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Harders RH, Morthorst TH, Landgrebe LE, Lande AD, Fuglsang MS, Mortensen SB, Feteira-Montero V, Jensen HH, Wesseltoft JB, Olsen A. CED-6/GULP and components of the clathrin-mediated endocytosis machinery act redundantly to correctly display CED-1 on the cell membrane in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2024; 14:jkae088. [PMID: 38696649 PMCID: PMC11228867 DOI: 10.1093/g3journal/jkae088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 04/03/2024] [Accepted: 04/16/2024] [Indexed: 05/04/2024]
Abstract
CED-1 (cell death abnormal) is a transmembrane receptor involved in the recognition of "eat-me" signals displayed on the surface of apoptotic cells and thus central for the subsequent engulfment of the cell corpse in Caenorhabditis elegans. The roles of CED-1 in engulfment are well established, as are its downstream effectors. The latter include the adapter protein CED-6/GULP and the ATP-binding cassette family homolog CED-7. However, how CED-1 is maintained on the plasma membrane in the absence of engulfment is currently unknown. Here, we show that CED-6 and CED-7 have a novel role in maintaining CED-1 correctly on the plasma membrane. We propose that the underlying mechanism is via endocytosis as CED-6 and CED-7 act redundantly with clathrin and its adaptor, the Adaptor protein 2 complex, in ensuring correct CED-1 localization. In conclusion, CED-6 and CED-7 impact other cellular processes than engulfment of apoptotic cells.
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Affiliation(s)
- Rikke Hindsgaul Harders
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
| | - Tine H Morthorst
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, Aarhus, DK-8000, Denmark
| | - Line E Landgrebe
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, Aarhus, DK-8000, Denmark
| | - Anna D Lande
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, Aarhus, DK-8000, Denmark
| | - Marie Sikjær Fuglsang
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, Aarhus, DK-8000, Denmark
| | - Stine Bothilde Mortensen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
| | - Verónica Feteira-Montero
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
| | - Helene Halkjær Jensen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
| | - Jonas Bruhn Wesseltoft
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
| | - Anders Olsen
- Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, Aalborg, DK-9220, Denmark
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2
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Ma Y, Jiang T, Zhu X, Xu Y, Wan K, Zhang T, Xie M. Efferocytosis in dendritic cells: an overlooked immunoregulatory process. Front Immunol 2024; 15:1415573. [PMID: 38835772 PMCID: PMC11148234 DOI: 10.3389/fimmu.2024.1415573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 05/09/2024] [Indexed: 06/06/2024] Open
Abstract
Efferocytosis, the process of engulfing and removing apoptotic cells, plays an essential role in preserving tissue health and averting undue inflammation. While macrophages are primarily known for this task, dendritic cells (DCs) also play a significant role. This review delves into the unique contributions of various DC subsets to efferocytosis, highlighting the distinctions in how DCs and macrophages recognize and handle apoptotic cells. It further explores how efferocytosis influences DC maturation, thereby affecting immune tolerance. This underscores the pivotal role of DCs in orchestrating immune responses and sustaining immune equilibrium, providing new insights into their function in immune regulation.
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Affiliation(s)
- Yanyan Ma
- Department of Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Tangxing Jiang
- Department of Emergency Medicine, Qilu Hospital of Shandong University, Jinan, China
| | - Xun Zhu
- Department of Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Yizhou Xu
- Department of Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Ke Wan
- Department of Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Tingxuan Zhang
- Department of Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Miaorong Xie
- Department of Emergency and Critical Care Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China
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3
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Yarychkivska O, Sharmin R, Elkhalil A, Ghose P. Apoptosis and beyond: A new era for programmed cell death in Caenorhabditis elegans. Semin Cell Dev Biol 2024; 154:14-22. [PMID: 36792437 DOI: 10.1016/j.semcdb.2023.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Revised: 01/27/2023] [Accepted: 02/02/2023] [Indexed: 02/16/2023]
Abstract
Programmed cell death (PCD) is crucial for normal development and homeostasis. Our first insights into the genetic regulation of apoptotic cell death came from in vivo studies in the powerful genetic model system of C. elegans. More recently, novel developmental cell death programs occurring both embryonically and post-embryonically, and sex-specifically, have been elucidated. Recent studies in the apoptotic setting have also shed new light on the intricacies of phagocytosis in particular. This review provides a brief historical perspective of the origins of PCD studies in C. elegans, followed by a more detailed description of non-canonical apoptotic and non-apoptotic death programs. We conclude by posing open questions and commenting on our outlook on the future of PCD studies in C. elegans, highlighting the importance of advanced imaging tools and the continued leveraging of C. elegans genetics both with classical and modern cutting-edge approaches.
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Affiliation(s)
| | | | | | - Piya Ghose
- The University of Texas at Arlington, USA.
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4
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Benson CA, Olson KL, Patwa S, Kauer SD, King JF, Waxman SG, Tan AM. Conditional Astrocyte Rac1KO Attenuates Hyperreflexia after Spinal Cord Injury. J Neurosci 2024; 44:e1670222023. [PMID: 37963762 PMCID: PMC10851682 DOI: 10.1523/jneurosci.1670-22.2023] [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: 09/01/2022] [Revised: 08/24/2023] [Accepted: 09/19/2023] [Indexed: 11/16/2023] Open
Abstract
Spasticity is a hyperexcitability disorder that adversely impacts functional recovery and rehabilitative efforts after spinal cord injury (SCI). The loss of evoked rate-dependent depression (RDD) of the monosynaptic H-reflex is indicative of hyperreflexia, a physiological sign of spasticity. Given the intimate relationship between astrocytes and neurons, that is, the tripartite synapse, we hypothesized that astrocytes might have a significant role in post-injury hyperreflexia and plasticity of neighboring neuronal synaptic dendritic spines. Here, we investigated the effect of selective Rac1KO in astrocytes (i.e., adult male and female mice, transgenic cre-flox system) on SCI-induced spasticity. Three weeks after a mild contusion SCI, control Rac1wt animals displayed a loss of H-reflex RDD, that is, hyperreflexia. In contrast, transgenic animals with astrocytic Rac1KO demonstrated near-normal H-reflex RDD similar to pre-injury levels. Reduced hyperreflexia in astrocytic Rac1KO animals was accompanied by a loss of thin-shaped dendritic spine density on α-motor neurons in the ventral horn. In SCI-Rac1wt animals, as expected, we observed the development of dendritic spine dysgenesis on α-motor neurons associated with spasticity. As compared with WT animals, SCI animals with astrocytic Rac1KO expressed increased levels of the glial-specific glutamate transporter, glutamate transporter-1 in the ventral spinal cord, potentially enhancing glutamate clearance from the synaptic cleft and reducing hyperreflexia in astrocytic Rac1KO animals. Taken together, our findings show for the first time that Rac1 activity in astrocytes can contribute to hyperreflexia underlying spasticity following SCI. These results reveal an opportunity to target cell-specific molecular regulators of H-reflex excitability to manage spasticity after SCI.Significance Statement Spinal cord injury leads to stretch reflex hyperexcitability, which underlies the clinical symptom of spasticity. This study shows for the first time that astrocytic Rac1 contributes to the development of hyperreflexia after SCI. Specifically, astrocytic Rac1KO reduced SCI-related H-reflex hyperexcitability, decreased dendritic spine dysgenesis on α-motor neurons, and elevated the expression of the astrocytic glutamate transporter-1 (GLT-1). Overall, this study supports a distinct role for astrocytic Rac1 signaling within the spinal reflex circuit and the development of SCI-related spasticity.
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Affiliation(s)
- Curtis A Benson
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Kai-Lan Olson
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Siraj Patwa
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Sierra D Kauer
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Jared F King
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Stephen G Waxman
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Andrew M Tan
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510,
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
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5
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Gao Y, Jiao Y, Gong X, Liu J, Xiao H, Zheng Q. Role of transcription factors in apoptotic cells clearance. Front Cell Dev Biol 2023; 11:1110225. [PMID: 36743409 PMCID: PMC9892555 DOI: 10.3389/fcell.2023.1110225] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 01/09/2023] [Indexed: 01/20/2023] Open
Abstract
The human body generates 10-100 billion cells every day, and the same number of cells die to maintain homeostasis. The genetically controlled, autonomously ordered cell death mainly proceeds by apoptosis. Apoptosis is an important way of programmed cell death in multicellular organisms, timely and effective elimination of apoptotic cells plays a key role in the growth and development of organisms and the maintenance of homeostasis. During the clearance of apoptotic cells, transcription factors bind to specific target promoters and act as activators or repressors to regulate multiple genes expression, how transcription factors regulate apoptosis is an important and poorly understood aspect of normal development. This paper summarizes the regulatory mechanisms of transcription factors in the clearance of apoptotic cells to date.
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Affiliation(s)
| | | | | | | | - Hui Xiao
- *Correspondence: Hui Xiao, ; Qian Zheng,
| | - Qian Zheng
- *Correspondence: Hui Xiao, ; Qian Zheng,
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6
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Yuan L, Li P, Jing H, Zheng Q, Xiao H. trim-21 promotes proteasomal degradation of CED-1 for apoptotic cell clearance in C. elegans. eLife 2022; 11:76436. [PMID: 35929733 PMCID: PMC9388098 DOI: 10.7554/elife.76436] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 08/02/2022] [Indexed: 11/13/2022] Open
Abstract
The phagocytic receptor CED-1 mediates apoptotic cell recognition by phagocytic cells, enabling cell corpse clearance in Caenorhabditis elegans. Whether appropriate levels of CED-1 are maintained for executing the engulfment function remains unknown. Here, we identified the C. elegans E3 ubiquitin ligase tripartite motif containing-21 (TRIM-21) as a component of the CED-1 pathway for apoptotic cell clearance. When the NPXY motif of CED-1 was bound to the adaptor protein CED-6 or the YXXL motif of CED-1 was phosphorylated by tyrosine kinase SRC-1 and subsequently bound to the adaptor protein NCK-1 containing the SH2 domain, TRIM-21 functioned in conjunction with UBC-21 to catalyze K48-linked poly-ubiquitination on CED-1, targeting it for proteasomal degradation. In the absence of TRIM-21, CED-1 accumulated post-translationally and drove cell corpse degradation defects, as evidenced by direct binding to VHA-10. These findings reveal a unique mechanism for the maintenance of appropriate levels of CED-1 to regulate apoptotic cell clearance.
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Affiliation(s)
- Lei Yuan
- College of Life Sciences, Shaanxi Normal University, Xi'An, China
| | - Peiyao Li
- College of Life Sciences, Shaanxi Normal University, Xi'An, China
| | - Huiru Jing
- College of Life Sciences, Shaanxi Normal University, Xi'An, China
| | - Qian Zheng
- College of Life Sciences, Shaanxi Normal University, Xi'An, China
| | - Hui Xiao
- College of Life Sciences, Shaanxi Normal University, Xi'An, China
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7
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Odiba AS, Ezechukwu CS, Liao G, Li S, Chen Z, Liu X, Fang W, Jin C, Wang B. Loss of NSE-4 Perturbs Genome Stability and DNA Repair in Caenorhabditis elegans. Int J Mol Sci 2022; 23:ijms23137202. [PMID: 35806213 PMCID: PMC9266361 DOI: 10.3390/ijms23137202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 05/15/2022] [Accepted: 05/24/2022] [Indexed: 02/04/2023] Open
Abstract
The Structural Maintenance of Chromosomes (SMC) complex plays an important role in maintaining chromosome integrity, in which the SMC5/6 complex occupies a central position by facilitating mitotic and meiotic processes as well as DNA repair. NSE-4 Kleisin is critical for both the organization and function of the SMC5/6 complex, bridging NSE1 and NSE3 (MAGE related) with the head domains of the SMC5 and SMC6 proteins. Despite the conservation in protein sequence, no functional relevance of the NSE-4 homologous protein (NSE-4) in Caenorhabditis elegans has been reported. Here, we demonstrated the essential role of C. elegans NSE-4 in genome maintenance and DNA repair. Our results showed that NSE-4 is essential for the maintenance of chromosomal structure and repair of a range of chemically induced DNA damage. Furthermore, NSE-4 is involved in inter-sister repair during meiosis. NSE-4 localizes on the chromosome and is indispensable for the localization of NSE-1. Collectively, our data from this study provide further insight into the evolutionary conservation and diversification of NSE-4 function in the SMC-5/6 complex.
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Affiliation(s)
- Arome Solomon Odiba
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
- Department of Genetics and Biotechnology, University of Nigeria, Nsukka 410001, Nigeria
| | - Chiemekam Samuel Ezechukwu
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
- Department of Zoology and Environmental Biology, University of Nigeria, Nsukka 410001, Nigeria
| | - Guiyan Liao
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
- Correspondence: (G.L.); (B.W.)
| | - Siqiao Li
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
| | - Zhongliang Chen
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Z.C.); (X.L.)
| | - Xihui Liu
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Z.C.); (X.L.)
| | - Wenxia Fang
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
| | - Cheng Jin
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Bin Wang
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning 530007, China; (A.S.O.); (C.S.E.); (S.L.); (W.F.); (C.J.)
- Guangxi Key Laboratory of Sugarcane Genetic Improvement, Sugarcane Research Institute, Guangxi Academy of Agricultural Sciences, Nanning 530007, China; (Z.C.); (X.L.)
- Correspondence: (G.L.); (B.W.)
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8
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Peña-Ramos O, Chiao L, Liu X, Yu X, Yao T, He H, Zhou Z. Autophagosomes fuse to phagosomes and facilitate the degradation of apoptotic cells in Caenorhabditis elegans. eLife 2022; 11:72466. [PMID: 34982028 PMCID: PMC8769646 DOI: 10.7554/elife.72466] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 01/03/2022] [Indexed: 12/17/2022] Open
Abstract
Autophagosomes are double-membrane intracellular vesicles that degrade protein aggregates, intracellular organelles, and other cellular components. During the development of the nematode Caenorhabditis elegans, many somatic and germ cells undergo apoptosis. These cells are engulfed and degraded by their neighboring cells. We discovered a novel role of autophagosomes in facilitating the degradation of apoptotic cells using a real-time imaging technique. Specifically, the double-membrane autophagosomes in engulfing cells are recruited to the surfaces of phagosomes containing apoptotic cells and subsequently fuse to phagosomes, allowing the inner vesicle to enter the phagosomal lumen. Mutants defective in the production of autophagosomes display significant defects in the degradation of apoptotic cells, demonstrating the importance of autophagosomes to this process. The signaling pathway led by the phagocytic receptor CED-1, the adaptor protein CED-6, and the large GTPase dynamin (DYN-1) promotes the recruitment of autophagosomes to phagosomes. Moreover, the subsequent fusion of autophagosomes with phagosomes requires the functions of the small GTPase RAB-7 and the HOPS complex. Further observations suggest that autophagosomes provide apoptotic cell-degradation activities in addition to and in parallel of lysosomes. Our findings reveal that, unlike the single-membrane, LC3-associated phagocytosis (LAP) vesicles reported to facilitate phagocytosis in mammals, it is the canonical double-membrane autophagosomes that facilitate the clearance of C. elegans apoptotic cells. These findings add autophagosomes to the collection of intracellular organelles that contribute to phagosome maturation, identify novel crosstalk between the autophagy and phagosome maturation pathways, and discover the upstream signaling molecules that initiate this crosstalk.
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Affiliation(s)
- Omar Peña-Ramos
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
| | - Lucia Chiao
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
| | - Xianghua Liu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
| | - Xiaomeng Yu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
| | - Tianyou Yao
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
| | - Henry He
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
| | - Zheng Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, United States
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9
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Lukácsi S, Farkas Z, Saskői É, Bajtay Z, Takács-Vellai K. Conserved and Distinct Elements of Phagocytosis in Human and C. elegans. Int J Mol Sci 2021; 22:ijms22168934. [PMID: 34445642 PMCID: PMC8396242 DOI: 10.3390/ijms22168934] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/12/2021] [Accepted: 08/17/2021] [Indexed: 12/12/2022] Open
Abstract
Endocytosis provides the cellular nutrition and homeostasis of organisms, but pathogens often take advantage of this entry point to infect host cells. This is counteracted by phagocytosis that plays a key role in the protection against invading microbes both during the initial engulfment of pathogens and in the clearance of infected cells. Phagocytic cells balance two vital functions: preventing the accumulation of cell corpses to avoid pathological inflammation and autoimmunity, whilst maintaining host defence. In this review, we compare elements of phagocytosis in mammals and the nematode Caenorhabditis elegans. Initial recognition of infection requires different mechanisms. In mammals, pattern recognition receptors bind pathogens directly, whereas activation of the innate immune response in the nematode rather relies on the detection of cellular damage. In contrast, molecules involved in efferocytosis—the engulfment and elimination of dying cells and cell debris—are highly conserved between the two species. Therefore, C. elegans is a powerful model to research mechanisms of the phagocytic machinery. Finally, we show that both mammalian and worm studies help to understand how the two phagocytic functions are interconnected: emerging data suggest the activation of innate immunity as a consequence of defective apoptotic cell clearance.
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Affiliation(s)
- Szilvia Lukácsi
- MTA-ELTE Immunology Research Group, Eötvös Loránd Research Network (ELKH), Eötvös Loránd University, Pázmány Péter s. 1/C, 1117 Budapest, Hungary; (S.L.); (Z.B.)
| | - Zsolt Farkas
- Department of Biological Anthropology, Eötvös Loránd University, Pázmány Péter s. 1/C, 1117 Budapest, Hungary; (Z.F.); (É.S.)
| | - Éva Saskői
- Department of Biological Anthropology, Eötvös Loránd University, Pázmány Péter s. 1/C, 1117 Budapest, Hungary; (Z.F.); (É.S.)
| | - Zsuzsa Bajtay
- MTA-ELTE Immunology Research Group, Eötvös Loránd Research Network (ELKH), Eötvös Loránd University, Pázmány Péter s. 1/C, 1117 Budapest, Hungary; (S.L.); (Z.B.)
- Department of Immunology, Eötvös Loránd University, Pázmány Péter s. 1/C, 1117 Budapest, Hungary
| | - Krisztina Takács-Vellai
- Department of Biological Anthropology, Eötvös Loránd University, Pázmány Péter s. 1/C, 1117 Budapest, Hungary; (Z.F.); (É.S.)
- Correspondence:
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10
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Yang Y, Dong W, Wu Q, Wang D. Response of G protein-coupled receptor CED-1 in germline to polystyrene nanoparticles in Caenorhabditis elegans. NANOSCALE ADVANCES 2021; 3:1997-2006. [PMID: 36133095 PMCID: PMC9419163 DOI: 10.1039/d0na00867b] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 02/16/2021] [Indexed: 05/30/2023]
Abstract
The deposition of a certain amount of nanopolystyrene (NPS) can be observed in the gonad of Caenorhabditis elegans. However, we still know little about the response of germline towards NPS exposure. In the germline of C. elegans, NPS (1-1000 μg L-1) increased the expression levels of two G protein-coupled receptors (GPCRs), namely PAQR-2 and CED-1. Moreover, susceptibility to NPS toxicity was observed in ced-1(RNAi) worms, which suggested that the protective response of germline was mediated by GPCR CED-1. In the germline, five proteins (CED-10, VPS-34, SNX-1, RAB-7, and RAB-14) functioned as downstream targets of GPCR CED-1 in controlling NPS toxicity. Furthermore, these five targets in the germline regulated NPS toxicity by affecting the activities of p38 MAPK and insulin signaling pathways in intestinal cells. Therefore, we raised a GPCR CED-1-mediated signaling cascade in the germline in response to NPS exposure, which is helpful for understanding the molecular basis of the germline in response to NPS exposure.
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Affiliation(s)
- Yunhan Yang
- Medical School, Southeast University Nanjing 210009 China
| | - Wenting Dong
- Medical School, Southeast University Nanjing 210009 China
| | - Qiuli Wu
- Medical School, Southeast University Nanjing 210009 China
| | - Dayong Wang
- Medical School, Southeast University Nanjing 210009 China
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11
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Cherra SJ, Goncharov A, Boassa D, Ellisman M, Jin Y. C. elegans MAGU-2/Mpp5 homolog regulates epidermal phagocytosis and synapse density. J Neurogenet 2020; 34:298-306. [PMID: 32366143 DOI: 10.1080/01677063.2020.1726915] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Synapses are dynamic connections that underlie essential functions of the nervous system. The addition, removal, and maintenance of synapses govern the flow of information in neural circuits throughout the lifetime of an animal. While extensive studies have elucidated many intrinsic mechanisms that neurons employ to modulate their connections, increasing evidence supports the roles of non-neuronal cells, such as glia, in synapse maintenance and circuit function. We previously showed that C. elegans epidermis regulates synapses through ZIG-10, a cell-adhesion protein of the immunoglobulin domain superfamily. Here we identified a member of the Pals1/MPP5 family, MAGU-2, that functions in the epidermis to modulate phagocytosis and the number of synapses by regulating ZIG-10 localization. Furthermore, we used light and electron microscopy to show that this epidermal mechanism removes neuronal membranes from the neuromuscular junction, dependent on the conserved phagocytic receptor CED-1. Together, our study shows that C. elegans epidermis constrains synaptic connectivity, in a manner similar to astrocytes and microglia in mammals, allowing optimized output of neural circuits.
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Affiliation(s)
- Salvatore J Cherra
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA.,Department of Neuroscience, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Alexandr Goncharov
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA
| | - Daniela Boassa
- National Center for Microscopy and Imaging Research, University of California San Diego, La Jolla, CA, USA
| | - Mark Ellisman
- National Center for Microscopy and Imaging Research, University of California San Diego, La Jolla, CA, USA.,Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, CA, USA.,Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA.,Department of Cellular and Molecular Medicine, School of Medicine, University of California San Diego, La Jolla, CA, USA
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12
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Duong T, Rasmussen NR, Ballato E, Mote FS, Reiner DJ. The Rheb-TORC1 signaling axis functions as a developmental checkpoint. Development 2020; 147:dev.181727. [PMID: 32041790 DOI: 10.1242/dev.181727] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 01/22/2020] [Indexed: 12/12/2022]
Abstract
In many eukaryotes, the small GTPase Rheb functions as a switch to toggle activity of TOR complex 1 (TORC1) between anabolism and catabolism, thus controlling lifespan, development and autophagy. Our CRISPR-generated, fluorescently tagged endogenous Caenorhabditis elegans RHEB-1 and DAF-15/Raptor are expressed ubiquitously and localize to lysosomes. LET-363/TOR and DAF-15/Raptor are required for development beyond the third larval stage (L3). We observed that deletion of RHEB-1 similarly conferred L3 arrest. Unexpectedly, robust RNAi-mediated depletion of TORC1 components caused arrest at stages prior to L3. Accordingly, conditional depletion of endogenous DAF-15/Raptor in the soma revealed that TORC1 is required at each stage of the life cycle to progress to the next stage. Reversal of DAF-15 depletion permits arrested animals to recover to continue development. Our results are consistent with TORC1 functioning as a developmental checkpoint that governs the decision of the animal to progress through development.
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Affiliation(s)
- Tam Duong
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Texas A&M University, Houston, TX 77030, USA
| | - Neal R Rasmussen
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Texas A&M University, Houston, TX 77030, USA
| | - Elliot Ballato
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Texas A&M University, Houston, TX 77030, USA
| | - F Sefakor Mote
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Texas A&M University, Houston, TX 77030, USA
| | - David J Reiner
- Center for Translational Cancer Research, Institute of Biosciences and Technology, Texas A&M Health Science Center, Texas A&M University, Houston, TX 77030, USA
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13
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Haley R, Zhou Z. The small GTPase RAB-35 facilitates the initiation of phagosome maturation and acts as a robustness factor for apoptotic cell clearance. Small GTPases 2019; 12:188-201. [PMID: 31607221 DOI: 10.1080/21541248.2019.1680066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
We recently identified the novel function of the small GTPase RAB-35 in apoptotic cell clearance in Caenorhabditis elegans, a process in which dying cells are engulfed and degraded inside phagosomes. We have found that RAB-35 functions in two separate steps of cell corpse clearance, cell corpse recognition and the initiation of phagosome maturation. During the latter process, RAB-35 facilitates the removal of phosphatidylinositol-4,5-bisphosphate (PI(4,5)P2) from the membranes of nascent phagosomes and the simultaneous production of phosphatidylinositol-3-P (PI(3)P) on these same membranes, a process that we have coined the PI(4,5)P2 to PI(3)P shift. RAB-35 also promotes the recruitment of the small GTPase RAB-5 to the phagosomal surface. During these processes, the activity of RAB-35 is controlled by the candidate GTPase-activating protein (GAP) TBC-10 and the candidate guanine nucleotide exchange factor (GEF) FLCN-1. Overall, RAB-35 leads a third pathway during cell corpse clearance that functions in parallel to the two known pathways, one led by the phagocytic receptor CED-1 and the other led by the CED-10/Rac1 GTPase. Here, we further report that RAB-35 acts as a robustness factor that maintains the clearance activity and embryonic viability under conditions of heat stress. Moreover, we obtained additional evidence suggesting that RAB-35 acts upstream of RAB-5 and RAB-7. To establish a precise temporal pattern for its own dissociation from phagosomal surfaces, RAB-35 controls the removal of its own GAP. We propose that RAB-35 defines a largely unexplored initial phase of phagosome maturation.
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Affiliation(s)
- Ryan Haley
- 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
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14
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Di G, Li Y, Zhao X, Wang N, Fu J, Li M, Huang M, You W, Kong X, Ke C. Differential proteomic profiles and characterizations between hyalinocytes and granulocytes in ivory shell Babylonia areolata. FISH & SHELLFISH IMMUNOLOGY 2019; 92:405-420. [PMID: 31212011 DOI: 10.1016/j.fsi.2019.06.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/11/2019] [Accepted: 06/13/2019] [Indexed: 06/09/2023]
Abstract
The haemocytes of the ivory shell, Babylonia areolata are classified by morphologic observation into the following types: hyalinocytes (H) and granulocytes (G). Haemocytes comprise diverse cell types with morphological and functional heterogene and play indispensable roles in immunological homeostasis of invertebrates. In the present study, two types of haemocytes were morphologically identified and separated as H and G by Percoll density gradient centrifugation. The differentially expressed proteins were investigated between H and G using mass spectrometry. The results showed that total quantitative proteins between H and G samples were 1644, the number of up-regulated proteins in G was 215, and the number of down-regulated proteins in G was 378. Among them, cathepsin, p38 MAPK, toll-interacting protein-like and beta-adrenergic receptor kinase 2-like were up-regulated in G; alpha-2-macroglobulin-like protein, C-type lectin, galectin-2-1, galectin-3, β-1,3-glucan-binding protein, ferritin, mega-hemocyanin, mucin-17-like, mucin-5AC-like and catalytic subunit of protein kinase A were down-regulated in G. The results showed that the most significantly enriched KEGG pathways were the pathways related to ribosome, phagosome, endocytosis, carbon metabolism, protein processing in endoplasmic reticulum and oxidative phosphorylation. For phagosome and endocytosis pathway, the number of down-regulation proteins in G was more than that of up-regulation proteins. For lysosome pathway, the number of up-regulation proteins in G was more than that of down-regulation proteins. These results suggested that two sub-population haemocytes perform the different immune functions in B. areolata.
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Affiliation(s)
- Guilan Di
- College of Fisheries, Henan Normal University, Xinxiang, 453007, China
| | - Yanfei Li
- College of Fisheries, Henan Normal University, Xinxiang, 453007, China
| | - Xianliang Zhao
- College of Fisheries, Henan Normal University, Xinxiang, 453007, China
| | - Ning Wang
- College of Fisheries, Henan Normal University, Xinxiang, 453007, China
| | - Jingqiang Fu
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Min Li
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Miaoqin Huang
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Weiwei You
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
| | - Xianghui Kong
- College of Fisheries, Henan Normal University, Xinxiang, 453007, China.
| | - Caihuan Ke
- State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China.
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15
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Farkas Z, Petric M, Liu X, Herit F, Rajnavölgyi É, Szondy Z, Budai Z, Orbán TI, Sándor S, Mehta A, Bajtay Z, Kovács T, Jung SY, Afaq Shakir M, Qin J, Zhou Z, Niedergang F, Boissan M, Takács-Vellai K. The nucleoside diphosphate kinase NDK-1/NME1 promotes phagocytosis in concert with DYN-1/Dynamin. FASEB J 2019; 33:11606-11614. [PMID: 31242766 PMCID: PMC6819981 DOI: 10.1096/fj.201900220r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Phagocytosis of various targets, such as apoptotic cells or opsonized pathogens, by macrophages is coordinated by a complex signaling network initiated by distinct phagocytic receptors. Despite the different initial signaling pathways, each pathway ends up regulating the actin cytoskeletal network, phagosome formation and closure, and phagosome maturation leading to degradation of the engulfed particle. Herein, we describe a new phagocytic function for the nucleoside diphosphate kinase 1 (NDK-1), the nematode counterpart of the first identified metastasis inhibitor NM23-H1 (nonmetastatic clone number 23) nonmetastatic clone number 23 or nonmetastatic isoform 1 (NME1). We reveal by coimmunoprecipitation, Duolink proximity ligation assay, and mass spectrometry that NDK-1/NME1 works in a complex with DYN-1/Dynamin (Caenorhabditis elegans/human homolog proteins), which is essential for engulfment and phagosome maturation. Time-lapse microscopy shows that NDK-1 is expressed on phagosomal surfaces during cell corpse clearance in the same time window as DYN-1. Silencing of NM23-M1 in mouse bone marrow–derived macrophages resulted in decreased phagocytosis of apoptotic thymocytes. In human macrophages, NM23-H1 and Dynamin are corecruited at sites of phagosome formation in F-actin–rich cups. In addition, NM23-H1 was required for efficient phagocytosis. Together, our data demonstrate that NDK-1/NME1 is an evolutionarily conserved element of successful phagocytosis.—Farkas, Z., Petric, M., Liu, X., Herit, F., Rajnavölgyi, É., Szondy, Z., Budai, Z., Orbán, T. I., Sándor, S., Mehta, A., Bajtay, Z., Kovács, T., Jung, S. Y., Afaq Shakir, M., Qin, J., Zhou, Z., Niedergang, F., Boissan, M., Takács-Vellai, K. The nucleoside diphosphate kinase NDK-1/NME1 promotes phagocytosis in concert with DYN-1/dynamin.
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Affiliation(s)
- Zsolt Farkas
- Department of Biological Anthropology, Eötvös Loránd University, Budapest, Hungary
| | - Metka Petric
- INSERM, Unité 1016, Institut Cochin, Paris, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Xianghua Liu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Floriane Herit
- INSERM, Unité 1016, Institut Cochin, Paris, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Éva Rajnavölgyi
- Department of Immunology, University of Debrecen, Debrecen, Hungary
| | - Zsuzsa Szondy
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Zsófia Budai
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Tamás I Orbán
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Sára Sándor
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Anil Mehta
- Division of Medical Sciences, Ninewells Hospital Medical School, Dundee, United Kingdom
| | - Zsuzsa Bajtay
- Department of Immunology and MTA-ELTE Immunology Research Group, Eötvös Loránd University, Budapest, Hungary
| | - Tibor Kovács
- Department of Genetics, Eötvös Loránd University, Budapest, Hungary
| | - Sung Yun Jung
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA.,Verna and Marrs McLean Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas, USA
| | - Muhammed Afaq Shakir
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Jun Qin
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA.,Verna and Marrs McLean Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas, USA
| | - Zheng Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, USA
| | - Florence Niedergang
- INSERM, Unité 1016, Institut Cochin, Paris, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche (UMR) 8104, Paris, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Mathieu Boissan
- Sorbonne Université, University Pierre and Marie Curie (UPMC) Paris 06, INSERM, Unité Mixte de Recherche (UMR) S938, Saint-Antoine Research Center, Paris, France; and.,Assistance Publique-Hôpitaux de Paris (AP-HP), Hospital Tenon, Service de Biochimie et Hormonologie, Paris, France
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16
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Morris C, Foster OK, Handa S, Peloza K, Voss L, Somhegyi H, Jian Y, Vo MV, Harp M, Rambo FM, Yang C, Hermann GJ. Function and regulation of the Caenorhabditis elegans Rab32 family member GLO-1 in lysosome-related organelle biogenesis. PLoS Genet 2018; 14:e1007772. [PMID: 30419011 PMCID: PMC6268011 DOI: 10.1371/journal.pgen.1007772] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 11/30/2018] [Accepted: 10/17/2018] [Indexed: 02/07/2023] Open
Abstract
Cell type-specific modifications of conventional endosomal trafficking pathways lead to the formation of lysosome-related organelles (LROs). C. elegans gut granules are intestinally restricted LROs that coexist with conventional degradative lysosomes. The formation of gut granules requires the Rab32 family member GLO-1. We show that the loss of glo-1 leads to the mistrafficking of gut granule proteins but does not significantly alter conventional endolysosome biogenesis. GLO-3 directly binds to CCZ-1 and they both function to promote the gut granule association of GLO-1, strongly suggesting that together, GLO-3 and CCZ-1 activate GLO-1. We found that a point mutation in GLO-1 predicted to spontaneously activate, and function independently of it guanine nucleotide exchange factor (GEF), localizes to gut granules and partially restores gut granule protein localization in ccz-1(-) and glo-3(-) mutants. CCZ-1 forms a heterodimeric complex with SAND-1(MON1), which does not function in gut granule formation, to activate RAB-7 in trafficking pathways to conventional lysosomes. Therefore, our data suggest a model whereby the function of a Rab GEF can be altered by subunit exchange. glo-3(-) mutants, which retain low levels of GLO-3 activity, generate gut granules that lack GLO-1 and improperly accumulate RAB-7 in a SAND-1 dependent process. We show that GLO-1 and GLO-3 restrict the distribution of RAB-7 to conventional endolysosomes, providing insights into the segregation of pathways leading to conventional lysosomes and LROs.
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Affiliation(s)
- Caitlin Morris
- Department of Biology, Lewis & Clark College, Portland, Oregon, United States of America
| | - Olivia K. Foster
- Department of Biology, Lewis & Clark College, Portland, Oregon, United States of America
| | - Simran Handa
- Department of Biology, Lewis & Clark College, Portland, Oregon, United States of America
| | - Kimberly Peloza
- Department of Biology, Lewis & Clark College, Portland, Oregon, United States of America
| | - Laura Voss
- Department of Biology, Lewis & Clark College, Portland, Oregon, United States of America
| | - Hannah Somhegyi
- Department of Biology, Lewis & Clark College, Portland, Oregon, United States of America
| | - Youli Jian
- State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - My Van Vo
- Department of Biology, Lewis & Clark College, Portland, Oregon, United States of America
| | - Marie Harp
- Department of Biology, Lewis & Clark College, Portland, Oregon, United States of America
| | - Fiona M. Rambo
- Department of Biology, Lewis & Clark College, Portland, Oregon, United States of America
| | - Chonglin Yang
- State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Greg J. Hermann
- Department of Biology, Lewis & Clark College, Portland, Oregon, United States of America
- * E-mail:
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17
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Kutscher LM, Keil W, Shaham S. RAB-35 and ARF-6 GTPases Mediate Engulfment and Clearance Following Linker Cell-Type Death. Dev Cell 2018; 47:222-238.e6. [PMID: 30220571 PMCID: PMC6200590 DOI: 10.1016/j.devcel.2018.08.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 07/18/2018] [Accepted: 08/17/2018] [Indexed: 12/11/2022]
Abstract
Clearance of dying cells is essential for development and homeostasis. Conserved genes mediate apoptotic cell removal, but whether these genes control non-apoptotic cell removal is a major open question. Linker cell-type death (LCD) is a prevalent non-apoptotic developmental cell death process with features conserved from C. elegans to vertebrates. Using microfluidics-based long-term in vivo imaging, we show that unlike apoptotic cells, the C. elegans linker cell, which dies by LCD, is competitively phagocytosed by two neighboring cells, resulting in cell splitting. Subsequent cell elimination does not require apoptotic engulfment genes. Rather, we find that RAB-35 GTPase is a key coordinator of competitive phagocytosis onset and cell degradation. RAB-35 binds CNT-1, an ARF-6 GTPase activating protein, and removes ARF-6, a degradation inhibitor, from phagosome membranes. This facilitates phosphatidylinositol-4,5-bisphosphate removal from phagosome membranes, promoting phagolysosome maturation. Our studies suggest that RAB-35 and ARF-6 drive a conserved program eliminating cells dying by LCD.
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Affiliation(s)
- Lena M Kutscher
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY 10065, USA
| | - Wolfgang Keil
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY 10065, USA; Center for Studies in Physics and Biology, The Rockefeller University, New York, NY 10065, USA
| | - Shai Shaham
- Laboratory of Developmental Genetics, The Rockefeller University, New York, NY 10065, USA.
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18
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Haley R, Wang Y, Zhou Z. The small GTPase RAB-35 defines a third pathway that is required for the recognition and degradation of apoptotic cells. PLoS Genet 2018; 14:e1007558. [PMID: 30138370 PMCID: PMC6107108 DOI: 10.1371/journal.pgen.1007558] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/12/2018] [Indexed: 01/18/2023] Open
Abstract
In metazoans, apoptotic cells are swiftly engulfed by phagocytes and degraded inside phagosomes. Multiple small GTPases in the Rab family are known to function in phagosome maturation by regulating vesicle trafficking. We discovered rab-35 as a new gene important for apoptotic cell clearance from a genetic screen targeting putative Rab GTPases in Caenorhabditis elegans. We further identified TBC-10 as a putative GTPase-activating protein (GAP), and FLCN-1 and RME-4 as two putative Guanine Nucleotide Exchange Factors (GEFs), for RAB-35. We found that RAB-35 was required for the efficient incorporation of early endosomes to phagosomes and for the timely degradation of apoptotic cell corpses. More specifically, RAB-35 promotes two essential events that initiate phagosome maturation: the switch of phagosomal membrane phosphatidylinositol species from PtdIns(4,5)P2 to PtdIns(3)P, and the recruitment of the small GTPase RAB-5 to phagosomal surfaces. These functions of RAB-35 were previously unknown. Remarkably, although the phagocytic receptor CED-1 regulates these same events, RAB-35 and CED-1 appear to function independently. Upstream of degradation, RAB-35 also facilitates the recognition of apoptotic cells independently of the known CED-1 and CED-5 pathways. RAB-35 localizes to extending pseudopods and is further enriched on nascent phagosomes, consistent with its dual roles in regulating apoptotic cell-recognition and phagosome maturation. Epistasis analyses indicate that rab-35 acts in parallel to both of the canonical ced-1/6/7 and ced-2/5/10/12 clearance pathways. We propose that RAB-35 acts as a robustness factor, defining a novel pathway that aids these canonical pathways in both the recognition and degradation of apoptotic cells.
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Affiliation(s)
- Ryan Haley
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, United States of America
| | - Ying Wang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, United States of America
| | - Zheng Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, United States of America
- * E-mail:
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19
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Rocheleau CE. C. elegans RAB-35: Dual roles in apoptotic cell clearance. PLoS Genet 2018; 14:e1007534. [PMID: 30138327 PMCID: PMC6107104 DOI: 10.1371/journal.pgen.1007534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Christian E. Rocheleau
- Division of Endocrinology and Metabolism, Department of Medicine, McGill University, Montreal, Quebec, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
- Program in Metabolic Disorders and Complications, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
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20
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Kumar S, Calianese D, Birge RB. Efferocytosis of dying cells differentially modulate immunological outcomes in tumor microenvironment. Immunol Rev 2018; 280:149-164. [PMID: 29027226 DOI: 10.1111/imr.12587] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Programmed cell death (apoptosis) is an integral part of tissue homeostasis in complex organisms, allowing for tissue turnover, repair, and renewal while simultaneously inhibiting the release of self antigens and danger signals from apoptotic cell-derived constituents that can result in immune activation, inflammation, and autoimmunity. Unlike cells in culture, the physiological fate of cells that die by apoptosis in vivo is their rapid recognition and engulfment by phagocytic cells (a process called efferocytosis). To this end, apoptotic cells express specific eat-me signals, such as externalized phosphatidylserine (PS), that are recognized in a specific context by receptors to initiate signaling pathways for engulfment. The importance of carefully regulated recognition and clearance pathways is evident in the spectrum of inflammatory and autoimmune disorders caused by defects in PS receptors and signaling molecules. However, in recent years, several additional cell death pathways have emerged, including immunogenic cell death, necroptosis, pyroptosis, and netosis that interweave different cell death pathways with distinct innate and adaptive responses from classical apoptosis that can shape long-term host immunity. In this review, we discuss the role of different cell death pathways in terms of their immune potential outcomes specifically resulting in specific cell corpse/phagocyte interactions (phagocytic synapses) that impinge on host immunity, with a main emphasis on tolerance and cancer immunotherapy.
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Affiliation(s)
- Sushil Kumar
- New Jersey Medical School, Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, Newark, NJ, USA
| | - David Calianese
- New Jersey Medical School, Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, Newark, NJ, USA
| | - Raymond B Birge
- New Jersey Medical School, Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers University, Newark, NJ, USA
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21
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Sarode GS, Sarode SC, Maniyar N, Sharma NK, Patil S. Carcinogenesis-relevant biological events in the pathophysiology of the efferocytosis phenomenon. Oncol Rev 2017; 11:343. [PMID: 29285321 PMCID: PMC5733395 DOI: 10.4081/oncol.2017.343] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 12/01/2017] [Indexed: 01/05/2023] Open
Abstract
The effective removal of cells undergoing programmed cell death, which is referred to as efferocytosis, prevents the leakage of intracellular contents into the surrounding tissue, which could lead to tissue damage and inflammation. Efferocytosis involves a coordinated orchestration of multiple steps that lead to a swift, coherent and immunologically silent removal of dying cells. The release of wound healing cytokines, which resolve inflammation and enhance tissue repair, is an important feature of efferocytosis. However, in addition to the healing cytokines released during efferocytosis, the immunosuppressive action of cytokines promotes the tumor microenvironment, enhances the motility of cancer cells and promotes the evasion of antitumor immunity. The aim of the present review was to comprehensively discuss the efferocytosis phenomenon, the important players associated with this process and their role in cancer-related biological events.
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Affiliation(s)
- Gargi Sachin Sarode
- Department of Oral Pathology and Microbiology, Dr. D. Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth, Sant-Tukaram Nagar, Pimpri, Pune, Maharashtra, India
| | - Sachin C Sarode
- Department of Oral Pathology and Microbiology, Dr. D. Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth, Sant-Tukaram Nagar, Pimpri, Pune, Maharashtra, India
| | - Nikunj Maniyar
- Department of Oral Pathology and Microbiology, Dr. D. Y. Patil Dental College and Hospital, Dr. D.Y. Patil Vidyapeeth, Sant-Tukaram Nagar, Pimpri, Pune, Maharashtra, India
| | - Nilesh Kumar Sharma
- Cancer and Translational Research Lab, Dr. D.Y. Patil Biotechnology & Bioinformatics Institute, Dr. D.Y. Patil Vidyapeeth, Pune, Maharashtra, India
| | - Shankargouda Patil
- Department of Oral and Maxillofacial Surgery and Diagnostic Sciences, Division of Oral Pathology, College of Dentistry, Jazan University, Jazan, Saudi Arabia
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22
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Serizier SB, McCall K. Scrambled Eggs: Apoptotic Cell Clearance by Non-Professional Phagocytes in the Drosophila Ovary. Front Immunol 2017; 8:1642. [PMID: 29238344 PMCID: PMC5712531 DOI: 10.3389/fimmu.2017.01642] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/09/2017] [Indexed: 01/20/2023] Open
Abstract
For half of a century, it has been known that non-professional phagocytes, such as fibroblasts, endothelial, and epithelial cells, are capable of efferocytosis (engulfment of apoptotic cells). Non-professional phagocytes differ from professional phagocytes in the range and efficiency of engulfment. Much of the recognition and underlying signaling machinery between non-professional and professional phagocytes is the same, but it is not known how the engulfment capacity of non-professional phagocytes is controlled. Moreover, the signaling networks involved in cell corpse recognition, engulfment, and phagosome maturation are only partially understood. The Drosophila ovary provides an excellent system to investigate the regulation of phagocytic activity by epithelial cells, a major class of non-professional phagocytes. During Drosophila oogenesis, mid-stage egg chambers undergo apoptosis of the germline in response to nutrient deprivation. Epithelial follicle cells then undergo major cell shape changes and concomitantly engulf the germline material. Our previous work has established that Draper and the integrin α-PS3/β-PS heterodimer are required in follicle cells for germline cell clearance. In addition, we have characterized phagosome maturation pathways, and found that the JNK pathway amplifies the engulfment response. In this review, we discuss recent advances on the interplay between engulfment pathways in the follicular epithelium for cell clearance in the Drosophila ovary. We also provide a comparison to apoptotic cell clearance mechanisms in C. elegans and mammals, illustrating strong conservation of efferocytosis mechanisms by non-professional phagocytes.
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Affiliation(s)
- Sandy B Serizier
- Department of Biology, Boston University, Boston, MA, United States.,Graduate Program in Molecular Biology, Cell Biology and Biochemistry, Boston University, Boston, MA, United States
| | - Kimberly McCall
- Department of Biology, Boston University, Boston, MA, United States
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23
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Boateng R, Nguyen KCQ, Hall DH, Golden A, Allen AK. Novel functions for the RNA-binding protein ETR-1 in Caenorhabditis elegans reproduction and engulfment of germline apoptotic cell corpses. Dev Biol 2017; 429:306-320. [PMID: 28648844 PMCID: PMC5603194 DOI: 10.1016/j.ydbio.2017.06.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 06/01/2017] [Accepted: 06/08/2017] [Indexed: 01/31/2023]
Abstract
RNA-binding proteins (RBPs) are essential regulators of gene expression that act through a variety of mechanisms to ensure the proper post-transcriptional regulation of their target RNAs. RBPs in multiple species have been identified as playing crucial roles during development and as having important functions in various adult organ systems, including the heart, nervous, muscle, and reproductive systems. ETR-1, a highly conserved ELAV-Type RNA-binding protein belonging to the CELF/Bruno protein family, has been previously reported to be involved in C. elegans muscle development. Animals depleted of ETR-1 have been previously characterized as arresting at the two-fold stage of embryogenesis. In this study, we show that ETR-1 is expressed in the hermaphrodite somatic gonad and germ line, and that reduction of ETR-1 via RNA interference (RNAi) results in reduced hermaphrodite fecundity. Detailed characterization of this fertility defect indicates that ETR-1 is required in both the somatic tissue and the germ line to ensure wild-type reproductive levels. Additionally, the ability of ETR-1 depletion to suppress the published WEE-1.3-depletion infertility phenotype is dependent on ETR-1 being reduced in the soma. Within the germline of etr-1(RNAi) hermaphrodite animals, we observe a decrease in average oocyte size and an increase in the number of germline apoptotic cell corpses as evident by an increased number of CED-1::GFP and acridine orange positive apoptotic germ cells. Transmission Electron Microscopy (TEM) studies confirm the significant increase in apoptotic cells in ETR-1-depleted animals, and reveal a failure of the somatic gonadal sheath cells to properly engulf dying germ cells in etr-1(RNAi) animals. Through investigation of an established engulfment pathway in C. elegans, we demonstrate that co-depletion of CED-1 and ETR-1 suppresses both the reduced fecundity and the increase in the number of apoptotic cell corpses observed in etr-1(RNAi) animals. Combined, this data identifies a novel role for ETR-1 in hermaphrodite gametogenesis and in the process of engulfment of germline apoptotic cell corpses.
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Affiliation(s)
- Ruby Boateng
- Department of Biology, Howard University, Washington, DC 20059, USA
| | - Ken C Q Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - David H Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Andy Golden
- National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anna K Allen
- Department of Biology, Howard University, Washington, DC 20059, USA
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24
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Presumptive TRP channel CED-11 promotes cell volume decrease and facilitates degradation of apoptotic cells in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2017; 114:8806-8811. [PMID: 28760991 PMCID: PMC5565440 DOI: 10.1073/pnas.1705084114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Apoptotic cells undergo a series of morphological changes. These changes are dependent on caspase cleavage of downstream targets, but which targets are significant and how they facilitate the death process are not well understood. In Caenorhabditis elegans an increase in the refractility of the dying cell is a hallmark morphological change that is caspase dependent. We identify a presumptive transient receptor potential (TRP) cation channel, CED-11, that acts in the dying cell to promote the increase in apoptotic cell refractility. CED-11 is required for multiple other morphological changes during apoptosis, including an increase in electron density as visualized by electron microscopy and a decrease in cell volume. In ced-11 mutants, the degradation of apoptotic cells is delayed. Mutation of ced-11 does not cause an increase in cell survival but can enhance cell survival in other cell-death mutants, indicating that ced-11 facilitates the death process. In short, ced-11 acts downstream of caspase activation to promote the shrinkage, death, and degradation of apoptotic cells.
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25
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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.
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26
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Baruah PS, Beauchemin M, Parker JA, Bertrand R. Expression of human Bcl-xL (Ser49) and (Ser62) mutants in Caenorhabditis elegans causes germline defects and aneuploidy. PLoS One 2017; 12:e0177413. [PMID: 28481930 PMCID: PMC5421811 DOI: 10.1371/journal.pone.0177413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 04/26/2017] [Indexed: 11/18/2022] Open
Abstract
An interesting feature of Bcl-xL protein is the presence of an unstructured loop domain between α1 and α2 helices, a domain not essential for its anti-apoptotic function and absent in CED-9 protein. Within this domain, Bcl-xL undergoes dynamic phosphorylation and dephosphorylation at Ser49 and Ser62 during G2 and mitosis in human cells. Studies have revealed that when these residues are mutated, cells harbour mitotic defects, including chromosome mis-attachment, lagging, bridging and mis-segregation with, ultimately, chromosome instability and aneuploidy. We undertook genetic experiments in Caenorhabditis elegans to understand the importance of Bcl-xL (Ser49) and (Ser62) in vivo. Transgenic worms carrying single-site S49A, S62A, S49D, S62D and dual site S49/62A mutants were generated and their effects were analyzed in germlines of young adult worms. Worms expressing Bcl-xL variants showed decreased egg-laying and hatching potency, variations in the length of their mitotic regions but not of their transition zones, appearance of chromosomal abnormalities at their diplotene stages, and increased germline apoptosis, with the exception of the S62D variants. Some of these transgenic strains, particularly the Ser to Ala variants, also showed slight modulations of lifespan compared to their controls. In addition, RNAi experiments silencing expression of the various Bcl-xL variants reversed their effects in vivo. Our in vivo observations confirmed the importance of Ser49 and Ser62 within Bcl-xL loop domain in maintaining chromosome stability.
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Affiliation(s)
- Prasamit Saurav Baruah
- Centre de recherche, Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal (Québec) Canada
- Institut du cancer de Montréal, Montréal (Québec) Canada
| | - Myriam Beauchemin
- Centre de recherche, Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal (Québec) Canada
- Institut du cancer de Montréal, Montréal (Québec) Canada
| | - J. Alexander Parker
- Centre de recherche, Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal (Québec) Canada
- Département de neurosciences, Université de Montréal, Montréal (Québec) Canada
| | - Richard Bertrand
- Centre de recherche, Centre hospitalier de l’Université de Montréal (CRCHUM), Montréal (Québec) Canada
- Institut du cancer de Montréal, Montréal (Québec) Canada
- Département de médecine et Spec. médicales, Université de Montréal, Montréal (Québec) Canada
- * E-mail:
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27
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Yang C, Wang X. Cell biology in China: Focusing on the lysosome. Traffic 2017; 18:348-357. [DOI: 10.1111/tra.12483] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/27/2017] [Accepted: 03/27/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Chonglin Yang
- State Key Laboratory of Conservation and Utilization of Bio-Resources in Yunnan, Center for Life Sciences, and School of Life Sciences; Yunnan University; Kunming China
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology; Chinese Academy of Sciences; Beijing China
| | - Xiaochen Wang
- State Key Laboratory of Biomolecules, Institute of Biophysics; Chinese Academy of Sciences; Beijing China
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28
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Yin J, Huang Y, Guo P, Hu S, Yoshina S, Xuan N, Gan Q, Mitani S, Yang C, Wang X. GOP-1 promotes apoptotic cell degradation by activating the small GTPase Rab2 in C. elegans. J Cell Biol 2017; 216:1775-1794. [PMID: 28424218 PMCID: PMC5461019 DOI: 10.1083/jcb.201610001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 02/10/2017] [Accepted: 03/03/2017] [Indexed: 12/17/2022] Open
Abstract
Rab2 regulates multiple membrane traffic processes, but how it is recruited to and activated on the target membrane remains unclear. Here, Yin et al. identify a conserved protein, GOP-1, that activates UNC-108/Rab2 to promote phagosome, endosome, and DCV maturation. Apoptotic cells generated by programmed cell death are engulfed by phagocytes and enclosed within plasma membrane–derived phagosomes. Maturation of phagosomes involves a series of membrane-remodeling events that are governed by the sequential actions of Rab GTPases and lead to formation of phagolysosomes, where cell corpses are degraded. Here we identified gop-1 as a novel regulator of apoptotic cell clearance in Caenorhabditis elegans. Loss of gop-1 affects phagosome maturation through the RAB-5–positive stage, causing defects in phagosome acidification and phagolysosome formation, phenotypes identical to and unaffected by loss of unc-108, the C. elegans Rab2. GOP-1 transiently associates with cell corpse–containing phagosomes, and loss of its function abrogates phagosomal association of UNC-108. GOP-1 interacts with GDP-bound and nucleotide-free UNC-108/Rab2, disrupts GDI-UNC-108 complexes, and promotes activation and membrane recruitment of UNC-108/Rab2 in vitro. Loss of gop-1 also abolishes association of UNC-108 with endosomes, causing defects in endosome and dense core vesicle maturation. Thus, GOP-1 is an activator of UNC-108/Rab2 in multiple processes.
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Affiliation(s)
- Jianhua Yin
- National Institute of Biological Sciences, Beijing 102206, China.,Graduate Program in Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yaling Huang
- National Institute of Biological Sciences, Beijing 102206, China
| | - Pengfei Guo
- National Institute of Biological Sciences, Beijing 102206, China
| | - Siqi Hu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Sawako Yoshina
- Deparment of Physiology, School of Medicine and Institute for Integrated Medical Sciences, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Nan Xuan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Qiwen Gan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shohei Mitani
- Deparment of Physiology, School of Medicine and Institute for Integrated Medical Sciences, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Chonglin Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaochen Wang
- National Institute of Biological Sciences, Beijing 102206, China .,Graduate Program in Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.,National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
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29
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Aflaki E, Borger DK, Grey RJ, Kirby M, Anderson S, Lopez G, Sidransky E. Efferocytosis is impaired in Gaucher macrophages. Haematologica 2016; 102:656-665. [PMID: 28011901 PMCID: PMC5395106 DOI: 10.3324/haematol.2016.155093] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Accepted: 12/16/2016] [Indexed: 11/09/2022] Open
Abstract
Gaucher disease, the inherited deficiency of lysosomal glucocerebrosidase, is characterized by the presence of glucosylceramide-laden macrophages resulting from impaired digestion of aged erythrocytes or apoptotic leukocytes. Studies of macrophages from patients with type 1 Gaucher disease with genotypes N370S/N370S, N370S/L444P or N370S/c.84dupG revealed that Gaucher macrophages have impaired efferocytosis resulting from reduced levels of p67phox and Rab7. The decreased Rab7 expression leads to impaired fusion of phagosomes with lysosomes. Moreover, there is defective translocation of p67phox to phagosomes, resulting in reduced intracellular production of reactive oxygen species. These factors contribute to defective deposition and clearance of apoptotic cells in phagolysosomes, which may have an impact on the inflammatory response and contribute to the organomegaly and inflammation seen in patients with Gaucher disease.
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Affiliation(s)
- Elma Aflaki
- Section of Molecular Neurogenetics, Medical Genetics Branch, National Institutes of Health, Bethesda, MD, USA
| | - Daniel K Borger
- Section of Molecular Neurogenetics, Medical Genetics Branch, National Institutes of Health, Bethesda, MD, USA
| | - Richard J Grey
- Section of Molecular Neurogenetics, Medical Genetics Branch, National Institutes of Health, Bethesda, MD, USA
| | - Martha Kirby
- Flow Cytometry Core, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Stacie Anderson
- Flow Cytometry Core, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Grisel Lopez
- Section of Molecular Neurogenetics, Medical Genetics Branch, National Institutes of Health, Bethesda, MD, USA
| | - Ellen Sidransky
- Section of Molecular Neurogenetics, Medical Genetics Branch, National Institutes of Health, Bethesda, MD, USA
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30
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Guillou A, Troha K, Wang H, Franc NC, Buchon N. The Drosophila CD36 Homologue croquemort Is Required to Maintain Immune and Gut Homeostasis during Development and Aging. PLoS Pathog 2016; 12:e1005961. [PMID: 27780230 PMCID: PMC5079587 DOI: 10.1371/journal.ppat.1005961] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/29/2016] [Indexed: 12/11/2022] Open
Abstract
Phagocytosis is an ancient mechanism central to both tissue homeostasis and immune defense. Both the identity of the receptors that mediate bacterial phagocytosis and the nature of the interactions between phagocytosis and other defense mechanisms remain elusive. Here, we report that Croquemort (Crq), a Drosophila member of the CD36 family of scavenger receptors, is required for microbial phagocytosis and efficient bacterial clearance. Flies mutant for crq are susceptible to environmental microbes during development and succumb to a variety of microbial infections as adults. Crq acts parallel to the Toll and Imd pathways to eliminate bacteria via phagocytosis. crq mutant flies exhibit enhanced and prolonged immune and cytokine induction accompanied by premature gut dysplasia and decreased lifespan. The chronic state of immune activation in crq mutant flies is further regulated by negative regulators of the Imd pathway. Altogether, our data demonstrate that Crq plays a key role in maintaining immune and organismal homeostasis.
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Affiliation(s)
- Aurélien Guillou
- Department of Entomology, Cornell University, Ithaca, NY, United States Of America
| | - Katia Troha
- Department of Entomology, Cornell University, Ithaca, NY, United States Of America
| | - Hui Wang
- Department of Cell & Molecular Biology, The Scripps Research Institute, La Jolla, CA, United States Of America
| | - Nathalie C. Franc
- Department of Cell & Molecular Biology, The Scripps Research Institute, La Jolla, CA, United States Of America
| | - Nicolas Buchon
- Department of Entomology, Cornell University, Ithaca, NY, United States Of America
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31
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Defective Phagocytic Corpse Processing Results in Neurodegeneration and Can Be Rescued by TORC1 Activation. J Neurosci 2016; 36:3170-83. [PMID: 26985028 DOI: 10.1523/jneurosci.1912-15.2016] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
UNLABELLED The removal of apoptotic cell corpses is important for maintaining homeostasis. Previously, defects in apoptotic cell clearance have been linked to neurodegeneration. However, the mechanisms underlying this are still poorly understood. In this study, we report that the absence of the phagocytic receptor Draper in glia leads to a pronounced accumulation of apoptotic neurons in the brain of Drosophila melanogaster. These dead cells persist in the brain throughout the lifespan of the organism and are associated with age-dependent neurodegeneration. Our data indicate that corpses persist because of defective phagosome maturation, rather than recognition defects. TORC1 activation, or inhibition of Atg1, in glia is sufficient to rescue corpse accumulation as well as neurodegeneration. These results suggest that phagocytosis of apoptotic neurons by glia during development is essential for brain homeostasis in adult flies. Furthermore, it suggests that TORC1 regulates Draper-mediated phagosome maturation. SIGNIFICANCE STATEMENT Previously, defects in dead cell clearance were linked to neurodegeneration, but the exact mechanisms are not well understood. In this study, we report that the absence of an engulfment receptor leads to a pronounced accumulation of dead neurons in the brain of the fruit fly Drosophila melanogaster. These dead cells persist in the brain throughout the lifespan of the organism and are associated with age-dependent neurodegeneration. Our data indicate that corpses persist because of defective degradation of cells rather than recognition of dead cells.
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32
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Meehan TL, Joudi TF, Timmons AK, Taylor JD, Habib CS, Peterson JS, Emmanuel S, Franc NC, McCall K. Components of the Engulfment Machinery Have Distinct Roles in Corpse Processing. PLoS One 2016; 11:e0158217. [PMID: 27347682 PMCID: PMC4922577 DOI: 10.1371/journal.pone.0158217] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 06/13/2016] [Indexed: 01/10/2023] Open
Abstract
Billions of cells die in our bodies on a daily basis and are engulfed by phagocytes. Engulfment, or phagocytosis, can be broken down into five basic steps: attraction of the phagocyte, recognition of the dying cell, internalization, phagosome maturation, and acidification. In this study, we focus on the last two steps, which can collectively be considered corpse processing, in which the engulfed material is degraded. We use the Drosophila ovarian follicle cells as a model for engulfment of apoptotic cells by epithelial cells. We show that engulfed material is processed using the canonical corpse processing pathway involving the small GTPases Rab5 and Rab7. The phagocytic receptor Draper is present on the phagocytic cup and on nascent, phosphatidylinositol 3-phosphate (PI(3)P)- and Rab7-positive phagosomes, whereas integrins are maintained on the cell surface during engulfment. Due to the difference in subcellular localization, we investigated the role of Draper, integrins, and downstream signaling components in corpse processing. We found that some proteins were required for internalization only, while others had defects in corpse processing as well. This suggests that several of the core engulfment proteins are required for distinct steps of engulfment. We also performed double mutant analysis and found that combined loss of draper and αPS3 still resulted in a small number of engulfed vesicles. Therefore, we investigated another known engulfment receptor, Crq. We found that loss of all three receptors did not inhibit engulfment any further, suggesting that Crq does not play a role in engulfment by the follicle cells. A more complete understanding of how the engulfment and corpse processing machinery interact may enable better understanding and treatment of diseases associated with defects in engulfment by epithelial cells.
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Affiliation(s)
- Tracy L. Meehan
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
- * E-mail: (KM); (TM)
| | - Tony F. Joudi
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Allison K. Timmons
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Jeffrey D. Taylor
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Corey S. Habib
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Jeanne S. Peterson
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Shanan Emmanuel
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
| | - Nathalie C. Franc
- The Scripps Research Institute, Department of Immunology and Microbial Science, La Jolla, California, United States of America
| | - Kimberly McCall
- Department of Biology, Boston University, Boston, Massachusetts, United States of America
- * E-mail: (KM); (TM)
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33
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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.
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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.
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34
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Barrett A, Hermann GJ. A Caenorhabditis elegans Homologue of LYST Functions in Endosome and Lysosome-Related Organelle Biogenesis. Traffic 2016; 17:515-35. [PMID: 26822177 DOI: 10.1111/tra.12381] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/25/2016] [Accepted: 01/25/2016] [Indexed: 01/20/2023]
Abstract
LYST-1 is a Caenorhabditis elegans BEACH domain containing protein (BDCP) homologous to LYST and NBEAL2, BDCPs controlling organelle biogenesis that are implicated in human disease. Unlike the three other BDCPs encoded by C. elegans, mutations in lyst-1 lead to smaller lysosome-related organelles (LROs), smaller lysosomes, increased numbers of LROs and decreased numbers of early endosomes. lyst-1(-) mutations do not obviously disrupt protein trafficking to lysosomes or LROs, however, the formation of gut granules is diminished.
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Affiliation(s)
- Alec Barrett
- Department of Biology, Lewis & Clark College, 0615 SW Palatine Hill Rd., Portland, OR, 97219, USA
| | - Greg J Hermann
- Department of Biology, Lewis & Clark College, 0615 SW Palatine Hill Rd., Portland, OR, 97219, USA
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35
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Phagocytosis genes nonautonomously promote developmental cell death in the Drosophila ovary. Proc Natl Acad Sci U S A 2016; 113:E1246-55. [PMID: 26884181 DOI: 10.1073/pnas.1522830113] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Programmed cell death (PCD) is usually considered a cell-autonomous suicide program, synonymous with apoptosis. Recent research has revealed that PCD is complex, with at least a dozen cell death modalities. Here, we demonstrate that the large-scale nonapoptotic developmental PCD in the Drosophila ovary occurs by an alternative cell death program where the surrounding follicle cells nonautonomously promote death of the germ line. The phagocytic machinery of the follicle cells, including Draper, cell death abnormality (Ced)-12, and c-Jun N-terminal kinase (JNK), is essential for the death and removal of germ-line-derived nurse cells during late oogenesis. Cell death events including acidification, nuclear envelope permeabilization, and DNA fragmentation of the nurse cells are impaired when phagocytosis is inhibited. Moreover, elimination of a small subset of follicle cells prevents nurse cell death and cytoplasmic dumping. Developmental PCD in the Drosophila ovary is an intriguing example of nonapoptotic, nonautonomous PCD, providing insight on the diversity of cell death mechanisms.
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Cherra SJ, Jin Y. A Two-Immunoglobulin-Domain Transmembrane Protein Mediates an Epidermal-Neuronal Interaction to Maintain Synapse Density. Neuron 2016; 89:325-36. [PMID: 26777275 PMCID: PMC4871750 DOI: 10.1016/j.neuron.2015.12.024] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Revised: 08/17/2015] [Accepted: 12/08/2015] [Indexed: 02/06/2023]
Abstract
Synaptic maintenance is essential for neural circuit function. In the C. elegans locomotor circuit, motor neurons are in direct contact with the epidermis. Here, we reveal a novel epidermal-neuronal interaction mediated by a two-immunoglobulin domain transmembrane protein, ZIG-10, that is necessary for maintaining cholinergic synapse density. ZIG-10 is localized at the cell surface of epidermis and cholinergic motor neurons, with high levels at areas adjacent to synapses. Loss of zig-10 increases the number of cholinergic excitatory synapses and exacerbates convulsion behavior in a seizure model. Mis-expression of zig-10 in GABAergic inhibitory neurons reduces GABAergic synapse number, dependent on the presence of ZIG-10 in the epidermis. Furthermore, ZIG-10 interacts with the tyrosine kinase SRC-2 to regulate the phagocytic activity of the epidermis to restrict cholinergic synapse number. Our studies demonstrate the highly specific roles of non-neuronal cells in modulating neural circuit function, through neuron-type-specific maintenance of synapse density.
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Affiliation(s)
- Salvatore J. Cherra
- Division of Biological Sciences, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yishi Jin
- Division of Biological Sciences, Section of Neurobiology, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
- Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA 92093, USA
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Gao Y, Li S, Xu D, Wang J, Sun Y. Changes in apoptotic microRNA and mRNA expression profiling in Caenorhabditis elegans during the Shenzhou-8 mission. JOURNAL OF RADIATION RESEARCH 2015; 56:872-82. [PMID: 26286471 PMCID: PMC4628221 DOI: 10.1093/jrr/rrv050] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 07/21/2015] [Indexed: 05/07/2023]
Abstract
Radiation and microgravity exposure have been proven to induce abnormal apoptosis in microRNA (miRNA) and mRNA expression, but whether space conditions, including radiation and microgravity, activate miRNAs to regulate the apoptosis is undetermined. For that purpose, we investigated miRNome and mRNA expression in the ced-1 Caenorhabditis elegans mutant vs the wild-type, both of which underwent spaceflight, spaceflight 1g-centrifuge control and ground control conditions during the Shenzhou-8 mission. Results showed that no morphological changes in the worms were detected, but differential miRNA expression increased from 43 (ground control condition) to 57 and 91 in spaceflight and spaceflight control conditions, respectively. Microgravity altered miRNA expression profiling by decreasing the number and significance of differentially expressed miRNA compared with 1 g incubation during spaceflight. Alterations in the miRNAs were involved in alterations in apoptosis, neurogenesis larval development, ATP metabolism and GTPase-mediated signal transduction. Among these, 17 altered miRNAs potentially involved in apoptosis were screened and showed obviously different expression signatures between space conditions. By integrated analysis of miRNA and mRNA, miR-797 and miR-81 may be involved in apoptosis by targeting the genes ced-10 and both drp-1 and hsp-1, respectively. Compared with ground condition, space conditions regulated apoptosis though a different manner on transcription, by altering expression of seven core apoptotic genes in spaceflight condition, and eight in spaceflight control condition. Results indicate that, miRNA of Caenorhabditis elegans probably regulates apoptotic gene expression in response to space environmental stress, and shows different behavior under microgravity condition compared with 1 g condition in the presence of space radiation.
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Affiliation(s)
- Ying Gao
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Linghai Road 1, Dalian 116026, China
| | - Shuai Li
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Linghai Road 1, Dalian 116026, China
| | - Dan Xu
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Linghai Road 1, Dalian 116026, China
| | - Junjun Wang
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Linghai Road 1, Dalian 116026, China
| | - Yeqing Sun
- Institute of Environmental Systems Biology, College of Environmental Science and Engineering, Dalian Maritime University, Linghai Road 1, Dalian 116026, China
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Meehan TL, Kleinsorge SE, Timmons AK, Taylor JD, McCall K. Polarization of the epithelial layer and apical localization of integrins are required for engulfment of apoptotic cells in the Drosophila ovary. Dis Model Mech 2015; 8:1603-14. [PMID: 26398951 PMCID: PMC4728319 DOI: 10.1242/dmm.021998] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/14/2015] [Indexed: 12/28/2022] Open
Abstract
Inefficient clearance of dead cells or debris by epithelial cells can lead to or exacerbate debilitating conditions such as retinitis pigmentosa, macular degeneration, chronic obstructive pulmonary disease and asthma. Despite the importance of engulfment by epithelial cells, little is known about the molecular changes that are required within these cells. The misregulation of integrins has previously been associated with disease states, suggesting that a better understanding of the regulation of receptor trafficking could be key to treating diseases caused by defects in phagocytosis. Here, we demonstrate that the integrin heterodimer αPS3/βPS becomes apically enriched and is required for engulfment by the epithelial follicle cells of the Drosophila ovary. We found that integrin heterodimer localization and function is largely directed by the α-subunit. Moreover, proper cell polarity promotes asymmetric integrin enrichment, suggesting that αPS3/βPS trafficking occurs in a polarized fashion. We show that several genes previously known for their roles in trafficking and cell migration are also required for engulfment. Moreover, as in mammals, the same α-integrin subunit is required by professional and non-professional phagocytes and migrating cells in Drosophila. Our findings suggest that migrating and engulfing cells use common machinery, and demonstrate a crucial role for integrin function and polarized trafficking of integrin subunits during engulfment. This study also establishes the epithelial follicle cells of the Drosophila ovary as a powerful model for understanding the molecular changes required for engulfment by a polarized epithelium. Summary: Apical integrin localization, mediated by polarized and directed trafficking, is crucial for proper engulfment by epithelial cells.
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Affiliation(s)
- Tracy L Meehan
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Sarah E Kleinsorge
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Allison K Timmons
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Jeffrey D Taylor
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Kimberly McCall
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
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Eom HJ, Roca CP, Roh JY, Chatterjee N, Jeong JS, Shim I, Kim HM, Kim PJ, Choi K, Giralt F, Choi J. A systems toxicology approach on the mechanism of uptake and toxicity of MWCNT in Caenorhabditis elegans. Chem Biol Interact 2015; 239:153-63. [PMID: 26111764 DOI: 10.1016/j.cbi.2015.06.031] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 05/05/2015] [Accepted: 06/21/2015] [Indexed: 01/08/2023]
Abstract
The increased volumes of carbon nanotubes (CNTs) being utilized in industrial and biomedical processes carries with it an increased risk of unintentional release into the environment, requiring a thorough hazard and risk assessment. In this study, the toxicity of pristine and hydroxylated (OH-) multiwall CNTs (MWCNTs) was investigated in the nematode Caenorhabditis elegans using an integrated systems toxicology approach. To gain an insight into the toxic mechanism of MWCNTs, microarray and proteomics were conducted for C. elegans followed by pathway analyses. The results of pathway analyses suggested endocytosis, phagocytosis, oxidative stress and endoplasmic reticulum (ER) stress, as potential mechanisms of uptake and toxicity, which were subsequently investigated using loss-of-function mutants of genes of those pathways. The expression of phagocytosis related genes (i.e. ced-10 and rab-7) were significantly increased upon exposure to OH-MWCNT, concomitantly with the rescued toxicity by loss-of-function mutants of those genes, such as ced-10(n3246) and rab-7(ok511). An increased sensitivity of the hsp-4(gk514) mutant by OH-MWCNT, along with a decreased expression of hsp-4 at both gene and protein level suggests that MWCNTs may affect ER stress response in C. elegans. Collectively, the results implied phagocytosis to be a potential mechanism of uptake of MWCNTs, and ER and oxidative stress as potential mechanisms of toxicity. The integrated systems toxicology approach applied in this study provided a comprehensive insight into the toxic mechanism of MWCNTs in C. elegans, which may eventually be used to develop an "Adverse Outcome Pathway (AOP)", a recently introduced concept as a conceptual framework to link molecular level responses to higher level effects.
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Affiliation(s)
- Hyun-Jeong Eom
- School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, Seoul 130-743, Republic of Korea
| | - Carlos P Roca
- Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Catalunya, Spain
| | - Ji-Yeon Roh
- School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, Seoul 130-743, Republic of Korea
| | - Nivedita Chatterjee
- School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, Seoul 130-743, Republic of Korea
| | - Jae-Seong Jeong
- School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, Seoul 130-743, Republic of Korea
| | - Ilseob Shim
- Risk Assessment Division, National Institute of Environmental Research, Incheon 404-708, Republic of Korea
| | - Hyun-Mi Kim
- Risk Assessment Division, National Institute of Environmental Research, Incheon 404-708, Republic of Korea
| | - Phil-Je Kim
- Risk Assessment Division, National Institute of Environmental Research, Incheon 404-708, Republic of Korea
| | - Kyunghee Choi
- Risk Assessment Division, National Institute of Environmental Research, Incheon 404-708, Republic of Korea
| | - Francesc Giralt
- Departament d'Enginyeria Quimica, Universitat Rovira i Virgili, Tarragona, Catalunya, Spain
| | - Jinhee Choi
- School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul, Seoul 130-743, Republic of Korea.
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40
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Abstract
Cellular debris created by developmental processes or injury must be cleared by phagocytic cells to maintain and repair tissues. Cutaneous injuries damage not only epidermal cells but also the axonal endings of somatosensory (touch-sensing) neurons, which must be repaired to restore the sensory function of the skin. Phagocytosis of neuronal debris is usually performed by macrophages or other blood-derived professional phagocytes, but we have found that epidermal cells phagocytose somatosensory axon debris in zebrafish. Live imaging revealed that epidermal cells rapidly internalize debris into dynamic phosphatidylinositol 3-monophosphate-positive phagosomes that mature into phagolysosomes using a pathway similar to that of professional phagocytes. Epidermal cells phagocytosed not only somatosensory axon debris but also debris created by injury to other peripheral axons that were mislocalized to the skin, neighboring skin cells, and macrophages. Together, these results identify vertebrate epidermal cells as broad-specificity phagocytes that likely contribute to neural repair and wound healing.
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41
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Takács-Vellai K, Vellai T, Farkas Z, Mehta A. Nucleoside diphosphate kinases (NDPKs) in animal development. Cell Mol Life Sci 2015. [PMID: 25537302 DOI: 10.07/s00018-014-1803-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In textbooks of biochemistry, nucleoside diphosphate conversion to a triphosphate by nucleoside diphosphate 'kinases' (NDPKs, also named NME or NM23 proteins) merits a few lines of text. Yet this essential metabolic function, mediated by a multimeric phosphotransferase protein, has effects that lie beyond a simple housekeeping role. NDPKs attracted more attention when NM23-H1 was identified as the first metastasis suppressor gene. In this review, we examine these NDPK enzymes from a developmental perspective because of the tractable phenotypes found in simple animal models that point to common themes. The data suggest that NDPK enzymes control the availability of surface receptors to regulate cell-sensing cues during cell migration. NDPKs regulate different forms of membrane enclosure that engulf dying cells during development. We suggest that NDPK enzymes have been essential for the regulated uptake of objects such as bacteria or micronutrients, and this evolutionarily conserved endocytic function contributes to their activity towards the regulation of metastasis.
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Affiliation(s)
- Krisztina Takács-Vellai
- Department of Biological Anthropology, Eötvös Loránd University, Pázmány Péter stny. 1/C, 1117, Budapest, Hungary,
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42
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Takács-Vellai K, Vellai T, Farkas Z, Mehta A. Nucleoside diphosphate kinases (NDPKs) in animal development. Cell Mol Life Sci 2015; 72:1447-62. [PMID: 25537302 PMCID: PMC11113130 DOI: 10.1007/s00018-014-1803-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Revised: 12/04/2014] [Accepted: 12/08/2014] [Indexed: 12/25/2022]
Abstract
In textbooks of biochemistry, nucleoside diphosphate conversion to a triphosphate by nucleoside diphosphate 'kinases' (NDPKs, also named NME or NM23 proteins) merits a few lines of text. Yet this essential metabolic function, mediated by a multimeric phosphotransferase protein, has effects that lie beyond a simple housekeeping role. NDPKs attracted more attention when NM23-H1 was identified as the first metastasis suppressor gene. In this review, we examine these NDPK enzymes from a developmental perspective because of the tractable phenotypes found in simple animal models that point to common themes. The data suggest that NDPK enzymes control the availability of surface receptors to regulate cell-sensing cues during cell migration. NDPKs regulate different forms of membrane enclosure that engulf dying cells during development. We suggest that NDPK enzymes have been essential for the regulated uptake of objects such as bacteria or micronutrients, and this evolutionarily conserved endocytic function contributes to their activity towards the regulation of metastasis.
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Affiliation(s)
- Krisztina Takács-Vellai
- Department of Biological Anthropology, Eötvös Loránd University, Pázmány Péter stny. 1/C, 1117, Budapest, Hungary,
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43
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Shklover J, Mishnaevski K, Levy-Adam F, Kurant E. JNK pathway activation is able to synchronize neuronal death and glial phagocytosis in Drosophila. Cell Death Dis 2015; 6:e1649. [PMID: 25695602 PMCID: PMC4669801 DOI: 10.1038/cddis.2015.27] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 01/12/2015] [Accepted: 01/13/2015] [Indexed: 02/07/2023]
Abstract
Glial phagocytosis of superfluous neurons and damaged or aberrant neuronal material is crucial for normal development and maintenance of the CNS. However, the molecular mechanisms underlying the relationship between neuronal death and glial phagocytosis are poorly understood. We describe a novel mechanism that is able to synchronize neuronal cell death and glial phagocytosis of dying neurons in the Drosophila embryonic CNS. This mechanism involves c-Jun N-terminal kinase (JNK) signaling, which is required for developmental apoptosis of specific neurons during embryogenesis. We demonstrate that the dJNK pathway gain-of-function in neurons leads to dJNK signaling in glia, which results in upregulation of glial phagocytosis. Importantly, this promotion of phagocytosis is not mediated by upregulation of the glial phagocytic receptors SIMU and DRPR, but by increasing glial capacity to degrade apoptotic particles inside phagosomes. The proposed mechanism may be important for removal of damaged neurons in the developing and mature CNS.
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Affiliation(s)
- J Shklover
- Department of Genetics and Developmental Biology, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - K Mishnaevski
- Department of Genetics and Developmental Biology, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - F Levy-Adam
- Department of Genetics and Developmental Biology, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - E Kurant
- Department of Genetics and Developmental Biology, Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Technion-Israel Institute of Technology, Haifa 31096, Israel
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Chung WS, Allen NJ, Eroglu C. Astrocytes Control Synapse Formation, Function, and Elimination. Cold Spring Harb Perspect Biol 2015; 7:a020370. [PMID: 25663667 DOI: 10.1101/cshperspect.a020370] [Citation(s) in RCA: 490] [Impact Index Per Article: 54.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Astrocytes, through their close associations with synapses, can monitor and alter synaptic function, thus actively controlling synaptic transmission in the adult brain. Besides their important role at adult synapses, in the last three decades a number of critical findings have highlighted the importance of astrocytes in the establishment of synaptic connectivity in the developing brain. In this article, we will review the key findings on astrocytic control of synapse formation, function, and elimination. First, we will summarize our current structural and functional understanding of astrocytes at the synapse. Then, we will discuss the cellular and molecular mechanisms through which developing and mature astrocytes instruct the formation, maturation, and refinement of synapses. Our aim is to provide an overview of astrocytes as important players in the establishment of a functional nervous system.
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Affiliation(s)
- Won-Suk Chung
- Stanford University, School of Medicine, Department of Neurobiology, Stanford, California 94305
| | - Nicola J Allen
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, La Jolla, California 92037
| | - Cagla Eroglu
- Duke University Medical Center, Cell Biology and Neurobiology Departments, Duke Institute for Brain Sciences, Durham, North Carolina 27710
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45
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46
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Signaling by the engulfment receptor draper: a screen in Drosophila melanogaster implicates cytoskeletal regulators, Jun N-terminal Kinase, and Yorkie. Genetics 2014; 199:117-34. [PMID: 25395664 DOI: 10.1534/genetics.114.172544] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Draper, the Drosophila melanogaster homolog of the Ced-1 protein of Caenorhabditis elegans, is a cell-surface receptor required for the recognition and engulfment of apoptotic cells, glial clearance of axon fragments and dendritic pruning, and salivary gland autophagy. To further elucidate mechanisms of Draper signaling, we screened chromosomal deficiencies to identify loci that dominantly modify the phenotype of overexpression of Draper isoform II (suppressed differentiation of the posterior crossvein in the wing). We found evidence for 43 genetic modifiers of Draper II. Twenty-four of the 37 suppressor loci and 3 of the 6 enhancer loci were identified. An additional 5 suppressors and 2 enhancers were identified among mutations in functionally related genes. These studies reveal positive contributions to Drpr signaling for the Jun N-terminal Kinase pathway, supported by genetic interactions with hemipterous, basket, jun, and puckered, and for cytoskeleton regulation as indicated by genetic interactions with rac1, rac2, RhoA, myoblast city, Wiskcott-Aldrich syndrome protein, and the formin CG32138, and for yorkie and expanded. These findings indicate that Jun N-terminal Kinase activation and cytoskeletal remodeling collaborate in Draper signaling. Relationships between Draper signaling and Decapentaplegic signaling, insulin signaling, Salvador/Warts/Hippo signaling, apical-basal cell polarity, and cellular responses to mechanical forces are also discussed.
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47
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Guo P, Wang X. Rab GTPases act in sequential steps to regulate phagolysosome formation. Small GTPases 2014; 1:170-173. [PMID: 21686272 DOI: 10.4161/sgtp.1.3.14511] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Accepted: 12/17/2010] [Indexed: 11/19/2022] Open
Abstract
During apoptosis, apoptotic cells are recognized and quickly engulfed by phagocytes. The internalized cell corpses are enclosed within membrane-bound vesicles called phagosomes. Cell corpse degradation depends on the phagosomes undergoing a maturation process, but regulation of phagosomal maturation is not well understood. Recently, we identified C. elegans Rab GTPase 14 as a novel regulator of apoptotic cell degradation. Loss of rab-14 function affects several steps of phagosome maturation, causing accumulation of persistent cell corpses. RAB-14 and UNC-108 (Rab GTPase 2) function redundantly to regulate phagosome maturation. Three Rabs, RAB-14, UNC-108/RAB2 and RAB-7, act cooperatively to control phagolysosome formation. RAB-14 and UNC-108 recruit lysosomes, while RAB-7 mediates fusion of lysosomes to phagosomes. Our data thus reveal the sequential action of Rab GTPases in regulating tethering, docking and fusion of lysosomes to phagosomes.
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Affiliation(s)
- Pengfei Guo
- National Institute of Biological Sciences; Beijing, China
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48
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Xu M, Liu Y, Zhao L, Gan Q, Wang X, Yang C. The lysosomal cathepsin protease CPL-1 plays a leading role in phagosomal degradation of apoptotic cells in Caenorhabditis elegans. Mol Biol Cell 2014; 25:2071-83. [PMID: 24829385 PMCID: PMC4072580 DOI: 10.1091/mbc.e14-01-0015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
In Caenorhabditis elegans, the lysosomal cathepsin protease CPL-1 is indispensable for clearance of apoptotic cells by playing a leading role in destruction of cell corpses in phagolysosomes. During programmed cell death, the clearance of apoptotic cells is achieved by their phagocytosis and delivery to lysosomes for destruction in engulfing cells. However, the role of lysosomal proteases in cell corpse destruction is not understood. Here we report the identification of the lysosomal cathepsin CPL-1 as an indispensable protease for apoptotic cell removal in Caenorhabditis elegans. We find that loss of cpl-1 function leads to strong accumulation of germ cell corpses, which results from a failure in degradation rather than engulfment. CPL-1 is expressed in a variety of cell types, including engulfment cells, and its mutation does not affect the maturation of cell corpse–containing phagosomes, including phagosomal recruitment of maturation effectors and phagosome acidification. Of importance, we find that phagosomal recruitment and incorporation of CPL-1 occurs before digestion of cell corpses, which depends on factors required for phagolysosome formation. Using RNA interference, we further examine the role of other candidate lysosomal proteases in cell corpse clearance but find that they do not obviously affect this process. Collectively, these findings establish CPL-1 as the leading lysosomal protease required for elimination of apoptotic cells in C. elegans.
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Affiliation(s)
- Meng Xu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, ChinaGraduate University of Chinese Academy of Sciences, Beijing 100109, China
| | - Yubing Liu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Liyuan Zhao
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, ChinaGraduate University of Chinese Academy of Sciences, Beijing 100109, China
| | - Qiwen Gan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, ChinaGraduate University of Chinese Academy of Sciences, Beijing 100109, China
| | - Xiaochen Wang
- National Institute of Biological Sciences, Beijing 102206, China
| | - Chonglin Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
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Lant B, Derry WB. Fluorescent visualization of germline apoptosis in living Caenorhabditis elegans. Cold Spring Harb Protoc 2014; 2014:420-7. [PMID: 24692492 DOI: 10.1101/pdb.prot080226] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Visualization of apoptosis using fluorescent tools is quite straightforward in living Caenorhabditis elegans. Several transgenic lines are available that mark dying cells with fluorescent proteins, making it possible to quantify kinetics at various stages of the apoptotic process. Proteins required for the engulfment of cell corpses are particularly useful for detecting early apoptotic stages using this approach. For example, expression of the engulfment protein CED-1 fused to green fluorescent protein (CED-1::GFP) creates a halo around cells during early apoptosis, before their refractile morphology can be detected by differential interference contrast (DIC) optics. In addition, vital dyes such as acridine orange (AO) and SYTO-12 are selectively retained in apoptotic cells and can be used to visualize apoptosis in the germlines of living animals. It is also possible to use vital dyes in combination with transgenic strains expressing fluorescent markers of cell corpses to examine, in detail, multiple stages of apoptosis in vivo. Because of the high optical contrast of fluorescent reagents, apoptosis can be visualized even at low magnification, facilitating the use of screening platforms to identify apoptosis regulators. This protocol describes multiple uses of fluorescent reagents for visualization of germline apoptosis in living C. elegans, including AO staining, time-course studies using fluorescent proteins, and low-throughput screening of cell death genes using RNA interference (RNAi).
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Affiliation(s)
- Benjamin Lant
- Developmental and Stem Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada
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50
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Small GTPase CDC-42 promotes apoptotic cell corpse clearance in response to PAT-2 and CED-1 in C. elegans. Cell Death Differ 2014; 21:845-53. [PMID: 24632947 PMCID: PMC4013519 DOI: 10.1038/cdd.2014.23] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 11/27/2013] [Accepted: 12/17/2013] [Indexed: 12/26/2022] Open
Abstract
The rapid clearance of dying cells is important for the well-being of multicellular organisms. In C. elegans, cell corpse removal is mainly mediated by three parallel engulfment signaling cascades. These pathways include two small GTPases, MIG-2/RhoG and CED-10/Rac1. Here we present the identification and characterization of CDC-42 as a third GTPase involved in the regulation of cell corpse clearance. Genetic analyses performed by both loss of cdc-42 function and cdc-42 overexpression place cdc-42 in parallel to the ced-2/5/12 signaling module, in parallel to or upstream of the ced-10 module, and downstream of the ced-1/6/7 module. CDC-42 accumulates in engulfing cells at membranes surrounding apoptotic corpses. The formation of such halos depends on the integrins PAT-2/PAT-3, UNC-112 and the GEF protein UIG-1, but not on the canonical ced-1/6/7 or ced-2/5/12 signaling modules. Together, our results suggest that the small GTPase CDC-42 regulates apoptotic cell engulfment possibly upstream of the canonical Rac GTPase CED-10, by polarizing the engulfing cell toward the apoptotic corpse in response to integrin signaling and ced-1/6/7 signaling in C. elegans.
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