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Environmental Pollution (Barking, Essex... Nov 2017The environmental safety of cerium (Ce) applications in many fields has been debated for almost a century because the cellular effects of environmental Ce on living...
The environmental safety of cerium (Ce) applications in many fields has been debated for almost a century because the cellular effects of environmental Ce on living organisms remain largely unclear. Here, using new, interdisciplinary methods, we surprisingly found that after Ce(III) treatment, Ce(III) was first recognized and anchored on the plasma membrane in leaf cells. Moreover, some trivalent Ce(III) was oxidized to tetravalent Ce(IV) in this organelle, which activated pinocytosis. Subsequently, more anchoring sites and stronger valence-variable behavior on the plasma membrane caused stronger pinocytosis to transport Ce(III and IV) into the leaf cells. Interestingly, a great deal of Ce was bound on the pinocytotic vesicle membrane; only a small amount of Ce was enclosed in the pinocytotic vesicles. Some pinocytic vesicles in the cytoplasm were deformed and broken. Upon breaking, pinocytic vesicles released Ce into the cytoplasm, and then these Ce particles self-assembled into nanospheres. The aforementioned special behaviors of Ce decreased the fluidity of the plasma membrane, inhibited the cellular growth of leaves, and finally, decreased plant yield. In summary, our findings directly show the special cellular behavior of Ce in plant cells, which may be the cellular basis of plant yield reduction induced by environmental Ce.
Topics: Cell Membrane; Cerium; Pinocytosis; Plant Leaves; Soil Pollutants
PubMed: 28738302
DOI: 10.1016/j.envpol.2017.07.034 -
Archives Roumaines de Pathologie... Jun 1965
Topics: Leukocytes; Pinocytosis; Toxins, Biological
PubMed: 5877528
DOI: No ID Found -
Frontiers in Immunology 2023Invariant chain (Ii, CD74) is a type II transmembrane glycoprotein that acts as a chaperone and facilitates the folding and transport of MHC II chains. By assisting the...
Invariant chain (Ii, CD74) is a type II transmembrane glycoprotein that acts as a chaperone and facilitates the folding and transport of MHC II chains. By assisting the assembly and subcellular targeting of MHC II complexes, Ii has a wide impact on the functions of antigen-presenting cells such as antigen processing, endocytic maturation, signal transduction, cell migration, and macropinocytosis. Ii is a multifunctional molecule that can alter endocytic traffic and has several interacting molecules. To understand more about Ii's function and to identify further Ii interactors, a yeast two-hybrid screening was performed. Retinoic Acid-Induced 14 (Rai14) was detected as a putative interaction partner, and the interaction was confirmed by co-immunoprecipitation. Rai14 is a poorly characterized protein, which is believed to have a role in actin cytoskeleton and membrane remodeling. In line with this, we found that Rai14 localizes to membrane ruffles, where it forms macropinosomes. Depletion of Rai14 in antigen-presenting cells delays MHC II internalization, affecting macropinocytic activity. Intriguingly, we demonstrated that, similar to Ii, Rai14 is a positive regulator of macropinocytosis and a negative regulator of cell migration, two antagonistic processes in antigen-presenting cells. This antagonism is known to depend on the interaction between myosin II and Ii. Here, we show that Rai14 also binds to myosin II, suggesting that Ii, myosin II, and Rai14 work together to coordinate macropinocytosis and cell motility.
Topics: Tretinoin; Histocompatibility Antigens Class II; Pinocytosis; Cytoskeletal Proteins; Myosin Type II
PubMed: 37545539
DOI: 10.3389/fimmu.2023.1182180 -
Vie Medicale (Paris, France : 1920) Nov 1960
Topics: Cell Biology; Cytodiagnosis; Pinocytosis
PubMed: 13721502
DOI: No ID Found -
Nature Reviews. Cardiology Dec 2022
Topics: Humans; Foam Cells; Pinocytosis; Atherosclerosis
PubMed: 36195684
DOI: 10.1038/s41569-022-00798-3 -
The Journal of Cell Biology Dec 1978Pinocytosis was measured in monkey aortic smooth muscle cells (SMC), bovine aortic endothelial cells, and Swiss 3T3 cells in culture as cellular uptake of... (Comparative Study)
Comparative Study
Pinocytosis was measured in monkey aortic smooth muscle cells (SMC), bovine aortic endothelial cells, and Swiss 3T3 cells in culture as cellular uptake of [U-(14)C]sucrose and horseradish peroxidase (HRP) from the tissue culture medium. Monkey arterial SMC and Swiss 3T3 cells were maintained in a quiescent state of growth at low cells density in medium containing 5 percent monkey plasma-derived serum (PDS). Replacement of PDS with 5 percent monkey whole blood serum (WBS) from the same donor, or addition to PDS of partially purified platelet-derived growth factor(s) (PF), resulted in a marked stimulation of pinocytosis as well as of cellular proliferation. In SMC, enhancement of the rate of pinocytosis occurred 4-6 h after exposure to WBS or PF, and the rate was up to twofold higher than the rate in medium containing PDS. In contrast, [(3)H]thymidine uptake by SMC did not increase until 12-16 h after exposure to PF. In endothelial cells the presence of PF or WBS did not enhance either the rate of pinocytosis or the rate of proliferation over that in PDS. Thus, endothelial cells did not become quiescent at subconfluent densities in PDS but maintained rates of proliferation and pinocytosis that were equivalent to those in WBS. By autoradiography, the fraction of labeled nuclei in SMC cultures 24 h after change of medium increased from 0.061 +/- 0.004 in quiescent cultures to 0.313 +/- 0.028 after exposure to WBS or PF. In contrast, labeling indices of endothelial cells were similar for cultures grown in PDS, WBS, or PF at any single time point after change of medium. These findings suggest that the rate of pinocytosis maybe be coupled in some fashion to growth regulation, which may be mediated in part by specific growth factors, such as that derived from the thrombocyte.
Topics: Animals; Aorta; Blood Platelets; Cattle; Cell Division; Culture Techniques; Endothelium; Growth Substances; Haplorhini; Mice; Muscle, Smooth; Pinocytosis
PubMed: 103882
DOI: 10.1083/jcb.79.3.663 -
Acta Physiologica Scandinavica Nov 1975The effect of membrane stabilizing drugs on cation induced pinocytosis was studied in Amoeba proteus. Initially the presence of local anesthetic drugs during a...
The effect of membrane stabilizing drugs on cation induced pinocytosis was studied in Amoeba proteus. Initially the presence of local anesthetic drugs during a pinocytosis cycle had a stimulating effect on channel formation, however, the capacity to develop pinocytotic channels was reversibly inhibited after a period of treatment with these drugs. Imipramine, vinblastine and the phenothiazines had effects similar to local anaesthetics. The local anesthetics inhibited pinocytosis in the following order: dibucaine greater than tetracaine greater than bupivacaine greater than lidocaine greater than procaine, and the phenothiazines: thioridazine greater than prochlorperazine greater chlorpromazine greater than prometazine. Pinocytosis, when induced by Na+ or tris, was more affected by the drugs and by calcium binding agents than pinocytosis induced by K+. After pretreatment with inhibitory concentration of dibucaine (3 x 10(-4) M) the depolarization of the membrane and the conductance increase during pinocytosis were normal, while the increase of oxygen uptake during the pincoytosis cycle was abolished. Addition of Ca++ before, during or after dibucaine treatment decreased the effect of the drug. Conversely, in dibucaine-treated cells, cation induced pinocytosis was less inhibited by Ca++ than pinocytosis in normal cells. Addition of EGTA to the inducing solutions potentiated the inhibitory effect of the drug. It is suggested that these drugs release Ca++ from the cell surface and at higher concentration or after prolonged incubation time interfere with a Ca++ mechanism which couples the membrane and contractile systems in the cytoplasm.
Topics: Amoeba; Anesthetics, Local; Antipsychotic Agents; Calcium; Depression, Chemical; Drug Interactions; Imipramine; Phenothiazines; Pinocytosis; Potassium; Sodium; Tromethamine; Vinblastine
PubMed: 242188
DOI: 10.1111/j.1748-1716.1975.tb10051.x -
The Journal of Experimental Medicine Feb 1967The pinocytosis-inducing effect of a number of molecular species was studied in cultures of mouse macrophages. Agents were added to a basal medium containing 1% NBCS-No....
The pinocytosis-inducing effect of a number of molecular species was studied in cultures of mouse macrophages. Agents were added to a basal medium containing 1% NBCS-No. 199 and allowed to interact with cells for 150 min. Vesicle counts were then performed and compared to control cells in the basal medium. Certain proteins, i.e. albumin and fetuin, with isoelectric points of five and below were found to be potent stimulators of vesicle formation. Basic proteins including lysozyme, histone, and protamine had little influence at sublethal concentrations. The pinocytosis-stimulating activity of bovine plasma albumin could be markedly depressed by removal of bound fatty acids. The addition of either oleic or linoleic acid to de-fatted albumin restored its inducing properties to initial levels. The activity of fetuin could be abolished by either mild acid hydrolysis or neuraminidase digestion. Both procedures removed the majority of the sialic acid content of fetuin. The D and L isomers of polyglutamic acid were found to produce a marked increase in pinosome production. In contrast, poly-DL-lysine was not effective. Neutral and basic amino acids were without significant effect on pinocytosis, whereas aspartic and glutamic acids were stimulatory. The amides of glutamic and aspartic acid did not induce pinocytosis. The unnatural D isomers of glutamic, aspartic, leucine, and phenylalanine inhibited pinocytosis. The inhibition by D-glutamic acid could be reversed with the L isomer. A number of acid mucopolysaccharides, including heparin, hyaluronic acid, and chondroitin sulfate, were excellent inducers. High molecular weight dextran was without significant stimulatory effect whereas dextran sulfate was very active. Both desoxyribonucleic acid and ribonucleic acid enhanced pinosome formation. A number of low molecular weight anions including N-acetylneuraminic acid were found to enhance vesicle formation. In general, anionic molecules were better inducers than either neutral or cationic species. The minimum effective dose of macroanions was a function of molecular weight and their activity appeared unrelated to specific chemical groupings.
Topics: Amino Acids; Animals; Glutamates; Glycosaminoglycans; Macrophages; Mice; Neuraminic Acids; Nucleic Acids; Pinocytosis; Polysaccharides; Proteins
PubMed: 4225263
DOI: 10.1084/jem.125.2.213 -
The Journal of Cell Biology Jan 1980Mild acid hydrolysis of phosphomannan secreted by the yeast hansenula holstii (NRRL Y- 2448) produces two phosphomannyl fragments which differ strikingly in their...
Mild acid hydrolysis of phosphomannan secreted by the yeast hansenula holstii (NRRL Y- 2448) produces two phosphomannyl fragments which differ strikingly in their potency as inhibitors of pinocytosis of human beta-glucuronidase by human fibroblasts. The larger molecular weight polyphosphomonoester fragment is 100,000-fold more potent an inhibitor of enzyme uptake than the smaller penta-mannosyl-monophosphate fragment. Binding to attached fibroblasts at 3 degrees C was much greater with the polyphosphomonoester fragment than with the pentamannosyl-monophosphate. The larger molecular weight fragment was also subject to adsorptive pinocytosis and was taken up by fibroblasts at a rate 30- fold greater than the rate of uptake of pentamannosyl-monophosphate. Evidence that the polyphosphomonoester fragment is taken up by the phosphomannosyl-recognition system that mediates uptake of lysosomal enzymes includes: (a) its pinocytosis is inhibited by the same compounds that competitively inhibit enzyme pinocytosis (mannose-6-phosphate and phosphomannan from saccharomyces cerevisiae mutant mnn-1); (b) alkaline phosphatase treatment greatly reduces its susceptibility to pinocytosis; (c) its pinocytosis is competitively inhibited by high-uptake human beta-glucuronidase; and (d) this inhibition by high-uptake enzyme is dramatically reduced by prior treatment of the enzyme with alkaline phosphatase or endoglycosidase-H. Endoglycosidase-H treatment human beta-glucuronidase dramatically reduced its susceptibility to pinocytosis by fibroblasts. The phosphomannosyl components of high- uptake enzyme released by endoglycosidase-H treatment were much less effective inhibitors of polyphosphomonoester pinocytosis than when present on the phosphomannyl-enzyme. These results suggest that high-uptake acid hydrolases may be polyvalent ligands analogous to the polyphosphomonoester mannan fragment whose pinocytosis depends on interaction of more than one phospho-mannosyl recognition marker with pinocytosis receptors on fibroblasts.
Topics: Alkaline Phosphatase; Fibroblasts; Glucuronidase; Hexosephosphates; Humans; Mannans; Mannosephosphates; Pinocytosis; Polysaccharides; Receptors, Drug
PubMed: 7350171
DOI: 10.1083/jcb.84.1.77 -
Current Opinion in Microbiology Jun 2016The proposed order Megavirales comprises the nucleocytoplasmic large DNA viruses (NCLDV), infecting a wide range of hosts. Over time, they co-evolved with different host... (Review)
Review
The proposed order Megavirales comprises the nucleocytoplasmic large DNA viruses (NCLDV), infecting a wide range of hosts. Over time, they co-evolved with different host cells, developing various strategies to penetrate them. Mimiviruses and other giant viruses enter cells through phagocytosis, while Marseillevirus and other large viruses explore endocytosis and macropinocytosis. These differing strategies might reflect the evolution of those viruses. Various scenarios have been proposed for the origin and evolution of these viruses, presenting one of the most enigmatic issues to surround these microorganisms. In this context, we believe that giant viruses evolved independently by massive gene/size gain, exploring the phagocytic pathway of entry into amoebas. In response to gigantism, hosts developed mechanisms to evade these parasites.
Topics: Acanthamoeba; DNA, Viral; Evolution, Molecular; Giant Viruses; Host-Pathogen Interactions; Mimiviridae; Pinocytosis; Virus Internalization
PubMed: 27039270
DOI: 10.1016/j.mib.2016.03.009