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

The formation of macrophage-derived foam cells is a typical feature of atherosclerosis (AS). Reverse cholesterol efflux (RCT) is one of important factors for the formation of macrophage foam cells. In this study, macrophage form cells were induced by oxidized low density lipoprotein (ox-LDL) and then treated with different concentrations of ferulic acid, so as to observe the effect of ferulic acid on the intracellular lipid metabolism in the ox-LDL-induced macrophage foam cell formation, the cholesterol efflux and the mRNA expression and protein levels of ATP binding cassette transporter A1 (ABCA1) and ATP binding cassette transporter G1 (ABCG1) that mediate cholesterol efflux, and discuss the potential mechanism of ferulic acid in resisting AS. According to the findings, compared with the control group, the ox-LDL-treated group showed significant increase in intracellular lipid content, especially for the cholesterol content; whereas the intracellular lipid accumulation markedly decreased, after the treatment with ferulic acid. The data also demonstrated that the mRNA and protein expressions of ABCA1 and ABCG1 significantly increased after macrophage foam cells were treated with different concentrations of ferulic acid. In summary, ferulic acid may show the anti-atherosclerosis effect by increasing the surface ABCA1 and ABCG1 expressions of macrophage form cells and promoting cholesterol efflux.
ATP Binding Cassette Transporter 1 ; analysis ; genetics ; ATP Binding Cassette Transporter, Sub-Family G, Member 1 ; ATP-Binding Cassette Transporters ; analysis ; genetics ; Animals ; Cells, Cultured ; Cholesterol ; metabolism ; Coumaric Acids ; pharmacology ; Foam Cells ; drug effects ; metabolism ; Lipoproteins ; analysis ; genetics ; Mice

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.
ATP-Binding Cassette Transporters/genetics/*metabolism ; Cell Line, Tumor ; Cell Survival/drug effects ; Cisplatin/*pharmacology ; Drug Resistance, Neoplasm/drug effects ; Equilibrative-Nucleoside Transporter 2/genetics/metabolism ; Humans ; Jurkat Cells ; K562 Cells ; Kaempferols/pharmacology ; Multidrug Resistance-Associated Proteins/genetics/metabolism ; Neoplasm Proteins/genetics/*metabolism ; RNA, Messenger/metabolism ; Receptors, Aryl Hydrocarbon/metabolism ; Tetrachlorodibenzodioxin/*pharmacology ; Up-Regulation/*drug effects ; Vault Ribonucleoprotein Particles/genetics/metabolism

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can induce drug transporter genes such as the ATP-binding cassette G member 2 (ABCG2), which contributes to multidrug resistance. We investigated the effect of TCDD pretreatment on drug transporters induction from cancer cells of various origins. Cell viabilities after treatment of cisplatin were measured to evaluate acquiring cisplatin resistance by TCDD. Acquring cisplatin resistance was found only in cisplatin senstivie cancer cells including gastric SNU601, colon LS180, brain CRT-MG and lymphoma Jurkat cells which showed a significant increase in cell viability after combined treatment with TCDD and cisplatin. High increase of ABCG2 gene expression was found in SNU601 and LS180 cells with a mild increase in the expression of the ABCC3, ABCC5,and SLC29A2 genes in SNU601 cells, and of major vault protein (MVP) in LS180 cells. The AhR inhibitor kaempferol suppressed the upregulation of ABCG2 expression and reversed the TCDD-induced increase in cell viability in LS180 cells. However, in CRT-MG cells, other transporter genes including ABCC1, ABCC5, ABCA3, ABCA2, ABCB4, ABCG1, and SLC29A1 were up-regulated. These findings suggested the acquiring cisplatin resistance by TCDD associated with cancer cell-type-specific induction of drug transporters.
ATP-Binding Cassette Transporters/genetics/*metabolism ; Cell Line, Tumor ; Cell Survival/drug effects ; Cisplatin/*pharmacology ; Drug Resistance, Neoplasm/drug effects ; Equilibrative-Nucleoside Transporter 2/genetics/metabolism ; Humans ; Jurkat Cells ; K562 Cells ; Kaempferols/pharmacology ; Multidrug Resistance-Associated Proteins/genetics/metabolism ; Neoplasm Proteins/genetics/*metabolism ; RNA, Messenger/metabolism ; Receptors, Aryl Hydrocarbon/metabolism ; Tetrachlorodibenzodioxin/*pharmacology ; Up-Regulation/*drug effects ; Vault Ribonucleoprotein Particles/genetics/metabolism

BACKGROUND: Acinetobacter baumannii is one of the most important pathogens capable of colonization in burn patients, leading to drug-resistant wound infections. This study evaluated the distribution of the AdeABC efflux system genes and their relationship to ciprofloxacin resistance in A. baumannii isolates collected from burn patients. METHODS: A total of 68 A. baumannii clinical strains were isolated from patients hospitalized in Motahari Burns Center in Tehran, Iran. Ciprofloxacin susceptibility was tested by the disk diffusion and agar dilution methods. PCR amplification of the adeRS-adeB drug efflux genes was performed for all resistant and susceptible isolates. To assess the role of the drug efflux pump in ciprofloxacin susceptibility, carbonyl cyanide 3-chlorophenylhydrazone (CCCP) was used as an efflux pump inhibitor (EPI). RESULTS: Approximately 95.6% of the Acinetobacter isolates were resistant to ciprofloxacin, with minimum inhibitory concentration (MIC) values ranging from 4 to > or =128 microg/mL. The susceptibility of 86.1% of the resistant isolates increased by factors of 2 to 64 in the presence of CCCP. All resistant isolates were positive for the adeRS-adeB genes, and 73.2% of them had mutations in the AdeRS regulatory system. CONCLUSIONS: The results showed that AdeABC genes are common in A. baumannii, which might be associated with ciprofloxacin non-susceptibility, as indicated by the observed linkage to the presence of the genes essential for the activity of the AdeABC, several single mutations occurring in the adeRS regulatory system, and an increase of ciprofloxacin susceptibility in the presence of a CCCP EPI.
ATP-Binding Cassette Transporters/antagonists & inhibitors/genetics/*metabolism ; Acinetobacter Infections/diagnosis/microbiology ; Acinetobacter baumannii/*drug effects/genetics/isolation & purification ; Anti-Bacterial Agents/*pharmacology ; Bacterial Proteins/antagonists & inhibitors/genetics/*metabolism ; Base Sequence ; Ciprofloxacin/*pharmacology ; DNA, Bacterial/chemistry/genetics/metabolism ; Drug Resistance, Bacterial ; Humans ; Hydrazones/pharmacology ; Microbial Sensitivity Tests ; Mutation ; Polymerase Chain Reaction

OBJECTIVEto investigate the effects of antidiabetic drug metformin on proliferation and apoptosis in human hepatocellular carcinoma cell line Huh-7 cells.

METHODSHuh-7 cells were treated with metformin at different concentrations. Cell viability was determined by MTT assay. Cell apoptosis and CD133(+) expression rate were detected by flow cytometery (FCM). Expressions of PTEN, Akt, p-Akt, Bcl-2, Bax proteins in the cells were measured by Western blot. The effect of metformin on the hepatosphere formation was observed in the serum-free suspension culture. Reverse transcription-polymerase chain reaction (RT-PCR) was used to validate the expression levels of stemness marker genes CD133, β-catenin, and ABCG2 mRNA in the hepatospheres.

RESULTSThe proliferation of Huh-7 cells was inhibited by metformin in a dose- and time-dependent manner. The early and late cell apoptosis rates induced by metformin at dose of 10 mmol/L for 48 hrs were (22.29 ± 0.8)% and (13.87 ± 1.2)%, respectively, and 25 mmol/L for 48 hrs (15.28 ± 2.1)% and (25.89 ± 2.3)%, respectively. Western blotting results revealed that the expression of CD133, phosphorylated Akt and the Bcl-2/Bax ratio were downregulated, and PTEN was upregulated in the Huh-7 cells after treated with 25 mmol/L metformin for 48 hrs. Metformin inhibited the formation of hepatospheres. Metformin also downregulated the expression of several cancer stem cells (CSCs)-related genes which are involved in the signaling pathways governing the self-renewal, proliferation and differentiation of CSCs in the hepatospheres.

CONCLUSIONSMetformin inhibits the proliferation of human hepatocellular carcinoma Huh-7 cells and enhances their apoptosis in vitro. It may be related to the downregulation of PI3K/Akt signal pathway and selectively targeting CD133(+) cells.

AC133 Antigen ; ATP Binding Cassette Transporter, Sub-Family G, Member 2 ; ATP-Binding Cassette Transporters ; genetics ; metabolism ; Antigens, CD ; genetics ; metabolism ; Antineoplastic Agents ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Glycoproteins ; genetics ; metabolism ; Humans ; Liver Neoplasms ; metabolism ; pathology ; Metformin ; administration & dosage ; pharmacology ; Neoplasm Proteins ; genetics ; metabolism ; PTEN Phosphohydrolase ; metabolism ; Peptides ; genetics ; metabolism ; Phosphatidylinositol 3-Kinases ; metabolism ; Phosphorylation ; Proto-Oncogene Proteins c-akt ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RNA, Messenger ; metabolism ; Signal Transduction ; drug effects ; Time Factors ; bcl-2-Associated X Protein ; metabolism ; beta Catenin ; metabolism

Cancer stem cells (CSCs) are resistant to chemo- and radio-therapy, and can survive to regenerate new tumors. This is an important reason why various anti-cancer therapies often fail to completely control tumors, although they kill and eliminate the bulk of cancer cells. In this study, we determined whether or not adenine nucleotide translocator-2 (ANT2) suppression could also be effective in inducing cell death of breast cancer stem-like cells. A sub-population (SP; CD44+/CD24-) of breast cancer cells has been reported to have stem/progenitor cell properties. We utilized the adeno-ANT2 shRNA virus to inhibit ANT2 expression and then observed the treatment effect in a SP of breast cancer cell line. In this study, MCF7, MDA-MB-231 cells, and breast epithelial cells (MCF10A) mesenchymally-transdifferentiated through E-cadherin knockdown were used. ANT2 expression was high in both stem-like cells and non-stem-like cells of MCF7 and MDA-MB-231 cells, and was induced and up-regulated by mesenchymal transdifferentiation in MCF10A cells (MCF10AEMT). Knockdown of ANT2 by adeno-shRNA virus efficiently induced apoptotic cell death in the stem-like cells of MCF7 and MDA-MB-231 cells, and MCF10AEMT. Stem-like cells of MCF7 and MDA-MB-231, and MCF10AEMT cells exhibited increased drug (doxorubicin) resistance, and expressed a multi-drug resistant related molecule, ABCG2, at a high level. Adeno-ANT2 shRNA virus markedly sensitized the stem-like cells of MCF7 and MDA-MB-231, and the MCF10AEMT cells to doxorubicin, which was accompanied by down-regulation of ABCG2. Our results suggest that ANT2 suppression by adeno-shRNA virus is an effective strategy to induce cell death and increase the chemosensitivity of stem-like cells in breast cancer.
ATP-Binding Cassette Transporters/*genetics/metabolism ; Adenine Nucleotide Translocator 2/antagonists & inhibitors/genetics ; Adenoviridae/*genetics ; Antineoplastic Agents/pharmacology ; Apoptosis/drug effects/genetics ; Breast Neoplasms ; Cadherins/antagonists & inhibitors/genetics ; Cell Line, Tumor ; Cell Survival/drug effects/genetics ; Cell Transdifferentiation/drug effects ; Doxorubicin/pharmacology ; Drug Resistance, Neoplasm/drug effects/*genetics ; Epithelial-Mesenchymal Transition/drug effects ; Female ; Gene Expression Regulation, Neoplastic/drug effects ; Gene Knockdown Techniques ; Humans ; Neoplasm Proteins/*genetics/metabolism ; Neoplastic Stem Cells/drug effects/*metabolism/pathology ; RNA, Small Interfering/*genetics ; Signal Transduction/drug effects

The incidence of diabetes mellitus is increasing among companion animals. This disease has similar characteristics in both humans and animals. Diabetes is frequently identified as an independent risk factor for infections associated with increased mortality. In the present study, homozygous diabetic (db/db) mice were infected with Listeria (L.) monocytogenes and then treated with the anti-diabetic drug exendin-4, a glucagon-like peptide 1 analogue. In aged db/db mice, decreased CD11b+ macrophage populations with higher lipid content and lower phagocytic activity were observed. Exendin-4 lowered high lipid levels and enhanced phagocytosis in macrophages from db/db mice infected with L. monocytogenes. Exendin-4 also ameliorated obesity and hyperglycemia, and improved ex vivo bacteria clearance by macrophages in the animals. Liver histology examined during L. monocytogenes infection indicated that abscess formation was much milder in exendin-4-treated db/db mice than in the control animals. Moreover, mechanistic studies demonstrated that expression of ATP binding cassette transporter 1, a sterol transporter, was higher in macrophages isolated from the exendin-4-treated db/db mice. Overall, our results suggest that exendin-4 decreases the risk of infection in diabetic animals by modifying the interaction between intracellular lipids and phagocytic macrophages.
ATP-Binding Cassette Transporters/metabolism ; Age Factors ; Animals ; Blood Chemical Analysis ; Cholesterol/metabolism ; Diabetes Mellitus, Type 2/*drug therapy/genetics ; Dyslipidemias/drug therapy/genetics ; Female ; Hyperglycemia/drug therapy/genetics ; Hypoglycemic Agents/*therapeutic use ; Injections, Intraperitoneal ; *Lipid Metabolism/drug effects ; Listeria monocytogenes/*drug effects/immunology ; Listeriosis/*drug therapy/immunology/microbiology ; Macrophages/drug effects/*metabolism ; Mice ; Obesity/drug therapy/genetics ; Peptides/*therapeutic use ; Phagocytosis/drug effects ; Venoms/*therapeutic use

OBJECTIVETo investigate the role of ATP-binding cassette transporter G1 (ABCG1) in endothelial dysfunction induced by high glucose.

METHODSHuman aortic endothelial cells (HAECs) were incubated in the presence of 5.6 or 30 mmol/L glucose for 24-72 h with or without a 2-h pretreatment with the LXR agonist 22(R)-hydroxycholesterol. Real-time PCR and Western blotting were used to measure the mRNA and protein expressions of ABCG1; the intracellular cholesterol efflux and endothelial nitric oxide synthase (eNOS) activity were measured by scintillation counting.

RESULTSHigh glucose time-dependently suppressed ABCG1 expression and cholesterol efflux to HDL in HAECs. High glucose also decreased eNOS activity. ABCG1 down-regulation induced by high glucose, along with decreased cholesterol efflux and eNOS activity, was abolished by treatment of the cells with the LXR agonist.

CONCLUSIONEndothelial dysfunction induced by high glucose is associated with decreased ABCG1 expression.

ATP Binding Cassette Transporter, Sub-Family G, Member 1 ; ATP-Binding Cassette Transporters ; genetics ; metabolism ; Aorta ; cytology ; Cell Line ; Down-Regulation ; drug effects ; Endothelial Cells ; cytology ; metabolism ; physiology ; Glucose ; pharmacology ; Humans

ATP-binding cassette transporter A1 (ABCA1) promotes cholesterol and phospholipid efflux from cells to lipid-poor apolipoprotein A-I (apoA-I), and plays a key role in the initial steps of the whole process of reverse cholesterol transport (RCT). Upregulation of ABCA1 is beneficial for atherosclerosis (AS) prevention and/or therapy, which indicated that ABCA1 was a target for anti-AS drug development. In the previous study, a high-throughput screening method was established using ABCA1p-LUC HepG2 cell line to find the upregulators of ABCA1. In the present study, compound 2030421B was found using this method, with EC50 of 0.50 microg x mL(-1). The compound was further identified as an upregulator of ABCA1 expression by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting analysis. Studies also showed that the 2030421B could induce apoA-I-mediated cholesterol efflux and inhibit lipids uptake into mouse peritoneal macrophages RAW264.7.
ATP Binding Cassette Transporter 1 ; ATP-Binding Cassette Transporters ; genetics ; metabolism ; Animals ; Anticholesteremic Agents ; administration & dosage ; chemistry ; pharmacology ; Apolipoprotein A-I ; metabolism ; Benzaldehydes ; administration & dosage ; chemistry ; pharmacology ; Biological Transport ; Cells, Cultured ; Cholesterol ; secretion ; Dose-Response Relationship, Drug ; Hep G2 Cells ; High-Throughput Screening Assays ; Humans ; Lipid Metabolism ; Lipids ; analysis ; Macrophages, Peritoneal ; cytology ; metabolism ; Mice ; Molecular Structure ; RNA, Messenger ; Up-Regulation ; drug effects