Antifungal drug resistance is a significant clinical problem, and antifungal agents that can evade resistance are urgently needed. In infective niches, resistant organisms often co-existed with sensitive ones, or a subpopulation of antibiotic-susceptible organisms may evolve into resistant ones during antibiotic treatment and eventually dominate the whole population. In this study, we established a co-culture assay in which an azole-resistant Candida albicans strain was mixed with a susceptible strain labeled with green fluorescent protein to mimic in vivo conditions and screen for antifungal drugs. Fluconazole was used as a positive control to verify the validity of this co-culture assay. Five natural molecules exhibited antifungal activity against both susceptible and resistant C. albicans. Two of these compounds, retigeric acid B (RAB) and riccardin D (RD), preferentially inhibited C. albicans strains in which the efflux pump MDR1 was activated. This selectivity was attributed to greater intracellular accumulation of the drugs in the resistant strains. Changes in sterol and lipid compositions were observed in the resistant strains compared to the susceptible strain, and might increase cell permeability to RAB and RD. In addition, RAB and RD interfered with the sterol pathway, further aggregating the decrease in ergosterol in the sterol synthesis pathway in the MDR1-activated strains. Our findings here provide an alternative for combating resistant pathogenic fungi.
ATP-Binding Cassette Transporters ; genetics ; metabolism ; Antifungal Agents ; chemistry ; metabolism ; pharmacology ; Azoles ; pharmacology ; Biosynthetic Pathways ; drug effects ; genetics ; Candida albicans ; chemistry ; drug effects ; metabolism ; Cell Membrane ; chemistry ; metabolism ; Coculture Techniques ; Drug Resistance, Fungal ; drug effects ; Ergosterol ; metabolism ; Fungal Proteins ; genetics ; metabolism ; Lipids ; chemistry ; Molecular Structure ; Permeability ; Phenyl Ethers ; chemistry ; metabolism ; pharmacology ; Sterols ; chemistry ; metabolism ; Stilbenes ; chemistry ; metabolism ; pharmacology ; Triterpenes ; chemistry ; metabolism ; pharmacology

OBJECTIVE: To observe the expression of aquaporin 4 (AQP4) in diffuse brain injury (DBI) of rats and to explore the corresponding effect of AQP4 for brain edema. METHODS: The rat model of DBI was established using Marmarou's impact-compression trauma model. Brain water content was measured by dry-wet weight method. Blood-brain barrier permeability was evaluated by Evans blue (EB) staining. Immunohistochemical method was used to observe the expression of AQP4. RESULTS: Brain water content increased after 3 h and peaked at 24 h after DBI. Brain EB content significantly increased and peaked at 12 h after DBI. The expression of AQP4 significantly increased after 3 h and peaked at 24 h after DBI, and the number of AQP4 positive astrocytes increased. CONCLUSION The increment of the permeability of blood-brain barrier and the expression of AQP4 may contribute to the development of brain edema in rat DBI. The change of AQP4 expression in astrocytes may also contribute to determine DBI.
Animals ; Aquaporin 4/metabolism* ; Astrocytes ; Blood-Brain Barrier/metabolism* ; Brain ; Brain Edema/metabolism* ; Brain Injuries/metabolism* ; Cell Membrane Permeability/genetics* ; Disease Models, Animal ; Permeability ; Rats ; Water

OBJECTIVETo study the synergistic effects of hypothermia and hypoxia on the damage of pulmonary microvascular endothelial cells (PMVEC) in rat.

METHODSPrimary PMVECs were obtained by complex phosphoesterasum digesting from isolated lung tissues of Wistar rats, the PMVECs were identified by phase contrast microscope and immunofluorescence studies for CD31 antigen and bandeiraea simplicifolia isolectin (BSI) binding test. Factorial design was adopted in trial according to hypothermia and hypoxia existing or not. Using corresponding kit measured the levels of lactate dehydrogenase (LDH) activity in cell medium. Level of nitric oxide (NO) concentration was measured by Griess Assay. RT-PCR was used to examine the expression of vascular endothelial growth factor (VEGF), endothelin-1 (ET-1) mRNA in PMVECs.

RESULTSThe monolayer of cultured PMVECs displayed the shape of pavingstone. CD31 antigen and binding BSI results by fluorescence microscope identified the cultured cells were PMVECs. Compared to the control group, LDH activity and VEGF, ET-1 expression levels were significantly increased in hypothermia group, hypoxia group and hypoxia combined with hypothermia group. And the levels of NO concentration were reduced in these three groups. The results of One-way ANOVA showed that there was a synergistic effect between hypothermia and hypoxia.

CONCLUSIONHypothermia and hypoxia both have an effect on PMVECs whether in altering the cell permeability or in releasing of vasoactive substances including NO and ET-1. In addition, there is a synergistic effect between hypothermia and hypoxia.

Animals ; Cell Hypoxia ; Cell Membrane Permeability ; Cells, Cultured ; Cold Temperature ; Endothelial Cells ; cytology ; metabolism ; Endothelin-1 ; metabolism ; Endothelium, Vascular ; cytology ; Lung ; blood supply ; Male ; Nitric Oxide ; metabolism ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar ; Vascular Endothelial Growth Factor A ; metabolism

To construct, express, purify and identify the Myc-R9-EGFP fusion protein and validate its transduction activity in the cultured porcine embryo fibroblasts. cDNA of pig c-Myc gene was amplified by RT-PCR with specific primers of 9 arginine (R9) from the primordial genital ridges and inserted into prokaryotic expression vector pET-28a-EGFP. After DNA sequencing confirmation, the recombinant plasmid was then transformed into BL21 (Escherichia coli) strain. After IPTG induction, the target fusion protein was efficiently induced to express, successfully purified by Novagen His-Bind kit, identified by SDS-PAGE and Western blotting. Finally, its high transduction activity in the porcine embryo fibroblasts was validated. The purified Myc-R9-EGFP fusion protein and the validation of its transduction activity in fibroblasts have provided an experimental foundation for further studies on the biological characterization of Myc protein, and soundly facilitated the further study of establishing pig induced pluripotent stem cells by recombinant protein.
Animals ; Arginine ; genetics ; metabolism ; Cell Line ; Cell Membrane Permeability ; drug effects ; Escherichia coli ; genetics ; metabolism ; Fibroblasts ; cytology ; metabolism ; Genetic Vectors ; genetics ; Green Fluorescent Proteins ; genetics ; metabolism ; Proto-Oncogene Proteins c-myc ; genetics ; metabolism ; Recombinant Fusion Proteins ; genetics ; metabolism ; pharmacokinetics ; Swine

This study was aimed to construct eukaryotic expression vectors carrying the small hairpin RNA (shRNA) targeting TRPC6 gene and investigate the effect of TRPC6 knockdown on puromucin aminonucleoside (PAN)-induced podocyte injury. Two DNA sequences containing the small hairpin structure targeting TRPC6 were designed, synthesized and then inserted into the green fluorescence protein (GFP)-contained plasmids (pGC) to establish the plasmids pGCsi-TRPC6A and pGCsi-TRPC6B. Plasmids expressing scrambled shRNA were used as negative control and named pGCsi-NC. These plasmids were transfected into a conditionally immortalized murine podocyte cell line by using liposome. Flow cytometry was used to examine the transfection efficiency. TRPC6 mRNA and protein expression levels were detected by RT-PCR and Western blotting. Cultured podocytes were divided into four groups: control group, PAN treatment group, PAN+TRPC6 shRNA transfected group and PAN+scrambled shRNA transfected group. The paracelluar permeability to BSA was evaluated by Millicell-PCF Inserts and cell viability was measured by the trypan blue assay. Immunofluorescent assay was used to observe the distribution of α-actinin-4 and α-tubulin. The results showed that the transfection efficiency of the shRNA expression vector was about 45%. Expression levels of TRPC6 mRNA and protein were downregulated after transfection with pGCsi-TRPC6A and pGCsi-TRPC6B. Knocking down TRPC6 gene could effectively reverse the PAN-induced increase in the paracelluar permeability to BSA. The distribution of α-actinin-4 and α-tubulin was disrupted after treatment with PAN, which was reversed by knocking down TRPC6 gene. It was concluded that knocking down TRPC6 gene could effectively prevent podocytes from the permeability increase induced by PAN, which may be related to the regulation of podocyte cytoskeleton.
Animals ; Cell Membrane Permeability ; drug effects ; physiology ; Cell Survival ; drug effects ; physiology ; Cells, Cultured ; Gene Knockdown Techniques ; Mice ; Mice, Knockout ; Podocytes ; drug effects ; physiology ; Puromycin Aminonucleoside ; pharmacology ; TRPC Cation Channels ; genetics ; metabolism

Trans-trans farnesol (tt-farnesol) is a bioactive sesquiterpene alcohol commonly found in propolis (a beehive product) and citrus fruits, which disrupts the ability of Streptococcus mutans (S. mutans) to form virulent biofilms. In this study, we investigated whether tt-farnesol affects cell-membrane function, acid production and/or acid tolerance by planktonic cells and biofilms of S. mutans UA159. Furthermore, the influence of the agent on S. mutans gene expression and ability to form biofilms in the presence of other oral bacteria (Streptococcus oralis (S. oralis) 35037 and Actinomyces naeslundii (A. naeslundii) 12104) was also examined. In general, tt-farnesol (1 mmol x L(-1)) significantly increased the membrane proton permeability and reduced glycolytic activity of S. mutans in the planktonic state and in biofilms (P < 0.05). Moreover, topical applications of 1 mmol x L(-1) tt-farnesol twice daily (1 min exposure/treatment) reduced biomass accumulation and prevented ecological shifts towards S. mutans dominance within mixed-species biofilms after introduction of 1% sucrose. S. oralis (a non-cariogenic organism) became the major species after treatments with tt-farnesol, whereas vehicle-treated biofilms contained mostly S. mutans (>90% of total bacterial population). However, the agent did not affect significantly the expression of S. mutans genes involved in acidogenicity, acid tolerance or polysaccharide synthesis in the treated biofilms. Our data indicate that tt-farnesol may affect the competitiveness of S. mutans in a mixed-species environment by primarily disrupting the membrane function and physiology of this bacterium. This naturally occurring terpenoid could be a potentially useful adjunctive agent to the current anti-biofilm/anti-caries chemotherapeutic strategies.
Actinomyces ; physiology ; Biofilms ; drug effects ; Cell Membrane Permeability ; drug effects ; Colony Count, Microbial ; Durapatite ; Farnesol ; pharmacology ; Gene Expression Regulation, Bacterial ; drug effects ; Glycolysis ; Humans ; Hydrogen-Ion Concentration ; Microbial Viability ; drug effects ; Plankton ; drug effects ; Saliva ; microbiology ; Streptococcus mutans ; drug effects ; genetics ; physiology ; Streptococcus oralis ; physiology

OBJECTIVETo observe the effect of 25-hydroxyvitamin D3 on the permeability and ZO-1 expression in normal human airway epithelial cells.

METHODSMTT assay was used to assess the viability of human airway epithelial cell line 16HBE following a 24-hour exposure to different concentrations of 25-hydroxy vitamin D3, and the transepithelial electrical resistance (TER) of the cell monolayer was measured using a Millicell-ERS voltohmmeter. Real-time quantitative RT-PCR was employed to determine the changes of ZO-1 mRNA expression in the cells following the exposures.

RESULTSExposure to 25-hydroxyvitamin D3 resulted in significantly increased permeability of 16HBE cells, but the exspression of ZO-1 showed no obvious changes. 25-hydroxyvitamin D3 at 4×10(-9) mol/L showed the strongest effect in increasing the permeability of cell monolayer.

CONCLUSION25-hydroxyvitamin D3 increases the permeability of normal bronchial airway epithelial cell monolayer in vitro, but this effect is not mediated by upregulation of ZO-1 expression.

Bronchi ; cytology ; metabolism ; Calcifediol ; pharmacokinetics ; pharmacology ; Cell Line ; Cell Membrane Permeability ; drug effects ; Epithelial Cells ; cytology ; metabolism ; Humans ; RNA, Messenger ; genetics ; metabolism ; Zonula Occludens-1 Protein ; genetics ; metabolism

OBJECTIVETo determine the relationship of thick greasy tongue fur formation and permeability of vascular endothelial cells (ECs) with the protein expression of zonula occludens-1 (ZO-1).

METHODSSprague Dawley rats were randomly divided into a model group of severe acute pancreatitis (SAP) and a sham-operated (SO) group. The SAP rats were further divided into two subgroups on the basis of tongue-coating status: a thick greasy tongue fur group (SAP-TGF) and a normal tongue fur group (SAP-NF). Six rats were chosen randomly from every group mentioned above for an Evans blue assay 5 days after model establishment. For the histomorphology analysis, the expressions of ZO-1 protein and mRNA were studied by hematoxylin-eosin (H&E) staining, transmission electron microscope, Western blot, and Q-PCR using blood and tongue tissues, which were collected from 8 rats randomly chosen from each group.

RESULTSThe papillae density of the rat tongue surface and the caryocinesis frequency of the basal layer were significantly increased in the SAP-TGF group compared with the SO group (P<0.05). Evans blue levels in the tongue tissue of the SAP-TGF group were significantly higher than that of the SO and SAP-NF groups (P<0.05). Vascular ECs were wider and obviously fissured in the SAP-TGF group under transmission electron microscope observation. The protein and mRNA expression of ZO-1 in the SAP-TGF group were lower than those in the SAP-NF (P<0.05).

CONCLUSIONSReproductive activity enhancement of glossal epithelial cells was one of the main characteristics of thick greasy tongue fur formation. An increase in vasopermeability was closely associated with thick greasy tongue fur formation. Tight junction structural variation of vascular ECs might play an important role in the pathological and physiological process of thick greasy tongue fur formation.

Animals ; Blotting, Western ; Cell Membrane Permeability ; Endothelial Cells ; cytology ; Evans Blue ; metabolism ; Gene Expression Regulation ; Male ; Membrane Proteins ; genetics ; metabolism ; Phosphoproteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Tongue ; pathology ; ultrastructure ; Zonula Occludens-1 Protein

OBJECTIVETo study the effect of hypoxia-inducible factor-1alpha (HIF-1alpha) inhibition caused by RNA interference on permeability of hypoxic vascular endothelial (VE) cells.

METHODSPlasmid pcDNA6.2-GW/EmGFP-miR was applied to construct the RNA interference expression vector targeted to human HIF-1alpha gene. VE cells were divided into normal control group (NC), hypoxia group (H, cells were treated for hypoxia in mixed gas with 1% O(2) for 6 hours), transfection group (T), and transfection hypoxia group (TH, transfected with vector and treated with hypoxia). Expression of HIF-1alpha mRNA in NC and T groups were determined with RT-PCR. Expression of HIF-1alpha protein in each group was determined with Western blot. The permeability of VE cell monolayer was detected by fluorospectrophotometer. Another sample of VE cells were divided into dimethyloxallyl glycine (DMOG) group, transfected with DMOG group (TD), normal control group (NC), and transfection group (T), with 1 mmol/L DMOG (HIF-1alpha specific derivant) replacing hypoxia treatment. The expression of HIF-1alpha protein in each group was determined with Western blot. All data were recorded as density value ratio except for permeability data, which was recorded as fluorescence intensity value. Data were processed with t test (pairwise comparison among groups).

RESULTSThe relative content of HIF-1alpha mRNA of cells in NC group (0.765 +/- 0.069) was significantly higher than that of cells in T group (0.093 +/- 0.007, t = 16.696, P < 0.05). Content of HIF-1alpha protein of cells in TH group (0.591 +/- 0.029) was significantly lower than that of cells in H group (2.612 +/- 0.259, t = 13.415, P < 0.05). Content of HIF-1alpha protein of cells in TD group (0.566 +/- 0.008) was significantly lower than that of cells in DMOG group (3.243 +/- 0.551, t = 6.975, P < 0.05). The permeability of cell monolayer in H group (41.6 +/- 11.1) was significantly higher than that of cell monolayer in NC group (9.4 +/- 1.5, t = 6.238, P < 0.05). The permeability of cell monolayer in TH group (13.3 +/- 4.5) was markedly lower than that of cell monolayer in H group (t = 5.430, P < 0.05).

CONCLUSIONSThe expression of HIF-1alpha gene in vascular endothelial cells is effectively inhibited by specific RNA interference, which significantly prevents the hypoxia-induced increase in vascular endothelial cell permeability.

Base Sequence ; Cell Hypoxia ; Cell Line ; Cell Membrane Permeability ; Endothelial Cells ; metabolism ; Humans ; Hypoxia-Inducible Factor 1, alpha Subunit ; genetics ; metabolism ; Molecular Sequence Data ; RNA Interference ; RNA, Messenger ; genetics ; Transfection

To investigate the modulation on the P-glycoprotein in the jejunum by combined use of Glycyrrhiza inflata and Kansui with ussing chamber and rt-pcr, Rhodamine 123 (R123), a P-gp substrate and fluorescein sodium (CF), a model drug of non-P-gp substrate transported by a passive diffusion were taken as investigational drugs. Because these two drugs can be easily assayed and widely used in various research fields. The permeability of R123 or CF via Wistar rat jejunum membranes was evaluated by in vitro ussing chamber after oral administration of four different decoctions of Glycyrrhiza inflata and Kansui for 1 week. And the concentration of R123 or CF was determined by the fluorospectrophotometry in the receiving solution. Meanwhile the expression of mdr1a in P-glycoprotein was detected by real-time fluorescent quantitative PCR. After oral administration of combined decoction of the single drug, the absorptive directed permeability of R123 increased significantly (P < 0.01). On the other hand, Kansui and combine decoction of the two drugs also decrease the permeability of secretory directed transport (P < 0.05). No action of Glycyrrhiza inflata was found on the secretory transport of R123 [Papp = (2.56 +/- 0.38) x 10(-5), cm x s(-1)] across the jejunum tissues, while Papp of control group was found [Papp = (2.35 +/- 0.27) x 10(-5), cm x s(-1)]. After oral administration of Kansui decoction for 1 week and 2 weeks, the levels of mdr1a expression in Wistar rats were lower than that of the control group, but there were no significant difference in the results. Meanwhile, Glycyrrhiza inflata had no effect on transport of CF across the jejunum tissues, though the other three groups could decrease the permeability of CF, as compared with control group. Kansui may slightly inhibit P-glycoprotein function in the intestinal membrane. For another, some compositions in Kansui inhibit P-glycoprotein function, and some others strengthen the tight junction between cells in the intestinal membrane to decrease permeability of CF. As the inhibitory action to P-glycoprotein was enhanced by combination of Glycyrrhiza inflata and Kansui, based on the results, it may be one of the mechanisms of creating toxicity once co-administration of Glycyrrhiza inflata and Kansui.
ATP Binding Cassette Transporter, Sub-Family B ; genetics ; metabolism ; ATP-Binding Cassette, Sub-Family B, Member 1 ; antagonists & inhibitors ; pharmacokinetics ; Administration, Oral ; Animals ; Biological Transport ; drug effects ; Cell Membrane Permeability ; drug effects ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; pharmacology ; Euphorbia ; chemistry ; Fluorescein ; pharmacokinetics ; Glycyrrhiza ; chemistry ; Intestinal Absorption ; Intestinal Mucosa ; metabolism ; Jejunum ; metabolism ; Male ; Plants, Medicinal ; chemistry ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; Rhodamine 123 ; pharmacokinetics