OBJECTIVETo investigate the molecular mechanisms and effective target points of lipid-lowering drug, Rhizoma Curcumae Longae, and study the effect of curcumin on the expression of low density lipoprotein (LDL) receptors in macrophages in mice.

METHODSMacrophages in mice were treated with curcumin, which was purified from the ethanolly extraction of Rhizoma Curcumae Longae for 24 h. The LDL receptors expressed in the macrophages were determined by enzyme-linked immunosorbent assay (ELISA) and assay of DiI labeled LDL uptake by flow cytometer.

RESULTSIt was found for the first time that 10 micromol/L-50 micromol/L curcumin could obviously up-regulate the expression of LDL receptor in macrophages in mice, and a dose-effect relationship was demonstrated.

CONCLUSIONOne of the lipid-lowering mechanisms of traditional Chinese medicine, Rhizoma Curcumae Longae, was completed by the effect of curcumin through the up-regulation of the expression of LDL receptor.

Animals ; Cell Line ; Curcumin ; pharmacology ; Gene Expression ; drug effects ; Hypolipidemic Agents ; pharmacology ; Macrophages ; drug effects ; Mice ; Receptors, LDL ; drug effects ; genetics ; Up-Regulation ; drug effects ; genetics

This study was purposed to investigate the changes of apoptosis-related gene expression in T lymphocytic leukemia JM cells induced with matrine, and its possible mechanism. JM cells was induced with 0.4 mg/ml matrine for 4 days, the total RNA was extracted from JM cells before and after matrine induction, the differential expression of apoptosis-related genes were screened with cDNA Expression Array Kit, the expression change of a part of gene was checked by Western blot. The results indicated that after induction of JM cells with matrine, differential expression of 31 genes were found by gene chip hybridization, the expression of caspase 8 was up-regulated more than 5 times. Western blot analysis showed that the up-regulation of caspase 8 gene expression positively correlated with induction time. It is concluded that differential expressions of many apoptosis-related genes in JM cells can be induced by matrine, in which gene expression of caspase 8 is up-regulated notably.
Alkaloids ; pharmacology ; Apoptosis ; drug effects ; genetics ; Caspase 8 ; metabolism ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Leukemia ; genetics ; Quinolizines ; pharmacology ; Up-Regulation

OBJECTIVETo determine the distribution and the predominant gene carrying model of drug inactive enzyme genes in bacterial isolates, and the mechanism of its induction and inhibition.

METHODSThe β-lactam, aminoglycosides and macrolides inactive enzyme genes were detected by PCR and sequencing in S. aureus, E.coli, K. pneumoniae, A. baumannii and E. cloacae isolates. The expression of inactive enzyme genes were examined by real-time fluorescent quantitative RT-PCR when the bacterial isolates were treated with antibiotics or a histidine kinase blocker closantel.

RESULTSIn 63 isolates of E.coli, 4 kinds of β-lactam, 2 aminoglycosides and 1 macrolides inactive enzyme-encoding genes were detected and the predominant gene-carrying models were [TEM+CTX-M]+aac(3)-II+mphA (25.4 %) and [TEM+CTX-M]+ aac (6')-I b (20.6%). In 24 isolates of S.aureus, 2 kinds of β-lactam and 3 aminoglycosides inactive enzyme-encoding genes were detected and the predominant gene-carrying models were aph (3')(41.7%) or aac (6)-I e-aph (2)-I a (25.0%). In 28 isolates of K.pneumoniae, 4 kinds of β-lactam and 2 aminoglycosides inactive enzyme-encoding genes were detected and the predominant gene-carrying models were [TEM+SHV]+[aac(6')-I b+aac (3)-II](28.6 %) and [TEM+SHV]+[aac(6')-I b+aac (3)-II]+ mphA (17.8 %). The isolates of A.baumannii and E.cloacae also had a predominant model to carry 2 or 3 kinds of inactive enzyme-encoding genes. 1/4 MIC of penicillin, cefotaxime or streptomycin induced the up-regulation of expression of 3 β-lactam or 4 aminoglycosides inactive enzyme-encoding genes (P<0.05), and this effect was inhibited by closantel (P<0.05).

CONCLUSIONThe bacterial isolates frequently carry multiple kinds of inactive enzyme-encoding genes with different predominant gene-carrying models.Low concentration antibiotics can induce the up-regulation of inactive enzyme gene expression, which can be inhibited by histidine kinase blocker.

Anti-Bacterial Agents ; pharmacology ; Bacteria ; enzymology ; genetics ; Drug Resistance, Multiple, Bacterial ; genetics ; Gene Expression Regulation, Bacterial ; Up-Regulation ; drug effects ; beta-Lactamases ; genetics

Expression strain of des-pGlu1-brazzein was constructed and the conditions using lactose as inducer was also optimized. The Influences of three factors which were lactose concentration, induction time and inducing temperature on the growth of strain and on the yield of des-pGlul-Brazzein was analyzed in detail. The result indicated that high lactose concentration inhibit the growth of strains (P < 0.01) but made no difference on expression of target protein between 0.5%-5% (P > 0.05), Biomass would be improved as time passed (P < 0.01), but the yield of target protein didn't increase obviously at 30 degrees C compared with at 37 degrees C. Further result showed that the greater expressed level of des-pGlul-Brazzein, as high as about 20% of total cell protein, could be achieved after the strain had been induced with 0.5% lactose under 28 degrees C - 30 degrees C for 4 h.
Dose-Response Relationship, Drug ; Escherichia coli ; drug effects ; genetics ; Isopropyl Thiogalactoside ; pharmacology ; Lactose ; pharmacology ; Plant Proteins ; genetics ; Plasmids ; genetics ; Temperature ; Time Factors ; Up-Regulation ; drug effects

OBJECTIVETo investigate the effects of tumor suppressor gene PTEN on apoptosis and protein expression of p53 in HepG2 cells, as well as to explore its mechanisms.

METHODSHepG2 cells were transfected with GFP plasmids containing wild-type PTEN or G129E-PTEN and C124A-PTEN in vitro. Both the expression of wild-type p53 and the phosphorylation of protein kinase B (PKB/Akt) and focal adhesion kinase (FAK) were detected by Western blotting. Flow cytometry and confocal microscopy were used to analyze apoptosis of the transfected cells.

RESULTSCompared with the control, the expression of phosphorylated FAK and phosphoylated Akt were down-regulated in HepG2 cells transfected with wild-type PTEN (-65%, -93%) and G129E-PTEN (-65%, -35%), whereas the apoptosis percentage increased to (19.8+/-1.2)% and (9.2+/-0.6)%, and p53 expression was up-regulated by 120% and 50%, respectively. However, in the cells transfected with C124A-PTEN, neither the phosphorylation of FAK and Akt nor the apoptosis percentage and p53 expression had changed.

CONCLUSIONPTEN can dephosphrylate FAK through its protein phosphatase activity, and suppress phosphorylation of Akt mainly through its lipid phosphatase activity. Consequently, it can induce apoptosis of HepG2 cells and up-regulate p53 expression.

Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; genetics ; pathology ; Gene Expression Regulation, Neoplastic ; Humans ; Liver Neoplasms ; genetics ; pathology ; PTEN Phosphohydrolase ; genetics ; Tumor Suppressor Protein p53 ; biosynthesis ; genetics ; Up-Regulation

The mutation and reduction of mitochondrial DNA (mtDNA) have been suggested as factors in the carcinogenesis. However, whether the depletion of mtDNA induces multidrug resistance in cancer cells has not been fully investigated. To elucidate the association of cellular mtDNA content and drug resistance, we generated HCT-8 colon cancer cells which revealed a marked decrease in cellular mtDNA and ATP content, concomitant with a lack of mRNAs encoded by mtDNA. The mtDNA-depleted cells showed a decreased sensitivity and accumulation of anti-cancer drugs, suggesting that mtDNA depletion could develop multidrug resistance (MDR) phenotype in HCT-8 cells. We found that the expression level of MDR1 mRNA and its translated product P-glycoprotein was increased in the mtDNA- depleted cells, indicating that the decrease of sensitivity and accumulation of anti-cancer drug in the mtDNA-depleted cells might be due to a substantial increase in the expression of P-glycoprotein. Furthermore, increased expression of MDR1 mRNA and P-glycoprotein was due to an increase of mRNA stability rather than transcriptional activation. Taken together, these results indicate that mtDNA depletion can induce an increased P-glycoprotein expression via an increase of mRNA stability and suggest that the mtDNA depletion in cancer cells plays an important role in the induction of MDR phenotype.
Cell Line, Tumor ; DNA, Mitochondrial/*metabolism ; Doxorubicin/pharmacology ; Gene Expression Regulation, Neoplastic/drug effects ; Humans ; P-Glycoprotein/*genetics/metabolism ; Paclitaxel/pharmacology ; Promoter Regions, Genetic/genetics ; *RNA Stability/drug effects ; RNA, Messenger/genetics/metabolism ; Up-Regulation/drug effects/*genetics

OBJECTIVETo explore the effects of bufalin on inhibiting proliferation, up-regulating methylation of Wilm' tumor 1 gene (WT1) as well as its possible mechanisms in human erythroid leukemic (HEL) cells.

METHODSThe HEL cells were treated with bufalin at various concentrations to observe cellular morphology, proliferation assay and cell cycle. The mRNA and protein expression levels of WT1 were detected by reverse transcription polymerase chain reaction (RT-PCR), Western blot and immunocytochemistry, DNA methylation of WT1 and protein expression levels of DNA methyltransferase 3a (DNMT3a) and DNMT3b were analyzed by methylation-specific PCR, and Western blot respectively.

RESULTSThe bufalin was effective to inhibit proliferation of HEL cells in a dose-dependent manner, their suppression rates were from 23.4%±2.1% to 87.2%±5.4% with an half maximal inhibit concentration (IC) of 0.046 μmol/L. Typical apoptosis morphology was observed in bufalin-treated HEL cells. The proliferation index of cell cycle decreased from 76.4%±1.9% to 49.7%±1.3%. The expression levels of WT1 mRNA and its protein reduced gradually with increasing doses of bufalin, meanwhile, the methylation status of WT1 gene changed from unmethylated into partially or totally methylated. While, the expression levels of DNMT3a and DNMT3b protein gradually increased by bufalin treatment in a dose-dependent manner.

CONCLUSIONSBufalin can not only significantly inhibit the proliferation of HEL cells and arrest cell cycle at G/Gphase, but also induce cellular apoptosis and down-regulate the expression level of WT1. Our results provide the evidence of bufalin for anti-leukemia, its mechanism may involve in increasing WT1 methylation status which is related to the up-regulation of DNMT3a and DNMT3b proteins in erythroid leukemic HEL cells.

Apoptosis ; drug effects ; genetics ; Bufanolides ; pharmacology ; Cell Cycle Checkpoints ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Cell Shape ; drug effects ; DNA (Cytosine-5-)-Methyltransferases ; metabolism ; DNA Methylation ; drug effects ; genetics ; Gene Expression Regulation, Leukemic ; drug effects ; Humans ; Leukemia, Erythroblastic, Acute ; enzymology ; genetics ; pathology ; RNA, Messenger ; genetics ; metabolism ; Up-Regulation ; drug effects ; genetics ; WT1 Proteins ; genetics ; metabolism

OBJECTIVEEven though phenylacetate (PA) bas been shown to inhibit the growth and induce differentiation in rat C6 glioma cell line, its mechanisms are still poorly understood. This study is aimed to identify which Hox gene is related to glioma and to observe the change in expression on mRNA level as treated by phenylasetate.

METHODSTwenty-two kinds of Hox gene were divided into 3 groups according to their primer sequence. Semiquantitative reverse transcription- polymerase chain reaction (RT-PCR) was used to investigate the mRNA expression of Hox gene groups and some Hox gene in rat C6 glioma cell line following differentiation induced by PA. The level of Hox gene expression was expressed as ratio expression rate (RER) of Hox gene/beta-actin according to computer image analysis and the difference between C6 cells and PA treated C6 cells was analyzed by student t-test.

RESULTSIt was found that Hox genes matching to primers P2 were mildly expressed in C6 cells and the expression of HoxB2 mRNA was significantly up-regulated in PA treated C6 cells (P < 0.001).

CONCLUSIONThe weak expression of HoxB2 may be involved in glioma origin and the mechanisms of PA action are correlated with transcription process in the glioma cells.

Animals ; Antimetabolites, Antineoplastic ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Genes, Homeobox ; genetics ; Glioma ; genetics ; pathology ; Phenylacetates ; pharmacology ; RNA, Messenger ; drug effects ; genetics ; metabolism ; Rats ; Tumor Cells, Cultured ; Up-Regulation ; drug effects

OBJECTIVEIn order to investigate the possible mechanism of its function to degrade lipid, we detect the effects of hawthorn flavanone to the influence on blood-fat levels and adipogenesis genes transcription expression in fat and muscle tissue of hyperlipoidemia mouse.

METHODIn this experiment, a total of 48 mouse were randomised to four groups and irrigated with two different concentrations (1.5 g kg(-1) body weight and 3.0 g kg(-1) body weight) of hawthorn flavanone, and killed in 0 h, 1 h, 2 h and 4 h. To estimate the content of TC, TG and HCL-C in blood: Total RNA was isolated from adipose and muscle, Real-time RT-PCR was used to analyze expression changes of adipogenesis genes (SREBP-1c, FAS, HSL and TGH) with time series; to analyze the correlation between TG in blood and some kinds of adipogenesis genes and the ratio of FAS/HARMEAN (HSL, TGH) mRNA in adipose.

RESULTHawthorn flavanone was able to cut down the level ofTC, TG and HDL significantly in blood and achieved the lowest level at 1 h. In adipose tissue, hawthorn flavanone up-regulated FAS, HSL and TGH, and achieved the level of significance (P<0.05), the expression level of FAS and TGH was ascend after 1 h, but HSL descend. The expression level of SREBP-1c was descend rapidly and achieved the level of significance after treating with hawthorn flavanone at 1 h (P<0.05), after that it rise again to even higher than the level of before treatment. After treating with hawthorn flavanone, the ratio of FAS/HARMEAN (HSL, TGH) in adipose was significantly descend and achieved the lowest level at 1 h (P<0.01), but it was descendsubsequently. In muscle tissue, hawthorn flavanone was able to significantly up-regulated the expression of FAS and HSL and lower dose group showed greater increasing, the change of SREBP-1c was similar in adipose tissue except the more heavily upgrade.

CONCLUSIONHawthorn flavanone had the function of depressing the concentration of blood-fat, it co-adjusted lipid metabolism of animal by regulating the transcription expression of FAS, HSL, TGH and SREBP-1c especially HSL and SREBP-1c transcription level.

Adipose Tissue ; drug effects ; metabolism ; Animals ; Crataegus ; chemistry ; Flavanones ; pharmacology ; Gene Expression Regulation ; drug effects ; Hyperlipidemias ; blood ; genetics ; Lipids ; blood ; Lipogenesis ; drug effects ; Lipolysis ; drug effects ; genetics ; Male ; Mice ; RNA, Messenger ; genetics ; metabolism ; Sterol Regulatory Element Binding Protein 1 ; genetics ; Triglycerides ; blood ; Up-Regulation ; drug effects ; fas Receptor ; genetics

OBJECTIVETo investigate the molecular pathway of substance P (SP) to induce osteoblastic differentiation.

METHODSMesenchymal stem cells were isolated and cultured. The cultures were divided into four groups with Group A (control group) cultured without any factors, Group B cultured with SP, Group C cultured with SP and SP receptor neurokinin-1 (NK1) antagonist, and Group D cultured with SP NK1 antagonist respectively to induce osteoblastic cells differentiation. Osterix gene expression was detected by reverse transcription-polymerase chain reaction (RT-PCR) for three times after 1-2 weeks of cultivation and the results were analyzed by one-way analysis of variance (ANOVA).

RESULTSThe log phase of bone marrow stromal cells appeared at 4-6 days. ALP staining revealed that the majority of cells, more than 95%, were positive and small blue-purple granules were found in the cytoplasm. And Group B, treated with SP, showed a higher level of ALP activity than the other three groups. Meanwhile, RT-PCR found that Osterix expression in Group B was obviously up-regulated, compared with other groups. But Osterix expression in Group D had no remarkable differences, compared with the controls.

CONCLUSIONSSP can up-regulate Osterix gene expression to stimulate differentiation of mesenchymal stem cells into osteoblastic cells at the final stage. The regulatory effect of SP on Osterix expression was dependant on SP NK1 receptors.

Alkaline Phosphatase ; analysis ; Animals ; Cell Differentiation ; drug effects ; Gene Expression Regulation ; drug effects ; Osteoblasts ; cytology ; drug effects ; Rats ; Rats, Wistar ; Reverse Transcriptase Polymerase Chain Reaction ; Substance P ; pharmacology ; Transcription Factors ; genetics ; Up-Regulation