ABSTRACT
Krüppel-like transcription factor 2 (KLF2) plays a key regulatory role in endothelial inflammation, thrombosis, angiogenesis and macrophage inflammation and polarization, and up-regulation of KLF2 expression has the potential to prevent and treatment atherosclerosis. In this study, trichostatin C (TSC) was obtained from the secondary metabolites of rice fermentation of Streptomyces sp. CPCC 203909 as a KLF2 up-regulator by using a high throughput screening model based on a KLF2 promoter luciferase reporter assay. TSC significantly inhibited the adhesion of tumor necrosis factor-α (TNFα) induced monocytes (THP-1) to human umbilical vein endothelial cells (HUVECs). Western blot results showed that TSC decreased TNFα induced the protein expression increase of vascular cell adhesion molecule-1 (VCAM-1), and thereby inhibited endothelial inflammation. The results of histone deacetylase (HDAC) overexpression and molecular docking experiments showed that TSC upregulated the expression of KLF2 by inhibiting subtypes of HDAC 4/5/7. In conclusion, this study suggests that TSC up-regulates the expression of KLF2 through inhibiting HDAC 4/5/7 and thus inhibits TNFα induced endothelial inflammation, and it has the potential to prevent and treat atherosclerosis.
ABSTRACT
Osteoprotegerin (OPG), secreted by osteoblasts, is a marker of bone turnover. OPG can inhibit osteoclastic differentiation by binding receptor activator of nuclear factor-κB ligand (RANKL). In this study, we found that rutaecarpine (RUT) had the up-regulating OPG activity, and it could significantly increase OPG protein levels in both mouse embryonic osteogenic precursor MC3T3-E1 and human osteosarcoma U-2OS cells. Osteoblastogenic differentiation calcified nodules staining results showed that RUT significantly promoted the osteogenic differentiation of MC3T3-E1 cells. Osteoclastic differentiation tartrate resistant acid phosphatase (TRAP) staining results showed that RUT obviously inhibited the osteoclast differentiation of mouse macrophages RAW264.7 induced by RANKL. In vivo studies showed that low-dose RUT group (5 mg·kg-1·day-1) and high-dose RUT group (45 mg·kg-1·day-1) treatments for 3 months significantly increased bone density in ovariectomized (OVX) rats; calcein double labeling experiment and toluidine blue staining results indicated that low-dose RUT group promoted bone formation and decreased bone loss in vivo; immunohistochemistry results showed that low-dose RUT group increased the expression of OPG in rat femur. All animal procedures were performed in accordance with the regulations of the Institutional Animal Care and Use Committee of Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences. In summary, this study demonstrated that RUT could up-regulate OPG expression and had promoting osteoblastic differentiation and inhibiting osteoclastic differentiation effects in vitro and in vivo.
ABSTRACT
The purpose of this research is to study the anti-atherosclerotic effects and mechanisms of berberine (BBR) in high fat diet (HFD) fed ApoE-/- mice, and then to lay a solid foundation of the clinical studies of BBR treatment. The hyperlipidemic ApoE-/- mice model was established by feeding HFD for 12 weeks. Mice were randomly divided into control group (chow diet), model group, BBR group (BBR-L: 50 mg·kg-1, BBR-H: 150 mg·kg-1) and atorvastatin (5 mg·kg-1) group. Mice were intragastric administration with BBR in 0.5% sodium salt of caboxy methyl cellulose. After 12 weeks, enface aortas were stained with oil red O, and the lesions area were analyzed by Image J software. The inflammatory factor levels were detected by suspension microarray kits. Liver total cholesterol (TC), triglyceride (TG) and free fatty acids (FFA) were determined by commercial kits. Western blot was performed to examine the inflammatory pathway related and cholesterol and lipid transport related proteins' expression. All animal experiments were performed in accordance with the Regulation on the Administration of Laboratory Animals of Institute of Medicinal Biotechnology. After 12 weeks treatment, compared with model group, BBR treatment significantly reduced the lesions area of en face aortas and obviously inhibited serum proinflammatory factors such as IL-1β and IL-6 compared with model group. In addition, BBR treatment obviously reduced liver TC, TG and FFA levels compared with model group. Furthermore, mechanic study showed that BBR significantly inhibited MAPKs and NF-κB pathways, and increased cholesterol and lipid regulated proteins expression such as p-AMPK, LDLR, ABCA1 and SR-BI. In conclusion, BBR can obviously reduce enface aortas lesions in ApoE-/- mice, which is related to inhibit inflammation and liver cholesterol and lipid accumulation.
ABSTRACT
Liver fibrosis is a tissue repair compensatory response to liver injury caused by various chronic factors, ultimately leading to liver cirrhosis, liver failure and even hepatocellular carcinoma. Abnormal activation of hepatic stellate cells is the cellular basis of liver fibrosis development. Pepstatin Pr, the derivative of pepstatin A, was isolated from Streptomyces sp. CPCC 202950. Our purpose was to investigate the anti-fibrotic activity of pepstatin Pr and explore its molecular mechanism. Hepatic stellate cell LX-2 was stimulated by TGFβ1 and sub- sequently treated with pepstatin Pr. Its cytotoxicity was detected by sulforhodamine B (SRB) assay. The expression of COL1A1, α-SMA and cathepsin D, signaling proteins TGFβ, Smad and YAP/TAZ were detected by Western blot or real-time PCR. The results showed that pepstatin Pr was not cytotoxic to LX-2 cells. And pepstatin Pr significantly reduced the mRNA and protein expression of COL1A1 and α-SMA, which are important liver fibrosis markers. Pepstatin Pr also repressed the protein expression level of cathepsin D, TGFβ1, YAP/TAZ, the phospholation level of Smad2, and YAP nuclear translocation. In conclusion, pepstatin Pr exhibits anti-fibrotic effects in TGFβ1-stimulaed LX-2 cells by mediating YAP-TGFβ-Smad pathway.
ABSTRACT
Shikimate kinase is a key protein of the shikimic pathway, which is essential for the survival of Mycobacterium tuberculosis. In this study, a screening assay for Mycobacterium tuberculosis shikimate ki-nase (MtSK) inhibitor was developed. A 120 000-compound library was screened by the enzyme assay and the phenotype screening using Mycobacterium smegmatis. A hit compound named IMB-T5297[(E)-3-(3-(3- chloro-5-methoxy-4-(prop-2-yn-1-yloxy)phenyl)acryloyl)-6-methyl-2H-pyran-2,4(3H)-dione] was identified to be a selective inhibitor of MtSK with a half maximal inhibitory concentration (IC50) value of 1.745 μg·mL-1, which also showed antibacterial activity. The interaction between compound and protein was analyzed by surface plasmon resonance (SPR) experiment, which showed the KD value was 2.151×10-5 mol·L-1. The binding model of MtSK and compound was simulated by the computer program. Five key amino acids in the binding pocket were indispensable site-directed mutated to verify the model. IMB-T5297 inhibited Mycobacterium tuberculosis H37Rv with a minimum inhibitory concentration (MIC) value of 49.723 μg·mL-1 and displayed low cytotoxicity to mammalian cells. In this study, IMB-T5297 was identified as a selective inhibitor of MtSK enzyme with anti-tuberculosis activity. With additional structural modification, the compound has a potential to become a novel anti-tuberculosis compound.
ABSTRACT
Berberine is an original antibacterial drug in China, and is widely used for its diverse biological functions. It is first used in clinic to treat intestinal bacterial infections. Berberine has different inhibitory effects on various microorganisms, but the effect is very weak with the minimum inhibitory concentration over 64 μg·mL-1 in most of the study bacteria. The effect is better for Bacillus dysteriae, which is one aspect of its selectivity. At the same time, because of the poor absorption of berberine in oral administration, it is retained in the intestine to reach a high concentration, which provides a basis for tissue selectivity in the treatment of intestinal bacterial infections. In this paper, we reviewed the antibacterial action, mechanism, clinical application of berberine, in order to provide a clue for the future direction of berberine research.
ABSTRACT
With the method of fluorescence polarization (FP), we screened small molecule inhibitors for PLK1 PBD to identify the lead compounds for antitumor drugs. FP led to the identification of a potent hit, F083-0063, whose inhibition rate was (99.7±0.4)% at 10 μg·mL-1. The IC50 was calculated to be 1.9±0.1 μmol·L-1 using Graphpad Prism 5. The effect of the compound on cells' multiplication was measured by MTT assay which showed that F083-0063 inhibited the proliferation of many tumor cell lines. Flow cytometry analysis indicated that the F083-0063 promoted cell apoptosis and induced cell G2/M arrest. Migration abilities of cells, evaluated using scratch test, increased significantly in the presence of F083-0063 with the mi-gration rate as low as (37.6±0.7)% at 20 μmol·L-1. Molecular linkage technique found F083-0063 had good affinity with PLK1 PBD. The results of Western blotting showed that the expression of cyclin-dependent proteins was increased after treatment with F083-0063. In summary, F083-0063 has an antitumor activity and is expected to be an antitumor lead compound targeting PLK1 PBD.
ABSTRACT
Eight compounds were isolated from the rice fermentation of Streptomyces sp. CPCC 202950 by a combination of various chromatographic techniques including column chromatography over silica, Sephadex LH-20, flash C₁₈, and reversed-phase HPLC. Their structures were identified as 3-[(3'-amino-3'-oxoprop-1'-en-2'-yl)oxy]benzamide (1), m-hydroxybenzamide (2), leptosphaepin (3), 5-methyluracil (4), feruloylamide (5), p-hydroxyphenylacetoamide (6), vanillamide (7), cyclo (L-val-L-ala) (8). Among them, 1 was a new benzamide analogue, and 2 was a new natural product. In the preliminary assays, none of the compounds 1-8 exhibited obvious inhibition of HIV-1 protease activity, and toxic with the Hela, HepG2, and U2OS cells. (IC₅₀ > 10 μmol•L⁻¹).
ABSTRACT
This study was designed to identify inducers of ATP-binding cassette transporter A1(ABCA1) and CD36 and lysosomal integral membrane protein-II analogous-1(CLA-1) and to evaluate the in vitro effect of the active compound on lipid metabolism. Among 20000 compounds screened, E23869 was found as a positive hit using cell-based high throughput screening models. The up-regulating activities of E23869 in ABCA1p-LUC and CLA-1p-LUC HepG2 cells were 196% and 198%, respectively. The EC50 values of E23869 in ABCA1p-LUC and CLA-1p-LUC HepG2 cells were 0.25 μmol·L-1 and 0.66 μmol·L-1, respectively. E23869 significantly upregulated the protein levels of ABCA1, scavenger receptor class B type I (SR-BI)/CLA-1 and ATP-binding cassette transporter G1(ABCG1) in both macrophages RAW264.7 and L02 cells by Western blotting analysis. Foam cell assay showed that E23869 inhibited lipids accumulations in macrophages RAW264.7. Cholesterol efflux assay showed that E23869 induced HDL-mediated cholesterol efflux in macrophages RAW264.7. Moreover, E23869 up-regulated ABCA1, SR-BI/CLA-1 and ABCG1 expressions through activation of PPARα and PPARγ. In addition, E23869 weakly promoted in vitro differentiation of mouse preadipocytes 3T3-L1. In conclusion, E23869 up-regulated ABCA1, SR-BI/CLA-1 and ABCG1 expressions to promote cholesterol efflux, which is a good leading compound for regulation of lipid metabolism.
ABSTRACT
Bone morphogenetic protein 2 (BMP2) plays a key role in bone development and reestablishment. In the study, we screened up-regulators of BMP2 among 20 000 compounds through a cell-based high throughput screening model and a positive compound E40071[2-(4-(5-methyl-3-phenylpyrazolo[1,5-a]pyrimidin-7-yl) piperazin-1-yl)ethan-1-ol] was found as the positive hit. The EC50 value of E40071 was 2.73 μmol·L-1. In vitro, E40071 upregulated the mRNA levels of BMP2 and the downstream transcription factors, Runx2 and Osx in MC3T3-E1 (subclone 14). Protein expression of Runx2 was up-regulated by E40071 through induction of Smad1/5/8 phosphorylation. The alkaline phosphatase (ALP) activity was increased by E40071. Moreover, E40071 promoted the mineralization of MC3T3-E1 (subclone 14) by Alizarin red S staining. In addition, E40071 markedly inhibited osteoclast differentiation of mice macrophage Raw264.7 induced by RANKL and reduced the expression of osteoclast differentiation markers, including MMP9 and NFATc1. The results suggest that E40071 is able to promote bone formation activity of osteoblasts and inhibit differentiation of osteoclasts.
ABSTRACT
By using a cell-based high throughput screening model for the CLA-1 up-regulator, Streptomyces 203909 was found to produce up-regulator of CLA-1. A novel trichostatin analogue was isolated from the rice fermentation of Streptomyces sp. CPCC 203909by a combination of various chromatographic techniques including column chromatography (CC) over silica gel, flash C18 CC, and reversed-phase HPLC. Its structure was identified as (-)-(R,2E,4Z)-7-[(4'-dimethylamino) phenyl]-4,6-dimethyl-7-oxohepta-2,4-dienoyl-L-glutamine (1) by the spectroscopic and chemical methods, and combination with the CD spectroscopy and Marfey's method. In the prelimi- nary assays, Compound 1 showed cytotoxicity against human embryonic kidney 293 cell line with IC50 value 35.3 [µmol · L(-1).
Subject(s)
Humans , Cell Survival , Fermentation , Hep G2 Cells , Hydroxamic Acids , Chemistry , Metabolism , Pharmacology , Molecular Structure , Streptomyces , Chemistry , MetabolismABSTRACT
ATP-binding cassette transporter A1 (ABCA1) and scavenger receptor class B type I (SR-BI/CLA-1) are the key proteins in reverse cholesterol transport (RCT). The high expression of ABCA1 and SR-BI/CLA-1 can decrease the danger of atherosclerosis. The purpose of the study is to find ABCA1 and CLA-1up-regulators for treating atherosclerosis by using cell-based high throughput screening models. Among 20 000 compounds screened, E0869 [1-(3, 4-dimethylphenyl)-1-oxopropan-2-yll4-((methylsulfonyl)methyl)benzoate] was found as the positive hit. The up-regulated activities of E0869 in ABCAl1-LUC and bCA-l1-LUC HepG2 cell were 160% and 175%, respectively. The EC50 values of E0869 in ABCAl1-LUC and CLA-l1-LUC HepG2 cell were 3.79 and 1.42 pμol- x ,(-1) respectively. E0869 could upregulate the mRNA and protein levels of ABCA1, SR-BI/CLA-1 and ABCGJ1genes in HepG2 and RAW264.7 cells by Real-Time Quantitative PCR and Western blotting analysis, but could not influence the expression of FAS, SREBP-l1 and CD36. Foam cell assay showed that E0869 could inhibit lipids accumulation in mouse peritoneal macrophages RAW264.7. Cholesterol efflux assay showed that E0869 could induce HDL-mediated cholesterol efflux in mouse peritoneal macrophages RAW264.7. In conclusion, E0869 could up-regulate ABCA1 and CLA-1 activity, and had good anti-atherosclerotic activity in vitro.
Subject(s)
Animals , Humans , Mice , ATP Binding Cassette Transporter 1 , Metabolism , Atherosclerosis , Drug Therapy , Biological Transport , Cholesterol , Hep G2 Cells , High-Throughput Screening Assays , Macrophages, Peritoneal , RNA, Messenger , Scavenger Receptors, Class B , Metabolism , Up-RegulationABSTRACT
Eleven compounds were isolated from the culture of Streptomyces sp. CPCC 202950 by a combination of various chromatographic techniques including column chromatography over macroporous resin HP-20, MCI, and reversed-phase HPLC. Their structures were identified as 1H-pyrrole-2-carboxamide(1),5'-deoxy-5'-methylthioinosine(2), vanillamide(3), trans-3-methylthioacrylamide(4), 1,2,3,4-Tetraydro-1H-pyrido[3,4-b]indole-3-carboxylic acid(5), cyclo(L-pro-L-tyr) (6), N-[2-(4-hydroxyphenyl)]ethylacetamide(7), benzamide (8), cyclo ('L-leucyl-trans-4-hydroxy-L-proline)(9), cyclo-(Phe-Gly) (10), and tryptophan (11). Among them, compounds 1 and 2 were new natural products. In the preliminary assays, none of the compounds exhibited obvious inhibition of HIV-1 protease activity (IC50 > 10 micromol x L(-1)).
Subject(s)
Culture Media , Chemistry , Metabolism , HIV Protease , HIV Protease Inhibitors , Chemistry , Molecular Structure , Spectrometry, Mass, Electrospray Ionization , Streptomyces , Chemistry , MetabolismABSTRACT
In the previous study, a high-throughput screening method was established to find the antagonists of CD36. In the present study, a new compound named IMB-1680 was found using this method. The anti-atherosclerotic activities of IMB-1680 were then evaluated. Dose-dependent activities of IMB-1680 were detected by using Sf9 [hCD36] and CHO [hCD36] models. Fluorescence microscopic photography and flow cytometry were used to analyze uptake of mLDL. Foam cell test with RAW264.7 macrophages was used to examine lipid accumulation. The results showed that IMB-1680 inhibited CD36 activity with IC50 of 2.80 and 8.79 micromol x L(-1) in Sf9[hCD36] and CHO [hCD36] cells, respectively. Fluorescence microscopic photography and flow cytometry revealed that IMB-1680 could significantly reduce DiI-AcLDL uptake. Meanwhile, IMB-1680 also could reduce lipids accumulation in RAW264.7 macrophages. In all, the data indicated that IMB-1680 might be a potent effective anti-atherosclerotic leading compound.
Subject(s)
Animals , Humans , Mice , CD36 Antigens , Genetics , Metabolism , CHO Cells , Cells, Cultured , Cricetulus , Dose-Response Relationship, Drug , Foam Cells , Cell Biology , High-Throughput Screening Assays , Lipoproteins, LDL , Metabolism , Macrophages , Cell Biology , Metabolism , Molecular Structure , Plasmids , Receptors, Scavenger , Sf9 Cells , Spodoptera , TransfectionABSTRACT
This study is to explore new lead compounds by inhibition of Pin1 for anticancer therapy using temperature sensitive mutants. As Pin1 is conserved from yeast to human, we established a high-throughput screening method for Pin1 inhibitors, which employed yeast assay. This method led to the identification of one potent hits, 8-11. In vitro, 8-11 inhibited purified Pin1 enzyme activity with IC50 of (10.40 +/- 1.68) micromol x L(-1), induced G1 phase arrest and apoptosis, showed inhibitory effects on a series of cancer cell proliferation, reduced Cyclin D1 expression, was defined as reciprocally matched for protein-ligand complex in virtual docking analysis and reduced cell migration ability. In vivo, we could observe reduction of tumor volume after treatment with 8-11 in xenograft mice compared with vehicle DMSO treatment. Altogether, these results provide for the first time the involvement of 8-11 in the anticancer activity against Pin1.
Subject(s)
Animals , Humans , Mice , Apoptosis , Cell Proliferation , Cyclin D1 , Metabolism , Drug Screening Assays, Antitumor , Methods , G1 Phase , High-Throughput Screening Assays , Methods , NIMA-Interacting Peptidylprolyl Isomerase , Neoplasms , Pathology , Peptidylprolyl Isomerase , Temperature , Xenograft Model Antitumor Assays , YeastsABSTRACT
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.
Subject(s)
Animals , Humans , Mice , ATP Binding Cassette Transporter 1 , ATP-Binding Cassette Transporters , Genetics , Metabolism , Anticholesteremic Agents , Chemistry , Pharmacology , Apolipoprotein A-I , Metabolism , Benzaldehydes , Chemistry , Pharmacology , Biological Transport , Cells, Cultured , Cholesterol , Bodily Secretions , Dose-Response Relationship, Drug , Hep G2 Cells , High-Throughput Screening Assays , Lipid Metabolism , Lipids , Macrophages, Peritoneal , Cell Biology , Metabolism , Molecular Structure , RNA, Messenger , Up-RegulationABSTRACT
Scavenger receptor CD36 could bind and endocytose oxLDL into macrophages which were then differentiated into foam cells that constitute the atherosclerotic lesion core, and was considered to be a potential target to treat atherosclerosis. In the establishment of the compound library of berberine (BBR, 1) analogues, we discovered that 13-hexylberberine (2) showed an antagonistic activity against CD36. Taking 2 as the lead compound, 21 derivatives were synthesized and their antagonistic activities were evaluated via an ELISA-like high-throughput screening (HTS) model. The primary structure-activity relationships were studied. It was indicated that the introduction of suitable groups at the 2- and 3-position of the aromatic ring A or at the 9-position of the aromatic ring D could enhance the activity. Among the 21 studied compounds, 7g bearing a benzyloxyl group at the 9-position provided a highest CD36 antagonistic activity with the IC50 value of 7.7 micromol L(-1). Besides, its antagonistic activity was further verified with Sf9 insect cell HTS model. So berberine analogues are a new family of CD36 receptor antagonists and worthy to be studied further.
Subject(s)
Animals , Berberine , Chemistry , Pharmacology , CD36 Antigens , Metabolism , Cell Line , Cell Survival , Enzyme-Linked Immunosorbent Assay , High-Throughput Screening Assays , Receptors, Scavenger , Spodoptera , Cell Biology , Virology , Structure-Activity RelationshipABSTRACT
<p><b>OBJECTIVE</b>To develop a high-throughput screening assay for Farnesoid X receptor (FXR) agonists based on mammalian one-hybrid system (a chimera receptor gene system) for the purpose of identifying new lead compounds for dyslipidaemia drug from the chemical library.</p><p><b>METHODS</b>cDNA encoding the human FXR ligand binding domain (LBD) was amplified by RT-PCR from a human liver total mRNA and fused to the DNA binding domain (DBD) of yeast GAL4 of pBIND to construct a GAL4-FXR (LBD) chimera expression plasmid. Five copies of the GAL4 DNA binding site were synthesized and inserted into upstream of the SV40 promoter of pGL3-promoter vector to construct a reporter plasmid pG5-SV40 Luc. The assay was developed by transient co-transfection with pG5-SV40 Luc reporter plasmid and pBIND-FXR-LBD (189-472) chimera expression plasmid.</p><p><b>RESULTS</b>After optimization, CDCA, a FXR natural agonist, could induce expression of the luciferase gene in a dose-dependent manner, and had a signal/noise ratio of 10 and Z' factor value of 0.65.</p><p><b>CONCLUSION</b>A stable and sensitive cell-based high-throughput screening model can be used in high-throughput screening for FXR agonists from the synthetic and natural compound library.</p>
Subject(s)
Humans , Base Sequence , Cell Line , DNA Primers , DNA, Complementary , DNA-Binding Proteins , Chemistry , Genetics , Hypolipidemic Agents , Plasmids , Receptors, Cytoplasmic and Nuclear , Chemistry , Genetics , Reproducibility of Results , Transcription Factors , Chemistry , Genetics , TransfectionABSTRACT
<p><b>OBJECTIVE</b>To develop a new high-throughput screening model for human high-density lipoprotein (HDL) receptor (CD36 and LIMPII analogous-1, CLA-1) agonists using CLA-1-expressing insect cells.</p><p><b>METHODS</b>With the total RNA of human hepatoma cells BEL-7402 as template, the complementary DNA (cDNA) of CLA-1 was amplified by reverse transcription-polymerase chain reaction (RT-PCR). Bac-to-Bac baculovirus expression system was used to express CLA-1 in insect cells. CLA-1 cDNA was cloned downstream of polyhedrin promoter of Autographa californica nuclear polyhedrosis virus (AcNPV) into donor vector pFastBac1 and recombinant pFastBac1-CLA-1 was transformed into E. coli DH10Bac to transpose CLA-1 cDNA to bacmid DNA. Recombinant bacmid-CLA-1 was transfected into Spodoptera frugiperda Sf9 insect cells to produce recombinant baculovirus particles. Recombinant CLA-1 was expressed on the membrane of Sf9 cells infected with the recombinant baculoviruses. A series of parameters of DiI-lipoprotein binding assays of CLA-1-expressing Sf9 cells in 96-well plates were optimized.</p><p><b>RESULTS</b>Western blot analysis and DiI-lipoprotein binding assays confirmed that CLA-1 expressed in insect cells had similar immunoreactivity and ligand binding activity as its native counterpart. A reliable and sensitive in vitro cell-based assay was established to assess the activity of CLA-1 and used to screen agonists from different sample libraries.</p><p><b>CONCLUSION</b>Human HDL receptor CLA-1 was successfully expressed in Sf9 insect cells and a novel high-throughput screening model for CLA-1 agonists was developed. Utilization of this model allows us to identify potent and selective CLA-1 agonists which might possibly be used as therapeutics for atherosclerosis.</p>
Subject(s)
Animals , Humans , Baculoviridae , Genetics , Metabolism , Biological Assay , Carbocyanines , Metabolism , Cell Line, Tumor , Cholesterol, HDL , Metabolism , DNA, Complementary , Genetics , Metabolism , Fluorescent Dyes , Metabolism , Gene Expression , Lipoproteins, HDL , Genetics , Metabolism , Lipoproteins, LDL , Metabolism , Receptors, Lipoprotein , Genetics , Metabolism , Recombinant Proteins , Genetics , Metabolism , Reverse Transcriptase Polymerase Chain Reaction , Scavenger Receptors, Class B , Genetics , Metabolism , Spodoptera , Genetics , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To identify a new peptide deformylase (PDF) gene (Genebank Accession AY238515) from Enterococcus faecium and to establish a new screening model targeted on PDF.</p><p><b>METHODS</b>A new PDF gene was identified by BLAST analysis and PCR and was subsequently over-expressed in the prokaryotic expression host E. coli B121(DE3). Over-expressed protein was purified for enzymatic assay by metal affinity chromatography and a new screening model was established for novel antibiotics.</p><p><b>RESULT</b>A new PDF gene of Enterococcus faecium was identified successfully. Ten positive samples were picked up from 8000 compound library and the microbial fermentation broth samples.</p><p><b>CONCLUSION</b>A new PDF of gene Enterococcus faecium was first identified and the model had a high efficacy. Positive samples screened may be antibacterial agents of broad spectrum.</p>