Caracterização das proteínas caveolinas -1 e -2 na placenta de conceptos bovinos clonados transgênicos / Caracterization of caveolin -1 and -2 proteins in cloned and transgenic placenta of cattle

A utilização da transgenia com a proteína fluorescente verde (GFP) como marcador de células de origem fetal nas placentas de clones bovinos servirá de modelo inédito para estudo morfofisiológico e imunológico da interação materno-fetal, visto que possibilitará o seu mapeamento, diferenciando as células fetais das maternas. Tal modelo terá aplicação direta, principalmente porque estes são animais que apresentam problemas em relação ao seu desenvolvimento. Com o auxílio deste modelo, pretende-se verificar o transporte de substâncias entre a mãe e o feto via endocitose, pela imunolocalização das proteínas chamadas de caveolinas. Para tanto foram utilizados 06 bovinos clonados e 30 bovinos de inseminação artificial (IA) com idade até 90 dias de gestação, os quais tiveram seu desenvolvimento interrompido mediante abate humanitário das receptoras e ovariosalpingohisterectomia, com posterior recuperação do útero gestante. Foram coletados os placentônios e o cório. Uma parte das amostras foi recortada e fixada, por imersão, em solução de parafolmaldeído a 4% ou formoldeído a 10% em tampão fosfato de sódio (PBS) a 0,1M pH 7.4, solução de Zamboni (4% de paraformoldeído, 15% de ácido pícrico, em tampão fosfato de sódio a 0,1M pH 7.4), metacarn (60% de metanol, 30% de clorofórmio, e 10% de ácido acético glacial), para verificação da morfologia e realização de imuno-histoquímica para as proteínas caveolinas -1 e -2 (CAV -1 e CAV-2)...

The transgenic application of green fluorescent protein (GFP) as fetal cell marker on cattle cloned placenta could provide an exclusive model for studying the morphologic and immunologic maternal-fetal interactions, providing information about its mapping, distinguishing the fetal from maternal cells. This model will have direct application, mainly because these animals present problems during its development. With this model's support, we intend to verify the substances transport between mother and fetus during endocytosis, through the immunolocalization of protein named caveolae. For these, we used 06 cloned bovine and 30 cattle samples of artificial insemination (AI) with 90 days of pregnancy, which had been their development interrupted by humanitarian slaughter of the recipient and recovery of the pregnant uterus. We collected the placentome and the chorion. A part of the samples was cut and fixed, by immersion, on a solution containing 4% of parafomaldehyde or 10% of formaldehyde on a sodium phosphate buffer (PBS), at 0,1M pH 7.4, Zamboni solution (4% of paraformaldehyde, 15% of picric acid, on sodium phosphate buffer 0,1M pH 7.4), metacarn (60% of metanol, 30% of chloroform, and 10% glacial acetic acid), for morphologic and immunohistochemistry verification for caveolinas proteins -1 and -2 (CAV -1 and CAV- 2). The caveolins -1 were found in fetal and maternal villi, but its strongest staining was observed in the endometrial stroma. The caveolins -2 had positive staining in trophoblast and chorioallantoic membrane, and specifically in giant trophoblastic binucleated cell. Therefore the results were compared between cloned cattle and from AI or natural mating, for assisting on detection of the reason of many placental alterations, embryonic losses, spontaneous abortion, post-natal mortality and large offspring syndrome on laboratory-manipulated animals. The result suggests that the proteins caveolins -1 and -2 (CAV-1 and CAV-2)...

Mechanism of cellular uptake and transport mediated by integrin receptor targeting trimethyl chitosan nanoparticles / 药学学报

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.

Research progress of the molecule mechanisms of Ebola virus infection of cells / 病毒学报

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.

A review on the influences of size and surface charge of liposome on its targeted drug delivery in vivo / 药学学报

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.

Mechanism of oligochitosan-induced macrophage activation / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To study the mechanism of oligochitosan-induced macrophage activation.</p><p><b>METHODS</b>Oligochitosan 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.</p><p><b>RESULT</b>Macrophage 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.</p><p><b>CONCLUSION</b>Macrophage could uptake oligochitosan via mannose receptor mediated pinocytosis. Mannose receptor is crucial for the oligochitosan-induced macrophages activation.</p>

Effect of borneol on the intercellular tight junction and pinocytosis vesicles in vitro blood-brain barrier model / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the mechanism of borneol in opening the blood-brain barrier (BBB).</p><p><b>METHODS</b>Borneol 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.</p><p><b>RESULTS</b>Borneol 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.</p><p><b>CONCLUSION</b>Borneol 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.</p>

Effect of arsenic on cell growth of the cellular slime mould, Dictyostelium discoideum.

The growing D. discoideum cells were killed in a dose-dependent manner when exposed to 100 and 140 ppm of arsenic (As2O3) at mid-log phase for 20 min. Reduced plaque sizes and changed cell and colony morphologies were observed in the treated cells. Endocytotic functions (both phagocytosis and pinocytosis) were also inhibited in the treated cells. Arsenic treated cell showed a lower DNA and protein synthetic activities. These findings are discussed in relation to known mechanism of action of the heavy metal on growth-related cellular functions.

Inhibition of endocytotic functions in Dictyostelium discoideum treated with a carbamate pesticide.

Administration of a carbamate pesticide carbaryl (1-Naphthyl-N-methyl carbamate) at a concentration of 60 and 100 ppm greatly inhibits the endocytotic functions during growth of the cellular slime mold D. discoideum. The ingestion of fluorescien isothiocynate (FITC) labeled E. coli is reduced between 30 and 40% in the treated cells as compared to controls. Similarly, the uptake of FITC-labeled dextran, which has been used as fluid-phase marker for pinocytosis also show 40-50% inhibition in the treated cells. 3H-leucine uptake and incorporation are also inhibited in the treated cells. SDS-PAGE analysis of cytoskeletal proteins shows a higher actin association with the membrane of treated cells. The results demonstrate the detrimental effects of Carbamate on the soil microbe even at a very low concentration and the efficacy of the slime mold cells as a biosensor for the carbamate-induced cytotoxicity.

The Effect of Mitomycin C(MMC) on Inhibition of Cellular Proliferation and Type_I Collagen, Laminin Synthesis of Pterygial Mesenchymal Cell

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.

Sodium chloride stress induced morphological and ultrastructural changes in Aspergillus repens.

Halotolerant fungus, A. repens, showed a considerable difference in its growth rate, morphology, ultrastructural and molecular composition under NaCl stress as compared to control i.e. non-stressed condition. Light microscopic observations revealed significant differences in their mycelial thickness, their branching and septa. Transmission electron microscopic observations of both the conditions depicted significant differences in the qualitative and quantitative changes in mitochondria. Frequent pinocytotic vesiculation (vacuoles) of plasma membrane was observed in fungus under stress but no such vesiculation in control. The multivesiculate structures observed under stress with their origin from the cell membranes and subsequent release into vacuoles have not been reported in fungi under normal physiological conditions. The observations on pinocytosis are discussed in relation to ion compartmentation and salt tolerance in A. repens.

Fine structure and detoxification kinetics in kupffer cells after injection of endotoxin in rats / 영남의대학술지

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.