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Methods in Molecular Biology (Clifton,... 2017Cells depend on the lysosome for sequestration and degradation of macromolecules in order to maintain metabolic homeostasis. These membrane-enclosed organelles can... (Review)
Review
Cells depend on the lysosome for sequestration and degradation of macromolecules in order to maintain metabolic homeostasis. These membrane-enclosed organelles can receive intracellular and extracellular cargo through endocytosis, phagocytosis, and autophagy. Lysosomes establish acidic environments to activate enzymes that are able to break down biomolecules engulfed through these various pathways. Recent advances in methods to study the lysosome have allowed the discovery of extended roles for the lysosome in various diseases, including cancer, making it an attractive and targetable node for therapeutic intervention. This review focuses on key aspects of lysosomal biology in the context of cancer and how these properties can be exploited for the development of new therapeutic strategies. This will provide a contextual framework for how advances in methodology could be applied in future translational research.
Topics: Animals; Autophagy; Endocytosis; Humans; Lysosomes; Neoplasms; Phagocytosis
PubMed: 28456991
DOI: 10.1007/978-1-4939-6934-0_19 -
ELife Dec 2022The centrosome decides which branch extending from the body of microglia will successfully engulf and clear away dead neurons.
The centrosome decides which branch extending from the body of microglia will successfully engulf and clear away dead neurons.
Topics: Centrosome; Microglia; Neurons; Phagocytosis
PubMed: 36508246
DOI: 10.7554/eLife.84659 -
Glia Jun 2022Elimination of dead or live cells take place in both a healthy and diseased central nervous system (CNS). Dying or dead cells are quickly cleared by phagocytosis for the... (Review)
Review
Elimination of dead or live cells take place in both a healthy and diseased central nervous system (CNS). Dying or dead cells are quickly cleared by phagocytosis for the maintenance of a healthy CNS or for recovery after injury. Live cells or parts thereof, such as the synapses and myelin, are appropriately eliminated by phagocytosis to maintain or refine neural networks during development and adulthood. Microglia, the specific population of resident macrophages in the CNS, are classically considered as primary phagocytes; however, astrocytes have also been highlighted as phagocytes in the last decade. Phagocytic targets and receptors are reported to be mostly common between astrocytes and microglia, which raises the question of how astrocytic phagocytosis differs from microglial phagocytosis, and how these two phagocytic systems cooperate. In this review, we address the consequences of astrocytic phagocytosis, particularly focusing on these elusive points.
Topics: Astrocytes; Central Nervous System; Microglia; Phagocytes; Phagocytosis
PubMed: 35142399
DOI: 10.1002/glia.24145 -
Blood Jun 2022
Topics: B7-H1 Antigen; Extracellular Vesicles; Humans; Macrophages; Neoplasms; Phagocytosis; Tumor Suppressor Protein p53
PubMed: 35737407
DOI: 10.1182/blood.2022016100 -
Current Opinion in Cell Biology Dec 2021Neuronal-immune interactions are known to play crucial roles in brain development and homoeostasis. Of great relevance in this context are microglia, brain macrophages... (Review)
Review
Neuronal-immune interactions are known to play crucial roles in brain development and homoeostasis. Of great relevance in this context are microglia, brain macrophages that phagocytose neurons that die during development, and many neurological disorders. Single-cell RNA sequencing methods have significantly advanced our understanding of microglial heterogeneity and transcriptional response to environmental changes. Here, we review recent work showing how microglia adopt a similar molecular signature during development and disease characterised by the expression of genes linked to phagocytosis and lipid uptake and metabolism. These studies show that in many neurodegenerative conditions, microglia accumulate cholesterols and lipid-rich debris, pointing to lipid processing and transport as promising targets for developing new therapeutical treatments against neurodegenerative disorders.
Topics: Brain; Macrophages; Microglia; Neurons; Phagocytosis; Weight Prejudice
PubMed: 34455405
DOI: 10.1016/j.ceb.2021.07.007 -
Cell and Tissue Research Sep 2019The uptake of macromolecules and larger energy-rich particles into the cell is known as phagocytosis. Phagocytosed material is enzymatically degraded in membrane-bound... (Review)
Review
The uptake of macromolecules and larger energy-rich particles into the cell is known as phagocytosis. Phagocytosed material is enzymatically degraded in membrane-bound vesicles of the endosome/lysosome system (intracellular digestion). Whereas most, if not all, cells of the animal body are equipped with the molecular apparatus for phagocytosis and intracellular digestion, a few cell types are specialized for a highly efficient mode of phagocytosis. These are the ("professional") macrophages, motile cells that seek out and eliminate pathogenic invaders or damaged cells. Macrophages form the backbone of the innate immune system. Developmentally, they derive from specialized compartments within the embryonic mesoderm and early vasculature as part of the process of hematopoiesis. Intensive research has revealed in detail molecular and cellular mechanisms of phagocytosis and intracellular digestion in macrophages. In contrast, little is known about a second type of cell that is "professionally" involved in phagocytosis, namely the "enteric phagocyte." Next to secretory (zymogenic) cells, enteric phagocytes form one of the two major cell types of the intestine of most invertebrate animals. Unlike vertebrates, these invertebrates only partially digest food material in the intestinal lumen. The resulting food particles are absorbed by phagocytosis or pinocytosis and digested intracellularly. In this review, we provide a brief overview of the enteric phagocytes described electron microscopically for diverse invertebrate clades, to then to compare these cells with the "canonical" phagocyte ultrastructure established for macrophages. In addition, we will review observations and speculations associated with the hypothesis that macrophages are evolutionarily derived from enteric phagocytes. This idea was already proposed in the late nineteenth century by Elias Metschnikoff who pioneered the research of phagocytosis for both macrophages and enteric phagocytes. We presume that modern approaches to better understand phagocytosis will be helped by considering the deep evolutionary relationship between the two cell types.
Topics: Animals; Biological Evolution; Macrophages; Phagocytosis
PubMed: 31485720
DOI: 10.1007/s00441-019-03096-6 -
Sheng Li Xue Bao : [Acta Physiologica... Apr 2022With the acceleration of the aging society, neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD), have become a rapidly growing... (Review)
Review
With the acceleration of the aging society, neurodegenerative diseases, such as Alzheimer's disease (AD) and Parkinson's disease (PD), have become a rapidly growing global health crisis. Recent studies have indicated that microglia-neuron interactions are critical for maintaining homeostasis of the central nervous system. Genome-Wide Association Studies and brain imaging studies have suggested that microglia are activated in early stage of neurodegenerative diseases. Microglia are specialized phagocytes in the brain. The discovery of a new phagocytic pathway, trogocytosis, suggests that there is a close interaction between microglia and surviving neurons. In this review, we summarize the important roles of microglia in neurodegenerative diseases, and further analyze the functions and molecular mechanisms of microglia phagocytosis and trogocytosis.
Topics: Alzheimer Disease; Genome-Wide Association Study; Humans; Microglia; Neurodegenerative Diseases; Phagocytosis
PubMed: 35503076
DOI: No ID Found -
Pharmacology & Therapeutics Jan 2022Cell death and the clearance of apoptotic cells are tightly regulated by various signaling molecules in order to maintain physiological tissue function and homeostasis.... (Review)
Review
Cell death and the clearance of apoptotic cells are tightly regulated by various signaling molecules in order to maintain physiological tissue function and homeostasis. The phagocytic removal of apoptotic cells is known as the process of efferocytosis, and abnormal efferocytosis is linked to various health complications and diseases, such as cardiovascular disease, inflammatory diseases, and autoimmune diseases. During efferocytosis, phagocytic cells and/or apoptotic cells release signals, such as "find me" and "eat me" signals, to stimulate the phagocytic engulfment of apoptotic cells. Primary phagocytic cells are macrophages and dendritic cells; however, more recently, other neighboring cell types have also been shown to exhibit phagocytic character, including endothelial cells and fibroblasts, although they are comparatively slower in clearing dead cells. In this review, we focus on macrophage efferocytosis of vascular cells, such as endothelial cells, smooth muscle cells, fibroblasts, and pericytes, and its relation to the progression and development of cardiovascular disease. We also highlight the role of efferocytosis-related molecules and their contribution to the maintenance of vascular homeostasis.
Topics: Apoptosis; Cardiovascular Diseases; Endothelial Cells; Humans; Macrophages; Phagocytosis
PubMed: 34171333
DOI: 10.1016/j.pharmthera.2021.107919 -
Zoological Research May 2019Macrophages exist in most tissues and play a variety of functions in vertebrates. Teleost fish species are found in most aquatic environments throughout the world and... (Review)
Review
Macrophages exist in most tissues and play a variety of functions in vertebrates. Teleost fish species are found in most aquatic environments throughout the world and are quite diverse for a group of vertebrate animals. Due to whole genome duplication and environmental adaptation, teleost monocytes/macrophages possess a variety of different functions and modulations compared with those of mammals. A deeper understanding of teleost monocytes/macrophages in the immune system will not only help develop teleost-specific methods of disease prevention but will also help improve our understanding of the various immune mechanisms in mammals. In this review, we summarize the differences in polarization and phagocytosis of teleost and mammalian macrophages to improve our understanding of the various immune mechanisms in vertebrates.
Topics: Animals; Fishes; Macrophages; Monocytes; Phagocytosis
PubMed: 31011129
DOI: 10.24272/j.issn.2095-8137.2019.035 -
BMB Reports Oct 2017The human body loses several billions of cells daily. When cells die in vivo, the corpse of each dead cell is immediately cleared. Specifically, dead cells are... (Review)
Review
The human body loses several billions of cells daily. When cells die in vivo, the corpse of each dead cell is immediately cleared. Specifically, dead cells are efficiently recognized and cleared by multiple types of neighboring phagocytes. Early research on cell death focused more on molecular mechanisms of cell death regulation while the cellular corpses were merely considered cellular debris. However, it has come to light that various biological stimuli following cell death are important for immune regulation. Clearance of normal dead cells occurs silently in immune tolerance. Exogenous or mutated antigens of malignant or infected cells can initiate adaptive immunity, thereby inducing immunogenicity by adjuvant signals. Several pathogens and cancer cells have strategies to limit the adjuvant signals and escape immune surveillance. In this review, we present an overview of the mechanisms of dead cell clearance and its immune regulations. [BMB Reports 2017; 50(10): 496-503].
Topics: Animals; Apoptosis; Cell Death; Cytophagocytosis; Humans; Immune Tolerance; Immunity, Innate; Phagocytes; Phagocytosis
PubMed: 28768566
DOI: 10.5483/bmbrep.2017.50.10.147