scholarly journals bfc, a novel serpent co-factor for the expression of croquemort, regulates efferocytosis in Drosophila melanogaster

PLoS Genetics ◽  
2021 ◽  
Vol 17 (12) ◽  
pp. e1009947
Author(s):  
Qian Zheng ◽  
Ning Gao ◽  
Qiling Sun ◽  
Xiaowen Li ◽  
Yanzhe Wang ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Apoptotic Cell ◽  
Scavenger Receptor ◽  
Apoptotic Cells ◽  
Zinc Finger Domain ◽  
Related Protein ◽  
Developmental Defects ◽  
Surface Receptors ◽  
Gata Transcription Factor ◽  
Direct Binding

Efferocytosis is the process by which phagocytes recognize, engulf, and digest (or clear) apoptotic cells during development. Impaired efferocytosis is associated with developmental defects and autoimmune diseases. In Drosophila melanogaster, recognition of apoptotic cells requires phagocyte surface receptors, including the scavenger receptor CD36-related protein, Croquemort (Crq, encoded by crq). In fact, Crq expression is upregulated in the presence of apoptotic cells, as well as in response to excessive apoptosis. Here, we identified a novel gene bfc (booster for croquemort), which plays a role in efferocytosis, specifically the regulation of the crq expression. We found that Bfc protein interacts with the zinc finger domain of the GATA transcription factor Serpent (Srp), to enhance its direct binding to the crq promoter; thus, they function together in regulating crq expression and efferocytosis. Overall, we show that Bfc serves as a Srp co-factor to upregulate the transcription of the crq encoded receptor, and consequently boosts macrophage efferocytosis in response to excessive apoptosis. Therefore, this study clarifies how phagocytes integrate apoptotic cell signals to mediate efferocytosis.

scholarly journals Oxidized phosphatidylserine–CD36 interactions play an essential role in macrophage-dependent phagocytosis of apoptotic cells

2006 ◽  
Vol 203 (12) ◽  
pp. 2613-2625 ◽  
Author(s):  
Michael E. Greenberg ◽  
Mingjiang Sun ◽  
Renliang Zhang ◽  
Maria Febbraio ◽  
Roy Silverstein ◽  
...  
Keyword(s):  
Molecular Species ◽  
Essential Role ◽  
Apoptotic Cell ◽  
Scavenger Receptor ◽  
Apoptotic Cells ◽  
Class B ◽  
Oxidized Phosphatidylcholine ◽  
Cell Engulfment

The phagocytosis of apoptotic cells within an organism is a critical terminal physiological process in programmed cell death. Evidence suggests that apoptotic cell engulfment and removal by macrophages is facilitated by phosphatidylserine (PS) displayed at the exofacial surface of the plasma membrane; however, neither the macrophage receptors responsible for PS recognition, nor characterization of the PS molecular species potentially involved, have been clearly defined. We show that the class B scavenger receptor CD36 plays an essential role in macrophage clearance of apoptotic cells in vivo. Further, macrophage recognition of apoptotic cells via CD36 is shown to occur via interactions with membrane-associated oxidized PS (oxPS) and, to a lesser extent, oxidized phosphatidylcholine, but not nonoxidized PS molecular species. Mass spectrometry analyses of oxPS species identify structures of candidate ligands for CD36 in apoptotic membranes that may facilitate macrophage recognition. Collectively, these results identify oxPS–CD36 interactions on macrophages as potential participants in a broad range of physiologic processes where macrophage-mediated engulfment of apoptotic cells is involved.

scholarly journals The inflammatory response induced by Pseudomonas aeruginosa in macrophages enhances apoptotic cell removal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adriana Valeria Jäger ◽  
Paula Arias ◽  
Maria Virginia Tribulatti ◽  
Marcela Adriana Brocco ◽  
Maria Victoria Pepe ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Pseudomonas Aeruginosa ◽  
Inflammatory Response ◽  
Apoptotic Cell ◽  
Bacterial Pathogen ◽  
Environmental Cues ◽  
Apoptotic Cells ◽  
Phagocytic Function ◽  
Inflammatory Stimulus ◽  
Inflammatory Conditions

AbstractPathogens phagocytosis and the uptake of apoptotic cells (efferocytosis) are essential macrophages tasks, classically considered as mutually exclusive. Macrophages have been observed to polarize into either pro-inflammatory/microbicidal or anti-inflammatory/efferocytic phenotypes. However, macrophage functions have shown to be more complex. Furthermore, little is known about the regulation of efferocytosis under inflammatory conditions. In this study, we elucidate the modulation of the macrophage efferocytic function during an inflammatory stimulus. We find that bone marrow-derived macrophages (BMDM) are very efficient in engulfing both the bacterial pathogen Pseudomonas aeruginosa and apoptotic cells. BMDM showed a high bactericidal capacity unaffected by the concomitant presence of apoptotic material. Plasticity in macrophage programming, in response to changing environmental cues, may modulate efferocytic capability. In this work, we further show that, after phagocyting and processing Pseudomonas aeruginosa, macrophages highly increase their efferocytic capacity without affecting their phagocytic function. Moreover, we demonstrate that Pseudomonas aeruginosa enhances efferocytosis of these phagocytes through the IL-6 signaling pathway. Our results show that the inflammatory response generated by the bacterial processing enhances these macrophages’ capacity to control inflammation through an increased efferocytosis.

scholarly journals Cytotoxicity, Antiproliferative Effects, and Apoptosis Induction of Methanolic Extract ofCynometra caulifloraLinn. Whole Fruit on Human Promyelocytic Leukemia HL-60 Cells

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
T-Johari S. A. Tajudin ◽  
Nashriyah Mat ◽  
Abu Bakar Siti-Aishah ◽  
A. Aziz M. Yusran ◽  
Afnani Alwi ◽  
...  
Keyword(s):  
Cell Death ◽  
Methanolic Extract ◽  
Apoptotic Cell ◽  
Mouse Fibroblast ◽  
Promyelocytic Leukemia ◽  
Apoptotic Cell Death ◽  
Apoptotic Cells ◽  
3T3 Cells ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

Methanolic extract ofCynometra cauliflorawhole fruit was assayed for cytotoxicity against the human promyelocytic leukemia HL-60 and the normal mouse fibroblast NIH/3T3 cell lines by using the MTT assay. The CD50of the extract for 72 hours was 0.9 μg/mL whereas the value for the cytotoxic drug vincristine was 0.2 μg/mL. The viability of the NIH/3T3 cells was at 80.0% when treated at 15.0 μg/mL. The extract inhibited HL-60 cell proliferation with dose dependence. AO/PI staining of HL-60 cells treated with the extract revealed that majority of cells were in the apoptotic cell death mode. Flow cytometry analysis of HL-60 cells treated at CD50of the extract showed that the early apoptotic cells were 31.0, 26.3 and 19.9% at 24, 48, and 72 hours treatment, respectively. The percentage of late apoptotic cells was increased from 62.0 at 24 hours to 64.1 and 70.2 at 48 and 72 hours, respectively. Meanwhile, percent of necrotic cells were 4.9, 6.6, and 8.5 at 24, 48, and 72 hours, respectively. This study has shown that the methanolic extract ofC. cauliflorawhole fruit was cytotoxic towards HL-60 cells and induced the cells into apoptotic cell death mode, but less cytotoxic towards NIH/3T3 cells.

Structure of the insect head as revealed by the EN protein pattern in developing embryos

Development ◽  
1996 ◽  
Vol 122 (11) ◽  
pp. 3419-3432 ◽  
Author(s):  
B.T. Rogers ◽  
T.C. Kaufman
Keyword(s):  
Drosophila Melanogaster ◽  
Pattern Formation ◽  
Protein Pattern ◽  
Related Protein ◽  
Specific Expression ◽  
Tissue Specific Expression ◽  
Single Segment ◽  
Dorsal Ridge ◽  
Insect Embryos ◽  
Comparative Embryology

The structure of the insect head has long been a topic of enjoyable yet endless debate among entomologists. More recently geneticists and molecular biologists trying to better understand the structure of the head of the Dipteran Drosophila melanogaster have joined the discourse extrapolating from what they have learned about Drosophila to insects in general. Here we present the results of an investigation into the structure of the insect head as revealed by the distribution of engrailed related protein (Engrailed) in the insect orders Diptera, Siphonaptera, Orthoptera and Hemiptera. The results of this comparative embryology in conjunction with genetic experiments on Drosophila melanogaster lead us to conclude: (1) The insect head is composed of six Engrailed accumulating segments, four postoral and two preoral. The potential seventh and eighth segments (clypeus or labrum) do not accumulate Engrailed. (2) The structure known as the dorsal ridge is not specific to the Diptera but is homologous to structures found in other insect orders. (3) A part of this structure is a single segment-like entity composed of labial and maxillary segment derivatives which produce the most anterior cuticle capable of taking a dorsal fate. The segments anterior to the maxillary segment produce only ventral structures. (4) As in Drosophila, the process of segmentation of the insect head is fundamentally different from the process of segmentation in the trunk. (5) The pattern of Engrailed accumulation and its presumed role in the specification and development of head segments appears to be highly conserved while its role in other pattern formation events and tissue-specific expression is variable. An overview of the pattern of Engrailed accumulation in developing insect embryos provides a basis for discussion of the generality of the parasegment and the evolution of Engrailed patterns.

Kinase cascades regulating entry into apoptosis

1997 ◽  
Vol 61 (1) ◽  
pp. 33-46
Author(s):  
P Anderson
Keyword(s):  
Cell Death ◽  
Cell Surface ◽  
Cell Survival ◽  
Tyrosine Kinases ◽  
Uv Light ◽  
Apoptotic Cell ◽  
Paracrine Factors ◽  
Surface Receptors ◽  
Promote Cell Survival ◽  
Necrosis Factor

All cells are constantly exposed to conflicting environment cues that signal cell survival or cell death. Survival signals are delivered by autocrine or paracrine factors that actively suppress a default death pathway. In addition to survival factor withdrawal, cell death can be triggered by environmental stresses such as heat, UV light, and hyperosmolarity or by dedicated death receptors (e.g., FAS/APO-1 and tumor necrosis factor [TNF] receptors) that are counterparts of growth factor or survival receptors at the cell surface. One of the ways that cells integrate conflicting exogenous stimuli is by phosphorylation (or dephosphorylation) of cellular constituents by interacting cascades of serine/threonine and tyrosine protein kinases (and phosphatases). Survival factors (e.g., growth factors and mitogens) activate receptor tyrosine kinases and selected mitogen-activated, cyclin-dependent, lipid-activated, nucleic acid-dependent, and cyclic AMP-dependent kinases to promote cell survival and proliferation, whereas environmental stress (or death factors such as FAS/APO-1 ligand and TNF-alpha) activates different members of these kinase families to inhibit cell growth and, under some circumstances, promote apoptotic cell death. Because individual kinase cascades can interact with one another, they are able to integrate conflicting exogenous stimuli and provide a link between cell surface receptors and the biochemical pathways leading to cell proliferation or cell death.

scholarly journals Hydrocortisone decreases apoptosis in jejunum of horses subjected to experimental ischemia and reperfusion

2011 ◽  
Vol 31 (6) ◽  
pp. 471-476 ◽  
Author(s):  
Geraldo Eleno S. Alves ◽  
Heloisa M.F. Mendes ◽  
Tiago G.S. Alves ◽  
Rafael R. Faleiros ◽  
Anilton C. Vasconcelos ◽  
...  
Keyword(s):  
Cell Death ◽  
Time Course ◽  
Apoptotic Cell ◽  
Treated Group ◽  
Apoptotic Cell Death ◽  
Apoptotic Cells ◽  
Ischemia And Reperfusion ◽  
Beneficial Effects ◽  
Time Zero ◽  
Venous Ischemia

In order to evaluate the effect of hydrocortisone on apoptosis in the jejunum of horses subjected to ischemia and reperfusion, ten horses were paired and grouped into two groups - treated (n=5) and non treated (n=5). Segments of the jejunum were used as controls (C), or as venous ischemia (VIsc), which were subjected to 2h of ischemia followed by 2 or 12h of reperfusion. C samples were collected at time zero (prior to ischemia) and VIsc samples were collected at 2h of ischemia and at 2 and 12h of reperfusion. TUNEL positive apoptotic cells were counted in 10 microscopical fields in deep mucosa from each horse throughout the time course. After 12h of reperfusion, the number of apoptotic cells in treated group were significantly lower than in untreated animals, indicating that hydrocortisone inhibits apoptosis. These results indicate that hydrocortisone has a beneficial effects favoring the maintenance of jejunal integrity in horses with ischemia and reperfusion injuries by preventing apoptotic cell death.

scholarly journals Different Roles of a Rat Cortical Thymic Epithelial Cell LineIn Vitroon Thymocytes and Thymocyte Hybridoma Cells: Phagocytosis, Induction of Apoptosis, Nursing and Growth Promoting Activities

2002 ◽  
Vol 9 (2) ◽  
pp. 63-72 ◽  
Author(s):  
Dragana Vucevic ◽  
Miodrag Colic ◽  
Petar Popovic ◽  
Sonja Gašic
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Apoptotic Cell ◽  
Hybridoma Cells ◽  
Thymic Epithelial Cell ◽  
Apoptotic Cells ◽  
Th Cells ◽  
Nursing Activity ◽  
Induction Of Apoptosis ◽  
Stimulation Of

In this work, the interaction between a rat cortical thymic epithelial cell (TEC) line (R-TNC.1) with nursing activity and thymocytes as well as BWRT 8 thymocyte hybridoma (TH) cells has been studied. The R-TNC.1 cell line significantly bound thymocytes and TH. Binding was stronger during the first 30 min of cell incubation and was followed by a progressive deadhesion. Among adherent thymocytes the proportion of apoptotic cells increased with culture time which was a consequence of higher capacity of the line for binding of apoptotic than viable cells and induction of apoptosis in a subset of adherent thymocytes. Emperiopolesis activity of this thymic nurse cell (TNC) line was manifested by engulfment of thymocytes as well as TH cells. A subset of viable intra-TNC thymocytes has been triggered to die by apoptosis, whereas other internalized thymocytes have been stimulated to proliferate, as measured by an increase in the percentage of cells in mitosis and higher incorporation of bromodeoxyuridine (BrdU), in comparison to thymocytes cultivated alone. A significant stimulation of proliferation of engulfed TH cells was also observed. The R-TNC.1 cell line efficiently phagocytosed both apoptotic thymocytes and TH, and the process is followed by intra-TNC destruction of ingested cells. Cumulatively, these results suggest different role of the R-TNC.1 clone: phagocytosis of apoptotic cells; induction of apoptotic cell death in a subset of both bound and internalized thymocytes and stimulation of proliferation of a subset of intra-TNC thymocytes or TH cells.

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