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Caro-Gómez LA, Rosas-Trigueros JL, Mixcoha E, Zamorano-Carrillo A, Martínez-Martínez J, Benítez-Cardoza CG. Anti-apoptotic Bcl-2 protein in apo and holo conformation anchored to the membrane: comparative molecular dynamics simulations. J Biomol Struct Dyn 2022:1-15. [DOI: 10.1080/07391102.2022.2101145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Affiliation(s)
| | - Jorge L. Rosas-Trigueros
- Laboratorio Transdisciplinario de Investigación en Sistemas Evolutivos, SEPI de la ESCOM del Instituto Politécnico Nacional, Mexico City, Mexico
| | - Edgar Mixcoha
- Catedrático-CONACYT Instituto Nacional de Psiquiatría Ramon de la Fuente Muñiz, Mexico City, Mexico
| | - Absalom Zamorano-Carrillo
- Laboratorio de Bioquímica y Biofísica Computacional, ENMH, Instituto Politécnico Nacional, Mexico City, Mexico
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2
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Mohammed GH, Elsayed Essawy AEW, Bayoumi AH, Rouby Mostafa SA, Elsayed RM. Possible protective role of L-thyroxin on the parotid gland of adult male albino rat in carbimazole induced hypothyroidism: histological, histomorphometry, and ultrastructural study. Ultrastruct Pathol 2022; 46:80-95. [DOI: 10.1080/01913123.2022.2027590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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3
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Heng J, Heng HH. Karyotype coding: The creation and maintenance of system information for complexity and biodiversity. Biosystems 2021; 208:104476. [PMID: 34237348 DOI: 10.1016/j.biosystems.2021.104476] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Revised: 07/02/2021] [Accepted: 07/03/2021] [Indexed: 12/22/2022]
Abstract
The mechanism of biological information flow is of vital importance. However, traditional research surrounding the genetic code that follows the central dogma to a phenotype faces challengers, including missing heritability and two-phased evolution. Here, we propose the karyotype code, which by organizing genes along chromosomes at once preserves species genome information and provides a platform for other genetic and nongenetic information to develop and accumulate. This specific genome-level code, which exists in all living systems, is compared to the genetic code and other organic codes in the context of information management, leading to the concept of hierarchical biological codes and an 'extended' definition of adaptor where the adaptors of a code can be not only molecular structures but also, more commonly, biological processes. Notably, different levels of a biosystem have their own mechanisms of information management, and gene-coded parts inheritance preserves "parts information" while karyotype-coded system inheritance preserves the "system information" which organizes parts information. The karyotype code prompts many questions regarding the flow of biological information, including the distinction between information creation, maintenance, modification, and usage, along with differences between living and non-living systems. How do biological systems exist, reproduce, and self-evolve for increased complexity and diversity? Inheritance is mediated by organic codes which function as informational tools to organize chemical reactions, create new information, and preserve frozen accidents, transforming historical miracles into biological routines.
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Affiliation(s)
- Julie Heng
- Harvard College, 86 Brattle Street Cambridge, MA, 02138, USA
| | - Henry H Heng
- Molecular Medicine and Genomics, Wayne State University School of Medicine, Detroit, MI, 48201, USA; Department of Pathology, Wayne State University School of Medicine, Detroit, MI, 48201, USA.
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4
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Mushtaq AU, Ådén J, Clifton LA, Wacklin-Knecht H, Campana M, Dingeldein APG, Persson C, Sparrman T, Gröbner G. Neutron reflectometry and NMR spectroscopy of full-length Bcl-2 protein reveal its membrane localization and conformation. Commun Biol 2021; 4:507. [PMID: 33907308 PMCID: PMC8079415 DOI: 10.1038/s42003-021-02032-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 03/25/2021] [Indexed: 12/20/2022] Open
Abstract
B-cell lymphoma 2 (Bcl-2) proteins are the main regulators of mitochondrial apoptosis. Anti-apoptotic Bcl-2 proteins possess a hydrophobic tail-anchor enabling them to translocate to their target membrane and to shift into an active conformation where they inhibit pro-apoptotic Bcl-2 proteins to ensure cell survival. To address the unknown molecular basis of their cell-protecting functionality, we used intact human Bcl-2 protein natively residing at the mitochondrial outer membrane and applied neutron reflectometry and NMR spectroscopy. Here we show that the active full-length protein is entirely buried into its target membrane except for the regulatory flexible loop domain (FLD), which stretches into the aqueous exterior. The membrane location of Bcl-2 and its conformational state seems to be important for its cell-protecting activity, often infamously upregulated in cancers. Most likely, this situation enables the Bcl-2 protein to sequester pro-apoptotic Bcl-2 proteins at the membrane level while sensing cytosolic regulative signals via its FLD region.
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Affiliation(s)
| | - Jörgen Ådén
- Department of Chemistry, University of Umeå, Umeå, Sweden
| | - Luke A Clifton
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science&Innovation Campus, Didcot, Oxfordshire, UK
| | - Hanna Wacklin-Knecht
- European Spallation Source ERIC, ESS, Lund, Sweden
- Department of Chemistry, Division of Physical Chemistry, Lund University, Lund, Sweden
| | - Mario Campana
- ISIS Pulsed Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Science&Innovation Campus, Didcot, Oxfordshire, UK
| | | | - Cecilia Persson
- The Swedish NMR Center, University of Gothenburg, Gothenburg, Sweden
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5
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Drastichova Z, Rudajev V, Pallag G, Novotny J. Proteome profiling of different rat brain regions reveals the modulatory effect of prolonged maternal separation on proteins involved in cell death-related processes. Biol Res 2021; 54:4. [PMID: 33557947 PMCID: PMC7871601 DOI: 10.1186/s40659-021-00327-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 01/25/2021] [Indexed: 01/08/2023] Open
Abstract
Background Early-life stress in the form of maternal separation can be associated with alterations in offspring neurodevelopment and brain functioning. Here, we aimed to investigate the potential impact of prolonged maternal separation on proteomic profiling of prefrontal cortex, hippocampus and cerebellum of juvenile and young adult rats. A special attention was devoted to proteins involved in the process of cell death and redox state maintenance. Methods Long-Evans pups were separated from their mothers for 3 h daily over the first 3 weeks of life (during days 2–21 of age). Brain tissue samples collected from juvenile (22-day-old) and young adult (90-day-old) rats were used for label-free quantitative (LFQ) proteomic analysis. In parallel, selected oxidative stress markers and apoptosis-related proteins were assessed biochemically and by Western blot, respectively. Results In total, 5526 proteins were detected in our proteomic analysis of rat brain tissue. Approximately one tenth of them (586 proteins) represented those involved in cell death processes or regulation of oxidative stress balance. Prolonged maternal separation caused changes in less than half of these proteins (271). The observed alterations in protein expression levels were age-, sex- and brain region-dependent. Interestingly, the proteins detected by mass spectrometry that are known to be involved in the maintenance of redox state were not markedly altered. Accordingly, we did not observe any significant differences between selected oxidative stress markers, such as the levels of hydrogen peroxide, reduced glutathione, protein carbonylation and lipid peroxidation in brain samples from rats that underwent maternal separation and from the corresponding controls. On the other hand, a number of changes were found in cell death-associated proteins, mainly in those involved in the apoptotic and autophagic pathways. However, there were no detectable alterations in the levels of cleaved products of caspases or Bcl-2 family members. Taken together, these data indicate that the apoptotic and autophagic cell death pathways were not activated by maternal separation either in adolescent or young adult rats. Conclusion Prolonged maternal separation can distinctly modulate expression profiles of proteins associated with cell death pathways in prefrontal cortex, hippocampus and cerebellum of juvenile rats and the consequences of early-life stress may last into adulthood and likely participate in variations in stress reactivity. Supplementary Information The online version contains supplementary material available at 10.1186/s40659-021-00327-5.
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Affiliation(s)
- Zdenka Drastichova
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Vladimir Rudajev
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Gergely Pallag
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jiri Novotny
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic.
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6
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Alaimo A, Lorenzoni M, Ambrosino P, Bertossi A, Bisio A, Macchia A, Zoni E, Genovesi S, Cambuli F, Foletto V, De Felice D, Soldovieri MV, Mosca I, Gandolfi F, Brunelli M, Petris G, Cereseto A, Villarroel A, Thalmann G, Carbone FG, Kruithof-de Julio M, Barbareschi M, Romanel A, Taglialatela M, Lunardi A. Calcium cytotoxicity sensitizes prostate cancer cells to standard-of-care treatments for locally advanced tumors. Cell Death Dis 2020; 11:1039. [PMID: 33288740 PMCID: PMC7721710 DOI: 10.1038/s41419-020-03256-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 10/20/2020] [Accepted: 10/23/2020] [Indexed: 12/30/2022]
Abstract
Therapy resistance is a major roadblock in oncology. Exacerbation of molecular dysfunctions typical of cancer cells have proven effective in twisting oncogenic mechanisms to lethal conditions, thus offering new therapeutic avenues for cancer treatment. Here, we demonstrate that selective agonists of Transient Receptor Potential cation channel subfamily M member 8 (TRPM8), a cation channel characteristic of the prostate epithelium frequently overexpressed in advanced stage III/IV prostate cancers (PCa), sensitize therapy refractory models of PCa to radio, chemo or hormonal treatment. Overall, our study demonstrates that pharmacological-induced Ca2+ cytotoxicity is an actionable strategy to sensitize cancer cells to standard therapies.
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Affiliation(s)
- Alessandro Alaimo
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Marco Lorenzoni
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Paolo Ambrosino
- Department of Science and Technology (DST), University of Sannio, Benevento, Italy
| | - Arianna Bertossi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Alessandra Bisio
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Alice Macchia
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Eugenio Zoni
- Department for BioMedical Research, Urology Research Laboratory, University of Bern, Bern, Switzerland
| | - Sacha Genovesi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Francesco Cambuli
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Veronica Foletto
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Dario De Felice
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | | | - Ilaria Mosca
- Department of Medicine and Health Sciences, University of Molise, Campobasso, Italy
| | - Francesco Gandolfi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Matteo Brunelli
- Department of Pathology AOUI, University of Verona, Verona, Italy
| | - Gianluca Petris
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Anna Cereseto
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | - Alvaro Villarroel
- Biofisika Institute (CSIC, UPV/EHU), University of the Basque Country, Leioa, Spain
| | - George Thalmann
- Department for BioMedical Research, Urology Research Laboratory, University of Bern, Bern, Switzerland.,Department of Urology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | | | - Marianna Kruithof-de Julio
- Department for BioMedical Research, Urology Research Laboratory, University of Bern, Bern, Switzerland.,Department of Urology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | | | - Alessandro Romanel
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy
| | | | - Andrea Lunardi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, Italy.
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7
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A general model on the origin of biological codes. Biosystems 2019; 181:11-19. [DOI: 10.1016/j.biosystems.2019.04.010] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/16/2019] [Accepted: 04/16/2019] [Indexed: 01/09/2023]
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8
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Barbieri M. What is code biology? Biosystems 2018; 164:1-10. [DOI: 10.1016/j.biosystems.2017.10.005] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 10/04/2017] [Accepted: 10/05/2017] [Indexed: 01/29/2023]
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9
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Membrane insertion of the BAX core, but not latch domain, drives apoptotic pore formation. Sci Rep 2017; 7:16259. [PMID: 29176554 PMCID: PMC5701199 DOI: 10.1038/s41598-017-16384-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 10/31/2017] [Indexed: 12/31/2022] Open
Abstract
Despite intensive research effort, how the paradigmatic proapoptotic protein BAX forms lethal apoptotic pores at the mitochondrial outer membrane (MOM) remains incompletely understood. Here, we used biophysical tools and minimalist model systems to identify the specific regions in BAX driving apoptotic pore formation, and to gain more insight into underlying mechanisms. Fluorescence mapping revealed that fully active BAX adopts a BH3-in-groove dimeric conformation in MOM-like membranes, with BAX α4-α5 helices belonging to its core domain inserting deeper into the membrane lipid bilayer than BAX α6-α8 helices belonging to its latch domain. In our reconstituted systems, antiapoptotic BCLXL formed canonical heterodimeric BH3-in-groove complexes with BAX, and blocked membrane insertion of BAX core α4-α5 helices, but not BAX latch α6-α8 helices. Moreover, poly(ethylene glycol) (PEG) conjugation (PEGylation) at multiple individual sites along the BAX core, but not latch domain, potently inhibited BAX pore-forming activity. Additional combined computational and experimental evidence revealed that the BAX core α5 helix displays a bilayer-destabilizing membrane interaction mode that is absent in BAX latch α6-α8 helices. Based on this collective set of evidence, we propose that membrane insertion of the BAX core, but not latch domain, is critical for BAX apoptotic pore formation.
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10
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Barbieri M. A new theory of development: the generation of complexity in ontogenesis. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2015.0148. [PMID: 26857661 DOI: 10.1098/rsta.2015.0148] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/01/2015] [Indexed: 06/05/2023]
Abstract
Today there is a very wide consensus on the idea that embryonic development is the result of a genetic programme and of epigenetic processes. Many models have been proposed in this theoretical framework to account for the various aspects of development, and virtually all of them have one thing in common: they do not acknowledge the presence of organic codes (codes between organic molecules) in ontogenesis. Here it is argued instead that embryonic development is a convergent increase in complexity that necessarily requires organic codes and organic memories, and a few examples of such codes are described. This is the code theory of development, a theory that was originally inspired by an algorithm that is capable of reconstructing structures from incomplete information, an algorithm that here is briefly summarized because it makes it intuitively appealing how a convergent increase in complexity can be achieved. The main thesis of the new theory is that the presence of organic codes in ontogenesis is not only a theoretical necessity but, first and foremost, an idea that can be tested and that has already been found to be in agreement with the evidence.
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Affiliation(s)
- Marcello Barbieri
- Dipartimento di Morfologia ed Embriologia, via Fossato di Mortara 64a, Ferrara 44121, Italy
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11
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Lidman M, Pokorná Š, Dingeldein APG, Sparrman T, Wallgren M, Šachl R, Hof M, Gröbner G. The oxidized phospholipid PazePC promotes permeabilization of mitochondrial membranes by Bax. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1288-97. [PMID: 26947183 DOI: 10.1016/j.bbamem.2016.03.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 02/24/2016] [Accepted: 03/02/2016] [Indexed: 12/25/2022]
Abstract
Mitochondria play a crucial role in programmed cell death via the intrinsic apoptotic pathway, which is tightly regulated by the B-cell CLL/lymphoma-2 (Bcl-2) protein family. Intracellular oxidative stress causes the translocation of Bax, a pro-apoptotic family member, to the mitochondrial outer membrane (MOM) where it induces membrane permeabilization. Oxidized phospholipids (OxPls) generated in the MOM during oxidative stress directly affect the onset and progression of mitochondria-mediated apoptosis. Here we use MOM-mimicking lipid vesicles doped with varying concentrations of 1-palmitoyl-2-azelaoyl-sn-glycero-3-phosphocholine (PazePC), an OxPl species known to significantly enhance Bax-membrane association, to investigate three key aspects of Bax's action at the MOM: 1) induction of Bax pores in membranes without additional mediator proteins, 2) existence of a threshold OxPl concentration required for Bax-membrane action and 3) mechanism by which PazePC disturbs membrane organization to facilitate Bax penetration. Fluorescence leakage studies revealed that Bax-induced leakage, especially its rate, increased with the vesicles' PazePC content without any detectable threshold neither for OxPl nor Bax. Moreover, the leakage rate correlated with the Bax to lipid ratio and the PazePC content. Solid state NMR studies and calorimetric experiments on the lipid vesicles confirmed that OxPl incorporation disrupted the membrane's organization, enabling Bax to penetrate into the membrane. In addition, 15N cross polarization (CP) and insensitive nuclei enhanced by polarization transfer (INEPT) MAS NMR experiments using uniformly (15)N-labeled Bax revealed dynamically restricted helical segments of Bax embedded in the membrane, while highly flexible protein segments were located outside or at the membrane surface.
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Affiliation(s)
- Martin Lidman
- Department of Chemistry, University of Umeå, SE-901 87 Umeå, Sweden
| | - Šárka Pokorná
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v. v. i., Dolejškova 3, 182 23 Prague 8, Czech Republic; Department of Biochemistry, Charles University, Hlavova 8, 128 40 Prague 2, Czech Republic
| | | | - Tobias Sparrman
- Department of Chemistry, University of Umeå, SE-901 87 Umeå, Sweden
| | - Marcus Wallgren
- Department of Medical Chemistry and Biophysics, University of Umeå, SE-901 87 Umeå, Sweden
| | - Radek Šachl
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v. v. i., Dolejškova 3, 182 23 Prague 8, Czech Republic
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v. v. i., Dolejškova 3, 182 23 Prague 8, Czech Republic
| | - Gerhard Gröbner
- Department of Chemistry, University of Umeå, SE-901 87 Umeå, Sweden.
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12
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Abstract
BCL-2 family proteins are the regulators of apoptosis, but also have other functions. This family of interacting partners includes inhibitors and inducers of cell death. Together they regulate and mediate the process by which mitochondria contribute to cell death known as the intrinsic apoptosis pathway. This pathway is required for normal embryonic development and for preventing cancer. However, before apoptosis is induced, BCL-2 proteins have critical roles in normal cell physiology related to neuronal activity, autophagy, calcium handling, mitochondrial dynamics and energetics, and other processes of normal healthy cells. The relative importance of these physiological functions compared to their apoptosis functions in overall organismal physiology is difficult to decipher. Apoptotic and noncanonical functions of these proteins may be intertwined to link cell growth to cell death. Disentanglement of these functions may require delineation of biochemical activities inherent to the characteristic three-dimensional shape shared by distantly related viral and cellular BCL-2 family members.
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13
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Landeta O, Landajuela A, Gil D, Taneva S, DiPrimo C, Sot B, Valle M, Frolov VA, Basañez G. Reconstitution of proapoptotic BAK function in liposomes reveals a dual role for mitochondrial lipids in the BAK-driven membrane permeabilization process. J Biol Chem 2011; 286:8213-8230. [PMID: 21196599 PMCID: PMC3048708 DOI: 10.1074/jbc.m110.165852] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 12/18/2010] [Indexed: 12/11/2022] Open
Abstract
BAK is a key effector of mitochondrial outer membrane permeabilization (MOMP) whose molecular mechanism of action remains to be fully dissected in intact cells, mainly due to the inherent complexity of the intracellular apoptotic machinery. Here we show that the core features of the BAK-driven MOMP pathway can be reproduced in a highly simplified in vitro system consisting of recombinant human BAK lacking the carboxyl-terminal 21 residues (BAKΔC) and tBID in combination with liposomes bearing an appropriate lipid environment. Using this minimalist reconstituted system we established that tBID suffices to trigger BAKΔC membrane insertion, oligomerization, and pore formation. Furthermore, we demonstrate that tBID-activated BAKΔC permeabilizes the membrane by forming structurally dynamic pores rather than a large proteinaceous channel of fixed size. We also identified two distinct roles played by mitochondrial lipids along the molecular pathway of BAKΔC-induced membrane permeabilization. First, using several independent approaches, we showed that cardiolipin directly interacts with BAKΔC, leading to a localized structural rearrangement in the protein that "primes" BAKΔC for interaction with tBID. Second, we provide evidence that selected curvature-inducing lipids present in mitochondrial membranes specifically modulate the energetic expenditure required to create the BAKΔC pore. Collectively, our results support the notion that BAK functions as a direct effector of MOMP akin to BAX and also adds significantly to the growing evidence indicating that mitochondrial membrane lipids are actively implicated in BCL-2 protein family function.
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Affiliation(s)
- Olatz Landeta
- From the Unidad de Biofísica (Centro Mixto Consejo Superior de Investigaciones Cientificas-Universidad del Pais Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Ane Landajuela
- From the Unidad de Biofísica (Centro Mixto Consejo Superior de Investigaciones Cientificas-Universidad del Pais Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - David Gil
- CIC-BIOGUNE Structural Biology Unit, Parque Tecnologico Zamudio, Bizkaia, 48160 Derio, Spain
| | - Stefka Taneva
- From the Unidad de Biofísica (Centro Mixto Consejo Superior de Investigaciones Cientificas-Universidad del Pais Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain
| | - Carmelo DiPrimo
- Université de Bordeaux, INSERM U869, Institut Européen de Chimie et de Biologie, Pessac F-33607, France, and
| | - Begoña Sot
- the MRC Centre for Protein Engineering and MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, United Kingdom
| | - Mikel Valle
- CIC-BIOGUNE Structural Biology Unit, Parque Tecnologico Zamudio, Bizkaia, 48160 Derio, Spain
| | - Vadim A Frolov
- From the Unidad de Biofísica (Centro Mixto Consejo Superior de Investigaciones Cientificas-Universidad del Pais Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain,; the Departamento de Bioquímica y Biología Molecular, UPV/EHU, Leioa 48940, Spain,; Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Spain
| | - Gorka Basañez
- From the Unidad de Biofísica (Centro Mixto Consejo Superior de Investigaciones Cientificas-Universidad del Pais Vasco/Euskal Herriko Unibertsitatea (UPV/EHU), P.O. Box 644, 48080 Bilbao, Spain,.
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14
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Crimi M, Esposti MD. Apoptosis-induced changes in mitochondrial lipids. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1813:551-7. [PMID: 20888373 DOI: 10.1016/j.bbamcr.2010.09.014] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 09/20/2010] [Accepted: 09/22/2010] [Indexed: 10/19/2022]
Abstract
Apoptosis is an active and tightly regulated form of cell death, which can also be considered a stress-induced process of cellular communication. Recent studies reveal that the lipid network within cells is involved in the regulation and propagation of death signalling. Despite the vast growth of our current knowledge on apoptosis, little is known of the specific role played by lipid molecules in the central event of apoptosis-the piercing of mitochondrial membranes. Here we review the information regarding changes in mitochondrial lipids that are associated with apoptosis and discuss whether they may be involved in the permeabilization of mitochondria to release their apoptogenic factors, or just lie downstream of this permeabilization leading to the amplification of caspase activation. We focus on the earliest changes that physiological apoptosis induces in mitochondrial membranes, which may derive from an upstream alteration of phospholipid metabolism that reverberates on the mitochondrial re-modelling of their characteristic lipid, cardiolipin. Hopefully, this review will lead to an increased understanding of the role of mitochondrial lipids in apoptosis and also help revealing new stress sensing mechanisms in cells. This article is part of a Special Issue entitled Mitochondria: the deadly organelle.
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Affiliation(s)
- Massimo Crimi
- Department of Biotechnology, University of Verona, Strada le Grazie 15, Cà Vignal 1, 37134 Verona, Italy
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15
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Manoranjan B, Provias JP. Hemimegalencephaly: a fetal case with neuropathological confirmation and review of the literature. Acta Neuropathol 2010; 120:117-30. [PMID: 20237789 DOI: 10.1007/s00401-010-0663-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Revised: 02/24/2010] [Accepted: 02/25/2010] [Indexed: 11/25/2022]
Abstract
Hemimegalencephaly (HME) is a developmental abnormality of the central nervous system, identified by an abnormal increase in the size of one cerebral hemisphere. HME may present as either a syndromic or isolated case. To date the literature on HME has focused primarily on non-fetal pediatric patients, largely related to surgical resection specimens of the HME hemisphere. We present the case of a male fetus at 22 weeks gestation with intracranial abnormalities identified on a follow-up ultrasound. Gross examination of the fetal brain confirmed the increased size of the right cerebral hemisphere. The ipsilateral brain stem and cerebellum were not involved. Light microscopy demonstrated the presence of accelerated cortical differentiation along with several migrational anomalies in the HME hemisphere. Based on the gross and microscopic findings, a diagnosis of fetal hemimegalencephaly was made. The periventricular proliferative zone of the abnormal hemisphere contained a normal population of neuroepithelial precursor cells. An exhaustive immunohistochemical study found immunoreactivity for calretinin and synaptophysin, while the Ki-67 proliferation labeling was not increased in the HME hemisphere. Our case is the first autopsied report on fetal hemimegalencephaly and confirms that the key pathogenic changes may present as early as 20-22 weeks gestation. The major pathological features of our case are in keeping with a disturbance in accelerated neuronal differentiation and migrational abnormalities.
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Montero J, Mari M, Colell A, Morales A, Basañez G, Garcia-Ruiz C, Fernández-Checa JC. Cholesterol and peroxidized cardiolipin in mitochondrial membrane properties, permeabilization and cell death. BIOCHIMICA ET BIOPHYSICA ACTA 2010; 1797:1217-24. [PMID: 20153716 PMCID: PMC2889134 DOI: 10.1016/j.bbabio.2010.02.010] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 02/04/2010] [Accepted: 02/08/2010] [Indexed: 02/06/2023]
Abstract
Mitochondria are known to actively regulate cell death with the final phenotype of demise being determined by the metabolic and energetic status of the cell. Mitochondrial membrane permeabilization (MMP) is a critical event in cell death, as it regulates the degree of mitochondrial dysfunction and the release of intermembrane proteins that function in the activation and assembly of caspases. In addition to the crucial role of proapoptotic members of the Bcl-2 family, the lipid composition of the mitochondrial membranes is increasingly recognized to modulate MMP and hence cell death. The unphysiological accumulation of cholesterol in mitochondrial membranes regulates their physical properties, facilitating or impairing MMP during Bax and death ligand-induced cell death depending on the level of mitochondrial GSH (mGSH), which in turn regulates the oxidation status of cardiolipin. Cholesterol-mediated mGSH depletion stimulates TNF-induced reactive oxygen species and subsequent cardiolipin peroxidation, which destabilizes the lipid bilayer and potentiates Bax-induced membrane permeabilization. These data suggest that the balance of mitochondrial cholesterol to peroxidized cardiolipin regulates mitochondrial membrane properties and permeabilization, emerging as a rheostat in cell death.
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Affiliation(s)
- Joan Montero
- Liver Unit and Centro de Investigaciones Biomédicas Esther Koplowitz, IMDiM, Hospital Clínic i Provincial and CIBEREHD, IDIBAPS, and Department of Cell Death and Proliferation, Instituto Investigaciones Biomédicas de Barcelona, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
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17
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Marí M, Colell A, Morales A, von Montfort C, Garcia-Ruiz C, Fernández-Checa JC. Redox control of liver function in health and disease. Antioxid Redox Signal 2010; 12:1295-331. [PMID: 19803748 PMCID: PMC2864660 DOI: 10.1089/ars.2009.2634] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Reactive oxygen species (ROS), a heterogeneous population of biologically active intermediates, are generated as by-products of the aerobic metabolism and exhibit a dual role in biology. When produced in controlled conditions and in limited quantities, ROS may function as signaling intermediates, contributing to critical cellular functions such as proliferation, differentiation, and cell survival. However, ROS overgeneration and, particularly, the formation of specific reactive species, inflicts cell death and tissue damage by targeting vital cellular components such as DNA, lipids, and proteins, thus arising as key players in disease pathogenesis. Given the predominant role of hepatocytes in biotransformation and metabolism of xenobiotics, ROS production constitutes an important burden in liver physiology and pathophysiology and hence in the progression of liver diseases. Despite the recognized role of ROS in disease pathogenesis, the efficacy of antioxidants as therapeutics has been limited. A better understanding of the mechanisms, nature, and location of ROS generation, as well as the optimization of cellular defense strategies, may pave the way for a brighter future for antioxidants and ROS scavengers in the therapy of liver diseases.
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Affiliation(s)
- Montserrat Marí
- Liver Unit, Hospital Clinic, IDIBAPS-CIBEK, CIBEREHD, and Department of Cell Death and Proliferation, IIBB-CSIC, Barcelona, Spain
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18
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Sun T, Lin X, Wei Y, Xu Y, Shen P. Evaluating bistability of Bax activation switch. FEBS Lett 2010; 584:954-60. [PMID: 20096692 DOI: 10.1016/j.febslet.2010.01.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 01/15/2010] [Indexed: 12/26/2022]
Abstract
Mitochondrial apoptotic pathway is precisely controlled by BCL-2 family. Complex interactions of BCL-2 family proteins constitute a bistable switch of which detailed experimental and theoretical delineation remains elusive. In this paper, combined approaches were used to explore the bistability of Bax activation switch. We found that Bax activation is indeed in an 'all-or-none' manner. The 'variable-delay, snap-action' nature for Bax activation is further explored theoretically. We suggest that bistability is largely attributed to topological structure and shows considerable robustness. Therefore, our study characterizes dynamics and sensitivities in intrinsic apoptotic pathway.
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Affiliation(s)
- Tingzhe Sun
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, People's Republic of China
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Berman SB, Chen YB, Qi B, McCaffery JM, Rucker EB, Goebbels S, Nave KA, Arnold BA, Jonas EA, Pineda FJ, Hardwick JM. Bcl-x L increases mitochondrial fission, fusion, and biomass in neurons. ACTA ACUST UNITED AC 2009; 184:707-19. [PMID: 19255249 PMCID: PMC2686401 DOI: 10.1083/jcb.200809060] [Citation(s) in RCA: 192] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Mitochondrial fission and fusion are linked to synaptic activity in healthy neurons and are implicated in the regulation of apoptotic cell death in many cell types. We developed fluorescence microscopy and computational strategies to directly measure mitochondrial fission and fusion frequencies and their effects on mitochondrial morphology in cultured neurons. We found that the rate of fission exceeds the rate of fusion in healthy neuronal processes, and, therefore, the fission/fusion ratio alone is insufficient to explain mitochondrial morphology at steady state. This imbalance between fission and fusion is compensated by growth of mitochondrial organelles. Bcl-xL increases the rates of both fusion and fission, but more important for explaining the longer organelle morphology induced by Bcl-xL is its ability to increase mitochondrial biomass. Deficits in these Bcl-xL–dependent mechanisms may be critical in neuronal dysfunction during the earliest phases of neurodegeneration, long before commitment to cell death.
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Affiliation(s)
- Sarah B Berman
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
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Membrane binding by tBid initiates an ordered series of events culminating in membrane permeabilization by Bax. Cell 2008; 135:1074-84. [PMID: 19062087 DOI: 10.1016/j.cell.2008.11.010] [Citation(s) in RCA: 444] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2008] [Revised: 09/15/2008] [Accepted: 11/04/2008] [Indexed: 01/04/2023]
Abstract
In normal circumstances, the Bcl-2 family dutifully governs when cells die. However, the rules of engagement between the pro- and antiapoptotic family members are still contested, and how Bax is transformed from a cytosolic monomer to an outer mitochondrial membrane-permeabilizing oligomer is unclear. With fluorescence techniques and an in vitro system, the combination of tBid and Bax produced dramatic membrane permeabilization. The membrane is not a passive partner in this process beause membranes are required for the protein-protein interactions to occur. Simultaneous measurements of these interactions revealed an ordered series of steps required for outer membrane permeabilization: (1) tBid rapidly binds to membranes, where (2) tBid interacts with Bax, causing (3) Bax insertion into membranes and (4) oligomerization, culminating in (5) membrane permeabilization. Bcl-XL prevents membrane-bound tBid from binding Bax. Bad releases tBid from Bcl-XL, restoring both tBid binding to Bax and membrane permeabilization.
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Etxebarria A, Terrones O, Yamaguchi H, Landajuela A, Landeta O, Antonsson B, Wang HG, Basañez G. Endophilin B1/Bif-1 stimulates BAX activation independently from its capacity to produce large scale membrane morphological rearrangements. J Biol Chem 2008; 284:4200-12. [PMID: 19074440 DOI: 10.1074/jbc.m808050200] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Endophilin B1/BAX-interacting factor 1 (Bif-1) is a protein that cooperates with dynamin-like protein 1 (DLP1/Drp1) to maintain normal mitochondrial outer membrane (MOM) dynamics in healthy cells and also contributes to BAX-driven MOM permeabilization (MOMP), the irreversible commitment point to cell death for the majority of apoptotic stimuli. However, despite its importance, exactly how Bif-1 fulfils its proapoptotic role is unknown. Here, we demonstrate that the stimulatory effect of Bif-1 on BAX-driven MOMP and on BAX conformational activation observed in intact cells during apoptosis can be recapitulated in a simplified system consisting of purified proteins and MOM-like liposomes. In this reconstituted model system the N-BAR domain of Bif-1 reproduced the stimulatory effect of Bif-1 on functional BAX activation. This process was dependent on physical interaction between Bif-1 N-BAR and BAX as well as on the presence of the mitochondrion-specific lipid cardiolipin. Despite that Bif-1 N-BAR produced large scale morphological rearrangements in MOM-like liposomes, this phenomenon could be separated from functional BAX activation. Furthermore, DLP1 also caused global morphological changes in MOM-like liposomes, but DLP1 did not stimulate BAX-permeabilizing function in the absence or presence of Bif-1. Taken together, our findings not only provide direct evidence for a functional interplay between Bif-1, BAX, and cardiolipin during MOMP but also add significantly to the growing body of evidence indicating that components of the mitochondrial morphogenesis machinery possess proapoptotic functions that are independent from their recognized roles in normal mitochondrial dynamics.
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Affiliation(s)
- Aitor Etxebarria
- Unidad de Biofísica, Centro Mixto Consejo Superior de Investigaciones Cientificas, Universidad del Pais Vasco/Euskal Herriko Unibertsitatea, 48080 Bilbao, Spain
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Regulation of antiapoptotic MCL-1 function by gossypol: mechanistic insights from in vitro reconstituted systems. Biochem Pharmacol 2008; 76:1563-76. [PMID: 18762177 DOI: 10.1016/j.bcp.2008.08.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2008] [Revised: 08/02/2008] [Accepted: 08/05/2008] [Indexed: 12/11/2022]
Abstract
Small-molecule drugs that induce apoptosis in tumor cells by activation of the BCL-2-regulated mitochondrial outer membrane permeabilization (MOMP) pathway hold promise for rational anticancer therapies. Accumulating evidence indicates that the natural product gossypol and its derivatives can kill tumor cells by targeting antiapoptotic BCL-2 family members in such a manner as to trigger MOMP. However, due to the inherent complexity of the cellular apoptotic network, the precise mechanisms by which interactions between gossypol and individual BCL-2 family members lead to MOMP remain poorly understood. Here, we used simplified systems bearing physiological relevance to examine the impact of gossypol on the function of MCL-1, a key determinant for survival of various human malignancies that has become a highly attractive target for anticancer drug design. First, using a reconstituted liposomal system that recapitulates basic aspects of the BCL-2-regulated MOMP pathway, we demonstrate that MCL-1 inhibits BAX permeabilizing function via a "dual-interaction" mechanism, while submicromolar concentrations of gossypol reverse MCL-1-mediated inhibition of functional BAX activation. Solution-based studies showed that gossypol competes with BAX/BID BH3 ligands for binding to MCL-1 hydrophobic groove, thereby providing with a mechanistic explanation for how gossypol restores BAX permeabilizing function in the presence of MCL-1. By contrast, no evidence was found indicating that gossypol transforms MCL-1 into a BAX-like pore-forming molecule. Altogether, our findings validate MCL-1 as a direct target of gossypol, and highlight that making this antiapoptotic protein unable to inhibit BAX-driven MOMP may represent one important mechanism by which gossypol exerts its cytotoxic effect in selected cancer cells.
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