Ebola virus can cause severe Ebola hemorrhagic fever. The mortality rate is 90 percent. Up till now, there is no effective vaccine or treatment of Ebola virus infection. Relaed researches on Ebola virus have become a hot topic in virology. The understanding of molecular mechanisms of Ebola virus infection of cells are important for the development of vaccine and anti-virus drugs. Therefore, this review summarized the recent research progress on the mechanisms of Ebola virus infection.
Carrier Proteins ; physiology ; Ebolavirus ; pathogenicity ; Hemorrhagic Fever, Ebola ; etiology ; Humans ; Membrane Fusion ; Membrane Glycoproteins ; physiology ; Pinocytosis

This study investigated a nano drug delivery system built by one sort of modified trimethyl chitosan (TMC). The TMC was modified by cRGDyk, ligand of integrin receptor avβ3. Single factor screening was used to optimize the prescription in which the particle sizes of TMC nanoparticle (TMC NPs) and cRGDyk modified TMC nanoparticle (C-TMC NPs) were (240.3 ± 4.2) nm and (259.5 ± 3.3) nm. Electric potential of those two nanoparticles were (33.5 ± 0.8) mV and (25.7 ± 1.6) mV. Encapsulation efficiencies were (76.0 ± 2.2) % and (74.4 ± 2.0) %. Drug loading efficacies were (50.1 ± 2.1) % and (26.1 ± 1.0) %. Then the cellular uptake, uptake mechanism and transport efficacy of TMC NPs and C-TMC NPs were investigated using Caco-2 cell line. The uptake rate and accumulating drug transit dose of C-TMC NPs were 1.98 and 2.84 times higher than TMC NPs, separately. Mechanism investigations revealed that caveolae-mediated endocytosis, clathrin-mediated endocytosis and macropinocytosis were involved in the intercellular uptake of both TMC NPs and C-TMC NPs. What is more, free cRGDyk could remarkably inhibit the uptake of C-TMC NPs.
Biological Transport ; Caco-2 Cells ; Caveolae ; Chitosan ; chemistry ; Clathrin ; Endocytosis ; Humans ; Integrin alphaVbeta3 ; chemistry ; Nanoparticles ; Particle Size ; Pinocytosis

The purpose of this study is to investigate that the biological effect of mitomycin C(MMC) on inhibition of cellular proliferation, extracellular synthesis of type_I coolagen, lamini, and study of myofibroblast is derived directly from the primary and recurrent pterygial mesenchymal cell by MMC concentration and duration of exposure time used clinically. Human pterygial mesenchymal cells were exposed for 3 minutes, 5 minutes, and 10 minutes to MMC 0.01%, 0.03%, 0.05%, and DMEM(control). After cells were incubated for 24 hours, [H3] thymidine proliferative assay, immunoassay of type_I collagen and laminin, immunohistochemical and ultrastructual study of -smooth muscle actin were perfromed in vitro. Recurrent pterygal mesenchymal cells were more proliferated and stronger than primary pterygial cells in proliferation and inhibition of cellular proliferation assay. In immunoassay of extracellular matrix, the higher the concentration of MMC and longer the duration of exposure time, the inhibition of laminin are strong. However, there was a little effect of inhibition of synthesis of type-I collagen. Also the results of positive responsed immunohistochemical and ultrastructual finding such as a few pinocytosis, microfilaments, microtendon, and basal lamina like materal by TEM of myofibroblast were revealed. We think that the reccurent pterygial tissue have more effect on inhibition of cellular proliferation and laminin synthesis than primary pterygium. Therefore, reconsideration of MMC concentreation and duration time should be need in case of recurrent tissue, further experimental and clinical research on the myofibroblast and inhibition of type-I collagen also should be need.
Actin Cytoskeleton ; Actins ; Basement Membrane ; Cell Proliferation* ; Collagen* ; Extracellular Matrix ; Humans ; Immunoassay ; Laminin* ; Mitomycin* ; Myofibroblasts ; Pinocytosis ; Pterygium ; Thymidine

Liposomes can be cleared by the reticuloendothelial system (RES) when it is in the blood circulation in the body. And they can accumulate in the organs rich in RES in the body by passive targeting. Targeting of the liposomes is an important factor for its use as a drug carrier, and particle size as well as surface charge are important for its in vivo targeting. In this paper, studies on the influences of particle size and surface charge of the liposomes on cell binding and phagocytosis mechanism were reviewed. A comprehensive review on passive targeting effect of the particle size and surface charge of liposomes on blood, liver, spleen as well as tumor tissue was made. At last, an outlook for future research directions was made.
Animals ; Drug Carriers ; chemistry ; Drug Delivery Systems ; Humans ; Liposomes ; chemistry ; pharmacokinetics ; Mononuclear Phagocyte System ; metabolism ; Neoplasms ; metabolism ; Particle Size ; Phagocytosis ; Pinocytosis ; Surface Properties ; Tissue Distribution

The aim of this study was to clarify the role of Kupffer cells in the mechanism of endotoxin-induced liver injury. The study on fine structure of Kupffer cells was performed after the injection of endotoxin. The endotoxin(Escherichia soli lipopolysaccharide 026: B6, 1.5mg/100 g of body weight) was intraperitoneally injected in Sprague-Dewley rats. Animals were sacrificed at 1/4, 1/2, 1, 2, 4, 8, 16, 24, 72 and 120 hours after the injection of endotoxin. Livers were extirpated and processed to be examined by light and electron microscopy. The results obtained were summerized as follows: Early changes observed in liver after endotoxin injection included the increased number and hypertrophy of Kupffer cells, infiltration of neutrophils and presence of fibrin thrombi within the sinusoids. The coritinuous increase of the Kupffer cells in number with hypertrophy, congestion and infiltration of inflammatory cells within the sinusoids were observed. Hepatocytes showed* fatty change and occasional necrosis. At 72 hours the congestion decreased. At 120 hours the number of Kupffer cells was increased, but the morphology of Kupffer cells became similar to that of the control group. The numbers and sizes of primary and secondary lysosomes and amount of euchromatin of Kupffer cells increased. Swellings and increase in number of mitochondria, Golgi complex, smooth endoplasmic reticulum, rough endoplasmic reticulum were evident. Microthrombi were present within the sinusoids. The swelling of rough endoplasmic reticulum and mitochondria, decrease of glycogen particles, fatty change, hypoxic vacuoles, pyknotic nuclei and occasional necrosis were observed in hepatocytes. At 72 hours the number of secondary lysosomes in Kupffer cells decreased. At 120 hours the morphology of Kupffer cells became similar to that of the control group. According to these results, it was postulated that the endotoxin was initially taken up by pinocytosis into Kupffer cells and degraded in secondary lysosomes of activated Kupffer cells. Kupffer cells may play an important role in the defense mechanism of liver during endotoxemia. The dysfunction of Kupffer cells and ischemia by sinusoidal microthrombi may cause liver injury.
Animals ; Endoplasmic Reticulum, Rough ; Endoplasmic Reticulum, Smooth ; Endotoxemia ; Estrogens, Conjugated (USP) ; Euchromatin ; Fibrin ; Glycogen ; Golgi Apparatus ; Hepatocytes ; Hypertrophy ; Ischemia ; Kinetics* ; Kupffer Cells* ; Liver ; Lysosomes ; Microscopy, Electron ; Mitochondria ; Necrosis ; Neutrophils ; Pinocytosis ; Rats* ; Vacuoles

OBJECTIVETo study the mechanism of oligochitosan-induced macrophage activation.

METHODSOligochitosan was chemically modified with fluorophore 2-aminoacridone (2-AMAC). The cellular events of 2-AMAC-oligochitosan-macrophage interaction were analyzed with confocal laser microscopy and the fluorescence intensity of cells was analyzed by BD LSR flow cytometer. The mechanism of oligochitosan uptake by macrophages was studied by competitive inhibition test and the effect of calcium, trypsin and colchicine on oligochitosan recognition and internalization were also determined. RT-PCR was performed to investigate the level of TNF-alpha secretion.

RESULTMacrophage could bind and uptake oligochitosan, which was dependent on the temperature: the uptake proceeded rapidly at 37 degrees C and at 4 degrees C macrophage could only bind oligochitosan. EDTA decreased oligochitosan uptake. Trypsin treatment significantly reduced the internalization, and uptake was recovered by trypsin termination. Colchicine significantly inhibited the internalization process and was dose dependent. 0.1 mol/L mannose inhibited TNF-alpha expression induced by oligochitosan.

CONCLUSIONMacrophage could uptake oligochitosan via mannose receptor mediated pinocytosis. Mannose receptor is crucial for the oligochitosan-induced macrophages activation.

Cells, Cultured ; Chitin ; analogs & derivatives ; pharmacology ; Humans ; Lectins, C-Type ; metabolism ; Macrophage Activation ; drug effects ; Macrophages ; cytology ; Mannose-Binding Lectins ; metabolism ; Pinocytosis ; drug effects ; Receptors, Cell Surface ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo explore the mechanism of borneol in opening the blood-brain barrier (BBB).

METHODSBorneol contained serum was prepared and using Matin-Darby canine kidney epithelium (MDCKE) cell line as the in vitro BBB model to observe the effects of borneol on intercellular tight junction (ICTJ) and pinocytosis vesicles of BBB model.

RESULTSBorneol reduced the ICTJ and caused increase of the number and enlarged the diameter of vesicles. The ICTJ was opened firstly 4 hrs after borneol treatment, then the pinocytosis was affected 24 hrs later. The effects disappeared 24 hrs after removal of the borneol contained serum, indicating that the above-mentioned effects were reversible.

CONCLUSIONBorneol could obviously loosen the ICTJ in BBB, accelerate the transportation of substance through the intercellular passage, it also could increase the number and volume of pinocytosis vesicles in BBB cells, thus to accelerate the transportation of substance by way of cell pinocytosis.

Animals ; Blood-Brain Barrier ; drug effects ; physiology ; Bornanes ; pharmacology ; Cell Line ; Cell Membrane Permeability ; Epithelial Cells ; cytology ; Kidney ; cytology ; Male ; Models, Neurological ; Pinocytosis ; drug effects ; Rabbits ; Tight Junctions ; drug effects