1
|
Furuta Y, Zhou Z. How do necrotic cells expose phosphatidylserine to attract their predators—What’s unique and what’s in common with apoptotic cells. Front Cell Dev Biol 2023; 11:1170551. [PMID: 37091984 PMCID: PMC10113483 DOI: 10.3389/fcell.2023.1170551] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 03/27/2023] [Indexed: 04/09/2023] Open
Abstract
Phosphatidylserine (PS) is a lipid component of the plasma membrane. It is asymmetrically distributed to the inner leaflet in live cells. In cells undergoing apoptosis, phosphatidylserine is exposed to the outer surfaces. The exposed phosphatidylserine acts as an evolutionarily conserved “eat-me” signal that attracts neighboring engulfing cells in metazoan organisms, including the nematode Caenorhabditis elegans, the fruit fly Drosophila melanogaster, and mammals. During apoptosis, the exposure of phosphatidylserine to the outer surface of a cell is driven by the membrane scramblases and flippases, the activities of which are regulated by caspases. Cells undergoing necrosis, a kind of cell death frequently associated with cellular injuries and morphologically distinct from apoptosis, were initially believed to allow passive exposure of phosphatidylserine through membrane rupture. Later studies revealed that necrotic cells actively expose phosphatidylserine before any rupture occurs. A recent study in C. elegans further reported that the calcium ion (Ca2+) plays an essential role in promoting the exposure of phosphatidylserine on the surfaces of necrotic cells. These findings indicate that necrotic and apoptotic cells, which die through different molecular mechanisms, use common and unique mechanisms for promoting the exposure of the same “eat me” signal. This article will review the mechanisms regulating the exposure of phosphatidylserine on the surfaces of necrotic and apoptotic cells and highlight their similarities and differences.
Collapse
|
2
|
Luke CJ, Markovina S, Good M, Wight IE, Thomas BJ, Linneman JM, Lanik WE, Koroleva O, Coffman MR, Miedel MT, Gong Q, Andress A, Campos Guerrero M, Wang S, Chen L, Beatty WL, Hausmann KN, White FV, Fitzpatrick JAJ, Orvedahl A, Pak SC, Silverman GA. Lysoptosis is an evolutionarily conserved cell death pathway moderated by intracellular serpins. Commun Biol 2022; 5:47. [PMID: 35022507 PMCID: PMC8755814 DOI: 10.1038/s42003-021-02953-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 12/07/2021] [Indexed: 01/02/2023] Open
Abstract
Lysosomal membrane permeabilization (LMP) and cathepsin release typifies lysosome-dependent cell death (LDCD). However, LMP occurs in most regulated cell death programs suggesting LDCD is not an independent cell death pathway, but is conscripted to facilitate the final cellular demise by other cell death routines. Previously, we demonstrated that Caenorhabditis elegans (C. elegans) null for a cysteine protease inhibitor, srp-6, undergo a specific LDCD pathway characterized by LMP and cathepsin-dependent cytoplasmic proteolysis. We designated this cell death routine, lysoptosis, to distinguish it from other pathways employing LMP. In this study, mouse and human epithelial cells lacking srp-6 homologues, mSerpinb3a and SERPINB3, respectively, demonstrated a lysoptosis phenotype distinct from other cell death pathways. Like in C. elegans, this pathway depended on LMP and released cathepsins, predominantly cathepsin L. These studies suggested that lysoptosis is an evolutionarily-conserved eukaryotic LDCD that predominates in the absence of neutralizing endogenous inhibitors.
Collapse
Affiliation(s)
- Cliff J Luke
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA.
- Siteman Cancer Center, and Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA.
| | - Stephanie Markovina
- Siteman Cancer Center, and Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
- Radiation Oncology, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Misty Good
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Ira E Wight
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Brian J Thomas
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - John M Linneman
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Wyatt E Lanik
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Olga Koroleva
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Maggie R Coffman
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Mark T Miedel
- Department of Computational and Systems biology, Drug Discovery Institute, University of Pittsburgh, Pittsburgh, PA, USA
| | - Qingqing Gong
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Arlise Andress
- Radiation Oncology, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Marlene Campos Guerrero
- Radiation Oncology, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Songyan Wang
- Radiation Oncology, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - LiYun Chen
- Radiation Oncology, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Wandy L Beatty
- Molecular Microbiology, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Kelsey N Hausmann
- Molecular Microbiology, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Frances V White
- Department of Pathology and Immunology, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - James A J Fitzpatrick
- Cell Biology and Physiology, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
- Neuroscience, and Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Anthony Orvedahl
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Stephen C Pak
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA
| | - Gary A Silverman
- Departments of Pediatrics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA.
- Siteman Cancer Center, and Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA.
- Cell Biology and Physiology, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA.
- Genetics, Washington University School of Medicine and the Children's Discovery Institute of St. Louis Children's Hospital, St. Louis, MO, USA.
| |
Collapse
|
3
|
Furuta Y, Pena-Ramos O, Li Z, Chiao L, Zhou Z. Calcium ions trigger the exposure of phosphatidylserine on the surface of necrotic cells. PLoS Genet 2021; 17:e1009066. [PMID: 33571185 PMCID: PMC7904182 DOI: 10.1371/journal.pgen.1009066] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 02/24/2021] [Accepted: 01/18/2021] [Indexed: 11/18/2022] Open
Abstract
Intracellular Ca2+ level is under strict regulation through calcium channels and storage pools including the endoplasmic reticulum (ER). Mutations in certain ion channel subunits, which cause mis-regulated Ca2+ influx, induce the excitotoxic necrosis of neurons. In the nematode Caenorhabditis elegans, dominant mutations in the DEG/ENaC sodium channel subunit MEC-4 induce six mechanosensory (touch) neurons to undergo excitotoxic necrosis. These necrotic neurons are subsequently engulfed and digested by neighboring hypodermal cells. We previously reported that necrotic touch neurons actively expose phosphatidylserine (PS), an “eat-me” signal, to attract engulfing cells. However, the upstream signal that triggers PS externalization remained elusive. Here we report that a robust and transient increase of cytoplasmic Ca2+ level occurs prior to the exposure of PS on necrotic touch neurons. Inhibiting the release of Ca2+ from the ER, either pharmacologically or genetically, specifically impairs PS exposure on necrotic but not apoptotic cells. On the contrary, inhibiting the reuptake of cytoplasmic Ca2+ into the ER induces ectopic necrosis and PS exposure. Remarkably, PS exposure occurs independently of other necrosis events. Furthermore, unlike in mutants of DEG/ENaC channels, in dominant mutants of deg-3 and trp-4, which encode Ca2+ channels, PS exposure on necrotic neurons does not rely on the ER Ca2+ pool. Our findings indicate that high levels of cytoplasmic Ca2+ are necessary and sufficient for PS exposure. They further reveal two Ca2+-dependent, necrosis-specific pathways that promote PS exposure, a “two-step” pathway initiated by a modest influx of Ca2+ and further boosted by the release of Ca2+ from the ER, and another, ER-independent, pathway. Moreover, we found that ANOH-1, the worm homolog of mammalian phospholipid scramblase TMEM16F, is necessary for efficient PS exposure in thapsgargin-treated worms and trp-4 mutants, like in mec-4 mutants. We propose that both the ER-mediated and ER-independent Ca2+ pathways promote PS externalization through activating ANOH-1. Necrosis is a type of cell death that exhibits distinct morphological features such as cell and organelle swelling. Necrotic cells expose phosphatidylserine (PS)–a type of phospholipid—on their outer surfaces. Receptor molecules on phagocytes detect PS on necrotic cells and subsequently initiate the engulfment process. As necrosis is associated with stroke, cancer, neurodegenerative diseases, and heart diseases, studying necrotic cell clearance has important medical relevance. In the model organism the nematode C. elegans, we previously identified membrane proteins that promote the exposure of PS on necrotic cell surfaces by studying neurons that are induced to undergo necrosis by dominant mutations in ion channels. Here, in C. elegans, we have discovered that the necrotic insults trigger an increase of the cytoplasmic calcium ion (Ca2+), which in turn promotes PS externalization on necrotic cell surfaces. Furthermore, we have identified two different mechanisms that increase cytoplasmic Ca2+ levels, one dependent on the Ca2+ contribution from the endoplasmic reticulum (ER), the other independent of the ER. The Ca2+ signal targets ANOH-1, a worm homolog of mammalian proteins capable of externalizing PS, for promoting PS exposure on necrotic cells. Our findings reveal novel upstream regulatory mechanisms that promote necrotic cell clearance in animals.
Collapse
Affiliation(s)
- Yoshitaka Furuta
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- School of Pharmacy, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, Japan
| | - Omar Pena-Ramos
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Zao Li
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Lucia Chiao
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Zheng Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
| |
Collapse
|
4
|
Bolobolova EU, Dorogova NV, Fedorova SA. Major Scenarios of Genetically Regulated Cell Death during Oogenesis in Drosophilamelanogaster. RUSS J GENET+ 2020. [DOI: 10.1134/s1022795420060034] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
5
|
C. elegans Blastomeres Clear the Corpse of the Second Polar Body by LC3-Associated Phagocytosis. Cell Rep 2018; 23:2070-2082. [DOI: 10.1016/j.celrep.2018.04.043] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 02/22/2018] [Accepted: 04/10/2018] [Indexed: 12/16/2022] Open
|
6
|
Programmed Cell Death During Caenorhabditis elegans Development. Genetics 2017; 203:1533-62. [PMID: 27516615 DOI: 10.1534/genetics.115.186247] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 04/22/2016] [Indexed: 12/21/2022] Open
Abstract
Programmed cell death is an integral component of Caenorhabditis elegans development. Genetic and reverse genetic studies in C. elegans have led to the identification of many genes and conserved cell death pathways that are important for the specification of which cells should live or die, the activation of the suicide program, and the dismantling and removal of dying cells. Molecular, cell biological, and biochemical studies have revealed the underlying mechanisms that control these three phases of programmed cell death. In particular, the interplay of transcriptional regulatory cascades and networks involving multiple transcriptional regulators is crucial in activating the expression of the key death-inducing gene egl-1 and, in some cases, the ced-3 gene in cells destined to die. A protein interaction cascade involving EGL-1, CED-9, CED-4, and CED-3 results in the activation of the key cell death protease CED-3, which is tightly controlled by multiple positive and negative regulators. The activation of the CED-3 caspase then initiates the cell disassembly process by cleaving and activating or inactivating crucial CED-3 substrates; leading to activation of multiple cell death execution events, including nuclear DNA fragmentation, mitochondrial elimination, phosphatidylserine externalization, inactivation of survival signals, and clearance of apoptotic cells. Further studies of programmed cell death in C. elegans will continue to advance our understanding of how programmed cell death is regulated, activated, and executed in general.
Collapse
|
7
|
Nicotinamide is an endogenous agonist for a C. elegans TRPV OSM-9 and OCR-4 channel. Nat Commun 2016; 7:13135. [PMID: 27731314 PMCID: PMC5064019 DOI: 10.1038/ncomms13135] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 09/07/2016] [Indexed: 12/30/2022] Open
Abstract
TRPV ion channels are directly activated by sensory stimuli and participate in thermo-, mechano- and chemo-sensation. They are also hypothesized to respond to endogenous agonists that would modulate sensory responses. Here, we show that the nicotinamide (NAM) form of vitamin B3 is an agonist of a Caenorhabditis elegans TRPV channel. Using heterologous expression in Xenopus oocytes, we demonstrate that NAM is a soluble agonist for a channel consisting of the well-studied OSM-9 TRPV subunit and relatively uncharacterized OCR-4 TRPV subunit as well as the orthologous Drosophila Nan-Iav TRPV channel, and we examine stoichiometry of subunit assembly. Finally, we show that behaviours mediated by these C. elegans and Drosophila channels are responsive to NAM, suggesting conservation of activity of this soluble endogenous metabolite on TRPV activity. Our results in combination with the role of NAM in NAD+ metabolism suggest an intriguing link between metabolic regulation and TRPV channel activity. TRPV are cation channels activated by physical and chemical stimuli. Here the authors show that nicotinamide is a soluble, endogenous agonist for orthologous TRPV channels from C. elegans and Drosophila, unveiling a metabolic-based regulation for TRPV channel activity.
Collapse
|
8
|
Wang X, Yang C. Programmed cell death and clearance of cell corpses in Caenorhabditis elegans. Cell Mol Life Sci 2016; 73:2221-36. [PMID: 27048817 PMCID: PMC11108496 DOI: 10.1007/s00018-016-2196-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 03/18/2016] [Indexed: 01/01/2023]
Abstract
Programmed cell death is critical to the development of diverse animal species from C. elegans to humans. In C. elegans, the cell death program has three genetically distinguishable phases. During the cell suicide phase, the core cell death machinery is activated through a protein interaction cascade. This activates the caspase CED-3, which promotes numerous pro-apoptotic activities including DNA degradation and exposure of the phosphatidylserine "eat me" signal on the cell corpse surface. Specification of the cell death fate involves transcriptional activation of the cell death initiator EGL-1 or the caspase CED-3 by coordinated actions of specific transcription factors in distinct cell types. In the cell corpse clearance stage, recognition of cell corpses by phagocytes triggers several signaling pathways to induce phagocytosis of apoptotic cell corpses. Cell corpse-enclosing phagosomes ultimately fuse with lysosomes for digestion of phagosomal contents. This article summarizes our current knowledge about programmed cell death and clearance of cell corpses in C. elegans.
Collapse
Affiliation(s)
- Xiaochen Wang
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing, 102206, China.
| | - Chonglin Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing, 100101, China.
| |
Collapse
|
9
|
Li Z, Zhou Z. How are necrotic cells recognized by their predators? WORM 2015; 5:e1120400. [PMID: 27073733 PMCID: PMC4805362 DOI: 10.1080/21624054.2015.1120400] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 11/08/2015] [Accepted: 11/10/2015] [Indexed: 11/22/2022]
Abstract
Necrosis is a type of cell death often caused by cell injury and is linked to human diseases including neuron degeneration, stroke, and cancer. Cells undergoing necrosis are engulfed and degraded by engulfing cells, their predators. The mechanisms by which necrotic cells are recognized and removed remain elusive. Here we comment on our recent findings that reveal new molecular mechanisms of necrotic-cell recognition. Through studying the C. elegans touch neurons undergoing excitotoxic necrosis, we identified a receptor/ligand pair that enables engulfing cells to recognize necrotic neurons. The phagocytic receptor CED-1 is activated through interaction with its ligand phosphatidylserine (PS), exposed on the surface of necrotic cells. Furthermore, against the common belief that necrotic cells have ruptured plasma membrane, we found that necrotic C. elegans touch neurons actively present PS on their outer surfaces while maintaining plasma membrane integrity. We further identified 2 mechanisms governing the presentation of PS, one of which is shared with cells undergoing apoptosis, a “cell suicide” event, whereas the other is unique to necrotic neurons. The influx of Ca2+, a key necrosis-triggering factor, is implicated in activating a neuronal PS-scramblase for PS exposure. We propose that the mechanisms controlling PS-exposure and necrotic-cell recognition by engulfing cells are likely conserved from worms to humans.
Collapse
Affiliation(s)
- Zao Li
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine , Houston, TX, USA
| | - Zheng Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine , Houston, TX, USA
| |
Collapse
|
10
|
Necrotic Cells Actively Attract Phagocytes through the Collaborative Action of Two Distinct PS-Exposure Mechanisms. PLoS Genet 2015; 11:e1005285. [PMID: 26061275 PMCID: PMC4464654 DOI: 10.1371/journal.pgen.1005285] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 05/14/2015] [Indexed: 11/19/2022] Open
Abstract
Necrosis, a kind of cell death closely associated with pathogenesis and genetic programs, is distinct from apoptosis in both morphology and mechanism. Like apoptotic cells, necrotic cells are swiftly removed from animal bodies to prevent harmful inflammatory and autoimmune responses. In the nematode Caenorhabditis elegans, gain-of-function mutations in certain ion channel subunits result in the excitotoxic necrosis of six touch neurons and their subsequent engulfment and degradation inside engulfing cells. How necrotic cells are recognized by engulfing cells is unclear. Phosphatidylserine (PS) is an important apoptotic-cell surface signal that attracts engulfing cells. Here we observed PS exposure on the surface of necrotic touch neurons. In addition, the phagocytic receptor CED-1 clusters around necrotic cells and promotes their engulfment. The extracellular domain of CED-1 associates with PS in vitro. We further identified a necrotic cell-specific function of CED-7, a member of the ATP-binding cassette (ABC) transporter family, in promoting PS exposure. In addition to CED-7, anoctamin homolog-1 (ANOH-1), the C. elegans homolog of the mammalian Ca(2+)-dependent phospholipid scramblase TMEM16F, plays an independent role in promoting PS exposure on necrotic cells. The combined activities from CED-7 and ANOH-1 ensure efficient exposure of PS on necrotic cells to attract their phagocytes. In addition, CED-8, the C. elegans homolog of mammalian Xk-related protein 8 also makes a contribution to necrotic cell-removal at the first larval stage. Our work indicates that cells killed by different mechanisms (necrosis or apoptosis) expose a common "eat me" signal to attract their phagocytic receptor(s); furthermore, unlike what was previously believed, necrotic cells actively present PS on their outer surfaces through at least two distinct molecular mechanisms rather than leaking out PS passively.
Collapse
|
11
|
Yang JR, Ruan S, Zhang J. Determinative developmental cell lineages are robust to cell deaths. PLoS Genet 2014; 10:e1004501. [PMID: 25058586 PMCID: PMC4110091 DOI: 10.1371/journal.pgen.1004501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 05/24/2014] [Indexed: 11/18/2022] Open
Abstract
All forms of life are confronted with environmental and genetic perturbations, making phenotypic robustness an important characteristic of life. Although development has long been viewed as a key component of phenotypic robustness, the underlying mechanism is unclear. Here we report that the determinative developmental cell lineages of two protostomes and one deuterostome are structured such that the resulting cellular compositions of the organisms are only modestly affected by cell deaths. Several features of the cell lineages, including their shallowness, topology, early ontogenic appearances of rare cells, and non-clonality of most cell types, underlie the robustness. Simple simulations of cell lineage evolution demonstrate the possibility that the observed robustness arose as an adaptation in the face of random cell deaths in development. These results reveal general organizing principles of determinative developmental cell lineages and a conceptually new mechanism of phenotypic robustness, both of which have important implications for development and evolution.
Collapse
Affiliation(s)
- Jian-Rong Yang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Shuxiang Ruan
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| |
Collapse
|
12
|
Abstract
Similar to other organisms, necrotic cell death in the nematode Caenorhabditis elegans is manifested as the catastrophic collapse of cellular homeostasis, in response to overwhelming stress that is inflicted either in the form of extreme environmental stimuli or by intrinsic insults such as the expression of proteins carrying deleterious mutations. Remarkably, necrotic cell death in C. elegans and pathological cell death in humans share multiple fundamental features and mechanistic aspects. Therefore, mechanisms mediating necrosis are also conserved across the evolutionary spectrum and render the worm a versatile tool, with the capacity to facilitate studies of human pathologies. Here, we overview necrotic paradigms that have been characterized in the nematode and outline the cellular and molecular mechanisms that mediate this mode of cell demise. In addition, we discuss experimental approaches that utilize C. elegans to elucidate the molecular underpinnings of devastating human disorders that entail necrosis.
Collapse
Affiliation(s)
- Vassiliki Nikoletopoulou
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece.
| |
Collapse
|
13
|
Troulinaki K, Tavernarakis N. Necrotic cell death and neurodegeneration: The involvement of endocytosis and intracellular trafficking. WORM 2013; 1:176-81. [PMID: 24058844 PMCID: PMC3670410 DOI: 10.4161/worm.20457] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 04/20/2012] [Indexed: 11/26/2022]
Abstract
Necrosis, one of the two main types of cell death, contributes critically in many devastating pathological conditions in human, including stroke, ischemia, trauma and neurodegenerative diseases. However, unlike apoptosis, the molecular mechanisms underlying necrotic cell death and neurodegeneration are poorly understood. Caenorhabditis elegans offers a powerful platform for a thorough and systematic dissection of the molecular basis of necrotic cell death. Similarly to humans, neuronal necrosis can be induced by several well-characterized genetic lesions and by adverse environmental conditions in the nematode. The availability of precisely-defined C. elegans neurodegeneration models provides a unique opportunity for comprehensive delineation of the cellular and molecular mechanisms mediating necrotic cell death. Through genetic dissection of such models, we recently uncovered an unexpected requirement for specific proteins involved in endocytosis and intracellular trafficking, in the execution of necrosis. Moreover, initiation of necrotic cell death is accompanied by a sharp increase in the formation of early and recycling endosomes, which subsequently disintegrate during the final stage of cell death. These findings implicate endocytic and intracellular trafficking processes in the cellular destruction during necrosis. Indeed, endocytosis synergizes with two other essential cellular processes, autophagy and lysosomal proteolysis to facilitate necrotic neurodegeneration. In this commentary, we consider the contribution of endocytosis and intracellular trafficking to cell injury and discuss the crosstalk between these processes and other molecular mechanisms that mediate necrosis.
Collapse
Affiliation(s)
- Kostoula Troulinaki
- Institute of Molecular Biology and Biotechnology; Foundation for Research and Technology; Heraklion, Crete Greece
| | | |
Collapse
|
14
|
Li Z, Lu N, He X, Zhou Z. Monitoring the clearance of apoptotic and necrotic cells in the nematode Caenorhabditis elegans. Methods Mol Biol 2013; 1004:183-202. [PMID: 23733578 DOI: 10.1007/978-1-62703-383-1_14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The nematode Caenorhabditis elegans is an excellent model organism for studying the mechanisms -controlling cell death, including apoptosis, a cell suicide event, and necrosis, pathological cell deaths caused by environmental insults or genetic alterations. C. elegans has also been established as a model for understanding how dying cells are cleared from animal bodies. In particular, the transparent nature of worm bodies and eggshells make C. elegans particularly amenable for live-cell microscopy. Here we describe methods for identifying apoptotic and necrotic cells in living C. elegans embryos, larvae, and adults and for monitoring their clearance during development. We further discuss specific methods to distinguish engulfed from unengulfed apoptotic cells, and methods to monitor cellular and molecular events occurring during phagosome maturation. These methods are based on Differential Interference Contrast (DIC) microscopy or fluorescence microscopy using GFP-based reporters.
Collapse
Affiliation(s)
- Zao Li
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | | | | | | |
Collapse
|
15
|
Calixto A, Jara JS, Court FA. Diapause formation and downregulation of insulin-like signaling via DAF-16/FOXO delays axonal degeneration and neuronal loss. PLoS Genet 2012; 8:e1003141. [PMID: 23300463 PMCID: PMC3531479 DOI: 10.1371/journal.pgen.1003141] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Accepted: 10/18/2012] [Indexed: 01/21/2023] Open
Abstract
Axonal degeneration is a key event in the pathogenesis of neurodegenerative conditions. We show here that mec-4d triggered axonal degeneration of Caenorhabditis elegans neurons and mammalian axons share mechanistical similarities, as both are rescued by inhibition of calcium increase, mitochondrial dysfunction, and NMNAT overexpression. We then explore whether reactive oxygen species (ROS) participate in axonal degeneration and neuronal demise. C. elegans dauers have enhanced anti-ROS systems, and dauer mec-4d worms are completely protected from axonal degeneration and neuronal loss. Mechanistically, downregulation of the Insulin/IGF-1-like signaling (IIS) pathway protects neurons from degenerating in a DAF-16/FOXO–dependent manner and is related to superoxide dismutase and catalase-increased expression. Caloric restriction and systemic antioxidant treatment, which decrease oxidative damage, protect C. elegans axons from mec-4d-mediated degeneration and delay Wallerian degeneration in mice. In summary, we show that the IIS pathway is essential in maintaining neuronal homeostasis under pro-degenerative stimuli and identify ROS as a key intermediate of neuronal degeneration in vivo. Since axonal degeneration represents an early pathological event in neurodegeneration, our work identifies potential targets for therapeutic intervention in several conditions characterized by axonal loss and functional impairment. Axonal degeneration and neuronal loss are currently considered crucial pathological factors in neurodegenerative diseases. Therefore, delaying or blocking these procesess is key for neuroprotection. In this work, we used an in vivo approach combining invertebrate (C. elegans) and vertebrate (mice) model systems to identify a novel and unexpected player in the mechanisms of axonal degeneration. Here, we demonstrate that both neuronal somas and axons degenerate through a step dependent on oxidative stress that can be efficiently delayed by genetic downregulation of a pathway controlling oxidative stress resistance. Impressively, we discovered that diapause formation, which is a state related to hibernating conditions, fully prevents neuronal degeneration. We uncovered new players in the degenerative mechanisms of neurons with relevance for several conditions associated to axonal degeneration, such as multiple sclerosis, motoneuron, and Parkinson diseases, offering novel potential targets for neuroprotection.
Collapse
Affiliation(s)
- Andrea Calixto
- Department of Cellular Biology, Faculty of Biology, Pontifical Catholic University of Chile, Santiago, Chile
- * E-mail: (AC); (FAC)
| | - Juan S. Jara
- Millennium Nucleus for Regenerative Biology, Faculty of Biology, Pontifical Catholic University of Chile, Santiago, Chile
| | - Felipe A. Court
- Millennium Nucleus for Regenerative Biology, Faculty of Biology, Pontifical Catholic University of Chile, Santiago, Chile
- NeuroUnion Biomedical Foundation, Santiago, Chile
- * E-mail: (AC); (FAC)
| |
Collapse
|
16
|
Pinto SM, Hengartner MO. Cleaning up the mess: cell corpse clearance in Caenorhabditis elegans. Curr Opin Cell Biol 2012. [PMID: 23206434 DOI: 10.1016/j.ceb.2012.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Genetic and cell biology studies have led to the identification in Caenorhabditis elegans of a set of evolutionary conserved cellular mechanisms responsible for the clearance of apoptotic cells. Based on the phenotype of cell corpse clearance mutants, corpse clearance can be divided into three distinct, but linked steps: corpse recognition, corpse internalization, and corpse degradation. Work in recent years has led to a better understanding of the molecular pathways that mediate each of these steps. Here, we review recent developments in our understanding of in vivo cell corpse clearance in this simple but most elegant model organism.
Collapse
Affiliation(s)
- Sérgio Morgado Pinto
- Institute of Molecular Life Sciences, University of Zurich, 8057 Zurich, Switzerland; Graduate Program in Areas of Basic and Applied Biology (GABBA), Universidade do Porto, Porto, Portugal
| | | |
Collapse
|