Nonea obtusifolia (Willd.) DC. of five extracts from Palestine. Methods The antimicrobial activity was estimated using well diffusion method for N. obtusifolia plant of five extracts against eight ATCC (American Type Culture Collection) and clinical isolates. The cytotoxic effects for these extracts were evaluated against HeLa (cervical) carcinoma cells using MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Moreover, the lipase and α-amylase inhibitory properties were determined using standard biomedical assays. Results The acetone extract of N. obtusifolia plant showed a more potent α-amylase inhibitory compared with acarbose with IC50 values of 25.7 ± 0.08 and 28.18 ± 1.22 μg/ml, respectively. Additionally, the acetone and methanol extracts revealed moderate antilipase activity compared to orlistat with IC50 values of 30.19 ± 0.11, 33.11 ± 0.13, and 12.3 ± 0.35 μg/ml, respectively. The methylene chloride extract was found to inhibit the growth of all the tested bacterial and fungal strains and also found to have potential cytotoxic effect against HeLa cancer cell line. Conclusion This research work reports for the first time the biological activity of N. obtusifolia from Palestine, and the results were promising indicating that N. obtusifolia extracts contain valuable bioactive molecules that have a potential anti-α-amylase, antilipase, antibacterial, and antifungal cytotoxic potentials. Therefore, N. obtusifolia could have a medical significance in the future.
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Mohamad Anuar NN, Nor Hisam NS, Liew SL, Ugusman A. Clinical Review: Navitoclax as a Pro-Apoptotic and Anti-Fibrotic Agent. Front Pharmacol 2020; 11:564108. [PMID: 33381025 PMCID: PMC7768911 DOI: 10.3389/fphar.2020.564108] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 10/14/2020] [Indexed: 12/13/2022] Open
Abstract
B-cell lymphoma 2 (BCL-2) family proteins primarily work as a programmed cell death regulator, whereby multiple interactions between them determine cell survival. This explains the two major classes of BCL-2 proteins which are anti-apoptotic and pro-apoptotic proteins. The anti-apoptotic proteins are attractive targets for BCL-2 family inhibitors, which result in the augmentation of the intrinsic apoptotic pathway. BCL-2 family inhibitors have been studied extensively for novel targeted therapies in various cancer types, fibrotic diseases, aging-related as well as autoimmune diseases. Navitoclax is one of them and it has been discovered to have a high affinity toward BCL-2 anti-apoptotic proteins, including BCL-2, BCL-W and B-cell lymphoma-extra-large. Navitoclax has been demonstrated as a single agent or in combination with other drugs to successfully ameliorate tumor progression and fibrosis development. To date, navitoclax has entered phase I and phase II clinical studies. Navitoclax alone potently treats small cell lung cancer and acute lymphocytic leukemia, whilst in combination therapy for solid tumors, it enhances the therapeutic effect of other chemotherapeutic agents. A low platelet count has always associated with single navitoclax treatments, though this effect is tolerable. Moreover, the efficacy of navitoclax is determined by the expression of several BCL-2 family members. Here, we elucidate the complex mechanisms of navitoclax as a pro-apoptotic agent, and review the early and current clinical studies of navitoclax alone as well as with other drugs. Additionally, some suggestions on the development of navitoclax clinical studies are presented in the future prospects section.
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Affiliation(s)
- Nur Najmi Mohamad Anuar
- Programme of Biomedical Science, Centre for Toxicology & Health Risk Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Nur Syahidah Nor Hisam
- Programme of Biomedical Science, Centre for Toxicology & Health Risk Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Sze Ling Liew
- Programme of Biomedical Science, Centre for Toxicology & Health Risk Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Azizah Ugusman
- Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Cheras, Malaysia
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Oxidative stress and mitochondrial dysfunction in early-onset and late-onset preeclampsia. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165961. [PMID: 32916282 DOI: 10.1016/j.bbadis.2020.165961] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/02/2020] [Accepted: 09/03/2020] [Indexed: 02/06/2023]
Abstract
Preeclampsia is a pregnancy-specific syndrome with multisystem involvement which leads to foetal, neonatal, and maternal morbidity and mortality. This syndrome is characterized by the onset of clinical signs and symptoms and delivery before (early-onset preeclampsia, eoPE), or after (late-onset preeclampsia, loPE), the 34 weeks of gestation. Preeclampsia is a mitochondrial disorder where its differential involvement in eoPE and loPE is unclear. Mitochondria regulate cell metabolism and are a significant source of reactive oxygen species (ROS). The syncytiotrophoblast in eoPE and loPE show altered mitochondrial structure and function resulting in ROS overproduction, oxidative stress, and cell damage and death. Mitochondrial dysfunction in eoPE may result from altered expression of several molecules, including dynamin-related protein 1 and mitofusins, compared with loPE where these factors are either reduced or unaltered. Equally, mitochondrial fusion/fission dynamics seem differentially modulated in eoPE and loPE. It is unclear whether the electron transport chain and oxidative phosphorylation are differentially altered in these two subgroups of preeclampsia. However, the activity of complex IV (cytochrome c oxidase) and the expression of essential proteins involved in the electron transport chain are reduced, leading to lower oxidative phosphorylation and mitochondrial respiration in the preeclamptic placenta. Interventional studies in patients with preeclampsia using the coenzyme Q10, a key molecule in the electron transport chain, suggest that agents that increase the antioxidative capacity of the placenta may be protective against preeclampsia development. In this review, the mitochondrial dysfunction in both eoPE and loPE is summarized. Therapeutic approaches are discussed in the context of contributing to the understanding of mitochondrial dysfunction in eoPE and loPE.
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The Recombinant Fragment of Human κ-Casein Induces Cell Death by Targeting the Proteins of Mitochondrial Import in Breast Cancer Cells. Cancers (Basel) 2020; 12:cancers12061427. [PMID: 32486420 PMCID: PMC7352597 DOI: 10.3390/cancers12061427] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 05/24/2020] [Accepted: 05/29/2020] [Indexed: 12/22/2022] Open
Abstract
Breast cancer is still one of the most common cancers for women. Specified therapeutics are indispensable for optimal treatment. In previous studies, it has been shown that RL2, the recombinant fragment of human κ-Casein, induces cell death in breast cancer cells. However, the molecular mechanisms of RL2-induced cell death remain largely unknown. In this study, mechanisms of RL2-induced cell death in breast cancer cells were systematically investigated. In particular, we demonstrate that RL2 induces loss of mitochondrial membrane potential and cellular ATP loss followed by cell death in breast cancer cells. The mass spectrometry-based screen for RL2 interaction partners identified mitochondrial import protein TOM70 as a target of RL2, which was subsequently validated. Further to this, we show that RL2 is targeted to mitochondria after internalization into the cells, where it can also be found in the dimeric form. The importance of TOM70 and RL2 interaction in RL2-induced reduction in ATP levels was validated by siRNA-induced downregulation of TOM70, resulting in the partial rescue of ATP production. Taken together, this study demonstrates that RL2–TOM70 interaction plays a key role in RL2-mediated cell death and targeting this pathway may provide new therapeutic options for treating breast cancer.
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Yi H, Qiu MZ, Yuan L, Luo Q, Pan W, Zhou S, Zhang L, Yan X, Yang DJ. Bcl-2/Bcl-xl inhibitor APG-1252-M1 is a promising therapeutic strategy for gastric carcinoma. Cancer Med 2020; 9:4197-4206. [PMID: 32346976 PMCID: PMC7300393 DOI: 10.1002/cam4.3090] [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: 07/26/2019] [Revised: 02/12/2020] [Accepted: 04/14/2020] [Indexed: 12/31/2022] Open
Abstract
Gastric carcinoma is the third major cause of cancer‐related death in China. Bcl‐2 and other BH3 family proteins are critically important in the process of apoptosis pathway, which may be a promising target. APG‐1252‐M1 specifically connects to Bcl‐2 and Bcl‐xl. The antitumor effect of APG‐1252‐M1 in six gastric cancer cells was identified by the Cell Counting Kit‐8 assay. The expression level of proapoptotic proteins was evaluated by Western blot. Meanwhile, the cell cycle and apoptosis distributions were analyzed by flow cytometry and JC‐1. Xenograft models were used to investigate the roles of APG‐1252‐M1 in suppressing the growth of tumors and enhancing the chemotherapy antitumor effect. The antitumor effect of APG‐1252‐M1 was time‐ and dose‐dependent and acted by initiating apoptosis. The change of cell cycle distribution was not discovered in gastric cancer cells treated with APG‐1252‐M1. APG‐1252‐M1 also exhibited synergy with chemotherapy in vivo. The combined group inhibited xenograft tumor growth more obviously than the other groups. Moreover, Ki‐67 was remarkably decreased in the combination group compared to other groups. In conclusion, APG‐1252‐M1 had a strong antitumor effect by inducing apoptosis and was synergistic with chemotherapy.
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Affiliation(s)
- Hanjie Yi
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.,Department of Medical Oncology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Miao-Zhen Qiu
- Department of Medical Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Luping Yuan
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Qiuyun Luo
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Wentao Pan
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Suna Zhou
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Lin Zhang
- Department of Clinical Laboratory Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Xianglei Yan
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
| | - Da-Jun Yang
- Department of Experimental Research, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China
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Yalcin CO, Abudayyak M. Effects of boric acid on cell death and oxidative stress of mouse TM3 Leydig cells in vitro. J Trace Elem Med Biol 2020; 61:126506. [PMID: 32299013 DOI: 10.1016/j.jtemb.2020.126506] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 01/30/2020] [Accepted: 03/26/2020] [Indexed: 12/01/2022]
Abstract
BACKGROUND Boron (B) is an abundant element on earth and presents at physiological pH in the form of boric acid (BA). It has both positive and negative effects on biological systems. BA and sodium borates have been considered as being toxic to the reproduction system in animal experiments. Unfortunately, the molecular mechanism underlying the toxic effects of BA is not fully understood. METHODS Here, we demonstrate the influence of BA on mouse TM3 Leydig cells which are male reproductive system cells targeted by BA exposure. The cytotoxicity was evaluated by MTT and NRU assays. Annexin V-FITC/PI double staining kit, mitochondria membrane potential (ΔΨm) assay kit with JC-1 and caspase-3 colorimetric assay kit were used to indicate the cell death pathway. To estimate the role of oxidative stress in BA induced toxicity, glutathione (GSH) level, catalase (CAT) and superoxide dismutase (SOD) activities were measured manually. RESULTS The cell viability assays showed that BA was not cytotoxic within the tested concentrations up to 1000 μM. Sub-toxic concentrations were used for detecting oxidative stress status. BA exposure was significantly reduced GSH level at 1000 μM and CAT activity in a concentration-dependent manner. However, SOD activity was increased at the tested concentrations (100-1000 μM). Moreover, ΔΨm was significantly decreased at 500 and 1000 μM of BA, while caspase-3 activity was not changed apparently. CONCLUSION These findings demonstrated that BA is not cytotoxic and apoptotic but may slightly induces oxidative stress in TM3 Leydig cells at higher concentrations.
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Affiliation(s)
- Can Ozgur Yalcin
- Karadeniz Technical University, Faculty of Pharmacy, Department of Pharmaceutical Toxicology, Trabzon, Turkey; Karadeniz Technical University, Drug and Pharmaceutical Technology Application and Research Center, Trabzon, Turkey.
| | - Mahmoud Abudayyak
- Karadeniz Technical University, Faculty of Pharmacy, Department of Pharmaceutical Toxicology, Trabzon, Turkey
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Salminen TS, Vale PF. Drosophila as a Model System to Investigate the Effects of Mitochondrial Variation on Innate Immunity. Front Immunol 2020; 11:521. [PMID: 32269576 PMCID: PMC7109263 DOI: 10.3389/fimmu.2020.00521] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/06/2020] [Indexed: 12/14/2022] Open
Abstract
Understanding why the response to infection varies between individuals remains one of the major challenges in immunology and infection biology. A substantial proportion of this heterogeneity can be explained by individual genetic differences which result in variable immune responses, and there are many examples of polymorphisms in nuclear-encoded genes that alter immunocompetence. However, how immunity is affected by genetic polymorphism in an additional genome, inherited maternally inside mitochondria (mtDNA), has been relatively understudied. Mitochondria are increasingly recognized as important mediators of innate immune responses, not only because they are the main source of energy required for costly immune responses, but also because by-products of mitochondrial metabolism, such as reactive oxygen species (ROS), may have direct microbicidal action. Yet, it is currently unclear how naturally occurring variation in mtDNA contributes to heterogeneity in infection outcomes. In this review article, we describe potential sources of variation in mitochondrial function that may arise due to mutations in vital nuclear and mitochondrial components of energy production or due to a disruption in mito-nuclear crosstalk. We then highlight how these changes in mitochondrial function can impact immune responses, focusing on their effects on ATP- and ROS-generating pathways, as well as immune signaling. Finally, we outline how being a powerful and genetically tractable model of infection, immunity and mitochondrial genetics makes the fruit fly Drosophila melanogaster ideally suited to dissect mitochondrial effects on innate immune responses to infection.
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Affiliation(s)
- Tiina S. Salminen
- School of Biological Sciences, Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Pedro F. Vale
- School of Biological Sciences, Institute of Evolutionary Biology, The University of Edinburgh, Edinburgh, United Kingdom
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Al Kahtani MA. Effect of both selenium and biosynthesized nanoselenium particles on cadmium-induced neurotoxicity in albino rats. Hum Exp Toxicol 2019; 39:159-172. [DOI: 10.1177/0960327119880589] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Because cadmium (Cd) is not naturally degradable by ecosystems, it interferes with many types of food chains. Cd accumulates in the kidney, liver and in the nervous tissues, especially the brain. The neurotoxicity of Cd is very high, as it alters the integrity, and increases the permeability, of the blood–brain barrier. Cd penetrates and accumulates in neurons in the brains of rats. This study reveals that Cd decreases antioxidant enzymes and increases oxidative stress in the brain. In addition, Cd increases lipid peroxidation of brain tissues. Cd increases the expression of the Cu/Zn superoxide dismutase gene. It also affects cholinergic, glutamatergic, gamma-Aminobutyric acid (GABAergic), dopamine, serotonin and acetylcholine neurotransmitters in brain tissue. Consequently, Cd increases the formation of amyloid β, a neurotoxic index, and induces apoptosis by changing the quality and the quantity of Bcl-2, Bax and p53 proteins. In conclusion, both selenium and nanoselenium show potential antioxidant activity and promote recovery from the neurotoxic action of Cd.
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Affiliation(s)
- MA Al Kahtani
- Department of Biology, Science College, King Khalid University, Abha, Saudi Arabia
- Research Centre for Advanced Materials Science (RCAMS), King Khalid University, Abha, Saudi Arabia
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Phenotypic selection with an intrabody library reveals an anti-apoptotic function of PKM2 requiring Mitofusin-1. PLoS Biol 2019; 17:e2004413. [PMID: 31181072 PMCID: PMC6586363 DOI: 10.1371/journal.pbio.2004413] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 06/20/2019] [Accepted: 05/21/2019] [Indexed: 12/22/2022] Open
Abstract
Bcl-2 family proteins control a decisive apoptotic event: mitochondrial outer membrane permeabilization (MOMP). To discover MOMP-regulating proteins, we expressed a library of intracellular single-chain variable fragments (scFvs) (“intrabodies”) and selected for those rescuing cells from apoptosis induced by BimS (the short isoform of Bim). One anti-apoptotic intrabody, intrabody 5 (IB5), recognized pyruvate kinase M2 (PKM2), which is expressed in cancer cells. PKM2 deletion ablated this clonogenic rescue; thus, IB5 activated a latent cytoprotective function of PKM2. This resulted not from pyruvate kinase activity per se but rather from the formation of an active tetrameric conformation of PKM2. A stably tetrameric PKM2 mutant, K422R, promoted cell survival even in the absence of IB5, and IB5 further increased survival. Mitochondria isolated from IB5-expressing cells were relatively resistant to MOMP in vitro. In cells, IB5 expression up-regulated Mitofusin-1 (Mfn1) and increased mitochondrial length. Importantly, Mfn1 deficiency abrogated IB5’s cytoprotective effect. PKM2’s anti-apoptotic function could help explain its preferential expression in human cancer. Proteins belonging to the Bcl-2 family regulate a common form of cell death known as apoptosis. Typically, these proteins function in apoptosis by controlling the formation of large pores in the mitochondrial outer membrane (MOM). While many proteins that regulate apoptosis have been identified over the years, some may still be unknown. Here, we used an unbiased approach in which we first expressed in cultured tumor cells a library of intracellular single-chain antibodies termed “intrabodies.” We then selected for intrabodies that allowed cells to evade apoptosis. We identified pyruvate kinase isoform M2 (PKM2), a major glycolytic enzyme that has been linked to cancer development, as the specific target of one such anti-apoptotic intrabody. We showed that the PKM2-specific intrabody promoted cell survival not by neutralizing its target but rather by activating an anti-apoptotic function of PKM2. While this cell survival function of PKM2 was not related to changes in the levels of Bcl-2 family proteins or to effects on the enzymatic activity of PKM2, we found that cell survival requires the increased expression of a MOM protein, Mitofusin-1 (Mfn1), known to regulate mitochondrial fusion. We conclude that this cell survival function of PKM2 could contribute to a role in cancer progression for this protein.
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Boeck C, Gumpp AM, Koenig AM, Radermacher P, Karabatsiakis A, Kolassa IT. The Association of Childhood Maltreatment With Lipid Peroxidation and DNA Damage in Postpartum Women. Front Psychiatry 2019; 10:23. [PMID: 30833908 PMCID: PMC6387959 DOI: 10.3389/fpsyt.2019.00023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 01/14/2019] [Indexed: 12/21/2022] Open
Abstract
Childhood maltreatment (CM) is associated with an increased risk for the development of psychiatric and somatic disorders in later life. A potential link could be oxidative stress, which is defined as the imbalance between the amount of reactive oxygen species (ROS) and the neutralizing capacity of anti-oxidative defense systems. However, the findings linking CM with oxidative stress have been inconsistent so far. In this study, we aimed to further explore this association by investigating biological markers of DNA and lipid damage due to oxidation in a comprehensive approach over two study cohorts of postpartum women (study cohort I and study cohort II). The severity of CM experiences (maltreatment load) was assessed in both studies using the Childhood Trauma Questionnaire. In study cohort I (N = 30), we investigated whether CM was associated with higher levels of structural DNA damage in peripheral blood mononuclear cells (PBMC) by two methods that are highly sensitive for detecting nuclear DNA strand breaks (comet assay and γH2AX staining). In study cohort II (N = 117), we then assessed in a larger cohort, that was specifically controlled for potential confounders for oxidative stress measurements, two established serum and plasma biomarkers of oxidative stress, one representing oxidative DNA and RNA damage (8-hydroxy-2'-deoxyguanosine and 8-hydroxyguanosine; 8-OH(d)G) and the other representing lipid peroxidation (8-isoprostane). In study cohort I, the analyses revealed no significant main effects of maltreatment load on cellular measures of nuclear DNA damage. The analyses of peripheral oxidative stress biomarkers in study cohort II revealed a significant main effect of maltreatment load on free 8-isoprostane plasma levels, but not on total 8-isprostane plasma levels and 8-OH(d)G serum levels. Taken together, by combining different methods and two study cohorts, we found no indications for higher oxidative DNA damages with higher maltreatment load in postpartum women. Further research is needed to investigate whether this increase in free 8-isoprostane is a marker for oxidative stress or whether it is instead functionally involved in ROS-related signaling pathways that potentially regulate inflammatory processes following a history of CM.
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Affiliation(s)
- Christina Boeck
- Clinical and Biological Psychology, Institute of Psychology and Education, Ulm University, Ulm, Germany
| | - Anja M Gumpp
- Clinical and Biological Psychology, Institute of Psychology and Education, Ulm University, Ulm, Germany
| | - Alexandra M Koenig
- Clinical and Biological Psychology, Institute of Psychology and Education, Ulm University, Ulm, Germany
| | - Peter Radermacher
- Institute of Anesthesiological Pathophysiology and Process Engineering, University Hospital Ulm, Ulm, Germany
| | - Alexander Karabatsiakis
- Clinical and Biological Psychology, Institute of Psychology and Education, Ulm University, Ulm, Germany
| | - Iris-Tatjana Kolassa
- Clinical and Biological Psychology, Institute of Psychology and Education, Ulm University, Ulm, Germany
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Sab concentrations indicate chemotherapeutic susceptibility in ovarian cancer cell lines. Biochem J 2018; 475:3471-3492. [PMID: 30322886 DOI: 10.1042/bcj20180603] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 10/08/2018] [Accepted: 10/11/2018] [Indexed: 01/05/2023]
Abstract
The occurrence of chemotherapy-resistant tumors makes ovarian cancer (OC) the most lethal gynecological malignancy. While many factors may contribute to chemoresistance, the mechanisms responsible for regulating tumor vulnerability are under investigation. Our analysis of gene expression data revealed that Sab, a mitochondrial outer membrane (MOM) scaffold protein, was down-regulated in OC patients. Sab-mediated signaling induces cell death, suggesting that this apoptotic pathway is diminished in OC. We examined Sab expression in a panel of OC cell lines and found that the magnitude of Sab expression correlated to chemo-responsiveness; wherein, OC cells with low Sab levels were chemoresistant. The Sab levels were reflected by a corresponding amount of stress-induced c-Jun N-terminal kinase (JNK) on the MOM. BH3 profiling and examination of Bcl-2 and BH3-only protein concentrations revealed that cells with high Sab concentrations were primed for apoptosis, as determined by the decrease in pro-survival Bcl-2 proteins and an increase in pro-apoptotic BH3-only proteins on mitochondria. Furthermore, overexpression of Sab in chemoresistant cells enhanced apoptotic priming and restored cellular vulnerability to a combination treatment of cisplatin and paclitaxel. Contrariwise, inhibiting Sab-mediated signaling or silencing Sab expression in a chemosensitive cell line resulted in decreased apoptotic priming and increased resistance. The effects of silencing on Sab on the resistance to chemotherapeutic agents were emulated by the silencing or inhibition of JNK, which could be attributed to changes in Bcl-2 protein concentrations induced by sub-chronic JNK inhibition. We propose that Sab may be a prognostic biomarker to discern personalized treatments for OC patients.
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Roest G, La Rovere RM, Bultynck G, Parys JB. IP 3 Receptor Properties and Function at Membrane Contact Sites. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 981:149-178. [PMID: 29594861 DOI: 10.1007/978-3-319-55858-5_7] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) is a ubiquitously expressed Ca2+-release channel localized in the endoplasmic reticulum (ER). The intracellular Ca2+ signals originating from the activation of the IP3R regulate multiple cellular processes including the control of cell death versus cell survival via their action on apoptosis and autophagy. The exact role of the IP3Rs in these two processes does not only depend on their activity, which is modulated by the cytosolic composition (Ca2+, ATP, redox status, …) and by various types of regulatory proteins, including kinases and phosphatases as well as by a number of oncogenes and tumor suppressors, but also on their intracellular localization, especially at the ER-mitochondrial and ER-lysosomal interfaces. At these interfaces, Ca2+ microdomains are formed, in which the Ca2+ concentration is finely regulated by the different ER, mitochondrial and lysosomal Ca2+-transport systems and also depends on the functional and structural interactions existing between them. In this review, we therefore discuss the most recent insights in the role of Ca2+ signaling in general, and of the IP3R in particular, in the control of basal mitochondrial bioenergetics, apoptosis, and autophagy at the level of inter-organellar contact sites.
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Affiliation(s)
- Gemma Roest
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium
| | - Rita M La Rovere
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium
| | - Geert Bultynck
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium.
| | - Jan B Parys
- Laboratory for Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, KU Leuven, Leuven, Belgium.
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28
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Singh PK, Weber A, Häcker G. The established and the predicted roles of dynein light chain in the regulation of mitochondrial apoptosis. Cell Cycle 2018; 17:1037-1047. [PMID: 30019621 DOI: 10.1080/15384101.2018.1464851] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
The mitochondrial pathway of apoptosis is regulated by the interplay between the members of Bcl-2 family. Within this family, BH3-only proteins are the sensors of apoptotic stimuli and can trigger apoptosis either by inhibiting the anti-apoptotic Bcl-2-family proteins or by directly activating the effectors Bax and Bak. An expanding body of research suggests that a number of non-Bcl-2 proteins can also interact with Bcl-2 proteins and contribute to the decision of cell fate. Dynein light chain (LC8, DYNLL or DLC), a hub protein and a dimerizing engine has been proposed to regulate the pro-apoptotic activity of two BH3-only proteins, Bim and Bmf. Our recent work has provided insight into the mechanisms through which DLC1 (DYNLL1) modulates Bim activity. Here we discuss the present day understanding of Bim-DLC interaction and endeavor to evaluate this interaction in the light of information from studies of DLC with other binding partners.
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Affiliation(s)
- Prafull Kumar Singh
- a Institute of Medical Microbiology and Hygiene, Faculty of Medicine , Medical Center-University of Freiburg , Freiburg , Germany
| | - Arnim Weber
- a Institute of Medical Microbiology and Hygiene, Faculty of Medicine , Medical Center-University of Freiburg , Freiburg , Germany
| | - Georg Häcker
- a Institute of Medical Microbiology and Hygiene, Faculty of Medicine , Medical Center-University of Freiburg , Freiburg , Germany.,b BIOSS Centre for Biological Signalling Studies , University of Freiburg , Freiburg , Germany
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Bim regulates the survival and suppressive capability of CD8 + FOXP3 + regulatory T cells during murine GVHD. Blood 2018; 132:435-447. [PMID: 29769260 DOI: 10.1182/blood-2017-09-807156] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 05/09/2018] [Indexed: 12/29/2022] Open
Abstract
CD8+ Foxp3+ T cells (Tregs) are a potent regulatory population whose functional and ontological similarities to CD4+ Fox3+ T cells have not been well delineated. Using an experimental model of graft-versus-host disease (GVHD), we observed that CD8+ Tregs were significantly less potent than CD4+ Tregs for the suppression of GVHD. To define the mechanistic basis for this observation, we examined the T-cell repertoire and the transcriptional profile of in vivo-derived CD4+ and CD8+ Tregs that emerged early during this disease. Polyclonal and alloantigen-induced CD8+ Tregs had repertoire diversity that was similar to that of conventional CD8+ T cells, indicating that a restricted repertoire was not the proximate cause of decreased suppression. Transcriptional profiling revealed that CD8+ Tregs possessed a canonical Treg transcriptional signature that was similar to that observed in CD4+ Tregs, yet distinct from conventional CD8+ T cells. Pathway analysis, however, demonstrated that CD8+ Tregs had differential gene expression in pathways involved in cell death and survival. This was further confirmed by detailed mRNA sequence analysis and protein expression studies, which demonstrated that CD8+ Tregs had increased expression of Bim and reduced expression of Mcl-1. Transplantation with CD8+ Foxp3+ Bim-/- Tregs resulted in prolonged Treg survival and reduced GVHD lethality compared with wild-type CD8+ Tregs, providing functional confirmation that increased expression of Bim was responsible for reduced in vivo efficacy. Thus, Bim regulates the survival and suppressive capability of CD8+ Tregs, which may have implications for their use in regulatory T-cell therapy.
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Aouacheria A, Baghdiguian S, Lamb HM, Huska JD, Pineda FJ, Hardwick JM. Connecting mitochondrial dynamics and life-or-death events via Bcl-2 family proteins. Neurochem Int 2017; 109:141-161. [PMID: 28461171 DOI: 10.1016/j.neuint.2017.04.009] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 04/17/2017] [Indexed: 12/12/2022]
Abstract
The morphology of a population of mitochondria is the result of several interacting dynamical phenomena, including fission, fusion, movement, elimination and biogenesis. Each of these phenomena is controlled by underlying molecular machinery, and when defective can cause disease. New understanding of the relationships between form and function of mitochondria in health and disease is beginning to be unraveled on several fronts. Studies in mammals and model organisms have revealed that mitochondrial morphology, dynamics and function appear to be subject to regulation by the same proteins that regulate apoptotic cell death. One protein family that influences mitochondrial dynamics in both healthy and dying cells is the Bcl-2 protein family. Connecting mitochondrial dynamics with life-death pathway forks may arise from the intersection of Bcl-2 family proteins with the proteins and lipids that determine mitochondrial shape and function. Bcl-2 family proteins also have multifaceted influences on cells and mitochondria, including calcium handling, autophagy and energetics, as well as the subcellular localization of mitochondrial organelles to neuronal synapses. The remarkable range of physical or functional interactions by Bcl-2 family proteins is challenging to assimilate into a cohesive understanding. Most of their effects may be distinct from their direct roles in apoptotic cell death and are particularly apparent in the nervous system. Dual roles in mitochondrial dynamics and cell death extend beyond BCL-2 family proteins. In this review, we discuss many processes that govern mitochondrial structure and function in health and disease, and how Bcl-2 family proteins integrate into some of these processes.
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Affiliation(s)
- Abdel Aouacheria
- Institute of Evolutionary Sciences of Montpellier (ISEM), CNRS UMR 5554, University of Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
| | - Stephen Baghdiguian
- Institute of Evolutionary Sciences of Montpellier (ISEM), CNRS UMR 5554, University of Montpellier, Place Eugène Bataillon, 34095 Montpellier, France
| | - Heather M Lamb
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA
| | - Jason D Huska
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA
| | - Fernando J Pineda
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA; Department of Biostatistics, Johns Hopkins University, Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA
| | - J Marie Hardwick
- Department of Molecular Microbiology and Immunology, Johns Hopkins University Bloomberg School of Public Health, 615 North Wolfe St., Baltimore, MD 21205, USA.
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Birkinshaw RW, Czabotar PE. The BCL-2 family of proteins and mitochondrial outer membrane permeabilisation. Semin Cell Dev Biol 2017; 72:152-162. [PMID: 28396106 DOI: 10.1016/j.semcdb.2017.04.001] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 03/03/2017] [Accepted: 04/06/2017] [Indexed: 01/24/2023]
Abstract
Apoptosis is a form of programmed cell death critical for the development and homeostasis of multicellular organisms. A key event within the mitochondrial pathway to apoptosis is the permeabilisation of the mitochondrial outer membrane (MOM), a point of no return in apoptotic progression. This event is governed by a complex interplay of interactions between BCL-2 family members. Here we discuss the roles of opposing factions within the family. We focus on the structural details of these interactions, how they promote or prevent apoptosis and recent developments towards understanding the conformational changes of BAK and BAX that lead to MOM permeabilisation. These interactions and structural insights are of particular interest for drug discovery, as highlighted by the development of therapeutics that target pro-survival family members and restore apoptosis in cancer cells.
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Affiliation(s)
- Richard W Birkinshaw
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Australia; Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia.
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Gillissen B, Richter A, Richter A, Preissner R, Schulze-Osthoff K, Essmann F, Daniel PT. Bax/Bak-independent mitochondrial depolarization and reactive oxygen species induction by sorafenib overcome resistance to apoptosis in renal cell carcinoma. J Biol Chem 2017; 292:6478-6492. [PMID: 28154184 DOI: 10.1074/jbc.m116.754184] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Revised: 01/26/2017] [Indexed: 12/23/2022] Open
Abstract
Renal cell carcinoma (RCC) is polyresistant to chemo- and radiotherapy and biologicals, including TNF-related apoptosis-inducing ligand (TRAIL). Sorafenib, a multikinase inhibitor approved for the treatment of RCC, has been shown to sensitize cancer cells to TRAIL-induced apoptosis, in particular by down-regulation of the Bak-inhibitory Bcl-2 family protein Mcl-1. Here we demonstrate that sorafenib overcomes TRAIL resistance in RCC by a mechanism that does not rely on Mcl-1 down-regulation. Instead, sorafenib induces rapid dissipation of the mitochondrial membrane potential (ΔΨm) that is accompanied by the accumulation of reactive oxygen species (ROS). Loss of ΔΨm and ROS production induced by sorafenib are independent of caspase activities and do not depend on the presence of the proapoptotic Bcl-2 family proteins Bax or Bak, indicating that both events are functionally upstream of the mitochondrial apoptosis signaling cascade. More intriguingly, we find that it is sorafenib-induced ROS accumulation that enables TRAIL to activate caspase-8 in RCC. This leads to apoptosis that involves activation of an amplification loop via the mitochondrial apoptosis pathway. Thus, our mechanistic data indicate that sorafenib bypasses central resistance mechanisms through a direct induction of ΔΨm breakdown and ROS production. Activation of this pathway might represent a useful strategy to overcome the cell-inherent resistance to cancer therapeutics, including TRAIL, in multiresistant cancers such as RCC.
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Affiliation(s)
- Bernhard Gillissen
- From the Department of Hematology, Oncology, and Tumor Immunology, University Medical Center Charité, Campus Berlin-Buch, Humboldt University, Berlin, Germany.,the German Cancer Consortium and German Cancer Research Center, Im Neuenheimer Feld, 69120 Heidelberg, Germany
| | - Anja Richter
- From the Department of Hematology, Oncology, and Tumor Immunology, University Medical Center Charité, Campus Berlin-Buch, Humboldt University, Berlin, Germany.,the German Cancer Consortium and German Cancer Research Center, Im Neuenheimer Feld, 69120 Heidelberg, Germany
| | - Antje Richter
- From the Department of Hematology, Oncology, and Tumor Immunology, University Medical Center Charité, Campus Berlin-Buch, Humboldt University, Berlin, Germany
| | - Robert Preissner
- the Institute of Physiology and Experimental Clinical Research Center, University Medical Center Charité, 13125 Berlin, Germany
| | - Klaus Schulze-Osthoff
- the German Cancer Consortium and German Cancer Research Center, Im Neuenheimer Feld, 69120 Heidelberg, Germany.,the Interfaculty Institute for Biochemistry, University of Tübingen, Hoppe-Seyler-Strasse 4, 72076 Tübingen, Germany, and
| | - Frank Essmann
- the German Cancer Consortium and German Cancer Research Center, Im Neuenheimer Feld, 69120 Heidelberg, Germany.,the Interfaculty Institute for Biochemistry, University of Tübingen, Hoppe-Seyler-Strasse 4, 72076 Tübingen, Germany, and
| | - Peter T Daniel
- From the Department of Hematology, Oncology, and Tumor Immunology, University Medical Center Charité, Campus Berlin-Buch, Humboldt University, Berlin, Germany, .,the German Cancer Consortium and German Cancer Research Center, Im Neuenheimer Feld, 69120 Heidelberg, Germany.,Clinical and Molecular Oncology, Max Delbrück Center for Molecular Medicine, 13125 Berlin-Buch, Germany
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33
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Bansal Y, Kuhad A. Mitochondrial Dysfunction in Depression. Curr Neuropharmacol 2017; 14:610-8. [PMID: 26923778 PMCID: PMC4981740 DOI: 10.2174/1570159x14666160229114755] [Citation(s) in RCA: 205] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 06/02/2015] [Accepted: 02/27/2016] [Indexed: 02/06/2023] Open
Abstract
Abstract: Background Depression is the most debilitating neuropsychiatric disorder with significant impact on socio-occupational and well being of individual. The exact pathophysiology of depression is still enigmatic though various theories have been put forwarded. There are evidences showing that mitochondrial dysfunction in various brain regions is associated with depression. Recent findings have sparked renewed appreciation for the role of mitochondria in many intracellular processes coupled to synaptic plasticity and cellular resilience. New insights in depression pathophysiology are revolving around the impairment of neuroplasticity. Mitochondria have potential role in ATP production, intracellular Ca2+ signalling to establish membrane stability, reactive oxygen species (ROS) balance and to execute the complex processes of neurotransmission and plasticity. So understanding the various concepts of mitochondrial dysfunction in pathogenesis of depression indubitably helps to generate novel and more targeted therapeutic approaches for depression treatment. Objective The review was aimed to give a comprehensive insight on role of mitochondrial dysfunction in depression. Result Targeting mitochondrial dysfunction and enhancing the mitochondrial functions might act as potential target for the treatment of depression. Conclusion Literature cited in this review highly supports the role of mitochondrial dysfunction in depression. As impairment in the mitochondrial functions lead to the generation of various insults that exaggerate the pathogenesis of depression. So, it is useful to study mitochondrial dysfunction in relation to mood disorders, synaptic plasticity, neurogenesis and enhancing the functions of mitochondria might show promiscuous effects in the treatment of depressed patients.
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Affiliation(s)
| | - Anurag Kuhad
- Pharmacology Research Laboratory, University Institute of Pharmaceutical Sciences UGC-Centre of Advanced Study, Panjab University, Chandigarh - 160 014 India.
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Duangprompo W, Aree K, Itharat A, Hansakul P. Effects of 5,6-Dihydroxy-2,4-Dimethoxy-9,10-Dihydrophenanthrene on G2/M Cell Cycle Arrest and Apoptosis in Human Lung Carcinoma Cells. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2016; 44:1473-1490. [DOI: 10.1142/s0192415x16500828] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
5,6-dihydroxy-2,4-dimethoxy-9,10-dihydrophenanthrene (HMP) is an active compound isolated from the rhizome extracts of Dioscorea membranacea Pierre, a Thai medicinal plant. This study aimed to investigate the growth-inhibitory and apoptosis-inducing effects of HMP in human lung cancer A549 cells. The antiproliferative and cytotoxic effects of HMP were analyzed by a Sulforhodamine B assay. Cell division, cell cycle distribution and membrane asymmetry changes were each performed with different fluorescent dyes and then analyzed by flow cytometry. Real-time PCR and immunoblotting were used to detect cell cycle- and apoptosis-related mRNA levels and proteins, respectively. The nuclear morphology of the cells stained with DAPI and DNA fragmentation were detected by fluorescence microscopy and gel electrophoresis, respectively. The results showed that HMP exerted strong antiproliferative and cytotoxic activities in A549 cells with the highest selectivity index. It halted the cell cycle in [Formula: see text]/M phase via down-regulation of the expression levels of regulatory proteins Cdc25C, Cdk1 and cyclinB1. In addition, HMP induced early apoptotic cells with externalized phosphatidylserine and subsequent apoptotic cells in sub-[Formula: see text] phase. HMP increased caspase-3 activity and levels of the cleaved (active) form of caspase-3 whose actions were supported by the cleavage of its target PARP, nuclear condensation and DNA apoptotic ladder. Moreover, HMP significantly increased the mRNA and protein levels of proapoptotic Bax as well as promoted subsequent caspase-9 activation and BID cleavage, indicating HMP-induced apoptosis via both intrinsic and extrinsic pathways. These data support, for the first time, the potential role of HMP as a cell-cycle arrest and apoptosis-inducing agent for lung cancer treatment.
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Affiliation(s)
- Wipada Duangprompo
- Biochemistry and Molecular Biology, Department of Preclinical Science, Faculty of Medicine, Thailand
| | - Kalaya Aree
- Microbiology and Immunology, Department of Preclinical Science, Faculty of Medicine, Thailand
| | - Arunporn Itharat
- Department of Applied Thai Traditional Medicine, Faculty of Medicine, Thailand
| | - Pintusorn Hansakul
- Biochemistry, Department of Preclinical Science, Faculty of Medicine, Thammasat University (Rangsit Campus), Klongluang, Thailand
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Yee YH, Chong SJF, Pervaiz S. The anti-oxidant and pro-oxidant dichotomy of Bcl-2. Biol Chem 2016; 397:585-93. [DOI: 10.1515/hsz-2016-0127] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 03/31/2016] [Indexed: 11/15/2022]
Abstract
Abstract
Across a wide spectrum of cellular redox status, there emerges a dichotomy of responses in terms of cell survival/proliferation and cell death. Of note, there is emerging evidence that the anti-apoptotic protein, Bcl-2, in addition to its conventional activity of titrating the pro-apoptotic effects of proteins such as Bax and Bak at the mitochondria, also impacts cell fate decisions via modulating cellular redox metabolism. In this regard, both pro- and anti-oxidant effects of Bcl-2 overexpression have been described under different conditions and cellular contexts. In this short review, we attempt to analyze existing observations and present a probable explanation for the seemingly conflicting redox regulating activity of Bcl-2 from the standpoint of its pro-survival function. The consequential effect(s) of the dual redox functions of Bcl-2 are also discussed, particularly from the viewpoint of developing novel therapeutic strategies against cancers rendered refractory due to the aberrant expression of Bcl-2.
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36
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Pro-apoptotic Bax molecules densely populate the edges of membrane pores. Sci Rep 2016; 6:27299. [PMID: 27255832 PMCID: PMC4891688 DOI: 10.1038/srep27299] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 05/16/2016] [Indexed: 11/28/2022] Open
Abstract
How the pro-apoptotic Bax protein permeabilizes the mitochondrial outer membrane is not fully understood. Previously, using cryo-electron microscopy (cryo-EM), we showed that activated Bax forms large, growing pores. Whether formed in liposomes or in mitochondrial outer membranes, Bax-induced pores exhibit the same morphology, with negative curvature flanking the edges and with no visible protein structure protruding from the membranes. Here we used cryo-EM to show that gold-labeled Bax molecules, after activation by Bid, became localized strictly at pore edges. This argues that Bax acts at short range to deform the membrane. Also, Bax molecules populated the walls of both small and large pores at the same density, implying that Bax is continuously recruited to the pores as they widen. Moreover, because all Bax molecules became oligomerized after membrane insertion, we infer that Bax oligomers are present at pore edges. We suggest that oligomerization may promote pore enlargement.
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Necroptotic Cell Death Signaling and Execution Pathway: Lessons from Knockout Mice. Mediators Inflamm 2015; 2015:128076. [PMID: 26491219 PMCID: PMC4600508 DOI: 10.1155/2015/128076] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2014] [Revised: 03/24/2015] [Accepted: 04/16/2015] [Indexed: 12/31/2022] Open
Abstract
Under stress conditions, cells in living tissue die by apoptosis or necrosis depending on the activation of the key molecules within a dying cell that either transduce cell survival or death signals that actively destroy the sentenced cell. Multiple extracellular (pH, heat, oxidants, and detergents) or intracellular (DNA damage and Ca(2+) overload) stress conditions trigger various types of the nuclear, endoplasmic reticulum (ER), cytoplasmatic, and mitochondrion-centered signaling events that allow cells to preserve the DNA integrity, protein folding, energetic, ionic and redox homeostasis, thus escaping from injury. Along the transition from reversible to irreversible injury, death signaling is highly heterogeneous and damaged cells may engage autophagy, apoptotic, or necrotic cell death programs. Studies on multiple double- and triple- knockout mice identified caspase-8, flip, and fadd genes as key regulators of embryonic lethality and inflammation. Caspase-8 has a critical role in pro- and antinecrotic signaling pathways leading to the activation of receptor interacting protein kinase 1 (RIPK1), RIPK3, and the mixed kinase domain-like (MLKL) for a convergent execution pathway of necroptosis or regulated necrosis. Here we outline the recent discoveries into how the necrotic cell death execution pathway is engaged in many physiological and pathological outcome based on genetic analysis of knockout mice.
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Reactive oxygen species and mitochondria: A nexus of cellular homeostasis. Redox Biol 2015; 6:472-485. [PMID: 26432659 PMCID: PMC4596921 DOI: 10.1016/j.redox.2015.09.005] [Citation(s) in RCA: 682] [Impact Index Per Article: 75.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 09/08/2015] [Accepted: 09/09/2015] [Indexed: 02/07/2023] Open
Abstract
Reactive oxygen species (ROS) are integral components of multiple cellular pathways even though excessive or inappropriately localized ROS damage cells. ROS function as anti-microbial effector molecules and as signaling molecules that regulate such processes as NF-kB transcriptional activity, the production of DNA-based neutrophil extracellular traps (NETs), and autophagy. The main sources of cellular ROS are mitochondria and NADPH oxidases (NOXs). In contrast to NOX-generated ROS, ROS produced in the mitochondria (mtROS) were initially considered to be unwanted by-products of oxidative metabolism. Increasing evidence indicates that mtROS have been incorporated into signaling pathways including those regulating immune responses and autophagy. As metabolic hubs, mitochondria facilitate crosstalk between the metabolic state of the cell with these pathways. Mitochondria and ROS are thus a nexus of multiple pathways that determine the response of cells to disruptions in cellular homeostasis such as infection, sterile damage, and metabolic imbalance. In this review, we discuss the roles of mitochondria in the generation of ROS-derived anti-microbial effectors, the interplay of mitochondria and ROS with autophagy and the formation of DNA extracellular traps, and activation of the NLRP3 inflammasome by ROS and mitochondria.
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Tan SC, Ankathil R. Genetic susceptibility to cervical cancer: role of common polymorphisms in apoptosis-related genes. Tumour Biol 2015; 36:6633-44. [PMID: 26242271 DOI: 10.1007/s13277-015-3868-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/29/2015] [Indexed: 12/13/2022] Open
Abstract
Cervical cancer is a common malignancy which poses a significant health burden among women, especially those living in the developing countries. Although human papillomavirus (HPV) infection has been unequivocally implicated in the etiopathogenesis of the cancer, it alone is not adequate to contribute to the malignant transformation of cervical cells. Most HPV infections regress spontaneously, and only a small proportion of women have persistent infections which eventually lead to malignancy. This suggests that interplays between HPV infection and other cofactors certainly exist during the process of cervical carcinogenesis, which synergistically contribute to the differential susceptibility of an individual to the malignancy. Undoubtedly, host genetic factors represent a major element involved in such a synergistic interaction, and accumulating evidence suggests that polymorphisms in apoptosis-related genes play an important role in the genetic susceptibility to cervical cancer. This review consolidates the recent literatures on the role of common polymorphisms in apoptosis-related genes in genetic susceptibility to cervical cancer.
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Affiliation(s)
- Shing Cheng Tan
- Human Genome Centre, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia.
| | - Ravindran Ankathil
- Human Genome Centre, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150, Kubang Kerian, Kelantan, Malaysia.
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40
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Maléth J, Hegyi P, Rakonczay Z, Venglovecz V. Breakdown of bioenergetics evoked by mitochondrial damage in acute pancreatitis: Mechanisms and consequences. Pancreatology 2015; 15:S18-22. [PMID: 26162756 DOI: 10.1016/j.pan.2015.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 06/11/2015] [Accepted: 06/12/2015] [Indexed: 02/07/2023]
Abstract
Acute pancreatitis is a severe inflammatory disease with unacceptably high mortality and without specific therapy. Clinical studies revealed that energy supplementation of patients via enteral feeding decreases systemic infections, multi-organ failure and mortality. These clinical observations have been supported by in vitro and in vivo experimental studies which showed that the most common pancreatitis inducing factors, such as bile acids, ethanol and non-oxidative ethanol metabolites induce intracellular ATP depletion and mitochondrial damage both in pancreatic acinar and ductal cells. Notably, the in vitro supplementation of ATP prevented the cellular damage and restored cell functions in both cell types. These observations suggest that either prevention of mitochondrial damage or restoration of intracellular ATP level might provide therapeutical benefits.
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Affiliation(s)
- József Maléth
- First Department of Medicine, University of Szeged, Szeged, Hungary
| | - Péter Hegyi
- First Department of Medicine, University of Szeged, Szeged, Hungary; MTA-SZTE Lendulet Translational Gastroenterology Research Group, Szeged, Hungary
| | - Zoltán Rakonczay
- First Department of Medicine, University of Szeged, Szeged, Hungary
| | - Viktória Venglovecz
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary.
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41
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García-Niño WR, Zazueta C. Ellagic acid: Pharmacological activities and molecular mechanisms involved in liver protection. Pharmacol Res 2015; 97:84-103. [DOI: 10.1016/j.phrs.2015.04.008] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 04/16/2015] [Accepted: 04/18/2015] [Indexed: 12/23/2022]
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Iyer S, Bell F, Westphal D, Anwari K, Gulbis J, Smith BJ, Dewson G, Kluck RM. Bak apoptotic pores involve a flexible C-terminal region and juxtaposition of the C-terminal transmembrane domains. Cell Death Differ 2015; 22:1665-75. [PMID: 25744027 DOI: 10.1038/cdd.2015.15] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Revised: 01/07/2015] [Accepted: 01/21/2015] [Indexed: 12/22/2022] Open
Abstract
Bak and Bax mediate apoptotic cell death by oligomerizing and forming a pore in the mitochondrial outer membrane. Both proteins anchor to the outer membrane via a C-terminal transmembrane domain, although its topology within the apoptotic pore is not known. Cysteine-scanning mutagenesis and hydrophilic labeling confirmed that in healthy mitochondria the Bak α9 segment traverses the outer membrane, with 11 central residues shielded from labeling. After pore formation those residues remained shielded, indicating that α9 does not line a pore. Bak (and Bax) activation allowed linkage of α9 to neighboring α9 segments, identifying an α9:α9 interface in Bak (and Bax) oligomers. Although the linkage pattern along α9 indicated a preferred packing surface, there was no evidence of a dimerization motif. Rather, the interface was invoked in part by Bak conformation change and in part by BH3:groove dimerization. The α9:α9 interaction may constitute a secondary interface in Bak oligomers, as it could link BH3:groove dimers to high-order oligomers. Moreover, as high-order oligomers were generated when α9:α9 linkage in the membrane was combined with α6:α6 linkage on the membrane surface, the α6-α9 region in oligomerized Bak is flexible. These findings provide the first view of Bak carboxy terminus (C terminus) membrane topology within the apoptotic pore.
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Affiliation(s)
- S Iyer
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - F Bell
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia
| | - D Westphal
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - K Anwari
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - J Gulbis
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - B J Smith
- Department of Chemistry and Physics, La Trobe Institute for Molecular Sciences, La Trobe University, Melbourne, Victoria 3086, Australia
| | - G Dewson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
| | - R M Kluck
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3050, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria 3010, Australia
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44
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Mitochondrial cholesterol: mechanisms of import and effects on mitochondrial function. J Bioenerg Biomembr 2014; 48:137-51. [PMID: 25425472 DOI: 10.1007/s10863-014-9592-6] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 11/14/2014] [Indexed: 12/23/2022]
Abstract
Mitochondria require cholesterol for biogenesis and membrane maintenance, and for the synthesis of steroids, oxysterols and hepatic bile acids. Multiple pathways mediate the transport of cholesterol from different subcellular pools to mitochondria. In steroidogenic cells, the steroidogenic acute regulatory protein (StAR) interacts with a mitochondrial protein complex to mediate cholesterol delivery to the inner mitochondrial membrane for conversion to pregnenolone. In non-steroidogenic cells, several members of a protein family defined by the presence of a StAR-related lipid transfer (START) domain play key roles in the delivery of cholesterol to mitochondrial membranes. Subdomains of the endoplasmic reticulum (ER), termed mitochondria-associated ER membranes (MAM), form membrane contact sites with mitochondria and may contribute to the transport of ER cholesterol to mitochondria, either independently or in conjunction with lipid-transfer proteins. Model systems of mitochondria enriched with cholesterol in vitro and mitochondria isolated from cells with (patho)physiological mitochondrial cholesterol accumulation clearly demonstrate that mitochondrial cholesterol levels affect mitochondrial function. Increased mitochondrial cholesterol levels have been observed in several diseases, including cancer, ischemia, steatohepatitis and neurodegenerative diseases, and influence disease pathology. Hence, a deeper understanding of the mechanisms maintaining mitochondrial cholesterol homeostasis may reveal additional targets for therapeutic intervention. Here we give a brief overview of mitochondrial cholesterol import in steroidogenic cells, and then focus on cholesterol trafficking pathways that deliver cholesterol to mitochondrial membranes in non-steroidogenic cells. We also briefly discuss the consequences of increased mitochondrial cholesterol levels on mitochondrial function and their potential role in disease pathology.
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Abstract
The endoplasmic reticulum (ER) is a cellular compartment that has a key function in protein translation and folding. Maintaining its integrity is of fundamental importance for organism's physiology and viability. The dynamic regulation of intraluminal ER Ca(2+) concentration directly influences the activity of ER-resident chaperones and stress response pathways that balance protein load and folding capacity. We review the emerging evidence that microRNAs play important roles in adjusting these processes to frequently changing intracellular and environmental conditions to modify ER Ca(2+) handling and storage and maintain ER homeostasis.
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Affiliation(s)
- Fabian Finger
- Institute for Genetics and Cologne Cluster of Excellence Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany
| | - Thorsten Hoppe
- Institute for Genetics and Cologne Cluster of Excellence Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Str. 26, 50931 Cologne, Germany.
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46
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Disruption of SUMO-specific protease 2 induces mitochondria mediated neurodegeneration. PLoS Genet 2014; 10:e1004579. [PMID: 25299344 PMCID: PMC4191884 DOI: 10.1371/journal.pgen.1004579] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 07/08/2014] [Indexed: 12/20/2022] Open
Abstract
Post-translational modification of proteins by small ubiquitin-related modifier (SUMO) is reversible and highly evolutionarily conserved from yeasts to humans. Unlike ubiquitination with a well-established role in protein degradation, sumoylation may alter protein function, activity, stability and subcellular localization. Members of SUMO-specific protease (SENP) family, capable of SUMO removal, are involved in the reversed conjugation process. Although SUMO-specific proteases are known to reverse sumoylation in many well-defined systems, their importance in mammalian development and pathogenesis remains largely elusive. In patients with neurodegenerative diseases, aberrant accumulation of SUMO-conjugated proteins has been widely described. Several aggregation-prone proteins modulated by SUMO have been implicated in neurodegeneration, but there is no evidence supporting a direct involvement of SUMO modification enzymes in human diseases. Here we show that mice with neural-specific disruption of SENP2 develop movement difficulties which ultimately results in paralysis. The disruption induces neurodegeneration where mitochondrial dynamics is dysregulated. SENP2 regulates Drp1 sumoylation and stability critical for mitochondrial morphogenesis in an isoform-specific manner. Although dispensable for development of neural cell types, this regulatory mechanism is necessary for their survival. Our findings provide a causal link of SUMO modification enzymes to apoptosis of neural cells, suggesting a new pathogenic mechanism for neurodegeneration. Exploring the protective effect of SENP2 on neuronal cell death may uncover important preventive and therapeutic strategies for neurodegenerative diseases.
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47
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Apoptotic pore formation is associated with in-plane insertion of Bak or Bax central helices into the mitochondrial outer membrane. Proc Natl Acad Sci U S A 2014; 111:E4076-85. [PMID: 25228770 DOI: 10.1073/pnas.1415142111] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The pivotal step on the mitochondrial pathway to apoptosis is permeabilization of the mitochondrial outer membrane (MOM) by oligomers of the B-cell lymphoma-2 (Bcl-2) family members Bak or Bax. However, how they disrupt MOM integrity is unknown. A longstanding model is that activated Bak and Bax insert two α-helices, α5 and α6, as a hairpin across the MOM, but recent insights on the oligomer structures question this model. We have clarified how these helices contribute to MOM perforation by determining that, in the oligomers, Bak α5 (like Bax α5) remains part of the protein core and that a membrane-impermeable cysteine reagent can label cysteines placed at many positions in α5 and α6 of both Bak and Bax. The results are inconsistent with the hairpin insertion model but support an in-plane model in which α5 and α6 collapse onto the membrane and insert shallowly to drive formation of proteolipidic pores.
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48
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Wu H, Che X, Zheng Q, Wu A, Pan K, Shao A, Wu Q, Zhang J, Hong Y. Caspases: a molecular switch node in the crosstalk between autophagy and apoptosis. Int J Biol Sci 2014; 10:1072-83. [PMID: 25285039 PMCID: PMC4183927 DOI: 10.7150/ijbs.9719] [Citation(s) in RCA: 192] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 08/20/2014] [Indexed: 12/16/2022] Open
Abstract
Autophagy and apoptosis are two important catabolic processes contributing to the maintenance of cellular and tissue homeostasis. Autophagy controls the turnover of protein aggregates and damaged organelles within cells, while apoptosis is the principal mechanism by which unwanted cells are dismantled and eliminated from organisms. Despite marked differences between these two pathways, they are highly interconnected in determining the fate of cells. Intriguingly, caspases, the primary drivers of apoptotic cell death, play a critical role in mediating the complex crosstalk between autophagy and apoptosis. Pro-apoptotic signals can converge to activate caspases to execute apoptotic cell death. In addition, activated caspases can degrade autophagy proteins (i.e., Beclin-1, Atg5, and Atg7) to shut down the autophagic response. Moreover, caspases can convert pro-autophagic proteins into pro-apoptotic proteints to trigger apoptotic cell death instead. It is clear that caspases are important in both apoptosis and autophagy, thus a detailed deciphering of the role of caspases in these two processes is still required to clarify the functional relationship between them. In this article, we provide a current overview of caspases in its interplay between autophagy and apoptosis. We emphasized that defining the role of caspases in autophagy-apoptosis crosstalk will provide a framework for more precise manipulation of these two processes during cell death.
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Affiliation(s)
- Haijian Wu
- 1. Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaoru Che
- 2. Department of Cardiology, Zhejiang Provincial People's Hospital, Hangzhou, China
| | - Qiaoli Zheng
- 3. Clinical Research Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - An Wu
- 1. Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Kun Pan
- 4. Department of Neurological Surgery, Weill Cornell Medical College, New York, New York, USA
| | - Anwen Shao
- 1. Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Qun Wu
- 1. Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Jianmin Zhang
- 1. Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yuan Hong
- 1. Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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49
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Würstle ML, Zink E, Prehn JHM, Rehm M. From computational modelling of the intrinsic apoptosis pathway to a systems-based analysis of chemotherapy resistance: achievements, perspectives and challenges in systems medicine. Cell Death Dis 2014; 5:e1258. [PMID: 24874730 PMCID: PMC4047923 DOI: 10.1038/cddis.2014.36] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2013] [Revised: 12/20/2013] [Accepted: 01/02/2014] [Indexed: 12/14/2022]
Abstract
Our understanding of the mitochondrial or intrinsic apoptosis pathway and its role in chemotherapy resistance has increased significantly in recent years by a combination of experimental studies and mathematical modelling. This combined approach enhanced the quantitative and kinetic understanding of apoptosis signal transduction, but also provided new insights that systems-emanating functions (i.e., functions that cannot be attributed to individual network components but that are instead established by multi-component interplay) are crucial determinants of cell fate decisions. Among these features are molecular thresholds, cooperative protein functions, feedback loops and functional redundancies that provide systems robustness, and signalling topologies that allow ultrasensitivity or switch-like responses. The successful development of kinetic systems models that recapitulate biological signal transduction observed in living cells have now led to the first translational studies, which have exploited and validated such models in a clinical context. Bottom-up strategies that use pathway models in combination with higher-level modelling at the tissue, organ and whole body-level therefore carry great potential to eventually deliver a new generation of systems-based diagnostic tools that may contribute to the development of personalised and predictive medicine approaches. Here we review major achievements in the systems biology of intrinsic apoptosis signalling, discuss challenges for further model development, perspectives for higher-level integration of apoptosis models and finally discuss requirements for the development of systems medical solutions in the coming years.
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Affiliation(s)
- M L Würstle
- 1] Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland [2] Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - E Zink
- 1] Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland [2] Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - J H M Prehn
- 1] Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland [2] Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - M Rehm
- 1] Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland [2] Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
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50
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Delta-lactoferrin induces cell death via the mitochondrial death signaling pathway by upregulating bax expression. Biometals 2014; 27:875-89. [DOI: 10.1007/s10534-014-9744-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 04/23/2014] [Indexed: 10/25/2022]
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