RESUMO
Type 1 conventional dendritic (cDC1) cells are necessary for cross-presentation of many viral and tumor antigens to CD8+ T cells. cDC1 cells can be identified in mice and humans by high expression of DNGR-1 (also known as CLEC9A), a receptor that binds dead-cell debris and facilitates XP of corpse-associated antigens. Here, we show that DNGR-1 is a dedicated XP receptor that signals upon ligand engagement to promote phagosomal rupture. This allows escape of phagosomal contents into the cytosol, where they access the endogenous major histocompatibility complex class I antigen processing pathway. The activity of DNGR-1 maps to its signaling domain, which activates SYK and NADPH oxidase to cause phagosomal damage even when spliced into a heterologous receptor and expressed in heterologous cells. Our data reveal the existence of innate immune receptors that couple ligand binding to endocytic vesicle damage to permit MHC class I antigen presentation of exogenous antigens and to regulate adaptive immunity.
Assuntos
Apresentação de Antígeno , Apresentação Cruzada , Células Dendríticas/metabolismo , Lectinas Tipo C/metabolismo , Fagossomos/metabolismo , Receptores Imunológicos/metabolismo , Receptores Mitogênicos/metabolismo , Linfócitos T/metabolismo , Animais , Morte Celular , Técnicas de Cocultura , Células Dendríticas/imunologia , Células HEK293 , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Lectinas Tipo C/genética , Ligantes , Camundongos , NADPH Oxidases/metabolismo , Fagossomos/genética , Fagossomos/imunologia , Fosforilação , Células RAW 264.7 , Espécies Reativas de Oxigênio/metabolismo , Receptores Imunológicos/genética , Receptores Mitogênicos/genética , Transdução de Sinais , Quinase Syk/metabolismo , Linfócitos T/imunologiaRESUMO
The processes of life take place in multiple dimensions, but imaging these processes in even three dimensions is challenging. Here, we describe a workflow for 3D correlative light and electron microscopy (CLEM) of cell monolayers using fluorescence microscopy to identify and follow biological events, combined with serial blockface scanning electron microscopy to analyse the underlying ultrastructure. The workflow encompasses all steps from cell culture to sample processing, imaging strategy, and 3D image processing and analysis. We demonstrate successful application of the workflow to three studies, each aiming to better understand complex and dynamic biological processes, including bacterial and viral infections of cultured cells and formation of entotic cell-in-cell structures commonly observed in tumours. Our workflow revealed new insight into the replicative niche of Mycobacterium tuberculosis in primary human lymphatic endothelial cells, HIV-1 in human monocyte-derived macrophages, and the composition of the entotic vacuole. The broad application of this 3D CLEM technique will make it a useful addition to the correlative imaging toolbox for biomedical research.
Assuntos
Células Endoteliais/ultraestrutura , Imageamento Tridimensional , Macrófagos/ultraestrutura , Microscopia Eletrônica de Varredura/métodos , Sobrevivência Celular , Células Cultivadas , Células Endoteliais/microbiologia , Entose , HIV/ultraestrutura , Humanos , Espaço Intracelular/microbiologia , Macrófagos/virologia , Monócitos/citologia , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/ultraestruturaRESUMO
Dysregulation of nuclear envelope (NE) assembly results in various cancers; for example, renal and some lung carcinomas ensue due to NE malformation. The NE is a dynamic membrane compartment and its completion during mitosis is a highly regulated process, but the detailed mechanism still remains incompletely understood. Previous studies have found that isolated diacylglycerol (DAG)-containing vesicles are essential for completing the fusion of the NE in nonsomatic cells. We investigated the impact of DAG depletion from the cis-Golgi in mammalian cells on NE reassembly. Using advanced electron microscopy, we observed an enriched DAG population of vesicles at the vicinity of the NE gaps of telophase mammalian cells. We applied a mini singlet oxygen generator-C1-domain tag that localized DAG-enriched vesicles at the perinuclear region, which suggested the existence of NE fusogenic vesicles. We quantified the impact of Golgi-DAG depletion by measuring the in situ NE rim curvature of the reforming NE. The rim curvature in these cells was significantly reduced compared with controls, which indicated a localized defect in NE morphology. Our novel results demonstrate the significance of the role of DAG from the cis-Golgi for the regulation of NE assembly.
Assuntos
Diglicerídeos/metabolismo , Complexo de Golgi/metabolismo , Mitose , Membrana Nuclear/metabolismo , Células HeLa , HumanosRESUMO
Super-resolution light microscopy, correlative light and electron microscopy, and volume electron microscopy are revolutionising the way in which biological samples are examined and understood. Here, we combine these approaches to deliver super-accurate correlation of fluorescent proteins to cellular structures. We show that YFP and GFP have enhanced blinking properties when embedded in acrylic resin and imaged under partial vacuum, enabling in vacuo single molecule localisation microscopy. In conventional section-based correlative microscopy experiments, the specimen must be moved between imaging systems and/or further manipulated for optimal viewing. These steps can introduce undesirable alterations in the specimen, and complicate correlation between imaging modalities. We avoided these issues by using a scanning electron microscope with integrated optical microscope to acquire both localisation and electron microscopy images, which could then be precisely correlated. Collecting data from ultrathin sections also improved the axial resolution and signal-to-noise ratio of the raw localisation microscopy data. Expanding data collection across an array of sections will allow 3-dimensional correlation over unprecedented volumes. The performance of this technique is demonstrated on vaccinia virus (with YFP) and diacylglycerol in cellular membranes (with GFP).
Assuntos
Proteínas Luminescentes/análise , Microscopia Eletrônica de Varredura/métodos , Microscopia de Fluorescência/métodos , Imagem Individual de Molécula/métodos , Proteínas de Bactérias/análise , Diglicerídeos/análise , Desenho de Equipamento , Proteínas de Fluorescência Verde/análise , Razão Sinal-Ruído , VácuoRESUMO
To suggest and develop intelligent strategies to comprehend the regulation of organelle formation, a deeper mechanistic interpretation requires more than just the involvement of proteins. Our approaches link the formation of endomembranes with both signalling and membrane physical properties. Hitherto, membrane morphology, local physical structure and signalling have not been well integrated. Our studies derive from a cross-disciplinary approach undertaken to determine the molecular mechanisms of nuclear envelope assembly in echinoderm and mammalian cells. Our findings have led to the demonstration of a direct role for phosphoinositides and their derivatives in nuclear membrane formation. We have shown that phosphoinositides and their derivatives, as well as acting as second messengers, are modulators of membrane morphology, and their modifying enzymes regulate nuclear envelope formation. In addition, we have shown that echinoderm eggs can be exploited as a milieu to directly study the roles of phospholipids in maintaining organelle shape. The use of the echinoderm egg is a significant step forward in obtaining direct information about membrane physical properties in situ rather than using simpler models which do not provide a complete mechanistic insight into the role of phospholipids in membrane dynamics.
Assuntos
Bicamadas Lipídicas/química , Modelos Biológicos , Membrana Nuclear/química , Fosfolipídeos/química , Animais , Forma do Núcleo Celular , Equinodermos , Retículo Endoplasmático/química , Retículo Endoplasmático/metabolismo , Corantes Fluorescentes/química , Humanos , Bicamadas Lipídicas/metabolismo , Fusão de Membrana , Membrana Nuclear/metabolismo , Óvulo/química , Fosfatidilinositóis/química , Fosfatidilinositóis/metabolismo , Fosfolipídeos/metabolismoRESUMO
Autophagy is essential for neuronal development and its deregulation contributes to neurodegenerative diseases. NDR1 and NDR2 are highly conserved kinases, implicated in neuronal development, mitochondrial health and autophagy, but how they affect mammalian brain development in vivo is not known. Using single and double Ndr1/2 knockout mouse models, we show that only dual loss of Ndr1/2 in neurons causes neurodegeneration. This phenotype was present when NDR kinases were deleted both during embryonic development, as well as in adult mice. Proteomic and phosphoproteomic comparisons between Ndr1/2 knockout and control brains revealed novel kinase substrates and indicated that endocytosis is significantly affected in the absence of NDR1/2. We validated the endocytic protein Raph1/Lpd1, as a novel NDR1/2 substrate, and showed that both NDR1/2 and Raph1 are critical for endocytosis and membrane recycling. In NDR1/2 knockout brains, we observed prominent accumulation of transferrin receptor, p62 and ubiquitinated proteins, indicative of a major impairment of protein homeostasis. Furthermore, the levels of LC3-positive autophagosomes were reduced in knockout neurons, implying that reduced autophagy efficiency mediates p62 accumulation and neurotoxicity. Mechanistically, pronounced mislocalisation of the transmembrane autophagy protein ATG9A at the neuronal periphery, impaired axonal ATG9A trafficking and increased ATG9A surface levels further confirm defects in membrane trafficking, and could underlie the impairment in autophagy. We provide novel insight into the roles of NDR1/2 kinases in maintaining neuronal health.
Assuntos
Autofagia , Proteômica , Feminino , Gravidez , Animais , Camundongos , Autofagossomos , Neurônios , Proteostase , Proteínas de Membrana/genética , MamíferosRESUMO
Metastasis involves dissemination of cancer cells away from a primary tumour and colonization at distal sites. During this process, the mechanical properties of the nucleus must be tuned since they pose a challenge to the negotiation of physical constraints imposed by the microenvironment and tissue structure. We discovered increased expression of the inner nuclear membrane protein LAP1 in metastatic melanoma cells, at the invasive front of human primary melanoma tumours and in metastases. Human cells express two LAP1 isoforms (LAP1B and LAP1C), which differ in their amino terminus. Here, using in vitro and in vivo models that recapitulate human melanoma progression, we found that expression of the shorter isoform, LAP1C, supports nuclear envelope blebbing, constrained migration and invasion by allowing a weaker coupling between the nuclear envelope and the nuclear lamina. We propose that LAP1 renders the nucleus highly adaptable and contributes to melanoma aggressiveness.
Assuntos
Melanoma , Membrana Nuclear , Humanos , Isoformas de Proteínas/metabolismo , Movimento Celular , Membrana Nuclear/metabolismo , Melanoma/genética , Melanoma/metabolismo , Microambiente TumoralRESUMO
Vascularization is driven by morphogen signals and mechanical cues that coordinately regulate cellular force generation, migration, and shape change to sculpt the developing vascular network. However, it remains unclear whether developing vasculature actively regulates its own mechanical properties to achieve effective vascularization. We engineered tissue constructs containing endothelial cells and fibroblasts to investigate the mechanics of vascularization. Tissue stiffness increases during vascular morphogenesis resulting from emergent interactions between endothelial cells, fibroblasts, and ECM and correlates with enhanced vascular function. Contractile cellular forces are key to emergent tissue stiffening and synergize with ECM mechanical properties to modulate the mechanics of vascularization. Emergent tissue stiffening and vascular function rely on mechanotransduction signaling within fibroblasts, mediated by YAP1. Mouse embryos lacking YAP1 in fibroblasts exhibit both reduced tissue stiffness and develop lethal vascular defects. Translating our findings through biology-inspired vascular tissue engineering approaches will have substantial implications in regenerative medicine.
Assuntos
Células Endoteliais , Mecanotransdução Celular , Camundongos , Animais , Mecanotransdução Celular/fisiologia , Engenharia Tecidual/métodos , Morfogênese , Diferenciação Celular , Matriz ExtracelularRESUMO
Somatic mutations commonly occur in hematopoietic stem cells (HSCs). Some mutant clones outgrow through clonal hematopoiesis (CH) and produce mutated immune progenies shaping host immunity. Individuals with CH are asymptomatic but have an increased risk of developing leukemia, cardiovascular and pulmonary inflammatory diseases, and severe infections. Using genetic engineering of human HSCs (hHSCs) and transplantation in immunodeficient mice, we describe how a commonly mutated gene in CH, TET2, affects human neutrophil development and function. TET2 loss in hHSCs produce a distinct neutrophil heterogeneity in bone marrow and peripheral tissues by increasing the repopulating capacity of neutrophil progenitors and giving rise to low-granule neutrophils. Human neutrophils that inherited TET2 mutations mount exacerbated inflammatory responses and have more condensed chromatin, which correlates with compact neutrophil extracellular trap (NET) production. We expose here physiological abnormalities that may inform future strategies to detect TET2-CH and prevent NET-mediated pathologies associated with CH.
Assuntos
Dioxigenases , Neutrófilos , Humanos , Camundongos , Animais , Proteínas Proto-Oncogênicas , Células-Tronco Hematopoéticas/fisiologia , Medula Óssea , Hematopoese/genética , Mutação , Proteínas de Ligação a DNA/genética , Dioxigenases/genéticaRESUMO
A variable (GT)(n) repeat in the 5'-regulatory region of N-methyl-D-aspartate GRIN2A subtype has recently been identified and associated with psychiatric disorders. In this study, we examined the association of this polymorphism with alcohol dependence. Subject-control analysis included 206 alcohol-dependent and 168 control subjects. Average observed repeat numbers and genotype distributions were significantly different (P-value = 0.001) in alcohol-dependent subjects versus control subjects. Short alleles were significantly less frequent among alcohol-dependent subjects (odds ratio = 0.58, P-value = 7 × 10(-4)). These results could be replicated in an independent sample of 116 alcohol-dependent subjects. For the first time, a significant association was identified between this polymorphism and alcoholism.
Assuntos
Alcoolismo/genética , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas/genética , Receptores de N-Metil-D-Aspartato/genética , Adulto , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Rewiring of cellular programmes in malignant cells generates cancer-specific vulnerabilities. Here, using an unbiased screening strategy aimed at identifying non-essential genes required by tumour cells to sustain unlimited proliferative capacity, we identify the male-specific lethal (MSL) acetyltransferase complex as a vulnerability of genetically unstable cancers. We find that disruption of the MSL complex and consequent loss of the associated H4K16ac mark do not substantially alter transcriptional programmes but compromise chromosome integrity and promote chromosomal instability (CIN) that progressively exhausts the proliferative potential of cancer cells through a p53-independent mechanism. This effect is dependent on pre-existing genomic instability, and normal cells are insensitive to MSL disruption. Using cell- and patient-derived xenografts from multiple cancer types, we show that excessive CIN induced by MSL disruption inhibits tumour maintenance. Our findings suggest that targeting MSL may be a valuable means to increase CIN beyond the level tolerated by cancer cells without inducing severe adverse effects in normal tissues.
Assuntos
Proliferação de Células/genética , Instabilidade Cromossômica/genética , Complexos Multiproteicos/genética , Neoplasias/genética , Animais , Linhagem Celular Tumoral , Reprogramação Celular/genética , Proteínas Cromossômicas não Histona/genética , Proteínas de Ligação a DNA/genética , Xenoenxertos , Histona Acetiltransferases/genética , Humanos , Camundongos , Neoplasias/patologia , Fatores de Transcrição/genética , Proteína Supressora de Tumor p53/genética , Ubiquitina-Proteína Ligases/genéticaRESUMO
Interferon-inducible guanylate-binding proteins (GBPs) promote cell-intrinsic defense through host cell death. GBPs target pathogens and pathogen-containing vacuoles and promote membrane disruption for release of microbial molecules that activate inflammasomes. GBP1 mediates pyroptosis or atypical apoptosis of Salmonella Typhimurium (STm)- or Toxoplasma gondii (Tg)- infected human macrophages, respectively. The pathogen-proximal detection-mechanisms of GBP1 remain poorly understood, as humans lack functional immunity-related GTPases (IRGs) that assist murine Gbps. Here, we establish that GBP1 promotes the lysis of Tg-containing vacuoles and parasite plasma membranes, releasing Tg-DNA. In contrast, we show GBP1 targets cytosolic STm and recruits caspase-4 to the bacterial surface for its activation by lipopolysaccharide (LPS), but does not contribute to bacterial vacuole escape. Caspase-1 cleaves and inactivates GBP1, and a cleavage-deficient GBP1D192E mutant increases caspase-4-driven pyroptosis due to the absence of feedback inhibition. Our studies elucidate microbe-specific roles of GBP1 in infection detection and its triggering of the assembly of divergent caspase signaling platforms.
Assuntos
Caspases/imunologia , Proteínas de Ligação ao GTP/imunologia , Salmonella typhimurium/imunologia , Toxoplasma/imunologia , Morte Celular/imunologia , Células HEK293 , Humanos , Inflamassomos/imunologia , Interferon gama/farmacologia , Ligantes , Infecções por Salmonella/imunologia , Infecções por Salmonella/microbiologia , Células THP-1 , Toxoplasma/genética , Toxoplasmose/imunologia , Toxoplasmose/microbiologia , Vacúolos/imunologiaRESUMO
Toxoplasma gondii is an obligate intracellular parasite capable of invading any nucleated cell. Three main clonal lineages (type I, II, III) exist and murine models have driven the understanding of general and strain-specific immune mechanisms underlying Toxoplasma infection. However, murine models are limited for studying parasite-leukocyte interactions in vivo, and discrepancies exist between cellular immune responses observed in mouse versus human cells. Here, we developed a zebrafish infection model to study the innate immune response to Toxoplasma in vivo By infecting the zebrafish hindbrain ventricle, and using high-resolution microscopy techniques coupled with computer vision-driven automated image analysis, we reveal that Toxoplasma invades brain cells and replicates inside a parasitophorous vacuole to which type I and III parasites recruit host cell mitochondria. We also show that type II and III strains maintain a higher infectious burden than type I strains. To understand how parasites are cleared in vivo, we further analyzed Toxoplasma-macrophage interactions using time-lapse microscopy and three-dimensional correlative light and electron microscopy (3D CLEM). Time-lapse microscopy revealed that macrophages are recruited to the infection site and play a key role in Toxoplasma control. High-resolution 3D CLEM revealed parasitophorous vacuole breakage in brain cells and macrophages in vivo, suggesting that cell-intrinsic mechanisms may be used to destroy the intracellular niche of tachyzoites. Together, our results demonstrate in vivo control of Toxoplasma by macrophages, and highlight the possibility that zebrafish may be further exploited as a novel model system for discoveries within the field of parasite immunity.This article has an associated First Person interview with the first author of the paper.
Assuntos
Macrófagos/parasitologia , Rombencéfalo/microbiologia , Toxoplasma/crescimento & desenvolvimento , Toxoplasmose Animal/parasitologia , Toxoplasmose Cerebral/parasitologia , Peixe-Zebra/parasitologia , Animais , Modelos Animais de Doenças , Interações Hospedeiro-Parasita , Macrófagos/imunologia , Macrófagos/ultraestrutura , Microscopia Confocal , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Microscopia de Vídeo , Carga Parasitária , Rombencéfalo/imunologia , Rombencéfalo/ultraestrutura , Fatores de Tempo , Toxoplasma/imunologia , Toxoplasma/ultraestrutura , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/patologia , Toxoplasmose Cerebral/imunologia , Toxoplasmose Cerebral/patologiaRESUMO
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
RESUMO
YAP1 gene fusions have been observed in a subset of paediatric ependymomas. Here we show that, ectopic expression of active nuclear YAP1 (nlsYAP5SA) in ventricular zone neural progenitor cells using conditionally-induced NEX/NeuroD6-Cre is sufficient to drive brain tumour formation in mice. Neuronal differentiation is inhibited in the hippocampus. Deletion of YAP1's negative regulators LATS1 and LATS2 kinases in NEX-Cre lineage in double conditional knockout mice also generates similar tumours, which are rescued by deletion of YAP1 and its paralog TAZ. YAP1/TAZ-induced mouse tumours display molecular and ultrastructural characteristics of human ependymoma. RNA sequencing and quantitative proteomics of mouse tumours demonstrate similarities to YAP1-fusion induced supratentorial ependymoma. Finally, we find that transcriptional cofactor HOPX is upregulated in mouse models and in human YAP1-fusion induced ependymoma, supporting their similarity. Our results show that uncontrolled YAP1/TAZ activity in neuronal precursor cells leads to ependymoma-like tumours in mice.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Neoplasias Encefálicas/metabolismo , Proteínas de Ciclo Celular/metabolismo , Ependimoma/metabolismo , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Adulto , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Encéfalo/ultraestrutura , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Proteínas de Ciclo Celular/genética , Criança , Ependimoma/genética , Ependimoma/patologia , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Camundongos Knockout , Camundongos Transgênicos , Microscopia Eletrônica de Varredura , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transativadores/genética , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Proteínas de Sinalização YAPRESUMO
BACKGROUND/AIMS: Liver pathology induced by chemotherapy (steatosis or vascular injury) is known to increase the liver's sensitivity to ischemia/ reperfusion (I/R) injury, thereby increasing morbidity and mortality after liver resection. Our aim was to assess whether ischemic preconditioning (IP) reduces I/R injury to livers with chemotherapy-induced pathology. METHODS: We analyzed a series of livers from patients treated with chemotherapy for colorectal cancer who underwent IP (n=30) or not (n=31) before hepatectomy. All but one of the livers exhibited chemotherapy-induced steatosis and/ or peliosis before the I/R insult. RESULTS: Necrosis was less frequent (p=0.038) in livers with IP than in the others. IP had no influence on apoptosis as assessed by terminal transferase uridyl nick-end labeling (TUNEL) assay or caspase-3, -8 and -9 expression. IP induced a twofold increase in B-cell leukemia/ lymphoma 2 (Bcl-2; p<0.05), which was localized to hepatocytes of centrolobular and peliotic areas and colocalized with the autophagy protein beclin-1 in livers with IP, suggesting their coordinated role in autophagy. Increased expression of the phosphorylated Bcl-2 was observed in preconditioned livers and was associated with a decreased immunoprecipitation of beclin-1 and the increased expression of light chain 3 type II (LC3-II). The increased number of autophagic vacuoles seen by electron microscopy confirmed an association of autophagy in chemotherapy-injured livers following IP. However, the differences in protein expression were not reflected in postresection liver-injury tests or measure of patient morbidity. CONCLUSIONS: IP is associated with a reduction in necrosis of hepatocytes already damaged by chemotherapy and an activation of autophagy. Bcl-2 and beclin-1 could be major targets in the regulation of cell death during I/R injury.
Assuntos
Precondicionamento Isquêmico , Fígado/irrigação sanguínea , Fígado/patologia , Idoso , Apoptose , Proteínas Reguladoras de Apoptose/metabolismo , Autofagia , Proteína Beclina-1 , Neoplasias Colorretais/tratamento farmacológico , Feminino , Humanos , Fígado/lesões , Fígado/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/cirurgia , Masculino , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Necrose , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Traumatismo por Reperfusão/prevenção & controleRESUMO
Cancer metastasis depends on cell survival following loss of extracellular matrix attachment and dissemination through the circulation. The metastatic spread can be enhanced by the clustering of detached cancer cells and increased antioxidant defense. Here, we link these responses by describing how cell clustering limits reactive oxygen species (ROS). Loss of attachment causes mitochondrial perturbations and increased ROS production. The formation of cell clusters induces a hypoxic environment that drives hypoxia-inducible factor 1-alpha (Hif1α)-mediated mitophagy, clearing damaged mitochondria and limiting ROS. However, hypoxia and reduced mitochondrial capacity promote dependence on glycolysis for ATP production that is supported by cytosolic reductive metabolism. Preventing this metabolic adaptation or disruption of cell clusters results in ROS accumulation, cell death, and a reduction of metastatic capacity in vivo. Our results provide a mechanistic explanation for the role of cell clustering in supporting survival during extracellular matrix detachment and metastatic spread and may point to targetable vulnerabilities.
Assuntos
Mitocôndrias/metabolismo , Metástase Neoplásica/patologia , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Hipóxia Celular , Movimento Celular , Sobrevivência Celular , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , MitofagiaRESUMO
Metazoan cell death mechanisms are diverse and include numerous non-apoptotic programs. One program called entosis involves the invasion of live cells into their neighbors and is known to occur in cancers. Here, we identify a developmental function for entosis: to clear the male-specific linker cell in C. elegans. The linker cell leads migration to shape the gonad and is removed to facilitate fusion of the gonad to the cloaca. We find that the linker cell is cleared in a manner involving cell-cell adhesions and cell-autonomous control of uptake through linker cell actin. Linker cell entosis generates a lobe structure that is deposited at the site of gonad-to-cloaca fusion and is removed during mating. Inhibition of lobe scission inhibits linker cell death, demonstrating that the linker cell invades its host while alive. Our findings demonstrate a developmental function for entosis: to eliminate a migrating cell and facilitate gonad-to-cloaca fusion, which is required for fertility.