Biomaterial Database

Understanding photoreceptor outer segment phagocytosis: use and utility of RPE cells in culture. 2014

Francesca Mazzoni, and Hussein Safa, and Silvia C Finnemann

Department of Biological Sciences, Center for Cancer, Genetic Diseases, and Gene Regulation, Fordham University, Bronx, NY 10458, USA.

RPE cells are the most actively phagocytic cells in the human body. In the eye, RPE cells face rod and cone photoreceptor outer segments at all times but contribute to shedding and clearance phagocytosis of distal outer segment tips only once a day. Analysis of RPE phagocytosis in situ has succeeded in identifying key players of the RPE phagocytic mechanism. Phagocytic processes comprise three distinct phases, recognition/binding, internalization, and digestion, each of which is regulated separately by phagocytes. Studies of phagocytosis by RPE cells in culture allow specifically analyzing and manipulating these distinct phases to identify their molecular mechanisms. Here, we compare similarities and differences of primary, immortalized, and stem cell-derived RPE cells in culture to RPE cells in situ with respect to phagocytic function. We discuss in particular potential pitfalls of RPE cell culture phagocytosis assays. Finally, we point out considerations for phagocytosis assay development for future studies.

UI	MeSH Term	Description	Entries
D008954	Models, Biological	Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.	Biological Model,Biological Models,Model, Biological,Models, Biologic,Biologic Model,Biologic Models,Model, Biologic
D010587	Phagocytosis	The engulfing and degradation of microorganisms; other cells that are dead, dying, or pathogenic; and foreign particles by phagocytic cells (PHAGOCYTES).	Phagocytoses
D010588	Phagosomes	Membrane-bound cytoplasmic vesicles formed by invagination of phagocytized material. They fuse with lysosomes to form phagolysosomes in which the hydrolytic enzymes of the lysosome digest the phagocytized material.	Phagolysosomes,Phagolysosome,Phagosome
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013234	Stem Cells	Relatively undifferentiated cells that retain the ability to divide and proliferate throughout postnatal life to provide progenitor cells that can differentiate into specialized cells.	Colony-Forming Units,Mother Cells,Progenitor Cells,Colony-Forming Unit,Cell, Mother,Cell, Progenitor,Cell, Stem,Cells, Mother,Cells, Progenitor,Cells, Stem,Colony Forming Unit,Colony Forming Units,Mother Cell,Progenitor Cell,Stem Cell
D015398	Signal Transduction	The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.	Cell Signaling,Receptor-Mediated Signal Transduction,Signal Pathways,Receptor Mediated Signal Transduction,Signal Transduction Pathways,Signal Transduction Systems,Pathway, Signal,Pathway, Signal Transduction,Pathways, Signal,Pathways, Signal Transduction,Receptor-Mediated Signal Transductions,Signal Pathway,Signal Transduction Pathway,Signal Transduction System,Signal Transduction, Receptor-Mediated,Signal Transductions,Signal Transductions, Receptor-Mediated,System, Signal Transduction,Systems, Signal Transduction,Transduction, Signal,Transductions, Signal
D055214	Retinal Photoreceptor Cell Outer Segment	The light sensitive outer portion of a retinal rod or a cone photoreceptor cell. The outer segment contains a stack of disk membranes laden with photoreceptive pigments (RETINAL PIGMENTS). The outer segment is connected to the inner segment by a PHOTORECEPTOR CONNECTING CILIUM.	Retinal Outer Segment,Retinal Photoreceptor Outer Segment,Outer Segment, Retinal,Outer Segments, Retinal,Retinal Outer Segments
D023421	Models, Animal	Non-human animals, selected because of specific characteristics, for use in experimental research, teaching, or testing.	Experimental Animal Models,Laboratory Animal Models,Animal Model,Animal Model, Experimental,Animal Model, Laboratory,Animal Models,Animal Models, Experimental,Animal Models, Laboratory,Experimental Animal Model,Laboratory Animal Model,Model, Animal,Model, Experimental Animal,Model, Laboratory Animal,Models, Experimental Animal,Models, Laboratory Animal