-
Tidsskrift For Den Norske Laegeforening... Apr 1972
Topics: Cell Membrane; Inflammation; Leukocytes; Phagocytosis; Pinocytosis
PubMed: 5028891
DOI: No ID Found -
Journal of Nanoscience and... Oct 2013With the rapid development of biotechnology and nanomedicine, extensive research has focused on the investigations of delivering large-cargo molecules using... (Review)
Review
With the rapid development of biotechnology and nanomedicine, extensive research has focused on the investigations of delivering large-cargo molecules using nanoparticles through the cell membrane for disease diagnosis and treatment. Various inorganic and polymeric nanoparticles with optimized surface properties have been developed to carry these active cargo molecules such as organic molecules, oligonucleotides and proteins. Phagocytosis and pinocytosis have been suggested as the two major uptake mechanisms for nanoparticles to enter into cellular interior, but such mechanisms are still under debate. In order to enhance the efficiency of cellular uptake of nanoparticles and further understand the physiological process, it is important to investigate detailed interaction mechanisms between nanoparticles and cell membranes. Here, we will review the recent advances of the effect of nanoparticle properties (e.g., nanoparticle shape, size, charge, surface modification, etc.) on cellular uptake mechanisms. These will aid in the future design and development of nanoparticles with improved surface properties for drug and biomolecule delivery. Up to now, novel analytical techniques have been used to examine nanoparticle-cell membrane interactions, but their detailed uptake mechanisms and pathways still need more in-depth research. It is suggested that developing appropriate analytical techniques to study cellular uptake mechanisms of nanoparticles in real time is urgently desired.
Topics: Biotechnology; Nanoparticles; Phagocytosis; Pinocytosis; Surface Properties
PubMed: 24245105
DOI: 10.1166/jnn.2013.7525 -
The Biochemical Journal Jan 1983
Review
Topics: Animals; Cell Membrane; Endocytosis; Energy Metabolism; Models, Biological; Phagocytosis; Pinocytosis; Receptors, Drug; Surface Properties
PubMed: 6342614
DOI: 10.1042/bj2100001 -
Traffic (Copenhagen, Denmark) May 2001Phagocytosis and macropinocytosis are actin-dependent clathrin-independent processes primarily performed by cells like neutrophils and macrophages that result in the... (Review)
Review
Phagocytosis and macropinocytosis are actin-dependent clathrin-independent processes primarily performed by cells like neutrophils and macrophages that result in the internalization of particles or the formation of fluid-filled macropinosomes, respectively. Phagocytosis consists of a number of stages, including attachment of particles to cell surface receptors, engulfment of the particle dependent on actin polymerization and membrane exocytosis, and formation of phago-lysosomes. In contrast, the molecular steps regulating macropinocytosis are only just now being deciphered. Much remains to be learned concerning the signaling pathways that regulate these processes. Dictyostelium is a genetically and biochemically tractable professional phagocyte that has proven to be a powerful system with which to determine the nature of the molecular steps involved in regulating these internalization processes. This review summarizes what is currently understood concerning the molecular mechanisms governing phagocytosis and macropinocytosis in Dictyostelium and describes recent data concerning the common and distinct pathways that regulate these processes.
Topics: Animals; Dictyostelium; Phagocytosis; Phosphatidylinositols; Pinocytosis
PubMed: 11350627
DOI: 10.1034/j.1600-0854.2001.002005311.x -
Philosophical Transactions of the Royal... Feb 2019Nucleic acids are a rapidly emerging therapeutic modality with the potential to become the third major drug modality alongside antibodies and small molecules. Owing to... (Review)
Review
Nucleic acids are a rapidly emerging therapeutic modality with the potential to become the third major drug modality alongside antibodies and small molecules. Owing to the unfavourable physico-chemical characteristics of nucleic acids, such as large size and negative charge, intracellular delivery remains a fundamental challenge to realizing this potential. Delivery technologies such as lipids, polymers and peptides have been used to facilitate delivery, with many of the most successful technologies using macropinocytosis to gain cellular entry; mostly by default rather than design. Fundamental knowledge of macropinocytosis is rapidly growing, presenting opportunities to better tailor design strategies to target this pathway. Furthermore, certain types of tumour cells have been observed to have high levels of macropinocytic activity and traffic cargo to favourable destinations within the cell for endosomal release, providing unique opportunities to further use this entry route for drug delivery. In this article, we review the delivery systems reported to be taken up by macropinocytosis and what is known about the mechanisms for regulating macropinocytosis in tumour cells. From this analysis, we identify new opportunities for exploiting this pathway for the intracellular delivery of nucleic acids to tumour cells. This article is part of the Theo Murphy meeting issue 'Macropinocytosis'.
Topics: Drug Delivery Systems; Nucleic Acids; Pinocytosis; Tumor Cells, Cultured
PubMed: 30967005
DOI: 10.1098/rstb.2018.0156 -
Induction of membrane ruffling and fluid-phase pinocytosis in quiescent fibroblasts by ras proteins.Science (New York, N.Y.) Sep 1986Expression of the ras oncogene is thought to be one of the contributing events in the initiation of certain types of human cancer. To determine the cellular activities...
Expression of the ras oncogene is thought to be one of the contributing events in the initiation of certain types of human cancer. To determine the cellular activities that are directly triggered by ras proteins, the early consequences of microinjection of the human H-ras proteins into quiescent rat embryo fibroblasts were investigated. Within 30 minutes to 1 hour after injection, cells show a marked increase in surface ruffles and fluid-phase pinocytosis. The rapid enhancement of membrane ruffling and pinocytosis is induced by both the proto-oncogenic and the oncogenic forms of the H-ras protein. The effects produced by the oncogenic protein persist for more than 15 hours after injection, whereas the effects of the proto-oncogenic protein are short-lived, being restricted to a 3-hour interval after injection. The stimulatory effect of the ras oncogene protein on ruffling and pinocytosis is dependent on the amount of injected protein and is accompanied by an apparent stimulation of phospholipase A2 activity. These rapid changes in cell membrane activities induced by ras proteins may represent primary events in the mechanism of action of ras proteins.
Topics: Animals; Cell Cycle; Cell Membrane; Cells, Cultured; Culture Media; DNA; GTP-Binding Proteins; Humans; Microinjections; Oncogene Proteins, Viral; Phospholipases A; Phospholipases A2; Phospholipids; Pinocytosis; Rats; Time Factors
PubMed: 3090687
DOI: 10.1126/science.3090687 -
Archivum Histologicum Japonicum = Nihon... May 1964
Topics: Astrocytes; Cats; Cell Biology; Chick Embryo; In Vitro Techniques; Neuroglia; Pinocytosis; Research; Research Design; Tissue Culture Techniques
PubMed: 14172796
DOI: 10.1679/aohc1950.24.347 -
The Journal of Cell Biology Dec 1995The functional relationship between three Dictyostelium myosin Is, myoA, myoB, and myoC, has been examined through the creation of double mutants. Two double mutants,...
The functional relationship between three Dictyostelium myosin Is, myoA, myoB, and myoC, has been examined through the creation of double mutants. Two double mutants, myoA-/B- and myoB-/C-, exhibit similar conditional defects in fluid-phase pinocytosis. Double mutants grown in suspension culture are significantly impaired in their ability to take in nutrients from the medium, whereas they are almost indistinguishable from wild-type and single mutant strains when grown on a surface. The double mutants are also found to internalize gp126, a 116-kD membrane protein, at a slower rate than either the wild-type or single mutant cells. Ultrastructural analysis reveals that both double mutants possess numerous small vesicles, in contrast to the wild-type or myosin I single mutants that exhibit several large, clear vacuoles. The alterations in fluid and membrane internalization in the suspension-grown double mutants, coupled with the altered vesicular profile, suggest that these cells may be compromised during the early stages of pinocytosis, a process that has been proposed to occur via actin-based cytoskeletal rearrangements. Scanning electron microscopy and rhodamine-phalloidin staining indicates that the myosin I double mutants appear to extend a larger number of actin-filled structures, such as filopodia and crowns, than wild-type cells. Rhodamine-phalloidin staining of the F-actin cytoskeleton of these suspension-grown cells also reveals that the double mutant cells are delayed in the rearrangement of cortical actin-rich structures upon adhesion to a substrate. We propose that myoA, myoB, and myoC play roles in controlling F-actin filled membrane projections that are required for pinosome internalization in suspension.
Topics: Actins; Animals; Dictyostelium; Fungal Proteins; Mutagenesis; Myosin Type I; Myosins; Pinocytosis; Protozoan Proteins; Vacuoles
PubMed: 8522584
DOI: 10.1083/jcb.131.5.1205 -
European Journal of Biochemistry Jun 1989A simple method has been set up to measure the rate of fluid-phase pinocytosis in resident mouse peritoneal macrophages in culture. The method uses 125I-labelled...
A simple method has been set up to measure the rate of fluid-phase pinocytosis in resident mouse peritoneal macrophages in culture. The method uses 125I-labelled polyvinylpyrrolidone as a nondegradable marker of fluid-phase pinocytosis. The accumulation of 125I-labelled polyvinylpyrrolidone by the cells was directly proportional to its concentration in the culture medium up to at least 200 micrograms/ml. The estimates of the rate of fluid-phase pinocytosis were reproducible within each experiment (coefficient of variation 8.5%) but varied between individual experiments. Fluid-phase pinocytosis was undetectable at 4 degrees C and reduced greatly at 37 degrees C by metabolic inhibitors and 1 mM ZnSO4. High concentrations of human acetylated low-density lipoproteins, which are taken up rapidly by macrophages, decreased the rate of fluid-phase pinocytosis by up to about 70%. The inhibition was seen after only 2 h of incubation. Unmodified low-density lipoproteins, which are taken up only slowly by macrophages, did not usually inhibit fluid-phase pinocytosis (in fact, they sometimes increased it). Modified low-density lipoprotein uptake, leading to massive lipid accumulation in macrophages in the arterial wall, has been postulated to be involved in the pathogenesis of atherosclerosis. This study raises the possibility that the rate of fluid-phase pinocytosis in these lipid-laden arterial macrophages may be reduced.
Topics: Acetylation; Animals; Cells, Cultured; Dose-Response Relationship, Drug; Lipoproteins, LDL; Macrophages; Mice; Peritoneal Cavity; Pinocytosis; Povidone; Time Factors
PubMed: 2737210
DOI: 10.1111/j.1432-1033.1989.tb14846.x -
Sub-cellular Biochemistry 2022Macropinocytosis is a nonspecific mechanism by which cells compulsively "drink" the surrounding extracellular fluids in order to feed themselves or sample the molecules...
Macropinocytosis is a nonspecific mechanism by which cells compulsively "drink" the surrounding extracellular fluids in order to feed themselves or sample the molecules therein, hence gaining information about their environment. This process is cell-intrinsically incompatible with the migration of many cells, implying that the two functions are antagonistic. The migrating cell uses a molecular switch to stop and explore its surrounding fluid by macropinocytosis, after which it employs the same molecular machinery to start migrating again to examine another location. This cycle of migration/macropinocytosis allows cells to explore tissues, and it is key to a range of physiological processes. Evidence of this evolutionarily conserved antagonism between the two processes can be found in several cell types-immune cells, for example, being particularly adept-and ancient organisms (e.g., the social amoeba Dictyostelium discoideum). How macropinocytosis and migration are negatively coupled is the subject of this chapter.
Topics: Cell Movement; Dictyostelium; Pinocytosis
PubMed: 35378704
DOI: 10.1007/978-3-030-94004-1_5