The small molecule nutrients and cell growth factors required for the normal metabolism of chondrocyte mainly transport into the cartilage through free diffusion. However, the specific mass transfer law in the cartilage remains to be studied. In this study, using small molecule rhodamine B as tracer, the mass transfer models of cartilage were built under different pathways including surface pathway, lateral pathway and composite pathway. Sections of cartilage at different mass transfer times were observed by using laser confocal microscopy and the transport law of small molecules within different layers of cartilage was studied. The results showed that rhodamine B diffused into the whole cartilage layer through surface pathway within 2 h. The fluorescence intensity in the whole cartilage layer increased with the increase of mass transfer time. Compared to mass transfer of 2 h, the mean fluorescence intensity in the superficial, middle, and deep layers of cartilage increased by 1.83, 1.95, and 3.64 times, respectively, after 24 h of mass transfer. Under lateral path condition, rhodamine B was transported along the cartilage width, and the molecular transport distance increased with increasing mass transfer time. It is noted that rhodamine B could be transported to 2 mm away from cartilage side after 24 h of mass transfer. The effect of mass transfer under the composite path was better than those under the surface path and the lateral path, and especially the mass transfer in the deep layer of cartilage was improved. This study may provide a reference for the treatment and repair of cartilage injury.
Cartilage, Articular ; Rhodamines/pharmacology* ; Chondrocytes

BACKGROUND: Fluorescent dye Rhodamine 6G (R6G) is a substrate of multidrug resistance pumps and its accumulation is reduced in some azole-resistant Candida isolates with the upregulation of multidrug efflux transporter genes. Despite reports on species-specific differences in azole susceptibility in various Candida species, only a few studies have been reported on the R6G accumulation among clinical isolates of Candida species. In this study, we compared R6G accumulation between six different Candida species. METHODS: The intracellular accumulation of R6G and minimal inhibitory concentrations (MICs) of three triazole agents were investigated in 48 strains of six Candida species (14 C. albicans, 9 C. tropicalis, 8 C. glabrata, 8 C. krusei, 7 C. parapsilosis, and 2 C. haemulonii). R6G accumulation was measured by using flow cytometry and the geometric mean of the fluorescence intensity (GMF) was used to compare the accumulation between the Candida isolates. RESULTS: The GMF values for the C. tropicalis, C. albicans, C. krusei, C. parapsilosis, and C. glabrata isolates were 167.3+/-18.5, 126.9+/-6.6, 88.5+/-18.5, 50.8+/-7.0, and 38.1+/-3.9, respectively. C. glabrata had a significantly lower mean GMF than all the other Candida species (P<0.05). While some Candida strains with trailing growth phenomenon and increased fluconazole MIC did not have a reduced GMF, three Candida strains with increased MICs to all three triazole agents had a reduced GMF. CONCLUSIONS: This study found species-specific differences in R6G accumulation in Candida. In addition, the intracellular R6G accumulation can be used to investigate the drug efflux mechanism in azole-resistant Candida strains.
Antifungal Agents/pharmacology ; Azoles/pharmacology ; Candida/chemistry/isolation & purification/*metabolism ; Candidiasis/drug therapy ; Drug Resistance, Fungal ; Flow Cytometry/*methods ; Fluconazole/pharmacology ; Fluorescent Dyes/*analysis ; Humans ; Microbial Sensitivity Tests ; Rhodamines/*analysis ; Species Specificity

OBJECTIVETo investigate the dose and time-dependent effects of lipopolysaccharide (LPS) on cytoskeletal F-acitn and G-actin reorganizations by visualizing their distribution and measuring their contents in human umbilical vein endothelial cell line ECV-304.

METHODSF-actin was labeled with rhodamine-phalloidin and G-actin with deoxyribonuclease I (DNase I)conjugated with fluorescein isothiocyanate (FITC). Contents of cytoskeletal proteins were obtained by flow cytometry.

RESULTSF-actin was mainly distributed peripherally in endothelial cells under normal conditions. LPS stimulation caused the formation of stress fibers and filopodia. G-actin was normally seen in perinuclear and nuclear areas in control ECV-304 cells. Under LPS stimulation, G-actin dots appeared in the cytoplasmic region. The actin disorganization was accompanied by the time- and dose- dependent decrease in F-actin pool and increase in G-actin pool.

CONCLUSIONSLPS can induce characteristic morphological alterations of actin cytoskeleton and formation of intercellular gap in endothelial cells, accompanied by changes in F-actin and G-actin pools.

Actins ; drug effects ; Analysis of Variance ; Cells, Cultured ; Deoxyribonuclease I ; Dose-Response Relationship, Drug ; Endothelial Cells ; chemistry ; Escherichia coli ; Fluorescein-5-isothiocyanate ; Fluorescent Dyes ; Humans ; Lipopolysaccharides ; pharmacology ; Phalloidine ; Rhodamines ; Umbilical Veins ; cytology

OBJECTIVETo synthesize a tumor-targeting cell-penetrating peptide (CPP) and evaluate its biological activity and cytotoxicity in vitro.

METHODSWith fluorenylmethyloxycarbonyl (Fmoc) as the protective group of α-amino acid, the tumor-targeting CPP were synthesized with stepwise amino acid extension using solid-phase synthesis method. 5-carboxytetramethylrhodamine was added for fluorescence labeling in the presence of the coupling agents HATU and DMF. The purity of the CPP was measured by high-performance liquid chromatography and its molecular weight measured by mass spectrometry. Fluorescence microscope was used to assess the cell-penetrating activity?of the CPP in hepatocellular carcinoma cell lines SMMC-7721 and normal hepatocellular cell lines LO2. The growth activity of CPP-treated SMMC-7721 cells was measured by MTT assay.

RESULTSWith a purity of 96.05% and a relative molecular mass of 3504.9, the synthesized CPP showed no translocation activity in normal hepatocellular cell lines LO2, but showed strong ability to translocate into SMMC-7721 cells without affecting the biological activity of the cells.

CONCLUSIONUsing Fmoc solid-phase synthesis method, we have successfully synthesized the CPP with tumor-targeting activity.

Cell Line, Tumor ; Cell-Penetrating Peptides ; chemical synthesis ; pharmacology ; Drug Delivery Systems ; Drug Design ; Humans ; Liver Neoplasms ; drug therapy ; metabolism ; pathology ; Matrix Metalloproteinase 2 ; metabolism ; Rhodamines ; chemistry ; Solid-Phase Synthesis Techniques

The present study aimed to determine the role of Rho/Rho kinase (Rho/ROCK) phosphorylation on advanced glycation end products (AGEs)-induced morphological and functional changes in human dermal microvascular endothelial cells (HMVECs). HMVECs were respectively incubated with different concentrations of AGEs-modified human serum albumin (AGEs-HSA) for different time. In some other cases, HMVECs were pretreated with ROCK inhibitors (H-1152 or Y-27632). The morphological changes of F-actin cytoskeleton were visualized by rhodamine-phalloidin staining and the phosphorylation of Rho and ROCK were determined by Western blot. Endothelial monolayer permeability was assessed by measuring the flux of FITC-albumin across the endothelial cells. The results showed that the distribution of F-actin was significantly altered by AGEs-HSA in time and dose-dependent patterns. These effects were inhibited by ROCK inhibitors. The phosphorylation of Rho and RCOK was remarkably increased by AGEs-HSA treatment while total Rho and ROCK protein levels were not affected. The permeability of endothelial monolayer was dramatically increased by AGEs-HSA, and both ROCK inhibitors (H-1152 or Y-27632) attenuated these hyperpermeability responses. The results obtained suggest that the phosphorylation of Rho/ROCK plays an important role in AGEs-induced morphological and functional alterations in HMVECs.
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine ; analogs & derivatives ; pharmacology ; Actin Cytoskeleton ; metabolism ; Actins ; metabolism ; Amides ; pharmacology ; Endothelial Cells ; metabolism ; Endothelium, Vascular ; cytology ; Fluorescein-5-isothiocyanate ; analogs & derivatives ; metabolism ; Glycation End Products, Advanced ; pharmacology ; Humans ; Phalloidine ; analogs & derivatives ; Phosphorylation ; Pyridines ; pharmacology ; Rhodamines ; Serum Albumin ; metabolism ; pharmacology ; Serum Albumin, Human ; Signal Transduction ; rho-Associated Kinases ; metabolism

OBJECTIVE: To investigate the function and gene expression of active efflux transporters in drug-resistant candida albicans. METHODS: The broth microdilution method was performed to determined the minimal inhibitory concentration of 4 antifungal drugs to 20 candida albicans. We compared the efflux of Rhodamine 6G between sensitive and some of fluconazole-resistant candida albicans, and screened out the resistant strains with significantly increased efflux of Rhodamine 6G. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to measure the mRNA levels of active efflux gene CDR1 and CDR2. RESULTS: The efflux of Rhodamine 6G was significantly increased in some fluconazole-resistant strains when glucose was added, and the gene expressions of CDR1 and CDR2 were also obviously increased, compared with those in the sensitive strains. CONCLUSION The excessive expression of active efflux pump gene is related to the resistance to fluconazole in candida albicans. The measurement of Rhodamine 6G efflux is a useful method for the identification of drug-resistant strains induced by the excessive expression of active efflux pump.
Antifungal Agents ; pharmacology ; Biological Transport ; Candida albicans ; genetics ; physiology ; Drug Resistance, Fungal ; genetics ; Fluconazole ; pharmacology ; Fungal Proteins ; genetics ; physiology ; Gene Expression Regulation, Fungal ; Membrane Transport Proteins ; genetics ; physiology ; Microbial Sensitivity Tests ; RNA, Messenger ; biosynthesis ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Rhodamines ; metabolism

OBJECTIVE: This paper applied a transcriptomic approach to investigate the mechanisms of adriamycin (ADR) in treating proliferative vitreoretinopathy (PVR) using ARPE-19 cells. METHODS: The growth inhibitory effects of ADR on ARPE-19 cells were assessed by sulforhodamine B (SRB) assay and propidium iodide (PI) staining using flow cytometry. The differentially expressed genes between ADR-treated ARPE-19 cells and normal ARPE-19 cells and the signaling pathways involved were investigated by microarray analysis. Mitochondrial function was detected by JC-1 staining using flow cytometry and the Bcl-2/Bax protein family. The phosphorylated histone H2AX (γ-H2AX), phosphorylated checkpoint kinase 1 (p-CHK1), and phosphorylated checkpoint kinase 2 (p-CHK2) were assessed to detect DNA damage and repair. RESULTS: ADR could significantly inhibit ARPE-19 cell proliferation and induce caspase-dependent apoptosis in vitro. In total, 4479 differentially expressed genes were found, and gene ontology items and the p53 signaling pathway were enriched. A protein-protein interaction analysis indicated that the TP53 protein molecules regulated by ADR were related to DNA damage and oxidative stress. ADR reduced mitochondrial membrane potential and the Bcl-2/Bax ratio. p53-knockdown restored the activation of c-caspase-3 activity induced by ADR by regulating Bax expression, and it inhibited ADR-induced ARPE-19 cell apoptosis. Finally, the levels of the γ-H2AX, p-CHK1, and p-CHK2 proteins were up-regulated after ADR exposure. CONCLUSIONS The mechanism of ARPE-19 cell death induced by ADR may be caspase-dependent apoptosis, and it may be regulated by the p53-dependent mitochondrial dysfunction, activating the p53 signaling pathway through DNA damage.
Apoptosis ; Caspases/metabolism* ; Cell Proliferation ; Cell Survival/drug effects* ; Doxorubicin/pharmacology* ; Flow Cytometry ; Gene Expression Profiling ; Gene Expression Regulation ; Humans ; Membrane Potential, Mitochondrial ; Oligonucleotide Array Sequence Analysis ; Oxidative Stress/drug effects* ; Phosphorylation ; Propidium/chemistry* ; RNA, Small Interfering/metabolism* ; Retinal Pigment Epithelium/metabolism* ; Rhodamines/chemistry* ; Signal Transduction/drug effects* ; Transcriptome ; Tumor Suppressor Protein p53/metabolism* ; Vitreoretinopathy, Proliferative/drug therapy*